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[0001] This application claims the benefit of priority to U.S. Provisional Application Ser. No. 60/819,766, filed Jul. 10, 2006, which is incorporated by reference in its entirety. FIELD OF THE INVENTION [0002] The present invention relates to a screening method for detecting for the presence or absence of one or more target analytes, e.g., proteins, nucleic acids, or other compounds in a sample. In one application, the present invention utilizes nucleic acid reporter markers as biochemical barcodes in combination with metallic nanoparticles for detecting through measuring the shifts in resonance frequency of one or more analytes in a solution with a flow-based (flow cytometry or micro-capillary) method. BACKGROUND OF THE INVENTION [0003] The detection of analytes is important for both molecular biology research and medical applications. Diagnostic methods based on fluorescence, mass spectroscopy, gel electrophoresis, laser scanning and electrochemistry are now available for identifying a variety of protein structures. 1-4 Antibody-based reactions are widely used to identify the genetic protein variants of blood cells, diagnose diseases, localize molecular probes in tissue, and purify molecules or effect separation processes. 5 For medical diagnostic applications (e.g. malaria and HIV), antibody tests such as the enzyme-linked immunosorbent assay, Western blotting, and indirect fluorescent antibody tests are extremely useful for identifying single target protein structures. 6,7 Rapid and simultaneous sample screening for the presence of multiple antibodies would be beneficial in both research and clinical applications. However, it is difficult, expensive, and time-consuming to simultaneously detect several protein structures under assay conditions using the aforementioned related protocols. [0004] Polymerase chain reaction (PCR) and other forms of target amplification have enabled rapid advances in the development of powerful tools for detecting and quantifying DNA targets of interest for research, forensic, and clinical applications. 26-32 The development of comparable target amplification methods for proteins could dramatically improve medical diagnostics and the developing field of proteomics. 33-36 Although one cannot yet chemically duplicate protein targets, it is possible to tag such targets with oligonucleotide markers that can be subsequently amplified with PCR and then use DNA detection to identify the target of interest. 37-45 This approach, often referred to as immuno-PCR, allows one to detect proteins with DNA labels in a variety of different formats. To date, all immuno-PCR approaches involve heterogeneous assays, which involve initial immobilization of a target analyte to a surface with subsequent detection using an antibody with a DNA label (for example, see U.S. Pat. Nos. 5,635,602, and 5,665,539). The DNA label is typically strongly bound to the antibody (either through covalent interactions or streptavidin-biotin binding). [0005] Although these approaches are notable advances in protein detection, they have several drawbacks: 1) limited sensitivity because of a low ratio of DNA identification sequence to detection antibody; 2) slow target binding kinetics due to the heterogeneous nature of the target capture procedure, which increases assay time and decreases assay sensitivity; 3) complex conjugation chemistries that are required to chemically link the antibody and DNA-markers; and 4) require a PCR amplification step. 45 Therefore, a sensitive, and rapid method for detecting target analytes in a sample that is amenable to multiplexing and easy to implement is needed. [0006] For DNA detection methods, many assays have been developed using radioactive labels, molecular fluorophores, chemiluminescence schemes, electrochemical tags, and most recently, nanostructure-based labels. 61-70 Although some nanostructure-based methods are approaching PCR in terms of sensitivity, none thus far have achieved the 1-10 copy sensitivity level offered by PCR. A methodology that allows for PCR-like signal amplification without the complexity, expense, and time and labor intensive aspects associated with PCR would provide significant advantages over such PCR-based methods. Methods of synthesizing unique nanoparticle-oligonucleotide conjugates are well known, for example, in U.S. Pat. Nos. 6,750,016 and 6,506,564, which are hereby incorporated in their entirety. Previously, a method has been disclosed that utilizes reporter oligonucleotides as biochemical barcodes for detecting one or more analytes in a solution, as described in U.S. patent application Ser. No. 11/127,808, and International Patent Application Nos. PCT/US05/16545, filed May 12, 2005 and PCT/US04/20493, filed Jun. 25, 2004, which are hereby incorporated by reference in its entirety. [0007] Current techniques cover the shift in the frequency of scattered light as a consequence of target-mediated nanoparticle aggregation. 71 However, conventional photometric techniques are not sensitive enough to detect low target quantities (e.g. less than attomolar levels) in bulk experiments. Detection of single binding events have been reported using microscopy, 72 but this method is presently hampered by low throughput and is not amenable to automation. The biobarcode assay, such as that disclosed in U.S. patent application Ser. No. 11/127,808, provides high sensitivity but is limited in throughput due to the need for detection of barcodes by hybridization on a slide. Flow cytometry is a means of detecting rare micron-sized cells or particles in large populations, and has become adapted for high-throughput clinical screening (e.g. 24-tube and 96-well samplers). Combining the above techniques could offer a new means of rapidly and sensitively detecting barcodes or non-amplified targets via nanoparticle aggregation in a clinically applicable format. [0008] Conventional wisdom in flow cytometry holds that the signal from particles much smaller than one micrometer would be lost in the signal from sample debris and electronic noise and thus remain undetectable. However, the intensity of noble metal nanoparticle plasmon resonance scatter has been reported to be significantly higher than the fluorescence yield from standard fluorophores, 73-74 suggesting that they should be detectable by flow cytometry. Previous work has shown that gold nanoparticles can be used as labels to make cells, 75-76 or microparticles 77 detectable by flow analysis. However, there have been no reports that describe detection of individual nanoparticles by flow cytometry. The preliminary experiments shown below confirm the hypothesis that individual nanoparticles can be detected by this technique, opening new avenues for molecular diagnostics. [0009] A variety of novel bar coding systems have been developed as multiplex testing platforms for applications in biological, chemical and biomedical diagnostics. Instead of identifying a target through capture at a specific locus on an array, target analytes are captured by a bar coded tag, which then uniquely identifies the target akin to putting a UPC barcode on a product. This requires an appropriate surface functionalization to ensure that the correct target is captured with high efficiency. Moreover the tag, or barcode, has to be readable with minimal error and at high speed, typically by flow analysis. For quantitative assays the target may be labeled separately, or the tag may also serve as the label. A great variety of materials and physico-chemical principles have been exploited to generate a plethora of novel bar coding systems. Their advantages compared to microarray based assay platforms include in solution binding kinetics, flexibility in assay design, compatibility with microplate based assay automation, high sample throughput, and with some assay formats, increased sensitivity. [0010] The assay platform disclosed in U.S. patent application Ser. No. 11/127,808, filed May 12, 2005, which is hereby incorporated by reference in its entirety, uses bar coded nanoparticles for signal amplification, converting a single captured target into a multiplicity of bar codes. For detection and decoding, however, the bar codes have to be first released from the nanoparticle and then recaptured by hybridization on an array and further hybridized with nanoparticle probes for detection. This process adds significant time and reduces the sensitivity of the assay, since thousands of barcodes are required to generate a detectable signal over noise. Moreover, arrays are expensive and the required silver amplification increases assay variability. The invention herein describes a detection technology that avoids these problems. SUMMARY OF THE INVENTION [0011] The invention overcomes many of the problems of the prior art while greatly expanding the flexibility, adaptability and usefulness of techniques directed to the amplification of a signal to facilitate detection. The present invention relates to methods, probes, compositions, and kits that utilize binding moieties, such as oligonucleotides as biochemical barcodes, for detecting at least one specific target analyte in one solution. The approach takes advantage of recognition elements of specific binding pairs functionalized either directly or indirectly with nanoparticles, and the previous observation that hybridization events that result in the aggregation of gold nanoparticles can significantly alter their physical properties (e.g. optical, electrical, mechanical). 8-12 [0012] It is well known in the art that metallic nanoparticles of 30 nm or larger diameter will change color when brought into close proximity. This principle has been exploited by functionalizing such nanoparticles with DNA oligonucleotides or with antibodies for the detection of either nucleic acid or protein analytes. The color shift as a function of surface plasmon resonance can be detected most sensitively by observing the frequency of the scattered light. It is further known that fluorescently stained beads, cells or particles can be detected and separated by flow analysis, for example on a flow cytometer or in a microcapillary through laser enhanced fluorescence detection. In this method, particles pass in single file by a detection window, which allows counting of single events (single cells, particles or beads). Due to the confinement of the particles into a small sample volume, isolated from other particles, the background is significantly reduced, enabling signal to background ratios that make single particles detectable. This method can therefore deliver superior sensitivities over other methods, where a signal is measured from a bulk sample. Note that there are many types of coding systems for beads or particles, including shape and size of beads, radio-frequency encoding, or chemical encoding, whereby the signal may be detected by light reflection, diffraction, scatter, or spectral analysis. For example, it is known that metallic nanoparticles can be coded with Raman active dyes that give each particle a unique Raman signature. They are most sensitively detected by surface enhanced Raman spectroscopy (SERS). See International Application No. PCT/US03/14100, filed May 7, 2003, which is incorporated by reference in its entirety. [0013] In its current format, the biobarcode technology detects protein and nucleic acid targets through sandwiching between a magnetic bead and an amplifier nanoparticle that is coated with oligonucleotides of specific sequence (barcodes). By releasing the barcodes each captured target is converted into multiple surrogate targets, which are detected via hybridization to a microarray. [0014] In one aspect of the present invention, the array hybridization detection of the above mentioned released barcodes is replaced with a flow based method, such as either a flow cytometer or a microcapillary. Since a minimum of 10,000 target DNA molecules (e.g. barcode molecules) are required in the hybridization solution to generate sufficient hybridization events on a single spot in the microarray to achieve a detectable signal, the flow method is up to 1000 fold more sensitive, since single hybridization events can be measured, and the counting of 10 events may provide sufficient statistical significance. [0015] In another aspect of the present invention, target analytes can be detected directly. Analysis of protein or DNA targets by flow is faster than by capture on a slide or a microplate, as for example in a microplate-based ELISA, because is the flow-based analysis affords a homogeneous assay format (i.e. the nanoparticle probes that bind target do not have to be separated from nanoparticles that don't bind target), and because in solution hybridization kinetics are much faster than hybridizations to a solid surface. In assays where the presence of only a single target is to be measured, the target can be captured between two metallic nanoparticles, resulting in a change in the extinction characteristics of the nanoparticle probes that can be observed 79 as a color change based on measuring absorbance. Storhoff et al. had shown that this can be measured much more sensitively when measuring the scatter light. 71 This concept can be exploited via flow analysis by the binding of targets between two nanoparticles. Since each nanoparticle is basically analysed in a small confined volume, it is physically separated from the other particles and therefore even a very small number of aggregates can be detected. [0016] The combination of the biobarcode technology with the flow-based (flow cytometry or microcapillary) barcode detection method brings surprising new advantages over the existing biobarcode technology and conventional flow-based methods. For instance, it is known that more than 10,000 barcodes per assay are required to obtain a detectable signal by hybridization to a slide. Thus, assuming arguendo an amplification of 10 barcodes per captured target, one can detect about 1000 captured targets at best. However, if one could detect say 100 barcodes by flow analysis, the detection limit would improve by two logs. [0017] There are several ways by which the barcodes can be detected in a flow system. For example, a nanoparticle of a particular size, shape, and/or composition can be used as a probe to bind to a barcode specific for a captured target analyte, thereby permitting detection of one type of target analyte in a sample. In another example, aggregation of two nanoparticles having the particular sizes, shapes, and/or compositions (e.g. two 30 nm or larger nanoparticles) can be used to bind a specific barcode. Either way, using the present invention the released barcodes do not have to be recaptured on a microarray but can now be detected directly by flow in a simple and homogeneous detection format. [0018] The invention also provides methods for multiplex analysis (i.e. detecting multiple target analytes in a sample). In a typical multiplex analysis more than a single target is to be identified in a single assay. In the case of the biobarcode assay, multiple barcodes can be used and decoded. This can be achieved, for example, by binding the released barcodes to either a single or two or more nanoparticles, as described above, whereby each nanoparticle has a unique plasmon resonance frequency due to their specific size, shape, and/or composition. Aggregation of two particles would shift that specific frequency. In certain aspects of the invention, these methods can be combined, whereby some barcodes are detected by the unique signature of single nanoparticles, while others are detected by the unique signatures generated through aggregation of two or more particles. Thus, the unique resonance signatures of the nanoparticles would reveal which barcode is present. [0019] A further method of multiplexing is provided by coding the nanoparticles with Raman active dyes, which can be sensitively detected and decoded in flow by surface enhanced Raman spectroscopy. The main advantage of this type of multiplexing over conventional biobarcode assays, where decoding of barcodes is achieved via hybridization to an array, is assay speed and sensitivity. [0020] Another powerful approach to multiplexing is provided by combining the detectability of single nanoparticles with the coding power of fluorescently labeled microbeads. The microbeads can contain binding moieties as described herein, such that the microbeads can bind to either the target analyte or to the nanoparticles that are bound to the target analyte. Due to the large size of these beads they can be labeled with thousands of fluorescent molecules, providing for detectability and high coding capacity, achieved by varying the number and type of fluorophors. However, the binding of a single target analyte to such a microbead cannot be detected by conventional fluorescent labels, since that signal is too weak and would furthermore be swamped out by the fluorescence from the microbead. [0021] However, if one of the microbeads now binds a gold nanoparticle via a captured target, then this nanoparticle can be detected by scattered light. The frequencies of fluorescent light and scatter light involved can be chosen not to overlap. It is important to note that the number of photons scattered from a 60-80 nm particle is about 1,000,000 times larger than the number of photons generated by a standard fluorophor label. Thus, a single nanoparticle can be detected, while a “barcoded” microbead would have to bind sufficient target/bead to get labeled with ˜1,000,000 fluorophors. It follows that in order to achieve this much target binding, target molecules have to be in excess of beads in the traditional bead assay, requiring up-front target amplification by PCR. The approach described in this invention would allow for detection of a very small number of targets without amplification, since the binding of a single target to a bead, followed by the binding of a single nanoparticle probe, would make this complex detectable and decodable. [0022] In addition, barcodes or any other target can be captured by magnetic bead or other surface, and can then be labeled with a specific nanoparticle. The labeled target can be removed from the sample matrix, or the sample matrix can be washed away. The labeling particle can be released into solution and counted individually by flow based methods as described herein. [0023] In one aspect, the invention provides a method for detecting for the presence of one or more target analytes in a sample, wherein the method comprises the steps of: a) providing a plurality of nanoparticle probes conjugated to binding moieties capable of binding to a first binding site of the target analyte, wherein the nanoparticle probes comprise a metallic material and have an average diameter of less than 200 nanometers; b) providing a capture surface comprising binding moieties capable of binding to a second binding site of the target analyte; c) contacting the nanoparticle probes and capture surface with a sample believed to contain target analytes under conditions effective to allow for binding of the target analyte with the nanoparticle probes and the capture surface to form a complex in the presence of the target analyte; d) optionally washing the capture surface containing the complex formed in (c) to remove all non-bound nanoparticle probes; e) releasing the captured nanoparticle probes from the capture surface; f) subjecting the released nanoparticle probes to confinement conditions under which individual nanoparticle probes can be detected; g) irradiating nanoparticle probes in the confinement conditions with a light beam; and h) measuring scatter light generated in step (g) to determine the number of released nanoparticle probes as an indicator of the presence of target analyte in the sample. [0032] In another aspect, the invention provides a method for detecting for the presence of one or more target analytes in a sample comprising the steps of: a) providing a first nanoparticle probe conjugated to binding moieties capable of binding to a first binding site of the target analyte, wherein the nanoparticle probes comprise a metallic material and have an average diameter of less than 200 nanometers; b) providing a second nanoparticle probe conjugated to binding moieties capable of binding to a second binding site of the target analyte, wherein the nanoparticle probes comprise a metallic material and have an average diameter of less than 200 nanometers; c) contacting the first and second nanoparticle probes with a sample believed to contain target analytes under conditions effective to allow for binding of the target analyte with the binding moieties on the first and second nanoparticle probes to form a complex in the presence of the target analyte; d) subjecting the sample-nanoparticle probe mixture in (c) to confinement conditions under which individual nanoparticle probes or nanoparticle probe-target complexes can be detected; e) irradiating the complex with light of a frequency range that covers the plasmon resonance frequency of the nanoparticles; and f) measuring scatter light frequency to differentiate single from complexed nanoparticles, whereby the presence of complexed particles is indicative of the presence of the target analyte in the sample. [0040] In certain aspects, the nanoparticle probes bind to the target analyte indirectly via specific linker molecules. [0041] In other aspects, the binding moieties comprise oligonucleotides, antibodies, aptamers, or some combination thereof. [0042] In certain aspects, the nanoparticle probes are about 30 to about 150 nm in diameter. [0043] In additional aspects, the target analyte is a protein or hapten and the binding moieties are antibodies. The antibodies can be polyclonal antibodies or monoclonal antibodies. [0044] In further aspects, the target analyte is a sequence from a genomic DNA sample and the binding moieties are oligonucleotides, the oligonucleotides having a sequence that is complementary to at least a portion of the genomic sequence. The genomic DNA can be eukaryotic, bacterial, fungal or viral DNA. Also, the target analyte can be a sequence from episomal DNA sample and the binding moieties are oligonucleotides, the oligonucleotides having a sequence that is complementary to at least a portion of the episomal DNA sequence. [0045] In certain aspects, the confinement conditions are generated by flow cytometry or by capillary eletrophoresis. [0046] In other aspects, at least one of the nanoparticle probes can be further labeled with a Raman active group. The Raman active group can be used in equal or different concentrations. [0047] In additional aspects, the nanoparticle probes comprise gold, silver, copper, or platinum, or are core-shell nanoparticles. [0048] In yet other aspects, the target analyte can bind to the capture surface indirectly via specific linker molecules. [0049] In other aspects, the capture surface can be a microtiter well. In some aspects, the capture surface containing the complex formed in step (c) above can be isolated from all non-bound nanoparticle probes. In such cases, the capture surface can be a magnetic bead. [0050] In certain aspects, the plurality of nanoparticle probes used in a method of the invention comprises nanoparticle probes of different shapes, each differently shaped nanoparticle probe being conjugated to binding moieties that bind to a different target analyte, and wherein each differently shaped nanoparticle probe creates unique scatter light when irradiated, thereby indicating the presence of the target analyte to which it binds. The plurality of nanoparticle probes can comprise nanoparticle probes of different materials, each nanoparticle probe of different material being conjugated to binding moieties that bind to a different target analyte, and wherein each nanoparticle probe of different material creates unique scatter light when irradiated, thereby indicating the presence of the target analyte to which it binds. The plurality of nanoparticle probes can further comprise nanoparticle probes of different sizes, each nanoparticle probe of different size being conjugated to binding moieties that bind to a different target analyte, and wherein each nanoparticle probe of different size creates unique scatter light when irradiated, thereby indicating the presence of the target analyte to which it binds. [0051] In some aspects, the methods of the invention further comprise a step of providing one or more labeled microbeads that can bind to either the target analyte or to a nanoparticle probe, thereby capable of forming a complex with the nanoparticle probes and the target analyte. In these aspects, at least one microbead can be fluorescently labeled. [0052] Specific embodiments of the present invention will become evident from the following more detailed description of certain embodiments. DESCRIPTION OF THE FIGURES [0053] FIG. 1 indicates that gold and silver nanoparticles of various sizes can be used to resolve differences in relative scatter, and the side scatter patterns generated by each size particle are sufficiently different to allow identification of the nanoparticle's size. [0054] FIG. 2 demonstrates that silver staining of gold nanoparticles causes a large shift in side scatter, indicating a significant change in particle size and scatter properties. [0055] FIG. 3 indicates that Plasmon scatter light from silver particles can be seen by flow cytometry. [0056] FIG. 4 demonstrates that the complementary DNA-induced aggregation showed a time dependent increase in SSC and 630 nm intensity. The 630 nm scatter intensity of the aggregates were so intense as to begin to move off-scale. [0057] FIG. 5 indicates that increased amounts of dA80 target induced a new population with higher side scatter and 630 nm scatter, presumably dT30 nanoparticle dimers. [0058] FIG. 6 illustrates the detection of a viral target having at least a first portion and a second portion. The detection of the target is accomplished using two linker oligos (linker A and linker B), a nanoparticle probe A, and a nanoparticle probe B. Nanoparticle probe A is conjugated with at least one poly AC oligo. Linker A comprises at least a first portion and a second portion, said first portion comprising a poly GT oligo (complementary to the poly-AC oligo conjugated to Nanoparticle probe A) and said second portion comprising a sequence complementary to the first portion of the viral target. Nanoparticle probe B is conjugated with at least one poly-T oligos. Linker B comprises a first portion and a second portion, said first portion comprising a poly A oligo (complementary to the poly T oligo conjugated to Nanoparticle probe B), and said second portion comprising a sequence complementary to the second portion of the viral target. Increased amounts of the oligo target induced increased amounts of aggregates, and in the presence of constant target and probe, the fraction of aggregates increase over time. [0059] FIG. 7 is an illustratration showing the detection of a target molecule having at least a first portion and a second portion. [0060] FIG. 8 shows graphs illustrating the intensity changes by 535 nm laser correlate with size, similar to intensity changes induced by white light. [0061] FIG. 9 shows graphs illustrating the white light scatter of single nanoparticles and aggregated nanoparticles as measured by Ocean Optics spectrophotometer, and dot plots showing light scatter of single nanoparticles and aggregated nanoparticles as measured by MoFlow flow cytometer. [0062] FIG. 10 is an illustration showing a complex of methicillin resistant Staphylococcus aureus (MRSA) target with four 50 nm nanoparticle probes as described in Example 8 below. [0063] FIG. 11 shows detection of various concentrations of MRSA target using 50 nm nanoparticle probes and flow cytometry. [0064] FIG. 12 shows detection of prostate specific antigen (PSA) using 30 nm nanoparticle probes and flow cytometry. DETAILED DESCRIPTION OF THE INVENTION [0065] Unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular. [0066] As utilized in accordance with the present disclosure, the following terms, unless otherwise indicated, shall be understood to have the following meanings: [0067] The terms “target,” “analyte” or “target analyte” refer to the compound or composition to be detected, including drugs, metabolites, pesticides, pollutants, and the like. The analyte can be comprised of a member of a specific binding pair (sbp) and may be a ligand, which is monovalent (monoepitopic) or polyvalent (polyepitopic), preferably antigenic or haptenic, and is a single compound or plurality of compounds, which share at least one common epitopic or determinant site. The analyte can be a part of a cell such as bacteria or a cell bearing a blood group antigen such as A, B, D, etc., or an HLA antigen or a microorganism, e.g., bacterium, fungus, protozoan, or virus. If the analyte is monoepitopic, the analyte can be further modified, e.g. chemically, to provide one or more additional binding sites. In practicing this invention, the analyte has at least two binding sites. The monoepitopic ligand analytes will generally be from about 100 to 2,000 molecular weight, more usually from 125 to 1,000 molecular weight. Typical analytes may be much larger and include, but are not limited to episomal DNA, genomic DNA, viral nucleic acid molecules, proteins, peptides, nucleic acid segments, molecules, cells, microorganisms and fragments and products thereof, or any substance for which attachment sites, binding members or receptors (such as antibodies) can be developed. [0068] As used herein, the terms “barcode”, “biochemical barcode”, “biobarcode”, “reporter barcode” etc. are all interchangeable with each other and have the same meaning. In the preferred embodiment of the present invention, the biobarcodes are nucleic acids. The markers may be the same, or may be different. The biobarcode assay has been disclosed in U.S. patent application Ser. No. 11/127,808, filed May 12, 2005, U.S. patent application Ser. No. 10/877,750, filed Jun. 25, 2004, International Patent Application PCT/US04/020493 (Publication No. WO05/003394), filed Jun. 25, 2004, and International Patent Application PCT/US05/16545 (Publication No. WO2006/078289), filed May 12, 2005, all of which are incorporated by reference herein in their entirety. [0069] The polyvalent ligand analytes will normally be larger organic compounds, often of polymeric nature, such as polypeptides and proteins, polysaccharides, nucleic acids, and combinations thereof. Such combinations include components of bacteria, viruses, chromosomes, genes, mitochondria, nuclei, cell membranes and the like. [0070] For the most part, the polyepitopic ligand analytes to which the invention can be applied will have a molecular weight of at least about 5,000, more usually at least about 10,000. In the polymeric molecule category, the polymers of interest will generally be from about 5,000 to 5,000,000 molecular weight, more usually from about 20,000 to 1,000,000 molecular weight; among the protein analytes of interest, the molecular weights will usually range from about 5,000 to 200,000 molecular weight. [0071] A wide variety of proteins may be considered as belonging to the family of proteins having similar structural features, proteins having particular biological functions, proteins related to specific microorganisms, particularly disease causing microorganisms, etc. Such proteins include, for example, immunoglobulins, cytokines, enzymes, hormones, cancer antigens, nutritional markers, tissue specific antigens, etc. [0072] The types of proteins, blood clotting factors, protein hormones, antigenic polysaccharides, microorganisms and other pathogens of interest in the present invention are specifically disclosed in U.S. Pat. No. 4,650,770, the disclosure of which is incorporated by reference herein in its entirety. [0073] The analyte may be a molecule found directly in a sample, such as a body fluid from a host. The sample can be examined directly or may be pretreated to render the analyte more readily detectible. Furthermore, the analyte of interest may be determined by detecting an agent probative of the analyte of interest such as a specific binding pair member complementary to the analyte of interest, whose presence will be detected only when the analyte of interest is present in a sample. Thus, the agent probative of the analyte becomes the analyte that is detected in an assay. The body fluid can be, for example, urine, blood, plasma, serum, saliva, semen, stool, sputum, cerebral spinal fluid, tears, mucus, and the like. [0074] The term “sample” as used herein refers to any quantity of a substance that may comprise target analytes, and that can be used in a method of the invention. For example, the sample can be a biological sample or can be extracted from a biological sample derived from humans, animals, plants, fungi, yeast, bacteria, viruses, tissue cultures or viral cultures, or a combination of the above. A sample may contain or be extracted from solid tissues (e.g. bone marrow, lymph nodes, brain, skin), body fluids (e.g serum, blood, urine, sputum, seminal or lymph fluids), skeletal tissues, or individual cells. Alternatively, the sample can comprise purified or partially purified nucleic acid molecules and, for example, buffers and/or reagents that are used to generate appropriate conditions for successfully performing a method of the invention. In certain embodiments, a sample is or is in solution, and can be subject to flow based detection methods as described herein. [0075] The term “particle” as used herein specifically encompasses both nanoparticles and microparticles as defined and described hereinbelow. As used herein, the term “particle” refers to a small piece of matter that can preferably be composed of metals, silica, silicon-oxide, or polystyrene. A “particle” can be any shape, such as spherical or rod-shaped. [0076] In certain embodiments, the methods of the invention involve the use of nanoparticle probes. Nanoparticles useful in the practice of the invention include metal (e.g., gold, silver, copper and platinum), colloidal materials. The size of the nanoparticles is preferably from about 30 nm to about 200 nm (mean diameter). The nanoparticles can be any shape, such as spherical or rod-shaped. As used herein, a “metallic” nanoparticle comprises at least one metal. [0077] Methods of making metal nanoparticles are well-known in the art. See, e.g., Schmid, G. (ed.) Clusters and Colloids (VCH, Weinheim, 1994); Hayat, M. A. (ed.) Colloidal Gold: Principles, Methods, and Applications (Academic Press, San Diego, 1991); Massart, R., IEEE Taransactions On Magnetics, 17, 1247 (1981); Ahmadi, T. S. et al., Science, 272, 1924 (1996); Henglein, A. et al., J. Phys. Chem., 99, 14129 (1995); Curtis, A. C., et al., Angew. Chem. Int. Ed. Engl., 27, 1530 (1988). See also U.S. Pat. No. 6,506,564, which is incorporated by reference in its entirety. [0078] Nanoparticles useful in the methods of the invention can also be core-shell particles such as the ones described in U.S. patent application Ser. No. 10/034,451, filed Dec. 28, 2002 and International application no. PCT/US01/50825, filed Dec. 28, 2002, which are incorporated by reference in their entirety. [0079] Suitable nanoparticles are also commercially available from, e.g., Ted Pella, Inc. (gold), Amersham Corporation (gold), Nanoprobes, Inc. (gold). [0080] For stability purposes, a nanoparticle probe can have zero, one, or a plurality of oligonucleotides, as well as the binding moieties, attached to it. For example, nanoparticles can be incubated with binding moieties and oligonucleotides in a 3:1 ratio. In one embodiment, the oligonucleotides are polyadenosine oligonucleotides, for example Alo, which is an oligonucleotide consisting of 10 adenosines. [0081] Those of skill in the art will appreciate that nanoparticles can be designed to have different scatter light properties based on their size, composition, and shape. Thus, one of skill in the art can select a particular size, composition, and/or shape to represent the presence of a particular target analyte. For example, a gold, round, 30 nm nanoparticle will cause different scatter light than a silver, 60 nm, rod-shaped nanoparticle. Consequently, both probes can be used in one sample to detect the presence of two different target analytes, as discussed herein. [0082] As used herein, the term “linker molecule” refers to a binding moiety that serves as an indirect link between a nanoparticle probe and a target analyte, or between a capture surface and a target analyte. A linker molecule can be a “linker oligonucleotide” with at least two binding regions, one of which binds to a complementary oligonucleotide conjugated to a nanoparticle or capture surface, and the other which binds to a complementary portion of the target analyte. Other examples of linker molecules include streptavidin, avidin, or antibodies. Alternatively, linkers can be generated from any of the binding moieties described below, whereby, for an example, two different moieties are chemically linked, now having specificity for two different binding partners. [0083] The term “binding moieties” is used herein to refer to members of a specific binding pair. The term “specific binding pair (sbp) member” refers to one of two different molecules, which specifically binds to and can be defined as complementary with a particular spatial and/or polar organization of the other molecule. The members of the specific binding pair can be referred to as ligand and receptor (antiligand). These will usually be members of an immunological pair such as antigen-antibody, although other specific binding pairs such as biotin-avidin, enzyme-substrate, enzyme-antagonist, enzyme-agonist, drug-target molecule, hormones-hormone receptors, nucleic acid duplexes, IgG-protein A/protein G, polynucleotide pairs such as DNA-DNA, DNA-RNA, protein-DNA, lipid-DNA, lipid-protein, polysaccharide-lipid, protein-polysaccharide, nucleic acid aptamers and associated target ligands (e.g., small organic compounds, nucleic acids, proteins, peptides, viruses, cells, etc.), and the like are not immunological pairs but are included in the invention and the definition of sbp member. A member of a specific binding pair can be the entire molecule, or only a portion of the molecule so long as the member specifically binds to the binding site on the target analyte to form a specific binding pair. [0084] The term “ligand” refers to any organic compound for which a receptor naturally exists or can be prepared. The term ligand also includes ligand analogs, which are modified ligands, usually an organic radical or analyte analog, usually of a molecular weight greater than 100, which can compete with the analogous ligand for a receptor, the modification providing means to join the ligand analog to another molecule. The ligand analog will usually differ from the ligand by more than replacement of a hydrogen with a bond, which links the ligand analog to a hub or label, but need not. The ligand analog can bind to the receptor in a manner similar to the ligand. The analog could be, for example, an antibody directed against the idiotype of an antibody to the ligand. [0085] The term “receptor” or “antiligand” refers to any compound or composition capable of recognizing a particular spatial and polar organization of a molecule, e.g., epitopic or determinant site. Illustrative receptors include naturally occurring receptors, e.g., thyroxine binding globulin, antibodies, enzymes, Fab fragments, lectins, nucleic acids, nucleic acid aptamers, avidin, protein A, barstar, complement component C1q, and the like. Avidin is intended to include egg white avidin and biotin binding proteins from other sources, such as streptavidin. [0086] The term “specific binding” refers to the specific recognition of one of two different molecules for the other compared to substantially less recognition of other molecules. Generally, the molecules have areas on their surfaces or in cavities giving rise to specific recognition between the two molecules. Exemplary of specific binding are antibody-antigen interactions, enzyme-substrate interactions, polynucleotide interactions, and so forth. [0087] The term “non-specific binding” refers to the binding between molecules that is relatively independent of specific surface structures. Non-specific binding may result from several factors including hydrophobic interactions between molecules. [0088] In certain embodiments, a label can be used to further differentiate a target analyte in a sample. For example, nanoparticle probes can serve as labels directly, or their optical properties can be modified by linkage to a Raman-active group. A “capture surface” as used herein can be any surface capable of having antibodies, aptamers, oligonucleotides, or analytes bound thereto. Such surfaces include, but are not limited to, glass, metal, plastic, or materials coated with a functional group designed for binding of antibodies, aptamers, oligonucleotides, or analytes. The coating may be thicker than a monomolecular layer; in fact, the coating could involve porous materials of sufficient thickness to generate a porous 3-dimensional structure into which the antibodies, aptamers, oligonucleotides, or analytes can diffuse and bind to the internal surfaces. Binding of antibodies, aptamers, oligonucleotides, or analytes to a substrate can be accomplished by any method known to those of skill in the art and as described, for example, in U.S. patent application Ser. No. 11/124609, filed May 6, 2005, which is incorporated by reference in its entirety. [0089] A “capture surface” suitable for the methods of the invention include, but are not limited to, microplates, glass slides, nanoparticles, magnetic beads, or any suitable inorganic or organic molecule of sufficient size, or a combination thereof, that offers the appropriate surface for attachment of antibodies, aptamers, oligonucleotides, or analytes, and shows a minimum of non-specific binding to nanoparticle probes that are not bound to target analytes. In one embodiment, the surface is a magnetic (e.g., ferromagnetite) colloidal material. The complex formed between the nanoparticle probe, the target analyte, and the magnetic surface can be easily separated from any unbound components by the application of a magnetic field. In another embodiment, the complex can be separated by centrifugation. In certain embodiments, the magnetic surface is a magnetic bead, such as a magnetic microparticle. [0090] In certain embodiments, a nanoparticle probe bound to target analyte forms a complex with the capture surface through binding of the target analyte to a binding moiety that is attached to the capture surface itself. Once the complex is formed, any unbound probes are removed from the complex by suitable methods, such as, without limitation, washing, centrifugation, and application of a magnetic field. The complex can be disrupted by releasing the nanoparticle can be released from a capture surface using techniques well known to those of skill in the art. For example, specifically bound probes can be selectively released from the capture surface by any suitable methods, including but not limited to, target analyte displacement, epitope displacement, antibody displacement, aptamer displacement, target analyte destruction, antibody destruction, aptamer destruction, protease digestion, restriction digestion, a reducing agent, RNaseH digestion, chemical cleavage, and dehybridization, depending on what binding moiety is used to capture the target analyte bound nanoparticle probes. [0091] In some instances, a “detaching agent” can be used to release the capture nanoparticle probes from the capture surface. As used herein, a “detaching agent” refers to a solution or agent that can disrupt or destruct the linkage of a binding moiety to the capture surface, and detach and release the binding moiety in complex with the nanoparticle probe into solution. For example, where the binding moiety is an oligonucleotide, it can be detached and released from the capture surface by dehybridization, dissolution, or chemical cleavage. Representative detaching agents include, without limitation, iodine, a cyanide salt, and a basic agent. See also U.S. patent application Ser. No. 11/127808, and International Patent Application Nos. PCT/US05/16545, filed May 12, 2005 and PCT/US04/20493, filed Jun. 25, 2004, which are hereby incorporated by reference in its entirety. [0092] In certain embodiments, a sample having been contacted with nanoparticle probes will be spatially confined in a sample stream under confinement conditions (such as those described in the Examples herein). As used herein, “confinement conditions” refer to the spatial arrangement of the sample in such a manner that allows for analysis of individual nanoparticle probes within the sample using flow-based methods (e.g. flow cytometry or microcapillary electrophoresis). Confinement can be accomplished using methods well known to those of skill in the art. Conventional methods involve “electrokinetic focusing,” as discussed, for example, in U.S. Pat. No. 6,120,666, which is incorporated by reference. Electrokinetic techniques include electroosmosis and/or electrophoresis. Two common types of electrophoresis are steady state and capillary zone electrophoresis as discussed by Hahm and Beskok, 2005, Bull. Polish Acad. Sci. 53:325-334.Once in confinement conditions, the sample stream can be irradiated with a light beam. The confinement conditions permit the nanoparticle probes to flow single-file past the light beam, such as a laser beam (and in many instruments, past two or more laser beams). The momentary pulse of scatter light emitted as the particle crosses the beam is measured by photomultipliers at some angle (typically 90 degree angle) from the beam. Typically, two to three detectors are used with different wavelength bandpass filters, allowing the simultaneous detection of emissions at different wavelengths from different nanoparticles, or fluorescence light from the fluorescently coded microparticles, respectively. [0093] In addition to fluorescence, two types of light scatter are measured in traditional flow cytometry. Low-angle forward scatter (often called simply “forward scatter”) is roughly proportional to the diameter of the particle. Orthogonal, 90° or “side scatter” is proportional to the granularity. Thus, in the FACScan, each particle can provide up to five numbers: size, granularity, plus green, red, and far red fluorescence intensities. [0094] In a dot plot, each cell is represented by a dot, positioned on the X and Y scales according to the intensities detected for that cell. Scatter dot plots (X=forward scatter intensity; Y=side scatter intensity) are often informative (see examples below). Scatter scales are usually linear. Fluorescence dot plots typically plot X=green fluorescence intensity, Y=red fluorescence intensity. These two-color dot plots are often divided into four quadrants, the double negative cells, the green-only, red-only, and double positive cells. These are quantitated by giving the percentage of cells in each quadrant. Since fluorescence intensity often varies several orders of magnitude between cells, the scales are usually the logarithm of fluorescence intensity spanning four decades (a 10,000-fold range). [0095] Histograms are often used to interpret results of a flow-based assay. In a histogram, the X axis is intensity (of scatter or fluorescence), and the Y axis shows how many cells had each intensity. Thus, histograms show the distribution of intensities for a single parameter, while dot plots show the correlated distribution for two parameters. The density of dots in a region of a dot plot shows the “number of cells”, equivalent to the Y axis of a histogram. Indeed, dot plots are sometimes represented as pseudo-3D graphs where the Z axis is “number of cells”. [0096] As shown in the Examples herein, it is feasible to detect scatter light from individual gold and silver nanoparticles using a standard flow cytometer, and distinguish between different sizes and types of nanoparticles. More importantly, changes in nanoparticle scatter induced by several different phenomena can also be detected and differentiated. Most notably, the change in red scatter of 60 nm Au complementary DNA binding-induced aggregation was sufficiently high to make these nanoparticle aggregates detectable and countable. Therefore, the aggregation of two nanoparticles which are brought together via binding by linker oligonucleotides to a target oligonucleotide can be detected using flow cytometry. Aggregated nanoparticles formed very bright and tight scatter profiles, making them easy to detect, differentiate from nanoparticle monomers, and quantitate. [0097] Numerous parameters make themselves amenable to nanoparticle detection, permitting those of skill in the art to design sufficiently discriminating gating strategies. With the right parameters and sufficient signal intensity, detecting and quantifying very rare events, even straight nanoparticle-protein/DNA-nanoparticle complexes, is feasible. Multiplexing of analytes can be performed by including other unique tags or even different sized nanoparticles in the complex. Furthermore, the real-time nature of flow cytometry makes it easier to break down the assay for better quality control of materials and detecting causes of non-specific binding. [0098] An alternative way to analyze beads or tags is through capillary electrophoresis instead of flow cytometry. The concept is similar in that tags pass by an interrogation window in the capillary in single file, and are analyzed by laser-induced fluorescence measurement to decode the tags and quantify the captured target. [0099] In one embodiment of the present invention, a method is provided for detecting for the presence of one or more target analytes (or biobarcodes) in a sample, each target analyte having at least two binding sites for specific binding interactions with specific binding complements, in a sample. [0100] In another embodiment of the present invention, several different target analytes (or biobarcodes) may be detected, where each target analyte has at least two binding sites for specific binding interactions with specific binding complements, in a sample. [0101] In another embodiment of the present invention, several kinds of particle beads and several kinds of nanoparticle probes may be used to allow detection of multiple target analytes or biobarcodes. For instance, linkers that bind to a first kind of analyte would also bind to a particular size nanoparticle, and a particle bead with a particular fluorescent marker attached. Different combinations of nanoparticles and particle bead/fluorescent markers will allow for the detection of various different target analytes in the same solution. [0102] FIG. 7 provides an illustration of certain embodiments of the invention. FIG. 7 depicts the detection of a target molecule, said target having at least a first portion and a second portion The detection of the target is accomplished using two linker oligos (linker A and linker B), a nanoparticle probe A, and a nanoparticle probe B. Nanoparticle probe A is conjugated with at least one oligonucleotide sequence A. Linker A comprises at least a first portion and a second portion, said first portion comprising an oligonucleotide sequence A′ complementary to oligonucleotide sequence A, and said second portion comprising a sequence complementary to the first portion of the target. Nanoparticle probe B is conjugated with at least one oligonucleotide sequence B. Linker B comprises a first portion and a second portion, said first portion comprising an oligonucleotide sequence B′ complementary to the oligonucleotide sequence B, and said second portion comprising a sequence complementary to the second portion of the target. Examples [0103] The following examples are offered to illustrate, but not to limit, the invention. Example 1 Scatter Light Generated by Gold and Silver Nanoparticles in Flow Cytometry Assays [0104] Gold and silver nanoparticles of various sizes were used to demonstrate the capability of nanoparticles to be used in flow cytometry assays. Using a Dako CytoMation 405 nm laser (Dako Denmark A/S, Glostrup, Denmark) or the Dako MoFlo 530 nm laser, forward and side scatter was adjusted to detect sub-micron particles. Gold and silver nanoparticles were obtained from BBInternational Ltd., Cardiff, UK. To demonstrate scatter light from 40 nm and 60 nm particles, 10 6 Ag nanoparticles in 500 uL 4×SSC (Saline Sodium Citrate) were measured by side scatter in a 60 sec analysis ( FIG. 1 b - c ), and 10 6 Au nanoparticles in 500 uL 4×SSC were detected based on their red signal in a 60 second run ( FIG. 1 e - f ), and were compared to measurement of 4×SSC alone ( FIGS. 1 a and 1 d ). [0105] Nanoparticles of both types and sizes produced a bright and tight population, and larger nanoparticles produced more scatter. Aggregated nanoparticles might be the cause of the counts seen away from the main population. [0106] Under the conditions used, 40 nm gold nanoparticle lack sufficient scatter intensity to be clearly separated from background. However, in further experiments, analyzing 30, 40, 50, 60 and 80 nm gold nanoparticle with excitation from either 535 nm or 635 nm lasers allowed us to resolve differences in relative scatter between the sols (data not shown). These results indicate that changes in side scatter intensity are sufficient to distinguish Nanoparticle size. Example 2 Silver Amplification Induces Broad Side Scatter Shift of Gold Nanoparticles [0107] As shown in FIG. 2 , silver staining of gold nanoparticles causes a large shift in side scatter and forward scatter, indicating a significant change in particle size and scatter properties. The experiments were conducted using 2 uL 40 nm gold nanoparticles were mixed with silver solution (2 uL Signal Enhancement A (SEA; Nanosphere, Northbrook, Ill.) and 2 uL Signal Enhancement B (SEB; These solutions are commercially available from Nanosphere, Northbrook, Ill. There are functionally equivalent commercially available Silver Enhancement reagents available (e.g. Silver Enhancement Solution A, #S-5020 and Silver Enhancement Solution B, #S-5145 Sigma-Aldrich, St. Louis, Mo.) and reacted for 5 minutes at room temperature. The reaction was stopped by diluting with 500 uL water. Scatter was detected with the CytoMation 405 nm laser. Silver-coating of gold nanoparticles caused a large shift in side scatter and a forward scatter tail (See FIG. 2 b ) indicative of significant changes in particle size and scatter properties. Example 3 Silver Particles in Solution Detectable by Flow Cytometry [0108] As shown in FIG. 3 , Plasmon scatter light from silver particles can be seen by flow cytometry. A 100 uL aliquot of signal enhancement solution A (SEA) was transferred to a clear 1.5 mL tube. Due to opening of the box it was stored in, the SEA was briefly and randomly exposed to ambient light. Using the CytoMation 405 nm laser and 430 nm filter, silver particles induced by exposure to light were detected by side scatter ( FIG. 3 c ). An increased 430 nm signal was also detected ( FIG. 3 d ), indicating the plasmon scatter light from silver particles can be seen by flow cytometry. Example 4 Aggregation of Nanoparticles Detectable Using Flow Cytometry [0109] As shown in FIG. 4 , complementary DNA-induced aggregation of nanoparticles showed a time dependent increase in 4×SSC and 630 nm intensity. 2 uL 509 pM 60 nm dT30 gold nanoparticles (Nanosphere, Northbrook, Ill.)+2 uL 210 pM 60 nm dA30 gold nanoparticles (Nanosphere, Northbrook, Ill.) were mixed in 26 uL 4×SSC/2% dextran sulfate (Sigma-Aldrich, St. Louis, Mo., Cat #D-8906) at room temperature. 2 uL of the mix were resuspended in 600 uL 4×SSC and analyzed with the Dako MoFlo (535 nm laser and 530 nm filter, 635 nm laser and 630 nm filter) after 30 minutes and 45 minutes. The complementary DNA-induced aggregation showed a time dependent increase in SSC and 630 nm intensity. The 630 nm scatter intensity of the aggregates were so intense as to begin to move off-scale. (See R12 in FIG. 4 iii .) Example 5 Target Analytes Detected Using Nanoparticle Probes and Flow Cytometry [0110] As shown in FIG. 5 , increased amounts of dA80 target induced a new population with higher side scatter and 630 nm scatter, presumably dT30 dimers. 1 uL 509 pM 60 nm dT30 gold nanoparticles were mixed with increasing concentrations of dA˜80 target oligonucleotides (Biotin-BC1-dA30; Nanosphere, Northbrook, Ill.) in 20 uL 4×SSC/4% dextran sulfate and incubated overnight at room temperature. 4 uL of each mix was diluted in 400 uL 4×SSC. Light scatter was analyzed with the Dako MoFlo (535 nm laser and 530 nm filter, 635 nm laser and 630 nm filter), triggering on red signal. Example 6 Viral Target Detected Using Nanoparticle Probes and Flow Cytometry [0111] As shown in FIG. 6 , detection of a viral target, said target having at least a first portion and a second portion, can be accomplished using nanoparticle probes. The detection of the target was accomplished using two linker oligos (linker A and linker B), a nanoparticle probe A, and a nanoparticle probe B (illustrated in FIG. 6A ). Nanoparticle probe A is conjugated with at least one poly AC oligo. Linker oligo A comprises at least a first portion and a second portion, said first portion comprising a poly GT oligo (complementary to the poly-AC oligo conjugated to Nanoparticle probe A) and said second portion comprising a sequence complementary to the first portion of the viral target. Nanoparticle probe B is conjugated with at least one poly-T oligos. Linker oligo B comprises a first portion and a second portion, said first portion comprising a poly A oligo (complementary to the poly T oligo conjugated to Nanoparticle probe B), and said second portion comprising a sequence complementary to the second portion of the viral target. [0112] To detect the viral target derived from the West Nile Virus genome, a complex (as illustrated in FIG. 6A ) was formed by mixing an equimolar ratio of target oligo (5′-TGA CCA GTG CTA TCA ATC GGC GGA GCT CAA AAC AAA AGA AAA GAG GAG GAA AGA CCG GAA TTG CAG TCA TGA TTG-3′ SEQ ID NO: 1) and linker oligonucleotides (Linker Probe A: 5′-(GT)15-CAA TCA TGA CTG CAA TTC CGG TCT TTC CTC CTC TT-3′ SEQ ID NO: 2; Linker Probe B: 5-TTG AGC TCC GCC GAT TGA TAG CAC TGG TCA-(A)30 SEQ ID NO: 3; all synthesized by IDT, Coralville, Iowa) in 4×SSC (20×SSC (Ambion, Austin, Tex., cat #9770), diluted with DNA-grade water (Fisher Scientific, Pittsburgh, Pa., cat #BP2470-1) for 5 minutes at 80° C. The mixture was cooled to room temperature and serially diluted 3-fold. Then, 10 pM total nanoparticle probe mix were added in 20 uL 4×SSC/4% dextran sulfate (Sigma-Aldrich, D-8906, MW 500,000; St. Louis, Mo.). The mixture was incubated at room temperature for 2 hours. Detection was performed by flow cytometry. 1 uL of the sample was mixed in 400 uL 4×SSC and scatter light intensity at 630 nm was measured ( FIG. 6B ). [0113] Another reaction mixture was formed by mixing 230 pM target complex in 8 pM of total nanoparticle probe mix in 20 uL 4×SSC/4% dextran sulfate. 1 uL of the sample was mixed in 400 uL 4×SSC and scatter light intensity at 630 nm was measured over time and the increase in dimer/monomer ratio was calculated ( FIG. 6C ). Example 7 Scatter Intensity of Nanoparticles on MoFlow Cytometer Cersus Ocean Optics Spectrophotometer [0114] To determine if results discussed above using flow cytometry were consistent with results obtained with a spectrophotometer, the size-dependent scatter intensity of nanoparticles was determined on a MoFlow cytometer and an Ocean Optics spectrophotometer (Dunedin, Fla.). Various sizes of gold colloid (British Biocell International, Cardiff, UK) nanoparticles of various sizes (30 nm, 40 nm, 50 nm, 60 nm, and 80 nm) were diluted in phosphate-buffered saline (PBS) to 16 fM. The scatter intensity of these particle solutions were measured using an Ocean Optics spectrophotometer. Particle solutions were then analyzed on the MoFlo flow cytometer (run for 1 minute each). Detection was triggered by 488 nm signal and intensity measured at 535 nm. Intensity was normalized to levels over buffer background and plotted on a linear scale against the particle size. The dose response (relative signal intensity as a function of particle size) was identical on both instruments ( FIG. 8 ). As shown in FIG. 8 , the greater brightness of the 535 nm laser allowed 30 nm nanoparticles to be detected. [0115] The scatter intensity of nanoparticle aggregates was also tested using the Ocean Optics spectrophotometer and compared to the intensity of aggregates measured by flow cytometry. 60 nm nanoparticle probes were aggregated using ionic conditions under which the surface charge leads to particle aggregation (incubation in 0.8 M NaCl). Aggregated probes were concentrated by centrifugation at 200×g for 15 min at RT. The scatter properties of singlet and aggregated nanoparticles were measured on an Ocean Optics spectrophotometer with white light illumination to show the shift in the resonance frequency. Particles and aggregates were then analyzed on a MoFlo flow cytometer (565 nm laser trigger and 635 nm detection wavelength) and sorted (fractionated) based on their scatter intensities (FL4 window). The sorted particle fractions were re-analyzed on the cytometer to check for purity and to establish that particle aggregates can be clearly identified and sorted by this method. As shown in FIG. 9 , the enriched aggregate sample had an increased right-angle white light scatter detected by the spectrophotometer and an increased bright FL4 population detected by flow cytometry. The enriched aggregate sample was sorted based on FL4 intensity. Purity check showed they had sorted into two distinct populations. Example 8 [0116] Detection of DNA Target with 50 nm Probes and Protein Target with 30 nm Probes [0117] A MecA assay was designed to detect Methicillin resistant Staphylococcus aureus (MRSA) with four 50 nm nanoparticle probes as illustrated in FIG. 10 . 10 pM total nanoparticle probes produced as previously described 71 (2.5 pM each) in 70 uL 4×SSC/7.5% Formamide/4% dextran sulfate plus various concentrations of a 281 bp product derived by AmpliTaq PCR reaction from the MecA gene of MRSA (strain #700699 obtained from American Type Culture Collection, Manassas, Va.) were incubated at room temperature for 1.25 hours. For flow cytometry, 1 uL of hybridization reaction was mixed with 1 mL 4×SSC, and a 565 nm laser was used to detect 635 nm signal. The results are shown in FIG. 11 . [0118] To demonstrate that nanoparticle probes can be used to detect protein targets, 10 pM of 30 nm nanoparticles co-loaded with anti-PSA polyclonal antibody (R&D Systems, Minneapolis, Minn.) (and non-specific oligonucleotides added for use in biobarcode assays) were incubated with or without 200 ng prostate specific antigen (OEM Concepts, Toms River, N.J., Cat #H6M07-323) in PBS for 30 minutes at room temperature. An aliquot of each sample was diluted to 1 pM in PBS. The samples were run on the MoFlo flow cytometer for 1 minute, analyzed using a 565 nm signal and discriminated by pulse width. An increase in events brighter in FL3 and/or greater pulse width was detected, indicative of aggregated probe ( FIG. 12 ). 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The present invention relates to screening methods, compositions, and kits for detecting for the presence or absence of one or more target analytes, e.g. biomolecules, in a sample. In particular, the present invention relates to methods that utilize nanoparticle probes in an in-solution homogeneous assay system for high-sensitivity detection of target proteins or nucleic acids based on flow analysis of single particles.

BACKGROUND 1. Field of the Invention This invention relates to sound signal processing and reproduction, specifically to reproduction of a sound image using 3 or more loudspeakers, spaced apart and placed forward of the listener, to independently produce sounds separated from a stereo (2-channel) source according to the relative locations of the sound sources in the stereo mix. 2. Description of the Prior Art. I am not aware of any patents in the field of sonic separation into more than 3 forward channels. The more broadly related fields of stereo imaging, triphonic, quadraphonic, and surround sound are therefore reviewed. FIGS. 1A through 1D illustrate the relative loudspeaker and listener locations used with such sound reproduction systems. In these Figures, the names of inventors mentioned herein with respect to such systems ar found on the associated diagrams. Since the beginning of sound reproduction, inventors and engineers have attempted to make reproduced sound as similar as possible to its original source sound. Continued improvements in the state of the art have come about in many areas. Various types of distortion have been reduced. Frequency response has been made both broader and flatter. Unwanted noise has been greatly reduced. Various signal recording systems have been developed, including records, tapes, and optical discs. Monophonic sound reproduction has advanced to where a single loudspeaker in an anechoic room can be made to sound almost indistinguishable from a single instrument or vocal sound source. The reproduction of multiple sound sources, however, has been less successful. It was recognized early that 2 loudspeakers, each with its own signal, could create a better sound image than could a single loudspeaker. It was also shown by Clark, Dutton, and Vanderlyn in their article, "The `Stereosonic` Recording and Reproducing System," in the Jul.-Aug., 1957 issue of the IRE Transactions on Audio, that if sounds were properly recorded, and the listener properly located relative to the loudspeakers, then the location of the original sounds could be approximated by an apparent or virtual image between the loudspeakers within a limited frequency range. The preferred listener location is equidistant from both loudspeakers, at a distance greater than the distance between the speakers. There has been a great deal of research done on human hearing, acoustics in general, and psychoacoustics in particular, to better understand how sound localization takes place. An example of this research applied to audio imaging is found in an article by Bauer titled "Phasor Analysis of Some Stereophonic Phenomena," published in the Nov., 1961 issue of The Journal of the Acoustical Society of America. Bauer and other inventors have used this research to improve and expand the virtual image. This image, however, is different from the true image. The difference is in the reproduced sound field. In a live music performance, the various sounds come from many different locations in front of the listener. The locations of these sound sources can be heard from any listener location. When music is recorded in stereo, the sounds from all sources are mixed into only 2 channels, left and right. This is done in such a way that sounds from the left are heard more loudly from the left loudspeaker and sounds from the right are heard more loudly from the right loudspeaker. Sounds from the middle are mixed more equally into both channels. Research has shown that at the correct listener location, the sound pressures at the ears of the listener can be made to approximate the corresponding pressures at a live performance, thus creating a good virtual image. Unfortunately, the stereo sound field approximates the live sound field only at that location. That is where the listener must be to hear the virtual image correctly. Due to the phasor nature of the virtual image, it is also unstable with respect to both motion and attitude (direction) of the listener. That is, if the listener either moves from side to side or turns the head away from pointing directly forward, the virtual image will also move. This, of course is not true of the real image observed in a live performance. In fact, motion of the head is normally used by the brain to pinpoint the location of sound sources and distinguish them from their echoes in an echo rich environment. Another disadvantage of 2-loudspeaker systems is that when loudspeakers are placed more than about 30 degrees apart, as viewed by the listener, the virtual image between them is weakened. The result is that if the loudspeakers are spaced far enough apart to include the breadth of live sound sources, such as an orchestra which may span 90 degrees, then there is a significant hole in the middle from which very little sound seems to come. Even sounds which are mixed equally into both left and right channels seem to come from the 2 separate loudspeakers thus spaced and not from between them. For these reasons, stereo systems only image well when the listener is motionless, facing directly forward on the centerline between the loudspeakers, and at a sufficient distance from the loudspeakers. A further disadvantage of these constraints is that stereo systems do not fit well into most listening rooms. See FIG. 1A. To avoid early reflections from walls that will obscure the weak virtual image, both the loudspeakers 21 and 22 and the listener 20 must be placed away from the walls. This means that the loudspeakers and listener must be located near the middle of the room. In addition, to produce a good virtual image, the loudspeakers need to be at least 10 feet away from the listener and about half that distance apart. For best performance in a rectangular room 23 of normal proportions, the 2 loudspeakers must be located across a narrow end of the room, several feet from all walls, and the listener located at the other narrow end, several feet from the back wall. With these constraints, it is often impossible to achieve proper spacing. Movement through the listening room, which is often a living room, is made more difficult by the centrally located furniture. In general, then, the acoustical requirements for good stereo reproduction do not match the usual living requirements for the same room. Various attempts at improving the stereo image have been made. Systems have been designed to reflect sound off walls to broaden and fill in the virtual image. Other systems that add phase shifted left and right signals to the opposite channels to cancel acoustic crosstalk at the listener's ears have been built and successfully marketed. Such systems often improve the image for the properly placed listener in the right acoustic environment, but are sometimes even more sensitive to listener placement than is regular stereo. One more problem with stereo sound is that a great deal of th original ambient sound is obscured in the reproduction process. This seems to be a result of the weakness of the virtual image and its confinement to the region between the loudspeakers. Sound reflections from the listening room easily overpower the weak virtual image of reflected sounds from the original environment. A large and profitable industry has been built around devices to generate artificial ambience for both recording and reproduction of sound. These range from spring type reverberators to digital processing simulators of the measured echo environment of specific concert halls. In spite of all its shortcomings, stereo (2-channel) recording has become the industry standard. Even with such sweeping changes in the audio industry as the development of compact discs and high speed digital signal processing, stereo recordings remain the standard. Various advancements have been made in the area of quadraphonic sound. See FIG. 1C. The quadraphonic system uses 4 loudspeakers 30, 31, 32, and 33 arranged in a square around the listener 29 to create the illusion of the listener being completely surrounded b sound. The sounds thus reproduced seem to come from many directions. The effect of discrete quadraphonic sound can be a pleasant and startling one, but does not accurately represent what is heard at a live concert, where the sounds originate from the stage and orchestra pit in front of the listener. In 1976, Willcocks disclosed, in U.S. Pat. No. 3,944,735, a system for decoding 4 sound channels recorded onto 2 channels using various types of encoding. His invention works well for quadraphonically encoded sources; but such recordings are rare since stereo recording is the standard. Stereo mixed recordings were never intended for reproduction through 4 loudspeakers surrounding a listener. Rather, the sounds thus mixed were intended to be heard from 2 loudspeakers located in front of the listener to simulate the location of the original performers. Herein Willcocks' and various other subsequent quadraphonic systems such as those disclosed by Cooper (1979) in U.S. Pat. No. 4,149,031, and Christensen (1982) in U.S. Pat. No. 4,316,058, all fall short. They may decode encoded signals, but they were never intended to separate sounds from stereo mixed recordings or improve the forward image. Listener location requirements are more stringent for quadraphonic sound than for stereo. The listener must be equidistant from all 4 loudspeakers which must be at the 4 corners of a square. For this reason, quadraphonic systems have room fitting problems as great as those for stereo systems. Most listening rooms 34 are neither square nor large enough to provide sufficient spacing between the loudspeakers and the listener. With either quadraphonic or stereo sound, 2 people cannot enjoy the same sound image together because listener placement is so critical. In 1978, Doi and Wakabayashi disclosed, in their U.S. Pat. No. 4,069,394, a device for improving the stereo image using only 2 loudspeakers. Their FIGS. 6 and 8 show circuits which could, if used properly, perform some functions similar to some of those of my invention. Their FIG. 6 is a circuit diagram of a pair of voltage dividers. Their FIG. 8 is a circuit diagram of two differential amplifiers connected in parallel. These simple circuits, however, are not unique to their design or to mine and can be found in many texts on basic electronics such as Walter G. Jung's "Audio IC Op-Amp Applications," first published in 1975 by Howard W. Sams & Company. My invention and many others make use of similar voltage differencing circuitry. The stated object of Doi et al in using the circuitry of their FIGS. 6 and 8 is to produce from left and right inputs (L and R), outputs equivalent to L-ΔR and R-ΔL, where Δ is a fraction of 1. They specifically state that for "The circuits shown in FIGS. 6 and 8 . . . the quality of the sound image provided thereby is the same as that provided by an ordinary 2-channel stereophonic system." The inadequacy of these embodiments results from Doi et al's failure to recognize and satisfy the conditions of optimality which I define hereinafter relative to my invention. Other embodiments of Doi et al's invention are frequency dependent and employ both filters and phase compensation. These are required to compensate for frequency dependency of the virtual image as noted by Clark et al. Further, with the Doi et al invention, listener location is a critical as with regular stereo. A similar system to that of Doi et al was disclosed in 1980 by Kogure et al in U.S. Pat. No. 4,219,696. Their device attempts to simulate the sound of a quadraphonic system using only 2 front loudspeakers. This would seem to have little value for music reproduction, since 2 front loudspeakers naturally produce a virtual image of a music performance that is as accurate as that of a quadraphonic system. Their invention does not attempt to separate mixed forward sounds by location. In addition, since only 2 loudspeakers are used to simulate 4, it is more sensitive to listener location than a similar quadraphonic system would be. In 1985 Watanabe disclosed, in U.S. Pat. No. 4,524,451, a device for manually positioning single or multiple monophonic sound sources between many loudspeakers surrounding a listener. If all the original sound sources were available on separate channels, his device, if properly adjusted manually, would reproduce them very well. It does not, however, separate those sound sources out of 2 stereo channels once they are mixed. Various surround sound systems have been developed and used primarily to improve the sound of movies. See FIG. 1D. Many movie sound tracks are encoded into left 37 and right 39 channels. Sounds to be heard from the screen are encoded by recording them in phase in both channels. Sounds intended to come from behind the audience are encoded by recording them out of phase in the left and right channels. Surround sound decoders create a synthesized center channel 38 by adding the left and right signals. The derived center channel places all in-phase sounds near the center of the screen. Rear or "surround" channels 36 and 40 are decoded by differencing the left and right signals In 1986, Blackmer and Townsend disclosed, in their U.S. Pat. No. 4,589,129, a device for reproducing surround sound from encoded 2 channel recordings. Their system produces L, R, L+R, and L-R output signals, with various amplitude, phase, and frequency adjustments. It is very effective for movie sound tracks which have been encoded to simulate everyday sounds coming from all directions. But as with quadraphonic sound, surround sound does not accurately represent what is heard at a live music performance. Music is generally not intended to surround a listener 35, but to come from in front of the listener. Systems such as theirs, which use only whole combinations of left and right signals, lack the subtlety of imagery needed for accurate music reproduction. The surround sound listening room 41 must be rather large to provide sufficient distance between the loudspeakers and listener. The result of all virtual image systems, whether stereo or quadraphonic is that they produce a rather poor forward image. This is the major difference between live and reproduced sound. See FIG. 1B. Several triphonic systems have been developed to improve the forward image by adding a synthesized center channel 26 similar to that used in surround sound systems. Adequate listening room 28 spacing is often possible with such a system because a true central image is less vulnerable to wall reflections than is a virtual image. In 1986 Rosen disclosed, in his U.S. Pat. No. 4,594,730, a device for producing a center channel from the left and right stereo channels. His center channel is used to reproduce "direct" or monaural sounds, while the other 2 channels 25 and 27 reproduce "indirect" or ambient sounds. Such separation of "direct" and "indirect" sounds is accomplished by subtracting the signal generated for the center channel from both the left and right channels. Because the center channel is frequency band limited, however, the cancellation and resultant separation is not complete. Such frequency dependency is a very undesirable characteristic for a separation device. This is especially true for a center channel which is supposed to reproduce "direct" sounds. A listener 24 should hear the full spectrum of sound for each instrument or voice independent of its location. A greater problem with his approach is that, in fact, all original sound sources are "direct" and monaural, yet they come from many locations in a live performance, not just from the center. Even in a stereo recording, a monaural source can be recorded entirely in either the left or right channel. "Direct" does not mean directly in front. Still another weakness of the Rosen invention is its use of variable resistances, so that the listener can control the image. His is the wrong approach if accurate sonic separation and sound field reproduction are the goals; because at a live performance, the image is not listener controlled. Rosen also disclosed two 4-channel embodiments of his invention. In one of these, 2 loudspeakers are sent time delayed signals to enhance the ambient sound. This does nothing, however, to either separate the forward sounds or improve the image. The other 4-channel embodiment uses forward loudspeakers of which he states, "Acoustical center channel mixing is achieved when each individual channel of the 2 channel stereophonic source is fed to its own individual reproducer (therefore requiring at least 2 such reproducers) and when these reproducers are separated by a distance that is small when compared to the distance from the reproducers to a preferred listening location." His goal is clearly to emulate a 3 channel system by acoustical mixing, not to separate the sounds into more than 3 channels. Latshaw, in his 1987 U.S. Pat. No. 4,685,136, disclosed an invention that uses 3 or 4 forward loudspeakers. He states that when 4 loudspeakers are used, "The first center speaker and the second center speaker are located at the center of the front of the room as closely together as practical, so that as a close approximation, the acoustical power of the speakers is perceived as coming from substantially the same location." Like Rosen, Latshaw's goal is to emulate a 3 channel system by acoustical mixing. This again is contrary to the concept of sonic separation in which the loudspeakers are spread out to avoid mixing sounds and to enhance separation. Latshaw's device computes a time varying "commonality index" based on left and right time averaged signal envelopes. This is used to determine the mixture of left and right inputs in each of the output channels. Thus the image created by his device is both time varying and program dependent. His device also employs many directionality tests based on left and right signal envelope strength. These tests control switches in the signal processing path. Not only does his processing change with time due to the varying commonality index, but it changes discontinuously due to switching. The result is that sounds of lesser volume fail to hold their locations in the presence of louder sounds. That is, all sounds are erroneously steered in the direction of the loudest sounds. Even the louder sounds jump around as the various switching thresholds are crossed. In addition, the automatic balance feature of his design means that there is no true left or right locations, but all locations are relative to the momentary center or average between left and right. His invention is yet another example of a frequency dependent device which is not optimal for musical sound reproduction In 1988, Tofte disclosed in his U.S. Pat. No. 4,747,142, another device for generating a center channel and modified left and right channels. His is the only device of which I am aware that purports to approach the sonic separation problem. Tofte says that his invention "could be likened to a reversal of the studio's mix-down process, where many separate microphone signals are `panned` onto a final master tape through a mixing console equipped with individual balance controls for changing the apparent position of each microphone in the stereo image." His device uses logarithmic compression and expansion. Between the compression and expansion, frequency band limited signals from the left and right channels are added together. In addition to the deleterious effects of filtering, the effect of this log-add-antilog process is that the output contains a product, instead of a sum, of left and right signals. This nonlinearity enhances separation, but greatly increases distortion of the thus separated sounds. In addition, the sonic balance between loud and soft sounds is upset in the process. This results in a serious loss of realism for the listener. The work of Rosen, Latshaw, and Tofte shows that imaging improvements are possible using triphonic systems that remove part of a frequency band limited derived center channel from the left and right channels. Such systems work adequately for spoken voices, but fail to reproduce the full audio frequency spectrum from all channels. This limits their effectiveness for reproducing musical sounds. Because loudspeakers must be spaced no more than 30 degrees apart to maintain proper imaging between them, at least 4 loudspeakers are required to cover the full 90 degrees of the forward image. If fewer than 4 are used, then the breadth of the image must be reduced or the quality of the image between the loudspeakers is compromised. None of the prior art known to me and described above teaches the separation into more than 3 channels of forward sounds mixed in stereo. Those who have mentioned more than 3 forward channels (Rosen and Latshaw) have done so with regard to acoustical mixing of right and left channels to produce a middle channel, not with regard to a 4, 5, 6, or more channel separation of sounds. SUMMARY OF THE INVENTION If stereo mixed sound signals could be "unmixed" or separated and sent to loudspeakers with relative locations similar to the relative locations of the original sound sources, then a very accurate, realistic sound image could be created. Since only 2 channels are recorded, however, a method is needed to separate the mixed signals into 3 or more channels in a way which accurately represents the locations of the sounds in the original mix. To date, this has not been attempted for more than 3 loudspeakers; and the 3 loudspeaker implementations have not been consistent with the principles governing such separation. These principles have heretofore not been collectively recognized and therefore not applied to the development of such systems. Though it is impossible to completely separate mixed sounds; it is possible to partially separate them in a best or optimal way so that a sonically convincing illusion of such separation is created. My invention directly addresses and solves this separation and forward imaging problem. Insofar as possible, it separates the mixed sounds according to location and sends the separated signals to forward loudspeakers located near the relative locations of the original sound sources. This is done by summing and differencing fractions of the left and right signals in specific ratios for each channel which emphasize sounds from particular locations. Such fractional balancing produces a subtlety of imagery not possible using whole combinations. More particularly, my invention comprises an improved forward sound imaging system including first and second inputs for receiving left and right channel audio input signals of a stereophonic system and n output channels for connection to n loudspeakers spaced symmetrically left to right and forward of a listener, where n is any whole number greater than two. Between the inputs and output channels are n independent means, each responsive to the left and right audio input signals for developing a first through n-th audio output signal representative of a sum of a product of a first through n-th coefficient and the left audio input signal and a product of the n-th through first coefficient and the right audio input signal, in the first through n-th output channel, respectively. My invention reproduces each sound from a loudspeaker near the relative location of the original sound source. Thus, the image is realistic and convincing, and is less dependent on listener location than is a virtual image. In inventing my above described optimal sonic separator, I observed where the prior art fell short and sought to understand what the prior art had failed to teach. I discovered principles and formulated conditions which I believe an optimal sonic separator must satisfy. A review of the prior art revealed that such conditions were not collectively stated elsewhere, and that several of them were not stated anywhere. The names given my formulated conditions are also original with this invention. That is to say, not only is this invention novel, but the recognition and naming of the principles upon which it is founded and their formulation into mathematical conditions, is original. The combination of all these conditions yields a unique solution to the sonic separation problem. My invention is optimal therefore, in that it is uniquely consistent with the following eight principles of sonic separation: 1. Linearity--To avoid signal distortion, the separation process must be linear with respect to voltage. My invention avoids the problems associated with nonlinearity by using only linear combinations of the left and right input signals to produce all the separated output signals. The separation thus produced is sufficient to greatly enhance the image and sense of reality, and does not distort any of the individual sounds or disturb their relative volumes. Thus both low distortion and perfect sonic balance are preserved by my invention. 2. Symmetry--The entire separation process must be symmetric about the centerline between left and right. 3. Uniformity--The total output power for every input signal must be independent of its mixed location. In other words, the relative volumes of all sounds in the mix must remain unchanged by the separation process. 4. Normality--The total output power must be the same as the total input power. That is, the separation process must not change the total volume. 5. Integrity--The output from each channel must be greatest for signals mixed in the location of that channel's output. If a loudspeaker could be placed at the same relative location as each original sound source and could reproduce only the sound from that source, then the original sound field could be accurately reproduced, and the listener location would be much less important. Each loudspeaker added to a stereo system, if it reproduces most loudly those sounds which originated at its relative location, will improve the accuracy of the sound field reproduced by the system. 6. Balance--The power output from each channel must be the same when averaged over all mix locations. One of the problems observed with previous multi-loudspeaker systems is that when loudspeakers are added between the left and right loudspeakers, the image seems to be pulled toward the middle. This is an undesirable effect if it narrows the image. On the other hand, if the addition of extra loudspeakers allows the total spread of the loudspeakers to be increased, a broader image can be realized. With my invention, 4 or more loudspeakers can be spread over a 90 degree angle to separate their individual sounds. For best separation, the loudspeakers are placed so that the distance between each adjacent pair is the same. If the output from each loudspeaker is balanced with the others, and they are evenly spaced, then the pull toward the middle exactly compensates for the hole in the middle described earlier that occurs when 2 loudspeakers are widely spaced. Thus a smooth and even distribution of sound is achieved. This effect can be seen in FIG. 4. 7. Constancy--The separation process must remain constant and be independent of input program material, so that the image neither changes continuously nor jumps discretely. In my invention, optimal coefficients are chosen for the linear combinations of inputs based on acoustical and electronic principles. These coefficients do not depend on either time or program material. 8. Fidelity--The separation process must be independent of frequency within the audio band. The problems of frequency dependent imaging which Clark, Doi, and others point out can be avoided by using more loudspeakers to restore the stereo image based only on instantaneous relative amplitude of the left and right inputs and not on frequency. It is extremely important that the separation process be independent of frequency so that maximum signal cancellation occurs for sounds mixed away from each loudspeaker's location. Each of the separated channels must reproduce the entire audio frequency spectrum without phase shifting relative to frequency or to the other channels. This precludes the use of filter circuitry in the design. I have quantified these principles in terms of the relative location of mixed sounds between the left and right loudspeakers. This allowed me to formulate conditions and solve mathematical equations related to the location of sounds in the mix and their associated instantaneous relative voltages in the left and right input channels. Unlike some of the other systems with more than 2 loudspeakers, mine does not increase "indirect" or ambient sound, but rather uses the added loudspeakers to more accurately locate the "direct" sounds. With separated sound, the presence of a true and not just a virtual image results in the natural ambience of the recorded hall being heard much more clearly. Much less ambiance recovery processing is required. The listening room sound reflections, though still present, become less important. Placement of both the loudspeakers and the listeners becomes less critical as more loudspeakers are added. The loudspeakers and listeners can be placed much closer to the boarders of the room than with stereo. In fact, as in a live performance, some listening room reflections can actually aid in the localization of sounds. The loudspeakers can therefore be spaced along a long side of a rectangular room, with the listener located near the opposite wall. This arrangement is much more natural, and fits better into most living environments where audio systems are usually found. If the loudspeakers are slightly out of place, the effect on the sound image is minor, like that of shuffling chairs in the orchestra. It is the nature of loudspeakers and amplifiers to produce more distortion at greater volume. Most modern amplifiers produce almost no audible distortion until the point of clipping is reached, whereupon the distortion is very great. Similarly, most loudspeakers produce much less distortion when the excursion of their diaphragms is limited to the region of greatest linearity. This is one of the reasons why bi-amplification produces superior sound quality. In a properly bi-amplified system, neither the loudspeakers nor the amplifiers are required to work outside their range of optimal performance. Similarly, when the various sounds are separated and more loudspeakers and amplifiers are used to reproduce these sounds, both clipping and loudspeaker distortion are reduced substantially. In addition, as each amplifier and loudspeaker reproduces the simpler waveforms associated with separated sounds, that is, the waveforms of fewer and more similar instruments, rather than the extremely complex waveforms of the entire orchestra combined, the sound and texture of each instrument is heard with greater clarity and definition. Thus the principles of fidelity an balance work together to produce superior sound. The reproduction of deep bass generally requires a large bass speaker. When additional loudspeakers are used, the individual bass speakers need not be as large as for a regular stereo system. This is particularly true of the very low frequencies, because their long wavelengths reinforce for all loudspeakers placed within several feet of each other. Further objects and advantages of my invention will become apparent from a consideration of the drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A shows the preferred relative loudspeaker and listener locations used with prior stereo sound systems. FIG. 1B shows the preferred relative loudspeaker and listener locations used with prior triphonic sound systems. FIG. 1C shows the preferred relative loudspeaker and listener locations used with prior quadraphonic sound systems. FIG. 1D shows the preferred relative loudspeaker and listener locations used with prior surround sound systems. FIG. 2 shows the left and right relative input powers to my sonic separator as functions of mixed sound location. It also shows that their sum is always 1. FIG. 3 shows the relative output power from each channel of a 4 channel optimal sonic separator of my invention plotted against mixed location. This Figure also shows that the summed relative output power from all channels is always 1. FIG. 4 shows the sums of the relative power outputs from symmetric pairs of channels for my 4 channel optimal sonic separator. This Figure illustrates the effect of the balance condition on the localization of mixed sounds. FIG. 5 shows a block diagram of a preferred embodiment of the invention. FIG. 6 a preferred embodiment of an outer channel of the invention. FIG. 7 shows an alternative preferred embodiment of an outer channel of the invention. FIG. 8 shows another alternative preferred embodiment of an outer channel of the invention. FIG. 9 shows yet another alternative preferred embodiment of an outer channel of the invention. FIG. 10 shows a preferred embodiment of an inner channel of the invention. FIG. 11 shows an alternative preferred embodiment of an inner channel of the invention. FIG. 12 shows another alternative preferred embodiment of an inner channel of the invention. FIG. 13 shows yet another alternative preferred embodiment of an inner channel of the invention. FIG. 14A shows one way to set up and use my separated sound system to produce a realistic sound field. FIG. 14B shows an alternative way to set up and use my separated sound system to produce a realistic sound field. DETAILED DESCRIPTION OF THE INVENTION By using specific linear combinations of the left and right input signals, optimal output signals can be generated. Equations representing the interdependent conditions of optimality are developed and solved for the required linear coefficients. These conditions are sufficient to force a unique solution. The derivation of this solution follows; but first, some general definitions and concepts are presented. All equations that are referenced elsewhere herein are numbered to the left of the indented equation. Let n be the integer number of output channels in the separated mix (i.e. the number of loudspeakers to be used). n>2. Let i be a whole number from 1 to n that indexes evenly distributed output channel locations sequentially from left to right. Let x be a dimensionless real number between 0 and 1, inclusive, that represents the location of a signal in the mixed recording from left (x=0) through center (x=1/2) to right (x=1). Let y i be a dimensionless real number representing the relative voltage of a signal in the i-th channel, defined as the ratio of the signal voltage in the i-th channel to the monophonic voltage of the same signal before mixing. Since volume (power) is proportional to the square of voltage, y i 2 is also a dimensionless real number which represents the relative power of a signal in the i-th channel, defined as the ratio of the signal power in the i-th channel to the monophonic power of the same signal before mixing. Such voltage and power ratios can be expressed as functions of x. For example, when source sound signals are mixed into left (L) and right (R) signals during recording, industry standards require that the following 3 equations be satisfied: L(x)=y(left)=1 for x=0 R(x)=y(right)=1 for x=1 L(x).sup.2 +R(x).sup.2 =1 for all x in [0,1] This is done to make the volume independent of location (i.e. to provide uniformity) in the recording process. The relative volume from both loudspeakers of any sound thus recorded is 1 for all mixed locations. There are an infinite number of functions L and R of x which meet the above standards. Research has shown, however, that the following equations not only meet the standards, but closely approximate the relative voltages in the left and right channels for a sound source mixed at location x as perceived by a recording engineer located on the centerline between his 2 monitor loudspeakers. L(x)=cos (πx/2) R(x)=sin (πx/2) where π is the ratio of the circumference to the diameter of a circle, or approximately 3.141592654. FIG. 2 shows the left and right relative input powers L 2 and R 2 as functions of x and also shows that their sum is always 1. Let X be defined as the input column vector (L,R) T , where the superscript T represents the transpose of a matrix or vector. Let Y be defined as the column vector of relative output voltages (y 1 , y 2 , . . . , y n ) T . 1. Linearity--This condition can be stated in the following linear equation: Y=M X (1) where M is an n-by-2 real-valued matrix of dimensionless coefficients. 2. Symmetry--This condition requires that the matrix coefficients to be multiplied by the left channel signal be the same as those for the right channel signal, but in reverse order. This can be stated mathematically as: ##EQU1## where a i are real numbers A=(a 1 , a 2 , . . . , a n ) T A'=(a n , a n-1 , . . . a 1 ) T Note that symmetry as defined here for a nonsquare matrix differs from the usual term "symmetry," commonly defined with respect to a square matrix to mean "being symmetric about the principle diagonal." Note also that if n were equal to 2, then both symmetry definitions would be equivalent. The equations for y i can now be written as: y.sub.i =a.sub.i L(x)+a.sub.n-i+1 R(x) for all i=1,n y.sub.i =a.sub.i cos (πx/2)+a.sub.n-i+1 sin (πx/2) for all i=1, n 3. Uniformity--Since the total output volume (power) is proportional to the sum of squares of all the output channel voltages, uniformity requires that the vector inner products Y T Y and X T X be proportional, with the same constant of proportionality for all x in [0,1]. 4. Normality--This condition further requires that the constant of proportionality above be 1. That is, Y.sup.T Y=X.sup.T X (3) for all x in [0,1]. Thus Y and X have equal Euclidean length, 1, and are unit vectors in Euclidean n-space and 2-space, respectively. Substituting the linearity equation (1) into the above equation (3) yields (MX).sup.T MX=X.sup.T X X.sup.T (M.sup.T M)X=X.sup.T X X.sup.T (M.sup.T M-I)X=0 for all unit vectors X where I is the 2-by-2 identity matrix. This equation must hold for all unit vectors X, therefore M.sup.T M=I But M=(A|A'), therefore ##EQU2## Now A' T A'=A T A and A' T A=A T A', therefore the above matrix equation reduces to the following vector equations: A.sup.T A=1 (A is a unit vector) A.sup.T A'=0 (A is perpendicular to A') These can be further reduced to 2 scalar equations. More explicitly, the conditions for normality and uniformity can be restated as: ##EQU3## 5. Integrity--This condition is satisfied for the inner channels (2 through n-1) by choosing the ratio of a n-i+1 to a i in order to maximize y i , hence y i 2 , for particular values of x. Examples of inner channel y i 2 curves plotted as functions of x can be seen in curve 2 and 3 of FIG. 3. Curves 1 and 4 represent outer channels. For curve 2 of this Figure, a i has been set to 0.4916586598 and a n-i+1 to 0.2838592596. The power peak for these coefficients is at x=1/3. For curve 3, a i has been set to 0.2838592596 and a n-i+1 to 0.4916586598. The power peak for these coefficients is at x=2/3. To better understand this, recall from the symmetry equation (2) that y.sub.i =a.sub.i cos (πx/2)+a.sub.n-i+1 sin (πx/2) for all i=2, n-1 This has a maximum when the partial derivative of y i with respect to x is 0. Differentiation yields 0=-π/2 a.sub.i sin (πx/2)+π/2 a.sub.n-i+1 cos (πx/2) for 0<x<1 or, equivalently, ##EQU4## Since the locations of the n output channels are to be evenly distributed between x=0 and 1, the i-th output peak can be forced to occur exactly at the location of the i-th output channel by letting x=(i-1)/(n-1) (8) This condition, then, completely determines the ratio of a n-i+1 to a i . Let the corresponding coefficient ratios, c i , be defined by the left side of equation (6). Substituting the expression for x given in equation (8) into the integrity equation (7), results in c.sub.i =tan (π(i-1)/(n-1)/2) (9) for all i=2,n-1 Note that this ratio is positive for all i=2,n-1, and that a i is also positive for all inner channels, since otherwise, location shifting between corresponding (symmetric) left-side and right-side output channels would occur. Similarly, since a 1 , the linear coefficient for the left and right input channels, is used to produce the left-most and right-most output channels, respectively, a 1 must also be positive. In addition, |a 1 |>|a n |, since otherwise the integrity condition would be violated. Substituting the above equation (9) into the equation for uniformity (5) results in ##EQU5## This equation shows clearly that a n <0 for n>2. Thus for |a 1 |>|a n |, the only reasonable case, y 1 2 has its maximum at x=0; and y n 2 has its maximum at x=1, as desired. The integrity condition is thus characterized for all output channels. 6. Balance--This condition is satisfied when the integral of relative power with respect to mixed sound location is the same for all channels. That is, ##EQU6## which is true if and only if ##EQU7## 7. Constancy--This condition means that the processing used to separate the signals must not change with time or program material. One result of this is that no user variable elements are permitted in the design. In addition, the processing must remain independent of the input signals. That is, no program dependent factors can have an effect on the processing of the input signals. Mathematically, this is stated by saying that the matrix coefficients a i are constants for all i=1,n. 8. Fidelity--This condition means simply that the circuitry used to perform the separation processing must contain no frequency filters having a substantial effect within the audio spectrum. There are no equations associated with this condition. With the optimality conditions thus defined, a unique solution can be found. All conditions are satisfied by solving their corresponding equations simultaneously for the matrix coefficients a i , for all i=1,n. Using the definition of c i , equation (6) can be rearranged as a.sub.n-i+1 =c.sub.i a.sub.i (12) for all i=1,n For all the inner channels, equations (2) and (12) can be substituted into equation (11) to yield, ##EQU8## Let z=πx/2; then dz=π/2 dx, and dx=2/π dz. Equation (11) then becomes ##EQU9## a.sub.i =(2/(n(1+c.sub.i.sup.2 +4/πc.sub.i))).sup.1/2 (13) for all i=2,n-1 where c.sub.i =tan (π(i-1)/(n-1)/2) for all i=2,n-1 from equation (9). Thus all the inner a's are determined. The remaining coefficients, a 1 and a n , are found as follows using the known values for the inner a's. The normality condition, equation (4), requires that ##EQU10## All values on the right-hand side of this equation are known from equation (13). Therefore let the known value of equation (14) be called B. The uniformity condition, equation (5), further requires that ##EQU11## All values on the right-hand side of this equation are also known from equation (13). Therefore let the known value of equation (15) be called C. This equation now simplifies to a.sub.n =C/a.sub.1 (16) Substituting this equation into equation (14) yields a.sub.1.sup.2 +(C/a.sub.1).sup.2 =B a.sub.1.sup.4 -Ba.sub.1.sup.2 +C.sup.2 =0 a.sub.1.sup.2 =1/2(B+(B.sup.2 -4C.sup.2).sup.1/2) Note that the positive root of (B 2 -4C 2 ) is chosen to make a 1 2 , hence a 1 , both positive and as large as possible. Thus a.sub.1 =(1/2(B+(B.sup.2 -4C.sup.2).sup.1/2)).sup.1/2 Finally, equation (16) can now be used to solve for a n . Thus all a's are completely determined for any given n, and all the required conditions for optimality are satisfied. The calculated coefficient values for n=3 to 8 are given below. For n=3 a 1 =0.8849208857 a 2 =0.4513001479 a 3 =-0.1150791143 For n=4 a 1 =0.8047485087 a 2 =0.4916586598 a 3 =0.2838592596 a 4 =-0.1734229534 For n=5 a 1 =0.7461727884 a 2 =0.4852188414 a 3 =0.3495755914 a 4 =0.2009842248 a 5 =-0.2125819679 For n=6 a 1 =0.7006620866 a 2 =0.4684048718 a 3 =0.3686354401 a 4 =0.2678293246 a 5 =0.1521939687 a 6 =-0.2426558830 For n=7 a 1 =0.6634549638 a 2 =0.4496773381 a 3 =0.3716590125 a 4 =0.2954452984 a 5 =0.2145774309 a 6 =0.1204906796 a 7 =-0.2676527210 For n=8 a 1 =0.6317150534 a 2 =0.4314991170 a 3 =0.3680977089 a 4 =0.3070700208 a 5 =0.2448801701 a 6 =0.1772665138 a 7 =0.0984868577 a 8 =-0.2895985266 FIG. 3 shows the relative output power from each channel of a 4 channel optimal sonic separator plotted against recording mix location, x. It also shows the summed output power from all channels, which is equal to 1 for all values of x. From this we see that both uniformity and normality are satisfied. In addition, it can be seen that the channel peaks are at 0, 1/3, 2/3, and 1, as required by the integrity condition. Satisfaction of the symmetry condition is seen in FIG. 3 as symmetry of the collection of outputs about the line x=1/2. That is, if FIG. 3 were folded about the line x=1/2, the output curves from the right half would overlay those from the left half. FIG. 4 shows the results of satisfying the balance condition. The 2 curves plotted in FIG. 4 are the sums of the relative power outputs for symmetric pairs of channels (i and n-i+1) for a 4 channel optimal sonic separator. Note that the average sum for each pair is 1/2=2/n, as required to satisfy the balance condition. The importance of this result is that sounds mixed near the center will be reproduced mostly from the inner loudspeakers, while sounds mixed near either the left or right side will come mostly from the outer loudspeakers, particularly from the side where they were mixed. Thus the sounds are concentrated in the area near where they were mixed in the recording. This, combined with the integrity condition, produces the separation of mixed sounds. Note that if L and R were defined differently, the evaluation of the integral in equation (11) would yield slightly different results. The derivation procedure, however, would remain the same. For example, if L and R were defined as L=(1-x).sup.1/2 R=x.sup.1/2 then equations (2) and (13) would become, respectively, y.sub.i =a.sub.i (1-x).sup.1/2 +a.sub.n-i+1 x.sup.1/2 for all i=1,n and a.sub.i =(2/n(1+c.sub.i.sup.2 +π/2 c.sub.i))).sup.1/2 for all i=2, n-1 These changes in derived equations would produce slightly different coefficients as follows: For n=3 a 1 =0.8957905268 a 2 =0.4320876275 a 3 =-0.1042094732 For n=4 a 1 =0.8282442216 a 2 =0.4376276897 a 3 =0.3094495070 a 4 =-0.1635069335 For n=5 a 1 =0.7799349654 a 2 =0.4225551498 a 3 =0.3346936371 a 4 =0.2439623295 a 5 =-0.2039881030 For n=6 a 1 =0.7429386720 a 2 =0.4046827415 a 3 =0.3361909709 a 4 =0.2744987783 a 5 =0.2023413708 a 6 =-0.2344312902 For n=7 a 1 =0.7131966442 a 2 =0.3875303849 a 3 =0.3308154382 a 4 =0.2828677514 a 5 =0.2339218397 a 6 =0.1733088568 a 7 =-0.2587708282 For n=8 a 1 =0.6884009420 a 2 =0.3718585809 a 3 =0.3231893372 a 4 =0.2835080577 a 5 =0.2455251802 a 6 =0.2044028842 a 7 =0.1518106300 a 8 =-0.2790834139 PREFERRED EMBODIMENTS OF THE INVENTION FIG. 5 shows a block diagram of a preferred embodiment of the invention which performs the required processing for an n-channel optimal sonic separator. Please note that my invention is not limited to any specific number of channels. In the circuit of FIG. 5, multipliers 44, 45, 46, 47, and 48 are connected in parallel to the left input 42. These multiply the left input signal by a 1 , a 2 , . . . , a n , respectively. Multipliers 49, 50, 51, 52, and 53 are connected in parallel to the right input 43. These multiply the right input signal by a n , a n-1 , . . . , a 1 , respectively. The outputs from multipliers 44 and 49 are added by adder 54 to produce the first output signal at 59. The outputs from multipliers 45 and 50 are added by adder 55 to produce the second output signal at 60. The outputs from multipliers 46 and 51 are added by adder 56 to produce the i-th output signal at 61. This inner channel is replicated as many times as required to provide n channels. Appropriate values of a i and a n-i+l are used by the multipliers in each replicated channel. The outputs from multipliers 47 and 52 are added by adder 57 to produce the (n-1)-th output signal at 62. The outputs from multipliers 48 and 53 are added by adder 58 to produce the n-th output signal at 63. Because multiplication by a number is equivalent to division by the reciprocal of that number, any or all of the multipliers in this circuit could be replaced by a corresponding divider. Similarly, because addition of a number is equivalent to subtraction of the negative of that number, any or all of the adders in this circuit could be replaced by a corresponding differencer if one of the preceding multipliers were also an inverter. The adders and multipliers associated with any of the outputs could therefore be combined in many different forms to produce the desired linear combinations of inputs. Analog implementations of the invention may require slightly different circuitry for the inner and outer channels. This is a result of the fact that only the outer channels use a n , which is the only coefficient less than 0. FIGS. 6 through 9 illustrate several alternative analog embodiments of an outer channel. Similarly, FIGS. 10 through 13 illustrate several alternative analog embodiments of an inner channel. All these Figures for both the inner and outer channels are specific examples of possible implementations of the individual channels in FIG. 5. An n-channel optimal sonic separator consists of any 2 outer channel circuits effectively connected in parallel with n-2 inner channel circuits. Component values and multiplying factors are chosen for each output channel consistent with the optimal coefficients a i . In FIG. 6, resistances 66, 67, and 68 are chosen such that for voltages V and W at inputs 64 and 65, respectively, the voltage at the output of operational amplifier 69 is (1-a 1 )V-a n W. If resistance 66 is r, then resistance 67 is r(a 1 -1)/a n and resistance 68 is r(1-a 1 )/(a 1 +a n ). Resistances 70, 71, 72, and 73 are of one value. Thus the output at 75 of operational amplifier 74 is V-((1-a 1 )V-a n W)=a 1 V+a n W, as desired. In FIG. 7, resistances 78 and 80 are of one value and resistance 79 is half that value so that for a voltage W at input 77, the output of operational amplifier 81 is -W. If resistance 84 is r, then resistance 82 is r(1-a 1 +a n )/a 1 and resistance 83 is r(1-a 1 +a n )/(-a n ), so that for a voltage V at input 76, the output at 85 is a 1 V+a n W, as desired. In FIG. 8, if resistance 91 is r, then resistance 88 is r/(-a n ), resistance 89 is r/a 1 , and resistance 90 is r/(1-a 1 -a n ), so that for voltages V and W at inputs 86 and 87, respectively, the output at 93 of operational amplifier 92 is a 1 V+a n W, as desired. In FIG. 9, resistances 96 and 97 are of one value, and resistance 98 is half that value so that for a voltage V at input 94, the output of operational amplifier 99 is -V. If resistance 103 is r, then resistance 101 is r/(-a n ), resistance 100 is r/a 1 , and resistance 102 is r/(1+a 1 -a n ), so that for a voltage W at input 95, the output at 105 of operational amplifier 104 is a 1 V+a n W, as desired. In FIG. 10, if resistance 110 is r, then resistance 108 is r(1-a i -a n-i+1 )/a i and resistance 109 is r(1-a i -a n-i+1 )/a n-i+1 , so that for voltages V and W at inputs 106 and 107, respectively, the output at 112 of operational amplifier 111 is a i V+a n-i+1 W, as desired. In FIG. 11, resistances 115 and 117 are of one value and resistance 116 is half that value so that for a voltage V at input 113, the output of operational amplifier 118 is -V. If resistance 122 is r, then resistance 119 is r/a i , resistance 120 is r/a n-i+1 , and resistance 121 is r/(1+a i -a n-i+1 ), so that for a voltage W at input 114, the output at 124 of operational amplifier 123 is a i V+a n-i+1 W, as desired. In FIG. 12, if resistance 130 is r, then resistance 127 is r/a i , resistance 128 is r/a n-i+1 , and resistance 129 is r/(1+a i +a n-i+1 ), so that for voltages V and W at inputs 125 and 126, respectively, the output of operational amplifier 131 is -a i V-a n-i+1 W. Resistances 132 and 134 are of one value and resistance 133 is half that value, so that the output at 136 of operational amplifier 135 is a i V+a n-i+1 W, as desired. In FIG. 13, the resistances 139 and 141 are of one value and the resistance 140 is half that value, so that for a voltage V at input 137, the output of operational amplifier 142 is -V. The resistances 145 and 143 are also of one value, and the resistance 144 is half that value, so that for a voltage W at input 138, the output of operational amplifier 146 is -W. If resistance 150 is r, then resistance 147 is r/a i , resistance 148 is r/(a n-i+1 ), and resistance 149 is r/(1+a i +a n-i+1 ), so that the output at 152 from operational amplifier 151 is a i V+a n-i+1 W, as desired. The resistance values given for FIGS. 6 through 13 are examples. Other values which will also work will be obvious to those knowledgeable in the art, and are considered within the scope of the invention. Though the circuits shown in these Figures use analog technology, equivalent digital circuits could also easily be built by those skilled in the art. The scope of this invention includes both analog and digital implementations. For use with analog sound reproduction systems, a digital implementation of this invention would require analog-to-digital and digital-to-analog converters to interface with the analog system. Since these are not always required, however, they are not shown in the Figures. In addition to the various embodiments shown here, input, output, and internal buffers could be added wherever needed to provide isolation and stability of performance. In addition, inverters or non-frequency-dependent phase shifters could be added at either or both ends of the illustrated circuits without affecting substantially the design. This invention is intended to include all similar circuits as well as others which may produce outputs proportional to those of the optimal sonic separator. The uniqueness of this invention, however, lies not in device design or circuit topology, but rather in the concept and process of separating mixed audio signals according to mixed location, and in the formulation and solution of the conditions of optimality. There are many uses of this technology. It could be used in a recording studio to monitor the recording when making the mix-down. It could be used to reproduce both recorded and live stereo information. It could be used in theaters to enhance the forward image after appropriate surround sound decoding. Using additional sets of stereo track pairs, appropriately mixed with side and rear sounds, this device could be used to improve the sonic image at the sides and rear of the listener as well as in front. It is to be understood that additional embodiments and uses of this invention will be obvious to those skilled in the art. The embodiments described herein together with those additional embodiments and uses are considered to be within the scope of the invention. FIGS. 14A and 14B illustrate 2 ways to set up and use my separated sound system to produce a realistic sound field. The cases illustrated are for a 6 loudspeaker system. In FIG. 14A the loudspeakers 158, 159, 160, 161, 162, and 163 are arranged along the longest wall of the listening room 164 with the listeners 153, 154, 155, 156, and 157 near the opposite wall. In FIG. 14B the loudspeakers 168, 169, 170, 171, 172, and 173 are arranged in a listening room 174 in an arc equidistant from the central listening location 166. In both cases the loudspeakers are evenly spaced to produce the maximum separation between loudspeakers. Also, the angle between the left-most and right-most loudspeakers as viewed from the central listening location is about 90 degrees. In either case, the location of the loudspeakers and listeners is not critical. The 2 cases illustrated represent extremes of loudspeaker and listener placement, and any case between these extremes will work well. An advantage of the arc pattern is that the volume of each loudspeaker is the same at the central listening location. This balance is lost however for other listeners 165 and 167. Advantages of the straight arrangement are that the range of listening locations is more spread out and the system fits better into rectangular rooms. In either case, the loudspeakers, if they are directional, should be pointed toward the central listening location. This will provide improved balance in both cases. All the above arrangement suggestions hold true for any number of loudspeakers used with the optimal sonic separator. I have personally built, tested and independently verified my optimal sonic separator. The results are quite remarkable when compared with regular stereo. The forward image and apparent definition of the various instruments and voices is surprisingly lifelike. Listening from anywhere in front of the loudspeakers is like listening to the live performance from different locations in the concert hall. In fact, the difference between separated sound and stereo is more striking than between stereo and mono.

A method and system for separating and "unmixing" prerecorded and mixed right and left stereo sound input signals into three (3) or more output sound signals for sound reproduction by three or more loudspeakers spaced apart and located forward of a listener or listeners. The output sound signals are linear combinations of the right and left sound input signals and uniquely satisfy conditions of sound linearity, symmetry, uniformity, normality, integrity, balance, constancy, and fidelity to create a substantially more accurate sound image of the recorded performance than that created by reproducing only the stereophonic sound input signals.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application No. 60/866,569, filed 20 Nov. 2006, which is incorporated by reference herein in its entirety. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The invention is related to the measuring devices and measurement of anatomical pathologies. [0004] 2. Description of the Related Art [0005] The ability to accurately measure the dimensions of anatomical structures is of vital importance. In many cases, the anatomical geometry defines the treatment. A small object, small hole, or short length of anatomical pathology can go untreated because it has little to no clinical significance. Larger objects, holes, and longer length of anatomical pathology may lead to adverse clinical outcomes. [0006] Additionally, many anatomical pathologies are treated with devices, including implantable devices, that are sized to fit the pathology. Knowledge of the specific size of the pathology aids the selection of an appropriately sized treatment device. Using trial and error techniques to determine the proper size of an implantable treatment device undesirably prolongs the surgical procedure, and fitting and removing improperly sized devices often further traumatizes the already-injured anatomical site. [0007] Existing devices do not easily measure tunnel defects in soft tissue within body structures. Tunnel defects can be found in the heart (e.g., patent foramen ovale (PFO), left atrial appendage, mitral valve prolapse, aortic valve defects). Tunnel defects can be found through out the vascular system (e.g., venous valve deficiency, vascular disease, vulnerable plaque, aneurysms (e.g., neurovascular, abdominal aortic, thoracic aortic, peripheral). Tunnel defects can be found in non vascular systems (e.g., stomach with GERD, prostate, lungs). [0008] A device for measuring the width of a distended defect in tissue is disclosed. The device has a longitudinal axis. The device can have a first elongated member. The first elongated member can be configured to expand away from the longitudinal axis. The device can have a second elongated member. The first elongated member can be opposite with respect to the longitudinal axis to the second elongated member. The second elongated member can be configured to expand away from the longitudinal axis. The device can have a lumen, for example, in a catheter. The device can have a porous cover on the lumen. [0009] A method for sizing a tunnel defect. The method can include inserting a measurement tool into the tunnel defect. The method can include distending the tunnel defect into a distended configuration. The method can include measuring the tunnel defect in the distended configuration. Distending can include radially expanding the measurement tool. Measuring can include bending the first measuring wire around a front lip of the tunnel defect. Measuring can include emitting a contrast fluid in the tunnel defect. BRIEF SUMMARY OF THE INVENTION [0010] Tissue distension devices can be deployed to tunnel defects in tissue. The tissue distension devices can be used to substantially close tunnel defects to treat, for example, patent foramen ovale (PFO), left atrial appendage, mitral valve prolapse, aortic valve defects. Examples of tissue distension devices include those disclosed in U.S. patent application Ser. No. 10/847,909, filed 19 May 2004; Ser. No. 11/184,069, filed 19 Jul. 2005; and Ser. No. 11/323,640, filed 3 Jan. 2006, all of which are incorporated by reference herein in their entireties. [0011] To select a properly fitting tissue distension device, a measuring tool can first be deployed to measure the size of the tunnel defect. The tunnel defect can be measured in a relaxed or distended configuration. The tunnel defect can be distended by the measuring tool before or during measurement. BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIG. 1 illustrates a variation of the measurement tool in a first configuration. [0013] FIGS. 2 a, 2 b, 3 a and 3 b illustrate variations of cross-section A-A of FIG. 1 . [0014] FIGS. 4 and 5 illustrate various embodiments of cross-section B-B of FIG. 1 . [0015] FIGS. 5 through 11 and 13 through 16 illustrate variations of the measurement tool in a second configuration. [0016] FIG. 12 is a close-up view of the a portion of the measurement tool of FIG. 11 including the first measuring wire only, for illustrative purposes, transforming from a radially contracted to a radially expanded configuration. [0017] FIGS. 17 through 27 illustrate variations of the measuring wire. [0018] FIG. 28 illustrates a variation of cross-section C-C of FIG. 27 . [0019] FIG. 29 illustrates a variation of cross-section D-D of FIG. 27 . [0020] FIG. 30 illustrates a variation of a wire assembly. [0021] FIG. 31 illustrates a variation of a wire sub-assembly. [0022] FIG. 32 illustrates a variation of a wire assembly. [0023] FIG. 33 illustrates a variation of a wire sub-assembly. [0024] FIG. 34 illustrates a variation of a wire assembly. [0025] FIGS. 35-37 illustrate variations of the measurement tool. [0026] FIGS. 38 a and 38 b illustrate various sections of tissue having a tunnel defect. [0027] FIG. 39 illustrates the tunnel defect of FIG. 38 a or 38 b. [0028] FIGS. 40 through 42 illustrate a variation of a method for deploying an embodiment of the measurement tool. [0029] FIGS. 43 and 44 illustrate a variation of a method for using various embodiments of the measurement tool. [0030] FIG. 45 illustrates a variation of a method for using a variation of the measurement tool. [0031] FIGS. 46 and 47 illustrate a variation of a method for using a variation of the measurement tool. [0032] FIGS. 48 and 49 illustrate a variation of a method for using a variation of the measurement tool. DETAILED DESCRIPTION [0033] FIG. 1 illustrates an anatomical measurement tool 2 , such as a tool for measuring the width in a relaxed and/or distended configuration of a tunnel defect 156 in tissue 154 , in a radially contracted configuration. The measurement tool 2 can have a longitudinal axis 16 . The anatomical measurement tool 2 can have a catheter 26 , a first measuring wire 100 a, and a second measuring wire 100 b. The measuring wires 100 can be deformable, resilient, or combinations thereof over the length of the measuring wires 100 . [0034] The catheter 26 can have a catheter porous section 20 . The catheter 26 can be entirely substantially non-porous. The catheter 26 can have a catheter non-porous section 24 . The catheter porous section 20 can partially or completely circumferentially surround the catheter 26 . The catheter porous section 20 can have holes or pores in the catheter outer wall 28 . The pores can have pore diameters from about 1 μm (0.04 mil) to about 1 mm (0.04 in.), more narrowly from about 2 μm (0.08 mil) to about 300 μm (10 mil), for example about 150 μm (6.0 mil). [0035] The first 100 a and second measuring wires 100 b can each have at least one wire radially constrained section 10 and at least one wire radially unconstrained section 8 . The measuring wires 100 can transition from the wire constrained sections 10 to the wire radially unconstrained sections 8 at the wire proximal sheath ports 22 . The first 100 a and second measuring wires 100 b between the wire proximal sheath ports 22 and the wire distal anchor 14 can be the radially unconstrained sections 8 . The measuring wires 100 can be distally fixed to the catheter 26 at a wire distal anchor 14 . The wire distal anchor 14 can be a hinged or otherwise rotatable attachment, for example, to allow the measuring wire 100 to rotate away from the longitudinal axis 16 at the wire distal anchor 14 during use. [0036] The measurement tool 2 can have a tip 12 extending from a distal end of the catheter 26 . The tip 12 can be blunt or otherwise atraumatic (e.g., made or coated with a softer material than the catheter 26 , made with a soft substantially biocompatible rubber tip 12 ). A guide lumen 4 can extend from the tip 12 . The guide lumen 4 can be configured to slidably receive a guidewire 170 . The guide lumen 4 can exit through a dimple in the tip 12 . The tip 12 need not be dimpled at the exit of the guide lumen 4 . [0037] FIG. 2 a illustrates that the catheter 26 can have a catheter outer wall 28 . The catheter outer wall 28 can be porous, or non-porous, or partially porous and partially non-porous. The catheter 26 can have a fluid lumen 36 . The guide lumen 4 can be configured central to the cross-section of the catheter 26 or offset from the center of the cross-section, for example attached to the catheter outer wall 28 . The guide lumen can have a guide lumen wall 34 . [0038] The first measuring wire 100 a can removably and slidably reside in or removably and slidably attach to a recessed or raised first track 32 in the catheter outer wall 28 . The second measuring wire 100 b can removably and slidably reside in or removably and slidably attach to a recessed or raised second track 40 in the catheter outer wall 28 . [0039] To transform the measurement tool 2 from the radially contracted configuration to the radially expanded configuration, the first 100 a and second measuring wires 100 b in the wire radially constrained section 10 can be longitudinally translated, as shown by arrows 54 (not shown in FIG. 2 a ), in a distal direction. The first and second wires, for example, rotatably fixed at the wire distal anchor 14 and not radially constrained between the wire proximal sheath ports 22 and the wire distal anchor 14 , can translate, as shown by arrows 52 (not shown in FIG. 2 a ), radially outward from the longitudinal axis 16 . [0040] FIG. 2 b illustrates that the measuring wires 100 can have a configuration substantially equivalent to the configuration of the respective track 32 or 40 . The measuring wires 100 and catheter 26 can be configured to create a substantially smooth, flush, regular configuration to the radial exterior cross-section (e.g., at A-A) of the measurement tool 2 when the wires 100 are in a contracted configuration. For example, the radially exterior cross-section (e.g., at A-A) of the measurement tool 2 can be configured substantially as a circle when the wires 100 are in a contracted configuration. [0041] FIG. 3 a illustrates that the first 100 a and second measuring wires 100 b in the wire radially unconstrained section 8 can be adjacent to, and reside on or attach to, the catheter outer wall 28 . The catheter outer wall 28 can have no tracks for the measuring wires 100 . [0042] FIG. 3 b illustrates that the measuring wires 100 can have a low-profile configuration. The low-profile configuration can have a cross-sectional configuration (e.g., at A-A) of a semi-circle, crescent, arc, oval, rectangle, or combinations thereof. The low-profile configuration can have a larger angular dimension than radial dimension, when measured with respect to the substantial center of the measurement device in the longitudinal direction. The measuring wires 100 and catheter 26 can be configured to create a substantially smooth, flush and regular exterior surface of the measurement tool 2 when the wires 100 are in a contracted configuration. [0043] FIG. 4 illustrates that the first 100 a and second measuring wires 100 b can be slidably attached to and/or encased by first 48 and second sheaths 50 , respectively. The interior of the sheaths can be coated with a low-friction material (e.g., polytetraflouroethylene (PTFE), such as Teflon® by E.I. du Pont de Nemours and Company, Wilmington, Del.). [0044] FIG. 5 illustrates that the first sheath 48 and/or the second sheath 50 can be inside the catheter 26 (i.e., radially interior to the catheter outer wall 28 ). [0045] The wire distal anchor 14 and wire sheaths 48 and/or 50 can be fixedly attached to the catheter 26 . The wire distal anchor 14 and wire sheaths 48 and/or 50 can be slidably attached to the catheter 26 . [0046] The catheter outer wall 28 can be porous and/or non-porous, for example at different lengths along the catheter 26 . For example, the catheter outer wall 28 in FIGS. 3 a and 3 b can be porous and the catheter outer wall 28 in FIGS. 4 and 5 can be non-porous. [0047] The catheter 26 and/or tip 12 can have a stop. The stop can be longitudinally fixed with respect to the catheter 26 and/or the tip 12 . The stop can be the tip 12 , for example if the diameter of the tip 12 is larger than the diameter of the wire distal anchor 14 . The stop can be configured to interference fit against the wire distal anchor 14 when the wire distal anchor 14 is distally translated beyond a maximum translation point with respect to the catheter 26 and/or tip 12 . [0048] FIG. 6 illustrates the measurement tool 2 in a radially expanded configuration. The first 100 a and second measuring wires 100 b in the wire radially unconstrained section 8 can bow, flex, or otherwise be radially distanced or translate, as shown by arrows 52 , with respect to the longitudinal axis 16 from the catheter 26 . The first 100 a and second measuring wires 100 b can expand in a single plane (i.e., be coplanar). [0049] The measuring wires 100 can be longitudinally translated, as shown by arrows 54 , in the wire radially constrained sections 10 . The first 100 a and second measuring wires 100 b in the wire radially unconstrained sections 8 can be radially expanded or otherwise translated, as shown by arrows, away from the catheter 26 (e.g., longitudinal axis 16 ) into a radially expanded configuration, for example by distally translating the measuring wires 100 in the wire radially constrained sections 10 . The first 100 a and second measuring wires 100 b in the wire radially unconstrained sections 8 can be radially contracted or otherwise translated toward the catheter 26 (e.g., longitudinal axis 16 ) into a radially contracted configuration, for example by proximally translating the measuring wires 100 in the wire radially constrained section 10 . [0050] FIG. 7 illustrates that the catheter porous section 20 can have a porous section length 56 . The longitudinal distance between the wire distal anchor 14 and the wire proximal sheath ports 22 (i.e., the wire radially unconstrained section 8 ) can be an unconstrained wire longitudinal length 58 . The unconstrained wire longitudinal length 58 can be less than, substantially equal to (as shown in FIGS. 1 and 6 ), or greater than (as shown in FIG. 7 ) the catheter non-porous section 24 . [0051] FIG. 8 illustrates that the first and second wires can have substantially discrete angles when the wires are in the radially expanded configurations. Each wire 100 can have a wire first hinge point 60 and a wire second hinge point 66 . The wire hinge points 60 and/or 66 can be biased (e.g., before the measurement tool 2 is configured in the first configuration) to bend when the tension on the measuring wire 100 is decreased. The wire hinge points 60 and/or 66 can have hinges 106 , bends, seams, links, other articulations, or combinations thereof. [0052] The wire first hinge point 60 can have a wire first hinge angle 62 a. The wire second hinge point 86 can have a wire second hinge angle 62 b. In a radially expanded configuration, the wire hinge first and second angles 62 a and 62 b can be from about 10° to about 170°, more narrowly from about 30° to about 150°, yet more narrowly from about 45° to about 135°, for example about 125°. The wire hinge angle 62 when the measurement tool 2 is in a radially expanded configuration can be equivalent to the hinge angle 62 , described infra, when the measurement tool 2 is in a radially contracted configuration. [0053] FIG. 9 illustrates that the measurement tool 2 can have about 12 measuring wires 100 . The measuring wires 100 can be radially expandable in a configuration where the first measuring wire 100 a deploys substantially longitudinally adjacent to a third measuring wire 100 c. The measuring wires 100 can be radially expandable in a configuration where the second measuring wire 100 b deploys substantially longitudinally adjacent to a fourth measuring wire 100 d. [0054] The measuring wires 100 can each have a unique or paired longitudinal position for their wire proximal sheath ports 22 and wire distal anchors 14 . For example, the first 100 a and second measuring wires 100 b can exit from wire first proximal sheath ports 22 a (not shown on FIG. 9 ) and can be fixed at wire first distal anchors 14 a (not shown on FIG. 9 ). The third 100 c and fourth measuring wires 100 d can exit from wire second proximal sheath ports 22 b (not shown on FIG. 9 ) and can be fixed at wire second distal anchors 14 b (not shown on FIG. 9 ). The wire first distal anchors 14 a can be distal to the wire second distal anchors 14 b. The wire first proximal sheath ports 22 a can be at a substantially equivalent longitudinal position to the wire second distal anchors 14 b. The wire second distal anchors 14 b can be distal to the wire second proximal sheath ports 22 b. This longitudinal spacing of the wire distal anchors 14 and wire proximal sheath ports 22 can be used for all of the measuring wires 100 . [0055] The measuring wires 100 on each side of the catheter 26 (e.g., the first, third, fifth, seventh, ninth and eleventh measuring wires or the second, fourth, sixth, eighth, tenth and twelfth measuring wires) can pass through the same or different sheaths. [0056] FIG. 10 illustrates that the measuring wires 100 can have distal ends that are not attached to the catheter 26 when the measuring wires 100 are in radially expanded configurations. Any or all measuring wire 100 can have a terminal end 80 . When the measurement-tool 2 is in a radially expanded configuration, the terminal ends 80 can be unattached to the catheter 26 . When the measurement tool 2 is in a radially expanded configuration, the measuring wires 100 can have a medial turn 82 , bend, hinge 106 , or otherwise angle medially between the terminal ends 80 and the wire proximal ports. A length of the measuring wires 100 can be biased to turn or bend medially when that length of the measuring wire 100 is in a relaxed configuration. The measurement tool 2 can have about eight measuring wires 100 . [0057] FIG. 11 illustrates that the measuring wires 100 can form a substantially circular or oval loop when the measuring wire 100 is in the radially expanded configuration. The measurement tool 2 can have six measuring wires 100 . Each measuring wire 100 can have a separate proximal sheath port 22 (e.g., first, second, third, fourth, fifth and sixth proximal sheath ports 22 a, 22 b, 22 c, 22 d, 22 e, and 22 f ), and wire distal anchors 14 (e.g., wire first, second, third, fourth, fifth and sixth distal anchors 14 a, 14 b, 14 c, 14 d, 14 e and 14 f ) [0058] FIG. 12 illustrates that the loop of wire radially unconstrained section 8 can expand when the measuring wires 100 transform from the radially contracted configuration to the radially expanded configuration. The measuring wires 100 can be longitudinally translated, as shown by arrow 54 , in the wire radially constrained sections 10 . Along the length of the measuring wires 100 near the wire proximal port, the measuring wires 100 can translate along the longitudinal wire-axis, as shown by arrow 84 . The measuring wires 100 in the wire radially unconstrained sections 8 can be radially expanded or otherwise translated, as shown by arrow 52 , away from the catheter 26 (e.g., longitudinal axis 16 ) into a radially expanded configuration, for example by distally translating the measuring wires 100 in the wire radially constrained sections 10 . The measuring wires 100 in the wire radially unconstrained sections 8 can be radially contracted or otherwise translated toward the catheter 26 (e.g., longitudinal axis 16 ) into a radially contracted configuration, for example by proximally translating the measuring wires 100 in the wire radially constrained section 10 . [0059] FIG. 13 illustrates that the measuring wires 100 can exit from the respective wire sheaths at the respective wire proximal ports. The measuring wires 100 can all exit the wire proximal ports on the same side of the catheter 26 , or immediately turn to the same side of the catheter 26 after exiting the proximal wire ports. When the measurement tool 2 is in a radially expanded configuration, the measuring wires 100 can have a proximal turn, bend, hinge 106 , or otherwise angle proximally after exiting the proximal wire port. When the measurement tool 2 is in a radially expanded configuration, the measuring wires 100 can have a medial turn 82 , bend, hinge, or otherwise angle toward the longitudinal axis 16 , for example, between the proximal bend 90 and the terminal end 80 . Any length of the measuring wires 100 can be biased to turn or bend when that length of the measuring wire 100 is in a relaxed configuration. FIG. 14 illustrates that the measuring wire 100 can have a proximal turn, bend, hinge 106 , or otherwise angle proximally. [0060] FIG. 15 illustrates that the catheter 26 can be removably or fixedly attached to a coupler 96 . The coupler 96 can be removably or fixedly attached to a handle 98 . The coupler 96 can be made from any material disclosed herein including rubber, elastic, or combinations thereof. The coupler 96 can have a substantially cylindrical configuration. The coupler 96 can have threads. The coupler 96 can have slots. The couple can have a joint and/or hinge 106 . [0061] The coupler 96 can be flexible. The coupler 96 can substantially bend, for example, permitting the longitudinal axis 16 of the handle 98 to be a substantially non-zero angle (e.g., from about 0° to about 90°) with respect to the longitudinal axis 16 of the catheter 26 . The coupler 96 can permit substantially resistance free rotation between the longitudinal axis 16 of the catheter 26 and the longitudinal axis 16 of the handle 98 . [0062] FIG. 16 illustrates that the coupler 96 can be removably or fixedly attached to the catheter 26 on the proximal and distal end of the coupler 96 . The coupler 96 can have and/or be proximally adjacent to the wire proximal sheath ports 22 . [0063] The measuring wire 100 can have a low and/or high friction surface. The measuring wire 100 can have a higher friction surface on the side of the measuring wire 100 radially exterior to the catheter 26 and a lower friction surface on the side of the measuring wire 100 radially interior to the catheter 26 . The measuring wire 100 can have a surface having a substantially uniform friction around substantially the entire measuring wire 100 . [0064] The surface of the measuring wire 100 can be textured, for example knurled, pebbled, ridged, Toped, or combinations thereof. The surface of the measuring wire 100 can be textured on the side of the measuring wire 100 radially exterior to the catheter 26 and not substantially textured on the side of the measuring wire 100 radially interior to the catheter 26 . The surface of the measuring wire 100 can be substantially uniformly textured around substantially the entire measuring wire 100 . [0065] The surface of the measuring wire 100 can be encrusted with a granulized material, for example diamond, sand, a polymer, the material from which the measuring wire 100 is made, any other material described herein, or combinations thereof. The surface of the measuring wire 100 can be encrusted on the side of the measuring wire 100 radially exterior to the catheter 26 and not substantially encrusted on the side of the measuring wire 100 radially interior to the catheter 26 . The surface of the measuring wire 100 can be substantially uniformly encrusted around substantially the entire measuring wire 100 . [0066] FIG. 17 illustrates that the measuring wire 100 can have a wire body 104 and one or more markers 102 . The wire body 104 can have no markers 102 . The markers 102 can be echogenic, radiopaque, magnetic, or configured to be otherwise visible by an imaging technique known to one having ordinary skill in the art. The markers 102 can be made from any material disclosed herein including platinum (e.g., pure or as powder mixed in glue). [0067] The markers 102 can be uniformly and/or non-uniformly distributed along the length of the wire body 104 . The markers 102 can be uniformly and/or non-uniformly distributed along the radius of the wire body 104 . The markers 102 can be separate and discrete from the wire body 104 . The markers 102 can be attached to the wire body 104 . The markers 102 can be incorporated inside the wire body 104 . The marker 102 can have configuration symmetrical about one, two, three, or more axes. The marker 102 can have an omnidirectional configuration. The marker 102 can have a configuration substantially spherical, ovoid, cubic, pyramidal, circular, oval, square, rectangular, triangular, or combinations thereof. The marker's 102 radius can be smaller than or substantially equal to the wire body's 104 radius at the location of the marker 102 . FIG. 18 illustrates that the marker's 102 radius can be greater than the wire body's 104 radius at the location of the marker 102 . [0068] FIG. 19 illustrates that the marker 102 can have a unidirectional configuration. The marker 102 can be configured in the shape of an arrow. All or subsets of the markers 102 on a wire body 104 can be aligned, for example all of the unidirectionally configured markers 102 can be oriented in the same longitudinal or radial direction (e.g., distally, proximally) along the wire body 104 . [0069] FIG. 20 illustrates that the markers 102 can have alphanumeric characters. The alphanumeric characters can increase in value (e.g., 1, 2, 3, or A, B, C, or I, II, III) incrementally along the length and/or radius of the wire. The markers 102 can include unit values (e.g., mm, in.) [0070] FIG. 21 illustrates that the markers 102 can be configured as a cylinder (e.g., disc), ring (e.g., toroid, band), partial cylinder, partial ring, or combinations thereof. FIG. 22 illustrates that the markers 102 can be integrated with the measuring wire 100 . FIG. 23 illustrates that the markers 102 can be wires or threads. The markers 102 can extend along the length and/or radius of the wire body 104 . [0071] FIG. 24 illustrates that the wire body 104 can have one or more hinges 106 . The hinges 106 can be configured to allow bending or other distortion of the wire body 104 . The hinges 106 can be a change in material and/or a configuration. The hinge 106 can be configured by material absent from a side of the wire body 104 . For example, the hinge 106 can be an angled cut (i.e., the angled cut is not necessarily cut. The angled cut can be cut, crimped, molded, etched, or combinations thereof) in the side of the wire body 104 . The hinge 106 can have a stop to limit the bending of the measuring wire 100 . For example, for an angle cut hinge 106 , the stop can be the side of the hinge 106 . The hinge 106 can have a hinge angle 62 . The hinge angle 62 can correlate to the maximum angle of bending. The hinge angle 62 can be, as described elsewhere herein, or from about 1° to about 179°, more narrowly from about 15° to about 90°, yet more narrowly from about 20° to about 60°, for example about 45°. [0072] FIG. 25 illustrates that the hinge 106 can be a round cut. For example, the hinge 106 can be circular (e.g., semi-circular), oval, or combinations thereof. FIG. 26 illustrates that the hinge 106 can be a rectangular cut. For example, the hinge 106 can be rectangular (e.g., square). The hinge 106 can be any combination of the aforementioned configurations. The hinges 106 with various configurations can be on the same wire body 104 . The hinges 106 can be on various sides of, or otherwise distributed at various angles around, the measuring wire 100 . [0073] FIGS. 27 through 29 illustrate that the wire body 104 can be hollow. The measuring wire 100 can have one or more wire conduits 114 on the radial interior of the wire body 104 . The measuring wire 100 can have one or more wire conduit ports 110 in fluid communication with the one or more wire conduits 114 and the radial exterior of the measuring wire 100 . The wire conduit ports 110 can regulate release of material inside of the wire conduits 114 . For example, the wire conduit ports 110 (or wire conduits 114 themselves) can have and/or be filled and/or covered by an osmotic material, such as a matrix or film. The wire conduit ports 110 can all be on the same side of the measuring wire 100 . The wire conduit ports 110 can be on various sides of, or otherwise distributed at various angles around, the measuring wire 100 . [0074] FIG. 30 illustrates that a wire assembly 118 can have a measuring wire 100 connected to one or more other elements. The first measuring wire 100 a can be connected to the second measuring wire 100 b at a distal collar 122 and/or a proximal collar 124 . The first measuring wire 100 a can be attached to and/or integral with the distal collar 122 and/or proximal collar 124 . The second measuring wire 100 b can be attached to and/or integral with the distal collar 122 and/or proximal collar 124 . The wire assembly 118 can be made by being pressed, molded or cut from a tube, for example laser cut from a Nitinol tube. The collars can be cylindrical, have a rectangular, square, triangular, pentagonal, octagonal, oval cross section, or combinations thereof with respect to a longitudinal axis 16 . [0075] FIG. 31 illustrates that a wire sub-assembly 120 can have a first measuring wire 100 a connected to one or more other elements. The first measuring wire 100 a can be connected to a distal collar 122 and/or a proximal collar 124 . The first measuring wire 100 a can be attached to and/or integral with the distal collar 122 and/or proximal collar 124 . The wire sub-assembly 120 can be made by being pressed, molded, or cut from a tube, for example laser cut from a Nitinol tube. [0076] FIG. 32 illustrates that the wire assembly 118 can have a first wire sub-assembly 134 and a second wire sub-assembly 136 . The first wire sub-assembly 134 and the second wire sub-assembly 136 can be integral and/or attached or separate. The first wire sub assembly can be positioned 180° opposite to the positioning of the second wire sub-assembly 136 , with respect to a longitudinal axis 16 of the wire assembly 118 . [0077] FIG. 33 illustrates that the wire assembly 118 can have a first measuring wire 100 a that can have one or more hinges 106 . For example, the first measuring wire 100 a can have a wire distal hinge 144 and/or a wire proximal hinge 142 . The wire distal hinge 144 can be at the connection between the first measuring wire 100 a and the first wire distal collar 126 . The wire proximal hinge 142 can be at the connection between the first measuring wire 100 a and the first wire proximal collar 128 . The wire distal hinge 144 and the wire proximal hinge 142 can be configured to bend or otherwise rotate the first measuring wire 100 a radially outward from the central longitudinal axis 16 of the wire sub-assembly 120 when the measurement tool 2 is in a radially expanded configuration. [0078] The wire can have a wire first hinge 138 and/or a wire second hinge 140 . The wire first and/or second hinges can be on the first measuring wire 100 a, for example, between the wire distal hinge 144 and the wire proximal hinge 142 . The wire first hinge 138 and/or the wire second hinge 140 can be configured to bend or otherwise rotate the first measuring wire 100 a radially inward from the central longitudinal axis 16 of the wire sub-assembly 120 when the measurement tool 2 is in a radially expanded configuration. [0079] FIG. 34 illustrates that the wire assembly 118 can have wire distal hinges 144 , and/or wire proximal hinges 142 , and/or wire first hinges 138 , and/or wire second hinges 140 on the first measuring wire 100 a and/or the second measuring wire 100 b. [0080] FIG. 35 illustrates that the measurement tool 2 can have a wire assembly 118 connected to the catheter 26 . The wire assembly 118 can be integrated and/or attached to the catheter 26 . For example, the proximal collar 124 and/or distal collar 122 can be integral with and/or fixably and/or slidably attached to the catheter 26 . For example, the distal collar 122 can be slidably attached to the catheter 26 near or on the tip 12 and/or the proximal collar 124 can be fixedly attached to the catheter 26 . [0081] The wire assembly 118 can have a retraction leader 148 . The retraction leader 148 can be integral with or attached to the distal collar 122 . The retraction leader 148 can be rigid and/or flexible. The retraction leader 148 can be radially external to the catheter 26 and/or the retraction leader 148 can be slidably attached to a retraction leader conduit 146 or channel inside of the catheter 26 . The retraction leader conduit 146 or channel can be partially or completely open to the radial outside of the catheter 26 . For example, the retraction leader conduit 146 can be open to the radial outside of the catheter 26 for all or part of the retraction leader conduit's 146 length distal to the proximal conduit. [0082] FIG. 36 illustrates that the first wire sub-assembly 134 and the second wire sub-assembly 136 can be integral with and/or attached to the catheter 26 . The first wire sub-assembly 134 can be proximal, distal, or overlapping with the longitudinal position of the second wire sub-assembly 136 on the catheter 26 . The second wire distal collar 130 can be distal and/or proximal to the first wire distal collar 126 . The second wire proximal collar 132 and be distal and/or proximal to the first wire proximal collar 128 . The first wire distal collar 126 can be attached to or integral with a first retraction leader 148 . The second wire distal collar 130 can be attached to or integral with a second retraction leader 148 . [0083] FIG. 37 illustrates that the measurement tool 2 can have a catheter sheath 152 . The catheter sheath 152 can be slidably attached to the catheter 26 . In an undeployed configuration, the catheter sheath 152 can be radially outside and longitudinally overlapping the wire assembly 118 . The catheter sheath 152 can be sufficiently rigid to retain the wire assembly 118 in a radially contracted configuration. The catheter sheath 152 can have, for example at a distal end of the catheter sheath 152 , a catheter sheath port 150 through which the catheter 26 and other elements (e.g., the wire assembly and measuring wires), can exit and enter the catheter sheath 152 . [0084] Any or all elements of the measurement tool 2 and/or other devices or apparatuses described herein can be made from, for example, a single or multiple stainless steel alloys, nickel titanium alloys (e.g., Nitinol), cobalt-chrome alloys (e.g., ELGILOY® from Elgin Specialty Metals, Elgin, Ill.; CONICHROME® from Carpenter Metals Corp., Wyomissing, Pa.), nickel-cobalt alloys (e.g., MP35N® from Magellan Industrial Trading Company, Inc., Westport, Conn.), molybdenum alloys (e.g., molybdenum TZM alloy, for example as disclosed in International Pub. No. WO 03/082363 A2, published 9 Oct. 2003, which is herein incorporated by reference in its entirety), tungsten-rhenium alloys, for example, as disclosed in International Pub. No. WO 03/082363, polymers such as polyethylene teraphathalate (PET), polyester (e.g., DACRON® from E. I. Du Pont de Nemours and Company, Wilmington, Del.), polypropylene, aromatic polyesters, such as liquid crystal polymers (e.g., Vectran, from Kuraray Co., Ltd., Tokyo, Japan), ultra high molecular weight polyethylene (i.e., extended chain, high-modulus or high-performance polyethylene) fiber and/or yarn (e.g., SPECTRA® Fiber and SPECTRA® Guard, from Honeywell International, Inc., Morris Township, N.J., or DYNEEMA® from Royal DSM N.V., Heerlen, the Netherlands), polytetrafluoroethylene (PTFE), expanded PTFE (ePTFE), polyether ketone (PEK), polyether ether ketone (PEEK), poly ether ketone ketone (PEKK) (also poly aryl ether ketone ketone), nylon, polyether-block co-polyamide polymers (e.g., PEBAX® from ATOFINA, Paris, France), aliphatic polyether polyurethanes (e.g., TECOFLEX® from Thermedics Polymer Products, Wilmington, Mass.), polyvinyl chloride (PVC), polyurethane, thermoplastic, fluorinated ethylene propylene (FEP), absorbable or resorbable polymers such as polyglycolic acid (PGA), poly-L-glycolic acid (PLGA), polylactic acid (PLA), poly-L-lactic acid (PLLA), polycaprolactone (PCL), polyethyl acrylate (PEA), polydioxanone (PDS), and pseudo-polyamino tyrosine-based acids, extruded collagen, silicone, zinc, echogenic, radioactive, radiopaque materials, a biomaterial (e.g., cadaver tissue 154, collagen, allograft, autograft, xenograft, bone cement, morselized bone, osteogenic powder, beads of bone) any of the other materials listed herein or combinations thereof. Examples of radiopaque materials are barium sulfate, zinc oxide, titanium, stainless steel, nickel-titanium alloys, tantalum and gold. [0085] Any or all elements of the measurement tool 2 and/or other devices or apparatuses described herein, can be, have, and/or be completely or partially coated with agents and/or a matrix a matrix for cell ingrowth or used with a fabric, for example a covering (not shown) that acts as a matrix for cell ingrowth. The matrix and/or fabric can be, for example, polyester (e.g., DACRON® from E. I. Du Pont de Nemours and Company, Wilmington, Del.), polypropylene, PTFE, ePTFE, nylon, extruded collagen, silicone or combinations thereof. [0086] The measurement tool 2 and/or elements of the measurement tool 2 and/or other devices or apparatuses described herein and/or the fabric can be filled, coated, layered and/or otherwise made with and/or from cements, fillers, glues, and/or an agent delivery matrix known to one having ordinary skill in the art and/or a therapeutic and/or diagnostic agent. Any of these cements and/or fillers and/or glues can be osteogenic and osteoinductive growth factors. [0087] Examples of such cements and/or fillers includes bone chips, demineralized bone matrix (DBM), calcium sulfate, coralline hydroxyapatite, biocoral, tricalcium phosphate, calcium phosphate, polymethyl methacrylate (PMMA), biodegradable ceramics, bioactive glasses, hyaluronic acid, lactoferrin, bone morphogenic proteins (BMPs) such as recombinant human bone morphogenetic proteins (rhBMPs), other materials described herein, or combinations thereof. [0088] The agents within these matrices can include any agent disclosed herein or combinations thereof, including radioactive materials; radiopaque materials; cytogenic agents; cytotoxic agents; cytostatic agents; thrombogenic agents, for example polyurethane, cellulose acetate polymer mixed with bismuth trioxide, and ethylene vinyl alcohol; lubricious, hydrophilic materials; phosphor cholene; anti-inflammatory agents, for example non-steroidal anti-inflammatories (NSAIDs) such as cyclooxygenase-1 (COX-1) inhibitors (e.g., acetylsalicylic acid, for example ASPIRIN® from Bayer AG, Leverkusen, Germany; ibuprofen, for example ADVIL® from Wyeth, Collegeville, Pa.; indomethacin; mefenamic acid), COX-2 inhibitors (e.g., VIOXX® from Merck & Co., Inc., Whitehouse Station, N.J.; CELEBREX® from Pharmacia Corp., Peapack, N.J.; COX-1 inhibitors); immunosuppressive agents, for example Sirolimus (RAPAMUNE®, from Wyeth, Collegeville, Pa.), or matrix metalloproteinase (MMP) inhibitors (e.g., tetracycline and tetracycline derivatives) that act early within the pathways of an inflammatory response. Examples of other agents are provided in Walton et al, Inhibition of Prostoglandin E 2 Synthesis in Abdominal Aortic Aneurysms, Circulation, Jul. 6, 1999, 48-54; Tambiah et al, Provocation of Experimental Aortic Inflammation Mediators and Chlamydia Pneumoniae, Brit. J. Surgery 88 (7), 935-940; Franklin et al, Uptake of Tetracycline by Aortic Aneurysm Wall and Its Effect on Inflammation and Proteolysis, Brit. J. Surgery 86 (6), 771-775; Xu et al, Sp1 Increases Expression of Cyclooxygenase-2 in Hypoxic Vascular Endothelium, J. Biological Chemistry 275 (32) 24583-24589; and Pyo et al, Targeted Gene Disruption of Matrix Metalloproteinase-9 (Gelatinase B) Suppresses Development of Experimental Abdominal Aortic Aneurysms, J. Clinical Investigation 105 (11), 1641-1649 which are all incorporated by reference in their entireties. Methods of Use [0089] FIG. 38 a illustrates a section of tissue 154 that can have a tunnel defect 156 passing through the tissue 154 . The tunnel defect 156 can be substantially perpendicular to the face of the tissue 154 . For example, the tunnel defect 156 can be an atrial septal defect (ASD). FIG. 38 b illustrates that the tunnel defect 156 can be at a steep angle or substantially parallel to the face of the tissue 154 . For example, the tunnel defect 156 can be a patent foramen ovale (PFO). [0090] FIG. 39 illustrates that the tunnel defect 156 can have a defect front face 162 and a defect back face (not shown). A defect front lip 160 can be defined by the perimeter of the defect front face 162 . A defect back lip 158 can be defined by the perimeter of the defect back face. The tunnel defect 156 can have a defect height 164 , a defect depth 166 and a defect width 168 . [0091] FIG. 40 illustrates that a guidewire 170 can be deployed through the tunnel defect 156 . The guidewire 170 can be passed through the guide lumen 4 in the measurement tool 2 . The measurement tool 2 can be in a radially contracted (as shown) or radially expanded configuration. The measurement tool 2 can be translated, as shown by arrow, along the guidewire 170 . The measurement tool 2 can be translated to the tunnel defect 156 with or without the use of the guidewire 170 . [0092] FIG. 41 illustrates that the measurement tool 2 can be translated into the tunnel defect 156 . The guidewire 170 can be left in place or removed. The location of the measurement tool 2 can be monitored by dead reckoning, and/or imaging, and/or tracking along the length of the guidewire 170 . The measurement tool 2 can be positioned so that the tunnel defect 156 is located adjacent to the catheter porous section 20 . The measurement tool 2 can be positioned so that the tunnel defect 156 is located substantially between the most distal wire distal anchor 14 and the most proximal wire proximal sheath. [0093] FIG. 42 illustrates that the measurement tool 2 can be radially expanded. The measuring wires 100 in the wire radially constrained section 10 can be distally longitudinally translated, as shown by arrow 54 . The measuring wires 100 can translate radially (i.e., away from the longitudinal axis 16 ), as shown by arrows 52 . The measuring wires 100 can radially distend the tunnel defect 156 , for example causing the tunnel defect 156 to widen (shown by arrows similar to arrows 52 ) and shorten or otherwise contract in height, as shown by arrows 172 . The measuring wires 100 can radially distend the tunnel defect 156 , for example, until the tunnel defect 156 will no longer distend without structurally damaging the tunnel defect 156 . [0094] FIG. 43 illustrates that the measuring wires 100 can be radially translated beyond the extent that the tunnel defect 156 can be distended without structural damage. The measuring wires 100 can deform around the front and back defect lips. Portions of the measuring wires 100 can configure into wire overdeployment sections 176 proximal and distal to the tunnel defect 156 . The wire overdeployment sections 176 , or markers 102 thereon, can be imaged, for example using x-rays (e.g., radiography, fluoroscopy), ultrasound, or magnetic resonance imaging (MRI). The wire overdeployment sections 176 can illustrate the defect width 168 (i.e., the length between the wire deployment sections) when the defect is in a fully distended configuration. [0095] FIG. 44 illustrates that the measurement tool 2 can have no catheter porous section 20 , for example, when the measurement tool 2 is used for the measurement method as shown in FIG. 43 . The methods of use shown in FIGS. 43 and 44 can, for example, measure the defect depth 166 and/or the defect height 164 . [0096] FIG. 45 illustrates that contrast fluid or particles can be deployed into the fluid lumen 36 of the catheter 26 , for example, when tunnel defect 156 is in a fully distended configuration. The contrast fluid can be radiopaque, echogenic, visible contrast (e.g., dyes, inks), any other material disclosed herein, or combinations thereof. The fluid pressure of the contrast fluid or particles can be increased. The contrast fluid or particles can emit, as shown by arrows 180 , through the catheter porous section 20 . The contrast fluid or particles outside of the catheter 26 can configure into a marker cloud 178 . The marker cloud 178 can move into position around the tissue 154 . The marker cloud 178 can illustrate the defect dimensions (i.e., visible with imaging systems known to those having ordinary skill in the art, including x-ray, CAT, MRI, fiber optic camera, ultrasound/sonogram) when the defect is in a fully distended configuration. [0097] A drug can be deployed from the catheter porous section 20 , for example, similar to the method of deploying the contrast fluid. [0098] FIG. 46 illustrates that a proximal force, as shown by arrows, can be applied to the distal collar 122 . For example, the retraction leader 148 can be pulled proximally. [0099] FIG. 47 illustrates that the distal collar 122 can translate proximally, as shown by arrows 52 . The measuring wires 100 can expand radially away from the central longitudinal axis 16 of the measurement tool 2 . The wires can bend radially outward at the wire distal hinge 144 and the wire proximal hinges 142 . The wires can bend radially inward at the wire first hinge 138 and wire second hinge 140 . The wires can also form a curved or splined configuration (e.g., similar to the configuration shown in FIG. 6 , inter alia) instead of or in addition to the hinges 106 . [0100] The measuring wires 100 can be resiliently biased to the radially contracted configuration. When the proximal force is no longer applied to the distal collar 122 , the measuring wires 100 can straighten and distally force the distal collar 122 to translate to the position shown in FIG. 46 . [0101] The measurement wires can be deformable. The retraction leader 148 can be rigid. For example, to radially contract the measuring wires 100 , the retraction leader 148 can distally force the distal collar 122 to translate to the position shown in FIG. 46 . The measuring wires 100 can deform to the position shown in FIG. 46 . [0102] FIG. 48 illustrates that the wire assembly 118 can be radially constrained by the catheter sheath 152 . The catheter sheath 152 can radially encircle the measuring wires 100 and/or the entire wire assembly 118 . The catheter sheath 152 can longitudinally encompass the measuring wires 100 and/or the entire wire assembly 118 . A distal force, as shown by arrows, can be applied to the catheter sheath 152 . [0103] FIG. 49 illustrates that the measuring wires 100 can be resiliently biased to radially expand away from the center longitudinal axis 16 of the measurement tool 2 . When the catheter sheath 152 is retracted distal to the measuring wires 100 , the measuring wires 100 can radially expand, as shown by arrows. The distal collar 122 can proximally translate, as shown by arrows. [0104] The catheter sheath 152 can be rigid. The catheter sheath 152 can be distally translated, for example to radially contract the measuring wires 100 . The catheter sheath 152 can radially contract the measuring wires 100 as the catheter sheath 152 substantially underformably slides distally over the measuring wires 100 . [0105] A distension device size can be determined as described, supra. The measurement tool 2 can be radially contracted and removed from the tunnel defect 156 , or the coupler 96 and/or the elements of the measurement tool 2 proximal to the coupler 96 can be detached from the remainder of the measurement tool 2 and removed. If the entire measurement tool 2 is removed from the tunnel defect 156 , a distension device can be selected that has a size that substantially matches (e.g., is equivalent when the distension device is in a substantially or completely radially expanded configuration) the size of the distended tunnel defect 156 . The distension device can be deployed to the tunnel defect 156 , for example along the guidewire 170 . The guidewire 170 can be removed. The distension device can be, for example, a filter, stopper, plug, any distending device described in U.S. patent application Ser. No. 10/847,909, filed 19 May 2004; Ser. No. 11/184,069, filed 19 Jul. 2005; and Ser. No. 11/323,640, filed 3 Jan. 2006, all of which are incorporated by reference herein in their entireties, or any combinations thereof. [0106] Any elements described herein as singular can be pluralized (i.e., anything described as “one” can be more than one). Any species element of a genus element can have the characteristics or elements of any other species element of that genus. The above-described configurations, elements or complete assemblies and methods and their elements for carrying out the invention, and variations of aspects of the invention can be combined and modified with each other in any combination.

A measuring device for measuring tunnel defects in tissue is disclosed. The measuring device can size the defect to aid future deployment of a tissue distension device. Exemplary tunnel defects are atrial septal defects, patent foramen ovales, left atrial appendages, mitral valve prolapse, and aortic valve defects. Methods for using the same are disclosed.

This is a division of application Ser. No. 08/940,818 filed Sep. 30, 1997, which is a continuation of application Ser. No. 08/723,512 filed Sep. 30, 1996 (abandoned), which is a division of application Ser. No. 08/239,847 filed May 9, 1994 (now U.S. Pat. No. 5,587,794), which is a continuation of application Ser. No. 07/802,197 filed Dec. 4, 1991 (abandoned). BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus and method utilizing a projection system, wherein a surface state relating to an exposure area of the projection system is determined, such as for focal point position detection of the projection system. The invention is applicable to, e.g. a semiconductor manufacturing apparatus. 2. Related Background Art As a conventional focal point position detection apparatus in a semiconductor manufacturing apparatus, as disclosed in Japanese Laid-Open Patent Application No. 56-42205 proposed by the assignee of the present application, an oblique incidence type focal point position detection apparatus is used. This apparatus obliquely projects detection light onto a semiconductor wafer arranged at a position where a mask pattern is transferred by a projection lens. The focal point position detection apparatus uses the surface of a semiconductor wafer as a surface to be detected (to be referred to as a detection surface hereinafter), and projects a slit-like pattern onto the detection surface in a direction wherein the longitudinal direction of a slit becomes perpendicular to a plane defined between incident light and reflected light, i.e., a plane of incidence. The apparatus re-focuses the reflected light on a detection means comprising a photoelectric transducer, thereby detecting an incident position of the reflected light on the detection means. When the surface as the detection surface of the semiconductor wafer is displaced in the vertical direction (i.e., it approaches or is separated along the optical axis direction of the projection lens), slit reflected light incident on the detection means is image-shifted in a direction parallel to the plane of incidence, i.e., in the widthwise direction of the slit in correspondence with the vertical displacement. By utilizing this effect, the apparatus detects an image shift amount, thereby detecting the vertical position of the surface of the semiconductor wafer. In this manner, it is discriminated whether or not the wafer surface coincides with a focusing reference position of the projection lens, i.e., a conjugate plane with a lens projected by the projection lens. In this case, the apparatus re-focuses light reflected by a small slit-like pattern region projected on the detection surface, and detects an average position on the small slit-like detection region. In recent years, along with the increase in degree of integration of LSIs (Large Scale Integrations), demand has arisen for transferring a micropattern onto an exposure region (shot region) on a wafer. In order to meet this demand, a numerical aperture NA of the projection lens is increased. Thus, since the focal depth of a projection objective lens becomes shallow, it is important to accurately and reliably align the exposure region at the focal point position (within the focal depth) of the projection objective lens. The area of the exposure region by a projection/exposure apparatus is also increasing. Thus, an LSI chip having an increased exposure area is exposed in a single exposure operation, or a plurality of LSI chips are exposed in a single exposure operation. For this reason, it is important to accurately and reliably align the overall exposure region with an increased area with the focal point position (within the focal depth) of the projection objective lens. Furthermore, when a plurality of LSI chips are exposed at the same time, and when the size of an LSI chip to be exposed (the size of the exposure region) is to be changed, illumination light for position detection cannot be radiated on a proper position on the detection surface, and the position of the projection light must be changed. In order to solve this problem by the conventional focal point position detection apparatus in this situation, position detection on the exposure region on the wafer must be performed at a plurality of positions. For this reason, a stage, which places a wafer thereon, may be properly moved so as to project slit light from the focal point position detection apparatus onto necessary detection positions and to detect these positions. However, in this case, a decrease in throughput is inevitable. SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a high-performance surface position detection apparatus, which can accommodate a larger exposure region, and can also accommodate a case wherein a plurality of LSI chips are simultaneously exposed or a case wherein the size of an LSI chip to be exposed is changed, without decreasing the throughput in either case. In order to achieve the above object, according to one aspect of the present invention, a surface position detection apparatus includes: a projection optical system for projecting pattern light of a predetermined pattern on a detection surface from an oblique direction relative to the detection surface; an imaging optical system for forming an image of the pattern light reflected by the detection surface; light-receiving-side light-shielding means arranged at a position substantially conjugate with the detection surface in the imaging optical system, and having an opening with a predetermined shape; scanning means for scanning the image formed by the imaging optical system relative to the light-receiving-side light-shielding means; and means for dividing the pattern light into a plurality of portions corresponding to different parts of the pattern, and for selectively detecting at least one such portion of the pattern light passing through the aforementioned opening. According to another aspect of the present invention, a surface position detection apparatus includes: a first projection optical system for projecting first pattern light of a first predetermined pattern from an oblique direction onto a detection surface in a first orientation relative to the detection surface; a second projection optical system for projecting second pattern light of a second predetermined pattern from an oblique direction onto the detection surface in a second orientation relative to the detection surface; a first imaging optical system for forming an image of the first pattern light from the first projection optical system reflected by the detection surface; a second imaging optical system for forming an image of the second pattern light from the second projection optical system reflected by the detection surface; first light-receiving-side light-shielding means arranged at a position substantially conjugate with the detection surface in the first imaging optical system, and having a first opening with a predetermined shape; second light-receiving-side light-shielding means arranged at a position substantially conjugate with the detection surface in the second imaging optical system, and having a second opening with a predetermined shape; first scanning means for scanning the image formed by the first imaging optical system relative to the first light-receiving-side light-shielding means; second scanning means for scanning the image formed by the second imaging optical system relative to the second light-receiving-side light-shielding means; first means for dividing the first pattern light into a plurality of portions corresponding to different parts of the first pattern, and for selectively detecting at least one such portion of the first pattern light passing through the first opening; and second means for dividing the second pattern light into a plurality of portions corresponding to different parts of the second pattern, and for selectively detecting at least one such portion of the second pattern light passing through the second opening. According to still another aspect of the present invention, a surface position detection apparatus includes: a projection optical system. for projecting pattern light of a predetermined pattern through a projection objective lens from an oblique direction onto a detection surface, and including light shaping means at a position substantially conjugate with the detection surface for shaping light to conform with the predetermined pattern; an imaging optical system for forming an image of the pattern light reflected by the detection surface through an imaging objective lens; light-receiving-side light-shielding means arranged at a position substantially conjugate with the detection surface in the imaging optical system, and having an opening with a predetermined shape; scanning means for scanning the image formed by the imaging optical system relative to the light-receiving-side light-shielding means; means for dividing the pattern light into a plurality of portions corresponding to different parts of the pattern, and for selectively detecting at least one such portion of the pattern light passing through the opening; a first beam splitter arranged between the light shaping means and the projection objective lens; a second beam splitter arranged between the imaging objective lens and the light-receiving-side light-shielding means; light source means for supplying a parallel light beam onto the detection surface through the first beam splitter and the projection objective lens; and detection means for detecting an average state of the detection surface on the basis of the parallel light beam reflected from the detection surface, which beam is focused through the imaging objective lens and the second beam splitter. According to the present invention, since a plurality of pieces of position information of the detection surface on a region where the predetermined pattern light is projected can be obtained, positions of the detection surface can be detected with high accuracy without decreasing the throughput. Thus, an inclination state of the detection surface, a defocus state of the detection surface with respect to the focal point position of a projection lens, and the sectional shape of the detection surface can be accurately detected while accommodating an exposure region with an increased area, simultaneous exposure of LSI chips, and a change in LSI chip size (size of the exposure region). When a plurality of light components including a plurality of position information on the detection surface are selectively detected, only proper positions on the detection surface can be detected, and the influence of a pattern structure formed on the detection surface can be eliminated. Furthermore, when a plurality of detection signals including a plurality of position information on the detection surface are multiplied with weighting coefficients, a remarkably improved effect can be obtained. According to another of its aspects, the present invention provides an exposure apparatus comprising a projection system, a detection optical system which illuminates an exposure area formed by the projection system with light and receives light from the exposure area, and a detection system which designates positions of a plurality of detection points in the exposure area in accordance with a size of the exposure area formed by the projection system The detection system detects positions related to the plurality of detection points in the exposure area based on information of light received by the detection optical system. According to yet a further aspect, the invention provides a method of detecting focus position of a projection system in an exposure apparatus. The method comprises illuminating an exposure area formed by the projection system with light, receiving light from the exposure area, and designating positions of a plurality of detection points in the exposure area in accordance with a size of the exposure area formed by the projection system. The method additionally comprises detecting positions related to the plurality of detection points in the exposure area based on information of light received from the exposure area. In a preferred mode of the exposure apparatus and the focus position detecting method just described, the positions of the detection points are designated based on map information about the size of the exposure area. Other objects, features, and effects of the present invention will be sufficiently apparent from the following detailed description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A and 1B are views showing an arrangement of a surface position detection apparatus according to the first embodiment of the present invention; FIGS. 2A and 2B are views showing a state of a photoelectric transducer arranged adjacent to a light-receiving slit plate in the first embodiment of the present invention; FIG. 3 is a view showing the principle of position detection in the surface position detection apparatus of the present invention; FIG. 4 is a perspective view showing a state wherein a detection surface in FIGS. 1A and 1B is inclined; FIGS. 5A to 5C are views showing states of the detection surface when a projection optical system is viewed from the sheet surface direction of FIG. 1A; FIGS. 6A to 6C are plan views showing states of slit images focused on a light-receiving slit according to the states of the detection surface shown in FIGS. 5A to 5C; FIGS. 7A and 7B are views showing an arrangement of a surface position detection apparatus according to the second embodiment of the present invention; FIGS. 8A and 8B are views showing states of a transmittance variable member provided adjacent to a light-receiving slit plate in the second embodiment of the present invention or a projection slit plate in the third embodiment of the present invention; FIGS. 9A and 9B are views showing an arrangement of a surface position detection apparatus according to the third embodiment of the present invention; FIG. 10 is a view showing a position detection state when an LSI chip size is changed; FIG. 11 is a view showing a position detection state when a plurality of LSI chips are simultaneously exposed; FIG. 12 is a view showing a surface position detection apparatus for detecting an average state of a detection surface; FIG. 13 is a view showing a state wherein a local position on the detection surface and an average position on the overall detection surface are detected; FIG. 14 is a view showing a modification of FIG. 13, which shows the state wherein a local position on the detection surface and an average position on the overall detection surface are detected; and FIG. 15 is a view showing an arrangement of an apparatus obtained when the surface position detection apparatuses shown in FIGS. 1A and 1B and FIG. 12 are combined. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described hereinafter with reference to the accompanying drawings. FIG. 1A shows a schematic arrangement according to the first embodiment of the present invention. (A) of FIG. 1A is a schematic side view showing an optical path in an incident plane, and FIG. 1B is a schematic plan view showing an optical path when a detection surface 1 is viewed from a position immediately thereabove. Illumination light from a light source 11 illuminates a projection slit plate 13 as projection-side light-shielding means through a condenser lens 12. As shown in a plan view of (B) of FIG. 1A, the slit plate 13 has a linear pattern, and is arranged to be perpendicular to the optical axis, so that the longitudinal direction of this pattern extends in a direction perpendicular to the drawing surface of (A) of FIG. 1A. Light passing through the slit plate 13 is focused on the detection surface 1, which crosses an optical axis Ax of a projection lens L at a predetermined angle of incidence a, by a projection objective lens 14 and a reflection mirror 10M. More specifically, an image SL of the slit plate 13 is projected onto the detection surface 1 by projection objective lens 14, and the longitudinal direction of the slit image is perpendicular to the drawing surface of (A) of FIG. 1A. FIG. 1B illustrates the detection surface 1 at that time when viewed from a position immediately thereabove. Light reflected by the detection surface 1 is reflected by a reflection mirror 20M, and is focused by an imaging objective lens 21. The light is then reflected by a vibration mirror 22 as scanning means, which scans in a direction indicated by an arrow in FIG. 1A. Thereafter, the light is focused on a light-receiving slit plate 23 as light-receiving-side light-shielding means. More specifically, the slit image SL formed on the detection surface is re-focused on the light-receiving slit 23 by the focusing objective lens 21. The light-receiving slit plate 23 has a linear pattern like in the projection slit plate 13, as shown in (C) of FIG. 1A, and its longitudinal direction is perpendicular to a plane of incidence S, i.e., is perpendicular to the drawing surface of (A) of FIG. 1A. Light passing through the light-receiving slit 23 is detected by a photoelectric transducer 24. As shown in (D) of FIG. 1A, the photoelectric transducer 24 has a plurality of independent light-receiving portions (24a 1 , 24a 2 , 24a 3 , . . . 24a n ), which are linearly arranged in a direction parallel to the plane of incidence S (in a direction perpendicular to the drawing surface of (A) of FIG. 1A). FIG. 2A is a plan view showing a state of the light-receiving slit plate 23, and the photoelectric transducer 24 arranged adjacent to the plate 23, and FIG. 2B is a side view corresponding to FIG. 2A. The light-receiving portions 24a 1 , 24a 2 , 24a 3 , . . . , 24a n of the photoelectric transducer 24 can independently detect light components reflected by portions SLa 1 , SLa 2 , SLa 31 , . . . , SLa n of the linear pattern image SL projected on a linear detection region conjugate with these portions, as shown in FIG. 1B. The components between the light source 11 and the projection objective lens 14 constitute a projection optical system, and components between the imaging objective lens and the light-receiving slit plate 23 constitute an imaging optical system. The photoelectric transducer 24 and a detection section 25 constitute a detection means 200. The principle of detecting the displacement of the detection surface 1 will be described in detail below with reference to FIG. 3. Note that the same reference numerals in FIG. 3 denote members having the same functions as those in FIG. 1A. In place of the vibration mirror 22 shown in FIG. 1A, the light-receiving slit 23 is vibrated in a plane (a direction) perpendicular to the optical axis. For the sake of simplicity, the number of light-receiving surfaces of the photoelectric transducer 24 is assumed to be one. Assuming that the detection surface 1 is displaced downward from a reference position Z 0 by a distance ΔZ, while maintaining a horizontal state, as shown in FIG. 3, a displacement Δy of a slit image on the light-receiving slit plate 23 is given by: Δy=2·β·sin α·ΔZ where β is the focusing magnification of the light-receiving-side objective lens 21, and α is the angle of incidence defined between slit detection light and the normal to the detection surface 1 (the complement of the angle defined between the optical axis of the projection objective lens and the detection surface 1). The displacement ΔZ of the detection surface 1 can be detected based on the position shift amount Δy of the slit image on the light-receiving slit plate 23, which amount is obtained from the photoelectric transducer 24 according to the above-mentioned relation. In this case, the optical system is formed, so that when the entire detection surface 1 is at the level of the reference position Z 0 (in the horizontal state at the reference position Z 0 ), light reflected by the detection surface 1 and propagating along an optical axis 20a of the imaging optical system is incident at a reference position P 0 of the light-receiving slit plate 23 (FIG. 3). Note that the projection optical system has an optical axis 10a, and the imaging optical system has the optical axis 20a. When the light reflected by the detection surface 1 and propagating along the optical axis 20a of the imaging optical system is incident at the reference position P 0 of the light-receiving slit plate 23, and when the slit image SL is vibrated at a period T to have the reference position P 0 as the center, the intensity of modulated light, which reaches the light-receiving surface of the photoelectric transducer 24, is changed to almost a sine wave shape having a period T/2. Thus, a sine wave detection output can be obtained from the photoelectric transducer 24. When the detection output is synchronously detected by the detection section 25, if the reflected light reaching the light-receiving surface of the photoelectric transducer 24 is shifted by ΔZ in a direction perpendicular to its direction of incidence, a detection output corresponding to the position shift amount can be obtained. A method of detecting a displacement by a synchronous detection technique is disclosed in, e.g., Japanese Laid-Open Patent Application No. 56-42205, and is the principle of a photoelectric microscope. In the above description of the detection method, a case has been explained wherein the photoelectric transducer 24 is assumed to have one light-receiving surface. According to the first embodiment of the present invention, as shown in FIG. 1A, the light-receiving surface of the photoelectric transducer 24 has the individual light-receiving portions 24a 1 , 24a 2 , 24a 3 , . . . , 24a n along the longitudinal direction of the light-receiving slit plate 23. For this reason, as shown in FIG. 1B, the portions SLa 1 , SLa 2 , SLa 3 , . . . , SLa n of the slit image SL reflected by the corresponding portions of the detection surface 1 are received by the corresponding light-receiving portions 24a 1 , 24a 2 , 24a 3 , . . . , 24a n of the photoelectric transducer 24, thus obtaining the detection outputs SD 1 , SD 2 , SD 3 . . . , SD n . These detection outputs are synchronously detected by the detection section 25, thereby independently detecting a plurality of positions corresponding to the positions of the portions SLa 1 , SLa 2 , SLa 3 , . . . , SLa n of the projection slit image SL. Since the plurality of positions of the projection slit image SL on the detection surface 1 can be detected, not only focal points at the plurality of positions but also an inclination state of the detection surface 1 can be detected, as can be seen from FIG. 4, which shows an inclined state of the detection surface shown in FIG. 1. Furthermore, the sectional shape of the detection surface can also be detected. Detection of a state wherein the detection surface 1 is defocused from the reference position Z 0 , a state wherein the detection surface 1 is inclined with respect to the reference position Z 0 , and a state wherein the detection surface 1 is defocused and inclined with respect to the reference position Z 0 will be described in detail below with reference to FIGS. 5A to 5C (showing the principle of projection optical system when viewed from the optical axis 20a of the detection optical system shown in FIG. 1A) and FIGS. 6A to 6C (showing slit images formed on the light-receiving slit plate 23 shown in FIG. 1A). When the detection surface 1 is simply defocused from the reference position Z 0 , as shown in FIG. 5A, the center of vibration of the slit image SL crossing the light-receiving slit plate 23 is parallelly moved from P 0 to P 1 due to the vibration of the vibration mirror 22 shown in FIG. 1A in the direction of the arrow, as shown in FIG. 6A. Upon reception of the corresponding portions of the slit image SL by the light-receiving portions 24a 1 , 24a 2 , 24a 3 , . . . , 24a n of the photoelectric transducer 24, a plurality of detection outputs (optical modulation outputs) SD 1 , SD 2 , SD 3 , . . . , SD n , which are equal to each other, are obtained. When these detection outputs are synchronously detected by the detection section 25, the defocus amounts ΔZ of the corresponding portions of the detection surface 1 from the reference position Z 0 can be independently detected. When the detection surface 1 is simply inclined with respect to the reference position Z 0 , as shown in FIG. 5B, the center of vibration of the slit image SL crossing the light-receiving slit plate 23 is inclined from P 0 to P 2 according to an inclination θ 1 of the detection surface 1 due to the vibration of the vibration mirror 22 shown in FIG. 1A in the direction of the arrow. Upon reception of the corresponding portions SLa 1 , SLa 2 , SLa 3 . . . , SLa n of the slit image SL on the detection surface 1 by the light-receiving portions 24a 1 , 24a 2 , 24a 3 , . . . , 24a n of the photoelectric transducer 24, a plurality of detection outputs (optical modulation outputs) SD 1 , SD 2 , SD 3 . . . , SD n , which are different from each other according to the positions (inclinations) at the portions SLa 1 , SLa 2 , SLa 3 , . . . , SLa n of the slit image SL, can be obtained. When these detection outputs are synchronously detected by the detection section 25, the inclination θ 1 of the detection surface 1 with respect to the reference position Z 0 can be finally detected. When the detection surface 1 is defocused by ΔZ and is inclined by θ 2 with respect to the reference position Z 0 , as shown in FIG. 5C, the center of vibration of the slit image SL crossing the light-receiving slit plate 23 is parallelly moved from P 0 to P 3 by the defocus amount ΔZ with respect to the reference position Z 0 , and is inclined from P 3 to P 4 according to the inclination θ 2 of the detection surface 1 due to the vibration of the vibration mirror 22 shown in FIG. 1A in the direction of the arrow. Upon reception of the corresponding portions SLa 1 , SLa 2 , SLa 3 , . . . , SLa n of the slit image SL by the light-receiving portions 24a 1 , 24a 2 , 24a 3 , . . . , 24a n of the photoelectric transducer 24, a plurality of detection outputs (optical modulation outputs) SD 1 , SD 2 , SD 3 , . . . SD n , which are different from each other according to the positions (defocus amounts and inclinations) at the portions SLa 1 , SLa 2 , SLa 3 , . . . , SLa n of the slit image SL, can be obtained. When these detection outputs are synchronously detected by the detection section 25, the defocus amount ΔZ and the inclination θ 2 of the detection surface 1 with respect to the reference position Z 0 can be finally detected. As described above, according to the present invention, since the positions of a plurality of points on the detection surface can be measured at the same time, the defocus amount and the inclination of the detection surface can be sufficiently quickly detected, and the position of the detection surface can be detected with higher accuracy. In order to correct the surface state of the detection surface 1 obtained by measuring the positions of a plurality of points on the detection surface 1 in this manner to the reference position (reference plane) Z 0 , a correction amount calculating means 26 calculates a correction amount on the basis of the detection signals corresponding to the positions of the detection surface 1 detected by the detection section 25, and a drive means 27 moves a correction apparatus 32 on the basis of the correction signal. For example, the correction apparatus 32 moves an XY stage 31, which has a wafer as the detection surface 1 placed thereon, in a direction of an optical axis an AX of the projection lens L, or moves it to correct the inclination of the surface of an exposure region. In the above description, the detection method of a detection surface according to the present invention has been exemplified. When an exposure region of a semiconductor manufacturing apparatus is a detection surface, the following problems are posed depending on pattern structures formed on the detection surface. (A) When patterns having different reflectances, e.g., patterns of an Al (aluminum) layer and a non-Al layer, are patterned on a wafer, the detected light amount considerably changes due to a large difference between the reflectances of the Al and non-Al layers. (B) When both coarse and dense patterns are patterned on a wafer, the dense pattern requires stricter position detection accuracy than that of the coarse pattern. (C) When a stepped structure including high and low portions is present on a wafer, the height of the detection surface varies depending on detection positions due to the stepped structure, and position detection results include errors. (D) When the above-mentioned pattern structures (A) to (C) are present at the same time, the detected light amount changes due to patterns having different reflectances, the coarse and dense patterns require different position detection accuracy levels, and the height of the detection surface varies depending on detection positions due to the stepped structure. Therefore, in order to solve the above-mentioned problems due to the pattern structures, and to cope with a deficient chip (a chip present on a peripheral portion of a wafer, on which a pattern of an exposure region can only be partially transferred), as shown in FIG. 1A, it is preferable to arrange an input means 28 for inputting a map of a pattern based on a design value, which pattern is formed on the detection surface, and a selection means 29 for selecting an optimal one of the portions (SLa 1 , SLa 2 , SLa 3 , . . . , SLa n ) of the projection slit image SL projected on the detection surface 1 on the basis of output information (output signal) from the input means 28. (A) When the projection slit image SL is located on the detection surface 1 on which layers having different reflectances are patterned, the selection means 29 preferably selects a position to be detected by one of the following methods (A1) to (A3). (A1) The selection means 29 instructs the detection section 25 to detect only a portion having a high or low reflectance on the detection surface where the projection slit image SL is located. (A2) The selection means 29 instructs the detection section 25 to independently detect portions having high and low reflectances on the detection surface where the projection slit image SL is located, and to detect an average value of these pieces of detected information. (A3) The selection means 29 instructs the detection section 25 to independently detect portions having high and low reflectances on the detection surface where the projection slit image SL is located, to weight pieces of independently detected information, and to detect an average value of these pieces of detected information. (B) When the projection slit image SL is located on the detection surface where coarse and dense patterns are patterned, the selection means 29 preferably selects a detection position by one of the following methods (B1) and (B2). (B1) The selection means 29 instructs the detection section 25 to detect only a coarse or dense pattern portion on the detection surface where the projection slit image SL is located. (B2) The selection means 29 instructs the detection section 25 to independently detect coarse and dense pattern portions on the detection surface where the projection slit image SL is located, to weight pieces of independently detected information, and to detect an average value of these pieces of detected information. (C) When a stepped structure is formed on the detection surface, the selection means 29 preferably selects a position to be detected by one of the following methods (C1) to (C3). (C1) The selection means 29 instructs the detection section 25 to detect only a high or low portion of the stepped structure on the detection surface where the projection slit image SL is located. (C2) The selection means 29 instructs the detection section 25 to independently detect high and low portions of the stepped structure on the detection surface where the projection slit image SL is located, and to detect an average value of these pieces of detected information. (C3) The selection means 29 instructs the detection section 25 to independently detect high and low portions of the stepped structure on the detection surface where the projection slit image SL is located, to weight two pieces of detected information, and to detect an average value of these pieces of detected information. (D) When the projection slit image SL is located on a region where the above-mentioned pattern structures (A) to (C) are present on the stepped structure of the detection surface, the selection means 29 preferably selects a position to be detected by one of the following methods (D1) to (D6). (D1) The selection means 29 instructs the detection section 25 to detect only a high portion having a high (or low) reflectance of the stepped structure, or a low portion having a low (or high) reflectance of the stepped structure on the detection surface where the projection slit image SL is located. (D2) The selection means 29 instructs the detection section 25 to independently detect a high portion having a high (or low) reflectance of the stepped structure, and a low portion having a high (or low) reflectance of the stepped structure on the detection surface where the projection slit image SL is located, to weight these pieces of detected information, and to detect an average value of these pieces of detected information. (D3) The selection means 29 instructs the detection section 25 to independently detect a high portion having a high reflectance of the stepped structure, and a low portion having a high reflectance of the stepped structure on the detection surface where the projection slit image SL is located so as to obtain first information by weighting pieces of detected information, to independently detect a high portion having a low reflectance of the stepped structure, and a low portion having a low reflectance of the stepped structure on the detection surface where the projection slit image SL is located so as to obtain second information by weighting pieces of detected information, and to detect an average value of the first information and the second information. (D4) The selection means 29 instructs the detection section 25 to detect only a high portion having a dense (or coarse) pattern of the stepped structure, or a low portion having a dense (or coarse) pattern of the stepped structure on the detection surface where the projection slit image SL is located. (D5) The selection means 29 instructs the detection section 25 to independently detect a high portion having a dense (or coarse) pattern of the stepped structure, and a low portion having a dense (or coarse) pattern of the stepped structure on the detection surface where the projection slit image SL is located, to weight these pieces of detected information, and to detect an average value of these pieces of detected information. (D6) The selection means 29 instructs the detection section 25 to independently detect a high portion having a dense pattern of the stepped structure, and a low portion having a dense pattern of the stepped structure on the detection surface where the projection slit image SL is located so as to obtain first information by weighting pieces of detected information, to independently detect a high portion having a coarse pattern of the stepped structure, and a low portion having a coarse pattern of the stepped structure on the detection surface where the projection slit image SL is located so as to obtain second information by weighting pieces of detected information, and to detect an average value of the first information and the second information. A deficient chip, where only a portion of an exposure region is present, may often be present on a peripheral portion of a wafer as the detection surface 1. In this case, the selection means 29 may instruct the detection section 25 to detect a position of only a necessary portion to be exposed. The above description exemplifies some examples of methods to be selected by the selection means 29 according to the pattern structures on the detection surface. However, the present invention is not limited to these methods. For example, on the actual detection surface 1, a pattern structure having different reflectances, a pattern structure including both coarse and dense patterns, a stepped pattern structure, and the like are arbitrarily present. In this case, it is preferable that the selection means 29 properly selects the light-receiving portions (24a 1 , 24a 2 , 24a 3 , . . . , 24a n ) at a plurality of proper positions on the photoelectric transducer 24, and instructs the detection section 25 to weight and detect the position signals at the selected positions. In this manner, an optimal average surface can be detected in the direction of thickness of the detection surface without being influenced by the pattern structures at all. In order to increase a position detection speed, it is preferable that the selection means 29 properly selects only pieces of position information of the detection surface corresponding to proper positions. Alternatively, the light-receiving portions (24a 1 , 24a 2 , 24a 3 , . . . , 24a n ) on the photoelectric transducer 24 may be simultaneously detected in units of n portions. Furthermore, the arrangement of the selection means 29 may be omitted. In this case, information (data), which designates only a plurality of proper positions in consideration of the above-mentioned pattern structures on a wafer as the detection surface, is input in advance to the input means 28, and the detection section 25 may detect a plurality of predetermined positions on the detection surface on the basis of an instruction from the input means 28. The second embodiment of the present invention will be described below. FIGS. 7A and 7B show the schematic arrangement of the second embodiment. The same reference numerals in FIGS. 7A and 7B denote members having common functions to those in the first embodiment. A difference between the first and second embodiments is that, in the latter, a transmittance variable member 41 (partial light extraction means) having a plurality of linearly arranged electrochromic elements (to be referred to as ECDs hereinafter) serving as transmittance variable portions, a focusing lens 42, and a photoelectric transducer 43, which are arranged behind a light-receiving slit plate 23 to be adjacent to each other, are arranged in place of the photoelectric transducer 24 having the plurality of light-receiving portions. With this arrangement, an image SL of a projection slit plate 13 projected by a projection objective lens 14 onto a detection surface 1 is refocused on the light-receiving slit plate 23 by an imaging objective lens 21, and light transmitted through the transmittance variable member 41 is focused on the photoelectric transducer 43 by the focusing lens 42. FIG. 8A is a plan view showing the light-receiving slit plate 23 and the transmittance variable member 41 arranged adjacent to the slit plate 23 on the side of a light source, and FIG. 8B is a side view of FIG. 8A. ECDs 41a 1 , 41a 2 , 41a 3 , . . . , 41a n of the transmittance variable member 41 are arranged in correspondence with portions SLa 1 , SLa 2 , SLa 3 , . . . , SLa n of slit light SL projected on the detection surface 1, and a projection slit image SL formed on the light-receiving slit plate 23. The transmittance variable member 41 is electrically controlled so as to be able to selectively decolor one ECD to increase its transmittance, and to be able to color the remaining ECDs to have a transmittance of almost zero. For this reason, when the transmittance of only the ECD 41a 1 is increased, only light reflected by the portion SLa 1 of the slit light SL projected on the detection surface can be received by the photoelectric transducer 43, and the position of the portion SLa 1 of the slit light SL projected on the detection surface can be detected. Therefore, when a position where the transmittance of the ECD of the transmittance variable member 41 is to be increased is sequentially changed, the positions of the individual portions (SLa 1 , SLa 2 , SLa 3 , . . . , SLa n ) of the slit light SL projected on the detection surface 1 can be sequentially and selectively detected. The second embodiment comprises an input means 28 and a selection means 29 in the same manner as in the first embodiment, and a selection signal selected by the selection means 29 is transmitted to the transmittance variable member 41. The transmittance variable member 41 selectively and sequentially changes the position, where the transmittance of the ECD in the transmittance variable member 41 is to be increased, on the basis of this selection signal, so that the light intensity distribution of reflected light at different positions on the detection surface, on which the slit light is projected, can be sequentially detected by the photoelectric transducer 43. The sequentially detected output signals are subjected to signal processing by a synchronous detection method in a detection section 25 like in the first embodiment, and the positions at a plurality of selected points on the detection surface 1 can be detected. In this embodiment, since the selection method of the selection means, and the arrangement and operation for correcting the detection surface to a correct position are the same as those in the first embodiment, a detailed description thereof will be omitted. Weighting values may be set in accordance with the positions of points to be detected, and the transmittances of the ECDs (41a 1 , 41a 2 , 41a 3 , . . . , 41a n ) may be changed in accordance with the weighting value, so that light reflected by the detection surface is detected by the photoelectric transducer 43 in a single detection. In this manner, the detection signal can be equal to one obtained by weighting and averaging signals at the respective detection points, and arithmetic operations can be omitted. With the above arrangement, the second embodiment can also attain the same effects as that in the first embodiment. The third embodiment of the present invention will be described below. FIGS. 9A and 9B show the schematic arrangement of the third embodiment, and the same reference numerals in FIGS. 9A and 9B denote members having common functions to those in the first embodiment. A difference between the second and third embodiments is that, in the latter, a transmittance variable member 41 (partial light extraction means) having a plurality of ECDs (41a 1 , 41a 2 , 41a 3 , . . . , 41a n ) is arranged at a position at the light source side adjacent to a projection slit plate 13, instead of at a position adjacent to a slit plate 23. FIG. 9A is a plan view showing the projection slit plate 13, and a transmission variable member 51 arranged adjacent to the slit plate 13, and FIG. 9B is a side view of FIG. 9A. ECDs 51a 1 , 51a 2 , 51a 3 , . . . , 51a n of the transmittance variable member 51 are arranged in correspondence with portions SLa 1 , SLa 2 , SLa 3 , . . . , SLa n of slit light SL projected on a detection surface. The member 51 is electrically controlled so as to be able to selectively decolor one ECD to increase its transmittance, and to be able to color the remaining ECDs to have a transmittance of almost zero. For this reason, when the transmittance of only the ECD 51a 1 is increased, only the portion SLa 1 of the slit light SL to be projected onto the detection surface is projected on the detection surface 1, and only the corresponding reflected light component is received by a photoelectric transducer 43, thereby detecting the position of the portion SLa 1 of the slit light SL projected onto the detection surface 1. Therefore, when a position where the transmittance of the ECD of the transmittance variable member 51 is changed is selectively and sequentially changed, the corresponding portion of the slit light SL to be projected onto the detection surface 1 is selectively projected onto the detection surface 1, so that the projected light components are sequentially projected onto different positions on the detection surface 1. When the reflected light components are sequentially detected, a plurality of positions on the detection surface on which light is selectively and sequentially projected can be detected. In this embodiment, since the selection method of a selection means, and the arrangement and operation for correcting the detection surface to a correct position are the same as those in the first and second embodiments, a detailed description thereof will be omitted. With the above arrangement, the third embodiment can also attain the same effects as that in the first and second embodiments. In this manner, as has been described in the second or third embodiment, some of light components passing through the slit plate 13 or 23 arranged at a position conjugate with the detection surface 1 are caused to pass according to the position relative to the slit plate 13 or 23, so that the positions at a plurality of selected points on the detection surface 1 can be detected. Therefore, according to the present invention, liquid crystal elements may be used in place of the ECDs constituting the transmittance variable member. Furthermore, the same effect can be expected when light is mechanically shielded to extract some of light components passing through the slit plate 13 or 23. In this case, the following arrangement is preferable. That is a light-shielding member having a small rectangular or circular opening portion is arranged near the slit plate 13 or 23, and is vibrated in the longitudinal direction of the slit plate 13 or 23. Note that a plurality of parallel slit-like opening portions may be formed in the projection slit plate 13, and a plurality of parallel slit-like opening portions of the light-receiving slit plate 23 and detectors may be parallelly arranged in correspondence with the opening portions of the slit plate 13. Thus, since light including position information at more points on the detection surface can be detected, position detection with higher accuracy can be attained. A pattern having directivities in two orthogonal side directions of an exposure region 1a is often formed on a rectangular exposure region on a wafer as the detection surface 1. It is preferable to eliminate the influence of scattered light produced by this pattern for detection accuracy. For this purpose, as a preferable method of projecting a pattern image SL of the projection slit plate 13, the pattern image SL of the projection slit plate 13 is projected onto one diagonal of the rectangular exposure region. Furthermore, the optical axes of optical systems of two surface position detection apparatuses may be arranged to cross each other at the center of the detection surface, so that two projection slit images SL 1 and SL 2 can be projected on the two diagonals of the rectangular exposure region as the detection surface. Then, position detection at more measurement points on the entire two-dimensional detection surface can be realized. As a result, position detection with higher accuracy can be attained. More specifically, since the inclination of the exposure region on the wafer can be two-dimensionally measured, inclination correction (leveling) for causing the exposure region on the wafer to coincide with an image plane of the projection lens L can be performed, and the position detection accuracy on the entire exposure region on the wafer can be guaranteed. When exposure is performed for each chip on a wafer as the detection surface 1, even when the chip size (the size of an exposure region) is changed, multi-point position detection of the detection surface can be attained. For example, as shown in FIG. 10, two slit light beams SL 1 and SL 2 are projected onto the diagonals of a chip CS 1 having an M×N size, and multi-point position measurement along the diagonals of the chip CS 1 is performed. Even when an exposure operation of the M×N size chip CS 1 is switched to an exposure operation of an m×n size chip CS 2 smaller than the M×N size chip CS 1 , portions indicated by hatching of the two slit light beams LS 1 and SL 2 can always cover the m×n size chip CS 2 . Therefore, position measurement at a plurality of points on the m×n size chip CS 2 can be performed, thus attaining position detection with high accuracy. In this case, it is preferable that map data for chips having different sizes are input in advance to the input means, and the selection means instructs the detection section 25 to measure the positions of a plurality of proper positions within a reduced exposure region. Even when slit light is projected onto the detection surface in one direction, a change in chip size can be accommodated, as a matter of course. Even when a plurality of chips are exposed on a wafer as the detection surface 1 at the same time, the present invention can attain position detection at a plurality of points on the detection surface. For example, as shown in FIG. 11, even when two chips CS are juxtaposed in a rectangular exposure region 1a as the detection surface, portions indicated by hatching of two slit light beams SL 1 and SL 2 projected onto the diagonals of the exposure region 1a can cover these two chips CS. Therefore, since position measurement on a plurality of points on the chips CS can be performed, accurate position detection can be attained. Even when slit light is projected onto the detection surface in one direction, the present invention can accommodate a case wherein a plurality of chips are exposed at the same time. In order to eliminate the influence of thin film interference caused by a resist coated on a wafer as the detection surface, it is preferable that the light source 11 emits multi-wavelength light. An example of a combination of the surface position detection apparatus according to the present invention described above, and a surface position detection apparatus for detecting average plane information of the entire detection surface (to be referred to as a surface inclination detection apparatus hereinafter) will be described hereinafter. The arrangement of the surface inclination detection apparatus for detecting average plane information of the overall detection surface will be described below with reference to FIG. 12. As shown in FIG. 12, an inclination detection projection optical system 60 comprises a light source 61, a condenser lens 62, a diaphragm 63 having a small circular opening portion, and a projection objective lens 64. The condenser lens 62 forms an image of the light source 61 on the diaphragm 63, and a parallel light beam is supplied onto a wafer as a detection surface 1 by the projection objective lens 64 having a focal point on the diaphragm 63. An inclination detection imaging optical system 70 comprises an imaging objective lens 71, and a four-split light-receiving element 72. The parallel light beam supplied from the projection optical system 60 and reflected by the surface of the wafer 1 is formed by the imaging (or light-receiving) objective lens 71 on the four-split light-receiving element 72 arranged at the focal point position of the imaging objective lens 71. An optical axis 60a of the projection optical system 60 is symmetrical with an optical axis 70a of the imaging optical system 70 with respect to an optical axis Ax of a projection lens L. Therefore, a light beam from the projection optical system 60 is imaged at the center of the four-split light-receiving element 72 as long as the exposure region of the wafer 1 is perpendicular to the optical axis Ax of the projection lens L. When the exposure region of the wafer 1 is inclined by θ from the perpendicular state, a parallel light beam from the projection optical system 60 and reflected by the wafer 1 is inclined by 2 θ with respect to the optical axis 70a of the imaging optical system, and the light beam is focused at a position separated from the center on the four-split light-receiving element 72. In this manner, an average inclination amount of the exposure region of the wafer 1 can be detected on the basis of the position of the focused point on the four-split light-receiving element 72. FIG. 13 shows a state of the detection surface upon combination of the surface inclination detection apparatus shown in FIG. 12, and the surface position detection apparatus according to the present invention shown in FIGS. 1A, 1B, 7A, 7B, 9A, and 9B. The following description is made with reference to FIG. 13. A projection slit image SL is projected by the surface position detection apparatus on one diagonal of an exposure region (one shot region) 1a on the wafer 1 as the detection surface, and a parallel light beam is radiated by the surface inclination detection apparatus on a circular region D inscribing (or circumscribing) the exposure region 1a on the wafer 1 from a direction different from the projection direction of the projection slit image SL. In this manner, the surface position detection apparatus can perform position detection at a plurality of points in one diagonal direction, and the surface inclination detection apparatus can detect an average inclination of the exposure region 1a. The surface state of the two-dimensional exposure region 1a can be detected with high accuracy. Furthermore, as shown in FIG. 14, two surface position detection apparatuses may be arranged so as to be able to project projection slit images SL 1 and SL 2 onto two diagonals of the exposure region (one shot region) 1a on the wafer 1, and a parallel light beam may be radiated onto the circular region D inscribing (or circumscribing) the exposure region 1a on the wafer 1 from a direction different from the projection directions of these projection slit images SL 1 and SL 2 . As a result, the surface state of the two-dimensional exposure region 1a can be detected with higher accuracy. As shown in FIG. 15, the surface position detection apparatus and the surface inclination detection apparatus may be arranged using some common components so as to simplify the overall structure. In FIG. 15, the same reference numerals denote the same parts having the same functions as those in FIGS. 1A and 1B and FIG. 12. More specifically, in the apparatus shown in FIG. 15, first and second dichroic mirrors 10M' and 20M' are respectively arranged in place of the first and second reflection mirrors 10M and 20M in the surface position detection apparatus shown in FIG. 1A, and projection objective lenses 14' and 64 and imaging objective lenses 71 and 21' are arranged with the two dichroic mirrors 10M' and 20M' therebetween. A light source 61, a condenser lens 62, and a diaphragm 63 of a projection optical system of the surface inclination detection apparatus are arranged in the transmission direction of the first dichroic mirror 10M', and a four-split light-receiving element 72 is arranged in the transmission direction of the second dichroic mirror 20M'. With this arrangement, first wavelength light from a light source 11 propagates through a condenser lens 12, a projection slit plate 13, the projection objective lens 14', the first dichroic mirror 10M', and the projection objective lens 64, and an image SL of the projection slit plate 13 is projected onto an exposure region of a wafer 1. Thereafter, the light from the light source 11 reflected by the surface of the wafer 1 reaches a light-receiving element 24 through the imaging objective lens 71, the second dichroic mirror 20M', a vibration mirror 22, and a light-receiving slit plate 23, and position detection can be attained based on a plurality of output signals SD 1 , SD 2 , SD 3 , . . . , SD n from the light-receiving element 24. On the other hand, light from the light source 61, which supplies second wavelength light different from the first wavelength light from the light source 11, is converted into a parallel light beam to be radiated onto a circular region D inscribing (circumscribing) the exposure region of the wafer 1 through the condenser lens 62, the diaphragm 63, the first dichroic mirror 10M', and the focusing objective lens 64. Thereafter, the parallel light beam reflected by the exposure region of the wafer 1 is focused on the four-split light-receiving element 72 through the imaging objective lens 71, and the second dichroic mirror 20M', and an average inclination of the overall exposure region of the wafer 1 can be detected according to an output signal from the four-split light-receiving element 72. In this apparatus, the optical systems are arranged, so that their optical axes extend along one diagonal direction of the exposure region 1a of the wafer 1. Thus, inclination and multi-point position detection of the exposure region 1a can be attained, as shown in FIG. 13. Furthermore, when the surface position detection apparatus shown in FIG. 1 is arranged along the other diagonal direction of the exposure region 1a of the wafer 1, inclination and multi-point position detection of the exposure region 1a can be attained, as shown in FIG. 14. In FIG. 15, the dichroic mirrors 10M' and 20M' are employed. However, these mirrors may be replaced with half mirrors. In this case, the light source 61 preferably supplies light having the same wavelength as that from the light source 11.

In an exposure apparatus and method utilizing a projection system, a surface state relating to an exposure area of the projection system is determined by illuminating the exposure area with light, receiving light from the exposure area, designating positions of a plurality of detection points in the exposure area in accordance with a size of the exposure area, and detecting, based on information of received light corresponding to the plurality of detection points, positions related to the plurality of detection points.

CLAIM OF PRIORITY This application claims the benefit of U.S. Provisional Application Ser. No. 60/244,492, entitled “Intelligent CAD Objects Technology”, filed Oct. 30, 2000. This application also claims the benefit of U.S. Provisional Application Ser. No. 60/246,275, entitled “Intelligent CAD Objects”, filed Nov. 6, 2000. This application claims the benefit of U.S. Provisional Application Ser. No. 60/244,457, entitled “Item Data Integration System And Method”, filed Oct. 30, 2000. This application also claims the benefit of U.S. Provisional Application Ser. No. 60/246,276, entitled “Item Data Integration System And Method”, filed Nov. 6, 2000. This application claims the benefit of U.S. Provisional Application Ser. No. 60/244,493, entitled “Tracking Modules For Specified Objects”, filed Oct. 30, 2000. This application claims the benefit of U.S. Provisional Application Ser. No. 60/244,485, entitled “Module For Publishing Reports On Intelligent Object”, filed Oct. 30, 2000. LIMITED COPYRIGHT WAIVER A portion of the disclosure of this patent document contains material to which the claim of copyright protection is made. The copyright owner has no objection to the facsimile reproduction by any person of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office file or records, but reserves all other rights whatsoever. CROSS-REFERENCE TO RELATED APPLICATIONS This application relates to application Ser. No. 09/557,641 filed on Apr. 25, 2000, entitled “Agent Based Purchasing System” and naming Thomas A. Wucherer as inventor, the application being incorporated herein by reference in its entirety. This application relates to application Ser. No. 09/519,935 filed on Mar. 7, 2000, entitled “Integrated Business System for the Design, Execution and Management of Projects” and naming Cherisse M. Nicastro, Thomas A. Wucherer, Todd Nisbet and Anthony A. Marnell II as inventors, the application being incorporated herein by reference in its entirety. This application relates to U.S. patent application Ser. No. 10/021,661 filed on Oct. 30, 2001, entitled “Intelligent Object Builder” and naming Thomas A. Wucherer, Cherisse M. Nicastro, Anthony A. Mamell II and Anthony A. Marnell III as inventors, the application being incorporated herein by reference in its entirety. The present application is related to U.S. patent application Ser. No. 10/020,552 filed on Oct. 30, 2001, entitled “Business Asset Management System”, and naming Cherisse M. Nicastro, Thomas A. Wucherer, Todd Nisbet, Anthony A. Marnell II, Anthony A. Marnell III, and Herman Spencer, Jr., which patent application is incorporated by reference herein in its entirety. This application relates to U.S. patent application Ser. No. 10/016,615 filed on Oct. 30, 2001, entitled “Business Asset Management System Using Virtual Areas” and naming Cherisse M. Nicastro, Thomas A. Wucherer, Todd Nisbet, Anthony A. Marnell II, Anthony A. Mamell III, and Herman Spencer Jr. as inventors, the application being incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to integrating business management functions, and more particularly to an item data management system for use in the design and build industry to manage the lifecycles of items used in a project. 2. Description of the Related Art Designing and building an asset is a complicated and long process that requires the diverse services of many participants. These project participants may include architects, structural engineers, mechanical engineers, electrical engineers, interior designers, etc. (often referred to as disciplines) who are responsible for creating the design plans for the project. The project participants may include a purchasing agent or purchasing department that is responsible for purchasing items (e.g., furniture, fixtures and equipment, etc.) for integration into the project, as well as other individuals and entities, including but not limited to vendors and material manufacturers who provide items required to complete the project. Contractors and subcontractors actually build the project according to the design plans, which may include architectural drawings. Expeditors track and route purchased items to the site when needed by contractors and subcontractors. The project participants may further include accountants who are responsible for tracking the project's fiscal budget and paying for items purchased. A project manager may manage the participants, approving some or all changes to the project requested by the participants. Additionally, the project owner may participate to ensure that the project meets his or her requirements from initial conception through completion. A project typically involves many phases including design and build. These phases often overlap and each is highly dynamic. The design phase usually starts with one or more designers creating conceptual drawings of the project according to a developer's direction. The drawings generally include perimeter lines representing specific areas (e.g., restaurants, rooms, lobbies, offices, etc.) within the project. The drawings may also include graphical representations of items within the specified areas. For example, an architect may create a drawing of a restaurant area of a hotel/casino project. The restaurant drawing may include graphical representations of furniture, fixtures, and equipment (FF&E) such as tables, windows, ovens, refrigerators, a backup power generator, etc. The initial drawings, once completed, are provided to several other project participants involved in the design and build process. For example, the restaurant drawing example above may be provided to one or more structural engineers, mechanical engineers, electrical engineers and interior designers for their review, modification, and/or supplementation. These project participants may add further graphical representations of items to the initial set of drawings. An interior designer of the project may wish to add graphical representations of additional items such as chairs or art work to a dining room sub-area of the example restaurant drawing above. A structural engineer may also seek to add graphical representations of items to the restaurant drawing such as a platform on which the backup power generator (graphically represented in the drawing) rests. When project participants (e.g., engineers, interior designers, etc.) receive initial drawings of the project, the drawings give very little information about the items graphically represented. Typically, the drawings simply identify the items by title or type (e.g., “a table,” “a window,” “a backup power generator”). The engineers, interior designers, and other project participants further define or specify the characteristics or attributes of items originally contained in the drawings or items added to the drawings. The engineers or designers sometimes annotate specification information on the drawings, but often the engineer or designer creates a separate specification for each item graphically represented on the drawing. For example, an interior designer may create a separate specification for each type of chair graphically represented in the restaurant drawing. Each item specification contains descriptive information (such as size, material and finish, etc.) regarding a type of chair, and may reference other specifications such as fabric. Likewise, an electrical engineer may, for example, create a separate specification for the graphically represented backup power generator describing, for example, the generator's size, power generation capacity, weight, and other attributes. In addition to providing specifications for items contained on drawings, there are times when drawings are not created or items are not contained on a drawing which is created, but there are still specifications for items required. For instance, in the above restaurant example is remodeled, specifications for new furnishings may be created without a drawing. Alternately the designer may provide an item schedule which list many like items and their distinguishing characteristics or referenced items. FIG. 1 includes an example of a specification for an item to be included as part of a project. An interior designer developed this specification for an entertainment center to be included in the living room of a suite of a hotel project. Portion 110 of the specification includes general information about the specification, such as a specification number, and the area and project into which the item will be incorporated. Portion 120 includes manufacturer information, distributor information, a description of the item, the dimensions of the item, manufacturer catalog information and the manufacturer catalog description. Portion 130 describes the quantity of the item to be ordered, price information, and budget information for the item. Portion 140 indicates information about receiving a sample of the item, and portion 150 includes information about the finish for the item. Portion 150 also includes notes about the finish, notes about the interior dimensions, and a note that the specification was issued to the purchasing department on May 26, 1998. Portion 160 includes an image of the entertainment center. Portion 170 shows information about other specifications providing information about the entertainment center. Not all portions 110 through 160 are included as part of every specification, and specifications may have portions describing other information not shown. Other item specifications may contain different data or sections of information. For instance, Portion 120 may list the color, weave, repeat, and pattern for a fabric. The details required are identified by the type of item (e.g., hard furniture, upholstered furniture, fabric, oven, sink, faucet, chiller, etc.) Each of these types will have different characteristics or attributes to be described to differentiate like items. The type of item also may require references to other specifications required for an assembly. For example, furniture may reference fabric and paint while chillers may reference piping and pumps. Attributes and required references must be defined in templates for each type of item specification. Engineers and designers normally employ software applications for generating specifications for project items for which they have responsibility. These software applications generate electronic versions of specifications into which engineers or interior designers enter descriptive information. Engineers or designers usually enter a reference to a graphical representation in a drawing into the appropriate each specification so that the specification can be associated with an item represented on the drawing. The electronic specifications may be organized as flat files, templates, spreadsheets, or word-processing documents. Once the engineers or designers finish writing a an item's specification, the specification is ready to be provided or “published” to other project participants for review, modification, supplementation, and/or approval. The engineer or designer can send the specification as e-mail attachments if the recipient has a computer system with appropriate software applications for accessing the attachments. Alternatively, copies of the specification may be printed and distributed. The author saves one copy as the original specification in electronic version form, hard copy form, or both, for archiving purposes. Except for the graphical reference in the specification, specifications are forwarded to other project participants disassociated from their corresponding drawings. One or more revisions to item specifications may occur throughout the process. Indeed, revisions to an item specification can occur even after the corresponding item is purchased. In this latter case, the purchased item would normally be located and returned to its manufacturer, and the purchase price may be refunded, in whole or in part. Specification revisions may occur for a variety of reasons by a variety of project participants. For example, the project owner, upon receipt of a specification for one of the restaurant chairs, may desire the chair color to be different than originally specified or determine that the chair as originally specified is too expensive. Another interior designer for the project, upon receipt of the same specification for the restaurant chair, may notice that the originally specified fabric did not include fire treatment in accordance with local fire codes. The structural engineer, upon receipt of the specification for the backup power generator, may notice that his platform may not support the weight of the backup generator specified by the electrical engineer. Each reason for revision is communicated to the original author who, in response, revises the specification accordingly. Once revised, the specification is re-distributed to other project participants for further review, modification, supplementation, and/or approval. The author of the original specification has the responsibility for maintaining a history of all revisions to the specification. The author also has the responsibility to ensure that all necessary project participants have the most recent version of the specification. Once a specification for an item has been approved by all the necessary project participants, it may be submitted to the project's purchasing agent. The purchasing agent, in turn, may create a purchase order for the item using information from the specification. An example of a purchase order for several items, including the entertainment center of FIG. 1 , is shown in FIG. 2 . Page 1 of the purchase order shows the entertainment center of FIG. 1 as item 1 , page 2 shows orders for other items 2 - 5 , and page 3 shows general notes for the purchase order. The purchasing agent, like the project engineers and interior designers, may employ a computer system executing specialized software for generating a purchase order. Typically, the purchasing agent manually transfers specification information into the purchase order, as shown in FIG. 2 . The purchasing agent subsequently sends the purchase order to manufacturers via hard copy or e-mail attachment. The purchasing agent also sends a copy of the purchase order to the project's accountant. Coordinating communication of information regarding items in a construction project becomes more complex as the scale of the project increases. Collaboration and the exchange of information, including drawings and item specifications, between design and build participants also increase the complexity of each project. Effective and efficient collaboration is often the single most important key to bringing a project to fruition in a quality, timely and cost effective manner. However, as more fully exemplified above, collaboration and information exchange between participants, is typically a paper-based and chaotic process. Furthermore, it is difficult to determine the history of an item based upon the papers residing at different project participants. Managing change throughout the life cycle is also difficult in a paper-based or disparate application-based process. Decisions are not always based on all information available, for instance, an owner may choose not change the color of a fabric if the owner had known that the fabric had already been purchased and that a restocking fee would apply. What is needed is an item data management system that will integrate data throughout the item's lifecycle. Data from the separate applications should be presented as an integrated whole to users of the item data management system. An item data management system that is capable of providing budgeting, design specification, CAD drawings, purchasing, bid processing, receiving, invoicing, location, and maintenance data, or other processes in the item's lifecycle, about an item is desirable. Integrated data allows change management throughout the process. For example, designers may wish to be notified if they are deleting an item from a drawing that has already been purchased; Specifiers may wish to be notified if they are exceeding the approved budget for an item; Purchasing Agents may wait to purchase items if they know there is a revision in progress; Maintenance personnel may want to know when preventative maintenance is required or a warrantee for an item is expired; etc. The rules for managing these changes and notifications should be configured by project participants. SUMMARY OF THE INVENTION The invention, roughly described, comprises a method for constructing and managing data concerning items of an asset. In one aspect, the method comprises: providing a user data entry interface; receiving a plurality of data values, each into a data field of the interface, wherein the plurality of data fields comprise a specification for the item and each data field of the specification describes an attribute of the item, and storing the specification into a database on a computer system. In a further aspect, the invention comprises a data structure stored in a data store. The data structure includes a plurality of data values comprising an item specification provided in a plurality of data fields describing an item. The data fields may include at least one attribute value, at least one component value; and at least one allocation value. In a further aspect, the attribute is one of a group consisting of the following: a physical attribute of the item; and a functional attribute of the item. In still a further aspect the system tracks an item specification's references and required quantities of other specifications required for an assembly. In an additional aspect, the system regulates the project participants who can perform an action (e.g., view, modify, revise, publish) by the items status and discipline. In an additional aspect, they system allows project participants to link areas of the project to the item specification. In another aspect, the system routes an item for approval and publishing the item to project participants. In a supplementary aspect, the system tracks the history of changes to an item specification. In yet another aspect, the system provides change management to project participants notifying them when specific actions occur as defined by user set business rules. In yet another aspect, the step of providing occurs on a first computer and said step of storing occurs on a second computer. The computers can be coupled by a network, which in one embodiment is the Internet. In another aspect, the data interface comprises a template creation tool, a specification creation tool, and a specification management tool. In a further embodiment, the invention is a method of allowing users to manage an asset. The method includes the steps of providing an application server coupled to a network; providing, responsive to a client request, an item specification management toolset including at least one template definition application; and receiving data from the client and storing it in a database. In still another embodiment, the invention is a system for defining and managing an asset. The system includes a data store for item specification data provided on a host computer coupled to a network; and a data input toolset comprising at least an item type manager and an item specification manager. In another aspect, the system may include an item specification publisher and an item specification schedule builder. The data store may be provided on the host computer and the data input toolset is provided to a second, client computer. In another aspect the host computer is coupled to the Internet and the data input toolset is provided to a client computer via the Internet. The present invention can be accomplished using hardware, software, or a combination of both hardware and software. The software used for the present invention is stored on one or more processor readable storage media including hard disk drives, CD-ROMs, DVDs, optical disks, floppy disks, tape drives, RAM, ROM or other suitable storage devices. In alternative embodiments, some or all of the software can be replaced by dedicated hardware including custom integrated circuits, gate arrays, FPGAs, PLDs, and special purpose computers. These and other objects and advantages of the present invention will appear more clearly from the following description in which the preferred embodiment of the invention has been set forth in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described with respect to the particular embodiments thereof. Other objects, features, and advantages of the invention will become apparent with reference to the specification and drawings in which: FIG. 1 shows an example of an item specification to be included as part of a project. FIG. 2 shows an example of a purchase order for an item to be included as part of a project. FIG. 3 shows one example workflow for an item through the item's lifecycle. FIG. 4 shows a block diagram of an item data management system. FIG. 5 shows an example of a specification as a configurable data object. FIG. 6 is a flow diagram illustrating the life cycle of an item specification. FIG. 7 is an illustration of the relationship between item templates and item specifications. FIG. 8 is a depiction of how one embodiment of an item specification manager appears. FIG. 9 is a flow diagram of how Item templates are defined. FIG. 10 is a depiction of how the general properties page of one embodiment of an Item type wizard appears to a user. FIG. 11 is a depiction of how the attributes page of one embodiment of an item type wizard appears to a user. FIG. 12 is a depiction of a screen for entering attributes. FIG. 13 is a depiction of a screen for entering components. FIG. 14 is a depiction of a second screen for entering component information. FIG. 15 is a depiction of a screen for entering preference information and the type of information which may be added at this step in a definition process. FIG. 16 is a depiction of a page for selecting specifications in an item specification management application. FIG. 17 is a flowchart representing a process for specifying an item flow. FIGS. 18A-18M are depictions of the process screens in the flowchart of FIG. 17 . FIG. 19 is a depiction of the schedule building tool process flow. FIG. 20 is a depiction of the specification publishing tool process flow. DETAILED DESCRIPTION The creation of Item Specifications for use in an Intelligent Business Management System described in co-pending U.S. patent application Ser. No. 10/020,552 entitled BUSINESS ASSET MANAGEMENT SYSTEM (TRIRG-01000US0) by Cherisse M. Nicastro, Thomas A. Wucherer, W. Todd Nisbet, Anthony A. Marnell II, Anthony A. Marnell III, and Herman Spencer, Jr. (hereby fully incorporated by reference herein). Specifications are used throughout the life of a project from design, through procurement, execution, and asset tracking. Almost all users of the system shown in the co-pending application will have access to Specifications in some capacity. CAD users can associate Specifications to drawing objects; a purchasing agent scan access the uploaded counts from CAD to determine how many are required and the Project Manager can monitor progress and the budget. The system described in co-pending U.S. patent application Ser. No. 10/020,552 entitled BUSINESS ASSET MANAGEMENT SYSTEM (TRIRG-01000US0) by Cherisse M. Nicastro, Thomas A. Wucherer, W. Todd Nisbet, Anthony A. Marnell II, Anthony A. Marnell III, and Herman Spencer, Jr. (previously incorporated by reference herein) is a design build and management system which incorporates asset data into specifications for use in its system. It includes two data input means: one defined in co-pending U.S. patent application Ser. No. 10/021,661 entitled INTELLIGENT OBJECT BUILDER (TRIRG-08851US0) by Thomas A. Wucherer, W. Todd Nisbet, Anthony A. Marnell II, and Anthony A. Marnell III (hereby fully incorporated by reference herein) and the Item Specification Tool set described herein. The Item Specification Tool set is an independent application for creating intelligent objects without using a CAD system. The following terms will be used throughout the specification and are defined as follows: Attribute: A quality of characteristic inherent in or ascribed to an item specification. CAD: Acronym for “Computer-aided design.” Computer-aided design software is used by architects, engineers, drafters, artists and others to create precision drawings or technical illustrations. CAD software can be used to create two-dimensional (2-D) drawings or three-dimensional (3-D) models. Classification: The system of the present invention recognizes classifications as a category or class of item types . The classification tree displays the classes in a hierarchal fashion. Company: An organization or group that performs services or provides products within the system. A business enterprise; a firm. Individual company defaults and standards revolve around a company. Company Administrator: The first user for any company. This user is responsible for setting up licensing, company information, company defaults, users, vendors, and so forth. Component: The system supports components as a part of an Item Specification. A component is an existing Item Specification associated to another item specification; together, they make up a whole item or an assembly. An Item Specification can have multiple components. Document Set: A special type of folder in the Collaboration tool. A document set allows a user to group together any number of files into a common set. The actual files are stored in separate folders organized in whatever manner suits the user. The contents of the document set folder are merely shortcuts, or pointers, to the actual files. Only one copy of any given file needs to be maintained. Item Specification: The detail information about objects involved in building the parts and components of something. An example of an item would be a desk; an example of the item specification would be the description of the desk (height, width, depth, color, material, and so forth), its manufacturer(s), costs, delivery options, catalog numbers, and so forth. Item Type: A template for creating item specifications for broad categories of items. For example: a user might have an item type of “office furniture,” this item type forms a template a user would use to create the many item specifications for various desks required. Project: A plan or proposal; a scheme or undertaking requiring concerted effort. The system of the present invention allows any plan with more than one task to be considered as a project. Property: The base organizational point for the activities of a Company within the present system. The property is the larges hierarchal space in one or more virtual areas. The “Property” label may be customized using the Nomenclature options in Company Defaults. Qualification: The Qualification process is the act of ensuring that a company is suitable to perform work or provide materials for a specific project. The system provides the ability to qualify vendors and/or services before bidding and purchasing. Qualification is an information gathering process that can be used for screening purposes. Schedule: A schedule is a list of specified items, a reference number, a version number and the item status information. The system provides the ability to generate schedules, either by type or instance, for the entire project or specific virtual areas. The foregoing terminology is used herein for convenience in understanding the present invention. It should be understood that the aforementioned definitions are not intended as limiting the scope of the present invention to the particular terms which are defined. Other nomenclature may be used to represent the concepts and substance of the foregoing definitions. In understanding the tool set of the present invention, it is helpful to understand data flow in a project. FIG. 3 shows an example data flow for an item through several stages of an item's lifecycle. A project participant 312 originally provides a budget 330 for the project. From the budget 330 , different project participants produce specifications such as specification 332 for items to be purchased. The purchasing department 316 optionally may produce a bid package 334 from the specification to obtain bids for an item to be purchased. Subcontractors and vendors, among others, such as subcontractor 314 , submit bid responses such as bid response 336 to the purchasing department 316 . Purchasing department 316 decides to which subcontractor or vendor a contract 337 or purchase order to provide the item should be awarded. Contract 337 is communicated to project accountant 310 and project manager 320 . Each of project account 310 and project manager 320 may use respective computer system(s) (not shown) for managing different types of data associated with an item. Upon awarding contract 337 or directly upon receiving specification 332 , purchasing department 316 may produce a purchase order 338 or contract for ordering the item from a seller 318 . Vendor 318 sends the item 340 to the receiving department 322 and an invoice 342 to project accountant 310 . Receiving department 322 sends a receiving list 344 to project accountant 310 and project manager 320 . Receiving department 322 also places item 340 in storage. Storage manager 324 optionally sends item 340 to a warehouse and provides location data 348 to the project manager 320 . From the warehouse, warehouse manager 326 distributes item 340 to the construction site and provides location data 348 to the project manager 320 . Location data 348 regarding the current location of item 324 is provided by warehouse manager 326 to project manager 320 . Alternatively, storage manager 324 may send item 340 directly to the construction site and provide current location data 348 to project manager 320 . Project superintendent 328 then places the item in the appropriate location within the project. The stages of the lifecycle depicted in FIG. 3 include only those stages through the delivery of the item to the site and payment for the item. An item has a life beyond the stages depicted; for example, after being delivered to the site, the item is placed into a location within the project and often used for many years. The scope of the invention includes managing these stages of the lifecycle of the item. The stages shown in FIG. 3 are one example and used for illustration purposes only. As shown in FIG. 3 , many types of data flow to many project participants during the lifecycle of an item used in a project. The term “item data” is used herein to describe collectively these many types of data associated with the lifecycle of the item. Each of the project participants may use one or more application programs to track the different types of item data that he or she receives and/or generates. Often project participants use application programs that are not used by other project participants, so that data is sent via paper from one project participant to another. In such a paper-based system, each project participant manually enters the data into one or more respective application programs. Item data are described herein as objects of an object-oriented framework, although the scope of the invention includes other organizations of item data. For those unfamiliar with object-oriented frameworks, a brief summary is presented here. The building block of an object-oriented framework is an object. An object is defined through its state and behavior. The state of an object is set forth via attributes of the object, which are included as data fields in the object. The behavior of the object is set forth by methods of the object. Each object is an instance of a class, which provides a template for the object. A class defines zero or more data fields to store attributes of an object and zero or more methods. Each data field contains attribute information defining a portion of the state of an object. Objects that are instances of the same class have the same data fields, but the particular attribute values contained within the data fields may vary from object to object. Each data field can contain information that is direct, such as an integer value, or indirect, such as a reference or pointer to another object. FIG. 4 is an overview of the system described in co-pending U.S. patent application Ser. No. 10/020,552 in which the tool set of the present invention may be used. It should be understood, however, that the tool set presented herein has applications outside that of its use in building electronic specifications for use with collaborative tools and in electronic commerce transactions. As shown in FIG. 4 , the system includes an application server providing application toolsets to one or more client computers. The server and computers are coupled by a network, which may be a public network, a private network, or a combination of public and private networks such as the Internet. The toolsets are designed to facilitate the project creation and management by manipulating data describing basic elements of the project stored in at least one database on the application server or a separate database server. FIG. 4 shows the six general types of application toolsets accessible by a client device. Four types of applications support project data entry and modification, while two support system management and utilities. The specific functions of each of these groups of applications are set forth below. Each client device may comprise a personal computer, a thin client or any other type of processing device capable of supporting applications described herein, and the system may be accessed by different types of client devices—such devices need not be personal computers but do need to support the applications provided in the applications toolsets. Applications server 1020 also includes at last one database for property item data managed by the system of the present invention. In FIG. 4 , the databases are organized by property, but such organization is exemplary and not meant as limiting on the system of the present invention. Organization of the databases into one or more other data structures or classifications is contemplated as being within the scope of the present invention. The application toolsets provided in the system include: a Design Toolset 1100 , a Cost Management Toolset, a Project Teamwork Toolset and a Procurement Toolset. The Design Toolset allows users of the system to coordinate data input into the system 1000 . As noted above, data input tools include a CAD Intelligence plug-in agent, the Specification Builder presented herein, and a schedule tool. The Procurement Toolset 1200 includes a Bid/RFQ tool, a Purchase tool, a expediting tool, a shipment notification tool and a receiving tool. The Cost Management Toolset 1400 provides an Estimates tool, Budgeting tool, a Contracting tool, a Payment tool, and an Invoicing tool. Finally, a Project Teamwork Toolset 1600 includes Collaboration Tool, a Request for Information tool and Meeting Minutes tool. Two other sets of applications are provided—an administration tool set 1400 and a utilities tool set 1400 . The system described therein is provided in the context of its implementation in an Application Service Provider (ASP) model. In this context, the ASP model includes providing applications from an application server including databases organized by project or property to a client computer. In this context, an ASP is used to refer to an application server providing applications to a client device, as opposed to those applications which are installed in non-volatile memory on the client device. In one embodiment, the application toolsets may be implemented as a set of applications configured to run in another interpretive application, such as in Internet Browser. The application server 1020 is a server program in a computer in a distributed network that provides the business logic for an application program run on the client computer 1050 . The application server 1020 may comprise a portion of the system which may further include a graphical user interface (GUI) server, an application (business logic) server, and a database and transaction server. In one embodiment, the application server combines or works with a Web (Hypertext Transfer Protocol) server and is called a Web application server. The Web server provides several different ways to forward a request to an application server and to forward back a modified or new Web page to the user. These approaches include, but are not limited to, the Common Gateway Interface (CGI), FastCGI, Microsoft's Active Server Page, and the Java Server Page. In some cases, the Web application servers also support request “brokering” interfaces such as CORBA Internet Inter-ORB Protocol (IIOP) and Enterprise Java Beans. In general, a request, such as an HTTP request, from the client device is made to the application server via the network. If the request is for a particular application, the application will be transmitted to the client, loaded and run by the client by presenting a graphical input/output page to a user. The system is configured to have a “Home Page” and one or many “Project Page(s)” for each user. Representations of exemplary pages are shown in FIGS. 4B and 4C . The project page may be customized to provide any number of the tools, or a subset of the available tools, to the user depending on the level of access granted to the user by the Company Administrator. The project page will contain links to the applications which are accessible to the user, including the Specification Toolset or “Item Specification” Publisher, Type Manager, Manager Schedule Builder and Schedule Reporter, and the data supplying those applications and the applications themselves are provided by the applications server. In addition, security level access to the data is controlled by the application server. In general, data is created in the database by the design toolset applications. Data is stored in the system in the form of “intelligent objects”. When actions (budgeting, purchasing, delivering, maintenance scheduling) occur to that object, by any system user, the “intelligence” of the object is updated with this information. An example of the data which may be used in the system of the present invention is set forth in co-pending U.S. patent application Ser. No. 10/021,661. The data may be stored in a database in any of a number of object, relational or distributed database structures. In one embodiment, the data is organized in a series of name value pairs and relationship tables accessible via XML or SQL. In another embodiment, the data is provided in a relational database with each object represented by a single row of generic columns of attribute data, along with an attribute definition row. In yet another embodiment, the data is organized into object classes and subclasses in an object database. Specification Tools In one example of the present invention, a series of specification tools as provided includes an Item Type Manager, an Item Specification Manager, and Item Specification Wizard, a Specification Publisher and a Schedule Reporter. Item Specifications are defined as database entries that describe an individual object in the project. Any object that can have its own part number (or UPC code) can have its own Specification Number. Specifications can also be assembled from other component items. Item Specifications can also be linked to virtual areas. A virtual area is defined as a spatial representation or work breakdown of an asset which may contain other virtual areas. It should be understood that the specific tools described herein comprise one implementation of the invention and this implementation may be varied within the scope and spirit of the claims without departing from the invention. Item Types, as shown in FIG. 8 , is a term for templates. An Item Type is a way for users to determine which data fields will be required to define the Spec. Item Types are templates for creating item specifications for broad categories of items. The use of Item Types enables one to display all the item types for a selected classification. The system recognizes classifications as an organizational mechanism category or class for item types. The classification tree displays the organization in a hierarchal fashion. Disciplines are used as a category or class of trades, and are used to organize item types and control access. This function allows one to open and display all details of a selected item type. The Item Specification Manager also allows one to copy the attributes of a selected item type to create a new item type with the ability to edit the existing attributes. This process also provides the ability to delete an existing item type that has not yet been used to define an item specification. One may create a new item type for a selected classification by accessing the Item Type Wizard. Throughout the system as described in U.S. patent application Ser. No. 10/020,552, permissions are granted to all users based on their required duties. To work with Specs, several different permissions can be granted. Permissions include the ability to create, publish, revise, list, etc. The Item Type Wizard defines the general properties of the item type, including the type of attributes and components that will need to be specified in the item specification. Attributes are characteristics of the item type that are necessary to define the item specification. Components link item(s) required for the assembly or completion of a particular item specification. The system supports components as a part of an item specification. A component is an existing item specification associated to another item specification that makes up a whole item. For example, a door may require hardware, such as hinges, for completion. The hinge item type is a component of the door item type. Existing item types can be located through a search feature and added as components. This tool allows the user to create rules for the item type that define how a waste factor is calculated for the item, which CAD mark is associated with the item type, whether component cost should be calculated as an associated cost or rolled up into the cost of the original item, and so forth. The preferences defined apply to all item specifications that are created with this item type. FIG. 5 shows an example of the item specification as a configurable data object. Three items are shown, including a chair 510 , a drapery 520 and a fabric 530 . Specifications 512 , 522 and 532 are associated with the three items. Fabric 530 is a sub-item of chair 510 and has its own specification 532 . The drapery is made from the same fabric as the chair and fabric 530 is also a sub-item of drapery 520 . All of these items are specified as part of the guest room furnishings group for the Palazzo Suites area of the project. While each of the specifications 512 , 522 and 532 provides a specification for an item, each has different attributes. For example, the specification object 512 for chair 510 has a finish attribute, which in the example shown has a value of “dark cherry.” In contrast, specification object 522 for drapery 520 has a style attribute with a value of “Roman blinds” and specification object 532 for fabric 530 has a color attribute with a value of “red.” The ability of different specifications to have different attributes provides great flexibility to a user of the item data management system 400 . Standard specifications can be defined when information is to be tracked for many items of a particular type, but a new specification can be defined whenever additional information is needed for an item. FIG. 6 shows a simplified representation of the life of an item specification. In general an item type is created, a Specification is then created from the item type, the Specification is published and the Specification can be procured. Additional detail on the use of specifications can be found in co-pending U.S. patent application Ser. No. 10/020,552. FIG. 7 shows the relationship between item types and Specs. Shown in FIG. 7 is a basic example of a specification. From the one Item Type, two Item Specifications were created. You can create an unlimited number of Specifications from an unlimited number of Item Types. This is done by creating new Specifications and entering different data in the Data Fields. A Specification 604 is created from an existing Item Type template 602 . Once the Specification 604 is created, it is automatically saved with a unique Specification number. When a Specification is considered complete and final, it is then published. Publication is a pre-requisite for use with the procurement tools of co-pending U.S. patent application Ser. No. 10/020,552. Publication also records a copy of the item specification in its history log. As discussed below, if components are required to define part of the Specification, they can be created beforehand or added later. Once a Specification is created in a project, it may be exported to the company level so that it may be used in other properties and projects. Hence, Specifications can have a parent and child relationship. To create an Item type, one must first access the item type manager, shown in FIG. 8 . To create an item type, one must be logged in to a project and have the correct permissions assigned to the role of the user. Many classifications, such as Architectural related classifications, will have default Item Types that are ready for use. The manager screen is divided into different areas. The upper left area 810 displays the project's Classification Tree. This is a directory that will define how the Item Types (and Specs) are organized. The tree is similar to folders used in Microsoft Windows. Users can select folders to expand or collapse items in the tree. When one can no longer expand the tree, the lowest level is the classification entry. If there are custom Item Types listed under this classification, it will be displayed in the frame on the right 820 . FIG. 8 shows an Item Type for the classification for Furniture ( 12500 ) and pick on the text “ 12500 —Furniture”. Shown at 820 is a list of seven default Item Types that have been created for Furniture. The column Type Info indicates that these are all Default Item Types (Type Info=‘D’). It should be noted that default item types are not required. For example, a company may be setup with custom classifications and therefore not have any default Item Types. If this is the case, users need to set up custom types. Selecting to view an Item Type will open the Item Type Wizard, shown in FIGS. 9 and 10 . FIG. 9 is a flow chart showing the creation of an item type using the Type Wizard. Shown in FIG. 10 is an example of the Item Type Wizard page presented to a user. It includes four tabs on the left side of the window which roughly correspond to the steps shown in FIG. 9 . Each Tab opens a new page in which user input is required or optional in setting up a new Item Type. To create a new Item Type, a user selects the “New” button at the bottom of the screen to open the Item Type Manager. At step 902 , the user selects the “General Properties page” and fulfills three sub-steps to create an item type. First the user selects a classification by navigating through the project's classification tree 1025 to find the most suitable classification for the Item Type one is creating. Disciplines are then assigned using the right hand side of the screen at 1035 . A discipline is a broad area of operation with a project. Disciplines (such as Plumbing, Electrical, Architectural, and so forth) are used in later processes to categorize files, item types, item specifications, and to grant or restrict access to information. Disciplines can be reused to group item specifications. Users can be assigned permission to a role to perform tasks within specific disciplines. Finally, data is entered into the lower portion of the screen in FIG. 10 . The Name field 1042 is required and allows one to identify the name of the new item type. This name will appear every time this item type is referenced. The Type Code 1044 field allows one to define the code that will be used to identify this item type. Type Description field 1046 is a brief description or several key words that can be used for searching this item type. The Item Type Unit of Measure field 1048 specifies the measure that will be used for this item type from the available options in the drop-down list. All of the item specifications that use this item type will inherit this unit of measure type. The Default Item Type Unit of Measure 1050 automatically defaults to the corresponding units of measure that relate to the Unit of Measure Type chosen. Finally, the usage selector determines whether this item type will be purchased. Selection of “Purchased” may trigger creation of a number of pre-defined attributes relating to the Manufacturer and Vendor. Next, one moves to the attribute definition step at 904 . Attributes are the data fields that allow one to define how the Item Type will describe the Spec. In the television example, one attribute will be “Brand”. An exemplary attribute definition screen is shown in FIG. 11 . This screen is divided into three areas: the existing data from the previous page at 1110 , the attribute definition area 1120 and the existing attribute list at 1130 . In one embodiment, the system may include a number of predefined attributes. In FIG. 11 , these attributes are divided into two exemplary categories: General and Vendor. Companies may choose to work with one of a number of the industry standard codes available from any number of agencies, including the Construction Specifications Institute (CSI) Masterformat codes and in one embodiment, the default classification tree may be based on these codes. FIG. 12 shows how a first attribute—a brand attribute—is added. The Category field requires one to define a new category or enter an existing one for the attributes. The categories display as rows that contain the attribute fields. The Type field requires one to select the type of attribute to be defined. Available types are: Number, Text, Data Date, Duration, and Currency. A selection in this field changes the amount and type of attribute characteristics. The name field requires one to indicate the name of the attribute. This name displays as the field name when working with the Item Type. The Label field is the label that the user will see as name of the field for the attribute value. This will generally be the same as the Name field, with the exception being when data is the Type. The Comment field allows one to include any applicable comments about this attribute. The Start Row field requires one to identify the placement of the field to contain this attribute. The Row Span field requires one to identify the number of the rows that should appear in the attribute field for data entry (this field defaults to 1). The Default Value field allows one to define the default value which will display in the Item Specification attribute field as the Unit of Measure List. This field allows one to select an applicable unit of measure type for this attribute. This information may differ from the unit of measure type previously selected for the Item Type. The Default Unit of Measure field allows one to define a default unit of measure for this attribute. This Unit of Measure will display as the default when defining this attribute for an item Specification. The Drop List items allow users to specify items to appear as a drop-down list. If left blank, the field will display as a standard text entry field. This field allows one to type the options that should appear in the list. Additional Data Attributes linking the attributes to the system database discussed in co-pending U.S. patent application Ser. No. 10/020,552, if required, may also be provided. In one embodiment, a Type Field option allows one to link the attributes to the database if required. These choices will populate the attribute with “sub-attributes”. Examples of such attributes are: Vendor which allows one to search through a company's vendor list to select a company on record having sub-attributes such as address, city, state, zip, etc. Once the attributes are defined, if the item type uses components, one proceeds to the component definition process at 906 . If the item type does not use components, one proceeds directly to the assignment of preferences. FIGS. 13 and 14 show exemplary screens for adding components to the item type definition. Components are existing Item Specifications associated to another item specification; together, they make up a whole item. An Item Specification can have multiple components. In FIGS. 13 and 14 a new component “Table and Chair Set” is created from components Tables” and “Chairs”, which are themselves existing item types. FIG. 13 shows a page on defining the information for the item type “Tables and Chairs”, while the components are added at FIG. 14 . (In FIG. 14 , only the “Tables” component is shown.) A search function allows users to reveal every item type associated with the current product. Data is entered into the fields shown in FIG. 13 . Fields specified in FIGS. 13 and 14 have the same input data definitions as those shown and described above. At the preferences step 908 , the user is prompted to enter additional information characterizing how the Type will be used in the system of co-pending U.S. patent application Ser. No. 10/020,552. An exemplary preferences page is shown at FIG. 15 , showing the preferences that may be set by a user. The CAD Intelligence Mark Definition field allows one to select from a list of mark definitions that have been uploaded from the CAD Intelligence plug-in, described as an Intelligent Object Builder in co-pending U.S. patent application Ser. No. 10/021,661 to associate to this item type. If there are no mark definitions in the system this field displays “None” as the only option. The Bids, RFQs, or Purchase Orders field allows one to indicate how the default quantity will be calculated for this Item Specification. This is the default quantity that will be used for bids, request for quotes, and purchase orders. The Default Component Cost Behavior filed allows one to select whether the cost of the Item Specifications (should it be a component of another Spec), created with this item type, should be associated with the parent item Specification or not. The Default Waste Factor (per virtual area) field allows one to indicate percentage of estimated waste (based on quantity) that will be included in the quantity and cost calculations. The Default Absolute Waste (per virtual area) field allows one to identify a specific unit amount for each Virtual Area that this Specification will be associated with. Additional functions which may be added to the item type include but are not limited to the following: definition of reporting preferences including the selection of layout per attribute and specification data type; definition of a purchasing agent's ability to modify the requirements of a specification; etc. Item Specification Manager The Item Specification Manager, shown in FIG. 16 enables one to display all the item specifications for a selected classification and item type. A general outline of the functions of the Item Specification Manager is shown in FIG. 16 . This function allows one to open and display all details of a selected item specification. The manager also allows one to copy the attributes of a selected item specification to create a new item and provides the ability to edit the existing attributes. This process also provides the ability to delete an existing item specification that has not yet been published. One may create a new item specification for a selected classification by accessing the Item Specification Wizard. The Item Specification Wizard is explained below. Item Specification Wizard The Item Specification Wizard enables one to assign general properties to the item specification, such as: item specification number, name, physical classification, and item type. After one has created the item specification, one can define other general properties such as the base cost and budget code. One may also define which users for this property can view the item. The Item Specification Wizard allows one to define specific attributes and associate available components relating to the item specification. Components link item(s) required for the assembly or completion of a particular item specification. This tool also enables one to provide a vendor with written notes about the item specification, such as delivery requirements, special instructions, vendor terms or any other information that needs to be communicated to the vendor. This feature also enables one to preview the item specification information and prepare a report for printing. This Item Specification Wizard also provides the ability to calculate the total estimated cost, including component items, automatically. Costs are used for budgeting, bidding, and purchasing items. A history of the item specification is tracked to allow users the capability to view the historical status and specification changes for the item specification and its components over time, or view previous versions of the item specification. Any information that was defined for this item Specification using the CAD Intelligence plug-in Interface described in co-pending U.S. patent application Ser. No. 10/021,661 or the Item Specification Tool displays in the Item Specification Wizard. The Item Specification Wizard process flow is shown in FIG. 17 . The Item Specification Wizard contains a general information page 1716 which allows the drawn item Specification to be associated with an item in an online catalog created by the company and assigns this item to a budget code. One option of the general properties page allows the user to assign a budget code to the item Specification to track the cost and status of the item Specification via a Budget Code Search page and search for the existing budget code for that item. Once the system has returned the appropriate budget code it may be assigned to the item Specification by user action. This action returns the user to the Item Specification Wizard—General Properties page. An example of this page is shown in FIG. 18 . Pages shown in FIGS. 18 a through 18 o generally correspond to each box in FIG. 17 . Each page is designed to lead a user sequentially through the item set up process in the wizard. This sequence is presented in FIG. 17 . The user then needs to navigate to the next step in the process, which is defining the item spec's attributes. On attributes page 1218 ( FIG. 18 b ) allows Attributes to be defined to specify an item. Attributes include color, size, shape, distributor, vendors, contacts, etc. Defining these attributes ensures the correct item Specification is bid, purchased and ordered for the project. Searches for users 1220 , companies 1222 , and vendors 1224 may be used in entering attributes for the components. Vendors may be added 1226 at this stage as well, and vendor information for existing vendors retrieved for added vendors 1228 . Components 1230 ( FIG. 18 c ) are child item Specifications and associated with a parent item spec. In this case, the component is the fabric for the office chair. The components may be associated with the item Specification in this process. Components must already exist in the system in order to associate them to an item spec. The user must also have the appropriate access to locate and view these item specs. Because the drawing listed the fabric as a component this information displays on the Components page. This process allows you to add more than one component that may have been previously specified but not included on the drawing. If the user determines another fabric component needs to be added to the chair, the Items Search page 1232 ( FIG. 18 d ) is accessed to locate other components of fabric for selection. After the component(s) have been searched, selected and accepted the Item Specification Wizard displays the newly added component(s) and allows the user to edit, remove or save the information ( FIG. 18 e ). Next vendor notes 1240 ( FIG. 18 f ) may be optionally added. These include any notes to the vendor(s) about the item specification. These are not required in order to specify the item, but are available as a matter of convenience. The user may locate and select prefabricated notes for this process. The company creating the item Specification defines these notes in another process. The user may also type and format the notes to the vendor. Next user notes 1250 ( FIG. 18 g ) may be provided in order to accommodate and support internal processes for the company creating the item spec. The user may include internal notes that are not available to anyone without the designated permissions to access these notes. The cost definition 1760 ( FIG. 18 h ) is a required process of the system. The next required step is defining the virtual area association and the cost of the item. This information is required for RFQ (requesting quotes), Bids, and Purchase Orders. As shown therein, items may be added 1260 - 2 , deleted 1260 - 3 , and transferred 1260 - 4 to the project budget. Once this information is defined, the system transfers, tracks, and calculates the appropriate cost of each item and its component(s). This process allows the user to choose whether to calculate the cost of the component as one rolled up cost 1260 - 1 or as a separate item. For example, if the item Specification and the component are purchased as one item, such as the chair being sold with its component fabric already installed, then the component should be calculated as a rolled up cost. If the item and its component are purchased separately, such as when the fabric is not being installed on the chair by the vendor, then the item costs should be calculated as separate items although these costs are still associated as components of this chair. Another available feature of this page is the association of the item Specification to the virtual area. The user may specify the quantity of item Specifications for each virtual area. The user may access the virtual area page ( FIG. 18 i ) to specify the quantities for each area of the property or project. If the quantity of this item Specification is increased or decreased, the system recalculates the costs and displays the appropriate amount. Any calculated costs can then be transferred into the budget 1260 - 4 and calculated as pending cost or revenue. The Costs page also has a unique function allowing the user to view the details of each item Specification per virtual area as shown in FIG. 18A . Additional functions which may be added to the item costs page include but are not limited to the following: definition billing data from the specifier to their customer; designed quantities for areas to be used in conjunction with the multiplier to assist in defining a specified quantity and cost for an area; etc. Next, a user can display the history of the Item Specification at 1270 ( FIG. 18 j ). The history in this example is non-existent because the item Specification has not yet been published. The history of an item Specification does not begin until its first publication. Until that time, any changes made to the item specification are considered “Work In Progress”. After the item Specification has been published, any changes then become an official revision and are tracked and available for display. This page will be revisited later in this document to show the history of an item Specification after the publication. The next step in the Item Specification Wizard is defining preferences 1274 ( FIG. 18 k ). Defining preferences allows users to determine the behavior of the item Specification and the method of calculations for future processes within the item Specification lifecycle. The preferences default to the calculation of the quantity of item Specifications specified in the system minus the quantity of item Specifications purchased. This provides the proper calculations of item specifications that do not include the quantity of item Specifications included within a drawing. The user does have the option of specifying whether they would prefer the quantity of item Specifications calculated by the quantity displayed in the drawing multiplied by the designated virtual area multiplier (usually 1) minus the quantity of item Specifications purchased. The other information that may be defined in this step of the process is the waste factor. The waste factor is the quantity of the item specification that should be included in the cost, quoting, bidding and purchasing processes due to a certain amount of loss that may occur during the assemble or installation of the item spec. For example, if the user orders a chair with fabric as the component, the user may need to calculate a specific or percentage of that fabric will go to waste when assembling the chair. In this case it was calculated that 10% of this item specification will go to waste and should be calculated into the cost and quantity of the item spec. The Specification Wizard also provides a report view 1276 ( FIG. 18 l ). This page is a view of the item Specification report that summarizes all of the specifications defined for this item spec. This is available for the user to review before publishing or finishing the item spec. Finally, an attachments process 1280 ( FIG. 18 m ) allows the user to attach any images or documents to the item spec. These attachments are available for any user that accesses the item spec, such as through a Request for Quote (RFQ), bid, or purchase order. This process allows you to either search the system for previously uploaded images and documents or to attach files from the user's local drive (personal computer or local network). This page also allows users to upload images or documents from their local drive to attach to the item specification. Once the files have been attached to the item spec, the specifying step is complete. The Item Specification List shows that the item Specification has not only been drawn but is also specified in the system. Item Specification Schedule Builder A Schedule builder tool is provided to allow users to create two different types of item specification schedules (a list in tabular form). FIG. 19 shows the process flow for building schedules. The Schedule Builder tool enables one to schedule each instance in which the item specification occurs throughout the entire project and allows one to define an instance schedule report. The Schedule Builder tool also enables one to create reports based on item specifications and virtual area. It reports the quantities of item specifications in this project and allows one to define an item schedule report. Essentially, this is a search, collect, report and publish process. The Item schedule template wizard process is shown in FIG. 19 . A user will first enter general characteristics at 1910 about the schedule to be created. These can include the name, a description, and whether the schedule is an item based, virtual area based, or instance based schedule. Next, at step 1920 , the user must select the item types to be included in the schedule. At step 1930 , the user may optionally select a default virtual area for the schedule. At step 1940 the user is required to select the data to be included in the schedule. In this case, the available data can include item types, item specifications, item components, item quantities in virtual areas, instances or virtual areas. A further optional step is provided at 1950 wherein the user can select the sort order or grouping of the report. Finally, the user has the option of selecting formatting options at 1960 before generating the schedule at 1970 . Additional functions which may be added to the item schedule tool include but are not limited to the following: item schedule editor which allows project participant to edit specification in a the schedule grid; links to publishing tool including selection of a publications purpose which may defines whether or not the items are ready for purchase; exporting of schedule to other interfaces such as a CAD tool; etc. Item Specification Schedule Report Tool A Schedule Report tool is provided to allow one to run existing instance or item schedules for a specific virtual area or the entire property. These reports display on screen, an output of computer 1050 , such as a display, and allow a user to print each schedule or save the schedule locally in a common format, such as Microsoft Corporation's Excel® spreadsheet program. Publish Tool A publishing tool allows the item specification to be published and allows the system to track any and all changes by renumbering each published version of an item specification. Publishing an official version of the items specification provides one form of version control. In one embodiment, the system prevents users from altering any information for that item specification without creating a new version. Versions are particular form or variation of an earlier or original type. System 1000 maintains a numerical format of versions for tracking history. Publishing also allows one to create an Item Specification Book. A unique feature of the online Item Specification Book is the ability for it to be shared as different media. The Item Specification Book may be viewed online, printed, or saved to the user's personal computer or laptop for later use. Publishing an official version of the items specification provides one form of version control. In one embodiment, the system prevents users from altering any information for that item specification without creating a new revision. Revisions are particular form or variation of an earlier or original item. The system maintains a numerical format of versions for tracking history. Publishing an item spec allows the item spec to be quoted, qualified, bid and purchased in the system of co-pending U.S. patent application Ser. No. 10/020,552. A flowchart of the publishing process is shown in FIG. 20 . In publishing a specification or group of specifications, as shown in FIG. 20 , a user will first enter the general characteristics of the publication, which may include entering the number, the title, a description, a sort order, whether any revisions are to be included, and other special characteristics of item specifications to be published. Next, at 2020 , the user must select the item specifications to be published. The user may publish the specifications at this point at 2050 , or may optionally provide a routing selection for those users in the approval path of the specifications at 2030 , and my further optionally send copies to project partners as 2040 . Additional functions which may be added to the publish tool include but are not limited to the following: selection of a publications purpose which may define whether or not the items are ready for purchase; routing of the publication for approval; selection of specific project participants to publish the items to; etc. After the item specs have been published, they may be revised to change the attributes or define further details for the item. This status is referred to as a revision. Revisions are tracked to ensure the most recent version of the item is used and allows the ability to revert to a previous version, if applicable. The foregoing detailed description of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. The described embodiments were chosen in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.

A system and method for constructing data concerning items of an asset. The method comprises: providing a user data entry interface; receiving a plurality of data values, each into a data field of the interface, wherein the plurality of data fields comprise a specification for the item and each data field of the specification describes an attribute of the item, and storing the specification into a database on a computer system. The system includes a data store for item specification data provided on a host computer coupled to a network; and a data input toolset comprising at least an item type manager and an item specification manager.

CROSS-REFERENCE TO RELATED APPLICATIONS Argentine Record No P 2010 0103745 STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not Applicable. THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT Not Applicable. INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC Not Applicable BACKGROUND OF THE INVENTION 1—Field of the Invention This invention is related to elements employed in the petroleum industry in general but it particularly refers to a Free Mandrel System with protected casing. Its main specific purpose is to be applied to petroleum exploitation for the multiple selective injection of fluids, liquids or gases, in different formations of an injection well. 2—Description of Related Art The present state of technology of mandrel systems for the injection of fluids in several formations only use fixed installations at the bottom hole. Consequently, when it is necessary to repair or replace any of the injection valves placed inside the mandrel, they have to be brought up to the surface. In order to perform this operation, the well has to be depressurized so injection has to be stopped; each of the injection valves have to be raised one at a time from the bottom hole to the surface. After the necessary repair or replacements are made, each of the injection valves have to be lowered again one at a time, and only after they are re-installed, production is resumed. All of the above mentioned operations require not only specialized equipment and personnel but also, down time, during which the well is not operating, and lead time, between order and arrival of the equipment at the well site to start with the operations. The following documents are related to the present invention: Document Number Date Name Classification A U.S. Pat. No. 4,671,352 June 1987 Magee Jr. et al 166-334 B U.S. Pat. No. 4,462,465 July 1984 Strickland 166-334 C U.S. 2004238218(A1) December 2004 Runia. Douwe Johannes et al. E21B/60— D U.S. 2005011678(A1) January 2005 Akinlade Monsuru Olatunji et al. E21B21/00— E U.S. Pat. No. 4,050,516(A) September 1977 Canterbury Robert Houston E21B34/06— F U.S. Pat. No. 4,433,728 (A) February 1984 Sydansk Robert D et al C09K8/50— G U.S. Pat. No. 4,433,729 (A) February 1984 Sydansk Robert D C09K8/50 H RU2002126207 (A) February 2004 Stedzhemejer Dzhordzh Leo et al E21B43/00 BRIEF SUMMARY OF THE INVENTION The main object of the invention is a Free Mandrel System, Protected Casing which enables selective injection in several well formations, the setting up and simultaneous lifting of all Injection Valves installed in the well from the surface by using the injection fluid as power fluid. This process is performed by one operator without any kind of help, assistance or tool, only operating the valves of a surface component of the invention. In the present explanation for the embodiment of the invention, the Free Mandrel System is applied to a 139.5 mm (5″½) casing and it has been simplified to only two formations, an upper and a lower one, to facilitate the explanation and comprehension of its constructive layout structure which comprises five Assemblies: A Surface Assembly (SA), A Transport Assembly (TA), the Free Mandrel Assembly (FMA), a Fixed Bottom Hole Assembly (FBHA) and a Complementary Assembly (CA). (A) The Surface Assembly (SA) made up of an installation Mast ( 4 ), a Lubricator ( 3 ) with a Catcher ( 2 ) to release and catch the Free Mandrel Assembly (FMA), Standard Valves ( 6 1 , 6 2 , 6 3 , 6 4 , 6 5 ), Standard Retention Valve ( 7 ) and the Impeller Circulation Pump ( 5 ). (B) The Transport Assembly (TA) made up of a Fishing Neck with a Retention Valve, two Rubber Cups, which slide over a central tube, and a Lower Connector. (C) The Free Mandrel Assembly (FMA), it is the main dynamic element of the System comprising one mandrel for every formation to be selectively injected (only two in this simplified case), where each mandrel lodges its corresponding Injection Valve. The Free Mandrel Assembly has as many mandrels as formations an injection well may have. (D) The Fixed Bottom Hole Assembly (FBHA), which is the device that is screwed to the bottom of the 73.026 mm (2″⅞) tubing ( 9 ) string and over the On-Off Sealing Connector ( 43 ). When the FMA is inserted into the FBHA, the FMA complements the hydraulic circuits they both contain to accomplish selective injection in every formation. These two Assemblies are composed of designed-to-measure parts and are the core of the Invention. (E) A Complementary Assembly (CA), which is screwed to the lower part of the FBHA (D), and comprises several parts, some of them are standard and others are specifically designed to build the fluid circuit required for the operation of the Free Mandrel System, Protected Casing. The CA (E) is screwed in its interior part to the central and lower end of the Fixed Bottom Hole Assembly FBHA (D); the Telescopic Union Inner Body ( 37 ); the Telescopic Union Outer Body ( 39 ) and the Injector Tube ( 40 ). All of these parts have been specifically designed for the Free Mandrel System, Protective Casing. In its exterior part, the Complementary Assembly CA (E) is made up of the upper end of the On-Off Sealing Connector ( 43 ) screwed to the outer and lower end of the Fixed Bottom Hole Assembly FBHA (D). The lower end of the On-Off Sealing Connector ( 43 ) is screwed to the upper end of the Upper Packer F. H. ( 44 ) (standard parts) while the Injector Plug ( 41 ) (designed-to-measure part) is screwed at its lower end. To complete the installation, the 60.325 mm (2″⅜) tubing ( 47 ) string is screwed to the lower end of the Injector Plug ( 41 ) to fix the Lower Packer F.H. ( 46 ) in the adequate position to separate both formations. The 60.325 mm (2″⅜) tubing ( 47 ) string is screwed to the upper end of the Lower Packer F.H. ( 46 ) One or two 60.325 mm (2″⅜) tubing are placed below the Lower Packer F.H. ( 46 ), and the Shear Out ( 48 ) is placed on its end (standard parts) With this invention, the problems which derive from a fixed mandrel system are advantageously solved because the complete Free Mandrel Assembly FMA (C) is raised containing all the Injections valves that the injection well requires. The Free Mandrel Assembly FMA (C) is not fixed to the bottom of the well, it is free and travels through the tubing from the FBHA (D) (upstroke) to the surface and vice versa, driven by the Injection fluid which is used as power fluid. An additional advantage is that fluid injection is continuously pressurized in all formations so injection is not interrupted in any of the operational stages. That is to say, the fundamental purpose of fluid injection (secondary recovery) is to pressurize the formations to achieve a larger formation volume in the surrounding or adjacent producing wells. An important time and extra hand work advantage is achieved because no additional equipment such as Wireline, slikeline, or external personnel is not required for valve setting up or removal. This operation can be performed by control personnel of injector wells (either the operator or field supervisor) from the surface by handling the well head manifold valves at the moment it is required. Consequently, for example, for 2500 m deep installations, the FMA (C) described herein reaches the surface with all valves installed in about 30 minutes and requires a slightly shorter time in the down stroke. Both strokes are attained with the same injection fluid, used as power fluid. This advantage is utilized several times while the well is producing, thus, accumulatively, adding a significant value. Free Mandrel System, Protected Casing allows obtaining samples of the material deposited in the tubing string. With that purpose, strokes can be performed to bring the material to the surface to be analyzed. Strokes can be performed to verify the accumulated depositions and in increasing periods, that is to say, beginning with short periods and increasing them in order to define the most suitable one for each well without depressurizing the formations, and with no additional equipment or external personnel costs. To maximize the Casing ( 10 ) protection in case of long injection periods without replacing injection valves, Casing Protection fluid can be replaced from the surface by the well operator without employing pulling equipment to disconnect the On-Off Sealing Connector ( 43 ). Besides, it can block any formation to examine or stimulate others. This is achieved by removing the FMA (C), leaving the formation circuits in service and blocking one of them, or leaving one formation in service and blocking the remaining ones. For the two Formations used in this example, in the Upper Mandrel we can install a Blind Upper Injection Valve ( 51 ) and inject in the Lower Formation using the Lower Formation Injection Valve ( 21 ) ( FIG. 11 ). We can also use a Blind Lower Injection Valve ( 52 ) and inject only in the Upper Formation installing the Upper Formation Injection Valve ( 18 )( FIG. 9 ) This also allows determining if there is any interference between the formations by injecting fluid (at different pressures and volumes) in one and placing Amerada® Gauge, an instrument to measure pressure in the bottom hole, inside another mandrel to verify pressure variation in different injection flows. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS Here follows a list of the five assemblies which comprise the system, their Components, Vertical Passages and Annular Spaces with their respective reference characters as they will be identified in the detailed description of the system, drawings and claims: A—Surface Assembly (SA) B—Transport Assembly (TA) C—Free Mandrel Assembly (FMA) D—Fixed Bottom Hole Assembly (FBHA) E—Complementary Assembly (CA) Components of the five assemblies: 1 —Pipeline from Water Power Plant. 2 —Catcher. 3 —Lubricator. 4 —Mast. 5 —Impeller Circulation Pump. 6 1 —V1 Standard Valve. 6 2 —V2 Standard Valve. 6 3 —V3 Standard Valve. 6 4 —V4 Standard Valve. 6 5 —73.026 mm (2″⅞) Standard Full Passage Injection Valve 7 —Standard Retention Valve. 8 —Well Head. 9 —73.026 mm (2″⅞) Tubing i—Tubing ( 9 ) Interior (Direct) 10 —Casing. 11 —Fishing Neck. 12 —Retention Valve. 13 —Rubber Cups. 14 —Lower Connector. 15 —Outer Jacket. 16 —Outer Jacket Seal Ring. 17 —Middle Plug. 18 —Upper Formation Injection Valve. 19 —Middle Plug Radial Passage. 20 —Middle Plug Seal Ring. 21 —Lower Formation Injection Valve. 22 —Lower Plug. 23 —Lower Plug Seal Ring. 24 —Upper Body. 25 —Upper Packer Collar. 26 —Upper Packer Collar Seal Ring. 27 —Lock Nut. 28 —Lower Body. 29 —Lower Body Seal Ring. 30 —Spacer. 31 —Spacer Injection Outlet Perforation. 32 —Lower Packer Collar. 33 —Lower Packer Collar Seal Ring. 34 —Seat. 35 —Seat Seal Ring. 36 —Casing Protective Valve. 37 —Telescopic Union Inner Body. 38 —Telescopic Union Seal Ring. 39 —Telescopic Union Outer Body. 40 —Injection Tube. 41 —Injector Plug. 42 —Rupture Disc Passage. 43 —On-Off Sealing Connector. 44 —Upper Packer F.H. 46 —Lower Packer F. H. 47 —60.325 mm (2″⅜) Tubing 48 —Shear Out. 49 —Casing Upper Formation Perforations 50 —Casing Lower Formation Perforations 51 —Blind Upper Injection Valve. 52 —Blind Lower Injection Valve- Vertical Passages C 1 —It is placed in the Middle Plug ( 17 ). They are passages in the Free Mandrel Assembly central body C 2 —It is placed in the Lower Body (FBHA). The Annular Space (e 6 ) where the regulated pressure is discharged through the Upper Valve ( 18 ) and conducted to the Annular Space (e 9 ) placed between Telescopic Union Inner Body ( 37 ) and the interior of the Fixed Bottom Hole Assembly (D) FBHA eccentric vertical passage C 3 —Casing Protective Valve ( 36 ) Passage C 4 —Shear Out ( 48 ) passage Annular Spaces e 1 —Between the Casing ( 10 ) and the 73.026 mm (2″⅞) Tubing ( 9 ) e 2 —Between the Casing ( 10 ) and the FWBA (D) e 3 —Between the Casing ( 10 ) and the Injector Plug ( 41 ) e 4 —Between the Casing ( 10 ) and the 60.325 mm (2″⅜) tubing ( 47 ) e 5 —Between the Casing ( 10 ) and the Shear Out ( 48 ) e 6 —Between the FBHA (D) and the Middle Plug ( 17 ) e 7 —Between the Upper Mandrel Jacket ( 15 ) and the Upper Formation Injection Valve ( 18 ) e 8 —Between the FBHA (D) interior and the Lower Formation Injection Valve ( 21 ) e 9 —Between the lower inner part of the FBHA (D) and the Telescopic Union Inner Body ( 37 ) e 10 —Between the On-Off Sealing Connector ( 43 ) and the Telescopic Union Outer Body ( 39 ) e 11 —Between the Injector Plug ( 41 ) and the Injection Tube ( 40 ) The invention components are schematically represented in 21 different views of FIG. 1 . As the component parts of the Free Mandrel System have a great length but a relatively small diameter, the 27 Figures have been deliberately deformed so that the component parts can be distinguished to be explained. With the same purpose, an enlargement of FIG. 1 has been added divided into four partial views of FIG. 1 . In all Figures, except 6 and 22 , the following hydraulic flow circulations are identified and described to facilitate the comprehension of the Free Mandrel System, Protected Casing operations: 1—Injection fluid, provided by the Power Plant with the highest pressure flowing into all injection valves to be regulated according to the conditions of every formation. 2—Controlled fluid to be injected in the upper formation. It comes out through the lower end of the Upper Formation Injection Valve ( 18 ) 3—Controlled fluid to be injected in the lower formation. It comes out through the lower end of the Lower Formation Injection Valve ( 21 ) 4 —Fluid injected at low pressure through the Annular Space (e 1 )) to achieve the upstroke of the Free Mandrel Assembly, containing all the Injection Valves required by the well. The pressure is approximately 2 or 3 kg/cm 2 . (Obviously the higher the pressure, the faster the return speed, but the mentioned pressure is the recommended one). Again, 30′ return time is achieved in a 2500 m deep installation. 5—Fluid removed from the tubing as the Free Mandrel Assembly moves up to the surface. Its pressure is slightly lower than the one that pushes up the Free Mandrel Assembly. 6—White (empty space)=Settled fluid or only with hydrostatic pressure (for example in the Annular Space between the Casing ( 10 ) and the 70.026 mm (2″⅞) tubing ( 9 ) during the injection process). The 22 Figures are as follows: FIG. 1 is an elevational longitudinal view of the general layout of the invention. The view of the Free Mandrel System, Protected Casing in its entirety ( FIG. 1 ) has also been broken into four partial views to facilitate the understanding of the view ( FIG. 1 a : top left side, FIG. 1 b : top right side, FIG. 1 c : bottom left side, and FIG. 1 d : bottom right side). These partial views have been extended over four sheets which can be linked edge to edge so that no partial view contains parts of another partial view. The position of a series of transverse cross sectional lines, indicated with numbers I to VIII, correspond to cross-sectional views which show fluid flows The capital letters A, B, C, D and E show the position of the five structures that compose the equipment are: Surface Assembly (A); Transport Assembly (B); Free Mandrel Assembly (C); Fixed Bottom Hole Assembly (D); and Complementary Assembly (E). Four exploded views show the four main components that are inside the well: 1 The two free components, the Transport Assembly (TA) (B) and the Free Mandrel Assembly (FMA) (C) are shown on the left. 2 The two fixed components, the Fix Bottom Hole Assembly (FBHA) (D) and the Complementary Assembly (CA) (E) are shown on the right. FIG. 2 is an enlarged partial view of the surface section of the Free Mandrel System, Protected Casing where the Surface Assembly (SA (A), the only component of the invention located on the surface of the well site, is shown in detail. FIG. 3 is an elevational longitudinal view of the Transport Assembly (TA) (B). When the Free Mandrel System, Protective Casing is operating, the only fluid that circulates is the supplied by the Power Plant coming through 73.025 mm (2″⅞) tubing ( 9 ) (i), the Fishing Neck ( 11 ), Retention Valve ( 12 ), and Lower Connector ( 14 ), finally connecting with the Free Mandrel Assembly (FMA)(C). FIGS. 4 A and B are two elevational longitudinal views of the Free Mandrel Assembly (C) Incoming Injection fluid is divided into two streams: 1— FIG. 4 A shows how the fluid flows on the plane of Middle Plug Radial Passage ( 19 ). It enters through the upper part of the Outer Jacket ( 15 ), goes into the Upper Formation Injection Valve ( 18 ) which delivers the controlled fluid to be injected in the Upper Formation through the Middle Plug ( 17 ) Radial Passage ( 19 ). 2— FIG. 4B . It circulates through the Annular Space (e 7 ) to guide the fluid through the Middle Plug ( 17 ) Vertical Passages (C 1 ) and feed with injection fluid to the Lower Injection Formation Valve ( 21 ) which delivers the controlled fluid to inject in the Lower Formation through the Lower Plug ( 22 ). FIGS. 5 A and B are elevational longitudinal views of the Transport Assembly (TA) (B) and the Free Mandrel Assembly (FMA) (C) as they run together through the well from the Catcher ( 2 ) to the Fixed Bottom Hole Assembly (FBHA) (D) in their down stroke, and from the Fixed Bottom Hole Assembly (FBHA) (D) to the Catcher ( 2 ), in their upstroke. Different fluids are shown inside both assemblies, the incoming injection fluid, the one to be injected in the upper formation and the one to be injected in the lower formation. FIG. 5 B shows the fluid going through the Middle Plug Radial Passage ( 19 ) in a perpendicular plane. Vertical Passages C 1 , allow the injection fluid go into the Lower Injection Formation Valve ( 21 ) to release fluid at the pressure and volume to be injected in the Lower Formation. FIG. 6 is an elevational longitudinal view of the Fixed Bottom Hole Assembly (FBHA) (D) with its essential components which are designed-to-measure for the Free Mandrel System, Protected Casing. FIG. 7 A is an elevational longitudinal view of the Free Mandrel Assembly (FMA) (C) and Transport Assemblies (TA) (B) inserted in the Fixed Bottom Hole Assembly (FBHA) (D). The injection fluid entering through the 73.025 mm (2″⅞) Tubing ( 9 ) i, at the Upper Free Mandrel, the out coming fluid through the Middle Plug ( 17 ) Radial Passage ( 19 ), to be injected in the Upper Formation, on the plane of Middle Plug Radial Passage ( 19 ). FIGS. 7A and 7B are the same Figures but, in 7 B, the sectional plane is perpendicular to Radial Passage ( 19 ). The incoming Injection fluid flows to the Lower Formation Injection Valve ( 21 ) through the Middle Plug ( 17 ) Vertical Passages (C 1 ) to be injected in the Lower Formation. FIG. 8 is an elevational longitudinal view of the Fixed Bottom Hole Assembly (FBHA) (D) screwed to the Complementary Assembly (CA) (E) only down to the Injection Plug ( 41 ). The Transport Assembly (TA) (B) together with the Free Mandrel Assembly (FMA) (C) is inserted inside the FBHA (D) during simultaneous injection in both formations. Fluids are also shown as they flow through different passages. In FIG. 8 , the injection circuits of both formations are represented. The injection fluid enters through 73.026 mm (2″⅞) Tubing ( 9 ) (i), goes through the Transport Assembly (TA) (B), gets into the Free Mandrel Assembly (FMA) (C), reaches the Upper Formation Injection Valve ( 18 ) and comes out as controlled fluid towards the Upper Formation through the Middle Plug ( 17 ). The fluid goes on through the Annular Space (e 6 ) and the Spacer Injection Outlet Perforation ( 31 ). Then it channels through the FBHA (D) Vertical Passages (C 2 ), the Annular Spaces (e 9 ), (e 10 ) and (e 11 ), and the Rupture Disc Passage ( 42 ). Simultaneously, the other injection fluid stream that goes into the Upper Mandrel, flows through the Annular Space (e 7 ), the Middle Plug ( 17 ) Vertical Passages (C 1 ) until it reaches the upper end of the Lower Formation Injection Valve ( 21 ) which controls the fluid to be injected in the Lower Formation. The fluid goes through the Lower Plug ( 22 ) and continues through the inside of the Telescopic Union ( 37 and 39 ), the Injection Tube ( 40 ) and the Injector Plug ( 41 ) inner passage. Meanwhile the Annular Spaces (e 1 ), (e 2 ) and the vertical passages (C 3 ) are kept without pressure (white space). FIG. 9 is an elevational longitudinal view. It only shows the injection in the upper formation of the invention layout. The Transport Assembly (TA) (B), Free Mandrel Assembly (FMA) (C), Fixed Bottom Hole Assembly (FBH) (D) and Complementary Assembly (CA) (E) are represented while showing operative hydraulic flows. The Upper Formation Injection Valve ( 18 ) is regulating the flow and the Lower Formation Injection Valve ( 21 ) is replaced by a Blind Lower Injection Valve ( 52 ). The central passage (corresponding to the Lower Formation circuit) is shown without pressure or fluid (white space). Consequently, the Injection Plant pressure acts through 73.026 mm (2″⅞) Tubing ( 9 ) (i), as the regulated fluid is injected to the Upper Formation through the Casing Upper Formation Perforations ( 49 ). Through the Annular Spaces (e 1 ), (e 2 ) and the passage (C 3 ) there is no fluid circulation. There is only hydrostatic pressure (white space). FIG. 10 , a transverse cross sectional view on line III-III ( FIG. 1 ), shows the Upper Formation injection fluid in the Middle Plug ( 17 ) Radial Passage plane ( 19 ), the Fixed Bottom Hole Assembly (FBHA) (D), Vertical Passages (C 1 ) and Casing ( 10 ). The Annular Spaces (e 2 ) (white space) and (e 6 ) with the Upper Formation Injection Fluid are also shown. The Plant injection fluid circulation goes through the Middle Plug ( 17 ) Vertical Passages (C 1 ) and comes out regulated through the Middle Plug ( 17 ) Radial Passage ( 19 ) to the Annular Space (e 6 ) FIG. 11 is an elevational longitudinal view. It shows the injection in the Lower Formation of the invention layout. In this Figure, The Transport Assembly (TA) (B), Free Mandrel Assembly (FMA) (C), Fixed Bottom Hole (FBHA) (D) and Complementary (E) Assemblies are represented while showing operative hydraulic flows in the Annular Spaces (e 1 ), (e 2 ) and the passage (C 3 ) there is no pressure (white space) as only the Lower Injection Formation flow is represented. The injection fluid that enters through 73.026 mm (2″718) ( 9 ) (i) goes through the Transport Assembly (TA) (B) and comes into the Free Mandrel Assembly (FMA) (C) and reaches the Blind Upper Valve ( 51 ). The Annular Space (e 6 ), the FBHA (D) vertical passages (C 2 ), the Annular Spaces (e 9 ), (e 10 ) and (e 11 ) and the Rupture Disc passage ( 42 ) have no pressure. At the same time, the other injection fluid stream flows through the Annular Space (e 7 ) and Vertical Passages (C 1 ) until it reaches the upper end of the Lower Formation Injection Valve ( 21 ), which controls the fluid to be injected in the Lower Formation. Lower injection fluid stream goes through the Lower Plug ( 22 ) and continues through the interior of the Telescopic Union ( 37 and 39 ), Injection Tube ( 40 ), Injector Plug ( 41 ) inner passage, 60.325 (2″⅜) ( 47 ) Tubing, Lower Packer F.H. ( 46 ), the 60.325 mm (2″⅜) tubing ( 47 ) and Shear Out ( 48 ). Meanwhile, the Annular Spaces (e 1 )) and (e 2 ), and the vertical passage (C 3 ) are kept without pressure (white space). FIG. 12 , a transverse cross-sectional view on line IV-IV ( FIG. 1 ), shows lower formation fluid flowing out of the Lower Formation Injection Valve ( 21 ). As in the previous FIG. 11 ) the Casing ( 10 ), the Fixed Bottom Hole Assembly (FBHA) (D) and the Lower Plug ( 22 ) are also shown together with (C 2 ) and (C 3 ) (white space) Vertical Passages, and the Annular Space (e 2 ) (white space). FIG. 13 an elevational longitudinal view. It shows simultaneous injection in both formations. The incoming plant fluid is controlled by the corresponding Upper Injection Formation Valve ( 18 ) and Lower Injection Formation Valve ( 21 ). The Transport Assembly (TA) (B), Free Mandrel Assembly (FMA) (C), inserted in the Fixed Bottom Hole (FBHA) (D) and Complementary Assemblies (CA) (E) are represented while showing operative hydraulic flows. In the Annular Spaces (e 1 )) and (e 2 ), and Vertical Passage (C 3 ) there is no pressure as simultaneous Injection in the Upper and Lower Formations with regulated fluids are represented here. Upper Formation Injection Valve ( 18 ) and Lower Formation Injection Valve ( 21 ) are regulating injection fluids in both formations. Consequently, the injection fluid enters the 73.026 mm (2″⅞) Tubing ( 9 ) (i), goes through the Transport Assembly (TA) (B) and flows into the Free Mandrel Assembly (FMA) (C) through the Outer Jacket ( 15 ) and reaches the Upper Formation Injection Valve ( 18 ) from this lower end flows the upper formation regulated fluid. The injection fluid flows through the Middle Plug ( 17 ) Vertical Passages (C 1 ) reaches the Lower Formation Injection Valve ( 21 ) that releases the regulated fluid to inject in the Lower Formation. To complete the regulated fluid circuit to be injected in the Upper Formation, as shown in FIGS. 9 and 13 ), this fluid course comes out of the Rupture Disc Passage ( 42 ) until the fluid gets into the chamber delimited as follows: 1—At the upper end by the lower side of the Upper Packer F. H. ( 44 ) 2—On the outer side by the Casing ( 10 ) 3—On the inner side by the Injection Tube ( 40 ) and Injector Plug ( 41 ) 4—At the lower end by the upper side of the Lower Packer F. H. ( 46 ) That is to say, the regulated fluid is forced to go through the Casing Upper Formation Perforations ( 49 ) to the Upper Formation. To complete the regulated fluid circuit to be injected in the Lower Formation as shown in FIGS. 11 and 13 ) this fluid comes out of the Injector Plug central passage ( 41 ), 60.325 mm (2″⅜) Tubing ( 47 ), Lower Packer ( 46 ) F. H. inner passages, 60.325 mm (2″⅜) Tubing ( 47 ), and Shear Out ( 48 ), until it gets into the chamber delimited as follows: 1—At the upper end by the lower side of the Lower Packer ( 46 ) 2—On the outer side by the Casing ( 10 ) 3—On the inner side by the 60.325 mm (2″⅜) Tubing and the Shear Out ( 48 ) 4—At the lower end by the bottom hole That is to say, the regulated fluid is forced to go through the Casing Lower Formation Perforations ( 50 ) and enter the Lower Formation, FIG. 14 , a transverse cross-sectional view on line V-V ( FIG. 1 ), corresponds to Upper and Lower Formation simultaneous injection at the height of the Casing Protective Valve ( 36 ) of the Fixed Bottom Hole Assembly (D) lower end. Upper Formation injection fluid goes through the Annular Space (e 9 ) defined by the FBHA (D), inner diameter and the outer diameter of the inner body of the Telescopic Union ( 37 ) and the Lower Formation injection fluid goes through the inside of the Telescopic Union ( 37 ). Vertical Passages (C 3 ) and Annular Space (e 2 ) are without pressure (white space) FIG. 15 , a transverse cross-sectional view on line VI-VI ( FIG. 1 ), corresponds to the lower part of the Fixed Bottom Hole Assembly (D) below the Casing Protective Valve ( 36 ) with the simultaneous injection fluids of Annular Space (e 9 ) acting in the Upper injection fluid and Lower Formation fluid through the inside of the Injection Tube ( 40 ). Also, Annular Space (e 2 ) is without pressure (white space) FIG. 16 , a transverse cross-sectional view on line VII-VII ( FIG. 1 ), shows Upper and Lower Formation injection fluid and flow in the Injector Plug ( 41 ) plane through the Rupture Disc passage ( 42 ). Casing Upper Formation Perforations ( 49 ), Injection Tube ( 40 ) and the Injector Plug ( 41 ) together with Annular Spaces (e 3 ) and (e 11 ) can also be seen. Lower Formation fluid circulates through the inside of the Injection Tube ( 40 ) FIG. 17 , a transverse cross-sectional view on line VIII-VIII ( FIG. 1 ), only shows Lower Formation injection and fluid circulation in the Shear Out ( 48 ) passage plane and Casing Lower Formation Perforations ( 50 ) in that area. Annular Space (e 5 ) and the Shear Out inner passage (C 4 ) are also shown. FIG. 18 is an elevational longitudinal view. It represents fluid distribution during the Free Mandrel Assembly (FMA) (C) upstroke while the low pressure fluid is injecting in both formations without flow control. It is only when the Free Mandrel Assembly (FMA) (C), together with the Transport Assembly (TA) (B) is inserted in its position inside the Fixed Bottom Hole Assembly (FBHA) (D), that the injection in both formations is controlled. FIG. 18 represents the recovery chamber where it can be seen how low pressure fluid is injected through the Annular Space (e 1 )) to recover the TA (B) and the FMA (C). The initial upstroke is shown. Fluid with the necessary pressure to perform the TA and FMA upstroke has to be injected through the Annular Space (e 1 ). This fluid enters through the Casing Protective Valve ( 36 ). This makes the TA (B) and the FMA (C) move up to the surface where they will finally insert into the Catcher ( 2 ). Fluid with a pressure slightly lower than injection pressure flows over these assemblies. Low pressure fluid pressurizes both formations This particularity has already been mentioned as a technical operational advantage of the invention because the formations are never depressurized. FIG. 19 shows a transverse cross-sectional view on line I-I ( FIG. 1 ) with fluid circulation in simultaneous injection process in both formations. This takes place at the Well Head ( 8 ). The Casing ( 10 ) and the 73.026 mm (2″⅞) Tubing ( 9 ) (i) are shown. There is only hydrostatic pressure (white space) in the Annular Space between them (e 1 ). There is injection fluid in the inside of the Tubing ( 9 ) (i). FIG. 20 , a transverse cross-sectional view on line II-II ( FIG. 1 ), shows fluid circulation in the with Free Mandrel Assembly upstroke. Fluid displaced by the Transport Assembly (TA) (B) together with Free Mandrel Assembly (FMA) (C) flows inside the 73.026 mm (2″⅞) Tubing ( 9 ) (i), and the low pressure fluid released by the Impeller Circulation Pump ( 5 ), flows through Annular Space (e 1 ). It also shows Retention Valve ( 12 ) FIG. 21 is an elevational longitudinal view of the Surface Assembly when the Transport Assembly (TA) (B) together with the Free Mandrel Assembly (FMA) (C) are finishing their upstroke and arriving at the Lubricator ( 3 ). Fluid circulations are also shown FIG. 22 is an elevational longitudinal view of the general layout of the Complementary Assembly (CE) (E), It shows their components, as follows: 1 Internal components screwed at the central lower end of Fixed Bottom Hole Assembly (FBHA) (D): Telescopic Union Inner Body ( 37 ), Telescopic Union Seal Ring ( 38 ), Telescopic Union Outer Body ( 39 ), Injection Tube ( 40 ), screwed in its lower end to the Injector Plug ( 41 ). All of them are designed-to-measure parts for the Free Mandrel System, Protected Casing. 2 External components screwed on the lower end of the Fix Bottom Hole Assembly (FBHA) D screwed to the upper end of On-Off Sealing Connector ( 43 ) which, in its lower end is screwed to the upper end of Upper Packer F. H. ( 44 ) (both parts are of common use in the petroleum industry). The Injector Plug ( 41 ) screws in the Upper Packer F.H. ( 44 ) lower end. The Injector Plug ( 41 ) is a designed-to-measure part of the Free Mandrel System, Protected Casing. The Injector Plug ( 41 ) contains the Rupture Disc Passage ( 42 ). The Injector Plug ( 41 ) is also screwed, in its lower end, to the upper end of the last 60.235 mm (2″⅜) Tubing ( 47 ) required quantity to separate both packers in the injector well. At the lower end of 60.235 mm (2″⅜) Tubing ( 47 ) string, the Lower Packer F.H. ( 46 ) is screwed in its upper end. Another section of the 60.235 mm (2″⅜) Tubing ( 47 ) is connected to the Lower Packer F. H. ( 46 ) with the Shear Out ( 48 ) DETAILED DESCRIPTION OF THE INVENTION According to the scheme represented in FIG. 1 of the Free Mandrel System, Protected Casing, the invention layout is composed of: A—Surface Assembly (SA) B— Transport Assembly (TA) C— Free Mandrel Assembly (FMA) D—Fixed Bottom Hole Assembly (FBHA) E—Complementary Assembly (CA) 1-(A)—Surface Assembly (SA): It is schematically represented in FIG. 2 . It is the assembly which comprises standard parts such as valves ( 6 1 ), ( 6 2 ), ( 6 3 ), ( 6 4 ), ( 6 5 ,), ( 7 ) and ( 8 ), properly laid out to perform the required operations of the Free Mandrel System, Protected Casing, with the following additional parts designed-to-measure: the Lubricator ( 3 ) with the Catcher ( 2 ), the Mast ( 4 ) and the Impeller Circulation Pump ( 5 ), a low pressure pump, with no movable parts which makes the system work. The SA is screwed over the Well Head ( 8 ) in the 73.026 mm (2″⅞) Full Passage Standard Injection Valve ( 6 5 ). The Lubricator ( 3 ) with the Mast ( 4 ) and the Catcher ( 2 ) in its lower end is screwed on Standard Valve ( 6 5 ). Injection Fluid comes from the Water Injection Plant through Pipeline ( 1 ) which separates into two branches: the first branch goes into the SA (A) central passage into the well through Standard Valve ( 6 1 . When Standard Valve ( 6 1 ) is open, the well can inject simultaneously in all Formations. When it is shut, it does not allow the injection fluid flow and so the well does not operate. (Stand-By stage); the second branch connects with the Impeller Circulation Pump ( 5 ) through a second valve ( 6 2 ) which is shut during that operation. When it is open, it allows the injection fluid to flow to the Impeller Circulation Pump ( 5 ) which injects at low pressure in the Annular (e 1 )) to perform the FMA (C) upstroke, required to recover all installed Injection Valves. This procedure is used to drive the Impeller Circulation Pump ( 5 ) which uses this fluid as power fluid and injects a low pressure fluid in the Annular Space (e 1 ) with the fluid it sucks from 73.026 (2″⅞) Tubing ( 9 ) (i). The Impeller Circulation Pump ( 5 ) connects to the Annular Space (e 1 )) through the Well Head ( 8 ). Standard Valve ( 6 3 ), placed at the upper end of the Lubricator ( 3 ) is kept closed during the injection in several formations. It is only opened to retrieve the FMA (C) (upstroke). The Impeller Circulation Pump ( 5 ) allows low pressure injection fluid to circulate from the Casing ( 10 ) to the 73.026 (2″⅞) Tubing ( 9 ) (i) through the Casing Protective Valve ( 36 ) for the FMA (C) upstroke to the surface. Standard Retention Valve ( 7 ) is used to orient the low pressure injection fluid into the Annular Space (e 1 )) and to avoid pressurizing the Lubricator ( 3 ). When the FMA (C) upstroke starts up, the Standard Retention Valve ( 7 ) allows the fluid to be removed from the tubing as the FMA (C) moves up to the surface. The fluid pressure is slightly lower than the one that pushes the FMA (C) up to the surface and is sucked by the Impeller Circulation Pump ( 5 ) intake. This operation enables low pressure circulation to drive the Transport Assembly (B) together with the Free Mandrel Assembly (C) in their upstroke from the FBHA (D) until it is trapped in the Catcher ( 2 ). Valve ( 6 1 ) is kept open for the down stroke whereas Valves ( 6 2 ), ( 6 3 ) and ( 6 4 ) are kept shut. The injection fluid pushes and the FMA (C) inserts into the FBHA (D) while automatically beginning the selective injection in both Upper and Lower Formations For the down stroke operation, a flow, not larger than 400 m 3 /a day, is recommended to go through Valve ( 6 1 ) to prevent the FMA (C) from inserting into the FBHA (D) with excessive impact. In down strokes, the Operator opens Valve ( 6 1 ). Then, he can leave the location as the operation is completely automatic. Only in injected flows over 400 m 3 /a day, it is necessary for the Operator to liberate the flow completely after the FMA (C) is inserted in the FBHA (D) to leave the well in ideal operating conditions. The third Valve ( 6 3 ) is placed at the Lubricator ( 3 ) outlet and is closed while operating. When it is open, it allows the 73.026 (2″⅞) Tubing ( 9 ) (i) fluid to re-circulate to the Annular (e 1 )) for the FMA (C) upstroke. The 73.026 mm (2″⅞) Full Passage Standard Injection Valve ( 6 5 ) connected to the Well Head ( 8 ), allows the FMA (C) to run in both strokes, and the injection and return fluids flow to retrieve the FMA (C). 2-(B)—Transport Assembly—(TA): It is schematically represented in FIG. 3 . It is one of the dynamic components that moves together with the Free Mandrel Assembly (C) from the Surface Assembly (A) to its insertion in the Fixed Bottom Hole Assembly (D) during the FMA (C) down stroke or vice versa, upstroke. The TA (B) consists of the Fishing Neck ( 11 ), a Retention Valve ( 12 ), Rubber Cups ( 13 ) and the Lower Connector ( 14 ) screwed together. The Transport Assembly (B) is used to transport the Free Mandrel Assembly (C). The Transport Assembly (B) is designed-to-measure according to the operating requirements of the invention device and It is essential in the FMA (C) upstroke as the Rubber Cups ( 13 ) expand against the 73.026 mm (2″⅞) Tubing ( 9 ) (i) taking the utmost advantage of the fluid volume when they receive the upward injection fluid push. This push also closes the Retention Valve ( 12 ) for the greatest fluid flow efficiency. FIG. 5 shows the Transport Assembly (B) screwed to the Free Mandrel Assembly (C) upper end. The TA (B) ends in its upper extreme in an API normalized Fishing Neck ( 11 ). which allows it to be trapped by the Catcher ( 2 ) ( FIG. 2 ) at the end of the upstroke and detached from it at the down stroke start. In case of any inconvenience, as for example tubing leakage, the TA (B) and FMA (C) can be trapped by means of a Slickeline equipment. The TA (B) ends, in its lower extreme, in the Lower Connector ( 14 ) where it is screwed to the Free Mandrel Assembly (C). The assembly of (B) and (C) is schematically represented in FIGS. 5 A and 7 B. 3-(C)—Free Mandrel Assembly—FMA: It is schematically represented in FIG. 4 A/B. It is the main dynamic component of the Free Mandrel System that travels from SA (A), in its down stroke, to be inserted into the FBHA (D) (in FIG. 6 ) and automatically begins selective injection in different Formations. The Free Mandrel Assembly upstroke carries injection valves to be examined or removed. The FMA (C) is one of the five Assemblies composed of totally new parts. It has been graphically represented in FIGS. 4 A/B, 5 A/B, 7 A, 7 B, 8 , 9 , 11 , 13 and 18 . The FMA (C) has been designed-to-measure for the operations of the Free Mandrel System, Protected Casing applied to selective injection in several Formations. As mentioned above, can be applied to several formations but, in this specific explanation, has been reduced to only two formations, an upper and a lower one, for a better comprehension. Every Mandrel contains an Injection Valve in its interior, except the Lower one which is the only one integrated by an Injection Valve designed-to-measure for this purpose. A Free Mandrel Assembly designed to inject in two formations is schematically represented in FIG. 4 A/B. The difference between the Upper Mandrel which contains an Upper Formation Injection Valve ( 18 ) in its interior and the Lower Mandrel composed by a designed-to-measure Lower Formation Injection Valve ( 21 ) and the Lower Plug ( 22 ) can be observed in FIG. 4 A/B. The upper end of the Upper Free Mandrel is screwed at the lower end of the Transport Assembly (B) by the Outer Jacket ( 15 ) to the Lower Connector ( 14 ). The Outer Jacket ( 15 ) closes with the FBHA (D) Upper Packer Collar ( 25 ) through the Outer Jacket Seal Ring ( 16 ), which contains the Upper Formation Injector Valve ( 18 ) in its interior and is screwed to the Middle Plug ( 17 ) at its lower end. The Middle Plug ( 17 ) closes the FBHA (D) Lower Packer Collar ( 32 ) with Middle Plug Collar Seal Ring ( 20 ). The Lower Formation Injection Valve ( 21 ) is screwed in its upper end to the Middle Plug ( 17 ) lower end. The Lower Formation Injection Valve ( 21 ) in its lower end is screwed to the Lower Plug ( 22 ) which closes with Lower Plug Seal Rings ( 23 ) in the Seat ( 34 ) of the Fixed Bottom Hole Assembly (D) ( FIG. 6 ) FIG. 4 A/B shows the incoming injection fluid which comes out regulated from the Upper Formation Injection Valve ( 18 ) lower end to fulfill the upper formation required conditions, Whereas, the incoming injection fluid flows through the Annular Space (e 7 ) limited on the outside by the Upper Mandrel Jacket ( 15 ), goes through the Middle Plug ( 17 ), Vertical Passages (C 1 ) (only shown in FIG. 4 B), reaches the Lower Mandrel and is admitted by the Lower Formation Injection Valve ( 21 ) which transforms the fluid to fulfill the lower formation required conditions. As it has been previously described, the Upper Mandrel, which contains the Upper Formation Injection Valve ( 18 ), receives the Plant fluid and the regulated fluid for upper formation required conditions, finally comes out from the Upper Injection Valve ( 18 ) lower end. The incoming injection fluid moves through the annular (e 7 ) limited on the outside by the Upper Mandrel Jacket ( 15 ) and on the inside by the Upper Formation Injection Valve ( 18 ) This fluid reaches the Lower Mandrel through the Middle Plug ( 17 ) Vertical Passages (C 1 ) (only shown in FIG. 4B ) and is admitted by the Lower Formation Injection Valve ( 21 ). That is to say, the Lower Formation Injection Valve ( 21 ) receives the incoming injection fluid and transforms it into the fluid with the necessary conditions to be injected in the Lower Formation. 4-(D)—Fixed Bottom Hole Assembly—FBHA: It is schematically represented in FIG. 6 . This Assembly is static. All of its parts are designed-to-measure for the Free Mandrel System, Protective Casing. The Workover Equipment installs it with its lower end screwed to the On-Off Sealing Connector ( 43 ) upper end, and its upper end to the first 73.026 (2″⅞) Tubing ( 9 ) at its lower end screwed in the string that communicates the FBHA (D) with the Well Head ( 8 ) The FBHA (D) lodges the FMA (C) so that hydraulic circuits are complemented. They allow the Upper Packer F.H. ( 44 ) and the Lower Packer F.H. ( 46 ) to be fixed from the surface during the Free Mandrel System, Protected Casing installation, without having to resort to Slickline or Wireline equipment. When the installation is over, Selective Injection is performed in every Formation. The FMA (C) seals the Upper Packer Collar ( 25 ) with Outer Jacket Seal Ring ( 16 ) ( FIGS. 4 A/B and 6 ) and separates the injection fluid contained in the 73.026 mm (2″⅞) Tubing ( 9 ) (i) that enters the Upper Mandrel through the Transport Assembly (B). The Upper Free Mandrel is provided with a Middle Plug ( 17 ) in its lower end ( FIG. 4 A/B). This Middle Plug seals the Lower Packer Collar ( 32 ) with Middle Plug Seal Ring ( 20 ) ( FIGS. 4 A/B and 6 ) and prevents the fluid regulated by the Upper Formation Injection Valve from passing to the FBHA (D) lower chamber. The Lower Formation Injection Valve ( 21 ) receives Injection fluid through the Middle Plug ( 17 ), Vertical Passages (C 1 ), ( FIGS. 4B , 5 B and 7 B) regulates the flow that is required for the Lower Formation Injection, and channels it through the Lower Plug ( 22 ) ( FIGS. 4 A/B, 5 A/B, 7 A and 7 B) The Casing Protective Valve ( 36 ) is located in the lower chamber of the FBHA (D) ( FIG. 6 ). The Casing Protective Valve ( 36 ) allows low pressure fluid passage to go through the Annular Space (e 1 )) to 73.026 (2″⅞) Tubing ( 9 ) (i) Interior (Direct) but prevents the high pressure of injection fluid from passing from the 73.026 mm (2″⅞) Tubing (i) Interior (Direct) to the Annular Space (e 1 )) thus keeping the Casing ( 10 ) totally isolated from injection fluid high pressure and contact. In the upstroke, the low pressure fluid impulses the Free Mandrel Assembly (C) up to remove injection valves. FIGS. 7 A and B represent two views of the TA (C) assembled together with the FMA (C) inserted in the FBHA (D) in operating position, that is to say, ready to inject selectively in both Formations. 5-(E)—Complementary Assembly—CA: The CA (E) has been schematically represented in FIG. 22 . It is screwed in the lower part of the FBHA (D). It is composed of specific parts that correspond to the invention equipment design. They are complemented by other standard parts of common use in the Petroleum Industry. On the outside, the lower part of the FBHA (D) screws in the upper part of On-Off Sealing Connector ( 43 ) which, in its lower part screws in the Upper Packer F.H. ( 44 ) upper end ( 44 ). Both are standard parts of common use in the petroleum industry. The Injector Plug ( 41 ) screws in the Upper Packer F.H. ( 44 ) lower part. This Plug lodges the passage where the Rupture Disc is located ( 42 ). The Injector Plug is another designed-to-measure part of the Free Mandrel System, Protected Casing. This Rupture Disc ( 42 ) is used to fix the Upper Packer F.H. ( 44 ) and, once it has been fixed, pressure is raised until the Rupture Disc bursts and enables the circuit to perform Upper Formation Injection. The Telescopic Union Inner Body ( 37 ) is screwed to the FBHA (D) internally and in a concentric pattern. It slides and seals by means of Telescopic Union Seal Rings ( 38 ), the inside of the Telescopic Union Outer Body ( 39 ). The Telescopic Union has two functions: I) When the Upper Packer F.H. ( 44 ) is fixed, there is a longitudinal displacement that is absorbed by the Telescopic Union. II) The Telescopic Union allows On-Off Sealing Connector ( 43 ) rotation and longitudinal displacement to remove the FBHA (D) with the tubing string. The Injection Tube ( 40 ) is screwed in the lower part of the Telescopic Union Outer Body ( 39 ) and in the lower end of the Injector Plug ( 41 ). These three parts, Telescopic Union Outer Body ( 39 ), Injection Tube ( 40 ) and Injector Plug ( 41 ) are designed-to-measure for the Free Mandrel System, Protected Casing. The 60.325 mm (2″⅜) ( 47 ) Tubing that connect the Injector Plug ( 41 ) with the Lower Packer F.H. ( 46 ) are schematically represented in FIGS. 1 and 22 ). The required quantity of 60.325 mm (2″⅜) ( 47 ) to separate both packers are screwed in the lower part of the Injector Plug ( 41 ) and the Lower Packer F.H. ( 46 ), in its upper part. Other sections of the 60.325 mm (2″⅜) ( 47 ) Tubing connect the Lower Packer F.H. ( 46 ) with the Shear Out ( 48 ). The 60.325 mm (2″⅜) ( 47 ) Tubing is screwed in the lower part of the Lower Packer F.H. ( 46 ) and, at the other end, in the upper part of the Shear Out ( 48 ) which is also used to fix the Lower Packer F.H. (46). This circuit is closed by the Shear Out ( 48 ) interior ball that increases pressure in the 60.325 mm (2″⅜) Tubing ( 47 ). Once the Lower Packer F.H ( 46 ) is fixed, pressure continues increasing until the Shear Out ( 48 ) ball is displaced thus enabling the circuit to perform the Lower Formation Injection. Assembly Sequence for the Invention Equipment Installation: A) The assembly sequence of the fixed designed-to-measure components of the Free Mandrel System, Protective Casing and standard parts to be installed at the Well Head ( 8 ) is the following: I) The Shear Out ( 48 ) ( FIGS. 1 and 22 ) is assembled, ball included, in the 60.325 mm (2″⅜) ( 47 ) Tubing. II) The 60.325 mm (2″⅜) ( 47 ) Tubing is screwed with the Lower Packer ( 46 ). ( FIGS. 1 and 22 ) III) The 60.325 mm (2″⅜) Tubing ( 47 ) required for the separation between the Formations to be injected are screwed to the upper end of the Lower Packer. IV) The Injector Plug ( 41 ) ( FIGS. 1 and 22 ) is screwed to the last 60.325 mm (2″⅜) Tubing ( 47 ). The FBHA (D), factory assembled, is screwed to the CA (E) down to Injector Plug ( 41 ) ( FIGS. 1 and 22 ) including the Rupture Disc with the proper torque so that the Workover Equipment screws then Injector Plug ( 41 ) on the 60.325 mm (2″⅜) Tubing upper end ( 47 ), required by the well to comprise the distance of the Casing Upper Formation Perforations ( 49 ) V) The required quantity of 73.026 mm (2″⅞) Tubing ( 9 ) to reach the surface and to be screwed in the Full Passage Standard Injection Valve is assembled to the FBHA (D) upper end. VI) The Lubricator ( 3 ) will be installed on the 73.026 mm (2″⅞) Tubing Full Passage Standard Injection Valve ( 6 5 ) VII) The Mast ( 4 ) can be left assembled in the Lubricator or will be placed whenever a change of the Free Mandrel Assembly (C) is necessary. The other components of the SA (A) are assembled as indicated in FIG. 2 . B) Once the fixed components of the Free Mandrel System, Protective Casing are assembled in the well, additional operations are required to get the Free Mandrel System, Protected Casing installation ready to inject in several formations. The descriptions of these operations are the following: 1::1 Verification of the Tubing String Water Tightness As the complete Tubing String is assembled, water tightness tests are performed using the Full Blind Mandrel Assembly (c). (Not illustrated). The Full Blind Mandrel Assembly (C) is the one with a Blind Upper Injection Valve ( 51 ) in its Upper Mandrel and a Blind Lower Injection Valve ( 52 ) in its Lower Mandrel. Once the 73.026 mm (2″⅞) Tubing ( 9 ) (i) has been assembled up to surface, its water tightness is tested. The Well Head pressure is increased up to 3000 psi; the valve is closed and, for 20 minutes, it is necessary to verify that it keeps constant. Once tubing water tightness testing has been satisfactory, the Full Blind Mandrel Assembly is removed. 1::2 Lower Packer ( 46 ) Fixing The FMA (C) is lowered with the Blind Upper Injection Valve ( 51 ) screwed in the Middle Plug ( 17 ) upper end, and the fluid pumped by the Workover Equipment is only injected through the Lower Mandrel (Lower Formation Injection Valve ( 21 ) full passage). It pressurizes the Telescopic Union ( 37 and 39 ), the Injection Tube ( 40 ), the 60.325 mm (2″ ⅜) Tubing ( 47 ) and the Shear Out ( 48 ) with ball. (This circuit is closed). As the pressure is slowly increased, the Lower Packer F.H. ( 46 ) is fixed by cutting the pins. This is perceived by the impact of Jaws against the Casing ( 10 ). The proper fixing is verified according to the Packer supplier specifications. After that, the pressure is increased until the Shear Out ( 48 ) ball enables the Lower Formation Injection. Meanwhile, Formation admission tests are made according to the established program. The Lower Injection Circuit has no restrictions so the above mentioned tests can be performed. Pressures and volumes are also checked. During this operation, the pressure in the circuit to fix the Upper Packer ( 44 ) is null (white space). 1::3 Upper Packer F.H. ( 44 ) Fixing The FMA (C) is removed with the Blind Upper Injection Valve ( 51 ) which is replaced by Upper Formation Injection Valve ( 18 ) without restriction and the Blind Lower Injection Valve ( 52 ) is screwed in the Middle Plug ( 17 ) lower end. In this case, when the fluid is pumped through the 73.026 mm (2″⅞) Tubing ( 9 ), (i) it is all directed to the Upper Formation Injection Circuit. This is blocked in the Injector Plug ( 41 ) by the Rupture Disc ( 42 ). The Workover positions the Upper Packer F.H. ( 44 ) over the Casing Upper Formation Perforations ( 49 ) as the packer supplier recommends. When pressure is increased by the Workover Equipment Pump, the required pressure is reached by the rupture of the Upper Packer ( 44 ) pins and the Upper Packer F.H. ( 44 ) is fixed. Its proper position is checked according to what has been recommended by the manufacturer. Thereon, the pressure continues to be increased until the Rupture Disc bursts and this enables the circuit to inject in the Upper Formation. Admission tests are performed at different pressures according to the defined program. The Upper Injection Circuit has no restrictions so the above mentioned tests can be performed. 1::4 Down Stroke or FMA (C) Insertion Open Valves ( 6 1 ) and ( 6 5 ). Keep all the other valves closed. The FMA (C) is normally assembled for simultaneous injection with the Middle Plug ( 17 ), the Lower Plug ( 22 ) and corresponding regulated Injection Formation Valves according to the injection program. The Formation Selective Injection begins automatically when the FMA (C) arrives and inserts into the FBHA (D). After assembling the Well Head ( 8 ), the FMA (C) can be installed with the Workover Equipment Pump or with the Plant Injection Fluid. During the down stroke, fluid is injected in both formations without any type of control. In both cases, the fluid pushes the FMA (C) with the Upper and Lower Formation Injection Valves regulated according to the well Injection program until the FMA (C) inserts into the FBHA (D). At this moment, Selective Injection is automatically started in both formations according to what has been programmed. This is usually the last operation performed by the Workover Equipment. After the first installation has been performed and once the down stroke has begun, the Operator does not need to wait for the FMA (C) to reach and insert into the FBHA (D) as it will be accomplished in 20 or 25 minutes and Selective Injection will begin automatically. 1::5 Upstroke to Recover the FMA (C) on the Surface If for some reason, one or both injection valves need to be replaced, the upstroke is performed as follows: Close ( 6 1 ) Valve ( FIG. 2 ) and partially open Valve ( 6 2 ) and completely open Valve ( 6 3 ). This allows Injection Fluid to flow into the Impeller Circulation Pump ( 5 ). This component drives the low pressure fluid through the Annular Space (e 1 ), opens the Casing Protective Valve ( 36 ), goes into the FBHA (D) lower chamber and pushes the FMA (C) to the surface until it is hooked in the Catcher ( 2 ) of the SA (A). After the well is depressurized, the FMA (C) together with the TA (B) is removed by turning round the Catcher ( 2 ) and then, they are hoisted by the Mast ( 4 ). If the well is not depressurized, the Catcher ( 2 ) cannot be turned round. For safety reasons, it is designed to block itself, even if there is low pressure. In this case, the Operator can leave and perform other activities. When the operator comes back, he will find the FMA (C) in the Catcher ( 2 ) and the Formations already pressurized. If the operator needs to depressurize the well, he can proceed as follows: 1) Verify that the TA (B) together with the FMA (C) is hooked in the Catcher ( 2 ) 2) Verify all valves are closed 3) Open a purge valve included in the Lubricator. 4) The Lubricator will be at atmosphere pressure so the operator opens the Catcher ( 2 ) and releases the TA (B) together with the FMA (C) with the Mast ( 4 ) At the Well Head, the following components can be replaced: a) The Injector Valves by removing the used ones and placing new controlled units. b) The FMA (C) with the valves already installed. In both cases the task will be performed by the operator in a few minutes and the well will start up the selective injection in both formations. Obviously, FMA (C) replacement is faster with the valves already controlled. 1::6 Selective Injection Operation in Both Formations The Injection Fluid reaches the Surface Assembly (A) along a Pipeline ( 1 ) fed from the Water Plant and enters the System through V1 Standard Valve ( 6 1 ) completely open. Standard Valves ( 6 2 ), ( 6 3 ) and ( 6 4 ), shown in FIG. 2 , must be closed. The 73.026 mm (2″⅞) Standard Full Passage Injection Valve ( 6 5 ) has to be open to allow the FMA (C) to get through. The injection fluid, which enters the well through Standard Valve ( 6 1 ), fills the Lubricator ( 3 ) ( FIG. 2 ) and the fluid flows through 73.026 (2″⅞) Tubing ( 9 ) (i), goes through the Transport Assembly (TA) (B) and enters in the Free Mandrel Assembly (FMA) C, Upper Mandrel In the Upper Mandrel, the Upper Formation Injection Valve ( 18 ) ( FIGS. 4 A/B, 5 A/B, 7 A, 7 B, 8 , 9 and 13 ) intakes the injection fluid and regulates the flow that must be injected in the Upper Formation by guiding it through the Middle Plug ( 17 ) Radial Passage ( 19 ). This Upper Formation regulated fluid fills the chamber limited in the upper end by the Outer Jacket Seal Ring ( 16 ) that blocks the Upper Packer Collar ( 25 ). In the lower part, it is limited by Middle Plug Seal Ring ( 20 ) with the Lower Packer Collar ( 32 ). The Upper Formation regulated fluid is compelled to go through the Annular Space (e 6 ) to the FBHA (D) inner side passage (C 2 ) ( FIGS. 7A , 7 B, 8 and 13 ) through which it successively discharges in the Annular Spaces (e 9 ), (e 10 ) and (e 11 ). On the outside, they remain limited with the On-Off Sealing Connector ( 43 ) (interior) and the Upper Packer ( 44 ). On the inside, it is limited by the Telescopic Union (exterior) ( 37 and 39 ) and the Injection Tube ( 40 ). At the lower end, the limit is the Injector Plug. ( 41 ). The Upper Formation regulated fluid goes out through the Rupture Disc passages ( 42 ) ( FIGS. 1 , 8 , 9 and 13 ). The Upper Formation fluid, which is regulated by the Upper Formation Injection Valve ( 18 ) ( FIG. 4 A/B), is oriented through the Injector Plug ( 41 ) Rupture Disc passage ( 42 ) ( FIGS. 1 , 8 , 9 and 13 ) to the chamber limited by: I) The Upper Packer F.H. ( 44 ) lower side in the upper end ( FIGS. 1 , 8 , 9 and 13 ) II) The Well Casing ( 10 ) on the outside ( FIGS. 1 , 8 , 9 and 13 ) III) The Telescopic Union ( 37 and 39 ) and the Injector Tube ( 40 ) in the inside ( FIGS. 1 , 8 , 9 and 13 ) IV) The Lower Packer ( 46 ) upper side in the lower end ( FIGS. 1 , 9 and 13 ) The Upper Formation fluid regulated by the Upper Formation Injection Valve ( 18 ) ( FIGS. 1 , 9 and 13 ) is then pushed to inject in the Upper Formation through the Casing Upper Formation Perforations ( 49 ) ( FIGS. 9 and 13 ). This is the course taken by the regulated fluid to go into the Upper Formation ( FIG. 16 ). Injection fluid takes up the Upper Formation Injection Valve Annular Space (e 7 ) in the Upper Mandrel. The fluid flows through the Middle Plug ( 17 ) Vertical Passages (C 1 ) ( FIGS. 4B , 5 B, 7 B, 8 , 11 and 13 ). These passages run into a chamber and the injection fluid is taken by the upper part of the Lower Formation Injection Valve ( 21 ) ( FIGS. 4 b , 7 B, 11 and 13 ), which regulates the flow to be injected in the Lower Formation. This Lower Formation regulated fluid to be injected in the Lower Formation is conducted through the Lower Plug ( 22 ) inner part, Seat ( 32 ) inner part, Telescopic Union ( 37 and 39 ) inner part, Injection Tube ( 40 ), Injector Plug inner part ( 41 ), 60.325 mm (2″⅜) Tubing ( 47 ) and Lower Packer ( 46 ) inner part, and finally unloaded through the Shear Out ( 48 ) ( FIGS. 1 , 11 and 13 ) into the chamber limited by: I) Lower Packer F.H. ( 46 ) lower side in the Upper end ( FIGS. 1 , 11 and 13 ) II) The Well Casing ( 10 ) on the outside (FIGS. 1 , 11 , 13 and 17 ) III) The bottom hole in the lower end The Lower Formation regulated fluid is introduced through the Casing Lower Formation Perforations ( 50 ) in the above-mentioned Formation ( FIGS. 1 , 11 , 13 and 17 ). This is the course taken by the Lower Formation regulated fluid to go into the Lower Formation FIGS. 7A and 7B show two views of the Transport Assembly (TA) (B) screwed in the upper end of the Free Mandrel Assembly (FMA) (C) inserted into the FBHA (D) and injecting selectively in both formations. Both sections show the circuits that drive fluids to every formation. The Plant Fluid is taken to be regulated by the Upper Formation Injection Valve ( 18 ) for the Upper Formation and the Lower Formation Fluid is taken to be regulated by the Lower Formation Injection Valve ( 21 ). In FIG. 7A , the view of the TA (B) is parallel to the Middle Plug ( 17 ) Injection Passage ( 19 ). In FIG. 7B , view of the TA (B) is perpendicular to the Middle Plug ( 17 ) Injection Passage ( 19 ). FIG. 4 shows the fluid that has been regulated for the Upper Formation required conditions. According to the previous detailed explanations and in order to reinforce the invention operational comprehension here follows a summary of the injection fluid operative paths: Injection fluid flows through the component parts of the invention structure in two formations: Upper and Lower Formations in the simplified model adopted as an example to perform one of the possible applications of the invention. The fluid that comes from the Plant, injection fluid, goes into the Tubing ( 9 ) (i) through the 2″⅞ Standard Full Passage Injection Valve ( 6 5 ). To make this operation possible, the Standard Valve ( 6 1 ) must be open and the ( 6 2 ), ( 6 3 ), and ( 6 4 ) Standard valves shut. The fluid reaches the Free Mandrel Assembly (FMA) (C) ( FIG. 4 A/B) through the Transport Assembly (ta) (B) ( FIG. 3 ). Selective Injection is then performed in the two formations, Upper Formation and Lower Formation In a downward description, it can be observed that two watertight chambers have been formed. They make it possible to direct the fluid to be injected: 1—An upper chamber ( FIGS. 1 , 7 A, 7 B, 8 , 9 , 11 and 13 ) limited by the closure produced between the upper Outer Jacket Seal Ring ( 16 ) that packs in the Upper Packer Collar ( 25 ), and the Plant pressure (injection fluid) contained in the Tubing string up to this location. 2—At the same time, an Upper Mandrel chamber will also be determined. This is contained between said closure produced by the upper Outer Jacket Seal Ring ( 16 ) with the Upper Packer Collar ( 25 ) and the closure produced between the Middle Plug Seal Ring ( 20 ) with the Lower Packer Collar ( 32 ). This chamber contains the fluid to be injected in the Upper Formation with pressure regulated by Upper Formation Injection Valve ( 18 ) and channeled through the Middle Plug ( 17 ) Radial Passage ( 19 ). Both the Plant pressure, injection fluid, in the Annular Space (e 7 ) and in the (C 1 ) Vertical Passage and the Injection Pressure in the Upper formation coexist in this chamber. ( FIGS. 1 , 4 A/B, 5 A/B, 7 A, 7 B, 8 , 9 , and 13 ). The Free Mandrel Assembly (FMA) (C) ( FIG. 4 A/B) lodges the Upper Formation Injection Valve ( 18 ) that regulates the Upper Formation Injection flow pressure and is screwed in the Middle Plug ( 17 ) in its lower end The circuit that drives this already regulated fluid is driven ( FIGS. 1 , 9 and 13 ) through the Middle Plug ( 17 ) Radial Passage ( 19 ), Annular Space (e 6 ), FBHA (D) Vertical Passages (C 2 ) to Annular Spaces (e 9 ), (e 10 ) and (e 11 ), Injector Plug ( 41 ) through Rupture Disc ( 42 ) passage to Annular Space limited by: I The Upper Packer F.H. ( 44 ) lower end ( FIGS. 9 and 13 ) II The Lower Packer F.H. ( 46 ) upper end ( FIGS. 9 and 13 ) III On the outside by the Casing ( 10 ) ( FIGS. 9 and 13 ) The fluid to be injected goes through the Casing Upper Formation Perforations ( 49 ) and enters the Upper Formation. ( FIGS. 1 , 9 , 13 , 16 ). 3—The Lower chamber ( FIGS. 11 and 13 ) is determined by the closure of the Lower Packer Collar ( 32 ) and Middle Plug Seal Ring ( 20 ), Lower Plug ( 22 ) Lower Plug Seal Ring ( 23 ) with Seat ( 34 ). The Lower Formation Injection Valve ( 21 ) admits the Plant Fluid (injection fluid) by its upper end and regulates the pressure to be injected in the Lower Formation. Between the Upper Mandrel Jacket ( 15 ) and the outside of the Upper Formation Injection Valve ( 18 ), in the Annular Space (e 7 ), the Plant, injection fluid feeds the Lower Formation Injection Valve ( 21 ) through the Middle Plug ( 17 ) Vertical Passages (C 1 ). Lower Formation Injection Valve ( 21 ) transforms the pressure and the volume as requested for Lower Formation Injection. FIGS. 11 and 13 show in the FBHA (D) the circuit that drives Lower Formation Injection regulated flow to be injected in the Lower Formation. It must go through the Lower Plug ( 22 ), Seat ( 34 ), Telescopic Union ( 37 and 39 ), Injector Tube ( 40 ) through Injector Plug ( 41 ) central passage ( FIGS. 11 and 13 ). In the Injector Plug ( 41 ) lower end, the 60.325 mm (2″ ⅜) Tubing ( 47 ) strings are screwed. These tubing connect the Injector Plug ( 41 ) with the Lower Packer F.H. ( 46 ). The 60.325 mm (2″⅜) Tubing ( 47 ) and the Shear Out ( 48 ) are screwed to the Lower Packer F.H. ( 46 ) lower end. The Lower Formation Injection fluid flows through the Casing Lower Formation Perforations ( 50 ) ( FIGS. 1 , 11 13 and 17 ). 4—The Free Mandrel Assembly Recovery Chamber ( FIG. 18 ) is the chamber limited by the FBHA (D) inner diameter and the outside of the Lower Formation Injection Valve ( 21 ) Jacket, Annular Space (e 8 ) ( FIG. 18 ). The chamber is closed by the Casing Protective Valve ( 36 ). The fluid that fills the said chamber is at the pressure of the column that contains the Annular Space (e 1 ) To enable the Free Mandrel Assembly (C) upstroke, low pressure fluid is injected through the Annular Space (e 1 )) and 73.026 mm (2″⅞) Tubing 9 (i) (Direct) is depressurized by opening Standard Valve ( 6 3 ). The Casing Protective Valve ( 36 ) opens and lets the fluid in. This fluid pushes up the Free Mandrel Assembly (C) until it is caught in the Catcher ( 2 ). To remove the Free Mandrel Assembly (FMA) (C) together with the Transport Assembly (TA) (B), it is only necessary to operate the Surface Valves in the following way: 1—Close Standard Valve ( 6 1 ) 2—Open Standard Valve ( 6 2 ) 3—Open Standard Valve ( 6 3 ) 4—Keep Standard Valve ( 6 4 ) closed. With this configuration, the Plant Water enters through the Impeller Circulation Pump ( 5 ) to the Annular Space (e 1 ). This opens the Casing Protective Valves ( 36 ) allowing the fluid to enter and disconnect the Free Mandrel Assembly (FMA) (C) and the Transport Assembly (TA) (B) from the Fix Bottom Hole Assembly (FBHA) (D). From this moment on, the fluid produces the upward push that makes the Rubber Cups ( 13 ) expand and closes the Transport Assembly Valve ( 12 ) located in the Fishing Neck ( 11 ). The upward speed is proportional to the volume of the fluid injected in the Annular Space (e 1 ). The upstroke ends with the Free Mandrel Assembly (FMA) (C) and the Transport Assembly (TA) (B) hooked together in the Catcher ( 2 ) located in the Lubricator ( 3 ). To remove the Free Mandrel Assembly (FMA) (C) together with the Transport Assembly (TA) (B) from the well: 1) Turn Catcher ( 2 ) eye-bolt until it adopts the “Catching” position. In this position, the Catcher cage retains the assemblies when they make an impact in their upstroke. 2) Close all Surface Assembly Valves ( 6 1 , 6 2 , 6 3 , 6 4 ). 3) Wait until 73.026 mm (2″⅞) Tubing ( 9 ) (i) (Direct) pressure reaches zero. 4) Turn Catcher ( 2 ) 90° to remove Catcher from the Lubricator ( 3 ). 5) Raise the Free Mandrel Assembly (FMA) (C) and the Transport Assembly (TA) (B) with the Mast ( 4 ). 6) Lower the assemblies and unhook them for inspection or replacement. To install the Free Mandrel Assembly (FMA) (C) and the Transport Assembly (B), the reverse process has to be performed: 1) All surface Valves must be shut. ( 6 1 to 6 5 ). 2) The two assemblies are hooked together, installed in the hoisting system and then introduced in the Lubricator ( 3 ). 3) The Catcher ( 2 ) is turned 90° to close the Lubricator ( 3 ). 4) Open 73.026 (2″⅞) Standard Full Passage Injection Valve ( 6 1 ). 5) The Catcher eye-bolt is turned to the releasing position so that the Free Mandrel Assembly (FMA) (C) and the Transport Assembly (TA) (B) unhook from the Catcher ( 2 ) and start the downward movement. 6) Valve ( 6 1 ) is opened so that the fluid push makes the assemblies descend at a proper speed, according to the injected flow. A speed of about 70 to 85 meters/minute is considered reasonable for the down stroke. Once the two assemblies, Free Mandrel Assembly (FMA) (C) and Transport Assembly (TA) (B) are engaged in the Fixed Bottom Hole Assembly (FBHA) (D), the pressure begins to rise until it reaches the Pipeline pressure. In this moment, the system begins automatically to inject selectively in the two formations.

The Free Mandrel System, Protected Casing is to be applied in the petroleum industry for selective injection of fluids, liquids or gases, in different formations while keeping the casing isolated from fluid pressure. As it is hydraulically driven by the injection fluid, an operator can handle the provided surface valves. The system includes five assemblies: Surface, Transport, Free Mandrel, Fixed Bottom Hole and Complementary. The Free Mandrel Assembly is the dynamic main device that carries all the Injection valves together, one for each formation, from the Fixed Bottom Hole to the surface in 30′ and vice versa. As this operation is performed many times in the well lifetime, it allows a cumulative time and money saving. Workover equipment is only used for installing the system and for fixing the required packers. Formation Pressure is kept at any time when the system is either operated, set up, or pulled up.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of and claims priority from U.S. application Ser. No. 14/947,763, filed Nov. 20, 2015, which is assigned or under obligation of assignment to the same entity as this application, the entire contents of the application being herein incorporated by reference. BACKGROUND [0002] Many image editing software applications are available for adjusting, modifying, and otherwise manipulating digital images. These software applications generally allow a user to make global manipulations to an entire image, as well as make localized manipulations affecting only a selected portion of an image. Sometimes, a user may want to extract portions of an image and apply the extracted portions to a new background or other design. When extracting portions of an image, a user must first select the portion of the image to be extracted, then copy and/or extract the portion for association with another image. Sometimes, selection of a complex object within an image in preparation for extraction can be quite difficult. A simplified tool for both selecting and accurately refining the selection of a complex object would be very beneficial. SUMMARY [0003] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. [0004] Embodiments described herein are directed to defining a matting region while editing a selection mask associated with a source image. In essence, embodiments are directed to employing a boundary-detecting algorithm to facilitate the identification of a matting region in real time as a user modifies a hard selection. In this way, as a user is refining a selection and approaches a complex portion of a selected object, a region-defining algorithm can define the complex portion as a matting region, such that a matting algorithm can be selectively applied thereon to obtain a refined selection edge over the complex portion. [0005] At a high level, a selection cursor is overlaid on a displayed source image. A selection mask boundary is adjusted by applying a boundary-detecting feature of a hybrid algorithm thereon. In accordance with adjusting the selection mask boundary utilizing boundary-detecting feature of the hybrid algorithm, a matting region is simultaneously defined along the selection mask boundary as it is being adjusted by applying a region-defining feature of the hybrid algorithm thereon. A matting algorithm can then be applied to the matting region defined along the adjusted selection mask boundary to refine the selection edge. BRIEF DESCRIPTION OF THE DRAWINGS [0006] The present invention is described in detail below with reference to the attached drawing figures, wherein: [0007] FIG. 1 is a diagram illustrating an exemplary system, in accordance with implementations of the present disclosure; [0008] FIG. 2 is a diagram illustrating an exemplary component of the system of FIG. 3 , more particularly, the user interface module, in accordance with implementations of the present disclosure; [0009] FIG. 3 is a schematic illustration of a selection cursor configured in accordance with both the prior art and an embodiment of the present disclosure; [0010] FIG. 4 schematically illustrates an example methodology of defining a selection region using a selection cursor, as is described in the prior art; [0011] FIG. 5 is a diagram illustrating an exemplary subcomponent of the system of FIG. 1 and FIG. 2 , more particularly, the hybrid selection refining module, in accordance with implementations of the present disclosure; [0012] FIGS. 6A-6C schematically illustrate an example methodology of defining a selection region and matting region using a selection cursor, in accordance with implementations of the present disclosure; [0013] FIG. 7 illustrates an example source image selection mask having a defined selection region and matting region using a selection cursor, in accordance with implementations of the present disclosure; [0014] FIG. 8 is a flow diagram showing a method for adjusting a selection mask associated with a source image, in accordance with implementations of the present disclosure; [0015] FIG. 9 is a flow diagram showing a method for adjusting a selection mask associated with a source image, in accordance with implementations of the present disclosure; [0016] FIG. 10 is a flow diagram showing a method for adjusting a selection mask associated with a source image, in accordance with implementations of the present disclosure; and [0017] FIG. 11 is a block diagram of an exemplary computing environment suitable for use in implementations of the present disclosure. DETAILED DESCRIPTION [0018] The subject matter of the present invention is described with specificity herein to meet statutory requirements. However, the description itself is not intended to limit the scope of this patent. Rather, the inventors have contemplated that the claimed subject matter might also be embodied in other ways, to include different steps or combinations of steps similar to the ones described in this document, in conjunction with other present or future technologies. Moreover, although the terms “step” and/or “block” may be used herein to connote different elements of methods employed, the terms should not be interpreted as implying any particular order among or between various steps herein disclosed unless and except when the order of individual steps is explicitly described. [0019] Embodiments described herein are directed to providing a selection mask refinement feature operable to refine hard selections while automatically defining matting regions along detected object boundaries. More particularly, embodiments described herein are directed to a selection mask refinement feature that can adjust a hard selection mask using an edge-detecting algorithm, while simultaneously defining a matting region driven by the confines of the edge-detecting algorithm. Once a matting region is defined, a matting algorithm can then be selectively applied to the defined matting region to cooperatively make a refined and accurate selection mask around detected complex edges. In other words, embodiments can define a matting region or “soft selection” on detected complex edges while editing a hard selection mask associated with a source image. In this way, selection masks can be modified and accurately refined in a single step with a unitary selection tool. [0020] As was described briefly above, image editing software applications are often used to adjust, modify, and otherwise manipulate digital images. One example of such an application is Adobe® Photoshop®, developed by Adobe Systems Incorporated. Software such as this allows users to make localized adjustments to a selected portion of an image, copy selected portions of an image, or extract selected portions of an image. These operations can be useful, for example, if a user wishes to extract a foreground object from one image, and place the object onto a new background or design. Whenever an object is selected, however, such localized operations first require the creation of a “selection mask” which defines the portion of the image that is to be adjusted, copied, or extracted. After the selection is defined, the desired operation can then be applied to the portion of the image within the selection mask. [0021] Conventional selection tools may incorporate algorithms that assist in detecting edges or “boundaries” of a foreground object distinguishable from its background. In this way, objects having more definite or clearly-defined edges can easily be selected by a user employing a conventional selection tool. These conventional selection tools make what is known in the art as “hard selections.” Hard selections are typically made using a level set algorithm, which defines whether a selected portion of an image is clearly inside the selection, outside the selection, or along the selection boundary. In some instances, however, image backgrounds may be muddied, and unexpected colors or shadows may cover portions of the foreground object, which may cause the selection tool to select undesirable edges. Because edge-detecting algorithms are far from perfect, some image editing software applications have developed selection edge-adjustment features that can modify a hard selection edge by pushing and snapping portions of the hard selection to various edges as they are detected, based on inputs by a user. [0022] In some other instances, the object being selected can be too detailed for the conventional selection tool. That is, the object may include edges that are too complex for edge-detecting algorithms to make accurate and detailed selections. For example, portions of a lion's mane (i.e., wispy hairs) could be too complex for the conventional selection tool. More particularly, complex portions such as hair, eye lashes, feathers, grass, leaves, and other objects having fibrous or feathered characteristics can provide difficult for edge-detecting algorithms in conventional selection tools to accurately distinguish from their background. As conventional selection tools typically employ a level set algorithm for boundary detection, a portion of an image that may appear blurry or indefinite (i.e., the hairs standing out of the lion's mane) must either be determined as being part of a selection or not. Although conventional selection tools and selection-edge adjustment features are unable to make accurate and detailed selections of complex boundaries or edges, the edge-detecting features therein can still make a fairly decent determination of the object's boundary line. [0023] Separate tools having specialized algorithms are traditionally employed by users to specify complex regions of a source image, for analysis and refinement of the initially-defined hard selection. When image objects have edges that are too complex for the conventional selection tool, some image editing software applications provide what are called “soft selection” tools that allow a user to make or refine intricate selections to the complex edges. Although not described in detail herein, disclosure for such soft selection tools is incorporated herein with particular reference to U.S. Pat. No. 8,406,566, entitled METHODS AND APPARATUS FOR SOFT EDGE MASKING. A major setback of such soft selection tools is that it requires that the user manually specify where the complex edges of the object are. In this regard, it would be highly desirable to incorporate into a selection tool and/or a selection-edge adjustment feature, an additional soft selection feature that can utilize the edge-detecting features of conventional selection tools to automatically specify a region around the complex edges (also referenced herein as a “matting region”) utilized for making the soft selection. [0024] Turning now to FIG. 1 , a diagram is provided illustrating an exemplary system in accordance with implementations of the present disclosure. It should be understood that this and other arrangements described herein are set forth only as examples. Other arrangements and elements (e.g., machines, interfaces, functions, orders, and groupings of functions, etc.) can be used in addition to or instead of those shown, and some elements may be omitted altogether. Further, many of the elements described herein are functional entities that may be implemented as discrete or distributed components or in conjunction with other components, and in any suitable combination and location. Various functions described herein as being performed by one or more entities may be carried out by hardware, firmware, and/or software. For instance, various functions may be carried out by a processor executing instructions stored in memory. [0025] The system 100 can be a client only or a client-server system that can be utilized to make adjustments to selection masks associated with a source image. Among other components not shown, the system 100 can include any number of client devices, such as client devices 110 a and 110 b through 110 n, network 120 , and one or more remote server devices 130 . It should be understood that any number of servers and client devices may be employed within system 100 within the scope of the present disclosure. Each may comprise a single device or multiple devices cooperating in a distributed environment. Additionally, other components not shown may also be included within the distributed environment. [0026] It should further be understood that system 100 shown in FIG. 1 is an example of one suitable computing system architecture. Each of the servers and client devices shown in FIG. 1 may be implemented via a computing device, such as computing device 1100 , later described with reference to FIG. 11 , for example. The components may communicate with each other via network 120 . [0027] Network 120 may be wired, wireless, or both. Network 120 may include multiple networks, or a network of networks, but is shown in simple form so as not to obscure aspects of the present disclosure. By way of example, network 120 can include one or more wide area networks (WANs), one or more local area networks (LANs), one or more public networks, such as the Internet, and/or one or more private networks. Where network 120 includes a wireless telecommunications network, components such as a base station, a communications tower, or even access points (as well as other components) may provide wireless connectivity. Networking environments are commonplace in offices, enterprise-wide computer networks, intranets, and the Internet. Accordingly, network 120 is not described in significant detail. [0028] In various implementations, client devices 110 a and 110 b through 110 n are computing devices that are capable of accessing the Internet, such as the World Wide Web. Client devices might take on a variety of forms, such as a personal computer (PC), a laptop computer, a mobile phone, a tablet computer, a wearable computer, a personal digital assistant (PDA), an MP3 player, a global positioning system (GPS) device, a video player, a digital video recorder (DVR), a cable box, a set-top box, a handheld communications device, a smart phone, a smart watch, a workstation, any combination of these delineated devices, or any other suitable device. [0029] Client devices 110 a and 110 b through 110 n can include one or more processors, and one or more computer-readable media. The computer-readable media may include computer-readable instructions executable by the one or more processors. The instructions may correspond to one or more applications, such as browser 112 , image editing software 114 and/or user interface module 116 , shown on client device 110 a. [0030] Browser 112 , such as a web browser, can be an HTTP-compatible application (e.g. an Application that supports an HTTP protocol). A specific example of browser 112 is a Google® Chrome® web browser. Image editing software 114 may be independently installed on the client device as a standalone application, or can be accessed through a web-based application hosted by server 130 or other server(s) (not shown) and accessible to client devices by the browser 112 . In some instances, the image editing application 114 can be accessible over the web (e.g., a dynamic web application or a cloud-based web application) through the browser 112 . Accessing the dynamic web application 114 over the web can be accomplished on the client 110 a by visiting a Uniform Resource Identifier (URI or URL) to receive code (e.g., HTML) for rendering, the code being dynamically generated by the server 130 and communicated to the client 110 a over the network 120 . [0031] The image editing application 114 can be configured to, among other things, manipulate source images by at least making selections to objects and/or backgrounds using one or more selection editing tools. One example of such an application is Adobe® Photoshop®, developed by Adobe Systems Incorporated. In some embodiments, the image editing application can include a user interface module for facilitating the selection and manipulation of objects or backgrounds in source images, as will be described in more detail with regards to user interface module 116 . [0032] The user interface module 116 can be configured to provide information to, and to receive information and commands from, a user; it can be implemented with or otherwise used in conjunction with a variety of suitable input/output devices such as a display, a touchscreen, a speaker, a keyboard, a mouse and/or a microphone. [0033] The image editing application 114 can also be configured to read and/or manipulate image content 118 , which can comprise one or more source images. In various configurations, the image content 118 can be read, manipulated, and saved in memory as a new and/or separate asset. [0034] The server 130 can include one or more server computing device(s) configured in a network environment, or can include a single computing device hosting, in some embodiments, an application service for the image-editing software 114 . Each server computing device can include one or more processors, and one or more computer-readable media. The computer-readable media may include computer-readable instructions executable by the one or more processors. The instructions may correspond to one or more applications, such as image editing software 114 or user interface module 116 , shown on server device 130 . The server 130 can be configured to store, among other things, computer-readable instructions for hosting the image-editing software 114 , image content 116 , and more, in a memory (not shown). The memory can be comprised of one or more computer-readable media, or may comprise one or more database(s) (not shown) for storing data, as can be appreciated by one of ordinary skill in the art. [0035] The server 130 can comprise a web server, such as Apache®, ITS®, nginx®, or GWS®, among many others, and can be configured to communicate over the network 120 to provide application services for manipulating source images to users on a client device via browser 112 or image editing software application 114 . While the standard network protocol for communication is HTTP, it is contemplated that any network protocol can be used to distribute information between the server 130 and the image editing application 114 of client device 110 a . In more detail, if the image editing application 114 is communicated to the client device 110 a over the World Wide Web and accessed via browser 112 , the server 130 can be configured to provide dynamic code, or the like, to users for navigating a workflow directed to manipulating source images. If the image editing application 114 is a standalone application installed on the client device 110 a, in some embodiments, the server 130 can be configured to provide cloud services for viewing, manipulation, and storage of image content 116 by the image editing application 114 . [0036] Moving now to FIG. 2 , the user interface module 200 can be configured with the various selection editing techniques provided herein, so as to facilitate the process of selecting a targeted and refined portion of a digital image using an image editing software application, in accordance with an embodiment of the present invention. This functionality can be implemented using, for example, sub-modules including a hybrid selection refining module 210 , a cursor module 220 , and a display module 230 . Other modules may additionally or alternatively be included, in other embodiments. As will be appreciated, the image editing application may be local to the client device 110 a of FIG. 1 , or served to the client device 110 a by an application server 130 . In other embodiments, the selection editing techniques may be implemented in one or more dedicated modules with which the user interface module 200 interacts. These various selection editing techniques and sub-modules will be discussed in greater detail with reference to the example embodiments depicted in FIGS. 6A-6C . [0037] As was described, embodiments described herein employ a hybrid algorithm that includes aspects from both a conventional level set algorithm for making or editing the hard selection mask, in addition to a tri-regional level set algorithm for defining a matting region to apply the matting algorithm thereon. Although not described herein, disclosure for conventional level set algorithms for making and refining hard selection masks is incorporated herein with particular reference to U.S. Non-Provisional patent application Ser. No. 13/789,975, Attorney Docket No. 2976US01, entitled SELECTION EDITING USING A LOCALIZED LEVEL SET ALGORITHM (hereinafter referenced as “the Prior Art”). [0038] With reference to FIG. 3 , in one embodiment, a selection tool, such as selection cursor 300 of FIG. 3 , can include a hybrid level set algorithm that employs aspects from both the conventional level set and the regional level set to operate as a hybrid selection refining module, as will be described with reference to FIGS. 5-7 . The example selection cursor 300 includes an interior region 310 having a radius r, and a peripheral region 320 having a thickness t that generally surrounds the interior region 310 . The interior region 310 and peripheral region 320 meet at an interface 315 . The interior region 310 is also referred to herein as the central region 310 , even though the interior region 310 does not need to be positioned in the center of the selection cursor 300 . While the example selection cursor 300 has a circular configuration, it is contemplated that such a configuration is not limiting and selection cursors having other shapes and/or sizes can be employed within the scope of the prior art and embodiments described herein. In some embodiments, the relative dimensions of the radius r and the central region 310 and the thickness t of the peripheral region 320 of the selection cursor 300 are user-configurable. Thus, for instance, if a user wanted to use a selection cursor having a relatively larger central region and relatively smaller peripheral region, or vice-versa, the selection cursor could be configured according to such preference. However, in other embodiments, the shape and dimensions of the selection cursor are not configurable, and are otherwise predetermined by default. [0039] In some embodiments, the central region 310 of the selection cursor 300 is used to define a region of the source image that is to be included, within the selection region, in such embodiments, moving the central region 310 over a portion of the source image causes that portion of the source image to be included within the selection region. In this case, the selection cursor 300 is referred to as having a positive polarity, or as being a “selecting”, “growing” or “sourcing” selection cursor. However, in other embodiments the central region 310 of the selection cursor 300 is used to define a region of the source image that is to be excluded from the selection region. In such embodiments, moving the central region 310 over a portion of the source image causes that portion of the source image to be excluded from the selection region. In this case, the selection cursor 300 is referred to as having a negative polarity, or as being a “deselecting”, “shrinking” or “sinking” selection cursor. The polarity of the selection cursor 300 can be controlled, for example, via a configuration setting accessed using a control menu, a configuration setting accessed using a control panel, or through the use of an alternate selection control such as an alternate mouse button. In certain embodiments the polarity of the selection cursor 300 can be indicated to the user by a different appearance of the selection cursor, such as a different color or texture scheme. For more detail on the selection cursor 300 , disclosure for such is provided with particular reference to the Prior Art. [0040] By way of background, with brief reference to FIG. 4 , a conventional selection tool as described in the Prior Art demonstrates a selection cursor 300 used to define a new selection region or to expand an existing selection region. In this example, the selection cursor 300 has a positive polarity. The source image 400 includes a boundary 402 that is to be detected. The selection region 410 is optionally indicated by a boundary line 414 , which can be displayed to the user in real-time, or nearly in real-time, as the user moves the selection cursor 300 over the source image 400 , in some embodiments. As explained previously, portions of the source image 400 over which the cursor central region 310 passes are included within the selection region 410 . A level set algorithm is applied within the cursor peripheral region 320 , thereby allowing boundary 402 to be detected. In general, the selection region 410 expands outward from the cursor central region 310 toward the outer edge of the cursor peripheral region 320 , as indicated by arrows 416 in FIG. 4 . The arrows 416 correspond to a velocity vector associated with the rate of expansion of the selection region 410 . However, where a boundary is detected within the peripheral region 320 , such as boundary 402 , the expansion of selection region 410 is modified such that selection region 410 substantially conforms to, and is constrained by, the detected boundary 402 . [0041] With brief reference now to FIG. 5 , embodiments described herein are directed to a hybrid selection refining module 500 , which includes at least a conventional level set algorithm 510 and a regional level set algorithm 520 . On a high level, the conventional level set algorithm 510 can be employed to essentially “drive” the matting region-defining portion of the regional level set algorithm 520 . As was described in reference to FIG. 4 , the conventional level set algorithm was applied within the cursor peripheral region 320 , which allowed boundary 402 to be detected. The conventional level set algorithm, when applied within the cursor peripheral region 320 , would expand the selection region 410 and modify the selection region 410 such that selection region 410 substantially conforms to, and is constrained by, the detected boundary 402 . Complex portions such as hair, eye lashes, feathers, grass, leaves, and other objects having fibrous or feathered characteristics can be detected, albeit very roughly, by edge-detecting algorithms. At a minimum, the edge-detecting algorithms of conventional selection tools can determine that some portion of the complex portion may or may not be inside of the selection. [0042] Now, with regards to the hybrid selection refining module 500 in FIG. 5 , the conventional level set algorithm 510 can also be applied within the cursor peripheral region, but instead of driving the expansion of the selection region 410 , the conventional level set algorithm 510 is employed by hybrid selection refining module 500 to expand and detect boundaries for placement of a matting region. More particularly, although the edge-detecting aspects of the conventional level set algorithm 510 can oftentimes make a very rough determination of a complex boundary (such as boundary 602 in FIG. 6B ), it can at least roughly define a matting region, which is generally defined between the inside of a selection and the outside of the selection. [0043] By way of background, regional level set algorithms, such as regional level set algorithm 520 , are generally configured to define regions of images and shapes relative to one another. Tri-regional level set algorithms, in particular, can define whether a portion of an image is clearly within a first region (i.e., inside a selection), clearly within a second region (i.e., outside the selection), or within a third region (i.e., part of a matting region positioned somewhere in between the first and second regions). In essence, a tri-regional level set can define three definite regions of an image, in accordance with embodiments described herein. In contrast to the level set algorithm, which defines merely whether a region is defined inside or outside of a selection region, the tri-regional level set algorithm is configured to define three distinct regions—inside a selection, outside a selection, and a matting region. In embodiments described herein, the regional level set algorithm 520 essentially “piggy-backs” the edge-detecting features of the conventional level set algorithm 510 to define a matting region, as will be described with reference to FIGS. 6A-6C . [0044] Looking now to FIGS. 6A-6C , FIGS. 6A-6C illustrate an example methodology for defining a refined selection region employing the hybrid selection refining module. FIGS. 6A-6C illustrate an example methodology for defining an selection region 610 and a matting region 618 using a selection cursor 100 that is passed over a source image 600 in a direction indicated by arrow 612 , in accordance with an embodiment of the present invention. This technique can be used to define a new selection region 610 or to expand an existing selection region 610 , while also defining a matting region 618 for refinement of the selection region 610 . In this example, the selection cursor 100 has a positive polarity. The source image 600 includes a boundary 602 that is to be detected. The selection region 610 is optionally indicated by a selection boundary line 614 and a matting region 618 is optionally indicated by a matting region boundary line 616 , which can each be displayed to the user in real-time, or nearly in real-time, as the user moves the selection cursor 100 over the source image 600 , in some embodiments. [0045] Similar to the conventional selection tool, portions of the source image 600 over which the cursor central region 110 passes are included within the selection region 610 . A hybrid algorithm is applied within the cursor peripheral region 120 . The conventional level set portion of the hybrid algorithm (for instance, conventional level set algorithm 510 of FIG. 5 ) is applied within the cursor peripheral region 120 , which expands as the sub-region of the source image is analyzed, thereby allowing boundary 602 to be detected. The boundary-detection aspects of the conventional level set portion of the hybrid algorithm are particularly demonstrated by dotted line 615 . At the same time, the regional level set algorithm (for instance, regional level set algorithm 520 of FIG. 5 ) is also applied within the cursor peripheral region 620 , thereby allowing at least the defining of a matting region 618 . [0046] In more detail, the regional level set algorithm defines the first region (inside the selection) 610 , the second region (outside the selection) 619 , and the third region (the matting region) 618 . In some embodiments, the matting region 618 is characterized as surrounding a region outside and inside the boundary-detecting aspects of the conventional level set portion of the hybrid algorithm, demonstrated by dotted line 615 . In this way, the matting region is characterized as a thick line that corresponds to the boundary-detection aspects of the conventional level set portion of the hybrid algorithm. [0047] In general, the selection region 610 follows the expanding dotted line 615 driven by the conventional level set portion of the hybrid algorithm, while the matting region 618 is pushed outwardly by the dotted line 615 , while both regions 610 , 618 expand outward from the cursor central region 110 toward the outer edge of the cursor peripheral region 120 , as indicated by arrows 620 in FIG. 6A . The arrows 616 correspond to the velocity vector [0000] → v [0000] of Equation (3), above. However, where a boundary is detected within the peripheral region 120 , such as boundary 602 , the expansion of selection region 610 is modified such that selection region 610 is constrained by the detected boundary 602 . In more detail, the expansion of the selection region 610 is restricted from extending past the detected boundary 602 , while the expansion of matting region 618 extends past the detected boundary 602 , but is similarly modified such that matting region 618 is constrained from extending too far beyond the detected boundary 602 . Such modification is illustrated in FIG. 6B , which shows that the selection region 610 has expanded toward the outer edge of the cursor peripheral region 120 , except where such expansion is constrained by boundary 602 . Likewise, the matting region 618 has also expanded toward the outer edge of the cursor peripheral region 120 , and extends past the boundary 602 , but is constrained from extending beyond the outer edge of the cursor peripheral region 120 . In embodiments, a matting algorithm can be selectively applied to the defined matting region 618 , so as to refine the selection region 610 with a soft selection in addition thereon. Selective application of the matting algorithm can be facilitated by a user input, such as a mouse click, the release of a mouse input, or any other user interaction with an input device. [0048] If the user wishes to expand the selection region 610 across the detected boundary 602 , the user can simply move the cursor central region 110 across boundary 602 . Because portions of the source image 600 over which the cursor central region 110 passes are included within the selection region 610 regardless of any boundaries detected in the source image 600 , this will effectively expand the selection region 610 and the matting region 618 across the detected boundary 602 , as is illustrated in FIG. 6C . In this example case, the hybrid algorithm continues to be applied within the cursor peripheral region 120 such that other boundaries that may exist beyond boundary 602 are detected and matting regions are further defined. [0049] Referencing back now to FIG. 5 , hybrid selection refining module 500 includes the conventional level set 510 (“Φ”) and the regional level set 520 (“(r, Ψ)”). To this end, the grow and/or shrink velocity can be computed from a gradient of Φ. Utilizing Φ further facilitates the ability to retain the hard selection boundary, as is typical of the conventional level set algorithm. Further, edge snapping, as described above and in Prior Art with regards to the applications of the conventional level set algorithm, is applied for Φ only. As such, Φ and (r, Ψ) are updated by slightly varying velocities. This, however, causes a compatibility issue as Φ<0 is indicative that the position is located inside the selection, and when Φ<0, r cannot equal 1. Similarly, when Φ>0, r cannot equal 0. To solve this discrepancy, after updating Φ and (r, Ψ), compatibility is enforced by setting the following: [0000] if Φ<0 and r=1, set r=0 and Ψ=0 [0000] if Φ>0 and r=0, set r=1 and Ψ=0. [0000] To this end, in the following re-distancing step, Ψ will grow slightly by negotiating with neighbors so that the gradient of Ψ is close to 1. [0050] In some embodiments, the matting region can be thickened by employing the following: [0000] if r= 2, then Ψ=Ψ+ S [0000] if r= 0 or 1, then Ψ=Ψ− S [0000] if Ψ<0, then Ψ=−Ψand r= 2 [0000] where S is the speed of growth. [0051] While a tri-regional level set algorithm, without being conjoined with a level set algorithm, may be considered for use in selection tools, such as selection cursor 300 of FIG. 3 , for defining the various regions (i.e., inside, outside, and matting regions), the tri-regional level set algorithm alone may encounter problems in facilitating the grow and shrink operations of the selection cursor, as described in reference to FIG. 4 . More particularly, where the conventional level set described above is represented by the signed distance function Φ, the regional level set is represented by (r, Ψ), where r is an integer and Ψ is an unsigned (non-negative) distance to the trimap boundary (i.e., the selection boundary). The function r can be characterized as either r=0 (inside the selection), r=1 (outside the selection), or r=2 (part of the matting region). When computing a distance field's gradient using regional level sets, −Ψ of the neighbor is employed if the neighbor has a different r value. Problematically, however, using regional level set algebra, the velocity vector [0000] → v [0000] does not compute as required for grow and shrink operations. This is because the velocity vector is computed from the gradient of Ψ, and the gradient of Ψ depends on a regional algebra design—such as changing the sign of Ψ based on regional differences. Unfortunately, there is no regional algebra that computes high quality gradients that can be used for growing or shrinking operations. Use of regional level sets in the context of structural region definitions is further discussed in “Multi-Phase Fluid Simulations Using Regional Level Sets”, by Byungmoon Kim (2010), and also in “Simulation of bubbles”, by Wen Zheng et al. (2009). [0052] Looking now at FIG. 7 , a source image 700 portraying a lion is provided, so as to illustrate how the unselected region 720 , the selected region 710 , and the matting region 730 are each displayed and distinguished in an exemplary pass of the hybrid selection refining module (for instance, employing user interface module 400 of FIG. 4 ). In the illustrated embodiment, the selected region 710 shows a first portion of the underlying source image, the unselected region 720 shows a darker translucent mask over a second portion of the underlying source image, whereas the masking region 730 shows a lighter translucent mask over a third portion of the underlying source image. As described, upon making a selection with the hybrid selection refining module in accordance with embodiments described herein, the selected region 710 is established as part of the user's selection, the unselected region 720 is established as outside of the user's selection, while the matting region 730 is in a region between the selected region 710 and unselected region 720 . The matting region 730 can then be selectively processed by a matting algorithm so that a sub-region of the underlying source image corresponding to the matting region 730 is analyzed and a soft selection is made thereon for refinement of the selected region 710 . Application of the matting algorithm can refine the selected region 710 so that complex portions of the image, such as portion 740 , is accurately selected and appended to selected region 710 . [0053] Having described various aspects of the present disclosure exemplary methods are described below for adjusting a selection mask associated with a source image. Referring to FIG. 8 in light of FIGS. 1-3 and 5-6C , FIG. 8 is a flow diagram showing a method 800 for employing a hybrid level set algorithm for interactively editing a matting region and a selection. Each block of method 800 and other methods described herein comprises a computing process that may be performed using any combination of hardware, firmware, and/or software. For instance, various functions may be carried out by a processor executing instructions stored in memory. The methods may also be embodied as computer-usable instructions stored on computer storage media. The methods may be provided by a standalone application, a service or hosted service (standalone or in combination with another hosted service), or a plug-in to another product, to name a few. [0054] At block 810 , a source image or a portion thereof, and a selection mask associated therewith, is provided for display. The selection mask comprises a selected region and an unselected region separated by a selection mask boundary. By way of example, an object in a source image is roughly selected by employing a hard selection tool (i.e., a quick selection tool) that utilizes a conventional level set algorithm. The selected and unselected regions are separated by a mask boundary, which can be, for example, a dotted line, a defined line distinguished by the varying shades or colors of the selected and unselected regions, and the like. [0055] At block 820 , a selection cursor is provided for display over at least a portion of the source image. The selection cursor has an interior region and a peripheral region. By way of example, the selection cursor 100 of FIG. 1 can be employed as a selection cursor in accordance with embodiments described herein. [0056] At block 830 , an adjustment is processed to the selection mask boundary in a portion of the source image that is overlaid by the peripheral region of the selection cursor. The adjustment includes applying a hybrid algorithm to the selection mask boundary along an initial position of the selection mask. The hybrid algorithm comprises a boundary-detecting feature configured to detect a boundary as a result of applying the boundary-detecting feature and a region-defining feature configured to define at least a matting region along the detected boundary. [0057] Referring now to FIGS. 1-3 and 5-6C in light of FIGS. 3-8 , FIG. 9 is a flow diagram showing a method 900 for employing a hybrid level set algorithm for interactively editing a matting region and a selection. Each block of method 900 and other methods described herein comprises a computing process that may be performed using any combination of hardware, firmware, and/or software. For instance, various functions may be carried out by a processor executing instructions stored in memory. The methods may also be embodied as computer-usable instructions stored on computer storage media. The methods may be provided by a standalone application, a service or hosted service (standalone or in combination with another hosted service), or a plug-in to another product, to name a few. [0058] At block 910 , a selection cursor having an interior region and a peripheral region is overlaid on a displayed source image. By way of example only, a selection cursor such as selection cursor 300 of FIG. 3 is provided as a selection tool over a source image for control by one or more user inputs (e.g., mouse movements and click-inputs). At block 920 , a boundary within a region of the source image that is overlaid by the peripheral region of the selection cursor is detected by applying a boundary-detecting feature of a hybrid algorithm to a portion of the source image. At block 930 , at least a matting region is defined along the detected boundary. The matting region is defined by applying a region-defining feature of the hybrid algorithm to the portion of the source image. [0059] Referring to FIG. 10 in light of FIGS. 1-3 and 5-6C , FIG. 10 is a flow diagram showing a method 1000 for employing a hybrid level set algorithm for interactively editing a matting region and a selection. Each block of method 1000 and other methods described herein comprises a computing process that may be performed using any combination of hardware, firmware, and/or software. For instance, various functions may be carried out by a processor executing instructions stored in memory. The methods may also be embodied as computer-usable instructions stored on computer storage media. The methods may be provided by a standalone application, a service or hosted service (standalone or in combination with another hosted service), or a plug-in to another product, to name a few. [0060] At block 1010 , at least a portion of the source image and a selection mask associated therewith is provided for display. The selection mask comprises a selected region and an unselected region separated by a selection mask boundary. At block 1020 , a selection cursor is provided for display over at least a portion of the source image. The selection cursor can have an interior region and a peripheral region, similarly to that as was described in FIG. 1 . At block 1030 , an adjustment is processed to the selection mask boundary in a portion of the source image that is overlaid by the peripheral region of the selection cursor. The adjustment includes applying a hybrid algorithm to the selection mask boundary along an initial position of the selection mask. The hybrid algorithm comprises a boundary-detecting feature configured to detect a boundary as a result of applying the boundary-detecting feature and a region-defining feature configured to define at least a matting region along the detected boundary. At block 1040 , a matting algorithm is applied to the matting region that is defined along the detected boundary. [0061] Having described implementations of the present disclosure, an exemplary operating environment in which embodiments of the present invention may be implemented is described below in order to provide a general context for various aspects of the present disclosure. Referring initially to FIG. 11 in particular, an exemplary operating environment for implementing embodiments of the present invention is shown and designated generally as computing device 1100 . Computing device 1100 is but one example of a suitable computing environment and is not intended to suggest any limitation as to the scope of use or functionality of the invention. Neither should the computing device 1100 be interpreted as having any dependency or requirement relating to any one or combination of components illustrated. [0062] The invention may be described in the general context of computer code or machine-useable instructions, including computer-executable instructions such as program modules, being executed by a computer or other machine, such as a personal data assistant or other handheld device. Generally, program modules including routines, programs, objects, components, data structures, etc., refer to code that perform particular tasks or implement particular abstract data types. The invention may be practiced in a variety of system configurations, including hand-held devices, consumer electronics, general-purpose computers, more specialty computing devices, etc. The invention may also be practiced in distributed computing environments where tasks are performed by remote-processing devices that are linked through a communications network. [0063] With reference to FIG. 11 , computing device 1100 includes bus 1110 that directly or indirectly couples the following devices: memory 1112 , one or more processors 1114 , one or more presentation components 1116 , input/output (I/O) ports 1118 , input/output components 1120 , and illustrative power supply 1122 . Bus 1110 represents what may be one or more busses (such as an address bus, data bus, or combination thereof). Although the various blocks of FIG. 11 are shown with lines for the sake of clarity, in reality, delineating various components is not so clear, and metaphorically, the lines would more accurately be grey and fuzzy. For example, one may consider a presentation component such as a display device to be an I/O component. Also, processors have memory. The inventors recognize that such is the nature of the art, and reiterate that the diagram of FIG. 11 is merely illustrative of an exemplary computing device that can be used in connection with one or more embodiments of the present invention. Distinction is not made between such categories as “workstation,” “server,” “laptop,” “hand-held device,” etc., as all are contemplated within the scope of FIG. 11 and reference to “computing device.” [0064] Computing device 1100 typically includes a variety of computer-readable media. Computer-readable media can be any available media that can be accessed by computing device 1100 and includes both volatile and nonvolatile media, removable and non-removable media. By way of example, and not limitation, computer-readable media may comprise computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by computing device 1100 . Computer storage media does not comprise signals per se. Communication media typically embodies computer-readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of any of the above should also be included within the scope of computer-readable media. [0065] Memory 1112 includes computer-storage media in the form of volatile and/or nonvolatile memory. The memory may be removable, non-removable, or a combination thereof. Exemplary hardware devices include solid-state memory, hard drives, optical-disc drives, etc. Computing device 1100 includes one or more processors that read data from various entities such as memory 1112 or I/O components 1120 . Presentation component(s) 1116 present data indications to a user or other device. Exemplary presentation components include a display device, speaker, printing component, vibrating component, etc. [0066] I/O ports 1118 allow computing device 1100 to be logically coupled to other devices including I/O components 1120 , some of which may be built in. Illustrative components include a microphone, joystick, game pad, satellite dish, scanner, printer, wireless device, etc. The I/O components 1120 may provide a natural user interface (NUI) that processes air gestures, voice, or other physiological inputs generated by a user. In some instance, inputs may be transmitted to an appropriate network element for further processing. A NUI may implement any combination of speech recognition, touch and stylus recognition, facial recognition, biometric recognition, gesture recognition both on screen and adjacent to the screen, air gestures, head and eye tracking, and touch recognition associated with displays on the computing device 1100 . The computing device 1100 may be equipped with depth cameras, such as, stereoscopic camera systems, infrared camera systems, RGB camera systems, and combinations of these for gesture detection and recognition. Additionally, the computing device 1100 may be equipped with accelerometers or gyroscopes that enable detection of motion. The output of the accelerometers or gyroscopes may be provided to the display of the computing device 1100 to render immersive augmented reality or virtual reality. [0067] As described above, implementations of the present disclosure provide for adjusting a selection mask associated with a source image by employing a hybrid algorithm. The present invention has been described in relation to particular embodiments, which are intended in all respects to be illustrative rather than restrictive. Alternative embodiments will become apparent to those of ordinary skill in the art to which the present invention pertains without departing from its scope. [0068] From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects set forth above, together with other advantages which are obvious and inherent to the system and method. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

In various implementations, methods and systems are disclosed for accurately selecting a targeted portion of a digital image. In one embodiment, a selection cursor having a central and a peripheral region is provided. The central region is used to force a selection or a deselection and therefore moving the central region over a portion of the image causes that portion of the image to be selected or deselected, respectively. The peripheral region of the cursor surrounds the central region and defines an area where a hybrid level set algorithm for both boundary detection and region definition, particularly a matting region, is performed. This provides highly accurate boundary detection and matting region selection within a narrowly-focused peripheral region and eliminates the need to subsequently designate a matting region and apply a matting algorithm to complex portions of an object selection. Thus moving the peripheral region of the selection cursor over a boundary of the targeted portion of the image applies the hybrid algorithm in that boundary region, increasing the likelihood that the boundary will be detected accurately, and further defining at least a matting region along the detected boundary for an even more refined selection.

RELATED APPLICATIONS This application is a divisional of application Ser. No. 11/789,226, filed Apr. 24, 2007, and entitled Apparatus and Methods for Creating Cavities in Interior Body Regions,” which is a divisional of application Ser. No. 10/958,944, filed Oct. 5, 2004, and entitled “Structures and Methods for Creating Cavities in Interior Body Regions,” (now abandoned), which is a divisional of application Ser. No. 10/208,391, filed Jul. 30, 2002 (now U.S. Pat. No. 6,863,672), which is a divisional of application Ser. No. 09/055,805, filed Apr. 6, 1998 (now U.S. Pat. No. 6,440,138), each of which is incorporated herein by reference. FIELD OF THE INVENTION The invention relates to structures and procedures, which, in use, form cavities in interior body regions of humans and other animals for diagnostic or therapeutic purposes. BACKGROUND OF THE INVENTION Certain diagnostic or therapeutic procedures require the formation of a cavity in an interior body region. For example, as disclosed in U.S. Pat. Nos. 4,969,888 and 5,108,404, an expandable body is deployed to form a cavity in cancellous bone tissue, as part of a therapeutic procedure that fixes fractures or other abnormal bone conditions, both osteoporotic and non-osteoporotic in origin. The expandable body compresses the cancellous bone to form an interior cavity. The cavity receives a filling material, which provides renewed interior structural support for cortical bone. This procedure can be used to treat cortical bone, which due to osteoporosis, avascular necrosis, cancer, or trauma, is fractured or is prone to compression fracture or collapse. These conditions, if not successfully treated, can result in deformities, chronic complications, and an overall adverse impact upon the quality of life. A demand exists for alternative systems or methods which, like the expandable body shown in U.S. Pat. Nos. 4,969,888 and 5,108,404, are capable of forming cavities in bone and other interior body regions in safe and efficacious ways. SUMMARY OF THE INVENTION One aspect of the invention provides systems and methods for creating a cavity in cancellous bone. The systems and method comprise a cannula having an axis that establishes a percutaneous path leading into bone. The systems and method include a shaft having a distal end portion carrying an elongated loop structure or bristles capable of extension from the shaft to create a cavity forming structure. The shaft is sized for passage through the cannula into bone prior to extension of the elongated loop structure or bristles. The systems and methods include a controller to extend the elongated loop structure or bristles from the shaft in situ within cancellous bone to create the cavity forming structure. The shaft is movable relative to the axis of the cannula to move the cavity forming structure when extended within cancellous bone to form a cavity in the cancellous bone. The systems and methods include a tool sized for passage through the cannula, the tool being capable of dispensing a filling material into the cavity. Another aspect of the invention provides a kit comprising a cannula having an axis that establishes a percutaneous path leading into bone and a shaft having a distal end portion carrying an elongated loop structure or bristles capable of extension from the shaft to create a cavity forming structure. The shaft is sized for passage through the cannula into bone prior to extension of the elongated loop structure or bristles. The kit includes a controller to extend the elongated loop structure or bristles from the shaft in situ within cancellous bone to create the cavity forming structure. The shaft is movable relative to the axis of the cannula to move the cavity forming structure when extended within cancellous bone to form a cavity in the cancellous bone. The kit includes a tool sized for passage through the cannula, the tool being capable of dispensing a filling material into the cavity. The kit includes instructions for creating a cavity in cancellous bone by deploying the cannula percutaneously to establish a path leading into bone, introducing the shaft by movement within and along the axis of the cannula to place the elongated loop structure or bristles inside cancellous bone, extending the cavity forming structure in situ within the cancellous bone from the shaft, moving the shaft to form a cavity in the cancellous bone, and introducing the tool by movement within and along the axis of the cannula, and conveying filling material through the tool into the cavity. Another aspect of the invention provides media comprising instructions for creating a cavity in cancellous bone by deploying a cannula having an axis that establishes a percutaneous path leading into bone, introducing a shaft having a distal end portion carrying an elongated loop structure or bristles capable of extension from the shaft to create a cavity forming structure, by movement of the shaft within and along the axis of the cannula to place the elongated loop structure or bristles inside cancellous bone, extending the cavity forming structure in situ within the cancellous bone from the shaft, moving the shaft to form a cavity in the cancellous bone, and introducing a tool a tool sized for passage through the cannula, the tool being capable of dispensing a filling material into the cavity, by movement of the tool within and along the axis of the cannula, and conveying filling material through the tool into the cavity. Features and advantages of the inventions are set forth in the following Description and Drawings, as well as in the appended Claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a rotatable tool having a loop structure capable of forming a cavity in tissue, with the loop structure deployed beyond the associated catheter tube; FIG. 1A is an enlarged end view of the tool shown in FIG. 1 ; FIG. 2 is a side view of the tool shown in FIG. 1 , with the loop structure retracted within the catheter tube; FIG. 3 is a side view of the tool shown in FIG. 1 , with the loop structure deployed beyond the catheter tube to a greater extent than shown in FIG. 1 ; FIG. 4 is a side view of the tool shown in FIG. 1 inserted within a guide sheath for deployment in a targeted treatment area; FIG. 5 is a side view of another rotatable tool having a brush structure capable of forming a cavity in tissue, with the brush structure deployed beyond the associated drive tube; FIG. 5A is an enlarged end view of the tool shown in FIG. 5 ; FIG. 6 is a side view of the tool shown in FIG. 5 , with the brush structure retracted within the drive tube; FIG. 7 is a side view of the tool shown in FIG. 5 , with the brush structure deployed beyond the catheter tube to a greater extent than shown in FIG. 5 , and with the brush structure being rotated to cause the associated bristles to flare outward; FIG. 8 is a side view of the tool shown in FIG. 7 , with the brush structure deployed beyond the catheter tube to a greater extent than shown in FIG. 7 , and with the brush structure still being rotated to cause the associated bristles to flare outward; FIG. 9 is a side view of an alternative tool having an array of bristles carried by a flexible shaft, which is capable of forming a cavity in tissue; FIG. 10 is a side view of the tool shown in FIG. 9 as it is being deployed inside a cannula; FIG. 11 is the tool shown in FIG. 9 when deployed in a soft tissue region bounded by hard tissue; FIG. 12 is a side view of a tool having a rotatable blade structure capable of forming a cavity in tissue; FIG. 13 is a side view of an alternative curved blade structure that the tool shown in FIG. 12 can incorporate; FIG. 14 is a side view of an alternative ring blade structure that the tool shown in FIG. 12 can incorporate; FIG. 15 is a side view of the ring blade structure shown in FIG. 14 while being introduced through a cannula; FIG. 16 is a side view of a rotating tool capable of forming a cavity in tissue, with an associated lumen to introduce a rinsing liquid and aspirate debris; FIG. 17 is a perspective side view of a tool having a linear movement blade structure capable of forming a cavity in tissue, with the blade structure deployed beyond the associated catheter tube in an operative position for use; FIG. 18 is an end view of the tool shown in FIG. 17 , with the blade structure shown in its operative position for use; FIG. 19 is an end view of the tool shown in FIG. 17 , with the blade structure shown in its rest position within the catheter tube; FIG. 20 is a side view of the tool shown in FIG. 17 , with the blade structure shown in its rest position within the catheter tube, as also shown in an end view in FIG. 18 ; FIG. 21 is a side view of the tool shown in FIG. 17 , with the blade structure deployed beyond the associated catheter tube in an operative position for use, as also shown in an end view in FIG. 18 ; FIG. 22 is a side view of a tool having a linear movement energy transmitter capable of forming a cavity in tissue, with the energy transmitter deployed beyond the associated catheter tube in an operative position for use; FIG. 23 is a top view of a human vertebra, with portions removed to reveal cancellous bone within the vertebral body, and with a guide sheath located for postero-lateral access; FIG. 24 is a side view of the vertebra shown in FIG. 23 ; FIG. 25 is a top view of the vertebra shown in FIG. 23 , with the tool shown in FIG. 1 deployed to cut cancellous bone by rotating the loop structure, thereby forming a cavity; FIG. 26 is a top view of the vertebra shown in FIG. 23 , with the tool shown in FIG. 5 deployed to cut cancellous bone by rotating the brush structure, thereby forming a cavity; FIG. 27 is a side view of the vertebra shown in FIG. 23 , with the tool shown in FIG. 17 deployed to cut cancellous bone by moving the blade structure in a linear path, thereby forming a cavity; FIG. 28 is a side view of the vertebra shown in FIG. 23 , with the tool shown in FIG. 22 deployed to cut cancellous bone using an energy transmitter, which is both rotatable and movable in a linear path, thereby forming a cavity; FIG. 29 is a side view of the vertebra shown in FIG. 23 , after formation of a cavity by use of one of the tools shown in FIGS. 25 to 28 , and with a second tool deployed to introduce material into the cavity for therapeutic purposes; FIG. 30 is a plan view of a sterile kit to store a single use cavity forming tool of a type previously shown; and FIG. 31 is an exploded perspective view of the sterile kit shown in FIG. 30 . The invention may be embodied in several forms without departing from its spirit or essential characteristics. The scope of the invention is defined in the appended claims, rather than in the specific description preceding them. All embodiments that fall within the meaning and range of equivalency of the claims are therefore intended to be embraced by the claims. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The systems and methods embodying the invention can be adapted for use virtually in any interior body region, where the formation of a cavity within tissue is required for a therapeutic or diagnostic purpose. The preferred embodiments show the invention in association with systems and methods used to treat bones. This is because the systems and methods which embody the invention are well suited for use in this environment. It should be appreciated that the systems and methods which embody features of the invention can be used in other interior body regions, as well. I. Rotatable Cavity Forming Structures A. Rotatable Loop Structure FIG. 1 shows a rotatable tool 10 capable of forming a cavity in a targeted treatment area. The tool 10 comprises a catheter tube 12 having a proximal and a distal end, respectively 14 and 16 . The catheter tube 12 preferable includes a handle 18 to aid in gripping and maneuvering the tube 12 . The handle 18 can be made of a foam material secured about the catheter tube 12 . The catheter tube 12 carries a cavity forming structure 20 at its distal end 16 . In the illustrated embodiment, the structure 20 comprises a filament 22 of resilient inert material, which is bent back upon itself and preformed with resilient memory to form a loop. The material from which the filament 22 is made can be resilient, inert wire, like stainless steel. Alternatively, resilient injection molded inert plastic or shape memory material, like nickel titanium (commercially available as Nitinol™ material), can also be used. The filament 22 can, in cross section, be round, rectilinear, or an other configuration. As FIG. 1A shows, the filament 22 radiates from slots 24 in a base 26 carried by the distal end 16 of the catheter tube 12 . The free ends 28 of the filament 22 extend through the catheter tube 12 and are connected to a slide controller 30 near the handle 18 . As FIG. 2 shows, sliding the controller 30 aft (arrow A) retracts the filament 22 through the slots 24 , which progressively decreases the dimensions of the loop structure 20 . As FIG. 2 shows, in its farthest aft position, the filament 22 is essentially fully withdrawn and does not project a significant distance beyond the distal end 16 of the catheter tube 12 . As FIG. 3 shows, sliding the controller 30 forward (arrow F) advances the filament 22 through the slots 24 . The loop structure 20 forms, which projects beyond the distal end 16 of the catheter tube 12 . As it is advanced progressively forward through the slots 24 , the dimensions of the loop structure 20 progressively increase (compare FIG. 1 to FIG. 3 ). The controller 30 can include indicia 32 , through which the physician can estimate the dimensions of the loop structure 20 . In use (see FIG. 4 ), the catheter tube 12 is carried for axial and rotational movement within a guide sheath or cannula 34 . The physician is able to freely slide the catheter tube 12 axially within the guide sheath 34 (arrow S in FIG. 4 ). As FIG. 4 shows, when fully confined by the guide sheath 34 , the loop structure 20 , if projecting a significant distance beyond the distal end 16 , is collapsed by the surrounding sheath 34 . When free of the guide sheath 34 , the loop structure 20 springs open to assume its normal dimension. Thereafter, the physician can operate the controller 30 to alter the dimension of the loop structure 20 at will. When free of the guide sheath 34 , the physician is also able to rotate the deployed loop structure 20 , by rotating the catheter tube 12 within the guide sheath 34 (arrow R in FIG. 4 ). As will be described in greater detail alter, rotation of the loop structure 20 slices or cut through surrounding tissue mass. The materials for the catheter tube 12 are selected to facilitate advancement and rotation of the loop structure 20 . The catheter tube 12 can be constructed, for example, using standard flexible, medical grade plastic materials, like vinyl, nylon, polyethylenes, ionomer, polyurethane, and polyethylene tetraphthalate (PET). The catheter tube 12 can also include more rigid materials to impart greater stiffness and thereby aid in its manipulation and torque transmission capabilities. More rigid materials that can be used for this purpose include stainless steel, nickel-titanium alloys (Nitinol™ material), and other metal alloys. The filament 22 preferably carries one or more radiological markers 36 . The markers 36 are made from known radiopaque materials, like platinum, gold, calcium, tantalum, and other heavy metals. At least one marker 36 is placed at or near the distal extremity of the loop structure 20 , while other markers can be placed at spaced apart locations on the loop structure 20 . The distal end 16 of the catheter tube 12 can also carry markers. The markers 36 permit radiologic visualization of the loop structure 20 and catheter tube 12 within the targeted treatment area. Of course, other forms of markers can be used to allow the physician to visualize the location and shape of the loop structure 20 within the targeted treatment area. B. Rotatable Brush FIG. 5 shows an alternative embodiment of a rotatable tool 38 capable of forming a cavity in a targeted treatment area. The tool 38 comprises a drive shaft 40 , which is made from stiffer materials for good torsion transmission capabilities, e.g., stainless steel, nickel-titanium alloys (Nitinol™ material), and other metal alloys. The distal end 42 of the drive shaft carries a cavity forming structure 44 , which comprises an array of filaments forming bristles 46 . As FIG. 5A shows, the bristles 46 extend from spaced-apart slots 48 in a base 50 carried by the distal end 42 of the drive shaft 40 . The material from which the bristles 46 is made can be stainless steel, or injection molded inert plastic, or shape memory material, like nickel titanium. The bristles 46 can, in cross section, be round, rectilinear, or an other configuration. The proximal end 52 of the drive shaft 40 carries a fitting 54 that, in use, is coupled to an electric motor 56 for rotating the drive shaft 40 , and, with it, the bristles 46 (arrows R in FIGS. 7 and 8 ). When rotated by the motor 46 , the bristles spread apart (as FIG. 7 shows), under the influence of centrifugal force, forming a brush-like structure 44 . The brush structure 44 , when rotating, cuts surrounding tissue mass in the targeted treatment area. The free ends 58 of the bristles 46 extend through the drive shaft 40 and are commonly connected to a slide controller 60 . As FIG. 6 shows, sliding the controller 60 aft (arrow A in FIG. 6 ) shortens the distance the bristles 46 extend from the base 50 . As FIGS. 7 and 8 show, sliding the controller 60 forward (arrow F in FIG. 8 ) lengthens the extension distance of the bristles 46 . Using the controller 60 , the physician is able to adjust the dimension of the cutting area (compare FIG. 7 and FIG. 8 ). The array of bristles 46 preferably includes one or more radiological markers 62 , as previously described. The markers 62 allow radiologic visualization of the brush structure 44 while in use within the targeted treatment area. The controller 60 can also include indicia 64 by which the physician can visually estimate the bristle extension distance. The distal end 42 of the drive shaft 40 can also carry one or more markers 62 . The drive shaft 40 of the tool 38 is, in use, carried for axial and rotational movement within the guide sheath or cannula 34 , in the same manner shown for the tool 10 in FIG. 4 . The physician is able to freely slide the drive shaft 40 axially within the guide sheath to deploy it in the targeted treatment area. Once connected to the drive motor 56 , the drive shaft 40 is free to rotate within the guide sheath 34 to form the brush structure 44 . FIG. 9 shows an alternative embodiment of a rotatable tool 138 having an array of filaments forming bristles 140 , which is capable of forming a cavity in a targeted treatment area. The tool 138 includes a flexible drive shaft 142 , which is made, e.g., from twisted wire filaments, such stainless steel, nickel-titanium alloys (Nitinol™ material), and other metal alloys. The bristles 140 radially extend from the drive shaft 142 , near its distal end. The bristles 140 can be made, e.g., from resilient stainless steel, or injection molded inert plastic, or shape memory material, like nickel titanium. The bristles 140 can, in cross section, be round, rectilinear, or an other configuration. As FIG. 10 shows, the tool 138 is introduced into the targeted tissue region through a cannula 144 . When in the cannula 144 , the resilient bristles 140 are compressed rearward to a low profile, enabling passage through the cannula. When free of the cannula 144 , the resilient bristles 140 spring radially outward, ready for use. The proximal end of the drive shaft 142 carries a fitting 146 that, in use, is coupled to an electric motor 148 . The motor 148 rotates the drive shaft 142 (arrow R in FIG. 11 ), and, with it, the bristles 140 . As FIG. 11 shows, when deployed inside an interior body cavity with soft tissue S (e.g., cancellous bone bounded by hard tissue H (e.g., cortical bone), the physician can guide the tool 138 through the soft tissue S by allowing the rotating bristles 140 to ride against the adjoining hard tissue H. The flexible drive shaft 142 bends to follow the contour of the hard tissue H, while the rotating bristles 140 cut adjoining soft tissue S, forming a cavity C. In the illustrated embodiment, the drive shaft 142 carries a pitched blade 151 at its distal end. The blade 151 rotates with the drive shaft 142 . By engaging tissue, the blade 151 generates a forward-pulling force, which helps to advance the drive shaft 142 and bristles 140 through the soft-tissue mass. In the illustrated embodiment, the bristles 140 , or the cannula 144 , or both include one or more radiological markers 153 , as previously described. The markers 153 allow radiologic visualization of the bristles 140 while rotating and advancing within the targeted treatment area. C. Rotatable Blade Structure FIG. 12 shows an alternative embodiment of a rotatable tool 106 capable of forming a cavity in a targeted treatment area. The tool 106 , like the tool 38 , comprises a generally stiff drive shaft 108 , made from, e.g., stainless steel, nickel-titanium alloys (Nitinol™ material), and other metal alloys, for good torsion transmission capabilities. The distal end of the drive shaft 108 carries a cavity forming structure 110 , which comprises a cutting blade. The blade 110 can take various shapes. In FIGS. 12 and 13 , the blade 110 is generally L-shaped, having a main leg 112 and a short leg 116 . In the illustrated embodiment, the main leg 112 of the blade 110 is pitched radially forward of the drive shaft axis 114 , at a small forward angle beyond perpendicular to the drive shaft. The main leg 112 may possess a generally straight configuration (as FIG. 12 shows), or, alternatively, it may present a generally curved surface (as FIG. 13 shows). In the illustrated embodiment, the short leg 116 of the blade 110 is also pitched at a small forward angle from the main leg 112 , somewhat greater than perpendicular. In FIG. 14 , the blade 110 takes the shape of a continuous ring 126 . As illustrated, the ring 126 is pitched slightly forward, e.g., at an angle slightly greater than perpendicular relative to the drive shaft axis 114 . The material from which the blade 110 is made can be stainless steel, or injection molded inert plastic. The legs 112 and 116 of the blade 110 shown in FIGS. 12 and 13 , and the ring 126 shown in FIG. 14 , can, in cross section, be round, rectilinear, or another configuration. When rotated (arrow R), the blade 110 cuts a generally cylindrical path through surrounding tissue mass. The forward pitch of the blade 110 reduces torque and provides stability and control as the blade 110 advances, while rotating, through the tissue mass. Rotation of the blade 110 can be accomplished manually or at higher speed by use of a motor. In the illustrated embodiment, the proximal end of the drive shaft 108 of the tool 106 carries a fitting 118 . The fitting 118 is coupled to an electric motor 120 to rotate the drive shaft 108 , and, with it, the blade 110 . As FIG. 15 shows, the drive shaft 108 of the tool 108 is deployed subcutaneously into the targeted tissue area through a guide sheath or cannula 124 . Connected to the drive motor 120 , the drive shaft 108 rotates within the guide sheath 34 , thereby rotating the blade 110 to cut a cylindrical path P in the surrounding tissue mass TM. The blade 110 can be advanced and retracted, while rotating, in a reciprocal path (arrows F and A), by applying pushing and pulling forces upon the drive shaft 108 . The blade 110 can also be withdrawn into the cannula 124 to allow changing of the orientation of the cannula 124 . In this way, successive cylindrical paths can be cut through the tissue mass, through rotating and reciprocating the blade 110 , to thereby create a desired cavity shape. The blade 110 , or the end of the cannula 124 , or both can carry one or more radiological markers 122 , as previously described. The markers 122 allow radiologic visualization of the blade 110 and its position relative to the cannula 34 while in use within the targeted treatment area. D. Rinsing and Aspiration As FIG. 16 shows, any of the tools 10 , 38 , 106 , or 138 can include an interior lumen 128 . The lumen 128 is coupled via a Y-valve 132 to a external source 130 of fluid and an external vacuum source 134 . A rinsing liquid 136 , e.g., sterile saline, can be introduced from the source 130 through the lumen 128 into the targeted tissue region as the tools 10 , 38 , or 106 rotate and cut the tissue mass TM. The rinsing liquid 136 reduces friction and conducts heat away from the tissue during the cutting operation. The rinsing liquid 136 can be introduced continuously or intermittently while the tissue mass is being cut. The rinsing liquid 136 can also carry an anticoagulant or other anti-clotting agent. By periodically coupling the lumen 128 to the vacuum source 134 , liquids and debris can be aspirated from the targeted tissue region through the lumen 128 . II. Linear Movement Cavity Forming Structures A. Cutting Blade FIGS. 17 to 21 show a linear movement tool 66 capable of forming a cavity in a targeted treatment area. Like the tool 10 , the tool 66 comprises a catheter tube 68 having a handle 70 (see FIG. 20 ) on its proximal end 72 to facilitate gripping and maneuvering the tube 68 . The catheter tube 68 carries a linear movement cavity forming structure 74 at its distal end 76 . In the illustrated embodiment, the structure 56 comprises a generally rigid blade 78 , which projects at a side angle from the distal end 76 (see FIGS. 17 and 21 ). The blade 78 can be formed from stainless steel or cast or molded plastic. A stylet 80 is carried by an interior track 82 within the catheter tube 68 (see FIGS. 18 and 19 ). The track 82 extends along the axis of the catheter tube 68 . The stylet 80 is free to move in a linear aft path (arrow A in FIG. 20 ) and a linear forward path (arrow F in FIG. 21 ) within the track 82 . The stylet 80 is also free to rotate within the track 82 (arrow R in FIG. 17 ). The far end of the stylet 80 is coupled to the blade 78 . The near end of the stylet 80 carries a control knob 84 . By rotating the control knob 84 , the physician rotates the blade 78 between an at rest position, shown in FIGS. 19 and 20 , and an operating position, shown in FIGS. 17 , 18 , and 21 . When in the at rest position, the physician can push or pull upon the control knob 84 to move the blade 78 in a linear path within the catheter tube (see FIG. 20 ). By pushing on the control knob 84 , the physician can move the blade 78 outside the catheter tube 68 , where it can be rotated into the operating condition (see FIG. 21 ). When in the operating position, pushing and pulling on the control knob 84 moves the blade in linear strokes against surrounding tissue mass. In use, the catheter tube 68 is also carried for sliding and rotation within the guide sheath or cannula 34 , in the same manner shown in FIG. 4 . The physician is able to freely slide the catheter tube 68 axially within the guide sheath 34 to deploy the tool 66 in the targeted treatment site. When deployed at the site, the physician can deploy the blade 78 in the operating condition outside the catheter tube 68 and slide the blade 78 along tissue in a linear path. Linear movement of the blade 78 along tissue cuts the tissue. The physician is also able to rotate both the catheter tube 68 within the guide sheath 34 and the blade 78 within the catheter tube 68 to adjust the orientation and travel path of the blade 78 . The blade 78 can carry one or more radiological markers 86 , as previously described, to allow radiologic visualization of the blade 78 within the targeted treatment area. Indicia 88 on the stylet 80 can also allow the physician to visually approximate the extent of linear or rotational movement of the blade 78 . The distal end 76 of the catheter tube 68 can also carry one or more markers 86 . B. Energy Transmitters FIG. 22 shows an alternative embodiment of a linear movement tool 90 capable of forming a cavity in a targeted treatment area. The tool 90 is physically constructed in the same way as the linear movement tool 66 just described, so common reference numerals are assigned. However, for the tool 90 shown FIG. 22 , the far end of the stylet 80 carries, not a cutting blade 78 , but instead a transmitter 92 capable of transmitting energy that cuts tissue (shown by lines 100 in FIG. 22 ). A connector 94 couples the transmitter 92 to a source 96 of the energy, through a suitable energy controller 98 . The type of energy 100 that the transmitter 92 propagates to remove tissue in the targeted treatment area can vary. For example, the transmitter 92 can propagate ultrasonic energy at harmonic frequencies suitable for cutting the targeted tissue. Alternatively, the transmitter 92 can propagate laser energy at a suitable tissue cutting frequency. As before described, the near end of the stylet 80 includes a control knob 84 . Using the control knob 84 , the physician is able to move the transmitter 92 in a linear path (arrows A and F in FIG. 22 ) between a retracted position, housed with the catheter tube 68 (like the blade 78 shown in FIG. 20 ), and a range of extended positions outside the catheter tube 68 , as shown in FIG. 22 ). As also described before, the catheter tube 68 of the tool 90 is, in use, carried for sliding and rotation within the guide sheath or cannula 34 . The physician slides the catheter tube 68 axially within the guide sheath 34 for deployment of the tool 90 at the targeted treatment site. When deployed at the site, the physician operates the control knob 84 to linearly move and rotate the transmitter 92 to achieve a desired position in the targeted treatment area. The physician can also rotate the catheter tube 68 and thereby further adjust the location of the transmitter 92 . The transmitter 92 or stylet 80 can carry one or more radiological markers 86 , as previously described, to allow radiologic visualization of the position of the transmitter 92 within the targeted treatment area. Indicia 88 on the stylet 80 can also allow the physician to visually estimate the position of the transmitter 92 . The distal end 76 of the catheter tube 68 can also carry one or more markers 86 . III. Use of Cavity Forming Tools Use of the various tools 10 ( FIGS. 1 to 4 ), 38 ( FIGS. 5 to 8 ), 138 ( FIGS. 9 to 11 ), 106 ( FIGS. 12 to 15 ), 66 ( FIGS. 17 to 21 ), and 90 ( FIG. 22 ) will now be described in the context of deployment in a human vertebra 150 . FIG. 23 shows the vertebra 150 in coronal (top) view, and FIG. 24 shows the vertebra 150 in lateral (side) view. It should be appreciated, however, the tool is not limited in its application to vertebrae. The tools 10 , 38 , 138 , 106 , 66 , and 90 can be deployed equally as well in long bones and other bone types. As FIGS. 23 and 24 show, the vertebra 150 includes a vertebral body 152 , which extends on the anterior (i.e., front or chest) side of the vertebra 150 . The vertebral body 152 includes an exterior formed from compact cortical bone 158 . The cortical bone 158 encloses an interior volume of reticulated cancellous, or spongy, bone 160 (also called medullary bone or trabecular bone). The vertebral body 152 is in the shape of an oval disk. As FIGS. 23 and 24 show, access to the interior volume of the vertebral body 152 can be achieved. e.g., by drilling an access portal 162 through a side of the vertebral body 152 , which is called a postero-lateral approach. The portal 162 for the postero-lateral approach enters at a posterior side of the body 152 and extends at angle forwardly toward the anterior of the body 152 . The portal 162 can be performed either with a closed, minimally invasive procedure or with an open procedure. Alternatively, access into the interior volume can be accomplished by drilling an access portal through either pedicle 164 (identified in FIG. 23 ). This is called a transpedicular approach. It is the physician who ultimately decides which access site is indicated. As FIGS. 23 and 24 show, the guide sheath 34 (earlier shown in FIG. 4 ) is located in the access portal 162 . Under radiologic or CT monitoring, a selected one of the tools 10 , 38 , 66 , or 90 can be introduced through the guide sheath 34 . A. Deployment and Use of the Loop Tool in a Vertebral Body When, for example, the loop tool 10 is used, the loop structure 20 is, if extended, collapsed by the guide sheath 34 (as shown in FIG. 4 ), or otherwise retracted within the catheter tube 12 (as FIG. 2 shows) during passage through the guide sheath 34 . Referring to FIG. 25 , when the loop tool 10 is deployed outside the guide sheath 34 in the cancellous bone 160 , the physician operates the controller 30 in the manner previously described to obtain a desired dimension for the loop structure 20 , which can be gauged by radiologic monitoring using the on-board markers 36 . The physician manually rotates the loop structure 20 through surrounding cancellous bone 160 (as indicated by arrows R in FIG. 25 ). The rotating loop structure 20 cuts cancellous bone 160 and thereby forms a cavity C. A suction tube 102 , also deployed through the guide sheath 34 , removes cancellous bone cut by the loop structure 20 . Alternatively, the catheter tube 12 can include an interior lumen 128 (as shown in FIG. 16 ) to serve as a suction tube as well as to convey a rinsing liquid into the cavity as it is being formed. Synchronous rotation and operation of the controller 30 to enlarge the dimensions of the loop structure 20 during the procedure allows the physician to achieve a create a cavity C of desired dimension. Representative dimensions for a cavity C will be discussed in greater detail later. B. Deployment and Use of the Brush Tool in a Vertebral Body When, for example, the brush tool 38 is used, the physician preferable withdraws the bristles 46 during their passage through the guide sheath 34 , in the manner shown in FIG. 6 . Referring to FIG. 26 , when the brush tool 38 is deployed in cancellous bone 160 free of the guide sheath 34 , the physician advances the bristles 46 a desired distance (as shown in FIG. 5 ), aided by radiologic monitoring of the markers 62 , or the indicia 32 previously described, or both. The physician connects the drive shaft 40 to the motor 56 to rotate the bristles 46 , creating the brush structure 44 . As FIG. 26 shows, the rotating brush structure 44 cuts cancellous bone 160 and forms a cavity C. The suction tube 102 (or a lumen 128 in the drive shaft 40 , as shown in FIG. 16 ) introduces a rinsing fluid (with an anticoagulant, if desired) and removes cancellous bone cut by the brush structure 44 . By periodically stopping rotation of the brush structure 44 and operating the controller 60 (previously described) to increase the forward extension of the bristles 46 , the physician able over time to create a cavity C having the desired dimensions. C. Deployment and Use of the Linear Tools in a Vertebral Body When, for example, one of the linear movement tools 66 or 90 are used, the physician preferable withdraws the blade 78 or the transmitter 92 into the catheter tube 68 in the manner shown in FIG. 20 , until the distal end 76 of the catheter tube 68 is free of the guide sheath 34 . Referring to FIG. 27 , using the blade tool 66 , the physician operates the stylet 80 forward (arrow F) and aft (arrow A) to move the blade 78 in a linear path through cancellous bone 160 . The blade 78 scrapes loose and cuts cancellous bone 160 along its path, which the suction tube 102 removes. A cavity C is thereby formed. Synchronous rotation (arrow R) and linear movement (arrows F and A) of the blade 78 allow the physician to create a cavity C having a desired dimension. Referring to FIG. 28 , using the energy transmitting tool 90 , the physician rotates (arrow R) and pushes or pulls upon the stylet 80 (arrows F and A) to position the energy transmitter 92 at desired locations in cancellous bone 160 . The markers 86 aid the location process. Transmission by the transmitter 92 of the selected energy cuts cancellous bone 160 for removal by the suction tube 102 . A cavity C is thereby formed. Through purposeful maneuvering of the transmitter 92 , the physician achieves a cavity C having the desired dimension. D. Deployment of Other Tools into the Cavity Once the desired cavity C is formed, the selected tool 10 , 38 , 66 , 90 , 106 , or 138 is withdrawn through the guide sheath 34 . As FIG. 29 shows, an other tool 104 can now be deployed through the guide sheath 34 into the formed cavity C. The second tool 104 can, for example, perform a diagnostic procedure. Alternatively, the second tool 104 can perform a therapeutic procedure, e.g., by dispensing a material 106 into the cavity C, such as, e.g., bone cement, allograft material, synthetic bone substitute, a medication, or a flowable material that sets to a hardened condition. Further details of the injection of such materials 106 into the cavity C for therapeutic purposes are found in U.S. Pat. Nos. 4,969,888 and 5,108,404 and in copending U.S. patent application Ser. No. 08/485,394, which are incorporated herein by reference. E. Bone Cavity Dimensions The size of the cavity C varies according to the therapeutic or diagnostic procedure performed. At least about 30% of the cancellous bone volume needs to be removed in cases where the bone disease causing fracture (or the risk of fracture) is the loss of cancellous bone mass (as in osteoporosis). The preferred range is about 30% to 90% of the cancellous bone volume. Removal of less of the cancellous bone volume can leave too much of the diseased cancellous bone at the treated site. The diseased cancellous bone remains weak and can later collapse, causing fracture, despite treatment. However, there are times when a lesser amount of cancellous bone removal is indicated. For example, when the bone disease being treated is localized, such as in avascular necrosis, or where local loss of blood supply is killing bone in a limited area, the selected tool 10 , 38 , 66 , 90 , 106 , or 138 can remove a smaller volume of total bone. This is because the diseased area requiring treatment is smaller. Another exception lies in the use of a selected tool 10 , 36 , 66 , 90 , 106 , or 138 to improve insertion of solid materials in defined shapes, like hydroxyapatite and components in total joint replacement. In these cases, the amount of tissue that needs to be removed is defined by the size of the material being inserted. Yet another exception lays the use of a selected tool 10 , 36 , 66 , 90 , 106 , or 138 in bones to create cavities to aid in the delivery of therapeutic substances, as disclosed in copending U.S. patent application Ser. No. 08/485,394. In this case, the cancellous bone may or may not be diseased or adversely affected. Healthy cancellous bone can be sacrificed by significant compaction to improve the delivery of a drug or growth factor which has an important therapeutic purpose. In this application, the size of the cavity is chosen by the desired amount of therapeutic substance sought to be delivered. In this case, the bone with the drug inside is supported while the drug works, and the bone heals through exterior casting or current interior or exterior fixation devices. IV. Single Use Sterile Kit A single use of any one of the tools 10 , 38 , 138 , 106 , 66 , or 90 creates contact with surrounding cortical and cancellous bone. This contact can damage the tools, creating localized regions of weakness, which may escape detection. The existence of localized regions of weakness can unpredictably cause overall structural failure during a subsequent use. In addition, exposure to blood and tissue during a single use can entrap biological components on or within the tools. Despite cleaning and subsequent sterilization, the presence of entrapped biological components can lead to unacceptable pyrogenic reactions. As a result, following first use, the tools may not meet established performance and sterilization specifications. The effects of material stress and damage caused during a single use, coupled with the possibility of pyrogen reactions even after resterilization, reasonably justify imposing a single use restriction upon the tools for deployment in bone. To protect patients from the potential adverse consequences occasioned by multiple use, which include disease transmission, or material stress and instability, or decreased or unpredictable performance, each single use tool 10 , 38 , 66 , 90 , 106 , or 138 is packaged in a sterile kit 500 (see FIGS. 30 and 31 ) prior to deployment in bone. As FIGS. 30 and 31 show, the kit 500 includes an interior tray 508 . The tray 508 holds the particular cavity forming tool (generically designated 502 ) in a lay-flat, straightened condition during sterilization and storage prior to its first use. The tray 508 can be formed from die cut cardboard or thermoformed plastic material. The tray 508 includes one or more spaced apart tabs 510 , which hold the tool 502 in the desired lay-flat, straightened condition. The kit 500 includes an inner wrap 512 , which is peripherally sealed by heat or the like, to enclose the tray 508 from contact with the outside environment. One end of the inner wrap 512 includes a conventional peal-away seal 514 (see FIG. 31 ), to provide quick access to the tray 508 upon instance of use, which preferably occurs in a sterile environment, such as within an operating room. The kit 500 also includes an outer wrap 516 , which is also peripherally sealed by heat or the like, to enclosed the inner wrap 512 . One end of the outer wrap 516 includes a conventional peal-away seal 518 (see FIG. 31 ), to provide access to the inner wrap 512 , which can be removed from the outer wrap 516 in anticipation of imminent use of the tool 502 , without compromising sterility of the tool 502 itself. Both inner and outer wraps 512 and 516 (see FIG. 31 ) each includes a peripherally sealed top sheet 520 and bottom sheet 522 . In the illustrated embodiment, the top sheet 520 is made of transparent plastic film, like polyethylene or MYLAR™ material, to allow visual identification of the contents of the kit 500 . The bottom sheet 522 is made from a material that is permeable to EtO sterilization gas, e.g., TYVEC™ plastic material (available from DuPont). The sterile kit 500 also carries a label or insert 506 , which includes the statement “For Single Patient Use Only” (or comparable language) to affirmatively caution against reuse of the contents of the kit 500 . The label 506 also preferably affirmatively instructs against resterilization of the tool 502 . The label 506 also preferably instructs the physician or user to dispose of the tool 502 and the entire contents of the kit 500 upon use in accordance with applicable biological waste procedures. The presence of the tool 502 packaged in the kit 500 verifies to the physician or user that the tool 502 is sterile and has not be subjected to prior use. The physician or user is thereby assured that the tool 502 meets established performance and sterility specifications, and will have the desired configuration when expanded for use. The kit 500 also preferably includes directions for use 524 , which instruct the physician regarding the use of the tool 502 for creating a cavity in cancellous bone in the manners previously described. For example, the directions 524 instruct the physician to deploy and manipulate the tool 502 inside bone to cut cancellous bone and form a cavity. The directions 524 can also instruct the physician to fill the cavity with a material, e.g., bone cement, allograft material, synthetic bone substitute, a medication, or a flowable material that sets to a hardened condition. The features of the invention are set forth in the following claims.

Systems and method create a cavity in cancellous bone by use of a system or kit that includes a cannula having an axis that establishes a percutaneous path leading into bone and a shaft having a distal end portion carrying an elongated loop structure or bristles capable of extension from the shaft to create a cavity forming structure. The shaft is movable relative to the axis of the cannula to move the cavity forming structure when extended within cancellous bone to form a cavity in the cancellous bone. A tool is sized for passage through the cannula. The tool is capable of dispensing a filling material into the cavity.

BACKGROUND 1. Field The present disclosure relates generally to creation and definition of graphical icons in graphical user interfaces, and more particularly, to a method for automatically defining icons. 2. Description of the Related Art Graphical user interfaces (UI) are a predominant way for users to interact with software. UIs primarily consist of a plurality of graphical icons representing specific modules (e.g., functions, objects, etc.) of the software. Simplicity and functionality of UIs, and more specifically their icons, has contributed to dramatic increase in their popularity and their usage. UIs have even been implemented in enterprise level software. Currently, software developers that create software packages consisting of multiple products, such as enterprise infrastructure management software, generally produce different icon sets for each of the products, even though the icons represent the same software modules. For instance, a “Zoom In” function within one product would be represented by an icon having a “+” within a circle, while in another product would be represented by an icon in shape of a looking glass. Different icon sets make it difficult for users of the software to interpret and learn the UIs of these products, since the same modules are represented by different icons. In addition, use of different icons to represent similar modules makes the icons less recognizable and less intuitive thereby reducing their utility in UIs. Therefore, there is a need for a method to automatically define icons representing objects during software development based on the objects' functionality to ensure universal and/or consistent and minimal spanning icon coverage. This method would also eliminate duplicate icons and provide for more recognizable icons which are more easily learned by the users. SUMMARY The present disclosure provides for a method to create graphical icons for software modules. In general, a description of the software module is stored in a database and is normalized by comparing it to a set of definitions stored in a glossary. The normalized definition is then parsed to extract an object, an action, and a modifier of the module. The action is the processing call of the module performed on the object. Thereafter, the method searches an icon component library to obtain an icon component for each of the components of the modules (e.g., the object, the action, the modifier). Once the components are obtained, the components are assembled into an icon to represent the module. The icon is also stored in an icon library for subsequent use with other similar software modules. According to one aspect of the present disclosure, a method for generating a graphical icon to represent a software module is disclosed. The method includes the steps of processing a description of the module stored within a database through a glossary to obtain a normalized description, parsing the normalized description to abstract the module and identify at least one component of the module, obtaining at least one icon component for the at least one module component, and assembling the at least one icon component into the graphical icon. According to another aspect of the present disclosure, a set of computer-executable instructions for generating a graphical icon to represent a software module is disclosed. The computer-executable instructions includes the steps of processing a description of the module stored within a database through a glossary to obtain a normalized description, parsing the normalized description to abstract the module and identify at least one component of the module, obtaining at least one icon component for the at least one module component; and assembling the at least one icon component into the graphical icon. BRIEF DESCRIPTION OF THE DRAWINGS The above and other aspects, features, and advantages of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which: FIG. 1 is a block diagram of a system for creating graphical icons representing a software module according to the present disclosure; FIG. 2 is an illustration of a graphical icon; FIG. 3 is a flow diagram of a method for creating graphical icons according to the present disclosure; and FIG. 4 is an exemplary computer system for implementing various embodiments of the methods of the present disclosure. DETAILED DESCRIPTION Preferred embodiments of the present disclosure will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. The present disclosure provides for a system and method for creating graphical icons representing modules of a software package. Modules are stored within a database which includes an abstracted module description. The method normalizes the language describing the module and defines the module abstractly as having an object, an action, (e.g., the object is data being modified by the action, action is a software function), and a modifier (e.g., an additional action which further defines the action). This permits categorization of the modules. Initially, it is determined if the module has an existing fitting icon within an icon library. If not, then for each of the module's components, the method determines if an icon component exists within an icon component library. If not, then the method creates an icon component. Thereafter, the method assembles the components to create an icon and stores the created icon components and the icon, if any, in the corresponding libraries. Referring to FIG. 1 , a system for defining graphical icons for software modules (e.g., software modules of a software package) is illustrated. A software module can include any of the following: an object, which can be any type of data structure (e.g., a document, an image, etc.), an action, which can be a function performed by the software package (e.g., open a document, scrolling through a document, etc.), and other associated activities or components (e.g., modifier, which modifies the action, object state, etc.). Information concerning the objects, actions, modifiers, etc. is stored in a database 2 , which includes the names of the objects and their description, such as their state, attributes, etc. The database 2 can be an MDB database available from Computer Associates International, Inc., located in Islandia, N.Y. MDB is an integrated database schema that stores information technology (IT) management data used by plurality of Computer Associates' products. Generally, a software package includes a plurality of products which consist of multiple functions programmed to perform actions on objects. With regard to the MDB, any products deigned to function with the IT management include functions for manipulating the objects stored therein. Thus, a software module generally includes one or more functions which are part of a product and which are configured to perform an action on one or more objects stored in the database 2 and which may further include a modifier to modify the action. The database 2 is connected to a glossary 6 which includes normalized language terms used to describe the software modules, which include the objects, actions, and modifiers. The glossary 6 is built from and is synchronized with the database 2 and is continuously updated as well as updates the database 2 to ensure that the descriptions of the software modules are consistent. The software modules are assigned graphical icons based on their descriptions. Therefore, the database 2 is also connected to an icon library 4 which includes icons for software functions. An icon can be any graphical representation used to denote the software module within a graphical UI. The icon library 4 is also connected to an icon component library 8 which stores a plurality of graphical elements which may be used to create an icon. FIG. 3 shows a method for creating icons representing software functions which will be discussed in conjunction with FIG. 2 which shows a graphical icon for a software function designed to “increase viewing area.” It is envisioned that the method of creating icons may be utilized during product development, for instance, the software engineers request icons from a UI design team to represent newly written software modules. It is also envisioned that the present method may also be used retroactively, where a database defining software objects is synchronized with an icon library. In step 10 , a request is made for creation of an icon for a software module. The request is generally made by software development team and directed to a UI design team. The request at the minimum includes the name and description of the software module which may be obtained from generic documentation accompanying the code of the software module and is extracted from the database 2 . The request is made either concurrently or after the database 2 has been updated with the information concerning the software module. In step 12 , the description and/or the name of the software module is processed, which involves parsing the description and/or name and reviewing the parsed phrases/words against the glossary 6 to obtain a normalized description. As discussed above, the glossary 6 is synchronized with the database 2 . This insures that the terms contained within the glossary 6 allow for consistent comparisons of terms within the glossary 6 with the parsed terms of the software module description. For instance, the software developer uses a phrase “enlarge viewing area of a window by twenty five percent” to describe a module. The words of the description would be parsed and compared with the glossary 6 , where, for instance, a word “increase” is used to replace “enlarge” and the words “of a window” are truncated, “twenty five percent” is replaced by a numerical notation of “25%,” resulting in a normalized description “increase viewing area by 25%.” Thus, when another software module for increasing viewing area by 25% is created but has a different description, e.g. “expand window by one fourth,” this description will be parsed and replaced with the same normalized description, e.g., “increase viewing area by 25%.” In step 14 , the method determines whether the icon library 4 already includes an icon which would fit the normalized description of the software module. It is envisioned that in large scale software packages various teams of software developers have previously written modules designed to accomplish the same tasks. Such modules already have icons stored within the icon library 4 ; therefore, if the newly requested module matches in functionality, then the same icon will be used to represent the new task. For instance, if the module described as “expand window” already has an icon and another module for “increasing viewing area of a window” subsequently requests an icon, then the subsequent module will be assigned the previously created icon. This allows for recycling of previously created icons which in turn saves resources and allows for creation of consistent or universal UIs. If an icon which would fit with the description of the module already exists, then the process ends. If not then the method proceeds to step 16 . In step 16 , the normalized description of the software module is parsed to obtain an abstracted structure thereof. The software module, in an abstracted form, generally includes an object, an action (e.g., function), and, possibly, a modifier. The object is a component (e.g., document, image, screen, etc.) of the software module upon which the action (e.g., function) acts. The modifier typically further defines or sets parameters for the action or, alternatively, may be an additional action. For instance, with reference to the above example, the software module for “increasing the viewing area by 25%” relates to an object “viewing area” with an action “increase.” The modifier for the above module is the amount by which the viewing area is increased (e.g., 25%). The abstraction allows for easier categorization of the software modules which facilitates selection and/or creation of corresponding icons. After the object, the action, and the modifier are parsed, corresponding icon components for each of these components are obtained from the icon component library 8 or are designed anew if the icon components are not available. In step 18 , the icon component library 8 is searched and it is determined whether an icon component for the object exists in the icon component library 8 . Referring once again to the above example, the object “viewing area” has been previously used by another module; hence, an icon component already exists in the icon component library 8 which could represent the current object. If an icon component is not found, then in step 20 an icon component for the object is designed and added to icon component library 8 . For exemplative purposes, the “viewing area” object may be represented by the circle symbol, “◯” (identified by reference numeral 3 in FIG. 2 ). In step 22 , the icon component library 8 is searched for an icon component to represent the action component of the module and it is determined whether such an icon component exists. If not, then in step 24 a corresponding icon component is designed and stored in the icon component library 8 . Referring to our previous example, the “increase” action may be represented by a “+” symbol (identified by reference numeral 5 in FIG. 2 ). In step 26 , the searching process is repeated for a modifier component. The icon component library 8 is searched to find a corresponding icon component to represent the modifier and it is determined whether the icon component exists. If not, then in step 28 the icon component is designed and stored in the icon component library 8 . In the example, the increase “by 25%” is represented by the symbol “25%” (identified by reference numeral 9 in FIG. 2 ). Once the icon components have been obtained from the icon component library 8 or designed, in case they did not exist, then, in step 30 , the individual icon components representing the object, the action, and the modifier are assembled into a single icon representing the software module. In addition, the newly created icon is also stored in the icon library 4 . As shown in FIG. 2 , the circle “◯” symbol 3 , “+” symbol 5 , and 25% symbol 9 are combined to create an icon 7 (e.g., ◯+25%) representing the module “increase viewing area by 25%” An alternative icon 7 may be “◯+25%”. It is also envisioned that the modifier component 9 may be stored or referenced as “δ%” where “δ” is the specific variable (e.g., 25, 50, 75, etc.) selected by the user. Referring to FIG. 4 , the process as described in the present disclosure may be adapted as computer-executable instructions stored on a computer-readable media, e.g., data storage device 214 such as a hard drive, magnetic media, optical media, etc., or in read only memory (ROM) 206 of a computer system 200 . The computer system 200 comes equipped with a processor 202 and random access memory (RAM) 204 . In additional, the computer system 200 is configured with a keyboard 208 , mouse or other pointing device 210 and a display 212 . The computer-executable instructions may be loaded from the data storage device 214 to RAM 204 from which the processor 202 reads and executes each instruction, or the processor may access and execute the instructions directly from ROM 206 depending on the manner in which the instructions are stored. Additionally, the data storage device is used to store database 2 , glossary 6 , the icon library 4 , and the icon component library 8 as well as temporary and final results produced by the process as described above. The software module to be processed to generate a corresponding icon may be selected through a combination of keystrokes on the keyboard 208 and manipulation of the pointing device 210 , as known in the art. The display device 212 , ideally, provides a graphical interface allowing easy visualization of the file storage structure of the data storage device 214 as well as a graphical representation of the process outputs during and after execution. It is also envisioned that the current method may be used with a plurality of computer systems 200 arranged in a network (e.g., LAN, WAN, wireless, etc.). The described embodiments of the present disclosure are intended to be illustrative rather than restrictive, and are not intended to represent every embodiment of the present disclosure. Various modifications and variations can be made without departing from the spirit or scope of the disclosure as set forth in the following claims both literally and in equivalents recognized in law.

A method for generating a graphical icon to represent a software module is disclosed. The method includes the steps of processing a description of the module stored within a database through a glossary to obtain a normalized description, parsing the normalized description to abstract the module and identify at least one component of the module, obtaining at least one icon component for the at least one module component, and assembling the at least one icon component into the graphical icon.

PRIORITY OF INVENTION This application claims priority to U.S. Provisional Application No. 61/648,535 that was filed on 17 May 2012. The entire content of this provisional application is hereby incorporated herein by reference. FIELD OF THE INVENTION Disclosed herein are processes for making and purifying hydroxylated cyclopentapyrimidine compounds for the synthesis of inhibitors of AKT kinase activity. BACKGROUND OF THE INVENTION The Protein Kinase B/Akt enzymes are a group of serine/threonine kinases that are overexpressed in certain human tumors. International Patent Application Publication Number WO 2008/006040 and U.S. Pat. No. 8,063,050 discuss a number of inhibitors of AKT, including the compound (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one. While processes described in WO 2008/006040 and U.S. Pat. No. 8,063,050 are useful in providing hydroxylated cyclopenta[d]pyrimidine compounds as AKT protein kinase inhibitors, alternative or improved processes are needed, including for large scale manufacturing of these compounds and their intermediates. Additionally, the dihydrochloride salt of (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one is difficult to prepare in a form other than the amorphous form, and is hygroscopic making it difficult to process into drug forms. Therefore, what is also needed are additional salts and forms of (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one that have improved pharmaceutical properties such as stable, crystalline forms. BRIEF SUMMARY OF THE INVENTION Disclosed are processes for preparing, separating and purifying compounds detailed herein. Compounds provided herein include AKT protein kinase inhibitors, salts thereof, and intermediates useful in the preparation of such compounds. One aspect includes a process comprising reducing a compound of formula II, or a salt thereof: wherein R 1 is defined herein to form a compound of formula III: or a salt thereof. Another aspect includes a process that includes deptrotecting a compound of formula III or a salt thereof, wherein R 1 is an amino protecting group, to form a compound of formula IIIa or salt thereof. Another aspect includes a process that includes reacting a compound of formula IIIa or salt thereof with a compound of formula IV or salt thereof to form a compound of formula I or salt thereof, wherein R 2 in formulae IV and I is independently hydrogen or an amino protecting group. Another aspect includes a process for preparing a salt of a compound of formula Ia: the process comprising contacting a compound of formula I (wherein R 2 is hydrogen or an amino protecting group) with acid to form the salt of the compound of formula Ia, wherein R 2 is hydrogen. Another aspect includes a process for preparing a mono-hydrochloride salt of a compound of formula Ia: the process comprising contacting a compound of formula I, wherein R 2 is an amino protecting group, with acid to form the dihydrochloride salt, wherein R 2 is hydrogen, and contacting the dihydrochloride salt with base to form the monohydrochloride salt. Another aspect includes the monohydrochloride salt of (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one. Another aspect includes (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one benzene sulfonic acid salt. In one example, the benzene sulfonic acid salt is crystalline. Another aspect includes (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one p-toluene sulfonic acid salt. In one example, the p-toluene sulfonic acid salt is crystalline. DESCRIPTION OF THE FIGURES FIG. 1A shows the single crystal structure of the benzenesulfonic acid salt of a compound of formula Ia of Example 5, and FIG. 1B shows the calculated X-ray diffraction pattern of the single crystal. FIG. 2 shows the XRPD of a benzenesulfonic acid salt of a compound of formula Ia of Example 5. FIG. 3 shows the XRPD of a p-toluenesulfonic acid salt of a compound of formula Ia of Example 6. DETAILED DESCRIPTION OF THE INVENTION Reference will now be made in detail to certain embodiments of the invention, examples of which are illustrated in the accompanying structures and formulas. While the invention will be described in conjunction with the enumerated embodiments, it will be understood that they are not intended to limit the invention to those embodiments. On the contrary, the invention is intended to cover all alternatives, modifications, and equivalents which may be included within the scope of the present invention as defined by the claims. In the event that one or more of the incorporated literature and similar materials differs from or contradicts this application, including but not limited to defined terms, term usage, described techniques, or the like, this application controls. The term “alkyl” as used herein refers to a saturated linear or branched-chain monovalent hydrocarbon radical of one to twelve carbon atoms, and in another embodiment one to six carbon atoms, wherein the alkyl radical may be optionally substituted independently with one or more substituents described herein. Examples of alkyl groups include, but are not limited to, methyl (Me, —CH 3 ), ethyl (Et, —CH 2 CH 3 ), 1-propyl (n-Pr, n-propyl, —CH 2 CH 2 CH 3 ), 2-propyl (i-Pr, i-propyl, —CH(CH 3 ) 2 ), 1-butyl (n-Bu, n-butyl, —CH 2 CH 2 CH 2 CH 3 ), 2-methyl-1-propyl (i-Bu, butyl, —CH 2 CH(CH 3 ) 2 ), 2-butyl (s-Bu, s-butyl, —CH(CH 3 )CH 2 CH 3 ), 2-methyl-2-propyl (t-Bu, t-butyl, —C(CH 3 ) 3 ), 1-pentyl (n-pentyl, —CH 2 CH 2 CH 2 CH 2 CH 3 ), 2-pentyl (—CH(CH 3 )CH 2 CH 2 CH 3 ), 3-pentyl (—CH(CH 2 CH 3 ) 2 ), 2-methyl-2-butyl (—C(CH 3 ) 2 CH 2 CH 3 ), 3-methyl-2-butyl (—CH(CH 3 )CH(CH 3 ) 2 ), 3-methyl-1-butyl (—CH 2 CH 2 CH(CH 3 ) 2 ), 2-methyl-1-butyl (—CH 2 CH(CH 3 )CH 2 CH 3 ), 1-hexyl (—CH 2 CH 2 CH 2 CH 2 CH 2 CH 3 ), 2-hexyl (—CH(CH 3 )CH 2 CH 2 CH 2 CH 3 ), 3-hexyl (—CH(CH 2 CH 3 )(CH 2 CH 2 CH 3 )), 2-methyl-2-pentyl (—C(CH 3 ) 2 CH 2 CH 2 CH 3 ), 3-methyl-2-pentyl (—CH(CH 3 )CH(CH 3 )CH 2 CH 3 ), 4-methyl-2-pentyl (—CH(CH 3 )CH 2 CH(CH 3 ) 2 ), 3-methyl-3-pentyl (—C(CH 3 )(CH 2 CH 3 ) 2 ), 2-methyl-3-pentyl (—CH(CH 2 CH 3 )CH(CH 3 ) 2 ), 2,3-dimethyl-2-butyl (—C(CH 3 ) 2 CH(CH 3 ) 2 ), 3,3-dimethyl-2-butyl (—CH(CH 3 )C(CH 3 ) 3 , 1-heptyl, 1-octyl, and the like. The term “alkylene” as used herein refers to a linear or branched saturated divalent hydrocarbon radical of one to twelve carbon atoms, and in another embodiment one to six carbon atoms, wherein the alkylene radical may be optionally substituted independently with one or more substituents described herein. Examples include, but are not limited to, methylene, ethylene, propylene, 2-methylpropylene, pentylene, and the like. The term “alkenyl” as used herein refers to a linear or branched-chain monovalent hydrocarbon radical of two to twelve carbon atoms, and in another embodiment two to six carbon atoms, with at least one site of unsaturation, i.e., a carbon-carbon, sp 2 double bond, wherein the alkenyl radical may be optionally substituted independently with one or more substituents described herein, and includes radicals having “cis” and “trans” orientations, or alternatively, “E” and “Z” orientations. Examples include, but are not limited to, ethylenyl or vinyl (—CH═CH 2 ), allyl (—CH 2 CH═CH 2 ), 1-propenyl, 1-buten-1-yl, 1-buten-2-yl, and the like. The term “alkynyl” as used herein refers to a linear or branched monovalent hydrocarbon radical of two to twelve carbon atoms, and in another embodiment two to six carbon atoms, with at least one site of unsaturation, i.e., a carbon-carbon, sp triple bond, wherein the alkynyl radical may be optionally substituted independently with one or more substituents described herein. Examples include, but are not limited to, ethynyl (—C≡CH) and propynyl (propargyl, —CH 2 C≡CH). The term “alkoxy” refers to a linear or branched monovalent radical represented by the formula —OR in which R is alkyl, alkenyl, alkynyl or cycloalkyl, which can be further optionally substituted as defined herein. Alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, mono-, di- and tri-fluoromethoxy and cyclopropoxy. “Amino” means primary (i.e., —NH 2 ), secondary (i.e., —NRH), tertiary (i.e., —NRR) and quaternary (i.e., —N + RRRX − ) amines, that are optionally substituted, in which R is independently alkyl, alkoxy, a cycloalkyl, a heterocyclyl, cycloalkyl, -substituted alkyl or heterocyclyl-substituted alkyl wherein the alkyl, alkoxy, cycloalkyl and heterocyclyl are as defined herein Particular secondary and tertiary amines are alkylamine, dialkylamine, arylamine, diarylamine, aralkylamine and diaralkylamine wherein the alkyls and aryls are as herein defined and independently optionally substituted. Particular secondary and tertiary amines are methylamine, ethylamine, propylamine, isopropylamine, phenylamine, benzylamine dimethylamine, diethylamine, dipropylamine and diisopropylamine. The terms “cycloalkyl,” “carbocycle,” “carbocyclyl” and “carbocyclic ring” as used herein are used interchangeably and refer to saturated or partially unsaturated cyclic hydrocarbon radical having from three to twelve carbon atoms, and in another embodiment from three to 7 carbon atoms. The term “cycloalkyl” includes monocyclic and polycyclic (e.g., bicyclic and tricyclic) cycloalkyl structures, wherein the polycyclic structures optionally include a saturated or partially unsaturated cycloalkyl ring fused to a saturated, partially unsaturated or aromatic cycloalkyl or heterocyclic ring. Examples of cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclohexenyl, cyclohexadienyl, cycloheptenyl, and the like. Bicyclic carbocycles include those having 7 to 12 ring atoms arranged, for example, as a bicyclo [4,5], [5,5], [5,6] or [6,6] system, or as bridged systems such as bicyclo[2.2.1]heptane, bicyclo[2.2.2]octane, and bicyclo[3.2.2]nonane. The cycloalkyl may be optionally substituted independently with one or more substituents described herein. The term “aryl” as used herein means a monovalent aromatic hydrocarbon radical of 6-20 carbon atoms derived by the removal of one hydrogen atom from a single carbon atom of a parent aromatic ring system. Aryl includes bicyclic radicals comprising an aromatic ring fused to a saturated, partially unsaturated ring, or aromatic carbocyclic or heterocyclic ring. Exemplary aryl groups include, but are not limited to, radicals derived from benzene, naphthalene, anthracene, biphenyl, indene, indane, 1,2-dihydronapthalene, 1,2,3,4-tetrahydronapthalene, and the like. Aryl groups may be optionally substituted independently with one or more substituents described herein. The terms “heterocycle”, “hetercyclyl” and “heterocyclic ring” as used herein are used interchangeably and refer to a saturated or partially unsaturated carbocyclic radical of 3 to 12 ring atoms in which at least one ring atom is a heteroatom independently selected from nitrogen, oxygen and sulfur, the remaining ring atoms being C, where one or more ring atoms may be optionally substituted independently with one or more substituents described below. In one embodiment, heterocyclyl includes 3 to 7 membered ring atoms in which at least one ring atom is a heteroatom independently selected from nitrogen, oxygen and sulfur, the remaining ring atoms being C, where one or more ring atoms may be optionally substituted independently with one or more substituents described below. The radical may be a carbon radical or heteroatom radical. The term “heterocycle” includes heterocycloalkoxy. “Heterocyclyl” also includes radicals where heterocycle radicals are fused with a saturated, partially unsaturated, or aromatic carbocyclic or heterocyclic ring. Examples of heterocyclic rings include, but are not limited to, pyrrolidinyl, tetrahydrofuranyl, dihydrofuranyl, tetrahydrothienyl, tetrahydropyranyl, dihydropyranyl, tetrahydrothiopyranyl, piperidino, morpholino, thiomorpholino, thioxanyl, piperazinyl, homopiperazinyl, azetidinyl, oxetanyl, thietanyl, homopiperidinyl, oxepanyl, thiepanyl, oxazepinyl, diazepinyl, thiazepinyl, 2-pyrrolinyl, 3-pyrrolinyl, indolinyl, 2H-pyranyl, 4H-pyranyl, dioxanyl, 1,3-dioxolanyl, pyrazolinyl, dithianyl, dithiolanyl, dihydropyranyl, dihydrothienyl, dihydrofuranyl, pyrazolidinylimidazolinyl, imidazolidinyl, 3-azabicyco[3.1.0]hexanyl, 3-azabicyclo[4.1.0]heptanyl, azabicyclo[2.2.2]hexanyl, 3H-indolyl quinolizinyl and N-pyridyl ureas. Spiro moieties are also included within the scope of this definition. The heterocycle may be C-attached or N-attached where such is possible. For instance, a group derived from pyrrole may be pyrrol-1-yl (N-attached) or pyrrol-3-yl (C-attached). Further, a group derived from imidazole may be imidazol-1-yl (N-attached) or imidazol-3-yl (C-attached). Examples of heterocyclic groups wherein 2 ring carbon atoms are substituted with oxo (═O) moieties are isoindoline-1,3-dionyl and 1,1-dioxo-thiomorpholinyl. The heterocycle groups herein are optionally substituted independently with one or more substituents described herein. The term “heteroaryl” as used herein refers to a monovalent aromatic radical of a 5-, 6-, or 7-membered ring and includes fused ring systems (at least one of which is aromatic) of 5-10 atoms containing at least one heteroatom independently selected from nitrogen, oxygen, and sulfur. Examples of heteroaryl groups include, but are not limited to, pyridinyl, imidazolyl, imidazopyridinyl, pyrimidinyl, pyrazolyl, triazolyl, pyrazinyl, tetrazolyl, furyl, thienyl, isoxazolyl, thiazolyl, oxazolyl, isothiazolyl, pyrrolyl, quinolinyl, isoquinolinyl, indolyl, benzimidazolyl, benzofuranyl, cinnolinyl, indazolyl, indolizinyl, phthalazinyl, pyridazinyl, triazinyl, isoindolyl, pteridinyl, purinyl, oxadiazolyl, triazolyl, thiadiazolyl, thiadiazolyl, furazanyl, benzofurazanyl, benzothiophenyl, benzothiazolyl, benzoxazolyl, quinazolinyl, quinoxalinyl, naphthyridinyl, and furopyridinyl. Spiro moieties are also included within the scope of this definition. Heteroaryl groups may be optionally substituted independently with one or more substituents described herein. “Amino-protecting group” as used herein refers to groups commonly employed to keep amino groups from reacting during reactions carried out on other functional groups. Examples of such protecting groups include carbamates, amides, alkyl and aryl groups, imines, as well as many N-heteroatom derivatives which can be removed to regenerate the desired amine group. Particular amino protecting groups are Ac (acetyl), trifluoroacetyl, phthalimide, Bn (benzyl), Tr (triphenylmethyl or trityl), benzylidenyl, p-toluenesulfonyl, Pmb (p-methoxybenzyl), Boc (tert-butyloxycarbonyl), Fmoc (9-fluorenylmethyloxycarbonyl) and Cbz (carbobenzyloxy). Further examples of these groups are found in: Wuts, P. G. M. and Greene, T. W. (2006) Frontmatter, in Greene's Protective Groups in Organic Synthesis, Fourth Edition, John Wiley & Sons, Inc., Hoboken, N.J., USA. The term “protected amino” refers to an amino group substituted with one of the above amino-protecting groups. The term “substituted” as used herein means any of the above groups (e.g., alkyl, alkylene, alkenyl, alkynyl, cycloalkyl, aryl, heterocyclyl and heteroaryl) wherein at least one hydrogen atom is replaced with a substituent. In the case of an oxo substituent (“═O”) two hydrogen atoms are replaced. “Substituents” within the context of this invention include, but are not limited to, halogen, hydroxy, oxo, cyano, nitro, amino, alkylamino, dialkylamino, alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, substituted alkyl, thioalkyl, haloalkyl (including perhaloalkyl), hydroxyalkyl, aminoalkyl, substituted alkenyl, substituted alkynyl, substituted cycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocycle, substituted heterocycle, —NR e R f , —NR e C(═O)R f , —NR e C(═O)NR e R f , —NR e C(═O)OR f —NR e SO 2 R f , —OR e , —C(═O)R e —C(═O)OR e , —C(═O)NR e R f , —OC(═O)R e R f , —SR e , —SOR B , —S(═O) 2 R e , —OS(═O) 2 R e , —S(═O) 2 OR e , wherein R e and R f are the same or different and independently hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, heterocycle, substituted heterocycle. The term “halo” or “halogen” as used herein means fluoro, chloro, bromo or iodo. The term “a” as used herein means one or more. Reference to “about” a value or parameter herein includes (and describes) embodiments that are directed to that value or parameter per se. For example, description referring to “about X” includes description of “X”. “Pharmaceutically acceptable salts” include both acid and base addition salts. Exemplary salts include, but are not limited, to sulfate, citrate, acetate, oxalate, chloride, bromide, iodide, nitrate, bisulfate, phosphate, acid phosphate, isonicotinate, lactate, salicylate, acid citrate, tartrate, oleate, tannate, pantothenate, bitartrate, ascorbate, succinate, maleate, gentisinate, fumarate, gluconate, glucuronate, saccharate, formate, benzoate, glutamate, methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate, and pamoate (i.e., 1,1′-methylene-bis-(2-hydroxy-3-naphthoate)) salts. A pharmaceutically acceptable salt may involve the inclusion of another molecule such as an acetate ion, a succinate ion or other counter ion. The counter ion may be any organic or inorganic moiety that stabilizes the charge on the parent compound. “Pharmaceutically acceptable acid addition salt” refers to those salts which retain the biological effectiveness and properties of the free bases and which are not biologically or otherwise undesirable, formed with inorganic acids such as nicotinic acid, hippuric acid, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, carbonic acid, phosphoric acid and the like, and organic acids may be selected from aliphatic, cycloaliphatic, aromatic, araliphatic, heterocyclic, carboxylic, and sulfonic classes of organic acids such as formic acid, acetic acid, propionic acid, glycolic acid, gluconic acid, lactic acid, pyruvic acid, oxalic acid, malic acid, maleic acid, maloneic acid, succinic acid, fumaric acid, tartaric acid, citric acid, aspartic acid, ascorbic acid, glutamic acid, anthranilic acid, benzoic acid, cinnamic acid, mandelic acid, embonic acid, phenylacetic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, salicyclic acid, nicotinic acid, hippuric acid and the like. “Pharmaceutically acceptable base addition salts” include those derived from inorganic bases such as sodium, potassium, lithium, ammonium, calcium, magnesium, iron, zinc, copper, manganese, aluminum salts and the like. Particularly base addition salts are the nicotinamide, picolinamide, benzamide, ammonium, potassium, sodium, calcium and magnesium salts. Salts derived from pharmaceutically acceptable organic nontoxic bases includes salts of primary, secondary, and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines and basic ion exchange resins, such as isopropylamine, trimethylamine, diethylamine, triethylamine, tripropylamine, ethanolamine, 2-diethylaminoethanol, tromethamine, dicyclohexylamine, lysine, arginine, histidine, caffeine, procaine, hydrabamine, choline, betaine, ethylenediamine, glucosamine, methylglucamine, theobromine, purines, piperizine, piperidine, N-ethylpiperidine, polyamine resins and the like. Particularly organic non-toxic bases are isopropylamine, diethylamine, ethanolamine, tromethamine, dicyclohexylamine, choline, and caffeine. Compounds of the present invention, unless otherwise indicated, include compounds that differ only in the presence of one or more isotopically enriched atoms. For example, compounds of the present invention, wherein one or more hydrogen atoms are replaced by deuterium or tritium, or one or more carbon atoms are replaced by a 13 C or 14 C carbon atom, or one or more nitrogen atoms are replaced by a 15 N nitrogen atom, or one or more sulfur atoms are replaced by a 33 S, 34 S or 36 S sulfur atom, or one or more oxygen atoms are replaced by a 17 O or 18 O oxygen atom are within the scope of this invention. One aspect includes a process that includes stereoselectively reducing a compound of formula II or a salt thereof: wherein: R 1 is hydrogen or an amino protecting group; to form a compound of formula III: or a salt thereof. In certain embodiments, R 1 is hydrogen. In certain embodiments, R 1 is an amino protecting group. In certain embodiments, R 1 is acetyl (Ac), trifluoroacetyl, phthalimide, benzyl (Bn), trityl (Tr), benzylidenyl, p-toluenesulfonyl, para-methoxy benzyl (Pmb), t-butoxycarbonyl (Boc), Fluorenylmethyloxycarbonyl (Fmoc) or Carboxybenzyl (Cbz). In certain embodiments, R 1 is Boc group. In certain embodiments, the process of stereoselectively reducing a compound of formula II or a salt thereof includes contacting the compound of formula II, or a salt thereof, with a reducing agent. In certain embodiments, the reducing agent comprises an enzyme. In certain embodiments, the reducing agent comprises an enzyme that promotes or directs stereo selectivity of the reduction of the compound of formula II or a salt thereof. In certain embodiments, the reducing agent comprises an enzyme and hydride source. In one aspect, the enzymatic reducing agent comprises a ketoreductase enzyme, which may be a natural or genetically engineered enzyme. Ketoreductase enzymes participate in the stereoselective reduction of a carbonyl group, such as the stereoselective reduction of a ketone or an alcohol. Such enzymes include CRED (carbonylreductase) and KRED (ketoreductase) enzymes. A carbonylreductase or ketoreductase enzyme may be used with any suitable cofactor. In one aspect, the co-factor is NADH or NADPH. In one aspect, the ketoreductase enzyme is a NADPH-dependent ketoreductase enzyme that is used in conjunction with NADPH as a co-factor. However, it is understood that a NADPH-dependent ketoreductase enzyme may also be used in conjunction with cofactors other than NADPH, such as NADH. In another aspect, the ketoreductase enzyme is a NADH-dependent ketoreductase enzyme. However, it is understood that a NADH-dependent ketoreductase enzyme may also be used in conjunction with cofactors other than NADH, such as NADPH. In a particular variation, the reducing agent comprises a cofactor such as NADH or NADPH used in conjunction with an carbonylreductase or ketoreductase enzyme such as KRED-101, KRED-112, KRED-113, KRED-114, KRED-115, KRED-121, KRED-123, KRED-124, KRED-130, KRED-132, KRED-133, KRED-135, KRED-142, KRED-145 and KRED-153 (all commercially available from Codexis Inc, Redwood City, Calif., USA). In a particular variation, the reducing agent is NADPH used in conjunction with a carbonylreductase or ketoreductase enzyme such as KRED-101, KRED-112, KRED-113 and KRED-114. In another variation, the reducing agent comprises a cofactor such as NADH or NADPH used in conjunction with a carbonylreductase or ketoreductase enzyme such as KRED-107, KRED-108, KRED-109, KRED-110, KRED-116, KRED-121 and KRED-125 (all commercially available from Codexis Inc, Redwood City, Calif., USA). Other suitable carbonylreductase or ketoreductase enzymes may be used, such as Codexis-134, Codexis-150, Codexis-168, Codexis-112, Codexis-102, Codexis-151, Codexis-123, Codexis-103, Codexis-119, Codexis-128, Codexis-136, Codexis-174, Codexis-105, Codexis-129, Codexis-137, Codexis-161, Codexis-176, Codexis-154, Codexis-106, Codexis-131, Codexis-155, Codexis-148, Codexis-165, Codexis-129, Codexis-108, Codexis-116, Codexis-125, Codexis-149, Codexis-111, DAICEL-E073, DAICEL-E087, BCC 111, C-LEcta-ADH-44s, DAICEL-E005, DAICEL-E077, C-LEcta-ADH-24s, BCC 103, C-LEcta-ADH-14s, C-LEcta-ADH-16s, DAICEL-E007, DAICEL-E008, DAICEL-E080, DAICEL-E082, DAICEL-E052, BCC 101, C-LEcta-ADH-48s, BCC 109, EVO-1.1.211, DAICEL-E072 and C-LEcta-ADH-50s. Other suitable enzymes include alcohol dehydrogenase enzymes including ADH-1, ADH-2, ADH-3, ADH-A, ADH-B, ADH-III (available from DSM). Other suitable enzymes may be identified by methods known in the art. Suitable commerically available enzymes may be used, such as those that are commercially available from sources such as Codexis Inc, Redwood City, Calif., USA, and Almac Group Ltd., United Kingdom. Sources of hydrogen include hydrogen gas, and other sources used in transfer hydrogenation reactions, including water (optionally with formate or acetate salts such as sodium formate), diimide, hydrazine (or hydrazine hydrate), alcohols, such as methanol, ethanol and isopropanol, cycloalkenes, such as cyclohexene, cyclohexadiene, dihydronaphthalene and dihydroanthracene, organic acids (optionally with an amine such as trimethyl- or triethyl-amine), such as formic acid, acetic acid or phosphoric acid, silanes such as HSiR 3 (where R is independently an alkyl group, such as HSiMe 3 and HSiEt 3 ), NADH, NADPH, FADH 2 , ammonium salts, such as ammonium formate and ammonium chloride, and Hanztch esters such as those of the formula: wherein R 11 , R 12 , R 13 and R 14 are independently alkyl (In certain examples: R 11 and R 12 are methyl and R 13 and R 14 are ethyl; R 11 and R 12 are methyl and R 13 and R 14 are butyl; R 11 is methyl, R 12 is isopropyl and R 13 and R 14 are methyl; R 11 and R 12 are methyl, R 13 is methyl and R 14 is t-butyl; R 11 and R 12 are methyl and R 13 and R 14 are methyl; R 11 and R 12 are methyl and R 13 and R 14 are isobutyl; R 11 and R 12 are methyl and R 13 and R 14 are allyl). Another aspect includes a process that includes deptrotecting a compound of formula III or a salt thereof wherein R 1 is an amino protecting group, to form a compound of formula IIIa or a salt thereof. Another aspect includes a process that includes reacting a compound of formula IIIa or salt thereof with a compound of formula IV or salt thereof to form a compound of formula I or salt thereof: wherein R 2 in formulae IV and I is independently hydrogen or an amino protecting group. In certain embodiments, R 2 is hydrogen. In certain embodiments, R 2 is an amino protecting group. In certain embodiments, R 2 is Ac, trifluoroacetyl, phthalimide, Bn, Tr, benzylidenyl, p-toluenesulfonyl, Pmb, Boc, Fmoc or Cbz. In certain embodiments, R 2 is Boc group. Methods of making a compound of the formula IV or a salt thereof are described in U.S. Pat. No. 8,063,050, issued Nov. 22, 2011 to Mitchell (e.g., in Scheme A and Example 14). The process of making a compound of formula I, or a salt thereof, in one aspect includes conditions for amide bond formation comprising a coupling agent. In certain embodiments, the process further comprises a base, such as those described herein, for example an organic amine base, such as methylmorpholine. For example, the coupling reaction may be carried out using a peptide coupling reagent selected from carbonyl-diimidazole, carbonyl-diimidazole with N-methylimidazole, 2-chloro-4,6-dimethoxy-1,3,5-triazone, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide with N-methylimidazole, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide with hydroxybenzotriazole isobutylchloroformate, propanephosphonic anhydride, and propanephosphonic anhydride with 4-methylmorpholine. In one embodiment, the coupling agent comprises propanephosphonic anhydride. In one embodiment, the coupling agent comprises propanephosphonic anhydride and 4-methylmorpholine. Another aspect includes a process for preparing a salt of a compound of formula Ia the process comprising contacting a compound of formula I, wherein R 2 is an amino protecting group, with acid to form the salt of the compound of formula Ia, wherein R 2 is hydrogen. Another aspect includes salts of (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one, wherein the salt is selected from mono hydrochloride, di hydrochloride, mono tosylate, mono mesylate, mono besylate, bis hexafluorophosphate, mono oxalate, mono sulphuric, bis sulphuric, mono phosporic, bis phosphoric, mono glutamic, mono malonic, mono L-tartaric, mono fumaric, mono citric, mono L-malic, mono D-gluconic, mono-lactic, mono succinic and mono adipic salt. Another aspect includes (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one benzene sulfonic acid salt. In one example, the benzene sulfonic acid salt is crystalline. Another aspect includes (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one p-toluene sulfonic acid salt. In one example, the p-toluene sulfonic acid salt is crystalline. Another aspect includes a process for preparing a crystalline form of a salt of a compound of formula Ia, the process comprising contacting a compound of formula Ia, with acid to form a salt of compound of formula Ia. In one example, the salt when isolated is amorphous. In certain embodiments, the process further comprises contacting the salt with solvent to form the crystalline form of the salt of the compound of formula Ia. In one example, the salt is a mono-benzene sulfonic acid salt. In another example, the salt is a mono-p-toluene sulfonic acid salt. In another example, the solvent used to crystallize the salt is acetonitrile or nitromethane. Another aspect includes a process for preparing a mono-salt of a compound of formula Ia, the process comprising contacting a compound of formula I, wherein R 2 is an amino protecting group with acid to form a bis-salt of compound of formula Ia; and contacting the bis-salt with base to form the mono-salt of the compound of formula Ia, wherein R 2 is hydrogen. In one example, hydrochloric acid is used as the acid, the bis-salt formed is dihydrochloride salt, and the final product is the monohydrochloride salt of a compound of formula Ia. Another aspect includes a process for preparing a mono-hydrochloride salt of a compound of formula Ia, the process comprising contacting a compound of formula I, wherein R 2 is an amino protecting group with hydrochloric acid to form the dihydrochloride salt; and contacting the dihydrochloride salt with base to form the monohydrochloride salt of the compound of formula Ia, wherein R 2 is hydrogen. Another aspect includes the monohydrochloride salt of (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one. Bases for use in the process for converting the dihydrochloride salt of formula Ia to the monohydrochloride salt of formula Ia include organic bases, inorganic bases and resinous bases. Organic bases include amine bases such as ammonia, alkyl amines, for example methyl amine, dimethyl amine, diethyl amine, trimethyl amine, triethyl amine, butyl amine, tetra-methylethyldiamine, isopropyl amine and diisopropyl amine, aniline, indole, pyridine, pyrimidine, pyrrolidine, N-methylpyrrolidone, pyrrole, pyrazole, imidazole, morpholine, N-methylmorpholine, piperidine, piperazine, N,N-dimethylpiperizine, and the like. Inorganic bases include bicarbonate, carbonate and hydroxide bases, for example, ammonium hydroxide, ammonium carbonate, barium hydroxide, barium carbonate, calcium carbonate, calcium hydroxid, cesium carbonate, cesium hydroxide, lithium amide, lithium carbonate, lithium hydroxide, magnesium hydroxide, magnesium carbonate, potassium hydroxide, potassium bicarbonate, potassium carbonate, sodium bicarbonate, sodium carbonate, sodium hydroxide, sodium amide and soda lime. In certain embodiments, the base in the process for converting the dihydrochloride salt of formula Ia to the monohydrochloride salt of formula Ia comprises a resinous base. In certain embodiments, the process for converting the dihydrochloride salt to the monohydrochloride salt comprises contacting the compound of formula Ia, or a salt thereof, with a polymeric resin to form the monohydrochloride salt of formula Ia. In certain embodiments, the polymeric resin comprises functionalized styrene divinylbenzene copolymers, examples of which are commercially available (Amberlyst series, e.g., Amberlyst A-21 and Amberlite FPA51, available from Dow Chemical, Midland, Mich.). Scheme 1 shows a general method for preparing the compounds of the present invention. For a more detailed description of the individual reaction steps, see the Examples section below. Although specific starting materials and reagents are depicted in the Scheme and discussed below, other starting materials and reagents can be easily substituted to provide a variety of derivatives and/or reaction conditions. As shown in Scheme 1, a compound of formula II can be stereoselectively reduced to the alcohol of formula III with a ketoreductase. The compound of formula III can be deprotected with acid (where R 1 is an amino protecting group) to form a de-protected form of the alcohol of formula IIIc (where R 1 is hydrogen), for example hydrochloric acid. Deprotected compounds of formula III or IIIa can be coupled with a compound of formula IV using a coupling agent, for example propanephosphonic anhydride, to form a compound of formula I. Compounds of formula I can be deprotected or functionalized to form the deprotected form or salt form compound Ia, wherein R 2 is hydrogen, with acid. Also detailed herein is a product produced by any process, scheme or example provided herein. For example, in one aspect is provided a product produced by the process of: contacting the compound of formula II, or a salt thereof, with a reducing agent to form a compound of formula III, or a salt thereof; contacting the compound of formula III, or a salt thereof, with a compound of formula IV, or a salt thereof to form a compound of formula I or salt thereof; contacting the compound of formula I, or a salt thereof, with acid to form a salt form of compound of formula Ia; and contacting a bis salt of the compound of formula Ia with base to form a mono salt form. EXAMPLES The invention can be further understood by reference to the following examples, which are provided by way of illustration and are not meant to be limiting. Abbreviations used herein are as follows: CPME: Cyclopentyl methyl ether GDH: glutamate dehydrogenase IPA: isopropylalcohol NADP: Nicotinamide adenine dinucleotide phosphate TLC: thin layer chromatography HPLC: high pressure liquid chromatography Example 1 tert-butyl 4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate A 3000 L glass-lined reactor was evacuated and filled with nitrogen to normal pressure 3 times. Water (660.0 kg) was added into the reactor while maintaining the temperature in the range of 20-30° C. The stirrer was started, followed by the addition of potassium dihydrogen phosphate (9.2 kg), dipotassium phosphate (23.7 kg) and glucose (78.5 kg). The mixture was stirred until solid dissolved completely. Then 30.1 kg of this buffer mixture was discharged into a 50 L drum for future use. To the reactor was added (R)-tert-butyl 4-(5-methyl-7-oxo-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate (66.0 kg) and PEG400 (732.6 kg) and the mixture was heated to about 30-35° C. Maintaining the temperature at 30-35° C., a mixture of buffer solution (20.0 kg), KRED-101 (2.4 kg), GDH (3.4 kg) and NADP (2.2 kg) was added into the mixture. The mixture was then maintained at 32-37° C. for reaction while controlling the pH at 6.8-7.1. After about 6 h, the mixture was monitored by TLC and HPLC until ketone starting substrate was ≦1.0%. During the reaction, potassium hydroxide solution (total 46.2 kg) and extra enzyme buffer solution prepared with purified water (5.0 kg), KRED-101 (0.24 kg), GDH (0.34 kg) and NADP (0.22 kg) were added. To a glass-lined reactor, isopropyl acetate (1148.6 kg) was added. The reaction mixture from the previous paragraph was added to the reactor in three portions. Each time, it was stirred for 15-20 min and held for at least 0.5 h before separation at 20-30° C. This extraction process was repeated three times. The organic phases were combined. At 20-30° C., the combined organic phases were washed with purified water (329.3 kg). It was stirred for 25-30 min and held for at least 30 min before separation. The organic phase was left in the reactor and the washing process was repeated. The organic phase was decolorized with active carbon (6.6 kg) and stirred for 1-1.5 h. The mixture was filtered via a Nutsche filter. The cake was washed with isopropyl acetate (57.5 kg). The filtrates were combined. The filtrate was then transferred into a thin film evaporator and concentrated at ≦55° C. under reduced pressure until 500-600 L remained. The concentrated mixture was filtered and transferred into a glass-lined reactor, then concentrated at ≦55° C. under reduced pressure until 50-60 L remained. The mixture was then heated to 50-55° C. and stirred at this temperature for 0.5-1.5 h under nitrogen. n-Heptane (277.2 kg) was added into the mixture at the rate of 20-30 kg/h while maintaining the temperature at 50-55° C. The mixture was then cooled to 20-30° C. at the rate of 5-10° C./h. The mixture was stirred at 20-30° C. for 1 h, then heated to 50-55° C. and stirrer for 1-2 h, and then cooled to 15-20° C. at a rate of 5-10° C./h for crystallization. It was sampled to be analyzed by HPLC every 1-2 h until wt % of the mother liquid was ≦3% or the change of the wt % between consecutive samples was ≦0.5%. The mixture was then filtered with a centrifuge. The filter cake was washed with n-heptane (45.0 kg). The filtrate was transferred into a glass-lined reactor and concentrated at ≦45° C. under reduced pressure (≦−0.06 MPa) until no more distillate was observed (approximately 20 L remained). Isopropyl acetate (20.0 kg) was added, the mixture was heated to 45-55° C. and stirred for 0.5-1 h. The mixture was dried at 40-50° C. to give tert-butyl 4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate as grey solid (50.65 kg, 76.3% yield), HPLC rt=18.93 min, 99.9% pure, 100% de, 100% ee. The HPLC conditions are given in Table 1 below. TABLE 1 Column ACE-3-C18 column, 4.6 × 150 mm, 3 μm Column temperature 30° C. Mobile phase Mobile Phase A: 20 mM ammonium formate at pH 3.7 Mobile Phase B: methanol (MeOH) 0.8 mL/min Flow Rate Run Time 27 min Gradient Time (min) % B 0 5 5 30 20 80 26 100 29 100 29.1 5 34 5 Example 2 tert-butyl ((S)-2-(4-chlorophenyl)-3-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-oxopropyl)(isopropyl)carbamate To a three-neck 250 mL round bottom flask, equipped with a mechanical stirrer, a nitrogen inlet, and a thermocouple was charged tert-butyl 4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazine-1-carboxylate (9.8 g, 29.3 mmol), 2-propanol (41.6 mL) and 2.75 M HCl in 2-propanol (32 mL, 88 mmol). The mixture was heated to 55-65° C. until reaction completion. Distilled 2-propanol (−13%) to remove excess HCl. The reaction mixture was cooled to 5° C. and added 4-methylmorpholine (21 mL, 191 mmol) at a rate maintaining the temperature below 25° C. The mixture was stirred at room temperature for 30 min. (S)-3-((tert-butoxycarbonyl)(isopropyl)amino)-2-(4-chlorophenyl)propanoic acid (10.5 g, 30.8 mmol) and 2-propanol (24.5 mL) were added and the reaction mixture was cooled 0-5° C. Additional 2-propanol was added as required for rinse and to dilute reaction mixture to 10 vol total. Propanephosphonic anhydride (T3P) (50 wt % in EtOAc) (19.2 mL, 32.2 mmol) was added at a rate maintaining the temperature ≦10° C. The reaction mixture was warmed to room temperature. Upon reaction completion, water (10 mL, 1 vol) was added. CPME (100 mL) and then 1N aqueous NaOH (100 mL) were added. The mixture was stirred for 30 min and the layers were cut. The organic layer was consecutively washed with 1N aqueous NaOH (100 mL), 1N aqueous NH 4 OH (2×100 mL), and saturated aqueous NH 4 Cl (50 mL). The organic layer was washed with 14% aqueous NaCl (25 mL) and then concentrated to minimum stir volume at 65° C. under vacuum. CPME (100 mL) was added and the solution was distilled to minimum stir volume. CPME (100 mL) was added and the solution is distilled to minimum stir volume. CPME (100 mL) was added and the solution was heated to 50° C. Charcoal (7.35 g) was added. The mixture was stirred at 50° C. for 12 hours. The charcoal was filtered and the solution was distilled to minimum stir volume and CPME and heptane were added to obtain a final solution of 80 mL (8 vol) of a 35% CPME/heptane mixture. The mixture was heated to 70° C. to obtain a solution, and then cooled to 55° C. then seeded with 50 mg ((S)-2-(4-chlorophenyl)-3-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-oxopropyl)(isopropyl)carbamate. The mixture was held at 55° C. for 1 h and then cooled to room temperature. Heptane (29 mL) was added and the mixture was cooled to 0-5° C., filtered and washed with 15% CPME/Heptane (2×15 mL) and heptane (2×15 mL). The filter cake was dried at ≦55° C. to give tert-butyl ((S)-2-(4-chlorophenyl)-3-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-oxopropyl)(isopropyl)carbamate, isolated 14.1 g, 86% yield. Example 3 (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one monohydrochloride To a 500 mL reactor was added tert-butyl ((S)-2-(4-chlorophenyl)-3-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-oxopropyl)(isopropyl)carbamate (49 g) and 2-propanol (196 mL) and the reactor was heated to 50° C. A solution of HCl in 2-propanol (3M, 90 mL) was added to maintain the temperature from 50-70° C. The solution was maintained at 60° C. for 19 hours and the mixture was cooled to 0-5° C. Amberlyst® A-21 resin (60.5 g) was washed with water (50 mL) and purged with N 2 for 5 min to remove excess water. The resin was then washed with 2-propanol (50 mL) and purged with N 2 for 5 min to remove excess 2-propanol. The reaction mixture was re-circulated through the packed resin bed for at least 2 hours until pH 3.55-7.0 was reached. The resin bed was purged with N 2 for 5 min, collecting all the filtrates. The resin was washed with 2-propanol (294 mL), and the resin was purged with N 2 for 5 min, combining all the filtrates. To the combined solution was added decolorizing charcoal (20 g) and the mixture was stirred at 15-25° C. for 1-2 hours. The charcoal was then filtered and the solution was distilled under vacuum at 25-35° C. Charged EtOAc (333.0 mL) to obtain a ˜87.5:12.5 EtOAc:2-propanol ratio. A seed slurry (1 g) of (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one monohydrochloride in EtOAc:IPA (˜6 mL, 87.5:12.5) was added to the reactor and the mixture was stirred at 20-25° C. for 1 h. The slurry was constant volume solvent-switched to EtOAc at 20-30° C. until a ratio of EtOAc:2-propanol ≧97:3 was reached. The reactor was cooled to 0-10° C. and the slurry filtered. The filter cake was washed with EtOAc (115 mL) and dried under vacuum at 85° C. for 16 hours to afford (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one monohydrochloride as an off-white solid: 41.9 g (94% yield). Alternative Procedure Using Organic Amine Bases Using N-methylmorpholine: To a solution of tert-butyl ((S)-2-(4-chlorophenyl)-3-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-oxopropyl)(isopropyl)carbamate (5 g) in 2-propanol (317 g) was added HCl in 2-propanol. The solution was heated until complete deprotection. The solution was cooled to room temperature and then a solution of N-methylmorpholine (556.3 mg) was added dropwise. The resulting solid NMM.HCl was filtered off and the filtrate was concentrated and solvent-switched to ethyl acetate. The resulting solid (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one monohydrochloride was filtered and washed with ethyl acetate and dried under vacuum (99.8% purity by LC). Using piperazine: To a solution of tert-butyl ((S)-2-(4-chlorophenyl)-3-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-oxopropyl)(isopropyl)carbamate (50 g) in 1-propanol (128 g) was added HCl in 1-propanol (45.2 g, 5.5N). The solution was heated until complete deprotection. The solution was cooled to room temperature and then a solution of piperazine (7.3 g) in 1-propanol (36.5 g) was added dropwise. The resulting solid piperazine.HCl was filtered off and the filtrate was carbon treated, concentrated and solvent-switched to ethyl acetate. The resulting solid (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one monohydrochloride was filtered and washed with ethyl acetate and dried under vacuum (Yield 22.9 g, 99.8% purity by LC). Example 4 Salt Formation of (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one (S)-2-(4-Chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one was solid dosed into well plates. Various counter ions were stock dosed in MeOH/water mixtures and dosed into the well plates. Upon addition of the counter ion solution salt formation took place. The stock-solvent solutions were evaporated over several days. The well plates were dried under reduced pressure of 100 mBar for 24 h at rt, and then 10 mbar for 24 h at rt. Solid residues obtained after drying were harvested and subjected to XRPD. Example 5 (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one Benzene Sulfonic Acid Salt (S)-2-(4-Chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one free base (113.99 mg) was dissolved in methyl ethyl ketone (1 mL) Benzenesulfonic acid (39.98 mg) was dissolved in methyl ethyl ketone and the acid solution added to the solution of free base. Solid formed. Additional methyl ethyl ketone was added to ensure that the suspension could be mixed. The suspension was stirred overnight and the benzenesulfonic acid salt was isolated by filtration and dried in a vacuum oven for 2 hours at 50° C. The benzenesulfonic acid salt from above, 10.2 mg, was placed into a 20 mL vial, acetonitrile, 0.2 mL, added and the vial placed into a shaking block at 22° C. The slurry was shaken for 8 days to give a mixture of needles and plates. Single crystal structure determination was conducted on one of the plates from the slurry (See FIGS. 1A-1B ), and the data is shown in Table 2 below. TABLE 2 formula C30H38Cl1N5O5S1 formula weight 616.18 space group P 21 21 21 (No. 19) a, Å 19.3682(15) b, Å 25.4177(19) c, Å 26.121(3) α, deg 90 β, deg 90 γ, deg 90 V, Å 3 12859.4(19) Z 16 d calc , g cm −3 1.273 temperature, K 150 radiation Cu K α (1.54184) (wavelength, Å ) diffractometer Nonius_KappaCCD h, k, l range −22 to 21 −28 to 28 −30 to 30 θ range, deg 1.69-63.38 programs used SHELXTL 2008 data collected 12519 unique data 12519 R(F o ) 0.098 R w (F o 2 ) 0.194 goodness of fit 1.091 absolute structure Flack parameter (0.01 (3)) determination Alternative Procedure: (5)-2-(4-Chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one free base, 1.47 g, was added to a reactor fitted with overhead stirrer. Methyl ethyl ketone (MEK), 10 mL, was added and the solid dissolved. Benzenesulfonic acid, 454.6 mg, was dissolved in MEK, 10 mL, and the acid solution was added, via syringe, over 10 minutes to the solution of free base. The vial containing the acid solution was rinsed with MEK, 5 mL, and the rinse solution added to the reactor via the syringe. Solid was observed in the reactor after addition of 2-3 mL of the acid containing solution. The suspension was stirred for 3 hours and the solid isolated by vacuum filtration. The solid was dried under reduced pressure (house vacuum, about 50 torr) at 50° C. for 3 hours. The solid was subsampled, 950 mg, and slurried in acetonitrile, 3 mL, overnight at ambient conditions. The slurry was heated to 49° C. for 1 hour and then removed from the heating block and allowed to cool to room temperature on a magnetic stirring plate. The solid was isolated by vacuum filtration. The vial was rinsed with acetonitrile, 2×1 mL, to transfer the solid to the filter. The resulting solid was dried under reduced pressure at 50° C. using house vacuum to give crystalline besylate salt. The product was characterized by XRPD (See FIG. 2 ). Example 6 (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one p-toluene Sulfonic Acid Salt (S)-2-(4-Chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one free base, 202.4 mg, was dissolved in acetonitrile, 10 mL. p-Toluenesulfonic acid monohydrate, 83.5 mg, was dissolved in acetonitrile, 10 mg, and the two solutions mixed. The solution was slowly evaporated under a stream of nitrogen. The crystaline tosylate salt was analyzed after evaporating over 3 weeks (See FIG. 3 ).

The invention provides new processes for making and purifying salts of hydroxylated cyclopentapyrimidine compounds, which are useful as AKT inhibitors used in the treatment of diseases such as cancer, including the monohydrochloride salt of (S)-2-(4-chlorophenyl)-1-(4-((5R,7R)-7-hydroxy-5-methyl-6,7-dihydro-5H-cyclopenta[d]pyrimidin-4-yl)piperazin-1-yl)-3-(isopropylamino)propan-1-one.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. 12/194,628 filed Aug. 20, 2008, which claims the benefit of U.S. Provisional App. No. 60/957,098 filed Aug. 21, 2007. Each of the foregoing is hereby incorporated by reference in its entirety. BACKGROUND [0002] 1. Field [0003] The present invention is related to prepaid cards, and specifically to a prepaid card management platform with a graphical user interface and applications toward expense management. [0004] 2. Description of the Related Art [0005] The spending profiles common among businesses present a favorable market environment for card-based payment products. Many vendors are adopting card payments to provide customers with more choice and to accelerate the process of getting paid. As payers and recipients rely more heavily on electronic payments to transact business, which will grow beyond general retail merchant relationships, the use of paper-based payment products will decline. The needs and sophistication of buyers and sellers will change, creating demand for ways to streamline the operational cost of managing expenses. [0006] There is a need for prepaid corporate expense cards. The purchasing cycle can be split in two operational categories: the Decision to Buy and Payment. Payment tools such as credit cards and accounting software such as Quickbooks facilitate payments and organization of transactions in the Payment category, but few products help with the Decision to Buy category. There is a chasm between business owners keeping the full responsibility of approving transactions one by one and the possibility of easing some of that burden by enabling employees to control inadequacies of products available. Organizations understand that placing purchase responsibilities on employees pose risks, including: erroneous spending, theft and poor decision-making that can take time and money to resolve. These and other problems can be solved by using prepaid cards with strict spending management features built-in, and requiring no credit score to access. Card products available in the market today vary only slightly from each other. All have limited functionality and do little to provide owners with the controls needed to operate businesses more efficiently. Prepaid cards can provide these valuable controls, will dramatically improve the ways small businesses track and control spending, and help limit numerous points of risk for business owners. SUMMARY [0007] The present invention provides improved capabilities for a prepaid expense card management service and/or platform, where the management platform may be presented as a graphical user interface. The prepaid expense card management platform allows businesses to increase spending control and decrease overhead time associated with the administering of cash and check disbursement expenditures. [0008] The prepaid expense card management platform may include and/or be associated with an account administration facility, a funds management facility, the ability to auto-fund, a spend rules facility, a permissions facility, a data collection facility, portals, a graphical user interface, a payment network, a reporting engine, customer support functionality, an integrated voice response service, a billing engine, an alert engine, a search engine, a workflow engine, a community and forum, various types of users, various forms of platform access and real-time updates and information. [0009] In embodiments, the prepaid expense card management platform may provide a user with a plurality of functions and controls, such as manage profiles (create, store, edit, terminate the customer business, customer administrator and card demographic information on file), administer card accounts (generate account number, create account record, store account record, change card status, change card account balance, change spend rules, terminate card account, create request for personalized or non-personalized encoded card plastic), set spend rules (create, store, cancel daily limits, frequency limits, day of the week limits, time of day limits, merchant limits by defined category or merchant category code (MCC), network message data limits), define spend rules (create, edit and store user defined spending limitation per card or business program or modify current MCC category groupings), override spend rules on an ad hoc basis, systematic notifications (alerts posted to dashboard, sent via email, sms, mobile, customer service), manage access permissions (business administrator functionality, cardholder functionality, customer service functionality) service accounts (search stored records by business customer name, cardholder name, card account number, bank account number, administrator name, business owner name, email, system username, phone number, review stored accounts including profile, balance and transaction history, edit stored accounts, terminate stored accounts, refund/waive fees, release authorization holds), process network messages (authorization, settlement, reversal, advice), administer program fees (waive fees, store fee structure, modify fee structure), manage business funds (create and cancel one-time and scheduled ACH transfer funding requests, add/remove funds from card accounts, create funding rules for card accounts, manage linked business operating accounts, calculate burn rate and suggest funding amount), close business customer program (block all cards, move card and program funds, produce reports), use workflows (request business funding, request card funding, request spend authorization, receive authorization, new customer applications, application approval/decline notification, score applicants, identity verification), create workflow tickets, change workflow ticket status, attach documents to tickets, generate ticket emails, display, hear or download transaction data for business and card (as list, as user defined report, as pre-defined report, as expense report, as monthly statement, as graph or chart, as detail, as aggregate, as machine readable file, as 3rd party proprietary format, as email, as mobile message, as voice message, as customer service agent call, as IVR/VRU), add comments to transaction record for business and card, date setting, access to all audit trails, limit viewing of audit trails to those with a job-related need, protect audit trail files from unauthorized modifications, or the like. These functions and controls may be provided through or enabled through a graphical user interface. In an embodiment, the graphical user interface may be provided using a web browser, client side program or the like. Access to the platform, such as via the user interface, may be provided via a computer, network, laptop, handheld device, cell phone, wireless email device, Treo, Blackberry, personal digital assistant, palm top computer, pager, digital music player, a voice interface, telephone access and the like. [0010] In embodiments, the platform may provide methods and systems for managing expenses using prepaid cards, comprising providing a first account managed by a prepaid expense card management platform; providing at least one other account managed by the prepaid expense card management platform; and providing an account administration facility for allowing a user of the first account to perform at least one administrative action in connection with the at least one other account. In embodiments, the platform may provide methods and systems for managing expenses using prepaid cards, comprising providing a first account managed by a prepaid expense card management platform; providing at least one other account managed by the prepaid expense card management platform; and providing a funds management facility for allowing a user of the first account to perform at least one funding action in connection with the at least one other account. [0011] In embodiments, the platform may provide methods and systems for managing expenses using prepaid cards, comprising: providing a first account of managed by a prepaid expense card management platform; providing at least one other account managed by the prepaid expense card management platform; and providing a funds management facility which transfers funds between the first account and the at least one other account. In embodiments, the platform may provide methods and systems for managing expenses using prepaid cards, comprising: providing at least one account managed by a prepaid expense card management platform; issuing at least one prepaid expense card associated with the at least one account to at least one user; and providing a spend rules facility for the administration of spend rules in association with the at least one account. [0012] In embodiments, the platform may provide methods and systems for managing expense payments using prepaid expense cards, comprising providing a prepaid expense card management platform; and issuing at least one card associated with the platform to at least one individual. In embodiments, the platform may provide methods and systems for managing expenses using prepaid cards, comprising providing a prepaid expense card management platform, wherein the management platform is presented as a graphical user interface; issuing at least one prepaid card associated with the platform; and enabling management of the at least one prepaid card through the platform. BRIEF DESCRIPTION OF THE FIGURES [0013] The invention and the following detailed description of certain embodiments thereof may be understood by reference to the following figures: [0014] FIG. 1 depicts an embodiment of the prepaid expense card management platform. [0015] FIG. 2 depicts an embodiment of the account administration facility. [0016] FIG. 3 depicts an embodiment of the funds management facility. [0017] FIG. 4 depicts an embodiment of the prepaid expense card management platform GUI, showing the initial applications process screen asking for personal information. [0018] FIG. 5 depicts an embodiment of the prepaid expense card management platform GUI, showing a screen for entering bank information. [0019] FIG. 6 depicts an embodiment of the prepaid expense card management platform GUI, showing a screen for entering credit card and billing address information. [0020] FIG. 7 depicts an embodiment of the prepaid expense card management platform GUI, showing a table for entering a user's estimate for weekly petty cash. [0021] FIG. 8 depicts an embodiment of the prepaid expense card management platform GUI, showing an initial funding screen. [0022] FIG. 9 depicts an embodiment of the prepaid expense card management platform GUI, showing a confirm transfer screen for initial funding. [0023] FIG. 10 depicts an embodiment of the prepaid expense card management platform GUI, showing a confirmation screen for initial funding. [0024] FIG. 11 depicts an embodiment of the prepaid expense card management platform GUI, showing an employee name entry screen. [0025] FIG. 12A depicts an embodiment of the prepaid expense card management platform GUI, showing an employee spend locations screen. [0026] FIG. 12B depicts an embodiment of the prepaid expense card management platform GUI, showing an employee spend merchant categories screen. [0027] FIG. 13 depicts an embodiment of the prepaid expense card management platform GUI, showing the dashboard interface. [0028] FIG. 14 depicts an embodiment of the prepaid expense card management platform GUI, showing the card interface. [0029] FIG. 15 depicts an embodiment of the prepaid expense card management platform GUI, showing 1 of 3 of the card management registering employee screen. [0030] FIG. 16 depicts an embodiment of the prepaid expense card management platform GUI, showing 2 of 3 of the card management registering employee screen. [0031] FIG. 17 depicts an embodiment of the prepaid expense card management platform GUI, showing 3 of 3 of the card management registering employee screen. [0032] FIG. 18 depicts an embodiment of the prepaid expense card management platform GUI, showing 1 of 3 of the card management terminating employee screen. [0033] FIG. 19 depicts an embodiment of the prepaid expense card management platform GUI, showing 2 of 3 of the card management terminating employee screen. [0034] FIG. 20 depicts an embodiment of the prepaid expense card management platform GUI, showing 3 of 3 of the card management terminating employee screen. [0035] FIG. 21 depicts an embodiment of the prepaid expense card management platform GUI, showing the card management view transactions screen. [0036] FIG. 22 depicts an embodiment of the prepaid expense card management platform GUI, showing 1 of 4 of the card management add funds screen. [0037] FIG. 23 depicts an embodiment of the prepaid expense card management platform GUI, showing 2 of 4 of the card management add funds screen. [0038] FIG. 24 depicts an embodiment of the prepaid expense card management platform GUI, showing 3 of 4 of the card management add funds screen. [0039] FIG. 25 depicts an embodiment of the prepaid expense card management platform GUI, showing 4 of 4 of the card management add funds screen. [0040] FIG. 26 depicts an embodiment of the prepaid expense card management platform GUI, showing 1 of 4 of the card management remove card funds screen. [0041] FIG. 27 depicts an embodiment of the prepaid expense card management platform GUI, showing 2 of 4 of the card management remove card funds screen. [0042] FIG. 28 depicts an embodiment of the prepaid expense card management platform GUI, showing 3 of 4 of the card management remove card funds screen. [0043] FIG. 29 depicts an embodiment of the prepaid expense card management platform GUI, showing 4 of 4 of the card management remove card funds screen. [0044] FIG. 30 depicts an embodiment of the prepaid expense card management platform GUI, showing 1 of 2 of the card management block/unblock cardholder spend screen. [0045] FIG. 31 depicts an embodiment of the prepaid expense card management platform GUI, showing 2 of 2 of the card management block/unblock cardholder spend screen. [0046] FIG. 32 depicts an embodiment of the prepaid expense card management platform GUI, showing the card management total funds on cards screen. DETAILED DESCRIPTION [0047] The present invention provides a prepaid expense card service 102 that may incorporate all the best features of cash, checks, corporate credit, corporate debit, prepaid cards, and the like. The service provided by the present invention may be referred to as the prepaid expense card management platform 102 . To enroll in the prepaid expense card management platform 102 , a user may submit an application through a prepaid expense card management platform website, via mail, email, fax, telephone, and the like, and may be followed by a number of setup procedures. Once setup procedures are complete, users, such as business owners or assigned administrators, may access the prepaid expense card management platform's features and product functionality under a plurality of categories, such as account profile management, funds management, card management, transaction management, help and facts knowledge base, and the like. In embodiments, the prepaid expense card management platform 102 may be a financial resource for small business owners by creating payment products that transition petty cash spending from paper to electronic-based spending tied to physical and virtual card numbers, automating the controls for and maintenance of employee-driven (and/or contractor-driven) spending electronically, as opposed to the manual processes for storage, tracking and monitoring. [0048] In embodiments, the prepaid expense card management platform card may be implemented through a branded third party payment network and may feature a prepaid expense card management platform logo and design. In embodiments, the third party may be MasterCard, Visa, Discover and the like. In addition, for business applications, the logo and design may be conservatively implemented for appeal to the business market. The prepaid expense card management platform card may have features that are typically associated with credit cards and debit cards, such as a logo, hologram, magnetic strip on the back, signature panel, cardholder name, account information, expiration date, security code, embosed print, and the like. ATM or other PIN access may not be available for some cards, and thus may be limited to signature spending. Card package contents may be assembled by a fulfillment facility authorized by a third party to emboss and store cards, and may include card, card mailer, envelope, cardholder terms and conditions and the like. In embodiments, user information, such as terms and conditions, may be available on-line, via mail, via email, through a network or by other means. [0049] In certain embodiments, the prepaid expense card management platform card may be a network branded prepaid card which may utilize a payment network, or system, such as Visa, MasterCard, American Express or Discover to facilitate the transfer of funds from an issuing bank to a merchant at the point of sale, or may utilize an ATM network, such as Plus, Cirrus, Star, Most, Nyce, Interlink, and the like, to facilitate transfer of funds from an issuing bank to the cardholder in the form of cash. In embodiments, the transaction may travel through a network's infrastructure to transact a purchase. In certain embodiments, the network logo may appear on the face or the back of the card and sometimes not. [0050] In certain embodiments, the balance in the account which may be associated with the prepaid expense card management platform card may be the amount available for spending. In certain embodiments, borrowing may not be permitted and funds are to be added to an account prior to spending. In one particular an embodiment, the platform may utilize only one bank account where all card balances are pooled as opposed to a debit card where cash is stored in an individual demand deposit account in the account owner's name. In another embodiment, the prepaid expense card management platform may offer loans and/or overdraft protection and/or may allow for funding to be obtained from loans and/or overdraft protection. A database and transaction processing system may be charged with accurately tracking funds available for spending. [0051] In certain embodiments, the prepaid expense card management platform card may be an expense card for which funds on deposit are owned by a business entity, not by a cardholder. The funds may be prepaid funds. The card may be issued to an employee and/or contractor to facilitate corporate purchases. This embodiment may not function as an expense reimbursement program where employees and/or contractors pay business expenses out of pocket and expect a reimbursement from their employer either on a card or as a check. [0052] In certain embodiments, the prepaid expense card management platform card and/or platform 102 may have one or more of the following properties: Funds may or must be deposited into an account prior to spend; funds may be stored in a pooled account and some technical device or database may track spending and balances electronically, there may be no transfer of ownership of funds when money is allocated to a card—the money always belongs to the business; and cards may be issued to authorize designated employees and/or contractors to spend company money on business expenses. [0053] Referring to FIG. 1 , the prepaid expense card management platform 102 may include and/or be associated with an account administration facility 104 , a funds management facility 108 , the ability to auto-fund 110 , a spend rules facility 112 , a permissions facility 114 , a data collection facility 118 , portals 120 , a graphical user interface 122 , a payment network 124 , a reporting engine 128 , customer support functionality 130 , an integrated voice response service 132 , a billing engine 134 , an alert engine 138 , a search engine 140 , a workflow engine 142 , a community and forum 144 , various types of users 148 , various forms of platform access 150 and real-time updates and information 152 . [0054] The prepaid expense card management platform 102 may include an account administration facility 104 . Referring to FIG. 2 , the account administration facility 104 may enable administration of various accounts and levels of accounts on the platform 102 . An account may be a root account 202 from which all other accounts on the platform 102 may be managed. A root account 202 may allow for management of the various accounts of various business on the platform 102 . Various accounts may be associated with a business. Accounts may be associated with different businesses. Referring to FIG. 2 , account 204 may be associated with a different business than account 208 . Certain of the accounts may allow for management of certain other accounts associated with a business. For example, an administrator account may allow for management of all the accounts of the business. In embodiments, an account for a division manager may allow for administration of the accounts of members of the division. In embodiments, a given account may be permitted to administer any set of other accounts as determined by the platform 102 or a higher level account. [0055] The account management facility 104 may enable the management of profiles and/or accounts 210 . The account management facility 104 may enable creation, storing, editing and termination of profiles and/or accounts. The account management facility 104 may allow for the termination of a business or particular account. The account management facility 104 may enable manipulation of card demographic information. The account management facility 104 may enable the administration of accounts 212 . In embodiments, administration 212 may include generating account numbers, creating account records, storing account records, changing card status, changing card account balance, changing spend rules, terminating card accounts, creating requests for personalized or non-personalized cards and the like. The account management facility 104 may allow for batch administration. In an embodiment, the account management facility 104 may allow for a change of parameters to be applied to all or a group of accounts. The account management facility 104 may allow for the creation and termination of administration accounts. The account management facility 104 may allow for the creation and termination of card accounts. [0056] The account management facility 104 may enable account service 214 . Account service 214 functions may include searching stored records by business customer name, cardholder name, card account number, bank account number, administrator name, business owner name, email, system username, phone number and the like, reviewing stored accounts including profile, balance and transaction history information, editing stored accounts, terminating stored accounts, refunding and/or waiving certain fees, releasing authorization holds and the like. The account management facility 104 may also allow for registration and termination of employees and/or contractors, card issuance, viewing spend transactions by account, activation and deactivation of cards and the like. [0057] The account management facility 104 may provide for an administration dashboard 218 , that may include a cardholder list, cardholder balance, card active/block status, click-through to card account for more detail functionality, and the like. The account management facility 104 may allow a user to place one or more accounts into a state of suspension/inactivity or block status 220 . Block status 220 may be temporary and a user may be restored to active status. In an embodiment, a user on vacation may be assigned block status 220 . Account profile management may be available, with client company profile listing authorizing users and passwords for system access, registered bank account information, a view of available program balance information such as money on deposit and unallocated to cards, and the like. [0058] The prepaid expense card management platform 102 may include a funds management facility 108 . Referring to FIG. 3 , program funding 302 , that is, the money customers keep on deposit with the prepaid expense card management platform, may come from external funding sources 304 , such as from credit cards, lines of credit, cash deposits, loans or the like. In embodiments, program funding 302 may be largely or completely from cash deposits, where funds transfers may be available through a prepaid expense card management platform or card funding service, a third party funds transfer service, customer initiated funding via a banking websites' bill pay service online, a customer initiated wire transfer service, ACH transfer, or the like. The funds transfer service may be a system module enabling funds transfers from registered bank accounts to prepaid expense card management platform card accounts on the prepaid expense card management platform. Incoming funds may be reflected on the site as the prepaid expense card management platform account balance representing pooled business/expense funds prior to card account disbursement. During the customer account setup process, business bank account information may be registered online with the prepaid expense card management platform. Funding from a bank website may provide bill pay services enabling customers to initiate electronic payments from their accounts to designated payees. A prepaid expense card management platform card or the prepaid expense card management platform may be registered on the electronic payment networks as a payee (similar to utilities and other vendors) to receive payments initiated from bank websites. Wire transfers may be setup to receive wire transfers from customers who may need same day funding services. The program funding 302 may be allocated, in whole or in part, to one or more accounts, each with an associated card balance 308 . [0059] The funds management facility 108 may enable management of business funds, including, without limitation, creating and canceling one-time and scheduled ACH transfer funding requests, adding and removing funds from card accounts, creating funding rules for card accounts, managing linked business operating accounts, calculating burn rate, suggesting funding amounts and the like. The funds management facility 108 may also process network messages, including, without limitation, authorization, settlement, reversal and advice. The funds management facility 108 may enable adding and removing of card funds and manipulation of card balances. In embodiments, the cards may be re-loadable. In embodiments, the card funds may not be the property of the cardholder. [0060] The funds management facility 108 may enable funds management, such as for inbound and outbound funds management; inbound funds balance stored as ‘available balance’ or funds received notifications sent to authorized administrators, such as unable to load cards until funds arrival is confirmed; outbound, such as routing funds back to an external back account; addition and removal of cards; automatic load rules, such as a top-off feature that systematically adds funds to meet maximum card balance available, and set to occur at regular times, such as daily, weekly, monthly; or the like. [0061] The funds management facility 108 may enable auto-funding 110 of particular accounts. In embodiments, the auto fund rule may be configured to fund only if needed, and not arbitrarily. The auto fund feature 110 may reduce the amount of work required by administrators. The auto fund feature 110 may ensure that cards are allocated funds in a timely fashion. In an embodiment, a card holding sales person may begin work at 7 am Eastern time, but the system administrator may not begin work until 9 am Pacific time. On a Monday morning, the sales person may not receive funds on her card until after noon Eastern time, but she may have needed funds before that time. With the auto fund feature 110 the administrator could have configured an auto fund rule to add the allowed balance to the sales person's card prior to 7 am Eastern time. [0062] The prepaid expense card management platform 102 may include a spend rules facility 112 . The spend rules facility 112 may enable the creation, administration and management of spend rules. In embodiments, spend rules may include a plurality of limitations, such as limited spend by MCC, category of expenditure, amount of expenditure or series of expenditures, amount per transaction, frequency of expenditures, time constraints such as daily, day of the week, time of day, weekly, or monthly spend limits, or the like. Spend rules may relate to employee and/or contractor working hours, geographical zones, locations, gratuity rules, days of the week, and the like, and how much the employee and/or contractor should be allowed to spend. In embodiments, spend rules implemented by the spend rules facility 112 may put limits on the total spend per transaction, per location, per category of expenditure, per time period and the like. In an embodiment, a spend rule implemented by the spend rules facility 112 may require the user who is spending and the transaction to occur in the same place, such as by determining the location of the user based on the location of the user's cell phone, vehicle and the like. The spend rule may be defined by the business customer. The spend rule may require the employee and/or contractor to seek manager authorization prior to purchase. [0063] The spend rules facility 112 may allow a user to set spend rules, including, without limitation, the creation, storing and cancellation of spend rules. The spend rules facility 112 may allow a user to very the parameters of a certain spend rule. In embodiments, the spend rules facility 112 may allow a business administrator to vary the spending limits on certain account in real-time and to change the limits for certain categories of merchants. For example, if the price of fuel increases in a particular day, the administrator may increase the amount certain users who are company drivers can spend on fuel. The spend rules facility 112 may allow a user to override certain spend rules, such as on an ad hoc basis. In an embodiment, a user may receive a request to override a certain spend rule and may decide to honor such request. The spend rules facility 112 may allow for the definition of spend rules, including, without limitation, the creation, editing and storing of user defined spend rules. In an embodiment, a user may define the spending limitation per card or business program or modify the allowed MCC category groupings for certain accounts under such user's control. The spend rules facility 112 may allow for the implementation of certain spend rules or groups of spend rules. In an embodiment, the spend rules facility 112 may allow for the implementation of a global spend rule or a customized subset of spend rules applied to a selected group of users. [0064] The spend rules facility 112 may allow for allow for spend rules to be applied on an account level, card level, subset of accounts level, program level, sub-program level, business level, globally and the like. The spend rules facility 112 may allow for spend rules to be represented visually, such as in a graphical user interface. The spend rules facility 112 may also enable spend rules approval requests. In an embodiment, a card holder may request variation of a certain spend rule via the spend rules facility 112 . The spend rules facility 112 may also, alone or in conjunction with the alert engine 138 , generate alerts relating to spend rules. In an embodiment, the spend rules facility 112 may send an alert to an administrator when a user attempts more than once to violate a spend rule in a given period of time. In another embodiment, the spend rules facility 112 may permit some predetermined percentage spend beyond a give spend rule, but notify an administrator of the same. In another embodiment, the spend rules facility 112 may generate an alert relating to failed authorization as a result of card misuse. An alert may be in the form of an email, a window in a graphical user interface, a text message, a phone call, a page and the like. The spend rules facility 112 may permit spend rules and related data to be updated and varied in real-time. [0065] The prepaid expense card management platform 102 may include a permissions facility 114 . The permissions facility 114 may manage access permissions, including, without limitation, business administrator functionality, cardholder functionality, customer service functionality and the like. The permissions facility 114 may permit conditional access. The permissions facility 114 may allow for variation of access levels and available features by class of user or by particular user. The conditional access level may be varied and specified using the permissions facility 114 . Conditional access levels may be varied in real time or at set intervals. In an embodiment, a business owner or administrator may allow an accountant to have conditional access to the prepaid expense card management platform 102 . The accountant may have the ability to view transactions and collect expense data, such as for book keeping and tax purposes, but may not have the ability to fund cards or change spend rules. In another embodiment, a business owner or administrator may opt-in to a service provided by the prepaid expense card management platform 102 in which a consultant is given limited access to the platform in order to review and audit the expenses of a business, group of users or one particular user. The consultant may then provide advice regarding how to reduce and consolidate expenses. [0066] The prepaid expense card management platform 102 may include a data collection facility 118 . The data collection facility 118 may enable the collection, aggregation, analysis, sharing and the like of various types of data associated with the platform 102 . In an embodiment, the data collection facility 118 may collect and aggregate data, such as expense data, across various users of the platform and businesses using the platform. In another embodiment, a business owner or administrator may choose to opt into a data sharing program facilitated by the data collection facility 118 . In exchange for sharing their data the business may receive access to aggregate data of users of the platform. The data may be aggregated or made available by expense type, industry, business size, business type and the like. The information may be provided or discussed in the forums or blogs 144 associated with the platform 102 . [0067] The prepaid expense card management platform 102 may be implemented through a plurality of portals 120 , which may be tailored and designed for the user or a type or category of user. Types of portals 120 may include a main portal, a customer program administrator or user access portal, a cardholder site portal, a prepaid expense card management platform employee and/or contractor portal, a customer support portal and the like. The main portal may include a location on the web, an intranet or other network, with a home page, a product overview and descriptions section, fee descriptions, a customer login area, new customer application and payment of application fee feature, corporate information, and the like. [0068] The cardholder site portal may include a login from a main site, a view of balance available, a view of spend transactions, and the like. The prepaid expense card management platform employee and/or contractor portal may include access in conjunction with job responsibilities, and provide access to groups within the organization, such as a technology group accessing modules for system monitoring, maintenance, and updates; a finance group accessing settlement reporting for bank and funding purposes and program loading for funds received from customers; a marketing group accessing reporting to assist with ad campaign management; and the like. The customer support portal may provide support agents a tool for accessing customer account records and system support details for handing calls from program administrators and cardholders, such as a customer support portal login page, customer account access, fee reversal and addition access, multi-tier access for supervisors and agents, knowledge base resources, FAQs resources, help resources, and the like. [0069] The prepaid expense card management platform may present itself as a graphical user interface 122 (GUI or prepaid expense card management platform GUI) to users 148 . The prepaid expense card management platform GUI 122 may be presented in a way that reflects the sense of a trusted financial institution, as for example, the prepaid expense card management platform 102 website may have similar appearances to websites for a bank or major branded credit card such as the use of similar colors, themes, and layouts, in order to provide the user with a sense of trust. In embodiments, the prepaid expense card management platform GUI 122 may be implemented as on-line or off-line, as a stand-alone application, as an interactive web based-application, or any combination thereof. In embodiments, the prepaid expense card management platform GUI 122 may have functionality and design that promotes a sense that the prepaid expense card management platform GUI 122 is current, up-to-date, and cutting edge, such as the use of asynchronous Javascript and XML (Ajax), Comet, HTTP streaming, thumb nail viewers (such as viewers that allow a preview of a linked page before a user decides to click through to that page), the ribbon look such as on Microsoft 2007 products, tabbed down browsing, and the like, in keeping the website interactive, attractive, and convenient. [0070] In embodiments, the user may be walked through the initial application and registration through the prepaid expense card management platform GUI 122 . Initial functional sequences encountered by the user through the prepaid expense card management platform GUI 122 may include the applications process, the initial step-by-step introduction process, and the dashboard, which is a tool to provide the user with top-level information status of their program. FIG. 4 presents a screen depicting the initial applications process, where a user may be asked to complete a form 402 to provide information about their business and themselves, such as if they are a business owner or authorized representative of a company; personal information about the business owner, such as name, home, address, SSN, date-of-birth, phone number, email, demographic information, information regarding their authorization to open an account, and the like. The user may also be asked to select a username, password, security question/answer, provide bank account information, and the like. The user may also be asked to provide information about the business, such as the legal name of the business, years in business, type of business, D&B number, TIN/EID, industry sector, size of business, revenue, profit, and the like. The user may also be asked to present information such as bank account information and the like. When all required information has been entered, the user may select the submit button 404 , as shown in FIG. 4 , in order to enter the information into the system. In embodiments, bank account information may be submitted through a dedicated screen such as shown in FIG. 5 . In embodiments, the relevant country may be the United States or a different country. In embodiments, a session may be saved so that a user can resume the application process at the point at which it was previously stopped. [0071] In embodiments, the prepaid expense card management platform GUI 122 may present a screen for collecting credit card and billing address information, such as shown in FIG. 6 , and allow for the submission of the order. In an embodiment, a user may submit credit card information 602 which may be used for payment of fees and/or program funding. Submission of the order may be followed by an application confirmation, where the prepaid expense card management platform team or the platform itself may review the information submitted, verify the information against different sources for authenticity and/or assign a score to the applicant. The score may be used to determine whether to approve or deny the application. The prepaid expense card management platform may confirm and verify bank information, such as by originating two small outbound charges or deposits, which the user verifies upon accessing the platform. If everything or a sufficient amount is correct, the user may be notified of approval, and move to initial customer setup, where the user will be asked to transfer funds and register employees and/or contractors. Referring to FIG. 7 , the user may also be asked to complete a questionnaire or series of questions 702 to estimate weekly petty cash needs. In embodiments, the prepaid expense card management platform GUI may provide an estimation calculator 704 to aid the user in this estimate, which if used, may fill a table 702 , such as shown in FIG. 7 , automatically. Users that already know their weekly petty cash needs may fill in this table manually. [0072] In embodiments, the user may now be asked to initiate funding, such as with prepaid expense card management platform GUI screen shown in FIG. 8 . After entering funding information, the user may be presented with an opportunity to make changes before completing the process by clicking to confirm the transfer 902 , such as shown in FIG. 9 , and upon acceptance, be presented a confirmation page such as shown in FIG. 10 . With the entry of funding information complete, the user may be asked if they wish to receive email or other notification if the house or other account falls below a certain threshold, which may be set by the user or another user, or auto transfer on a schedule so the account has a minimum dollar amount on a certain day. In embodiments, the user may be able to configure these rules. [0073] In embodiments, the user may now register employees and/or contractors. For instance, the prepaid expense card management platform GUI may walk the user through the process of entering employees and/or contractors into the system and issuing cards, cards may be sent individually to the business address used to file the prepaid expense card management platform card or prepaid expense card management platform account application and sent to the attention of the business owner or authorized administrator. Then the user may set up employee and/or contractor spending controls and may enter the names 1102 of the employees (and/or contractors) and related job functions 1104 as shown in FIG. 11 . Title information or other information about the user may be collected. This information may be used to provide additional or automated services to the users. Further, it may be desirable to enter names that correspond to government ID numbers in the event that cashiers want to verify the cardholder. The user may now detail spend locations based on pre-established groups, or entered in by the user, as shown in FIG. 12A . In addition, a screen may be presented for the user to enter employee (and/or contractor) working hours, with drop-downs for hours from/to, time-zones, geographical zones, locations, gratuity rules, days of the week, and the like, and how much the employee (and/or contractor) should be allowed to spend. Referring to FIG. 12B , in an embodiment, the platform 102 may permit the categories of spending to be defined for a given user or set of users. Merchant categories may include travel, transportation, associations, organizations, automotive dealers, professional services, retail stores, educational services, entertainment, grocery stores, restaurants, healthcare, childcare services and the like. Daily limits may also be specified. In embodiments, the user may put limits on the total spend per transaction, per location, per category of expenditure, per time period, by network message data and the like. The interface may offer a tool to create and/or modify a user-defined spend rule. After each employee (and/or contractor) registration, the system may display a confirmation page summarizing the employee's (and/or contractor's) name, spend locations, time of day, amounts, and the like. The user may be able to edit to make revisions, or click a “Submit” button to accept. When all employees (and/or contractors) are entered, a final list may be presented, and may be edited or submitted as complete. In embodiments, the dashboard screen may appear for the user to begin using the system. [0074] In embodiments, the user may now be directed into the prepaid expense card management platform GUI main page, with the dashboard screen displayed, a tool to provide the user with top-level information status of their program. In embodiments, the main screen and dashboard may be launch points to other operations, and also provide alerts and reminders about things like program funding, statement availability, and the like. FIG. 13 shows an example of the dashboard screen, along with an example of status information 1302 that may be provided. In addition to the dashboard screen, the main page provides other functions such as for cards, funds, transactions, profiles, help/FAQs, and the like. In this particular embodiment, as users mouse over various features help may appear on the screen 1304 . In other embodiments, help windows or bubbles may appear. In other embodiments, help may not be provided or may be provided on a limited basis. The card management screen 1402 , as shown in FIG. 14 , provides the card management section containing all the control functionality for cards issued to employees (and/or contractors). [0075] In embodiments, the GUI 122 may provide a plurality of additional user card management functions, such as for registering an employee (and/or contractor) as shown in FIGS. 15-17 . Referring to FIG. 15 , a user may click on an “Employee” button 1502 and a table may separate to reveal “Add Employee” 1504 and “Cancel” 1508 buttons. Referring to FIG. 16 , a user may click “Add Employee” 1504 and the table may separate again to reveal a field of name entry 1602 . Once the name is entered, the user may click the “Done” button 1604 . Referring to FIG. 17 , the new employee may now appear as a registered user 1702 . The default balance 1704 may be set to $0.00 since no spend rules have been set. In addition, the default status may be set to inactive. [0076] In embodiments, the GUI 122 may provide a plurality of additional user card management functions, such as for terminating an employee (and/or contractor) as shown in FIGS. 18-20 . Referring to FIG. 18 , a user may click on the name of a particular employee 1802 and the table may separate to reveal a button for “Terminate Employee” 1804 and a button for “Cancel” 1808 . Referring to FIG. 19 , the user clicks the “Terminate Employee” 1804 button, the user may be asked to confirm such selection 1902 . Referring to FIG. 20 , the card use status may be changed permanently or temporarily to “Terminated.” An administrator may be instructed to collect the card from the employee and send back the card to prepaid expense card management platform provider or destroy the card. In certain embodiments, the card account cannot be re-opened. In embodiments, the system may automatically remove funds from the card account and add to the program funding or prepaid expense card management platform account. In certain embodiments, if the employee needs a new card, the employee may be re-registered for a new card account. In other embodiments, the employee's account may be restored to active status from being temporary blocked or inactivated. [0077] In embodiments, the GUI 122 may provide a plurality of additional user card management functions, such as for viewing transactions as shown in FIG. 21 . A user may click on the name of a particular employee 2102 and in response the table may separate to reveal the previous ten most recent transactions of the employee 2104 . In an embodiment, the GUI 122 may include a button for revealing all transactions 2108 of the particular employee. In embodiments, the GUI 122 may provide a plurality of additional user card management functions, such as for adding funds or auto funding as shown in FIGS. 22-25 . Referring to FIG. 22 , a user may click on the balance 2202 of a particular employee to issue funds. As a result, the table may separate to reveal options for funds management and present the current program funding balance 2204 . The user may elect to add funds to the employee's account by clicking the “Add Funds” button 2208 . FIG. 23 illustrates a particular embodiment of the GUI 122 presented in response to clicking the “Add Funds” button 2208 . The employee may enter the amount to fund 2302 and then may click the “Add Funds” button 2208 . As shown in FIG. 24 , the system may confirm the added balance and provide an updated program funding balance 2402 . The user may be presented with a “Close” button 2404 allowing the user to proceed. Once the “Close” button 2404 is clicked, the system may restore the table 2502 and display the updated information as shown in FIG. 25 . [0078] In embodiments, the GUI 122 may provide a plurality of additional user card management functions, such as for removing card funds as shown in FIGS. 26-29 . A user may click on a employee's account balance and the table may separate presenting the user with options for adding and removing funds 2602 . The user may click the “Remove Funds” button 2604 and, referring to FIG. 27 , may be presented with a field for entering the amount of funds to remove 2702 . The programming funding balance may also be displayed. The user may click the “Remove Funds” button 2604 to proceed. Referring to FIG. 28 , the system may then confirm the change and the revised program funding balance may appear. The user may then click the “Close” button 2802 to proceed. Once the “Close” button 2802 is clicked, the system may restore the table 2902 and display the updated information as shown in FIG. 29 . [0079] In embodiments, the GUI 122 may provide a plurality of additional user card management functions, such as for blocking/unblocking cardholder spend as shown in FIGS. 30-31 . Referring to FIG. 30 , a user may click on a desired employee's card use status 3002 . As a result the table may separate and present “Activate/Deactivate” and “Cancel” options 3004 . The user may click the “Activate/Deactivate” button to toggle the status and as shown in FIG. 31 the table 3102 may be restored with the updated card use status information. In embodiments, the GUI 122 may provide a plurality of additional user card management functions, such as for monitoring total funds on cards as shown in FIG. 32 . Referring to FIG. 32 , a user may click on the “Balance” column header 3202 to obtain a summary of the total balance allocated among the cards. In an embodiment, terminated employees (and/or contractors) may only be shown in certain views. In embodiments, the user may have the ability to customize the information that is presented in the user interface. The user interface may be characterized by a tree structure and a user may decide to hide aspects of the tree. In embodiments, the prepaid expense card management platform GUI 122 may provide a plurality of other functional interfaces within the system, and although only a select number of functional screens have been shown, they are meant to be examples of the prepaid expense card management platform GIU 122 and not limited to the functions discussed or illustrated. [0080] The platform 102 may be associated with one or more payment networks 124 . The payment network 124 may be associated with a credit card processor, such as Visa, MasterCard, American Express, Discover or the like, and may facilitate the transfer of funds from an issuing bank to a merchant at the point of sale. The payment network 124 may be an automated teller machine network, such as Plus, Cirrus, Star, Most, Nyce, Interlink, and the like, and may facilitate transfer of funds from an issuing bank to the cardholder in the form of cash. In embodiments, a transaction may travel through a payment network's 124 infrastructure to transact a purchase. [0081] The prepaid expense card management platform 102 may include a reporting engine 128 . The reporting engine 128 may allow for the generation of reports and summaries. The reports may be presented in the graphical user interface 122 or may be made separately available. In embodiments, reports may include a list, a user defined report, a pre-defined report, an expense report, a monthly statement, a graph, a chart, summary data, full detail data, a statement for a defined period, and the like. Reports may be generated for one account, a subset of accounts and/or for an entire business. The reporting engine 128 may allow a user to display, hear or download data. The report may be made available as a machine readable file, in a third party proprietary format (such as for Quicken, Quickbooks, Peachtree, MS Money, MS Small Business Management or the like), as email, as mobile message, as a voice message, as a customer service agent call, via an IVR/VRU, as a machine readable file for upload into an accounting or data management system and the like. In an embodiment, a report may be a cash flow report which may include the detail spent by user, by merchant, by merchant category, aggregate reports detailing all cardholder spending, cash inflows and outflows, and the like. The reports may be printable. The reporting engine 128 may allow for users to comment on and/or annotate reports. The reporting engine 128 may enable the creation, tracking and administration of audit trails. The reporting engine 128 may control access to audit trails, limit viewing of audit trails to those with a job-related need, protect audit trail files from unauthorized modifications and the like. [0082] The prepaid expense card management platform 102 may include customer support functionality 130 . Customer support 130 and product assistance may be offered via phone, email, instant message, chat, text message, forums, blogs, webinars or via any other means of communication. Customer support 130 may also include a knowledge base and other customer support material. Customer support 130 may play an integral role in managing customer relations. As the primary touch point between customers and the prepaid expense card management platform 102 , this customer support 130 may need to be managed as meticulously as possible. To maintain maximum control over this aspect of the business, live operator support may be managed internally. Once a steady call stream is established, calls may be outsourced to a vendor that may offer comprehensive support 24 hours by 7 days. An IVR solution 132 may be integrated to automate frequent questions customers and cardholders may have. The option to speak with prepaid expense card management platform agents may be made available. In embodiments, calls for the prepaid expense card management platform 102 may be more likely to be related to system functionality rather than actual cardholder balances. Questions and inquires from program administrators may include setting card spend rules and limits, status of card delivery, status of program account funding, downloading to accounting software, and the like. Questions and inquires from card holders may include balance inquiries, inquires about cards not working at certain merchants due to spend rules set by their program administrators, assistance with transactions at the point of sale, and the like. [0083] In embodiments, the platform 102 may include an integrated voice response (IVR) service 132 . An IVR 132 may provide customer administrators with tools to manage all or certain prepaid expense card management platform features over the phone. The use of an IVR 132 will allow certain functions to be available from the field. Phone functionality may be provided via a toll free number. Cardholders may have access to the automated system to verify balance information, inquire about charges and request changes. The IVR system 132 may allow voice commands, touch tone phone commands, pulse phone commands and the like. [0084] In embodiments, the platform 102 may include a billing engine 134 . The billing engine 134 may administer program fees, including, without limitation, waiving fees, storing fee structures, modifying fee structures and the like. There may be a plurality of fees associated with the prepaid expense card management platform 102 . Prepaid expense card management platform users may be offered a variety of pricing models to choose from, based on their frequency of use, and may be adjusted over time. Fees may be either recurring or non-recurring. Examples of non-recurring fees may be application processing fees, that cover the initial application review and for setting up the general prepaid expense card management platform account, registering bank information, and the like; card purchase fees whose cost is associated with buying cards; return funding fees that are associated with returning funds; replacement card fees; and the like. Recurring fees may be different for users based on their frequency of usage. The billing engine 134 may administer such fee arrangements. [0085] In embodiments, a transactional pricing schedule may be available for users who use the card infrequently, such as 10 transactions or less per card per month. Transactional pricing may include fees such as a monthly card maintenance fee, a spend transaction fee, a customer support fee, overdraft fees, report fees, subscription fees associated with accounting software, and the like. In embodiments, a subscription pricing schedule may be available for users who use the card more frequently, such as more than 10 transactions per card per month. Subscription pricing may include fees such as a monthly card account fee, report fees, subscription fees associated with accounting software, and the like. In embodiments, users may be able to move between pricing schedules as facilitated by the billing engine 134 . In embodiments, the billing engine 134 may compute and automatically apply the lowest cost pricing structure for a user or group of users. [0086] The prepaid expense card management platform 102 may include an alert engine 138 . The alert engine 138 may allow a business owner, administrator or other user to configure, receive and/or send alerts relating to any feature or aspect of the platform 102 . An alert may be sent via email, fax, mail, mobile, text message, SMS, instant message, telephone, voicemail, RSS feed, posted to a graphical user interface, posted to a dashboard and the like. An alert may be interactive. A user may be able to respond to an alert. In an embodiment, a business owner may configure an alert that alerts an administrator when a particular employee's (and/or contractor's) card balance falls below a specified level. The alert may be sent via text message to the administrator and may allow the administrator to choose whether to fund the account. The administrator may submit his response by responding yes or no to the text message. In this regard, a business owner or administrator may maintain a high degree of control over the spending process with a reduced level of effort. In another embodiment, a user may send an alert to another user. In an embodiment, a sales rep may send an alert to an administrator asking for additional funds to be added to the sales rep's account, for spend approval, to have card or business spend rules modified or the like. In other embodiments, alerts may be sent to customer service representatives. [0087] The prepaid expense card management platform 102 may include a search engine 140 . The search engine 140 may enable the searching, filtering and clustering of information relating to transactions, users 148 , spend rules and the like. The search engine 140 may enable the searching, filtering and clustering of information found in the forums, blogs and other community aspects 144 of the platform 102 . The platform data may also be downloaded into other applications and searched using those applications. [0088] The prepaid expense card management platform 102 may include a work flow engine 142 . The work flow engine 142 may allow for the creation, manipulation and use of work flows. In embodiments, the work flow engine 142 may enable the creation of a work flow including, without limitation, the creation of a work flow ticket, the changing of work flow ticket status, the ability to attach document to work flow tickets, the ability to generate emails and notifications related to work flow tickets and the like. The work flow engine 142 may enable the use of work flows, including, without limitation, requests for business funding, requests for card funding, requests for spend authorization, new customer applications, application approval/decline notification, authorization, scoring of applications, identify verification and the like. [0089] The prepaid expense card management platform 102 may include community aspects, forums, blogs and the like 144 . In embodiments, users may be provided access to an interactive online or networked medium, where business owners, entrepreneurs and/or users of the prepaid expense card management platform 102 may draw from sources, such as colleagues and business advisors, to find answers to questions and solve business problems. In embodiments, resources other than online resources may be available to the user, such as through trade organizations, magazines, and the like. The online resource may provide users with a place to interact, such as to post questions or open online discussions in a forum; post to or view weblogs or blogs; access a weblog or blog written by a professional service provider such as an accountant, attorney or consultant, who can offer tips or other relevant information; provide and receive referrals; logon to presentations or webinars, such as quarterly web presentations, that may provide business owners and other users with tips to lower operational costs and improve expense management processes; and the like. The interactive medium may generate a community in a Web 2.0 fashion. [0090] The prepaid expense card management platform 102 may be utilized by various groups and types of users 148 . Users 148 may be business users, non-business users, households, entities, individuals, students and the like. Users 148 may be employees or agents of a business or company or a subset of a business or company, independent contractors, agents and the like. Users 148 may be members of a family or household and the like. Users 148 may be members or employees of a non-profit or government and the like. User 148 may be members of an organization. [0091] In embodiments, access to the platform 102 may be provided using a web browser, client side program or the like. In embodiments, access to the platform 102 may be provided without the use of a web browser. Platform access 150 , such as via the user interface, may be provided via a computer, network, laptop, handheld device, cell phone, wireless email device, Treo, Blackberry, personal digital assistant, palm top computer, pager, digital music player, voice interface, telephone and the like. [0092] All aspects, functionalities and data associated with the platform 102 may be updated and varied in real-time 152 . In an embodiment, changes in a card balance may be viewable in real-time 152 . In embodiments, changes to spend rules may be implemented by the spend rules facility 112 in real-time 152 . In embodiments, card status and approval requests may be received and reviewed in real-time 152 . Real-time 152 updates may be provided via mobile, web, customer service and the like. Real-time 152 requests may be provided, received and/or processed via mobile, web, customer service and the like. [0093] The elements depicted in flow charts and block diagrams throughout the figures imply logical boundaries between the elements. However, according to software or hardware engineering practices, the depicted elements and the functions thereof may be implemented as parts of a monolithic software structure, as standalone software modules, or as modules that employ external routines, code, services, and so forth, or any combination of these, and all such implementations are within the scope of the present disclosure. Thus, while the foregoing drawings and description set forth functional aspects of the disclosed systems, no particular arrangement of software for implementing these functional aspects should be inferred from these descriptions unless explicitly stated or otherwise clear from the context. [0094] Similarly, it will be appreciated that the various steps identified and described above may be varied, and that the order of steps may be adapted to particular applications of the techniques disclosed herein. All such variations and modifications are intended to fall within the scope of this disclosure. As such, the depiction and/or description of an order for various steps should not be understood to require a particular order of execution for those steps, unless required by a particular application, or explicitly stated or otherwise clear from the context. [0095] The methods or processes described above, and steps thereof, may be realized in hardware, software, or any combination of these suitable for a particular application. The hardware may include a general-purpose computer and/or dedicated computing device. The processes may be realized in one or more microprocessors, microcontrollers, embedded microcontrollers, programmable digital signal processors or other programmable device, along with internal and/or external memory. The processes may also, or instead, be embodied in an application specific integrated circuit, a programmable gate array, programmable array logic, or any other device or combination of devices that may be configured to process electronic signals. It will further be appreciated that one or more of the processes may be realized as computer executable code created using a structured programming language such as C, an object oriented programming language such as C++, HTML, web XML, or any other high-level or low-level programming language (including assembly languages, hardware description languages, and database programming languages and technologies) that may be stored, compiled or interpreted to run on one of the above devices, as well as heterogeneous combinations of processors, processor architectures, or combinations of different hardware and software. [0096] Thus, in one aspect, each method described above and combinations thereof may be embodied in computer executable code that, when executing on one or more computing devices, performs the steps thereof. In another aspect, the methods may be embodied in systems that perform the steps thereof, and may be distributed across devices in a number of ways, or all of the functionality may be integrated into a dedicated, standalone device or other hardware. In another aspect, means for performing the steps associated with the processes described above may include any of the hardware and/or software described above. All such permutations and combinations are intended to fall within the scope of the present disclosure. [0097] While the invention has been disclosed in connection with the preferred embodiments shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art. Accordingly, the spirit and scope of the present invention is not to be limited by the foregoing examples, but is to be understood in the broadest sense allowable by law. [0098] While the invention has been described in connection with certain preferred embodiments, other embodiments would be understood by one of ordinary skill in the art and are encompassed herein. [0099] All documents referenced herein are hereby incorporated by reference.

A method and system for issuing and managing sponsor funded stored value cards, where a sponsor company funds an account associated with a stored value card. The stored value card is issued to a cardholder, who can withdraw funds from the account constrained through flexible spend rules. Sponsor funded stored value cards may reduce expenses and difficulties associated with written checks, provide the cardholder with usage flexibility, reduce risks associated with cardholder funds usage, and the like, especially when the cardholder is in a remote location.

CROSS REFERENCE TO RELATED APPLICATIONS This is a division of copending U.S. application Ser. No. 08/957,316, filed Oct. 23, 1997, which is a continuation of U.S. application Ser. No. 08/703,015, filed Aug. 26, 1996, now abandoned, which is a division of U.S. application Ser. No. 08/467,039, filed Jun. 6, 1995, now abandoned. BACKGROUND OF THE INVENTION The invention relates in general to a movable barrier operator for opening and closing a movable barrier or door. More particularly, the invention relates to a garage door operator that can learn force and travel limits when installed and can simulate the temperature of its electric motor to avoid motor failure during operation. A number of garage door operators have been sold over the years. Most garage door operators include a head unit containing a motor having a transmission connected to it, which may be a chain drive or a screw drive, which is coupled to a garage door for opening and closing the garage door. Such garage door openers also have included optical detection systems located near the bottom of the travel of the door to prevent the door from closing on objects or on persons that may be in the path of the door. Such garage door operators typically include a wall control which is connected via one or more wires to the head unit to send signals to the head unit to cause the head unit to open and close the garage door, to light a worklight or the like. Such prior art garage door operators also include a receiver and head unit for receiving radio frequency transmissions from a hand-held code transmitter or from a keypad transmitter which may be affixed to the outside of the garage or other structure. These garage door operators typically include adjustable limit switches which cause the garage door to operate or to halt the motor when the travel of the door causes the limit switch to change state which may either be in the up position or in the down position. This prevents damage to the door as well damage to the structure supporting the door. It may be appreciated, however, that with different size garages and different size doors, the limits of travel must be custom set once the unit is placed within the garage. In the past, such units have had mechanically adjustable limit switches which are typically set by an installer. The installer must go back and forth between the door, the wall switch and the head unit in order to make the adjustment. This, of course, is time consuming and results in the installer being forced to spend more time than is desirable to install the garage door operator. A number of requirements are in existence from Underwriter's Laboratories, the Consumer Product Safety Commission and the like which require that garage door operators sold in the United States must, when in a closing mode and contacting an obstruction having a height of more than one inch, reverse and open the door in order to prevent damage to property and injury to persons. Prior art garage door operators also included systems whereby the force which the electric motor applied to the garage door through the transmission might be adjusted. Typically, this force is adjusted by a licensed repair technician or installer who obtained access to the inside of the head unit and adjusts a pair of potentiometers, one of which sets the maximal force to be applied during the closing portion of door operation, the other of which establishes the maximum force to be applied during the opening of door operation. Such a garage door operator is exemplified by an operator taught in U.S. Pat. No. 4,638,443 to Schindler. However, such door operators are relatively inconvenient to install and invite misuse because the homeowner, using such a garage door operator, if the garage door operator begins to bind or jam in the tracks, may likely obtain access to the head unit and increase the force limit. Increasing the maximal force may allow the door to move passed a binding point, but apply the maximal force at the bottom of its travel when it is almost closed where, of course, it should not. Another problem associated with prior art garage door operators is that they typically use electric motors having thermostats connected in series with portions of their windings. The thermostats are adapted to open when the temperature of the winding exceeds a preselected limit. The problem with such units is that when the thermostats open, the door then stops in whatever position it is then in and can neither be opened or closed until the motor cools, thereby preventing a person from exiting a garage or entering the garage if they need to. SUMMARY OF THE INVENTION The present invention is directed to a movable barrier operator which includes a head unit having an electric motor positioned therein, the motor being adapted to drive a transmission connectable to the motor, which transmission is connectable to a movable barrier such as a garage door. A wired switch is connectable to the head unit for commanding the head unit to open and close the door and for commanding a controller within the head unit to enter a learn mode. The controller includes a microcontroller having a non-volatile memory associated with it which can store force set points as well as digital end of travel positions within it. When the controller is placed in learn mode by appropriate switch closure from the wall switch, the door is caused to cycle open and closed. The force set point stored in the non-volatile memory is a relatively low set point and if the door is placed in learn mode and the door reaches a binding position, the set point will be changed by increasing the set point to enable the door to travel through the binding area. Thus, the set points will be dynamically adjusted as the door is in the learn mode, but the set points will not be changeable once the door is taken out of the learn mode, thereby preventing the force set point from being inadvertently increased, which might lead to property damage or injury. Likewise, the end of travel positions can be adjusted automatically when in the learn mode because if the door is halted by the controller, when the controller senses that the door position has reached the previously set end of travel position, the door will then be commanded by a button push from the wall switch to keep travelling in the same direction, thereby incrementing or changing. The end of travel limits are set by pushing the learn button on the wall switch which causes the door to travel upward and continue travelling upward until the door has travelled as far as the installer wishes it to travel. The installer disables the learn switch by lifting his hand from the button. The up limit is then stored and the door is then moved toward the closed position. A pass point or position normalizing system consisting of a ring-like light interrupter attached to the garage door crosses the light path of an optical obstacle detector signalling instantaneously the position of the door and the door continues until it closes, where-upon force sensing in the door causes an auto-reverse to take place and then raises the door to the up position, the learn mode having been completed and the door travel limits having been set. The movable barrier operator also includes a combination of a temperature sensor and microcontroller. The temperature sensor senses the ambient temperature within the head unit because it is positioned in proximity with the electric motor. When the electric motor is operated, a count is incremented in the microcontroller which is multiplied by a constant which is indicative of the speed at which the motor is moving. This incremented multiplied count is then indicative of the rise in temperature which the motor has experienced by being operated. The count has subtracted from it the difference between the simulated temperature and the ambient temperature and the amount of time which the motor has been switched off. The totality of which is multiplied by a constant. The remaining count then is an indication of the extant temperature of the motor. In the event that the temperature, as determined by the microcontroller, is relatively high, the unit provides a predictive function in that if an attempt is made to open or close the garage door, prior to the door moving, the microcontroller will make a determination as to whether the single cycling of the door will add additional temperature to the motor causing it to exceed a set point temperature and, if so, will inhibit operation of the door to prevent the motor from being energized so as to exceed its safe temperature limit. The movable barrier operator also includes light emitting diodes for providing an output indication to a user of when a problem may have been encountered with the door operator. In the event that further operation of the door operator will cause the motor to exceed its set point temperature, an LED will be illuminated as a result of the microcontroller temperature prediction indicating to the user that the motor is not operating because further operation will cause the motor to exceed its safe temperature limits. It is a principal aspect of the present invention to provide a movable barrier operator which is able to quickly and automatically select end of travel positions. It is another aspect of the present invention to provide a movable barrier operator which, upon installation, is able to quickly establish up and down force set points. It is still another aspect of the present invention to provide a movable barrier operator which can determine the temperature of the motor based upon motor history and the ambient temperature of the head unit. Other aspects and advantages of the invention will become obvious to one of ordinary skill in the art upon a perusal of the following specification and claims in light of the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a garage having mounted within it a garage door operator embodying the present invention; FIG. 2 is a block diagram of a controller mounted within the head unit of the garage door operator employed in the garage door operator shown in FIG. 1; FIG. 3 is a schematic diagram of the controller shown in block format in FIG. 2; FIG. 4 is a schematic diagram of a receiver module shown in the schematic diagram of FIG. 3; FIGS. 5A-B are a flow chart of a main routine that executes in a microcontroller of the control unit; FIGS. 6A-G are a flow diagram of a learn routine executed by the microcontroller; FIGS. 7A-B are flow diagrams of a timer routine executed by the microcontroller; FIGS. 8A-B are flow diagrams of a state routine representative of the current and recent state of the electric motor; FIGS. 9A-B are a flow chart of a tachometer input routine and also determines the position of the door on the basis of the pass point system and input from the optical obstacle detector; FIGS. 10A-C are flow charts of the switch input routines from the switch module; and FIG. 11 is a schematic diagram of the switch module and the switch biasing circuit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings and especially to FIG. 1, more specifically a movable barrier door operator or garage door operator is generally shown therein and referred to by numeral 10 includes a head unit 12 mounted within a garage 14 . More specifically, the head unit 12 is mounted to the ceiling of the garage 14 and includes a rail 18 extending therefrom with a releasable trolley 20 attached having an arm 22 extending to a multiple paneled garage door 24 positioned for movement along a pair of door rails 26 and 28 . The system includes a hand-held transmitter unit 30 adapted to send signals to an antenna 32 positioned on the head unit 12 and coupled to a receiver as will appear hereinafter. An external control pad 34 is positioned on the outside of the garage having a plurality of buttons thereon and communicates via radio frequency transmission with the antenna 32 of the head unit 12 . A switch module 39 is mounted on a wall of the garage. The switch module 39 is connected to the head unit by a pair of wires 39 a. The switch module 39 includes a learn switch 39 b, a light switch 39 c, a lock switch 39 d and a command switch 39 e. An optical emitter 42 is connected via a power and signal line 44 to the head unit 12 . An optical detector 46 is connected via a wire 48 to the head unit 12 . A pass point detector 49 comprising a bracket 49 a and a plate structure 49 b extending from the bracket has a substantially circular aperture 49 c formed in the bracket, which aperture might also be square or rectangular. The pass point detector is arranged so that it interrupts the light beam on a bottom leg 49 d and allows the light beam to pass through the aperture 49 c. The light beam is again interrupted by the leg 49 e, thereby signalling the controller via the optical detector 46 that the pass point detector attached to the door has moved past a certain position following the controller to normalize or zero its position, as will be appreciated in more detail hereinafter. As shown in FIGS. 2 and 3, the garage door operator 10 , which includes the head unit 12 has a controller 70 which includes the antenna 32 . The controller 70 includes a power supply 72 which receives alternating current from an alternating current source, such as 110 volt AC, and converts the alternating current to +5 volts zero and 24 volts DC. The 5 volt supply is fed along a line 74 to a number of other elements in the controller 70 . The 24 volt supply is fed along the line 76 to other elements of the controller 70 . The controller 70 includes a super-regenerative receiver 80 coupled via a line 82 to supply demodulated digital signals to a microcontroller 84 . The receiver is energized by a line 87 coupled to the line 74 . The microcontroller 84 is also coupled by a bus 86 to a non-volatile memory 88 , which non-volatile memory stores set points and other customized digital data related to the operation of the control unit. An obstacle detector 90 , which comprises the emitter 42 and infrared detector 46 is coupled via an obstacle detector bus 92 to the microcontroller 84 . The obstacle detector bus 92 includes lines 44 and 48 . As can be seen in FIGS. 2, 3 and 11 , the wall switch 39 is connected via the connecting wires 39 a to a switch biasing module 96 which is powered from the 5 volt supply line 74 and supplies signals to and is controlled by the microcontroller 84 via a bus 100 coupled to the microcontroller 84 . The microcontroller 84 , in response to switch closures, will send signals over a relay logic line 102 to a relay logic module 104 connected to an alternating current motor 106 having a power take-off shaft 108 coupled to the transmission 18 of the garage door operator. A tachometer 110 is coupled to the shaft 108 and provides a tachometer signal on a tachometer line 112 to the microcontroller 84 , the tachometer signal being indicative of the speed of rotation of the motor. The power supply 72 includes a transformer 130 which receives alternating current on leads 132 and 134 from an external source of alternating current. The transformer steps down the voltage to 24 volts and feeds 24 volts to a pair of capacitors 138 and 140 which provide a filtering function. A 24 volt filtered DC potential is supplied on the line 76 to the relay logic 104 . The potential is fed through a resistor 142 across a pair of filter capacitors 144 and 146 , which are connected to a 5 volt voltage regulator 150 , which supplies regulated 5 volt output voltage across a capacitor 152 and a Zener diode 154 to the line 74 . Signals may be received by the controller at the antenna 32 and fed to the receiver 80 . The receiver 80 includes a pair of inductors 170 and 172 and a pair of capacitors 174 and 176 that provide impedance matching between the antenna 32 and other portions of the receiver. An NPN transistor 178 is connected in common base configuration as a buffer amplifier. Bias to the buffer amplifier transistor 178 is provided by resistors 180 , 181 . A resistor 188 , a capacitor 190 , a capacitor 192 and a capacitor 194 provide filtering to isolate a later receiver stage from the buffer amplifier 178 . An inductor 196 also provides power supply buffering. The buffered RF output signal is supplied on a line 200 , coupled between the collector of the transistor 178 and a receiver module 202 which is shown in FIG. 4 . The lead 204 feeds into the unit 202 and is coupled to a biasing resistor 220 . The buffered radio frequency signal is fed via a coupling capacitor 222 to a tuned circuit 224 comprising a variable inductor 226 connected in parallel with a capacitor 228 . Signals from the tuned circuit 220 are fed on a line 230 to a coupling capacitor 232 which is connected to an NPN transistor 234 at its 236 . The transistor has a collector 240 and emitter 242 . The collector 240 is connected to a feedback capacitor 246 and a feedback resistor 248 . The emitter is also coupled to the feedback capacitor 246 and to a capacitor 250 . The line 210 is coupled to a choke inductor 256 which provides ground potential to a pair of resistors 258 and 260 as well as a capacitor 262 . The resistor 258 is connected to the base 236 of the transistor 234 . The resistor 260 is connected via an inductor 264 to the emitter 242 of the transistor. The output signal from the transistor is fed outward on a line 212 to an electrolytic capacitor 270 . As shown in FIG. 3, the capacitor 270 capacitively couples the demodulated radio frequency signal to a bandpass amplifier 280 to an average detector 282 which feeds a comparator 284 . The comparator 284 also receives a signal directly from the bandpass amplifier 280 and provides a demodulated digital output signal on the line 82 coupled to the P 32 pin of the Z86E21/61 microcontroller 84 . The microcontroller 84 is energized by the power supply 72 and also controlled by the wall switch 39 coupled to the microcontroller by the leads 100 . From time to time, the microcontroller will supply current to the switch biasing module 96 . The microcontroller operates under the control of a main routine as shown in FIGS. 5A and 5B. When the unit is powered up, a power on reset is performed in a step 300 , the memory is cleared and a check sum from read-only memory within the microcontroller 84 is tested. In a step 302 , if the check sum and the memory prove to be correct, control is transferred to a step 304 , if not, control is transferred back to the step 300 . The last non-volatile state, which is indicative of the state of the operator, that is whether the operator indicated the door was at its up limit, down limit or in the middle of its travel, is tested for in a step 304 and if the last state is a down limit, control is transferred to a step 306 . If it was an up limit, control is transferred to a step 308 . If it was neither a down nor an up limit, control is transferred to a step 310 . In the step 306 , the position is set as the down limit value and a window flag is set. The operation state is set as down limit. In a step 308 , the position is set as up, the window flag is set and the operation state is set as up limit. In the step 310 , the position is set as outside the normal range, 6 inches below the secondary up limit. The operation state is set as stopped. Control is transferred from any of steps 306 , 308 and 310 to a step 312 where a stored simulated motor temperature is read from the non-volatile memory 88 . The temperature of a printed circuit board positioned within the head unit is read from the temperature sensor 120 which is supplied over a line 120 a to the microcontroller. In order to read the PC board temperature, a pin P 20 of the microprocessor 84 is driven high, causing a high potential to appear on a line 120 b which supplies a current through the RTD sensor 120 to a comparator 120 c. A capacitor 120 d connected to the comparator and to the temperature sensor, is grounded and charges up. The other input terminal to the comparator has a voltage divider 120 e connected to it to supply a reference voltage of about 2.5 volts. Thus, the microcontroller starts a timer running when it brings line 120 b high and interrogates a line 120 f to determine its state. The line 120 f will be driven high when the temperature at the junction of the RTD 120 and the capacitor 120 d exceeds 2.5 volts. Thus, the time that it takes to charge the capacitor through the resistance is indicative of the temperature within the head unit and, in this manner, the PC board temperature is read and if the temperature as read is greater than the temperature retrieved from the non-volatile memory, the temperature read from the PC board is then stored as the motor temperature. In a step 314 , constants related to the receipt and processing of the demodulated signal on the line 82 are initialized. In a step 316 , a test is made to determine whether the learn switch 39 b had been activated within the last 30 seconds. If it has not, control is transferred back to the step 314 . In a step 318 , a test is made to determine whether the command switch debounce timer has expired. If it has, control is transferred to a step 320 . If it is not, control is transferred back to the step 314 . In the step 320 , the learn limit cycle is begun as will be discussed in more detail as to FIGS. 6A through 6G. The main routine effectively has a number of interrupt routines coupled to it. In the event that a falling edge is detected on the line 112 from the tachometer, an interrupt routine related to the tachometer is serviced in the step 322 . A timer interrupt occurs every 0.5 millisecond in a step 324 as shown in FIGS. 7A through 7B. The obstacle detector 90 generates a pulse every 10 milliseconds during the time when the beam from the infrared emitter 42 has not been interrupted either by the pass point system 49 or by an obstacle, in a step 326 following which the obstacle detector timer is cleared in a step 328 . As shown in FIGS. 10A-C and 11 , operation of the switch biasing module 96 is controlled over the lines 100 by the microcontroller 84 . The microcontroller 84 , in the step 340 , tests to determine whether an RS232 digital communications mode has been set. If it has, control is transferred to a step 342 , as shown in FIG. 10C, testing whether data is stored in an output buffer to be output from the microcontroller 84 . If it is, control is transferred to a step 344 outputting the next bit, which may include a start bit, from the output buffer and control is then transferred back to the main routine. In the event that there is no data in the data buffer, control is transferred to the step 346 , testing whether data is being received over lines 100 . If it is being received, control is transferred to a step 348 to receive the next bit into the input buffer and the routine is then exited. If not, control is transferred to a step 350 . In the step 350 , a test is made to determine whether a start bit for RS232 signalling has been received. If it has not, control is transferred to a return step 352 . If it has, control is transferred to a step 354 in which a flag is set indicating that the start bit has been received and the routine is exited. As shown in FIG. 10A, if the response to the decision block 340 is no, control is transferred to a decision step 360 . The switch status counter is incremented and then a test is determined as to whether the contents of the counter are 29 . If the switch counter is 29 , control is transferred to a step 362 causing the counter to be zeroed. If the counter is not 29 , control is transferred to a step 364 , testing for whether the switch status is equal to zero. If the switch status is equal to zero, control is transferred to a step 366 . In a step 366 , a current source transistor 368 , shown in FIG. 11, is switched on, drawing current through resistors 370 and 372 and feeding current out through a line 39 a connected thereto to the switch module 39 and, more specifically, to a resistor 380 , a 0.10 microfarad capacitor 382 , a 1 microfarad capacitor 384 , a 10 microfarad capacitor 386 and a switch terminal 388 . The switch 39 e is coupled to the switch terminal 388 . The switch 39 d may be selectively coupled to the capacitor 386 . The switch 39 b may be selectively coupled to the capacitor 384 . The switch 39 c may be selectively coupled to the capacitor 382 . A light emitting diode 392 is connected to the resistor 380 . Current flows through the resistor 380 and the light emitting diode 392 back to another one of the lines 39 a and through a field effect transistor 398 to ground. In step 402 , the sense input on a line 100 coupled to the transistor 398 is tested to determine whether the input is high. If the input is high immediately, that is indicative of the fact that switches 39 b through 39 e are all open and in a step 404 , debounce timers are decremented for all switches and a got switch flag is set and the routine is exited. In the event that the test of step 402 is negative, control is then transferred to a step 406 testing after 10 microseconds if the sense in output on the line 100 connected to the field effect transistor 398 is high, which would be indicative of the switch 39 c having been closed. If it is high, in step 408 , the worklight timer is incremented, all other switch timers are decremented, the got switch flag is set and the routine is exited. In the event that the decision in step 406 is in the negative, control is transferred to a step 410 and the routine is exited. In the event that the decision from step 364 is in the negative, control is transferred to a step 412 wherein the switch status is tested as to whether it is equal to one. If it is, control is transferred to a step 414 testing whether the sensed input on the line 100 connected to the field effect transistor is high. If it is, control is transferred to step 416 to test the got switch flag, after which in a step 418 , the learn switch debouncer is incremented, all other switch counters are decremented, the got switch flag is set and the routine is exited. In the event that the answer to step 414 or 416 is in the negative, control is transferred to a return step 420 . In the event that the answer to step 412 is in the negative, control is transferred to a step 422 , as shown in FIG. 10B. A test is made as to whether the switch status is equal to 10. If it is, control is transferred to a step 424 where the sense out input is tested as high. Thus, the charging rate for the capacitors which, in effect, is sensed on the line 100 connected to the field effect transistor 398 which is coupled to ground, is indicative of which of the switches is closed because the switch 39 c has a capacitor that charges at 10 times the rate of the capacitor 384 connected to 39 b and 100 times the rate of the capacitor 386 selectively couplable to switch 39 d. After the switch measurement has been made, the transistor 368 is switched non-conducting by the line 368 b and the field effect transistor 398 is switched nonconducting by a line 450 connected to its gate. A transistor 462 , coupled via a resistor 464 to a line 466 , is switched on, biasing a transistor 468 on, causing current to flow through a diagnostic light emitting diode 470 to a field effect transistor 472 which is switched on via a voltage on a line 474 . In addition, the capacitors 386 , 384 and 382 , which may have been charged are discharged through the field effect transistor 472 . In order to perform all of the switching functions after the step 424 has been executed, control is transferred to a step 510 testing whether the got switch flag has been cleared. If it has, control is transferred to a step 512 in which the command timer is incremented and all other timers are decremented and the got switch flag is set and the routine is exited. If the got switch flag has not been cleared as detected in the step 510 , the routine is exited in the step 514 . In the event that the sense input is measured as being high in the step 424 , control is transferred to a step 516 where the vacation or lock flag counter is incremented and all other counters are decremented. The got switch flag is set and the routine is exited. In the event that the switch status equal 10 test in the step 422 is indicated to be no, control is then transferred to a step 520 testing whether the switch status is 11. If the switch status is 11 , indicating that the routine has been swept through 11 times, control is transferred to a step 522 in which the field effect transistors 398 and 472 are both switched on, providing ground pads on both sides of the capacitors causing the capacitors to discharge and the routine is then exited. In the event that the step 520 test is negative, control is transferred to a step 524 testing whether the routine has been executed 15 times. If it has, control is transferred to a step 526 to determine the bit which controls the status of the light emitting diode 470 , the diagnostic light emitting diode, has been set. If it has not been set, control is transferred to a step 528 wherein both transistors 368 and 468 are switched on and both the field effect transistors 398 and 472 are switched off. In order to test for short circuits between the source and drain electrodes of the field effect transistors 398 and 472 which might cause false operation signals to be supplied on the lines 100 to the microcontroller 84 , resulting in inadvertent operation of the electric motor. The routine is then exited. In the event that the test in step 526 indicates that the diagnostic LED bit has been set, control is transferred to a step 530 . In the step 530 , the transistors 468 and 472 are switched on allowing current to flow through the diagnostic LED 470 . In the event that the test in step 524 is negative, a test is made in a step 532 as to whether the routine has been executed 26 times. If it has not, the routine is exited in a step 534 . If it has, both of the field effect transistors 398 and 372 are switched on to connect all of the capacitors to ground to discharge the capacitors and the routine is exited. As shown in FIGS. 7A and 7B, when the timer interrupt occurs as in step 324 , control is transferred to a step 550 shown in FIG. 7A wherein a test is made to determine whether a 2 millisecond timer has expired. If it has not, control is transferred to a step 552 determining whether a 500 millisecond timer has expired. If the 500 millisecond timer has expired, control is transferred to a step 554 testing whether power has been switched on through the relay logic 104 to the electric motor 106 . If the motor has been switched on, control is transferred to a step 556 testing whether the motor is stalled, as indicated by the motor power having been switched on and by the fact that pulses are not coming through on the line 112 from the tachometer 110 . In the event that the motor has stalled, control is transferred to a step 558 . In the step 558 the existing motor temperature indication, as stored in one of the registers of the microcontroller 84 , has added to it a constant which is related to a motor characteristic which is added in when the motor is indicated to be stalled. In the event that the response to the step 556 is in the negative, indicating that the motor is not stalled, control is transferred to a step 560 wherein the motor temperature is updated by adding a running motor constant to the motor temperature. In the event that the response to the test in step 554 is in the negative, indicating that motor power is not on and that heat is leaking out of the motor so that the temperature will be dropping, the new motor temperature is assigned as being equal to the old motor temperature, less the quantity of the old motor temperature, minus the ambient temperature measured from the RTD probe 120 , the whole difference multiplied by a thermal decay fraction which is a number. All of steps 558 , 560 and 562 exit to a step 564 which test as to whether a 15 minute timer has timed out. If the timer has timed out, control is transferred to a step 566 causing the current, or updated motor temperature, to be stored in a non-volatile memory 88 . If the 15 minute timer has not been timed out, control is transferred to a step 568 , as shown in FIG. 7 B. Step 566 also exits to step 568 . A test is made in the step 568 to determine whether a obstacle detector interrupt has come in via step 326 causing the obstacle detector timer to have been cleared. If it has not, the period will be greater than 12 milliseconds, indicating that the obstacle detector beam has been blocked. If the obstacle detector beam, in fact, has been blocked, control is transferred to a step 570 to set the obstacle detector flag. In the event that the response to step 568 is in the negative, the obstacle detector flag is cleared in the step 572 and control is transferred to a step 574 . All operational timers, including radio timers and the like are incremented and the routine is exited. In the event that the 2 millisecond timer tested for in the step 550 has expired, control is transferred to a step 576 which calls a motor operation routine. Following execution of the motor operation routine, control is transferred to the step 552 . When the motor operation routine is called as shown in FIG. 8A, a test is made in a step 580 to determine the status of the motor operation state variable which may indicate if the up limit or down limit has been reached, the motor is causing the door to travel up or down, the door has stopped in mid-travel or an auto-reverse delay indicating that the motor has stopped in mid-travel and will be switching into up travel shortly. In the event that there is an auto-reverse delay, control is transferred to a step 582 , when a test is made for a command from one of the radio transmitters or from the wall control unit and, if so, the state of the motor is set indicating that the motor has stopped in mid-travel. Control is then transferred to a step 584 in which 0.50 second timer is tested to determine whether it has expired. If it has, the state is set to the up travel state following which the routine is exited in the step 586 . In the event that the operation state is in the up travel state, as tested for in step 580 , control is transferred to a step 588 testing for a command from a radio or wall control and if the command is received, the motor operational state is changed to stop in mid-travel. Control is transferred to a step 590 . If the force period indicated is longer than that stored in an up array location, indicated by the position of the motor. The state of the door is indicated as stopped in mid-travel. Control is then transferred to a step 592 testing whether the current position of the door is at the up limit, then the state of the door is set as being at the up limit and control is transferred to a step 594 causing the routine to be exited, as shown in FIG. 8 B. In the event that the operational state tested for in the step 580 is indicated to be at the up limit, control is transferred to a step 596 which tests for a command from the radio or wall control unit and a test is made to determine whether the motor temperature is below a set point for the down travel motor temperature threshold. The state is set as being a down travel state. If the temperature value exceeds the threshold or set point temperature value, an output diagnostic flag is set for providing an output indication in another routine. Control is then transferred to a step 598 , causing the routine to be exited. In the event that the down travel limit has been reached, control is transferred to a step 600 testing for whether a command has come in from the radio or wall control and, if it has, the state is set as auto-reverse and the auto-reverse timer is cleared. Control is then transferred to a step 602 testing whether the force period, as indicated, is longer than the force period stored in the down travel array for the current position of the door. Auto-reverse is then entered at step 582 on a later iteration of the routine. Control is transferred to a step 604 to test whether the position of the door is at the down limit position and the pass point detector has already indicated that the door has swept the passed the pass point, the state is set as a down limit state and control is transferred to a step 606 testing for whether the door position is at the down limit position and testing for whether the pass point has been detected. If the pass point has not been detected, the motor operational state is set to auto-reverse, causing auto-reverse to be entered in a later routine and control is transferred to a step 608 , exiting the main routine. In the event that the block 580 indicates that the door is at the down limit, control is transferred to a step 610 , testing for a command from the radio or wall control and testing the current motor temperature. If the current motor temperature is below the up travel motor temperature threshold, then the motor state variable is set as equal to up travel. If the temperature is above the threshold or set point temperature, a diagnostic code flag is then set for later diagnostic output and control is transferred to a return step 612 . In the event that the motor operational state is indicated as being stopped in mid-travel, control is transferred to a step 614 which tests for a radio or wall control command and tests the motor temperature value to determine whether it is above or below a down travel motor temperature threshold. If the motor temperature is above the travel threshold, then the door is left stopped in mid-travel and the routine is returned from in step 616 . In the event that the learn switch has been activated as tested for in step 316 and the command switch is being held down as indicated by the positive result from the step 318 , the learn limit cycle is entered in step 320 and transfers control to a step 630 , as shown in FIG. 6A in step 630 , the maximum force is set to a minimum value from which it can later be incremented, if necessary. The motor up and motor down controllers in the relay logic 104 are disabled. The relay logic 104 includes an NPN transistor 700 coupled to line 76 to receive 24 to 28 volts therefrom via a coil 702 of a relay 704 having relay contacts 706 . A transistor 710 coupled to the microcontroller is also coupled to line 76 via a relay coil 714 and together comprise an up relay 718 which is connected via a lead 720 to the electric motor 106 . A down transistor 730 is coupled via a coil 732 to the power supply 76 . The down relay 732 has an armature 734 associated with it and is connected to the motor to drive it down. Respective diodes 740 and 742 are connected across coils 714 and 732 to provide protection when the transistors 710 and 730 are switched off. In the step 632 , both the transistors 710 and 730 are switched off, interrupting either up motor power or down motor power to the electric motor 106 and the microcontroller delays for 0.50 second. Control is then transferred to a step 634 , causing the relay 704 to be switched on, delivering power to an electric light or worklight 750 associated with the head unit. The up motor relay 716 is switched on. A 1 second timer is also started which inhibits testing of force limits due to the inertia of the door as it begins moving. Control is then transferred to a step 636 , testing for whether the 1 second timer has timed out and testing for whether the force period is longer than the force limit setting. If both conditions have occurred, control is transferred to a step 640 as shown in FIG. 6 B. If either the 1 second timer has not timed out or the force period is not longer than the force limit setting, control is transferred to a step 638 which tests whether the command switch is still being held down. If it is, control is transferred back to step 636 . If it is not, control is transferred to the step 640 . In step 640 , both the up transistor 710 and the down transistor 730 are causing both the up motor and down motor command from the relay logic to be interrupted and a delay of 0.50 second is taken and the position counter is cleared. Control is then transferred to a step 641 in which the transistor 730 is commanded to switch on, starting the motor moving down and the 1 second force ignore timer is started running. A test is made in a step 642 to determine whether the command switch has been activated again. If it has, the force limit setting is increased in a step 644 following which control is then transferred back to the step 632 . If the command switch is not being held down, control is then transferred to a step 646 , testing whether the 1 second force ignore timer has timed out. The last 32 rpm pulses indicative of the force are ignored and a force period from the previous pulse is accepted as the down force. Control is then transferred to a step 648 and a test is made to determine whether the movable barrier is at the pass point as indicated by the pass point detector 49 interacting with the optical detector 46 . Control is then transferred to a step 650 . The position counter is complemented and the complemented value is stored as the up limit following which the position counter is cleared and a pass point flag is set. Control is then transferred back to the step 642 . In the event that the result of the test in step 648 is negative, control is transferred to a step 652 which tests whether the 1 second force delay timer has expired and whether the force period is greater than the force limit setting, indicating that the force has exceeded. If both of those conditions have occurred, control is transferred to a step 654 which tests whether the pass point flag has been set. If it has not been set, control is transferred to a step 656 , wherein the position counter is complemented and the complemented value is saved as the up limit and the position counter is cleared. In the event that the pass point flag has been set, control is transferred to a step 658 . In the event that the test in step 652 has been negative, control is transferred to a step 660 which tests the value of the obstacle reverse flag. If the obstacle reverse flag has not been set, control is transferred to the step 642 shown on FIG. 6 B. If the flag has been set, control is transferred to the step 654 . In a step 658 , both transistors 710 and 730 are switched off interrupting up and down power from the relays to the electric motor 106 and halting the motor and the microcontroller 84 then delays for 0.50 second. Control is then transferred to a step 660 . In step 660 , the transistor 710 is switched on switching on the up relay causing the motor to be turned to drive the door upward and the 1 second force ignore timer is started. Control is transferred to a decision step 662 testing for whether the command switch is set. If the command switch is set, control is transferred back to the step 664 causing the force limit setting to be increased, following which control is transferred to the step 632 , interrupting the motor outputs. If the command switch has not been set, control is transferred to the step 664 causing the maximum force from the 33rd previous reading to be saved as the up force, following which control is transferred to a decision block 666 which tests for whether the 1 second force ignore timer has expired and whether the force period is longer than the force limit setting. If both conditions are true, control is transferred to a step 668 . If not, control is transferred to a step 670 which tests for whether the door position is at the up limit. If the door position is at the up limit, control is transferred to the step 668 , switching off both of the motor outputs to halt the door and delaying for 0.50 second. If the position tested in step 670 is not at the upper limit, control is transferred back to the step 662 . Following step 668 control is transferred to step 674 , where the down output is turned on, and the 1 second force ignore timer is started. Control is then transferred to the step 676 during which the command switch is tested. If the command switch is set, control is transferred back to the step 644 causing the force limit setting to be increased and ultimately to the step 632 which switches off the motor outputs and delays for 0.50 second. If the command switch has not been set, control is transferred to a step 678 . If the position counter indicates that the door is presently at a point where a force transition normally occurs or where force settings are to change, and the 1 second force ignore timer has expired, the 33rd previous maximum force is stored and the down force array is filled with the last 33 force measurements. Control is then transferred to a step 680 which tests for whether the obstacle detector reverse flag has been set. If it has not been set, control is transferred to a step 682 which tests for whether the 1 second force ignore timer has expired and whether the force period is longer than the force limit setting. If both those conditions are true, control is transferred to a step 684 which tests for the pass point being set. If the pass point flag was not set, control is transferred to the step 688 . In the event that the obstacle reverse flag is set, control is also transferred to the step 686 , and then to 688 . In the event that the decision block 682 is answered in the negative, control is transferred back to the step 676 . If the pass point flag has been set as tested for in the step 684 , control is transferred to the step 686 wherein the current door position is saved as the down limit position. In step 688 , both the motor output transistors 710 and 730 are switched off, interrupting up and down power to the motor and a delay occurs for 0.50 second. Control is then transferred to the step 690 wherein the up transistor 710 is switched on, causing the up relay to be actuated, providing up power to the motor and the 1 second force ignore timer begins running. In the step 692 , a test is made for whether the command has been set again. If it has, control is transferred back to the step 644 , as shown in FIG. 6B, and following that to the step 632 , as shown in FIG. 6 A. If the command switch has not been set, control is transferred to the step 694 which tests for whether the position counter indicates that the door is at a sectional force transition point or barrier and the 1 second force ignore timer has expired. If both those conditions are true, the maximum force from the last sectional barrier is then loaded. Control is then transferred to a decision step 696 testing for whether the 1 second force ignore timer has timed out and whether the force period is indicated to be longer than the force period limit setting. If both of those conditions are true, control is then transferred to a step 698 causing the motor output transistors 710 and 730 to be switched off and all data is stored in the non-volatile memory 88 and the routine is exited. In the event that decision is indicated to be in the negative from the decision step 696 , control is transferred to a step 697 which tests whether the door position is presently at the up limit position. If it is, control is then transferred to the step 698 . If it is not, control is transferred to the step 692 . In the event that the rpm interrupt step 322 , as shown in FIG. 5B, is executed, control is then transferred to a step 800 , as shown in FIG. 9 A. In step 800 , the time duration from the last rpm pulse from the tachometer 110 is measured and saved as a force period indication. Control is then transferred to a decision block. Control is transferred to the step 802 , in which the operator state variable is tested. In the event that the operator state variable indicates that the operator is causing the door to travel down, the door is at the down limit or the door is in the auto-reverse mode, control is transferred to a step 804 causing the door position counter to be incremented. In the event that the door operator state indicates that the door is travelling upward, has reached its up limit or has stopped in mid-travel, control is transferred to a step 806 which causes the position counter to be decremented. Control is then transferred to a decision step 808 in which the pass point pattern testing flag is tested for whether it is set. If it is set, control is transferred to a step 810 which tests a timer to determine whether the maximum pattern time allotted by the system has expired. In the event that the pass point pattern testing flag is not set, control is transferred to a step 812 , testing for whether the optical obstacle detector flag has been set. If it is not set, the routine is exited in a step 814 . If the obstacle detector flag has been set, control is transferred to a step 816 wherein the pattern testing flag is set and the routine is exited. In the event that the maximum pattern time has timed out, as tested for in the step 810 , control is transferred to a step 820 wherein the optical reverse flag is set and the routine is exited. In the maximum pattern time has not expired, a test is made in a step 822 for whether the microcontroller has sensed from the obstacle detector that the beam has been blocked open within a correct timing sequence indicative of the pass point detection system. If it has not, the routine is exited in a step 824 . If it has, control is transferred to a step 826 . Testing for whether a window flag has been set. As to whether the rough position of the door would indicate that the pass point should have been encountered. If the window flag has been set, control is transferred to a step 828 , testing for whether the position is within the window flag position. If it has, control is transferred to a step 832 , causing the position counter to be cleared or renormalized or zeroed, setting the window flag and set a flag indicating that the pass point has been found, following which the routine is exited. In the event that the position is not within the window as tested for in step 828 , the obstacle reverse flag is set in a step 830 and the routine is exited. In the event that the test made in step 326 indicates that the window flag has not been set, control is then transferred directly to the step 832 . While there has been illustrated and described a particular embodiment of the present invention, it will be appreciated that numerous changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all those changes and modifications which fall within the true spirit and scope of the present invention.

A movable barrier operator includes a wall control switch module having a learn switch thereon. The switch module is connectable to a control unit positioned in a head of a garage movable barrier operator. The head unit also contains an electric motor which is connected to a transmission for opening and closing a movable barrier such as a garage door. The switch module includes a plurality of switches coupled to capacitors which, when closed, have varying charge and discharge times to enable which switch has been closed. The control unit includes an automatic force incrementing system for adjusting the maximal opening and closing force to be placed upon the movable barrier during a learn operation. Likewise, end of travel limits can also be set during a learn operation upon installation of the unit. The movable barrier operator also includes an ambient temperature sensor which is used to derive a motor temperature signal, which motor temperature signal is measured and is used to inhibit motor operation when further motor operation exceeds or is about to exceed set point temperature limits.

This application is a continuation of U.S. patent application Ser. No. 09/559,861 filed on Dec. 27, 2000 now U.S. Pat. No. 6,387,568. The disclosure of the above application is incorporated herein by reference. FIELD OF THE INVENTION This invention relates to improved materials usable as electrode active materials, and electrodes formed from it for electrochemical cells in batteries. BACKGROUND OF THE INVENTION Lithium batteries are prepared from one or more lithium electrochemical cells containing electrochemically active (electroactive) materials. Such cells typically include an anode (negative electrode), a cathode (positive electrode), and an electrolyte interposed between spaced apart positive and negative electrodes. Batteries with anodes of metallic lithium and containing metal chalcogenide cathode active material are known. The electrolyte typically comprises a salt of lithium dissolved in one or more solvents, typically nonaqueous (aprotic) organic solvents. Other electrolytes are solid electrolytes typically called polymeric matrixes that contain an ionic conductive medium, typically a metallic powder or salt, in combination with a polymer that itself may be ionically conductive which is electrically insulating. By convention, during discharge of the cell, the negative electrode of the cell is defined as the anode. Cells having a metallic lithium anode and metal chalcogenide cathode are charged in an initial condition. During discharge, lithium ions from the metallic anode pass through the liquid electrolyte to the electrochemically active (electroactive) material of the cathode whereupon they release electrical energy to an external circuit. It has recently been suggested to replace the lithium metal anode with an insertion anode, such as a lithium metal chalcogenide or lithium metal oxide. Carbon anodes, such as coke and graphite, are also insertion materials. Such negative electrodes are used with lithium-containing insertion cathodes, in order to form an electroactive couple in a cell. Such cells, in an initial condition, are not charged. In order to be used to deliver electrochemical energy, such cells must be charged in order to transfer lithium to the anode from the lithium-containing cathode. During discharge the lithium is transferred from the anode back to the cathode. During a subsequent recharge, the lithium is transferred back to the anode where it reinserts. Upon subsequent charge and discharge, the lithium ions (Li + ) are transported between the electrodes. Such rechargeable batteries, having no free metallic species are called rechargeable ion batteries or rocking chair batteries. See U.S. Pat. Nos. 5,418,090; 4,464,447; 4,194,062; and 5,130,211. Preferred positive electrode active materials include LiCoO 2 , LiMn 2 O 4 , and LiNiO 2 . The cobalt compounds are relatively expensive and the nickel compounds are difficult to synthesize. A relatively economical positive electrode is LiMn 2 O 4 , for which methods of synthesis are known. The lithium cobalt oxide (LiCoO 2 ), the lithium manganese oxide (LiMn 2 O 4 ), and the lithium nickel oxide (LiNiO 2 ) all have a common disadvantage in that the charge capacity of a cell comprising such cathodes suffers a significant loss in capacity. That is, the initial capacity available (amp hours/gram) from LiMn 2 O 4 , LiNiO 2 , and LiCoO 2 is less than the theoretical capacity because significantly less than 1 atomic unit of lithium engages in the electrochemical reaction. Such an initial capacity value is significantly diminished during the first cycle operation and such capacity further diminishes on every successive cycle of operation. For LiNiO 2 and LiCoO 2 only about 0.5 atomic units of lithium is reversibly cycled during cell operation. Many attempts have been made to reduce capacity fading, for example, as described in U.S. Pat. No. 4,828,834 by Nagaura et al. However, the presently known and commonly used, alkali transition metal oxide compounds suffer from relatively low capacity. Therefore, there remains the difficulty of obtaining a lithium-containing electrode material having acceptable capacity without disadvantage of significant capacity loss when used in a cell. SUMMARY OF THE INVENTION The invention provides novel lithium-metal-fluorophosphate materials which, upon electrochemical interaction, release lithium ions, and are capable of reversibly cycling lithium ions. The invention provides a rechargeable lithium battery which comprises an electrode formed from the novel lithium-metal-fluorophosphates. Methods for making the novel lithium-metal-fluorophosphates and methods for using such lithium-metal-fluorophosphates in electrochemical cells are also provided. Accordingly, the invention provides a rechargeable lithium battery which comprises an electrolyte; a first electrode having a compatible active material; and a second electrode comprising the novel lithium-metal-fluorophosphate materials. The novel materials, preferably used as a positive electrode active material, reversibly cycle lithium ions with the compatible negative electrode active material. Desirably, the lithium-metal-fluorophosphate is represented by the nominal general formula LiM 1−y MI y PO 4 F where 0≦y≦1. Such compounds include LiMPO 4 F for y=0. Such compounds are also represented by Li 1−x MPO 4 F and Li 1−x M 1−y MI y PO 4 F, where in an initial condition, “x” is essentially zero; and during cycling a quantity of “x” lithium is released where 0≦x≦1. Correspondingly, M has more than one oxidation state in the lithium-metal-fluorophosphate compound, and more than one oxidation state above the ground state M 0 . The term oxidation state and valence state are used in the art interchangeably. Also, MI may have more than one oxidation state, and more than one oxidation state above the ground state MI°. Desirably, M is selected from V (vanadium), Cr (chromium), Fe (iron), Ti (titanium), Mn (manganese), Co (cobalt), Ni (nickel), Nb (niobium), Mo (molybdenum), Ru (ruthenium), Rh (rhodium) and mixtures thereof. Preferably, M is selected from the group V, Cr, Fe, Ti, Mn, Co, and Ni. As can be seen, M is preferably selected from the first row of transition metals, and M preferably initially has a +3 oxidation state. In another preferred aspect, M is a metal having a +3 oxidation state and having more than one oxidation state, and is oxidizable from its oxidation state in lithium-metal-fluorophosphate compound. In another aspect, MI is a metal having a +3 oxidation state, and desirably MI is an element selected from the group V, Cr, Fe, Ti, Mn, Co, Ni, Nb, Mo, Ru, Rh, B (boron) and Al (aluminum). In a preferred aspect, the product LiM 1−y MI y PO 4 F is a triclinic structure. In another aspect, the “nominal general formula” refers to the fact that the relative proportions of the atomic species may vary slightly on the order of up to 5 percent, or more typically, 1 percent to 3 percent. In another aspect the term “general” refers to the family of compounds with M, MI, and y representing variations therein. The expressions y and 1−y signify that the relative amount of M and MI may vary and that 0≦y≦1. In addition, M may be a mixture of metals meeting the earlier stated criteria for M. In addition, MI may be a mixture of elements meeting the earlier stated criteria for MI. The active material of the counter electrode is any material compatible with the lithium-metal-fluorophosphate of the invention. Where the lithium-metal-fluorophosphate is used as a positive electrode active material, metallic lithium may be used as the negative electrode active material where lithium is removed and added to the metallic negative electrode during use of the cell. The negative electrode is desirably a nonmetallic insertion compound. Desirably, the negative electrode comprises an active material from the group consisting of metal oxide, particularly transition metal oxide, metal chalcogenide, carbon, graphite, and mixtures thereof. It is preferred that the anode active material comprises a carbonaceous material such as graphite. The lithium-metal-fluorophosphate of the invention may also be used as a negative electrode material. The starting (precursor) materials include a lithium containing compound, and a metal phosphate compound. Preferably, the lithium containing compound is in particle form, and an example is lithium salt. A particular example of a lithium salt is lithium fluoride (LiF). Preferably, the metal phosphate compound is in particle form, and examples include metal phosphate salt, such as FePO 4 and CrPO 4 . The lithium compound and the metal phosphate compound are mixed in a proportion which provides the stated general formula. In one aspect, the starting materials are intimately mixed and then reacted together where the reaction is initiated by heat. The mixed powders are pressed into a pellet. The pellet is then heated to an elevated temperature. This reaction can be run under an air atmosphere, or can be run under a non-oxidizing atmosphere. The precursors are commercially available, and include, for example, a lithium fluoride salt, and metal phosphate, such as CrPO 4 , FePO 4 , or MnPO 4 . In another aspect, the metal phosphate salt used as a precursor for the lithium metal phosphate reaction can be formed either by a carbothermal reaction, or by a hydrogen reduction reaction. Preferably, the phosphate-containing anion compound is in particle form, and examples include metal phosphate salt, diammonium hydrogen phosphate (DAHP), and ammonium dihydrogen phosphate (ADHP). The metal compound for making the precursor are typically metal oxides. In the carbo-thermal reaction, the starting materials are mixed together with carbon, which is included in an amount sufficient to reduce the metal oxide to metal phosphate. The starting materials for the formation of the metal phosphates are generally crystals, granules, and powders and are generally referred to as being in particle form. Although many types of phosphate salts are known, it is preferred to use diammonium hydrogen phosphate (DAHP), or ammonium dihydrogen phosphate (ADHP). Both DAHP and ADHP meet the preferred criteria that the starting materials decompose to liberate the phosphate anion which may then react with the metal oxide compound. Exemplary metal compounds are Fe 2 O 3 , Fe 3 O 4 , V 2 O 5 , VO 2 , MnO 2 , Mn 2 O 3 , TiO 2 , Ti 2 O 3 , Cr 2 O 3 , CoO, Ni 3 (PO 4 ) 2 , Nb 2 O 5 , Mo 2 O 3 , V 2 O 3 , FeO, Co 3 O 4 , CrO 3 , Nb 2 O 3 , MoO 3 . The starting materials are available from a number of sources. For example, the metal oxides, such as vanadium pentoxide or iron oxide, are available from suppliers including Kerr McGee, Johnson Matthey, or Alpha Products of Davers, Mass. Objects, features, and advantages of the invention include an electrochemical cell or battery based on lithium-metal-fluorophosphates. Another object is to provide a cathode active material which combines the advantages of good discharge capacity and capacity retention. It is also an object of the present invention to provide positive electrodes which can be manufactured economically. Another object is to provide a cathode active material which can be rapidly and cheaply produced and lends itself to commercial scale production for preparation of large quantities. These and other objects, features, and advantages will become apparent from the following description of the preferred embodiments, claims, and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the results of an x-ray diffraction analysis, of LiVPO 4 F prepared as above, using CuKα radiation, λ=1.5404 Å. Bars refer to simulated pattern from refined cell parameters SG=P−1 (triclinic) (1). The values are a=5.1738 Å (0.002), b=5.3096 Å (0.002), c=7.2503 Å (0.001); the angle α=72.4794 (0.06), β=107.7677 (0.04), γ=81.3757 (0.04), cell volume =174.35 Å 3 . The crystal system is triclinic. FIG. 2 is a voltage/capacity plot of LiVPO 4 F containing cathode cycled with a lithium metal anode in a range of 3.0 to 4.4 volts. The cathode contained 29.4 mg of LiVPO 4 F active material prepared by the method described above. FIG. 3 displays the differential capacity during cell charge and discharge vs. cell voltage for the electrochemical cell containing LiVPO 4 F. FIG. 4 shows the results of an x-ray diffraction analysis, of LiFePO 4 F prepared as above, using CuKα radiation, λ=1.5404 Å. Bars refer to simulated pattern from refined cell parameters SG=P−1 (triclinic). The values are a=5.1528 Å (0.002), b=5.3031 Å (0.002), c=7.4966 Å (0.003); the angle α=67.001° (0.02), β=67.164° (0.03), γ=81.512° (0.02), cell volume=173.79 Å 3 . The crystal system is triclinic. FIG. 5 shows the results of an x-ray diffraction analysis, of LiTiPO 4 F prepared as above, using CuKα radiation, λ=1.5404 Å. The x-ray diffraction pattern was triclinic. FIG. 6 shows the results of an x-ray diffraction analysis, of LiCrPO 4 F prepared as above, using CuKα radiation, λ=1.5404 Å. Bars refer to simulated pattern from refined cell parameters SG=P−1 (triclinic). The values are a=4.996 Å (0.002), b=5.307 Å (0.002), c=6.923 Å (0.004); the angle α=71.600°. (0.06), β=100.71° (0.04), γ=78.546°.(0.05), cell volume=164.54 Å 3 . The crystal system is triclinic. FIG. 7 is a diagrammatic representation of a typical laminated lithium-ion battery cell structure. FIG. 8 is a diagrammatic representation of a typical multi-cell battery cell structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides lithium-metal-fluorophosphates, which are usable as electrode active materials, for lithium (Li + ) ion removal and insertion. Upon extraction of the lithium ions from the lithium-metal-fluorophosphates, significant capacity is achieved. In one aspect of the invention, electrochemical energy is provided when combined with a suitable counter electrode by extraction of a quantity x of lithium from lithium-metal-fluorophosphates Li 1−x M 1−y MI y PO 4 F. When a quantity of lithium is removed per formula unit of the lithium-metal-fluorophosphate, metal M is oxidized. Accordingly, during cycling, charge and discharge, the value of x varies as x greater than or equal to 0 and less than or equal to 1. In another aspect, the invention provides a lithium ion battery which comprises an electrolyte; a negative electrode having an insertion active material; and a positive electrode comprising a lithium-metal-fluorophosphate active material characterized by an ability to release lithium ions for insertion into the negative electrode active material. The lithium-metal-fluorophosphate is desirably represented by the aforesaid nominal general formula LiM 1−y MI y PO 4 F. Desirably, the metal M is selected from the group: Ti, V, Cr, Mn, Fe, Co, Ni, Nb, Mo, and mixtures thereof. Preferably the metal M is selected from the group: Ti, V, Cr, Mn, Fe, Co, Ni, and mixtures thereof. Although the metals M and MI may be the same, it is preferred that M and MI be different, and desirably MI is an element selected from the group: Ti, V, Cr, Mn, Fe, Co, Ni, Nb, Mo, Al, B, and mixtures thereof. The present invention provides a new material, a lithium metal fluorophosphate, and demonstrates that with this new material significant capacity as a cathode active material is utilizable and maintained. A preferred approach for making the LiM 1−y MI y PO 4 F is a two staged approach (Example I). The first stage (Reaction 1a) involves the creation of the metal phosphate precursor, followed by the second stage (Reaction 1b) of reacting the metal phosphate with the commercially available lithium fluoride to produce the lithium metal fluorophosphate. The basic procedure is described with reference to exemplary starting materials, but is not limited thereby. In the first stage, the basic process comprises reacting a metal compound, for example vanadium pentoxide or ferric oxide, with a phosphoric acid derivative, preferably a phosphoric acid ammonium salt, such as ammonium dihydrogen phosphate ADHP) or diammonium hydrogen phosphate (DAHP). The powders were intimately mixed and dry ground for about 30 minutes to form a homogeneous mixture of the starting materials. Then the mixed powders were pressed into pellets. The reaction was conducted by heating the pellets in an oven at a preferred heating rate to an elevated temperature, and held at such elevated temperature for several hours. A preferred ramp rate of 2° C./minute was used to heat to a preferred temperature of 300° C. The reaction was carried out under a reducing atmosphere of hydrogen gas. The flow rate will depend on the size of the oven and the quantity needed to maintain the atmosphere. The pellets were allowed to cool to ambient temperature, then re-ground and repressed into pellets. The reaction was continued by reheating the pellets in an oven at a preferred heating rate to a second elevated temperature, and held at such elevated temperature for several hours to complete the reaction. A preferred ramp rate of 2° C./minute was used to heat to a preferred second elevated temperature is 850° C. The reaction was carried out under a reducing atmosphere of hydrogen gas. The pellets were then allowed to cool to ambient temperature. A preferred rate of cooling was about 2° C./minute. A preferred approach for the second stage (Reaction 1b)for making the LiM 1−y MI y PO 4 F is to start with the commercially available precursor, lithium fluoride LiF and mix with the metal phosphate MPO 4 . The precursors were intimately mixed and dry ground for about 30 minutes. The mixture was then pressed into pellets. Reaction was conducted by heating in an oven at a preferred ramped heating rate to an elevated temperature, and held at such elevated temperature for fifteen minutes to complete formation of the reaction product. A preferred ramp rate of 2° C./minute was used to heat to a preferred temperature of 700° C. The entire reaction was conducted under a normal air atmosphere. A covered nickel crucible to limit oxygen availability was used. In an alternative, a covered ceramic crucible can be used. The pellet was removed from the oven and allowed to cool to room temperature. Preferred cooling rates are from about 2° C./minute to about 60° C./minute, with a more preferred rate of about 50° C./minute. In another variation, the precursor metal phosphate was created prior to the creation of the lithium-metal-fluorophosphate using the carbo-thermal method in a two staged approach (Example II). The first stage (Reaction 2a) involves the creation of the metal phosphate precursor, followed by the second stage of reacting the metal phosphate with the commercially available lithium fluoride to produce the lithium metal fluorophosphate. The basic procedure is described with reference to exemplary starting materials, but is not limited thereby. In the first stage, the basic process comprises reacting a metal compound, for example vanadium pentoxide or ferric oxide, with a phosphoric acid derivative, preferably a phosphoric acid ammonium salt, such as ammonium dihydrogen phosphate (ADHP) or diammonium hydrogen phosphate (DAHP). The powders were intimately mixed and dry ground for about 30 minutes to form a homogeneous mixture of the starting materials. Then the mixed powders were pressed into pellets. The reaction was conducted by heating the pellets in an oven at a preferred heating rate to an elevated temperature, and held at such elevated temperature for several hours. A preferred ramp rate of 2° C./minute was used to heat to a preferred temperature of 300° C. The reaction was carried out under a non-oxidizing atmosphere of argon gas. The flow rate will depend on the size of the oven and the quantity needed to maintain the atmosphere. The pellets were allowed to cool to ambient temperature, then re-ground and repressed into pellets. The reaction was continued by reheating the pellets in an oven at a preferred heating rate to a second elevated temperature, and held at such elevated temperature for several hours to complete the reaction. A preferred ramp rate of 2° C./minute was used to heat to a preferred second elevated temperature was 850° C. The reaction was carried out under a non-oxidizing atmosphere of argon gas. After heating for a preferred time of 8 hours, the pellets were allowed to cool to ambient temperature at a preferred rate of 2° C./minute. A preferred approach for the second stage (Example II, Reaction 2b) for making the LiM 1−y MI y PO 4 F is to start with the commercially available precursor, lithium fluoride LiF and mix with the metal phosphate MPO 4 . The precursors were intimately mixed and dry ground for 30 minutes. The mixture was then pressed into pellets. Reaction was conducted by heating in an oven at a preferred ramped heating rate to an elevated temperature, and held at such elevated temperature for fifteen minutes to complete formation of the reaction product. A preferred ramp rate of 2° C./minute was used to heat to a preferred temperature of 700° C. The entire reaction was conducted under an air atmosphere, but a covered crucible was used to limit oxygen availability. The pellet was removed from the oven and allowed to cool to room temperature. In a variation of the second stage, lithium carbonate and ammonium fluoride were used in place of lithium fluoride (Example IV). The precursors were intimately mixed and dry ground for about 30 minutes. The mixture is then pressed into pellets. Reaction was conducted by heating in an oven at a preferred ramped heating rate (of 2° C./minute) to an elevated temperature, and held at such elevated temperature for about 15 minutes to complete formation of the reaction product. A preferred elevated temperature was 700° C. The reaction was conducted under an air atmosphere in a covered crucible to limit oxygen availability. The pellet was removed from the oven and allowed to cool to room temperature. Refer to Reaction 4 herein. A process for making lithium mixed-metal fluorophosphate, such as lithium aluminum vanadium fluorophosphate, the precursors aluminum phosphate and vanadium phosphate were made separately, then mixed with lithium fluoride (Example III, Reaction 3b). The vanadium phosphate was made as described in reaction 1(a) or reaction 2(a). The basic procedure for making aluminum phosphate is described with reference to exemplary starting materials, but is not limited thereby (Example III, Reaction 3a). The aluminum phosphate was made by intimately mixing aluminum hydroxide and ammonium dihydrogen phosphate powders, and dry grounding them for about 30 minutes. The mixed powders were then pressed into pellets. The reaction was conducted by heating the pellets in an oven at a preferred heating rate to an elevated temperature, and held at that elevated temperature for several hours. The reaction was carried out under an air atmosphere. The pellets were allowed to cool to ambient temperature, and then ground into powder. Exemplary and preferred ramp rates, elevated reaction temperatures and reaction times are described herein. In one aspect, a ramp rate of 2° C./minute was used to heat to an elevated temperature of about 950° C. and allowed to dwell for 8 hours. The precursor was then allowed to cool to room temperature. Refer to Reaction 3(a) herein. A preferred approach for making the lithium aluminum transition metal fluorophosphate was to use the aluminum phosphate and the transition metal phosphate generated above, and mix them with lithium fluoride (Reaction 3b). The powders were intimately mixed and dry ground for about 30 minutes. The mixture was then pressed into pellets. Reaction was conducted by heating in an oven at a preferred ramped heating rate to an elevated temperature, and held at such elevated temperature for about fifteen minutes to complete the formation of the reaction product. The entire reaction was completed under a normal air atmosphere. The pellet was removed from the oven and allowed to cool to room temperature. Exemplary and preferred reaction conditions are described herein. In one aspect, a ramp rate of 2° C./minute was used to heat to an elevated temperature of 700° C. and was allowed to dwell for 15 minutes. Refer to Reaction 3(b) herein. Recent research has indicated that doping of materials with non-transition metals or other elements, such as boron, tends to increase the operating voltage. Substitution of non-transition elements such as aluminum for transition metals tends to stabilize the structure of cathode active materials. This aids the stability and cyclability of the materials. The general aspects of the above synthesis route are applicable to a variety of starting materials. The metal compounds are reduced in the presence of a reducing agent, such as hydrogen or carbon. The same considerations apply to other metal and phosphate containing starting materials. The thermodynamic considerations such as ease of reduction, of the selected starting materials, the reaction kinetics, and the melting point of the salts will cause adjustment in the general procedure, such as the amount of reducing agent, the temperature of the reaction, and the dwell time. Referring back to the discussion of the reactions for generating the precursor metal-phosphates, Reactions 1(a) and 2(a), the reaction is initially conducted at a relatively low temperature from 200° C. to 500° C., preferably around 300° C., cooled to ambient temperature, then conducted at a relatively high temperature from 700° C. to a temperature below the melting point of the metal phosphate, preferably around 850° C. The melting point of the metal phosphates is believed to be in the range of 950° C. to 1050° C. It is preferred to heat the starting materials at a ramp rate of a fraction of a degree to 10° C. per minute and preferably about 2° C. per minute. After reaction, the products are cooled to ambient temperature with a cooling rate similar to the ramp rate, and preferably around 2° C./minute. Referring back to the discussion of the lithium fluoride and metal phosphate reaction (Reactions 1b, 2b, 3b, and 4), the temperature should be run at 400° C. or greater but below the melting point of the metal phosphate, and preferably at about 700° C. It is preferred to heat the precursors at a ramp rate of a fraction of a degree to 10° C. per minute and preferably about 2° C. per minute. Once the desired temperature is attained, the reactions are held at the reaction temperature from 10 minutes to several hours, and preferredly around 15 minutes. The time being dependent on the reaction temperature chosen. The heating may be conducted under an air atmosphere, or if desired may be conducted under a non-oxidizing or inert atmosphere. After reaction, the products are cooled from the elevated temperature to ambient (room) temperature (i.e. 10° C. to 40° C.). Desirably, the cooling occurs at a rate of about 50° C./minute. Such cooling has been found to be adequate to achieve the desired structure of the final product. It is also possible to quench the products at a cooling rate on the order of about 100° C./minute. In some instances, such rapid cooling may be preferred. As an alternative to the two stage process for producing the lithium metal fluorophosphate, a single stage process is used (Example V, Reaction 5). A mixture was made of a metal compound, for example vanadium pentoxide, ammonium dihydrogen phosphate, lithium fluoride and carbon. The mixture was dry ground for about 30 minutes to intimately mix the powders. The powders were pressed into pellets. The reaction was conducted by heating the pellets in an oven at a preferred rate to a first elevated temperature for several hours. A preferred temperature is 300° C. The reaction was carried out under a non-oxidizing atmosphere. The flow rate will depend on the size of the oven and the quantity needed to maintain the temperature. The pellets were allowed to cool, then re-ground and repressed into pellets. The reaction was continued by reheating the pellets in an oven at a preferred heating rate to a second elevated temperature, and held at such elevated temperature for several hours to complete the reaction. A preferred second elevated temperature is 850° C. The reaction was carried out under a non-oxidizing atmosphere. In one aspect, a ramp rate of 2° C./minute was used to heat to an elevated temperature of about 300° C. and allowed to dwell for 3 hours. The precursor material was allowed to cool to room temperature, and subsequently heated to 850° C. along with a dwell time of 8 hours. Refer to Reaction 5 herein. FIGS. 1 through 6 which will be described more particularly below show the characterization data and capacity in actual use for the cathode materials (positive electrodes) of the invention. Some tests were conducted in a cell comprising a lithium metal counter electrode (negative electrode). All of the cells had an EC/DMC (2:1) 1 molar LiPF 6 electrolyte. Typical cell configurations will now be described with reference to FIGS. 7 and 8 ; and such battery or cell utilizes the novel active material of the invention. Note that the preferred cell arrangement described here is illustrative and the invention is not limited thereby. Experiments are often performed, based on full and half cell arrangements, as per the following description. For test purposes, test cells are often fabricated using lithium metal electrodes. When forming cells for use as batteries, it is preferred to use an insertion positive electrode as per the invention and a graphitic carbon negative electrode. A typical laminated battery cell structure 10 is depicted in FIG. 7 . It comprises a negative electrode side 12 , a positive electrode side 14 , and an electrolyte/separator 16 there between. Negative electrode side 12 includes current collector 18 , and positive electrode side 14 includes current collector 22 . A copper collector foil 18 , preferably in the form of an open mesh grid, upon which is laid a negative electrode membrane 20 comprising an insertion material such as carbon or graphite or low-voltage lithium insertion compound, dispersed in a polymeric binder matrix. An electrolyte/separator film 16 membrane is preferably a plasticized copolymer. This electrolyte/separator preferably comprises a polymeric separator and a suitable electrolyte for ion transport. The electrolyte/separator is positioned upon the electrode element and is covered with a positive electrode membrane 24 comprising a composition of a finely divided lithium insertion compound in a polymeric binder matrix. An aluminum collector foil or grid 22 completes the assembly. Protective bagging material 40 covers the cell and prevents infiltration of air and moisture. In another embodiment, a multi-cell battery configuration as per FIG. 8 is prepared with copper current collector 51 , negative electrode 53 , electrolyte/separator 55 , positive electrode 57 , and aluminum current collector 59 . Tabs 52 and 58 of the current collector elements form respective terminals for the battery structure. As used herein, the terms “cell” and “battery” refer to an individual cell comprising anode/electrolyte/cathode and also refer to a multi-cell arrangement in a stack. The relative weight proportions of the components of the positive electrode are generally: 50-90% by weight active material; 5-30% carbon black as the electric conductive diluent; and 3-20% binder chosen to hold all particulate materials in contact with one another without degrading ionic conductivity. Stated ranges are not critical, and the amount of active material in an electrode may range from 25-95 weight percent. The negative electrode comprises about 50-95% by weight of a preferred graphite, with the balance constituted by the binder. A typical electrolyte separator film comprises approximately two parts polymer for every one part of a preferred fumed silica. The conductive solvent comprises any number of suitable solvents and salts. Desirable solvents and salts are described in U.S. Pat. Nos. 5,643,695 and 5,418,091. One example is a mixture of EC:DMC:LiPF 6 in a weight ratio of about 60:30:10. Solvents are selected to be used individually or in mixtures, and include dimethyl carbonate (DMC), diethylcarbonate (DEC), dipropylcarbonate (DPC), ethylmethylcarbonate (EMC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate, lactones, esters, glymes, sulfoxides, sulfolanes, etc. The preferred solvents are EC/DMC, EC/DEC, EC/DPC and EC/EMC. The salt content ranges from 5% to 65% by weight, preferably from 8% to 35% by weight. Those skilled in the art will understand that any number of methods are used to form films from the casting solution using conventional meter bar or doctor blade apparatus. It is usually sufficient to air-dry the films at moderate temperature to yield self-supporting films of copolymer composition. Lamination of assembled cell structures is accomplished by conventional means by pressing between metal plates at a temperature of about 120-160° C. Subsequent to lamination, the battery cell material may be stored either with the retained plasticizer or as a dry sheet after extraction of the plasticizer with a selective low-boiling point solvent. The plasticizer extraction solvent is not critical, and methanol or ether are often used. Separator membrane element 16 is generally polymeric and prepared from a composition comprising a copolymer. A preferred composition is the 75 to 92% vinylidene fluoride with 8 to 25% hexafluoropropylene copolymer (available commercially from Atochem North America as Kynar FLEX) and an organic solvent plasticizer. Such a copolymer composition is also preferred for the preparation of the electrode membrane elements, since subsequent laminate interface compatibility is ensured. The plasticizing solvent may be one of the various organic compounds commonly used as solvents for electrolyte salts, e.g., propylene carbonate or ethylene carbonate, as well as mixtures of these compounds. Higher-boiling plasticizer compounds such as dibutyl phthalate, dimethyl phthalate, diethyl phthalate, and tris butoxyethyl phosphate are particularly suitable. Inorganic filler adjuncts, such as fumed alumina or silanized fumed silica, may be used to enhance the physical strength and melt viscosity of a separator membrane and, in some compositions, to increase the subsequent level of electrolyte solution absorption. In the construction of a lithium-ion battery, a current collector layer of aluminum foil or grid is overlaid with a positive electrode film, or membrane, separately prepared as a coated layer of a dispersion of insertion electrode composition. This is typically an insertion compound such as LiMn 2 O 4 (LMO), LiCoO 2 , or LiNiO 2 , powder in a copolymer matrix solution, which is dried to form the positive electrode. An electrolyte/separator membrane is formed as a dried coating of a composition comprising a solution containing VdF:HFP copolymer and a plasticizer solvent is then overlaid on the positive electrode film. A negative electrode membrane formed as a dried coating of a powdered carbon or other negative electrode material dispersion in a VdF:HFP copolymer matrix solution is similarly overlaid on the separator membrane layer. A copper current collector foil or grid is laid upon the negative electrode layer to complete the cell assembly. Therefore, the VdF:HFP copolymer composition is used as a binder in all of the major cell components, positive electrode film, negative electrode film, and electrolyte/separator membrane. The assembled components are then heated under pressure to achieve heat-fusion bonding between the plasticized copolymer matrix electrode and electrolyte components, and to the collector grids, to thereby form an effective laminate of cell elements. This produces an essentially unitary and flexible battery cell structure. Examples of forming cells containing metallic lithium anode, insertion electrodes, solid electrolytes and liquid electrolytes can be found in U.S. Pat. Nos. 4,668,595; 4,830,939; 4,935,317; 4,990,413; 4,792,504; 5,037,712; 5,262,253; 5,300,373; 5,435,054; 5,463,179; 5,399,447; 5,482,795 and 5,411,820; each of which is incorporated herein by reference in its entirety. Note that the older generation of cells contained organic polymeric and inorganic electrolyte matrix materials, with the polymeric being most preferred. The polyethylene oxide of U.S. Pat. No. 5,411,820 is an example. More modern examples are the VdF:HFP polymeric matrix. Examples of casting, lamination and formation of cells using VdF:HFP are as described in U.S. Pat. Nos. 5,418,091; 5,460,904; 5,456,000; and 5,540,741; assigned to Bell Communications Research, each of which is incorporated herein by reference in its entirety. As described earlier, the electrochemical cell operated as per the invention, may be prepared in a variety of ways. In one embodiment, the negative electrode may be metallic lithium. In more desirable embodiments, the negative electrode is an insertion active material, such as, metal oxides and graphite. When a metal oxide active material is used, the components of the electrode are the metal oxide, electrically conductive carbon, and binder, in proportions similar to that described above for the positive electrode. In a preferred embodiment, the negative electrode active material is graphite particles. For test purposes, test cells are often fabricated using lithium metal electrodes. When forming cells for use as batteries, it is preferred to use an insertion metal oxide positive electrode and a graphitic carbon negative electrode. Various methods for fabricating electrochemical cells and batteries and for forming electrode components are described herein. The invention is not, however, limited by any particular fabrication method. Formation of Active Materials EXAMPLE I Reaction 1(a)—Using hydrogen to form precursors 0.5 V 2 O 5 +NH 4 H 2 PO 4 +H 2 →VPO 4 +NH 3 +2.5 H 2 O (a) Pre-mix reactants in following proportions using ball mill. Thus, 0.5 mol V 2 O 5 =  90.94 g 1.0 mol NH 4 H 2 PO 4 = 115.03 g (b) Pelletize the power mixture. (c) Heat to 300° C. at a rate of 2° C./minute in a flowing H 2 atmosphere. Dwell for 8 hours at 300° C. (d) Cool at 2° C./minute to room temperature. (e) Powderize and re-pelletize. (f) Heat to 850° C. in a flowing H 2 atmosphere at a rate of 2° C./minute. Dwell for 8 hours at 850° C. (g) Cool at 2° C./minute to room temperature. Reaction 1(b)—formation of lithium vanadium fluorophosphate LiF+VPO 4 →LiVPO 4 F (a) Pre-mix reactants in equi-molar portions using a ball mill. Thus, 1 mol LiF =  25.94 g 1 mol VPO 4 = 145.91 g (b) Pelletize powder mixture. (c) Heat to 700° C. at a rate of 2° C./minute in an air atmosphere in a covered nickel crucible. Dwell for 15 minutes at 700° C. (d) Cool to room temperature at about 50° C./minute. (e) Powderize pellet. EXAMPLE II Reaction 2(a)—Using a carbothermal method to form precursors. 0.5 V 2 O 5 +NH 4 H 2 PO 4 +C→VPO 4 +NH 3 +1.5H 2 O+CO (a) Pre-mix reactants in the following proportions using ball mill. Thus, 0.5 mol V 2 O 5 =  90.94 g 1.0 mol NH 4 H 2 PO 4 = 115.03 g 1.0 mol carbon =  12.0 g (Use 10% excess carbon → 13.2 g) (b) Pelletize powder mixture (c) Heat pellet to 300° C. at a rate of 2° C./minute in an inert atmosphere (e.g., argon). Dwell for 3 hours at 300° C. (d) Cool to room temperature at 2° C./minute. (e) Powderize and re-pelletize. (f) Heat pellet to 850° C. at a rate of 2° C./minute in an inert atmosphere (e.g. argon). Dwell for 8 hours at 850° C. under an argon atmosphere. (g) Cool to room temperature at 2° C./minute. (h) Powderize pellet. Reaction 2(b)—formation of lithium vanadium fluorophosphate LiF+VPO 4 →LiVPO 4 F (a) Pre-mix reactants in equi-molar portions using a ball mill. Thus, 1 mol LiF =  25.94 g 1 mol VPO 4 = 145.91 g (b) Pelletize powder mixture. (c) Heat to 700° C. at a rate of 2° C./minute in an air atmosphere in a nickel crucible. Dwell for 15 minutes at 700° C. (d) Cool to room temperature at about 50° C./minute. (e) Powderize pellet. EXAMPLE III Reaction 3(a)—Formation of aluminum phosphate.  Al(OH) 3 +NH 4 H 2 PO 4 →AlPO 4 +NH 3 +3H 2 O (a) Premix reactants in equi-molar portions using a ball mill. Thus, 1.0 mol Al (OH) 3 =  78.0 g 1.0 mol NH 4 H 2 PO 4 = 115.03 g (b) Pelletize powder mixture. (c) Heat to 950° C. at a rate of 2° C./minute in an air atmosphere. Dwell for 8 hours at 950° C. (d) Cool to room temperature at about 50° C./minute. (e) Powderize. Reaction 3(b)—Formation of lithium vanadium aluminum fluorophosphate 0.9 VPO 4 +0.1AlPO 4 +1.0LiF→LiV 0.9 Al 0.1 PO 4 F (a) Pre-mix reactants in the following proportions using ball mill. Thus, 0.9 mol VPO 4 = 131.3 g 0.1 mol AlPO 4 =  12.2 g 1.0 mol LiF =  25.9 g (b) Pelletize powder mixture. (c) Heat to 700° C. at a rate of 2° C./minute in a nickel crucible in either an air or inert atmosphere. Dwell for 15 minutes at 700° C. (d) Cool to room temperature at about 50° C./minute. (e) Powderize. EXAMPLE IV Reaction 4—Production of lithium vanadium fluorophosphate in an alternate formulation.  0.5 Li 2 CO 3 +NH 4 F+VPO 4 →LiVPO 4 F+0.5 H 2 O+NH 3 +0.5CO 2 (a) Pre-mix reactants in the following proportions using a ball mill. Thus, 0.5 mol Li 2 CO 3 =  37.0 g 1.0 mol NH 4 F =  37.0 g 1.0 mol VPO 4 = 145.9 g (b) Pelletize powder mixture. (c) Heat to 700° C. at a rate of 2° C./minutes in an air atmosphere. Dwell for 15 minutes at 700° C. (d) Cool to room temperature. (e) Powderize pellet. EXAMPLE V Reaction 5— Single step preparation of lithium vanadium fluorophosphate using lithium fluoride in a carbothermal method. 0.5 V 2 O 5 +NH 4 H 2 PO 4 +LiF+C→LiVPO 4 F+NH 3 +CO+1.5 H 2 O (a) Pre-mix reactants in the following proportions using a ball mill. Thus, 0.5 mol V 2 O 5 =  90.94 g 1.0 mol NH 4 H 2 PO 4 = 115.03 g 1.0 mol LiF =  25.94 g 1.0 mol carbon =  12.0 g (Use 10% excess carbon → 13.2 g) (b) Pelletize powder mixture. (c) Heat pellet to 300° C. at a rate of 2° C./minute in an inert atmosphere. Dwell for 3 hours at 300° C. (d) Cool to room temperature at 2° C./minute. (e) Powderize and repelletize. (f) Heat pellet to 750° C. at a rate of 2° C./minute in an inert atmosphere (e.g. argon). Dwell for 1 hour at 750° C. under an argon atmosphere. (g) Cool to room temperature at 2° C./minute. (h) Powderize pellet. EXAMPLE VI Reaction 6a—Formation of iron phosphate. 0.5 Fe 2 O 3 +(NH 4 ) 2 HPO 4 →FePO 4 +2NH 3 +3/2H 2 O (a) Pre-mix reactants in the following proportions using a ball mill. Thus, 0.5 mol Fe 2 O 3 =  79.8 g 1.0 mol (NH 4 ) 2 HPO 4 = 132.1 g (b) Pelletize powder mixture. (c) Heat to 300° C. at 2° C./minute in air atmosphere. Dwell 8 hours and cool to room temperature. (d) Re-pelletize. (e) Heat to 900° C. at 2° C./minute in air atmosphere. Dwell 8 hours and cool to room temperature. (f) Powderize. Reaction 6b—Formation of LiFePO 4 F FePO 4 +LiF→LiFePO 4 F (a) Pre-mix reactants in the following proportions using a ball mill. Thus, 1 mol FePO 4 = 150.8 g 1 mol LiF =  25.9 g (b) Pelletize. (c) Heat to 700° C. at 2° C./minute in air atmosphere. (d) 15 minute dwell. (e) Cool to room temperature. (f) Powderize. EXAMPLE VII Reaction 7a—Formation of titanium phosphate. TiO 2 +NH 4 H 2 PO 4 +0.5 H 2 →TiPO 4 +NH 3 +2 H 2 O (a) Pre-mix reactants in the following proportions using a ball mill. Thus, 1.0 mol TiO 2 = 79.9 g 1.0 mol NH 4 H 2 PO 4 = 115.0 g (b) Pelletize powder mixture. (c) Heat to 300° C. at 2° C./minute in air atmosphere. Dwell for 3 hours. (d) Cool to room temperature. (e) Re-pelletize. (f) Heat to 850° C. at 2° C./minute in H 2 atmosphere. Dwell for 8 hours. (g) Cool to room temperature. (h) Powderize. Reaction 7b—Formation of LiTiPO 4 F. TiPO 4 +LiF→LiTiPO 4 F (a) Pre-mix reactants in the following proportions using a ball mill. Thus, 1 mol TIPO 4 = 142.9 g 1 mol LiF = 25.9 g (b) Pelletize powder mixture. (c) Heat to 700° C. at 2° C./minute in inert atmosphere. (d) No dwell. (e) Cool to room temperature. (f) Powderize. EXAMPLE VIII Reaction 8a—Formation of chromium phosphate. 0.5 Cr 2 O 3 +1.0(NH 4 ) 2 HPO 4 →CrPO 4 +2NH 3 +3/2H 2 O (a) Pre-mix reactants in the following proportions using a ball mill. Thus, 0.5 mol Cr 2 O 3 = 76.0 g 1.0 mol (NH 4 ) 2 HPO 4 = 132.1 g (b) Pelletize powder mixture. (c) Heat to 500° C. at 2° C./minute in air atmosphere. Dwell 6 hours and cool to room temperature. (d) Re-pelletize. (e) Heat to 1050° C. at 2° C./minute in air atmosphere. Dwell 6 hours and cool to room temperature. (f) Powderize. Reaction 8b—Formation of LiCrPO 4 F CrPO 4 +LiF→LiCrPO 4 F (a) Pre-mix reactants in the following proportions using a ball mill. Thus, 1 mol CrPO 4 = 147.0 g 1 mol LiF = 25.9 g (b) Pelletize powder mixture. (c) Heat to 700° C. at 2° C./minute in air atmosphere. (d) 15 minute dwell. (e) Cool to room temperature. (f) Powderize. Characterization of Active Materials and Formation and Testing of Cells Referring to FIG. 1 , the final product LIVPO 4 F, prepared from VPO 4 metal compound per Reaction 1(b), appeared black in color. The product is a material with a triclinic crystal structure. The triclinic unit cell crystal structure is characterized by a lack of symmetry. In a triclinic crystal structure, a≠b≠c, and α≠β≠γ≠90°. This product's CuKα x-ray diffraction (XRD) pattern contained all of the peaks expected for this material as shown in FIG. 1 . The pattern evident in FIG. 1 is consistent with the single phase triclinic phosphate LiVPO 4 F. This is evidenced by the position of the peaks in terms of the scattering angle 2θ (theta), x axis. Here the space group and the lattice parameters from XRD refinement are consistent with the triclinic structure. The values are a=5.1738 Å (0.002), b=5.3096 Å (0.002), c=7.2503 Å (0.001); the angle α=72.4794 (0.06), β=107.7677 (0.04), γ=81.3757 (0.04), cell volume=174.35 Å 3 . The x-ray pattern demonstrates that the product of the invention was indeed the nominal formula LiVPO 4 F. The term “nominal formula” refers to the fact that the relative proportion of atomic species may vary slightly on the order of up to 5 percent, or more typically, 1 percent to 3 percent. In another aspect, any portion of P (phosphorous) may be substituted by Si (silicon), S (sulfur) and/or As (arsenic). The LiVPO 4 F, prepared as described immediately above, was tested in an electrochemical cell. The positive electrode was prepared as described above, using 22.5 mg of active material. The positive electrode contained, on a weight % basis, 80% active material, 8% carbon black, and 12% Kynar. Kynar is commercially available PVdF:HFP copolymers used as binder material. The negative electrode was metallic lithium. The electrolyte was 2:1 weight ratio mixture of EC and DMC within which was dissolved 1 molar LiPF 6 . The cells were cycled between 3.5 and 4.4 with performance as shown in FIG. 2 . FIG. 2 is an Electrochemical Voltage Spectroscopy (EVS) voltage/capacity profile for a cell with cathode material formed with LIVPO 4 F. FIG. 2 shows the results of the first cycle with the critical limiting current density less than 0.1 milliamps per square centimeter with ±10 mV steps between about 3.0 and 4.4 volts based upon 29.4 milligrams of the LiVPO 4 F active material in the cathode (positive electrode). In an as prepared, as assembled, initial condition, the positive electrode active material is LiVPO 4 F. The lithium is extracted from the LiVPO 4 F during charging of the cell. When fully charged, about 0.75 unit of lithium had been removed per formula unit. Consequently, the positive electrode active material corresponds to Li 1−x VPO 4 F where x appears to be equal to about 0.75, when the cathode material is at 4.4 volts versus Li/Li + . The extraction represents approximately 129 milliamp hours per gram corresponding to about 3.8 milliamp hours based on 29.4 milligrams active material. Next, the cell is discharged whereupon a quantity of lithium is re-inserted into the LiVPO 4 F. The re-insertion corresponds to approximately 109 milliamp hours per gram proportional to the insertion of essentially all of the lithium. The bottom of the curve corresponds to approximately 3.0 volts. FIG. 3 is an Electrochemical Voltage Spectroscopy differential capacity plot based on FIG. 2 . As can be seen from FIG. 3 , the relatively symmetrical nature of the peaks indicates good electrical reversibility. There are small peak separations (charge/discharge), and good correspondence between peaks above and below the zero axis. There are essentially no peaks that can be related to irreversible reactions, since peaks above the axis (cell charge) have corresponding peaks below the axis (cell discharge), and there is very little separation between the peaks above and below the axis. This shows that the LiVPO 4 F as high quality electrode material. Referring to FIG. 4 , the final product LiFePO 4 F, prepared from FePO 4 metal compound per Reaction 6(b), appeared brown in color. (Reactions 6a and 6b are carried out in the same manner as reactions 1a and 1b.) The product is a material with a triclinic crystal structure. This product's CuKα x-ray diffraction pattern contained all of the peaks expected for this material as shown in FIG. 4 . The pattern evident in FIG. 4 is consistent with the single phase triclinic phosphate LiFePO 4 F. This is evidenced by the position of the peaks in terms of the scattering angle 2θ (theta), x axis. Here the space group and the lattice parameters from XRD refinement are consistent with the triclinic structure. The values are a=5.1528 Å (0.002), b=5.3031 Å (0.002), c=7.4966 Å (0.003); the angle α=67.001° (0.02), β=67.164° (0.03), γ=81.512° (0.02), cell volume=173.79 Å 3 . The x-ray pattern demonstrates that the product of the invention was indeed the nominal formula LiFePO 4 F. Referring to FIG. 5 , the final product LiTiPO 4 F, prepared from TiPO 4 metal compound per Reaction 7(b), appeared green in color. (Reactions 7a and 7b are carried out in the same manner as reactions 1a and 1b.) The product is a material with a triclinic crystal structure. This product's CuKα x-ray diffraction (XRD) pattern contained all of the peaks expected for this material as shown in FIG. 5 . The pattern evident in FIG. 5 is consistent with the single phase triclinic phosphate LiTiPO 4 F. This is evidenced by the position of the peaks in terms of the scattering angle 2θ (theta), x axis. The x-ray diffraction pattern was triclinic. Referring to FIG. 6 , the final product LiCrPO 4 F, prepared from CrPO 4 metal compound per Reaction 8(b), appeared green in color. (Reactions 8a and 8b are carried out in the same manner as reactions 1a and 1b.) The product is a material with a triclinic crystal structure. This product's CuKα x-ray diffraction pattern contained all of the peaks expected for this material as shown in FIG. 6 . The pattern evident in FIG. 6 is consistent with the single phase triclinic phosphate LiCrPO 4 F. This is evidenced by the position of the peaks in terms of the scattering angle 2 θ (theta), x axis. Here the space group and the lattice parameters from XRD refinement are consistent with the triclinic structure. The values are a=4.996 Å (0.002), b=5.307 Å (0.002), c=6.923 Å (0.004); the angle α=71.600° (0.06), β=100.71° (0.04), γ=78.546° (0.05), cell volume=164.54 Å 3 . The x-ray pattern demonstrates that the product of the invention was indeed the nominal formula LiCrPO 4 F. As demonstrated by the above example, the methods described herein have successfully been used to make the LiM 1−y MI y PO 4 F compounds. These methods produce products which are essentially homogeneous, single phase compounds. Although small amounts of other materials or phases may be present, such does not alter the essential character of the products so produced. In summary, the invention provides new compounds LiM a MI b PO 4 F, more specifically, LiM 1−y MI y PO 4 F, which are adaptable to commercial scale production. The new compounds are triclinic compounds as demonstrated by XRD analysis. The new materials demonstrate relatively high specific capacity coupled to a desirable voltage range and energetic reversibility. These properties make these materials excellent candidates as cathode active compound for lithium ion applications. The new materials of the invention are easily and conveniently produced from available precursors with no loss of weight, or generation of waste products. The precursors can be produced by methods, such as carbothermal reduction. In other words, this invention provides new compounds capable of being commercially and economically produced for use in batteries. In addition, the use of lighter non-transition metals and elements mixed with the transition metal in the lithium metal fluorophosphate provides for structural stability and better recycling of the lithium ions. While this invention has been described in terms of certain embodiments thereof, it is not intended that it be limited to the above description, but rather only to the extent set forth in the following claims. The embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following claims.

The invention provides new and novel lithium-metal-fluorophosphates which, upon electrochemical interaction, release lithium ions, and are capable of reversibly cycling lithium ions. The invention provides a rechargeable lithium battery which comprises an electrode formed from the novel lithium-metal-fluorophosphates. The lithium-metal-fluorophosphates comprise lithium and at least one other metal besides lithium.

RELATED APPLICATIONS This application is a continuation of and claims priority to U.S. patent application Ser. No. 11/141,837, filed Jun. 1, 2005 now U.S. Pat. No. 7,464,862, and entitled “Apparatus and Method For POS Processing,” which claims priority to U.S. Provisional Patent Application Ser. Nos. 60/579,997 filed Jun. 15, 2004 and 60/631,300 filed Nov. 24, 2004. The content of all of these prior applications is hereby fully incorporated herein by reference. COPYRIGHT NOTICE A portion of the disclosure of this patent document may contain material, which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or patent disclosure as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. FIELD OF THE INVENTION The present invention relates to an apparatus and method for enhancing the functionality and security of point-of-sale terminals through the use of a portable non-volatile memory device using software and data carried within the device. BACKGROUND OF THE INVENTION In recent years, point-of-sale (POS) terminals and the software that supports POS business applications have become increasingly complex. New ‘modular’ applications have been developed to capitalize on the new POS terminal capabilities and serve to increase the utility value of the point-of-sale terminal. Concurrently, the internet has provided an opportunity to increase the communication bandwidth to the POS terminals, again increasing the type of functionality and transactions that can be supported. However, the POS terminals themselves lack the capacity to store large amounts of data and the business applications available to POS terminals are therefore limited. The number of merchants, terminals and transactions is increasing annually. Along with these increases, there has been an increase in fraud at the point-of-sale. Current methods fail to adequately prevent consumer and merchant fraud from occurring at the point-of-sale. Authenticating transactions originating from POS devices using secure tokens, digital certificates and other unique merchant identifiers used to control or limit individual user access and functionality are not easily supported by conventional methods. Also, the process of configuring the POS terminal to function in accordance with the merchant's needs and approved transactions is becoming increasingly complex and time consuming. One drawback to conventional methods for configuring POS devices is related to the current method of downloading the POS business application programs (eg. restaurant, retail, lodging, mail order, petroleum) and the merchant-specific configuration attributes (eg. Bar-tabs, tips, merchant-id, terminal-id, American Express SE number). Current methods rely on transferring (i.e. downloading) this information over dial or high-speed connections with a host-based system. The process is very time consuming, error prone and therefore expensive. Another drawback to conventional methods for introducing new products to the market is related to the fact that the POS business applications must first be certified by the credit card processors (such as Vital Processing, Nova Information Systems, Global Payments, RBS Lynk, First Data) in advance of commercial use. Certification must be completed separately by each processor for each type of POS terminal and business application prior to the device being approved for sale and support (as a ‘Class-A’ product). This certification process is generally manual in nature, time consuming and expensive and often requires 6 to 12 months per each business application. Any single change such as a line of source code (or for example an additional module added) to a business application requires that, the certification process start over again. POS terminal manufacturers (i.e. Verifone, Hypercom, Ingenico, others) are therefore constrained in their ability to sell and distribute new POS terminal models until the business applications are certified (and therefore supported) by the major processors. This scenario creates friction in the distribution channel as the manufacturers seek to gain market share with new innovative equipment because it requires them to wait for each of the major processors (i.e. First Data, Vital Processing, Global Payments, Nova Information Systems, RBS Lynk, others) to first certify the business applications. Finally, because of the high cost of the device and the security requirements, the POS terminal industry is generally constrained to sell terminals and software only for use by approved merchants and they do not typically sell terminals directly to consumers for use at the home or office. The price of non-volatile (flash) memory is rapidly decreasing while the capacity and available is increasing. The next generation of POS devices will support non-volatile, detachable flash memory from serial, USB, and other methods. In fact, POS manufacturers are in the very beginning stages of supporting USB devices on POS terminals and there are no commercial uses of this technology today on POS devices. Computer programs (i.e. Business Applications) can and should be developed to enhance the utility value, functionality and security of these next generation POS devices. It will be difficult for the industry to embrace this new technology using current methods. Therefore, a need exists for an apparatus and method that addresses these shortcomings in the prior art by utilizing the new capabilities provided through non-volatile, removable flash memory. SUMMARY OF THE INVENTION The present invention answers these needs by providing an apparatus and method for configuring, altering, controlling, securing, and extending the processing capability and functionality of POS devices using a non-volatile memory device using software and data carried within the device. According to the present invention design, a portable housing is provided with non-volatile memory inside. An interface is provided on the housing for communication between the non-volatile memory and the Removable Flash Enabled POS Device. Business software applications and configuration data are loaded into the non-volatile memory. The software applications can be loaded into the non-volatile memory by the POS terminal manufacturer, the Independent Sales Organization (ISO), by a payment processing company, or by the Merchant via a CD-ROM, the Internet, or other suitable means. Because the software ‘business applications’ and configuration data ‘merchant specific attributes’ reside (either fully or partially) on the removable storage device (non-volatile memory) and not on fully on the POS terminal (current industry standard), the present invention may be used to configure and inter-operate with multiple POS devices. It is thus an advantage of the present invention to provide an apparatus and method for quickly configuring, enhancing, controlling, securing, or extending the functionality of a Removable Flash Enabled POS Device without time consuming and expensive software modifications or host-based download processes. To this end, the present invention is highly portable, operates independently of any particular POS terminal, and is compatible with a wide variety of POS terminal devices. Embodiments of the present invention are described below by way of illustration. Other approaches to implementing the present invention and variations of the described embodiments may be constructed by a skilled practitioner and are considered within the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overview of the primary components which would be required to support all of the invention embodiments. Components include: (1) Removable-Flash Enabled POS Device; (2) Removable Flash Memory; (3) Dial-up, Wireless, or High-speed internet connection to Host Processor, (4) Host Processor; (5) Cable; (6) File Server; (7) Personal Computer. FIG. 2 is an overview of the basic required components which would be required to support a limited set of the invention embodiments. Components include: (1) Removable Flash Enabled POS Device; (2) Removable Flash Memory. DETAILED DESCRIPTION OF THE INVENTION As illustrated in FIG. 1 , in one exemplary embodiment, the invention comprises a host based processor used for transaction authorization and clearing and downloading information to the removable flash memory. The exemplary embodiment illustrated in FIG. 1 also comprises a removable flash memory containing programs and data, as well as an interface that may be USB or another method. The exemplary embodiment shown in FIG. 1 further comprises a PC used to store information collected on removable flash memory. As illustrated in the exemplary embodiment shown in FIG. 2 , the removable flash enabled POS terminal can process certain transactions in an offline mode when there is no connection to the host processor. Furthermore, the removable flash memory contains programs and data that interoperate with the enabled POS terminal. The data stored in the removable flash memory can include inventory, pricing, negative files, music, games, batched transactions, control totals and other related data which would normally exceed the capacity of the POS terminal. An embodiment of the invention allows for the secure storage of any persistent data (data of a permanent nature until changed or deleted) onto [ FIG. 1 : Removable Flash Memory]. This persistent data may be related to POS terminal configuration and, or transaction data. This data volume currently exceeds the storage capacity of the POS device [ FIG. 1 : Removable Flash Enabled POS Device] and therefore limits the utility value and overall functionality of the device to the merchant. An embodiment of the invention allows for the tracking of cardholder and related customer transaction activity on the [ FIG. 2 : Removable Flash Memory] for the purpose of gift and loyalty program tracking without the need for an online, host-based connection. An embodiment of the invention allows for the storage of known lost, stolen or fraudulent credit card and debit card numbers on the [ FIG. 2 : Removable Flash Memory], to prevent the use of these cards for POS transactions without the need for a host-based online connection (or in an offline mode). In connection with this embodiment, merchant-specific, employee-specific or location-specific fraud rules and limits may be defined and enforced without the need for an online connection to a host. An embodiment of the invention allows for the immediate configuration of a new or reconfiguration of a POS terminal device shown in [FIG. 2 —Removable Flash Enabled POS Device] using data and programs stored on the [ FIG. 2 : Removable Flash Memory] without the need to dial, download or connect the POS terminal with a central, host-based configuration process. An embodiment of the invention allows for the storage of daily transaction totals on the [ FIG. 1 : Removable Flash Memory] for internal control, balancing, and reconcilement purposes using the [ FIG. 1 : PC or FIG. 1 : File Server]. An embodiment of the invention allows for the secure storage of daily transactions (or batches of transactions) on the [ FIG. 1 : Removable Flash Memory] for the subsequent submission or ‘uploading’ to a host-based authorization system [ FIG. 1 : Host] and, or a local PC-based reporting process as shown in [ FIG. 1 : Personal Computer] or [ FIG. 1 : File Server]. An embodiment of the invention allows for the creation of authorized users and passwords for the merchant-specific POS device and would therefore require the [ FIG. 1 : Removable Flash Memory] to be connected to the POS device [ FIG. 1 : Removable Flash Enabled POS Device] prior to use and during use. This embodiment will also serve to control the functionality of the device [ FIG. 1 : Removable Flash Enabled POS Device] for specific users and therefore act as a ‘key’ to this POS device. An embodiment of the invention allows for protection of files and data stored on the POS device [ FIG. 1 : Removable Flash Enabled POS Device] or the removable storage device [ FIG. 1 : Removable Flash Memory] through the use of an encryption method which is compliant with current payment industry security standards set by Visa (i.e. CISP), MasterCard, and American Express. An embodiment of the invention allows for the merchant-specific configuration of a POS device [ FIG. 1 : Removable Flash Enabled POS Device] to be backed up onto [ FIG. 1 : Removable Flash Memory] and restored onto another identical POS device. An embodiment of the invention allows for an independent audit or sampling of POS transactions from [ FIG. 1 : Removable Flash Enabled POS Device] onto [ FIG. 1 : Removable Flash Memory] for use by internal or external auditors as part of Sarbanes Oxley or related internal control requirements. An embodiment of the invention provides a mechanism for capturing signatures and receipts from the POS device [ FIG. 1 : Removable Flash Enabled POS Device] onto [ FIG. 1 : Removable Flash Memory] which can be later transferred to [ FIG. 1 : Personal Computer] or [ FIG. 1 : File Server] and used for customer service, charge-back research and other related value-add purposes. An embodiment of the invention provides a mechanism for capturing check images and check data from [ FIG. 1 : Removable Flash Enabled POS Device] and storing this information onto [ FIG. 1 : Removable Flash Memory] formatted in compliance with Check 21 and, or NACHA's ARC requirements. This data can subsequently be transferred to [ FIG. 1 : Personal Computer] or [ FIG. 1 : File Server] or [ FIG. 1 : Host] and used for financial transaction fulfillment, clearing other related purposes. An embodiment of the invention provides a mechanism for storing and retrieving HTML and similar presentation content on the [ FIG. 1 : Removable Flash Memory] as required to format screens on [ FIG. 1 : Removable Flash Enabled POS Device]. An embodiment of the invention provides a means to store onto the [ FIG. 1 : Removable Flash Memory] and display marketing presentations such as flash or video presentations on the screen of the POS device [ FIG. 1 : Removable Flash Enabled POS Device]. An embodiment of the invention provides a means to conduct customer surveys on [ FIG. 1 : Removable Flash Enabled POS Device] and collect and store survey results on [ FIG. 1 : Removable Flash Memory]. This data can subsequently be transferred to [ FIG. 1 : Personal Computer] or [ FIG. 1 : File Server] or [ FIG. 1 : Host] and used for customer service other related purposes. An embodiment of the invention provides a means of storing product catalogs, inventory levels and pricing on [ FIG. 1 : Removable Flash Memory] or [ FIG. 2 : Removable Flash Memory] to allow customers to shop at the POS terminal [ FIG. 2 : Removable Flash Enabled POS Device] while in an offline mode. This inventory data can subsequently be transferred to [ FIG. 1 : Personal Computer] or [ FIG. 1 : File Server] or [ FIG. 1 : Host] and used for updating central inventory, re-order and other related purposes. An embodiment of the invention allows for local “stand-in” processing using data, logic and rules contained within the [ FIG. 2 : Removable Flash Memory] to authorize transactions when the host is down in lieu of (or in addition to) traditional voice authorizations. In connection with this embodiment, the locally authorized transactions would be uploaded to the host [ FIG. 1 : Host Processor] automatically whenever the online connection is restored. An embodiment of the present invention provides a means of storing onto [ FIG. 1 : Removable Flash Memory] and dispensing coupons from [ FIG. 1 : Removable Flash Enabled POS Device] to customers in order to encourage repeat sales and to calculate discounts on sale items for qualifying customers. An embodiment of the invention allows for music and games to be stored on to [ FIG. 1 : Removable Flash Memory] and played through the POS device [ FIG. 1 : Removable Flash Enabled POS Device]. An embodiment of the invention allows for the configuration of a virtual private network (VPN) or similar secure network over the [ FIG. 1 : Dial-up, Wireless or High-speed Internet connection to Host] to facilitate authentication to the network's processor [ FIG. 1 : Host Processor]. This embodiment also supports other advanced security mechanisms which otherwise would not be supportable by the POS device. In connection with this embodiment, a secure token, digital certificate, encryption key or other unique identifier is permanently stored on the non-volatile memory device [ FIG. 1 : Removable Flash Memory] and released to the payment network to authenticate each session and, or transaction. An embodiment of the invention facilitates the transfer (such as downloading from the internet or a wireless network) of large files (such as but not limited to: inventory levels, pricing, negative card files, bin tables, music, games, marketing presentations, etc.) through the connection POS device [ FIG. 1 : Removable Flash Enabled POS Device] over high-speed connections [ FIG. 1 : Dial-up, Wireless, or High-speed internet connection to Host Processor] and stored directly onto [ FIG. 1 : Removable Flash Memory]. An embodiment of the current invention would allow the POS device to route payment or non-payment transactions based on bin tables (and related rules) that are stored on the removable device. In connection with this embodiment, these bin tables would be updated periodically thought a connection such as [ FIG. 1 : Dial-up, Wireless, or High-speed internet connection to Host Processor] or via CD ROM. An embodiment of the invention integrates a Personal Computer with a POS device for merchant or home users. Connectivity would be provided to the non-volatile flash memory [ FIG. 1 : Removable Flash Memory] to create an interoperable application that fully leverages the capabilities of the PC [ FIG. 1 : PC]. In connection with this embodiment, a merchant or consumer will be able to initiate a card-centric (swipe and signature/or pin-based) financial transaction from their home or business using the [ FIG. 1 : Removable Flash Memory] and without the need for a separate POS device. This embodiment also creates a potentially huge new market for accepting secure payment transactions from millions of existing and future PCs. An embodiment of the invention would allow consumer credit card, pre-paid card, gift card, and other related personal account information to be securely stored on a consumer's personal non-volatile memory device (such as a USB flash memory device) [ FIG. 1 : Removable USB Flash Memory] and accessed by the POS terminal [ FIG. 1 : Removable Flash Enabled POS Device] when inserted into the POS terminal or via RFID. This embodiment would therefore replace the need for the consumer to provide a magnetic-stripe, smart-card or other card-centric payment device. Having thus described the invention in detail, it should be apparent that various modifications and changes may be made without departing from the spirit and scope of the present invention. Consequently, these and other modifications are contemplated to be within the spirit and scope of the following claims.

An apparatus and method for configuring, altering, controlling, securing, and extending the processing capability and functionality of PCs and POS devices using a non-volatile memory device using software and data carried within the apparatus.

[0001] This invention relates to a composition of labeled and non-labeled monoclonal antibodies directed to a human transmembrane protein for the simultaneous treatment and diagnosis of diseases which are associated with an overexpression of such a protein especially of cancer. The invention further relates to a method of first administering said composition, determine the change of labeled antibody concentration and afterwards administering the non-labeled monoclonal antibodies only such that the minimum required concentration of such non-labeled antibody for a favorable therapeutical effect is achieved and maintained in the treatment, while unfavorable side effects are minimized due to the lower systemic antibody concentration. BACKGROUND OF THE INVENTION Monoclonal Antibodies in the Therapy [0002] In an ongoing quest to improve the therapeutic arsenal against cancer, a fourth weapon other than surgery, chemotherapy and radiotherapy has emerged, i.e. targeted therapy. Targeted therapy includes, tyrosine kinase receptor inhibitors (small molecule inhibitors like imatinib, gefitinib, erlotinib), proteasome inhibitors (bortezomib), biological response modifiers (denileukin diftitox) and monoclonal antibodies (MAbs). The remarkable specificity of MAbs as targeted therapy makes them promising agents for human therapy. Not only can MAbs be used therapeutically to protect against disease, they can also be used to diagnose a variety of illnesses, measure serum protein and drug levels, type tissue and blood and identify infectious agents and specific cells involved in immune response. About a quarter of all biotech drugs in development are MAbs, and about 30 products are in use or being investigated. A majority of the MAbs are used for the treatment of cancer. (Gupta, N., et al., Indian Journal of Pharmacology 38 (2006) 390-396; Funaro, A., et al., Biotechnology Advances 18 (2000) 385-401; Suemitsu, N; et al., Immunology Frontier 9 (1999) 231-236). Labeled Monoclonal Antibodies and In-Vivo Imaging [0003] Several in vivo imaging methods are available for the quantification of therapeutic antibodies in tumor tissue usually based on labeled derivatives of the antibodies. Said labeled antibodies usually include antibodies labeled with radiolabels such as, e.g. 124 I, 111 In, 64 Cu, and others, for use in positron emission tomography. (PET) (see e.g. Robinson, M. K., et al., Cancer Res 65 (2005) 1471-1478; Lawrentschuk, N., et al., BJU International 97 (2006) 916-922; Olafsen, T., et al., Cancer Research 65 (2005) 5907-5916; and Trotter, D. E., et al., Journal of Nuclear Medicine 45 (2004) 1237-1244), 123 I, 125 I, and 99m Tc and others for use in single photon emission computed tomography (SPECT) (see e.g. Orlova, A., et al., Journal of Nuclear Medicine 47 (2006) 512-519; Dietlein, M., et al., European Journal of Haematology 74 (2005) 348-352). [0004] Also nonradioactive labels are known for in-vivo imaging techniques, e.g. near-infrared (NIR) fluorescence labels, activatable dyes, and engodogenous reporter groups (fluorescent proteins like GFP-like proteins, and bioluminescent imaging) (Licha, K., et al., Adv Drug Deliv Rev, 57 (2005) 1087-1108). Especially NIR fluorescence imaging can be used for the quantification of therapeutic antibodies in tumor tissue. Advantages of near infrared imaging over other currently used clinical imaging techniques include the following: potential for simultaneous use of multiple, distinguishable probes (important in molecular imaging); high temporal resolution (important in functional imaging); high spatial resolution (important in vivo microscopy); and safety (no ionizing radiation). [0005] In NIR fluorescence imaging, filtered light or a laser with a defined bandwidth is used as a source of excitation light. The excitation light travels through body tissues. When it encounters a near infrared fluorescent molecule (“contrast agent”), the excitation light is absorbed. [0006] The fluorescent molecule then emits light (fluorescence) spectrally distinguishable (slightly longer wavelength) from the excitation light. Despite good penetration of biological tissues by near infrared light, conventional near infrared fluorescence probes are subject to many of the same limitations encountered with other contrast agents, including low target/background ratios. [0007] Near infrared wavelengths (approximately 640-1300 nm) have been used in optical imaging of internal tissues, because near infrared radiation exhibits tissue penetration of up to 6-8 centimeters. See, e.g., Wyatt, J. S., Phil. Trans. R. Soc. B 352 (1997) 697-700; Tromberg, B. J., et al., Phil. Trans. R. Soc. London B 352 (1997) 661-667. [0008] The exact amounts of the antibody-label conjugates used for in vivo imaging depends on the different characteristics and aspects of the labels used, e.g. for NIR fluorescence labels the quantum yield of the label is one of the criteria for the amount of label or labeled antibody used (see e.g. WO 2006/072580). Administration and Monitoring of Non-Labeled Monoclonal Antibodies in the Therapy [0009] Factors affecting the successful therapy of malignant diseases include the antibody dose used and the schedule of administration, the half-life and fast blood clearance of the antibodies, the presence of circulating antigen, poor tumor penetration of the high/mol.-wt. monoclonal antibody (mAb) and the way in which these molecules are catabolized. At present, there is a lack of knowledge about many aspects of the physiological function and metabolism of antibodies. (Iznaga-Escobar, N., et al, Meth. Find. Exp. Clin. Pharm. (2004) 26(2) 123-127). [0010] The dosing and administration patterns of antibodies in the therapy of malignant diseases is usually based on the serum pharmacokinetic properties of such antibodies, like serum half-life, AUC at different dosages, the blood clearance and others (Iznaga-Escobar, N., et al., Meth. Find. Exp. Clin. Pharm. (2004) 26(2) 123-127; Lobo, E. D., et al., J. Pharm Sci. 93 (2004) 2645-2668; Tabrizi, M. A., et al., Drug Discovery Today 11 (2006) 81-88). [0011] For example, in tumor treatment, high serum levels of antibodies targeting solid tumors are actually thought to be basic requirements for subsequent therapeutic evaluation. This evaluation is often difficult as the serum levels often differ enormously from patient to patient. However, a therapeutic monoclonal antibody, which binds in the most optimal way to its relevant target, will have a faster serum clearance (target correlated/mediated clearance) compared to an antibody with lower affinity to the relevant target. This may be one reason why plasma levels of therapeutic antibodies do not always correlate with concentration of antibodies in tumor tissue (Clarke, K., et al., Cancer Res. 60 (2000) 4804-4811; Chrastina, A., et al., Int J Cancer 105 (2003) 873-881; Lub-de Hooge, M. N., et al., Brit J. Pharmacol. 143 (2004) 99-106; Robinson, M. K., et al., Cancer Res 65 (2005) 1471-1478; Kenanova, V., et al., Cancer Res. 65 (2005) 622-631; reviewed in Batra, S. K., et al., Curr Opin Biotechnol. 6 (2002) 603-608. Consequently, high serum levels of a therapeutic antibody (especially antibodies against tumor associated antigens) may indicate diminished binding to the target. Furthermore, in case a therapeutic antibody is overdosed (above the tumor saturation dose) free antibody can bind to lower affinity epitopes (or to Fc receptors on immune effector cells) and this may lead to unwanted side effects like e.g. cardiac failure in anti-HER2-antibody treatment due to the HER2 inhibition on cardiac myocytes (Grazette, L. P; et al.; J Am Coll Card (2004), 44(11), 2231-8; Negro, A., Recent Progress in Hormone Research 59 (2004) 1-12; Negro, A., et al., PNAS 103 (2006) 15889-15893). Therefore, measurements of serum levels alone together with the associated serum half-life may be misleading when the most appropriate administration pattern has to be defined. Thus, quantitative information regarding the tumor saturation dose is an important issue. Side Effects of Labeled Antibodies [0012] Monoclonal antibodies labeled with radioactive labels have one big drawback due to the cellular damage such labels can cause in healthy cells. Particularly, when these radioactive labeled antibodies are use for diagnosis these side effects are unwanted. Actually there exist different monoclonal antibodies covalently coupled to a nonradioactive label (Ballou, B., et al., Proceedings of SPIE—The International Society for Optical Engineering 2680 (1996) 124-131; Ballou, B., et al., Cancer detection and prevention (1998) 22 251-257; Becker, A., et al., Nature Biotechnology 19 (2001) 327-331; Montet, X., et al., Cancer Research 65 (2005) 6330-6336; Rosenthal, E, L., et al., The Laryngoscope 116 (2006) 1636-1641; Hilger, I., et al, European Radiology 14 (2004) 1124-1129; EP 1 619 501, WO 2006/072580, WO 2004/065491 and WO 2001/023005). [0013] These conjugates were used in in-vivo imaging techniques to detect the disease site and size (e.g. of tumors or inflammations). This diagnostic applications are all intended fort the diagnosis before or after a therapy by either surgery, or chemotherapeutic agents including monoclonal antibodies. Normally these labeled monoclonal antibodies were used in diagnostic doses in which the side effects of the used non-radioactive labels play a minor role (compared to the use of radioactive labels). [0014] However if these labeled monoclonal antibodies would be used for therapy the amount of nonradioactive label is critical due to the sometimes severe toxicities of these labels (especially of cyanine and carbocyanine dyes; see e.g. Kues, H. A.; Lutty, G. A; “Dyes can be deadly”; Laser Focus (1975) 11(5) 59-61.). It is therefore doubtful that these labeled monoclonal antibodies can be directly used as therapeutics or in therapeutic doses (see e.g Hilger, I., et al, European Radiology 14 (2004) 1124-1129) without causing unwanted side effects. Side Effects of Therapeutic Antibodies [0015] As the unwanted side effects of monoclonal antibody treatment play a major role in the course of that treatment and the maximum duration of such a treatment, the gathering of sufficient information about the time dependency of the antibody concentration at the disease area (region of interest, e.g. at the tumor or inflammation site) during a first treatment with said antibody is an important issue. This would allow the adoption of the dose scheduling for consecutive treatments/administrations in such a way that unwanted overdosing is minimized and the minimum of necessary antibody concentration is used. [0016] Also the differences in time dependency of the antibody concentration from patient to patient could be taken into account to optimize the individual dose scheduling with respect to a minimization of side effect. SUMMARY OF THE INVENTION [0017] The invention comprises a pharmaceutical composition comprising a) a monoclonal antibody binding to the extracellular domain of a human transmembrane protein and b) said antibody covalently coupled to a NIR fluorescence label, in a predetermined ratio of at least 1:9 of non-labeled to labeled antibody. [0020] Preferably the monoclonal antibody is a therapeutic monoclonal antibody. [0021] Typical ratios of non-labeled antibody to labeled antibody are at least 1:9. In one preferred embodiment the ratio is at least 2:1, in another preferred embodiment the ratio is at least 9:1, in still another preferred embodiment the ratio is at least 19:1. [0022] The maximum ratio is typically limited by the detection limit of the label. Thus an ideal ratio would be one with the lowest part of labeled antibody which still gives a sufficient NIR fluorescence signal or image during detection. In this way the non-labeled therapeutic monoclonal antibody would be affected least in his mode of action an therapeutic effect, while at the same time, important information about the kinetics of the labeled antibody in the region of e.g. a solid tumor can be gathered, which can be used as a base for an optimized dose interval or scheme. The ratio of non-labeled antibody to labeled antibody can be evaluated by a person skilled in the art in routine experiments. In this connection, the composition typically comprises the labeled antibody in an amount of at least 0.001 mg/kg body weight, preferably 0.01 mg/kg body weight, more preferably 0.1 mg/kg body weight. The exact amount can vary and depends e.g. on the label and its quantum yield. The amount can be defined by the skilled artisan by simple routine experiments. Thus the upper limit of the ratio also varies depending on the typical therapeutic dose and the detection limit of the label. Based on the typical dosages of monoclonal antibodies for therapeutic treatment (e.g the trastuzumab dose lays around 2 two 8 mg/kg body weight), one preferred maximum ratio is e.g. 500:1, another is 100:1, another is 50:1, still another is 20:1. [0023] Preferably the human protein is an overexpressed human protein, more preferably an overexpressed tumor-associated protein. [0024] Thus the invention comprises a pharmaceutical composition comprising a) a therapeutic monoclonal antibody binding to the extracellular domain of an overexpressed tumor-associated protein, wherein the overexpression is associated with the tumor disease, and b) said therapeutic monoclonal antibody covalently coupled to a NIR fluorescence label, in a predetermined ratio of at least 9:1 and at maximum 100:1 of non-labeled to labeled antibody. [0027] This composition can be used to treat a patient with a disease which is associated to the overexpression of such human protein (e.g. cancer with an associated protein overexpression such as HER-positive breast cancer) and serves at the same to determine an optimized dose interval (for the individual patient in dependency of his drug metabolism). [0028] The length of the dose interval is mainly determined based on two aspects. On the one hand, it has to be short enough such that the amount of the monoclonal antibody at the site of the disease is sufficient to exert an therapeutic effect, on the other hand is has to be long enough to minimize an overdosing and drug-associated side effects. [0029] Usually the dose interval is determined by separate measurements of 1) e.g. the serum level of the monoclonal antibody and 2) the efficacy of the treatment, which are correlated afterwards. However, using this approach, the different metabolism of different patients is neglected or is lost by the forming the average of a greater group of patients. Thus the new composition comprising non-labeled and labeled therapeutic monoclonal antibodies. [0030] Another embodiment of the invention is the use of said non-labeled a therapeutic monoclonal antibody binding to the extracellular domain of an overexpressed tumor-associated protein, wherein the overexpression is associated with the tumor disease [0000] for the manufacture of said pharmaceutical composition comprising a) a therapeutic monoclonal antibody binding to the extracellular domain of an overexpressed tumor-associated protein, wherein the overexpression is associated with the tumor disease, and b) said therapeutic monoclonal antibody covalently coupled to a NIR fluorescence label, in a predetermined ratio of at least 9:1 and at maximum 100:1 of non-labeled to labeled antibody, for a first tumor treatment characterized in that a second tumor treatment with a second pharmaceutical composition comprising the non-labeled monoclonal antibody and not the labeled monoclonal antibody is administered when the signal intensity of the antibody covalently coupled to a NIR fluorescence label at the tumor site is 80% of the maximum signal intensity at the tumor site measured after the first treatment. [0033] In another embodiment the second treatment is given when the signal intensity is 70%, in still another embodiment the signal intensity is 60%. [0034] Another embodiment of the invention is said composition [0000] comprising a) a therapeutic monoclonal antibody binding to the extracellular domain of an overexpressed tumor-associated protein, wherein the overexpression is associated with the tumor disease, and b) said therapeutic monoclonal antibody covalently coupled to a NIR fluorescence label, in a predetermined ratio of at least 9:1 and at maximum 100:1 of non-labeled to labeled antibody, for a first tumor treatment characterized in that a second tumor treatment with second pharmaceutical composition comprising the non-labeled monoclonal antibody and not the labeled monoclonal antibody is administered when the signal intensity of the antibody covalently coupled to a NIR fluorescence label in the region of the solid tumor is 80% of the maximum signal intensity in the region of the solid tumor measured after the first treatment. [0037] In another embodiment the second treatment is given when the signal intensity is 70%, in still another embodiment the signal intensity is 60%. [0038] Another embodiment of the invention is pharmaceutical composition comprising a) a therapeutic monoclonal antibody binding to the extracellular domain of an overexpressed tumor-associated protein, wherein the overexpression is associated with the tumor disease; and b) said therapeutic monoclonal antibody covalently coupled to a NIR fluorescence label, in a predetermined ratio of at least 9:1 and at maximum 100:1 of non-labeled to labeled antibody, for a first tumor treatment and a pharmaceutical composition comprising the non-labeled monoclonal antibody and not the labeled monoclonal antibody for a second tumor treatment. [0041] Another embodiment of the invention is the a container comprising a) a pharmaceutical composition comprising b) a therapeutic monoclonal antibody binding to the extracellular domain of an overexpressed tumor-associated protein, wherein the overexpression is associated with the tumor disease; and c) said therapeutic monoclonal antibody covalently coupled to a NIR fluorescence label, in a predetermined ratio of at least 9:1 and at maximum 100:1 of non-labeled to labeled antibody, for a first tumor treatment, and a) a pharmaceutical composition comprising the non-labeled therapeutic monoclonal antibody binding to the extracellular domain of an overexpressed tumor-associated protein, and not said labeled therapeutic monoclonal antibody, for a second tumor treatment. [0046] One embodiment of the invention is the use of said monoclonal antibody for the manufacture of said pharmaceutical composition for the treatment of cancer, preferably of solid tumors. [0047] Another embodiment of the invention is the use of a non-labeled therapeutic monoclonal antibody binding to the extracellular domain of an overexpressed tumor-associated protein for the manufacture of a pharmaceutical composition for the treatment of cancer, preferably of a solid tumor, characterized in that the non-labeled monoclonal antibody is co-administered with said antibody covalently coupled to a NIR fluorescence label in a predetermined ratio of at least 9:1 and at maximum 100:1 of non-labeled to labeled antibody. [0048] Another embodiment of the invention is the use of a non-labeled therapeutic monoclonal antibody binding to the extracellular domain of an overexpressed tumor-associated protein for the manufacture of a medicament for the treatment of a patient suffering from a solid tumor overexpressing said tumor-associated protein wherein the non-labeled antibody is co-administered with said antibody covalently coupled to a NIR fluorescence label. [0049] In one embodiment of the invention, a NIR fluorescence image of a said patient suffering from a solid tumor overexpressing said tumor-associated protein is acquired. [0050] In another embodiment of the invention, the NIR fluorescence signal of said antibody covalently coupled to a NIR fluorescence label in a region of the solid tumor is measured. [0051] Another embodiment of the invention is a non-labeled therapeutic monoclonal antibody binding to the extracellular domain of an overexpressed tumor-associated protein for the treatment of a patient suffering from a solid tumor overexpressing said tumor-associated protein [0000] wherein the non-labeled antibody is co-administered with said antibody covalently coupled to a NIR fluorescence label. [0052] Another embodiment of the invention is a method for acquiring a NIR fluorescence image of a patient suffering from a solid tumor overexpressing a tumor-associated protein which has received a dose of the pharmaceutical composition comprising a) a therapeutic monoclonal antibody binding to the extracellular domain of an overexpressed tumor-associated protein, wherein the overexpression is associated with the tumor disease; and b) said therapeutic monoclonal antibody covalently coupled to a NIR fluorescence label, in a predetermined ratio of at least 9:1 and at maximum 100:1 of non-labeled to labeled antibody, wherein the NIR fluorescence signal of the labeled therapeutic monoclonal antibody binding to the extracellular domain of an overexpressed tumor-associated protein in a region of the solid tumor is measured. [0055] Another embodiment of the invention is a method for determining the NIR fluorescence signal of a therapeutic monoclonal antibody covalently coupled to a NIR fluorescence label in a region of the solid tumor of a patient which has received a treatment with a pharmaceutical composition comprising a) a therapeutic monoclonal antibody binding to the extracellular domain of an overexpressed tumor-associated protein, wherein the overexpression is associated with the tumor disease; and b) said therapeutic monoclonal antibody covalently coupled to a NIR fluorescence label, in a predetermined ratio of at least 9:1 and at maximum 100:1 of non-labeled to labeled antibody. [0058] Another embodiment of the invention is the use of a monoclonal antibody binding to the extracellular domain of a human transmembrane protein for the manufacture of the pharmaceutical composition for the treatment of cancer characterized in that the monoclonal antibody is co-administered with an antibody covalently coupled to a NIR fluorescence label in a predetermined ratio of at least 1:9 of non-labeled to labeled antibody. [0059] Another embodiment of the invention is a method for determining the change of amount of the monoclonal antibody covalently coupled to a NIR fluorescence label during the treatment with a pharmaceutical composition comprising a) a monoclonal antibody binding to the extracellular domain of a human transmembrane protein and b) said antibody covalently coupled to a NIR fluorescence label, in a predetermined ratio of at least 1:9 of non-labeled to labeled antibody. [0062] Another embodiment of the invention is a method for determining the change of amount of a monoclonal antibody covalently coupled to a NIR fluorescence label during co-administration with said non-labeled monoclonal antibody. DETAILED DESCRIPTION OF THE INVENTION 1. Definitions [0063] The term “antibody” encompasses the various forms of antibodies including but not being limited to whole antibodies, human antibodies, humanized antibodies and genetically engineered antibodies like monoclonal antibodies, chimeric antibodies or recombinant antibodies as well as fragments of such antibodies as long as the characteristic properties according to the invention are retained. [0064] The terms “monoclonal antibody” or “monoclonal antibody composition” as used herein refer to a preparation of antibody molecules of a single amino acid composition. Accordingly, the term “human monoclonal antibody” refers to antibodies displaying a single binding specificity which have variable and constant regions derived from human germline immunoglobulin sequences. In one embodiment, the human monoclonal antibodies are produced by a hybridoma which includes a B cell obtained from a transgenic non-human animal, e.g. a transgenic mouse, having a genome comprising a human heavy chain transgene and a light human chain transgene fused to an immortalized cell. [0065] The term “therapeutic monoclonal antibody” as used herein refers to a monoclonal antibody as defined above which specifically binds to the extracellular domain of a human transmembrane protein and which has an therapeutic effect on a disease which is associated with the expression of said human transmembrane protein, when administered to a patient. Preferably the therapeutic monoclonal antibody has an therapeutic effect of a tumor or cancer disease, which is associated with the expression, preferably the overexpression of said tumor or cancer disease. Typically such an anti-tumor therapeutic monoclonal antibody can be selected from e.g. the non-limiting group consisting of alemtuzumab, apolizumab, cetuximab, epratuzumab, galiximab, gemtuzumab, ipilimumab, labetuzumab, panitumumab, rituximab, trastuzumab, nimotuzumab, mapatumumab, matuzumab and pertuzumab, preferably trastuzumab, cetuximab, and pertuzumab. [0066] The term “chimeric antibody” refers to a monoclonal antibody comprising a variable region, i.e., binding region, from one source or species and at least a portion of a constant region derived from a different source or species, usually prepared by recombinant DNA techniques. Chimeric antibodies comprising a murine variable region and a human constant region are especially preferred. Such murine/human chimeric antibodies are the product of expressed immunoglobulin genes comprising DNA segments encoding murine immunoglobulin variable regions and DNA segments encoding human immunoglobulin constant regions. Other forms of “chimeric antibodies” encompassed by the present invention are those in which the class or subclass has been modified or changed from that of the original antibody. Such “chimeric” antibodies are also referred to as “class-switched antibodies.” Methods for producing chimeric antibodies involve conventional recombinant DNA and gene transfection techniques now well known in the art. See, e.g., Morrison, S. L., et al., Proc. Natl. Acad Sci. USA 81 (1984) 6851-6855; U.S. Pat. No. 5,202,238 and U.S. Pat. No. 5,204,244. [0067] The term “humanized antibody” refers to antibodies in which the framework or “complementarity determining regions” (CDR) have been modified to comprise the CDR of an immunoglobulin of different specificity as compared to that of the parent immunoglobulin. In a preferred embodiment, a murine CDR is grafted into the framework region of a human antibody to prepare the “humanized antibody.” See, e.g., Riechmann, L., et al., Nature 332 (1988) 323-327; and Neuberger, M. S., et al., Nature 314 (1985) 268-270. Particularly preferred CDRs correspond to those representing sequences recognizing the antigens noted above for chimeric and bifunctional antibodies. [0068] The term “human antibody”, as used herein, is intended to include antibodies having variable and constant regions derived from human germline immunoglobulin sequences. Human antibodies are well-known in the state of the art (van Dijk, M. A., and van de Winkel, J. G., Curr. Opin. in Chemical Biology 5 (2001) 368-374). Based on such technology, human antibodies against a great variety of targets can be produced. Examples of human antibodies are for example described in Kellermann, S. A., et al., Curr Opin Biotechnol. 13 (2002)593-597. [0069] The term “recombinant human antibody”, as used herein, is intended to include all human antibodies that are prepared, expressed, created or isolated by recombinant means, such as antibodies isolated from a host cell such as a NS0 or CHO cell or from an animal (e.g. a mouse) that is transgenic for human immunoglobulin genes or antibodies expressed using a recombinant expression vector transfected into a host cell. Such recombinant human antibodies have variable and constant regions derived from human germline immunoglobulin sequences in a rearranged form. The recombinant human antibodies according to the invention have been subjected to in vivo somatic hypermutation. Thus, the amino acid sequences of the VH and VL regions of the recombinant antibodies are sequences that, while derived from and related to human germline VH and VL sequences, may not naturally exist within the human antibody germline repertoire in vivo. [0070] As used herein, “binding” or “specifically binding” refers to an antibody binding to the extracellular domain of human transmembrane protein for which the antibody is specific. Preferably the binding affinity is of about 10 −11 to 10 −8 M (KD), preferably of about 10 −11 to 10 −9 M. [0071] The term “nucleic acid molecule”, as used herein, is intended to include DNA molecules and RNA molecules. A nucleic acid molecule may be single-stranded or double-stranded, but preferably is double-stranded DNA. [0072] The “constant domains” are not involved directly in binding the antibody to an antigen but are involved in the effector functions (ADCC, complement binding, and CDC). [0073] The “variable region” (variable region of a light chain (VL), variable region of a heavy chain (VH)) as used herein denotes each of the pair of light and heavy chains which is involved directly in binding the antibody to the antigen. The domains of variable human light and heavy chains have the same general structure and each domain comprises four framework (FR) regions whose sequences are widely conserved, connected by three “hypervariable regions” (or complementarity determining regions, CDRs). The framework regions adopt a (β-sheet conformation and the CDRs may form loops connecting the β-sheet structure. The CDRs in each chain are held in their three-dimensional structure by the framework regions and form together with the CDRs from the other chain the antigen binding site. The antibody heavy and light chain CDR3 regions play a particularly important role in the binding specificity/affinity of the antibodies according to the invention and therefore provide a further object of the invention. [0074] The terms “hypervariable region” or “antigen-binding portion of an antibody” when used herein refer to the amino acid residues of an antibody which are responsible for antigen-binding. The hypervariable region comprises amino acid residues from the “complementarity determining regions” or “CDRs”. “Framework” or “FR” regions are those variable domain regions other than the hypervariable region residues as herein defined. Therefore, the light and heavy chains of an antibody comprise from N- to C-terminus the domains FR1, CDR1, FR2, CDR2, FR3, CDR3, and FR4. Especially, CDR3 of the heavy chain is the region which contributes most to antigen binding. CDR and FR regions are determined according to the standard definition of Kabat, E. A., et al., Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, Md. (1991) and/or those residues from a “hypervariable loop”. [0075] The term “human transmembrane protein” when used herein refers to a cell membrane proteins which is anchored in the lipid bilayer of cells. The human transmembrane protein will generally comprise an “extracellular domain” as used herein, which may bind an ligand; a lipophilic transmembrane domain, a conserved intracellular domain tyrosine kinase domain, and a carboxyl-terminal signaling domain harboring several tyrosine residues which can be phosphorylated. [0076] The human transmembrane proteins include molecules such as EGFR, HER2/neu, HER3, HER4, Ep-CAM, CEA, TRAIL, TRAIL-receptor 1, TRAIL-receptor 2, lymphotoxin-beta receptor, CCR4, CD19, CD20, CD22, CD28, CD33, CD40, CD80, CSF-1R, CTLA-4, fibroblast activation protein (FAP), hepsin, melanoma-associated chondroitin sulfate proteoglycan (MCSP), prostate-specific membrane antigen (PSMA), VEGF receptor 1, VEGF receptor 2, IGF1-R, TSLP-R, TIE-1, TIE-2, TNF-alpha, TNF like weak inducer of apoptosis (TWEAK), IL-1R, preferably EGFR, HER2/neu, CEA, CD20, or IGF1-R. [0077] The terms “cancer” and “tumor” as used herein refer to or describe the physiological condition in mammals that is typically characterized by unregulated cell growth. Examples of cancer or tumors include, but are not limited to, carcinoma, lymphoma, blastoma (including medulloblastoma and retinoblastoma), sarcoma (including liposarcoma and synovial cell sarcoma), neuroendocrine tumors (including carcinoid tumors, gastrinoma, and islet cell cancer), mesothelioma, schwannoma (including acoustic neuroma), meningioma, adenocarcinoma, melanoma, and leukemia or lymphoid malignancies. More particular examples of such cancers include squamous cell cancer (e.g. epithelial squamous cell cancer), lung cancer including small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung and squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer including gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, rectal cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma, anal carcinoma, penile carcinoma, testicular cancer, esophagael cancer, tumors of the biliary tract, as well as head and neck cancer. Preferably the cancer is a solid tumor. [0078] The term “solid tumors” when used herein refers to tumors selected from the group of gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, rectal cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma, anal carcinoma, penile carcinoma, testicular cancer, esophagael cancer, tumors of the biliary tract, as well as head and neck cancer. [0079] The term “overexpressed” human transmembrane protein or “overexpression” of the human transmembrane protein is intended to indicate an abnormal level of expression of the human transmembrane protein in a cell from a disease area like a tumor or a arthritic joint within a specific tissue or organ of the patient relative to the level of expression in a normal cell from that tissue or organ. Patients having a diseases like e.g. characterized by overexpression of the human transmembrane protein can be determined by standard assays known in the art. [0080] The terms “co-administration” or “co-administered” mean that the labeled antibody is administered simultaneously with the non-labeled antibody. [0081] It is self-evident that the antibodies are administered to the patient in therapeutically effective amount which is the amount of the subject compound or combination that will elicit the biological or medical response of a tissue, system, animal or human that is being sought by the researcher, veterinarian, medical doctor or other clinician. [0082] As used herein, the term “patient” preferably refers to a human in need of treatment to treat cancer, or a precancerous condition or lesion. However, the term “patient” can also refer to non-human animals, preferably mammals such as dogs, cats, horses, cows, pigs, sheep and non-human primates, among others, that are in need of treatment. [0083] The terms “antibody covalently coupled to a label” or “labeled antibody” as used herein refer to antibodies which are conjugated to an label. Conjugation techniques have significantly matured during the past years and an excellent overview is given in Aslam, M., and Dent, A., Bioconjugation, London (1998) 216-363, and in the chapter “Macromolecule conjugation” in Tijssen, P., “Practice and theory of enzyme immunoassays” (1990) Elsevier, Amsterdam. [0084] The term “non-labeled antibody” as used herein refers to an antibody which is not labeled. [0085] The term “NIR” as used herein means near-infrared. [0086] The term “region of a solid tumor” when used herein refers to a zone comprising the solid tumor. The region of a solid tumor can comprise either the whole solid tumor or only regional parts of it. The NIR fluorescence signal in the region of said solid tumor is measured, and the corresponding the NIR fluorescence images are acquired in either two-dimensional or three-dimensional form, e.g. in comparison with the surrounding non-tumorous tissue or in comparison with NIR fluorescence signals or images at different time points as a reference. [0087] The term “in a predetermined ratio” refers to the ratio of the non-labeled antibody labeled antibody, which is determined before preparation of such composition. The ratio is chosen in connection with the intended use of such composition for e.g. the imaging of solid tumors or malignant blood cells, the imaging apparatus (e.g external or endoscopic, etc.), and depends inter alia form the quantum yield of the on the label and the antibody used. [0088] Typical ratios of non-labeled antibody to labeled antibody are at least 1:9, preferably at least 2:1, and more preferably at least 9:1. The maximum ratio is typically limited by the detection limit of the label. In this connection, the composition typically comprises the labeled antibody in an amount of at least 0.001 mg/kg body weight, preferably 0.01 mg/kg body weight, more preferably 0.1 mg/kg body weight. The exact amount can vary and depends e.g. on the label and its quantum yield. The amount can be defined by the skilled artisan by simple routine experiments. 2. Detailed Description [0089] The invention comprises a pharmaceutical composition comprising a) a monoclonal antibody binding to the extracellular domain of a human transmembrane protein and b) said antibody covalently coupled to a NIR fluorescence label, in a predetermined ratio of at least 1:9 of non-labeled to labeled antibody. [0092] Preferably the human protein is an overexpressed human protein; and furthermore the overexpression is associated with a disease. [0093] In a preferred embodiment, said antibody is directed against an oncological target. such as a transmembrane protein in solid tumors or circulating malignant cells. In a preferred embodiment, said antibody is directed to EGFR, HER2/neu, HER3, HER4, Ep-CAM, CEA, TRAIL, TRAIL-receptor 1, TRAIL-receptor 2, lymphotoxin-beta receptor, CCR4, CD19, CD20, CD22, CD28, CD33, CD40, CD80, CSF-1R, CTLA-4, fibroblast activation protein (FAP), hepsin, melanoma-associated chondroitin sulfate proteoglycan (MCSP), prostate-specific membrane antigen (PSMA), VEGF receptor 1, VEGF receptor 2, IGF1-R, TSLP-R, TIE-1, TIE-2, TNF-alpha, TNF like weak inducer of apoptosis (TWEAK), IL-1R, preferably EGFR, HER2/neu, CEA, CD20, or IGF1-R. [0094] Preferably said antibody is an anti-HER2 antibody, preferably trastuzumab or pertuzumab. [0095] Preferably said antibody is an anti-EGFR antibody, preferably cetuximab nimotuzumab, or matuzumab. Preferably said antibody is an anti-IGF1R antibody. [0096] In one embodiment of the invention the pharmaceutical composition is characterized in that the antibody is selected from the group of: [0000] alemtuzumab, apolizumab, cetuximab, epratuzumab, galiximabgemtuzumab, ipilimumab, labetuzumab, panitumumab, rituximab, trastuzumab, nimotuzumab, mapatumumab, matuzumab and pertuzumab, preferably trastuzumab, cetuximab, and pertuzumab. [0097] The composition typically comprises the antibody covalently coupled to the label an amount of at least 0.001 mg/kg body weight, preferably 0.01 mg/kg body weight, more preferably 0.1 mg/kg body weight. The exact amount can vary and depends e.g. on the label and his quantum yield. The amount can be defined by the skilled artisan by simple routine experiments. [0098] Said antibody is labeled with a near infrared (NIR) fluorescence label suitable for the measurement of the tumor concentration using NIR florescence imaging. [0099] “Measurement” or “determining” of the NIR fluorescence signal in a region the solid tumor is performed after administration of the labeled antibody to the patient. Or, if the composition according to the invention is used, after the administration of the composition of the non-labeled antibody and the labeled antibody to the patient. The measurement can be performed on defined time points after administration, e.g., 1 day, 2 days or 3 or even more days or any other time point appropriate for acquiring a comparable NIR fluorescence signal or image in a region the solid tumor. The duration of the measurement or the time point after administration can be adjusted by a person skilled in the art in a way to get an appropriate NIR fluorescence signal or image. [0100] For the NIR fluorescence measurement different devices and techniques can be used, e.g. for external solid tumors like breast tumors, a SoftScan® apparatus from ART Advanced Research Technologies Inc. (http://www.art.ca/en/products/softscan.html) is suitable (Intes X, Acad. Radiol. 12 (2005) 934-947) For internal disease areas, like colorectal or lung cancer endoscopic techniques or a combination of microsurgery-endoscopy can be used. [0101] NIR fluorescence labels with excitation and emission wavelengths in the near infrared spectrum are used, i.e., 640-1300 nm preferably 640-1200 nm, and more preferably 640-900 nm. Use of this portion of the electromagnetic spectrum maximizes tissue penetration and minimizes absorption by physiologically abundant absorbers such as hemoglobin (<650 nm) and water (>1200 nm). Ideal near infrared fluorochromes for in vivo use exhibit: [0000] (1) narrow spectral characteristics, (2) high sensitivity (quantum yield), (3) biocompatibility, and (4) decoupled absorption and excitation spectra. [0102] Various near infrared (NIR) fluorescence labels are commercially available and can be used to prepare probes according to this invention. Exemplary NIRF labels include the following: Cy5.5, Cy5 and Cy7 (Amersham, Arlington Hts., IL; IRD41 and IRD700 (LI-COR, Lincoln, Nebr.); NIR-1, (Dejindo, Kumamoto, Japan); LaJolla Blue (Diatron, Miami, Fla.); indocyanine green (ICG) and its analogs (Licha, K., et al., SPIE—The International Society for Optical Engineering 2927 (1996) 192-198; Ito, S., et al., U.S. Pat. No. 5,968,479); indotricarbocyanine (ITC; WO 98/47538); and chelated lanthanide compounds. Fluorescent lanthanide metals include europium and terbium. Fluorescence properties of lanthanides are described in Lackowicz, J. R., Principles of Fluorescence Spectroscopy, 2nd Ed., Kluwa Academic, New York, (1999). [0103] Accordingly, said antibody is preferably labeled by a NIR fluorescence label selected from the group of Cy5.5, Cy5, Cy7, IRD41, IRD700, NIR-1, LaJolla Blue, indocyanine green (ICG), indotricarbocyanine (ITC) and SF64, 5-29, 5-36 and 5-41 (from WO 2006/072580), more preferably said antibody is labeled with a NIRF label selected from the group of Cy5.5, Cy5 and Cy7. [0104] The methods used for coupling of the NIR fluorescence labels are well known in the art. The conjugation techniques of NIR fluorescence labels to an antibody have significantly matured during the past years and an excellent overview is given in Aslam, M., and Dent, A., Bioconjugation (1998) 216-363, London, and in the chapter “Macromolecule conjugation” in Tijssen, P., “Practice and theory of enzyme immunoassays” (1990), Elsevier, Amsterdam. [0105] Appropriate coupling chemistries are known from the above cited literature (Aslam, supra). The NIR fluorescence label, depending on which coupling moiety is present, can be reacted directly with the antibody either in an aqueous or an organic medium. The coupling moiety is a reactive group or activated group which is used for chemically coupling of the fluorochrome label to the antibody. The fluorochrome label can be either directly attached to the antibody or connected to the antibody via a spacer to form a NIR fluorescence label conjugate comprising the antibody and a NIR fluorescence label. The spacer used may be chosen or designed so as to have a suitably long in vivo persistence (half-life) inherently. [0106] “Measurement” or “determining” of the NIR fluorescence signal in a region the solid tumor is performed after administration of the labeled antibody to the patient. Or, if the composition according to the invention is used, after the administration of the composition of the non-labeled antibody and the labeled antibody to the patient. The measurement can be performed on defined time points after administration, e.g., 1 day, 2 days or 3 or even more days or any other time point appropriate for acquiring a comparable NIR fluorescence signal or image in a region the solid tumor. The duration of the measurement or the time point after administration can be adjusted by a person skilled in the art in a way to get an appropriate NIR fluorescence signal or image. E.g. in the first week after administration the measurement can be performed daily or every two to three days, depending on the increase of the tumor concentration. In the second and the following weeks, the measurement can be preformed every two to five days, depending on the increase and the decrease of the tumor concentration of the antibody. As the increase and the decrease of the tumor concentration depends on the type of antibody, even other measurement periods maybe appropriate, e.g. one week or longer. The measurement will be adjusted in a way to detect the change of amount of labeled antibody. [0107] For the NIR fluorescence measurement different devices and techniques can be used, e.g. for external solid tumors like breast tumors, a SoftScan® apparatus from ART Advanced Research Technologies Inc. (http://www.art.ca/en/products/softscan.html) is suitable (Intes, X., Acad. Radiol. 12 (2005) 934-947) For internal disease areas, like colorectal or lung cancer endoscopic techniques or a combination of microsurgery-endoscopy can be used. [0108] To detect for example the amount of labeled antibody in malignant blood cells (in leukemias) a shant in combination with blood cell counting apparatus can be used to detect the amount signal per blood cell. [0109] An imaging system for NIR fluorescence measurement useful in the practice of this invention typically includes three basic components: (1) a near infrared light source, (2) a means for separating or distinguishing fluorescence emissions from light used for fluorochrome excitation, and (3) a detection system. [0110] The light source provides monochromatic (or substantially monochromatic) near infrared light. The light source can be a suitably filtered white light, i.e., bandpass light from a broadband source. For example, light from a 150-watt halogen lamp can be passed through a suitable bandpass filter commercially available from Omega Optical (Brattleboro, Vt.). In some embodiments, the light source is a laser. See, e.g., Boas, D. A., et al., 1994, Proc. Natl. Acad. Sci. USA 91 4887-4891; Ntziachristos, V., et al., 2000, Proc. Natl. Acad. Sci. USA 97 2767-2772; Alexander, W., 1991, J. Clin. Laser Med. Surg. 9 416-418. [0111] A high pass filter (700 nm) can be used to separate fluorescence emissions from excitation light. A suitable high pass filter is commercially available from Omega optical. [0112] In general, the light detection system can be viewed as including a light gathering/image forming component and a light detection/image recording component. Although the light detection system may be a single integrated device that incorporates both components, the light gathering/image forming component and light detection/image recording component will be discussed separately. [0113] A particularly useful light gathering/image forming component is an endoscope. Endoscopic devices and techniques that have been used for in vivo optical imaging of numerous tissues and organs, including peritoneum (Gahlen, J., et al., J. Photochem. Photobiol. B 52 (1999) 131-135), ovarian cancer (Major, A. L., et al., Gynecol. Oncol. 66 (1997) 122 132), colon (Mycek, M. A., et al., Gastrointest. Endoscopy. 48 (1998)390-394; Stepp, H., et al., Endoscopy 30 (1998) 379-386) bile ducts (Izuishi, K., et al., Hepatogastroenterology 46 (1999) 804 807), stomach (Abe, S., et al., Endoscopy 32 (2000) 281-286), bladder (Kriegmair, M., et al., Urol. Int. 63 (1999) 27-31; Riedl, C. R., et al., J. Endourol. 13 755-759), and brain (Ward, J., Laser Appl. 10 (1998) 224-228) can be employed in the practice of the present invention. [0114] Other types of light gathering components useful in the invention are catheter-based devices, including fiber optics devices. Such devices are particularly suitable for intravascular imaging. See, e.g., Tearney, G. J., et al., Science 276 (1997) 2037-2039; Boppart, S. A., et al., Proc. Natl. Acad. Sci. USA 94, 4256-4261. [0115] Still other imaging technologies, including phased array technology (Boas, D. A., et al., Proc. Natl. Acad. Sci. 19 USA 91 (1994) 4887-4891; Chance, B., Journal Ann. NY Acad. Sci. 838 (1998) 29-45), diffuse optical tomography (Cheng, X., et al., Optics Express 3 (1998) 118-123; Siegel, A., et al., Optics Express 4 (1999) 287-298), intravital microscopy (Dellian, M., et al., Journal Br. J Cancer 82 (2000) 1513-1518; Monsky, W. L., et al., Cancer Res. 59 (1999) 4129-4135; Fukumura, et al., Cell 94 (1998) 715-725), and confocal imaging (Korlach, J., et al., Proc. Natl. Acad. Sci. USA 96 (1999) 8461-8466; Rajadhyaksha, M., et al., J. Invest. Dermatol. 104 (1995)946-952; Gonzalez, S., et al., Journal Med. 30 (1999) 337-356) can be employed in the practice of the present invention. [0116] Any suitable light detection/image recording component, e.g., charge coupled device (CCD) systems or photographic film, can be used in the invention. The choice of light detection/image recording will depend on factors including type of light gathering/image forming component being used. Selecting suitable components, assembling them into a near infrared imaging system, and operating the system is within ordinary skill in the art. [0117] One embodiment of the invention is the use of said monoclonal antibody for the manufacture of said pharmaceutical composition for the treatment of cancer such as solid tumors or circulating malignant cells (e.g. in leukemias) characterized in that the pharmaceutical composition comprises said antibody covalently coupled to a NIR fluorescence label in a predetermined ratio of at least 1:9 of non-labeled to labeled antibody. [0118] Another embodiment of the invention is the use of said monoclonal antibody for the manufacture of a pharmaceutical composition for the treatment of solid tumors characterized in that the pharmaceutical composition comprises said antibody covalently coupled to a NIR fluorescence label in a predetermined ratio of at least 1:9 of non-labeled to labeled antibody. [0119] Another embodiment of the invention is the use of a monoclonal antibody binding to the extracellular domain of a human transmembrane protein for the manufacture of the pharmaceutical composition for the treatment of cancer characterized in that the monoclonal antibody is co-administered with an antibody covalently coupled to a NIR fluorescence label in a predetermined ratio of at least 1:9 of non-labeled to labeled antibody. [0120] Another embodiment of the invention is the use of the pharmaceutical composition comprising a) a monoclonal antibody binding to the extracellular domain of a human transmembrane protein and b) said antibody covalently coupled to a NIR fluorescence label, in a predetermined ratio of at least 1:9 of non-labeled to labeled antibody, for a first treatment and the use of the non-labeled antibody only for a second treatment. [0123] Another embodiment of the invention is the use of said pharmaceutical composition for the treatment of cancer, preferably solid tumors. [0124] Another embodiment of the invention is the use of a monoclonal antibody binding to the extracellular domain of a human transmembrane protein for the treatment of cancer, preferably solid tumors characterized in that the monoclonal antibody is co-administered with said antibody covalently coupled to a NIR fluorescence label in a predetermined ratio of at least 1:9 of non-labeled to labeled antibody. [0125] Another embodiment of the invention is the use of the pharmaceutical composition comprising a) a monoclonal antibody binding to the extracellular domain of a human transmembrane protein and b) said antibody covalently coupled to a NIR fluorescence label, in a predetermined ratio of at least 1:9 of non-labeled to labeled antibody, for a first treatment and the non-labeled monoclonal antibody only for a second treatment. [0128] Another embodiment of the invention is a method for determining the change of amount of the monoclonal antibody covalently coupled to a NIR fluorescence label during the treatment with a pharmaceutical composition comprising a) a monoclonal antibody binding to the extracellular domain of a human transmembrane protein and b) said antibody covalently coupled to a NIR fluorescence label, in a predetermined ratio of at least 1:9 of non-labeled to labeled antibody. [0131] Such method comprises e.g. the steps of a) measuring the NIR fluorescence intensity in a region of interest (ROI), e.g. a solid tumor, such as a solid tumor or per blood cell, at different time points starting after the treatment with the composition of non-labeled and b) determining the change of these NIR fluorescence intensities over the time, and c) correlating the intensities to the amount of labeled antibody in the ROI,), e.g. a solid tumor. [0135] Another embodiment of the invention is a method for determining the change of amount of the monoclonal antibody covalently coupled to a NIR fluorescence label in the region of interest during the treatment with said pharmaceutical composition. [0136] Another embodiment of the invention is a method for determining the change of amount of the monoclonal antibody covalently coupled to a NIR fluorescence label in the solid tumor during the treatment with said pharmaceutical composition. [0137] Another embodiment of the invention is a method for determining the change of amount of a monoclonal antibody covalently coupled to a NIR fluorescence label during co-administration with said non-labeled monoclonal antibody. [0138] Another embodiment of the invention is a container comprising said pharmaceutical composition comprising a) a monoclonal antibody binding to the extracellular domain of a human transmembrane protein and b) said antibody covalently coupled to a NIR fluorescence label, in a predetermined ratio of at least 1:9 of non-labeled to labeled antibody, for a first treatment of cancer, preferably of solid tumors, and a composition comprising the non-labeled monoclonal antibody alone for a second treatment. DESCRIPTION OF THE FIGURES [0141] FIG. 1 Optical Imaging for the Analysis of Target Expression In Vivo: [0142] In the H322M s.c. model a mab against IGF1R labeled with Cy5.5 was injected i.v. at a single dose of 100 microgram per mouse and NIRF signal was measured 2 ( FIG. 1 a ) and 5 days ( FIG. 1 b ) therafter. Acquisition time was 3 seconds. These pictures indicate that i) the tumor cells express the relevant surface molecule, ii) the mab localizes to tumor tissue and iii) the mab accumulates over time in the target tissue. [0143] FIG. 2 Optical Imaging for Pharmacokinetic Studies of Antibodies In Vivo: [0144] Mice with s.c. H322M tumors ( FIG. 2 a ) and without such tumors ( FIG. 2 b ) have been injected with 50 microgram per mouse (single dose) of an antibody against IGF1R. NIRF has been measured 4 days after application of antibody with an acquisition time of 4 seconds. FIG. 2 a indicates that in tumor carrying mice the Cy5.5-labeled mab targets tumor tissue, whereas in tumor free mice the mab “lightens up” the whole mouse indicating that the mab is confined to plasma compartment ( FIG. 2 b ) Accordingly, mab serum levels in tumor free mice (measured by Elisa) are higher compared to tumor carrying mice ( FIG. 2 c ) [0145] FIG. 3 Correlation of Antibody Tumor Concentrations with Serum Concentrations: [0146] Mice carrying H460M2 tumors s.c. have been injected i.v. with a single dose (50 μg) of an antibody against IGF1R labeled with Cy5.5. At different time points (squares) therafter NIR fluorescence intensity (median NIR fluorescence (NIRF) signal intensity [arbitrary units]) was measured with an acquisition time of 4 seconds. NIR fluorescence intensity was quantified by summing up the number and signal intensities of the pixels in the region of interest (ROI) (squares and full line). In parallel, serum levels (triangles and dotted line) of said antibody against IGF1R labeled with Cy5.5 (ng/ml) was measured by ELISA. The data show, that the ratio of NIR fluorescence intensity versus serum levels increases over time, indicating that the mab accumulates in tumor tissue ( FIG. 3 ) and that antibody concentration or the halftime of the antibody concentration in the tumor tissue is significantly longer than in serum. [0147] FIG. 4 Detection of Relevant Tumor-Associated Antigen Using a Composition of Labeled Antibody and Non-Labeled Antibody: [0148] The results show that the strongest NIR fluorescence signal was generated after a single injection of 50 μg Cy5-labeled anti-HER2-antibody per mouse ( FIG. 4 a ). After a single i.v. injection of a mixture of Cy5-labeled anti-HER2-antibody and non-labeled anti-HER2-antibody at a ratio of 1 to 2 (17 μg and 33 μg) detection of Her expressing tumor is clearly detectable ( FIG. 4 b ). FIG. 4 c demonstrates that an injection of a mixture of Cy5-labeled anti-HER2-antibody and non-labeled anti-HER2-antibody at a ratio of 1 to 9 (5 μg and 45 μg) generates a significant NIR fluorescence signal. This indicates that a combination of labeled and non-labeled therapeutic antibodies in ratio 1 to 9 is feasible for application in the clinical situation. [0149] The following examples and figures are provided to aid the understanding of the present invention, the true scope of which is set forth in the appended claims. It is understood that modifications can be made in the procedures set forth without departing from the spirit of the invention. EXAMPLES Introduction [0150] The current study examined the in-vivo imaging of antibodies covalently coupled to a NIR fluorescence label and mixtures of antibodies covalently coupled to a NIRF-label and said antibodies without label in human xenograft models. Further aims of the study were the determination of the change in the amount of said antibody covalently coupled to a NIR fluorescence label in vivo and the comparison to the change of the corresponding serum levels. Cell Lines and Culture Conditions [0151] The human breast cancer cell line KPL-4 has been established from the malignant pleural effusion of a breast cancer patient with an inflammatory skin metastasis and overexpresses ErbB family receptors. (Kurebayashi, J., et al., Br. J. Cancer 79 (1999) 707-17) Tumor cells are routinely cultured in DMEM medium (PAA Laboratories, Austria) supplemented with 10% fetal bovine serum (PAA) and 2 mM L-glutamine (Gibco) at 37° C. in a water-saturated atmosphere at 5% CO2. Culture passage is performed with trypsin/EDTA 1×(PAA) splitting twice/week. Cell passage P6 was used for in vivo study. Animals [0152] SCID beige (C.B.-17) mice; age 10-12 weeks; body weight 18-20 g (Charles River, Sulzfeld, Germany) are maintained under specific-pathogen-free condition with daily cycles of 12 h light/12 h darkness according to international guidelines (GV-Solas; Felasa; TierschG). After arrival, animals are housed in the quarantine part of the animal facility for one week to get accustomed to new environment and for observation. Continuous health monitoring is carried out on regular basis. Diet food (Alltromin) and water (acidified pH 2.5-3) are provided ad libitum. Tumor Growth Inhibition Studies In Vivo [0153] Tumor cells were harvested (trypsin-EDTA) from culture flasks (Greiner TriFlask) and transferred into 50 ml culture medium, washed once and resuspended in PBS. After an additional washing step with PBS and filtration (cell strainer; Falcon 100 μm) the final cell titer was adjusted to 0.75×10 8 /ml. Tumor cell suspension was carefully mixed with transfer pipette to avoid cell aggregation. Anesthesia was performed using a Stephens inhalation unit for small animals with preincubation chamber (plexiglas), individual mouse nose-mask (silicon) and Isoflurane (Pharmacia-Upjohn, Germany) in a closed circulation system. Two days before injection the fur of the animals was shaved. For intra mammary fat pad (i.m.f.p.) injection, cells were injected orthotopically at a volume of 20 μl into the right penultimate inguinal mammary fat pad of each anesthetized mouse. For the orthotopic implantation, the cell suspension was injected through the skin under the nipple. Tumor cell injection corresponds to day 1 of the experiment. Monitoring [0154] Animals were controlled daily for detection of clinical symptoms of adverse effects. For monitoring throughout the experiment, the body weight of the animals was documented two times weekly. [0000] Determination of Amount of Labeled Antibody in Tumor Tissue and of the Half-Time of that Amount in Tumor Tissue [0155] Non-invasive measurements of near infrared signals can be accomplished by labeling proteins with appropriate dyes. E.g. different monoclonal antibodies were labeled with a Cy5 or Cy5.5 or Cy7 dyes to monitor the tumor tissue saturation of these antibodies after i.v. injection into tumor carrying mice. NIR fluorescence measurements were performed immediately after application of antibodies and at different time points therafter using the BonSAI Imaging System from Siemens Medizintechnik, Germany. Aquisition time was held constant for the complete observation period. By summing up mean intensities of the pixels in the region of interest, the area under the curve (AUC) was constructed. [0000] Determination of Amount of Labeled Antibody in Serum of the Half-Time of that Amount in Serum [0156] Quantification of antibody serum levels by an established ELISA was performed to correlate these results with NIR fluorescence signal intensities. Results Example 1 Optical Imaging for the Analysis of Target Expression In Vivo [0157] In the H322M s.c. (subcutaneous) model a mab against IGF1R labeled with Cy5.5 was injected intravenous (i.v.) at a single dose of 100 microgram per mouse and NIR fluorescence signal was measured 2 ( FIG. 1 a ) and 5 days ( FIG. 1 b ) therafter. Aquisition time was 3 seconds. These pictures indicate that i) the tumor cells express the relevant surface molecule, ii) the mab localizes to tumor tissue and iii) the mab accumulates over time in the target tissue. Example 2 Optical Imaging for PK Studies of Antibodies In Vivo [0158] Mice carrying s.c. H322M tumors have been injected with 50 microgram per mouse (single dose) of an antibody against IGF1R. NIR fluorescence has been measured 4 days after application of antibody with an acquisition time of 4 seconds. FIG. 2 a indicates that in tumor carrying mice the Cy5.5-labeled mab targets tumor tissue, whereas in tumor free mice the mab “lightens up” the whole mouse indicating that the mab is confined to plasma compartment ( FIG. 2 b ) Accordingly, mab serum levels in tumor free mice (measured by Elisa) are higher compared to tumor carrying mice ( FIG. 2 c ). Example 3 Correlation of NIRF Signal Intensities of with Serum Levels [0159] Mice carrying H460M2 tumors s.c. have been injected i.v. with a single dose of an antibody against IGF1R labeled with Cy5.5. At different time points therafter NIR fluorescence was measured with an acquisition time of 4 seconds. NIR fluorescence intensity was quantified by summing up the number and signal intensities of the pixels in the region of interest (ROI). Serum levels of antibody (ng/ml) was measured by ELISA. The data show, that the ratio of NIR fluorescence versus serum levels (enrichment factor) increases over time from 31 to 79, indicating that the mab accumulates in tumor tissue ( FIG. 3 ) and that antibody concentration in the tumor tissue is significantly longer than in serum. Example 4 Detection of Relevant Tumor-Associated Antigen Using a Composition of Labeled Antibody and Non-Labeled Antibody [0160] SCID beige mice carrying KPL-4 tumors s.c. have been injected i.v. with a single dose of a Cy5-labeled anti-HER2-antibody at a dosage of 50 μg/mouse. In addition, different group of mice have been injected with 50 μg/mouse of a mixture of labeled anti-Her2 antibody and non-labeled antibody at different ratio i) ratio of labeled to non-labelled 1 to 2 and ii) ratio of labeled to non-labeled 1 to 9). Two days thereafter fluorescence intensities in the region of interest was measured with an acquisition time of 5 seconds. [0161] The results show that the strongest NIR fluorescence signal was generated after a single injection of 50 μg Cy5-labeled anti-HER2-antibody per mouse ( FIG. 4 a ). After a single i.v. injection of a mixture of Cy5-labeled anti-HER2-antibody and non-labeled anti-HER2-antibody at a ratio of 1 to 2 (17 μg and 33 μg) detection of Her expressing tumor is clearly detectable ( FIG. 4 b ). FIG. 4 c demonstrates that an injection of a mixture of Cy5-labeled anti-HER2-antibody and non-labeled anti-HER2-antibody at a ratio of 1 to 9 (5 μg and 45 μg) generates a significant NIR fluorescence signal. This indicates that a combination of labeled and non-labeled therapeutic antibodies in ratio 1 to 9 is feasible for application in the clinical situation. Example 5 Correlation of NIRF Signal Intensities with Serum Levels [0162] SCID beige mice carrying KPL-4 tumors s.c. are injected i.v. with a single dose of a Cy5-labeled antibody against Her2 at a dosage of 50 μg/mouse. In addition, different group of mice are injected with 50 μg/mouse of a mixture of Cy5-labeled anti-HER2-antibody and non-labeled anti-HER2-antibody at different ratio i) ratio of labeled to non-labeled 1 to 2 and ii) ratio of labeled to non-labeled 1 to 9. At different time points therafter NIR fluorescence signals are measured with an acquisition time of 5 seconds. NIR fluorescence intensity is quantified by summing up the number and signal intensities of the pixels in the region of interest (ROI). Serum levels of antibody (ng/ml) are measured by ELISA. Example 6 Reducing the Dose (and Drug Associated Side-Effects) by Prolonging the Dose Interval Based on the Antibody Concentration or the NIRF Intensity of the Labeled Antibody in the Region of the Solid Tumor Test Agents [0163] Pure trastuzumab and trastuzumab labeled with Cy-5 are provided as a 25 mg/ml stock solution in Histidine-HCl, alpha-alpha Trehalose (60 mM), 0.01% Polysorb, pH 6.0. Both solutions were diluted appropriately in PBS for injections. Cell Lines and Culture Conditions [0164] The human breast cancer cell line KPL-4 has been established from the malignant pleural effusion of a breast cancer patient with an inflammatory skin metastasis and overexpresses ErbB family receptors. (Kurebayashi et al. Br. J. Cancer 79 (1999) 707-17) Tumor cells are routinely cultured in DMEM medium (PAA Laboratories, Austria) supplemented with 10% fetal bovine serum (PAA) and 2 mM L-glutamine (Gibco) at 37° C. in a water-saturated atmosphere at 5% CO2. Culture passage is performed with trypsin/EDTA 1×(PAA) splitting twice/week. Cell passage P6 was used for in vivo study. Animals [0165] SCID beige (C.B.-17) mice; age 10-12 weeks; body weight 18-20 g (Charles River, Sulzfeld, Germany) are maintained under specific-pathogen-free condition with daily cycles of 12 h light/12 h darkness according to international guidelines (GV-Solas; Felasa; TierschG). After arrival, animals are housed in the quarantine part of the animal facility for one week to get accustomed to new environment and for observation. Continuous health monitoring is carried out on regular basis. Diet food (Alltromin) and water (acidified pH 2.5-3) are provided ad libitum. Tumor Growth Inhibition Studies In Vivo [0166] Tumor cells are harvested (trypsin-EDTA) from culture flasks (Greiner TriFlask) and transferred into 50 ml culture medium, washed once and resuspended in PBS. After an additional washing step with PBS and filtration (cell strainer; Falcon 100 μm) the final cell titer is adjusted to 0.75×10 8 /ml. Tumor cell suspension was carefully mixed with transfer pipette to avoid cell aggregation. Anesthesia is performed using a Stephens's inhalation unit for small animals with preincubation chamber (plexiglas), individual mouse nose-mask (silicon) and Isoflurane (Pharmacia-Upjohn, Germany) in a closed circulation system. Two days before injection the fur of the animals is shaved. For intra mammary fat pad (i.m.f.p.) injection, cells are injected orthotopically at a volume of 20 μl into the right penultimate inguinal mammary fat pad of each anesthetized mouse. For the orthotopic implantation, the cell suspension is injected through the skin under the nipple. Tumor cell injection corresponds to day 1 of the experiment. Monitoring [0167] Animals are controlled daily for detection of clinical symptoms of adverse effects. For monitoring throughout the experiment, the body weight of the animals was documented two times weekly and the tumor volume was measured by caliper twice weekly. Primary tumor volume is calculated according to NCI protocol (TV=1/2ab2, where a and b are long and short diameters of tumor size in mm, Teicher B. Anticancer drug development guide, Humana Press, 1997, Chapter 5, page 92). Calculation values were documented as mean and standard deviation. Treatment of Animals [0168] Tumor-bearing mice are randomized when the tumor volume was roughly 100 mm 3 (n=10 for each group). Each group is closely matched before treatment, which began 20 days after tumor cell injection. [0169] Group A: Vehicle group—receives 10 ml/kg PBS buffer intraperitoneally (i.p.) once weekly. [0170] Group B: trastuzumab is administered i.p. at a loading dose of 30 mg/kg, followed by once weekly doses of 15 mg/kg (maintenance dose). [0171] Group C: A composition of trastuzumab and Cy-5 labeled trastuzumab at a predetermined ratio of 9:1 is administered i.p. at a loading dose of 30 mg/kg. [0172] At different time points (usually once a day) therafter NIR fluorescence signals are measured with an acquisition time of 10 seconds. NIR fluorescence intensity is quantified by summing up the number and signal intensities of the pixels in the region of the solid tumor. [0173] First the maximum of the NIR fluorescence intensity is determined in dependency of the time. Then the time point for a first maintenance dose of 15 mg/kg only non-labeled trastuzumab is determined as the time point when the NIR fluorescence intensity has decreased by 10% compared to said maximum. The time interval between loading dose and first maintenance dose is then used as the general dosage interval between consecutive maintenance doses. The consecutive maintenance doses of 15 mg/kg only non-labeled trastuzumab are then given at this general dose. [0174] Group D: A composition of trastuzumab and Cy-5 labeled trastuzumab at a predetermined ratio of 9:1 is administered i.p. at a loading dose of 30 mg/kg. [0175] At different time points (usually once a day) therafter NIR fluorescence signals are measured with an acquisition time of 10 seconds. NIR fluorescence intensity is quantified by summing up the number and signal intensities of the pixels in the region of the solid tumor. [0176] First the maximum of the NIR fluorescence intensity is determined in dependency of the time. Then the time point for a first maintenance dose of 15 mg/kg only non-labeled trastuzumab is determined as the time point when the NIR fluorescence intensity has decreased by 20% compared to said maximum. The time interval between loading dose and first maintenance dose is then used as the general dosage interval between consecutive maintenance doses. The consecutive maintenance doses of 15 mg/kg only non-labeled trastuzumab are then given at this general dose. [0177] Group E: A composition of trastuzumab and Cy-5 labeled trastuzumab at a predetermined ratio of 9:1 is administered i.p. at a loading dose of 30 mg/kg. [0178] At different time points (usually once a day) therafter NIR fluorescence signals are measured with an acquisition time of 10 seconds. NIR fluorescence intensity is quantified by summing up the number and signal intensities of the pixels in the region of the solid tumor. [0179] First the maximum of the NIR fluorescence intensity is determined in dependency of the time. Then the time point for a first maintenance dose of 15 mg/kg only non-labeled trastuzumab is determined as the time point when the NIR fluorescence intensity has decreased by 30% compared to said maximum. The time interval between loading dose and first maintenance dose is then used as the general dosage interval between consecutive maintenance doses. The consecutive maintenance doses of 15 mg/kg only non-labeled trastuzumab are then given at this general dose. [0180] Then the treatment response of Group B and Groups C to is compared, to select an optimized, prolonged dosage interval wherein the treatment response is comparable to that of Group B (in spite the lower dosage, which presumably causes less drug-associated side effects).

This invention relates to a composition of labeled and non-labeled monoclonal antibodies directed to a human transmembrane protein for the simultaneous treatment and diagnosis of diseases which are associated with an overexpression of such a protein especially of cancer. The invention further relates to a method of first administering said composition, determine the change of labeled antibody concentration and afterwards administering the non-labeled monoclonal antibodies only such that the minimum required concentration of such non-labeled antibody for a favorable therapeutical effect is achieved and maintained in the treatment, while unfavorable side effects are minimized due to the lower systemic antibody concentration.

This application is a continuation of application Ser. No. 07/243,110, filed Sept. 2, 1988,now abandoned, which is a continuation of application Ser. No. 06/856,738, filed Apr. 28, 1986, now abandoned. FIELD OF THE INVENTION The invention pertains to a modular system for a semiconductor wafer processing machine. BACKGROUND OF THE INVENTION In the prior art semiconductor wafer processing machines generally perform one function only, e.g., sputter coating, etching, chemical vapor deposition etc., or perform limited multifunctions. Cassettes of wafers are carried by operators from one machine to another for different processes. This exposes the wafers to dust and gases during the transfer and requires additional time for vacuum pumping at each machine. OBJECTS OF THE INVENTION It is an object of the invention to provide a wafer processing machine in which a broad range of modular units for different processes may be assembled around a single vacuum environment. It is a further object of the invention to provide such a machine with isolation between the different processes. It is still another object of the invention to load and unload whole cassettes of wafers into the vacuum environment. It is still a further object of the invention to provide robot handling arms within the machine to move and align wafers between processing steps. SUMMARY OF THE INVENTION A wafer processing machine is provided with multiple loadlocks for loading whole cassettes into the vacuum environment. Wafer handling modules containing robot arms form a spine of the machine through which wafers are passed. Various processing modules are attached to the sides of the wafer handling modules. These and further constructional and operational characteristics of the invention will be more evident from the detailed description given hereinafter with reference to the figures of the accompanying drawings which illustrate one preferred embodiment and alternatives by way of non-limiting examples. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially schematic plan view of one embodiment of the system according to the invention. FIG. 2 shows a partial perspective view of the system shown in FIG. 1. FIG. 3 shows a partially schematic plan view of a second embodiment of the system according to the invention. FIG. 4 shows a partially cutaway side view of the gate valve module according to the invention. FIG. 5 shows a partially cutaway top view of the gate valve module of FIG. 4. FIG. 6 shows a schematic top view of the wafer transport arm according to the invention with the arm shown also in phantom in a second position. FIG. 7 shows a partial sectional view of the arm of FIG. 6. FIG. 7A shows a flow chart for deriving an actual cam profile from a theoretical cam profile. FIG. 7B shows one embodiment of an actual cam together with the path traced by the center of the wafer holder. FIG. 8 shows a schematic plan view of a particularly preferred embodiment of the loadlock module according to the invention. FIG. 9 shows a perspective view of the wafer handling arm and aligner of FIG. 8. FIG. 10 shows a schematic diagram of an embodiment of a sputter module according to the invention. FIG. 11 is a top view in partial section of the sputter module according to the invention. FIG. 12 is a perspective view in partial section of the module of FIG. 11. FIG. 13 is a sectional view of the drive mechanism of the module of FIGS. 11 and 12 along the section line 13--13 as shown in FIG. 15. FIG. 14 is a sectional view of the drive mechanism of the module of FIG. 11 along the section line 14--14. FIG. 15 is a sectional view through the module of FIG. 11 along the sectional line 15--15. FIG. 16 is a cross-sectional view of the mechanism for receiving the wafer from the transport arm along the section line 16--16 shown in FIG. 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings wherein reference numerals are used to designate parts throughout the various figures thereof, there is shown in FIG. 1 a partially schematic plan view of one embodiment of modular semiconductor wafer transport and processing system 1 of the present invention. Modular wafer processing system 1 includes wafer handler and loadlock module 400, gate valve modules 100a-100f, transfer modules 200a and 200b, process modules 300a-300d, and pass-through module 500 connected between transfer modules 200a and 200b. Wafer handler and loadlock module 400 is generally rectangular in plan view and region 407 exterior to loadlock chamber 406 and within the confines of module 400 is at atmospheric pressure. A controlled, low particulate atmosphere environment is provided in this portion of the system. In operation, a selected wafer to be processed is loaded from a selected one of semi-standard or equivalent wafer cassettes 402, 403 in wafer handler and loadlock module 400 by means of wafer handler 405 which transports the selected wafer from its cassette to wafer aligner and flat finder 408 and from wafer aligner 408 to loadlock chamber 406. Wafers may also be loaded from cassette 404 which is reserved for process qualification wafers. Cassette 401 is a storage cassette allowing wafers to cool after processing before being placed in one of the other cassettes or thin film monitor 409. Wafer cassettes 401-404 are tilted at a small angle relative to the horizontal, for example, 7 degrees, so that the planar surfaces of the wafers in cassettes 401-404 are offset from the vertical by this same small angle so that the wafers are tilted to be in a known direction relative to the wafer retaining slots in the cassette when resting in their cassettes. During the transfer of a selected wafer from its cassette into loadlock chamber 406, the wafer is first moved by wafer handler 405, while maintaining the surface of the wafer in a vertical orientation, to wafer aligner 408. The selected wafer is then rotated so that the planar surfaces of the wafer are horizontal and placed in load lock 406, which is then open to the atmosphere. The planar surfaces of the wafer then remain horizontal during the transport of the wafer through gate valve module 100a into transfer module 200a by transfer arm 201a which extends through entry/exit port 210 of transfer module 200a and gate valve module 100a to withdraw the wafer in loadlock chamber 406. Transfer module 200a has four ports, 210, 211, 212 and 213. Ports 210, 211 and 212 are controlled gate valve modules 100a, 100b and 100c, respectively. Port 211 and its corresponding gate valve module 100b connects chamber 215 of transfer module 200a with chamber 301a of process module 300a. Similarly, port 212 and corresponding gate valve module 100c connects chamber 215 of transfer module 200a with chamber 301b of processing module 300b. Interior chamber 215 of transfer module 200a is maintained at a selected pressure less than atmospheric pressure by a conventional pumping mechanism (not shown in FIG. 1). In order to increase the rate at which chamber 215 may be evacuated, chamber 215 is dimensioned relative to arm 201a to minimize the volume of chamber 215. After unloading the wafer from loadlock chamber 406, transfer arm 201a retracts into transfer chamber 215 and gate valve 100a is closed. Transfer arm 201a then rotates through a selected angle in order to present the wafer to a selected process port 211 or 212, or to transfer port 213. When a selected wafer is presented to a process port, e.g., port 211, the corresponding gate valve module, e.g., module 100b, which is closed during the transfer of the selected wafer from loadlock 406 into chamber 215 of transfer module 200a, is opened by means of a control system (not shown). Arm 201a is then extended through the process port, e.g., port 211, and the corresponding gate valve module, e.g., module 100b, into the corresponding process chamber, e.g., chamber 301a of the corresponding process module, e.g., 300a. The wafer is then off-loaded by means not shown in FIG. 1. The process modules 300a and 300b may be the same, so that the same operation is performed therein, or these modules may be different with different operations being performed therein. In either case, the provision of two process modules 300a and 300b connected to transfer module 200a via ports 211 and 212 and gate valve modules 100b and 100c, respectively, together with entry/exit port 210 and valve 100a connecting transfer module 200a to wafer handler and loadlock 400 permits non-serial processing of wafers and increased throughputs compared to sequential processing systems. The time required to transfer a wafer from a wafer cassette and off-load the wafer in a selected process module is typically much less than the time required for the processing of the wafer within the process module. Thus, when a first wafer has been transferred from an input cassette into a selected one of process modules 300a and 300b, during the initial period of processing in process chamber 300a, a second wafer may be transported from loadlock chamber 406 to process module 300 b. Transfer arm 201a may then rotate back to port 211 to await the completion of processing of the wafer in process module 300a. Thus, during a substantial portion of the time processing is occurring simulataneously in process modules 300a and 300b. If desired, process module 300b may be a pre-process module for sputter etch cleaning, or for deposition of a metal film by a process other than sputtering, for example chemical vapor deposition, when the main process stations are employed for sputter deposition. The wafers may then be processed in the remaining process chambers in system 1. The provision of the second entry/exit port 213 in transfer module 200a permits connection to additional process modules 300c and 300d. Transfer module 200a is connected to an identical transfer module 200b (corresponding parts bear the same numerals) via pass-through module 500. Pass-through module 500 connects entry/exit port 213 of transfer module 200a with entry/exit port 210 of transfer module 200b, thus forming a single vacuum chamber. When it is desired to transfer a wafer carried by arm 201a to one of process chambers 300c and 300d, the wafer is offloaded to a flat aligner 501 in pass-through module 500. The wafer is then on-loaded to arm 201b of transfer module 200b and transferred into the selected one of process modules 300c through 300e by arm 201b via corresponding gate valve modules 100d through 100f. When a wafer has been completely processed, it is returned from the processing module in which it resides to loadlock chamber 406 and thence to a selected cassette (401-404) via transfer arm 201a or via transfer arm 201b, pass-through chamber 501 and transfer arm 201a. Process module 300e is drawn with dashed lines to indicate that it is optional and to illustrate the capability of adding modules at will. The system shown in FIG. 1 may be expanded linearly by replacing gate valve 100f and process module 300e by a pass-through module, identical to pass-through module 500, connecting transfer module 200b with a transfer module (not shown) identical to transfer module 200b, which is in turn connected to a corresponding plurality of process chambers. The system shown in FIG. 1 may also be expanded in a non-linear fashion by replacing process module 300d by a pass-through module, identical to pass-through module 501, connecting transfer module 200b with a transfer module (not shown) identical to transfer module 200b which is connected to a corresponding plurality of process chambers. If desired, optional process module 300e may also be replaced by a second wafer handler and loadlock module identical to wafer handler and loadlock module 400. The configuration of the processing system shown in FIG. 1 permits non-serial processing, i.e., any wafer entering loadlock 406 may be transferred to a selected process chamber without passing through any other process chamber and any wafer may be transferred from a selected process chamber to any other selected process chamber or to loadlock chamber 406 without passing through any intermediate process chamber. The operation of the transfer arms, gate valves, flat aligners and loadlock chamber in system 1 are controlled by a master controller circuit (not shown). The master controller circuit is typically operated so that the gate valves are sequenced so that no given process chamber is in direct communication with another process chamber. Thus the system provides complete dynamic isolation. The non-serial processing afforded by system 1 permits continued operation of the remaining process modules when a particular process module is inoperative. The non-serial processing also permits the performance of a replacement process module or of any designated process module to be checked while the remainder of the system continues to operate. For example, if it is desired to check the performance of module 300c, a monitor wafer stored in cassette 404 may be transferred into process chamber 300c, processed and returned to cassette 404. During the processing in chamber 300c, the remainder of system 1 continues to process production wafers. FIG. 2 shows a partial perspective view of the semiconductor wafer transport and processing system shown in FIG. 1. In particular the housing of transfer module 200a is generally cylindrical in shape, and includes circular top 298, circular bottom 296 and cylindrical wall 297, joining top 298 and bottom 296. The housing may be made of any suitable vacuum compatible material, for example, stainless steel. The ports of each transfer chamber are defined by extensions of the housing which form horizontal slots extending from interior chamber 215 to the exterior of the housing. For example, port 210 (FIG. 1) is defined by housing extension 299a, shown in FIG. 2. FIG. 3 shows a partially schematic plan view of a second embodiment of the wafer transport and processing system of the present invention. Wafer transport and processing system 2 includes entry wafer handler and loadlock module 40a, exit wafer handler and loadlock module 40b, transfer modules 20a and 20b, gate valve modules 10a-10h, and process chambers 30b, 30c, 30f and 30g. Wafer handler and loadlock module 40a is the same as wafer handler and loadlock module 400 shown in FIG. 1. Transfer module 20a includes a vacuum chamber having ports 21a-21d for communicating the interior 23a of transfer module 20a with the exterior of module 20a. Ports 21a-21d are opened and closed by gate valve modules 10a-10d. Transfer module 20a is connected to an identical transfer module 20b via flat aligner 50a, thus forming a single vacuum chamber which is evacuated by conventional pumping means not shown in FIG. 3. Flat aligner 50a may be replaced by any suitable means for positioning a wafer in a desired rotational orientation. Transfer module 20b has four ports, 21e-21h, which are opened and closed by gate valve modules 10e-10h, respectively. The interior 31c of reactive ion etch module 30c is connected to interior chamber 23a of transfer module 20a and to interior chamber 23b of transfer module 20b via ports 21c and 21h, respectively, which are controlled by gate valve modules 10c and 10h, respectively. Similarly, the interior chamber 31b of sputter module 30b communicates with interior chambers 23a and 23b of transfer modules 20a and 20b via ports 21b and 21e, respectively, which are controlled by gate valve modules 10b and 10e, respectively. Port 21g, controlled by gate valve module 10g, connects interior chamber 23b of transfer module 20b with interior chamber 31g of chemical vapor deposition module 30g. Port 21f, controlled by gate valve module 10f, communicates interior chamber 23b of transfer module 20b with interior chamber 31f of rapid anneal module 30f. Master controller 60 communicates with each process chamber controller P and with entry module 40a and exit module 40b and operator control panel 51 via standard communication bus 61. In operation, a selected wafer is transported by a wafer handler (not shown in FIG. 3) from a selected wafer cassette (not shown in FIG. 3) in entry module 40a to flat finder 50b and thence to loadlock chamber 46a, which is the same as loadlock chamber 406 shown in FIG. 1. Transfer arm 201c of transfer module 20a extends into loadlock chamber 46a via port 21d which is opened and closed by gate valve module 10d. The selected wafer is then on-loaded to transport arm 201c which then retracts into interior chamber 23a of transfer module 20a. Arm 201c then rotates through a selected angle to present the selected wafer to port 21c or 21b or to flat finder 50a. A wafer transferred to flat finder 50a may be on-loaded onto either transport arm 201d or onto transport arm 201c. Wafers on-loaded from flat finder 50a to transport arm 201d are then retracted by transport arm 201d into chamber 23b rotated through a suitable angle and presented to a selected port 21g or 21f. The gate valve module controlling the selected port then opens the port and transport arm 201d extends into the interior chamber of the selected process module where it is off-loaded by means not shown in FIG. 3. When flat orientation is not required for a wafer or circularly symmetric substrate, the wafer or substrate can be transferred from transport arm 201c into process chamber 31c or process chamber 31b via gate valves 10c and 10b, respectively, and from there, via gate valves 10h and 10e, respectively, directly to transport arm 201d, bypassing flat finger 50a. When a wafer has been completely processed, the wafer is on-loaded to the transport arm servicing the process module in which the wafer is located, and transferred back to exit port 21a. For a wafer in process module 30b or 30c, this is accomplished through the retraction of transport arm 201c from the process chamber, followed by a suitable rotation of transport arm 201c, which is then extended through port 21a, which is controlled by gate valve module 10a, into loadlock chamber 46b. For a wafer in process module 30g or 30f, the wafer is first transferred to transport arm 201d and from arm 201d to arm 201c via flat finder 50a. Semicircular arc 25 denotes that the system shown in FIG. 3 may be expanded by adjoining a third transfer module similar to transfer module 20b to a flat finder located at semicircular arc 25. The modules shown in the embodiment of FIG. 3 are interchangeable, allowing the system to be configured with any combination of modules that may be desired. The system shown in FIG. 3 has the same advantage of non-serial processing as the system shown in FIG. 1. The system shown in FIG. 3 is somewhat more flexible in that transport arm 201d services four processing ports and transfer arm 201c services two processing ports and both an entry and exit module. If desired, entry module 41a may serve as both an entry and exit module and exit module 41b may be replaced by a process module. Similarly, if desired, any process module may be replaced by an exit module or by an entry module. FIGS. 4 and 5 show a partially schematic cross section and a partial cutaway cross section, respectively, of one embodiment of gate valve module 100. Gate valve module 100 controls the passage between port P 1 and port P 2 . Port P 1 is defined by extension 299x of the housing of a first chamber which is either a process chamber, a transfer chamber or a loadlock chamber, which extension forms a generally rectangular slot dimensioned to accommodate the extension therethrough of wafer transport arm 201 shown in FIG. 6. Such an extension (299a) of the housing of transfer module 200a is shown in perspective view in FIG. 2. Port P 2 is similarly defined by extension 299y of the housing of a second chamber (not shown in FIG. 4). Housing extensions 299a and 299y defining ports P 1 and P 2 are attached to valve body 102 by means of a first plurality of screws S 1 and a second plurality of screws S 2 driven through flanges 295 and 296 respectively. Valve body 102 may be made of stainless steel or other suitable material. Elastomeric O-rings 103 and 105 between flanges 295 and 296 respectively and body 102 provide a vacuum seal. Valve body 102 has a horizontal slot 160 which extends from port P 1 to port P 2 when valve gate 125 is lowered to the phantom position shown by the dashed lines in FIG. 4. Slot 160 is shown in side view in FIG. 5 and is dimensioned to accommodate the extension of wafer transport arm 201 shown in FIG. 6 from port P 1 to port P 2 . The dashed line A in FIG. 5 denotes the central plane of slot 160. When valve gate 125 is in its fully retracted position it does not extend into slot 160. This position is denoted by the dashed line in FIG. 4. When gate 125 is in its fully extended position, elastomeric O-ring 104, which is seated in notch 104a, forms a vacuum seal between port P 1 and port P 2 . Elastomeric strips 106 and 107 seated in notches 106a and 107a, respectively, do not perform a vacuum sealing function. Rather, when valve gate 125 is in its fully extended position, strips 106 and 107 provide contact between body 102 and gate 125 so that a rotational moment is produced on gate 125 which opposes the rotational moment on gate 125 produced by the contact between elastomeric O-ring 104, body 102 and valve gate 125. In cross-section, valve gate 125 is a union of two trapezoids 125a and 125b. Edge e 1 of trapezoid 125a extends from point 109 to point 108 forming an acute angle alpha of approximately 45° with the horizontal. A substantially larger angle is not desirable since it would then be difficult for elastomeric O-ring 104 to sealingly engage body 102 when valve gate 125 is fully extended. Edge e 2 of trapezoid 125b forms an angle beta with the horizontal. In the embodiment shown in FIG. 4 the angle alpha equals the angle beta but this is not critical. A novel feature of gate valve module 100 is the asymmetry of the cross section of valve gate 125. Since only O-ring 104 provides a vacuum sealing function, trapezoid 125b is made substantially narrower than trapezoid 125a; i.e., the length of line segment 126 is less than the length of line segment 127. In one embodiment, the difference in length between line segment 126 and line segment 127 is approximately one inch. Thus the distance between port P 1 and port P 2 is substantially reduced compared to prior art valve modules which employ two O-rings and wherein trapezoid 125b is congruent to trapezoid 125a. Bearings 110 and 111 serve to guide valve gate 125 as it translates vertically in slot 144 of body 102. Valve gate 125 is mounted on shaft 132 which is screwed into valve gate 125 by threaded extension 133 of shaft 132. Valve body 102 is mounted to housing 138 by screws (not shown). Metal bellows 130 is mounted by flange 134 to body 102 by screws 55. Stainless steel shaft 140 has a greater diameter than stainless steel shaft 132. Elastomeric O-ring 134a between flange 134 and valve gate body 102 provides a vacuum seal between the chambers (not shown) connected to ports P 1 and P 2 and the atmosphere exterior to valve module 100. Shaft 132 is coaxial with and rigidly mounted on shaft 140. Shaft 140 translates vertically in cylindrical cavity 141 formed by housing 138 thus causing valve gate 125 to translate vertically in slot 144. As shown in FIG. 5, shaft 132 is positioned so that longitudinal axis 128 of shaft 132 is located at the lengthwise midpoint of valve gate 125 having length L. Shaft 132 is also positioned so that the sum of the moments about the axis perpendicular to the plane of the cross-section shown in FIG. 4 and passing through axis 128 and the lower surface of valve body 125 is zero. These moments are caused by the forces acting upon O-ring 104 and elastomeric strips 106 and 107 when valve body 102 is fully extended. Housing 138 is mounted on air cylinder 150 by means of screws 56. Shaft 140 is translated vertically by a conventional air-driven piston mechanism 150. FIG. 6 shows a plan view and FIG. 7 shows a partially cut-away side view of wafer transport arm mechanism 201. Arm mechanism 201 is one embodiment of transfer arm 201a employed in transfer module 200a of FIG. 1 or of arm 201 in module 20 in FIG. 3. Arm mechanism 201 includes cam 242, a first rigid arm 252, pulley 254, second rigid arm 256 and wafer holder 280. Wafer holder 280, shown schematically in FIG. 6, is fixedly mounted on one end of arm 256. The other end of arm 256 is rotatably mounted to one end of arm 252 by means of shaft 272. Shaft 272, which passes through one end (252b) of arm 252, has one end fixedly attached to arm 256 and the other end fixedly attached to the center of pulley 254. Shaft 272 rotates about axis 273 against bearings 275, as shown in FIG. 7. Thus, arm 256 rotates with pulley 254. The other end (252a) of arm 252 is fixedly mounted on shaft 232 which is the inner shaft of dual shaft coaxial feedthrough 224 (FIG. 7). Vacuum feedthrough 224, for example a ferrofluidic feedthrough, provides a vacuum seal between the interior of housing 220 of wafer arm mechanism 201 and the exterior of housing 220. Vacuum feedthrough 224 is attached to housing 220 by means of flange 222. Such a ferrofluidic feedthrough is well known in the art; for example, a ferrofluidic feedthrough made by Ferrofluidic, Inc., may be used to implement the drive mechanism described herein. Outer shaft 238 of ferrofluidic feedthrough 224 is fixedly attached to cam 242. Both inner shaft 232 and outer shaft 238 are independently rotatable about the longitudinal axis 250 of shaft 232 and shaft 238 by means of a pair of motors (not shown). Axis 250 is perpendicular to the floor of and passes through the center of vacuum chamber 215 containing arm 201. Belt 243 is in contact with a portion of the perimeter of cam 242 and a portion of the perimeter of pulley 254. Belt 243 is fixed to cam 242 at point 242f on the perimeter of cam 242 and to pulley 254 at point 254f on the perimeter of the pulley. Belt 243 can be, for example, a stainless steel non-toothed belt or a metal cable. FIG. 6 shows transport arm mechanism 201 fully extended through port P 1 . In this embodiment, when arm 201 is fully extended through port P 1 , the angle θ between axis M, the midline of arm 252 passing through axis 250 and axis 273, and the midline A of port P 1 which passes through axis 250, is approximately 30°. In other embodiments, other angles may be selected in place of 30°. In operation, arm 201 is retracted through port P 1 by a counterclockwise rotation of arm 252 about axis 250 while holding cam 242 fixed. This is accomplished by rotating inner shaft 232 of ferrofluidic feedthrough 224 while outer shaft 238 remains fixed. Cam 242 is shaped so that as arm 252 rotates in a counterclockwise direction, stainless steel cable 243 wraps and unwraps around cam 242 thereby rotating pulley 254 so that wafer holder 280 moves in a generally linear path along midline A from its fully extended position to a retracted position inside vacuum chamber 215 as shown by phantom position 280'. Once wafer transfer arm 201 has been retracted inside chamber 215, both arm 252 and cam 242 are rotated through a selected angle by rotating both inner shaft 232 and outer shaft 238, respectively, through the same selected angles so that arm mechanism 201 is properly positioned to be extended through a second selected port. The ports P 1 through P 4 shown in FIG. 6 are 90° apart, so that for this embodiment shafts 232 and 238 are rotated through a multiple of 90° to position wafer transport arm 201 for an extension through another port. The extension is accomplished by rotating arm 252 about the axis of shaft 232 in a clockwise direction with respect to cam 242. Of importance, as stainless steel cable 243 wraps and unwraps from cam 242 as wafer transport arm 201 is extended or retracted through a selected port, there is no sliding or rolling friction between cam 242 and cable 243. Thus, this design is particularly suitable for maintaining a clean environment within vacuum chamber 215. Cam 242 must be specially shaped in order to ensure that wafer holder 280 retracts (and extends) in an approximately linear manner along axis A. If the motion is to be linear, elementary plane geometry establishes that the angle θ between port axis A and axis M and the angle phi between arm axis N connecting the center of wafer holder 280 and passing through axis 273 in the plane of FIG. 6 are related by the formula: phi=90°-θ+cos.sup.-1 [(d/f) sin θ] where d is the length of arm 252 from axis 250 to axis 273 and f is the length of axis N from axis 273 to the center of wafer holder 280. Table I shows a printout of θ, phi, the difference (decrement) delta phi in the angle phi for constant increments in the angle θ of 3°, the ratio of the decrement in phi divided by the corresponding increment in θ, the x,y coordinates of axis 273, and the stroke (the x coordinate of the center of wafer handler 280, for the case where d=10 inches and f=14 inches). TABLE I______________________________________ ##STR1##X Y THETA PHI DIFF RATIO STROKE______________________________________10.00 0.00 0.00 180.00 24.009.99 0.52 3.00 174.86 5.14 1.71 23.989.95 1.05 6.00 169.72 5.14 1.71 23.919.88 1.56 9.00 164.58 5.13 1.71 23.799.78 2.08 12.00 159.46 5.12 1.71 23.639.66 2.59 15.00 154.35 5.11 1.70 23.429.51 3.09 18.00 149.25 5.10 1.70 23.179.34 3.58 21.00 144.17 5.08 1.69 22.879.14 4.07 24.00 139.11 5.06 1.69 22.538.91 4.54 27.00 134.08 5.03 1.68 22.158.66 5.00 30.00 129.08 5.00 1.67 21.748.39 5.45 33.00 124.11 4.97 1.66 21.288.09 5.88 36.00 119.17 4.93 1.64 20.807.77 6.29 39.00 114.29 4.89 1.63 20.287.43 6.69 42.00 109.45 4.84 1.61 19.737.07 7.07 45.00 104.66 4.78 1.59 19.156.69 7.43 48.00 99.94 4.72 1.57 18.566.29 7.77 51.00 95.28 4.66 1.55 17.945.88 8.09 54.00 90.70 4.58 1.53 17.305.45 8.39 57.00 86.21 4.49 1.50 16.665.00 8.66 60.00 81.80 4.41 1.47 16.004.54 8.91 63.00 77.49 4.31 1.44 15.344.07 9.14 66.00 73.28 4.21 1.40 14.683.58 9.34 69.00 69.19 4.09 1.36 14.023.09 9.51 72.00 65.22 3.97 1.32 13.372.59 9.66 75.00 61.39 3.84 1.28 12.722.08 9.78 78.00 57.69 3.70 1.23 12.101.57 9.88 81.00 54.14 3.55 1.18 11.491.05 9.95 84.00 50.75 3.40 1.13 10.900.52 9.99 87.00 47.51 3.24 1.08 10.340.00 10.00 90.00 44.43 3.08 1.03 9.80-0.52 9.99 93.00 41.50 2.92 0.97 9.29-1.04 9.95 96.00 38.74 2.76 0.92 8.81-1.56 9.88 99.00 36.14 2.60 0.87 8.36-2.08 9.78 102.00 33.69 2.45 0.82 7.94-2.59 9.66 105.00 31.38 2.31 0.77 7.55-3.09 9.51 108.00 29.22 2.17 0.72 7.18-3.58 9.34 111.00 27.18 2.03 0.68 6.85-4.07 9.14 114.00 25.27 1.91 0.64 6.54-4.54 8.91 117.00 23.48 1.79 0.60 6.26-5.00 8.66 120.00 21.79 1.69 0.56 6.00-5.45 8.39 123.00 20.20 1.59 0.53 5.76-5.88 8.09 126.00 18.71 1.50 0.50 5.55-6.29 7.77 129.00 17.29 1.42 0.47 5.35-6.69 7.43 132.00 15.94 1.34 0.45 5.17-7.07 7.07 135.00 14.67 1.28 0.43 5.01-7.43 6.69 138.00 13.45 1.22 0.41 4.87-7.77 6.29 141.00 12.29 1.16 0.39 4.73-8.09 5.88 144.00 11.18 1.11 0.37 4.62-8.39 5.45 147.00 10.11 1.07 0.36 4.51-8.66 5.00 150.00 9.08 1.03 0.34 4.42-8.91 4.54 153.00 8.08 1.00 0.33 4.33-9.13 4.07 156.00 7.11 0.97 0.32 4.26-9.34 3.59 159.00 6.17 0.94 0.31 4.20-9.51 3.09 162.00 5.25 0.92 0.31 4.14-9.66 2.59 165.00 4.35 0.90 0.30 4.10-9.78 2.08 168.00 3.46 0.89 0.30 4.06-9.88 1.57 171.00 2.59 0.88 0.29 4.04-9.94 1.05 174.00 1.72 0.87 0.29 4.02-9.99 0.53 177.00 0.86 0.86 0.29 4.00-10.00 0.00 180.00 0.00 0.86 0.29 4.00______________________________________ Cam 242 is designed in two stages. First, the ratio between the decrement delta phi in the angle phi divided by the corresponding increment delta θ in the angle θ is computed for each θ. These ratios are then used to design a theoretical cam profile. If r represents the radius of pulley 254, for each angle θ (where 0≦θ <180°) a line segment having a length of (delta phi/delta θ) r is placed with one end at the origin, with the line segment extending from the origin at an angle of θ -90°. A smooth curve passing through the ends of these line segments (radii) defines one portion of the theoretical cam profile. The remaining portion of the theoretical cam profile (180°≦θ <360°) is defined by requiring that the cam profile be symmetric with respect to the origin, since cable 242 is of fixed length and must wrap on one side of cam 242 as it unwraps from the other side. Next, since cam 242 drives pulley 254 by means of a smooth stainless belt which wraps and unwraps on pulley 242, modifications to the above profile must be made to take into account this physical drive system. An iterative feed forward modification process is employed as described by the flow chart in FIG. 7a. Heuristically, the program starts with the selected angle θ 0 and the corresponding theoretical cam radius R 0 and then checks for "interference" between the initial radius R 0 and subsequent theoretical radii R 1 , R 2 , . . . R N corresponding to angles θ 0 +delta θ, θ 0 +2 delta θ, . . . , θ 0 +N (delta θ) for a selected positive integer N, and a selected delta θ. "Interference" is defined by the inequalities appearing in the flow chart. Whenever an interference is found, the theoretical radius R 0 is reduced by 0.001 and the process repeated until the initial radius has been reduced so that it does not "interfere". This reduced value R* 0 is then the initial radius (for the angle θ 0 ) of the actual cam. The entire process is then repeated for the next theoretical radius R 1 , and so on. The reduced radii R* 0 , R* 1 , . . . define a corresponding portion of the actual cam profile by passing a smooth curve through the end points of these radii. It should be observed that the constant 0.001 by which the radius is reduced and the maximum tolerance and 0.002 in the test inequalities in the flow chart of FIG. 7A may be replaced by other small constants depending on the degree of accuracy sought. FIG. 7b shows an actual cam profile and the motion of the point at the center of the wafer holder along the path P for the case where r=1, d=10, f=14, using the above process to define the active portion of the cam profile 242 where N=7 and delta θ=3°. In the above figure the active portion of the cam profile occurs for values of θ from 15° to 129°. An active portion of the cam profile is a portion of the profile from which the stainless steel belt 243 wraps and unwraps. The active cam is also defined by symmetry about the origin but the wrapping and unwrapping in the left half plane is not shown for the sake of clarity. The inactive portion of the cam may be defined in any manner which does not interfere with the active profile of the cam 242, as, for example, shown in FIG. 7b, which is drawn to scale. The fixed point 242f may be selected as any point in the inactive portion of the cam profile where the belt makes contact. The fixed point 254f is selected so that the induced rotation of pulley 254 does not cause the fixed point 254f on belt 243 to rotate off pulley 254. If desired, the belt may be extended from a first fixed point in the inactive region of the profile of cam 242, around pulley 254 and back to a second fixed point in the inactive region of the profile of cam 242. In the embodiment described above pulley 254 is circular. However, a similar process for defining the profile of cam 242 to provide linear motion may also be employed with circular pulley 254 being replaced by a noncircular cam (pulley). In another embodiment of the wafer handler and loadlock module 400 (FIG. 1) which is to be particularly preferred, three or more cassettes of wafers are loaded into the vacuum in separate loadlocks in order to facilitate high speed processing and wafer outgassing. As shown in FIG. 8, cassettes 402, 404 and 406 are shown in loadlock chambers 408, 410 and 412, respectively. The cassettes are loaded through doors 414, 416 and 418 from the clean room. These loadlock chambers are pumped from below by suitable pumping means (not shown). When suitable levels of vacuum are achieved valves 420, 422 or 424 (shown only schematically) may be opened to permit movement of the wafers from the cassette into the wafer loadlock handling chamber 426. Within the chamber 426, a handling arm driving mechanism 428 is mounted on a track 430. The handling arm driving mechanism 428 may be moved along the track 430 to align with each of the loadlock chambers 408, 410, 412. A two-piece arm 432 is mounted above and driven by the handling arm driving mechanism 428. The arm 432 is used to reach through any one of the valves 420, 422, 424 to pick up a wafer from a cassette or to return a wafer to the cassette. Elevators (not shown) below the tables on which the cassettes rest are used to raise or lower the cassettes to permit the arm to reach different wafers in each cassette. The arm 432 can be used to move the wafer to a resting table 434 from which it is picked up by another wafer handling device of the system. Hot wafers picked up by the arm 432 can be moved to storage cassettes 436 or 438 to permit the wafer to cool before moving the wafer back to the cassette. An important feature of the invention is the concentric wafer orientation device incorporated into the handling arm driving mechanism 428. A table 436 rests on a shaft (not shown) which is concentric with the shaft connecting the handling arm driving mechanism 428 to the handling arm 432. A view of this arrangement is shown in FIG. 9. A wafer is placed over the table 436 by the arm 432. The table 436 is rotated so that the wafer edge passes between light emitter 442 and light detector 440. Rotation of the edge of the wafer through the light beam provides light intensity variation information as a function of angle of rotation which permits the central computer to calculate the centroid of the wafer and the position of the flat. The computer then aligns the flat and stores the information on the true center for setting the wafer on the table 434. Further details of this embodiment of the loadlock module are given in the copending application U.S. Ser. No. 856,814 of Richard J. Hertel et al entitled "Wafer Transport System", filed on even date herewith, the continuation of which has now issued as U.S. Pat. No. 4,836,733 which is incorporated herein by reference. The wafer pass through module 500 can also use the same rotational flat alignment described above in the flat aligner 501. The rotatable table 436 receives the wafer into the module 500. The light emitter 442 and light detector 440 are used to provide light intensity information as previously described to permit aligning the wafer. FIG. 10 shows a schematic diagram of one embodiment of sputter module 350. Sputter module 350 includes pre-process vacuum chamber 301, wafer handler arm 340, valve 338 which provides a vacuum seal between process chamber 301 and sputter chamber 302, sputter source 304, heater 315, and match box 316. In operation, a wafer is transferred from the wafer transport arm mechanism (not shown in FIG. 10; see FIGS. 6, 7) in transfer chamber 200 to gate valve module 100tm to wafer handler arm 340 which is shown in more detail in FIGS. 11-14 and FIG. 16. Gate valve module 100tm is the same as gate valve module 100 shown in FIGS. 4 and 5. When the transfer of the wafer from the transport arm mechanism in chamber 200 to wafer handler arm 340 is complete, valve 100tm is closed via a control mechanism (not shown). In this manner the atmosphere in process chamber 302 is isolated from the atmosphere in transfer chamber 200. Wafer handler arm 340 then rotates the horizontal wafer W clipped thereto through 95° within process chamber 301 so that the planar surfaces of wafer W make an angle of 5° with the vertical. This rotation is shown in perspective view in FIG. 12. Wafer handler arm 340 then rotates with wafer W clipped thereto through valve opening 338 into process chamber 302 and then rotates with wafer W through 5° so that the planar surfaces of the wafer are vertical and a portion of the back surface of wafer W rests on heater 315. Heater 315 is well known in the art and may be, for example, part no. 682530 made by Varian Associates, Inc. Match box 316 provides an impedance transfer between the RF heating source (not shown) and the heater glow discharge. With the wafer at a selected temperature, sputter source 304 is then activated via a control mechanism (not shown in FIG. 10. Gas line 309 provides argon gas at a selected pressure to valve 310. Needle valve 311 controls the flow of argon from valve 310 to sputter chamber 302. Needle valve 312 controls the flow of argon to the cavity formed between the back surface of wafer W and heater 315. Switch 308 is a pressure activated switch which acts as a back up safety switch to cut power to sputter source 304 and all other electrical apparatus associated with the sputter module when the pressure in chamber 302 rises above a selected level less than or equal to atmospheric pressure. Interlock switch 306 is a safety switch which cuts power to source 304 when the access door (not shown) in FIG. 10 is opened. Similarly, interlock switch 314 is a safety switch which cuts power to heater 315 when cooling water flow fails. Gauges 318 and 319 measure pressure in chamber 301. Roughing gauge 318 measures pressures in the range between atmospheric pressure and 10.sup. -3 torr. Ion gauge 319 measures pressure less than approximately 10 -3 torr. Interlock switch 317 is a safety switch which cuts power to prevent opening of valve 338 when chamber 301 is at atmospheric pressure. A capacitance manometer gauge 320 is a pressure measuring device which senses pressure in chamber 301 and may be isolated from chamber 301 by valve 313. The pumping mechanism used to evacuate chamber 301 is well known and includes roughing pump 323 which reduces pressure in chambers 301 and 302 via valve 336 to a selected pressure, approximately 10 -2 torr; high vacuum pump 322, for example a cryopump, then further evacuates chambers 301 and 302 via valve 324 when valve 336 is closed. Valve 324 is closed to protect pump 322 when chamber 301 is vented to atmosphere. Chambers 301 and 302 are protected by a trap (not shown) in the pumping system foreline. Valve 325 is used to evacuate pump 322 for starting the pump. FIG. 16 shows a cross-sectional view of the mechanism by which a wafer is transferred from wafer transport arm mechanism 201 shown in FIGS. 6 and 7 to wafer arm 340 in sputter module preprocess chamber 301. A wafer is transported into chamber 301 by arm mechanism 201 (not shown in FIG. 16, but shown in FIG. 6) being extended through port P so that wafer W carried by wafer holder 280 of arm 201 is situated above a first table 500. Table 500 is rigidly mounted on shaft 501 which, driven by air cylinder 502, is linearly translatable vertically as indicated by double-headed arrow 518. Shaft 501 passes through flange 397 into vacuum chamber 301. Bellows 522 which is welded to flange 398 which is mounted to flange 397 of housing 396 and elastomeric O-ring 520 between bellows 522 and shaft 520 provide a vacuum seal between chamber 301 and the exterior atmosphere. Table 500 is dimensioned so that it may be elevated through the circular opening in wafer holder 280 (see FIG. 6) thus removing the wafer from wafer holder 280 which is then withdrawn from chamber 301 as explained in conjunction with FIGS. 6 and 7. At this point wafer W rests on table 500 as shown in FIG. 16. Note that the edge of wafer W extends beyond the perimeter of table 500 in the scalloped areas (not shown) of table 500 where clips will eventually engage the wafer's edge. Wafer arm mechanism 340 is rotated (as explained below) so that circular opening 342 (FIG. 11) in wafer holder plate 341 is centered above wafer W. A circular ceramic ring 511 is mounted beneath rim 510 of wafer plate 341. A plurality of flexible wafer clips are fixedly attached to ceramic ring 511 at approximately equal intervals. Two such clips, 512a and 512b, are shown in FIG. 16. A prong corresponding to each flexible wafer clip is rigidly attached to a second table 514. Prongs 514a and 514b corresponding to clips 512a and 512b are shown in FIG. 16. Table 514 is rigidly attached to shaft 502 which, driven by air cylinder 504, is linearly translatable in the vertical direction as indicated by double-headed arrow 516. Shaft 503 also passes through housing 396 of chamber 301. Bellows 523 mounted to flange 398 of housing 396 and elastomeric O-ring 521 between bellows 523 and shaft 503 provides a vacuum seal between the chamber 301 and the exterior atmosphere. When wafer W has been transferred to table 500, table 514 is then elevated so that each prong attached to table 514 engages its corresponding flexible wafer clip thereby opening the clip. Table 500 is then elevated so that wafer W is in line with the opened clips. Table 514 is then lowered causing the clips to close and engage the edge of wafer W. FIG. 16 shows clips 512a and 512b engaging the edge of wafer W in the phantom position W'. Table 500 is then also lowered. This completes the transfer of wafer W from arm 201 to arm 340. Arm extensions 345 and 346 of wafer plate 341 (FIG. 11) are rigidly attached to shaft 365 which extends between arm extensions 345 and 346. This is shown in enlarged scale in FIG. 13. Shaft 365 passes through gear box 360. Gear box 360 includes a conventional right angle gear mechanism 361 for coupling the rotation of drive shaft 367 to shaft 365. Drive shaft 367 is rotated by turning pulley 368 rigidly attached thereto and driven by a suitable mechanism, e.g., a belt attached to first motor M 1 in housing 370. Motor M 1 drives shaft 367 which in turn, via right angle gear mechanism 361, causes wafer arm 340 on shaft 365 to rotate 95° from the horizontal (as shown in FIG. 12) along with wafer W clipped to ceramic ring 511 attached to rim 510 of wafer arm plate 341. Shaft 367 is the inner shaft of a dual shaft coaxial feedthrough 388 (which may have ferrofluidic seals). Shaft 367 passes from vacuum chamber 301 through housing 396 to exterior pulley 368. Elastomeric O-ring 373 provides a vacuum seal between vacuum chamber 301 and the atmosphere exterior to chamber 301. Outer shaft 378 of ferrofluidic feedthrough 388, which is coaxial with inner shaft 367, also extends through housing 396 to pulley 369 which is rigidly attached thereto. Outer shaft 378 is rotated by rotating pulley 369 by a suitable means, e.g., a belt, attached to motor M 2 in housing 370. Elastomeric O-ring 372 between ferrofluidic housing 374 and outer shaft 378 provides vacuum seal between chamber 301 and the atmosphere exterior to chamber 301. Housing 374 is welded to flange 375. Flange 396a is bolted to flange 375. Flange 396a is welded to chamber wall 396. O-ring 371 provides a vacuum seal between chamber 301 (via flange 396a) and feedthrough 388. When wafer arm 340 has been rotated through approximately 95° from the horizontal, as shown in FIG. 12, it is then rotated through rectangular opening 338 into sputter chamber 302. This rotation is accomplished by rotating outer shaft 378 by means of motor M 2 . The end of shaft 378 interior to chamber 301 is rigidly attached to gear box housing 360. As shaft 378 is rotated in a counterclockwise direction, gear box 360, shaft 365 and wafer arm 340 all rotate in a counterclockwise direction as shown in FIG. 12. A rotation through an angle of approximately 90° places wafer W in front of heater 315. By again rotating inner shaft 367, wafer W attached to ceramic ring 511, which is attached to wafer arm plate 341, is rotated through an angle of approximately 5° so that its back surface comes in contact with heater 315. When wafer arm 340 is properly positioned with respect to heater 315, a pin (not shown) adjacent heater 315 engages the alignment aperture 344a in protusion 344 from wafer holder plate 341 shown in FIG. 11. Wafer holder plate 341 may be one removable plate/shield or two stainless steel layers 341a and 341b as shown in cross section in FIG. 15. Top layer 341a is removably attached to bottom layer 341b by two screws (not shown). Top layer 341a shields bottom layer 341b from sputter deposition and helps reduce sputter deposition build up on the edge shield 530 surrounding ceramic ring 511. Layer 341a is replaced whenever sputter depositions on layer 341a builds up to undesirable levels. Sputter source 304 is well known in the art; for example, sputter source 304 may be Varian CONMAG™ and is therefore not described further herein. Sputter source 304 pivots open on hinge 304a (FIG. 11) to allow access to source targets and shields. When wafer handler arm 340 is in preprocess chamber 301, preprocess chamber 301 may be vacuum isolated from sputter chamber 302 by means of rectangular door 351. Rectangular door 351 is attached to shaft 391 by brace 353. Shaft 391 is rotated by actuator 380 through a crank arm so that door 351 is in front of and slightly displaced from rectangular opening 338 to sputter chamber 302. As shown in FIG. 15, door 351 is dimensioned to be large than opening 338. Door 351 is slideable with shaft 391 and is linearly translated so that O-ring 352 sealingly engages the chamber housing surrounding opening 338. To this end, shaft 355 is translated along axis C so that end 355a engages door 351 and translates door 351 along axis C toward opening 338. The mechanism for driving shaft 355 contained in housing 381 is shown in more detail in FIG. 14. Shaft 355 is translated in either direction along axis C by a conventional air-driven piston attached to shaft 355. When shaft 355 is only partially extended toward opening 338, O-ring 383 provides a dynamic vacuum seal between chamber 301 and atmosphere. However, when shaft 355 is fully extended when door 351 is rotated away from its sealing position and is in its rest position as shown in FIG. 15, annular extension 355b of shaft 355 engages elastomeric O-ring 385 so that a static vacuum seal is formed between housing 381 and annular extension 355b. This novel static seal provides more reliable vacuum isolation between chamber 301 and atmosphere. Although the modular wafer transport and processing system of the present invention has been described primarily with respect to its application to semiconductor wafer or substrate processing, it should be understood that the inventive system is equally useful in the processing of many other wafer of disc-like workpieces. Neither is it required that other such workpieces have flats on their edges; workpieces which are fully circular in outline can be handled as well. More specifically, the inventive system is especially useful for processing any magnetic or optical storage medium in a wafer-like or disc-like form. This invention is not limited to the preferred embodiment and alternatives heretofore described, to which variations and improvements may be made including mechanically and electrically equivalent modifications to component parts, without departing from the scope of protection of the present patent and true spirit of the invention, the characteristics of which are summarized in the following claims.

A modular wafer processing machine is provided which is based on interconnected handling units having wafer handling arms. Each unit can pass a wafer to another unit in the same vacuum environment to a processing module.

FIELD OF THE INVENTION [0001] This invention relates to distribution troughs, particularly a plurality and network thereof; to distribution towers comprising said distribution troughs and particularly for use as absorption and drying towers in the sulphuric acid contact process; and carbon dioxide capture. BACKGROUND OF THE INVENTION [0002] Distributors are used to distribute a liquid throughout an area from a liquid feed source. Specifically, in an absorption tower a liquid is distributed across the top of a packed bed within the tower. A gas flows through the tower in generally counter-current flow to the liquid but it can also flow co-currently. The liquid is used to absorb a chemical out of the gas or a gas is used to strip a volatile component from a liquid. Examples in sulphuric acid production include absorption of sulphur trioxide gas, SO 3 , or of water vapour into a strong sulphuric acid solution; also the air stripping of sulphur dioxide, SO 2 , from a sulphuric acid stream. An example in carbon capture and storage processes is the absorption of carbon dioxide, CO 2 , from gas streams such as atmospheric air and particularly from flue gases produced by carbonaceous fuel burning power generation plants into a solution having preferential absorption for CO2 compared to other gaseous components such as an aqueous solution of alkylamines. A second example in carbon capture and storage processes is desorption of CO2 from said absorbing solution after changes in operating conditions such as temperature and pressure. The efficacy of absorption or desorption is directly related to the uniformity of the liquid distribution. [0003] A distributor may be considered as a single apparatus that may include several distribution stages such as a single inlet source of liquid that is first split into several but generally a few flows (for example, less than, but not necessarily limited to, 10) for a header or manifold system. Liquid is then distributed to a secondary system of several conduits, typically a greater number of conduits than in the first manifold, through one or more feed points in each secondary conduit. Each secondary conduit distributes liquid to many discharge points (e.g. >20); and may include a final stage of discharge means, such as down comer tubes, that direct the many discharge flows on to the packing. Additional stages of increasingly finer distribution can be contemplated, but preferable designs will limit these stages to as few as possible for cost-effectiveness. [0004] There are many design variations for liquid distributors, but there are three distributor types generally recognized as pan or tray, closed conduit or pipe, and trough types. The pan or tray type of distributor has various means such as holes for a uniform liquid distribution but must also provide means such as gas risers for gas flow. The tray or pan type is seldom employed in towers larger than 1.5 meters diameter as they are relatively expensive and generally limited to smaller gas flows. [0005] Pipe distributors are of relatively simple fabrication, generally using readily available piping components. A pipe distributor is typically an inlet pipe through the vessel side wall or vessel top head leading to a central manifold with several radial, horizontal pipe branches; or an inlet pipe into a single central horizontal pipe header through the wall and several perpendicular, horizontal side pipe branches; with a multitude of discharge orifices along the branch pipes. Pipe distributors can occupy a small overall cross-sectional area when designed for pressurized operation with high allowable pressure drop across small discharge orifices. However, disadvantages of pressurized pipe distributors include difficulty obtaining even liquid distribution when the inlet liquid also contains some gas or solids; requiring disassembly for cleaning; and producing fine liquid drops which are carried over with upward-flowing, high velocity gas. [0006] Trough distributors use one or more, troughs to distribute the liquid throughout the tower. The troughs are generally arranged parallel to each other across the tower. The liquid distribution rate out of the troughs is controlled by the number of exit liquid discharge points, the size of the liquid discharge exits, and the surface height above the exits. An initial feed system comprised of a central feed pipe or feed trough is usually fed by means of an inlet pipe through the wall of the column, where the inlet pipe leads to the center of the feed pipe or feed trough or one end of the feed conduit. The initial feed system will split the inlet feed liquid into smaller flows to the distribution troughs and can be located above and perpendicularly across the lower troughs with liquid flow into each lower trough through a single inlet, or through two liquid flows from the opposite sides of the central feed pipe or trough, or through multiple liquid flows supplied by branches from the central feed pipe or feed trough. The trough type of distributor has an advantage over closed conduit type distributors of being open for easy inspection and solids clean out. [0007] There are two main types of trough distributors based upon the kind of liquid exits: weir-type and orifice-type. Weir-type distributors have overflow weirs at or near the top of the trough, and are very sensitive to even small variations in liquid height having a large detrimental impact on uniform distribution. Orifice based distributors have submerged exits in the trough. Submerged orifices have flow rates less sensitive to the height of the liquid above them. However, orifices are more prone to becoming blocked with suspended solids that settle out when compared to weir-type distributors. Both orifices and weirs can be obstructed by large particles. [0008] Distributors may also employ down comers, which are closed conduits, i.e. tubes, which further distribute liquid from discharge points of trough or conduit type distributors across the cross-section of the tower and down to the packing. These are effective in allowing for reduced number of distributor conduits while minimizing liquid entrainment within the gas stream. [0009] In the sulphuric acid industry, pipe and trough distributors were traditionally made from ductile iron because of its ability to form a protective barrier to strong sulphuric acid. However, this barrier can be eroded off if the flow becomes turbulent. This means that the acid has to enter the distribution trough at a low velocity, which is generally achieved by having an overhead piping network to introduce the acid to the trough, splitting the total flow into smaller flows, at several points. Ductile iron troughs or pipes were also designed with large corrosion allowances making them very heavy. [0010] Liquid introduced into packed towers will entrain solids, generally fine particles, from the slow wear of packing and other materials. Larger particles of solids found in the liquid are often small pieces of broken packing; usually occurring during the filling of the tower with the packing. Although means such as strainers or filters are employed to remove solids, such devices are not perfect and, in the sulphuric acid industry, the materials of construction suitable for filter elements have limited life. The solids in the liquid can build up deposits in distributors that cause mal-distribution and a periodic cleaning the equipment is required with subsequent loss of production. However, a higher liquid velocity will retard the formation of deposits by maintaining most solids in suspension to be swept out of the distributor. [0011] Many distributors in sulphuric acid towers are now manufactured out of improved acid resistant materials allowing higher velocities in acid contacted equipment, piping, etc. with reduced size, weight, and corrosion. Cost-effective acid resistant metal alloys are austenitic stainless steels having high silicon content such as SARAMET®, registered to Aker Solutions Canada, Inc. for use in sulphuric acid plants. However, as liquid capacity is increased through a trough distributor, i.e. reducing size with higher velocities, difficulty arises in maintaining a calm liquid surface at a uniform height above each discharge exit; thus different methods of introducing the liquid into the troughs at multiple entrance points have been employed in order to maintain low velocity and minimal disturbance of the liquid surface. In large towers of diameters greater than about 2 meters, several feed conduits are typically employed to provide several liquid entry points into the distribution troughs. However, the additional feed conduits reduce cost-effectiveness and are inconvenient when cleaning is required. [0012] There is, however, a need for an improved distributor, assembly and towers comprising such distributors. LIST OF PUBLICATIONS [0013] [0000] U.S. Pat. No. 3,146,609; 4,479,909; 5,014,740; 3,419,251; 4,557,877; 5,884,658; 4,267,978; 4,991,646; 5,919,405; and 4,272,026; 4,994,210; 6,758,463 B2. SUMMARY OF THE INVENTION [0014] An objective of the present invention is to provide a trough distributor with a simple and convenient feed conduit means while also providing for an even distribution of liquid. [0015] A further objective of the invention is to provide a trough distributor that will reduce cleaning frequency by preventing sedimentation that will block discharge orifices. [0016] Another objective of the invention is for its use in an improved and cost-effective tower for direct gas-liquid contact in for mass and/or heat transfer processes. [0017] Another further objective of the invention is its use in an improved sulphuric acid process. Additionally, the objectives of the invention include its use in the improvement of other large-scale processes involving adsorption and desorption operations and including carbon capture and sequestration. [0018] The invention relates to a two-section, trough-type liquid distributor for use generally in direct gas-liquid contact devices for mass and/or heat transfer, and more specifically in columns with one or more sections of packing having random or structured packing. The invention is of particular utility in aspects of minimizing the number of feed liquid entry points for individual troughs of the distributor, most preferably reduced to one entry point; and of providing for liquid velocities to keep fine solids suspended in the flow streams throughout the distributor, thus avoiding build-up of finely divided sediments. The invention is of utility for both weir-type and submerged-orifice-type trough distributors with the latter type as a preferred embodiment. The invention may be used for reduced distributor size in many applications, or for high flow capacity, and has particular application in absorption and drying towers in sulphuric acid plants. The invention also has particular application in the distribution of solutions used in absorption and desorption towers in carbon capture and sequestration plants. [0019] Accordingly, in one broad aspect, the invention provides a liquid distribution trough contained within a tower for the purpose of mass or thermal exchange between at least a first liquid and a second fluid; [0020] said trough having an upper section and a lower section; [0021] said lower section for receiving said first liquid; [0022] a horizontal dividing member separating said upper section from said lower section and having at least one dividing member portion defining an aperture to allow for passage of said liquid fluid from said lower section to said upper section; [0023] a feed conduit means in communication with said lower section to provide feed first liquid flow to said lower section; [0024] said lower section having at least one inlet portion defining a liquid inlet in communication with said feed conduit means; and [0025] a first baffle adjacent said inlet portion operably impacted by said first liquid flow and to hinder preferential flow along the walls of said trough and said dividing member. [0026] Preferably, the distributor has a set of at least one second baffle adjacent at least one of said dividing member apertures to direct a portion of said first liquid flow through said dividing member apertures into said upper section of said trough. [0027] Yet more preferably, the distributor has a plurality of deflectors within said upper section, each of said deflectors located adjacent a dividing member aperture and having a portion defining a vertical surface and a portion defining a horizontal surface to effect a reverse essentially horizontal uniform distribution of flow of said first liquid over the lower surface of said upper section of said trough. [0028] The feed conduit means, preferably, comprises a central feed conduit selected from a trough and a pipe. [0029] Preferably, the upper section has portions defining discharge exits selected from weir-type or submerged orifice type by which the first liquid exits the upper section of the trough; and the discharge exits of the distribution troughs are submerged orifice type located on the upper trough section at a common elevation. [0030] Preferably, the discharge exits communicate with downcomers which direct the first liquid flow. [0031] Preferably, the first baffle is also so located ahead of the one aperture as to operably induce turbulence that provides more uniform velocity throughout the cross-section of the lower section of the trough and maintain suspension of most entrained solids. [0032] Preferably, the set of at least one second baffle is also so located as to induce turbulence along the length of the trough that provides more uniform velocity throughout the cross-section of the lower section of the trough and maintain suspension of most entrained solids. [0033] The deflector is, preferably, of a shape having vertical and horizontal surfaces selected from planar and curvilinear faces, wherein more preferably, the vertical face is perpendicular to the longitudinal axis of the distribution trough along which the first fluid flows and the horizontal face is perpendicular to the vertical axis of the trough. [0034] Preferably, the deflectors have angular or curvilinear shaped side-extensions to the faces perpendicular to the longitudinal axis of the distribution trough, which extend at least partly to the side walls of the upper section of the trough. [0035] Preferably, the dividing member comprises a unitary plate having the apertures, or alternatively it comprises a plurality of plates providing the apertures between adjacent plates. [0036] Preferably, each of the second set of baffles is aligned adjacent the downstream back edges of the apertures in the dividing member. [0037] Preferably, the second set of baffles is an attached lower portion or continued lower portion of the deflector assemblies, wherein the lower portion extends through the openings into the lower trough section. [0038] Preferably, the second set of baffles and the deflector assemblies are integrally formed portions of the plates. [0039] Preferably, the distributor has screens to retain large particles in the lower trough section, adjacent the apertures. [0040] The screens are, preferably, sized to retain particles larger than the size of the discharge exits of the troughs; preferably or alternatively sized to retain particles larger than about one fifth the size of the discharge exits of the troughs. [0041] Preferably, the feed conduit means comprises an at least one downcomer for each liquid entrance to said trough. [0042] In a further aspect, the invention provides a network of distribution troughs as hereinabove defined. [0043] In a yet further aspect, the invention provides, a tower for mass and/or heat transfer comprising one or more sections adapted to receive packing and incorporating a distributor or network thereof as hereinabove defined. [0044] Preferably, the absorption tower and/or as the drying tower is of use in the sulphuric acid contact process. [0045] In a yet further aspect, the invention provides, a sulphuric acid plant comprising an absorption tower and/or a drying tower having a distributor or a network of distributors as hereinabove defined. [0046] In one preferred embodiment of the invention, an improved distributor is provided that does not require a network of feed conduits or a feed conduit with branching feed conduits. A single overhead conduit not having any branching feed conduits feeding several distribution troughs is sufficient. Where most prior art trough distributors have multiple liquid entrances, this embodiment of the invention requires only one entrance for each distribution trough. Each trough is divided into a longitudinal open upper section and a longitudinal, essentially enclosed, lower section having a single inlet flow entering therein. Instead of reducing flow velocities with multiple pipes, according to the invention, dispersing the liquid into the lower section, a single entry point is used with energy dissipation and flow deflecting baffle systems that are built into the lower section and into a separating partition plate or plates. There are spaced apertures in the partition plate or plates separating the upper and lower sections, for flow from the lower section into the upper section. Baffles are positioned in the vicinity of the aperture-openings, in the lower section, which baffles redirect a portion of the flow into the upper section. In the upper section a plurality of vertical and horizontal deflector assemblies are also positioned, comprised of vertical and horizontal surfaces, following the openings that re-direct the liquid flow for better distribution. The deflector assemblies cause a turbulent back flow of liquid along the top surface of partitioning plates which prevents solids from accumulating in spaces between exit orifices. The backflow is beneficial towards maintaining a uniform distribution of liquid throughout the upper section. Surprisingly, the additional and backward turbulence induced by the deflectors at the apertures is mostly restrained to the lower region of the upper section and the liquid surface above is made calmer than without the flow direction change. This is achieved by preventing the bulk fluid flow entering the upper section from directly impacting the free surface, and, instead, dissipating its energy to turbulence. The surface calming and improved distribution caused by the deflector, according to the invention, and energy dissipation systems resulting therefrom in the practise of the invention are beneficial to both submerged orifice type and weir type distributors. However, the benefits from sweeping suspended solids in the upper trough section are primarily beneficial to submerged orifice type distributors. [0047] The invention is described in greater detail hereinbelow based upon a submerged orifice type, two-section trough distributor. [0048] Some of the advantages of the invention may be summarized as follows: Requires only one entrance per trough distributor, which Eliminates the need for an overhead pipe distributor network of multiple conduits; Reduces tower materials and fabrication labour/time costs; and Reduces installation and constructions time and costs. Design doesn't require tuning of adjusting inlets after installation to balance flow lengthwise along the trough; Field installation of additional feed conduits are not required; Reduces commissioning time and costs Further reduces construction cost Provides faster start-up for more production profit Distribution is insensitive to inlet velocity (limited to material limits); Uses a system of baffles to induce turbulence and redistribute flow throughout the lower section of the trough; Deflectors control the direction of flow to maintain a uniform distribution along the length of each trough; Greater flexibility in production rates matching demand; Less sedimentation issues compared to prior art due to increased liquid velocity and surface shear caused by deflectors in upper portion of the trough. Longer time for solids build-up reduces frequency of cleaning More on-line production profit Further reduces maintenance time/labour costs. BRIEF DESCRIPTION OF THE DRAWINGS [0066] In order that the invention may be better understood, preferred embodiments will now be described, by way of example only, with reference to the accompanying drawings, wherein:— [0067] FIG. 1 is an isometric view of a sulphuric acid absorption tower shown generally as 100 , according to the prior art; [0068] FIG. 2 is an isometric view of sulphuric acid absorption tower shown generally as 200 , according to the invention; [0069] FIG. 3 is a horizontal cross-sectional plan view of the absorption tower of FIG. 1 , on the plane AA-AA′, according to the prior art; [0070] FIG. 4 is a horizontal cross-sectional plan view of the absorption tower of FIG. 2 , on the plane A-A′, according to the invention; [0071] FIG. 5 is an enlarged plan view portion below the feed conduit network 3 a , in part, of FIG. 3 , denoted as outlined location VV of FIG. 3 , according to the prior art; [0072] FIG. 6 is an enlarged plan view portion below the feed conduit 3 , in part, of FIG. 4 , denoted as outlined location V of FIG. 4 ; according to the invention; [0073] FIG. 7 is a vertical partial cross-section view BB-BB', of FIG. 5 , down the longitudinal center of the trough, according to the prior art; [0074] FIG. 8 is a vertical partial cross-section view B-B′, of FIG. 6 , down the longitudinal center of the trough having geometry and flow patterns, according to the invention; [0075] FIG. 9 is a vertical cross-section view CC-CC′, of FIG. 5 , according to the prior art; [0076] FIG. 10 is a vertical cross-section view C-C′, of FIG. 6 , according to the invention; [0077] FIG. 11 a is a fabrication plan view of a particular prepared plate 27 b before bending, to combine several components of the invention in a single fabricated item; [0078] FIG. 11 b is a side view of the prepared plate 27 b of FIG. 11 a after bending, combining several components of the invention in a single fabricated item; [0079] FIGS. 12 a and 12 b show wire frame isometric illustrations of a portion of a distribution trough of the invention near the liquid inlet of the distribution trough, including an exploded view of the components ( FIG. 12 b ); [0080] FIGS. 13 a and 13 b show wire frame isometric illustrations of a portion of a distribution trough of the invention at a distribution trough end, including an exploded view of the components ( 13 b ); [0081] FIG. 14 shows examples of alternate baffle and deflector geometries according to the invention, [0082] and wherein the same numerals denote like parts. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0083] The detailed description below exemplifies use of the invention in facilities that produce sulphuric acid, and in particular to use of the invention in absorption towers of these facilities. While the following detailed description is based on the use of the invention in a sulphuric acid plant, the invention itself is well suited to other processes with absorption towers, particularly with large absorption towers, such as carbon capture processes. [0084] FIG. 1 shows a packed tower 100 of recent prior art, having distribution trough network 1 a and an overhead feed distribution network 3 a . Sulphuric acid is distributed into distribution troughs 1 a at multiple feed points 14 a to reduce its velocity for acceptable erosion/corrosion rates, and also provide for a uniform distribution. Although the recent use of superior corrosion resistant high silicon austenitic stainless steel as the material of construction has reduced the size of distributor troughs 1 a due to higher allowed velocities, flow capacity limitations occur in providing a uniform flow distribution and, thus, multiple feed points 14 a are still required to reduce velocity for acceptable uniformity of flow distribution. A horizontal cross-section view of tower 100 shown as plane AA-AA′ in FIG. 1 is presented in FIG. 3 for greater detail of the prior art distribution troughs 1 a and the feed distribution piping network 3 a. [0085] Tower 200 shown in FIG. 2 has two liquid distribution troughs 1 according to the invention. Troughs 1 distribute inlet liquid flow 8 uniformly across the top of packing shown as 6 supported by packing support 5 . Liquid flows downward and exits tower 200 as the exit liquid flow 9 . In counter current tower 200 , as shown, inlet SO 3 -containing gas flow 10 enters tower 200 into vestibule 4 . The gas travels upwards through packing support 5 and packing 6 where heat and/or mass transfer occurs between the sulphuric acid and the SO 3 containing gas. SO 3 -depleted gas then passes past the liquid distribution system comprising the simple inlet feed conduit network 3 and improved distribution troughs 1 having single inlets 14 and flow deflectors 19 of use according to the invention. As the SO 3 depleted gas flows upward past the liquid distribution system liquid droplets may be entrained and the gas then passes through mist eliminators 7 to remove any liquid carry-over before exiting tower 200 as gas outlet flow 11 . Sulphuric acid inlet feed conduit 3 is shown with feed flow 8 , split into flows entering through single inlets 14 of each distributor trough 1 . A cross-section plan view of the tower, shown as plane A-A′ in FIG. 2 is presented in FIG. 4 for greater detail of the improved distribution troughs 1 and the corresponding feed distribution piping network 3 . [0086] FIG. 3 , shows a tower plan view at cross-section plane AA-AA′ of FIG. 1 , having two distribution troughs 1 a according to the prior art, each having multiple inlets 14 a and, on trough side ledges 24 , multiple submerged orifices 12 , under which downcomer tubes 13 are attached for directing distribution trough exit flows over the entire cross-sectional area and down to packing 6 . Feed liquid flow 8 is distributed through the feed distribution piping network 3 a to multiple inlets 14 a of prior art distribution troughs 1 a . As shown, feed distribution piping network 3 a comprises a central feed conduit and smaller branching feed conduits. The number of multiple inlets 14 a is chosen for distributing smaller inlet flows as the number of inlets 14 a is increased to thereby cause lower velocities throughout the length of distribution troughs 1 a . Lower velocities throughout the length of prior art distribution troughs 1 a were necessary to ensure an even distribution of liquid. In older prior art distribution troughs constructed of ductile iron, lower velocities were also necessary to avoid accelerated wear. More detail for the outlined portion VV in FIG. 3 , below feed distribution piping network 3 a , is shown in the enlarged view of FIG. 5 and subsequent cross-sectional views of FIGS. 7 and 9 . [0087] FIG. 4 shows two distribution troughs 1 according to the invention, each having its own single inlet 14 and, on trough side ledges 24 , multiple submerged orifices 12 , under which downcomer tubes 13 are attached for directing distribution trough exit flows over the entire cross-sectional area and down to the packing 6 . Feed liquid flow 8 is distributed through feed distribution piping network 3 to single inlets 14 of improved distribution troughs 1 , according to the invention. As shown, feed distribution piping network 3 comprises only a central feed conduit. Single inlets 14 , as compared to the multiple inlets of the prior art, inject higher velocity inlet flow into distribution troughs 1 , which includes flow deflectors 19 that are one of the distinguishing features of the invention. Improved distribution trough 1 is shown to include a partitioning plate or plates 15 , lying attached to and overlapping the inside edges of ledges 24 , and which divide improved distribution trough 1 into an upper open section 17 above ledges 24 and a lower trough section 18 under partitioning plate or plates 15 . As better shown in FIGS. 8 and 12 , inlet pipe 14 is connected into lower section 18 . The inlet flow into lower trough section 18 passes through apertures 16 of partitioning plate/plates 15 , which apertures are covered by flow deflectors 19 in this view into upper section 17 . More detail for the outlined portion V, below feed distribution piping network 3 , is shown in the enlarged view of FIG. 6 and subsequent cross-sectional views of FIGS. 8 and 10 . [0088] FIG. 5 , enlargement of FIG. 3 plan-view outlined portion VV, shows two of multiple inlets 14 a into prior art distribution trough 1 a . Along a portion of trough length, longitudinally, the vertical cross-section view BB-BB′ as located in FIG. 5 , is projected in FIG. 7 for comparison with a similar cross-section side view in distribution trough 1 of the invention. Similarly, across the trough 1 (side-to-side), the vertical cross-section view CC-CC′ as located in FIG. 7 , is projected in FIG. 9 . [0089] FIG. 6 , enlargement of FIG. 4 plan-view outlined portion V, indicates horizontal partition plate/plates 15 that create lower trough section 18 , attached onto horizontal side ledges 24 of trough 1 where multiple submerged orifices 12 are located such that all orifices 12 have a common liquid height above. Horizontal partition plates 15 incorporate deflectors 19 , a significant feature of the invention, appearing as rectangles from above and which cover apertures 16 in plate/plates 15 . Along a portion of trough length, longitudinally, the vertical cross-section view B-B′ as located in FIG. 6 , is projected in FIG. 8 to best illustrate side views of deflectors 19 and flow patterns due to deflector and baffle features of the invention. Across the trough (side-to-side), the vertical cross-section view C-C′ as located in FIG. 6 , is projected in FIG. 10 to best illustrate the horizontal ledges 24 and face view of a typical deflector assembly 19 . [0090] FIG. 7 , longitudinal cross-section BB-BB′ from FIG. 5 , shows a portion of a distribution trough 1 a according to the recent prior art, wherein multiple inlets 14 a provide divided sulphuric acid inlet flows 23 a into the lower region. For clarity, a majority of the downcomers 13 has been removed and the included downcomers are truncated. The included downcomers 13 are shown, behind the trough wall with dashed lines, to extend up to the side horizontal ledge 24 where the downcomers are in fluid communication with submerged orifices (not shown) while submerged orifices 12 are shown in FIG. 9 . In this case of recent prior art, the multiplicity of divided inlet flows 23 a into trough 1 a provide for low velocities suitable for ensuring even distribution of discharge flows along the length of distribution trough 1 a. [0091] FIG. 8 , longitudinal cross-section B-B′ from FIG. 6 , shows the two sections of improved distribution trough 1 as upper section 17 and a lower section 18 , separated by a horizontal partitioning plate or plates 15 , which are attached on the inside edges of horizontal ledges 24 . For clarity, the liquid height in upper section 17 is not shown. Also a majority of downcomers 13 has been removed while included downcomers 13 are truncated. Upward extension of the included downcomers to the horizontal side ledge 24 has been not be shown. FIG. 7 shows the extension as dashed lines. Inlet liquid feed distribution conduit 3 ( FIG. 2 ) directs a liquid flow portion 23 a , shown in FIG. 8 , into each distribution trough 1 by means of a single pipe inlet 14 ( FIGS. 2 , 4 , 6 and 8 ). The inlet pipe diameter is constrained by the width of lower section 18 of trough 1 . There are openings 16 in the horizontal plate or between each plate section 15 , through which the fluid flows from lower section 18 into upper section 17 . Flow arrows 23 (a through e) show the general direction of sulphuric acid fluid flow. Flow 23 e through openings 16 is redirected by deflectors 19 , first upwards and then back along the lower surface of upper section 17 , opposite to its horizontal inlet direction of travel in the lower section. [0092] In FIG. 8 , when a straight pipe is used for single inlet 14 , inlet flow 23 a impacts the far wall, generally the bottom floor of the trough, flow arrow 23 b , and preferentially flows along the floor. An “inlet” baffle or similar obstruction 22 on the floor opposing the inlet flow and positioned close to inlet 14 , up to a short distance past first opening 16 , redirects the sulphuric acid flow upwards and away from the opposing floor, flow arrow 23 c . A minimum of one such baffle 22 on either side of flow inlet 23 b is required on the impacted floor. Inlet baffle 22 has been found to be important for inducing turbulence that helps to provide a more uniform velocity profile across the enclosed lower trough section 18 . Other profiles for baffle 22 may also be used provided that they disrupt the preferential flow along the wall opposing the inlet pipe and, preferably, induce turbulence. [0093] Beyond the inlet region, there are multiple apertures or openings 16 between upper 17 and lower 18 sections of trough 1 . There is a vertical baffle 20 in lower section 18 in the vicinity of each opening 16 to re-direct a portion of sulphuric acid flow up through opening 16 . Equally sized baffles 20 are conveniently fabricated and installed but, some are scaled to adjust the flow rate through each opening 16 in long distributors. Baffles 20 functions at any elevation between the bottom and separating plate 15 in lower trough section 18 . In a most preferred embodiment, baffles 20 are located at the bottom of horizontal partitioning plates 15 so that a deflector 19 , partitioning plate 15 , and vertical baffle 20 can be fabricated from a single piece of formable material. High silicon austenitic stainless steel is the preferred material in towers for sulphuric acid production and can be formed into plates incorporating several features, as shown in FIG. 11 , using bending and cutting machines. Each of baffles 20 also redirects sulphuric acid flow within lower trough section 18 , as illustrated by flow arrow 23 d . Thus, these baffles 20 also induce turbulence that provides a more uniform liquid flow profile in lower trough section 18 . In ductile iron distributors of prior art for sulphuric acid service, this turbulence would quickly corrode the exposed surfaces. [0094] Referring again to FIG. 8 , deflectors assemblies 19 are provided at the downstream edge of openings 16 . In the absence of deflector assemblies 19 , high inlet flow velocities cause flow through one opening 16 to continue in the horizontal direction and add to horizontal liquid flow from the next opening 16 . This results in the surface height of the liquid to be higher at the far ends of trough 1 than at the center in a stationary pattern and high upward velocity causes significant local liquid level disturbances. Deflectors 19 provide obstruction across both the horizontal and upward directions of flow, and are located at openings 16 to maintain low average velocity in upper section 17 by directing flows through openings 16 into a horizontal, but reverse direction, 23 e , along the bottom surfaces of upper trough section 17 . A significant benefit is found in keeping the reverse horizontal liquid flow with an average velocity that is sufficient to maintain a shear force to sweep away settling solids. [0095] FIG. 9 , cross-section view CC-CC′ of FIG. 5 , is a side-to-side cross-section through inlet pipe 14 a and distribution trough 1 a of recent prior art showing the use of many submerged orifices 12 , which are located at a common elevation on horizontal wall sections 24 of trough 1 a . This case of recent prior art shows no dividing partition for two trough sections although inlet pipes 14 a are shown to extend into lower portion 18 a of the trough. The prior art uses a multiplicity of inlet pipes 14 a to provide many divided inlet flows 23 a into trough for low velocities suitable for ensuring even distribution of liquid discharge flows along the length of distribution trough 1 a. [0096] FIG. 10 , cross-section view C-C′ of FIG. 6 , is a side-to-side cross-section of the improved distribution trough 1 through a typical opening 16 , (see FIG. 8 ) showing that deflector 19 spans the entire width of lower section 18 of trough 1 with side overlap above horizontal dividing wall plates 15 . Liquid flow up-ward directing baffles 20 are shown located at the top of lower section 18 . The cross-section as shown in FIG. 10 shows the use of many submerged orifices 12 located at a common elevation on horizontal side ledges 24 of trough 1 . Flow arrows indicate typical flow paths into upper section 17 and into submerged orifices 12 , as well as indicating back-eddy currents that maintain suspension of fine particles, and a sweeping action for re-entrainment of settled solids. [0097] In a preferred embodiment, horizontal partitioning plate or plates 15 between lower 18 and upper sections 17 is also used to support screens or similar filtering devices in openings 16 to restrain large solids particles entrained in the inlet flow in lower section 18 . The size of screen openings are chosen to pass solids that are small enough to avoid blockage of orifices 12 , i.e. less than the orifice size and, preferably, less than one fifth of the orifice size. [0098] FIGS. 11 a and 11 b illustrate a deflector assembly 19 and baffle 20 formed as parts of a particular plate section 27 b of dividing partition plates 15 , from a single piece of plate material or sheet metal. Other differently dimensioned and bent plate sections 27 a , 27 c , and 27 d at the inlet of and at the end of a distribution trough 1 are illustrated in FIGS. 12 a , 12 b , 13 a and 13 b. [0099] In FIG. 11 a , particular plate 27 b is cut to a suitable width and a length that includes lengths for horizontal and vertical portions 19 a and 19 b of deflector 19 , a length portion for opening 16 , and a length portion for lower section baffle 20 . The so-prepared plate is bent along lines 28 a , 28 b , and 28 c to form the profile illustrated in FIG. 11 b . FIGS. 11 a and 11 b illustrate a section of the horizontal plates with perforations 25 that are used for openings 16 , and for support of finer screen 26 , if necessary. For multiple partition plates 27 b between the upper and lower sections, a consistent length of partition plate between opening 16 and deflector 19 is preferred but is varied as necessary, e.g. the distance between the openings may be altered at the trough ends and center. Before bending, particular plate 27 b is further prepared with punched, drilled, or cut holes 29 for bolting assembly, having opening perforations 25 , and removal of corners 30 for fitting baffle 20 into lower trough section 1 . [0100] For clarity, FIGS. 12 a , 12 b , 13 a and 13 b do not include down comers that are attached under orifices 12 . [0101] FIG. 12 , isometric wire frame assembly and exploded views of an inlet portion of trough 1 , shows partition plates 27 b , as described above and another particular partitioning plate 27 a that is used at central trough inlet 14 supplying inlet liquid flow 23 a . Inlet partition plate 27 a as shown is truncated but extends similarly in the opposite direction from inlet 14 , i.e. symmetrically about centre-line 31 . Partition plate 27 a includes perforated end sections for the first of apertures 16 on either side of inlet 14 . Partition plate 27 a also incorporates inlet bottom baffle 22 as the lower part of an extended and bent portion 33 of partition plate 27 a , having opening 32 passing liquid through lower section 18 of trough 1 . Extended portion 33 with bottom baffle 22 may also be prepared as a separate piece and attached, e.g. welded to partition plate 27 a. [0102] FIGS. 13 a and 13 b , isometric wire frame assembly and exploded views of an end portion of trough 1 , show two particular partition plates 27 c and 27 d forming the last sections of partitioning plates 15 before an end wall 36 of the trough. At the end regions of each trough 1 a perforated plate and/or screen 34 extending from separating plate to the bottom of the lower section 18 of trough 1 is included as a final means to filter and collect sedimentation. A diagonal perforated plate 34 or screen is preferably attached to one of the final separating plates 27 c or 27 d in trough 1 as shown on the second last plate 27 c in FIGS. 13 a and 13 b , so that plate 27 c and diagonal screen 34 can be removed in unison for cleaning of any accumulated sedimentation. The preferred geometry is a general diagonal direction extending downwards from the rear of the penultimate aperture 16 to trough 1 bottom and extends towards the end of trough 1 such that solids are directed into a pocket where they can accumulate without preventing flow through the end openings. These are particularly useful during initial operation after new packing is introduced with some likely breakage creating larger sized solids. [0103] FIGS. 12 a , 12 b , 13 a and 13 b also indicate the use of bolts 35 to hold some removable plates in place which is necessary to facilitate solids clean-out. Other plates are permanently fixed in place by welding. [0104] The side shape of deflectors 19 is not limited to the preferred angular form as shown in FIG. 8 and FIG. 14 a but may also be, by way of example, of different curvilinear shapes as shown in FIGS. 14 b, c, d and e . In FIG. 14 b , the leading edge 21 of deflector 19 is shown to overlap an aperture 16 and a portion of partitioning plate 15 . FIGS. 14 a and 14 b show baffle 20 in lower trough section 18 to be aligned with deflector 19 , while FIGS. 14 c, d and e also show different positions of vertical baffle 20 in lower trough section 18 . Various geometries may be contemplated for the baffles and deflectors of use in the practise of the invention in accordance with the foregoing principles to allow for convenient fabrication and installation. Example [0105] The successful functioning of the present invention was discovered from experimental testing conducted using a small scale distributor trough. The small scale model was made of clear material to allow observation of liquid flow within trough 1 and to determine the overall performance of the distributor improvements compared to an equivalently sized model according to the prior art. The effects of individual features used in improved distributor 1 were also observed by inserting and removing various components. Test work was used to adjust computer simulation models for accurate reproduction and computer simulation gave further insight into the flow patterns and effects of experimentally added features. [0106] Each added feature used in the improved distributor 2 was insufficient on its own per se to improve the overall performance of distributor 1 . Thus, starting from an empty trough shell, each feature addressed a performance difficulty but often created a new one. The complete assembly of the improved distributor, according to the invention, was able to address all difficulties encountered. [0107] The following description provides the effects of each feature as visually observed and further depicted in computer simulations. [0108] The number and diameter of inlet pipes into the distribution trough determined the inlet velocity for any given flow rate. [0109] In an empty trough 1 , without any additional features, the use of multiple inlets achieved a calm liquid surface with a near uniform distribution. Problems with the introduction of the liquid to trough 1 at a low velocity included settling of suspended solids and calmness of the liquid surface. These were significantly affected in an inverse relation to each other by changes in inlet velocity. Furthermore, the cost of adding more inlets to each trough 1 is expensive and additional conduits made periodic cleaning more complicated and time-consuming, and, thus, thereby contribute to lost production and profit. However, just reducing the number of inlets, which increased inlet velocity, caused a detrimental effect on liquid surface calmness, height and liquid distribution. [0110] In physical testing, and subsequent computer simulation, the number of inlets to the distribution trough model was reduced from ten to one. As the number of inlets was reduced to one, a flow pattern developed which formed a standing wave near the inlet. This leads to a very non-uniform liquid surface height and distinct liquid level difference before and after the standing wave. [0111] A prior art feature comprising a partitioning plate having regularly spaced apertures to create an enclosed bottom section in fluid communication with an open upper section was installed and tested. At high liquid flow throughput, with the inlet liquid flow introduced into the bottom section, the standing wave flow pattern near the central feed inlet did not reappear. There was no distinct jump in liquid surface height as was observed in trials with no partition. However, flow rates through the partition apertures at the ends of the trough were substantially higher than the flow rates through the apertures closer to the central inlet. A stationary pattern of variable liquid height in the upper trough section was observed with the highest liquid levels at the outer ends of the trough, decreasing to the lowest level in the center. Subsequent computer simulations to model fluid flow in the trough with, and without, a partition were adjusted to reproduce the visually observed liquid surface patterns. With a partitioned trough, results of the adjusted model indicated the presence of a strong preferential current at the bottom of the lower trough section. [0112] The variable liquid surface height in the trough prevents the equal discharge flow rates through submerged orifices having equally sized opening diameter and other means to achieve equal discharge flows are impractical. Such means include adjusting orifice diameters for the different liquid surface heights but this would greatly limit the range of operating capacity. [0113] Baffles were introduced into the bottom section of the partitioned trough to balance flows through the apertures in the partitioning plate. Baffles were located both in the vicinity of each aperture and in the entrance region of the trough on the floor opposing the inlet flow. The baffles could be adjusted in position and size to achieve a reasonable balance of flows through the apertures. [0114] The two locations of baffles addressed different issues. Baffles on the trough floor near the inlet disrupted the initial preferential flow along the bottom by inducing turbulence and redistributing the flow currents throughout the lower section of the trough. In the absence of the inlet bottom baffles the performance of the trough remained very similar to a trough with no baffles, i.e. high outer end liquid heights. A singular bottom baffle on each side of the entrance region was insufficient to properly distribute the flow through each aperture along the length of the trough, and an additional baffle in the vicinity of each aperture was found to be necessary. These additional baffles re-direct a portion of the flow from the lower section of the trough into the upper section, but in order for the additional baffles to function properly, it was necessary to first have even flow current across the lower trough cross-section, which was caused by the inlet baffles. However, as subsequently seen in computer simulation, the additional baffles also contributed to inducing turbulence and redistributing and maintaining even flow currents in the lower section along the trough length. Although the computer simulation showed an even liquid flow through the apertures, there was still a visually observed pattern of large liquid height differences between the outer ends and the center of the partitioned trough. [0115] Flow entering the upper section was still primarily horizontal towards the ends of the trough. Introducing vertical deflectors at the downstream side of each aperture on top of the partitioning plate, was found to direct flow primarily upwards, further improving liquid distribution along the length of the trough. However, the vertical flows also caused standing waves to form above each opening. This allowed for the possibility of splashing and also for localized uneven discharge flows due to the surface waves. [0116] Horizontal deflectors were placed over each aperture in conjunction with the vertical deflectors and the combined deflector assemblies were able to prevent standing waves above the apertures. In further testing, the addition of the deflector assemblies was found to minimize the previously found requirements for adjusting positions and sizes of baffles in the lower trough section. Mostly equal spacing and baffle sizes were now sufficient for achieving a remarkably calm and even height of liquid surface along the length of the trough at much higher flow capacity then used in previous trough designs. Further computer simulation, using adjusted model parameters for reproducing the visual results, indicated that the deflector assemblies in the upper section also redirected liquid to sweep over the bottom of the upper trough. The liquid velocity was generally maintained above solid settling velocity and the average shear stress across the bottom was able to either sweep settled particles out through the discharge orifices or cause re-entrainment. [0117] In conclusion, it was seen that the combined effect of the baffles and deflector assemblies clearly provided an improved distribution trough with a reduced number of inlets, a uniform distribution along the length of the trough, a calm liquid surface, and reduced settling of solids when compared to the prior art. [0118] Although this disclosure has described and illustrated certain preferred embodiments of the invention, it is to be understood that the invention is not restricted to those particular embodiments. Rather, the invention includes all embodiments which are functional or mechanical equivalence of the specific embodiments and features that have been described and illustrated.

A liquid distribution trough contained within a tower for the purpose of mass or thermal exchange between at least a first liquid and a second fluid; the trough having an upper section and a lower section; the lower section for receiving the first liquid; a horizontal dividing member separating the upper section from the lower section and having at least one dividing member portion defining an aperture to allow for passage of the liquid fluid from the lower section to the upper section; a feed conduit means in communication with the lower section to provide feed first liquid flow to the lower section; the lower section having at least one inlet portion defining a liquid inlet in communication with the feed conduit means; and a first baffle adjacent the inlet portion operably impacted by the first liquid flow and to hinder preferential flow along the walls of the trough and the dividing member. The trough and tower are of particular value in a sulphuric acid plant and a carbon dioxide capture plant.

This application is a continuation-in-part of my application entitled "Olefin Polymerization Catalyst Component", Ser. No. 875,845, filed June 18, 1986, and now U.S. Pat. No. 4,710,482. FIELD OF THE INVENTION This invention relates to a process for preparing crystalline olefin polymerization catalyst components having improved activity and morphological properties. This crystalline polymerization catalyst component is prepared from a crystalline magnesium compound described more fully below. BACKGROUND OF THE INVENTION Numerous proposals are known from the prior art to provide olefin polymerization catalysts by combining a solid component comprising at least magnesium, titanium and chlorine with an activating organoaluminum compound. These may be referred to as supported coordination catalysts or catalyst systems. The activity and stereospecific performance of such compositions is generally improved by incorporating an electron donor (Lewis base) in the solid component and by employing as a third catalyst component an electron donor which may be complexed in whole or in part with the activating organoaluminum compound. For convenienve of reference, the solid titanium-containing constituent of such catalysts is referred to herein as "procatalyst", the organoaluminum compound, whether used separately or partially or totally complexed with an electron donor, as "cocatalyst", and the electron donor compound, whether used separately or partially or totally complexed with the organoaluminum compound, as "selectivity control agent" (SCA). Supported coordination catalysts of this type are disclosed in numerous patents. The catalyst systems of this type which have been disclosed in the prior art generally are able to produce olefin polymers in high yield and, in the case of catalysts for polymerization of propylene or higher alpha-olefins, with high selectivity to stereoregular polymer. However, further improvements in productivity at high stereoregularity are still being sought. The objective of workers in this art is to provide catalyst systems which exhibit sufficiently high activity to permit the production of polyolefins in such high yield as to obviate the necessity of extracting residual catalyst components in a deashing step. In the case of propylene and higher olefins, an equally important objective is to provide catalyst systems of sufficiently high selectivity toward isotactic or otherwise stereoregular products to obviate the necessity of extracting atactic polymer components. Although many chemical combinations provide active catalyst systems, practical considerations have led the workers in the art to concentrate on certain preferred components. The procatalysts typically comprise magnesium chloride, titanium chloride, generally in tetravalent form, and as electron donor an aromatic ester such as ethyl benzoate or ethyl-p-toluate. The cocatalyst typically is an aluminum trialkyl such as aluminum triethyl or aluminum tri-isobutyl, often used at least partially complexed with a selectivity control agent. The selectivity control agent typically is an aromatic ester such as ethyl-paramethoxybenzoate (ethyl anisate) or methyl-p-toluate. While the selection of cocatalyst and selectivity control agent affects the performance of those catalyst systems, the component which appears to be subject to most significant improvement with respect to activity and productivity of the system is the procatalyst. Preferred methods of preparing such procatalysts are claimed in U.S. Pat. Nos. 4,329,253; 4,393,182; 4,400,302; 4,328,328; 4,478,952 and 4,414,132. These procatalysts are highly active and stereospecific. The typical manner of preparing such procatalysts involves the reaction of the magnesium compound, titanium tetrachloride and electron donor in the presence of a halohydrocarbon. The resulting solid particles are then contacted with additional quantities of TiCl 4 and are completed by washing off excess TiCl 4 usingl ight hydrocarbons (e.g., isooctane and isopentane) and drying. The procatalysts described above have excellent polymerization activity (polymer yield) and stereospecific performance (isotactic content). However, for some applications the polymer morphology is not ideal. In olefin polymerization, polymer morphology is known to be a replica of catalyst morphology. Still further, the procatalyst morphology also depends upon the morphology of the starting magnesium compound. Accordingly, if one desires to have optimal catalyst morphology (e.g. spheroidal particles), then it is desirable to employ starting magnesium compounds of the same morphology. A number of different approaches to improve morphology are suggested in the patent literature. One approach, disclosed in GB No. 2,101,610, involves reacting a solid particulate material with an organic magnesium compound, treating the supported magnesium composition with oxygen, carbon dioxide or a hydroxyl compound, reacting the treated product with a carbonyl compound and simultaneously or subsequently reacting with a transition metal compound. Another approach, disclosed in U.S. Pat. No. 4,465,783, involves the spray drying of a transition metal composition, or a support for a transition metal compound, suspended in a liquid medium. Still another method is disclosed in DE No. 2,839,188, where solid magnesium dialkoxide particles are dispersed into a suitable liquid phase, followed by spray-drying. However, the process of the '188 patent is not attractive as the dispersed solid particles will tend to clog the fine orifices of the spray-drying equipment and will foul the pumping and metering systems. In U.S. Pat. No. 4,540,679, use is made of a magnesium hydrocarbyl carbonate support. In the '679 patent, a suspension of magnesium alcoholate with carbon dioxide is reacted with a transition metal component to precipitate a "magnesium hydrocarbyl carbonate" support. The patentees use a number of techniques, including prepolymerization and the use of triethyl aluminum (TEA) to remove ethanol, to improve productivity. However, these techniques are not desirable because, for example, prepolymerization is an additional step and the addition of TEA adds ash to the polymer product. The above-mentioned approaches to morphology control all depend upon starting from roughly spherical amorphous, non-stoichiometric shapes. A new method to improve morphology is greatly desired. A new approach has now been found, unique in that the magnesium precursor is a molecule with a definite stoichiometry which forms crystalline particles of well defined shape, and that permits the preparation of crystalline procatalyst molecules which form procatalyst particles having not only excellent productivity and selectivity, but also possessing excellent morphology. The polymer particles will have the shape of the procatalyst particles which have the shape of the magnesium precursor particles. Also, surprisingly, the shape of the polymer particle can be changed by changing X, the counter ion. The organomagnesium compounds commonly used to produce magnesium/titanium procatalysts, such as diethoxy magnesium, are non-crystalline and produce a procatalyst which is also non-crystalline. Furthermore, the polymer particles produced with such catalysts are of widely varying shape and, for the most part, are useless for controlled morphology applications. The crystalline catalyst components of the present invention are thus very different from the commonly used procatalysts and produce olefin polymers with much different morphological properties. SUMMARY OF THE INVENTION The present invention relates to an improved solid catalyst component for the polymerization of olefins. In particular, the present invention relates to a magnesium halide/titanium halide catalyst component comprised of molecules which form crystalline solids and are useful for the polymerization of olefins which has been obtained by contacting a crystalline alkoxy magnesium compound with a halide of tetravalent titanium, optionally in the presence of an electron donor, and then contacting the resulting halogenated product with a tetravalent titanium halide. The resulting product may then be washed to remove unreacted titanium compounds and the solid product recovered. In a preferred embodiment, the magnesium compound is comprised of crystalline molecules having the formula [Mg 4 (OR) 6 (R'OH) 10 ]X where X is a counter ion or ions having a total charge of -2 and R and R', which may be the same or different, are selected from alkyl groups of 1 to 4 carbon atoms. Preferred elements for X are chlorine and bromine. Other preferred counter ions are shown in FIGS. 5 through 12. When either is present, the particles of this compound have a crystal habit which is an essentially regular rhombic dodedecahedron. An average of such a structure is that it is essentially tangential to a spherical surface and thus has a very close to optimum morphology which will carry through to the polymer. As shown in the examples which follow, propylene polymers made with catalysts according to the present invention have high bulk densities up to and greater than 0.4 grams per cubic centimeter. Also, as shown in the examples, the catalysts of the present invention possess an unexpected balance of excellent catalytic properties, including: high activity high selectivity to isotactic structures good resin shape (morphology) low catalytic decay high bulk density (See Illustrative Embodiment II) greater productivity per reactor volume narrow range of particle distribution, especially including low fines (See Illustrative Embodiment II) Another advantage is that the alkoxy species in the catalyst appears to be resident on the Mg instead of the Ti as with prior art catalysts prepared from magnesium ethoxide, which may help to explain the high activity of this catalyst. Another important aspect of the invention relates to the preparation of the halogenated product from the starting magnesium crystalline compound. This halogenation takes place in the presence of a tetravalent titanium halide (e.g. TiCl 4 ) and an optical electron donor (e.g. an ester of an aromatic carboxylic acid). As shown in the examples, it is also much preferred that the halogenation also takes place in the presence of a halohydrocarbon (e.g. chlorobenzene). BRIEF DESCRIPTION OF THE DRAWINGS There are a number of important aspects to the present invention. One, as mentioned above, relates to the dodecahedron structure. FIG. 1 shows the molecular structure of the dication as determined by single crystal X-ray diffraction, where the blackened circles are Mg, the small open circles are methoxy (OCH 3 ) and the large open circles are methanol (CH 3 OH). Note that two bromide ions serve only to balance the positive charge but are not essential to the molecular structure. Another important aspect relates to the method by which the stable magnesium crystal is prepared. FIG. 2 shows a ternary phase diagram for the system magnesium methoxide, magnesium chloride, methanol. Until this invention the narrow triangle ABC was the only region of component concentrations which could be employed to achieve the stable crystal Mg 4 (OMe) 6 Cl 2 ·10MeOH. FIG. 3 shows the precursor, procatalyst and polymer particle shape when X=Cl. FIG. 4 shows the precursor, procatalyst and polymer particle shape when X=Br. FIG. 5 shows the precursor, procatalyst and polymer particle shape when X=methacrylate or a methacrylate/resorcinolate mixture. FIG. 6 shows the precursor, procatalyst and polymer particle shape when X=butyrate. FIG. 7 shows the precursor, procatalyst and polymer particle shape obtained with the Mg compound of FIG. 1 when X is resorcinolate or an acetate/resorcinolate mixture. FIG. 8 shows the precursor, procatalyst and polymer shape produced with the Mg compound of FIG. 1 when X is acrylate or acetate. FIG. 9 shows the precursor, procatalyst and polymer shape produced with the Mg compound of FIG. 1 when X is 2,4-pentanedionate. FIG. 10 shows the precursor, procatalyst and polymer shape produced with the Mg compound of FIG. 1 when X is propionate. FIG. 11 shows the precursor, procatalyst and polymer shape produced with the Mg compound of FIG. 1 when X is benzoate. FIG. 12 shows the precursor, procatalyst and polymer shape produced with the Mg compound of FIG. 1 when X is chloroacetate. DETAILED DESCRIPTION OF THE INVENTION The key aspect of the present invention involves the use and preparation of an alkoxy magnesium compound formed of crystalline molecules. One example of such a magnesium compound has the formula [Mg 4 (OR) 6 (R'OH) 10 ]X, where X is a counter ion or ions having a total charge of -2 and R and R', which may be the same or different, are alkyl groups of 1 to 4 carbon atoms. In a preferred embodiment, X is selected from the group consisting of 2BR - , 2Cl - , methacrylate, butyrate, resorcinolate, acrylate, acetate, propionate, 2,4-pentanedionate, chloroacetate and benzoate. The most preferred counter ions for X are 2Br - and 2Cl - because they have the best particle shapes, i.e. the closest to spherical. R and R' are preferably --CH 2 CH 3 or --CH 3 , with --CH 3 being the most preferred of the two There are a number of means to prepare such starting magnesium compounds. One way is disclosed in the article "Alkoxymagnesium Halides" by Turova et al, JOURNAL OF ORGANOMETALLIC CHEMISTRY, 42, pages 9-17 (1972), which disclosure is herein incorporated by reference. The phase diagram shown in the attached FIG. 2 is similar to the phase diagram shown in FIG. 1 of the Turova article. As mentioned above it is much preferred that the "R" and "R'" in the crystal structure be a methyl group. Accordingly, the remainder of the disclosure will reference methanol, methyl or methoxy groups. One method to prepare molecules with the crystal structures of the present invention (as disclosed in Turova et al) involves preparing solutions of MgCl 2 in methanol and Mg(OCH 3 ) 2 in methanol, then mixing the controlled solutions in a mole ratio of MgCl 2 to Mg(OCH 3 ) 2 of 1:3 and then removing the methanol solvent until the crystals are formed. If desired, small amounts of vaseline oil may be added to improve crystallization. Another equivalent method disclosed herein involves the use of Mg metal, MgCl 2 and methanol. In this method three equivalents of the Mg is dissolved in a methanolic solution of MgCl 2 to again provide the 3:1 mole ratio of methoxide to chloride. The extremely narrow stability range required by the ternary phase relationship would tend to make either of the above methods difficult for commercial implementation. As discussed in the above-mentioned article by Turova, it requires great care to control solution concentrations and conditions to prepare stable crystal structures. Such care may be possible under laboratory conditions, but such level of care may be very difficult under commercial plant conditions. Accordingly, applicant has also discovered a method for preparing such structures by using a "buffer" technique. In this technique advantage is taken of the ability of the Si(OR) 4 to virtually buffer the methanolic solution over a wide range of effective methoxide concentrations to prevent the irreversible polymerization represented by k 1 , in the following scheme where the pertinent tetramer/monomer equilibrium is represented by the equilibrium constant K and where in normally, non-buffered solutions k 1 , and k 2 (reaction rates) become rapid either at temperatures above 30° C. or at concentrations above about 8% Mg(OCH 3 ) 2 (by weight in CH 3 OH). In any reasonable commercial process concentrations of 12 to 25% and temperatures above 30° C. would be expected to be used and thus this stabilization technique becomes essential. It allows one to obtain up to a 28% concentration at the boiling point of CH 3 OH (67° C.). ##STR1## In the above scheme, magnesium methoxide and methanol are in equilibrium in solution with the crystalline magnesium compound. If conditions are not right, then as shown in Equation 2, (Mg(OCH 3 ) 2 MeOH) precipitate occurs. If concentrations are extremely high, this precipitate polymerizes to [Mg(OCH 3 ) 2 ] n , polymer. However, if Si(OR) 4 is added to the system, then it is possible to operate effectively in a wide range of concentrations outside of the narrow wedge (ABC) described in Turova. This is shown in FIG. 2 where Si(OR) 4 has been generated in situ as illustrated in Equation 3, by circle D which represents the effective methoxy/chloro concentrations of examples 5 and 6 below. This buffering approach effectively opens the wedge by moving the line AC to the right. Materials other than just SiCl 4 can be used to buffer the solution. Anything that can abstract methoxy and does not provide an anion so large as to seriously distort the crystal shape may be used. These compounds include silicon tetrachloride, silicon tetrabromide, tetramethoxy silane, tetraethoxy silane and phenyltrimethoxy silane as well as oxalic acid, acetic acid and formic acid, where if Si(OR) 4 is not generated in situ it must be added to the solution. Phosphorous compounds such as P(OCH 3 ) 3 , PCl 3 and PBr 3 may also be used so that P(OR) 3 is present. Another method for producing stable alkoxy magnesium compounds within the scope of the present invention involves treating the buffer compound, such a silicon tetrahalide, with an alkoxy magnesium compound, such as dimethoxy magnesium. This would then be followed by the addition of methanol, for example, thereby generating the stabilizing Si(OR) 4 species in situ. The alkoxy magnesium compound of the present invention can then be produced simply adding to this solution a solution of dimethoxy magnesium. The stabilized alkoxy magnesium compounds above may be subjected to a further stabilizing treatment. One method involves treating the above produced compounds with hydrogen chloride gas. Catalysts treated in this manner will produce a polymer with extremely high bulk density, very low polymer fines and good shape replication but with an extremely rough polymer surface. The alkoxy magnesium compounds above may also be boiled in an inert hydrocarbon, e.g. isooctane or cyclohexane. Any liquid hydrocarbon that forms azeotropes with methanol may be used. This stabilizing method produces a polymer with high bulk density, perfect shape replication and a smooth surface, but the productivity is lower than with the HCl treatment. If there is no treatment, then the polymer has a high bulk density but the shape retention is not as good. It is theorized that these methods remove excess methanol groups from the alkoxy magnesium compound and that a consequence of this removal is an increase in the stability of the crystal structure. Another advantage of this approach is to decrease the Ti level in the final procatalyst by decreasing the amount of sparingly soluble (Cl)(OMe)Ti species which may be formed upon contact with TiCl 4 . The boiling procedure has a tendency to decrease the activity of the catalyst. This can be at least partially prevented by first adding an amount of Si(OR) 4 and then proceeding with the boiling operation. In addition to Mg(OCH 3 ) 2 , other starting components include halogen containing magnesium compounds and magnesium dialkoxides. Examples of halogen containing magnesium compounds that can be used as starting materials for the reaction are alkoxy magnesium halides, such as isobutoxy magnesium chloride, ethoxy magnesium chloride, and ethoxy magnesium bromide. Preferred magnesium compounds are magnesium dialkoxides. In such compounds the alkoxide groups suitable have from 1 to 4 carbon atoms. Examples of these preferred groups of compounds are magnesium di-isopropoxide, magnesium diethoxide, magnesium dibutoxide, and ethoxy magnesium isobutoxide. Magnesium dimethoxide is particularly preferred. The basic molecular structure of the magnesium compound made according to the procedure discussed immediately above when X=2Cl - or 2Br - is illustrated in FIG. 1. The structure of particles of this compound is basically a dodecahedron structure. Furthermore, the polymer produced with the magnesium material of FIG. 1 produces polymer particles with a dodecahedron type structure as shown in FIGS. 3 or 4. Once the uniformly optimized particles of the magnesium compound have been obtained, it is then necessary to convert the compounds to magnesium halides in a metathesis reaction (digestion), such as that disclosed in U.S. Pat. No. 4,414,132. In the halogenation with a halide of tetravalent titanium, the magnesium compounds are preferably reacted to form a magnesium halide in which the atomic ratio of halogen to magnesium is at least 1.2. Better results are obtained when the halogenation proceeds more completely, i.e., yielding magnesium halides in which the atomic ratio of halogen to magnesium is at least 1.5. The most preferred reactions are those leading to fully halogenated reaction products, i.e., magnesium-dihalides. Such halogenation reactions are suitably effected by employing a molar ratio of magnesium compound to titanium compound of 0.005:1 to 2:1, preferably 0.01:1 to 1:1. These halogenation reactions may be conducted in the additional presence of a halohydrocarbon and/or an electron donor. An inert hydrocarbon diluent or solvent may also be present. When using an inert diluent or solvent, this may be used as a complete substitute for the halohydrocarbon. Suitable halides of tetravalent titanium include aryloxy- or alkoxy-di- and trihalides, such as dihexanoxy-titanium dichloride, diethoxy-titanium dibromide, isopropoxy-titanium tri-iodide and phenoxytitanium trichloride. Titanium tetrahalides are preferred. The most preferred halide is titanium tetrachloride. Suitable halohydrocarbons are compounds such as butyl chloride, amyl chloride and the following more preferred compounds. Preferred aliphatic halohydrocarbons are halogen-substituted hydrocarbons with 1 to 12, particularly less than 9, carbon atoms per molecule, comprising at least two halogen atoms, such as dibromomethane, trichloromethane, 1,2-dichloroethane, dichlorobutane, 1,1,3-trichloroethane, trichlorocyclohexane, dichlorofluoroethane, trichloropropane, trichlorofluorooctane, dibromodifluorodecane, hexachloroethane and tetrachloroisooctane. Carbon tetrachloride and 1,1,3-trichloroethane are preferred aliphatic halohydrocarbons. Aromatic halohydrocarbons may also be employed, e.g., chlorobenzene, bromobenzene, dichlorobenzene, dichlorodibromobezene, naphthyl chloride, chlorotoluene, dichlorotoluenes, and the like. Chlorobenzene and dichlorobenzene are preferred aromatic halohydrocarbons. Suitable electron donors which may be used in the preparation of the solid catalyst component are ethers, esters, ketones, phenols, amines, amides, imines, nitriles, phosphines, phosphites, stibines, arsines, phosphoramides and alcoholates. Examples of suitable donors are those referred to in U.S. Pat. No. 4,136,243 or its equivalent British Specification No. 1,486,194 and in British Specification No. 1,554,340 or its equivalent German Offenlegungsschrift No. 2,729,126. Preferred donors are esters, diesters and diamines, particularly esters and diesters of aromatic carboxylic acids, such as ethyl and methyl benzoate, p-methoxy ethyl benzoate, p-ethoxy methyl benzoate, ethyl acrylate, methyl methacrylate, ethyl acetate, dimethyl carbonate, dimethyl adipate, isobutyl phthalate, dihexyl fumarate, dibutyl maleate, ethylisopropyl oxalate, p-chloro ethyl benzoate, p-amino hexyl benzoate, isopropyl naphthenate, n-amyl toluate, ethyl cyclohexanoate, propyl pivalate, N,N,N',N'-tetramethylethylene diamine, 1,2,4-trimethyl piperazine, 2,2,5,5-tetraethyl piperidine and similar compounds. The electron donors may be used singly or in combination. Preferred electron donors for use in preparing the titanium constituent are ethyl benzoate and isobutyl phthalate. The halogenation normally proceeds under formation of a solid reaction product which may be isolated from the liquid reaction medium by filtration decantation or another suitable method and may be subsequently washed with an inert hydrocarbon diluent, such as n-hexane, iso-octane or toluene, to remove any unreacted material, including physically absorbed halohydrocarbon. Subsequent to halogenation, the product is contacted with a tetravalent titanium halide such as a dialkoxy-titanium diahalide, alkoxy-titanium trihalide, phenoxy-titanium trihalide or titanium tetrahalide. The most preferred titanium compounds are titanium tetrahalides and especially titanium tetrachloride. This treatment increases the content of tetravalent titanium in the solid catalyst component. This increase should preferably be sufficient to achieve a final atomic ratio of tetravalent titanium to magnesium in the solid catalyst component of from 0.005 to 3.0, particularly of from 0.02 to 1.0. To this purpose the contacting with the tetravalent titanium chloride is most suitably carried out at a temperature of from 60° to 136° C. during 0.1-6 hours, optionally in the presence of an inert hydrocarbon or halohydrocarbon diluent. Particularly preferred contacting temperatures are from 70° to 120° C. and the most preferred contacting periods are between 0.5 to 3.5 hours. The treatment may be carried out in successive contacts of the solid with separate portions of TiCl 4 , which may contain suitable electron donors chosen from the previous list. The preferred halogen atom, possibly contained in the titanium compound which serves as halogenating agent and in the tetravlaent titanium halide with which the halogenated product is contacted, is chlorine. After the treatment with tetravalent titanium halide the catalyst component is suitably isolated from the liquid reaction medium and washed to remove unreacted titanium compound. The titanium content of the final, washed catalyst constituent is suitably between about 1.5 to 3.6 percent by weight or up to about 4.5 percent. The material used to wash the catalyst component is an inert, light hydrocarbon liquid. Preferred light hydrocarbon liquids are aliphatic, alicyclic and aromatic hydrocarbons. Examples of such liquids include iso-pentane, n-hexane, iso-octane and toluene, with iso-pentane being most preferred. The amount of light hydrocarbon liquid employed is 5 to 100 cc/gm of procatalyst in each of 2 to 6 separate washes, preferably about 25 cc/gm. The resulting solid component is the procatalyst, which is used with cocatalyst and selectivity control agent in the polymerization process. Suitable electron donors, which may optionally (and preferably) be used in combination with or reacted with an organoaluminum compound as selectivity control agents and which are also used in the preparation of the solid catalyst component are ethers, esters, ketones, phenols, amines, amides, imines, nitriles, phosphines, silanes, phosphites, stilbines, arsines, phosphoramides and alcoholates. Examples of suitable donors are those referred to in U.S. Pat. No. 4,136,243 or its equivalent British Specification No. 1,486,194 and in British Specification No. 1,554,340 or its equivalent German Offenlegungsschrift No. 2,729,126. Preferred donors are esters and organic silicon compounds. Preferred esters are esters of aromatic carboxylic acids, such as ethyl and methyl benzoate, p-methoxy ethyl benzoate, p-ethoxy methyl benzoate, p-ethoxy ethyl benzoate, ethyl acrylate, methyl methacrylate, ethyl acetate, dimethyl carbonate, dimethyl adipate, dihexyl fumarate, dibutyl maleate, ethylisopropyl oxalate, p-chloro ethyl benzoate, p-amino hexyl benzoate, isopropyl naphthenate, n-amyl toluate, ethyl cyclohexanoate, propyl pivalate. Examples of the organic silicon compounds useful herein include alkoxysilanes and acyloxysilanes of the general formula R 1 n Si(OR 2 ) 4-n where n is between zero and three, R 1 is a hydrocarbon group or a halogen atom and R 2 is a hydrocarbon group. Specific examples include trimethylmethoxy silane, triphenylethoxy silane, dimethyldimethoxy silane, phenyltrimethoxy silane and the like. The donor used as selectivity control agent in the catalyst may be the same as or different from the donor used for preparing the titanium containing constituent. Preferred electron donors for use in preparing the titanium constituent are ethyl benzoate and isobutyl phthalate. Preferred as selectivity control agent in the total catalyst is p-ethoxy ethyl benzoate, phenethyltrimethoxy silane and diphenyldimethoxy silane. The organoaluminum compound to be employed as cocatalyst may be chosen from any of the known activators in olefin polymerization catalyst systems comprising a titanium halide but is most suitably free of halogens. While trialkylaluminum compounds, dialkylaluminum halides and dialkylaluminum alkoxides may be used, trialkylaluminum compounds are preferred, particularly those wherein each of the alkyl groups has 2 to 6 carbon atoms, e.g., triethylaluminum, tri-n-propylaluminum, triisobutylaluminum, triisopropylaluminum and dibutyl-n-amylaluminum. Preferred proportions of selectivity control agent, employed separately, in combination with, or reacted with an organoaluminum compound, calculated as mol per mol aluminum compound, are in the range from 0.005 to 1.5, particularly from 0.1 to 0.5. Preferred portions of selectivity control agent calculated as mol per mol Ti is in the range of 0.1 to 50, particularly 0.5 to 20. Proportions of electron donor contained in the solid catalyst component, calculated as mol per mol of magnesium, are suitably in the range of from 0.01 to 10, e.g., from 0.01 to 10 and from 0.05 to 5.0 and especially from 0.05 to 0.5. To prepare the final polymerization catalyst composition, procatalyst, cocatalyst and selectivity control agent, if used may be simply combined, most suitably employing a molar ratio to produce in the final catalyst an atomic ratio of aluminum to titanium of from 1 to 150, and suitably from about 10 to about 150. Preferably the components are premixed before they are injected into the reactor but they may be injected separately into the reactor. The catalysts of this invention tend to exhibit very good activity at much lower A1:Ti ratios, e.g., below 80:1 and even below 50:1, than prior art catalysts of the same type. It may, however, be advantageous under some conditions to employ them at higher A1:Ti ratios. Increasing the A1:Ti ratio tends to increase catalyst activity at the expense of increased catalyst residue in the unextracted product. These factors, as well as the desired level of isotacticity, will be considered in selecting the A1:Ti ratio for any given process and desired product. In general, A1:Ti ratios in the range of 30:1 to 100:1 and especially of about 50:1 to 80:1 will be found advantageous. The present invention is also concerned with a process for polymerizing an alpha monoolefin such as ethylene or butylene, preferably propylene, employing the novel catalyst components and compositions. These polymerization may be carried out by any of the conventional techniques, such as gas phase polymerization or slurry polymerization using liquid monomer or an inert hydrocarbon diluent as liquid medium. Hydrogen may be used to control the molecular weight of the polymer without detriment to the stereospecific performance of the catalyst with constant or intermittent supply of the novel catalyst compositions or one or more of the catalyst components to the polymerization reactor. The activity and stereospecificity of the novel catalyst compositions are so pronounced that there is no need for any catalyst removal or polymer extraction techniques. Total metal residues in the polymer, i.e., the combined aluminum, magnesium and titanium content, can be as low as 150 ppm, even less than 75 ppm. It is well known that supported coordination procatalysts and catalyst systems of the type used herein are highly sensitive, in varying degrees, to catalyst poisons such as moisture, oxygen, carbon oxides, acetylenic compounds and sulfur compounds. It will be understood that in the practice of this invention, as well as in the following examples, both the equipment and the reagents and diluents are carefully dried and freed of potential catalyst poisons. The productivity of the procatalyst is determined as kg polymer/g procatalyst in a standard one or two hour batch reaction; it may also be expressed as kg polymer/g Ti. Catalyst activity is sometimes reported as kg polymer/g procatalyst/hr. If determined in a standard one hour test, activity thus is numerically the same as productivity. The selectivity to isotactic polypropylene is determined by measuring the amount of xylene soluble polymer (XS), in accordance with regulations of the U.S. Food and Drug Administration. The XS test is carried out as follows: The sample is completely dissolved in xylene, which contains oxidation inhibitor, in a stirred flask by heating under reflux at 120° C. The flask is then immersed in a water bath at 25° C. without stirring for one hour, during which the insoluble portion precipitates. The precipitate is filtered off and the solubles present in the filtrate are determined by evaporating a 10 ml aliquot of the filtrate, drying the residue under vacuum, and weighing the residue. The xylene-solubles consist of amorphous material with some low molecular weight crystalline material. (FDA regulations 121.2501 and 1.1.2510, 1971.) The numerical value of XS in the case of propylene homopolymer is typically about 2 percent less than the amount of polymers extractable in refluxing n-heptane. Thus the isotacticity index of polypropylene (amount insoluble in refluxing n-heptane) is approximately 100-(XS+2). Catalyst productivity at standard conditions exhibits an inverse relationship with stereoselectivity. This relationship is characteristic for any given procatalyst. It is generally possible to control these variables, within limits, by changing the proportion of selectivity control agent (SCA). Increasing the amount of SCA increases selectivity to isotactic or stereoregular polymer but reduces activity, and hence productivity, in a standard one hour test. The following examples illustrate the invention: ILLUSTRATIVE EMBODIMENT I Preparation of the magnesium containing precursors A. Preparations using exact stoichiometry (i.e. OCH 3 /Cl=3.0) 1. (Staying within the metastable wedge.) Anhydrous magnesium chloride was dissolved in methanol and about 1/6 of the solvent distilled away. 3.0 equivalent of magnesium metal was added slowly, to maintain a gentle reflux, then the reaction kept under reflux to finish the magnesium consumption. After standing, a mixture of pumpkin shaped crystals and some grey powder was obtained. The product was slurried in a mixture of methanol/isopropanol and the grey powder decanted. After washing again with the methanol/isopropanol solution, the crystals were dried under moving nitrogen to give a recovery of 65% basis total magnesium. (Analysis: Mg=15.5%, Cl=12.2%, Mg/Cl=1.85 mol/mol). The mother liquor had the approximate composition of 8.5% Mg(OCH 3 ) 2 +3.0% MgCl 2 , a stable solution according to the ternary phase diagram. 2. (Leaving the metastable wedge by dilution.) The preparation was carried out as in example 1 except that, at the end of the reflux, an equal volume of isooctane was added to the hot methanol solution together with enough isopropanol to yield a homogeneous solution. Upon cooling, the yield of crystalline product was essentially quantitative, based on total magnesium. (Analysis: Mg=14.1%, Cl=10.4%, Mg/Cl=2.0 mol/mol). In contrast to example 1, the product appeared to be a mixture of crystalline forms. B. Preparations using excess chloride (i.e. OCH 3 /Cl <3). 3. (Moving outside the metastable wedge via high Cl concentration.) Commercially available magnesium chloride was dissolved in 8% commercially available methanolic magnesium methoxide (70 g MgCl 2 per quart of solution). After standing overnight the floculant magnesium was filtered away from the solution. 1.5 liter of the clear solution was mixed with 1.5 l of of isooctane and 0.8 l of isopropanol was added to insure homogeniety. The solution was stirred at 230 rpm with a teflon paddle stirrer. After a day, the precipitate was collected, washed with isooctane and dried under moving nitrogen. The yield, based on total magnesium, was 42%. (Analysis: Mg=15.9%, Cl=22.8%, Mg/Cl=1.0 mol/mol). The product appeared to be a mixture of at least two compounds consisting of well formed crystals in the 5-30 micron range. 4. Anhydrous magnesium chloride was dissolved in methanol then 1.0 equivalent of magnesium turnings was added at a rate so as to maintain a gentle reflux. After magnesium addition was finished, heat was applied and reflux was continued overnight. Then an equal volume of isooctane was added, to the hot solution, together with sufficient isopropanol to homogenize. The solution was allowed to cool, with vigorous stirring, to give spheroidal amorphous product in the size range of 20-80 microns. The yield, based on total magnesium, was 81.5%. C. Preparation with excess chloride in the presence of SiCl x (OCH 3 ) y buffer. 5. Magnesium (43 g, 1.77 mol) was added, in 5-8 g portions, to 1200 ml of methanol in a 2 l erlenmeyer flask. The solvent was heated gently to initiate the magnesium dissolution. After that, the heat of reaction was sufficient to maintain a gentle reflux. After all of the magnesium had dissolved, silicon tetrachloride (45 g, 264 mmol; 20% excess basis total Cl) was added slowly (since this presents a rather exothermic acid/base reaction). Two of these preparations were combined and sufficient methanol distilled away to bring the total volume to 1.6 to 1.7 l. The hot solution, `A`, was then poured into a 2 l reaction kettle, equipped with a large bladed paddle stirrer and stainless steel baffles, and stirred at high speed until the solution had cooled and a large mass of small crystals was obtained. The crystals were collected upon a coarse fritted funnel, washed twice with a mixture of 500 g isooctane/150 g isopropanol, washed twice with isooctane and dried under moving nitrogen for about 20 minutes. The yield was 420 g (71%). Visible and scanning electron microscopic examination reveal the product to be of a homogeneous crystal type in the shape of rhombic dodecahedrons such as seen in FIG. 3. 6. 105 g of the hot solution `A`, from example 5, was mixed with 61 g of toluene to give a clear solution. Upon stirring overnight 8.1 g of well formed, transparent crystals, in the shae of rhombic dodecahedrons such as seen in FIG. 3, were obtained. In the above examples, the crystals made in Example 1 demonstrate the preparation according to the invention, and make good catalysts. Example 2 is outside the wedge ABC and does not make good catalysts. Likewise examples 3 and 4 are also outside the invention. Examples 5 and 6 show buffered systems according to the present invention. Preparation of the Procatalysts The procatalysts (examples 7-17) were prepared as follows: Electron donor (type and amount shown in Table 1) were added along with 150 ml of a 1:1 (vol:vol) mixture of titanium tetrachloride and chlorobenzene to 50 mmol of the appropriate magnesium precursor (Table 1) and stirred at room temperature for 15 minutes. The mixture was then stirred for an hour at 100, 110 or 120° C. (as shown on tables) and filtered hot. The residual solid was slurried in 150 ml of the 1:1 titanium tetrachloride/chlorobenzene solution, 0.2 to 0.4 ml of phthaloyl chloride (as shown on table) was added (U.S. Patent No. 4,535,068), and the slurry stirred for 30-60 minutes at 110° C. After a hot filtration, the solid was slurried in 150 ml of the 1:1 titanium tetrachloride/chlorobenzene solution and stirred at 110° C. for 30 minutes and filtered hot. The reaction vessel was cooled to below 40° C. and the solid was washed 6 times with 150 ml portions of isopentane then dried for 100 minutes, at 40° C., under moving nitrogen. The titanium content of the various procatalysts is shown in Table 1. TABLE 1______________________________________ Mg Tita-Exam- Pre- Electron niumple # cursor Donor (% wt) Comments______________________________________ 7 1 iBP (9.7 mmol) 3.44 8 1 iBP (6.0) 4.63 9 1 iBP (7.5) 4.0610 1 MpT (16.7) 5.3011 2 iBP (7.6) 4.1012 3 iBP (17.3) 4.9813 4 iBP (11.1) 4.8114 5 iBP (9.9) 4.6715 5 iBP (8.7) 2.00 The magnesium precursor was boiled in isooctane for 1 hr to remove 92% of the bound methanol.16 5 iBP (8.7) 4.4917 6 iBP (8.7) 4.04______________________________________ iBP = isobutylphthalate MpT = methylp-toluate Liquid Pool (LIPP) and Gas Phase Propylene Polymerizations LIPP polymerizations were carried out for two hours at 67° C. in a 1 gal autoclave, using 2.7 l of propylene, 132 mmol of hydrogen, and sufficient catalyst to provide 8 micromoles of titanium. Triethylaluminum (70 mol/mol Ti) was mixed with 17.5 mmol of SCA (ethyl-p-ethoxybenzoate for example #23, diphenyldimethoxysilane for all others) and either premixed with the procatalyst 5 to 30 minutes before injection or injected directly to the autoclave before procatalyst injection. Gas phase polymerizations were carried out, for two hours at 67° C., at a pressure of 300 psig, with a 10 g/min propylene flow, in a 4 gal autoclave equipped with a ribbon stirrer. After gas flow had been established in the autoclave, the SCA was injected (17.5 mol/mol Ti) followed by the triethyl aluminum (70 mol/mol Ti) followed by the procatalyst (sufficient to provide 8 micromoles of titanium). The results are shown in Table 2. Note that examples 23-26 are really counterexamples using catalysts prepared from magnesium chloro methoxides which are not pure Mg 4 (OMe) 6 (MeOH) 10 Cl 2 and that is why their productivities are so much poorer than the others. Catalyst nos. 7-17 are those made in Examples 7-17, respectively. TABLE 2__________________________________________________________________________ExampleCatalyst Productivity X.S. Phase Morphology# # (Kg PP/g cat) (% wt) (g/l) Details__________________________________________________________________________18 7 44.7 6.8 l19 7 24.0 4.5 g 0.37 b.d., 84.5% of polymer at 0.25-2.0 mm20 8 40.6 9.1 l 0.32 b.d., 85.6% of polymer at 0.50-2.0 mm21 8 20.4 13.8 g 0.35 b.d., 88.6% of polymer at 0.50-2.0 mm22 9 40.9 6.1 l 0.39 b.d., 87.1% of polymer at 0.25-2.0 mm23 10 18.8 (1 hr) 7.9 l24 11 24.9 6.5 l25 12 6.0 8.5 l26 13 10.5 9.7 l27 14 66.1 7.2 l 0.43 b.d.28 14 15.8 5.4 g29 15 34.3 3.4 l 0.37 b.d., 84.3% of polymer at 0.25-2.0 mm30 15 10.2 2.0 g31 16 46.1 6.2 l 0.39 b.d., 80.7% of polymer at 0.5- 2.0 mm32 17 63.9 7.5 l 0.36 b.d.33 17 20.9 5.4 g__________________________________________________________________________ "g" is gas phase polymerization; X.S. is xylene solubles "l" is liquid phase polymerization "b.d." is bulk density ILLUSTRATIVE EMBODIMENT II In this Illustrative Embodiment, the preparation of the magnesium containing precursors was carried out according to preparation C in Embodiment Illustrative I with the exception that bromide replaced chloride in all cases. The resulting crystals were in the shape of dodecahedrons, such as seen in FIG. 4. Some of the magnesium precursors were post treated with HCl gas in isooctane or by boiling them in an inert hydrocarbon to remove some of the methanol groups and improve the stability. The catalyst preparation was carried out as set forth in Illustrative Embodiment I with the details and modifications shown in Table 3. TABLE 3______________________________________Ex-am- Tita-ple nium,No. Electron Donor % wt. Comments______________________________________34 iBp (2.5 ml) 3.91 0.3 ml PC, 110° C. digest35 iBp (3.0 ml) 3.12 0.3 ml PC, 120° C. digest36 iBp (2.5 ml) 3.08 0.3 ml PC, 120° C. digest37 iBp (2.5 ml) 2.93 0.4 ml PC, 110° C. digest, 120° C. wash38 iBp (3.0 ml) 3.91 no PC; 120° C. digest39 iBp (1.73 ml + 0.3 mlEB) 4.41 120° C. digest. Post treatment with HCl in isooctane40 iBp (1.73 ml + 0.3 mlEB) 5.06 110° C. digest. Post treatment with HCl in isooctane41 iBp (1.73 ml + 0.3 mlEB) 4.75 100° C. digest. Post treatment with HCl in isooctane42 iBp (3.0 ml) 3.23 0.3 ml PC, 110° C. digest, boiling iso- octane post treatment43 iBp (2.5 ml) 3.37 0.3 ml PC, 110° C. digest, boiling iso- octane post treatment44 iBp 1.00 Boiled in decalin45 iBp (1.73 ml + 0.3 mlEB) -- --46 iBp (1.73 ml + 0.3 mlEB) -- Standard magnesium chloride supported catalyst via Mg(OEt).sub.2______________________________________ iBp = diisobutylphthalate PC = phthaloyl chloride EB = ethyl benzoate The catalyst from Table 3 were utilized in the polymerization of propylene both in liquid phase and gas phase operations. The polymerizations were carried out according to the procedures set forth in Illustrative Embodiment I and the results of the polymerizations are set forth below in Table 4. TABLE 4__________________________________________________________________________ExampleCatalyst Productivity X.S. Phase Morphology# Example # (Kg PP/g cat) (% wt) (g/l) Details__________________________________________________________________________47 34 61.4 4.8 l b.d. = 0.3348 34 19.5 4.0 g b.d. = 0.3549 35 50.7 4.1 l b.d. = 0.44450 35 19.0*, 35 .sup. 1.9*, 4.5 g b.d. = 0.36*, 0.3951 36 48.8 3.6 l b.d. = 0.40552 36 .sup. 20.8*, 37.9 .sup. 2.3*, 3.0 g b.d. = 0.35*, 0.3853 37 48.8 4.1 l b.d. = 0.3954 37 28.8 4.4 g b.d. = 0.39455 38 58.2 6.1 l b.d. = 0.4156 38 33.5 5.2 g b.d. = 0.405, 2.7% fines below 120 microns *Two hour polymerizations at 67° C. 57 39 32.0 5.7 l b.d. = 0.41958 40 41.6 6.6 l b.d. = 0.448, 0.4% fines below 120 microns59 41 37.0 7.4 l b.d. = 0.412 The above three polymerizations were all in liquid phase at 67° C. 60 42 18.6 3.7 l b.d. = 0.37861 42 16.9 4.1 l b.d. = 0.37262 42 11.9 7.4 l b.d. = 0.41263 43 8.7 4.9 l64 44 0.1 l65 45 35.2 g b.d. = 0.378, 0.7% fines below 120 microns66 46 18.01 2.4 g b.d. about 0.3, 7.5% fines below 120 microns__________________________________________________________________________ "g" is gas phase polymerization "l" is liquid phase polymerization "b.d." is bulk density It can be seen by reviewing the results of Example 66 that a standard magnesium chloride catalyst produces polymer with a relatively high amount of fines below 120 microns, i.e. 7.5%. Examples 56 and 65, which utilize catalysts which were not post treated but which were prepared according to the present invention, give polymer with much lower fines, i.e. 2.7% and 0.7% below 120 microns. Example 58 wherein the catalyst was prepared according to the present invention and was post treated with hydrogen chloride gave polymer with the lowest percentage of fines of all, i.e. 0.4% below 120 microns. The bulk density of the polymer produced in the above three examples wherein the catalyst was prepared according to the present invention was higher than the bulk density of the polymer prepared from the standard magnesium supported catalyst. ILLUSTRATIVE EMBODIMENT III Example 65 Preparation of Unstabilized Mg(OMe) 2 Solution Mg turnings (28.2 g, 1.16 mol) were added in 2 gm portions, over the course of an hour, to 750 ml of methanol. If this unstabilized solution is allowed to heat above 45° C. the Mg(OMe) 2 is liable to undergo spontaneous polymerization to an intractable solid. The warm solution was filtered through a medium porosity glass frit and diluted to 900 ml. Preparation of MgBr 2 /Si(OMe) 4 Solution Silicon tetrabromide (52.4 g, 0.151 mol) was added dropwise to 234 ml (0.302 mol) of the above Mg(OMe) 2 solution followed by 50 ml of methanol, thereby generating the stabilizing Si(OR) 4 species in situ. Preparation of Mg 4 (OMe) 6 (MeOH) 10 Br 2 A 50° C. solution of this MgBr 2 /Si(OMe) 4 (100 mmol Mg) was added rapidly to a stirred 50° C. solution of Mg(OMe) 2 (258 mmol Mg) prepared above. After stirring 45 minutes, the crystalline precipitate was collected by filtration, washed once with an isooctane/isopropanol (4:1) solution, twice with isooctane and then dried under moving nitrogen. The yield was 57.0 gm (84%) of crystals of the shape shown in FIG. 4 with average particle size of 20 microns. Upon boiling in isooctane for 1 hour, a 20 gm sample decreased in weight to 17 gm, indicating a loss of 44.5% of the bound methanol. Example 66 A solution of commercially available 8% Mg(OMe) 2 in methanol (270 gm, 0.25 mol) was heated to 47° C. whereupon silicon tetrabromide (33 mmol) was added dropwise over about 5 minutes. After stirring 15 minutes, the crystalline precipitate was collected by filtration, washed 3 times with isooctane and dried under moving nitrogen. The yield was 25.2 gm (52.8%) of crystals in the size range of 30-80 microns with shapes consisting of a mixture of the dodecahedra of FIG. 3 and 4. Example 67 Preparation of Stabilized Mg(OMe) 2 Solution Tetramethoxysilane or tetraethoxysilane (7.73 gm, 50.8 mmol; 10.6 gm, 50.8 mmol) is dissolved in 270 ml MeOH and then magnesium (9.4 gm, 387 mmol) is added in 1 gm portions, as hydrogen evolution subsides, over a one hour period. The solution is filtered through a medium porosity glass frit and diluted with MeOH to 270 ml (if necessary). Preparation of MgBr 2 Solution Bromine (20.6 g, 258 mmol) is dissolved in 150 ml of ice cooled methanol. Magnesium (3.13 g, 129 mmol) is added in 0.5 g portions over 2 hours, with rapid stirring. Tetramethoxysilane (2.58 gm, 17 mmol) was added to the solution. Preparation of Mg 4 (OMe) 6 (MeOH) 10 Br 2 The MgBr 2 solution (above) was heated to 62° C. and added rapidly to a stirred solution of Mg(OMe) 2 (above), also at 62° C. After stirring at 55°-64° C. for 1 hour, the solid was collected by filtration, washed twice with isooctane/isopropanol (3/1) solution, twice with isooctane and then dried under moving nitrogen. The yield was 73.3 gm (75.2%) of crystals of the shape of FIG. 4. Analysis: 12.94% Mg, 63.7% MeOH. Example 68 Preparation of MgBr 2 Solution As in Example 67 using 19.0 gm Br 2 in 134 ml methanol plus 2.89 gm Mg. Preparation of Stabilized Mg(OMe) 2 Solution As in Example 67 using 11.8 gm phenyltrimethoxysilane dissolved in 270 ml methanol plus 8.68 gm Mg. Preparation of Mg 4 (OMe) 6 (MeOH) 10 Br 2 As in Example 67 via rapid mixing of the above two solutions at 60° C. Yield: 70.7 gm (78.6%). Analysis: 12.83% Mg, 67.02% methanol and 20.46% bromine. Example 69 Preparation of Mg Br 2 Solution As in Example 67 using 19.0 gm Br 2 in 134 ml methanol plus 2.89 gm Mg. Preparation of Stabilized Mg(OMe) 2 Solution As in Example 67 using 7.38 gm trimethoxyphosphite (P(OME) 3 ) dissolved in 270 ml methanol plus 8.68 gm magnesium. Preparation of Mg 4 (OMe) 6 (MeOH) 10 Br 2 As in Example 67 via rapid mixing of the above two solutions at 58° C. Yield 68.1 gm (75.7%). Example 70 Preparation of Mg 4 (OEt) 6 (MeOH) 3 Br 2 2.0 gm of Mg 4 (OMe) 6 Br 2 (Example 67) was slurried in 200 gm of tetraethoxysilane in a sealed bottle and gently rolled in an oil bath. After 17.5 hours at 35° C. the slurry had become milky. The temperature was then held at 50° C. for 27 hours, at 75° C. for 2.3 hours, at 105° C. for 14 hours (whereupon the milkiness had disappeared and definitely crystalline product was being produced) and then finally at 125° C. for 8 hours. The mixture was cooled to room temperature and the solids were collected on a coarse fritted glass funnel, washed twice with isooctane and dried under moving nitrogen. The yield was 16.3 g of 12-50 micron clusters of nearly cubic parallelipipeds. Analysis: 23.2% Br, 15.75% Mg, 46.6% EtOH, and 15.2% MeOH. Example 71 A catalyst was prepared from the Mg 4 (OEt) 6 (MeOH) 3 Br 2 of Example 70 according to the procatalyst preparation procedure of Illustrative Embodiment I with the exception that 0.35 ml of p-toluoyl chloride was used instead of phthaloyl chloride. 1.74 ml of isobutylphalate was added as the electron donor and the catalyst contained 2.71% titanium. This catalyst was used to polymerize propylene according to the LIPP polymerization procedure set forth in Illustrative Embodiment I. 0.56 mmol of triethyl aluminum, 0.105 mmol of diphenyldimethoxy silane and 5.7 micromols of titanium were used. The productivity of the catalyst was determined to be 39.5 kg of polypropylene per gm of catalyst and the polymer contained 4.1% xylene solubles. The bulk density of the polymer was 0.295 and its shape was cubes and agglomerates of cubes. ILLUSTRATIVE EMBODIMENT IV Example 72 To 111 gm of 12% Mg(OMe) 2 solution (stabilized and containing 154 mmol Mg, 19 mmol Si(OR) 4 ) stirred at room temperature was added dropwise a solution of 8.6 gm resorcinol (78.1 mmol) in 9.0 gm of methanol. After 37% of the resorcinol had been added, precipitation began. The Mg(OMe) 2 solution was then heated to 60° C. and the rest of the resorcinol solution was added. After stirring one hour at 60° C., the solution was allowed to cool. The solids were collected by filtration, washed with isopropanol/isooctane solution (1:3,wt:wt), then isooctane and then dried under moving nitrogen to yield 30.4 gm (96.3%) of crystalline material. Under microscopic examination the crystal shape appeared as in FIG. 7. Example 73 100 gm of 12% Mg(OMe) 2 solution (stabilized and containing 139 mmol Mg) was heated to 60° C. Then a mixture of 3.74 gm resorcinol (34 mmol) and 6.28 gm methacrylic acid (77.6 mmol) in 10 ml of methanol was added dropwise to give a crystalline precipitate. After filtering and i-C 8 wash and N 2 drying, 16.0 gm of very dense crystals were obtained in the shape of short square cylinders as in FIG. 5 (under microscope). Example 74 To 100 gm of 12% Mg(OMe) 2 solution (stabilized and containing 139 mmol Mg and 17 mmol Si(OR) 4 ) at 60° C. was added 7.31 gm of 2,4-pentanedione (73 mmol) to obtain a clear solution. To this was added 3.74 gm of resorcinol (34 mmol) as a 53% solution in methanol. After stirring at 60° C. for less than 1 hour, a voluminous precipitate appeared. Filtration, i-C 8 wash and N 2 drying yielded 17.9 gm of fluffy crystalline powder. Tiny crystalline flakes were seen in a microscope (FIG. 9). Example 75 Preparation of Catalyst from the Resorcinolate Species: (Mg(OCH 3 ) 6 (CH 3 OH) 10 ) (C 6 H 4 OHO) 2 Prepared in Example 72 40 g was placed in 300 gm of cyclohexane with 120 g of tetraethoxysilane (TEOS). This mixture was placed in a 110° C. oil bath and allowed to boil about 1.5 hours (to lose about 20% of the total volume). After filtration and drying, 32.1 g of solid material was obtained. 7.8 gm of this material (containing 49 mmol of Mg) was then subjected to a standard 115° C. catalyst preparation where 2.5 ml of isobutylphthalate was used in a digest of 200 ml of 50/50 TiCl 4 /Cb and 0.5 ml phthaloyl chloride plus 0.5 ml phthaloyl chloride plus 0.5 ml of p-toluoyl chloride were used in 200 ml of 50/50 TiCl 4 /CB as a first wash. 200 ml of 50/50 TiCl 4 /CB were used as a second wash. A 10 minute wash of 100 ml of 50/50 TiCl 4 /CB @115° C. was then applied followed by 6 150 ml isopentane washes and N 2 drying @40° C. The yield was 6.5 gm of dark brown powder. Analysis: Ti=3.23%, Mg=19.6%, Cl=63.1%. Examples 76-78 The catalyst made in Example 75 was used to polymerize propylene by the LIPP procedure set forth in Illustrative Embodiment I. In two of the examples, a different selectivity control agent, tetramethylpiperidine (TMP), was used in place of the diphenyldimethoxy silane (DPDMS). The results of the polymerizations are shown in Table 5. TABLE 5__________________________________________________________________________ Productivity (kgExampleTitanium TEA SCA SCA polypropylene/gm XyleneNo. (mmol) (mmol) (mmmol) (type) catalyst/hr) Solubles (% wt)__________________________________________________________________________76 0.006 0.42 0.048 TMP 71.8 8.377 0.0045 0.32 0.014 DPDMS 50.0 5.078 0.0045 0.32 0.048 TMP+ 58.0 4.6 0.014 DPDMS__________________________________________________________________________ With TMP as the selectivity control agent, a high yield is obtained but the xylene solubles are also high. With DPDMS, a lower yield is obtained but the xylene solubles are low. When the two selectivity control agents are mixed together, an intermediate yield is obtained but the xylene solubles are lower still. Illustrative Embodiment V 106 gm of 8% Mg(OMe) 2 solution (97 mmol Mg, 12 mmol Si(OR) 4 ) was stirred at 60° C. To this solution was added dropwise a solution of 51 mmol of the appropriate acid shown in Table 6 in 10 ml of methanol. After precipitation, the solids were collected by filtration, washed twice with isooctane and then dried under moving nitrogen. Yields and crystal shapes are shown in Table 6. The acetate salt is prepared in the same manner but must be ice-cooled to give a precipitate of crystals in the shape of FIG. 8. TABLE 6______________________________________Ex- Productam- Molecular Yield Yieldple Acid used Weight (gm) (%) Shape______________________________________79 Chloroacetic 198.2 10.9 56.5 FIG. 1280 Methacrylic 194.0 13.4 71.0 FIG. 581 Methacrylic (via 194.0 27.1 90.6 FIG.12% Mg(OMe).sub.2) 5 & 682 Acrylic 186.98 8.3 45.6 FIG. 883 Propionic 187.99 8.2 44.8 FIG. 1084 Butyric 195.0 8.4 44.3 FIG. 685 Benzoic 212.01 12.9 62.6 FIG. 11______________________________________ ILLUSTRATIVE EMBODIMENT VI In Situ Generation of Phosphorous Esters as Stabilizing Agents Example 86 In like manner to Example 69, 9:4 gm of Mg was dissolved in methanol to prepare a solution volume of 310 ml. Phosphorous trichloride (9.3 gm, 68 mmol) was added dropwise to 64 ml of that solution, then the remainder of the magnesium methoxide solution (246 ml) was added rapidly at 50° C. Cooling to room temperature yielded a crop of large, well formed crystals. Example 87 The above experiment was repeated using 18.4 g of phosphorous tribromide instead of PCl 3 to yield 29.4 g of well formed crystals with average particle size of 19.5 microns. ILLUSTRATIVE EMBODIMENT VII Demonstration of Thermal Instability of Mg(OMe) 2 Solutions Example 88 A 250 g sample of commercially available 8% Mg(OMe) 2 in methanol turned quite cloudy upon heating to 50° C. It was then heated to boiling and 1/3 of the solvent was boiled away. After cooling, the solvent was replaced but the white precipitate die not redissolve. The precipitate was collected on a fritted filter, washed with isooctane and dried under moving nitrogen (weight 5.0 gm). Assuming the product to be Mg(OMe) 2 ° 2 MeOH polymer (m.w. 150.44), that implies that more than 14% of the Mg(OMe) 2 had decomposed to that intractable polymer. On the other hand, the Si(OR) 4 stabilized 12-15% solutions described herein may be refluxed nearly indefinitely with practically no observable signs of decomposition.

Crystalline magnesium olefin polymerization catalyst components capable of producing polymer with improved activity and morphological properties are disclosed and claimed. In particular, the components are prepared by reacting a crystalline alkoxy magnesium compound with a halide of tetravalent titanium.

TECHNICAL FIELD The present invention relates to an automatic door with flexible curtain. BACKGROUND Automatic doors with flexible curtain typically comprise two lateral uprights, a transverse case connecting the upper ends of the lateral uprights, and a curtain movable between a closing position in which it obstructs the opening formed by the transverse uprights and the case and an opening position in which the curtain is folded or rolled into the case. Driving means, conventionally arranged in or on one of the sides of the case, allow displacement of the curtain from the closing position to the opening position and vice versa. An important issue in the field of the automatic doors with flexible curtain concerns securing the operation of these doors in order to avoid, during displacement of the curtain from the opening position to the closing position, a collision between the curtain on the one hand and a person or a vehicle on the other hand, which may cause injury to the person or deterioration of the vehicle and/or deterioration of the curtain. A solution known from patent FR2877684 consists of integrating into the curtain means for detecting an encounter with an obstacle in order to secure the operation of the door. The means for detecting an encounter with an obstacle are connected by a wired connection to the electronics or electromechanics for controlling the driving means of the curtain. Therefore, the triggering of the means for detecting an encounter with an obstacle allows for example, via the control electronics or electromechanics, ordering the driving means to stop the closing of the curtain and to move it in the opposite direction in order to open it. This solution offers high reliability of detection of an obstacle and allows quite satisfactorily to preserve the physical integrity of the vehicle or of the person accidentally hit by the curtain, and the physical integrity of the curtain itself. However, the wired connection connecting the detection means to the control electronics or electromechanics is at least partially exposed to attack from the outside environment. This may be problematic when the door is for example exposed to bad weather and hydrometric variations, due to the increased risk of deterioration of the quality of the electrical connection. In addition, the wired connection is easily accessible; thus it risks to be sectioned, accidentally when a vehicle passes nearby or with malicious intent. Moreover, given the speed of displacement of the curtain and the frequency of its displacements, the wired connection between the means for detecting an encounter with an obstacle and the control electronics or electromechanics is subject to a risk of premature wear, or even breakage upon a displacement of the curtain. This results in reliability problems that can be limited only by means of regular maintenance. Then, the wired connection is limitative in terms of dimensioning of the door that it equips; it is difficult to implement as a solution to detect obstacles similar to that described in the patent FR2877684 for a door of significant dimensions, for example intended for the passage of an aircraft into or out of a hangar. Finally, and most importantly, within the framework of applications in the fields of pharmaceuticals or food processing, the door can mark the entry or exit point of a clean room and must thus be cleaned regularly. However, cleaning the wired connection, typically a spiral wire that extends or retracts as to whether the door closes or opens, may be tedious when done by hand, or can cause premature wear of this wired connection when it is carried out by means of cleaning products which can be corrosive (after a number of cleaning operations, the spiral wire gradually loses its flexibility and could end up breaking). BRIEF SUMMARY The present invention aims to overcome all or part of these drawbacks by proposing a door with flexible curtain offering high efficiency of detection of obstacles and great ease of cleaning, while being less sensitive to attack from the outside environment and the main causes of premature wear. To this end, the present invention provides a door with flexible curtain comprising a structure including uprights and a transverse element allowing to guide a flexible curtain provided with a ballasting and sealing element at its free end and at least one reinforcing element parallel to the ballasting and sealing element, the door also comprising driving means supported by the structure allowing to maneuver the curtain between an opening position and a closing position, and means for detecting encounter with an obstacle likely to cause, when activated, the stopping and/or reverse displacement of the curtain, carried at least partly by a supporting element and integrated within the lower part of the curtain, the means for detecting encounter with an obstacle being situated upstream of the ballasting and sealing element, on the closing trajectory of the curtain, between the reinforcing element and the ballasting and sealing element, characterized in that the door comprises at least one emitter, each emitter cooperating with the means for detecting encounter with an obstacle in order to emit a radio signal following the triggering of the means for detecting encounter with an obstacle, the radio signals emitted by each emitter can be received by at least one receiver cooperating with the means for driving the curtain consecutively to the triggering of the means for detecting encounter with an obstacle, and in that the curtain comprises at least one support means arranged in proximity to one of the uprights in order to support each emitter in a lateral area of the curtain. Therefore, the door according to the invention equipped with a wireless connection is freed from the traditional constraints connected to wired connections, particularly in terms of the time spent to the cleaning of this wired connection, in terms of attack from the outside environment and in terms of wear of this wired connection. The door according to the invention allows thus transmitting with great reliability a signal following the triggering of the detection means. Moreover, it is noted that the arrangement of the emitter in a lateral area of the curtain, that is to say in an area of little exposure to collision risks, substantially limits the risk of deterioration of the emitter which may result from the accidental collision of a vehicle or a person with the curtain. It is noted that, the means for detecting encounter with an obstacle may correspond to means for detecting encounter with an obstacle by contact, that is to say, they may correspond to means for detecting a contact between the curtain and an obstacle. According to a characteristic of the door according to the invention, the communication between each receiver and each emitter is bidirectional in order to control a state of correct operation of each emitter. According to a form of execution, each emitter comprises a secondary receiver, each receiver integrating at least one secondary emitter capable of emitting a radio signal towards the secondary receiver of each emitter in order to control the state of correct operation of each emitter. Advantageously, the state of correct operation corresponds to a charge level of at least one built-in battery or battery cell integrated into each emitter greater than a predetermined charge level threshold. According to one possibility, the receiver is configured to control a state of correct operation of each emitter only during the displacement of the curtain towards the closing position. This has the advantage of limiting the energy consumption of each emitter, thus increasing their battery life. Advantageously, the door comprises alerting means intended to inform a user of the absence of the state of correct operation of the emitter or at least one of the emitters. According to an embodiment, the emitter or the at least one of the emitters onboard at least one amplifier of an infrared signal transmitted between an emitting cell and a receiving cell of the means for detecting encounter with an obstacle. Therefore, the amplifier of the infrared signal is less exposed to the risk of breakage following a contact between the curtain and an obstacle, this contact leading to the cutoff of the infrared signal by deformation of the ballasting and sealing element. According to one embodiment, each support means corresponds to at least one pocket adapted to contain the emitter or the at least one of the emitters. According to an embodiment, the pocket is arranged inside the curtain. According to one possibility, the pocket is suspended from a sleeve containing the supporting element, and is attached to the sleeve by welding. The pocket can be suspended from the sleeve containing the supporting element of the cells, when the means for detecting encounter with an obstacle comprise emitting/receiving cells. According to a form of execution, the curtain comprises an inspection shutter arranged to permit access to the emitter or at least one of the emitters. The inspection shutter may advantageously offer direct access to the emitter or the at least one of the emitters, or give access to the pocket if this emitter is placed in the pocket. According to one possibility, each emitter is spaced apart from one of the uprights by a distance comprised between 5 cm and 40 cm, preferably between 10 cm and 15 cm. Advantageously, the emitter or the at least one of the emitters is arranged inside the curtain, preferably in the lower part of the curtain between the reinforcing element and the ballasting and sealing element. An emitter placed outside risks indeed de be clung and deteriorated in the case of a light touch of the curtain by a person or a vehicle. In addition, the emitter placed in the lower part of the curtain is in proximity to the means for detecting encounter with an obstacle. The required connection between the emitter and the means for detecting encounter with an obstacle is thus easier to implement. Advantageously, the alerting means may comprise at least one indicator lamp. This indicator lamp is placed to be easily visible to a user. According to one possibility, the supporting element coincides with the reinforcing element. BRIEF DESCRIPTION OF THE DRAWINGS Other characteristics and advantages of the present invention will become apparent from the below description of an embodiment of the invention, given by way of non-limiting example, with reference to the accompanying drawings in which: FIGS. 1 and 3 are partial cross-sectional side views of the lower part of a vertical rolling door curtain according to an embodiment of the invention (emitter not visible), FIGS. 2 and 4 are sectional views, respectively along line II-II of FIG. 1 and line IV-IV of FIG. 3 , FIG. 5 is a schematic front view of the vertical rolling door curtain, FIG. 6 is a front view of the inside of the lower part of a vertical rolling door curtain, FIG. 7 is a schematic perspective and partial sectional view of the lower part of a vertical rolling door curtain, FIG. 8 is a schematic sectional and profile view of the lower part of a vertical rolling door curtain, FIGS. 9 and 10 are respectively front and profile views of a pocket for supporting an emitter of a door according to an embodiment of the invention, FIG. 11 is a perspective view showing an inspection shutter of the door curtain according to an embodiment of the invention. DETAILED DESCRIPTION FIGS. 1 and 3 show the lower part of a door 1 with vertical rolling flexible curtain 2 . Generally, it is about doors having a structure comprising uprights 4 and a transverse element 5 allowing to guide the curtain 2 , and driving means 3 (electric motor, reducer, control electronics or electromechanics) supported by the structure allowing to maneuver the curtain 2 between an opening position and a closing position. As is also visible in FIGS. 2 and 4 , the curtain 2 comprises at its free end a ballasting and sealing element 6 and means for detecting encounter with an obstacle, such as those described in the patent document FR2877684. According to the embodiment illustrated in FIGS. 1 to 11 and given by way of example, the means for detecting encounter with an obstacle comprise an emitting cell 8 , that emits an optical (infrared) beam 10 parallel to and upstream of the ballasting and sealing element 6 , and a receiving cell 12 arranged facing the emitting cell 8 . An emitting/receiving cell cooperating with a passive beam-return cell can also be considered. Several emitting cell 8 /receiving cell 12 couples can also be considered in order to increase the width of the door 1 . The detecting means also comprise at least one detecting flag 14 for each emitting cell 8 /receiving cell 12 couple. The detecting flag 14 can be constituted by an L-profile. It is supported here by the ballasting and sealing element 6 . The operation of the detecting device is as follows. When the ballasting and sealing element 6 encounters an obstacle during its descent, it deforms as it is constituted for its essential part by a spring 16 and a foam sheath 18 . The deformation of the ballasting and sealing element 6 modifies the base of the detecting flag 14 which cuts off the beam 10 which is normally parallel to the ballasting and sealing element 6 . The beam 10 being cutoff, a signal is sent to the control electronics or electromechanics of the door 1 which then gives the order, on the one hand, to stop the closing of the curtain 2 , and on the other hand, to re-open it. As is visible in FIGS. 1 to 4 , the emitting cell 8 and the receiving cell 12 are each supported by a prop 20 . Each prop 20 is here fastened to a supporting element 22 . The supporting element 22 is substantially parallel to the ballasting and sealing element 6 and allows supporting the means for detecting encounter with an obstacle. The supporting element 22 may correspond to a reinforcing element 24 or a transverse stiffening bar integrated into the curtain 2 , as is the case in FIGS. 1 to 5 , or be dissociated therefrom, as is the case in FIGS. 6 to 8 . According to one possibility, each reinforcing element 24 is guided but not retained, and is adapted to withstand multidirectional shocks. It is noted that each prop 20 may present a plurality of areas 26 for hosting the emitting cell 8 or the receiving cell 12 , such that the center distance existing between the ballasting and sealing element 6 and the axis of the beam 10 can be varied. According to the embodiment illustrated in FIGS. 1 and 2 , it is noted that the curtain 2 presents, not only a single apron, but two aprons 34 , 36 . At the end of the curtain 2 , a U-shaped tarpaulin 30 fixed to each one of the aprons 34 , 36 is provided, in which a sleeve 32 receiving the ballasting and sealing element 6 is formed. In addition, the curtain 2 can comprise two adjacent reinforcing elements 24 connected by a spacer 25 . In the embodiment of FIGS. 3 and 4 , it is noted that the curtain 2 presents a single apron 28 which, at its lower end, presents a U-shaped tarpaulin 30 which is fixed on each one of the faces of the apron. A sleeve 32 is formed in the U-shaped tarpaulin in order to receive the ballasting and sealing element 6 . As is visible in FIG. 5 , the door 1 comprises quite remarkably at least one emitter 38 intended to cooperate with the means for detecting encounter with an obstacle in order to emit a radio signal following the triggering of the means for detecting encounter with an obstacle. Therefore, each receiving cell 12 can be connected to an emitter 38 , for example by a wired connection 40 . When the door 1 comprises several emitters 38 , the emitters 38 operate independently of one another. According one a possibility, the door 1 comprises at least two detecting assemblies, for example at least two emitting cell 8 /receiving cell 12 couples, and two emitters 38 , each emitter 38 being associated with one of the detecting assemblies. Therefore, quite advantageously, the alignment of several detecting assemblies aligned parallel to the ballasting and sealing element 6 and associated each with an emitter 38 allows the production of doors 1 of large width. For example, the door 1 may comprise two beams 10 of 5 m, each one associated with an emitter 38 independent of one another, in order to produce a door 1 with a width of approximately 10 m. In the example of FIG. 5 , two emitters 38 have been represented. As can be seen in FIG. 5 , the emitters 38 are remarkably arranged in proximity to one of the uprights 4 , in other words in proximity to one of the lateral edges 42 of the curtain 2 . Quite advantageously, the emitters 38 are therefore situated in an area less exposed to the risks of collision with a person or a vehicle. Each emitter 38 is distant from one of the uprights 4 by a predetermined distance d which may be comprised between 5 cm and 40 cm, and preferably between 10 cm and 15 cm. Each emitter 38 can cooperate with a receiver 44 located in the vicinity of the door 1 , that is to say by a distance which enables the establishment of a radio connection between each emitter 38 and the receiver 44 . The receiver 44 can be single. The receiver 44 is adapted to receive the radio signals emitted by each emitter 38 . The receiver 44 is intended to cooperate with control electronics or electromechanics in order to control the means for driving the curtain 2 so as to stop and/or move the curtain 2 consecutively to the triggering of the means for detecting encounter with an obstacle. It is noted that, advantageously, when the door 1 comprises a detecting assembly with infrared beam 10 , the emitter 38 associated with this detecting assembly can onboard at least one amplifier 60 of an infrared signal transmitted between the emitting cell 8 and the receiving cell 12 of this detecting assembly. Quite remarkably, the communication between each emitter 38 and the receiver 44 is bidirectional. In other words, the radio signals can be emitted from each emitter 38 to the receiver 44 , and from the receiver 44 to each emitter 38 . The frequency can be for example in the order of 2.4 GHz. The communication can be simultaneous for a better response time (the emitter 38 and the receiver 44 can emit and receive signals simultaneously). Thus, the receiver 44 is capable of monitoring a state of correct operation of each emitter 38 , at least during the displacement of the curtain 2 up to the closing position and, where appropriate, only in this case in order to increase the battery life of the emitters 38 . The receiver 44 may for example examines each emitter 38 about the charge level of the battery cell(s) or battery(ies) it integrates in order to supply. According to one possibility, the receiver 44 can therefore integrate at least one secondary emitter (not represented) capable of emitting a radio signal, and each emitter 38 can integrate a secondary receiver (not represented) capable of receiving one of the radio signals emitted by the secondary emitter or one of the secondary emitters integrated into the receiver 44 . The door 1 can comprise alerting means, for example an indicator lamp (not represented), intended to alert a user when the receiver 44 has detected a low level of battery charge for the emitter or one of the emitters 38 . In this case, the indicator lamp illuminates in order to indicate this low battery state to a user, and it can be considered to move the curtain 2 to the opening position while awaiting the intervention of an operator. The operator may proceed to the replacement of the used battery cell or battery by moving the curtain 2 in maintenance mode and accessing, where appropriate, the concerned emitter 38 via an inspection shutter 45 , visible in FIG. 11 . Each inspection shutter 45 is arranged to permit access to an emitter 38 . The inspection shutter 45 may correspond to a cutout arranged in the curtain 2 in order to delimit an opening 47 permitting access to the emitter 38 . It may comprise closing means, for example of the hook and loop types, intended to maintain the cutout folded over the opening 47 in order to obstruct it. The inspection shutter 45 is arranged in proximity to the emitter 38 . It is dimensioned in order to allow passage of the emitter 38 through the opening 47 it delimits. Ideally, the inspection shutter 45 is also shaped in order to permit access to means for detecting encounter with an obstacle. It may thus allow the replacement of an emitting cell 8 or a receiving cell 12 . At least one support means, such as a pocket 46 represented in FIGS. 6 to 10 , allows supporting each emitter 38 . The pocket 46 may correspond to a PVC canvas; its dimensions (for example length L in the order of 300 mm and height h in the order of 120 mm) are adapted to contain the emitter 38 (the dimensions of which can be in the order of 15 cm in length, 3 cm in height and 2 cm in width). The pocket 46 is arranged in proximity to one of the uprights 4 in order to support each emitter 38 in a lateral area of the curtain 2 . According to the embodiment illustrated in FIGS. 6 to 8 , the pocket 46 is situated in the curtain 2 , such that the emitter 38 it contains is situated in the curtain 2 . More precisely, the pocket 46 may be arranged in the lower part of the curtain 2 , in particular in the U-shaped tarpaulin 30 , between the reinforcing element 24 or the supporting element 22 and the ballasting and sealing element 6 . The emitter 38 it contains is therefore in immediate proximity to the means for detecting encounter with an obstacle. As is visible in FIGS. 6 to 8 , the pocket 46 may be suspended from a sleeve 48 containing the supporting element 22 . An upper portion 50 of the pocket 46 is for example welded to the sleeve 48 . As is visible in FIGS. 9 and 10 , the pocket 46 may correspond to a cutout, two opposite edges of which are folded one against the other and welded to one another in order to delimit an internal volume intended to receive the emitter 38 . The pocket 46 comprises two ends, one of which ( FIG. 10 ) is locked (welded edges) and the other of which (to the right of FIG. 9 ) is intended to allow the insertion or removal of the emitter 38 in or out of the pocket 46 . Closing means, for example of the snap button, hook and loop, slide fastener, or self-locking collar types 52 (inserted in holes 54 arranged on the pocket 46 ), allow closing the end intended to the insertion or removal of the emitter 38 . Of course, the invention is in no way limited to the embodiment described above, this embodiment having been given only by way of example. Modifications remain possible, especially from the point of view of the constitution of the various elements or by the substitution of technical equivalents, without for all that departing from the field of protection of the invention. Therefore, the invention can also be applied to doors with horizontal or vertical folding or rolling flexible curtain. It is noted that the means for detecting encounter with an obstacle is not limited to an infrared beam transmitted between an emitting cell and a receiving cell. They may also comprise a mechanical system with a cable which, at one of its ends, is retained by a spring at a prop 20 and, at its other end, is retained through a pull-type contact. It is also conceivable to use an air flange associated with a pressure switch. When the door 1 comprises several aligned detecting assemblies, these may be of different types (for example infrared system and mechanical system). Where appropriate, the emitters 38 are configured to receive the signals outputted by the detecting assembly to which they are associated. The invention also allows the production of assemblies comprising several doors 1 and a single receiver 44 placed in the vicinity of each one of these doors 1 in order to cooperate with the emitter 38 or the emitters 38 of each one of the doors 1 .

A flexible curtain has a ballasting and sealing element and a reinforcing element, and is able to move between an open position and a closed position. The door comprises a detection unit configured to detect an encounter of the ballasting and sealing element with an obstacle. The door also comprises a wireless emitter arranged inside the curtain, close to an upright, in a lateral region of the curtain. The emitter cooperates with the detection unit and emits a radio signal when the obstacle is detected by the detection unit. The radio signal is received by a receiver which cooperates with a driving unit so as to stop or reversely move the curtain.

BACKGROUND OF THE INVENTION The present invention relates to a transmission system for transmitting frequency-division multiplexed (hereinafter abbreviated as FDM) signals each being modulated by a speech signal or the like. An FDM carrier telephony system has, as indispensable constituent elements, a number of filters for suppressing undesired spectra such as undesired side bands and carriers contained in amplitude-modulated signals. Also, filters are further needed to shape the frequency spectra, which tend to spread over the frequency axis due to the frequency modulation signals, into desired transmission bands. For this purpose, a conventional FDM signal transmission system has a filter at a stage following the respective modulator in a one-to-one correspondence. One example of such a conventional FDM transmission system is described in "Phillips Telecommunication Review", Vol. 33, No. 2, pp. 86-96, published in June issue 1975 (Literature 1). However, such a conventional system is costly to manufacture because of the need for at least as many filters as there are transmission channels. SUMMARY OF THE INVENTION An object of the present invention is therefore to provide an FDM signal transmission system free from the above-mentioned disadvantage. The present system comprises a plurality of input terminals for modulation signals, a plurality of modulator means provided in a one-to-one correspondence to said input terminals and associated with a plurality of carriers having a predetermined frequency difference therebetween for modulating the plurality of carriers respectively with said plurality of modulation signals, respectively, means for combining the modulated signals to arrange them on the same frequency axis, and a comb filter for suppressing undesired spectra contained in the output signal of said combining means. The present invention is compact and economical because it eliminates the requirement of filters placed after each amplitude-modulator or FSK (frequency shift keying)-modulator. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a block diagram of a first embodiment of the present invention. FIG. 2 shows a diagram for explaining the operation of the first embodiment. FIG. 3 shows a block diagram of a second embodiment of the present invention. FIG. 4 shows a diagram for explaining the operation of the second embodiment. FIGS. 5(a) and 5(b) show block diagrams of a comb filter to be used in the present system. FIG. 6 shows a diagram for showing a distribution of signal components of an FSK-modulated signal. FIG. 7 shows a block diagram of a third embodiment of the present invention. FIG. 8 shows a diagram for explaining the operation of the third embodiment. FIG. 9 shows a block diagram of a fourth embodiment of the present invention. FIG. 10 shows a diagram for explaining the operation of the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 the first embodiment comprises basic converter stages 3 and 4 having a plurality of input terminals 1 1 , 1 2 and 1 3 and 2 1 , 2 2 and 2 3 , respectively, to which modulation signals are applied, and output terminals 5 and 6 from which a first-stage FDM signal is obtained. An adder 7 combines the output signals of the basic converter stages 3 and 4 into the combined FDM signal at an output terminal 8. The stage 3 includes amplitude modulators 3 1 , 3 2 and 3 3 for amplitude-modulating the carriers C 1 , C 3 and C 5 from a carrier source 9 with the input modulation signals appearing at terminals 1 1 -1 3 , respectively. An adder 3 4 combines the output signals of modulators 3 1 -3 3 on the same frequency axis, and a comb filter 3 5 suppresses undesired spectra in the combined signal. The stage 4 has the same contruction as the stage 3. The adders 3 4 , 4 4 and 7 are formed of, for instance, a well-known hybrid coil or an operational amplifier. With regard to the comb filters 3 5 and 4 5 , reference is made to the disclosure in the "PROCEEDINGS OF THE IEEE", Vol. 55, No. 2, pp. 149-171, published in February 1967, especially FIG. 20(a) on page 166, (Literature 2). Since the input signal to the filter disclosed in FIG. 20(a) of Literature 2 consists of values selectively sampled from a continuous wave, in case where such filters are employed as the comb filters 3 5 and 4 5 in the first embodiment, it is necessary to use A-D (analog-to-digital) and D-A (digital-to-analog) converters at a stage preceding or following each of such filters. However, if a charge transfer device (CTD) with the functions of sampling an input signal and transferring the sampled values in response to a clock signal is employed as a delay element in the comb filter, the input signal applied to such a filter may be a continuous signal. FIGS. 5(a) and 5(b) show block diagrams of comb filters using the CTD for the latter purpose. In these figures, however, for the purpose of representing one CTD having the above-mentioned functions, a delay element and a sampler are illustrated. Referring further to FIG. 1, clock signals required for the charge transfer and sampling are fed from a clock signal source 9'. The comb filters 3 5 and 4 5 constructed in the above-described manner permit pass bands and elimination bands to occur alternately at a predetermined period. Now the operation of the present system with the structure mentioned previously will be explained in detail with reference to FIGS. 1 and 2. The speech signals applied as inputs to the modulators will have equal band-widths of ΔF 1 , as shown in the upper part of FIG. 2. Also, it is assumed that the frequencies of the carriers C 1 , C 3 and C 5 and C 2 , C 4 and C 6 applied to the amplitude modulators 3 1 -3 3 and 4 1 -4 3 , respectively, differ from each other by ΔF 2 /2, also as indicated in FIG. 2. Thus, the modulated signals will have upper and lower side bands and will be arranged along the frequency axis at intervals of ΔF 2 /2 as shown at (a) through (f) of FIG. 2 ((a) to (f) in FIG. 2 1 ). Odd-numbered ones of those modulated signals are combined by the adder 3 4 and then, undesired spectra (upper side bands) appearing within the range represented by reference character S are suppressed by the comb filter 3 5 , so that the consequent frequency spectra are arranged on the frequency axis at an interval of ΔF 2 /2 as shown in line 2 of FIG. 2. Likewise, even-numbered ones of the modulated signals are converted into frequency spectra arranged respectively on the frequency axis at an interval of ΔF 2 , as shown in line 3 of FIG. 2. Next, the modulated signals from which undesired spectra are suppressed by the comb filters 3 5 and 4 5 , in the above-described manner, are combined by the adder 7. As a result, the frequency spectra of the respective output signals of the comb filters 3 5 and 4 5 are jointly arranged on the frequency axis in an interlaced relation as shown in line 4 of FIG. 2. The value of ΔF 2 is to be at least as large as 2ΔF 1 to insure that the selected side bands of adjacent channels do not overlap in frequency. For instance, in one embodiment the values selected are: ΔF.sub.1 = 3.1 KHz and ΔF.sub.2 = 8.9 KHz. Referring to FIG. 3 showing a second embodiment of the present invention, telegraph signals are employed as input modulation signals. More particularly, a basic converter stage 14 is comprised of input terminals 10 1 -10 3 to which the telegraph signals are supplied. FSK-modulators 14 1 -14 3 are provided for the respective terminals 10 1 -10 3 . An adder 14 4 combines the output signals from the FSK-modulators, and a comb filter 14 5 provides spectra-shaping of the combined signal. Reference numerals 15-17 designate the other basic converter stages with construction similar to the stage 14. FSK-modulator 14 1 is a frequency-modulator in which two oscillators having different oscillation frequencies f 1 and f 2 are switched depending on the mark and space information of the telegraph signal, and the center frequency f 0 on the modulator is represented by f 1 + f 2 /2. The other FSK-modulators are similarly constructed. The output signals of the converter stages 14 and 15 are combined together by an adder 22, while the output signals of the converter stages 16 and 17 are combined together by an adder 23. Moreover, the output signal of the adder 23 is, after passing through an amplitude modulator 24, combined with that of the adder 22 by another adder 25. Now the operation of the present system with the construction illustrated in FIG. 3 will be described in conjunction with FIG. 4. As is well-known, spectra of a modulated signal obtained by the FSK-modulation of carriers f 1k and f 2k in an FSK-modulator having a center frequency f o k , expands over an infinite frequency range, and the general distribution of the spectra is represented as shown in FIG. 6 which illustrates the respective components by relative levels with respect to the component at the center frequency f o k . Reference character f p represents a frequency dependent upon the telegraph transmission speed. For instance, f p is equal to 50 Hz for a telegraph speed of 100 B (baud). Reference characters f o k-4 , f o k-3 , . . . f o k+3 and f o k+4 represents the positions of the respective center frequencies of the FSK-modulators of FIG. 3, and the interval of their respective center frequencies corresponds to that between the channels to be frequency-division multiplexed. According to the C.C.I.T.T. recommendation, regulation is made on the levels of the respective signal spectra of the FSK-modulated signal having a center frequency of f o k , and according to this regulation, it is remarked that even if spectra having levels lower than the level of the center frequency f o k by -40 dB or more are not suppressed, these unsuppressed spectra will not substantially give an adverse effect upon the transmission signals in the other channels. As a result, of the signal spectra within the frequency ranges of -2f p --14f p and +2f p -+14f p are suppressed, no adverse influence is given upon the modulated signals having center frequencies f o k-4 and f o k+4 separated from the center frequency f o k by 4 channels. It will not be assumed that the center frequencies of the FSK-modulators 14 1 -14 3 and 15 1 -15 3 have an interval ΔF 2 /2 are equal to f o 1 , f o 3 and f o 5 and f o 2 , f o 4 and f o 6 , respectively, as shown in line 1 of FIG. 4. The output frequency bands FSK-modulators 14 1 -14 3 shown by the cross-hatched sections of line 2 are combined by the adder 14 4 . The output of adder 15 4 is shown similarly in line 4. Assuming that the center frequencies of the FSK-modulators 16 1 -16 3 and 17 1 -17 3 are equal to those of the FSK-modulators 14 1 -14 3 and 15 1 -15 3 , respectively, the first-stage FDM signals combined by the adders 16 4 and 17 4 will also be as shown in lines 2 and 4 of FIG. 4. THe first-stage FDM signals combined by the adders 14 4 and 16 4 as shown in line 2 are applied to the comb filters 14 5 and 16 5 which suppress frequencies in the ranges S', resulting in an output frequency spectrum as shown in line 3. Likewise, line 5 represents the frequency spectrum output of the comb filters 15 5 and 17 5 . The frequency response characteristics of filters 15 5 and 17 5 differ from those of 14 5 and 16 5 by ΔF 2 /2. The output signals of the comb filters 14 5 and 15 5 and the comb filters 16 5 and 17 5 are respectively combined together by the adders 22 and 23, resulting in the spectrum of line 6. The output signal of the adder 23 is frequency-shifted by ΔF 2 /2 (line 7b) relative to the output signal of the adder 22 (line 7a) by the amplitude modulator 24. The output signal of the adder 22 and and the output signal of the amplitude modulator 24 are combined together by the adder 25 to result in the spectrum of line 8. It should be noted that the frequency-shift caused by the amplitude modulator 24 carried out with a frequency such that the individual transmission bands may not overlap with each other after the combining operation of adder 25, and that in the example of FIG. 4, this frequency width is selected at ΔF 2 /4. The carriers and clock signals required for the operations of the FSK-modulators, the amplitude modulator and the comb filters are supplied from a carrier source 27 and a clock signal source 27' of FIG. 3. In the illustrated embodiment, the transmission speed is selected at 100 bauds, the center frequency and shift width of the FSK-modulator 14 1 are selected at 480 Hz and 120 Hz, respectively, and the transmission bandwidth of the modulated signal after the spectra shaping and the difference between the respective center frequencies f o 1 to f o 6 are selected at ΔF 1 = 120 Hz and ΔF 2 /2 = 480 Hz, respectively. The third embodiment shown in FIG. 7 comprises a first converter stage 36 including a plurality of input terminals 34 1 -34 12 to which modulation signals are fed, FSK-modulators 36 1 -36 12 connected to these input terminals and having center frequencies equal to a frequency 4 m (m being an integer) times as high as the transmission bandwidth ΔF 1 /1 of the modulated signals, an adder 36 13 for combining the output signals of these FSK-modulators on the same frequency axis, and a comb filter 36 14 for eliminating undesired spectra in the combined signal; a second converter stage 37 having the same construction as said first converter stage 36; an adder 40 for combining the output signals of these first and second converter stages; a modulator 41 for amplitude-modulating a predetermined carrier with the output signal of the adder 40; and a band-pass filter 42 for eliminating undesired spectra from the output signal of the modulator 41. Now the operation of the transmission system of the present invention of FIG. 7 will be described by referring to FIG. 8. Among the FSK-modulators 36 1 . . . 36 12 , the center frequencies of the odd-numbered FSK-modulators 36 1 , 36 3 , . . . and 36 11 are represented by reference characters f 1 , f 5 , . . . and f 21 , while among the FSK-modulators 37 1 , . . . , and 37 12 , the center frequencies of the odd-numbered FSK-modulators 37 1 , 37 3 , . . . , and 37 11 are represented by reference characters f 3 , f 7 , . . . , and f 23 , and the differences between adjacent ones of said center frequencies such as f 1 and f 3 or f 3 and f 5 are made equal to 4ΔF 1 (ΔF 1 being a transmission bandwidth of a signal that has been shaped in spectra after FSK-modulated). Likewise, the center frequencies of the even-numbered FSK-modulators 36 2 , 36 4 , . . . , and 36 12 and 37 2 , 37 4 , . . . , 37 12 , are represented by reference characters f 2 , f 6 , . . . , and f 22 and f 4 , f 8 . . . , and f 24 respectively adjacent ones differing from each other by 4ΔF 1 . In addition, the differences between the center frequencies f 1 and f 2 and between the center frequencies f 3 and f 4 are selected equal to or larger than 8ΔF 1 . Under the above-mentioned assumption, the center frequencies f 1 , f 5 , . . . , and f 21 and f 2 , f 6 , . . . , and f 22 are respectively frequency-converted by telegraph signals fed to the input terminals 34 1 , 34 3 . . . , and 34 11 and 34 2 , 34 4 . . . , and 34 12 in the FSK-modulators 36 1 , 36 3 . . . , and 36 11 and 36 2 , 36.sub. 4, . . . , and 36 12 , and then, combined by the adder 36 13 (FIG. 8, line 2). The combined signal has its undesired spectra suppressed by the comb filter 36 14 resulting in a spectrum as shown in line 4 of FIG. 8. Similar operations are carried out in the basic converter stage 37, and the output signal takes the spectra as shown in FIG. 8, lines 1 and 3. After the output signals of the comb filters 36 14 and 37 14 are combined by the adder 40, as shown in line 5, if a carrier frequency f a is applied to the modulator 41 and modulated by such combined output signal, and if the lower side band is passed by the band-pass filter 42, a frequency-division multiplexed signal having spectra on the frequency axis is obtained as shown in line 6 of FIG. 8. It is to be noted that the center frequencies f 1 , . . . , and f 24 are supplied from the carrier source 27 constructed of a single oscillator and an appropriate number of frequency-dividers and/or frequency multipliers. In the third embodiment, the transmission speed is selected at 50 bauds, the center frequencies f 1 , f 23 and f 2 , f 24 of the FSK-modulators 36 1 , 37 11 and 36 2 , 37 12 are selected at 480 Hz, 3120 Hz and 4080 Hz, 6720 Hz, respectively, and the transmission bandwidth ΔF 1 and the carrier frequency f a of the modulated signal are selected at ΔF 1 = 60Hz and f a = 3540 Hz, respectively. The comb filters 36 13 and 37 13 have such response characteristics that pass-bands are iterated at every 480Hz. The fourth embodiment shown in FIG. 9 adapted to the 100 bauds carrier telegraphy has basic converter stages 45 and 46 which are the same as basic converter stages 36 and 37, respectively, of FIG. 7 except for the number of FSK-modulators. The difference between the construction of this embodiment and that of FIG. 7 lies in that the system of FIG. 9 comprises an adder 49 for combining the output signals of the converter stages 45 and 46 and also branching the thus combined signal into two signal paths, a high-pass filter 50 for eliminating a low-frequency component from the signal on one of the two signal paths, a modulator 51 for frequency-shifting the output signal of the high-pass filter 50, an adder 52 for combining the signal modulated by this modulator 51 with the signal on the other signal path, and a band-pass filter 53 for suppressing undesired components of the output signal of this adder 52. Next, the operation of the fourth embodiment will be explained with reference to FIG. 10. Assuming that the center frequencies of the FSK-modulators 45 1 , 45 3 , 45 5 , 46 1 , 46 3 and 46 5 and 45 2 , 45 4 , 45 6 , 46 2 , 46 4 and 46 6 are equal to f 1 , f 5 , f 9 , f 3 , f 7 and f 11 and f 2 , f 6 , f 10 , f 4 , f 8 , and f 12 , respectively, the center frequencies f 1 to f 12 are frequency-converted in the FSK-modulators 45 1 to 45 6 and 46 1 to 46 6 by the telegraph signals given to the input terminals 43 1 to 43 6 and 44 1 to 44 6 , respectively, thus converted signals are combined by the adder 45 7 and 46 7 , respectively, and have their undesired spectra suppressed by the comb filters 45 8 and 46 8 , respectively, as illustrated in lines 3 and 4 of FIG. 10. The suppressed signals are combined by the adder 49 and also branched into two signal paths, and the signal appearing on one of the signal paths has its low frequency components suppressed by the high-pass filter 50 as shown in line 6 (FIG. 10, line 6). The output signal of the high-pass filter 50 is, after being frequency-shifted by the modulator 51, combined with the signal appearing on the other signal path by the adder 52, and then, has its undesired components suppressed by the bandpass filters 53 as shown in FIG. 10, line 7. It should be noted that the present system of FIG. 3 can be modified as follows: (1) In at least one basic converter stage of FIG. 3, amplitude-modulators are interposed at the rear of the individual FSK-modulators while selecting the center frequencies of the carrier supplied to these FSK-modulators at the same frequency, and by appropriately selecting the carrier frequencies supplied to the interposed individual amplitude-modulators, and the individual transmission bands of the input signal components given to the subsequent comb filters are arranged on the frequency axis as shown in FIG. 4, lines 2 or 4. (2) At the stage preceding the comb filters 15 5 and 17 5 of FIG. 3 are disposed amplitude-modulators, the center frequencies of the carriers supplied to the individual FSK-modulators in the basic converter stages 15 and 17 which include these comb filters 15 5 and 17 5 are made to coincide with the center frequencies of the carriers supplied to the individual FSK-modulators in the basic converter stages 14 and 16 which include the comb filters 14 5 and 16 5 , and by appropriately selecting the carrier frequencies supplied to the interposed amplitude-modulators, the individual transmission bands of the input signal components fed to the comb filters 15 5 and 17 5 are arranged on the ferquency axis as shown in FIG. 4, line 4. (3) Any arbitrary one basic converter stage of FIG. 3 is replaced by another basic converter stage that is combined with first said basic converter stage by one combining means, an amplitude-modulator is interposed at the rear of the comb filter in either one of the above-mentioned two basic converter stages including such replaced stage, and by appropriately selecting the carrier frequency supplied to that amplitude-modulator, the output signal of said combining means is made to have spectra shown in FIG. 4, line 6. (4) The basic converter stage or stages of FIG. 3 are modified by employing at least two of the modifications (1), (2), and (3).

A frequency division multiplexing system is disclosed having a plurality of individual modulators which modulate respective modulating signals onto respective carrier frequencies. The carrier frequencies are selected to have a frequency separation so that when modulated signals are combined, significant parts thereof do not overlap in frequency. The combined modulated signals are filtered by comb filters which suppress portions of the frequency spectra intermediate the significant portions.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an equalizer, and more particularly, to a continuous-time adaptive equalizer. [0003] 2. Description of the Related Art [0004] As is well known in the art, when a signal is transferred via a transmission line, the signal decays during the transmission process. This means that for transmission lines having a great length, the signal decay is more obvious. Therefore, when the signal arrives at the destination (for example, a receiver), the signal received by the receiver may contain distortions. [0005] In order to solve the above-mentioned problem, an equalizer is often established logically in front of (i.e., before) the receiver such that the original signal can be recovered from the decayed signal. This allows the receiver to correctly process the received signal. [0006] For example, in the data transmission of a USB interface, a PCI-E interface of a computer system, or the data transmission of an HDMI interface of an LCD, high-frequency portions of the signal often decay in the transmission process. Therefore, the aforementioned equalizer is often established at the receiving ends of the above-mentioned interfaces to provide an appropriate gain for the high-frequency portions of the signal such that the original signal can be recovered from the decayed signal. In this way, said computer system or said LCD can process the recovered signal. [0007] In “ISSCC2005/SESSION18/HIGH-SPEED INTERCONNECTS AND BUILDING BLOCKS/18.1 (A 10 Gb/s CMOS Adaptive Equalizer for Backplane Applications)” published by Srikanth Gandi, Jri Lee, Daishi Takeuchi, and Brhzad Razavi, a continuous-time adaptive equalizer is disclosed. Please refer to FIG. 1 . FIG. 1 is a block diagram of a conventional continuous-time adaptive equalizer 100 . As shown in FIG. 1 , the continuous-time adaptive equalizer 100 comprises an active high-pass filter 110 , a slicer 120 , a boost control module 130 , a swing control module 140 , and a buffer 150 . [0008] The active high-pass filter 110 is utilized to perform the above-mentioned amplifying (signal recovery) operation. In other words, the active high-pass filter 110 performs the amplifying operation on the high-frequency portions of the received data signal D in to output a processed data signal D out . The processed data signal D out is then buffered by the buffer 150 , and is further outputted to a following receiver (not shown in FIG. 1 ). [0009] However, when the equalizer 100 receives the data signal D in , the equalizer 100 cannot predict the condition of the data signal D in . For example, the equalizer 100 cannot determine the degree of signal decay. Therefore, the equalizer 100 requires an adjusting mechanism to dynamically adjust the filtering frequency band of the active high-pass filter according to the properties of the data signal D in . [0010] In this case, the slicer 120 and the boost control module 130 are utilized as the above-mentioned adjusting mechanism. As shown in FIG. 1 , the slicer 120 and the boost control module 130 form a feedback loop to control the filtering frequency band of the active high-pass filter 110 . [0011] The slicer 120 converts the signal at node A (D out ) into a square wave. The boost control module 140 outputs a feedback signal to the active high-pass filter 110 according to the difference between the signals at the node A and node B such that the filtering frequency band (i.e., the frequency response) of the active high-pass filter 110 can gradually approach a desired frequency band according to the feedback signal. In this way, the data signal D out eventually may resemble the originally transmitted data signal. [0012] However, if only the boost control loop is utilized, the accuracy of the data signal D out cannot be guaranteed. Please note, the equalizer 100 cannot determine the amplitude of the data signal D out when receiving the data signal D out . It is apparent that if the square wave outputted from the slicer 120 does not correspond to the signal D out at the node A, then the boost control module 130 may lock the entire equalizer 100 on an incorrect operational point. This will cause the active high-pass filter 110 have incorrect frequency responses such that the data signal D out cannot be recovered as the original data signal. [0013] Therefore, the swing control module 140 is established to solve the above-mentioned problem. In this case, the slicer 120 and the swing control module 140 form another feedback loop. The additional feedback loop is utilized to control the slicer 120 to output a square wave having a desired amplitude. In other words, the swing control module 140 outputs another feedback signal according to the amplitude differences between the signals at node A and node B such that the slicer 120 is controlled to output the square wave having the same amplitude as the signal at the node A. [0014] Utilizing these two above-mentioned feedback loops, the equalizer 100 can ensure that the outputted data signal D out is very close to corresponding to the original data signal. This results in an improvement to the signal transmission quality. [0015] Unfortunately, the above-mentioned equalizer 100 has disadvantages. As shown in FIG. 1 , two feedback loops lie in the same signal route. As is well known, the, two feedback loops cannot work simultaneously. In fact, if the two feedback loops were simultaneously in operation then the stability of the entire equalizer 100 may be reduced. For example, the two feedback loops may introduce an oscillation, and thus the stability of the equalizer 100 is reduced by said oscillation. Therefore, in the actual application, in order to increase the stability of the equalizer 100 , the operational speed (i.e., the frequency band) of the swing control module 140 (the swing control loop) must be greater than that of the boost control module 130 . In other words, the equalizer 100 should firstly use the swing control module 140 to make the amplitudes of the signals at the node A and node B equal. Secondly, after the amplitudes of the signals at the node A and node B are adjusted, the equalizer 100 is switched such that the boost control module 130 becomes active and starts operation. In this way, the boost control module 130 can start to perform the above-mentioned feedback control to adjust the high frequency swing of the data signal D out such that the high frequency swing of the data signal D out can be outputted correctly. [0016] To speak more simply, the circuit designer must evaluate and analyze the stability of the equalizer 100 and thereafter implement a more complex design to ensure that the equalizer 100 operates correctly. If the equalizer 100 is poorly designed, (for example, the operating time of the swing control module 140 is insufficient to make the amplitudes of the signals at the node A and node B equal to one another), the boost control module 130 cannot correctly perform the feedback control such that the active high-pass filter 130 has incorrect frequency responses and the original data cannot be recovered. [0017] Furthermore, if the frequency bandwidth of the boost control module 130 is lower than the swing control module 140 , larger capacities must be utilized in the boost control module 140 . This increases the space requirements of the entire circuit and thereby increases the power consumption of the equalizer 100 . SUMMARY OF THE INVENTION [0018] In view of the above-mentioned problems, an object of the invention is to provide a continuous-time adaptive equalizer, which utilizes two individual loops respectively performing the boost control operation and the swing control operation, such that the above-mentioned problems are solved. [0019] According to an embodiment of the claimed invention, an equalizer, for equalizing a first transmission signal on a transmission line is disclosed. The equalizer comprises: a filter, configured to receive the first transmission signal, to perform a filtering operation on the first transmission signal according to a feedback signal to generate an output signal; a first slicer, coupled to the filter, configured to generate a first sliced signal according to a signal level of the output signal and to adjust an amplitude of the first sliced signal according to an amplitude control signal; a boost control module, coupled to the filter and the first slicer, configured to generate the feedback signal according to the output signal and the first sliced signal; and a control circuit, coupled to the first slicer, configured to receive a second transmission signal on the transmission line and to output the amplitude control signal according to an amplitude of the second transmission signal. [0020] According to another embodiment of the claimed invention, a signal equalizing method, for equalizing a first transmission signal on a transmission line is disclosed. The signal equalizing method includes: receiving the first transmission signal; performing a filtering operation on the first transmission signal according to a feedback signal to generate an output signal; generating a first sliced signal according to a signal level of the output signal and adjusting an amplitude of the first sliced signal according to an amplitude control signal; generating the feedback signal according to the output signal and the first sliced signal; receiving a second transmission signal on the transmission line and outputting the amplitude control signal according to an amplitude of the second transmission signal. [0021] The claimed invention continuous-time adaptive equalizer utilizes two individual loops to respective perform the boost control operation and the swing control operation. Therefore, the claimed invention does not suffer from the disadvantages of the dual loop according to the prior art. This reduces the complexity of the circuit design, and also reduces the area requirements of the entire circuit and thereby the circuit's power consumption. BRIEF DESCRIPTION OF THE DRAWINGS [0022] FIG. 1 is a block diagram of a conventional continuous-time adaptive equalizer. [0023] FIG. 2 is a block diagram of a continuous-time adaptive equalizer according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0024] Please refer to FIG. 2 . FIG. 2 is a block diagram of a continuous-time adaptive equalizer according to an embodiment of the present invention. As shown in FIG. 2 , the continuous-time adaptive equalizer 200 comprises an active high-pass filter 210 , two slicers 220 and 221 , a boost control module 230 , a swing control module 240 , and two buffers 250 and 251 . [0025] The boost control module 230 and the swing control module 240 have the same functions, operations, and circuit configurations as the boost control module 130 and the swing control module 140 . One skilled in the art can easily understand the operation and thus further details are omitted herein. [0026] Before illustrating the techniques of the present invention, please note, in some transmission interfaces, such as HDMI, DVI, LVDS, and RSDS interfaces, a clock signal is transferred along with the data signal. In addition, as is well known in the art, the above-mentioned clock signal and the data signal have the same amplitude. [0027] Please note, the present invention utilizes the above-mentioned characteristic to perform the swing control operation. That is, the present invention utilizes the above-mentioned clock signal to perform the swing control operation. This mechanism can work as efficiently as, or even more efficiently than, utilizing the data signal to perform the swing control operation as in done in the prior art. [0028] In addition, as shown in FIG. 2 , the equalizer 200 comprises two signal routes, where one signal route is utilized to receive the data signal D in in the boost control loop. The other signal route is utilized to receive the clock signal CK in in the swing control loop. [0029] Similarly, the active high-pass filter 210 is utilized to perform the filtering operation. In other words, the active high-pass filter 210 amplifies the high frequency portions of the received signal D in and outputs an equalized data signal D out . The equalized data signal D out is buffered by the buffer 250 , and then outputted to a following receiver (not shown in FIG. 2 ). [0030] The slicer 220 and the boost control module 230 form a boost control loop to control the filtering band of the active high-pass filter 210 . The slicer 220 converts the signal D out at node A into a square wave signal. The boost control module 240 outputs a feedback signal to the active high-pass filter 210 according to the difference between the signals at node A and node B such that the filtering frequency band (i.e., the frequency response) of the active high-pass filter 210 will gradually approach a desired frequency band according to the feedback signal. In this way, the data signal D out can also eventually resemble the originally transmitted signal. [0031] Moreover, similarly, in order to ensure that the boost control module 230 can work correctly to lock the entire circuit on a correct operational point (i.e., to make the active high-pass filter 210 have correct frequency responses), the equalizer 200 needs another adjusting mechanism to make the square wave signal outputted from the slicer 220 have the same amplitude as that of the signal at the node A. [0032] As is shown in FIG. 2 , the clock signal is CK in is buffered by the buffer 251 and then outputted as the clock signal CK out . Please note, in this embodiment, the clock signal CK in is further utilized for the above-mentioned mechanism. That is, the slicer 221 and the swing control module 240 further utilize the clock signal CK in to perform the swing control operation such that the square wave signal outputted from the slicer 220 has the same amplitude as that of the signal at the node A. [0033] In this embodiment, the slicer 221 converts the clock signal CK in into a square wave signal. As mentioned previously, the clock signal CK in and the data signal D in substantially have the same amplitude. Therefore, if the slicer 221 and the slicer 220 have the same structure, to detect the difference between the input and the output of the slicer 221 is equivalent to detecting the difference between the input and the output of the slicer 220 . [0034] Therefore, in this embodiment, the swing control module 240 detects the difference between the amplitude (or the equivalent signal level) of the square wave outputted from the slicer 221 and the amplitude of the clock signal CK in and outputs an amplitude control signal to the slicer 221 according to the difference. This amplitude control signal can control the slicer 221 to output a square wave signal having the same amplitude as that of the clock signal CK in . In addition, the above-mentioned square wave signal is also inputted into the slicer 220 . Therefore, when the amplitude of the square wave signal outputted from the slicer 221 is the same as that of the clock signal CK in , the square wave signal outputted from the slicer 220 and the data signal D out have the same amplitude. [0035] Furthermore, in another embodiment according to the present invention, the amplitude control signal outputted from the swing control module 240 can control a current source inside the slicer 220 and the slicer 221 to change the current provided by the current source. Likewise the amplitude control signal can be designed to control a resistance of a resistor inside the slicer 220 and the slicer 221 . In this way, the slicers 220 and 221 can be controlled to output square wave signals having the same amplitude as that of the input signals (e.g., the data signal D i n or the clock signal CK in ). [0036] Please note, the clock signal CK in often has a more completed waveform than the data signal. Therefore, detecting the difference between the input and the output of the slicer 221 should be better than detecting the difference between the input and the output of the slicer 220 . [0037] From the above disclosure, it can be understood that through using the aforementioned swing control loop, the present invention slicer 220 outputs a square wave signal having the same amplitude as that of the data signal D out . Therefore, the boost control loop can also operate correctly to make the data signal D out resemble with the original data. [0038] Please note, the present invention uses two individual loops. That is, the two individual and independent loops lie in different signal routes. The two loops are used to perform the boost control operation and the swing control operation. Therefore, the two independent loops can work simultaneously without oscillation occurring. As a result, the present invention continuous-time adaptive equalizer 200 has improved stability over the prior art. In addition, when the adaptive equalizer 200 is being designed, an analysis of the stability of the circuit should not be very complex. Additionally, because there are no large capacitors required in the circuit design, the circuit area is reduced. [0039] Furthermore, because two loops can work simultaneously, this allows the swing control module 240 to simultaneously adjust the amplitudes of the signals at node A and node B while the boost control module 230 is performing the feedback control operation. Therefore, in contrast to the prior art equalizer, the present invention does not need to consider the operation time of the swing control module 240 or that this might be insufficient to make the amplitudes of the signals of node A and node B equal to one another. Please note, the swing control module 240 continuously adjusts the amplitudes of the signals at the node B and the order of the operations of the swing control module 240 and the boost control module 230 are not predetermined. Therefore, after the entire system operates for a while, the swing control module 240 can generate the amplitudes of signals at node A and node B, this ensures that the data signal D out can correctly correspond to the original signal data. [0040] In the above disclosure, the present invention continuous-time adaptive equalizer 200 utilizes the clock signal to perform the feedback control operation, and therefore is mainly utilized in HDMI, DVI, LVDS, and RSDS interfaces. However, the above-mentioned interfaces are only regarded as embodiments, and not limitations of the present invention. In the actual implementation, as long as a reference signal and the data signal correspond to the same amplitude, the reference signal can be utilized in the amplitude control mechanism. [0041] For example, in USB or PCI-E interfaces, there is no clock signal being transferred. But there are multiple data signals being transferred at the same time. Therefore, the present invention can utilize another data signal as the reference signal of the amplitude control mechanism. In other words, in FIG. 2 , the clock signal CK in can be replaced by another data signal and the same objective is achieved. [0042] The present invention can even utilize the same data signal as the reference signal. In other words, in FIG. 2 , the clock signal CK in can be replaced by the data signal D in (or the data signal D out ) and the same objective is achieved. [0043] Please note, in the above disclosure, the slicers 250 and 251 are utilized to convert the data signal (or clock signal) into square wave signals. However, the slicer is only regarded as a preferred embodiment, not a limitation of the present invention. In the actual implementation, a circuit capable of converting signals into square wave signals can be utilized to replace the slicers 250 and 251 . For example, a sample-and-hold circuit, a 1-bit ADC, a comparator, and a data recovery circuit can all be used as replacements for the slicer. These changes also obey the spirit of the present invention. [0044] In addition, one skilled in the art can understand and implement the above-mentioned active high-pass filter 210 . For example, for an aspect of frequency responses, the active high-pass filter 210 has adjustable poles and zeros. That is, the active high-pass filter 210 can adjust its poles and zeros according to the received feedback signal such that the frequency responses of the filter 210 can be adjusted (this equivalently adjusts the filtering band and the gain of the filter 210 ). As mentioned previously, in an embodiment of the present invention, the active high-pass filter 210 can comprise adjustable capacitors or resistors. These adjustable devices can be adjusted according to the feedback signal such that the aforementioned mechanism can be achieved. For example, the resistance and the capacitance can be adjusted. [0045] In contrast to the prior art, the present invention continuous-time adaptive equalizer utilizes two individual loops to respective perform the boost control operation and the swing control operation. Therefore, the present invention does not have the disadvantages of the dual loop according to the prior art. This reduces the complexity of the circuit design, and also reduces the area (i.e., space) requirements of the entire circuit and thereby power consumption is reduced. [0046] While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad invention, and that this invention should not be limited to the specific construction and arrangement shown and described herein, since various other modifications may occur to those ordinarily skilled in the art.

An equalizer is disclosed. The equalizer includes a filter, configured to receive the first transmission signal, to perform a filtering operation on the first transmission signal according to a feedback signal to generate an output signal; a first slicer, configured to generate a first sliced signal according to a signal level of the output signal and to adjust an amplitude of the first sliced signal according to an amplitude control signal; a boost control module, configured to generate the feedback signal according to the output signal and the first sliced signal; and a control circuit, configured to receive a second transmission signal on the transmission line and to output the amplitude control signal according to an amplitude of the second transmission signal.

CROSS REFERENCE TO RELATED APPLICATION This application is a division of U.S. Pat. application Ser. No. 07/919,961, filed Jul. 27, 1992, now U.S. Pat. No. 5,374,237, which is a continuation-in-part application of U.S. Pat. application Ser. No. 07/628,177, filed Dec. 17, 1990, now abandoned. All applications are by William L. McCarty, Jr., inventor. BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates generally to therapy of the temporomandibular joint and particularly to a method and apparatus for providing therapeutic treatment of the joint. 2. Description of the Prior Art Surgery is often required to correct internal derangements of the temporomandibular joint. Post-operative care has varied widely with little agreement among clinicians as to the most effective manner of managing such care. A common practice involves loose intermaxillary fixation for the first one or two days following surgery. However, this practice does little more than prevent damage to the joint especially if the patient becomes nauseated after surgery. After removal of fixation it has been fairly common practice to initiate limited motion typically in rotation. Such procedures have ranged from having the patient put his thumb between the upper and lower incisors to guide him in measuring jaw opening and also to allow him to judge the desired degree of limitation. Recently, an apparatus capable of providing continuous passive motion in rotation, that is, the opening and closing of the mouth, has been available from Vitech, Inc. of Houston, Tex. and has been marketed under the trademark "Trans-Jaw". A product similar to the "Trans-Jaw" has been distributed by the Therabite Corporation of Bryn Mawr, Pa. and is referred to by the trademark "Therabite". The "Therabite" product is intended to provide rotational motion for the purpose of improving mandibular range of motion. These and other therapeutic methods and apparatus have been employed but with limited success. Many other conditions involving disorders of the temporomandibular joint have also been treated to less than satisfactory conclusions due to deficiencies in state of the art treatment methodology. Such conditions include both rehabilitation situations following arthroscopy, fractures and/or trauma, osteoarthritis and even relatively routine rehabilitation of stiff, painful jaw joints. In these conditions and in other conditions including open joint surgery such as arthroplasty, meniscectomy and total joint replacement, as examples, methodology relating to rehabilitation has been limited in part by a lack of understanding of the complexity of the general subject of temporomandibular joint disorders as well as a lack of progress in this area directed to truly effective rehabilitative procedures and apparatus capable of assisting in the practice of such procedures. The present invention provides an effective therapeutic method and an apparatus capable of practice of the method, the invention providing a substantial advance in the art of rehabilitative care post-operatively, post-trauma and also in rehabilitative treatment of chronic and acute disorders involving the temporomandibular joint. SUMMARY OF THE INVENTION The invention provides a novel therapeutic method for rehabilitation of the temporomandibular joint, hereinafter often referred to as TMJ, by the induction of translatory motion of the joint. The therapeutic methodology of the invention can be applied post-operatively in open joint surgery situations including arthroplasty, meniscectomy, total joint replacement, ankylosis, etc. Further, the rehabilitative methodology of the invention can also be applied after arthroscopy, after fractures and/or trauma and as treatment for various diseases affecting the TMJ such as osteoarthritis, etc. and for routine rehabilitation of stiff, painful jaw joints and the like. The present therapeutic methodology preferably involves continuous passive motion of the mandible in a translatory sense. This translatory movement of the mandible with the resulting translation of the TMJ biaxially significantly improves upon prior treatment modalities involving only rotation of the joint. Treatment according to the present method results in more rapid rehabilitation of the TMJ with a patient regaining maximum potential use of the joint more rapidly and with greater facility than with prior rehabilitative techniques. The invention further provides various embodiments of apparatus for effecting translatory motion of the temporomandibular joint in a continuous and passive manner. The apparatus of the invention effectively comprises continuous passive motion devices which move the mandible without the requirement for exertion on the part of the patient other than to close in order to engage those portions of the apparatus held within the mouth of the patient. Motion of the TMJ is thus effected in rehabilitative therapy even prior to the time within which the patient could move the mandible voluntarily. Preferred embodiments of the apparatus take the form of hand-held devices which drive a plate element in a translatory motion through use of various forms of cam-like eccentric arrangements. In one embodiment, the "throw" or degree of motion afforded the plate element is infinitely adjustable within a predetermined range of motion. In the several embodiments, the plate element receives a registration on a distal end thereof formed as an impression in an acrylic material mounted distally of the plate element and configured to be received within the mouth of a user with the registration receiving the teeth of the lower jaw. A second plate element opposing the first-mentioned plate element is provided with a registration of the teeth of the upper jaw and effectively acts to hold the apparatus within a frame of reference with only the mandible being moved to effect the therapeutic method of the invention. As is defined herein and as is apparent from the description of the invention, translatory motion has components of motion in both side-to-side and front-to-back senses and encompasses such motions. The use of translatory motion therapeutically is herein described in detail and forms the basis for the methods and apparatus herein disclosed. Accordingly, it is an object of the invention to provide a therapeutic method and apparatus for rehabilitation of the temporomandibular joint through induction of translatory motion of the joint, the methodology and apparatus of the invention being useful post-operatively or pre-operatively in rehabilitative therapy involving a variety of conditions, diseases and disorders affecting the temporomandibular joint. It is another object of the invention to provide methodology and apparatus capable of treatment of the temporomandibular joint through continuous passive motion of the joint in a translatory sense. It is a further object of the invention to provide therapeutic methodology and apparatus capable of effecting rehabilitative treatment of surgery of the temporomandibular joint including arthroplasty, meniscectomy, total joint replacement and the like and including rehabilitation of disease conditions including osteoarthritis and the like as well as post-arthroscopic conditions and conditions including fractures and/or trauma with resultant adhesions as well as routine rehabilitation of stiff, painful jaw joints. Other objects and advantages of the invention will become more readily apparent in light of the following detailed description of the preferred embodiments. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustrating a sagittal section of a healthy temporomandibular joint; FIG. 2 is a schematic illustrating a lateral view of a temporomandibular joint prior to forward translation; FIG. 3 is a schematic illustrating a lateral view of translation in a forward direction of a temporomandibular joint; FIG. 4 is a schematic illustrating a frontal view of the condyle translating forwardly in the fossa; FIG. 5A, 5B and 5C are schematics illustrating translation of the temporomandibular joint as seen from the base of the skull; FIG. 6 is a perspective view of a first embodiment of the apparatus of the invention; FIG. 7 is an exploded view in perspective of the apparatus of FIG. 6 less the power source and motor; FIG. 8 is an elevational view in partial section of the apparatus of FIG. 6 less the power source and motor; FIG. 9 is a plan view of the apparatus of FIG. 8; FIG. 10 is a sectional view of the apparatus of FIG. 8 taken along lines 10--10 of FIG. 8; FIG. 11 is an exploded view of a detailed perspective of upper portions of the apparatus of FIG. 8; FIG. 12 is an exploded view of a detailed perspective of lower portions of the apparatus of FIG. 8; FIG. 13 is a plan view of a double eccentric arrangement seen also in FIG. 12; FIG. 14 is a side elevational view in section of a detailed portion of a registration mounted to a plate according to the invention; FIG. 15 is a perspective view of a second embodiment of the apparatus of the invention shown in a systems arrangement wherein a power source is separate from the graspable portion of the system; FIG. 16 is a perspective view of a second embodiment of the invention; FIG. 17 is an exploded view of the apparatus of FIG. 16 with the apparatus opened to illustrate the plate arrangement; FIG. 18 is a plan view of the apparatus of FIG. 16; FIG. 19 is a side elevational view of the apparatus of FIG. 16; FIG. 20 is a view of the apparatus of FIG. 19 taken from the underside thereof; FIG. 21 is a side elevational view in partial section of the apparatus of FIG. 16; FIG. 22 is a sectional view taken along lines 22--22 of FIG. 21; FIG. 23 is a sectional view taken along lines 23--23 of FIG. 21 and being partially cut away; FIG. 24 is a sectional view taken along lines 24--24 of FIG. 21; FIGS. 25, 26 and 27 are schematics illustrating the locations of the plates of the apparatus in several positions; FIGS. 28A, 28B, 28C, 28D and 28E are schematics illustrating the location of the condyle within the temporomandibular joint on movement occasioned by clockwise motion of the apparatus of the invention; FIGS. 29A, 29B, 29C, 29D and 29E are schematics illustrating the location of the condyle within the temporomandibular joint on movement occasioned by counter-clockwise motion of the apparatus of the invention; FIG. 30 is a perspective view of a third embodiment of the apparatus of the invention shown in a systems arrangement wherein a power source is separate from but electrically connected to the graspable portion of the system; FIG. 31 is an exploded view of a portion of the third embodiment of the invention; FIG. 32 is a perspective view of a portion of the casing of the third embodiment of the invention; FIGS. 33a, 33b and 33c are perspective views of examples of eccentric cams used in the third embodiment of the invention; FIG. 34 is a perspective view of a tool used to adjust the position of one of the cams of FIG. 33 on the drive shaft of the third embodiment of the invention; FIG. 35 is a side elevational view of the third embodiment of the invention; FIG. 36 is a plan view in partial section of the apparatus of FIG. 35 taken along lines 36--36; FIG. 37 is a side elevational view in partial section of the apparatus of FIG. 36 taken along lines 37--37; and, FIGS. 38, 39 and 40 are schematics illustrating the location of the plates of the apparatus in several positions. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings and particularly to FIG. 1, the temporomandibular joint is illustrated in sagittal section so that further reference herein to the temporomandibular joint can be better appreciated. The joint as seen in FIG. 1 is a healthy joint and is shown in order to relate the various portions of the joint and surrounding structures to the following discussion of translatory motion of the joint. The mandible is seen at 1 to include the condyle 3 which opposes the disc 4 in the temporal portion of zygomatic arch 2. The articular eminence is shown at 5. The glenoid fossa 7 is seen to lie between the articular eminence 5 and the ear canal 6. FIGS. 2, 3 and 4 illustrate translation of the condyle 3 from a back position as seen in FIG. 2 to a forward translatory position as seen in FIG. 3. FIGS. 2 and 3 illustrate translatory motion from a lateral view. FIG. 2 represents the "back" position and FIG. 3 represents the "front" position with the condyle 3 translating forwardly. FIG. 4 provides a frontal view of the condyle 3 translating forwardly within the fossa 7. As can further be appreciated by reference to FIGS. 5A, 5B and 5C wherein translation of the TMJ is seen from the base of the skull, the first motion of the temporomandibular joint from the closed position of FIG. 5A is, on opening of the mouth, a rotation up to approximately 25 mm of interincisal opening as seen in FIG. 5B. In order for the law to open any further after a rotation of approximately 25 mm, the jaw must translate forwardly and downwardly such as to the position of FIG. 5C which corresponds to the opening illustrated in FIG. 3. Again referring to FIGS. 2 and 3, the condyle 3 translates down the slope of the articular eminence 5, over the midslope and into the anterior recess forward of the articular eminence 5. The motion thus described is normal motion. However, following surgery, arthroscopy and/or other traumatic events, translation does not tend to occur readily especially when opening is emphasized as therapy. In such conventional situations, either decreased or no translation occurs and a patient soon loses the ability to translate the joint. The loss of ability to translate occurs due to adhesion formation, primarily in the anterior recesses and also due to the formation of tough, fibrous adhesions between the tympanic plate (not shown) and redundant soft tissue in the posterior of the condyle. As these fibrous tissues bind down to the pitted bearing surfaces of the condyle 3 and fossa 7, degenerative changes occur with resultant fibrous ankylosis, degenerative joint disease and the further opportunity for formation of a bony ankylosis. The present methodology thus teaches rehabilitation of the temporomandibular joint by effecting translatory motion of the joint and particularly by effecting such translatory motion continuously and passively. By effecting translatory motion, the joint is less likely to form adhesions and is further less likely to degenerate with resultant fibrous ankylosis, etc. Further, translation of the temporomandibular joint does not cause the degree of muscle spasm which occurs through the use of therapy which emphasizes opening or rotation. Translation can also be achieved in a gentle manner which does not overload the masticatory muscles. While rotation or opening can be employed in the rehabilitation of the joint, emphasis on translation according to the invention results in at least some opening of the mouth, such opening occurring naturally either during effectation of translation or otherwise. Opening is usually enhanced by virtue of translation. In motion provided continuously and passively through use of the apparatus of the invention, the motion imparted to the mandible invariably has both a component of motion in a side-to-side sense and a component of motion in a front-to-back sense. The method of the invention thus provides for translatory motion of the temporomandibular joint as described herein. The invention further provides for translatory motion both continuously and passively through use of the apparatus of the invention. The several embodiments of the apparatus of the present invention are capable of effecting translatory motion necessary for rehabilitation of the temporomandibular joint, the apparatus essentially comprising devices which will generally be referred to as CPM devices and which function to effect movement of the temporomandibular joint both continuously and passively. The passive motion effected by the apparatus of the invention is, of course, of paramount importance. Referring now to FIGS. 6 through 14, a first embodiment of the present apparatus is seen generally at 10 to include a power source/motor unit 12 which can conveniently be grasped by a user. The unit 12 can take the form of any of a number of rechargeable, hand-held, typically battery-powered devices such as are commercially available. The unit 12 can simply comprise a motor unit with the power source being connected to the motor unit but provided at a remote location. While not shown in the drawings, the unit 12 includes a replaceable and/or rechargeable battery which powers an electric motor (not shown) disposed internally of the unit 12. The electric motor directly drives female coupling 14 which can take the form of an adjustable chuck or similar connector which receives a shaft as will be described hereinafter. The unit 12 is preferably reversible in order that the coupling 14 can be driven in both clockwise and counter-clockwise rotation. The unit 12 typically rotates the coupling 14 at a rate of approximately 120 to 150 rpm, a rotational rate of approximately 130 rpm being commonly employed. It should be understood that the initial rotational rate provided by the unit 12 can be geared down in a conventional manner such that the "speed" of the apparatus can be chosen as desired. The unit 12 could be configured to provide a rotational rate of less than 30 rpms, for example, which could be converted to translatory motion within the apparatus 10 without a gearing down from a higher rotational speed. However, motor units 12 are readily available as rechargeable, battery-powered devices having rotational speeds of approximately 150 rpm. Accordingly, it becomes convenient to select such a unit 12 for convenience and economy. In a preferred practice of the present method, the rotational speed which will be converted to translatory motion within the apparatus 10 is preferably on the order of 25 to 30 revolutions per minute and can vary within a range of revolutions per minute with determining factors being the physical and emotional comfort of the patient when using the apparatus 10. While the apparatus 10 can be driven at speeds at only a few revolutions per minute on the low side, and over 35 revolutions per minute, for example, on the high side, a general range of about 8 to 35 revolutions per minute is preferred in practice since a patient is not intimidated by such a speed and the therapy progresses at a satisfactory rate at such angular speeds. In order to reduce the rotational rate typically provided by commercially available battery/motor units, a gear reduction box is provided as will be described hereinafter. As noted above, the power source/motor unit 12 can be configured to provide a rotational output which is directly used in the apparatus 10 without the necessity for the reduction gearbox. For purposes of economy and convenience, however, the relatively inexpensive battery/motor combinations used for powering electric screwdrivers and the like can be used, devices of this nature usually requiring a reduction of rotational rate for use within the present environment. With continuing reference to FIG. 6, the power source/motor unit 12 is further seen to include a handle 16. A switch 18 mounted on the unit 12 is used to select either clockwise or counter-clockwise operation of the unit 12. A safety stop element 20 mounted on the unit 12 can be depressed to inhibit rotation of the coupling 14, the stop element 20 being one safety feature of the apparatus. A further safety feature is provided by the switch 18 which only causes actuation of the unit 12 and thus rotation of the coupling 14 when actually depressed by a user. In other words, release of finger pressure from the switch 18, regardless of rotational direction, discontinues rotation of the coupling 14 and thus operation of the apparatus 10. It is to be understood that the structure thus noted as comprising the power source/motor unit 12 is conventional. The apparatus 10 is now seen to comprise a translatory drive unit 22 which is driven by the power source/motor unit 12. Although not shown in the drawings, a cover can be formed over the unit 22 for the sake of convenience and appearance. The unit 22 can be readily mounted to and demounted from the unit 12 as will be described in greater detail hereinafter. The translatory drive unit 22 receives rotary motion from the unit 12 at a rate such as that referred to above and converts this rotary motion first to a reduced rotary motion and then to a translatory motion which is directly imparted to the mandible of a user in order to move the temporomandibular joint of the user in a translatory fashion. The translatory drive unit 22 connects to the unit 12 by means of shaft 24 which is received within the coupling 14. As is conventional in that art relating to portable, battery-powered motor drive units as referred to above, the shaft 24 is of a size which fits flushly and snugly into the coupling 14 without the requirement for providing an adjustable chuck although such an adjustable coupling could be employed if desired. The shaft 24 connects to and transmits motion through a joint 26 which can conveniently take the form of any suitably sized universal joint which will allow some degree of "play" between the translatory drive unit 22 and the unit 12 so as to render the apparatus 10 more comfortable and convenient for use by a patient. The joint 26 connects at its other end with a shaft 28 which is not readily seen in FIG. 6 but which can be seen in FIG. 7 inter alia. The shaft 28 extends into reduction gearbox 30 and is coupled to a 25-tooth gear 32 which drives 100-tooth gear 34, the gears 32 and 34 being shown in other figures including FIGS. 7 and 8. The reduction gearbox 30 reduces the rotational speed of the shaft 28 in a 4:1 ratio, shaft 36 exiting the reduction gearbox 30 rotating at a speed of one revolution per minute for each four revolutions per minute of the shaft 28 which entered the gearbox 30. As with much of the structure referred to in this general discussion of FIG. 6, the shaft 36 is not easily seen in FIG. 6 but can be seen in FIG. 7 inter alia. Rotation of the shaft 36 drives a double eccentric arrangement 38 best seen in FIGS. 7, 12 and 13 inter alia and which will be described in detail hereinafter. The double eccentric arrangement 38 couples to drive bar 40 which mounts a yoke-shaped plate 42 for movement in an eliptical fashion. The yoke-shaped plate 42 has a registration 44 formed of an acrylic material cured by ultraviolet radiation to yield an impression of the teeth or other structure associated with the, mandible of a user. The teeth of the mandible or lower jaw are thus received into the registration 44 mounted to the plate 42. Similarly, the teeth of the upper jaw are received within registration 46 formed of an acrylic material cured by ultraviolet radiation from a direct impression of the teeth or other structure of the upper jaw, this registration 46 being carried by yoke-shaped plate 48. The plate 48 is fixed to a stationary bar 50, the bar 50 being adjustable relative to the drive bar 40. The drive bar 40 and stationary bar 50 are effectively received on the shaft 36, the shaft 36 extending above the stationary bar 50 and having mounting cap 52 received thereon to hold the assembly of the drive bar 40 and stationary bar 50 together. The mounting cap 52 connects fixedly to the shaft 36 by means of a set screw 54 as best seen in consideration of both FIGS. 7 and 11. Referring now to FIGS. 7, 11 and 12, the bars 40 and 50 are seen to be respectively formed with slots 41 and 51, said slots being alignable on removal from the unit 22 to facilitate formation of the registration 44 and 46. Screw 43 and nut 45, seen in FIG. 6, hold the bars 40 and 50 together so that impressions can be taken to form the registration 44 and 46. The screw 43 is inserted through the slots 41 and 51 and the nut 45 is used to hold the bars 40, 50 relative to each other while impressions are formed. The bars 40, 50 can be moved relative to each other with the screw 43 and nut 45 loosely attached until the bars 40, 50 are suitably positioned. The nut 45 is then tightened on the screw 43 to hold the bars 40, 50 together. With this structural description of the apparatus 10 having now been provided, it can be seen in FIG. 6 that the registrations 44 and 46, and those portions of the plates 42 and 48 mounting said registrations, are received within the mouth of a user, the registration 44 receiving the teeth of the mandible while the registration 46 receives the teeth of the upper jaw. It is not necessary for all of the teeth to fit within the registrations 4.4 and 46, it only being necessary that the registrations 44 and 46 adequately "grip" or hold to the mandible and upper jaw respectively so that the apparatus 10 can function as required. The registrations 44 and 46 are not shown elsewhere in all of the drawings, not only for ease of illustration but also due to the necessity to show certain structure of the plates 42 and 48 as will be discussed hereinafter. In operation, the registration 46 mounted on plate 48 stays in a fixed position along with the upper jaw of the user. The registration 44 connected through the plate 42 to the drive bar 40 and thus the double eccentric arrangement 38 is caused to move the mandible of a user in a manner such that any point of the plate 42 and thus of the registration 44 moves to define a substantially eliptical geometrical figure. This eliptical motion of the registration 44 causes translatory motion in the temporomandibular joint bilaterally. This translatory motion of the joints can be caused to occur over a range of motion varying from only slightly more than "no motion" to approximately 7 mm and even more depending upon the "throw" built into the double eccentric arrangement 38. Within the range of the double eccentric arrangement 38, the "throw" of the apparatus 10 can be infinitely varied in this embodiment of the invention. As a practical matter, the practitioner initiates treatment with a "throw" which results in approximately 1 to 2 mm of translatory motion of the temporomandibular joints with the degree of motion increasing with selection of different settings. At the termination of therapy, the throw of the apparatus 10 will typically be set in the range of 7 mm but can be more or less depending upon particular treatment situations. In a usual practice of the present methodology, the apparatus 10 is used for a period of approximately five to ten minutes for each treatment session with a total of approximately four treatment sessions each day. According to desired treatment modalities, the period of each treatment session and the number of sessions can vary. In a usual treatment situation, the apparatus 10 can be caused to operate more rapidly when the "throw", that is, the degree of motion imparted to the mandible, is low. As a practical matter, however, it is more convenient to adjust only the "throw" of the apparatus 10 and allow said apparatus 10 to operate at a constant "speed" regardless of the degree of the "throw". The motion of the registration 44 must be forward of centric occlusion, that is, the motion imparted through the registration 44 to the mandible must be forward of the "bite" of the patient. In other words, this motion must be forward of the normal way in which the upper and lower teeth fit together. If motion is created behind centric occlusion, then the condyle 3 (shown in FIGS. 1-5) of the temporomandibular joint can be jammed into the tympanic plate (not shown) of the joint. The apparatus 10 is thus configured to prevent motion behind centric occlusion. Referring now to FIGS. 7 and 14, formation of the registration 46 on the yoke-shaped plate 48 can be appreciated. The plate 48 has a yoke portion 56 comprised of two arms 58, the arms 58 essentially forming a U-shaped structure which is sized to be received within the mouth and to accommodate the bite of a patient. Suitably shaped depressions 60 are seen to be formed in the upper surface of the arms 58. These depressions 60 receive portions of a rope 62 as can best be seen in FIG. 14, the rope 62 forming the registration 46 as will shortly be described. Once formed from the rope 62, the registration 46 connects to the plate 48 through flow of the acrylic material forming the rope 62/registration 46 into the depressions 60. The acrylic material used to form the registration 46, as well as the registration 44 which is formed in a substantially identical fashion, is an acrylic material marketed under the trademark "Triad" by Dentsply International, Inc. The acrylic material comes in the form of a "rope" as noted above by the reference to the rope 62. The rope 62 is formed to the shape of the arms 58 and then pressed onto the arm 58 with portions of the rope 62 flowing into the depressions 60. An impression is then taken in the rope 62 of the teeth of the upper jaw of the patient. This impression is then cured by means of ultraviolet radiation to form the registration 46. The registration 44 is formed in an essentially identical manner except that the impression is of the teeth of the lower jaw or mandible. While it is not necessary to impress in the rope 62 all of the teeth of the patient, it is preferred to impress as many teeth as possible so that the registrations 44 and 46 will have maximum retentive capability to the mandible and upper jaw respectively. It is necessary to provide custom shaped indentations in the registrations 44 and 46 so that said registrations can be retained in the mouth during operation of the apparatus 10. It is also possible to form the depressions 60 with undercut areas 63 to facilitate attachment of the registrations 44 and 46 to the plates 42 and 48. However, attachment is satisfactory using substantially cylindrical depressions. The registrations 44 and 46 can be easily removed from the plates 42 and 48 by means of a wedging tool such as a screwdriver so that new registrations can be formed on said plates. Alternatively, the plates 42 and 48 can be formed of a "plastic" material and can be disposable items which are not reused. The plates 42 and 48 are connected respectively to the drive bar 40 and the stationary bar 50 by means of set screws 64. It is desired to removably connect the plates 42, 48 to the bars 40, 50 so that the plates 42, 48 can be discarded if desired. Insets 66, 68 are respectively formed in upper and lower portions of the bars 40, 50 to receive anterior ends of said plates 42, 48. Removal of the mounting cap 52 by loosening of the set screw 54 allows removal of the stationary bar 50 from the shaft 36. As best seen in FIG. 11, the stationary bar 50 is seen to be configured in a substantially rectangular solid shape having a cutout 70 located anteriorly of the bar 50, the cutout 70 being substantially rectangular in shape and being defined laterally by parallel opposed arms 72 which are portions of the bar 50. On interior surfaces of the arms 72 are located rails 74, one each of the rails 74 being disposed on one each of the arms 72. An adjustment plate 76 has U-shaped channels 78 and 80 formed on oppositely disposed sides of said plate 76, the channels 78 and 80 receiving the rails 74 therewithin for sliding movement of the adjustment plate 76 within the cutout 70. A set screw 82 extends through one of the arms 72 and its associated rail 74 to engage the adjustment plate 76 on a facing surface of the plate 76 defining the "floor" of the U-shaped channel 80. The set screw 82 thus mounts the adjustment plate 76 in any desired position within the cutout 70. The location of the adjustment plate 76 within the cutout 70 is thus set by the practitioner according to the oral dimensions of the potential user. A T-shaped mounting element 84 is received at the opening of the cutout 70 in the bar 50 and removably held therein by means of set screws 86 which extend through the sides of the arms 72 at distal ends thereof to be received into threaded apertures 88 formed one each at distal ends of arms 90 of the element 84. For ease of illustration, only one of the screws 86 is shown, the other screw 86 not being visible in FIG. 11. Leg 92 of the mounting element 84 extends to the surmounting position relative to vertical extension bar 94 which is mounted to the reduction gearbox 30 at the anterior end thereof. The height of the vertical extension bar 94 is dimensioned to accommodate the thickness of both the drive bar 40 and the stationary bar 50. Distally of the leg 92 a slot 96 is formed in said leg 92 so that machine screw 98 can be received within threaded aperture 100 formed at an upper face of the vertical extension bar 94 and medially of its length. Further adjustment of the location of the stationary bar 50 along its longitudinal axis is thus possible through use of the slot 96, the machine screw 98 mounting the assembly thus formed in association with the stationary bar 50 to the vertical extension bar 94 and thus to the reduction gearbox 30 which essentially forms a base structure for the translatory drive unit 22. A brass bushing 102 is fitted centrally within the adjustment plate 76 and receives the shaft 36 therethrough. The stationary bar 50 and those structural elements associated therewith do not move during operation of the apparatus 10 but are maintained stationary relative to the upper jaw, the teeth of the upper jaw fitting into the registration 46 as aforesaid. The stationary bar 50 and that structure associated therewith also remains stationary relative to the movement of the drive bar 40 as will further be described hereinafter. Referring again to FIG. 7 inter alia, the drive bar 40 is seen to be removably connected to the plate 42 in a manner substantially identical to the arrangement described relative to the stationary bar 50 and the plate 48. The anterior end of the plate 42 is received within the inset 66 and mounted to the drive bar 40 by means of set screws 64. It should be understood that the plate 42 and drive bar 40 (as well as the plate 48 and bar 50) can be formed unitarily. The drive bar 40 assumes the general conformation of a rectangular solid having a circular cutout 104 which receives circular major eccentric 106 therewithin. As is best seen in FIGS. 12 and 13, the major eccentric 106 is formed with an offset circular cutout 110 within which minor eccentric 112 is disposed. The minor eccentric 112 is provided with a circular aperture 114 offset from the center of the minor eccentric 112 for receiving the shaft 36 therethrough. The minor eccentric 112 is rigidly fixed to the shaft 36 by a press fit of said shaft 36 into the circular aperture 114. This fitting is such that the minor eccentric 112 does not turn on the shaft 36 but is fixed thereto. The double eccentric arrangement 38 is employed to set the "throw" of the translatory drive unit 22. A mark 116 is formed on the minor eccentric 112 essentially at the periphery of the eccentric 112 and on that diameter of the eccentric 112 which extends through the center of the circular cross-section of the shaft 36. Marks 118, 120, 122, 124, 126, and 128 are positioned about the periphery of the major eccentric 106 over a semicircular portion thereof as shown best in FIG. 13. Alignment of the mark 116 on the minor eccentric 112 with the mark 118 on the major eccentric 106 would essentially result in no motion of the drive bar 40. At the opposite extreme, alignment of the mark 116 on the minor eccentric 112 with the mark 128 on the major eccentric 106 will result in the greatest possible motion. While the mark 118 would not be directly utilized in a setting of the double eccentric arrangement 38, the mark 118 is useful as a zero reference so that small translatory motions can be employed when desired such as at the initiation of therapy. In a practical apparatus, the major eccentric 106 would have a diameter of approximately 13/16 inch with the diameter of the minor eccentric 112 being approximately 7/16 inch. Once the mark 116 on the minor eccentric 112 is positioned relative to the marks 118 through 128 of the major eccentric 106 as desired, a set screw 130 is employed to fix the eccentrics 106 and 112 relative to each other, thereby providing a desired "throw" or degree of motion for a given progression of therapy. Once the double eccentric arrangement 38 is set, the drive bar 40 is placed thereover such that the major eccentric 106 is received within the cutout 104 in the drive bar 40, a set screw then being used to fix the double eccentric arrangement 38 to the drive bar 40 and to that structure associated with the drive bar 40. The shaft 36 extends from the double eccentric arrangement 38 and into reduction gearbox 30 for connection to the 100-tooth gear 34 as aforesaid. The shaft 36 terminates in this connection to the gear 34. The gear 34 is directly driven through the 25-tooth gear 32 by means of the shaft 28 which extends into the reduction gearbox 30 from the joint 26. As is conventional with reduction gearbox structures, the interior of the box 30 is conveniently lubricated in order to facilitate smooth operation of the apparatus. In the embodiments of the invention shown herein, the plates 42 and 48 are shown as being of the same size. In the embodiment of FIGS. 6-14, the stationary bar 50 can be adjusted as aforesaid and a certain amount of jaw discrepancy can thus be accommodated through the adjustment mechanisms provided as functional portions of the stationary bar 50. However, certain conditions such as Class 2 and Class 3 malocclusions can require longer plates. In a Class 2 malocclusion, commonly known as retrognathia, the leg portion of the plate 48 would be made longer in order to accommodate the "bite" of a retrognathic patient since such as patient has the lower jaw or mandible located further back than is typical. A Class 3 malocclusion, commonly known as prognathia, is characterized by having the lower jaw more forward than is typical. Accordingly, the leg of the plate 42 can be made longer to accommodate such a patient. Referring now to FIG. 15, another embodiment of the invention is seen to be comprised of a translatory drive unit 200 oppositely connected by means of a bellows joint 202 to a motor unit 204 having a motor (not shown) disposed internally of said unit 204 and operable by means of switch 206 in a manner similar to that described relative to the embodiment of FIGS. 6 through 14. The motor unit 204 drives shaft 208 which then drives the translatory drive unit 200 through the bellows joint 202. The bellows joint 202 is of substantially conventional structure and comprises upper and lower mounting collars 210 and 212, the collars being tightenable by means of tangentially oriented machine screws 214 and 216 respectively. The screws 214 and 216 are tightened to positively hold the bellows joint 202 to the shaft 208 and shaft 218 exiting the translatory drive unit 200. Bellows 220 of the bellow joint 202 connect in a conventional fashion to the upper and lower mounting collars 210 and 212 to provide a universal joint which is essentially similar in function to the joint 26 described above. As can be inferred from the foregoing disclosure, the shaft 218 exiting the translatory drive unit 200 joins to the bellows joint 202 and is positively affixed thereto by means of the upper mounting collar 210 as tightened by the screw 214. Similarly, the shaft 208 extending from the motor unit 204 joins to the bellows joint 202 by means of the lower mounting collar 212 as tightened by the screw 216. The function of the bellows joint 202 is to provide "give" or flexibility so that the user of the apparatus of FIG. 15 is not required to maintain the apparatus in a strictly maintained relation with the mouth. The universal joint 26 of FIG. 6 functions similarly but is formed of upper and lower plates 222 and 224 respectively having holes disposed about the periphery of said plates 222, 224 through which rod-like connecting elements 226 extend (as seen in FIG. 6). The universal joint 26 is conventional in function such that the lower plate 224 can skew relative to the stationary upper plate 222 to provide a desired freedom of motion. It should be understood that the bellows joint 202 and universal joint 26 can be used interchangeably with either joint being functional with the unit 12 or with the apparatus of FIG. 15 as well as other apparatus described herein. Still referring to FIG. 15, a battery pack 228 is connected to the motor unit 204 by means of an insulated cord 230. The battery pack 228 is intended to be positioned remotely from the translatory drive unit 200/motor unit 204 and can be rechargeable as is conventional. The battery pack 228 could be worn on the user by means of straps or belts (not shown) in a manner which facilitates portable use of the apparatus of FIG. 15. A console (not shown) can replace the battery pack 228 and can be used to convert AC wall power to DC current. Such a console would be connected to the motor unit 204 by means of an insulated cord such as the cord 230. The console would be remotely located relative to the motor unit 204 and the drive unit 200 and would conveniently be located on a desk or similar horizontal work surface. Flexible cable drive is also possible. The motor unit 204 can be shaped to facilitate being grasped by a user so that a user can hold the motor unit 204 while using the apparatus. The motor unit 204 can contain a biplanetary gear reduction system (not shown) which facilitates gearing down of the translatory drive unit 200 to a desired unit speed. The battery pack 228 can include a toggle switch 232 for controlling forward and reverse and a toggle switch 234 for power actuation. The battery pack 228 can also be provided with a rheostat (not shown) which enables a selection of a range of revolutions per minute for the output of the translatory drive unit 200. Although not shown in FIG. 15, the motor unit 204 can be configured to include a pistol grip or other grip so that the unit 204 can be readily grasped by a user. The translatory drive unit 200 can be further seen in FIGS. 16 through 26 to comprise a casing 236 and a clam shell plate 238 hingedly mounted to said casing 236 by means of hinge arrangement 240. The casing 236 and clam shell plate 238 form the main body of the translatory drive unit 200, the casing 236 further serving to enclose a series of gears as will be described hereinafter. The casing 236 and clam shell plate 238 are preferably formed of hardened anodized aluminum and are shaped with arcuate portions both for convenience and appearance. The plate 238 is formed with an aperture 242 which aligns with a threaded bore 244 formed in upper planar surface 246, the aperture 242 and the bore 244 being located anteriorly of the unit 200 near the hinge arrangement 240. A screw 248 (shown best in FIG. 21) is received within the aperture 242 and threaded bore 244 and acts to positively hold the clam shell plate 238 to the casing 236 when the screw 248 is tightened. The clam shell plate 238 fixedly mounts upper bar 250, the bar 250 mounting the yoke-shaped plate 48 which is identical to the plate 48 described relative to the embodiment of FIGS. 6 through 14. The plate 48 of FIG. 16 inter alia also mounts registration 46 in a manner exactly as described hereinabove relative to the embodiment of FIGS. 6 through 14. As best seen in FIGS. 17 and 21 inter alia, a drive bar 252 is mounted for movement relative to the surface 246 of the casing 236 as will be described hereinafter, the drive bar 252 mounting the yoke-shaped plate 42 which bears registration 44. The plate 42 and registration 44 of FIG. 16 are preferably identical to the corresponding structure of the embodiment of FIGS. 6 through 14. Further, the registrations 44 and 46 are mounted to the plates 42 and 48 respectively according to the procedures described above. The plates 42 and 48 are preferably formed of a plastic material such that said plates can be discarded along with the registrations 44 and 46 after use of the unit 200. The plates 42 and 48 are mounted, preferably removably, to the bars 252 and 250 respectively by means of screws 254. The stationary upper bar 250 has a threaded bore 256 capable of aligning with any portion of a slot 258 formed in the clam shell plate 238. Accordingly, a screw 260 can be utilized in combination with a washer 262 to mount the stationary upper bar 250 to the clam shell plate 238. As can be readily seen in the drawings, the screw 260 is received within the slot 258 along any portion of said slot with the stationary upper bar 250 being moved in a longitudinal sense to align the threaded bore 256 with a desired portion of the slot 258 such that the screw 260 can be received through the slot and into the threaded bore 256. Tightening of the screw 260 causes the upper stationary bar 250 and thus the plate 48 to be mounted stationarily relative to the clam shell plate 258. Through use of the slot 258 formed in the clam shell plate 238, the location of the plate 48 can be adjusted "forwardly" or "backwardly" in order to provide a desired range of adjustment for the plate 48. As is clearly seen in FIG. 17 inter alia, the stationary upper bar 250 is received within an inset 264 formed in the clam shell plate 238. A larger inset 266 is formed below the inset 264 in the clam shell plate 238, the inset 266 receiving the drive bar 252. The drive bar 252 is formed with an arcuate rear portion 268 and has a circular aperture 270 formed in the anterior portion thereof, the aperture 270 receiving any one of a series of eccentric cams 272 (only one of the cams 272 being shown). Each of the cams 272 is formed with a six-sided aperture 274 for receiving a six-sided drive pin 276. The pin 276 is driven by means of a gear and shaft arrangement located internally of the casing 236 as will be described hereinafter. Rotation of the eccentric cam 272 by means of the drive pin 276 causes movement of the drive bar 252/plate 42/registration 44 to cause the mandible of a patient to be moved and thereby to move the condyle of the temporomandibular joint in a translatory motion. The selection of a particular eccentric cam 272 and the operation of the translatory drive unit 200 will be further described hereinafter after completion of a discussion of the remaining structure of the unit 200. Referring now to FIGS. 19, 21 and 23 inter alia, the casing 236 is seen to comprise a bottom plate 278 having apertures 280, 282 and 284 formed therein. The aperture 280 receives a brass bushing 286 which mounts a reduced gear drive shaft 288. The aperture 282 receives a bushing 290 which mounts drive shaft 292. The drive shafts 288 and 292 extend externally of the casing 236 and, internally of the casing 236, the shafts 288 and 292 respectively mount gears 294 and 296. The aperture 284 receives bushing 298, the bushing 298 mounting shaft 300. The head of the shaft 300 comprises the six-sided drive pin 276 which extends externally of the casing 236 in surmounting relation to the planar surface 246 where said drive pin 276 receives a selected one of the plurality of eccentric cams 272 as noted above. The shaft 300 further mounts gear 302 within the interior of the casing 236. The gears 294,296 and 302 form a gear reduction arrangement so that the six-sided drive pin 276 can be driven at a desired speed for rotation of one of the eccentric cams 272. A shaft coupling 304 as seen best in FIG. 19 can be received and held on to either one of the drive shafts 288 or 292 in order to provide desired gear reduction. A set of the arcuate cams 272 preferably includes a total of fourteen of the cams 272 with each cam representing a one-half millimeter increment from 1/2 mm to 7 mm. Each eccentric cam 272 includes a six-sided aperture 270 which is located at varying distances from the center of the cams 272 in order to change the "throw" from 1/2 mm to 7 mm. The eccentric cam 272 which is mounted on the drive pin 276 at any given time causes motion to be transmitted from the motor unit 204 to the plate 42 and thus the registration 44 to transfer translatory motion to the condyles of the joints on either side of the mandible. Drive through the shaft 288 results in a lower rotational output of the shaft 300 for a given RPM of the motor unit 204 as compared to driving of the shaft 292 which produces a higher rotational output from the given input of the motor unit 204. As can be seen in FIG. 21, a screw 306 is received within slot 308 formed longitudinally in the upper bar 250. The drive bar 252 has an alignable threaded bore 310 formed therein which receives the distal end of the screw 306. The screw 306 can receive a washer 312 to provide a more positive mounting of the bars 250 and 252 together. Use of the screw 306 to mount the bars 250, 252 together is for the purpose of forming the registrations 44 and 46 on the plates 42 and 48 respectively as has previously been described. The screw 306 is only used in taking impressions on the plates 42 and 48 and is not utilized during operation of the apparatus to impart translatory motion to the temporomandibular joint. The length of the slot 308 is chosen in order to allow adjustment of the plates 42 and 48 relative to each other to accommodate differing positions of the upper jaw and mandible as occurs between individual patients. The screw 306 is not left in place on assembly of the plates 42/48 to the unit 200, this assembly being shown in FIG. 21 solely for the purpose of illustration. Referring now particularly to FIG. 17, an index line 314 is seen to be drawn on the distal portion of the surface 246, the index line extending substantially along a longitudinally oriented line of symmetry of the surface 246. Each of the eccentric cams 272 is provided with an index line 316. The two index lines 315 and 316 essentially extend from forwardmost corners of the six-sided drive pin 276 and six-sided aperture 274 respectively. The index lines 314 and 316 are aligned with each other when each of the eccentric cams 272 is mounted on the drive pin 276. Care must be taken that the drive bar 252 is at its most posterior limit when mounting the cams 272. At that posterior limit, the bars 250, 252 having the plates 48 and 42 mounted thereto respectively are mounted to the casing 236/clam shell plate 238. The registrations 44 and 46 are then secured within the mouth of the patient and the upper stationary bar 250 is firmly tightened to the clam shell plate 238 as aforesaid with the index lines 314 and 316 being aligned. In this manner, all movement will be forward of centric occlusion. In operation, the several embodiments of the apparatus function in a similar manner to translate the temporomandibular joint. As is seen in FIGS. 28a through 28e and 29a through 29e, the movement of the condyle in the fossa is shown. FIGS. 28a through 28e illustrate clockwise turning of the drive pin 276 to cause the right joint to move in the manner shown. Counter-clockwise movement is seen in FIGS. 29a through 29e. Referring particularly to FIGS. 28a through 28e, the lateral and medial references are indicated in each of the figures. In FIG. 28a, the condyle 3 is seen to be in a neutral position relative to the articular eminence 5. In FIG. 28b, the condyle 3 has moved laterally and rotated slightly anteriorly according to the motion provided by the-apparatus and methodology of the invention. In FIG. 28c, the condyle 3 has moved forward, toward, to or past the articular eminence 5. On the backward stroke as seen in 28d, the condyle 3 has moved medially and the lateral pole has rotated slightly posteriorly. FIG. 28e illustrates return of the condyle to a neutral position. Considering now FIGS. 29a through 29e, counter-clockwise turning of the drive pin 276 causes the motion of the condyle 3 as seen in the figures. The condyle 3 is seen to be in a neutral position in the fossa 7 as seen in FIG. 29a. FIG. 29b shows the condyle 3 to have moved medially with the medial pole rotating slightly anteriorly. In FIG. 29c, the condyle 3 has moved toward, to or past the articular eminence 5. On the backward stroke as is shown in FIG. 29d, the condyle 3 has moved laterally with the medial pole rotating slightly posteriorly. FIG. 29e again shows the neutral position of the condyle 3. Referring once again to FIGS. 25, 26 and 27, the motion of the drive bar 252 and associated plate 42 during clockwise motion of the drive pin 276 is seen to cause the indicated movement of said plate 42. In essence, any point on the plate 42.effectively scribes out an oval on each rotation of the drive pin 276, this movement causing the temporormandibular joint on each side of the mandible to be moved in translation both continuously and passively for the purpose of rehabilitation of the temporomandibular joint as described herein. Referring now to FIGS. 30 through 40, a third embodiment of the invention is shown to comprise apparatus 400 having a translatory drive unit 402 and a motor housing/handle 404. The apparatus 400 is similar in structure and operation to the two embodiments of the invention previously described in an explicit fashion relative to FIGS. 6 through 14 and 15 through 27 respectively. Many of the structural elements of the third embodiment of FIGS. 30 through 40 are very similar to or are essentially identical to corresponding structure described hereinabove relative to the first two embodiments of the apparatus of the invention. Having thus so indicated, reference will not be further made back to similar or identical structure and operation which is common to the third embodiment of FIGS. 30 through 40 and the previously described embodiments. Further not be is taken that certain structure present in the first two embodiments are not present in the embodiment of FIGS. 30 through 40, a particular feature being a universal joint structure coupling a handle element and a translatory drive unit. As is clearly seen in FIGS. 30 through 40, the translatory drive unit 402 is mounted in a fixed relation to the motor housing/handle 404. The motor housing/handle 404 essentially constitutes a visible casing which holds a motor (not shown) internally thereof, this casing being graspable by a user who holds the motor housing/handle 404 while the apparatus 400 is in use. The motor which is not shown can take the form of a number of conventional motors presently available and can contain gear reduction elements (not shown) which are of conventional construction. The motor contained within the motor housing/handle 404 is electrically connected through cord 406 and cable connections 408 and 410 respectively to control module 412. The cord 406 and cable connections 408 and 410 are of conventional construction and merely serve to connect the apparatus 400 to the control module 412 so that power can be applied to the motor (not shown) contained within the motor housing/handle 404 for operation of the translatory drive unit 402. Control is also effected through the control module 412 such as by means of on/off switch 414, forward/reverse switch 416 and speed selector 418. Control switch structure can also be provided on the apparatus 400 and particularly on the motor housing/handle 404 although such structure is not shown in the drawings related to this embodiment. The control module 412 essentially comprises a housing constructed of sufficiently strong plastic or other material and contains rechargeable batteries (not shown) which power the motor (not shown) contained within the motor housing/handle 404. It is to be understood that the control module 412 and associated switches and the like can be configured in a manner conventional in the art. The control module 412 is conveniently placed when in use in the patient's lap, on a horizontal surface or on a belt loop. The control module 412 can also be configured to contain a battery charger (not shown). Although also not shown in the drawings, the switches 414 and 416 as well as the speed selector 418 can be provided with light emitting diodes which indicate function. As is shown in FIG. 30, a light emitting diode or other luminaire is provided as a low battery warning light 420. The control module 412 can thus be formed as a portable unit or as a console unit intended for stationary operation on a table top or the like. While the apparatus 400 can be driven other than by the use of the control module 412, the module 412 is simple and convenient in structure and operation and is of particular utility in the providing of power through the use of rechargeable batteries (not shown) to drive the motor (not shown) contained within the motor housing/handle 404, which motor is conveniently taken to be driven by direct current as is provided by conventional rechargeable batteries. The motor housing/handle 404 is shaped to facilitate grasping by a user so that a user can hold the motor housing/handle 404 while using the apparatus 400. The body of the motor housing/handle 404 can be knurled such as is conventional in the art in order to further facilitate grasping and retention in the hand by a user. The translatory drive unit 402 is provided with upper and lower casings 422 and 424 respectively, these casings essentially enclosing most structure forming the translatory drive unit 402 with the very obvious exception of upper and lower plates 426 and 428 and the registrations 430 and 432 respectively formed on said plates. The lower casing 424 joins to the motor housing/handle 404 at the distal end thereof and is connected by means of fasteners which essentially join the lower casing 424 to the motor and speed reduction arrangement (if any) which are contained within the motor housing/handle 404 and which are not shown as aforesaid. The upper and lower casings 422 and 424 as well as the motor housing/handle 404 is preferably constructed of high grade anodized aluminum although other materials can conveniently be employed including materials generally referred to as plastics. It is to be understood that plastic or polymeric materials used in the construction of any portion of the apparatus 400 require a desired degree of rigidity, appropriate durometer, etc., with the exception of the registrations 430 and 432 which are preferably formed of curable acrylic materials or the like as is described herein. The upper and lower plates 426 and 428 can be constructed of stainless steel/hard anodized aluminum or in the alternative can be formed of a rigid polymeric material such as a material manufactured by DuPont and known under the trademark of DELRIN. The plates 426 and 428 are intended for single patron use especially in view of the fact that the registrations 430 and 432 are custom fit to the plates 426 and 428 respectively for each individual patient who is to be treated with the apparatus 400. The formations of registrations such as the registrations 430 and 432 onto plates such as the upper and lower plates 426 and 428 have been described in detail relative to the previous embodiments of the invention. The shape of the plates 426 and 428 including yoke-shaped portions designed to fit the mouth have also been previously described relative to the other embodiments of the invention. It is to be seen that the upper plate 426 has a portion referred to as upper bar 436 while the lower plate 428 has a portion referred to as the drive bar 438, the upper bar 436 and the drive bar 438 being of increased thickness relative to the yoke portions of the plates 426 and 428 respectively. The upper bar 436 has a slot 444 and a threaded aperture 448 disposed anteriorly of the slot 444, the plates being loosely joined by screw 434 through slot 444 and threaded aperture 442 in the lower plate 428 when adjusting relative plate position for each patient prior to apparatus assembly (not shown). When assembled, threaded stem 433 of the screw 434 is received within threaded aperture 448 in the upper plate 426 with the shank portion of the screw 434 being received through the slot 435 in the upper casing 422. The structure of the upper casing 422 can be seen particularly in FIGS. 31 and 32 as well as in FIGS. 35 and 37. Referring also to these figures inter alia, the manner by which the upper plate 426 is fitted to the upper casing 422 can be appreciated. The upper bar 436 is seen to be received within the upper bar cut out 466 formed in the upper casing 422, the cut out 466 surmounts drive bar cut out 468 through which the lower plate 428 and particularly the drive bar 438 of said plate 428 extends. The upper casing 422 further comprises a rear wall 470 which engages ledge 471 formed in the lower casing 424 as best seen in FIGS. 31 and 35. The upper bar 36 of the upper plate 426 is seen to be received between upper shoulders 474 formed in the shaped recess portions of the upper casing 422, the upper bar 436 fitting substantially flushly with the upper shoulders 474. Lower shoulders 476 formed in the upper casing 422 are more Widely spaced apart than are the upper shoulders 474 and receive the drive bar 438 of the lower plate 428 for motion therewithin. Chord shoulders 478 which are planar portions disposed diametrically oppositely apart on the under side of the upper casing 424 and cooperate with the rear wall 470 on the upper casing 422 and the ledge 471 on the lower casing 424 to cause the upper and lower casings 422 and 424 to fit together only one way. Upper perimetrical portions of the upper casing 422 can be beveled at 472 to provide a pleasing appearance and to avoid sharp edges. The upper casing 422 is provided with threaded apertures 452 which extend through the chord shoulders 478 and align with threaded apertures 454 formed in the chord cut outs 480 of the lower casing 424. Threaded screws 450 (only on screw 450 being shown in FIG. 31) are received within the apertures 452 and 454 to hold the upper and lower casings 22 together. It will readily be understood that the apertures 452 need not be threaded as desired. The plates 426 and 428 are joined together loosely as aforesaid and fitted for a patient's occlusion, the slot 444 only being used for this purpose. The shank of the screw 434 would be essentially centered in the slot 444 for Class I skeletal discrepancy, forward in slot 444 for Class II and rearward in slot 444 for Class III. After adjustment, the upper plate 426 is is secured to the upper casing 422 and the lower plate 428 is engaged with the drive portions of the apparatus 400 as described hereinafter. Completing the description of the upper plate 426, it is to be seen that the yoke-shaped portion of the upper plate 426 which is received into the mouth of the user is provided with depressions 446 which facilitate holding of the registration 430 (shown best in FIG. 30) as has been previously described relative to essentially identical structure utilized in embodiments of the invention previously described. The under side of the yoke-shaped portion of the lower plate 28 is also provided with the depressions 446 for mounting of the registration 432. In the anterior end of the lower plate 428 a cam aperture 440 is formed, this aperture being circular in conformation (as seen in this embodiment), the cam aperture 440 receiving any one of a series of eccentric cams such as the cam 456 as is seen in FIG. 31. Eccentric cams 482, 484 and 486 are shown in FIGS. 33a, 33b and 33c respectively and will be described hereinafter relative to the degree of motion which is imparted by said eccentric cams as determined by a selection of the cams. As is the case with the cams 482, 484 and 486, the eccentric cam 456 is provided with a half-moon aperture 462 which receives half-moon stem 460 of drive shaft 458. The drive shaft 458 extends through the lower casing 424 centrally thereof to connect the eccentric cam 456 to the motor (not shown) held within the motor housing/handle 404. The drive shaft 458 is driven in a rotary motion which rotates the eccentric cam 456. Since the eccentric cam 456 is received within the cam aperture 440 formed in the drive bar 438 of the lower plate 428, the lower plate 428 is caused to move in a manner which imparts translatory motion to the lower jaw of a user of the apparatus 400 and in a manner such as has been previously described herein. As has also been described herein, the registration 430 is received in the upper jaw of a user whereas the registration 432 is received by the teeth or structures of the lower jaw. Since the upper plate 426 remains substantially stationary during operation of the apparatus 400, the lower plate 428 moves relative to the upper plate 426 to impart translatory motion to the lower jaw of a user. Completing the structure of the lower casing 424, it is seen that screws 464 can be utilized to fasten the lower casing 424 to motor and/or gear reduction structure (not shown) held within the motor housing/handle 404 and which may extend into lower portions of the lower casing 424. Referring now to FIGS. 31, 33a through 33c and 34 in particular, it is to be seen that the eccentric cams 456, 482, 484 and 486 are all provided with alignment tool engagement apertures 488 which are placed one each on either side of the half-moon aperture 462 formed in each eccentric cam respectively, the apertures 488 essentially lie along a diameter of the substantially circular cams. The cams can be formed of bronze/stainless steel and a set of ten cams is typically provided with the apparatus 400. These cams are incrementally graduated from 1/2 mm to 5 mm in a preferred use of the apparatus 400. Although not shown in the drawings, each cam is marked by millimeter increment which indicates the degree of motion or "throw" provided by each of the cams. Each cam is also provided with an index line 500 which essentially constitutes a scribed line on the upper surface of the cam. The index line 500 on each cam is aligned with a scribed line 502 formed on an upper surface of the lower casing 424 such that the index line 500 and the scribed line 502 can be aligned to set the apparatus 400 to an initial position. An alignment tool 496 having alignment pins 498 is utilized to align one of the eccentric cams, such as the cam 456 in FIG. 34. The alignment pins 498 are received within the alignment tool engagement apertures 488 and the alignment tool 496 is then manually manipulated such that the index line 500 aligns with the scribed line 502 as aforesaid. Alignment of the index line 500 and the scribed line 502 ensures that the cam 456 (or any of the other cams) is in its most backward position with all subsequent movement being forward of centric occlusion. The eccentric cams 482, 484 and 486 are respectively provided with half-moon apertures 490, 492 and 494. While the apertures 462, 490, 492 and 494 could be chosen to assume other shapes which would allow driving by means of the drive shaft 458, the half-moon shape has been chosen for illustrative convenience in the description of this embodiment of the invention. Of particular importance in this situation is the location of the apertures 462, 490, 492 and 494. As will be noted in FIGS. 31 and 34, the aperture 462 is almost located along the diameter of the cam 456 extending through the alignment tool engagement apertures 488. The eccentric cam 456 thus provides only a small degree of translatory motion. As the apertures 490,492 and 494 extend further toward the periphery of the cams 482, 484 and 486 respectively, it is to be seen that a greater degree of translatory motion is imparted to the lower jaw of a user by means of the motion imparted to the lower plate 428. As can be seen in FIGS. 38, 39 and 40, the position of the lower plate 428 on rotation of the eccentric cam 456 can be seen. In these figures, the eccentric cam 456 is rotated through one-half of a revolution by the drive shaft 458 thereby causing distal portions of the lower plate 428 (which bear the registration 432) to move from an initial position to the greatest extent to one side at a quarter turn, as seen in FIG. 39, and then to its most inward position at one-half turn. It can then be seen from the motion illustrated in FIGS. 38 through 40 that the fullest lateral extent on the opposite side of the lower plate 428 occurs at 3/4 turn with the initial position being returned to at a full 360° revolution of the eccentric cam of the drive shaft 458. The following case histories are exemplary of treatment procedures and results obtained through practice of the present method and using apparatus configured according to the invention. EXAMPLE I A 43 year old female with a four year history of bilateral temporomandibular joint pain and severe headaches clinically associated with temporomandibular joint dysfunction. Previous therapy consisted of a series of intra oral splints, physical therapy, medication and bilateral arthroscopy undertaken approximately two years previous. Patient's chief complaint was severe bilateral temporomandibular joint pain and limited range of motion. Diagnosis was bilateral internal derangement with bilateral fibrous ankylosis, secondary to arthroscopy. Patient underwent bilateral menisectomies with joint debridement. Range of motion prior to surgery was as follows: maximum opening--43 mm; lateral excursion to right--5 mm; lateral excursion to left--7 mm. Rehabilitation utilizing the methodology and apparatus of the invention was provided for seven consecutive days and obtained the following range of motion: maximum opening--43 mm; right lateral excursion--9 mm; left lateral excursion--11 mm. Patient related an approximate 80% reduction of pain. EXAMPLE II A 27 year old female with a fifteen year history of left temporomandibular joint pain and limited motion. Previous patient treatment involved a series of intra oral devices, tooth equilibration restorative dentistry, medication and physical therapy. A diagnosis based on history, examination, corrected serial tomograms and arthrograms indicated a chronic closed lock with moderate degenerative joint disease, left temporomandibular joint. The arthrogram revealed a perforation of the articular brisc. A menisectomy was conducted. Prior to surgery, the patient exhibited the following range of motion: maximum opening--35 mm; right lateral excursion--7 mm; left lateral excursion--6 mm. Rehabilitation utilizing the methodology and apparatus of the invention was conducted for eight days of consecutive therapy and at the end of rehabilitation the range of motion was as follows: maximum opening--43 mm; right lateral excursion--9 mm; left lateral excursion--9 mm. The patient used the device intermittently over the following two months and at the end of two months the range of motion was as follows: maximum opening--43 mm; right lateral excursion--11 mm; left lateral excursion--11 mm. The patient related an approximate 90% reduction of pain. EXAMPLE III A 44 year old female with a long history of right sided temporomandibular joint pain. Prior to presentation, the patient had undergone two open joint surgeries on the right side, both being disc plications. The workup consisted of Corrected serial tomograms, history and examination. A diagnosis of fibrous-bony ankylosis was indicated. Range of motion prior to surgery was as follows: maximum opening--11 mm; right lateral excursion--4 mm; left lateral excursion--0 mm. The patient had a marked deviation on opening to the left side. Patient underwent a menisectomy and debridement. Immediately after surgery, patient was started on rehabilitation using the methodology and apparatus of the invention. After two weeks, motion was as follows: maximum opening--31 mm; right lateral excursion--9 mm; left lateral excursion--5 mm. Patient had less deviation to the left side. No attempt was made to force the patient's mouth open and only translatory motion was emphasized. Patient related a 50% to 60% reduction of pain. EXAMPLE IV A 23 year old male with a previous history of a fractured mandible. Approximately two years after sustaining trauma, patient incurred severe bilateral joint pain and limited motion. Patient was treated with a series of intra oral splints and physical therapy with no apparent improvement. Patient underwent surgery approximately one year prior to presentation. Both joints were subjected to surgery twice with the last surgery involving bilateral proplast implants. Diagnosis involved advanced degenerative joint disease and fibrous ankylosis, both left and right temporomandibular joints. Patient underwent bilateral joint surgery consisting of removal of proplast implants, joint debridement and arthroplasty. Prior to surgery, the range of motion was as follows: maximum opening--7 mm; left lateral excursion--2 mm; right lateral excursion--2 mm. Following surgery the patient was rehabilitated according to the invention for approximately seven weeks. At the end of that time period, range of motion was as follows: maximum opening--40 mm; left lateral excursion--6 mm; right lateral excursion--7 mm. Patient related an approximate 80% reduction of symptoms. EXAMPLE V A 45 year old male involved in a motor vehicle accident involving sustainment of multiple facial fractures including multiple fractures of mandible and maxilla with the right mandibular condyle being displaced into the cranial base. Four months after both open and closed reductions of facial fractures, patient developed a fibrous and bony ankylosis of the right mandibular condyle along with ankylosis of the right coronoid process and temporalis muscles with advanced adhesions around the right pterygoid plates and medial surface of the mandible. The patient shortly underwent a menisectomy and arthroplasty of the right temporomandibular joint, coronoidectomy of the right side with freeing of adhesions between the right pterygoid plate and ramus of the mandible. Prior to surgery, opening was as follows: maximum opening--4 mm; left lateral excursion--0 mm; right lateral excursion--4 mm. Immediately after surgery the patient was rehabilitated according to the invention for approximately five weeks. At the end of five weeks, range of motion was as follows: maximum opening 25 mm; left lateral excursion--6 mm; right lateral excursion--6 mm. Patient had only a slight reduction in pain as pain was never a problem, the problem being a matter of severe limited range of motion. EXAMPLE VI A 33 year old female with a six year history of bilateral temporomandibular joint pain and associated headaches. Treatment previously consisted of orthognathic surgery to correct a Class II malocclusion, arthroscopy being undertaken twice on the left side and once on the right side. Patient also had a series of intraoral devices and physical therapy. Patient's primary complaint was bilateral joint pain with associated headaches. Diagnosis based on serial tomograms and arthrograms revealed advanced degenerative joint disease with chronic closed lock and fibrous ankylosis of the left joint and moderate degenerative joint disease with displaced disc and moderate intracapsular adhesions of the right joint. Patient underwent bilateral menisectomies and an arthroplasty on the left side. Prior to surgery, range of motion was as follows: maximum opening--15 mm; right lateral excursion--1 to 2 mm; left lateral excursion--3 mm. Immediately after surgery the patient was rehabilitated according to the invention and the following range of motion was obtained: maximum opening--43 mm; right lateral excursion--8 mm; left lateral excursion--8 mm. The patient related a 75% reduction in symptomology. EXAMPLE VII A 39 year old male in an industrial accident sustained trauma to the left temporomandibular joint. Previous treatment consisted of multiple intra oral splints, medications, physical therapy and four surgeries conducted on the left joint consisting of reconstructive arthroplasty, arthroscopy, placement of sylastic implant and removal of sylastic implant. Diagnosis involved bony-fibrous ankylosis and advanced degenerative joint disease of the left temporomandibular joint. The patient underwent menisecotmy, debridement and arthroplasty. Prior to surgery range of motion was as follows: maximum opening--25 mm; right lateral excursion--3 mm; left lateral excursion--5 mm with marked deviation on opening to the left. Immediately after surgery, rehabilitation was conducted according to the invention and after two weeks the following range of motion was obtained: maximum opening--35 mm; right lateral excursion--8 mm; left lateral excursion--11 mm with degree of deviation to the left side being markedly reduced. Patient related that his temporomandibular joint pain was 90% reduced but his primary complaint of headaches which began shortly after the accident remained essentially the same. EXAMPLE VIII A 33 year old female who was assaulted with resultant trauma to both left and right temporomandibular joints. Patient's primary complaint following the injury was bilateral joint pain and limited range of motion. Patient underwent therapy with intra oral devices and physical therapy without relief. Diagnosis based on history, examination, corrected tomograms and arthrograms showed early degenerative joint changes with moderate fibrous adhesions and interal derangement bilaterally. Approximately three years after the accident, the patient underwent bilateral menisectomies, joint debridement and arthroplasty. Range of motion following surgery was slightly decreased over normal. Three years after surgery, the patient returned complaining of right-sided joint pain and limited motion. Range of motion was measured as follows: maximum opening--31 mm; right lateral excursion--5 mm; left lateral excursion--2 mm. The patient tried for approximately four weeks using apparatus configured according to the invention but without surgery and the following range of motion was obtained: maximum opening--41 mm; right lateral excursion--8 mm; left lateral excursion--8 mm. Patient related an 80% to 90% reduction of symptomology. EXAMPLE IX A 39 year old female with primary complaint of pain in the left temporomandibular joint and limited motion. Patient had a previous diagnosis of closed lock, left temporomandibular joint. Patient also exhibited a facial asymmetry due to approximately 12 mm of condylar loss on the left side. Patient previously received a treatment plan consisting of condylatomy with intermaxillary fixation followed by orthodontic therapy and mandibular and maxillary osteotomies. Patient sought a second opinion for the treatment. Patient also had previously undergone recurrent bouts of acute synovitis in the left joint. At time of presentation, range of motion was as follows: maximum opening--24 mm; right lateral excursion--6 mm; left lateral excursion--8 mm. Patient underwent therapy only with use of the methodology and apparatus of the invention and used the apparatus of the invention for approximately one and a half weeks. Range of motion at the end of therapy being as follows: maximum opening--38 mm; right lateral excursion--10 mm; left lateral excursion--11 mm. Patient related approximately 50% reduction of symptomology. EXAMPLE X A 70 year old male related no temporomandibular joint dysfunction prior to tooth extraction. Shortly after tooth extraction patient noticed a decrease in range of motion. Pain was not a significant complaint. Diagnosis based on history, examination, corrected serial tomograms and arthrograms showed an acute closed lock. Range of motion was as follows: maximum opening--17 mm; right lateral excursion--5 mm; left lateral excursion--9 mm. Without other treatment, patient was treated according to the methodology of the invention and an apparatus configured according to the invention. After one month, the following range of motion was obtained: maximum opening--42 mm; right lateral excursion--9 mm; left lateral excursion--10 mm. Since pain was not a significant problem, no quantification of pain reduction was indicated. Since continuous passive motion (also known widely as CPM) according to the invention involves translatory motion having components of motion in both side-to-side and front-to-back senses, it is to be understood that the invention encompasses such motions both with or without a component of motion in the other sense. The apparatus of the invention can be configured within the framework of structure herein presented to effect such motion. The methodology of the invention is further understood to encompass such motion. While the methodology and apparatus of the invention have been described in relation to certain protocols and embodiments of an apparatus, it is to be understood that the invention can be practiced other than as explicitly described without departing from the scope of the invention, the invention being defined according to the recitations of the appended claims.

A therapeutic method for rehabilitating the temporomandibular joint by induction of translatory motion of the joint either post-operatively or as therapy for a variety of conditions, the invention also contemplates apparatus capable of practicing the present method by continuously and passively moving the joint in a translatory sense.

BACKGROUND OF THE INVENTION This invention relates generally to key telephone systems, and more specifically concerns an improved system which realizes substantial reductions in installation costs, permits use of relatively small central units, provides compatibility with telephone apparatus speaker phones, automatic dialers, etc., and provides additional advantages, as will be seen. The use of key telephones is a well established solution to many business telephone needs. These needs range from use as a primary telephone system for small and medium size business to supplemental service associated with PBX's, for the larger business. Such systems are ideal for business requiring up to five central office lines; or four lines plus an intercom. SUMMARY OF THE INVENTION It is a major object of the invention to provide a key telephone system incorporating combinations of the following advantages: 1. Business pre-wiring is made practical. 2. The system is compatible with several standard type station sets. 3. It is fully compatible with telephone apparatus such as speaker phones, automatic dialers, etc. 4. Intercom features, not found on small key systems, are incorporated. 5. Complete common or split bell arrangements are provided without requirements for additional apparatus. 6. System functions are partitioned for fast trouble isolation. The system design concept is based on the principle that only one wire pair on a key system is used for talking. It is then possible to move the switching function to a central point where all station sets gain access to the telephone lines and to run only one talk pair to the individual station sets. This central point in the system is the central cabinet. Once this is done, it remains only to accomplish the other functions (selection, indication and audible) on as few other wire pairs as possible. Two additional pairs are used; one for control data and the other for power. Accordingly, the system design reduces the number of wire pairs to each station set to three without sacrificing any of the system functions. This feature alone offers an immediate advantage of lower installation costs resulting from time materials and labor cost reductions. The design also permits the use of a small central unit with all terminations self contained. Basically, the invention is concerned with a telephone system comprising a plurality of station sets each having a push button actuable line select switches, and comprises: (a) multiple adapter units each connected with and proximate to a station set, (b) multiple supervisory circuits to each of which at least two of said adapter units are connected via a talk pair, a control pair and a power pair, said circuits being remote from said adapters, (c) system control means connected with said supervisory units via a data control bus for an asynchronously transmitting to each adapter unit via said supervisory circuits data including a start pulse causing the adapter to poll the line select and other switches in the station sets, and a data word corresponding to light, bell ringing or intercom bell ringing information. In addition, dual line and intercom circuitry is provided to interface between the system control means and the central office, for purpose as will appear. These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following description and drawings, in which: DRAWING DESCRIPTION FIG. 1a is a block diagram of a conventional key system; FIG. 1b is an overall block diagram of a system installation in accordance with the present invention; FIG. 2 is an expanded block diagram of the present system installation, with reference to a single station unit or set adapter, and emphasizing the use of three wire-pairs; FIG. 3 is an overall system block diagram, and showing various cards used in the central cabinet, and with reference also to multiple set adapter or station units; FIG. 4 is a circuit diagram illustrative of system data pathing; FIG. 5 is a data format illustration; FIG. 6 is a graph showing switch settings in the set adapter for operation of the bell for line and intercom ringing; FIG. 7 is a representation of a data transmission sequence for light and bell information; FIG. 7a is a block diagram showing the involvement of basic elements in system data flow; FIG. 7b is a timing diagram illustrating timing details involved in one complete cycle of data transmission and return; FIG. 8 is a block diagram of a system or common control card; FIGS. 8a and 8b are detailed circuit diagrams illustrative of the FIG. 8 card; FIG. 8c illustrates data formats; FIGS. 8d-8j are timing diagrams; FIG. 9 is a block diagram of a dual set supervisor (dual station) card, as incorporated in FIG. 2; FIG. 9a is a detailed circuit diagram illustrative of the FIG. 10 card; FIG. 10 is a block diagram of a line circuit, two such line circuits being on in each dual line card, as represented in FIG. 2; FIG. 10a is a detailed circuit diagram illustrative of the FIG. 10 card, including two FIG. 10 circuits; FIG. 11 is a block diagram of a dial intercom card; FIGS. 11a and 11b are detailed circuit diagrams illustrative of the FIG. 11 card; FIG. 11c is a dial signal timing diagram; FIG. 11d is an intercom card tabulation; FIG. 12 is a timing diagram showing ring signal timing; FIG. 13 is a block diagram of a tone decoder card usable along with the intercom option of FIG. 11; FIG. 13a is a detailed circuit diagram illustrative of the FIG. 13 card; FIG. 14 is a block diagram of a power supply card, as also seen in FIG. 2; FIG. 14a is a detailed circuit diagram illustrative of the FIG. 14 card; FIG. 15 is a timing diagram showing one complete frame of data transmission and return (see also FIG. 7b); FIG. 16 is a block diagram of a key set adapter card, i.e. station unit card; FIGS. 16a and 16b are detailed circuit diagrams illustrative of the FIG. 16 card; FIG. 16c is a Keyset Adapter Timing Diagram; and FIG. 17 is a detailed circuit diagram of an optional privacy circuit card. DETAILED DESCRIPTION In FIGS. 1b, 2 and 3, the improved telephone system comprises a plurality of station sets, as for example at 10, each including a plurality of key buttons 11. A set adapter or station unit 12 is provided for each set, each adapter adapted to process data to and from its associated station set, and to drive the lights and ringer at the set. An electronic control unit (ECU) or control cabinet 13 is typically located in the same building as the adapters, or in the vicinity of the latter, there being three pairs of wires running from the ECU to each adapter. More specifically, and as shown in FIG. 3, the ECU typically incorporates a plurality of station cards, as for example dual set supervisory circuits 14, one card for each of at least two adapters, as shown. Two parallel groups of wires run from each card 14 to the two respective adapters associated with the card 14, and each group includes three wire pairs, i.e. a talk pair 15 a power transmission pair 16 and a control pair 17 used for transmission of data related to signaling and switch status. The voice pair 15 consists of the standard tip/ring telephone circuit with metallic switching in the central cabinet. The central cabinet 13 is therefore a transparent link between the central office 180 and the standard 500 type network of the station sets. The control pair 17 is a half-duplex data path which is used alternately to transmit switch status to the central cabinet and the light/audible status to the station set. The data speed is central cabinet adjusted to accommodate the wink/flash rates of the lights and the switch response time required. The power pair distributes approximately 43V AC power to the station sets. The AC voltage also synchronizes the data flow in the system. Accordingly, the system basically consists of a single wall mounted central cabinet plus a wall mounted or desk-top key set adapter for each station set. The central cabinet contains control electronics, intercom, line switches, wire terminations, and a power supply. Quick-connect terminal blocks are completely enclosed within the central cabinet and do not require any cross-connects or jumper wiring. It contains the circuit for system control, line management (hold and ring detection) and optional functions such as intercom. All line switching takes place in the central cabinet and is handled by protected dry switched reed relays. As seen in FIG. 3, the cabinet houses the system control card 18, dual line cards 19, dual set supervisor cards 14 and the power supply 21a. A dial intercom card 21 is used in place of one of the dual line cards on a system incorporating the intercom option. As will be seen, each supervisor circuit or card 14 is operable to select a talk pair for a particular station set 10, to send data to and receive data from the adapter 12 associated with that set, and to provide light data for a particular line associated with that set. The card 14 interfaces two station sets to the central cabinet. This card switches the voice pair to the selected central office line (trunk), and it also contains circuitry for the data send/receive functions. A system using one or two station sets requires one dual set supervisor 14. For each dual set supervisor added (up to eight), two station sets can be added. The system control card 18 of FIGS. 3 and 8 contains the central timing circuitry, performs the data processing functions, and controls all of the decision making functions of the system. All of the control and status signals for the individual station sets and line circuits (trunks) are processed by this card. The dual line card 19 of FIGS. 3 and 10 contains the circuitry for those functions associated with the management of two central office lines (trunks). These functions include ring detection, line hold, and light data. This card interfaces the two lines to the Central Cabinet. The number of Dual Line Cards required for a particular application is listed in Table 1: Table 1______________________________________Dual Line Card RequirementsCentral Office Lines Number of Dual Line(Trunks) Used Cards Required______________________________________1 12 13 24 25 3______________________________________ The dial intercom card 21 of FIG. 11 is typically inserted in the central cabinet in place of one of the dual line cards. It contains the talk battery and the dialing register, and decodes the dialing signal, selects the station, and sends a two short-ring ringing signal to the called station. The ring signals continue until the call is answered or abandoned. The dial intercom card is compatible with rotary dialing station sets. An option card (see FIG. 13) provides compatibility with tone dial station sets. Systems using the intercom option are limited to four central office lines (trunks). The intercom tone card of FIG. 13 is an optional unit used on the dial intercom card when the system uses tone or a mixture of tone and rotary dial station sets. It contains the tone detectors and logic required to convert the tone signals to binary bits, which are compatible with the dial intercom card counting register. The set adapter 12 of FIGS. 3 and 16 processes data to and from the central cabinet and drives the light and audible signals at the station set. One set adapter is required for each station set. This unit also contains the circuitry for monitoring the line select switches. Any of three set adapter configurations may be used. One is wall mounted and measures approximately 5 × 7 inches by 1 inch deep for example. This unit accommodates the 50 pin set tail plug of the standard key set, such as the 564/2564 types. It also provides terminations for the three wire pairs from the central cabinet. It contains the set electronics which makes the standard keysets compatible with the present system. A set of small switches is contained inside the wall unit for setting the line ringing arrangement and the intercom number when the intercom option is used. The under the phone version of the set adapter first directly underneath single line set Models. The front section of the adapter contains the lamps and switches, and the electronics are contained in the thin section beneath the station set. Terminations for connection to the station set and back to the central cabinet are located at the rear of the set adapter. The three wire pairs are connected back to the central cabinet through a standard mounting cord and station block. A third version of the set adapter is a desk top unit which permits the use of any decorator or standard type station set. All of the key set functions are contained in this unit. Again, only three wire pairs are returned to the central cabinet. Referring now to FIG. 4, the data path originates at the system control card 18 which contains a power driver 23 for sending data via bus 24 to all station sets in the system. These data signals are processed through the dual set supervisor 14 which drives the data pair 17 for each key set adapter 12. A matching impedance 25 for each data pair is located on the respective dual set supervisor 14. Associated with each of these matching networks is a "receive" circuit 25a which responds to data returning from the key set adapter 12. This data is gated onto a common return data bus 24a when requested, by a control signal from the system control card. The driver 23 on the system control card is balanced to reduce any electro-magnetic interference generated by the system. It thus prevents interference with other systems and provides common mode noise rejection from other sources. Data is returned in a balanced condition for these same reasons. This balance is maintained, through the dual set supervisor 14 out to the individual key set adapter 12. The data format is illustrated in FIG. 5. Data transmission is of the asynchronous type, somewhat similar to the standard used for data transmission to teletype sets. The data transmission sequence is begun by a "start pulse" 26 which is transmitted from the system control card 18 to each key set adapter. The key set adapter responds, by polling each of the line select switches in the respective station sets. This is followed by the transmission of an 8-bit data word, at 28, from the central cabinet to all station units. Five bits of data (see also FIG. 8c) are associated with the lights or bell. The information in these five positions is interpreted as light data when the last bit is in the "light" state. When the last bit is in the "bell" state, the five line bits refer to the bell signals. There are two types of bell information, one concerned with lines ringing, and the other with intercom ringing. This is indicated by the first bit. Data transmission may contain any one of three types of information: (1) light, (2) "line ringing" bell, or (3) "intercom ringing" bell. The state of the first and last bits identifies which of the three types of information is contained in the word being transmitted. If the last (8th) bit is in the true (on) state, the data contains light information. If this bit is in the false (off) state, the data controls either the "line ringing" or "intercom ringing" bell functions. When the first bit is in the true (on) state, the data controls the "intercom ringing" bell functions. Otherwise during a bell data transmission, any previous "light" information is stored so that the lights will not be affected by the "bell" data. FIG. 6 shows the switch settings in the Set Adapter 12 for operation of the bell for line and intercom ringing. Note that the first five switches are concerned with lines ringing and the last four switches are concerned with the intercom dialing number. The control circuits of the adapter compare the two functions bits (first and last) with the switch setting in order to determine the disposition of the five line bits. The light data is stored during ring information transmission so that ring signals do not appear in the visual display. The data transmission sequence for light and bell information is illustrated in FIG. 6. The data transmission rate is 96 frames (words) per second. Note that two frames of light information are followed by two frames of bell information. This sequence of light vs bell information corresponds to a light or bell data update of 24 times per second. This update rate produces the 24 Hz bell ringing frequency which is compatible with the standard ringers used in the station sets. FIG. 7a shows the essential elements involved in the system data flow. Only one Set Adapter 12 is indicated but up to sixteen could be involved in the polling scheme. The control circuits on the System Control Card 18 consist mostly of a binary count-down chain from the power supply frequency. The various control and timing signals for the system are derived from this counter. The control circuit 12a in each Set Adapter contains similar count-down chains driven by the same power frequency. The control circuit at the Set Adapter is synchronized to the Central Unit control circuit by a sync pulse (Start Bit). See FIG. 7b in this regard. The data flow consist essentially of the exchange of information between the shift registers of the Central Unit and the Set Adapters. FIG. 7b gives the details of one complete cycle of data transmission and return. The total frame is divided into four phases (T0-T3). The first two phases are the active portion and the last two phases are quiescent for synchronization purposes. The process begins when the System Control Card produces the start bit. During the T0 phases the load control signal on the Common Card causes the loading of a single bit into the last position of its shift register. This bit is shifted out immediately by the shift clock. The transmit data is then quiescent for the remainder of the T0 period. When the start bit is received, it initiates the return data action at the Set Adapters. In the block diagram of the system control card as illustrated in FIG. 8, all system timing functions are controlled by the clock signal at 30 which is derived from the system AC power 31. This clock signal is used for the operation of the timing chain 32 which provides all of the shifting, strobing and control timing periods. It governs the data rate to the key set adapter, the wink and flash rates of the lights on the station sets as well as the timing for ringing the station sets. The control logic 33 is responsive to signals from the time chain and to data returned at 24a and the key set adapter. It uses these signals to produce the control signals at 35 required for the operation of the system. The station address is used to determine which station set is providing the return data that is shifted at 36 into the data register 37. The station address and various strobe pulses are presented to the data bus 24 along with the data for communicating with the other electronic cards in the system. Return data, from the addressed key set adapter, is presented to the system control card 18 by the data bus 24a. This return data is tested in the return data test circuit 38 to verify that it is a valid return. A faulty key set adapter at the addressed station set, or no key set adapater present at a particular address would present an invalid data condition. Such data would be blocked, thereby preventing false operation of the system. Valid data passes into the data register 31 during the proper portion of the control cycle (FIG. 5). When the data word is completely assembled into the data register, it is presented to the data bus for transmission to the dual set supervisor 14, dual line cards 19 (in the case of hold or reset of ring detection), or to the dial intercom card 21 (when an intercom call is answered). At this point, and with reference to FIG. 9 the line select register (i.e. LSR) strobe signal at 40 effects loading of the data into the appropriate dual set supervisor LSR 41 or 141. At the proper time the control logic 33 also causes the "light" data received from the dual line cards and dual set supervisor to be strobbed into the data register 37 via the data bus 42. See the control line 43 from logic 33 to bus driver 44. It is then shifted out to the data driver circuit 23 which provides the signal at 24 required by the dual set supervisor 14 for driving the individual control wire pairs 17 to the key set adapters 12. The control bus gate transfers parallel information from the data register onto the control bus at the proper time. This is the "select" information which goes to the line select registers on the dual set supervisor. Referring to FIG. 9, the dual set supervisor serves three functions; (1) selects the voice pair 15 for a particular station set, (2) sends data to and receives data from the key set adapter via connections 17, and (3) is the source 59 and 159 of light data at 60 for a selected line. A block diagram of the dual set supervisor is illustrated in FIG. 9. Two of the three wire pairs that connect to a key set adapter originate at this card. The third wire pair 16 (power) originates from a common tie point for all key set adapters. When a particular station address appears at its associated dual set supervisor 14, the return data path is enabled via decode unit 46, enable connections 47 and 48 and buffers 49 and 50 so that data from the station set flows to the system control card via path 24a. The system control card of FIG. 8 then presents parallel data back to the control data bus 42. At the proper time in the data transmission sequence, the line select register strobe signal 40 is gated through the address decode circuitry 46. This causes data presented by the control data bus 42 to be loaded into the appropriate select register 41 and 141. The information in the select register is used to drive the associated line select matrix 51 or 151 which in turn connects the station set circuit 12 to the desired line. The selected line information is retained in the line select register 41 or 141 until it is updated by a new data word from the station sets. This storage allows the system to sequence from station set to station set in processing information. The content of the line select register is gated onto the data bus 42, along with other sources of light information, during the time that light information at 60 is being assembled onto the control data bus 42. At the proper time, this information is loaded into the shift register 37 on the system control card, to be transmitted via the control wire pairs to the station sets. When the FIG. 8 system control card receives a "hold" signal from a station set, a hold strobe pulse will appear at 52. This pulse is used in FIG. 9 to override any loading of data into the select register. This is necessary because line select information is also coming from the station set that originated the hold command. This dual information is required for the operation of the hold circuit on the dual line card 19. The motherboard wiring at central cabinet 13 determines the address of a particular dual set supervisor 14. This permits the address decode circuit on all of the dual set supervisors to be identical so that these cards are readily interchangeable. Referring to FIG. 10 a dual line card 19 contains two of these illustrated circuits. The main functions of the line circuit are ring detection, holding, and display of the light data showing the conditions of the line circuits. The ring detector 62 is bridged across the tip and ring leads 63 and 64 of its associated central office line (trunk), so that the detector responds to the ringing voltage from the central office and rejects unwanted signals such as line interference, hook switch spikes and dial pulse spikes. The data output at 65 of the ring detector is maintained between rings by a timing circuit in 62. The timing circuit is reset when any station set in the system selects that particular associated line. The output of the ring detector is presented to the light data gate 66. When this output is coincident with the flash rate signal at 67 and the light data enable signal at 68 the proper data bit is presented at 69 to the system control card via the control data bus. This causes light data to be transmitted for one half second with a pause of one half second. This corresponds with the flash rate of the station set lights. The line ring enable signal at 71 allows the light data gate to operate during the collection of data for bell data transmissions. The bits in the transmitted data word are therefore the same for line ringing information as for light flash information. The difference, of course, is the frame of transmission in which they occur. The light data sequence for "hold" is identical to the operation just described for line ringing except the wink rate signal at 72 and the hold latch 73 are used as the source of data for gate 66a, corresponding to gate 66. The "hold" latch circuit 73 is activated when the coincidence of a line data bit at 74 and the hold strobe signal at 75 corresponds to a particular lines hold circuit. The hold set circuit 76 continues to receive signals so long as the hold button on the station set is depressed. During this period, the hold latch is set to "On", which causes the hold relay 77 to bridge the holding circuit 73 across tip and ring via bridge 80. When this circuit is completed, the central office talk battery furnishes current to the current regulator and current detector. The current detector is optically coupled back to the hold latch circuit. The action of current through the current detector 78 is to NOT reset the hold latch via connection 79. This is necessary to maintain the hold latch during the period required to operate the hold relay and obtain a feedback from the current detector. This feedback removes the reset signal, in other words. Once this hold latch arrangement is in the set condition and the hold set signal has ceased, any interruption in the central office talk battery will cause the hold latch to reset. The hold circuit relay 77 will then fall out. This corresponds to a held party hang-up. Also, the bridging of any other station set across tip and ring 63 and 64 will drop out the current detector 78 thereby re-setting the hold latch. This is the normal method of re-setting the hold circuit when someone seizes the line. The dual line card circuit of FIG. 10 also contains provisions for use of the key system in the event of a power failure. This is accomplished by means of a Form B relay being connected across tip and ring. As long as power is present, this relay is energized and keeps tip and ring disconnected from the by-pass arrangement. When a power failure occurs, the relay de-energizers and tip and ring are fed directly to the designated station sets. Referring to FIG. 11 the dial intercom card 21 supplies the talk battery 84 for the intercom path and it also provides signaling to the dialed station set. The talk battery 84 provides a constant current source with the proper impedance to battery and ground. The current detector 85 in series with the talk battery, permits the sensing of the off-hook condition and the dial pulses. The signal at 86 from the current detector is processed through pulse separator 87. This circuit removes any switch contact bounce and provides the control pulses at 90-92 for operation of the intercom circuits. The off-hook circuit has a long time constant; therefore, the dial pulses 90 will not interrupt the steady state condition of the off-shore signal 92 as long as any station set is off-hook. The dial pulse circuit has a much shorter time constant which enables it to faithfully reproduce the dial pulse timing sequence. The dial pulses are further treated to produce the inter-digit pulse 91 which signal the control logic circuit 93 when the required interdigit time-out has occurred. The dial intercom card operates in the following sequence: All of the logic at 93 on the dial intercom card is held in the reset condition when the station sets are all on-hook. Therefore, when a station set goes off-hook, the counting register 96 is in the condition required for receiving pulses corresponding to the first digit dialed. After the first digit has been dialed, the inter-digit pulse at 91 causes the control logic 93 to control the register via connection 97 to direct the dial pulses 90 to the second portion of the counting register. During the dialing time there can only be one station set off-hook or dialing could not proceed. The reason for this is that the current detector 78 in FIG. 10 would not sense the interruption of talk battery current by the dialing station set. During the interval between the two dialed digits, the fifth data bit supplied at 99 on the control data bus is sensed. The occurrence of the fifth data bit indicates the station address of the dialing station set. This condition causes a load pulse to be sent at 102 from the control logic circuit 93 to the calling station register 103 enabling storage of the dialing station set address data at 104 in the calling station register. Upon completion of the dialing of the second digit, the control logic permits the coincidence of the intercom ring signal 100 and the data enable signal 101 to cause the contents of the station register 103 to be gated onto the control data bus. This information is merged with the proper control bits and sent out to all station sets. The key set adapter of the dialed station set then decodes the information in order to ring the station set ringers. The timing sequence for "intercom" ring in relation to the "line" ring is illustrated in FIG. 12. This ringing pattern continues until the call is answered. Answered condition is indicated by the occurrence of the fifth data bit on the control data bus from any station, other than the calling station. If the fifth data bit is from any station set other than the one dialing, it will cause a reset as at 104, 105 and 106 applied to logic 93, and the ringing stops. The comparator 107 compares the address of the answering station against the calling station register 103. If the fifth data bit corresponds with the calling station, the comparator circuit 107 will inhibit the called party reset circuit 105 so that the fifth data bit from the calling station set is ignored. Ringing will therefore continue until either the call is answered or the calling party hangs up. The hang up condition produces a reset signal. During the ringing time, the control logic circuit produces a ring back tone at 108 which is superimposed onto the talk pair so that the calling party hears a tone. The intercom tone adapter is an optional unit as seen in FIG. 13 which is attached to the dial intercom card of FIG. 11 through a board-to-board connector. The interconnection between the two cards is such that the dial intercom card operates in a normal manner when the intercom tone adapter is not used. When the intercom tone adapter is used, both rotary dial and tone dial station sets can be used on the same system. In this case, the dialed number detection circuitry which operates (dial intercom card or intercom tone adapter) depends on which type of station set is being dialed. The interface between the two cards is concerned with the transfer of the tone detected digits directly into the counting register 96 and in the generation and use of certain sequencing signals. A tone present signal at 109 is used on the intercom card to advance the digit count logic 110. The completion of the dialing process causes the count/load line 111 on the intercom tone adapter to transfer the information to the counting register 96 on the dial intercom card. The called party off-hook signal is used as the reset signal at 112. The net result is that the tone dialing sequence causes a parallel transfer of the dialed number directly into the counting register of the dial intercom card. A pre-amp circuit 113 is connected to the tip and ring circuit 114 and 115 on the dial intercom card. The pre-amp circuit 113 connects the balanced differential signal of tip and ring to a single ended signal at 116 which is then presented to the tone detectors 117. Only the numbers one through eight are used; therefore only six detectors 117 are required. The outputs of the tone detectors are fed to a digit encoder 118 which converts the dual tone system (DTMF) to a binary format at 120 which is compatible with the one produced in the counting register on the dial intercom card. The information 120 from the digit encoder is stored in a 4-bit latch 121 until dialing is complete. The tone present signal, which is sent at 122 to the dial intercom card, is used for sequencing to the "dialing complete" condition. Since the 4-bit number has been placed into the counting register 96 the circuitry on the dial intercom card produces the calling signals just as though dialing had been originated from a rotary dial. A block diagram of the power supply is illustrated in FIG. 14. It produces a special 48 VAC high frequency voltage, as shown, which is distributed to all of the key set adapters. Each key set adapter contains a small ferrite core transformer. The transformer operates from this 48 VAC to produce the voltages required by the key set adapter. The main output transformer 130 on the power supply, has other secondary windings 131 and 132 which are used to produce the voltage required in the central cabinet. The 117 VAC commercial power input at 133 to the power supply is rectified at 134 and filtered to produce 115 VDC. This DC voltage is used to power the oscillator/power amplifier combination 135. All of the circuits associated with the power line (rectifier, power amplifier, oscillator, and AGC circuits) are coupled to the power line wires as a reference. The output power transformer and an optical coupler 136 serve to isolate the incoming power line voltage from the voltage outputs to the key system. The oscillator is controlled and produces the signal that drives the power amplifier stage. The power amplifier produces approximately 100 watts of output power. Voltage regulation is provided by a feedback, from the power amplifier, through the 5 VDC power supply 137, comparator 138 and optical coupler 136 to an AGC circuit 139. The output of the 5 VDC power supply is fed to the voltage comparator 138 circuit, which is referenced to a precision 5 VDC. The resultant drives a LED type optical coupler 136. The output of the optical coupler drives the AGC circuit 139 which regulates the voltage supply to the oscillator 140. The results is a closed loop feedback which maintains the required regulation. A more complete discussion of the data transmission is given here before describing the details of the key set adapter 12. One complete frame of data transmission and return is detailed in FIG. 15. The total frame is divided into four phases (T0-T3). The first two phases are the active portion of the transmission. The last two phases are quiescent for synchronization purposes. The process begins when the system control card produces the start bit. During the T0 phase, the load control on the system control card causes the loading of a single bit into its last position of the shift resiger. This bit is shifted out immediately upon the first shift edge of the clock pulse (the positive going edge). The line marked "transmit data" illustrated that the start bit lasts for the period between two consecutive positive edges of the shift clock. The transmit data is then quiescent for the remainder of the T0 period. The start bit initiates the return data action when it is received at the key set adapter. At the beginning of phase T1, a new load control signal occurs which is coincident with the "data enable" signal. This causes the shift register on the system control card to be loaded from the control data bus. The data enable signal gates the output of the various cards onto the control data bus. These outputs combine to make up the composite light or ring data bit pattern (word). Two flag bits are also loaded into the shift register. The last flag bit tells the key set adapter whether the data is light information or ringing information. The first flag bit tells the key set adapter whether the ringing information is "intercom ringing" or "line ringing". A strobe pulse is generated when the return information from the selected station set has been assembled in the system control card shift register. This strobe pulse occurs in the middle of the time period when the return data is available. This is the end of the T0 period. This strobe pulse is used to clock the return data into the appropriate dual line and dual station supervisor cards. A block diagram of the key set adapter or station unit is illustrated in FIG. 16. The data transceiver 142 interfaces the data pair to the circuits within the key set adapter. The control logic 143 is triggered into action upon receipt at 144 of the first part of the transmit data frame (start bit). The start bit sets the control logic into the operate condition as illustrated in FIG. 15. The timing chain 145 is now allowed to run. The control logic, along with the timing chain, generates the T0 and T1 periods. The shift clock signal at 146 on the key set adapter is identical to the one on the central cabinet (FIG. 8) except that it is delayed by one half shift clock period. This difference optimizes data transfer. The start bit is also fed at 147 into the key set adapter shift register 148. Until this time the shift register has been held in the reset state, therefore it is cleared of all information. The start bit proceeds through the shift register as the T0 period progresses. The receipt of the start pulse which is connected at 147 to the switch scanner is used to load the switch status into a shift register within the switch scanner 150. The clock signal 46 causes this data to be sequentially presented to the data transceiver where it is transmitted back to the control unit via the data pair as the Return Data Word, presented also in FIGS. 8c and 15. Light and ring information is then fed from the data transceiver 142 to the shift register 148 on the key set adapter. At the end of the T1 period the shift register will contain a complete data word representing either the light or bell information for that particular transmission frame. The control logic and timing chain produce a load pulse at 152 at the end of the T1 period, which causes the register data to be strobbed into the proper circuit. It will be recalled that there are three potential uses for this data depending on the two control flags. The light/ring (L/R) flag (8th bit) will cause the data to be strobbed into the light register 153 during a frame associated with light data. This information is retained in the light register until it is replaced by a subsequent frame containing light information. The output of the light register is fed to the light driver circuit 154. The light drivers are capable of powering the lamps 154a in the station set and to which they are connected at 154b. The rate that information is put into the light register is sufficient to insure that the wink and flash rate is properly reproduced at the station set. The bell circuits are responsive to the inverse state of the L/F flag; therefore a transmission containing bell information will be presented to the bell circuits at the end of the T1 period. The state of the intercom/line (ICM/LINE) flag (1st bit) determines whether the particular transmission is a line or intercom ring signal. The two decoders 155 and 156 associated with the line ring and intercom ring functions are responsive to the state of this flag. Depending upon which decoder is enabled, the settings of the associated switches 180, and the code transmitted, the bell driver 157 will be strobbed on. The control logic 143 will be strobbed to its reset state, by the timing chain 145, at the end of the T1 period. This shuts down all operations within the key set adapter for the periods corresponding to T2 and T3 of the system control card timing chain. This period provides time for the synchronization of all key set adapters with the system control card during power start up. It also provides a re-synchronization period which minimizes malfunctions resulting from extreme external noise conditions during system operation. This re-synchronization takes place between every transmission sequence. The Key Set Adapter power supply 160 contains a clock stripping circuit. This circuit insures that the timing functions within the key set adapter are in exact synchronization with corresponding functions in the central cabinet. Tip and ring of the voice pair are brought into the key set adapter and pass directly out to the station set, as indicated at 161. Therefore, the total action of the electronics in the key set adapter is concerned with line selection, display of information and ringing the station set, but have no effect on the voice pair. DETAILED DESCRIPTION OF SYSTEM CONTROL CARD Referring now to FIGS. 8a and 8b, these circuits provide the timing, logic control, and data handling for the Central Cabinet; their functions are: to receive and process serial information from all stations attached to the system; to generate serial information to be sent to all stations attached to the system; to use the power supply frequency (49,152Hz) to generate all timing and control signals for the system; (all timing in the system is relative to the power supply frequency); to control all devices which supply information to the data buss and process this information; to supply information to other devices via the data buss and provide control signals which cause these devices to accept such information; and, to provide the power driver for sending serial information to all stations. 1.0 Timing Chain The 49,152Hz frequency of the power supply is supplied to a series of Flip/Flop counters arranged as dividers. The input rate is divided down to one fourth Hertz (1/4 Hz). Various control signals are derived from the timing chain by appropriate gating arrangements. This timing chain runs continuously and all systems functions are time referenced to it. 1.1 Clocks Squaring Circuit The RAW CLOCK signal in FIG. 8b is derived from one of the power supply rectifier circuits. Its levels, rise times, and duty cycle are not critical. It is important that the waveform be free of glitches which would cause the squaring circuit (A6) to produce more than one output cycle per input cycle. The capacitor C2 is used to filter a low level glitch caused by the rectifiers response time. 1.2 First Divide By 16 The divide by 16 (A5) counter produces the shift clocks 3.072KHz and the 6.144 KHz gating term. The basic reason for the ÷ 16 is to provide a small increment in the synchronization of the station adapter to the start pulse from the Central Cabinet. 1.3 Divide By 32 (Circuits CT0 through Ct4). This section of the timing chain provides the timing and control of the data transmission frame. See FIG. 8b. The first half of the period is active and the second half is quiescent. The quiescent time allows all associated station circuits to catch up if they are out of sync with the Central Cabinet. The signals derived from this section are associated with loading the shift register, shifting data processing data from it. 1.4 Divide By 16 (CT5 thru CT8) This section provides the 4 bit address for processing information relative to the 16 stations. Also, certain functional signals are derived from this section. 1.5 Divide By 3 (CT9 & CT10) The ÷ 3 allows data transmission rates which produce 24Hz ringing signals and line/ring periods (which are related to 1 second) consistent with standard key system. The wink rate is derived from this counter. Note that the IC package A20 is a ÷ 12 counter. The ÷ 2 section is used for CT4 and only the ÷ 3 section is used here. 1.6 Divide By 8 (CT11 thru CT13) This section produces the ringing periods and the flash rate. It is held in the reset state until one of the ring detectors operates or the intercom dialing is complete. Based on the assumption that most of the time an incoming call will be answered before another one comes in, the one second ringing period begins when a call is detected, thus there is no delay in the bell. 2.0 Control Signals A number of control signals are derived from the timing chain. Some of these are used only on the System Control Card and others are brought out to the edge connector for connection to other cards in the Central Cabinet. Where necessary, these signals are buffered with power gates. The Timing Diagrams, FIGS. 8d -8j show the details of these signals. The details of the use of these signals are given in the description of the associated circuits either elsewhere in this System Control Card descript or in the description of the cards which contain them. 3.0 Data Handling Circuits Data handling is mostly concerned with data gathering, distribution, and the conversion from serial to parallel and visa versa. Additionally, certain control signals are developed based on the data present. 3.1 Serial Data In (Return Data) The address lines A0 thru NA3 select one at a time each of the station adapters by means of the address circuitry on the respective Set Supervisor Cards. Data from the station is connected to the System Control Card on the common OR buss line RID. Refer to the signals RID and Data Out on the timing diagram of FIG. 8e. The flow of Return Data is initiated by the leading edge of the Start Pulse. 3.1.1 Data Pair Open Detector At the beginning of T0 period the output of the data receiver on the Dual Set Supervisor card corresponding to the addressed station is connected to the RID terminal (pin 5) of this card. Since this is one half shift clock before the Start Pulse, there should be no return data present (low-true). However, if the data pair is open, the signal will be incorrectly low at this time. The clock developed by A7-12 will test RID at the leading edge of the Start Pulse and inhibit the flow of data into the shift register if it is low. This test will be performed for the data returned from each station in turn. 3.1.2 Shift Register Serial-In At the beginning of T0 period the shift register is empty. At t = 1.5 the positive edge of the shift clock will sample the first return bit. This will continue for a total of 7 edges (where t = 7.5). The shift/load control is high during this time so that meaningless data is gated onto the data buss. From t = 7.5 to 8.5 the return data is in the correct position for use. 3.2 Processing of Return Data Once the return data is in position for correct parallel output, various circuits process this information. 3.2.1 Line Select Data The outputs B, C, and D are connected to the decoder A25. If a line is being selected by the particular station that is being poled, the appropriate output of the decoder will go low. This will be inverted by the data buss gate and the data buss line (D1 through D5) corresponding to the selected line will go high. The LSR pulse (Load Select Register) goes true (high) from t = 7.75 to 8.0. This pulse causes the data to be loaded into the respective line select registers as well as performing functions described elsewhere. If no selection is being made this operation will clear the line select register. 3.2.2 Busy The outputs B, C, and D are also fed into a negative input OR gate (A28-12). All three of these outputs will be high for no line selection. If any of the three are low, the busy gate will be enabled. Since the return data will be valid up until t = 8.5 where the station data is loaded into the shift register, this bit will become part of the station data word. Note that this complete transaction occurs within one transmission frame so that a busy display system could decipher the station data. 3.2.3 Nite Mode F/F The Nite bit (F output) is loaded into the Nite Mode F/F by LSR. This flip flop can be set by any station and thus hold its state for operation with line ringing signals. It is held reset during the last two seconds of the four second system cycle. 3.2.4 Privacy Release This bit (E output) is connected to pin 17 for use on the Privacy Card. 3.2.5 Hold The Hold bit (A output) is ANDed with LSR to form the strobe (H.S.). This occurs when the poled station has the HOLD button depressed. 3.3 Serial Data OUT (Station Data) The station data is parallel loaded into the shift register and shifted out at the 3KHz shift rate. The shift register is loaded 96 times per second. 3.3.1 Loading From t = 8 to t = 9 the load/shift control is low which causes data buss (D1 thru D5) and the appropriate function control bits to be loaded into the shift register. This also includes miscellaneous bits such as Nite and Busy. 3.3.2 Transmission The shift clock edge at t = 8.5 loads the data and immediately begins the transmission at that time. Each shift clock advances the data to the last stage (H out) until at t = 16.5 the register is cleared. 3.3.3 Start Bit OR Gate The data out (H out) is low-true. The shift register output and the start F/F outputs are ORed at (A17-3) 3.3.4 data Driver The output of the OR gate is fed to the cross coupled NAND gates (A22-3,6). The purpose is to provide a slight delay in switching from high to low and visa-versa. This prevents opposing drivers in the output stage (A26) from having a cross-over glitch. A26 contains two source and two sink transistors which are capable of 600 ma. These are arranged in two totem pole configurations to produce the two outputs LD & HD. The outputs HD & LD alternately switch between +15 volts and ground (within a few tenths of a volt). This action provides an AC balanced twisted pair driver. All station data pairs are driven through a pair each of 300 ohm resistors from this point. 3.4 Collection of Station Data Station data consists of a Start Pulse during T0 and an 8 bit data word during T1. The 8 data word is a composite of information from other cards in the Control Cabinet along with function codes and miscellaneous information derived on the System Control Card. 3.4.1 Start Pulse The Start Pulse F/F is enabled by the Start Pulse Enable signal and is set low by the shift clock at t = 0.5. 3.4.2 Start Pulse Squelch Note on the timing Diagram II that the Return Data begins half way through the Start Pulse. Since Data Out overrides Return Data it is necessary to foreshorten the Start Pulse in order to sample the Return Data in the middle of its first cell time. Shorting the Start Pulse is no problem as only the leading edge is used by the station adapters. 3.4.3 Function Code Bits The first and eight bits define the function of the particular station data word being transmitted. Which of the three basic words transmitted can be determined from the complete system cycle diagram along with its details. These bits are generated on the System Control Card, but are also a function of inputs from other cards. 3.4.4 Light Data Light data is collected from several other cards. The data buss (D1 thru D5) is a collector OR arrangement. This property is used to form the composite data field which represents each of the five lights. Light data is transmitted a minimum of 48 times per second in a pattern of two light and two ring transmission. Part of the time it is transmitted at the full rate of 96 per second. 3.4.4.1 LDE The primary use of LDE (Light Data Enable) is to gate the contents of the Line Select Registers onto the data buss. As a result, any line that is selected will contribute a data bit. The LDE pulse occurs for each light transmission so that the net results at the station set is a steady lamp indication for a selected line. 3.4.4.2 MWNK The use of the MWNK signal is to gather light data for lines that are on "hold". MWNK is derived from LDE but has two 1/12 second skips per second. This pattern of pulses is used to interrogate the hold circuits for each line. Therefore, some light transmissions will contain data collected by MWNK and others won't. The result is that station lights corresponding to held lines will wink in coincidence with MWNK. 3.4.4.3 mflsh this pulse is used to gather light and ring data for lines that are ringing. The use of this pulse for ring data is described in paragraphs 3. 4. 5. The flash pattern is 1/2 second on and 1/2 second off. MFLSH is derived from LDE with this pattern superimposed so that the lights for ringing lines will flash at this rate. 3.4.5 Ring Data Ring data is OR'ed onto the data buss (D1 thru D5) in the same fashion as light data. Line ring is gated by MFLSH because the source circuit for light flash and line ring is the same; namely, the ring detector. The strobing signal for intercom ring is generated on the intercom card. 3.4.6 Miscellaneous Bits 3.4.6.1 Nite Bit The Nite Bit is transmitted along with line ringing data when the Nite MOde F/F has been set. A30-8 and A28-6 generate the Nite Bit. The data buss lines are ORed and tested during MFLSH. Thus, when any line rings, the Nite Bit indicates that one of the lines is ringing. 3.4.6.2 Busy The generation of the busy information is described in paragraph 3.2.2. The output of 29-13 is fed back to the Shift Register input B. 3.4.6.3 sync The sync bit is used to allow remote devices to synchronize with the central unit return data poling scheme. It is transmitted along with light data when the central unit has just received data from station #15. The reset gate has a dual task; one of them is generating the sync bit. The reset bit is gated into the Shift Register input H by LDE. 4.0 miscellaneous Circuits 4.1 ICM Enable The ICM Ring Gate (A22-8) is disabled under two conditions: (1) There is no intercom card or (2) if there is a card, but the ring condition has not been met. The disabling of intercom function codes is necessary because if they were generated without proper data present there would be false ringing. The intercom card returns the signal ICM Enable only when it is ready to ring and ISEL is true. NISEL is used to enable a second interm card so that there will be no conflict between the codes generated by the two cards. DETAILED DESCRIPTION OF DUAL SET SUPERVISOR CARDS Section I -- General Description Referring now to FIG. 9a, this circuit switches the station voice pair and provides the individual data pair circuits for the station sets. It is a dual circuit. The Timing Diagram in FIG. 8d should be referenced. The circuit functions are: to provide the matching impedance between the data driver on the System Control Card and the station data pair; to provide the data receivers for return data from the station sets; to provide the Line Select Registers corresponding to the associated station sets; and, to provide the relay switch matrix for the associated station set. Section II -- Detailed Description 1.0 Address Circuit The system can be implemented with up to 8 Dual Set Supervisor Cards for a total of 16 stations in a system. The address circuit selects one of these stations for return data and the associated Line Select Register. 1.1 Decoder A3 is configured in a 1 to 16 decode arrangement. A3-11 and A3-3 select 1 of 8 cards. The last address bit (A0, NA0) selects 1 of 2 circuits on the card. The three higher order terms have dual terminals. The back plane wiring is arranged to pick-up these terms so that the card address is peculiar to the slot and not to the card itself. 1.2 Strobe Pulses The two strobe pulses LSR & HS are received at the card by the differential receivers (A14). The pulses are qualified by the address circuit output. 2.0 Data Circuit The return data receivers are selected by the output of the address circuit. This selection is valid for the full transmission frame corresponding to the addressed station set. Refer to the system control card timing Diagram of FIGS. 8e and 8f. 2.1 Transmit Circuit The purpose of the resistors R1 through R4 are: 2.1.1 To connect the data pairs to the data driver on the System Control Card. The data sent is the same for all stations; 2.1.2 To provide isolation between the data pairs for individual return data and in the case of short circuits, etc; and 2.1.3 To act as a current source to minimize the effect of loop resistance change; 2.2 Receive Circuit The receive circuit is selected by the address decoder output. When selected its output is gated onto the buss line RID (pin 5). This is a collector OR point for all cards in the system. The data is low-true. 2.2.1 Receive Operation When data is being transmitted from the Central Cabinet, the data pairs will be terminated at the station in a very low impedance (less than 100 ohms). For this reason the voltage will never be high enough across the data pair to operate the Central Cabinet receiver. Data is returned to the Central Cabinet by opening the circuit at the station set end. The data return is timed so that HD will be positive with respect to LD. The voltage across the data pair will then rise until current flows through the coupler LED. This causes the input to the Schmidt Trigger to go low and thus presenting a high-true signal to the open collector NAND 3.0 line Select Circuit After the serial data is received from the selected station it is presented in parallel to the data buss (D1 thru D5) by the System Control Card. 3.1 Line Select Register The LSR pulse always occurs and will cause the data to be loaded into the Line Select Register. If the return data does not contain a select request, the Line Select Register will be cleared by the null data. If the return data contains a hold request, the H.S. pulse will be present along with LSR. The H.S. pulse is gated into the clear terminal of the Line Select Register. This will override any data inputs and will leave the register cleared. 3.2 Switch Matrix The output of the Line Select Register is connected to the relay drivers. The relay corresponding to the data is caused to operate. The five lines are respectively connected to the five relays. The other side of these relays are connected together to form the voice pair to the station set. 4.0 Light Data Circuit The output of the Line Select Register is also connected to the open collector NAND gates. When LDE occurs, the line busy status is gated onto the ORed data buss (D1 thru D5). At this time all stations will have their data ORed onto the buss so the result is the busy status of the lines. DETAILED DESCRIPTION OF DUAL LINE CARD Section I -- General Description 1.0 Referring now to FIG. 10a this dual line card circuit provides the interface between the present system and the existing central office lines. Functions are: to detect the presence of a ringing voltage across the C.O. line and provide line status data to the data buss in response to the signal MFLSH; in response to a hold command to place a holding impedance across the C.O. line and provide line status data to the data buss in response to the signal MWNK; and to provide for the release of the holding impedance if the line is selected by any station or if the held party hangs-up. Section II -- General Description AL1 schematic references in the description below refer only to the odd numbered line circuit since there are two identical circuits per card. 1.0 Ring Detector The Central Office presents an approximately 90 volt 20Hz signal for about 1 second with an interval of 3--6 seconds. 1.1 Optical Coupler The LED of A1 is set to respond to the presence of the ringing voltage. The series resistor R5 and capacitor C1 set the effective threshold for the detection of ringing voltage without causing a false load on the line. The capacitor C1 makes the circuit similar to a normal bell where there is no D.C. load back to the C.O. for "on-hook" conditions. The diode D9 protects the optical coupler during the negative half cycle of the ringing voltage. 1.2 Noise Reject and Time-Out Circuit The level detector (A3-5) has dual thresholds at 3.33 volts for turn on and 1.66 volts for turn off (1.66 volts hysterises). The capacitor, C5, is normally charged to +5 volts keeping the output A3-5 at the low state. When the LED of coupler A1 goes on, the output collector goes to ground. This begins to discharge C5. Noise on the line will be ignored. When the ringing signal lasts long enough, the voltage at C5 will drop to the lower threshold so that output of the detector goes higher. During the interval between rings, the capacitor C5 starts to charge back up to +5 volts. The time constant of R8 and C5 is set so that the upper threshold will not be reached between ring signals. If the incoming call is abandoned, the time out will occur in about 2 ring intervals. The output A3-5 remains at a steady high state during the time that ring signals are present. 1.3 Line Select Squelch The F/F A9 is clocked by LSR and has the associated Data Buss line connected to its "D" input. When any station selects that particular line, the F/F will be set on. The open collector A7-6 will turn off allowing a very fast charge of C5 through R9 & D8. This causes the output of A3-5 to go low. 1.4 Data The ring detector output is gated to the data buss line when MFLSH occurs. This is both for light and line ring data. 1.5 Ring Cycle Control When the ring detector is high, the gate A14-4 clamps RCC, the common reset line, low. This allows the ring interval counter on the System Control Card to begin its timing period. The effect of this is that the bells at station sets which are set to ring on this line will begin ringing immediately when the ring detector operates. 2.0 Hold Circuit 2.1 Hold Bridge When the hold relay K3 operates, the hold bridge circuit is placed across the C.O. tip/ring pair. This maintains the supervisory current when the station set goes on-hook. 2.1.2 Current Regulator The voltage regulator Q1 is arranged in a constant current configuration to maintain a 23 ma maximum hold current. It automatically adjusts to the loop length. 2.1.2 Latch Feedback The coupler A11 is part of the latching circuit for the hold relay K3. After the relay closes, there must be a current developed through the LED in order to maintain the relay operated. 2.1.3. Bridge Dropout When a station selects a line that is on hold, the voltage across the tip/ring pair drops to the point that the current through the LED will no longer maintain the latch. Relay K3 will then remove the bridge from the tip/ring pair. The zener diode insures that the current drops rapidly to the drop-out point. 2.2 Hold F/F The data buss line is connected to the "D" input of the hold F/F (A9-9). The F/F is clocked by the Hold Strobe (H.S.) signal. This F/F will remain on until a signal is received from the hold bridge optical coupler (A11). The gate A10-13 combines the feedback signal with the reset to turn off the Hold F/F. 2.3 hold Latch The hold latch consists of the relay K3, coupler A11 and inverters. The Hold F/F drives the open collector A7-2 to ground energizing the relay K3. This places the bridge circuit across the tip-ring pair. The C.O. battery current flows through the LED of the coupler (A11) which drives the collector (A11-5) to ground. The double inversion drives A7-4 to ground. The contact of K3 is closed so that the feedback will maintain the relay latched when the Hold F/F resets. The hold latch is broken when the LED current drops due to either a station set being bridged across the tip/ring pair or the C.O. breaking talk battery. 2.4 Hold Data The output of A8-4 is a high true signal for the Hold condition. This is used to produce light data when MWNK occurs. DETAILED DESCRIPTION OF DIAL INTERCOM CARD Section I -- General Description Referring not to FIGS. 11a and 11b, this Dial Intercom Card circuitry provides the local talk battery and rotary dial signaling for the intercom link. It also operates in conjunction with the Tone Decoder Card to provide tone dial signaling. Functions of the circuit are to provide the local talk battery for the intercom link; to provide means for detection of the rotary dial pulses and the off-hook conditions; to provide means for interpretation of the rotary dial pulses; to generate the ICM Ringing data for inclusion in the station data word; to stop ring generation once the call is answered; and to provide means for operation in conjunction with the Tone Decoder Card, Fig. 3a. Section II -- Detailed Description 1.0 Voice Pair Interface 1.1 Talk Battery The intercom link on a key system is not connected to a C.O. line so it is necessary to supply a local talk battery. When the ICM card is installed in place of a line circuit the station sets are connected to this talk battery when this line is selected. The talk battery consists of two current regulators; one sourcing current from the +15V supply and the other sinking current to the -15V supply. The current is set at about 30 ma. 1.2 Loop Current Detector The loop current supplied by the talk battery passes through the LED of coupler A4. Therefore, the off-hook and dial pulse breaks in current are monitored by this coupler. The output of the coupler A4-5 is squared up by the Schmidt Trigger A3-8. The signal (high) at TP4 represents the loop current. 1.3 Signal Separation 1.3.1 Dial Pulse The output of A3-8 is connected to the retriggerable one-shot A5-4. The clock frequency is supplied to the other input. This particular signal is used because it is available. The time out of the one-shot is set short compared to the dial pulse length but long compared to contact bounce of the phone's rotary dial. The one-shot fires when loop current is first detected and continues to retrigger as long as this signal is present. When the loop current signal falls out, the one-shot will begin its final time out. Any contact bounce will occur within this time-out interval and simply restart the time-out period. The net result is that the output A5-4 will go low for off-hook and go high for each dial pulse. 1.3.2 Interdigit Pulse The one-shot A6-12 will trigger on the positive going edge of the dial pulses. Its time outs are about 2 dial pulse intervals. The output A6-12 will go low during the receipt of dial pulses. The positive edge at the end of dial pulsing marks the end of a digit. 1.3.3. Off-Hook A5-5 operates identically with A5-4 except the time-out is longer. The Q output A5-5 goes high for loop current and remains high during dial pulsing because of the long time-out. 2.0 Control Logic 2.1 Dial Sequence Register The F/F's A10 control the operation of the logic on the ICM card. They are reset to their initial state by the on-hook condition or the call being answered. The off-hook signal release them for operation. The connection is essentially a shift register where the interdigit signal is the shift clock. The initial state is First Digit and Dial Not Complete. The positive edge of the interdigit pulse advances the first F/F to the second digit. The next positive edge advances the second F/F to Dial Complete. The tone present signal from the Tone Decoder card has the same effect. 2.2 Data Buss Gate At the end of the dialing sequence the dialing register will contain a five bit binary value as a function of the digits dialed. At the proper time this value is gated onto the data buss for inclusion in the intercom ring station data word. The gate enable signal is derived by 4 input AND (A13-8 & A3-4). The inputs are: Lights/Ring Flag, Intercom Ring, Data Enable and Dial Complete. 2.3 Call Answered It is necessary to cancel the intercom ring signal once another station picks up on the intercom line. The gate A8-6 monitors the data buss line D5 for return data from some other station and generates a pulse from LSR to reset the Dialing Sequence Register upon receipt of this signal. However, the function of this circuit is inhibited during the receipt of return data from the calling station (See paragraph 2.4). 2.4 Calling Station Inhibit During the time interval between the first and second digits dialed the gate A13-6 responds to data from the calling station to generate a pulse from LSR which clocks the calling station register (A7). The 1's complement of the station address is present at the input to the register so that register will be loaded with calling station address. These clock pulses continue for the full length of the interdigit time (at the rate of 6 per second). Once the dialing is complete the calling station address remains in the register. Note that this is the only return data possible during the interdigit time as only one station can be off-hook during the dialing process. The comparison of the stored address and the actual address results in a signal at A3-10 which is true (high) for all address of the system scan except for the station that did the dialing. As explained in paragraph 2.3 this prevents the return data from the calling station from reseting the Dialing Sequence Register. 3.0 Dial Pulse Counting Register A12 & A18-9 form a dial pulse counter than can be parallel loaded from the Tone Decoder Card. 3.1 First Digit Counting The dial pulses will be directed into A18-11 by the gate A11-6 under the control of the dialing sequence register. A18-9 will carry into A12-5 for the highest order bit. For the first digits of 1 or 2 pulses (zero is actually 10 pulses) the count will be (0,1) and (1,0) (D5, D4) respectively. The dial pulses from the second digit will thereafter be directed to the second digit portion of the counting register by the dialing sequence register. 3.1.2 3 or More For first dialed digits of 3 or more the operation is the same until the third dial pulse is received. This pulse advances the counter to (1,1). The NAND gate A17-8 will be satisfied and will set the F/F A10-9 to its second digit state. This causes the remaining pulse, if any, to go into the second digit portion of the counting register. Thus at the end of the first digit the sequence logic will advance to dial complete. The resultant binary values shown on page Y will be gated onto the data buss. Therefore, there are eight numbers that can be dialed as single digits. The number in the first digit portion of the register is (1,1) and the number in the second digit portion of the register is 3 less than the number dialed. 3.2 Second Digit Counting For two digit dialing (where the first digit is a 1 or 2) the sequence logic directs the second dialed digit into second digit portion of the dial counting register. 4.0 Miscellaneous 4.1 Tone Decoder Compatibility When the Tone Decoder Card is installed either rotary or tone dialing are operative on the same system. The sequence and control logic on this card controls both cards. 4.1.1 Tone Present This signal has the same nature as the interdigit. It debounced by the one-shot A6-4. 4.1.2 parallel Data Load The terminals T1 thru T5 present the binary results of the Tone Decoder Card. The Load/Count Signal causes a jam transfer of this data into the Dial Counting Register. 4.2 Power Supply In order to provide a clean signal for the talk battery there is a separate power supply to deliver H5V and -15V. The 48 volt 49KHz frequency is used as a source. DETAILED DESCRIPTION OF TONE DECODER CARD Section I--General Description Referring now to FIG. 13a, this circuit provides the option of tone and rotary dialing when this card is installed in the system along with the Intercom option of FIGS. 11a and 11b. Its function is to provide the detection of MTDF signals on the intercom path; to covert the detected tones into Binary Digital Codes compatible with those produced by the (rotary) Dial Intercom Card; and to provide control logic which causes this card to operate in conjunction with the Dial Intercom Card. Section II--Detailed Description 1.0 Input Amplifier The differential amplifier provides a single-ended output from the balanced tip/ring pair while maintaining the balance on the pair. The gain is 0.1. 2.0 Tone Decoder There are two pre-packaged tone decoders installed on the card. One for the four high tones and one for the four low tones. The output of the differential input amplifier is coupled to both of these. They each contain the amplification, filtering and tone detectors required to meet the specifications in Section III. The outputs are high-true open collectors. Output pull-up resistors are required. 3.0 Number Conversion When a number is being dialed, one output from each detector will become active. The two input NANDS (A8, A10, A7-11, A7-8) are arranged to convert these pairs of tones into 10 unitary low true signals. These signals are connected to the priority encoder All. The output is a BCD digit (low-true). 4.0 Control Logic The description of this section is done by means of following the sequence of operation for the two major conditions; namely, one and two digit dialing. In both cases the tones must be detected and converted to compatible formats, cause the sequencing of the Dial Intercom Card, and jam the results into the dialing register of the Dial Intercom Card. 4.1 One Digit Dialing When the first digit dialed is not a 1 or 2 the dialing will be complete at the end of the first digit. For rotary dialing the first three pulses go into the first digit portion of the register and the remaining pulses go into the second digit portion of the register. Therefore, the register contains the number "3" (1,1) for T5 & T4 (first digit portion) and the number dialed less 3 in the second digit portion. The tone control logic must produce the same result. 4.1.1 Sequence of Operation When a pair of tones is detected, at least one of the encoder (All) outputs will go low producing a high output from A12. This signal is inverted and sent to the Intercom Card for debounce treatment the same as rotary dial signals. This signal comes back on pin 5 as D TONE. The gate A5 requires tone present, but not a "1" or "2" during the first digit. The process begins when these conditions are met by A5-8 going low. The F/F A3-5 is set and its output drives T4 high (1). The output of gate A6-8 is also held high for the other bit (T5). The output of A5-8 is inverted and applied to the B1 & B3 inputs of the Adder A4. The inputs B1, B2, B3 are respectively 101 which is the two's complement of "3". This produces a result at Σ1, Σ2, Σ3 which is the output of the encoder A11 minus three. This is the desired number for second digit portion of the dialing register (T1, T2, T3). At this moment all five bits (T1 thru T5) that are connected to the Dial Intercom Card have the correct value for single digit dialing. The load pulse must now be produced. The leading edge of D TONE (pin 5) is delayed long enough to allow all operations just described to settle out. The one-shot A3-13 produced a short strobe pulse at the leading edge of D TONE. All the conditions for gate A5-6 are met: i.e. a first digit that is not a 1 or 2. The pulse is fed through A6-3 and A6-11 to cause the parallel transfer of the bits T1 thru T5 into the dialing register of the Dialing Intercom Card. When the TONE present signal stops, the dialing will be completed just as though rotary dialing had occured. The one exception to the above is for a first digit of "0" to occur. The output of the encoder is 0, 0, 0. The rotary dialing results would have been 1, 1, 1, (7). The inverter A9-6 sets the B2 input to a (1) so that the outputs Σ1, Σ2, Σ3 respectively are 1, 1, 1 as desired. 4.2 Two Digit Dialing When the first dialed digit is a "1" or "2" it is necessary to dial another digit before dialing is complete. The binary result for each digit corresponds the pulses of the digits dialed. 4.2.1 Sequence of Operation The OR A12 produces a TONE present signal. Since the first digit is a "1" or "2" the gate A5-8 is inhibited. If the first digit is a "1" the F/F A3-5 is clocked to the reset state. This produces the codes for T5, T4 as 1, 0. If the first digit is a "2" the results will be 0, 1. Note that D TONE leading edge caused a strobe pulse but this is blocked both at A5-6 and at A6-6. The trailing edge of D TONE causes the F/F A3-9 to reset. This enables the A6-6 so that the strobe pulse caused by the second digit will pass through to become a load pulse. Note that the inputs to the adder are 0, 0, 0 for B1, B2, B3 and that the second digit gets loaded into the dialing register unmodified. DETAILED DESCRIPTION OF POWER SUPPLY CARD Section I--General Description Referring now to FIG. 14a, it will be noted that the power supply is somewhat unusual in that power distribution is done at 49.152KHz. There are two reasons for this (1) The 49,152Hz signal is used as a system clock. (2) The multiple voltages required by the Key Set Adapter (see FIGS. 16a and 16b) are easily derived by means of a small ferrite transformer. Had DC power been used, costly DC-to-DC transformation circuitry would have been required at each Adapter. The power supply supplies 48 volts AC to the Adapters via one pair of the three pairs of connecting wires. In addition, 5 volt and 15 volt supplies are derived for use in the central equipment. 2.0 Block Diagram Description (Refer to FIG. 14) 2.1 input Rectifier-Filter 117 Volt 60 cycle power is supplied to a rectifier-filter combination and develops approximately 115 volts DC. This DC voltage is used to power the rest of the power supply board. 2.2 Oscillator The oscillator is a Colpitts type, oscillating at a frequency of 49.152KHz. Its amplitude is controlled by a feedback loop controlled by the 5 volt DC output. 2.3 Power Amplifier The oscillator is transformer coupled into a power amplifier operating Class B. This is a standard push-pull transformer output power amplifier with feedback from the output transformer to minimize distortion. The power transformer has three outputs: (1) 48 volts AC which is distributed to the adapters. (2) Approximately 15 volts AC which is rectified and filtered to provide 15 volts DC to the central unit. (3) Approximately 8 volts AC which is filtered, rectified, and regulated, to provide 5 volts DC to the central unit. 2.4 Regulator A regulating feedback loop compares the 5 volt DC to a reference voltage and, through an optical coupler, controls the amplitude of the oscillator. The output transformer is designed such that when the 5 volt output is correct, the 15 volt and 43 volt outputs will also be within specification. Section II--Detailed Description 1.0 Rectifier and Filter 117 Volt 60 cycle is supplied to the power supply through F1, a 2 amp fuse, and R14, a 3 ohm 10 watt resistor. The purpose of R14 is to limit surges at turn-on. The AC is rectified by a bridge consisting of diodes D11 through D14. The rectified voltage is filtered by a 25,000 microfarad, 200 volt capacitor located in the central unit. The DC voltage across this capacitor is approximately 115 volts. 1.1 Oscillator The oscillator consists of Q3 operating into a tank circuit made up of the primary of T1 and capacitors C1 and C2. Q3 operates in the grounded base mode. R1 and R6 provide bias current to the oscillator transistor Q3. C3 establishes the base of Q3 at AC ground. Feedback to sustain oscillation is supplied from the junction of C1 and C2. The tank circuit resonates at 49.152KHz. Q5, in series with the supply voltage to the oscillator, shuts down the oscillator in the event of over-current conditions. This protection circuitry is described in a later section. Oscillator amplitude is controlled by Q4. R9 and R16 provide a bias network sufficient in themselves to saturate Q4. The transistor portion of the AC optical coupler acts to shunt some of the base current to Q4. Thus the degree of conduction of Q4 is controlled by the optical coupler. C4 and C7 are filters to insure that the emitter circuitry of Q3 is at AC ground. R15, a 100K resistor, establishes the minimum oscillator current. Without R15 it is possible for the entire regulating loop to be stable at output voltages lower than the design values. 1.2 Power Amplifier The secondary of T1 is center-tapped and provides base drive to Q1 and Q2, the power amplifier transistors. The secondary windings of T1 are in series with and opposing feedback windings on the power output transformer. R2 and R3 provide damping to insure stability. Emitter resistors R4 and R5 provide a small amount of current feedback which helps to linearize the power amplifier. 115 Volt DC is provided to the collectors of Q1 and Q2 through the center tap of the primary winding on power output transistor T2. Secondary winding 7-8 of T2 provides 48 volts AC to the adapters. 1.3 15 Volt DC Supply Secondary winding 13-6 of T2 provides approximately 15 volts AC to a bridge consisting of diodes D2 through D5. The full wave output of the bridge is filtered by C5 and C6 and is provided to the central cabinet. The series network consisting of R20, the LED portion of A4, and R21 provides current sensing for the 15 volt output. The transistor portion of optical coupler A4 will be discussed in Section 3.6. In addition to supplying power to the central cabinet, the 15 volt output is fed to a three terminal regulator A1 to provide a 5 volt reference for the regulation loop. 1.4 5 Volt DC Supply T2 secondary 9-10 provides about 8 volts RMS to a bridge consisting of diodes D6 through D9. Current from this bridge, after passing through a current sense circuit similar to that in the 15 volt supply, is filtered by capacitors C8, C9, and C10. This voltage is fed to the non-inverting input of operational amplifier A2 where it is compared to the 5 volt reference voltage supplied by A1. The resulting error signal establishes a current through the LED portion of optical coupler A3. The level of this current determines the degree of conduction of the transistor in optical coupler A3 and thus controls the amplitude of the oscillator. R13 converts the op amp output to a current and R24 sets the gain of op amp A2 at 100. 1.5 Protection Circuitry Over-current limiting in the 15 volt DC supply and the 5 volt supply and an over-voltage circuit in the 5 volt supply protect the KTS-1 circuitry in the event of power supply malfunction. Optical couplers A4 and A5 have their transistors across R17, bias resistor for Q5. Excess current through either of the LED's in A4 or A5 will cause base current for Q5 to be shunted thus shutting off Q5 and turning off the oscillator. DETAILED DESCRIPTION OF KEY SET ADAPTER Section I--General Description Referring now to FIGS. 16a and 16b, the illustrated circuit provides the electrical interface between a standard Key telephone (such as the 564) and the 3 pair station wiring of the present system. Functions of the circuit are: to transmit and receive data over the data pair; to provide the proper drive for the lights and the bell of the attached phone in response to data received; to provide the proper interpretation of data received relative to the programming switches; to generate the return data as a function of the various user operated switches (line select etc.); to use the AC power 49,152Hz to provide circuit power and synchronize the circuit operation with the Central Cabinet; and to provide proper connection to the standard 50 pin Key telephone set-tail connector. Section II--Detailed Description 1. Data Transceiver 1.1 Receiver The data pair terminates in the optical coupler A8. The diode D2 protects the coupler when the data state is reversed in polarity to the coupler. The quiescent condition is reverse so that this coupler is normally off. Whenever the Central Cabinet data driver reverses, the LED lights, causing the output collector to go low. The Schmidt Trigger squares and inverts this signal. The term maded "Data" goes high for the START BIT which corresponds to a true sense for the data. 1.2 Transmit The LED of the coupler A9 is normally on. This means that the transistor Q1 is also normally driven into saturation. Thus, the back-to-back arrangement of Q1 and D3 provides a short circuit when the adapter is receiving data. Data is only transmitted back when the Central Cabinet data driver is in the condition of HD more positive than LD. To transmit Return Data the LED of A9 is turned off for each data cell that is in the true state. Q1 will then shut-off and interrupt the current flow in the data pair. The data pair is fed by equal value resistors (300 ohms) from +15 volts and ground. The net result is that the voltage excursions of LD & HD will be equal and opposite maintaining an AC balance. The receiver in the Central Cabinet will respond to this condition. 2. Synchronization & Timing 2.1 Clock Stripper The cathode of D8 sees a half wave rectified signal at 49,152Hz. The level goes from slightly negative to about 20 volts positive at the sine wave peak. The input to the Schmidt Trigger A13-13 sees a voltage of about ground in one state to about +5 volt in the other state. The Schmidt Trigger squares this into a cleam signal suitable for driving the counter chain. The duty cycle will not be 50% but there will be only one cycle of output for each cycle of input. 2.2 Counter Chain Before the Start Pulse occurs, the counter is held in the cleared state so that all outputs are in the low state. When the lock-up circuit is released by the Start Pulse, the counter begins to count at the power supply frequency. The timing signals developed from this counter are similar to the Central Cabinet signals except that they are 8 counts later. The fact that the driving clock for both is derived from the same power supply maintains a close phase relationship once the counter is started. There are only two signals derived from this counter: the Shift Clock and the Load Pulse. Note that the first positive edge of the Shift Clock is delayed 8 clock cycles from that of the Central Cabinet. This positions the sampling edge of the shift clock in the middle of the data cells as they arrive from the Central Cabinet. Also, it causes the return data to arrive at the Central Cabinet so that shift clock there samples in the middle. 2.3 The Lock-Up Circuit The action of the Lock-Up Circuit and the counter in response to the clock frequency is to end up in the reset or locked state. This requires about half of the time between the expected arrival of successive Start Pulses. Under the worst conditions, it would take only two transmissions for this circuit to synchronize with the Central Cabinet. The positive going leading edge of the Start Pulse clears the F/F A1-5 which remoes the reset signal from the counters and the shift register. The counting continues until the 8 input NAND A2-8 is satisfied. The low signal first disables the other term of the AND (A4-3) and then sets the F/F A1-5. The net result at the output of A4-3 at this moment is zero. However, when the clock advances the counter, the other input term of the AND gate (A4-3) will go true which satisfies the AND gate, causing the output to go true. A unique condition exists in that this reset action simply holds the counter in the state that is had just arrived; namely, the zero condition. This avoids the logic race problem. The circuit will remain locked until the next positive edge of DATA which should be at the next Start Pulse. 3. Data Flow Refer to FIG. 8c for the Data Formats. 3.1 Return Data 3.1.1 Switch Information The line select switches and the special purpose switches are monitored to make up the return data word. The bits which represent each switch are shown as follows: ______________________________________LINE SELECTED A2 A1 A0______________________________________1 1 1 02 1 0 13 1 0 04 0 1 15 0 1 0none 1 1 1______________________________________ The five line select switches are encoded into the three bits A0 through A1. The remaining switches could not be encoded along with line select because they must be independent as they may or may not be transmitted simultaneously. 3.1.2 Return Data Shift Register The Shift Register (A7) has a quiescent condition of a high output. This causes the return data LED to be on. The inversion of the Start Pulses is used as a load control. The load control will, therefore, be low during the first positive edge of the Shift Clock. This loads the Shift Register at t = 0.5 and immediately begins the transmission of return data. This continues with each positive edge of the Shift Clock until t = 8 where the signal CT 8 will inhibit the loading of any more data. The Shift Register output is left in the high state. 3.2 Station Data Beginning at t = 8 the Central Cabinet sends the data required for the adapter circuits. This information is fed serially into the shift register (A6), analyzed and used to cause the appropriate action. 3.2.1 Station Data Shift Register Before the arrival of the start pulse the shift register A6 is held reset. The start pulse will be loaded into the shift register and then it steps down through the register during TO phase (but this will be of no consequence). At t = 8 the station data will begin to shift into the register. When the load pulse occurs at the end of the last (t) period, the data will be in position at the shift register outputs. The load pulse is used to take action on the assembled data word. Inverted data is fed into the shift register. This inversion simplifies the processing functions described below. 3.2.2 Light Data The last bit eceived (L/R) will be true for light data. This enables the gate A4-11 so that the light data will be parallel loaded into the Light Data Register. Only those transmissions containing light data will be thus loaded. The light data register stores the previous information until it receives a new load pulse. 3.2.3 Ring Data The L/R bit will enable the bell F/F gate A15-8 for bell information transmissions. The results of one of the two decoders will then determine if the bell rings. Note that the Bell F/F A1-9 is always set for any transmission which does not reset it. Transmission for bell ringing always alternate between two for bell and two for lights. This will cause the bell F/F to produce a 24 Hz square wave. See FIG. 5 for the bell ringing switch settings. 3.2.3.1 Line Ring Decoder When the ICM/Line bit selects the Line Ring Decoder its output is connected to the bell F/F gate A15-8. The Line Ring Decoder is a negative input OR gate. The inputs are connected to the Shift Register outputs through the programming switches. Therefore a bit and its associated switch must combine to produce a ring signal. Any combination of switches may be selected as they all operate independent of each other. 3.2.3.2 ICM Decoder The intercom information is in binary form so that it is necessary to use a digital comparator to decode ICM ring information. When the bit pattern corresponds to the switches and the ICM/Line bit selects the ICM decoder a true will be presented to the bell F/F gate (A15-8). 4. miscellaneous Circuits 4.1 Bell Driver The Bell is a capacitive load for the steay DC condition. It is necessary to drive it with a totem pole type circuit to charge and discharge the capacitor. The normal condition is for Q4 to be on. When the bell F/F switches state, Q4 will go off and Q3 will go on. This presents a 150 volt p-p square wave to the bell terminals. 4.2 Power Supply The supply produces 10 volts for lamps, 5 volts for logic and 150 volts for the bell. The transformer is a balanced load for the power pair. The one chip regulator A19 supplied the +5 volts from the +10 rectifies output. DETAILED DESCRIPTION OF PRIVACY CARD Section I-- General Description Referring to FIG. 17, the illustrated circuit is an option which provides exclusive use (privacy) of a CO line to the station which initially seizes the line. It also provides means for the release of privacy for adding other stations to the conversation. Its functions are to monitor the flow of data on the data buss to determine the activity on the lines; to remember which station initially seizes a line; to quelches data from any other station once a line is in use; to monitor the return data from the station which initially seized a line for the privacy release bit and defeats the feature once this bit is received; and after a privacy release function has been set and subsequently all stations go on-hook, to restore the privacy feature automatically. Section II--Detailed Description 1. Method of Operation There are five independent circuits - one for each line. The last two (lines 4 and 5) may be operated with intercom circuits. These two may also be defeated where privacy is not desired with intercom. Each circuit contains a counter which automatically syncs with the station address that seized the line. The circuits associated with the counter clamps line select bits from other stations to ground and prevents a selected. Reference below is to only of the five circuits (line 5). 2. Station Counter & Sync The 4 bit counter A12-8 is clocked by the Station address advance. The counter advances until the negative input AND A20-8 is satisfied (count of 15). The transition to this count clocks the F/F A11-6 to its reset state. This F/F will then hold the counter at the count of 15. Whenever data buss line D5 goes high at LSR time the F/F A11-6 will be set. At the end of this transmission frame (corresponding to the station which seized the line) the counter will advance. The counter will advance until it goes back to the reset (locked) state at the beginning of the frame for the seizing station. The line select bit from the seizing station will again resync the counter. The action repeats as long on the seizing station remains off-hook. 3. Data Squelch The output of A21-8 will be high for all station addresses except the seizing station's. Note that the third term for the gate A13-8 is effectively LSR. It is in fact LSR for lines 1 thru 3. Assume for now that the output of the Privacy Release F/F A11-8 is true (see paragraph 4.). This provides an all true input for A13-8 which clamps D5 to ground during LSR. As a result all stations except the seizing station are prevented from selecting that line. The special term ICTRL provides a means whereby the intercom card allows a second station on without releasing privacy. If this term is grounded the privacy feature is defeated completely. 4. Privacy Release If the seizing station sends the Privacy Release bit (PVRL) the gate A19-2 will be satisfied and will set the Privacy Release F/F (A11-8). This will inhibit the Squelch Gate A13-8 and thus allow any station to seize the line. 5. Privacy Release Reset The input terms of the gate A4-8 are satisfied when light data for that line is not present. This occurs when all stations release the line. The Privacy Release F/F A11-8 is restored to its non-release state by this signal.

An improved key telephone system realizes substantial reduction in installation costs, permits use of relatively small central units, provides compatability with telephone apparatus speaker phones, automatic dialers, etc., and provides additional advantages. The system basically embodies: (a) multiple adapter units each connected with and proximate to a station set, (b) multiple supervisory circuits to each of which at least two of said adapter units are connected via a talk pair and a control pair, said circuits being remote from said adapters, (c) system control means connected with said supervisory circuits via a data control bus for asynchronously transmitting to each adapter unit, via said supervisory circuits, data including a start pulse causing the adapter to poll the line select and other switches in the station sets, and return the results of said polling to the system control means via the supervisory circuit in the form of a data word, following which the system control means transmits a data word corresponding to light, bell ringing or intercom bell ringing information.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional application of copending U.S. patent application Ser. No. 13/545,853, filed Jul. 10, 2012, which is a divisional application of U.S. patent application Ser. No. 12/092,253, filed Dec. 19, 2008, and issued as U.S. Pat. No. 8,237,019, which is a U.S. National Phase application filed under 35 U.S.C. §371 claiming priority to PCT Application No. PCT/EP2006/010535, filed Nov. 1, 2006 and which claims priority to PCT Application No. PCT/EP2005/011718, filed Nov. 1, 2005, each of which is incorporated herein in reference in their entirety. [0002] The Sequence Listing associated with this application is filed in electronic format via EFS-Web and is hereby incorporated by reference into the specification in its entirety. The name of the text file containing the Sequence Listing is 123498_ST25.txt. The size of the text file is 90,740 bytes, and the text file was created on Dec. 5, 2012. BACKGROUND OF THE INVENTION [0003] The present invention relates to disease resistant plants, in particular plants resistant to organisms of the phylum Oomycota, the oomycetes. The invention further relates to plant genes conferring disease resistance and methods of obtaining such disease resistant plants for providing protection to Oomycota pathogens. [0004] Resistance of plants to pathogens has been extensively studied, for both pathogen specific and broad resistance. In many cases resistance is specified by dominant genes for resistance. Many of these race-specific or gene-for-gene resistance genes have been identified that mediate pathogen recognition by directly or indirectly interacting with avirulence gene products or other molecules from the pathogen. This recognition leads to the activation of a wide range of plant defense responses that arrest pathogen growth. [0005] In plant breeding there is a constant struggle to identify new sources of mostly monogenic dominant resistance genes. In cultivars with newly introduced single resistance genes, protection from disease is often rapidly broken, because pathogens evolve and adapt at a high frequency and regain the ability to successfully infect the host plant. Therefore, the availability of new sources of disease resistance is highly needed. [0006] Alternative resistance mechanisms act for example through the modulation of the defense response in plants, such as the resistance mediated by the recessive mlo gene in barley to the powdery mildew pathogen Blumeria graminis f. sp. hordei . Plants carrying mutated alleles of the wildtype MLO gene exhibit almost complete resistance coinciding with the abortion of attempted fungal penetration of the cell wall of single attacked epidermal cells. The wild type MLO gene thus acts as a negative regulator of the pathogen response. This is described in WO9804586. [0007] Other examples are the recessive powdery mildew resistance genes, found in a screen for loss of susceptibility to Erysiphe cichoracearum . Three genes have been cloned so far, named PMR6, which encodes a pectate lyase-like protein, PMR4 which encodes a callose synthase, and PMR5 which encodes a protein of unknown function. Both mlo and pmr genes appear to specifically confer resistance to powdery mildew and not to oomycetes such as downy mildews. [0008] Broad pathogen resistance, or systemic forms of resistance such as SAR, has been obtained by two main ways. The first is by mutation of negative regulators of plant defense and cell death, such as in the cpr, lsd and acd mutants of Arabidopsis . The second is by transgenic overexpression of inducers or regulators of plant defense, such as in NPR1 overexpressing plants. [0009] The disadvantage of these known resistance mechanisms is that, besides pathogen resistance, these plants often show detectable additional and undesirable phenotypes, such as stunted growth or the spontaneous formation of cell death. [0010] It is an object of the present invention to provide a form of resistance that is broad, durable and not associated with undesirable phenotypes. [0011] In the research that led to the present invention, an Arabidopsis thaliana mutant screen was performed for reduced susceptibility to the downy mildew pathogen Hyaloperonospora parasitica . EMS-mutants were generated in the highly susceptible Arabidopsis line Ler eds1-2. Eight downy mildew resistant (dmr) mutants were analysed in detail, corresponding to 6 different loci. Microscopic analysis showed that in all mutants H. parasitica growth was severely reduced. Resistance of dmr3, dmr4 and dmr5 was associated with constitutive activation of plant defence. Furthermore, dmr3 and dmr4, but not dmr5, were also resistant to Pseudomonas syringae and Golovinomyces orontii. [0012] In contrast, enhanced activation of plant defense was not observed in the dmr1, dmr2, and dmr6 mutants. The results of this research have been described in Van Damme et al. (2005) Molecular Plant-Microbe Interactions 18(6) 583-592. This article does however not disclose the identification and characterization of the DMR genes. BRIEF SUMMARY OF THE INVENTION [0013] According to the present invention it was now found that DMR1 is the gene encoding homoserine kinase (HSK). For Arabidopsis five different mutant dmr1 alleles have been sequenced each leading to a different amino acid change in the HSK protein. HSK is a key enzyme in the biosynthesis of the amino acids methionine, threonine and isoleucine and is therefore believed to be essential. The various dmr1 mutants show defects in HSK causing the plants to accumulate homoserine The five different alleles show different levels of resistance that correlate to different levels of homoserine accumulation in the mutants. [0014] The present invention thus provides a plant, which is resistant to a pathogen of viral, bacterial, fungal or oomycete origin, characterized in that the plant has an altered homoserine level as compared to a plant that is not resistant to the said pathogen. [0015] This form of resistance is in particular effective against pathogens of the phylum Oomycota, such as Albugo, Aphanomyces, Basidiophora, Bremia, Hyaloperonospora, Pachymetra, Paraperonospora, Perofascia, Peronophythora, Peronospora, Peronosclerospora, Phytium, Phytophthora, Plasmopara, Protobremia, Pseudoperonospora, Sclerospora, Viennotia species. [0016] The resistance is based on an altered level of homoserine in planta. More in particular, the resistance is based on an increased level of homoserine in planta. Such increased levels can be achieved in various ways. [0017] First, homoserine can be provided by an external source. Second, the endogenous homoserine level can be increased. This can be achieved by lowering the enzymatic activity of the homoserine kinase gene which leads to a lower conversion of homoserine and thus an accumulation thereof. Alternatively, the expression of the homoserine kinase enzyme can be reduced. This also leads to a lower conversion of homoserine and thus an accumulation thereof. Another way to increase the endogenous homoserine level is by increasing its biosynthesis via the aspartate pathway. Reducing the expression of the homoserine kinase gene can in itself be achieved in various ways, either directly, such as by gene silencing, or indirectly by modifying the regulatory sequences thereof or by stimulating repression of the gene. [0018] Modulating the HSK gene to lower its activity or expression can be achieved at various levels. First, the endogenous gene can be directly mutated. This can be achieved by means of a mutagenic treatment. Alternatively, a modified HSK gene can be brought into the plant by means of transgenic techniques or by introgression, or the expression of HSK can be reduced at the regulatory level, for example by modifying the regulatory sequences or by gene silencing. [0019] In one embodiment of the invention, an increase (accumulation) in homoserine level in the plant is achieved by administration of homoserine to the plant. This is suitably done by treating plants with L-homoserine, e.g. by spraying or infiltrating with a homoserine solution. [0020] Treatment of a plant with exogenous homoserine is known from WO00/70016. This publication discloses how homoserine is applied to a plant resulting in an increase in the phenol concentration in the plant. The publication does not show that plants thus treated are resistant to pathogens. In fact, WO00/70016 does not disclose nor suggest that an increase in endogenous homoserine would lead to pathogen resistance. [0021] Alternatively, endogenous homoserine is increased by modulating plant amino acid biosynthetic or metabolic pathways. [0022] In one embodiment, the increased endogenous production is the result of a reduced endogenous HSK gene expression thus leading to a less efficient conversion of homoserine into phospho-homoserine and the subsequent biosynthesis of methionine and threonine. This reduced expression of HSK is for example the result of a mutation in the HSK gene leading to reduced mRNA or protein stability. [0023] In another embodiment reduced expression can be achieved by downregulation of the HSK gene expression either at the transcriptional or the translational level, e.g. by gene silencing or by mutations in the regulatory sequences that affect the expression of the HSK gene. An example of a method of achieving gene silencing is by means of RNAi. [0024] In a further embodiment the increase in endogenous homoserine level can be obtained by inducing changes in the biosynthesis or metabolism of homoserine. In a particular embodiment this is achieved by mutations in the HSK coding sequence that result in a HSK protein with a reduced enzymatic activity thus leading to a lower conversion of homoserine into phospho-homoserine. Another embodiment is the upregulation of genes in the aspartate pathway causing a higher production and thus accumulation of L-homoserine in planta. BRIEF DESCRIPTION OF THE DRAWINGS [0025] FIG. 1 shows orthologous HSK sequences that have been identified in publicly available databases and obtained by PCR amplification on cDNA and subsequent sequencing. FIG. 1 shows the alignment of the amino acid sequences of the HSK proteins of Arabidopsis thaliana and orthologs from Citrus sinensis, Populus trichocarpa (1), Populus trichocapa (2), Solanum tuberosum (2), Vitis vinifera, Lactuca sativa, Solanum tuberosum (1), Solanum lycopersicum, Nicotiana benthamiana, Ipomoea nil, Glycine max, Phaseolus vulgaris, Cucumis sativus, Spinacia oleracea, Pinus taeda, Zea mays , and Oryza sativa using the CLUSTAL W (1.82) multiple sequence alignment programme (EBI). Below the sequences the conserved amino acids are indicated by the dots, and the identical amino acids are indicated by the asterisks. The black triangles and corresponding text indicate the amino acids that are substituted in the five Arabidopsis dmr mutants. [0026] Table 2 shows the Genbank accession numbers and GenInfo identifiers of the Arabidopsis HSK mRNA and orthologous sequences from other plant species. [0027] FIG. 2 shows the percentage of conidiophore formation by two Hyaloperonospora parasitica isolates, Cala2 and Waco9, on the mutants dmr1-1, dmr1-2, dmr1-3 and dmr1-4 and the parental line, Ler eds1-2, 7 days post inoculation. The conidiophores formed on the parental line were set to 100%. [0028] FIG. 3 is a graphic overview of the three major steps in the cloning of DMR1. a) Initial mapping of dmr1 resulted in positioning of the locus on the lower arm of chromosome 2 between positions 7.42 and 7.56 Mb. Three insert/deletion (INDEL) markers were designed (position of the markers F6P23, T23A1 and F5J6 is indicated by the black lines). These markers were used to identify recombinants from several 100 segregating F2 and F3 plants. Primer sequences of these INDEL markers and additional markers to identify the breakpoints in the collected recombinants is presented in table 3. b) One marker, At2g17270 (indicated by the grey line), showed the strongest linkage with resistance. The dmr1 locus could be further delimited to a region containing 8 genes, at2g17250-at2g17290. The eight genes were amplified and sequenced to look for mutations in the coding sequences using the primers described in table 4. DNA sequence analysis of all 8 candidate genes led to the discovery of point mutations in the At2g17265 gene in all 5 dmr1 mutants. c) Each dmr1 mutant has a point mutation at a different location in the At2g17265 gene, which encodes homoserine kinase. [0029] FIG. 4 shows a schematic drawing of the HSK coding sequence and the positions and nucleotide substitutions of the 5 different dmr1 mutations in the HSK coding sequence (the nucleotide positions, indicated by the black triangles, are relative to the ATG start codon which start on position i). The 5′UTR and 3′UTR are shown by light grey boxes. Below the nucleotide sequence the protein sequence is shown. The HSK protein contains a putative transit sequence for chloroplast targeting (dark grey part). The amino acid changes resulting from the 5 dmr1 mutations are indicated at their amino acid (aa) position number (black triangles) in the HSK protein. [0030] FIG. 5 shows the position of the homoserine kinase enzyme in the aspartate pathway for the biosynthesis of the amino acids threonine, methionine and isoleucine. [0031] FIG. 6 shows the number of conidiophores per Ler eds 1-2 seedlings 5 days post inoculation with two different isolates of H. parasitica , Waco9 and Cala2. The inoculated seedlings were infiltrated with dH2O, D-homoserine (5 mM) or L-homoserine (5 mM) at 3 days post inoculation with the pathogen. Seedlings treated with L-homoserine show a complete absence of conidiophore formation and are thus resistant. [0032] FIG. 7 shows the growth and development of H. parasitica in seedlings treated with water, D-homoserine (5 mM), or L-homoserine (5 mM) as analysed by microscopy of trypan blue stained seedlings. [0033] a: Conidiophore formation after HS treatment on Ler ed1-2 seedlings (10× magnification). No conidiophore formation was detected after L-homoserine infiltration, whereas control plants show abundant sporulation. [0034] b: Haustorial development is affected by L-homoserine (5 mM) infiltration (40× magnification), but not in plants treated with water or D-homoserine. [0035] FIGS. 8 and 9 show the nucleotide and amino acid sequence of the homoserine kinase gene (At2g17265, NM — 127281, GI:18398362) and protein (At2g17265, NP — 179318, GI: 15227800) of Arabidopsis thaliana , respectively (SEQ ID NOs: 99-100). [0036] FIG. 10 shows the nucleotide and the predicted amino acid sequence of the homoserine kinase coding sequence (CDS) and protein, respectively, of Lactuca sativa (SEQ ID NOs. 101-102) [0037] FIG. 11 shows the nucleotide and the predicted amino acid sequence of the homoserine kinase coding sequence (CDS) and protein, respectively, of Vitis vinifera (SEQ ID NOs: 103-104) [0038] FIG. 12 shows the nucleotide and the predicted amino acid sequence of the homoserine kinase coding sequence (CDS) and protein, respectively, of Cucumis sativus (SEQ ID NOs: 105-106) [0039] FIG. 13 shows the nucleotide and the predicted amino acid sequence of the homoserine kinase coding sequence (CDS) and protein, respectively, of Spinacia oleracea (SEQ ID NOs: 107-108) [0040] FIG. 14 shows the nucleotide and the predicted amino acid sequence of the homoserine kinase coding sequence (CDS) and protein, respectively, of Solanum lycopersicum (SEQ ID NOs: 109-110) DETAILED DESCRIPTION [0041] This invention is based on research performed on resistance to Hyaloperonospora parasitica in Arabidopsis but is a general concept that can be more generally applied in plants, in particular in crop plants that are susceptible to infections with pathogens, such as Oomycota. [0042] The invention is suitable for a large number of plant diseases caused by oomycetes such as, but not limited to, Bremia lactucae on lettuce, Peronospora farinosa on spinach, Pseudoperonospora cubensis on members of the Cucurbitaceae family, e.g. cucumber, Peronospora destructor on onion, Hyaloperonospora parasitica on members of the Brasicaceae family, e.g. cabbage, Plasmopara viticola on grape, Phytophthora infestans on tomato and potato, and Phytophthora sojae on soybean. [0043] The homoserine level in these other plants can be increased with all techniques described above. However, when the modification of the HSK gene expression in a plant is to be achieved via genetic modification of the HSK gene or via the identification of mutations in the HSK gene, and the gene is not yet known it must first be identified. To generate pathogen-resistant plants, in particular crop plants, via genetic modification of the HSK gene or via the identification of mutations in the HSK gene, the orthologous HSK genes must be isolated from these plant species. Orthologs are defined as the genes or proteins from other organisms that have the same function. [0044] Various methods are available for the identification of orthologous sequences in other plants. [0045] A method for the identification of HSK orthologous sequences in a plant species, may for example comprise identification of homoserine kinase ESTs of the plant species in a database; designing primers for amplification of the complete homoserine kinase transcript or cDNA; performing amplification experiments with the primers to obtain the corresponding complete transcript or cDNA; and determining the nucleotide sequence of the transcript or cDNA. [0046] Suitable methods for amplifying the complete transcript or cDNA in situations where only part of the coding sequence is known are the advanced PCR techniques 5′RACE, 3′RACE, TAIL-PCR, RLM-RACE and vectorette PCR. [0047] Alternatively, if no nucleotide sequences are available for the plant species of interest, primers are designed on the HSK gene of a plant species closely related to the plant of interest, based on conserved domains as determined by multiple nucleotide sequence alignment, and used to PCR amplify the orthologous sequence. Such primers are suitably degenerate primers. [0048] Another reliable method to assess a given sequence as being a HSK ortholog is by identification of the reciprocal best hit. A candidate orthologous HSK sequence of a given plant species is identified as the best hit from DNA databases when searching with the Arabidopsis HSK protein or DNA sequence, or that of another plant species, using a Blast programme. The obtained candidate orthologous nucleotide sequence of the given plant species is used to search for homology to all Arabidopsis proteins present in the DNA databases (e.g. at NCBI or TAIR) using the BlastX search method. If the best hit and score is to the Arabidopsis HSK protein, the given DNA sequence can be described as being an ortholog, or orthologous sequence. [0049] HSK is encoded by a single gene in Arabidopsis and rice as deduced from the complete genome sequences that are publicly available for these plant species. In most other plant species tested so far, HSK appears to be encoded by a single gene, as determined by the analysis of mRNA sequences and EST data from public DNA databases, except for potato, tobacco and poplar for which two HSK homologs have been identified. The orthologous genes and proteins are identified in these plants by nucleotide and amino acid comparisons with the information that is present in public databases. [0050] Alternatively, if no DNA sequences are available for the desired plant species, orthologous sequences are isolated by heterologous hybridization using DNA probes of the HSK gene of Arabidopsis or another plant or by PCR methods, making use of conserved domains in the HSK coding sequence to define the primers. For many crop species, partial HSK mRNA sequences are available that can be used to design primers to subsequently PCR amplify the complete mRNA or genomic sequences for DNA sequence analysis. [0051] In a specific embodiment the ortholog is a gene of which the encoded protein shows at least 50% identity with the Arabidopsis HSK protein or that of other plant HSK proteins. In a more specific embodiment the homology is at least 55%, more specifically at least 60%, even more specifically at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or at least 99%. [0052] After orthologous HSK sequences are identified, the complete nucleotide sequence of the regulatory and coding sequence of the gene is identified by standard molecular biological techniques. For this, genomic libraries of the plant species are screened by DNA hybridization or PCR with probes or primers derived from a known homoserine kinase gene, such as the above described probes and primers, to identify the genomic clones containing the HSK gene. Alternatively, advanced PCR methods, such as RNA Ligase Mediated RACE (RLM-RACE), can be used to directly amplify gene and cDNA sequences from genomic DNA or reverse-transcribed mRNA. DNA sequencing subsequently results in the characterization of the complete gene or coding sequence. [0053] Once the DNA sequence of the gene is known this information is used to prepare the means to modulate the expression of the homoserine kinase gene in anyone of the ways described above. [0054] More in particular, to achieve a reduced HSK activity the expression of the HSK gene can be down-regulated or the enzymatic activity of the HSK protein can be reduced by amino acid substitutions resulting from nucleotide changes in the HSK coding sequence. [0055] In a particular embodiment of the invention, downregulation of HSK gene expression is achieved by gene-silencing using RNAi. For this, transgenic plants are generated expressing a HSK anti-sense construct, an optimized micro-RNA construct, an inverted repeat construct, or a combined sense-anti-sense construct, so as to generate dsRNA corresponding to HSK that leads to gene silencing. [0056] In an alternative embodiment, one or more regulators of the HSK gene are downregulated (in case of transcriptional activators) by RNAi. [0057] In another embodiment regulators are upregulated (in case of repressor proteins) by transgenic overexpression. Overexpression is achieved in a particular embodiment by expressing repressor proteins of the HSK gene from a strong promoter, e.g. the 35S promoter that is commonly used in plant biotechnology. [0058] The downregulation of the HSK gene can also be achieved by mutagenesis of the regulatory elements in the promoter, terminator region, or potential introns. Mutations in the HSK coding sequence in many cases lead to amino acid substitutions or premature stop codons that negatively affect the expression or activity of the encoded HSK enzyme. [0059] These and other mutations that affect expression of HSK are induced in plants by using mutagenic chemicals such as ethyl methane sulfonate (EMS), by irradiation of plant material with gamma rays or fast neutrons, or by other means. The resulting nucleotide changes are random, but in a large collection of mutagenized plants the mutations in the HSK gene can be readily identified by using the TILLING (Targeting Induced Local Lesions IN Genomes) method (McCallum et al. (2000) Targeted screening for induced mutations. Nat. Biotechnol. 18, 455-457, and Henikoff et al. (2004) TILLING. Traditional mutagenesis meets functional genomics. Plant Physiol. 135, 630-636). The principle of this method is based on the PCR amplification of the gene of interest from genomic DNA of a large collection of mutagenized plants in the M2 generation. By DNA sequencing or by looking for point mutations using a single-strand specific nuclease, such as the CEL-I nuclease (Till et al. (2004) Mismatch cleavage by single-strand specific nucleases. Nucleic Acids Res. 32, 2632-2641) the individual plants that have a mutation in the gene of interest are identified. [0060] By screening many plants, a large collection of mutant alleles is obtained, each giving a different effect on gene expression or enzyme activity. The gene expression or enzyme activity can be tested by analysis of HSK transcript levels (e.g. by RT-PCR), quantification of HSK protein levels with antibodies or by amino acid analysis, measuring homoserine accumulation as a result of reduced HSK activity. These methods are known to the person skilled in the art. [0061] The skilled person can use the usual pathogen tests to see if the homoserine accumulation is sufficient to induce pathogen resistance. [0062] Plants with the desired reduced HSK activity or expression are then back-crossed or crossed to other breeding lines to transfer only the desired new allele into the background of the crop wanted. [0063] The invention further relates to mutated HSK genes encoding HSK proteins with a reduced enzymatic activity. In a particular embodiment, the invention relates to the dmr1 alleles dmr1-1, dmr1-2, dmr1-3, dmr1-4 and dmr1-5. [0064] In another embodiment, the invention relates to mutated versions of the HSK genes of Lactuca sativa, Vitis vinifera, Cucumis sativus, Spinacia oleracea and Solanum lycopersicum as shown in FIGS. 10-14 (SEQ ID NOs: 101-110). [0065] The present invention demonstrates that plants having an increased homoserine level show resistance to pathogens, in particular of oomycete origin. With this knowledge the skilled person can actively modify the HSK gene by means of mutagenesis or transgenic approaches, but also identify so far unknown natural variants in a given plant species that accumulate homoserine or that have variants of the HSK gene that lead to an increase in homoserine, and to use these natural variants according to the invention. [0066] In the present application the terms “homoserine kinase” and “HSK” are used interchangeably. [0067] The present invention is illustrated in the following examples that are not intended to limit the invention in any way. In the examples reference is made to the following figures. EXAMPLES Example 1 Characterization of the Gene Responsible for Pathogen Resistance in dmr Mutants [0068] Van Damme et al., 2005, supra disclose four mutants, dmr1-1, dmr1-2, dmr1-3 and dmr1-4 that are resistant to H. parasitica . The level of resistance can be examined by counting conidiophores per seedling leaf seven day post inoculation with the H. parasitica Cala2 isolate (obtainable from Dr. E. Holub (Warwick HRI, Wellesbourne, UK or Dr. G. Van den Ackerveken, Department of Biology, University of Utrecht, Utrecht, NL). For the parental line, Ler eds1-2 (Parker et al., 1996. Plant Cell 8:2033-2046), which is highly susceptible, the number of conidiophores is set at 100%. The reduction in conidiophore formation on the infected dmr1 mutants compared to seedlings of the parental line is shown in FIG. 2 . [0069] According to the invention, the gene responsible for resistance to H. parasitaca in the dmr1 mutants of van Damme el al., 2005, supra has been cloned by a combination of mapping and sequencing of candidate genes. [0070] DMR1 was isolated by map-based cloning. The dmr1 mutants were crossed to the FN2 Col-0 mutant to generate a mapping population. The FN2 mutant is susceptible to the H. parasitica isolate Cala2, due to a fast neutron mutation in the RPP7A gene (Sinapidou et al., 2004, Plant J. 38:898-909). All 5 dmr1 mutants carry single recessive mutations as the F1 plants were susceptible, and approximately a quarter of the F2 plants displayed H. parasitica resistance. [0071] The DMR1 cloning procedure is illustrated in FIG. 3 and described in more detail below. The map location of the dmr1 locus was first determined by genotyping 48 resistant F2 plants to be located on the lower arm of chromosome 2. From an additional screen for new recombinants on 650 F2 plants ˜90 F2 recombinant plants between two INDEL (insertion/deletion) markers on BAC T24112 at 7.2 Mb and BAC F5J6 at 7.56 Mb (according to the TIGR Arabidopsis genome release Version 5.0 of January 2004) were identified, which allowed to map the gene to a region containing a contig of 5 BACs. [0072] The F2 plants were genotyped and the F3 generation was phenotyped in order to fine map the dmr1 locus. The dmr1 mutation could be mapped to a ˜130 kb region (encompassing 3 overlapping BAC clones: F6P23, T23A1, and F5J6) between two INDEL markers located on BAC F6P23, at 7.42 Mb and F5J6 at 7.56 Mb (according to the TIGR Arabidopsis genome release Version 5.0 of January 2004). This resulted in an area of 30 putative gene candidates for the dmr1 locus, between the Arabidopsis genes with the TAIR codes AT2g17060 and AT2g17380. Additionally cleaved amplified polymorphic sequences (CAPS) markers were designed based on SNPs linked to genes AT2g17190, AT2g17200, AT2g17270, At2g17300, At2g17310 and At2g17360 genes. [0073] Analyses of 5 remaining recombinants in this region with these CAPS marker data left 8 candidate genes, At2g17230 (NM — 127277, GI:30679913), At2g17240 (NM — 127278, GI:30679916), At2g17250 (NM — 127279, GI:22325730), At2g17260 (NM — 127280, GI:30679922). At2g17265 (NM — 127281, GI:18398362), At2g17270 (NM — 127282, GI:30679927), At2g17280 (NM — 127283, GI:42569096), At2g17290 (NM — 127284, GI:30679934). Sequencing of all the 8 genes resulted in the finding of point mutations in the AT2g17265 coding gene in the five dmr1 alleles: dmr1-1, dmr1-2, dmr1-3, dmr1-4 and dmr1-5, clearly demonstrating that AT2g17265 is DMR1. FIG. 3 shows a scheme of dnrl with point mutations of different alleles. [0074] At2g17265 encodes the homoserine kinase (HSK) enzyme, so far the only Arabidopsis gene exhibiting this function. [0075] In Arabidopsis , HSK is encoded by a single gene. At2g17265 (Lee & Leustek, 1999, Arch. Biochem. Biophys. 372: 135-142). HSK is the fourth enzyme in the aspartate pathway required for the biosynthesis of the amino acids methionine, threonine and isoleucine. HSK catalyzes the phosphorylation of homoserine to homoserine phosphate ( FIG. 5 ). Example 2 Amino Acid Analysis [0076] Homoserine phosphate is an intermediate in the production of methionine, isoleucine and threonine in Arabidopsis . Since homoserine kinase has a key role in the production of amino acids, free amino acid levels were determined in the parental line Ler eds1-2 and the four different dmr1 mutants. For this amino acids from total leaves were extracted with 80% methanol, followed by a second extraction with 20% methanol. The combined extracts were dried and dissolved in water. After addition of the internal standard, S-amino-ethyl-cysteine (SAEC) amino acids were detected by automated ion-exchange chromatography with post column ninhydrin derivatization on a JOEL AminoTac JLC-500/V (Tokyo, Japan). [0077] Amino acid analysis of four different dmr1 mutants and the parental line, Ler eds 1-2 showed an accumulation of homoserine in the dmr1 mutants, whereas this intermediate amino acid was not detectable in the parental line Ler eds1-2. There was no reduction in the level of methionine, isoleucine and threonine in the dmr1 mutants (Table 1). [0000] TABLE 1 Concentration (in pmol/mg fresh weight) of homoserine, methionine, threonine and isoleucine in above-ground parts of 2-week old seedlings of the parental line Ler eds 1-2 and the mutants dmr1-1, dmr1-2, dmr1-3 and dmr1-4. Homoserine Methionine Isoleucine Threonine dmr1-1 964 29 12 264 dmr1-2 7128 14 29 368 dmr1-3 466 11 16 212 dmr1-4 6597 11 32 597 Ler eds 1-2 0 7 10 185 Due to the reduced activity of the HSK in the dmr1 mutants, homoserine accumulates. This effect could be further enhanced by a stronger influx of aspartate into the pathway leading to an even higher level of homoserine. The high concentration of the substrate homoserine would still allow sufficient phosphorylation by the mutated HSK so that the levels of methionine, isoleucine and threonine are not reduced in the dmr1 mutants and the parental line, Ler eds1-2 (Table 1). Example 3 Pathogen Resistance is Achieved by Application of L-Homoserine [0078] To test if the effect is specific for homoserine the stereo-isomer D-homoserine was tested. Whole seedlings were infiltrated with water, 5 mM D-homoserine and 5 mM L-homoserine. Only treatment with the natural amino acid L-homoserine resulted in resistance to H. parasitica . Seedlings treated with water or D-homoserine did not show a large reduction in pathogen growth and were susceptible to H. parasitica . The infiltration was applied to two Arabidopsis accessions, Ler eds1-2 and Ws eds1-1, susceptible to Cala2 and Waco9, respectively. Conidiophore formation was determined as an indicator for H. parasitica susceptibility. Conidiophores were counted 5 days post inoculation with H. parasitica and 2 days post infiltration with water, D-homoserine or L-homoserine. ( FIG. 6 ). L-homoserine infiltration clearly results in reduction of conidiophore formation and H. parasitica resistance. This was further confirmed by studying pathogen growth in planta by trypan blue staining of Arabidopsis seedlings. Plants were inoculated with isolate Cala2. Two days later the plants were treated by infiltration with water, 5 mM D-homoserine, and 5 mM L-homoserine. Symptoms were scored at 5 days post inoculation and clearly showed that only the L-homoserine-infiltrated seedlings showed a strongly reduced pathogen growth and no conidiophore formation ( FIG. 7 ). [0079] Microscopic analysis showed that only in L-homoserine treated leaves the haustoria, feeding structures that are made by H. parasitica during the infection process, are disturbed. Again it is shown that increased levels of homoserine in planta lead to pathogen resistance. Example 4 Identification of HSK Orthologs in Crops 1. Screening of Libraries on the Basis of Sequence Homology [0080] The nucleotide and amino acid sequences of the homoserine kinase gene and protein of Arabidopsis thaliana are shown in FIGS. 8 and 9 (SEQ ID NOs: 99-100). [0081] Public libraries of nucleotide and amino acid sequences were compared with the sequences of FIGS. 8 and 9 (SEQ ID NOs: 99-100). [0000] This comparison resulted in identification of the complete HSK coding sequences and predicted amino acid sequences in Citrus sinensis, Populus trichocarpa (1), Populus trichocarpa (2), Solanum tuberosum (2), Solanum tuberosum (1), Nicotiana benthamiana, Ipomnoea nil, Glycine max, Phaseolus vulgaris, Pinus taeda, Zea mays , and Oryza sativa . The sequence information of the orthologous proteins thus identified is given in FIG. 1 . For many other plant species orthologous DNA fragments could be identified by BlastX as reciprocal best hits to the Arabidopsis or other plant HSK protein sequences. 2. Identification of Orthologs by Means of Heterologous Hybridisation [0082] The HSK DNA sequence of Arabidopsis thaliana as shown in FIG. 8 (SEQ ID NO: 99) is used as a probe to search for homologous sequences by hybridization to DNA on any plant species using standard molecular biological methods. Using this method orthologous genes are detected by southern hybridization on restriction enzyme-digested DNA or by hybridization to genomic or cDNA libraries. These techniques are well known to the person skilled in the art. As an alternative probe the HSK DNA sequence of any other more closely related plant species can be used as a probe. 3. Identification of Orthologs by Means of PCR [0083] For many crop species, partial HSK mRNA or gene sequences are available that are used to design primers to subsequently PCR amplify the complete cDNA or genomic sequence. When 5′ and 3′ sequences are available the missing internal sequence is PCR amplified by a HSK specific 5′ forward primer and 3′ reverse primer. In cases where only 5′, internal or 3′ sequences are available, both forward and reverse primers are designed. In combination with available plasmid polylinker primers, inserts are amplified from genomic and cDNA libraries of the plant species of interest. In a similar way, missing 5′ or 3′ sequences are amplified by advanced PCR techniques, 5′RACE, 3′RACE, TAIL-PCR, RLM-RACE or vectorette PCR. [0084] As an example the sequencing of the Lactuca sativa (lettuce) HSK cDNA is provided. From the Genbank EST database at NCBI several Lactuca HSK ESTs were identified using the tblastn tool starting with the Arabidopsis HSK amino acid sequence. Clustering and alignment of the ESTs resulted in a consensus sequence for a 5′HSK fragment and one for a 3′ HSK fragment. To obtain the complete lettuce HSK cDNA the RLM-RACE kit (Ambion) was used on mRNA from lettuce seedlings. The 5′ mRNA sequence was obtained by using a primer that was designed in the 3′HSK consensus sequence derived from ESTs (R1S1a: GCCTTCTTCACAGCATCCATTCC—SEQ ID NO: 1) and the 5′RACE primers from the kit. The 3′ cDNA sequence was obtained by using two primers designed on the 5′RACE fragment (Let3 RACEOut: CCOTTGCGGTTAATGAGATT—SEQ ID NO: 2, and Let3RACEInn: TCGTGTTGGTGAATCCTGAA—SEQ ID NO: 3) and the 3′RACE primers from the kit. Based on the assembled sequence new primers were designed to amplify the complete HSK coding from cDNA to provide the nucleotide sequence and derived protein sequence as presented in FIG. 10 (SEQ ID NOs: 101-102). A similar approach was a used for Solanum lycopersicum (FIG. 14 —SEQ ID NOs: 109-110) and Vitis vinifera (FIG. 11 —SEQ ID NOs: 103-104). [0085] The complete HSK coding sequences from more than 10 different plants species have been identified from genomic and EST databases. From the alignment of the DNA sequences, conserved regions in the coding sequence were selected for the design of degenerate oligonucleotide primers (for the degenerate nucleotides the abbreviations are according to the IUB nucleotide symbols that are standard codes used by all companies synthesizing oligonucleotides, G=Guanine, A=Adenine, T=Thymine, C=Cytosine, R=A or G, Y=C or T, M=A or C, K=G or T, S=C or G, W=A or T, B=C or G or T, D=G or A or T, H=A or C or T, V=A or C or G, N=A or C or G or T). [0086] The procedure for obtaining internal HSK cDNA sequences of a given plant species is as follows: [0087] 1. mRNA is isolated using standard methods, [0088] 2. cDNA is synthesized using an oligo dT primer and standard methods, [0089] 3. using degenerate forward and reverse oligonucleotides a PCR reaction is carried out, [0090] 4. PCR fragments are separated by standard agarose gel electrophoresis and fragments of the expected size are isolated from the gel, [0091] 5. isolated PCR fragments are cloned in a plasmid vector using standard methods, [0092] 6. plasmids with correct insert sizes, as determined by PCR, are analyzed by DNA sequencing. [0093] 7. Sequence analysis using blastX reveals which fragments contain the correct internal HSK sequences, [0094] 8. The internal DNA sequence can then be used to design gene- and species-specific primers for 5′ and 3′ RACE to obtain the complete HSK coding sequence by RLM-RACE (as described above). [0095] As an example the sequencing of the Cucumis sativus (cucumber) HSK cDNA is provided. For cucumber two primer combinations were successful in amplifying a stretch of internal coding sequence from cDNA; combination 1: primer F1Kom (GAYTTTCYTHGGMTGYGCCGT—SEQ ID NO: 4) and M1RC (GCRGCGATKCCRGCRCAGTT—SEQ ID NO: 5), and combination 2: primer M1Kom (AACTGYGCYGGMATCGCYGC—SEQ ID NO: 6) and R1Kom (CCATDCCVGGAATCAANGGVGC—SEQ ID NO: 7). After cloning and sequencing of the amplified fragments cucumber HSK-specific primers were designed for 5′ RACE (Cuc5RACEOut: AGAGGATTTTACTAAGTTATTCGTG—SEQ ID NO: 8 and Cuc5RACEInn: AGACATAATCTCCCAAGCCATCA—SEQ ID NO: 9) and 3′ RACE (Cuc3RACEOut: TGATGGCTTGGGAGATATGTCT—SEQ ID NO: 10 and Cuc3RACEInn: CACGAATAAACTTAGTAAAAATCCTCT—SEQ ID NO: 11). Finally the complete cucumber HSK cDNA sequence was amplified and sequenced (FIG. 12 —SEQ ID NOs: 105-106). A similar approach was a used for spinach, Spinacia oleracea (FIG. 13 —SEQ ID NOs: 107-108). [0096] Orthologs identified as described in this example can be modified using well-known techniques to induce mutations that reduce the HSK expression or activity. Alternatively, the genetic information of the orthologs can be used to design vehicles for gene silencing. All these sequences are then used to transform the corresponding crop plants to obtain plants that are resistant to Oomycota. Example 5 Reduction of Homoserine Kinase Expression in Arabidopsis by means of RNAi [0097] The production of HSK silenced lines has been achieved in Arabidopsis by RNAi. A construct containing two ˜750 bp fragments of the HSK exon in opposite directions was successfully transformed into the Arabidopsis Col-0 accession. The transformants were analysed for resistance to H. parasitica , isolate Waco9. Several transgenic lines were obtained that confer resistance to H. parasitica . Analysis of HSK expression and homoserine accumulation confirm that in the transformed lines the HSK gene is silenced, resulting in resistance to H. parasitica. Example 6 Mutation of Seeds [0098] Seeds of the plant species of interest are treated with a mutagen in order to introduce random point mutations in the genome. Mutated plants are grown to produce seeds and the next generation is screened for increased accumulation of homoserine. This is achieved by measuring levels of the amino acid homoserine, by monitoring the level of HSK gene expression, or by searching for missense mutations in the HSK gene by the TILLING method, by DNA sequencing, or by any other method to identify nucleotide changes. [0099] The selected plants are homozygous or are made homozygous by selfing or inter-crossing. The selected homozygous plants with increased homoserine levels are tested for increased resistance to the pathogen of interest to confirm the increased disease resistance. Example 7 Transfer of a Mutated Allele into the Background of a Desired Crop [0100] Introgression of the desired mutant allele into a crop is achieved by crossing and genotypic screening of the mutant allele. This is a standard procedure in current-day marker assistant breeding of crops. Tables [0101] [0000] TABLE 2 GI numbers (GenInfo identifier) and Genbank accession number for Expressed Sequence Tags (ESTs) and mRNA sequences of the Arabidopsis HSK mRNA and orthologous sequences from other plant species. Species Common name Detail GI number Genbank Arabidopsis thaliana Thale cress mRNA 39104571 AK117871 Citrus sinensis Sweet Orange ESTs 55935768 CV886642 28618675 CB293218 55935770 CV886643 28619455 CB293998 Glycine max Soybean ESTs 10846810 BF069552 17401269 BM178051 8283472 BE021031 16348965 BI974560 7285286 AW597773 58024665 CX711406 58017647 CX704389 20449357 BQ253481 16105339 BI893079 37996979 CF808568 37996460 CF808049 6072786 AW102173 26057235 CA800149 6455775 AW186458 6072724 AW102111 9203587 BE329811 Ipomoea nil Japanese moming glory ESTs 74407098 CJ761918 74402449 CJ757269 74402115 CJ756935 74388670 CJ743490 Nicotiana Tobacco ESTs 39880685 CK295868 Benthamiana 39859026 CK284950 39864851 CK287885 39864855 CK287887 39859024 CK284949 39864853 CK287886 39880683 CK295867 39864849 CK287884 Oryza sativa Rice mRNA 50916171 XM_468550 32970537 AK060519 Phaseolus vulgaris Common Bean ESTs 62708660 CV535256 62710636 CV537232 62708052 CV534648 62709395 CV535991 62710761 CV537357 62708535 CV535131 62708534 CV535130 62711318 CV537914 62707924 CV534520 62710733 CV537329 62709601 CV536197 62709064 CV535660 62708834 CV535430 Pinus taeda Loblolly Pine ESTs 70780626 DR690274 67490638 DR092267 48933532 CO162991 34354980 CF396563 67706241 DR117931 17243465 BM158115 34349136 CF390719 66981484 DR057917 48932595 CO162054 66689208 DR011702 48933450 CO162909 34350236 CF391819 67706323 DR118013 48932678 CO162137 66981399 DR057832 34354850 CF396433 Populus trichocarpa 1 Poplar Genome v1.0, LG_IX, 149339-148242 Expression confirmed by ESTs Populus trichocarpa 2 Poplar Genome v1.0, scaffold_66, 1415935-1417032 Expression confirmed by ESTs Solanum tuberosum 1 Potato ESTs 66838966 DR037071 61238361 DN588007 39804315 CK251362 39801776 CK250065 9250052 BE340521 39832341 CK275363 21917848 BQ116921 9249876 BE340345 39815050 CK258070 39804985 CK251702 39804987 CK251703 39825384 CK268406 39832342 CK275364 66838967 DR037072 9250394 BE340863 39804317 CK251363 39825385 CK268407 21375072 BQ516203 Solanum tuberosum 2 Potato ESTs 39813353 CK256373 39793361 CK246131 39793359 CK246130 39813352 CK256372 Zea Mays Maize ESTs 76071237 DT948407 76913306 DV165065 71446162 DR827212 71449720 DR830770 78117576 DV535963 91048486 EB158904 71439095 DR820145 76936546 DV174774 76012246 DT939416 78085419 DV513812 71766843 DR964780 76924795 DV170131 71449067 DR830117 91875652 EB405609 71450175 DR831225 78103551 DV521979 78090555 DV518929 78104654 DV523072 76926251 DV170768 78111568 DV529965 71773353 DR971257 71425952 DR807002 93282458 EB674722 78074199 DV502633 76293328 DV032896 78075462 DV503896 91054750 EB165168 86469295 DY235665 74243218 DT651132 74242899 DT650813 101384764 EB814428 91054750 EB165168 71440426 DR821476 78121780 DV540164 78103550 DV521978 86469794 DY235664 91877777 EB407734 67014441 CO443190 76924794 DV170130 76021236 DT948406 71446161 DR827211 78110960 DV529358 78074736 DV503170 71428043 DR809093 86469052 DY235422 71440425 DR821475 78121779 DV540163 78104653 DV523071 37400920 CF637820 78074198 DV502632 71449719 DR830769 Solanum lycopersicum Tomato 58213736 BP877213 7333245 AW621598 4386685 AI482761 Unigene SGN-U223239 Sequence described in this patent from Sol Genomics Network application Lactuca sativa Lettuce Sequence described in this patent application Vitis vinifera Grape vine Sequence described in this patent application Spinacia oleracea Spinach Sequence described in this patent application Cucumis sativus Cucumber Sequence described in this patent application A GI number (genInfo identifier, sometimes written in lower case, “gi”) is a unique integer which identifies a particular sequence. The GI number is a series of digits that are assigned consecutively to each sequence record processed by NCBI. The GI number will thus change every time the sequence changes. The NCBI assigns GI numbers to all sequences processed into Entrez, including nucleotide sequences from DDBJ/EMBL/GenBank, protein sequences from SWISS-PROT, PIR and many others. The GI number thus provides a unique sequence identifier which is independent of the database source that specifies an exact sequence. If a sequence in GenBank is modified, even by a single base pair, a new GI number is assigned to the updated sequence. The accession number stays the same. The GI number is always stable and retrievable. Thus, the reference to GI numbers in the table provides a clear and unambiguous identification of the corresponding sequence. [0000] TABLE 3 Primer sequences on insertion/deletion (INDEL, size difference indicated in brackets) markers and cleaved amplified polymorphics sequences (CAP, polymorphic restriction site indicated in brackets) used in the mapping of the DMR1 locus. Primer name: BAC Forward SEQ Reverse SEQ TYPE GI number of and/or TAIR At code primer sequence ID NO: primer sequence ID NO: (size/enzyme) TAIR At code T24112 AATCCAAATTTCTT 12 AAACGAAGAGTGAC 13 INDEL 18398180 (At2g16670) GCGAGAACACA 14 AATGGTTGGAG 15 (33) F5J6 CCGTCAGATCAGTC 16 CAGAAGCTGATGAT 17 INDEL 23506018 (AT2g17370-80) CTCATCTTGTT 18 CGTGGAAAGTA 19 (30) 30679966 F6P23 CGGTTTCATGTCGA 20 AAGAAGAGAACTGC 21 INDEL 22325728 (AT2g17060) GGAAGATCATA 22 GTCAACCTTCC 23 (37) T23A1 TCCTTCCATGTCCG 24 AACAAATTTGCTTC 25 INDEL 42570808 (AT2g17220-30) AAACCA 26 CAGCCTTT 27 (26) AT2g17190 GAATAGAGGTTGAT 28 CTCTTGTATGTTTT 29 CAP 30679898 GGAAATCAAGA 30 ACTGGGCTGAT 31 (MseI) AT2g17200 CCTCTCCACCCATT 32 CGATCCATTTCGTC 33 CAP 30679902 TCTAATTTCG 34 AAGCAATCTAC 35 (MboII) AT2g17270 GATGCAGCTAAATT 36 ACGAAAATATCAAA 37 CAP 30679927 ATCAGTGTGAA 38 AAGCTCCTTC 39 (NlaIII) AT2g17300-05 AGGTAGGATGGTAT 40 GCATGTTTTCTCTA 41 CAP 30679937 TATGTTTGAACT 42 AGCGATAGAAG 43 (EcoRI) 22325732 AT2g17310 ATGGGTAACGAAAG 44 CACATGTATAAGGT 45 CAP 42569097 AGAGGATTAGT 46 CTTCCCATAGA 47 (MseI) AT2g17360 CCAACAAGTATCCT 48 CCACATCAAACTTA 49 CAP 30679959 CTTTTGTTGTT 50 ATGAACTCCAC 51 (MaeIII) [0000] TABLE 4 Primer sequences used for amplifying and sequencing of eight candidate DMR1 genes for which the TAIR and GI codes are indicated Primer name Primer sequence SEQ ID NO: TAIR codes GI codes MvD17230_F TTCCCGAAGTGTACATTAAAAGCTC 52 At2g17230 30679913 MvD17230_R TATGTCATCCCCAAGAGAAGAAGAC 53 At2g17230 30679913 MvD17240_F CAATAAAAGCCTTTAAAAGCCCACT 54 At2g17240 30679916 MvD17240_R TAGCTTCTGAAACTGTGGCATTACA 55 At2g17240 30679916 MvD17250_1F CATGATTTGAGGGGTATATCCAAAA 56 At2g17250 22325730 MvD17250_1R GGAGGTGGGATTTGAGATAAAACTT 57 At2g17250 22325730 MvD17250_2F TAGCCTAGAACTCTCTGTTCGCAAG 58 At2g17250 22325730 MvD17250_2R CATTATTTTGCGTAGTTGTGAGTGG 59 At2g17250 22325730 MvD17250_3F CGAAGAAATCCTACAATCAACCATC 60 At2g17250 22325730 MvD17250_3R TCTCACAATTCCCATCTCTTACTCC 61 At2g17250 22325730 MvD17260_1F TTACTCATTTGGGTGAACAGAACAA 62 At2g17260 30679922 MvD17260_1R ATCATCCCTAATCTCTCTGCTTCCT 63 At2g17260 30679922 MvD17260_2F GATTAAGATACGGGGAATGGAGTCT 64 At2g17260 30679922 MvD17260_2R ATGCAGACAAATAAGATGGCTCTTG 65 At2g17260 30679922 MvD17260_3F GTTGTTGCTCCTGTCACAAGACTTA 66 At2g17260 30679922 MvD17260_3R GAACAAAGACGAAGCCTTTAAACAA 67 At2g17260 30679922 MvD17265_F GAGGACTGCATCTAGAAGACCCATA 68 At2g17265 18398362 MvD17265_R TGGGCTCTCAACTATAAAGTTTGCT 69 At2g17265 18398362 MvD17270_F1 TAACGGTAAAGCAACGAATCTATCC 70 At2g17270 30679927 MvD17270_R1 TCAAACTGATAACGAGAGACGTTGA 71 At2g17270 30679927 MvD17270_F2 TTGCGTTCGTTTTTGAGTCTTTTAT 72 At2g17270 30679927 MvD17270_R2 AAACCAGACTCATTCCTTTGACATC 73 At2g17270 30679927 MvD17280_F1 TTTAGGATCTCTGCCTTTTCTCAAC 74 At2g17280 42569096 MvD17280_R1 GAGAAATCAATAGCGGGAAAGAGAG 75 At2g17280 42569096 MvD17280_F2 GCTTAAATAGTCCTCCTTTCCTTGC 76 At2g17280 42569096 MvD17280_R2 TCTGCTGGTTCTCATGTTGATAGAG 77 At2g17280 42569096 MvD17290_F1 CTCTCCTTCATCATTTCACAAATCC 78 At2g17290 30679934 MvD17290_R1 TTCCTCTCGCTGTAATGACCTCTAT 79 At2g17290 30679934 MvD17290_F2 TGCCACAGGTGTTGACTATGC 80 At2g17290 30679934 MvD17290_R2 TGCTCTTAAACCCGCAATCTC 81 At2g17290 30679934 MvD17290_F3 GAAGATGGCTTTAAAGGTCAGTTTGT 82 At2g17290 30679934 MvD17290_R3 AGCAACAACAACTAAAAGGTGGAAG 83 At2g17290 30679934

The present invention relates to a plant, which is resistant to a pathogen of viral, bacterial, fungal or oomycete origin, wherein the plant has an increased homoserine level as compared to a plant that is not resistant to the said pathogen, in particular organisms of the phylum Oomycota. The invention further relates to a method for obtaining a plant, which is resistant to a pathogen of viral, bacterial, fungal or oomycete origin, comprising increasing the endogenous homoserine level in the plant.

This application is a continuation of U.S. patent application Ser. No. 08/304,663 filed on Sep. 9, 1994 now U.S. Pat. No. 5,590,896. BACKGROUND OF THE INVENTION This invention relates to a stroller. More particularly, the invention relates to a three-wheeled child's stroller that has a selectively lockable, 360 degree pivoting front caster wheel and that folds conveniently and compactly for storage or portability. The stroller's design and wheel size are more suitable for rougher terrain and higher traveling speeds than a conventional stroller having small wheels. Further, the stroller is more compact and maneuverable than a conventional "jogging stroller" having three large bicycle-type wheels and tires. The invention also relates to a stroller having a convenient fold and automatic spring-loaded side latches for locking the stroller in the unfolded configuration. Additionally, the invention relates to a stroller having a reclining seat back and a child restraint seat belt. There are a variety of types of conventional three-wheeled collapsible strollers known. For example, U.S. Pat. No. 3,881,739 to Laune describes a child's stroller having three wheels of a relatively small size, as are usually associated with a conventional stroller. The front wheel is of a steerable, caster type and has a brake and is lockable in a forward-only orientation. The stroller frame comprises of a pair of horizontal side elements pivoted on each other at their front ends and having upright members at their rear ends. The front ends meet at a front pivot point with articulated connections, which allow the side elements and upright members to collapse upon each other to fold the stroller, reducing the space occupied by the stroller. Footrests are provided on the front tubes below the seat and above and behind the front wheel. A disadvantage of the stroller described in the patent to Laune is that it is limited to use only at relatively low speeds and only on relatively smooth surfaces by the small wheel diameters--a stroller with small wheels and tires is difficult to maneuver on bumpy surfaces. Thus, a conventional small-wheeled stroller is not well suited to some surfaces commonly encountered by users of strollers, such as bumpy pavement, grass, or packed dirt. Another disadvantage of this stroller is that although the stroller folds longitudinally, bringing the two rear wheels in close proximity to each other, this fold produces a lengthy and cumbersome end product--the stroller in its folded state is necessarily at least as long as its wheelbase. Accordingly, there exists a need both for a stroller that is operable on slightly uneven or bumpy surfaces and a fold for such a stroller that will yield a folded configuration which is compact for easy storage and/or portability. Various bar linkages and fold patterns for strollers are known. Also, various latches for latching a folding stroller frame in a fully unfolded operative position are known. For example, U.S. Pat. No. 4,415,180 to Payne, Jr. illustrates a folding stroller utilizing a latch member which is pivotally connected to the first frame member and biased to a position wherein it embraces an end of a second member. The latch member may be released by finger pressure pivoting the latch member against the spring bias. The latch member has a cam surface thereon, so that the end of the second member may contact the cam surface and pivot the latch member whereby the second member will be snapped into a latched position without finger manipulation. The latch member pivots around a generally horizontal axis that is perpendicular to the tube axis. The conventional four-wheeled stroller disclosed in the patent to Payne, Jr. also suffers from the disadvantage that it is limited for use only on relatively smooth surfaces due to the small wheel diameters. This stroller also is not suitable for use on the uneven or bumpy surfaces commonly encountered by users of strollers. Another type of latch member for latching first and second frame members into a parallel, unfolded position is known in which the latch is mounted to and rotates about the longitudinal axis of one frame member. The latch has a resilient portion defining a groove that snaps partially around and onto the other frame member, to latch the frame members together. A disadvantage of this design is that the latch must be manually rotated and engaged and rotated and disengaged whenever the user wishes to fold or unfold the stroller frame. Thus, when unfolding the frame (the latch is disengaged when the frame is folded), the latch must be manually engaged once the stroller is in its usable, unfolded configuration. Accordingly, this type of latch suffers from the disadvantage that the user must manually engage the latch by rotating it each time the stroller is unfolded. U.S. Pat. No. 5,188,389 to Baechler et al. discloses a foldable three-wheeled "all-terrain" baby stroller of the type commonly referred to as a "jogging stroller." This stroller is better equipped to accommodate higher speeds and bumpy or uneven surfaces than a small-wheeled conventional stroller due to the utilization of large wheels. A disadvantage of the stroller disclosed in the Baechler et al. patent is that the lower frame bars connecting the front and rear wheels do not fold--therefore even when folded the stroller is necessarily at least as long as its wheel base. Yet another drawback to the design is the absence of a directionally pivoting front wheel, which makes the simple task of turning the stroller an arduous one--the operator must push down on the handle to raise the front wheel off the ground to change direction. Another "jogging stroller" is disclosed in U.S. Pat. No. 5,029,891 to Jacobs. The stroller includes three large-diameter wheels arranged in a tricycle configuration, a foldable frame to which the wheels are attached, and an infant holder made from flexible material supported by the frame. The frame includes a pivotally connected upper portion and a lower portion, whereby the portions may be folded against one another reducing the space occupied by the stroller. The front wheel is centrally located directly in front of the child. A floor panel intended for a foot rest is mounted to the front tubes and extends forward from under the child's seat and a fender covering the back side of the front wheel is attached to the floor panel and front axle. A disadvantage of the stroller disclosed in the Jacobs patent is that this configuration places the occupants legs mostly or completely behind the front wheel, again elongating the overall length of the stroller. Further, the Jacobs patent depicts that the lower frame bars connecting the front and rear wheels do not fold--therefore once again even when folded the stroller is necessarily at least as long as its wheel base, as in the Laune and Baechler et al patents. Also, the provision of a floor panel and a separate fender increases the weight and complexity of the stroller as compared to a single unitary footrest/fender member. Another drawback in the stroller of the Jacobs patent is the implementation of a non-pivoting front wheel, again making steering cumbersome and difficult, as in the stroller disclosed in the Baechler et al. patent. Accordingly, there exists a need for a stroller combining the advantages of a "jogging stroller"--the ability to traverse somewhat bumpy and/or uneven terrain--with the advantages of a conventional stroller--ease of maneuverability, compactness and convenient and compact foldability. Reclining seats for strollers are also known. For example, U.S. Pat. No. 4,836,573 to Gebhard discloses an apparatus for supporting a child in a fully reclining (horizontal) position and in a sitting (generally upright) position. The child support is pivotable from the first, generally horizontal position for use as a bassinet to the second, generally upright or slightly tilted position for use as a forward-facing stroller seat. In the first configuration, a first planar member acts as a whole body support for a child to provide a bassinet or baby carriage configuration. In the second configuration, the first planar member is provided as a back rest and a second planar member is provided as a seat. A disadvantage of the configuration described in the Gebhard patent is that it does not provide for conversion between an upright seated position and a reclined seated position--rather it only provides for a choice between one slightly reclined position or a fully lying down position. Accordingly, there exists a need for a stroller seat back that is conveniently adjustable between a relatively upright, seated position, and a more inclined, reclining seated position. Another seat back recline is described as U.S. Pat. No. 4,462,607 to Nakao et al., in which the upper back section of a seating platform is suspended from the handle by an adjustable loop. Wheel brakes employing a lever partially mounted to the stroller frame and having a pin that engages radial teeth in the wheel to brake the wheel when the lever is depressed are also known, as illustrated in U.S. Pat. No. 5,257,799 to Cone et al. A disadvantage of the wheel brake of the type shown in the Cone et al. patent is that the brake must be manually set or released--since it does not automatically set when the stroller is folded, the user typically must set the brake when unfolding the stroller if it has not been set before folding. Seat belt assemblies for child and infant seats are also known. For example, U.S. Pat. No. 4,962,965 to Glover discloses a seat belt assembly for use in a high chair comprising a pair of generally horizontally extending waist straps each coupled at one end to a portion of the high chair seat, and having a buckle part at the other end, a crotch strap permanently secured to a front central extent of the seat portion and having a free front end, and a main buckle permanently attached to the free end of the crotch strap with the main buckle also having a pair of attachment mechanisms for removably receiving the buckle parts of the ends of the waist straps. Accordingly, there is a need for a three-wheeled collapsible stroller which can be used on terrain that is more bumpy or uneven than the smooth terrain suitable for a conventional small-wheeled stroller, but that is also more maneuverable than a conventional three-wheeled "jogging stroller." Furthermore, there is a need for such a stroller to be conveniently collapsible into a compact form for transportation and storage. Additionally, there is a need for a three wheeled stroller seat back that is quickly and conveniently adjustable between reclined and upright seating positions. Moreover, there is a need for a brake mechanism for the rear wheels of a folding stroller that automatically sets the brakes of the rear wheels when the stroller is fully folded. SUMMARY OF THE INVENTION The invention solves the problems and avoids the drawbacks of the prior art by providing a three-wheeled collapsible stroller which can be used on terrain that is more bumpy or uneven than the smooth terrain suitable for a conventional small-wheeled stroller, but that is also more maneuverable than a conventional three-wheeled "jogging stroller." The stroller has a folding frame and automatic side latches so that it is conveniently collapsible into a compact form for transportation and storage. The stroller also has a seat back that is quickly and conveniently adjustable between reclined and upright seating positions, and that is capable of remaining in the same position when unfolded and folded. The stroller also has a means for automatically setting the brakes of the rear wheels when the stroller is fully folded. In one aspect, the invention relates to a folding stroller having a front wheel; a front member having a front wheel supporting portion for supporting the front wheel, and a pair of front member ends; a rear handle member having a handle portion and a pair of handle member ends; a pair of rear wheels; a rear support member having a pair of rear wheel supporting portions, each rear wheel supporting portion supporting a respective one of the rear wheels, and the rear support member having a pair of rear support ends; a pair of side members each having a first side member end and a second side member end. The handle member ends are pivotally connected to the front member ends, and the rear support member ends are pivotally connected to a medial portion of the handle member, the first side member ends are pivotally connected to portions of the front member and the second side member ends are pivotally connected, to portions of the rear member. In another aspect, the invention relates to an automatic latch mechanism having a first tube having a first longitudinal axis, a pivot mount location, and a first end; and a second tube having a second longitudinal axis and a second end. A pivot mount is attached to the first tube at the first pivot mount location and has the second end pivotally mounted thereto the first and second tubes are pivotally connected to one another and are movable from a folded position where the first and second longitudinal axes are angled relative to each other to an unfolded position where said first and second longitudinal axes are parallel and offset. A latch handle is mounted about the first tube proximate to the first end, and is rotatable around the first longitudinal axis of the first tube. The latch handle defines a groove engagable with the second tube when the first and second tubes are in the unfolded position. The latch is rotatable between a first, engaging position wherein the groove engages the second tube, and a second, nonengaging position where the groove is not engaging the second tube, and the latch handle has a camming surface adapted for camming contact with the second tube when the tubes are in the unfolded angled position. A spring is provided for biasing the latch handle towards the first, engaging position. In another aspect the invention relates to a reclining seatback assembly, having a first frame portion; a second frame portion spaced apart from the first frame portion; and a generally rigid seatback portion. A first flexible web extends between the first frame portion and the seatback portion, and has a first extended configuration in which the seatback is suspended in a first reclining position and a second, foreshortened configuration in which the seatback is suspended in a second position more upright than the first position. A second flexible web extends between the second frame portion and the seatback portion, the second web also having a first extended configuration in which the seatback is suspended in first, reclined position and a second, foreshortened configuration in which the seatback is suspended in a second position more upright than the first position. The webs may be selectively foreshortened to move the seatback from the first position to the second position. In still another aspect, the invention relates to a foldable stroller having a folded configuration and an unfolded configuration having a first frame portion; a wheel rotatably mounted to the first frame portion; and a brake lever pivotally mounted to the first frame portion, the brake lever including a wheel engaging portion being pivotable between a first position at which the wheel engaging does not contact the wheel and a second position at which the wheel engaging portion engages the wheel to brake the wheel. A second frame portion is connected to the first frame portion for relative movement with respect to the first frame portion and the second frame portion contacts the brake lever to urge the brake lever into the second position when the stroller is in the folded configuration. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a perspective view of the stroller. FIG. 1B is a perspective view of an alternative embodiment of the stroller with an access flap opened. FIG. 1C is a perspective view of the frame of the stroller with the seat assembly removed. FIG. 2 is an exploded view of the frame of the stroller with the seat assembly removed. FIG. 3A is a side view of the front end of the stroller. FIGS. 3B and 3C are bottom views of the front end of the stroller. FIG. 4A is a perspective view of the seat back in an upright position. FIG. 4B is a perspective view of the seat back in a reclined position. FIG. 5A is a side partially cutaway/sectional view of an automatically latching side latch mechanism. FIG. 5B is an end view of the side latch mechanism in a locked position. FIG. 5C is an end view of the side latch mechanism in an open unlocked position. FIG. 5D is a top cut away/sectional view of the automatically-latching side label mechanism. FIGS. 6A and 6B are side and top views, respectively, of the side hinge and side latch mechanism in a partially folded angled position. FIGS. 6C and 6D are side and bottom views, respectively, of the side hinge and side latch mechanism in an intermediate partially folded angled position. FIGS. 6E and 6F are side and bottom views, respectively, of the side hinge and side latch mechanism in a completely unfolded and locked position. FIG. 7 is a perspective view of the child restraint seatbelt. FIGS. 8A and 8B are side and top views, respectively, of a part of the stroller in the fully folded position. FIG. 8C is a side view of the part of the stroller shown in FIG. 8A in a nearly fully folded position. FIG. 9 is a rear view of the side hinge in the fully folded position. FIGS. 10A, 10B, 10C, 10D, 10E and 10F are schematic side views representing the folding sequence of the stroller frame. FIGS. 11A and 11B are front and rear views of the fabric seating assembly removed from the stroller frame and laid generally flat. DETAILED DESCRIPTION Reference will now be made in detail to presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. 1. Overall Stroller Configuration The overall stroller configuration will now be described. Several of the features described briefly under this heading are described in more detail below under separate headings. As shown in FIGS. 1A, 1B, 1C and 2 the stroller generally comprises a foldable frame including a handle tube 20, front tubes 40, 45, a rear support tube 30, and two seat tubes 50, 60. (The handle tube 20 may include a padded grip portion 770. A front fork assembly 110 supports a front wheel assembly 320 which is selectively lockable into a straight-ahead position and releasable to pivot in a caster-type fashion. Two rear axle mounting brackets 280, 290 support an axle tube 70 to which are mounted two rear wheels 260, 270 that are independently removable. Each rear bracket 280, 290 features a brake mechanism actuated by depressing a brake lever 300, 310, and releasable by raising the brake lever 300,310. A pivoting arched canopy wireframe 725 pivots on the handle tube 20 to support a piece of canopy fabric 729 that may be flipped into an extended canopy shading position or a retracted position. A fabric seating assembly 800 (illustrated in more detail in FIGS. 4A, 4B, 11A and 11B) is suspended between the handle tube 20 and the front tubes 40, 45 and includes a rigid seatback 801 suspended at its sides by fabric web 815, 820. The seatback 801 has a reclined position in which it is supported by the side webs 815, 820 stretched taut (as best shown in FIG. 4B). The side webs also each feature an extension web 900, 905 extending from a part of each side web. A male clip 915 on the end of one extension web 905 and a female clip 910 on the other extension web 900 can be clipped together, thereby pulling the side webs 815, 820 in behind the rigid back panel 801 to secure the seat back in an upright position (as best shown in FIG. 4A). The side fabric webs 815, 820 are attached to the handle tube 20 at attachment points located near the canopy pivot, and near parts 120 and 130. In the illustrated embodiment, the webs are attached to the tubes with hook and loop fasteners. In another preferred embodiment the webs may be more permanently attached to the handle tube by screws. The side webs 815, 820 and the front of the seat bottom 805 are also attached to the front tubes 40, 45 at a location just above the pivoting connection of the seat tubes 50, 60 and the lower portion of the front tubes 40, 45. Near the vertex of the seat bottom 805 with the seat back 801, the side webs 815,820 (and hence the seat bottom 805 and the seat back 801 ) are attached to the seat tubes in a sliding manner, e.g., by a strap 920, 925 passing outside and under the seat tubes 50, 60. This sliding connection permits the stroller frame to be folded, while the seat back remains in either the upright or reclining position, as described in more detail below with reference to the folding sequence. Referring now particularly to FIG. 2, the handle tube 20 is pivotally connected at its lower ends to the front tubes 40, 45 by means of an upper pivot mount 200 and an upper left pivot mount 190. The front tubes 40, 45 have their vertex at a heady vertical head tube 41 which has a conventional headset assembly for mounting a fork shaft 780 of the fork 110 so that the fork 110 may pivot along the longitudinal axis of the head tube, which is offset slightly back from vertical. The front wheel 320 is mounted at the bottom of the fork 110. A footrest 80 may be provided mounted to the lower front part of the front tubes 40, 45 over the front wheel 320 as shown and may include a decorative cap 82. This footrest 80 also serves as a fender and a fairing over the front wheel 320. Left and right seat tubes 50, 60 are mounted to the front tubes 40, 45 by right front seat tube pivot mount 180 and left front seat tube pivot mount 170 as shown. Both seat tubes 50, 60 are pivotally mounted at their other ends to the rear tube 30 by left and right rear seat tube pivot mounts 750 and 755, respectively. The rear tube 30 is generally U-shaped and is pivotally mounted at its top ends to the handle tube 20 by means of a upper right pivot mount 230 and a upper left pivot mount 220. Right and left axle brackets 280, 290 are mounted at the lower comers of the rear tube 30. The right and left axle brackets 280, 290 each have a hole for receiving an axle tube 70 that extends therebetween and the left and right wheels 260, 270 are each mountable detachably on stub axles 340, 350, respectively that fit in the left and right ends of the axle tube 70, respectively. The ends of the axle tube may be fitted with sleeves 420, 430. Each of the left and right rear wheels 260, 270 includes a two-piece center hub including an outer center hub 325, 330 and an inner center hub 360, 370 with a stub axle 340, 350 that can be inserted therethrough. The end of the stub axles 340, 350, after being inserted through the wheels 260, 270 are inserted into the ends of the axle tube 70. Spring-loaded pins 380, 390 engage annular grooves 341, 351 in the stub axles 340, 350 to removably secure the wheels in the axle tube 70. In this way the rear wheels 260, 270 are each removably attached. The stub axles 340, 350 each have a tapered end so that when inserted they slidingly contact the end of the pin 380, 390 at an angle and push it out against the spring force, permitting the stub axle 340, 350 to be fully inserted. Once fully inserted, the pin 380, 390 engages the annular groove 341, 351 so as to secure the stub axle 340, 350. The wheel 260, 270 is disengaged by simultaneously pulling out on a spring loaded pin 380, 390 and pulling off the wheel. A brake pedal 300, 310 is pivotally mounted to each axle bracket 280, 290 and is pivotable between two detented positions. In an upper position, the brake pedal 300, 310 does not interfere with rotation of the wheel 260, 270. However, when the brake pedal 300, 310 is depressed, a pin 301, 311 (depicted in FIG. 8A) extending outwardly from the brake pedal engages radial teeth 361,371 on the inner center hub 360, 370 to lock the wheel 260, 270 and prevent it from rotating. Returning again to the frame, optional right and left upper covers 120, 130 are provided over the lower portions of the handle tube and cover the pivoting connection of the rear tube 30 and the handle tube 20. An inwardly spring-biased pivoting latch 140, 150 on each side rotates about the longitudinal axis of the front tubes 40, 45 and has an inner groove 141, 151 for engaging the handle tube 20 to hold the stroller in the fully unfolded position. Optional left and right lower covers 90, 100 cover the upper ends of the front tubes 40, 45 and also covers the pivoting connections of the front tubes 40, 45 to the handle tube 20. The construction and operation of the side latches 140, 150 and the folding sequence of the frame are both discussed in more detail below. Each of the wheels 260, 270, 320 has a foam rubber tire 261, 271, 321 having an all-terrain type tread mounted on to a rim with a spoked intermediate hub 262, 272, 322 and two-piece plastic center hub 325, 360, 330, 370, 323 and 324. On the front wheel 320, a conventional roller bearing type axle 329 is provided and is mounted to the lower end of the fork 110. The rear wheels 260, 270 frictionally rotate on the stub axles 340, 350 that are inserted into sleeves 420, 430 on the ends of the axle tube 70, which is mounted to the rear tube 30 by the axle mounting brackets 280, 290. As noted above, each rear wheel 260, 270 has its own independently operable brake 300, 310. At the front of the seat bottom, a leg rest flap 810 is provided that may be flipped up as shown in FIG. 1B to provide access to a cargo compartment 999 located under the seat bottom. The cargo compartment 999 is a fabric basket suspended from the lower part of the rear tube 30 just above the wheel mounting brackets and attached to the front tubes 40, 45 underneath the footrest 80. 2. Lockable Pivoting Front Caster Referring particularly to FIGS. 2 and 3A through 3C, the front fork assembly 110 includes a body portion having a left fork 110a, a right fork 110b, and a fork shaft 780. A shaft 780 extends into a conventional head set assembly 42 in the center head tube 41, to secure the front fork assembly 110 to the front tubes 40, 45 so that the front fork assembly 110 is free to rotate 360 degrees, in either direction, with respect to the frame of the stroller. The fork 110 also includes a swivel locking pin 525. In this embodiment, the locking pin 525 is a conventional bolt which extends through the fork crown 790 and extends outward from the fork crown 790. The front wheel 320 is rotatably mounted to the front fork assembly 110 by a front axle assembly, which is a conventional axle assembly that includes a ball bearing assembly, and a front axle 329 that extends through the axle bore of the front wheel. Axle nuts are tightened over washers on the outside of the fork to secure the wheel in place. The front fork assembly 110 has a design that is similar to that of a conventional caster in that when the stroller is traveling in the forward direction, the axis of rotation of the front wheel is horizontally displaced rearwardly from the vertical rotational axis of swivel of the shaft 780. In other words when moving in the forward direction, the front wheel 320 will be urged by friction between itself and the traveling surface to swivel to a stable position in which the front wheel trails the head assembly 42. This feature is accomplished by constructing the front fork assembly 110 so that although the shaft 780 is rotatably positioned to the stable position, the fork sides 110a, 110b depend from the crown 790 at a slight rearward angle (with respect to the axis of rotation of shaft 780). Furthermore, in this stable position, the locking pin 525 extends rearward from the crown 790. A footrest retainer 580 includes a body portion 581 which has left and right arms 582, 583, which are generally "L" shaped and depend downward from body portion 581 along the inner sides and under the left and right sides of the front tubes 40, 45 respectively. Left and right guide rails 585, 586 depend downward from the left and right arms 582, 583, respectively, and are oriented so that the rail's longest sides are parallel with the forward and rearward directions of motion of the stroller. In this embodiment, left guide rail 585 includes a rib 587 that protrudes from the outside surface. The front portion 584 of the body portion 581 is semi-circular shaped to mate with head tube 41. Consequently, when the footrest retainer 580 is mounted, the body portion 581 rests on top of the front tubes 40, 45 with the front portion 584 abutting against the head tube 41, while the arms 582, 583 extend down along the inside and under the front tubes 40, 45. The footrest 80 includes a body portion 81, a grooved feet receiving portion 83, and right and left rear frame receiving portions 84a, 84b, respectively. The footrest 80 is fastened to the footrest retainer 580 in any conventional fashion such as by two screws (not shown), which extend through the body portion 581 of footrest retainer 580 and into the underside of the footrest 80. The right and left frame receiving portions 84a, 84b are shaped to receive the upwardly extending portions of front tubes 40, 45 and act to prevent foot rest 80 from moving in a rearward direction. Once the footrest retainer 580 and the footrest 80 are mechanically coupled (by screws or any other conventional manner), the assembly (footrest retainer 580 and footrest 80) is prevented from moving in an upwardly vertical direction, with respect to the stroller frame, by the arms 582, 583 of footrest retainer 580, which extend under the front tubes 40, 45. The assembly is prevented from moving rearwardly because the right and left frame receiving portions 84a, 84b of the footrest 80 abut against pivot mounts 170 and 180, which are attached to the front tubes 40, 45. The assembly cannot move downward since the body portion 581 of footrest retainer abuts against the top sides of the front tubes 40, 45. Furthermore, the assembly cannot move in the forward direction because the semi-circular front portion 584 of the body portion 581 of the footrest retainer 580 abuts against the rear side of the head tube 41. Consequently, once footrest 80 and footrest retainer 580 are mechanically coupled (as with screws), they are fixed in position and cannot move in any direction with respect to the stroller frame. A swivel lock 600 includes a body portion 601 having a right slot 602 and a left slot 603 which are sized and shaped to receive right and left guide rails 586, 585, of footrest retainer 580, respectively. The left slot 603 has a first notch 604 and a second notch 605, which are sized and shaped to receive a rib 587 of the left guide rail 585. In addition, at least the left slot 603 has a handle 608 that extends outwardly and downwardly from its forward-most outside corner. The body portion 601 also includes a locking groove 610 positioned between left and right inwardly directed cam surfaces 616, 615, respectively. The groove 610 is sized and shaped to receive the locking pin 525. The swivel lock 600 is slidably fastened to the footrest retainer 580 by screws 618, which extend through washers 619 and into the left and right guide rails 586, 585, respectively. Therefore, the swivel lock 600 is prevented from moving in the vertical direction by screws 618 and prevented from moving in a horizontal direction that is perpendicular to the longitudinal center-line of the stroller because the slots 602, 603 are substantially the same width (and therefore do not allow the swivel lock 600 to slide laterally) as rails 585, 586, respectively. However, the swivel lock 600 can slide horizontally along a path that is parallel to the longitudinal center-line of the stroller (and thus parallel with the longer sides of guide rails 585, 586) between a first forward engaging position, shown in FIG. 3C, and a second rearward non-engaging position, shown in FIG. 3B. In the first forward engaging position, locking pin 525 is disposed in locking groove 610 and since swivel lock 600 cannot move laterally (as discussed above), groove 610 acts to hold locking pin 525 in the rearward position so that the front fork assembly 110 is locked in the stable forward position (and the front wheel 320 is positioned for forward movement). Since the locking pin 525 is fixed to the fork assembly 110, the front fork assembly 110 is prevented from swiveling and is in a swivel lock mode. Furthermore, in the first forward engaging position, the rib 587 of the left guide rail 585 engages the first notch 604 of the left slot 603 to provide resistance to the swivel lock 600 from inadvertently sliding backward. In the second rearward non-engaging position shown in FIG. 3B, the swivel lock 600 is positioned rearwardly further away from front fork assembly 110 so that the swivel lock (and therefore the locking groove 610) does not engage the locking pin 525. In this position, the front fork assembly is free to rotate and is in a free swivel mode. Furthermore, in the second rearward non-engaging position the rib 587 of the left guide rail 585 engages the second notch 605 of the left slot 603 to provide resistance to the swivel lock 600 from inadvertently sliding forward. For transition from the free swivel mode to the swivel lock mode, the user rotates the front wheel 320 (and therefore the front fork assembly 110) to approximately the stable forward position, in which the front wheel is positioned for forward movement of the stroller and the locking pin extends substantially rearward of the fork 110. The user then slides swivel lock 600 forward, utilizing the handle 608, from the rearward nonengaging position to the forward engaging position. If the locking pin 525 is perfectly aligned with the locking groove 610, the locking pin 525 will simply gradually (as the user slides swivel lock 600) extend into locking groove 610. If the locking pin 525 is not perfectly aligned with the locking groove 610, the locking pin 525 will strike either right or left inwardly directed cam surfaces 615, 616, respectively, which will commonly direct the locking pin 525 into alignment with the locking groove 610. In either instance, the front fork assembly will end up in the swivel lock mode. For transition from the swivel lock mode to the free swivel mode, the user simply slides the swivel lock 600 rearward, utilizing handle 608, from the forward engaging position to the rearward nonengaging position. In this position as discussed above, the locking pin 525 is no longer disposed in locking groove 610 and therefore front fork assembly 110 is free to swivel. 3. Seat Back Recline The seat back recline will now be described making particular reference to FIGS. 4A, 4B, 11A and 11B. Shown in FIG. 11A is the front view of the overall design of the components comprising the reclining stroller seat assembly. The seat assembly consists of a back rest portion 801 permanently attached to a seat portion 805 which is permanently attached to a leg rest flap 810. Attached along the periphery of the back rest portion 801 and the seat portion 805 are left and right web sections 815, 820 which when attached to the frame of the stroller function as the sides of the stroller seat. Both left and right web sections 815, 820 contain appendages 825, 826 which are intended to fold around the handle tube 20, fastened to the upper portion of the handle tube 20 by the right and left canopy mounts 735, 736, through holes 890, 895 in the web section, the lower section of the web appendage fastened to the handle tube 20 by hook-and-loop type fasteners 865, 870, 875, 880, or alternatively, fabric retainers with screws. Attached to the front of the back rest portion 801 are right and left side waist straps 835, 830, which may be attached by a horizontal step 850, Stitched to the seat portion 805 is the center crotch portion 855. The back rest portion 801, the seat portion 805, and the leg rest flap 810 consist of a light weight rigid backing, such as hard board, plywood or plastic, with a foam-like material attached to the front side for the comfort of the occupant. Stitched to the back side of the left and fight webs 815, 820 are the left and right extension webs 900, 905. The extension webs 900, 905 are appropriately angled inward from the top of the web sections 815, 820 to the intersection of the back rest portion 801 and the seat portion 805, Attached to the left extension web 900 via a fabric loop is a male buckle part 915 and attached to the right extension web 905 via a fabric loop is a female buckle part 910. When the male 915 and female 910 buckle parts are joined, the seat back portion 801 is positioned in the upright position (shown in FIG. 4A) and when uncoupled lies in the reclined position (shown in FIG. 4B). The seat portion 805 of the stroller seat remains in the same position and angle irrespective of the position of the seat back 801. The back rest portion 801 pivots at the intersection of the back rest portion 801 and the seat portion 805. Therefore, in the preferred embodiment, the exterior webs 900, 905 serve as a means for foreshortening the webs 815, 820 to pull the back rest panel 801 into a more upright position. In alternative embodiments, the webs 815, 820 might be forshortened in other ways. For example, the webs 815, 820 might each include a pair of zipper halves arranged in V-configuration with part of the webs 815, 820 serving as a gusset or dart between the zipper halves. When the zipper halves are unzipped, the seat back rest panel 801 reclines, supported by the webs 815, 820. When the zippers are zipped, the seat back rest portion 801 is pulled up into a more upright position, because the gusset or dart portions of the webs 815, 820 would be taken up as slack, and the webs 815, 810 are effectively foreshortened by the distance between the unzipped zipper halves, which are now zipped together As illustrated by the rear view in FIG. 11B, just below the intersection of the back rest portion 801 and the seat portion 805 lies a horizontal strip to which the right and left sliding seat mount straps 925, 920 are attached. At the end of the left sliding seat mount strap 920 lies a conventional buckle consisting of two seem-circular rings 935. The end of the right sliding seat mount strap 925 is interwoven between the rings 935 at the end of the left sliding seat mount strap 920 to couple the left and right sliding seat mount straps around the left and right seat tubes 50 and 60. The loop formed by the left 920 and right 925 sliding seat mount straps around and under the left and right seat tubes 50, 60 slides along the tubes during the folding process. This allows the seat back to remain in the upright or reclined position when folded and unfolded. As seen in FIG. 11B, just below the intersection of the seat portion 805 and the leg rest flap 810 lies a horizontal strip 940 which extends beyond the length of the leg rest flap 810 in both directions. The ends of the horizontal step section 940 are attached to the left and right front tubes 40, 45 via screws near the juncture of the front tubes 40, 45 and the handle tube 20. The leg rest flap 810 pivots about the intersection of the seat portion 805 and the leg rest flap 810. 4. Automatically Latching Side Frame Latches The front tubes 40, and 45 have optional lower cover members 100, 90, as well as spring-loaded latch handles 140, 150. When the frame is in the fully extended, unfolded orientation, the lower grooves 141, 151 in the latch handles 140, 150 engage the handle tube 20 to hold the frame in the fully unfolded position. The left side latch handle 140 and its associated parts are illustrated in detail in FIGS. 5A through 6F. The right side latch handle 150 is symmetrically opposite and operates in the same manner as the left side latch handle 140. The latch handles 140, 150 are biased into this locked position by coil torsion springs 670, 680, having one end 671 (spring 670 is shown in detail in FIG. 5A) attached internally to the cover member 100, which is fixed to the front tube 40 and the other end 672 connected to the latch handle 140. To release the stroller from the fully unfolded locked position, the latch handles 140, 150 are simultaneously rotated outward so that the inner grooves 141, 151 clear the handle tube 20. With the latch handles 140, 150 so rotated outward, the handle tube 20 may be pivoted downward relative to the front tubes 40, 45 to begin the folding procedure. The entire stroller frame may be then be folded in the sequence shown in FIGS. 10A through 10F (the folding sequence is discussed in more detail below). To reconfigure the stroller from the folded position to the open unfolded position, the handle tube 20 is pivoted relative to the front tubes 40, 45 and will move through a range of angled positions including the angled position shown in FIGS. 6A and 6B. As the handle tube 20 continues to be pivoted, it reaches the intermediate position shown in FIGS. 6C and 6D, at which point the lower edges 142 of the latch handles 140, 150 come into a sliding camming contact with a portion of the handle tube 20. This camming contact urges the latch handles 140, 150 to be rotated outwardly, against the spring biased pressure. This permits the handle tube 20 to continue to be pivoted upwards relative to the front tubes 40, 45 until the handle tube 20 and the front tubes 40, 45 are substantially parallel as shown in FIGS. 6E and 6F. At this point, the side latch handles 140, 150 are free to rotate inward so that the inner grooves 141, 151 engage and entrap the handle tube 20. (The locked position with the latches 140, 150 rotated inward is shown in FIG. 5B, 6E and 6F.) The inward biasing force on the latch handles 140, 150 that is provided by the torsional coil springs 670,680 urges the handles into this closed position. The stroller is now locked in the completely unfolded operative position until both latch handles 140, 150 are simultaneously rotated outward (the latches are shown rotated outward in FIG. 5C) against the spring pressure again to permit folding of the stroller. 5. Seat Belt Restraint Shown in FIG. 7 is a seat belt assembly constructed in accordance with the present invention. The seat belt assembly of the present invention includes a pair of waist straps 830, 835, that are permanently attached to a horizontal strip 850 located on the front section of the back rest portion 801. The forward ends of the waist straps 830, 835 are coupled to female buckle parts 840, 845 adapted to engage with adjacent male buckle parts 856, 857 located on the main buckle 855 (male buckle 857 is hidden in FIG. 7). Both waist straps 830, 835 are adjustable at the intersection of the female buckle parts 840, 845 and the corresponding waist straps 830, 835. This is to accommodate children of smaller or larger sizes. As can be readily observed from FIG. 7, both female buckle parts 840, 845 are attached to their corresponding waist straps 830, 835 via weaving the waist strap 830, 835 through three parallel openings on the female buckle part 840, 845. The end of each waist strap 830, 835 is folded over itself to prevent the waist straps 830, 835 from completely disassociating themselves from their corresponding female parts 840, 845. The third component of the seat belt arrangement consists of a center crotch strap 855 constructed to extend upwardly from the seat bottom 805 to the waist straps 830, 835. The center crotch section 855 is positioned between the legs of the child seated in the stroller. The crotch strap 855 has its remote end permanently attached to the surface of the seat 805 through stitching. This creates a permanent attachment therebetween to prevent removal of the crotch strap 855 from the stroller seat 805. As can be readily seen in FIG. 7, the male backle parts 856, 857 of the seat belt assembly are permanently attached to a center crotch section 855 of the restraining device by a stitched loop 858 of conventional strapping material which is stitched to the material comprising the center crotch section 855. Thus, the male buckle parts 856, 857 are always in position for use and always attached to the crotch strap 855. This configuration prohibits use of the waist straps 830, 835 without the center crotch strap 855 since the male buckle parts 856, 857 are permanently attached to the center crotch strap 855. The center crotch strap 855 is constructed such that the material creates an envelope surrounding the otherwise exposed male buckle parts 856, 857, said envelope decreasing in width traveling down towards the seat 805. In a preferred embodiment the envelope is stitched closed, allowing sufficient room for the male buckle parts 856, 857 and the femalebuckle parts 840, 845 to be completely covered when in the locked position. The overall appearance of the center crotch strap 855, when viewed from the front of the stroller is tapered as shown. The envelope is formed by folding a portion back on itself and stitching the top of the free end of the center crotch material 855 to its location of intersection with the remaining center crotch strap material 855. In alternative embodiments, the envelope might partially cover the male and female buckle parts or not cover them at all. As illustrated in FIG. 7, each female buckle part 840, 845 has a receptacle for receiving the free ends of the male buckle parts 856, 857 attached to the center crotch strap 855. The female buckle parts 840, 845 are adapted to receive the inwardly flexible resilient finger of their counterpart male buckle parts 856, 857. The female buckle parts 840, 845 are rectangular in nature, having an opening in the center allowing for direct access to the male parts 856, 857 by the user when the male parts 856, 857 are in the locked position, said opening being the means by which the male 856, 857 and female parts 840, 845 are uncoupled. As illustrated in FIG. 7, each male part 856, 857 has a central resilient appendage movable by the operator for coupling and uncoupling with respect to the female parts 840, 845. When inserted, the resilient finger of the male buckle parts 856, 857 cams downward towards the underside of the female parts 840, 845 due to the inclination of the male appendage with respect to the female opening. When in the locked position, the resilient finger will spring back to its original position, effectively locking the male 856, 857 and female parts 840, 845 together until the resilient finger is urged inwardly by the user so as to uncouple the seat belt. The side straps 830, 835, horizontal strip 850, male part connecting strap 858, and the center crotch section 855 are fabricated in the preferred embodiment of conventional strapping material. 6. Automatically Engaging Brake when Frame Folded Turning now to FIGS. 8A through 8C, it will be seen that the handle tube 20 and the rear tube 30 are arranged so that when the stroller frame is fully folded, a portion of the handle tube 20 contacts each of the brake members 300, 310 and forces the brake levers 300, 310 downward so that they the engage a wheel tooth to lock the respective rear wheel 260, 270. In this way, fully folding the stroller frame always locks both rear wheels. Then, the brake 300, 310 is held in the locked position by the frictional contact of the pins 301, 311 in the wheel teeth 361, 371 so that when the stroller is unfolded, the rear wheels 260, 270 are already locked and remain locked. This is advantageous, since this will prevent the stroller from rolling away immediately after it has been unfolded and also hold the stroller stable while, for example, putting a child or other objects in the stroller. Also, since the rear wheels 260, 270 are automatically locked when the stroller is fully folded, the folded stroller may be set on its rear wheels 260, 270 and rested leaning against a wall, for example, and the rear wheels will not roll out from under the bottom of the stroller. After the stroller is unfolded, the brakes 300, 310 can be easily released when desired, by manually raising both rear brake levers 300, 310. 7. Folding Sequence and Hinge Angles The folding sequence will now be described making particular reference to FIGS. 10A through 10F. Depicted in FIG. 10A is the stroller as it appears in the fully unfolded position. Note the orientations and connections of the handle tube 20, the rear support tube 30, the left and right seat tubes 50 and 60 (only tube 50 is visible), and the left and right front tubes 40 and 45 (only tube 45 is visible). To commence the folding process, the spring loaded latches 140, 150 am rotated out away from the handle tube 20 by the user (in the manner shown in FIG. 5c). As illustrated in FIG. 10B, when the latches 140, 150 are disengaged, the frame begins to fold about the intersection between the handle tube 20 and the front tubes 40, 45 located just below the location of the latches 140, 150. While the handle tube 20 rotates downward, the left and right front tube 40 are pulled upward, effectively pulling the front wheel 320 toward the rear wheels 260, 270. There is additional rotation at both the intersection of the left front tube 40 and the left seat tube 50 and at the intersection of the right front tube 45 and the right seat tube 60 (only the right seat tube 60 is visible). The left and right seat tubes 50, 60 are pulled upward and toward the rear support tube 30 at this intersection. The left and right seat tubes 50, 60 also rotate about the intersection with the rear support tube 30. The rotation is the same as that about the intersections of the front tubes and the seat tubes; upward and towards the rear. As illustrated in FIG. 10C, as the frame collapses, the front tubes 40, 45, the handle tube 20, and the seat tubes 50, 60 all continue to rotate toward the rear support tube 30 in the same fashion as described above. The ends of the front tubes 40, 45, once connected to the handle tube 20, now lie in a plane perpendicular to the horizontal. The handle tube grip 770, which was originally angled upward, is now angled downward via rotation about the front tubes 40, 45 and the rear support tube 30. As further illustrated in FIG. 10C, the reclining seat shifts its position as the rotation occurs. The reclining seat remains fixed at the handle tube 20 intersection (via screws through holes 890, 895 in the seat fabric webs 815, 820) and at the connections to the head tubes 40, 45 (via screws through leg rest flap located just above the horizontal strap 940). However, the seat bottom 805 slides along the left and right seat tubes 50, 60 during the folding process. As also illustrated in FIG.10C, the loop formed by the coupling of the seat mount straps 920, 925 around the seat tubes 50, 60 slides upward and towards the front of the stroller. The back rest portion 801 now lies on the other side of the handle tube 20, rotating about its connection with the seat portion 805. The seat portion 805 and the exposed end of the leg rest flap 810 are brought closer together throughout the folding process. The sliding loop formed by the seat mount straps 920, 925 provides an important advantage. (Of course other sliding or travelling connections might be used). Since the loop slides along the seat tubes as discussed above, the entire folding and unfolding process may be performed with the seat back in either of the reclined or upright positions--the stroller thus returns, when unfolded, to the same seat back position (reclined or upright) it had before folding. Also, a rigid non-bending seat back may be utilized and still achieve the fold described above. FIG. 10D illustrates the folding process near its most folded state. At this stage, the back rest portion 801 extends through the handle tube 20 and lies in nearly the same plane as the seat portion 805. The loop formed by the coupled seat mount straps 920, 925 has substantially traversed the seat tubes 50, 60 toward the intersection of the seat tubes 50, 60 and the front tubes 40, 45. The seat tubes 50, 60 protrude through the u-shaped space defined by the rear support tube 30. FIG. 10E illustrates the completely folded state of the stroller with its wheels attached. Note that the back rest portion 801 is bent backward in relation to the seat portion 805. The seat tubes 50, 60 are in direct contact with the rear of the back rest portion 801 and are protruding through the handle tube 20. The horizontal aspects of all of the members are nearly parallel with one another, with the exception of the bend in the front tubes 40, 45 and the fork assembly 110. As FIG. 10F illustrates, the stroller can be compressed even further by removing the wheels, which may optionally be laid flat between the rear portion of the back rest 801 and the front fork assembly 110. Note that this folding process may be accomplished whether the seat is in the upright or reclined position. As shown in FIG. 9, the handle tube 20 and the seat tube 40, which are generally parallel when the stroller is fully unfolded, are angled in two planes when the stroller is folded. This is because the fold axis on both sides is the same axis and is perpendicular to the center line of the stroller. This fold axis is therefore similar to that of a four wheeled stroller having generally parallel sides when both unfolded and folded. In such a stroller the fold axis is generally perpendicular to the axis of the longitudinal axis of the tubes. However, in the case of the preferred embodiment of the invention, the fold axis is not perpendicular to the longitudinal axis of tubes 40 and 20 as shown. The pivot mount 190 and bushing 650 are shaped to account for the difference in angles of the fold axis and the longitudinal axis of the tubes. The other fold axis of the pivot points of the stroller fold are similarly perpendicular to the center line of the stroller--not necessarily perpendicular to the various tube members themselves.

A three-wheeled collapsible stroller which can be used on terrain that is more bumpy or uneven than the smooth terrain suitable for a conventional small-wheeled stroller, but that is also more maneuverable than a conventional three-wheeled "jogging stroller." The stroller has a folding frame and automatic side latches so that it is conveniently collapsible into a compact form for transportation and storage. The stroller also had a seat back that is quickly and conveniently adjustable between reclined and upright seating positions and that remains in the same reclined or upright position when folded and unfolded. The brakes of the rear wheels are automatically set when the stroller is fully folded.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation, pursuant to 35 U.S.C. § 120, of U.S. patent application Ser. No. 10/134,815 filed on Apr. 29, 2002. BACKGROUND OF INVENTION [0002] Information Security encompasses the protection of information against unauthorized disclosure, transfer, modification, or destruction, whether accidental or intentional. Information security has become a prevalent concern of organizations as a result of the trends towards e-commerce, e-business, universal email and web access, and well-publicized security exploits. As a result, organizations are attempting to apply information security principles in a pragmatic framework. [0003] To enable organizations to apply information security principles in a pragmatic framework, a number of information standards and tools have been developed. One widely recognized standard, BS7799/ISO17799, was developed by the British Standards Institution (BSI) and adopted by the International Organization for Standardization (ISO). The BS7799/ISO17799 standard is a comprehensive set of controls that outline best mode practices in information security. The aim of BS7799/ISO17799 is to serve as a single reference point to determine the appropriate information security policy for a variety of systems and organizations. The BS7799/ISO17799 standard includes 10 sections, each addressing a specific area of information security. See, “ISO17799 Security Standard: ISO 17799 Compliance & Positioning.” [0004] The process of managing compliance with the BS7799/ISO17799 is a non-trivial task. As a result, a number of risk analysis and risk management products have been developed to help organizations comply with the BS7799/ISO17799 standard. One such product is COBRA, which was developed by C & A Systems, Inc. COBRA is used to semi-automate the assessment process. COBRA utilizes a series of online questionnaires to obtain information about the current security policy. Using the answers from the questionnaires, COBRA creates reports that provide information about the organization's current compliance position, on a pass/fail basis, with respect to each section of the BS7799/ISO17799 standard. [0005] Another tool that has been developed to enable organizations to apply information security principles in a pragmatic framework is the Systems Security Engineering Capability Maturity Model (SSE-CMM). The SSE-CMM is derived from concepts of the Software Engineering Institute (SEI) Capability Maturity Model initially created for software development. The SSE-CMM describes the essential characteristics of an organization's security engineering process that must exist to ensure good security engineering. The SSE-CMM does not prescribe a process or standard such as BS7799/ISO17799, but rather uses a model that captures practices generally observed in the industry. Additionally, the SSE-CMM is based on a maturity model that defines specific goals and practices for the entire life cycle of an organization. Further, the SSE-CMM defines an overall assessment process and roles for security engineering within an organization. See, “System Security Engineering Capability Maturity Model-Model & Appraisal Method Summary April 1999.” The resulting assessment obtained from applying the SSE-CCM is typically not associated with a reporting tool to report the maturity level. SUMMARY OF INVENTION [0006] In general, in one aspect, the invention relates to a method for assessing an information security policy and practice of an organization, comprising determining a risk associated with the information security policy and practice, collecting information about the information security policy and practice, generating a rating using a security maturity assessment matrix, the collected information, and the risk associated with the information security policy and practice, generating a list of corrective actions using the rating, executing the list of corrective actions to create a new security information policy and practice, and monitoring the new security information policy and practice. [0007] In general, in one aspect, the invention relates to an apparatus for assessing an information security policy and practice of an organization, comprising means for determining a risk associated with the information security policy and practice, means for collecting information about the information security policy and practice, means for generating a rating using a security maturity assessment matrix, the collected information, and the risk associated with the information security policy and practice, means for generating a list of corrective actions using the rating, means for executing the list of corrective actions to create a new security information policy, and means for monitoring the new security information policy. [0008] In general, in one aspect, the invention relates to a computer system for assessing an information security policy and practice of an organization, comprising a processor, a memory, an input means, and software instructions stored in the memory for enabling the computer system under control of the processor, to perform determining a risk associated with the information security policy and practice, collecting information about the information security policy and practice using the input means, generating a rating using a security maturity assessment matrix, the collected information, and the risk associated with the information security policy and practice, generating a list of corrective actions using the rating, executing the list of corrective actions to create a new security information policy and practice, and monitoring the new security information policy and practice. [0009] Other aspects and advantages of the invention will be apparent from the following description and the appended claims. BRIEF DESCRIPTION OF DRAWINGS [0010] FIG. 1 illustrates a typical computer system. [0011] FIG. 2 illustrates a flowchart detailing the Security Maturity Assessment method in accordance with one embodiment of the invention. [0012] FIG. 3 illustrates a portion of a Security Maturity Assessment Reporting Tool report in accordance with one or more embodiments of the invention. [0013] FIG. 4 illustrates a flowchart detailing the Security Maturity Assessment method in accordance with another embodiment of the invention. DETAILED DESCRIPTION [0014] Exemplary embodiments of the invention will be described with reference to the accompanying drawings. Like items are denoted by like reference numerals throughout the drawings for consistency. [0015] In the following detailed description of the invention, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid obscuring the invention. [0016] The invention relates to a method for assessing a security maturity of an organization. Further, the invention relates to assessing the security maturity of an organization using a security assessment matrix. Further, the invention relates to basing the security assessment matrix on the BS7799/ISO17799 standard and the Capability Maturity Model (CMM). Further, the invention relates to a method for providing quantitative, action-oriented results using the security assessment matrix. Further, the invention relates to a method to compare the security maturity of an organization to a pre-determined goal, or to the security maturity of the same organization at another point in time, or to the security maturity level mandated by another organization or authority. [0017] The invention may be implemented on virtually any type computer regardless of the platform being used. For example, as shown in FIG. 1 , a typical computer ( 28 ) includes a processor ( 30 ), associated memory ( 32 ), a storage device ( 34 ), and numerous other elements and functionalities typical of today's computers (not shown). The computer ( 28 ) may also include input means, such as a keyboard ( 36 ) and a mouse ( 38 ), and output means, such as a monitor ( 40 ). Those skilled in the art will appreciate that these input and output means may take other forms in an accessible environment. [0018] The Security Maturity Assessment (SMA) method involves five distinct stages: (1) management awareness and commitment, (2) security maturity assessment, (3) corrective action plan (CAP), (4) corrective action plan execution (CAPE), and (5) ongoing monitoring. Each of the aforementioned stages is explained below in greater detail. Those skilled in the art will appreciate that the names used to denote the stages may vary without detracting from the invention. [0019] FIG. 2 illustrates a flowchart detailing the SMA method in accordance with one embodiment of the invention. The SMA method is initiated by ensuring that an organization's management is aware and committed to improving the organization's information security practices and policies (Step 100 ). An assessment entity (e.g., individual/company conducting assessment) then assesses the organization's information security practices and policies (Step 102 ). Using the information gained in Step 102 , the assessment entity develops a corrective action plan (Step 104 ). The corrective action plan is subsequently executed (Step 106 ). If the organization desires continuous monitoring after the execution of the corrective action plan (Step 108 ), then the assessment entity may continuously monitor revised information security policies and practices of the organization (Step 110 ). Following the continuous monitoring, the method may return to Step 100 to ensure that the organization's management is still aware and committed, or potentially proceed directly to Step 102 if the organization's management continues to be aware and committed. If the organization desires not to have continuous monitoring after the execution of the corrective action plan (Step 108 ), then the method ends. [0020] The management awareness and commitment stage is the first stage of the SMA method and is used to raise awareness within the management of the organization being assessed and to initiate gathering of information. Specifically, in the management awareness and commitment stage, an assessment entity gathers information to understand the organization's business goals. Further, the assessment entity gathers information to understand the associated risks in terms of information security. For example, if the organization is using a wireless Local Area Network (LAN), there are different information security risks to consider than if the organization is using a conventional LAN where all computers are connected via Ethernet cable. Additionally, the assessment entity creates awareness in the organization by presenting the security maturity assessment methodology and method. In one or more embodiments of the invention, the assessment entity may also provide additional information about the underlying standards, e.g.) the ISO standard. In one or more embodiments of the invention, the assessment entity may also provide an explanation of the concept of a maturity model as it applies to the security assessment. [0021] The security maturity assessment stage is initiated by the assessment entity identifying participants required to perform the SMA. Additionally, the assessment entity, in conjunction with the organization, determines the effect and cost to be used to perform the SMA. A time line is also set to allow the assessment entity and the organization to have a means to track the progress of the SMA. At this point, in one or more embodiments of the invention, the assessment entity may request that the organization sign an assessment contract to ensure commitment by the organization to follow through with the SMA. Once the aforementioned steps have been completed, the assessment entity proceeds to perform the SMA. [0022] The assessment entity initiates the SMA by collecting documents detailing the organization's existing information security policies and practices. After review of the collected documents, additional information is typically obtained via interviews with participants identified at the beginning of this stage. Using the information obtained from the collected documents and the interviews, a preliminary rating is generated. The preliminary rating details the maturity of individual sections and the overall maturity level of the organization's information security practices and policies. [0023] In one or more embodiments of the invention, the preliminary rating is generated using a security assessment matrix (SAM). The SAM defines each level of maturity for each information security item. The SAM includes 61 rows corresponding to the groups of the BS7799/ISO17799 standard information security items, and 5 columns defining the maturity level. The five maturity levels, arranged from least mature to most mature, are Initial (Level 1), Repeatable (Level 2), Defined (Level 3), Managed (Level 4), and Optimizing (Level 5). For each intersection of row and column, there is a paragraph that defines a specific “capability maturity” level. The paragraphs contained in a given row of the SAM represent successive capability maturity levels for the same information security item. Further, some rows of the SAM represent successive capability maturity levels associated with a single information security item, as described in one paragraph of the BS7799/ISO17799 standard. Other rows of the SAM may represent successive capability maturity levels of information security items that the BS7799/ISO17799 standard describes in separate paragraphs or sections. [0024] In one or more embodiments of the invention, an item definition for each information security item is included in the SAM. The item definition acts as a legend for the level definitions for a particular information security item. Further, in one or more embodiments of the invention, the SAM includes level definitions as follows: Level 1—Initial; Level 2—Not written down, but communicated via coaching; Level 3—Written down; Level 4—Responsibility is defined; Level 5—Process exists for catching deviations and improving the information security to prevent them. Further, in one or more embodiments of the invention, the SAM includes scope requirements. The scope requirements indicate to which various aspect of an organization's operations the criteria set forth in a particular row of the SAM must be applied. [0025] The combination of a certain level definition (e.g., Level 1) with one information security item (i.e., a specific row of the SAM) yields a specific criterion that one skilled in the art can apply to establish if the organization being assessed meets, fails or exceeds this level of maturity for this information security item. Furthermore, those skilled in the art can apply the general definition of the maturity level (Level 1 through 5) to a specific information security item in such a way that they can readily determine whether the organization being assessed meets, fails or exceeds this level of maturity for this security item, even if the specific criterion set forth at the intersection of this row and column of the SAM is, for any reason, not directly applicable in the case of this organization. [0026] Table 1 illustrates the SAM in accordance with one or more embodiments of the invention: TABLE 1 Security Assessment Matrix Level 1 Level 2 Level 3 Level 5 (Initial) (Repeatable) (Defined) Level 4 (Managed) (Optimizing) Level Process exists Definitions → for catching Not written deviations and Item down, but making ISO 17799 Definitions communicated Responsibility is constant Scope Categories ↓ via coaching Written down defined improvements Requirements III.1 Information Coverage of No security Security policy Specific Security policy Clear Goal and Security Policy Security Policy policy in exists, but as a policy exists, covers all areas of responsibilities principle of Review of effective place general clearly stating business. Security and every implementation of statement. in detail what policy is owned by mechanisms in information information security Inferring what is mandated appropriate functions place to security policy is specifically or prohibited. including IT but also upgrade policy Information Review of mandated or A “normal” Finance, HR, Legal, if required sharing Information prohibited person can etc. Organization after every management Security Policy requires easily policies define the breach of and consulting understand it. roles and policy, also if responsibilities specialized Reviews responsibilities in business personnel. No carried out at following changes regular reviews. intervals, but procedures. Reviews (acquisition, no clear carried out - intervals divestiture, or management and responsibility for major changes responsibility the reviews are in process such to trigger defined explicitly in as reviews or the policy. outsourcing) exploit results occur. Availability of No security Security policy There is a Security policy Each security Staff Security Policy to policy is discussed Security communication is incident is awareness and Employees communication with employees Policy part of written IT and subject to a education Security Education to and contract or manual, Personnel post mortem Responsibilities and Technical employees temporary mentioned on procedures. Training procedure that and Training (non- personnel upon public notice and/or includes a emergency existent, or hiring. board and/or communication on review of arrangements limited to on web page. security policy occur whether Well defined IT at least once a year. applicable policy personnel). policies were Security correctly training communicated. integrated into Users are personnel taught the development incident program reporting Management procedures. responsibility to provide security training, including the specification of a clear desk and clear screen policy for all employees. Review of Security Issued once, Occasionally Reviewed at A clearly There is a defined General Process never reviewed if intervals, but designated person mechanism to management reviewed senior no clear or body has review and responsibility management, management responsibility for upgrade the auditors, etc., responsibility the process, and policy after every ask to trigger reviews it security incident reviews of regularly. (is anything exploit results missing from the policy that could have prevented the problem?) IV.1 Information Responsibility for the No responsibility Specific A matrix for A specific party is Security Individual Security Infrastructure protection of individual assets is assigned. individuals are the responsible for responsibility is a assets refer to aware of their responsibility defining and required field in the responsibility of protection maintaining the the asset organization's to protect some of assets responsibility management physical assets. The list exists and is matrix for the process, so rows assets (e.g., of assigned published. protection of in the matrix are computers, responsibilities individual assets. created when new printers, is not Successive assets are media, etc.) documented. versions of the acquired. Assets matrix are without a archived to help in responsible party future is immediately investigations. flagged for corrective action. Security in job No formally Specific Responsibility A specific party is Job descriptions Interpretation definition and defined individuals are for security responsible for and personnel is based on resourcing process. aware of their decision developing job screening SSO/IRT responsibility. making has responsibilities, arrangements are type position. been assigned personnel periodically and screening and reviewed to documented. confidentiality conform to the agreements. changing security needs of the business. Also personnel are required to sign and agree to confidentiality agreements. Information security No formally Key members Training for A specific party is Security education and defined of personnel personnel is responsible for curriculum is training training plan are trained on defined and defining the periodically an ad-hoc performed training plan reviewed to basis. periodically. developing conform to the training schedules changing needs for all personnel of the business. Training records are reviewed against policy and exceptions lead to training program updates. Approval process No approval Informal, A clear A specific party is The approval for the acquisition process undocumented approval responsible for process is and installation of exists. knowledge of process is defining and periodically IT facilities. steps to be defined for maintaining the reviewed to followed when the approval process conform to the acquiring or acquisition for IT facility changing needs installing IT and acquisition and of the business. facilities exists. installation of installation. The approval IT facilities process for each and published acquisition and across the installation of IT enterprise. facilities is reviewed for accuracy and corrective action is taken where appropriate. IV.2 Security of Security Control of No control Physical access The access Third-party access The access logs Third Party Third Party Access mechanism control allows control rules is linked to the rest and the list of Access to Information ad hoc are of the authorized third Processing Facilities decisions by IT documented. organization's parties is staff, who have There is a security system regularly audited been told formal through the and changes to informally contract with issuance of access procedures is what to do. each party tokens, and made when the that requires accesses are need arises. access. logged. IV.3 Outsourcing Security Controls None; IT, Security, The There is a registry Procedures are Critical for External contractors Legal, or procedures for of contractors. reviewed on at applications Contractors are handled Purchasing contractor They sign the least an annual stay in house by task apply some security are security policy, basis for possible Approval of owner regular steps documented NODE and IP improvements. business without when a in writing and agreements. owners. specific contract is personnel and Audits are run at Implications policies or issued. These managers least quarterly to for business procedures. steps are not have access to make sure the list continuity specifically them and are of contractors is plans. documented. aware of their current. The Security contents. owner of the standards and process is defined. compliance Security incident procedures. V.1 Accountability Coverage of Asset No inventory Manual Inventory Schedule, triggers, There is a process Information for Assets Inventory inventory, performed roles and to review what Asset Maintenance occasional, on according to responsibly, are happened after Inventory demand. written defined. each inventory. Software procedures, Ownership is clear Inventories are Asset but schedule and known incremental, not Inventory and triggering throughout the IT from scratch Physical events are not organization and every time. Asset Asset well defined. management. inventories are Inventory Typically not automated. Services automated. Inventory Ease of Alteration Information There is There is a There are control There is a Printed of Information assets can be informal documented mechanisms (e.g., mechanism in Reports Assets altered knowledge that change access controls) to place to review Screen without classified procedure that prevent alteration the effectiveness Displays control documents applies to all without proper of the change Magnetic cannot be classified authorization. control process Media altered at will, information and detect the Electronic but no assets. No need for Messages systematic systematic improvements. File Transfers procedures. control mechanisms in place. Coverage of No Covers some There is an Information Information Information Information procedures in information Information handling handling training Asset Handling place for assets. Little Handling procedures are is part of written Inventory Procedures handling formality. No manual, owned by IT and Personnel Software information. regular mentioned on appropriate procedures. Asset reviews. the public functions including Processes in Inventory Applied by few web page, and IT but also place to report Physical business units. covering Finance, HR, and learn from Asset essentially all Legal, etc. cases when Inventory types of assets Organization information has Services and all policies define the been handled Inventory business roles and incorrectly. Printed units. responsibilities in Reports following Screen procedures. Displays Magnetic Media Electronic Messages File Transfers (“Handling” = copying, storage, electronic transmission, spoken transmission, destruction) V.2 Information Classification of No Ad hoc Information Ownership of the Security Printed Classification Information Assets classification classification, asset classification is classification is Reports Labeling of at document classification clearly defined as reviewed Engineering Information Assets owner's is published part of company periodically. List files (photos, initiative. and “pushed” procedures and is of documents microfiche, Most to all potential known of with highest etc.) documents not document management. classification is Screen marked. If owners. It reviewed Displays marked, labels covers periodically. Magnetic are security. Declassification Media inconsistent. Classified procedures exist. Electronic No systematic information is Messages awareness labeled, File Transfers campaign. consistently. VI.1 Security in Job Screening of Incomplete Screening of Documented and A specific party is Procedures are Applicant Definition and new or a lack of applicants is published responsible for reviewed regularly refers to all Resourcing applicants. screening of performed procedures for defining and for improvements employees Complete applicants. informally, is applicant maintaining the and compliance. (contractor, checking of Contractor not documented, screening exist screening procedure. Security issues found permanent, the new hiring are and is not and are used by Results of the to be related to or part time) applicant's not vetted performed the organization. screening are failings in the CV. through HR. consistently. captured in the screening procedure Screening of applicant's HR file. mandate immediate contractor review and update of and the procedure. temporary staff VI.2 User Training Security Little Discussed with Documented in Roles and Audits of the security awareness of awareness of employees and writing and made responsibilities to acknowledgments are personnel corporate contract or available to all maintain and performed. A system security. temporary staff. Employees communicate the of re- personnel upon receive a copy of security policy are acknowledgment hiring. security policy on defined. occurs periodically hiring and are Acknowledgement and upon changes to required to of the policy is the security policy. acknowledge tracked and stored Incidents are receipt. as part of the HR analyzed for policy of the performance employee. improvement to the security awareness procedures. Security No education Security Security A specific party is Training plans are education or training is education and education is responsible for periodically reviewed and technical provided. technical documented and defining and to conform to the training training are not included as part maintaining the changing needs of the provided of the hiring security education business. Training consistently and process. and technical records are reviewed the Technical training program. against policy and responsibility is training roadmaps Training records are exceptions lead to at the discretion exist for each captured in the corrective actions. of management. employee. employee's file. Review and planning for future training is part of the appraisal process. VI.3 Responding to Disciplinary None Managers have The definition of The documented After each incident Security Process for documented. intuitive violations, process includes that causes the Incidents and Company Reaction is awareness of investigation roles and procedure to be Malfunctions Security ad hoc. need, can quote process, and list responsibilities for invoked, the process Violation multiple levels of applicable each step, and a is reviewed and, of penalty, penalties is clear workflow. when applicable, the including but not documented, process is revised limited to firing. distributed, (including the Managers and signed by the training or the HR appropriate penalty clauses). independently parties, and agree on how to personnel has initiate and been educated as conduct to the content. disciplinary actions. VII.1 Secure Areas Protection The IT Access control is List of secure All access to secure Auditing of access from equipment is provided on an perimeters and IT areas is control system logs is unauthorized left ad hoc basis access rights to performed by a done periodically. access. unattended typically by IT those areas are mechanism (e.g., Changes in facilities Physical with no manager. No documented and badge access control and management entry control controls defined list of published. system) that allows trigger a review and to office, beyond access rights is for personal revision of the access room. physical published or identification and procedures. Physical building managed. auditing. Access security for access. control is managed IT facilities. centrally for granting and revoking rights and is linked to hiring and termination policies. VII.2 Equipment Fire alarm The fire Procedures for The fire alarm Reaction to actual Security system in not alarm system the fire alarm system is tested. alarms is reviewed present. exists and system are Procedures exist and improvements people have visible and for evaluation of implemented into been posted, the fire alarm the current system informally including system including and alternative made aware evacuation path, damage systems reviewed of the behavioral assessment and where necessary. system. actions, Halon recovery, warnings, etc. evacuation headcount, etc. Personal No policies Policies for There is a A specific party is The personal workstation for personal personal documented responsible for workstation policy is policy workstations workstations policy for defining and regularly reviewed to exist. exist but are not personal maintaining the ensure it conforms to published or workstations and personal the changing needs of adopted fully steps are taken to workstation the business. Personal across the spread its policy. workstation needs are organization. awareness among Sensitive reviewed and changes employees. information is are made where protected by necessary. Audits are means of carried out to ensure encryption. that the organization maintains a recognized workstation policy to ensure efficient management. Protection There are no There is an There is a formal A specific party is The safety threat policy from procedures informal safety documented responsible for is regularly reviewed to environmental in place to threat protection policy in place. It defining and ensure it conforms with threats and protect from policy in place. details all the maintaining the the changing needs of hazards. safety threats This is not steps that need to safety threat the business. The Protection or hazards. enforced be followed to control guidelines. policy is regularly from human throughout the protect from reviewed and changes carelessness organization and potential hazards. are made where (eating, the details of the necessary to ensure smoking, policy are not continued compliance. drinking). documented. Protection from power and communication cabling from interception or damage. VII.3 General Controls Inspection of Incoming There is no There is a A responsible The key goods incoming goods are formal process documented party is identified screening process is goods for not to inspect process whereby to manage the regularly reviewed to hazards inspected. incoming goods. all incoming processes and ensure they conform to It is carried out goods are procedures for the changing needs of in an adhoc inspected per a inspecting the business. Goods manner. defined plan. incoming goods screening needs are for safety reviewed and changes compliance. are made where necessary. The organization maintains historical files of incoming goods; these are regularly reviewed to ensure that there are no discrepancies. Process of There is no An informal A formal process An inventory of Audits of the removal of standardized process exists is documented organizational organization's property organization's procedure for property and published the property is are carried out property for removal removal. to organization maintained and periodically and of property. for property updated regularly. changes to the removal removal. A group or process are made individual is where necessary. identified to verify that the process is followed. Equipment There are no Equipment Equipment is A responsible Record of equipment maintenance equipment maintenance is covered by party is identified maintenance is maintenance carried out on an insurance and the to oversee examined to determine policies and ad hoc basis equipment equipment fault patterns or abuses. the based on maintenance maintenance Appropriate changes equipment manufacturer controls the policies are are incorporated into maintenance recommended determination of followed. the maintenance is done only service intervals risk. policies. on failure. Sensitive Data Data disposal Data disposal A responsible The disposal procedure data disposal disposal procedure is procedure is party is identified is audited regularly and procedure procedure is informally formally defined to oversee that the appropriate steps not defined. defined. and published to disposal procedure incorporated into the the organization. is followed. procedure. VIII.1 Operational Management None - each Common Documented in Roles and Procedures include a Reporting Procedures and Responsibilities incident is awareness of writing and made responsibilities are mechanism to evolve procedures Responsibilities and handled ad procedures. available to all IT defined. them. Incidents are cover: Procedures hoc on a best Effort for staff (and other Escalation and analyzed to suggest All types of Incident effort basis. repeatability department staff reporting chains improvements. There security Reporting includes staff with IT roles) exist. Issues and is a quality incident Procedures meetings, requests are improvement process, Contingency training recorded as documented and plans sessions, trouble tickets. applied. Audit trails coaching and similar Recover actions and authority VIII.2 System Planning Testing of None; new Testing is A formal The responsibility Policy is Includes issues and Acceptance new systems are informal and is document to define, review, periodically of capacity information placed in performed based defining the and ensure reviewed and planning and systems operation on individuals' testing and compliance with revised upon any Systems requirements without any knowledge, not deployment of the testing policy change in the Acceptance. and upgrades formal test on a formal new and is defined. There production systems Issues to be prior to procedure. process. upgraded systems are system level or organizational considered deployment is defined. tools that prevent structure. Testing include: unauthorized methodology and Performance changes to tools are and Computer production continuously Capacity systems. examined to Requirements Documents exist determine Error Recovery detailing applicability to the and Restart interfaces into the organization and Procedures change then introduced. Security management Controls/Issues process. Manual Processes Business Continuity Arrangements Additional Load on existing machines Training in the operation of the new equipment VIII.3 Protection Detection and No IT staff has A formal, A specific party is The procedure Procedures Against protection detection, informally documented responsible for includes a cover: Malicious against protection defined procedure for defining and mechanism for All types of Software malicious measures, procedures for detecting and maintaining the evolution. Incidents virus and software. reporting, detecting and handling detection and are analyzed to malicious User or recovery handling malicious protection suggest software awareness of procedures malicious software and procedures, improvements. The incident procedures to exist, and software and virus attacks informing and toolset is Contingency deal with dealing virus attacks. exists and is training the users, continuously plans malicious with There are no communicated to managing the examined and Audit trails and software malicious common tools, all employees as detection and updated to provide similar Procedures software formal part of the recovery efforts, maximum protection Recover actions for reporting and virus documentation, corporate security and selecting and against changing and authority and recovery attacks is or training policy. A maintaining the treats. from virus entirely programs for all standard set of protective tools. attacks reactive employees. protective tools is and defined and handled in deployed. an ad hoc Training is given manner. to all employees. Policy No policy Software A software A specific party is List of authorized relating to or monitoring licensing policy responsible for software is licensed monitoring policies are is documented monitoring and periodically software and exists informal and and published to maintaining reviewed to conform prohibition of regarding performed on an all employees. authorized to the changing unauthorized software ad hoc basis. The software licenses needs of the software installation. IT organization, for the enterprise. business. Software when involved in A software audits are reviewed software inventory and exceptions lead procurement, licensing tool is to corrective actions. applies controls used to monitor informally. and ensure compliance. VIII.4 Housekeeping Monitoring of No Informal Capacity plan and Ownership of the New technology, processing monitoring monitoring as capacity capacity plan and contractual power and exists. part of system management capacity agreements, and storage to Capacity management process covering management supplier selection ensure adjustments procedures processing process is defined. are continuously availability are performed on an power, memory, Formal researched and performed as needed basis. disc space, mechanism for introduced into the in reaction No management LAN/WAN business managers environment in to capacity plan or capacity, backup to place order to provide the problems. model is capacity, number requirements into necessary resources specifically of user the plan and a link while optimizing the defined. workstations, exists between the costs. physical space capacity planning and power. process and the budgeting process. VIII.5 Network Covered by other Management questions in this section VIII.6 Media Handling Procedures No IT staff has Formal, A specific party is Procedures are Media includes: and Security and controls procedures informally documented responsible for periodically IT computer to protect or controls defined procedures for defining and reviewed to address room media computer are in place procedures and protecting maintaining the changes in the type (e.g., backup media to protect controls for computer media procedures for the or volume of tapes, computer protecting exist and are access control computer media to removable hard media. computer media. communicated to systems and be handled. Audit drives, CD- There is no all employees as auditing of access logs are reviewed ROMs, etc.) formal part of the to computer and exceptions lead User media documentation, corporate security media. to corrective action. (e.g., CD- access logs, or policy. Controls ROMs, floppy training programs are in place to discs, etc.) for all employees. limit and track access to media. Training is given to all employees. VIII.7 Exchanges of Security of No defined No corporate A corporate A specific party is The standards are Standards for Information and exchange of procedures standard or policy standard for the responsible for periodically secure Software data and to secure exists addressing security exchange defining and reviewed to address exchange of software with the securing the of data and maintaining the changes to the data data and other exchange exchange of data software with standards for the being exchanged or software with organizations. of data or and software with other secure exchange the means of 3rd parties and software. other organizations is of data and exchanging. The outsourcing organizations. documented and software. An information vendors. published to all information classification policy Information employees. classification continually evolves. classification policy determines policy what can be and how it is transmitted. IX.1 Business Documentation No An informal, An access policy A specific party is The access policy Access rights Requirements of business awareness undocumented statement responsible for statement is encompasses for Access requirements or practice access control defining access defining and periodically accounts for Control for access of access practice is rights of each maintaining the reviewed to conform network, control. control. applied on an ad user or group of access policy to the changing operating Access policy hoc basis. users exists and is statement and needs of the system, and statement published. ensuring it is in business. Security application defining the alignment with incidents are access. access right of business reviewed and ACLs, user and each user or requirements. modifications to the system group of users. access policy accounts, etc. Protection of statement are made Automatic connected where appropriate. identification of services from terminals and unauthorized portable use. devices. Review of user Timeout of access right remote systems and left unattended capabilities for extended Policy periods of time concerning the use of network and network services. Network controls in place IX.2 User Access System of No An informal, A user account A specific party is The user account Deletion vs. Management formal control undocumented policy defining responsible for policy is disabling registration/de- over user account access rights, defining and periodically accounts. registration for access to practice is privilege levels, maintaining the reviewed to conform Unique id for access to IT IT applied on an ad and user account to the changing all users. services. services. hoc basis. creation/deletion policy. User needs of the Immediate rules exists and is account business. Audit account published. creation/deletion requirements are removal for records are reviewed and users who archived. modifications to the change duties user account policy or leave the are made where company. appropriate. User's Multiple accounts privilege in per individual are overriding created or deleted system/application through a single restriction. point of control. Record kept of all privileges allocated. System routine to grant privilege to users. Access control to program source library IX.3 User Security of user Passwords An informal, A published A specific party The password policy is Limit the number Responsibilities password. User are not undocumented password is responsible periodically reviewed of password password used. password policy defines for defining and to conform to the attempt before confidentiality practice is password maintaining the changing needs of the the system locks level applied on an strength (e.g., password policy. business. Periodic out the user. ad hoc basis. length, Record of audits (cracking) of Record and make inclusion of password passwords are user aware of special histories is performed to ensure unsuccessful characters), archived. compliance and logon attempts aging, and exceptions are noted, Enforcement of usage. documented, and password rules corrective action is taken. Good-practice No An informal, A good-practice A specific party A process exists to No display of guidelines to guidelines undocumented guidelines is responsible solicit suggestions for system identifiers users in exist. guidelines is statement is for defining and best-practice guidelines until logon has ensuring good provided to defined and maintaining the from internal and been successful security. users on an ad incorporated good-practice external sources and to General notice hoc basis. into user guidelines. incorporate them into warning that the training the organization's user system should programs. security guidelines. only be used by authorized users If error occurs at logon do not indicate what the error was Cryptographic No An informal, A good-practice A specific party A process exists to Controls guidelines undocumented guidelines is responsible solicit suggestions for exist. guidelines is statement is for defining and best-practice guidelines provided to defined and maintaining the from internal and users on an ad incorporated good-practice external sources and to hoc basis. into user guidelines. incorporate them into training the organization's user programs. The security guidelines. guidelines cover: encryption, digital signatures, key management, non-repudiation services IX.4 Network Covered in other area in this Access Control section IX.5 Operating Covered in other area in this System Access section Control IX.6 Application Covered in other area in this Access Control section IX.7 Monitoring Covered in other area in this System Access section and Use IX.8 Mobile Mobile No An informal, A good-practice A specific party A process exists to Laptop, Mobile, Computing and Computing and guidelines undocumented guidelines is responsible solicit suggestions for and Palmtop Teleworking Teleworking exist. guidelines is statement is for defining and best-practice guidelines security to ensure provided to defined and maintaining the from internal and company users on an ad incorporated good-practice external sources and to information is not hoc basis. into user guidelines. incorporate them into compromised. training the organization's user programs. security guidelines. X.1 Security Risk There is no An informal A published A specific party The risk assessment Requirements assessment and framework undocumented risk assessment is responsible and risk management of Systems risk of risk risk and risk for defining and policies are management assessment. assessment management maintaining the periodically reviewed used for and risk procedure risk assessment to conform to the analyzing management exists. and risk changing needs of the security practice is management business. Changes are requirement applied on an guidelines. made to the policy ad-hoc basis. An archive is where required. kept of the risks identified and the action taken to manage the risk. Safety check No safety An informal There is a A specific party The safety checks are while procuring checks are procedure documented is responsible regularly reviewed to new program carried out exists whereby procedure that for defining and ensure that they and software when new programs is followed maintaining the conform to the procuring and software before any software safety changing needs of the new are assessed software is check business. There is a software. before being purchased. guidelines. regular risk analysis is put in to the This ensures Modifications to carried out to ensure operational that all software vendor supplied safety of existing environment. purchased packages are systems and This task in conforms to made to comply compromise to their performed on company with system security is controlled. an ad-hoc security requirements Emphasis is given on basis. guidelines. and vendor quality certification of consent is new products. obtained before doing so. X.2 Security in Validation There is no An informal There is a A specific party The validation control Application control while validation process exists published is responsible procedure is regularly Systems data input to of where data is standard which for defining and reviewed to ensure that application information both verified describes the maintaining the they conform to the system on before it is validation tests validation changing needs of the Data validation application entered in to that are control business. Periodic of stored systems. applications performed. guidelines. audits are performed of information and existing There is a data on application Output Data data is documented systems to ensure Validation verified. Basic process which compliance. tests like is followed. Exceptions are noted, missing or documented and incomplete corrective action is data, invalid taken. characters in fields are performed on an ad-hoc basis. X.3 Cryptographic Cryptographic There are There is an There is a A specific party The cryptographic Controls control no informal documented is responsible controls are regularly cryptographic practice procedure for defining and reviewed to ensure that controls employed which defines maintaining the they conform to the or existing whereby some the steps which cryptography changing needs of the system files are outlines which control business. Audits are architecture encrypted. document guidelines. carried regularly to does not This is done at classifications Separate key ensure that information support the user need to be management that should be cryptography. discretion and encrypted and procedures are encrypted is kept on an ad-hoc the process to used for digital encrypted and that the basis. be followed to signatures and encryption method achieve this. encryption. used is adequate. Vulnerabilities There are There is a There is a A specific party The key management of no key process in documented is responsible system is regularly cryptographic management place where by key for defining and reviewed to ensure keys. procedures. suitable key management maintaining the they conform to the Key management system which key management changing needs of the management exists, based defines the system. business. Key system. upon an steps to be Separate key management needs are Documentation informal set of followed. This management reviewed and changes of key standards, ensures that the procedures are are made where management procedures and type of used for digital necessary. Audits are system secure algorithm and signatures and carried out to ensure (activation & methods. length of keys encryption. that the organization de-activation are considered Cryptographic maintains a recognized date, certificate to identify level keys have certification authority information) of defined to ensure key cryptographic activation and protection and efficient protection deactivation key management. dates. All keys are protected against modification and destruction in case of private key compromise. X.4 Security of Protection and No change An informal There is a A specific party The change control System Files control of control procedure documented is responsible policy is regularly system test procedure exists for standard for defining and reviewed to ensure data. in place and change available to maintaining the that it conforms to Change control no control. This employs change control the changing needs procedure provisions task is describing the guidelines. of the business. Control of for the performed on procedures to Version control Version control operational protection an ad-hoc follow to ensure for software logs are audited and software of system basis. that the change update is any exceptions are test data. control maintained and documented, noted procedures are archives are kept and corrective followed of all versions. action is taken if correctly necessary. X.5 Security in Awareness of There is no An informal There is a A specific party The software The new software is Development software process in procedure documented is responsible update policy is put in a test and Support upgrade to place to exists to standard for defining and regularly reviewed environment to check Processes enhance the monitor monitor available to maintaining the to ensure that it for anomalies with security level security risk vendor web employees software update conforms to the security policies posed by sites to obtain describing the guidelines. An changing needs of before software software procedures to archive is kept the business. implementation installed on updates. This follow to ensure of all software Periodic audits are machines. task is that all software upgrades. performed of Software performed on installed on Change control software upgrades upgrade an ad-hoc their machines procedures and to ensure does not basis. is of the latest contractual compliance. take into Security issues version. agreements exist Exceptions are account the defined by the All security to escalate noted, documented security of vendors are issues with the security issues to and corrective the new only new release appropriate action is taken if releases considered. specific to levels and necessary. organizational remedy them. system platform are identified and confirmed with the vendor. XI.1 Aspects of Contents of No plan. There is some There is a Employees are Includes process Risk analysis of critical Business Business knowledge of written and trained, and for improvement business processes. Continuity Continuity what to do in properly training is after each Identifies events that Management Process case of disaster distributed plan. periodically invocation. can cause interruptions Procedures and (e.g., based on Process refreshed. to business processes, Schedules training or on includes: Plan includes and includes assessment Included in the prior -Fallback alternate of the impact of those Process experience) procedures communication interruptions. but no -Resumption methods if documented procedures communication process. -Maintenance is severely schedules affected. Process also includes: -Assignment of responsibilities -Conditions for activation Development of Plan does A set of There is a The The process is Business continuity Business not exist. measures can written business management reviewed in case process covers events Continuity Some be applied in continuity chain of change in that are specific to the Process awareness case of a process that responsible for system, staff, local environment (i.e., Testing of of measures business includes risks, executing the disaster recovery flood, power outage, Business that can be interruption. events, roles business contractor or political unrest, fire, Continuity taken in They do not and continuity contract, hurricane, earthquakes, Process case of a constitute responsibilities, process is business, etc.) and business needs Review and business formal, technical define, and all application, (i.e., credit card center Update of interruption. defined, measures, managers and locations, or cannot be down more Continuity Actions published, or reporting, and staff know what legislation. than a few minutes) Process would occur managed plan. communication. the chain is. Post-mortem Reasons that in an ad hoc The plan has Testing occurs at reviews after Cause Review manner. been tested at least annually execution with of the Plan least once. and maintains documented the business improvement continuity actions. process. XII.1 Compliance Restrictions in No Ad hoc Systematic Clear Periodic review Copyright policy with Legal Place on the restrictions restriction on restrictions, responsibility to of the policy for Acquisition procedures Requirements Use of in place. some documented, enforce the continuing Copyright awareness Materials for documents based on the restrictions. improvement. information Which There only. information Training is Periodic review Maintenance of licenses May Be classification provided. of the Check on software Intellectual Employees are restrictions to held/used Property Rights aware. make sure Policy on software they're disposal appropriate. Compliance with licenses Safeguards No Some Clear Safeguards in Periodic review Personnel information against loss, safeguards organizational responsibilities place covering of systems in Copyright information destruction or employed. data backed up to ensure that all place and Company confidential falsification of No defined and secured. organization organizational security of information organizational hierarchy as Backups may records are not records. systems that deal Public web sites records to whom be kept onsite. compromised. Training with has access No logs kept Some user provided to organizational to what of user activity is educate users. records. Each information. activity. logged. Management incident is Organizational responsibly to subject to a post data is kept ensure that mortem securely. records are kept procedure that Documents are accurate and includes a publicly secure. Access review of available that rights and whether describe the privileges in applicable policy and place to restrict policies were procedures that access to certain correctly employees organizational communicated. should follow records. Web Users are taught to maintain sites protected the incident integrity and from reporting safety of defacement. procedures. Full organizational Critical files audit logs records. identified and maintained with protected against system falsification by start/finish CRC checks, times, system etc. errors and corrective action and name of person making alterations to the information. Compliance Knowledge Data Legislation is Processes and There is a with data of protection applied and procedures are regular process protection legislation legislation is Data protection put in to place in place to legislation is limited to discussed with legislation is for monitoring review changes specific employees and made available to ensure that the in legislation, or people or contract or to employees in company is new needs of the departments temporary a centralized continually business. (HR, Legal, personnel location. compliant. The Training is etc.) and is upon hiring Impact of responsibility to provided to not into specific legislation and do so is clearly users to ensure documented. departments. concerned data assigned. the continued has been compliance with written up and legislation. The made available process and to employees. responsibility to All affected receive, processes investigate and include correct any appropriate reported protection exception is steps. defined. Compliance of No Standards and Standards and A clearly There is a regular Intellectual Property information published codes of codes of designated process in place to Rights systems with codes of practice are practice are person or body review changes in Copyright published practice and generally defined and has published standards Data Protection Act standards or no understood but published responsibility for or codes of codes of awareness are applied internally and the reviewing, practice. Findings practice inconsistently are made maintaining, and of non-compliance through the available to training users on result in corrective organization. employees in a the published action. centralized standards or location. codes of practice. XII.2 Reviews of Documentation No Some Documents are Responsibilities Documents are Laws on protection Security Policy of regulatory documentation documentation made publicly are assigned to created as soon as and/or correction of and Technical and contractual exists. exists although available on the individuals to there is a change in personal information Compliance requirements it does not corporate web produce the contractual or (employees and/or for each cover all site or on a documents as regulatory clients, suppliers, information details of public notice soon as a new requirements of the etc.) system regulatory/contractual board. Full system is project. Procedures for requirements documentation sourced. Documentation is disclosure to proper for each IS. exists for Templates exist available to authorities. There is no contractual and for the creation personnel with ISO 9000 standard regulatory of documents correct clearance. requirements document requirements and there is a Periodic inventory Regulatory agencies template used, for all central of information (e.g., FDA or FCC in documents are information repository where systems includes the United States) created as and systems in the they are stored. checks that when required organization. The templates compliance by individual have designated requirements exist. employees. owners. Exceptions trigger There is no a well-defined central data process to review store for the procedures in order documents to eliminate this (need to ask risk. people who know). XII.3 System Audit Control Against No controls Terms of use Terms of use of The Periodic reviews of Considerations Computer or of computer organizations responsibility of who is authorized Misuse safeguards equipment are computer managers is to do what. Safeguard of in place discussed with equipment are defined. Tools Information Audit Tools to employees and available from a employed to gathered from Prevent Misuse contract or centralized monitor usage of monitoring tools is temporary location computer used to make personnel (Intranet site, equipment. decisions for future upon hiring. office notice Staff has well policy. boards, etc) defined roles There is an incident and access rights review procedure. to computer file Periodic “white systems. hat” intrusion Personnel are attempts are made made aware that and followed by their computer corrective actions. related activities are being monitored, and to what extent. Review/Audit No process Occasionally Reviewed at A clearly There is a defined of information is in place reviewed or intervals, but no designated mechanism to systems to audited if clear person or body review and upgrade ensure they are senior management has the policy after in compliance management, responsibility to responsibility for every security with security auditors, etc., trigger reviews the process, and incident (Is policies and ask of exploit reviews it anything missing standards results regularly. from the policy that could have prevented the problem?) Coverage of No Few Clear Audit tools are Safeguards in place System Regime coverage safeguards in responsibilities only available covering all audit (event logging) exists. place. Audit to ensure that for use by key tools. Periodic tools are not audit tools are personnel. review of systems managed not misused. Access rights in place and securely and Training and privileges security of systems user access is provided to are enforced to that audit systems. not monitored. educate users. maintain Users are educated security. on the importance of safeguarding their audit tools. Compliance of No Standards and Standards and A clearly There is a regular Intellectual Property information published codes of codes of designated process in place to Rights systems with codes of practice are practice are person or body review changes in Copyright published practice and generally defined and has published standards Data Protection Act standards or no understood but published responsibility for or codes of codes of awareness are applied internally and the reviewing, practice. Findings practice inconsistently are made maintaining, and of non-compliance through the available to training users on result in corrective organization. employees in a the published action. centralized standards or location. codes of practice. [0027] Referring to the Security Assesment Matrix shown in Table 1, to perform the assessment for a given item, the assessment entity need only perform the following steps: (i) find the item in question, first by category then by sub-category; (ii) read the descriptions under each maturity level and determine if requirements of that maturity level are met; and (iii) record the highest maturity level for that item that is met by the organization's current information security policies and practices. [0028] Once the preliminary rating has been completed, it may be displayed in a graphical manner. In one embodiment of the invention, the preliminary rating is displayed using a Security Maturity Assessment Reporting Tool (SMART). SMART allows the preliminary rating to be shown at a detailed level, i.e., all 61 elements are shown, or at a summary level, i.e., only 10 broad categories are shown. Further, SMART allows the organization to compare the preliminary rating to a predefined goal, an industry average, or to a prior assessment. Additionally, the layout of the SMART report allows an organization to readily identify areas that require improvement. [0029] FIG. 3 illustrates a portion of a SMART report in accordance with one or more embodiments of the invention. A first column ( 10 ) lists the broad categories. A second column ( 12 ) lists the items within each of the categories. A third column ( 14 ) graphically represents the “assessed capability maturity” (ACM) ( 16 ). The third column is sub-divided into five levels (L 1 , L 2 , L 3 , L 4 , and L 5 ) corresponding to the maturity levels listed above. For each item, the ACM is represented by shading the corresponding row up to the appropriate level. If the ACM is not at a goal ( 18 ), i.e., the level at which the organization wishes to be for the particular item, then an additional shading representing a gap ( 20 ) between the goal ( 18 ) and the ACM ( 16 ) is present. [0030] For example, in FIG. 3 , Category 2 contains four items: Item D ( 2 ), Item E ( 4 ), Item F ( 6 ), and Item G ( 8 ). Specifically, looking at item G ( 8 ), the ACM ( 16 ) is at a level 2 ( 22 ), while the goal ( 18 ) is at level 3 ( 24 ). Thus, a gap ( 20 ) is present between level 2 ( 22 ) and level 3 ( 24 ) on the row containing Item G ( 8 ). Thus, the organization can readily see that Item G ( 8 ) is below the goal ( 18 ). By contract, the organization can also readily see that capabilty maturity level for Item F ( 6 ) is at the goal ( 26 ) set for this item, so there is no gap relative to Item F ( 6 ). [0031] Returning back to the SMA phase, once the preliminary rating has been completed, the assessment entity reviews the preliminary rating with the organization. During the review, the preliminary rating may be revised, if neccessary. Once this has been completed, a final rating is generated. [0032] During the corrective action plan (CAP) phase, the CAP is generated using the final rating and the Security Assessment Matrix. The proposed actions are aimed at improving the items that have gaps and bringing the items up to the goal. Additionally, items in the CAP may also be prioritized according to the needs and resources of the organization. During the corrective action plan execution phase, the CAP is executed. For example, if the SAM states that for a certain item to be at Level 3, “the policy is written down,” and to be at Level 4, “there is an assigned manager in charge of applying this policy,” then it follows that if an organization is assessed at Level 3 for this item, and its goal is to be at Level 4, then the CAP should include the following action: “Put a manager in charge of this policy.” [0033] The monitoring phase of the SMA includes periodic SMART reports to ensure that goals are met and maintained. Further, during this phase, the assessment entity may detect change in the environment that might require additions or changes to the security practices and/or policies. Additionally, during the monitoring phase, the assessment entity may provide assistance for debriefing the organization in the event of an information security incident. In one or more embodiments of the invention, the monitoring phase is optional. [0034] FIG. 4 illustrates a flowchart detailing the SMA method in accordance with another embodiment of the invention. Initially, the organization's business goals are determined (Step 112 ), as well as the associated risk in terms of information security (Step 114 ). Written documentation is then collected about the organization's existing information security policies and practices (Step 116 ). Additional information is then collected via interviews (Step 118 ). Using the information gathered in Steps 112 through 118 , the SAM rating is generated (Step 120 ). If additional information is obtained (Step 122 ), then step 120 may be repeated. If no additional information is obtained (Step 122 ), then a list of corrective actions is proposed. (Step 124 ). The corrective actions are subsequently prioritized (Step 126 ) and executed (Step 128 ) to generate modified information security policies and procedures. The modified information security policies and procedures are them monitored (Step 130 ). If there is a change in the information security environment, e.g., a first organization merges with a second organization resulting in the first organization's network being integrated into the second organization's network, or if the time for a periodic review arrives (Step 132 ), then the process proceeds back to Step 116 . [0035] The invention, in one ore more embodiments, may have one or more of the following advantages. The SMA method is a systematic approach that includes a process, a detailed method for assessment (i.e., SAM), and a reporting tool (i.e., SMART). Further, the SMA method covers all aspects of information security and explicitly defined what each level means for each item. Further, the SMA method is action oriented. Further, each item is assessed as a capability maturity rather than pass/fail, allowing an organization to readily gauge where the organization is with respect to a particular information security item and to measure progress over time or against a goal, even if that progress is gradual. Additionally, the security assessment matrix may be used as a list of recommendations to detail how the organization may attain its information security goals. [0036] Further, the SMA method is easy to apply, as each item and corresponding set of criteria for each maturity level associated with the item are clearly defined. Further, the SMA method is flexible, as it may be used for multiple purposes. For example, the SMA may be used for the purpose of establishing to a customer or regulatory authority that an organization has the required capabilty to perform a certain task. The SMA may also be used for the purpose of internally monitoring, over time, improvements decided by the organization's management. The SMA may also be used for the purpose of meeting a certain industry standard or reaching a goal established through analysis of the competition's security capabilities. [0037] Further, the invention produces an objective rating of an organization's information security practices and policies removing the subjective element of the assessment process. [0038] While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.

In general, the invention relates to a method for assessing an information security policy and practice of an organization. The method includes collecting information about the information security policy and practice of the organization, generating a rating for each of a plurality of information security items using a security maturity assessment matrix and the collected information, and generating a graphical assessment of the ratings. The security maturity assessment matrix includes a first dimension and a second dimension, where the first dimension corresponds to the information security items and the second dimension corresponds to maturity levels. Further, each rating is derived using the first dimension and the second dimension.

FIELD OF THE INVENTION [0001] The invention relates generally to power-driven conveyors and, more particularly, to belt conveyors advancing on steep inclines to elevate articles, especially tires. BACKGROUND OF THE INVENTION [0002] In a tire manufacturing plant, tires molded in rows of tires presses are deposited on a trench conveyor and transported to an inspection, balance, or trim station. Because trench conveyors are typically positioned below the presses at a relatively low elevation, incline conveyors are used to elevate the tires received from the trench conveyor to the level of the presses or higher for transport to subsequent finishing stations. Belt conveyors, such as modular plastic belt conveyors with high-friction conveying-surface characteristics, work well on shallow inclines. On steeper inclines, however, belts with conveying surfaces textured with inverted cones or other non-skid protrusions work well when new. As the protrusions wear, tires begin to slide down the conveying surface as the belt advances up a steep incline. Rubber-topped belts are not so susceptible to wear, but the slippery mold-release material used to ease ejection of the tires from the presses coats the rubber conveying surface of the belt, which then loses its effectiveness as a high-friction surface. Consequently, incline angles are limited to a maximum of about 25° off horizontal. Such shallow inclines have a large footprint, taking up valuable floor space. Even if tires could be prevented from sliding along the conveying surface on steep inclines, there must be provisions to prevent tires from falling away from the belt. A wall or other static structure in sliding contact with high-friction articles, such as tires, being lifted on the incline may damage the articles and will increase the load, requiring an oversized belt and drive system. [0003] In tire warehouses or stores and service stations stocking large numbers of tires, the tires are usually stacked to great heights. Further, the tires may be stacked on shelves or second levels and thus begin to be stacked at heights over 6 feet. Conveyors may be used to elevate the tires to the level of the tire storage or higher for transport to additional floors. Traditional conveyors use friction or protrusions to prevent the tires from sliding down the inclined conveyor or from falling off of the side of the conveyor belt. However, friction and protrusions are not fail-safe methods and tires often fall off of the conveyor causing harm to people and property located near the conveyor. [0004] The tire distribution process often includes transporting large quantities of tires from the plants where they are manufactured to the various facilities where tires are delivered to consumers and/or mounted on vehicles. The processes for transporting tires from these plants to wholesalers, retailers, and service centers typically involve the use of large vessels. For example, semi-trailers are used for transportation over the road, rail cars are used for transportation via rail, and shipping containers are used for transportation over water. Further, these vessels often provide storage of tires prior to and after transport. [0005] To minimize the costs associated with such storage and transportation, it is desirable to pack tires into each storage and/or transportation vessel in such a manner as to maximize the density of tires within the vessel, while providing satisfactory stability of the loaded tires and avoiding permanent deformation of the loaded tires. Maintenance of tires under a compressive load has been found to improve the stability of the loaded tires. However, compression may lead to permanent deformation of tires in some stacking configurations. [0006] Additionally, to minimize the costs associated with storing the tires once they arrive at their destination (e.g., facilities where tires are delivered to consumers and/or mounted on vehicles such as warehouses and car repair shops), it is desirable to pack tires into the storage location in such a manner as to maximize the density of tires within the storage location, while providing satisfactory stability of the stored tires to prevent injury and save space and avoiding permanent deformation of the stored tires, which may be stored for months or even years. [0007] When the storage and/or transportation within the vessel is complete, tires are typically manually unloaded from the vessel onto a conveyor or pallet. A variety of implements exist for such handling of tires. For example, U.S. Pat. No. 3,822,526, issued to Black in 1974 and incorporated herein in its entirety, discloses a device for manipulating tires. However, a device does not exist that sufficiently eliminates the difficulties of manually stacking tires in a storage and/or transportation vessel, and unloading the compressed tires from the same vessel. Moreover, no sufficient device currently exists to eliminate the reliance on the vessel to maintain a compressive load on tires. Although loaders for tires exist, for example, a machine loader and a loader to create a straight stack of tires, the existing loaders are not designed to stack tires in a herringbone pattern. Further still, the current practice is to rest tires directly against the wall and floor of the trailer or boxcar. As a result, the weight of the stacks is unevenly distributed causing further compression and strain on tires. Thus, a lower-compression system for cradling tires during storage and shipping is desired. [0008] Belt conveyors for tires have been produced to transport tires up to various heights. See U.S. Pat. Pub. No. 2008/0053796 to DePaso et al. (“DePaso”). The entire disclosure of DePaso is incorporated by reference in its entirety. [0009] Thus, there is a need for an elevating conveyor capable of transporting articles, especially tires and solar panels, up steep inclines. Additionally, there is a need for an elevating conveyor capable of transporting large tires, such as tractor trailer tires and tractor tires, and solar panels. SUMMARY OF THE INVENTION [0010] Certain embodiments of the present invention relate to a conveyor embodying features that address these needs. [0011] Although many of the embodiments are focused on conveyors for tires, the invention may be used in any application where articles are conveyed to different locations. For example, some embodiments are directed to a conveyor for tires while other embodiments are directed to conveyors for solar panels, boxes, wheels, large spools, large rings, rubber components, etc. Further, some embodiments are directed to a conveyor for traditional car and/or SUV tires while other embodiments are directed to a conveyor for tractor trailer (i.e., eighteen-wheelers, semi trucks, semi trailers, or semis) tires, tractor tires, and/or farm machinery tires. Typically, the size and shape of the tire changes depending upon the use of the tire. For example, tires for small cars and/or light trucks may range from about 24″ to about 32″ in diameter. Tires for a large trucks and/or semi trailers may range from about 32″ to about 48″ in diameter. Tires for tractors or other farm machinery may range from about 32″ to about 74″ in diameter. [0012] One aspect of the present invention is to provide a conveyor to move tires or articles up to different heights. The height and angle of the conveyor may be adjustable in some embodiments. [0013] On a conventional tire inspection line, tires brought on a conveyor or like equipment may be stopped at a midway point where information may be read from the barcode affixed to the tires. This is done to identify the type and size of the tires being inspected and sort them into the tires to be sent to the next process and elsewhere. Therefore, one aspect of the present invention is to provide a tire sorting apparatus capable of reliably reading information from a tire identifier, such as a barcode, formed on the surface of a tire without damaging the tire. [0014] It is also an aspect of the present invention to provide a conveyor system comprising a conveyor belt, support elements to support the articles being conveyed, a support frame for the belt and to raise the conveyor belt upward, and a power source. The conveyor belt may include sections secured together, one or more pieces of belt material, strengthening mechanisms either below or between the one or more pieces of belt material to support the support elements, an upper surface, and an under surface. The power source may comprise electrical components and a motor. Note that the terms “cleat” and “support element” can be used interchangeably herein. [0015] In some embodiments, the conveyor may be specially designed to move passenger car and light truck tires upwardly at incline angles up to 60 degrees. In other embodiments, the conveyor may be specially designed to move semi truck and tractor tires upwardly at incline angles up to 60 degrees. [0016] In various embodiments, the features of the conveyor include: a 18″ wide 2 ply rubber covered top belt sliding flat at 58 FPM, one or more 4″ high urethane cleats bolted to the belt on approximately 60″ centers, a curved cleat pattern to fit tire contour, one up/stop/down switch at the bottom end, a 1 hp 115V 13 FLA electric motor with speed reducer mounted under bottom end, a thermal overload motor protector, a rubber lagged conveyor belt drive pulley, a plain idler pulley with belt tensioner, a high strength steel tubing truss conveyor frame, and a base plate. In additional embodiments, the conveyor may include: an off switch at the top end, a portable stand with casters to hold the top end at a fixed height, a portable stand with casters with a hand-winch adjustable top end height, up/emergency and stop/down switches at both ends of the conveyor with UL listing, a 24″ wide belt for tractor trailer size tires, a 6″ high single cleat for vertical tire lift installation, straight cleats for handling boxes, bags, and general merchandise, and a smooth or rough top belt for shallow inclines. In some embodiments, the width of the belt is larger than 24″ and in other embodiments the width of the belt is less than 24″. [0017] Advantages of a conveyor of one embodiment of the present invention include: specially designed to move tractor trailer tires up the conveyor at incline angles up to 55 degrees, available 10 feet long and longer in 1 foot increments, 24″ wide, 2 ply rubber covered top belt sliding flat at 58 FPM, 6″ high urethane cleats bolted to the belt on approximately 60″ centers, a curved cleat pattern to fit tire contour, one up/stop/down switch at the bottom end, a 1½ hp 115V 18 FLA electric motor with speed reducer mounted under bottom end, a thermal overload motor protector, all electrical prewired, a rubber lagged conveyor belt drive pulley, a plain idler pulley with belt tensioner, a high strength steel tubing truss conveyor frame, and a base plate. To select the conveyor size, take the floor-to-floor vertical distance and add the overhang desired, usually 2-3 feet. This sum equals the Total Vertical Distance (TVD). Use the table below as a guide for the conveyor length required. In some embodiments, the maximum recommended incline of operation is 60 degrees. [0000] Floor to Floor Total Conveyor required Vertical length Vertical Recommended Distance at a 55 Distance Overhang (TVD) degree incline  8 ft. + 2 ft. = 10 ft. high 12 ft. long conveyor 10 ft. + 2 ft. = 12 ft. high 15 ft. long conveyor 12 ft. + 2 ft. = 14 ft. high 17 ft. long conveyor 14 ft. + 2 ft. = 16 ft. high 20 ft. long conveyor [0018] In various embodiments, the cleats may be attached, secured, or interconnected to the belt using a set of two bolts. Further, the bolts may be ¼″×1¼″ #1 elevator bolts with hardware. The cleats may also include holes for the bolts or other interconnection mechanisms. [0019] In some embodiments, the cleats may flip up when going up the conveyor and flip down when going down the back of the conveyor. In one embodiment, the cleats may be hinged to the belt such that they can flip up and down. Other flip mechanisms may also be contemplated by one skilled in the art. In some embodiments, the cleats are permanently attached to the belt. In other embodiments, the cleats are removable. In one embodiment, the cleats are attached without the use of screws. [0020] In some embodiments, the cleats may be flexible. Thus, each cleat may be constructed entirely from an elastomeric material that provides flexibility. In one embodiment, the cleat or support element is flexible along the length of cleat such that when a tire or article is positioned on the conveyor belt, the two cleats bend in a direction opposite the direction of belt travel along the conveying path. In other embodiments they may be rigid. [0021] In various embodiments, the cleats or tire support elements have a unique shape to hold tires on a conveyor belt. Thus, the first and second tire support elements each has a front section having an tire-supporting face that has a first curve that is curved along the tire support element's length and toward the direction of belt travel. The tire support element also has a back section with a second curve that is curved along its length and in the direction of belt travel. The second curve is typically greater than the first curve. Additionally, each of tire engaging support elements has a flat conveyor contacting surface that engages the outer tire-conveying surface of the conveyor belt. The support element may also have a top surface that is positioned at an angle relative to the flat conveyor contacting surface. [0022] In various embodiments, the system may comprise one or more motors, which may be changed out to use motors having different power capabilities. In further embodiments, the motor(s) may be detachable and removable. [0023] In some embodiments, the conveyor is foldable for storage flat on the ground or flat against a wall. In other embodiments, the conveyor may be foldable and stored in the location of use. Therefore, when a user needs to use the conveyer, he or she just has to pull the conveyor down. The pull-down and storage motion may be similar to a Murphy bed in some embodiments. Further, the conveyor may be pulled down from a specific rack or other storage area. [0024] In various embodiments, the conveyor may have rubber feet to help it stick to the ground/floor. The feet may be made of materials other that rubber in alternate embodiments. Thus, the bottom of the conveyor may contact the floor in one or more places depending on the embodiment. In other embodiments, the conveyor may be positioned on a rail such that the conveyor can slide along the rail to different storage areas. Thus, in an embodiment, the conveyor moves along the rails in a similar manner as library ladders. One skilled in the art can image a rail system similar to the rail systems described herein. [0025] In various embodiments, the conveyor may include an endless conveyor belt looped around rotating drive elements, such as sprockets, drums, or pulleys, which advance the conveyor belt in a direction of belt travel along a conveying path. The endless conveyor belt may have an outer, article-conveying surface and an inner, drive surface engaged by the drive elements. On a steeply inclined elevating portion of the conveying path, the articles are conveyed vertically or at a steep angle. The articles are maintained in position and blocked from sliding down the outer surface of the conveyor belt on the steeply inclined portion of the conveying path by support elements or cleats that extend outwardly from the outer surface. The support elements are periodically spaced along the length of the conveyor belt to form individual bins for the articles. A steep incline for a given conveyor belt may be defined as a conveying path that is so steep that typical vibrations, jolts, or surges cause conveyed articles supported on support elements to fall from the conveyor belt advancing along the incline. In various embodiments, the conveyor may be inclined up to an angle of 60 degrees relative to the horizontal plane. [0026] In some embodiments, once the articles are conveyed up the incline, they may be transferred to an outfeed conveyor for transport to downstream finishing stations or other storage sections. Further details of exemplary slide-preventing cleats or pair of cleats may extend outwardly from the outer, article-conveying surface of the conveyor belt. In an embodiment, the cleats may be integrally formed with the belts. In another embodiment, the cleats may be secured to a threaded insert in the belt by a bolt or the like through a bore formed in a block of the cleat. [0027] In some embodiments, the cleats are secured to the conveyor belt. In other embodiments, the cleats are secured to a metal drive belt provided under the conveyor belt. Thus, the conveyor belt may have apertures in the belt such that the cleats can extend upwardly from the drive belt and above the conveyor belt. In alternative embodiments, the cleats are secured to a metal (or other material) support within the conveyor belt (i.e., between two layers of the conveyor belt). The cleats may be secured or interconnected to a belt or other part of the conveyor through the use of screws, pins, rivets, bolts, nails, glue, adhesive, sewing, clamps, bonding, welding, or any other mechanism now known or later conceived. [0028] In various embodiments, the cleats are various sizes and shapes depending on the tire or article to be conveyed. In one embodiment, the conveyor belt may include support elements or cleats of many different sizes. The cleats may fold up in order to support an article to convey or may fold down such that it does not inhibit or interfere with the articles being conveyed. Thus, in this embodiment, the cleats that are of a size not currently being utilized are folded down such that they are substantially flat against or within the belt. In other embodiments, the cleats that are of a size not currently being utilized may be folded into the center of the conveyor belt such that they do not interfere with the articles being conveyed. [0029] In various embodiments, the conveyor belt may be a modular plastic conveyor belt constructed of a series of individual belt modules made of a thermoplastic polymer, such as polypropylene, polyethylene, acetal, or a composite material, in an injection molding process. A threaded metallic insert may be inserted into the module during or after molding to serve as an attachment point for a support element. The details of one such insert and its use are described in U.S. Pat. No. 6,926,134, “Plastic Conveyor Belt Module with Embedded Fasteners,” which is incorporated by reference herein in its entirety. Of course, other methods may be used to fasten the support elements to the conveyor belt. [0030] In some embodiments, the conveyor belt sections comprising cleats may be interconnected to one another and to other similar belt sections without cleats in a side-by-side orientation and end-to-end by hinge rods through hinge eyes to form an endless conveyor belt. [0031] In one embodiment, the system may comprise two cleats that are spaced apart laterally across the width of the conveyor belt. The cleats may have article-supporting faces defining planes oblique to the direction of belt travel and intersecting at a point on the belt below or behind the cleats on the steep incline. The two cleats provide two points of support for round articles, such as tires, and the space between them allows debris or fluids to drop from the tire and off of the belt. [0032] In one embodiment, the belt is replaced with rollers or a roller array. The rollers provide a low-friction, rolling restraining surface that is especially useful with high-friction articles, such as tires. Further, the conveyor belt described as a plastic conveyor belt may be a flat belt or a flat-top chain in other embodiments. Another embodiment of an elevating belt conveyor embodying features of the present invention may include a roller array to prevent conveyed articles from falling off the belt. [0033] One skilled in the art will appreciate that the conveyor and its features may vary depending upon the combination of elements in various embodiments. In some embodiments, the cleats have a rounded shape such that the curve of the cleat matches the curve of the tire being conveyed or transported. Thus, the curve of the cleat is slightly larger than the curve of the tire so that the tire will sit in and fit into the cleat. In still other embodiments, the cleat may have a different shape. For example, the cleat may not be curved. Rather, the cleat may be flat like a wall or tile. The cleat may also be shaped like a post or rod. Still further, the cleat may be V-shaped or U-shaped and only one cleat may be used to support each tire or conveyed article. [0034] In some embodiments, the cleat may only come up to the midpoint of the side of the tire. In other embodiments the height of the cleat is greater than the height of the tire lying on its side, i.e., the width of the tire. In still further embodiments, the height of the cleat is somewhere between the midpoint of tire's side height and the top of the tire's side when the tire is lying on its side. [0035] In various embodiments, one cleat per tire or conveyed article may be used. In other embodiments, two cleats per tire or conveyed article may be used. In other embodiments, 3 or more cleats per tire or conveyed article may be used. Additionally, in some embodiments one cleat may be used for one tire or conveyed article and two or more cleats may be used for another tire or article. Thus, the number of cleats could change throughout the conveyor. [0036] In still more embodiments, the position of the cleats may be varied depending upon the shape and size of the tire or article conveyed. For example, the cleats may be spaced further apart and positioned at less of an angle relative to horizontal if the radius of the tire is large, whereas the cleats may be positioned closer together and at a greater angle relative to horizontal if the radius of the tire is small. [0037] Although the invention has been described with application to tires, the invention also finds application to transporting other articles. For example, boxes, solar panels, windows, construction equipment, car or automobile components, tractor components, pallets of products, etc. may be transported on the conveyors. [0038] In some embodiments, the conveyor may be configured with a conveyor belt, roller bars, and/or any other mechanism for moving tires. The conveyor may be configured to be located at any height above a platform to facilitate access by a worker. In one embodiment, the conveyor may be configured about three feet above the platform. The conveyor may be configured to automatically move tires in one or more directions. For example, in one embodiment, the conveyor may be configured to move tires from a placement station to any desired location, such as, for example, a tire loading system, a tire unloading system, a forklift, a railcar, and/or a tire rack. In another embodiment, the conveyor may be configured to move tires to/from a location such as, for example, a tire unloading system, a forklift, a railcar, a tire rack, a tire storage location or the like to/from the placement station for manual loading of tires into racks or storage areas in the tire load station. [0039] In some embodiments of the conveyor system, humans may load articles or tires onto the conveyor (typically the bottom of the conveyor) and unload articles or tires off of the conveyor (typically the top of the conveyor) as a part of the system. In various embodiments, one or more persons load the tires and a different one or more persons unload the tires or articles. In alternate embodiments, machines or robots may load and unload the articles and tires. In additional embodiments a combination of humans, robots, and machines may be used to load and unload the articles or tires. [0040] Lean manufacturing principles may be applied throughout embodiments of the invention to facilitate efficiency in tire loading, unloading, and/or storage. For example, in one embodiment, value stream mapping is used to analyze logistics data provided by a company to create Pareto analysis to identify high volume, high turn-over tire SKUs (i.e., stock control units). A manufacturing plant analysis is implemented to determine the capacity and production rate of a given customer to determine the size, capacity, number, and/or breadth of tire loading, unloading and/or storage needed to fulfill capacity and production goals. For example, for higher customer inventory levels, fully-automated loading, unloading and/or storage systems may be desired. However, for lower inventory levels, customers may use partially-automated loaders, unloaders, and/or storage systems to maximize efficiency and lower overall costs. [0041] In yet other embodiments, the systems and methods of the present invention are facilitated by one or more human and/or computerized operators. For example, an operator monitors robot loaders and/or unloaders, monitors system settings and/or identifies racks that require replacement or repair. Operators also drive forklifts, load/unload tires, and/or the like to facilitate overall system usage. [0042] One aspect of embodiments of the present invention is to provide a system capable of handling all sizes of vehicle tires, providing maximum compression of tires, and minimizing the manual labor required for loading, unloading, stacking, and/or storing the articles or tires. [0043] In some embodiments of the system, tires are ricked or stacked in a herringbone pattern to facilitate compression and/or space management. The system and method also includes the stacking of tires in any other suitable arrangement that would allow the transport rack to perform similar functions. Moreover, the system and method may include any variation or angle of herringbone patterns that would allow the transport rack to perform similar functions as disclosed herein. [0044] As one with ordinary skill in the art appreciates, the proper alignment of tires in the herringbone pattern depends upon the geometry of tires being stacked. Thus, the system contemplates and accommodates incorporation of an automated system for control of the loader system. The control system automatically senses tire geometry based on sensors located at an upstream position on the conveyor, or alternatively, accommodates the manual input of information. In both cases, however, the control system uses information that is indicative of tire geometry, such as outside diameter, inside diameter, and/or tread width, to determine the rotation and translation of each tire to produce the desired stacking pattern. With respect to herringbone stacking patterns, the relevant output variables may include the angle of deviation from vertical associated therewith the axis of rotation of tires in successive rows as well as the number of tires in each row and the number of rows in each stack. Furthermore, the control system may determine the appropriate amount of compression to apply to the stacked load, and the corresponding number of rows in the stack, to avoid permanent deformation of tires. The control system may consider a variety of factors in determining the appropriate compressive loads to apply. In one embodiment, these factors include the material properties and/or hardness of tires (usually rubber), tire geometry and stacked orientation, and the time and temperature environment to which compressed tires will be subjected. In addition, empirical data and experience may be incorporated to optimize the control of the system. [0045] As used herein, warehouse racks include any type of rack that is distinct, including for example, pallets, racks such as those manufactured by Ohio Rack, Inc., or the like. [0046] In some embodiments, the conveyor system may comprise one or more scanners to facilitate identifying each tire or article. For example, in one embodiment, the system comprises two scanners configured on both sides of a two-lane conveyor. The scanners may be configured both above and below the conveyor and/or articles to facilitate reading the articles' labels/SKUs. In alternate embodiments, the scanner may be a barcode scanner, a radio-frequency scanner, optical scanners, vision systems and/or any other type of scanner for reading and/or identifying tire or article labels and/or SKUs. The scanner may be configured with a CPU and/or any other computing system or unit. The scanner may also be configured to communicate with the rack loading system, conveyor, and/or any other part of the system or any other system described herein. Alternatively, RFID tags and readers may be used with the system. [0047] In one embodiment, each tire on a conveyor and/or a warehouse storage area is the same type, size, and/or SKU number, or may be designated for the same destination or storage area. Tires may be delivered to storage areas and/or a warehouse rack on a conveyor. In additional or alternative embodiments, articles and tires may be delivered to storage areas and/or a warehouse rack on two or more conveyors. Further, the tire or article may be scanned and identified then loaded on to the appropriate conveyor for storage in the appropriate area. Thus, one type of tire may be loaded onto one conveyor to be stored in a first area and a different type of tire or article may be loaded onto a second conveyor to be stored in a second area that is different from the first area. [0048] In some embodiments, the conveyor system and the rack loading system may also be configured to stack tires or articles based upon identification information received from the scanner. For example, in one embodiment, the rack loading system may be configured to receive tire identification information from the scanner and to use the tire identification information to determine what tire stacking configuration to use. That is, for smaller diameter tires, the rack loading system may stack tires in layers of five tires, for example. For larger diameter tires, the rack loading system may stack tires in layers of four tires, for example. [0049] In various embodiments, the one or more conveyors may elevate the tires to a stop position in front of one or more position pick-and-place loaders. The pick-and-place loaders may each comprise a support-mounted actuator system, each of which controls an extendable/retractable arm that is adapted to seize the tire or article from the conveyor. [0050] In some embodiments, the system is configured to sort and queue tires horizontally. For example, the system comprises one or more tire transportation devices, such as, access conveyors that connect to one or more sub-conveyors. In an embodiment, an access conveyor may move the tires from the main unloading conveyor to various sub-conveyors. The sub-conveyors, in turn, may move tires to/from towers. Some conveyors may be configured to be computer-controlled devices to facilitate sorting, queuing and/or routing of the tires. In one embodiment, the tires are loaded randomly and scanners are used to sort, queue and/or route the tires when they are unloaded from towers. [0051] In another embodiment, some conveyors may be configured with one or more scanners to obtain tire identifying information to facilitate sorting and queuing the tires. The scanners may be configured like scanners and communicate with the conveyors to facilitate directing each SKU of tire to a different sub-conveyor for loading into a particular tower. Each tower is configured to hold between 10 and 30 tires of a single SKU. [0052] In one embodiment, a queuing system may comprise an inbound queue of tires or articles that have been unloaded from a trailer, railcar, forklift and/or other transportation mechanism. For example, a number of tires or articles are queued on each side of the queuing system. [0053] In various embodiments, the system may also be configured with a control panel to facilitate worker operation of the conveyor. For example, the worker may use a panel to raise or lower the conveyor in order to facilitate access to tires, storage areas, and racks. In another embodiment, a load station may be configured with one or more scanners or cameras to detect the height of rack, storage floor, storage area, tires, and the conveyors and raise or lower the conveyor based on whether the height of the racks, tires, storage floor, storage area, or conveyor meets a predetermined height. [0054] The scanner computing unit or any other computing unit used or described herein may be connected with each other via a data communication network. The network may be a public network and assumed to be insecure and open to eavesdroppers. In the illustrated implementation, the network is embodied as the Internet. In this context, the computers may or may not be connected to the Internet at all times. For example, the customer computer may employ a modem to occasionally connect to the Internet, whereas the bank computing center might maintain a permanent connection to the Internet. Specific information related to the protocols, standards, and application software utilized in connection with the Internet may not be discussed herein. For further information regarding such details, see, for example, Dilip Naik, “Internet Standards and Protocols” (1998); “Java 2 Complete,” various authors (Sybex 1999); Deborah Ray and Eric Ray, “Hosting HTML 4.0” (1997); Loshin, “TCP/IP Clearly Explained” (1997). All of these texts are incorporated by reference herein in their entireties. [0055] It may be appreciated that many applications of the present invention may be formulated. One skilled in the art may appreciate that a network may include any system for exchanging data or transacting business, such as the Internet, an intranet, an extranet, DSL, WAN, LAN, Ethernet, satellite communications, and/or the like. It is noted that the network may be implemented as other types of networks, such as an interactive television (ITV) network. The users may interact with the system via any input device such as a keyboard, mouse, kiosk, smart phone, e-reader, tablet, laptop, Ultrabook™, personal digital assistant, handheld computer (e.g., Palm Pilot®), cellular phone, or the like. Similarly, embodiments of the invention could be used in conjunction with any type of personal computer, network computer, workstation, minicomputer, mainframe, smart phone, etc. Moreover, although the invention is frequently described herein as being implemented with TCP/IP communications protocols, it may be readily understood that the invention may also be implemented using IPX, Appletalk, IP-6, NetBIOS, OSI or any number of existing or future protocols. Moreover, the present invention contemplates the use, sale or distribution of any goods, services or information over any network having similar functionality described herein. [0056] In accordance with various embodiments of the invention, the Internet Information Server, Microsoft Transaction Server, and Microsoft SQL Server, may be used in conjunction with the Microsoft operating system, Microsoft NT web server software, a Microsoft SQL database system, and a Microsoft Commerce Server. Additionally, components such as Access or SQL Server, Oracle, Sybase, Informix MySQL, Interbase, etc., may be used to provide an ADO-compliant database management system. The term “webpage” as it is used herein is not meant to limit the type of documents and applications that might be used to interact with the user. For example, a typical website might include, in addition to standard HTML documents, various forms, Java applets, Javascript, active server pages (ASP), common gateway interface scripts (CGI), extensible markup language (XML), dynamic HTML, cascading style sheets (CSS), helper applications, plug-ins, and/or the like. [0057] A system user may interact with the system via any input device such as, a keypad, keyboard, mouse, kiosk, smart phone, e-reader, tablet, laptop, Ultrabook™, personal digital assistant, handheld computer (e.g., Palm Pilot®, Blackberry®, iPhone®, iPad®, Android®), cellular phone, or the like. Similarly, the invention could be used in conjunction with any type of personal computer, network computer, work station, minicomputer, mainframe, smart phone, tablet, or the like running any operating system such as any version of Windows, MacOS, iOS, OS/2, BeOS, Linux, UNIX, Solaris, MVS, tablet operating system, smart phone operating system, or the like, including any future operating system or similar system. [0058] In one embodiment of the present invention, a tire sorting apparatus that includes a mounting means for mounting a tire in a plane perpendicular to the center axis of the tire, a tire grip means for gripping the inner periphery of the tire and positioning the center axis of the tire, an identifier reading means for reading a tire identification marking formed on the surface of the tire, and a holding means for holding the identifier reading means. The tire grip means may further include three grip arms arranged at the vertexes of a triangle within a plane perpendicular to the center axis of the tire and extending in a direction parallel to the center axis of the tire and an arm opening and closing mechanism for opening the three grip arms concentrically around the circle circumscribing the triangle. The holding means may further include a holding unit for holding the identifier reading means and a rotation drive unit for rotating the holding means around a rotating axis parallel to the center axis of the tire. And the center of the circumscribing circle is aligned with the rotating axis of the holding unit. [0059] Some embodiments of the system of the present invention may further include a tire inside diameter detecting means for detecting a tire inside diameter from positional data or travel distance data of the three grip arms when the grip arms are gripping a tire. This allows not only acquisition of information from a tire identifier of a tire but also accurate measurement of the inside diameter of the tire. Hence, the possibility of rechecking the information on the tire identifier may further improve the accuracy of tire sorting. [0060] Some embodiments of the system of the present invention may include a rotation radius changing means for changing the distance between the identifier reading means and the rotation axis of the holding unit and a detecting position control means for controlling the rotation radius changing means in such a manner as to move the identifier reading means to the position of the tire identifier based on the data of the tire inside diameter detected by the tire inside diameter detecting means. Thus, the rotation radius of the identifier reading means may be changed according to the tire size. Therefore, information may be read from the tire identifier even when there is a change in tire size. [0061] Additional embodiments of the system of the present invention may provide a tire sorting apparatus that has a mounting means having a plurality of rotating bodies rotating in contact with the lower surface of the tire and a through hole through which the three grip arms may be extended toward the inner periphery of the tire. [0062] In some embodiments of the system, devices to help in the compression of the tire stacks may be included. Some tire stacking systems, however, continue to rely heavily upon manual labor to accomplish the stacking of tires. For example, U.S. Pat. No. 5,697,294 issued to Keller et al. on Dec. 16, 1997, (“Keller I”) discloses an exemplary tire compression device and U.S. Pat. No. 5,816,142 issued to Keller et al. on Oct. 6, 1998, (“Keller II”) discloses another tire compression device intended for use with a forklift. Both Keller I and Keller II are incorporated by reference herein in their entireties. The Keller I and Keller II devices allow a preset load to compress a stack of tires as the stack is loaded into a truck trailer. Initially, the forklift elevates and supports the preset load. Then, once tires are stacked beneath the elevated load, the forklift allows the load to be lowered against a stack of tires. As a result, the load exerts a downward pressure on the stack of tires, thereby compressing the tires. Once the initial stack is compressed, additional uncompressed tires are loaded on top of the stack until the stack reaches the ceiling of the truck trailer. Then, the forks of the forklift are raised, partially releasing the pressure applied against the compressed portion of the stack and allowing it to expand, while compressing the previously uncompressed portion until the entire stack is equally compressed. This process is repeated, stack by stack, until the entire trailer is full of stacked, compressed tires. Other devices exist that load tires into a truck trailer and similarly compress tires within the trailer. In each of these cases, tires are maintained in compression by the storage and/or transportation vessel itself. However, no assurance exists that the vessel was designed or is suitable to maintain such loads. In fact, vessels are frequently damaged as a result of such use. [0063] Various embodiments of the present invention include an apparatus for loading a tire onto a rack. The apparatus includes an automated tire conveyor, one or more scanners, and one or more robots to pick the tires off of the conveyor. The system may additionally include an apparatus for unloading a rack of tires, which includes a load station configured with a lift. The lift raises a rack of tires to a platform, where an unloader may manually or automatically move tires from the rack to a conveyor. [0064] Further, some embodiments of the present invention include methods and systems for sorting and unloading tires into a store or warehouse for storage and sale as well. For example, the systems for sorting and unloading tires may include one or more automated conveyors, scanners, and storage structures. For example, in the sorting system, the scanner may read information off of incoming tires and communicate the tire information to a system of conveyors, which in turn directs each tire to a specific storage structure based upon the tire information (e.g., size, type, etc.). [0065] In various embodiments, drive-in storage may also be included in the conveyor system configured with one or more computing systems, such as those described herein, to communicate with other loading or unloading systems of the system disclosed herein. For example, an unloading system within the system disclosed herein may communicate with drive-in storage when a first rack, which is being unloaded, is all or partially-empty such that a second rack may be delivered from the drive-in storage to the unloader. In another embodiment, an unloader or loader communicates with the drive-in storage when daily customer orders show that there is additional demand for a specific tire SKU (i.e., stock control unit). The rack may then be pulled from the drive-in-storage using, for example, a pull system applying lean manufacturing principles. [0066] In some embodiments, the conveyor system may also include a system for loading, sorting, or unloading tires. The system may be automated or computer controlled. The system may be used in a plant that manufactures tires, and sorts and stores tires coming off the assembly line, and then dispenses tires in a desired order for shipment. Further, the system may also be used for loading and unloading articles or tires at a final destination, such as a tire shop or warehouse, where tires may be stored. [0067] One aspect of the invention is a method for conveying articles up steep inclines. In one embodiment, the method for conveying articles up steep inclines comprises: (a) conveying articles on the conveying surface of an endless conveyor belt along a steep incline in a direction of belt travel; (b) blocking conveyed articles from sliding down the conveying surface of the conveyor belt on the steep incline; and (c) restraining conveyed articles leaning away from the conveying surface with a restraining surface moving in the direction of belt travel to prevent the leaning articles from falling away from the conveying surface of the conveyor belt on the steep incline. [0068] The present invention includes a method of packing tires that includes placing one or more rows of tires against a bottom frame, adding an intermediate frame on top of the one or more rows of tires, compressing the tires, and attaching a vertical member to the intermediate frame. The method additionally includes adding one or more additional rows of tires on top of the intermediate frame, adding a top frame, compressing the one or more additional rows of tires, and attaching a vertical member to the top frame. [0069] By way of providing additional background, context, and to further satisfy the written description requirements of 35 U.S.C. §112, the following references are incorporated by reference in their entireties for the express purpose of explaining the nature of conveyors and to further describe the various tools, pieces, and other apparatuses commonly associated therewith: [0070] U.S. Pat. Pub. No. 2012/0325903 to Takahashi describes a tire sorting apparatus for reliably reading information from a tire identifier, such as a barcode, formed on the surface of a tire without damaging the tire. Placed under a tire-mounting table is a tire grip that has three grip arms arranged circularly in a plane perpendicular to the tire center axis and link mechanisms for spreading the grip arms. Placed above the mounting table is a barcode reader rotating means for rotating a barcode reader held by a barcode reader holder. The rotation axis of the barcode reader is aligned with the center of the circle formed by the grip arms of the tire grip. [0071] U.S. Pat. Pub. No. 2009/0148260 to Leimbach et al., which is incorporated herein by reference in its entirety, discloses a tire loading apparatus and method of packing tires that includes placing the tires in a rack, compressing the tires, and assembling the rack. The apparatus includes one or more conveyors, scanners, and robots that load tires from a conveyor to a rack. A tire unloading apparatus is also disclosed. The unloading apparatus includes a scissor mechanism to rise and lower tire racks to an unloading platform. The unloading apparatus additionally includes one or more unloaders and conveyors. The sorting and unloading of tires is accomplished with one or more automated conveyors, scanners, and storage structures for reading information from incoming tires and using the tire information to sort and store the tires. A rack to improve compression and support of tires during storage and shipment is also disclosed. [0072] U.S. Pat. No. 6,527,499, issued to Leimbach, et al. on Mar. 4, 2003, (“Leimbach”) discloses an example of a tire loading system. The unloading system and method described herein may include features or steps (which may be in any order) described in Leimbach, which is incorporated by reference in its entirety. [0073] U.S. Pat. Pub. No. 2010/0043952 to Terasono discloses bead core and a bead filler and is incorporated by reference in its entirety. [0074] U.S. Pat. Pub. No. 2012/0092149 to Fujisawa discloses an inspection apparatus arranged with a plurality of cameras located at relatively displaced circumferential positions and set for the respective shooting positions different from each other in the axial direction of the tire. Thus the images of the inner circumferential surface of the tire are shot by the plurality of cameras as the tire is rotated circumferentially relative to the plurality of cameras. Fujisawa is incorporated herein by reference in its entirety. [0075] U.S. Pat. Pub. No. 2011/0013177 to Crim discloses an apparatus and method for verifying a laser etch on a rubber sample. In one embodiment, the apparatus includes a tire production line, a sample holding device, a laser having a diode, and a servo-assembly. The laser of the apparatus is configured to etch indicia on a sidewall of a tire on the tire production line and is further configured to etch at least one line in a rubber sample on the sample holding device. Crim is incorporated herein by reference in its entirety. [0076] U.S. Pat. No. 7,249,496, issued to Kunitake, et al. on Jul. 31, 2007, (“Kunitake”) discloses an uniformity inspection line with a decision-only line having first UF machines exclusive for the measurement of the uniformity of a tire sorted and distributed on an automatic sorting line and a correction-only line having second UF machines for the correction and re-measurement of the uniformity characteristics of a tire having uniformity characteristics outside specific values measured on the above decision-only line. Kunitake is incorporated herein by reference in its entirety. [0077] U.S. Pat. No. 7,340,946, issued to Gotou, et al. on Mar. 11, 2008, and U.S. Pat. Pub. No. 2007/0084275 to Gotou, et al. disclose a method and a device for inspecting a tire, the method comprising the steps of, in a rim assembly station separated from an inspection station having a tire inspector installed thereon, forming a rim/tire assembly in a setup by assembling one side and the other side rims and with an inspected tire and, when an inspection is performed, transforming the rim/tire assembly from the rim assembly station to the tire inspector on the inspection station, whereby a preparatory operation time in the tire inspector can be shortened to shorten a cycle time. The Gotou patent and Gotou publication are incorporated herein by reference in their entireties. [0078] U.S. Pat. No. 7,487,814, issued to Mizota, et al. on Feb. 10, 2009, discloses an object to provide a tire reinforcing layer forming device which can form, by a single device, plural reinforcing layers whose cord directions intersect one another. A reinforcing material piece, which is distributed to an upper conveying path, is affixed from a left end side of a drum toward a right side, while the drum is rotated in a direction of arrow CW. Mizota is incorporated herein by reference in its entirety. [0079] U.S. Pat. No. 7,347,317, issued to Aizawa, et al. on Mar. 25, 2008, discloses methods and devices for measuring elongation, wear, and internal temperature of a conveyor belt to catch signs of conveyor belt failure such as breakage by detecting a magnetic field from a magnetic body by using a magnesium sensor, as well as a rubber magnet sheet as a magnetic body and a method of producing the sheet, the rubber magnet sheet being able to be used while it is embedded in the conveyor belt. Aizawa is incorporated herein by reference in its entirety. [0080] U.S. Pat. No. 7,543,698, issued to Haskell, et al. on Jun. 9, 2009, and discloses an article elevator for moving lightweight open ended containers from a first level to a second level vertically spaced from the first level and is incorporated herein by reference in its entirety. The article elevator includes an input section at the first level for receiving container bodies. An elevator section is positioned for receiving container bodies from the input section. A discharge section is located at the second level for receiving container bodies from the elevator section. A plurality of arms is movably mounted above the input section, the elevator section, and the discharge section. Each of the arms moves a group of container bodies from the input section over the elevator section to the discharge section so that successive groups of container bodies are moved to the discharge section from the input section. [0081] U.S. Pat. No. 3,910,405, issued to Couperus, et al. on Oct. 7, 1975, and discloses a belt elevator for elevating loose bulk material from one level to another. The belt elevator comprises a pair of cooperating endless belt conveyors whose forward runs are juxtaposed to face one another with an edge of one in sealing engagement with the other, the material being retained therebetween. A first belt conveyor is provided with raised edges which engage and seal with the edges of the other. The first conveyor is also provided with generally evenly spaced transversely positioned cleats or raised portions which, together with the raised edges, forms pockets to contain material being elevated. The stiffness of the first belt conveyor is greater than that of the second belt conveyor. The second belt conveyor is troughed at the entry portion for receiving the material to be elevated which material is discharged from the first belt conveyor at a discharge point at the higher level. The belts are maintained in tension to insure edge engagement and the retention of material therebetween. Couperus is incorporated herein by reference in its entirety. [0082] U.S. Pat. Pub. No. 2007/0135960, to Shibao et al., discloses a production evaluation managing system in a factory including facilities in a plurality of production processes from materials to products and a means for evaluating the products based on at least one of inspection and testing characterized by comprising a network connecting the facilities in respective production processes with the evaluating means, and a means for collecting through the network field data of the facility in a production process pertaining to the production of a product corresponding to the information of evaluation results, based on the information of evaluation results of the products outputted from the evaluating means. By this, when a nonconformity is found from the information of evaluation results based on at least one of inspection and testing of the product, field data of the facility in a production process pertaining to production of a product corresponding to the information of evaluation results can be collected and analyzed immediately and the problem with the production process can be investigated immediately in a short time. Shibao is incorporated herein by reference in its entirety. [0083] U.S. Pat. Pub. No. 2007/0289847 to Nakamura is incorporated herein by reference in its entirety and discloses a rubber member conveying device and a rubber member supplying system. The device and the system rapidly promote the shrinkage of the rubber member, thereby avoiding the length variation of the rubber member in the processing step for the rubber member. A rubber member supplying system comprises a belt conveyor which supplies a to-be-cut material having an internal strain, a cutter which cuts the to-be-cut material supplied by the belt conveyor to form a rubber member, and a rubber member conveying part which conveys the rubber members. The rubber member conveying part comprises an endless belt, and rollers supported by supporting parts that are provided at the endless belt. The rubber member is conveyed on the rollers while exposed to vibrations. Accordingly, the shrinkage in the rubber member caused by the internal strain thereof is substantially completed in the conveying operation. [0084] U.S. Pat. No. 4,534,461, issued to Silverthorn, et al. on Aug. 13, 1985, and discloses a conveyor construction for conveying materials, such as grain, to an elevated location. The conveyor construction comprises a base or supporting structure and an auger conveyor is mounted horizontally on the base. Grain is fed into a hopper at one end of the auger and the discharge end of the auger is provided with a pair of kicker paddles which propel the grain laterally into the lower end of a vertical endless belt conveyor. The endless belt conveyor includes a plurality of integrally molded cleats that convey the grain upwardly within a vertical passage in the conveyor housing and the grain is discharged from the upper end of the housing. The vertical conveyor is mounted for pivoting movement relative to the auger conveyor to adjust the angularity of the vertical conveyor. Silverthorn is incorporated herein by reference in its entirety. [0085] U.S. Pat. No. 4,727,419, issued to Yamada, et al. on Feb. 23, 1988, and is incorporated herein by reference in its entirety. Yamada discloses a system in case of detecting tire information marks engraved in a side wall portion of tire in the form of protrusion or recess, width and inner diameter of tire are detected to provide a tire size signal, after a first camera head is driven into a given position in accordance with the tire side signal, an identification mark engraved in the size wall portion of tire is optically detected by the first camera head to derive a position signal, and after a second camera head is driven into a given position in accordance with the position signal, the tire information marks are optically detected by the second camera head to derive a tire information signal. In this manner, the tire information marks can be detected in a rapid and accurate manner. [0086] U.S. Pat. No. 4,700,078, issued to Mizuno, et al. on Oct. 13, 1987, and discloses a method and system for detecting tire information marks. Tire information marks for denoting tire kind, tire size, etc. formed in a surface of side wall of a tire as a protrusion or groove having a triangular cross section are optically detected by illuminating the surface of side wall of the tire from a first direction substantially perpendicular to the surface of the side wall of the tire and a second direction inclined with respect to the surface of the side wall of the tire, and picking up an image of the surface of the side wall of the tire thus illuminated from the two different directions to derive an image signal. The image signal thus derived is converted into a bivalent signal, and is thinned to produce a mark pattern. Then the mark pattern is compared with a thick standard mark pattern. When a substantial part of the detected mark pattern is included in the standard mark pattern, the detected mark pattern is recognized to be identical with the standard mark pattern. Mizuno is incorporated herein by reference in its entirety. [0087] U.S. Pat. No. 5,092,946, issued to Okuyama, et al. on Mar. 3, 1992, U.S. Pat. No. 5,415,217, issued to Okuyama, et al. on May 16, 1995, and U.S. Pat. No. 5,194,107, issued to Okuyama, et al. on Mar. 16, 1993. The Okuyama patents disclose a method and an apparatus for sticking a belt-like member, wherein a belt-like member prepared by cutting a raw material of the belt-like member on a conveyor at two front and rear locations, is conveyed by the conveyor, wrapped around a cylindrical drum and stuck to the drum. The inclination angle of the cut line at the leading end of the belt-like member is measured at the time of cutting, the inclination angle of the cut line at the trailing end is measured at the time of cutting, and by comparing the inclination of the cut line at the trailing end with the inclination angle at the leading end, an amount of connection for the inclination angle is calculated. The three Okuyama patents are incorporated by reference herein in their entireties. [0088] In one embodiment, the conveyor comprises an endless conveyor belt having an outer article-conveying surface. The conveyor belt advances in a direction of belt travel along a conveying path that includes a steeply inclined portion. The conveying belt also includes support elements that extend outward from the outer article-conveying surface of the conveyor belt at periodically spaced positions and retention means are disposed along the steeply inclined portion proximate the support elements prevent conveyed articles from falling away from the conveyor belt on the steeply inclined portion. [0089] In various embodiments, the conveyor system comprises an endless conveyor belt having an outer article-conveying surface. The conveyor belt advances in a direction of belt travel along a conveying path that includes a steeply inclined portion. The conveying belt further includes support elements that extend outward from the outer article-conveying surface of the conveyor belt. An article-restraining surface facing the article-conveying surface of the conveyor belt is positioned outward of the support elements across gaps along the steeply inclined portion of the conveying path. The article-restraining surface engages outwardly leaning conveyed articles moving upward on the steeply inclined portion of the conveying path in low-friction contact. The article-restraining surface may be the outer surface of a belt advancing in the direction of belt travel or the outer surfaces of an array of rollers rotating in the direction of belt travel on contact with outwardly leaning conveyed articles. [0090] In one embodiment, the conveyor for conveying articles up inclines comprises: an endless conveyor belt having an outer article-conveying surface and advancing in a direction of belt travel along a conveying path including an inclined portion; a plurality of support elements extending outwardly from the outer article-conveying surface of the conveyor belt and spaced apart at an increment approximately equal to about 1.5 times a length of the article conveyed, where the plurality of support elements comprises pairs of two support elements and each support element in the pair is positioned proximate to the other support element in the pair and with a space between the two support elements, where each support element comprises: curved section having an article-supporting face, which is curved at a first radius of curvature and is positioned in the direction of belt travel, and a back side opposite the article-supporting face, the back side is curved with a second radius of curvature, where the first radius of curvature is smaller than the second radius of curvature; a block-like bottom section with a flat bottom that engages the outer article-conveying surface of the conveyor belt; and a top opposite the bottom, where the top is positioned at an angle relative to the flat bottom; two securing mechanisms for each support element to secure the support elements on the conveyor belt; a support frame with a support stand positioned proximate to a floor surface and support bars; a drive pulley interconnected to the support frame and positioned at the bottom of the support frame, where an underside of the conveyor belt engages an outer surface of the drive pulley; a tail pulley interconnected to the support frame and positioned at the top of the support frame, where an underside of the conveyor belt engages an outer surface of the tail pulley; and a motor for moving the conveyor belt around the drive pulley and tail pulley. [0091] In a further embodiment, a first support element in one pair of support elements has an article-supporting face defining a first plane oblique to the direction of belt travel and a second support element in the pair of support elements has an article-supporting face defining a second plane oblique to the direction of belt travel. The first plane and the second plane intersect at a point on the conveyor belt below the first support element and the second support element. In another embodiment, the support elements are contoured in shape to mate with the conveyed article. In one embodiment, the support elements are made of an elastomeric material that conforms to the shape of a conveyed article on the inclined portion of the conveying path. In additional embodiments, the conveyor further comprising a retention mechanism for preventing the conveyed articles from falling off of the conveyor belt, said retention mechanism positioned along the inclined portion of the conveying path. The conveyor may alternatively comprise an article-restraining surface positioned above and facing the article-conveying surface of the conveyor belt, where the article-restraining surface is spaced away from the support elements, and where the article-restraining surface engages outwardly leaning conveyed articles moving upward on the inclined portion of the conveying path in low-friction contact. In one embodiment, the inclined portion of the conveying path is approximately 60 degrees as measured from a horizontal plane. [0092] One embodiment of a tire conveyor for conveying tires up an incline comprises: an endless conveyor belt having a lateral extent and a longitudinal extent, and an outer tire-conveying surface that is designed to advance in a direction of belt travel along a conveying path including an inclined portion; a first pair of first and second tire support elements, with each of said first and second tire support element having a same width (w), length (l) and height (h), with said first tire support element spaced a distance along said lateral extent of said conveyor belt from said second tire support element by at least twice the width, where said pair of first and second tire support elements are each interconnected to said outer tire-conveying surface by two independent fasteners that penetrate through said outer tire-conveying surface, said first tire support element being fastened to said outer tire-conveying surface at a first angle with respect to said lateral extent of said conveyor belt, and said second tire support element being fastened to said outer tire-conveying surface at a second angle with respect to said lateral extent of said conveyor belt, said first angle and said second angle being commensurate and opposite each other, where when a tire is placed in contact with said first and second tire support elements, the first tire support element is between a 4 o'clock and 5 o'clock position of the tire and the second tire support element is between a 7 o'clock and 8 o'clock position of the tire, where each of said first and second tire support elements has a front section having an tire-supporting face that has a first curve that is curved along its length and toward the direction of belt travel and a back section that has a second curve that is curved along its length and in the direction of belt travel, said second curve being greater than said first curve, each of said pair of tire engaging support elements having a flat conveyor contacting surface that engages the outer tire-conveying surface of the conveyor belt, each of said tire support elements constructed entirely from an elastomeric material that provides flexibility along said length of said tire support elements such that when a tire is positioned on said conveyor belt, said first and second tire support elements bend in a direction opposite the direction of belt travel along a conveying path; a second pair of first and second tire support elements spaced apart from said first pair of tire support elements by at least a distance of 1.5 times a length of a tire conveyed on said conveyor belt; a support frame with a support stand, said support frame having two, longitudinally extending side bar supports extending parallel to each other and connected to each other by a plurality of support struts; a drive pulley operably connected to said support frame that engages said conveyor belt; a tail pulley operably connected to said support frame that engages said conveyor belt; and a motor operably connected to said drive pulley. [0093] The tire conveyor may further comprise a tire-restraining mechanism interconnected to the support frame and positioned above and facing the tire-conveying surface of the conveyor belt, where the tire-restraining mechanism comprises at least one bar arranged in the direction of belt travel and at least two bars positioned perpendicular to the direction of belt travel, where the tire-restraining surface is spaced away from the support elements, and where the tire-restraining surface engages outwardly leaning conveyed tires moving upward on the inclined portion of the conveying path. In some embodiments, the tire conveyor comprises an array of rollers having outer surfaces forming the tire-restraining surface facing the tire-conveying surface, where the rollers are arranged to rotate in the direction of belt travel on contact with outwardly leaning conveyed tires. In additional embodiments, the tire conveyor further comprises a tire sorting apparatus comprising: a mount, where the mount positions a tire in a plane perpendicular to the center axis of the tire; a tire grip, where the tire grip grips the inner periphery of the tire and positions the center axis of the tire; an ID reader, where the ID reader reads a tire identification marking formed on the surface of the tire; and a holder, where the holder holds the ID reader, where the tire grip further includes three grip arms arranged at the vertexes of a triangle within a plane perpendicular to the center axis of the tire, where the holder further includes a holding unit for holding the ID reader, and a rotation drive unit for rotating the holder around a rotation axis parallel to the center axis of the tire, and where the center of the circumscribing circle is aligned with the rotation axis of the holding unit. Still further, the conveyor may comprise an apparatus for loading the tire onto a rack, the apparatus comprising: a first scanner configured to provide information regarding said tire; a tire conveyor configured to transport said tire; a robot configured to automatically move the tire from the tire conveyor onto the rack; and a computer configured to control the robot using the information from the first scanner. [0094] One embodiment of a method for conveying articles up steep inclines is provided, the method comprising: providing a conveyor for conveying articles up an incline, said conveyor comprising: an endless conveyor belt having a lateral extent and a longitudinal extent, and an outer article-conveying surface that is designed to advance in a direction of belt travel along a conveying path including an inclined portion; a plurality of support elements, with each support element having a same width (w), length (l), and height (h), where each support element of said plurality of support elements is interconnected to said outer conveying surface by two independent fasteners that penetrate through said outer article-conveying surface, where each of said support elements has a front section having an article-supporting face that oriented in the direction of belt travel, each of said support elements having a flat conveyor contacting surface that engages the outer article-conveying surface of the conveyor belt, each of said support elements constructed of urethane material that provides strength along the supporting elements such that when a conveyed article is positioned on said conveyor belt, said first and second supporting elements, where a second support element in the plurality of support elements is spaced apart from a first support element in the plurality of support elements by at least a distance of 1.5 times a length of an article conveyed on said conveyor belt; a support frame with a support stand, said support frame having two, longitudinally extending side bar supports extending parallel to each other and connected to each other by a plurality of support struts; a drive pulley operably connected to said support frame that engages said conveyor belt; a tail pulley operably connected to said support frame that engages said conveyor belt; and a motor operably connected to said drive pulley; moving said endless conveyor belt in the direction of belt travel using the motor, the drive pulley, and the tail pulley; conveying articles on the outer article-conveying surface of the conveyor belt; advancing the conveyed articles in the direction of belt travel along a conveying path including the inclined portion; blocking conveyed articles from sliding down the conveying surface of the conveyor belt on the inclined portion by using said plurality of support elements; and removing the conveyed articles from the conveyor belt. [0095] The method may, in some embodiments, further comprise sorting the conveyed articles using a sorting apparatus; and depending on the sorting step, loading a first type of conveyed article onto the conveyor belt. Additionally, the method comprises a method of unloading conveyed articles from a rack, the method comprising: moving the conveyed articles from the rack to the sorting apparatus; reading identification information on the conveyed articles using a computer-controlled vision system; removing the conveyed articles from the conveyor belt using a robot, where the identification information facilitates control of the second robot; and placing the conveyed articles in one of a loader and a storage structure. [0096] While various configurations of the conveyor are herein specified, this description is only exemplary and is not intended to limit or otherwise narrow the invention. The conveyor may include any number of components in any potential combination thereof as desired for achieving the desired function for desired article shape and size and incline. [0097] One or ordinary skill in the art will appreciate that embodiments of the present invention may be constructed of materials known to provide, or predictably manufactured to provide the various aspects of the present invention. For example, materials used in the support structure of the conveyor may include, for example, metal, composites, plastics, and other synthetic and natural materials. Further, the belt of the conveyor may be comprised of rubber, latex, synthetic rubber, synthetic materials, polymers, and natural materials. [0098] As used herein, the term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. It is also to be noted that the terms “comprising”, “including”, and “having” can be used interchangeably. [0099] As used herein, “at least one”, “one or more”, and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together. [0100] The phrases “device”, “apparatus”, “conveyor”, “conveyor apparatus”, and “conveyor device” are used herein to indicate the invention device. [0101] The phrase “removably attached”, “removable”, and/or “detachable” is used herein to indicate an attachment or connection of any sort that is readily releasable or disconnected. [0102] This Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the present invention. The present invention is set forth in various levels of detail in the Summary of the Invention as well as in the attached drawings and the Detailed Description, and no limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of elements, components, etc. in this Summary of the Invention. Additional aspects of the present invention will become more readily apparent from the Detailed Description, particularly when taken together with the drawings. [0103] The above-described benefits, embodiments, and/or characterizations are not necessarily complete or exhaustive, and in particular, as to the patentable subject matter disclosed herein. Other benefits, embodiments, and/or characterizations of the present disclosure are possible utilizing, alone or in combination, as set forth above and/or described in the accompanying figures and/or in the description herein below. However, the Detailed Description, the drawing figures, and the claims set forth herein, taken in conjunction with this Summary of the Invention, define the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0104] Those of skill in the art will recognize that the following description is merely illustrative of the principles of the invention, which may be applied in various ways to provide many different alternative embodiments. This description is made for illustrating the general principles of the teachings of this invention and is not meant to limit the inventive concepts disclosed herein. [0105] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description of the disclosure given above and the Detailed Description of the drawings given below, serve to explain the principles of the disclosures. [0106] FIG. 1 is a perspective view of an embodiment of a tire conveyor; [0107] FIG. 2 is a perspective view of an embodiment of a moveable elevating belt conveyor; [0108] FIG. 3 is a perspective view of an embodiment of a conveyor; [0109] FIG. 4 is an exploded view of the lower end of the conveyor shown in FIG. 3 ; [0110] FIG. 5 is an exploded view of the upper end of the embodiment of the conveyor shown in FIG. 3 ; [0111] FIG. 6 is an exploded view of the embodiment of the conveyor shown in FIG. 3 ; [0112] FIG. 7 is a perspective view of a section of a belt with cleats; [0113] FIG. 8 is a perspective view of a vertical conveyor; [0114] FIG. 9 is a perspective view of two curved cleats; [0115] FIG. 10 is a perspective view of an embodiment of an elevating belt conveyor conveying tires; [0116] FIG. 11 is a perspective view of an embodiment of an elevating belt conveyor conveying panels; [0117] FIG. 12 is a perspective view of an embodiment of an elevating conveyor; [0118] FIG. 13 is a perspective view of an embodiment of a system of multiple elevating conveyors; [0119] FIG. 14A is a top elevation view of an embodiment of cleats on a conveyor; [0120] FIG. 14B is a top elevation view of a second embodiment of cleats on a conveyor; and [0121] FIG. 14C is a top elevation view of a third embodiment of cleats on a conveyor. [0122] It should be understood that the drawings are not necessarily to scale, and various dimensions may be altered. In certain instances, details that are not necessary for an understanding of the invention or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein. DETAILED DESCRIPTION [0123] The invention described herein relates to a conveyor used in any application where an article (such as a tire) may need to be transported or lifted more than five feet. Such applications include moving tires and articles during manufacture, after manufacture to be shipped, loading tires and articles on the shipping vessels, unloading the tires and articles off of the shipping vessels, and moving the tires and articles within stores and warehouses to their final storage place. [0124] It should be appreciated that the particular implementations and embodiments shown and described herein are illustrative of the invention and are not intended to otherwise limit the scope of the present invention in any way. Indeed, for the sake of brevity, trivial and conventional features and aspects of the present invention are not described in extensive detail herein. It should be understood that the legal scope of the description is defined by the words of the claims set forth at the end of this disclosure. The detailed description is to be construed as exemplary only and does not describe every possible embodiment since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims. Furthermore, the connecting lines shown in the various figures shown herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements of the system. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical conveyor apparatus, conveying system, conveying method, tire sorting system, and tire loading system. [0125] Referring now to FIG. 1 , an embodiment of the conveyor 100 of the present invention is shown. The embodiment of the conveyor 100 shown in FIG. 1 may convey tires 120 and comprise a belt 106 , rounded cleats 107 , an electrical box 118 , and a support frame 110 . The support frame 110 may comprise a support stand 102 , side panels 104 , support bars 108 , a drive pulley 122 interconnected to the support frame 110 at a point with a pin or other connecting mechanism 124 , a tail pulley, and a side plate 124 . The conveyor 100 has a lower end 112 , and an upper end 114 . The support stand 102 and side panels 104 may be any metal material. In other embodiments, the support stand 102 and side panels 104 may be composites or durable plastics. The tires 120 may be any tire of any shape or size. The belt 106 may have one or more seams 120 . [0126] In some embodiments, the support stand 102 may be replaceable and may be replaced with various support stands or wheels to move the conveyor from location to location. The support stand 102 may also be secured to the ground or to a floor surface to prevent movement of the conveyor 100 . [0127] FIG. 2 shows an embodiment of an elevating belt conveyor 200 . The conveyor 200 may comprise cleats 207 A, 207 B, a belt 210 , and a stand 250 with wheels 254 . The stand 250 may comprise rear tall support bars 252 , a rear horizontal support bar 256 , side horizontal support bars 258 , a front horizontal support bar 260 , and wheels 254 . In various embodiments, the stand 250 may be configured in ways other than that shown in FIG. 2 . One skilled in the art will contemplate other configurations known now or in the future. [0128] In various embodiments, the stand 250 may have wheels 254 . In other embodiments, the stand may not have wheels 254 . Further, the stand 250 may be removable and the conveyor may be secured to the ground or floor to prevent movement. In some embodiments, the wheels are detachable to prevent movement of the conveyor. Alternatively or additionally, the wheels may be lockable to prevent movement of the conveyor. [0129] The conveyor 200 may also comprise a pulley 270 , a crankshaft 272 or other means for tightening the pulley 270 and/or the belt 210 . In some embodiments the underside 280 of the belt may be visible. The side of the conveyor 200 may have a side support or shield. The pulley 270 may be a plain idler pulley with a belt tensioner 272 . The lower pulley 122 may also be a drive pulley for a rubber lagged conveyor belt. The electrical system may comprise an electrical box 218 with a motor. The motor may have a thermal overload motor protector to protect the motor from overheating. [0130] Referring now to FIGS. 3-7 , different components of an embodiment of a conveyor are shown. FIG. 3 is a perspective view of an embodiment of a conveyor 300 . FIG. 4 is an exploded view of the lower end of the embodiment of the conveyor shown in FIG. 3 . FIG. 5 is an exploded view of the upper end of the embodiment of the conveyor shown in FIG. 3 . FIG. 6 is an exploded view of the embodiment of the conveyor shown in FIG. 3 . FIG. 7 is a perspective view of a section of a belt with cleats. [0131] FIG. 3 shows a conveyor 300 with the conveyor belt removed to show other components. In some embodiments the conveyor belt is also included. The conveyor 300 may comprise side bars 170 , a tail pulley 529 , a drive pulley 528 , a base plate 512 with a pin, and pin only hardware 512 PO. [0132] The lower end of the conveyor 300 is shown in FIG. 4 . The lower end of the conveyor 300 may comprise a bearing with 3-hole triangular flangettes 149 A, a motor 193 , a speed reducer 510 , a base plate 512 , a drive pulley 528 , a drive shaft 530 , a chain guard 535 , a 12 tooth sprocket 540 , a 30 tooth sprocket 542 , and a section of roller chain 545 . [0133] The bearing with 3-hole triangular flangettes 149 A may comprise a 1″ bearing. In one embodiment, the motor 193 may be a 1 hp 115V 56C TEFC motor. In one embodiment, speed reducer 510 may include a ⅞″ O.D. shaft. In one embodiment, base plate 512 may include a pin and pin only hardware 512 PO. In an embodiment, the drive pulley 528 may include a 1″ bore. In an embodiment, the drive shaft 530 may include a 1″ O.D. In one embodiment, the 12 tooth sprocket 540 may include a ⅞″ bore. In one embodiment, the 30 tooth sprocket 542 may include a 1″ bore. In an embodiment, the section of roller chain 545 may be #40 roller chain (137 pitches+connecting link). [0134] The upper end of the conveyor 300 is shown in FIG. 5 . The upper end of the conveyor 300 may comprise a bearing with 3-hole triangular flangettes 149 , a take-up frame 515 with a screw (right hand side), a take-up frame 517 with a screw (left hand side), a tail pulley 529 , a tail shaft 531 , a forward/reverse drum switch 195 A, an ON/OFF motor rated toggle switch 195 BSD, a main E-stop starter station 195 C, a remote E-stop station 195 D, an E-stop switch (Red), a reverse switch (black), a forward switch (green), and a set of (2) nose wings 180 with hardware. [0135] In some embodiments, the bearing with 3-hole triangular flangettes 149 may be a 1″ bearing. In an embodiment, the tail pulley 529 may comprise a 1″ bore. In an embodiment, the tail shaft 531 may comprise a 1″ O.D. (outside diameter). [0136] The conveyor 300 is shown in FIG. 6 . FIG. 7 shows a piece of the belt 505 with cleats 507 A, 507 B. In an embodiment, the belt 505 may be 18″ wide 1/32″ thick. Further, there may be a set of two bolts on each cleat. In embodiments, the cleats may be a set of two cleats where one cleat 507 A is the right hand side cleat with hardware and the other cleat 507 B is the left hand side cleat with hardware. Further, the belt 505 may comprise a set of #20×18″ long hammer-on lacing 524 or a set of #RS 125×18″ long staple lacing 526 . [0137] FIG. 8 shows a perspective view of a vertical conveyor 800 . The conveyor 800 may include a control switch 802 to turn the conveyor 800 on and off. One embodiment of a tire rack 804 for holding tires 120 is also shown in FIG. 8 . The vertical conveyor 800 conveys tires 120 upward to high levels or high shelves of the rack 804 and conveys tires 120 downward from high levels or shelves of the rack 804 to the ground for use or transport. [0138] FIG. 9 shows a perspective view of two curved cleats 507 A, 507 B. In some embodiments, the cleats are 4″ cleats 507 A, 507 B. In an embodiment, the cleats 507 A, 507 B may include a set of two bolts. Further, the bolts may be ¼″×1¼″ #1 elevator bolts with hardware. The cleats 507 A, 507 B may also include holes 902 for the bolts or other attachment/connection mechanisms. The cleats 507 A, 507 B may have a flat lower area 904 (also called a “block” herein) and a curved section 906 . The curved section 906 has a back side (i.e., side show and side facing away from the tire or article) and an article-supporting face 908 (not shown, and is positioned opposite the back side 906 ). The cleats 507 A, 507 B also have a top 912 , a bottom 910 , and sides 914 . [0139] FIG. 10 is a perspective view of an embodiment of an elevating belt conveyor conveying tires 920 to an upper floor 922 . The conveyor may comprise a belt 910 and cleats 907 A, 907 B. The belt 910 may have a seam 1020 and an upper surface and a lower surface. The conveyor may also have an electrical box 918 with power buttons, and an emergency stop button, etc. [0140] FIG. 11 shows an embodiment of an elevating conveyor 1000 conveying solar panels 1002 . The conveyor may comprise a conveyor belt 1010 , a support frame 1110 , cleats 1007 A, 1007 B, a stand 1050 , and a retention mechanism 1100 . The retention mechanism 1100 has a lower end 1100 A and an upper end 1100 B. The retention mechanism 1100 is interconnected to the support frame 1110 and does not run the entire length of the support frame 1110 such that articles may be loaded onto the conveyor belt 1010 at the bottom of the elevating conveyor 1000 and removed at the top of the elevating belt conveyor 1000 . In one embodiment, the retention mechanism 1100 is a set of bars made of the same material or a similar material to the support frame 1110 . Articles, such as solar panels 1002 , do not touch the retention mechanism 1100 unless the article falls away from the conveyor belt 1010 . At that point, the retention mechanism 1100 keeps the article from completely falling off of the conveyor 1000 . In some additional embodiments, the retention mechanism may also prevent the articles from moving from side to side on the conveyor 1000 or from falling off of the side of the conveyor 1000 . [0141] FIG. 12 shows an embodiment of an elevating conveyor 1200 used in industrial uses. The elevating conveyor 1200 may comprise a support frame 1208 , motor 1206 , pulley 1210 , electrical system 1204 , drive pulley 1210 , and one or more cleats 1202 . In some embodiments, the support frame 1208 may comprise support feet 1222 (alternative to a single support stand as shown in FIG. 1 as element 102 ). Either a support stand or support feet (even more than two feet) maybe be used in the various embodiments described herein. [0142] FIG. 13 shows an embodiment of a system of multiple elevating conveyors 1200 A, 1200 B, 1200 C. [0143] Other embodiments of cleats or support elements are shown in FIGS. 14A-14C . Note that the term “cleat” and the term “support element” may be used interchangeably herein. FIG. 14A shows an embodiment of cleats holding a tire on a conveyor. The cleats in FIG. 14A are posts 58 that have article-supporting faces 60 contoured to complement the shape of and to mate with a conveyed article. The posts or cleats 58 also have article-supporting faces 60 that define a plane 1406 A, 1406 B oblique to the direction of belt travel 1402 and intersecting at a point 1408 below the posts or cleats 58 on the belt. The angle defined by the cleats or posts 58 may also be measured from the horizontal line 1404 . The cleats in FIG. 14B are chevron-shaped flights 62 serving as pockets for conveyed articles. Each flight may be a single piece or segmented. In FIG. 14C , each cleat constitutes a pair of pins 64 between which an elastomeric band 66 is strung. The weight of the conveyed article pushing on the elastomeric band stretches the band to conform to the outer surface of the conveyed article 10 . These are just a few additional examples of cleats that are usable in the conveyors of FIGS. 1-13 . Other support elements, such as buckets, transverse flights, or arrays of pins, could alternatively be used. [0144] While various embodiment of the present invention have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and alterations are within the scope and spirit of the present disclosure, as set forth in the following claims. [0145] The foregoing discussion of the disclosure has been presented for purposes of illustration and description. The foregoing is not intended to limit the disclosure to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the disclosure are grouped together in one or more embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed disclosure requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the disclosure. [0146] Moreover, though the present disclosure has included descriptions of one or more embodiments and certain variations and modifications, other variations and modifications are within the scope of the invention, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative embodiments to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter. Further, the invention(s) described herein is capable of other embodiments and of being practiced or of being carried out in various ways. It is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

A conveyor for transporting and elevating articles and a method and system for conveying articles up inclines is provided. The conveyor has a conveyor belt and a plurality of support elements extending outward from the article-conveying surface of the conveyor belt advancing upward along the incline. The support elements prevent conveyed articles from sliding down the conveyor belt on the incline. The article-conveying surface of the conveyor belt may provide a low-friction retention surface to articles leaning away from the conveyor belt on the incline.

FIELD OF THE INVENTION The present invention relates to conveyors for use in automotive assembly plants in which the track for the conveyor is mounted underneath the floor. The present invention relates to a floor conveyor which is operable to continuously convey automotive bodies on a conveyor line in an automobile assembly plant which carries out various operations, such as working, assemblying and painting, etc. In particular, the present invention provides a conveyor which stably supports the automotive bodies so as to limit swaying of the bodies as they are conveyed and worked upon. The invention also provides apparatus which prevents essential parts of the conveyor in a painting booth from being stained by sprayed paint or other coating material. BACKGROUND OF THE INVENTION Floor conveyors for use in automotive assembly plants are disclosed in Japanese Patent Publication No. 40145/1980 and U.S. Pat. No. 4,408,540. Such structures are not satisfactory for use in assembly plants. In Japanese Patent Publication No. 40145/1980, the conveyor is mounted in a housing which is laid on top of the floor surface in the assembly plant which therefore provides a barrier to the movement of other objects across the conveyor line. The top opening of the housing is covered by a rubber or other elastic material for preventing entry of coating material into the housing. However, if an operator must cross over the conveyor, he cannot step on the rubber cover and it is also dangerous to straddle the housing. Such arrangement therefore restricts the ability of the operators to pass from one side to the other of the conveyor and thereby causes a reduction in work efficiency. Even though the top opening of the housing is covered by the elastic material, when the conveyor operates to move the automobile body past the painting operation, the support leg for the automotive body must pass through the cover material which creates a spacing adjacent the support which may permit coating material to enter within the housing. The automobile body is mounted on a carrier which travels along the rail, and to limit swaying of the body the carrier is provided with front, rear, right and left (i.e, four) guide rollers. On straight sections this is no problem, but going around curves or up slopes there must be sufficient clearance to permit the turning movement and it is possible that the rollers will derail. The conveyor shown in U.S. Pat. No. 4,408,540 eliminates the enlarged upper opening which is characteristic of the Japanese patent and provides a narrow opening between closely-spaced rails. If the conveyor mounts an object such as a vehicular body having a large width (normally 1.5-2.0 meters) or another object whose center of gravity may be offset to one side owing to the presence of the steering wheel or the like, it is possible that the center of gravity of the body fails outside of the path of the carriers, and the carrier tends to tilt, even though guide rollers may be positioned between the traveling rollers. Even if the center of gravity of the body is normally directly over the rail, it is subject to swaying by reason of any small force which may occur in the normal handling operations involved in working on the automotive body. Swaying movement of the body on the conveyor is particularly serious when operations are being performed on both sides of the body at the same time. For this reason, the conveyor shown in the U.S. patent has not proved satisfactory. The effect of swaying of the vehicular body will be described more concretely with reference to FIG. 11 of the attached drawings. In this figure, the automotive body M is shown supported on a stand mounted on a carrier between rails R. In the full-line position, the center of gravity of the body is directly over the center line of the rails. When a force f is applied to the right side of the body M, it sways to the position shown in broken lines in the figure. If the height from a horizontally central surface H of the rails R to a point where the manual pushing force (f) is applied to a vehicular body M is L, a moment of inclination in a manual operation is fL. If the weight of the vehicular body is W, and an outside spacing between carrier rollers is (s 1 ), a moment of stability resisting the moment of inclination is 1/2(Ws 1 ). Therefore, when the moment of inclination fL is FL>1/2 (Ws 1 ), the vehicular body W is inclined by the manual pushing force. For example, if the height L, outside spacing (s 1 ) and load W of the vehicular body are L=1,500 mm, (s 1 )=100 mm, and W=200 kg, respectively, the manual pushing force (f) is (f)>6.7 kg. This magnitude of the force (f) does not allow the traveling rollers to be moved laterally relative to the rail R, and it will be appreciated that the vehicular body may be easily inclined or swayed by the manual pushing force. In the event that the center of gravity of the vehicular body is deflected, the vehicular body may be inclined even by further smaller force (f). Further, if a vertical spacing (d) between an inner surface of the rail R and the traveling rollers is d=3 mm, an amount of inclination during swaying of the vehicular body at the manually pushing point is 3×1,500/100=4.5 mm. In other words, the vehicular body is likely to be inclined by its deflection of the center of gravity or an external force, and is inclined by a centrifugal force at curvature. For these reasons, there occur many problems which create a bad influence on the life of the rail, difficulty in manual operation, and reduction in quality, e.g. in painting, the painted surface is waved because of the swaying of the vehicular body upon passing through a connection of the rail. Consequently, this prior art conveyor is not satisfactory. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a floor conveyor which may limit inclination and swaying of a vehicular body during conveying. It is another object of the present invention to provide a floor conveyor which includes a narrow guide slot in the working floor constituting a passage for a support leg for supporting the vehicular body on the conveyor, and permits safe travel on the working floor and traveling of a vehicle or the like across a conveyor line. It is further object of the present invention to provide a floor conveyor which may prevent foreign matter and sprayed paint or other coating material from entering and adhering to an essential part of the conveyor under the floor through the guide slot in the working floor. According to the present invention, a pair of steel rails, such as channel members having a substantially rectangular channel recess on one side, are oppositely arranged just under a working floor with sufficiently large spacing therebetween to form a carrier track. Cylindrical traveling rollers arranged at front and rear portions of a carrier are inserted into the channels of the rails, so as to reduce lateral inclination of the carrier due to swaying of a vehicular body as it is conveyed. Further, vertical-axis guide rollers are rotatably supported adjacent to the traveling rollers of the carrier at substantially central position just above the traveling rollers, and are inserted into a guide slot having a width smaller than a spacing between the channels. The slot is formed by the inner edges of right and left guide plates fixed on the channel members, so as to limit lateral movement of the carrier during traveling and maintain the rollers within the channels, also reducing lateral inclination of the carrier. The guide plates cover a wide opening at the top of a receiving space under the working floor which houses the carrier track having a relatively large spacing between opposed channel members, and the essential parts of a conveyor such as the carrier and a carrier drive chain, leaving only the narrow guide slot uncovered. Accordingly, the essential parts of the conveyor are protected from adhesion of dust and particles of coating material entering from above the working floor, and the life of the conveyor is prolonged. Furthermore, safe passage over the working floor may be secured and work efficiency in the assembly plant may be improved. Additionally, vehicles are permitted to travel over the working floor. A stand mounting thereon an object to be conveyed is connected for pivotal movement on horizontal axes at front and rear portions thereof to the upper ends of support legs which are respectively pivotally supported in the central portion of two carriers so as to be forwardly and rearwardly inclined, and thereby to be moved over the floor surface. The support legs are inserted through the guide slots, and in the present instance, each leg has a C-shaped bent portion above the floor surface which is recessed sidewardly with respect to a conveying direction. In the case that a vehicular body as a conveyed object is spray-coated in a painting booth, there is provided in the painting booth a tunnel-like shielding cover overlying the guide slot so as to provide a passage for part of the C-shaped bent portion as above mentioned, so as to prevent foreign matter from entering and adhering to the essential parts of the conveyor under the floor through the guide slot. Other features of the present invention will be apparent from the following detailed description of the preferred embodiments in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The drawings show preferred embodiments of the present invention, in which: FIG. 1 is a plan view of a conveyor embodying the present invention apart from the floor surface, showing in broken lines an automotive body carried by the conveyor; FIG. 2 is an elevational view of FIG. 1; FIG. 3 is a cross section taken along the line III--III in FIG. 2 showing its position relative to a floor surface; FIG. 4 is an enlarged fragmentary vertical sectional view showing a stand, supporting leg, and a carrier; FIG. 5 is a cross section taken along the line V--V in FIG. 4 showing in broken lines floor struts and shielding cover means for the guide slot; FIG. 6 is a cross section taken along the line VI--VI in FIG. 4; FIG. 7 is a schematic horizontal sectional view of a painting booth in which a conveyor of the present invention is installed; FIGS. 8, 9 and 10 are fragmentary diagrammatic horizontal sectional views of various modifications of a shielding cover; and FIG. 11 is a view of a prior art structure showing a condition where swaying is generated in a floor conveyor. DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 to 3, a floor conveyor of the present invention is arranged along a conveyor feeding line between a shop floor F (FIG. 3) and a working floor 1 laid on a level higher than the floor F. A floor board 2 is laid on the working floor 1. Struts 3 and U-shaped support plates 4 are longitudinally arranged at given intervals and are fixed to both sides of the floor conveyor by a suitable means such as welding, to level the upper ends of the struts 3 and to secure them to the lower surface of the floor board 2. Channel member rails 5a of steel having oppositely-facing C-shaped cross sections are in contact with the inner surfaces of the upper ends of the struts 3 and the upper ends of the supporting plates 4 which are lower in height than the inner surface and are fixed such that the upper surfaces of the channel member rails 5a are level with the upper ends of the struts 3 to form a carrier track 5. Four carriers 6 (6a, 6b, 6c and 6d) are substantially the same and are interconnected to form a traveling structure. As shown in FIGS. 4 and 6, traveling rollers 8 are rotatably supported on axles mounted at front and rear portions of a hollow box-like carrier frame 7, to travel in the inside channels of the channel members 5a. The rollers 8 ride on the lower flange and a small clearance spacing is provided between the rollers 8 and the upper flange. As shown in FIG. 6, guide rollers 9 are rotatably supported on vertical axes and are disposed in a laterally central position at the front and rear portions of the frame 7, and are positioned in a guide slot 11 formed by inside edges 10a of a pair of guide plates 10 fixed to the upper surface of the channel members 5a, thereby permitting the carriers 6a to 6d to be guided as they travel along the center of the track 5, preventing sideward deflection of the traveling rollers 8 and derailing of the carriers at curved points where rail spacing is enlarged and at switches or junctions. The carriers 6a and 6b and the carriers 6c and 6d are connected with each other by respective connecting rods 12 through universal joints mounted on both ends of the connecting rods 12, and the carriers 6b and 6c are connected with each other by a vehicle mounting stand 13 to construct a traveling structure 6A (FIG. 1). A track 14 consisting of a pair of channel member rails is fitted in the U-shaped recess of the support plate 4 under the carrier track 5 to construct a chain trolley track 14, and endless driving chains 17 are connected at equal intervals to a plurality of trolleys 16 traveled by rollers 15 on the rails, thereby moving the trolleys 16 in a direction as depicted by the arrow in FIG. 2. Hooks 18 are vertically pivotably supported by pins 19 on the trolleys 16 at intervals corresponding to substantially entire length of the carrier connector 6A. The hooks 18 are provided at their front portions with weights 20 projecting forwardly from the trolleys 16 and are normally biased such that engagement pawls 21 formed at the rear portions of the hooks 18 are raised to an upper engaging position. A downwardly-projecting engagement piece 22 is fixed to the frame 7 of the leading carrier 6a, and the pawl 21 is engaged with a rear slant surface 22a of the engagement piece 22 so as to convey the traveling structure 6A in the direction of the arrow in FIG. 2. When a front slant surface 18a of the hook 18 abuts against a stopper 23 provided in the conveying lane, the hook 18 is rotated to disengage the pawl 21 from the engagement piece 22, thereby stopping the traveling structure 6A. An engagement release piece 24 having a bottom surface 24a leveled to the stopper 23 is fixed to the frame 7 of the fourth and last carrier 6d. When the hook 18 of a trailing traveling structure 6A approaches a leading traveling structure 6A at rest (not shown), the front slant surface 18a of the hook 18 drawing the trailing structure 6A collides with the engagement release piece 24 of the leading structure 6A at rest, the hook 18 is disengaged from the engagement piece 22 to stop the trailing structure 6A. Accordingly, the leading and trailing structrures 6A may be stored on a conveyor line, being in contact with each other, and when the stopper 23 is sidewardly retracted, the engagement piece 22 is engaged with a subsequent hook 18 to start the leading traveling structure 6A. FIGS. 4 and 5 show a connection from the carriers 6b and 6c to the stand 13. The hollow box-like carrier frame 7 has a width substantially equal to a rail spacing (s) of the carrier track 5. Small diameter portions 25a of thrust metal bearings 25 are inserted into holes formed on both sides of the frame 7 at a central portion between the front and rear traveling rollers, and an axle 26, which is in contact with the inside ends of the small diameter bearings at both ends thereof, and the right and left thrust metal bearings 25 are fastened by a common bolt 27 as inserted through both the axle and the thrust metal bearings, thereby fixing the thrust metal bearings 25 to the frame 7 and pivotally supporting the axle 26. A lower vertical portion 29 of a C-shaped support leg 28 is welded to the axle 26 at its central portion. The C-shaped support leg 28 has a lower horizontal bent portion 52 mounting a vertical bent portion 30 offset to one side of the rail 5, and pin 32 which is axial alignment with the lower vertical portion 29 is fixed at its base portion 33 to an upper horizontal portion 31. The stand 13 mounting an automotive body M thereon is constructed of a longitudinal member 34 formed of a square box beam, horizontal members 35 formed of similar box beams and fixed at right angles to front and rear lower surface of the longitudinal member, upright struts 36 fixed to both ends of the horizontal members 35, and a strut 37 fixed to a front end of the longitudinal member 34. The pins 32 are inserted through holes of metal fittings 38 (FIGS. 4 and 5) fixed to central lower surfaces of the horizontal members 35, so as to support the stand 13 on the support leg 28, and the horizontal members 35 are horizontally rotatably fixed by nuts 39. Perpendicular members 40 are fixed to the metal fittings 38 and the vertical members 34 to further strongly assemble both members 38 and 34 into a unitary assembly. The rail spacing (s) is set to a sufficiently large value such that even when the center of gravity of the vehicular body M mounted on the stand 13 is sidewardly offset because of difference in a vehicular structure such as a position of a steering wheel and a fuel tank, it is always within the spacing (s), thus allowing the right and left traveling rollers 8 to be stably supported on the rail channel member 5a. However, since the floor opening portion above the spacing (s) is covered with a guide plate 10 except for a guide slot 11 of a small width (less than about 50 mm) which prevents a foot or a wheel from entering it, there is no danger from traveling on the working floor, and a truck, etc. is permitted to safely cross the guide slot 11. With this arrangement, as the axle 26 is arranged at the central portion of the carriers 6b and 6c, acceleration of the shaft tube 26 is suppressed relative to lateral acceleration received by the traveling rollers 8 at curved or switched positions of the track 5, and the shaft tube 26 constitutes a pivot having a sufficient length nearly equal to an entire width of the carrier, thus restricting the swaying motion of the vehicular body M to be sufficiently small, as limited by the clearance between the rollers 8 and the underside of the top flange of the channel members 5a. FIG. 7 shows an example of a painting booth for the vehicular body M. Tracks 5 and 14 are introduced to a position just under a floor 43 in a painting booth 42 including a paint-flushing space 41 under the floor, and a grating 45 (instead of the floor board 2) is laid on floor beams 44 provided over the flushing space 41 to the substantially same level as the track 5. There is provided a tunnel-like shielding cover 46 (see FIG. 5) covering the guide channel 11 over the entire length of the painting booth, and a passage 47 of small width through which the lower substantially horizontal portion 52 of the C-shaped support leg 28 passes is opened to one side of the shielding cover 46. As shown in broken lines in FIG. 5, the shielding cover 46 consists of shielding plates 48 and 49 bolted to both side struts 3 at the bases thereof. The shielding plate 48 has an upper plate portion 50 which enters into a recess 30a of the C-shaped support leg 28 and a lip 51 of small width downwardly bent at its tip end. The shielding plate 49 is bent upwardly slantwise toward the lower vertical portion 29 beneath the lower horizontal portion 52 of the C-shaped support leg 28, and a tip end of the shielding plate 49 is spaced from the lip 51 to form the passage 47 allowing the lower horizontal portion 52 to pass therethrough between the plate 49 and the lip 51. As the passage 47 opens downwardly slantwise, there is no possibility that ventilating air discharged downwardly from a ceiling of the booth 42 through the grating 45 will suck sprayed coating material, such as paint, into the passage 47, thereby keeping the interior of the shielding cover 46 clean. FIGS. 8 and 9 show other embodiments of the shielding cover. In FIG. 8, a passage 47a for the vertical bent portion 30 is formed by using shielding plates 48a and 49a. In FIG. 9, elastic members 55 such as rubber is mounted on the shielding plates 48a and 49a so as to close the passage 47a by engaging around the vertical portion 30. In FIG. 10 showing a further embodiment, the lower horizontal portion 52' of the C-shaped support leg 28' is arranged near the floor surface, and the shielding cover 46' is formed of a single shielding plate 48b fixed to the strut 3 on one side. A passage 47b for the lower horizontal portion 52' is formed between an end vertical portion 56 and the floor surface. An upper surface of the shielding plate 48b is inclined downwardly toward the one side, so as to prevent a coating material sprayed on the upper surface from flowing down to the side where the passage 47b is located. While selected embodiments of the invention have been illustrated and described, the invention is defined by the appended claims.

A floor conveyor eliminates inclination and rolling of a vehicular body during conveying. A pair of channel members having a substantially rectangular recess on one side are oppositely arranged just under a working floor with sufficiently large spacing defined therebetween to form a carrier track, and cylindrical travelling rollers arranged at front and rear portions of a carrier are inserted into the recess of the rails. Vertical shaft guide rollers are rotatably supported on the travelling roller shafts of the carrier. At a substantially central position just above the roller shafts the rollers have a width smaller than a spacing between the rails. The support legs are inserted through the guide channels, and comprise a C-shaped structure where a part of the support legs on the floor surface is recessed sidewardly with respect to a conveying direction.

BACKGROUND OF THE INVETNION The present invention relates to an apparatus used to inform the operator of a submerged remotely operated vehicle (hereinafter R.O.V.) of the amount of inclination of a camera's vision axis from a reference axis defined relative to the R.O.V. that carries the camera. DESCRIPTION OF THE PRIOR ART Methods and apparatus have been developed for drilling and completing oil and gas wells in the ocean floor in a manner such that after completion of the well the wellhead assembly including its various components is positioned beneath the surface of the water, preferably on the ocean floor. These facilities are often positioned in water depths greater than the depth at which a diver can safely and readily work. It may therefore be seen that the adjustment of any of the wellhead components from time to time, or the re-entry into a well to carry out maintenance or reconditioning work, presents a considerable problem when the wellhead assembly is positioned below the surface of the water. As disclosed in U.S. Pat. No. 3,099,316 issued July 30, 1963 to Glenn D. Johnson a remotely operated vehicle (R.O.V.) may be used in place of a diver to perform the above mentioned well operation and maintenance tasks. The R.O.V. disclosed in this patent '316 is mounted on a track that encircles the well. Television cameras and floodlights are carried by the R.O.V. and are remotely-controlled by an operator positioned, say, at the surface on an operating barge, the video signals from the television camera being transmitted to the barge through cable. The camera may pan and tilt in different directions as the R.O.V. tracks around the wellhead. In recent years, however, more sophisticated R.O.V.'s have been developed that can freely swim through the water and hover at selected positions away from the wellhead. The operator, however, of these more sophisticated devices sometimes experiences disorientation due to the change of his visual references as the camera is swiveled from a straight ahead direction. For example, if the camera is panned to the left 90° for several minutes as the R.O.V. hovers in front of the wellhead the operator may begin to assume that actuation of the R.O.V.'s thrusters will cause the R.O.V. to be driven left 90°. Unfortunately, actuation of the R.O.V.'s thrusters will drive the R.O.V. into the wellhead. Since each R.O.V. may cost approximately $200,000 to $700,000, the cost of damage to the R.O.V. may be quite expensive. Well operations may also be curtailed until the R.O.V. can be repaired, not to mention the possibility of the R.O.V. damaging the wellhead. A method and apparatus needs to be developed therefore that eliminates or reduces R.O.V. operator disorientation, and thereby reduces the possibility of collision damage to the R.O.V. and/or the associated wellhead equipment that the R.O.V. is attempting to repair. SUMMARY OF THE INVENTION The present invention consists of presenting an indication to the R.O.V. operator of the amount of inclination of the R.O.V. camera's vision axis from a reference axis defined relative to the R.O.V., the vision axis being the "line of sight" of the lens of the camera. When the vision axis of the camera is aligned with a desired R.O.V. reference axis and therefore there is no inclination between the axes, a moveable indicator such as a crosshair will be viewed in the center of the operator's television screen. If the reference axis happens to be aligned with the forward direction of motion of the R.O.V., a crosshair centered in the middle of the television viewing screen will inform the operator that the R.O.V. will travel towards the object(s) viewed by the camera when the R.O.V.'s thrusters are actuated in that forward direction. If the camera and therefore its vision axis is turned to the left, the crosshair which represents the location of the reference axis will correspondingly move to the right on the television viewing screen. In other words, since the center of the camera's vision axis will always appear in the center of the television screen, the crosshair or "moveable indicator" will move away from the center of the television screen whenever there is any amount of inclination between the vision axis and the reference axis. The amount of distance that the crosshair moves away from the center of the television screen indicates the relative amount of inclination that exists between the reference and vision axes. To insure that the crosshair is maintained over the location of the reference axis as long as the reference axis remains within the television view, scaling factors may be incorporated into the moveable indicator signal generation equipment, the apparatus of the present invention, in order to adjust for variations in camera lens focal lengths which define the outer limits of the field of view of the television screen. Depending on the camera viewing angle and the range of the pan and tilt mechanisms, the operator may be able to turn the camera so that the reference axis indicator falls outside the viewing screen. In this case, limiting values may be placed in the software to cause the crosshair to remain with the edge of the screen and to blink and thereby indicate to the operator which direction the camera must be moved to bring it back into view. Additionally or as an alternative, secondary reference indicators at say 90° from the reference axis may be used with appropriate identifying symbols to advise the operator of current camera orientation. The apparatus of the present invention is also useful for sighting and alignment for directional surveys where it is desired to establish the direction of heading or azimuth of a wellhead or flowline using a compass mounted on the R.O.V. Here typically the compass is aligned with a principal axis of the vehicle and the television screen presents both a digital and an analog display of the compass reading which is the heading or azimuth of the vehicle. The crosshair of the present invention by pointing in the direction of the vehicle (and compass) provides a "sight" like a gunsight which permits the operator to align the vehicle and compass along for example a flowline to obtain the heading of the flowline even though the camera may have its center of view not aligned with that of the vehicle. The R.O.V. cameras are situated normally so that their view is largely unobstructed and they therefore present no view of the R.O.V. itself which if available could give the operator a visual reference with respect to the R.O.V. in order to know at all times which way the camera is pointing with respect to the R.O.V. Existing television monitors already may present camera pan and tilt angles in degrees. But it is very difficult for the operator to relate those numbers to the current direction in which the camera is pointed. It is an object of this invention therefore to provide the operator with a natural and intelligible artificial visual indication of the direction of a reference axis of the vehicle so he will know more intuitively which way the camera's vision axis is pointing with respect to the vehicle. It is well recognized that this could be accomplished by mounting an array of mechanical reference markers or crosshairs on the vehicle out in front of the cameras, but these would be in the way when moving the R.O.V. up to a work area and would be subject to damage and would also be in the way of the manipulator arms when they are working. It is an object of the invention to provide the operator of a R.O.V. that carries a camera with a visual indication of the inclination of the camera to a reference axis that is defined relative to the R.O.V. It is an object of the invention to minimize the risk of collisions between an R.O.V. and an adjacent wellhead. It is a feature of the invention to provide an indicator to the R.O.V. operator that indicates the amount of inclination of the camera's vision axis from the reference axis, the reference axis being defined relative to the R.O.V. It is a further feature of the invention to provide a moveable indicator on the operator's television screen that indicates this amount of inclination. These and other features, objects, and advantages of the present invention will become apparent from the following detailed description, wherein reference is made to the figures in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic representation showing a R.O.V. submerged in a body of water beneath a floating vessel. FIG. 2 is a schematic representation showing the camera viewing an object oriented away from the camera's reference axis, and the associated presentation of the object and a moveable indicator on the moveable indicator display means. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1 a vessel 10 is shown floating upon the surface 11 of a body of water 12. A remotely operated vehicle (hereinafter R.O.V.) 13 is shown submerged in the body of water 12. A camera 14 is shown operatively engaged to the R.O.V. 13. Vision axis 15 is shown aligned with reference axis 16, both axes 15, 16 passing through the origin 17 of the mutually orthogonal pan axis 18 and tilt axis 19. The camera 14 carries viewing means 20, such as a lens well known to the art, the viewing means 20 being shown positioned at the origin 17 of the tilt and pan axes 18, 19. Note that for the sake of clarity the pan and tilt axes 18, 19 are defined with respect to the central point of movement of the viewing means 20 and not with respect to the central point of movement of the camera 14. The camera vision axis 15 and reference axis 16 are shown passing through the viewing means 20, origin 17, a reference indicator 21, and a viewed object 22 such as a submerged sphere. The camera vision axis 15 is defined through the viewing means 20 and objects located centrally in front of and viewed by the viewing means 20. In FIGS. 1 and 2 the camera's 14 vision axis 15 is shown aligned with the camera's longitudinal axis. As discussed later, it should be recognized that the vision axis 15 need not be aligned with the camera's longitudinal axis (not shown for clarity). Forming a portion of the camera position control and position measurement apparatus 23 an interface 25 well known to the art is shown producing a tilt actuation signal 24 which is subsequently received by a tilt actuator 26 operatively engaged to the camera 14. Actuation of the tilt actuator 26 causes the viewing means 20 of the camera 14 to move with respect to tilt axis 19. The inclination of the viewing means 20 relative to the tilt axis will be indicated by the value of a tilt inclination signal 27 generated by the tilt actuator 26, by means well known to the art. It is well recognized that other means of actuation and measurement of the resultant inclination of the viewing means 20 of the camera 14 may be used. In a similar manner a pan actuation signal 28 is produced by interface 25 and causes the actuation of pan actuator 29. A pan inclination signal 30 generated by pan actuator 29 indicates the position of the viewing means 20 of the camera 14 with respect to the pan axis 18 by means well known to the art. In a preferred embodiment the tilt and pan actuators 26, 29 respectively form camera inclination signal means by producing or generating the tilt and pan inclination signals 27, 30 respectively, though it is well recognized that other devices may be used to generate these signals 27, 30. It is well recognized that in a typical installation the origin 17 of the pan and tilt axis 18, 19 may be chosen to be located at the central point of movement of the camera 14, instead of at the central point of movement of the viewing means 20. The axes 18, 19 may be located at the central point of movement of camera 14 as long as the vision axis 15 of the viewing means 20 coincides with the central longitudinal axis of the camera 14. But vision axis 15 inclination measurement problems will result if the viewing means 20 (or lens) is oriented at any angle that does not coincide with the central longitudinal axis of the camera 14. For example, if the viewing means 20 is installed in the camera 14 at a 15° angle offset from the longitudinal axis of the camera 14, the vision axis 15 inclination signals if generated from reference to the camera's 14 longitudinal axis would be in error by 15°. To precisely define, therefore, the true inclination of the vision axis 15 relative to the reference axis 16, and for purposes of clarity the origin 17 of the pan and tilt axis 18, 19 is shown located at the central point of movement of the viewing means 20. It is well recognized that the value of the tilt and pan inclination signals 27 and 30 respectively may be adjusted or modified if the camera's 14 vision axis 15 does not coincide with the central longitudinal axis of the camera 14. The direction of the preferred motion of R.O.V. 13 is shown by arrow 31. The direction may be maintained by operation of thrusters 32, 32A located on the R.O.V. 13. A video signal 33 is shown produced by camera 14 and received by interface 25. Signal transmission means 34 such as a multiplex cable 35 well known to the art coupled at either end to multiplex devices 36 also well known to the art transmits signals 24, 27, 28, 30, 33 to and from the floating vessel 10 and the R.O.V. 13. Referring in more detail now to the equipment located on the vessel 10, in a preferred embodiment a camera position controller 37 such as a joy stick well known to the art produces a position demand signal 38 to interface 39. The interface 39 compares the demand signal 38 with the existing tilt and pan inclination signals 27, 30, respectively. If necessary the interface 39 will continue to generate tilt and/or pan actuation signals 24, 28 which will cause the continued movement of the viewing means 20 until the conditions of the position demand signal 38 are satisfied, by means and methods common to feedback control systems well known to the art. It is well recognized that the camera position controller 37 position demand signal 38 may be used to indicate the position of the camera 14, such that, in an alternative embodiment, the position demand signals 38 may be used in place of the signals 27, 30 from the camera inclination signal means. The camera vision axis inclination indication apparatus 40, the object of the present invention, comprises a moveable indicator signal generation means 41 that includes a micro-processor 48 well known to the art that may incorporate for example appropriate analog to digital conversion equipment (not shown) to process input and output signals as necessary, a moveable indicator signal transmission means 42 such as an electrical conduit well known to the art, and a moveable indicator display means 43 such as a cathode ray tube having a television screen well known to the art. Video signal 33 produced by camera 14 is input into the display means 43 and subsequently presents a view of objects located in the field of view of camera vision axis 15 to the R.O.V. 13 operator, by means well known to the art. Notice that display means 43 and the camera position controller 37 both form portions of an operator's console 44 used by the operator of the R.O.V. 13. Signal generation means 41 receive the tilt and pan inclination signals 27, 30 respectively from the multiplex 36. Signal generation means 41 may also receive a thruster selection signal 45. As explained later, computations carried out by the signal generation means 41 on the basis of signals 27, 30, (45) will cause a moveable indicator 46 to be properly located and presented on the moveable indicator display means 43, as a representation to the operator of the amount of inclination from the reference axis 16 to the camera's 14 vision axis 15, or, from another perspective, the amount of inclination from the vision axis 15 to the reference axis 16, both amounts of inclination having the same value. Referring now to FIG. 2, the viewing means 20 of camera 14 for purpose of illustration is shown to have a 30° pan and 40° tilt inclination 47, in the process of viewing the viewed object 22. Object 22 has moved from its position shown in FIG. 1 and the camera's viewing means 20 has been moved to keep object 22 in the center of its vision. Tilt and pan inclination signals 27, 30 respectively, generated by the tilt and pan actuators 26, 29 respectively are shown being received by the moveable indicator signal generation means 41, while video signal 33 is shown being received by the display means 43. A compilation of the functions performed by the microprocessor 48, such as a Leibnitz Lann Model 107LE Video Overlay Unit manufactured by Liebnitz Lann Ltd. Balmakeith Industrial Estate, Nairn, Scotland, Telex 75688, located within the signal generation means 41 is tabulated in FIG. 2 for further reference. The eraseable programmable read only memories of the microprocessor 48 are programmed to interpret signals 27, 30 and thereafter output the desired moveable indicator signals 51. An unscaled moveable indicator signal 49 is shown leaving the eraseable programmable read-only memory section of the microprocessor 48 prior to being received by the scaling factor portion of the microprocessor 48. A viewing area 50 is defined within the boundaries of the moveable indicator display means 43. The viewing area 50 forms the display portion of the cathode ray tube mentioned earlier. The camera vision axis inclination indication apparatus 40 is used to determine the amount of inclination from the camera vision axis 15 to the reference axis 16. The vehicle 13 will carry camera inclination signal means in a preferred embodiment consisting of a tilt and pan actuator 26, 29 respectively, which are operatively engaged to the camera 14. The inclination signal means produce camera tilt and pan inclination signals 27, 30 which indicate the amount of inclination from the vision axis 15 to the vehicle 13. The inclination signals 27, 30 are transmittable from the inclination signal means 26, 29 by use of signal transmission means 34 which comprise in a preferred embodiment the multiplex cable 35 which is used in conjunction with the multiplex devices 36 well known to the art. The microprocessor 48 of the signal generation means 41 defines the location of the camera's vision axis 15 by means well known to the art. The microprocessor 48 also defines the location of reference axis 16 relative to the vehicle 13. For example, in a preferred embodiment the reference axis 16 may be defined parallel to the longitudinal axis of the vehicle 13 or parallel to the direction 31 of preferred motion of the vehicle 13. Once both axes 15, 16 are defined by the microprocessor 48 the amount of inclination from the vision axis 15 to the reference axis 16 may be easily calculated. The moveable indicator display means 43 is capable of receiving the moveable indicator signal 51 generated by the signal generation means 41 and thereafter displaying the moveable indicator 46 upon the viewing area 50 of the display means 43. Moveable indicator signal transmission means 42 are capable of receiving the moveable indicator signal 51 from the signal generation means 41 and producing the signal 51 to the moveable indicator display means 43 by means well known to the art. As can be seen in FIG. 2 the camera's 14 vision axis 15 has been moved away from an orientation parallel to the reference axis 16 in order to view the object 22. The display means 43 presents the object 22 in the center of the viewing area 50. The moveable indicator 46 is presented in the lower right hand corner of the viewing area 50, however, because it indicates the location of reference axis 16. Since the reference axis 16 in a preferred embodiment may be selectively aligned with the direction 31 of preferred motion of the R.O.V. 13, the operator needs only note the location of the moveable indicator 46 in order to know where the R.O.V. 13 will be directed upon actuation of thrusters 32, 32A. If the reference axis 16 has been aligned in this direction 31 the R.O.V. 13 will tend to drive forward in a direction to the lower right of the viewed object 22 when thrusters 32, 32A are actuated. It is understood, of course, that the reference axis 16 may remain aligned with, for example, the longitudinal axis of the R.O.V. 13, or perhaps even oriented to a particular compass heading, dependent upon the choice of the operator of the R.O.V. Referring to FIG. 1 it can be seen that the vision axis 15 is lined up directly with the reference axis 16 and viewed object 22. As shown on the moveable indicator display means 43 in FIG. 1 the moveable indicator 46 is positioned over the viewed object 22. In this example since the moveable indicator 46 is centered directly over the viewed object 22 if the direction of thrust of the thrusters 32, 32A is aligned with the reference axis 16 and the thrusters 32, 32A are subsequently energized then the camera 14 will eventually collide with the viewed object 22. In a preferred embodiment of the present invention the reference axis 16 remains in a fixed orientation relative to the remotely operated vehicle 13. In other words, the reference axis 16 in a first mode of operation may always remain parallel to the longitudinal axis of the remotely operated vehicle 13. If this is the case, the operator of the R.O.V. 13 will become accustomed to a set reference axis 16 regardless of the possible changes in the direction 31 of the R.0.V's due to changes in the actuation pattern of thrusters 32, 32A. It is well recognized, however, that the operator in a second mode of operation may desire to have the signal generation means 41 redefine the reference axis 16 every time that a new direction 31 of preferred motion results from a different actuation pattern of thrusters 32, 32A. The microprocessor 48 may be programmed by means well known to the art to operate in either the first or second mode of operation. The second mode of operation where the reference axis 16 is reoriented every time a different thruster 32, 32A pattern is used may be affected by the microprocessor 48 by inclusion of the thruster 32, 32A selection signal 45 into the signal generation means 41. The thruster selection signal 45 would include the number and direction of thrusters 32, 32A that are to be actuated or that are currently actuated in order to allow the signal generation means 41 to properly calculate the heading of the R.O.V. under operation or anticipated operation of each particular combination of thrusters 32, 32A. It is well recognized that whereas only two thrusters 32, 32A are shown in FIG. 1, additional thrusters (not shown) are typically incorporated into the R.O.V. 13 in order to allow it to move freely in three dimensions. Referring more specifically to FIGS. 1 and 2 it can be seen that in a preferred embodiment, the camera vision axis inclination indication apparatus 40 is carried by and used on a first vehicle comprising the floating vessel 10. The first vehicle is tethered to a second vehicle comprising the remotely operated vehicle 13. It is well understood, however, that the inclination indication apparatus 40 may be directly mounted on the vehicle 13 that also carries the camera 14. In order for the moveable indicator 46 to represent correctly the position of the reference axis 16 on the viewing area 50, a scaling factor must be applied to the unscaled movable indicator signal 49 to accommodate the particular focal length chosen for the viewing means 20 of camera 14. This factor will be fixed for any fixed focal length lens such as a narrow, standard or wide angle lens. In the event a variable focal length or zoom lens is used, its control or feedback signal must be input to the movable indicator signal generation means 41 to adjust the scaling factor to accommodate the focal length in use at any time by the operator. The sweep angles of the pan and tilt actuators 29 and 26 respectively are likely to exceed the viewing angles subtended by even a wide angle lens, and this would tend at times to make the movable indicator 46 "fall outside" of the viewing area 50. In this event the movable indicator signals 51 should be limited by the microprocessor 48 program to values just less than the outside limits of the viewing angles of the viewing means 20 of camera 14, and when these limits are reached, the movable indicator 46 should be caused to blink, or otherwise the representation of the moveable indicator 46 may be changed in some recognizable manner. This will indicate to the operator that the reference axis 16 as represented by the moveable indicator 46 is outside the view of the vision means 20 (lens) of the camera 14. This will also indicate to the operator the direction in which the lens 20 of the camera 14 must be moved to bring the moveable indicator 46 back into the viewing area 50. In a preferred embodiment the movable indicator 46 is shown as taking the form of a crosshair symbol well known to the art. It is well recognized however that many graphical presentations may be made to accomplish the same result. Many other variations and modifications may be made in the apparatus and techniques hereinbefore described, both by those having experience in this technology, without departing from the concept of the present invention. Accordingly, it should be clearly understood that the apparatus and methods depicted in the accompanying drawings and referred to in the foregoing description are illustrative only and are not intended as limitations on the scope of the invention.

Operators of submerged remotely operated vehicles (R.O.V.)'s must typically view the subsea environment by use of a submerged television camera carried by the R.O.V. Often no part of the vehicle is visible to the operator to give him a natural indication of the direction in which the camera is facing with respect to the vehicle. The apparatus of the present invention generates an artificial "crosshair" on his television viewing screen representing a selected reference axis of the vehicle. This not only reduces directional disorientation of the operator but also gives him a line of sight, independent of camera direction, which he can use to establish the azimuth of subsea features with respect to the vehicle's compass.

CROSS REFERENCE [0001] This application claims priority from U.S. application Ser. No. 09/356,491, filed Jul. 19, 1999, entitled “Method and Apparatus for Subsampling Phase Spectrum Information” and currently assigned to the assignee of the present application. BACKGROUND OF THE INVENTION [0002] I. Field of the Invention [0003] The present invention pertains generally to the field of speech processing, and more specifically to methods and apparatus for subsampling phase spectrum information to be transmitted by a speech coder. [0004] II. Background [0005] Transmission of voice by digital techniques has become widespread, particularly in long distance and digital radio telephone applications. This, in turn, has created interest in determining the least amount of information that can be sent over a channel while maintaining the perceived quality of the reconstructed speech. If speech is transmitted by simply sampling and digitizing, a data rate on the order of sixty-four kilobits per second (kbps) is required to achieve a speech quality of conventional analog telephone. However, through the use of speech analysis, followed by the appropriate coding, transmission, and resynthesis at the receiver, a significant reduction in the data rate can be achieved. [0006] Devices for compressing speech find use in many fields of telecommunications. An exemplary field is wireless communications. The field of wireless communications has many applications including, e.g., cordless telephones, paging, wireless local loops, wireless telephony such as cellular and PCS telephone systems, mobile Internet Protocol (IP) telephony, and satellite communication systems. A particularly important application is wireless telephony for mobile subscribers. [0007] Various over-the-air interfaces have been developed for wireless communication systems including, e.g., frequency division multiple access (FDMA), time division multiple access (TDMA), and code division multiple access (CDMA). In connection therewith, various domestic and international standards have been established including, e.g., Advanced Mobile Phone Service (AMPS), Global System for Mobile Communications (GSM), and Interim Standard 95 (IS-95). An exemplary wireless telephony communication system is a code division multiple access (CDMA) system. The IS-95 standard and its derivatives, IS-95A, ANSI J-STD-008, IS-95B, proposed third generation standards IS-95C and IS-2000, etc. (referred to collectively herein as IS-95), are promulgated by the Telecommunication Industry Association (TIA) and other well known standards bodies to specify the use of a CDMA over-the-air interface for cellular or PCS telephony communication systems. Exemplary wireless communication systems configured substantially in accordance with the use of the IS-95 standard are described in U.S. Pat. Nos. 5,103,459 and 4,901,307, which are assigned to the assignee of the present invention and fully incorporated herein by reference. [0008] Devices that employ techniques to compress speech by extracting parameters that relate to a model of human speech generation are called speech coders. A speech coder divides the incoming speech signal into blocks of time, or analysis frames. Speech coders typically comprise an encoder and a decoder. The encoder analyzes the incoming speech frame to extract certain relevant parameters, and then quantizes the parameters into binary representation, i.e., to a set of bits or a binary data packet. The data packets are transmitted over the communication channel to a receiver and a decoder. The decoder processes the data packets, unquantizes them to produce the parameters, and resynthesizes the speech frames using the unquantized parameters. [0009] The function of the speech coder is to compress the digitized speech signal into a low-bit-rate signal by removing all of the natural redundancies inherent in speech. The digital compression is achieved by representing the input speech frame with a set of parameters and employing quantization to represent the parameters with a set of bits. If the input speech frame has a number of bits N i and the data packet produced by the speech coder has a number of bits N o , the compression factor achieved by the speech coder is C r =N i /N o . The challenge is to retain high voice quality of the decoded speech while achieving the target compression factor. The performance of a speech coder depends on (1) how well the speech model, or the combination of the analysis and synthesis process described above, performs, and (2) how well the parameter quantization process is performed at the target bit rate of N o bits per frame. The goal of the speech model is thus to capture the essence of the speech signal, or the target voice quality, with a small set of parameters for each frame. [0010] Perhaps most important in the design of a speech coder is the search for a good set of parameters (including vectors) to describe the speech signal. A good set of parameters requires a low system bandwidth for the reconstruction of a perceptually accurate speech signal. Pitch, signal power, spectral envelope (or formants), amplitude spectra, and phase spectra are examples of the speech coding parameters. [0011] Speech coders may be implemented as time-domain coders, which attempt to capture the time-domain speech waveform by employing high time-resolution processing to encode small segments of speech (typically 5 millisecond (ms) subframes) at a time. For each subframe, a high-precision representative from a codebook space is found by means of various search algorithms known in the art. Alternatively, speech coders may be implemented as frequency-domain coders, which attempt to capture the short-term speech spectrum of the input speech frame with a set of parameters (analysis) and employ a corresponding synthesis process to recreate the speech waveform from the spectral parameters. The parameter quantizer preserves the parameters by representing them with stored representations of code vectors in accordance with known quantization techniques described in A. Gersho & R. M. Gray, Vector Quantization and Signal Compression (1992). [0012] A well-known time-domain speech coder is the Code Excited Linear Predictive (CELP) coder described in L. B. Rabiner & R. W. Schafer, Digital Processing of Speech Signals 396-453 (1978), which is fully incorporated herein by reference. In a CELP coder, the short term correlations, or redundancies, in the speech signal are removed by a linear prediction (LP) analysis, which finds the coefficients of a short-term formant filter. Applying the short-term prediction filter to the incoming speech frame generates an LP residue signal, which is further modeled and quantized with long-term prediction filter parameters and a subsequent stochastic codebook. Thus, CELP coding divides the task of encoding the time-domain speech waveform into the separate tasks of encoding the LP short-term filter coefficients and encoding the LP residue. Time-domain coding can be performed at a fixed rate (i.e., using the same number of bits, N 0 , for each frame) or at a variable rate (in which different bit rates are used for different types of frame contents). Variable-rate coders attempt to use only the amount of bits needed to encode the codec parameters to a level adequate to obtain a target quality. An exemplary variable rate CELP coder is described in U.S. Pat. No. 5,414,796, which is assigned to the assignee of the present invention and fully incorporated herein by reference. [0013] Time-domain coders such as the CELP coder typically rely upon a high number of bits, N 0 , per frame to preserve the accuracy of the time-domain speech waveform. Such coders typically deliver excellent voice quality provided the number of bits, N 0 , per frame is relatively large (e.g., 8 kbps or above). However, at low bit rates (4 kbps and below), time-domain coders fail to retain high quality and robust performance due to the limited number of available bits. At low bit rates, the limited codebook space clips the waveform-matching capability of conventional time-domain coders, which are so successfully deployed in higher-rate commercial applications. Hence, despite improvements over time, many CELP coding systems operating at low bit rates suffer from perceptually significant distortion typically characterized as noise. [0014] There is presently a surge of research interest and strong commercial need to develop a high-quality speech coder operating at medium to low bit rates (i.e., in the range of 2.4 to 4 kbps and below). The application areas include wireless telephony, satellite communications, Internet telephony, various multimedia and voice-streaming applications, voice mail, and other voice storage systems. The driving forces are the need for high capacity and the demand for robust performance under packet loss situations. Various recent speech coding standardization efforts are another direct driving force propelling research and development of low-rate speech coding algorithms. A low-rate speech coder creates more channels, or users, per allowable application bandwidth, and a low-rate speech coder coupled with an additional layer of suitable channel coding can fit the overall bit-budget of coder specifications and deliver a robust performance under channel error conditions. [0015] One effective technique to encode speech efficiently at low bit rates is multimode coding. An exemplary multimode coding technique is described in U.S. application Ser. No. 09/217,341, entitled VARIABLE RATE SPEECH CODING, filed Dec. 21, 1998, assigned to the assignee of the present invention, and fully incorporated herein by reference. Conventional multimode coders apply different modes, or encoding-decoding algorithms, to different types of input speech frames. Each mode, or encoding-decoding process, is customized to optimally represent a certain type of speech segment, such as, e.g., voiced speech, unvoiced speech, transition speech (e.g., between voiced and unvoiced), and background noise (nonspeech) in the most efficient manner. An external, open-loop mode decision mechanism examines the input speech frame and makes a decision regarding which mode to apply to the frame. The open-loop mode decision is typically performed by extracting a number of parameters from the input frame, evaluating the parameters as to certain temporal and spectral characteristics, and basing a mode decision upon the evaluation. [0016] Coding systems that operate at rates on the order of 2.4 kbps are generally parametric in nature. That is, such coding systems operate by transmitting parameters describing the pitch-period and the spectral envelope (or formants) of the speech signal at regular intervals. Illustrative of these so-called parametric coders is the LP vocoder system. [0017] LP vocoders model a voiced speech signal with a single pulse per pitch period. This basic technique may be augmented to include transmission information about the spectral envelope, among other things. Although LP vocoders provide reasonable performance generally, they may introduce perceptually significant distortion, typically characterized as buzz. [0018] In recent years, coders have emerged that are hybrids of both waveform coders and parametric coders. Illustrative of these so-called hybrid coders is the prototype-waveform interpolation (PWI) speech coding system. The PWI coding system may also be known as a prototype pitch period (PPP) speech coder. A PWI coding system provides an efficient method for coding voiced speech. The basic concept of PWI is to extract a representative pitch cycle (the prototype waveform) at fixed intervals, to transmit its description, and to reconstruct the speech signal by interpolating between the prototype waveforms. The PWI method may operate either on the LP residual signal or on the speech signal. An exemplary PWI, or PPP, speech coder is described in U.S. application Ser. No. 09/217,494, entitled PERIODIC SPEECH CODING, filed Dec. 21, 1998, assigned to the assignee of the present invention, and fully incorporated herein by reference. Other PWI, or PPP, speech coders are described in U.S. Pat. No. 5,884,253 and W. Bastiaan Kleijn & Wolfgang Granzow Methods for Waveform Interpolation in Speech Coding, in 1 Digital Signal Processing 215-230 (1991). [0019] In many conventional speech coders, the phase parameters of a given pitch prototype are each individually quantized and transmitted by the encoder. Alternatively, the phase parameters may be vector quantized in order to conserve bandwidth. However, in a low-bit-rate speech coder, it is advantageous to transmit the least number of bits possible to maintain satisfactory voice quality. For this reason, in some conventional speech coders, the phase parameters may not be transmitted at all by the encoder, and the decoder may either not use phases for reconstruction, or use some fixed, stored set of phase parameters. In either case the resultant voice quality may degrade. Hence, it would be desirable to provide a low-rate speech coder that reduces the number of elements necessary to transmit phase spectrum information from the encoder to the decoder, thereby transmitting less phase information. Thus, there is a need for a speech coder that transmits fewer phase parameters per frame. SUMMARY OF THE INVENTION [0020] The present invention is directed to a speech coder that transmits fewer phase parameters per frame. Accordingly, in one aspect of the invention, a method of processing a prototype of a frame in a speech coder advantageously includes the steps of producing a plurality of phase parameters of a reference prototype; generating a plurality of phase parameters of the prototype; and correlating the phase parameters of the prototype with the phase parameters of the reference prototype in a plurality of frequency bands. [0021] In another aspect of the invention, a method of processing a prototype of a frame in a speech coder advantageously includes the steps of producing a plurality of phase parameters of a reference prototype; generating a plurality of linear phase shift values associated with the prototype; and composing a phase vector from the phase parameters and the linear phase shift values across a plurality of frequency bands. [0022] In another aspect of the invention, a method of processing a prototype of a frame in a speech coder advantageously includes the steps of producing a plurality of circular rotation values associated with the prototype; generating a plurality of bandpass waveforms in a plurality of frequency bands, the plurality of bandpass waveforms being associated with a plurality of phase parameters of a reference prototype; and modifying the plurality of bandpass waveforms based upon the plurality of circular rotation values. [0023] In another aspect of the invention, a speech coder advantageously includes means for producing a plurality of phase parameters of a reference prototype of a frame; means for generating a plurality of phase parameters of a current prototype of a current frame; and means for correlating the phase parameters of the current prototype with the phase parameters of the reference prototype in a plurality of frequency bands. [0024] In another aspect of the invention, a speech coder advantageously includes means for producing a plurality of phase parameters of a reference prototype of a frame; means for generating a plurality of linear phase shift values associated with a current prototype of a current frame; and means for composing a phase vector from the phase parameters and the linear phase shift values across a plurality of frequency bands. [0025] In another aspect of the invention, a speech coder advantageously includes means for producing a plurality of circular rotation values associated with a current prototype of a current frame; means for generating a plurality of bandpass waveforms in a plurality of frequency bands, the plurality of bandpass waveforms being associated with a plurality of phase parameters of a reference prototype of a frame; and means for modifying the plurality of bandpass waveforms based upon the plurality of circular rotation values. [0026] In another aspect of the invention, a speech coder advantageously includes a prototype extractor configured to extract a current prototype from a current frame being processed by the speech coder; and a prototype quantizer coupled to the prototype extractor and configured to produce a plurality of phase parameters of a reference prototype of a frame, generate a plurality of phase parameters of the current prototype, and correlate the phase parameters of the current prototype with the phase parameters of the reference prototype in a plurality of frequency bands. [0027] In another aspect of the invention, a speech coder advantageously includes a prototype extractor configured to extract a current prototype from a current frame being processed by the speech coder; and a prototype quantizer coupled to the prototype extractor and configured to produce a plurality of phase parameters of a reference prototype of a frame, generate a plurality of linear phase shift values associated with the current prototype, and compose a phase vector from the phase parameters and the linear phase shift values across a plurality of frequency bands. [0028] In another aspect of the invention, a speech coder advantageously includes a prototype extractor configured to extract a current prototype from a current frame being processed by the speech coder; and a prototype quantizer coupled to the prototype extractor and configured to produce a plurality of circular rotation values associated with the current prototype, generate a plurality of bandpass waveforms in a plurality of frequency bands, the plurality of bandpass waveforms being associated with a plurality of phase parameters of a reference prototype of a frame, and modify the plurality of bandpass waveforms based upon the plurality of circular rotation values. BRIEF DESCRIPTION OF THE DRAWINGS [0029] [0029]FIG. 1 is a block diagram of a wireless telephone system. [0030] [0030]FIG. 2 is a block diagram of a communication channel terminated at each end by speech coders. [0031] [0031]FIG. 3 is a block diagram of an encoder. [0032] [0032]FIG. 4 is a block diagram of a decoder. [0033] [0033]FIG. 5 is a flow chart illustrating a speech coding decision process. [0034] [0034]FIG. 6A is a graph speech signal amplitude versus time, and FIG. 6B is a graph of linear prediction (LP) residue amplitude versus time. [0035] [0035]FIG. 7 is a block diagram of a prototype pitch period speech coder. [0036] [0036]FIG. 8 is a block diagram of a prototype quantizer that may be used in the speech coder of FIG. 7. [0037] [0037]FIG. 9 is a block diagram of a prototype unquantizer that may be used in the speech coder of FIG. 7. [0038] [0038]FIG. 10 is a block diagram of a prototype unquantizer that may be used in the speech coder of FIG. 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0039] The exemplary embodiments described herein below reside in a wireless telephony communication system configured to employ a CDMA over-the-air interface. Nevertheless, it would be understood by those skilled in the art that a subsampling method and apparatus embodying features of the instant invention may reside in any of various communication systems employing a wide range of technologies known to those of skill in the art. [0040] As illustrated in FIG. 1, a CDMA wireless telephone system generally includes a plurality of mobile subscriber units 10 , a plurality of base stations 12 , base station controllers (BSCS) 14 , and a mobile switching center (MSC) 16 . The MSC 16 is configured to interface with a conventional public switch telephone network (PSTN) 18 . The MSC 16 is also configured to interface with the BSCs 14 . The BSCs 14 are coupled to the base stations 12 via backhaul lines. The backhaul lines may be configured to support any of several known interfaces including, e.g., E 1 /T 1 , ATM, IP, PPP, Frame Relay, HDSL, ADSL, or xDSL. It is understood that there may be more than two BSCs 14 in the system. Each base station 12 advantageously includes at least one sector (not shown), each sector comprising an omnidirectional antenna or an antenna pointed in a particular direction radially away from the base station 12 . Alternatively, each sector may comprise two antennas for diversity reception. Each base station 12 may advantageously be designed to support a plurality of frequency assignments. The intersection of a sector and a frequency assignment may be referred to as a CDMA channel. The base stations 12 may also be known as base station transceiver subsystems (BTSs) 12 . Alternatively, “base station” may be used in the industry to refer collectively to a BSC 14 and one or more BTSs 12 . The BTSs 12 may also be denoted “cell sites” 12 . Alternatively, individual sectors of a given BTS 12 may be referred to as cell sites. The mobile subscriber units 10 are typically cellular or PCS telephones 10 . The system is advantageously configured for use in accordance with the IS-95 standard. [0041] During typical operation of the cellular telephone system, the base stations 12 receive sets of reverse link signals from sets of mobile units 10 . The mobile units 10 are conducting telephone calls or other communications. Each reverse link signal received by a given base station 12 is processed within that base station 12 . The resulting data is forwarded to the BSCs 14 . The BSCs 14 provides call resource allocation and mobility management functionality including the orchestration of soft handoffs between base stations 12 . The BSCs 14 also routes the received data to the MSC 16 , which provides additional routing services for interface with the PSTN 18 . Similarly, the PSTN 18 interfaces with the MSC 16 , and the MSC 16 interfaces with the BSCs 14 , which in turn control the base stations 12 to transmit sets of forward link signals to sets of mobile units 10 . [0042] In FIG. 2 a first encoder 100 receives digitized speech samples s(n) and encodes the samples s(n) for transmission on a transmission medium 102 , or communication channel 102 , to a first decoder 104 . The decoder 104 decodes the encoded speech samples and synthesizes an output speech signal S SYNTH (n). For transmission in the opposite direction, a second encoder 106 encodes digitized speech samples s(n), which are transmitted on a communication channel 108 . A second decoder 110 receives and decodes the encoded speech samples, generating a synthesized output speech signal S SYNTH (n). [0043] The speech samples s(n) represent speech signals that have been digitized and quantized in accordance with any of various methods known in the art including, e.g., pulse code modulation (PCM), companded μ-law, or A-law. As known in the art, the speech samples s(n) are organized into frames of input data wherein each frame comprises a predetermined number of digitized speech samples s(n). In an exemplary embodiment, a sampling rate of 8 kHz is employed, with each 20 ms frame comprising 160 samples. In the embodiments described below, the rate of data transmission may advantageously be varied on a frame-to-frame basis from 13.2 kbps (full rate) to 6.2 kbps (half rate) to 2.6 kbps (quarter rate) to 1 kbps (eighth rate). Varying the data transmission rate is advantageous because lower bit rates may be selectively employed for frames containing relatively less speech information. As understood by those skilled in the art, other sampling rates, frame sizes, and data transmission rates may be used. [0044] The first encoder 100 and the second decoder 110 together comprise a first speech coder, or speech codec. The speech coder could be used in any communication device for transmitting speech signals, including, e.g., the subscriber units, BTSs, or BSCs described above with reference to FIG. 1. Similarly, the second encoder 106 and the first decoder 104 together comprise a second speech coder. It is understood by those of skill in the art that speech coders may be implemented with a digital signal processor (DSP), an application-specific integrated circuit (ASIC), discrete gate logic, firmware, or any conventional programmable software module and a microprocessor. The software module could reside in RAM memory, flash memory, registers, or any other form of writable storage medium known in the art. Alternatively, any conventional processor, controller, or state machine could be substituted for the microprocessor. Exemplary ASICs designed specifically for speech coding are described in U.S. Pat. No. 5,727,123, assigned to the assignee of the present invention and fully incorporated herein by reference, and U.S. Pat. No. 5,784,532, entitled VOCODER ASIC, filed Feb. 16, 1994, assigned to the assignee of the present invention, and fully incorporated herein by reference. [0045] In FIG. 3 an encoder 200 that may be used in a speech coder includes a mode decision module 202 , a pitch estimation module 204 , an LP analysis module 206 , an LP analysis filter 208 , an LP quantization module 210 , and a residue quantization module 212 . Input speech frames s(n) are provided to the mode decision module 202 , the pitch estimation module 204 , the LP analysis module 206 , and the LP analysis filter 208 . The mode decision module 202 produces a mode index I M and a mode M based upon the periodicity, energy, signal-to-noise ratio (SNR), or zero crossing rate, among other features, of each input speech frame s(n). Various methods of classifying speech frames according to periodicity are described in U.S. Pat. No. 5,911,128, which is assigned to the assignee of the present invention and fully incorporated herein by reference. Such methods are also incorporated into the Telecommunication Industry Association Industry Interim Standards TIA/EIA IS-127 and TIA/EIA IS-733. An exemplary mode decision scheme is also described in the aforementioned U.S. application Ser. No. 09/217,341. [0046] The pitch estimation module 204 produces a pitch index I P and a lag value P 0 based upon each input speech frame s(n). The LP analysis module 206 performs linear predictive analysis on each input speech frame s(n) to generate an LP parameter a. The LP parameter a is provided to the LP quantization module 210 . The LP quantization module 210 also receives the mode M, thereby performing the quantization process in a mode-dependent manner. The LP quantization module 210 produces an LP index I LP and a quantized LP parameter {circumflex over (α)}. The LP analysis filter 208 receives the quantized LP parameter {circumflex over (α)} in addition to the input speech frame s(n). The LP analysis filter 208 generates an LP residue signal R[n], which represents the error between the input speech frames s(n) and the reconstructed speech based on the quantized linear predicted parameters {circumflex over (α)}. The LP residue R[n], the mode M, and the quantized LP parameter {circumflex over (α)} are provided to the residue quantization module 212 . Based upon these values, the residue quantization module 212 produces a residue index I R and a quantized residue signal {circumflex over (R)}[n]. [0047] In FIG. 4 a decoder 300 that may be used in a speech coder includes an LP parameter decoding module 302 , a residue decoding module 304 , a mode decoding module 306 , and an LP synthesis filter 308 . The mode decoding module 306 receives and decodes a mode index I M , generating therefrom a mode M. The LP parameter decoding module 302 receives the mode M and an LP index I LP . The LP parameter decoding module 302 decodes the received values to produce a quantized LP parameter {circumflex over (α)}. The residue decoding module 304 receives a residue index I R , a pitch index I P , and the mode index I M . The residue decoding module 304 decodes the received values to generate a quantized residue signal {circumflex over (R)}[n]. The quantized residue signal {circumflex over (R)}[n] and the quantized LP parameter {circumflex over (α)} are provided to the LP synthesis filter 308 , which synthesizes a decoded output speech signal ŝ[n] therefrom. [0048] Operation and implementation of the various modules of the encoder 200 of FIG. 3 and the decoder 300 of FIG. 4 are known in the art and described in the aforementioned U.S. Pat. No. 5,414,796 and L. B. Rabiner & R. W. Schafer, Digital Processing of Speech Signals 396-453 (1978). [0049] As illustrated in the flow chart of FIG. 5, a speech coder in accordance with one embodiment follows a set of steps in processing speech samples for transmission. In step 400 the speech coder receives digital samples of a speech signal in successive frames. Upon receiving a given frame, the speech coder proceeds to step 402 . In step 402 the speech coder detects the energy of the frame. The energy is a measure of the speech activity of the frame. Speech detection is performed by summing the squares of the amplitudes of the digitized speech samples and comparing the resultant energy against a threshold value. In one embodiment the threshold value adapts based on the changing level of background noise. An exemplary variable threshold speech activity detector is described in the aforementioned U.S. Pat. No. 5,414,796. Some unvoiced speech sounds can be extremely low-energy samples that may be mistakenly encoded as background noise. To prevent this from occurring, the spectral tilt of low-energy samples may be used to distinguish the unvoiced speech from background noise, as described in the aforementioned U.S. Pat. No. 5,414,796. [0050] After detecting the energy of the frame, the speech coder proceeds to step 404 . In step 404 the speech coder determines whether the detected frame energy is sufficient to classify the frame as containing speech information. If the detected frame energy falls below a predefined threshold level, the speech coder proceeds to step 406 . In step 406 the speech coder encodes the frame as background noise (i.e., nonspeech, or silence). In one embodiment the background noise frame is encoded at 1/8 rate, or 1 kbps. If in step 404 the detected frame energy meets or exceeds the predefined threshold level, the frame is classified as speech and the speech coder proceeds to step 408 . [0051] In step 408 the speech coder determines whether the frame is unvoiced speech, i.e., the speech coder examines the periodicity of the frame. Various known methods of periodicity determination include, e.g., the use of zero crossings and the use of normalized autocorrelation functions (NACFs). In particular, using zero crossings and NACFs to detect periodicity is described in the aforementioned U.S. Pat. No. 5,911,128 and U.S. application Ser. No. 09/217,341. In addition, the above methods used to distinguish voiced speech from unvoiced speech are incorporated into the Telecommunication Industry Association Interim Standards TIA/EIA IS-127 and TIA/EIA IS-733. If the frame is determined to be unvoiced speech in step 408 , the speech coder proceeds to step 410 . In step 410 the speech coder encodes the frame as unvoiced speech. In one embodiment unvoiced speech frames are encoded at quarter rate, or 2.6 kbps. If in step 408 the frame is not determined to be unvoiced speech, the speech coder proceeds to step 412 . [0052] In step 412 the speech coder determines whether the frame is transitional speech, using periodicity detection methods that are known in the art, as described in, e.g., the aforementioned U.S. Pat. No. 5,911,128. If the frame is determined to be transitional speech, the speech coder proceeds to step 414 . In step 414 the frame is encoded as transition speech (i.e., transition from unvoiced speech to voiced speech). In one embodiment the transition speech frame is encoded in accordance with a multipulse interpolative coding method described in U.S. Pat. No. 6,260,017, entitled MULTIPULSE INTERPOLATIVE CODING OF TRANSITION SPEECH FRAMES, filed May 7, 1999, assigned to the assignee of the present invention, and fully incorporated herein by reference. In another embodiment the transition speech frame is encoded at full rate, or 13.2 kbps. [0053] If in step 412 the speech coder determines that the frame is not transitional speech, the speech coder proceeds to step 416 . In step 416 the speech coder encodes the frame as voiced speech. In one embodiment voiced speech frames may be encoded at half rate, or 6.2 kbps. It is also possible to encode voiced speech frames at full rate, or 13.2 kbps (or full rate, 8 kbps, in an 8 k CELP coder). Those skilled in the art would appreciate, however, that coding voiced frames at half rate allows the coder to save valuable bandwidth by exploiting the steady-state nature of voiced frames. Further, regardless of the rate used to encode the voiced speech, the voiced speech is advantageously coded using information from past frames, and is hence said to be coded predictively. [0054] Those of skill would appreciate that either the speech signal or the corresponding LP residue may be encoded by following the steps shown in FIG. 5. The waveform characteristics of noise, unvoiced, transition, and voiced speech can be seen as a function of time in the graph of FIG. 6A. The waveform characteristics of noise, unvoiced, transition, and voiced LP residue can be seen as a function of time in the graph of FIG. 6B. [0055] In one embodiment a prototype pitch period (PPP) speech coder 500 includes an inverse filter 502 , a prototype extractor 504 , a prototype quantizer 506 , a prototype unquantizer 508 , an interpolation/synthesis module 510 , and an LPC synthesis module 512 , as illustrated in FIG. 7. The speech coder 500 may advantageously be implemented as part of a DSP, and may reside in, e.g., a subscriber unit or base station in a PCS or cellular telephone system, or in a subscriber unit or gateway in a satellite system. [0056] In the speech coder 500 , a digitized speech signal s(n), where n is the frame number, is provided to the inverse LP filter 502 . In a particular embodiment, the frame length is twenty ms. The transfer function of the inverse filter A(z) is computed in accordance with the following equation: A ( z )=1 −a 1 z −1 −a 2 z −2 − . . . −a p z −p , [0057] where the coefficients a 1 are filter taps having predefined values chosen in accordance with known methods, as described in the aforementioned U.S. Pat. No. 5,414,796 and U.S. application Ser. No. 09/217,494, both previously fully incorporated herein by reference. The number p indicates the number of previous samples the inverse LP filter 502 uses for prediction purposes. In a particular embodiment, p is set to ten. [0058] The inverse filter 502 provides an LP residual signal r(n) to the prototype extractor 504 . The prototype extractor 504 extracts a prototype from the current frame. The prototype is a portion of the current frame that will be linearly interpolated by the interpolation/synthesis module 510 with prototypes from previous frames that were similarly positioned within the frame in order to reconstruct the LP residual signal at the decoder. [0059] The prototype extractor 504 provides the prototype to the prototype quantizer 506 , which quantizes the prototype in accordance with a technique described below with reference to FIG. 8. The quantized values, which may be obtained from a lookup table (not shown), are assembled into a packet, which includes lag and other codebook parameters, for transmission over the channel. The packet is provided to a transmitter (not shown) and transmitted over the channel to a receiver (also not shown). The inverse LP filter 502 , the prototype extractor 504 , and the prototype quantizer 506 are said to have performed PPP analysis on the current frame. [0060] The receiver receives the packet and provides the packet to the prototype unquantizer 508 . The prototype unquantizer 508 unquantizes the packet in accordance with a technique described below with reference to FIG. 9. The prototype unquantizer 508 provides the unquantized prototype to the interpolation/synthesis module 510 . The interpolation/synthesis module 510 interpolates the prototype with prototypes from previous frames that were similarly positioned within the frame in order to reconstruct the LP residual signal for the current frame. The interpolation and frame synthesis is advantageously accomplished in accordance with known methods described in U.S. Pat. No. 5,884,253 and in the aforementioned U.S. application Ser. No. 09/217,494. [0061] The interpolation/synthesis module 510 provides the reconstructed LP residual signal {circumflex over (r)}(n) to the LPC synthesis module 512 . The LPC synthesis module 512 also receives line spectral pair (LSP) values from the transmitted packet, which are used to perform LPC filtration on the reconstructed LP residual signal {circumflex over (r)}(n) to create the reconstructed speech signal ŝ(n) for the current frame. In an alternate embodiment, LPC synthesis of the speech signal ŝ(n) may be performed for the prototype prior to doing interpolation/synthesis of the current frame. The prototype unquantizer 508 , the interpolation/synthesis module 510 , and the LPC synthesis module 512 are said to have performed PPP synthesis of the current frame. [0062] In one embodiment a prototype quantizer 600 performs quantization of prototype phases using intelligent subsampling for efficient transmission, as shown in FIG. 8. The prototype quantizer 600 includes first and second discrete Fourier series (DFS) coefficient computation modules 602 , 604 , first and second decomposition modules 606 , 608 , a band identification module 610 , an amplitude vector quantizer 612 , a correlation module 614 , and a quantizer 616 . [0063] In the prototype quantizer 600 , a reference prototype is provided to the first DFS coefficient computation module 602 . The first DFS coefficient computation module 602 computes the DFS coefficients for the reference prototype, as described below, and provides the DFS coefficients for the reference prototype to the first decomposition module 606 . The first decomposition module 606 decomposes the DFS coefficients for the reference prototype into amplitude and phase vectors, as described below. The first decomposition module 606 provides the amplitude and phase vectors to the correlation module 614 . [0064] The current prototype is provided to the second DFS coefficient computation module 602 . The second DFS coefficient computation module 606 computes the DFS coefficients for the current prototype, as described below, and provides the DFS coefficients for the current prototype to the second decomposition module 608 . The second decomposition module 608 decomposes the DFS coefficients for the current prototype into amplitude and phase vectors, as described below. The second decomposition module 608 provides the amplitude and phase vectors to the correlation module 614 . [0065] The second decomposition module 608 also provides the amplitude and phase vectors for the current prototype to the band identification module 610 . The band identification module 610 identifies frequency bands for correlation, as described below, and provides band identification indices to the correlation module 614 . [0066] The second decomposition module 608 also provides the amplitude vector for the current prototype to the amplitude vector quantizer 612 . The amplitude vector quantizer 612 quantizes the amplitude vector for the current prototype, as described below, and generates amplitude quantization parameters for transmission. In a particular embodiment, the amplitude vector quantizer 612 provides quantized amplitude values to the band identification module 610 (this connection is not shown in the drawing for the purpose of clarity) and/or to the correlation module 614 . [0067] The correlation module 614 correlates in all frequency bands to determine the optimal linear phase shift for all bands, as described below. In an alternate embodiment, cross-correlation is performed in the time domain on the bandpass signal to determine the optimal circular rotation for all bands, also as described below. The correlation module 614 provides linear phase shift values to the quantizer 616 . In an alternate embodiment, the correlation module 614 provides circular rotation values to the quantizer 616 . The quantizer 616 quantizes the received values, as described below, generating phase quantization parameters for transmission. [0068] In one embodiment a prototype unquantizer 700 performs reconstruction of the prototype phase spectrum using linear shifts on constituent frequency bands of a DFS, as shown in FIG. 9. The prototype unquantizer 700 includes a DFS coefficient computation module 702 , an inverse DFS computation module 704 , a decomposition module 706 , a combination module 708 , a band identification module 710 , an amplitude vector unquantizer 712 , a composition module 714 , and a phase unquantizer 716 . [0069] In the prototype unquantizer 700 , a reference prototype is provided to the DFS coefficient computation module 702 . The DFS coefficient computation module 702 computes the DFS coefficients for the reference prototype, as described below, and provides the DFS coefficients for the reference prototype to the decomposition module 706 . The decomposition module 706 decomposes the DFS coefficients for the reference prototype into amplitude and phase vectors, as described below. The decomposition module 706 provides reference phases (i.e., the phase vector of the reference prototype) to the composition module 714 . [0070] Phase quantization parameters are received by the phase unquantizer 716 . The phase unquantizer 716 unquantizes the received phase quantization parameters, as described below, generating linear phase shift values. The phase unquantizer 716 provides the linear phase shift values to the composition module 714 . [0071] Amplitude vector quantization parameters are received by the amplitude vector unquantizer 712 . The amplitude vector unquantizer 712 unquantizes the received amplitude quantization parameters, as described below, generating unquantized amplitude values. The amplitude vector unquantizer 712 provides the unquantized amplitude values to the combination module 708 . The amplitude vector unquantizer 712 also provides the unquantized amplitude values to the band identification module 710 . The band identification module 710 identifies frequency bands for combination, as described below, and provides band identification indices to the composition module 714 . [0072] The composition module 714 composes a modified phase vector from the reference phases and the linear phase shift values, as described below. The composition module 714 provides modified phase vector values to the combination module 708 . [0073] The combination module 708 combines the unquantized amplitude values and the phase values, as described below, generating a reconstructed, modified DFS coefficient vector. The combination module 708 provides the combined amplitude and phase vectors to the inverse DFS computation module 704 . The inverse DFS computation module 704 computes the inverse DFS of the reconstructed, modified DFS coefficient vector, as described below, generating the reconstructed current prototype. [0074] In one embodiment a prototype unquantizer 800 performs reconstruction of the prototype phase spectrum using circular rotations performed in the time domain on the constituent bandpass waveforms of the prototype waveform at the encoder, as shown in FIG. 9. The prototype unquantizer 800 includes a DFS coefficient computation module 802 , a bandpass waveform summer 804 , a decomposition module 806 , an inverse DFS/bandpass signal creation module 808 , a band identification module 810 , an amplitude vector unquantizer 812 , a composition module 814 , and a phase unquantizer 816 . [0075] In the prototype unquantizer 800 , a reference prototype is provided to the DFS coefficient computation module 802 . The DFS coefficient computation module 802 computes the DFS coefficients for the reference prototype, as described below, and provides the DFS coefficients for the reference prototype to the decomposition module 806 . The decomposition module 806 decomposes the DFS coefficients for the reference prototype into amplitude and phase vectors, as described below. The decomposition module 806 provides reference phases (i.e., the phase vector of the reference prototype) to the composition module 814 . [0076] Phase quantization parameters are received by the phase unquantizer 816 . The phase unquantizer 816 unquantizes the received phase quantization parameters, as described below, generating circular rotation values. The phase unquantizer 816 provides the circular rotation values to the composition module 814 . [0077] Amplitude vector quantization parameters are received by the amplitude vector unquantizer 812 . The amplitude vector unquantizer 812 unquantizes the received amplitude quantization parameters, as described below, generating unquantized amplitude values. The amplitude vector unquantizer 812 provides the unquantized amplitude values to the inverse DFS/bandpass signal creation module 808 . The amplitude vector unquantizer 812 also provides the unquantized amplitude values to the band identification module 810 . The band identification module 810 identifies frequency bands for combination, as described below, and provides band identification indices to the inverse DFS/bandpass signal creation 808 . [0078] The inverse DFS/bandpass signal creation module 808 combines the unquantized amplitude values and the reference phase value for each of the bands, and computes a bandpass signal from the combination, using the inverse DFS for each of the bands, as described below. The inverse DFS/bandpass signal creation module 808 provides the bandpass signals to the composition module 814 . [0079] The composition module 814 circularly rotates each of the bandpass signals using the unquantized circular rotation values, as described below, generating modified, rotated bandpass signals. The composition module 814 provides the modified, rotated bandpass signals to the bandpass waveform summer 804 . The bandpass waveform summer 804 adds all of the bandpass signals to generate the reconstructed prototype. [0080] The prototype quantizer 600 and of FIG. 8 and the prototype unquantizer 700 of FIG. 9 serve in normal operation to encode and decode, respectively, phase spectrum of prototype pitch period waveforms. At the transmitter/encoder (FIG. 8), the phase spectrum, φ k c , of the prototype, s c (n), of the current frame is computed using the DFS representation s c  ( n ) = ∑ k  C k c   j     nk  ( ω o c ) , [0081] where C k c are the complex DFS coefficients of the current prototype and ω o c is the normalized fundamental frequency of s c (n). The phase spectrum, φ k c , is the angle of the complex coefficients constituting the DFS. The phase spectrum, φ k r , of the reference prototype is computed in similar fashion to provide C k r and φ k r . Alternatively, the phase spectrum, φ k r , of the reference prototype was stored after the frame having the reference prototype was processed, and is simply retrieved from storage. In a particular embodiment, the reference prototype is a prototype from the previous frame. The complex DFS for both the prototypes from both the reference frame and the current frame can be represented as the product of the amplitude spectra and the phase spectra, as shown in the following equation: C k c =A k c e jφ k c . It should be noted that both the amplitude spectra and the phase spectra are vectors because the complex DFS is also a vector. Each element of the DFS vector is a harmonic of the frequency equal to the reciprocal of the time duration of the corresponding prototype. For a signal of maximum frequency of Fm Hz (sampled at a rate of at least of 2 Fm Hz) and a harmonic frequency of Fo Hz, there are M harmonics. The number of harmonics, M, is equal to Fm/Fo. Hence, the phase spectra vector and the amplitude spectra vector of each prototype consist of M elements. [0082] The DFS vector of the current prototype is partitioned into B bands and the time signal corresponding to each of the B bands is a bandpass signal. The number of bands, B, is constrained to be less than the number of harmonics, M. Summing all of the B bandpass time signals would yield the original current prototype. In similar fashion, the DFS vector for the reference prototype is also partitioned into the same B bands. [0083] For each of the B bands, a cross-correlation is performed between the bandpass signal corresponding to the reference prototype and the bandpass signal corresponding to the current prototype. The cross-correlation can be performed on the frequency-domain DFS vectors, γ θ i =(C {kb i } r e j{kb i }θ i ) T (C {kb i } ), where {k b i } is the set of harmonic numbers in the i th band b i , and θ i is a possible linear phase shift for the i th band b i . The cross-correlation may also be performed on the corresponding time-domain bandpass signals (for example, with the unquantizer 800 of FIG. 10) in accordance with the following equation: γ r 1 = ∑ n = 0 L - 1  [ ( ∑ { k b 1 }  C { k b 1 } r   j  ( ( n + r 1 )  %     L )  ( k b 1 )  ϖ o r )  ( ∑ { k b 1 }  C { k b 1 } c   j     n  { k b 1 }  ϖ o c ) ] , [0084] where L is the length in samples of the current prototype, ω o r and ω o c are the normalized fundamental frequencies of the reference prototype and the current prototype, respectively, and r i is the circular rotation in samples. The bandpass time-domain signals s bi r (n) and s bi c (n) corresponding to the band b i are given by, respectively, the following expressions: ∑ n = 0 L - 1  [ ∑ { k b 1 }  C { k b 1 } r   j     n  { k b 1 }  ϖ o r ]     and     ∑ n = 0 L - 1  [ ∑ { k b 1 }  C { k b 1 } c   j     n  { k b 1 }  ϖ o c ] . [0085] In one embodiment the quantized amplitude vector, Â k c , is used to get C k c , as shown in the following equation: C k c =Â k c e jφ k c . The cross-correlation is performed over all possible linear phase shifts of the bandpass DFS vector of the reference prototype. Alternatively, the cross-correlation may be performed over a subset of all possible linear phase shifts of the bandpass DFS vector of the reference prototype. In an alternate embodiment, a time-domain approach is employed, and the cross-correlation is performed over all possible circular rotations of bandpass time signals of the reference prototype. In one embodiment the cross-correlation is performed over a subset of all possible circular rotations of bandpass time signal of the reference prototype. The cross-correlation process generates B linear phase shifts (or B circular rotations, in the embodiment wherein cross-correlation is performed in the time domain on the bandpass time signal) that correspond to maximum values of the cross-correlation for each of the B bands. The B linear phase shifts (or, in the alternate embodiment, the B circular rotations) are then quantized and transmitted as representatives of the phase spectra in place of the M original phase spectra vector elements. The amplitude spectra vector is separately quantized and transmitted. Thus, the bandpass DFS vectors (or the bandpass time signals) of the reference prototype advantageously serve as codebooks to encode the corresponding DFS vectors (or the bandpass signals) of the prototype of the current frame. Accordingly, fewer elements are needed to quantize and transmit the phase information, thereby effecting a resulting subsampling of phase information and giving rise to more efficient transmission. This is particularly beneficial in low-bit-rate speech coding, where due to lack of sufficient bits, either the phase information is quantized very poorly due to the large amount of phase elements or the phase information is not transmitted at all, each of which results in low quality. The embodiments described above allow low-bit-rate coders to maintain good voice quality because there are fewer elements to quantize. [0086] At the receiver/decoder (FIG. 9) (and also at the encoder's copy of the decoder, as would be understood by those of skill in the art), the B linear phase shift values are applied to the decoder's copy of the DFS B-band-partitioned vector of the reference prototype to generate a modified prototype DFS phase vector: {circumflex over (φ)} {kb i } c =φ {kb i } r +{k b i }θ b i . The modified DFS vector is then obtained as the product of the received and decoded amplitude spectra vector and the modified prototype DFS phase vector. The reconstructed prototype is then constructed using an inverse-DFS operation on the modified DFS vector. In the alternate embodiment, wherein a time-domain approach is employed, the amplitude spectra vector for each of the B bands and the phase vector of the reference prototype for the same B bands are combined, and an inverse DFS operation is performed on the combination to generate B bandpass time signals. The B bandpass time signals are then circularly rotated using the B circular rotation values. All of the B bandpass time signals are added to generate the reconstructed prototype. [0087] Thus, a novel method and apparatus for subsampling phase spectrum information has been described. Those of skill in the art would understand that the various illustrative logical blocks and algorithm steps described in connection with the embodiments disclosed herein may be implemented or performed with a digital signal processor (DSP), an application specific integrated circuit (ASIC), discrete gate or transistor logic, discrete hardware components such as, e.g., registers and FIFO, a processor executing a set of firmware instructions, or any conventional programmable software module and a processor. The processor may advantageously be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The software module could reside in RAM memory, flash memory, registers, or any other form of writable storage medium known in the art. Those of skill would further appreciate that the data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description are advantageously represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. [0088] Preferred embodiments of the present invention have thus been shown and described. It would be apparent to one of ordinary skill in the art, however, that numerous alterations may be made to the embodiments herein disclosed without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited except in accordance with the following claims.

Method and apparatus for subsampling phase spectrum information by analyzing and reconstructing a prototype of a frame. The prototype is analyzed by correlating phase parameters generated from the prototype with phase parameters generated from a reference prototype in multiple frequency bands. The prototype is reconstructed using linear phase shift values by producing a set of phase parameters of the reference prototype, generating a set of linear phase shift values associated with the prototype, and composing a phase vector from the set of phase parameters and the set of linear phase shift values across multiple frequency bands. The prototype is reconstructed using circular rotation values by producing a set of circular rotation values associated with the prototype, generating a set of bandpass waveforms associated with the phase parameters of the reference prototype in multiple frequency bands, and modifying the set of bandpass waveforms based upon the circular rotation values.

RELATED APPLICATIONS This application claims priority of Provisional Application Ser. No. 60/070,850 filed Jan. 8, 1998. GOVERNMENT RIGHTS The United States Government has rights in this invention pursuant to Contract No. DE-AC03-76SF00098 between the United States Department of Energy and the University of California. BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates generally to the measurement of time varying electric fields, and more particularly to the measurement of electric fields with a frequency in the range of 1 MHz to 100 MHz. 2. Description of the Prior Art Non-invasive sensing of the shallow subsurface is necessary for environmental monitoring and management, e.g. detection and delineation of buried hazardous wastes, and monitoring the condition of clay containment caps. Electromagnetic methods have been used for subsurface characterization, but there is a need for increased resolution for waste form characterization, verification, and monitoring activities. In particular, a compact detector which can be used on the surface or in a borehole is desired. A window exists in the electromagnetic spectrum between ground penetrating radar (30 MHz to 1 GHz) and induction techniques (<100 kHz) that has not been utilized for these applications. The frequency band of 1 MHz to 100 MHz is important for environmental work because of good earth penetration and good resolution. However, the frequency range between 1.0 to 100 MHz has not been used for existing electromagnetic or radar systems to detect small objects in the upper few meters of the ground. Ground penetrating radar (GPR) can be used successfully in this depth range if the ground is resistive but most soils are, in fact, conductive (0.01 to 1.0 S/m) rendering G.P. inefficient. For example, in a soil of 0.2 S/m the maximum range for a typical GPR is only 17 cm. Other factors controlling the resolution of GPR system for small objects is the spatial averaging inherent in the electric dipole antenna and the scattering caused by soil inhomogeneities of dimensions comparable to the wavelength (and antenna size). For maximum resolution it is desirable to use the highest frequencies but the scattering is large and target identification is poor. While a traditional radar approach could be used, the antenna length at these frequencies must be too long to be practical. Accordingly it is desirable to have a detector of electric fields in the 1-100 MHz frequency range. A toroidal coil has been suggested as a transmitter if current is forced to flow through the winding (Wait, J. R., Excitation of a conducting half-space by a toroidal coil, IEEE Antennas and Propagation Magazine, Vol.37, No. 4, p.72-74, 1995). Generated within the toroid is a strong azimuthal magnetic field, which in turn can be considered equivalent to that of an electric dipole. SUMMARY OF THE INVENTION Accordingly it is an object of the invention to provide a simple and compact method and apparatus for detecting time varying electric fields, particularly in the frequency range of 1 MHz to 100 MHz. The invention is a simple and compact method and apparatus for detecting high frequncy electric fields, particularly in the frequency range of 1 MHz to 100 MHz, using a toroidal antenna. For typical geophysical applications the sensor will be used to detect electric fields for a wide range of spectrum starting from about 1 MHz, in particular in the frequency range between 1 to 100 MHz, to detect small objects in the upper few meters of the ground. Time-varying magnetic fields associated with time-varying electric fields induce an emf (voltage) in a toroidal coil. The electric field at the center of (and perpendicular to the plane of) the toroid is shown to be linearly related to this induced voltage. By measuring the voltage across a toroidal coil one can easily and accurately determine the electric field. The sensor will greatly simplify the cumbersome procedure involved with GPR measurements with its center frequency less than 100 MHz. The overall size of the toroidal sensor can be as small as a few inches. It is this size advantage that will not only allow easy fabrication and deployment of multi-component devices either on the surface or in a borehole, but it will render greatly improved resolution over conventional systems. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a schematic view of the high frequency electric field detector of the invention, showing a top planar view of the toroidal antenna. FIG. 1B is a cross-sectional view through the toroidal antenna where the toroidal has a circular cross-section. FIG. 1C is a cross-sectional view through the toroidal antenna where the toroid has a noncircular cross-section. FIG. 2 illustrates the magnetic fields at four points in space, in rectangular coordinates. FIG. 3 illustrates the magnetic fields at the four points in space of FIG. 2, in spherical coordinates. FIG. 4 shows a four loop electric field detector with a loop positioned at each of the four points in space of FIG. 3 . FIG. 5 illustrates the use of a toroidal antenna to measure electric field at a surface. FIG. 6 is a graph of induced voltage as a function of frequency. DETAILED DESCRIPTION OF THE INVENTION Basic Apparatus As shown in FIG. 1A, an electric field detector 10 according to the invention is formed of a toroidal antenna 12 connected to a voltage detector 14 . Toroidal antenna 12 is formed of a toroid 16 having a plurality of windings or loops 18 continuously and uniformly wound thereon. The ends of the windings 18 are connected by leads 20 to voltage detector 14 . As explained herein, detector 10 detects a perpendicular component of a time varying electric field, e.g. E y , at the center of toroid 16 by measuring the voltage induced in the windings 18 . Detector 10 is suitable for detecting electric fields with a frequency in the 1 MHz to 100 MHz range. Any voltage detector 14 may be used which can measure the induced voltage at the particular frequency. The toroid 16 is divided into four arbitrary quadrants 22 , 23 , 24 , 25 each of which has an equal number N of windings or loops 18 . The greater the number of windings, the greater the induced voltage so it will be easier to detect the voltage. As shown in FIG. 1B, toroid 16 may have a circular cross-section 16 a , of diameter “d” which will be the diameter of the windings or loops 18 wound on toroid 16 and A=πd 2 /4 will be the cross-sectional area of the windings. The toroid diameter, measured at the center of the cross-section, is “D”. Alternatively, toroid 16 may have a noncircular cross-section 16 b of area A, and a toroid diameter D. Theoretical Basis In a source-free region, Maxwell's equations in the frequency domain with an e iax time dependence are ∇× E=−iωμH , and  (1)  ∇× H =(δ+ i ωε) E.   (2) From equation (2) one can obtain the electric field as E = ∇ × H ( σ +      ω     ɛ ) , ( 3 ) from which each component of the electric field can be written as E x = 1 ( σ +      ω     ɛ )     ( ∂ H z ∂ y - ∂ H y ∂ z ) , ( 4 ) E y = 1 ( σ +      ω     ɛ )     ( ∂ H x ∂ z - ∂ H z ∂ x ) ,    and ( 5 ) E z = 1 ( σ +      ω     ɛ )     ( ∂ H y ∂ x - ∂ H x ∂ y ) . ( 6 ) Equations (4), (5), and (6) show that electric fields can be obtained by first measuring magnetic fields and taking their ‘rotation’. The rotation (curl) operation needs to be approximate in nature because in practice it cannot be evaluated at a point in space. As an example the solution of E y shown by equation (5) is obtained. First, magnetic fields H x1 , H x2 , H z1 , H z2 are measured at four points in space x 1 , x 2 , z 1 , z 2 about a center point “0” as shown in FIG. 2 . The distance between opposed pairs of points x 1 -x 2 , and z 1 -z 2 is D. Then the electric field at the center in the y-direction (orthogonal to to x-z plane) can be evaluated as E y0 = 1 D  ( σ +      ω     ɛ )     ( H x2 - H x1 - H z2 + H z1 ) , ( 7 ) where D is the distance used for making the difference measurement. The same distance is used for both components in this example. In cylindrical coordinates, FIG. 2 may be represented by FIG. 3, where the four points are designated by the angle φ in the plane, with the corresponding magnetic field components as shown therein. The electric field given by equation (7) can also be replaced by E y0 = 1 D  ( σ +      ω     ɛ )     ( H φ  1 + H φ  2 + H φ  3 + H φ  4 ) , ( 8 ) or, equivalently E y0 = 1 D  ( σ +      ω     ɛ )     ∑ j = 1 4  H φ  j . ( 9 ) Because of the geometrical similarity, any set of two pairs of orthogonal magnetic fields will give exactly the same electric field at the center. Thus, for N such sets, E y0 = 1 N     D  ( σ +      ω     ɛ )     ∑ j = 1 4  N  H φ  j . ( 10 ) This is a useful relationship relating the sum of azimuthal magnetic field measurements to the axial electric field at the center of such an arrangement. Inductive Electric Field Measurement Magnetic fields can be measured using a loop. In the presence of a time-varying magnetic field a small voltage (ΔV) is induced in a loop and is given by Δ V=−iωμ∫H·ds≅−iωμAH,   (11) where A is the area of the loop, and it is assumed that the magnetic field is normal to the loop. The magnetic field supporting this voltage can be estimated by H = Δ     V -      ω     μ     A . ( 12 ) Consider a four-loop system as shown in FIG. 4, with one loop at each of the four points of FIGS. 2-3. The magnetic field at each point will induce a voltage in the corresponding loop. If the loops are connected, then the total induced voltage will be the sum of the voltages induced in each loop. By substituting equation (12) into (9), one obtains E y0 = 1 D  ( σ +      ω     ɛ )     1 ( -      ω     μ     A )    ∑ j = 1 4  Δ     V j = 1 D     A     k 2    ∑ j = 1 4  Δ     V j , ( 13 ) where k is the propagation constant. For a measurement scheme using a toroid consisting of 4N continuously wound loops with N equal number of loops in each quadrant, and in view of equations (10) and (13), the electric field at the center is given by E y0 = 1 N     D     A     k 2    ∑ j = 1 4  N  Δ     V j . ( 14 ) Because all loops are wound continuously, the summation can be replaced by a total voltage induced in a toroid consisting of 4N loops. The final expression for the electric field then becomes E y0 = V N     D     A     k 2 . ( 15 ) The electric field measured this way may be called the ‘inductive’ measurement as opposed to the ‘capacitive’ one common to most of the electric field measurement schemes using antennae. Practical Considerations—Sensitivity Analysis The ‘inductive’ method of measuring the electric field is based on the voltage measurement using a toroid. Hence it is necessary to evaluate the amplitude of the expected emf induced within a typical toroidal and see if it can be measured. From equation (15), the voltage sum induced in a toroidal antenna is found to be V=k 2 NDAE y0   . (16) As shown in FIG. 5, a vertical magnetic dipole (VMD) source 30 , e.g. an electromagnetic transmitter, of unit moment, is at a position Tx, 10 m away from the point of measurement Rx on the surface 31 of a 100 ohm-m half space 32 , e.g. a geological formation. A toroidal antenna 12 is at position Rx and is connected to an associated voltage detector 14 . Specifications of the toroid are: the toroid diameter D=2″, loop diameter d=1″, and the number of turns in one quadrant N=25 (total number of turns is therefore 100). The overall size or outer diameter (D+d) of the toroid is 3′. The EM1D code is a computer code which simulates electromagnetic (EM) fields in one dimensional (1D) earth. The code is widely used and available from University of California Lawrence Berkeley National Laboratory, where it was developed. The electric field on the right hand side of equation (15) is obtained using the EM1D code over the half-space shown in FIG. 5 . FIG. 6 shows the induced voltage as a function of frequency. As a reference, this illustration also shows the electronic noise level of a commercial amplifier. As can be seen the voltage induced in the toroid is greater than the noise limit as the frequency is increased above 1 MHz. So, the 3″ toroid has enough sensitivity to cover a range of frequencies above 1 MHz. The smallness of the sensor is a great advantage over the conventional ‘capacitive’ linear antenna. At 30 MHz, for example, the linear antenna length will be about 17′, 68 times longer than the 3″ torroid. Furthermore, the size of the torroid stays the same for all frequencies because tuning is of much less concern for inductive measurements. The small size of the toroidal antenna of the invention, and its ability to detect voltages at the desired frequency range, makes it ideal for geophysical applications. However, it is not limited to geophysical applications, and may be used for other applications, to measure electric fields from any sources. In certain applications, such as geophysical characterization, it may be used with an associated electromagnetic transmitter or source, e.g. source 30 of FIG. 5, which will produce an electric field which carries information based on the material or objects through which it passes. The detector of the invention can then be used to detect the modified electric field to obtain the information about the material or objects through which the source field has passed. By changing the orientation of the toroid, the electric field in any direction can be measured. Since the antenna is so small, this is a great advantage in a small space such as a borehole, e.g. borehole 33 in FIG. 5 . Changes and modifications in the specifically described embodiments can be carried out without departing from the scope of the invention which is intended to be limited only by the scope of the appended claims.

A simple and compact method and apparatus for detecting high frequency electric fields, particularly in the frequency range of 1 MHz to 100 MHz, uses a compact toroidal antenna. For typical geophysical applications the sensor will be used to detect electric fields for a wide range of spectrum starting from about 1 MHz, in particular in the frequency range between 1 to 100 MHz, to detect small objects in the upper few meters of the ground. Time-varying magnetic fields associated with time-varying electric fields induce an emf (voltage) in a toroidal coil. The electric field at the center of (and perpendicular to the plane of) the toroid is shown to be linearly related to this induced voltage. By measuring the voltage across a toroidal coil one can easily and accurately determine the electric field.

This application is based upon and claims the benefit of priority under 35 U.S.C. § 120 for U.S. application Ser. No. 10/733,364, filed Dec. 12, 2003, U.S. application Ser. No. 10/200,762, filed Jul. 24, 2002, and U.S. application Ser. No. 09/110,076, filed Jul. 2, 1998, and under 35 U.S.C. § 119 from Japanese Patent Application 09-283834, filed Oct. 16, 1997, the entire contents of each of which are incorporated herein by reference. BACKGROUND OF THE INVENTION The present invention relates to an IPS In Plane Switching liquid crystal displaying apparatus by generating an electric field parallel to an array substrate to drive the liquid crystal. More particularly, the present invention relates to a construction of a highly bright liquid crystal displaying apparatus increased in aperture ratio by reducing influences of the leakage of electric field from a signal line, thereby reducing the light shielding area. DISCUSSION OF THE BACKGROUND In an active matrix type liquid crystal displaying apparatus, an IPS system where the direction of the electric field to be applied on the liquid crystal is made parallel to the array substrate is mainly used as a method of obtaining a wider viewing angle (for example, see Japanese Unexamined Patent Publication No. 254712/1996). It is reported that this system removes almost all of the change in the contrast and the inversion of the gradation level in changing the viewing-angle direction (see, for example, AsiaDisplay, 95 , page, 577 to 580 by M. Oh-e, and others). A construction of one pixel of the conventional IPS liquid crystal displaying apparatus is depicted in FIGS. 43 a and 43 b . FIG. 43 a is the plain view thereof. FIG. 43 b is a sectional view taken along a line A-A of FIG. 43 a . FIG. 44 is a circuit diagram showing an equivalent circuit of one pixel of the pixel electrode of an IPS liquid crystal displaying apparatus. FIG. 45 is a circuit diagram for illustrating the circuit of the IPS liquid crystal displaying apparatus. Referring to FIGS. 43 a and 43 b , reference numeral 1 denotes a glass substrate, numeral 2 denotes a scanning line, numeral 3 denotes a signal line, numeral 4 denotes a thin film transistor (TFT), numeral 5 denotes a driving electrode, numeral 6 denotes an opposite electrode, numeral 7 denotes an electrode for forming the storage capacitance, numeral 8 denotes common line, numeral 9 denotes a gate insulating film, numeral 10 denotes a passivation film, numeral 11 denotes a liquid crystal, numeral 12 denotes a BM (black matrix), numeral 14 denotes a contact hole, numeral 15 denotes a source electrode, and numeral 16 denotes a drain electrode. Numeral 20 denotes an array substrate comprising glass substrate 1 , a signal line 3 , a driving electrode 5 , an opposite electrode 6 . Numeral 30 denotes an opposite substrate arranged opposite to the array substrate 20 . Numeral 40 denotes a slit which is a gap between the signal line 3 and the opposite electrode 6 , and numeral 50 denotes an opening. Referring to FIG. 44 and FIG. 45 , the same reference numerals as those of FIGS. 43 a and 43 b depict the same parts or its equivalents as those of FIGS. 43 a and 43 b. The construction and operation of the conventional IPS liquid crystal displaying apparatus will be described according to FIGS. 43 a and 43 b , FIG. 44 and FIG. 45 . Referring to FIG. 45 , a plurality of grid shaped pixels encircled by the scanning line 2 and the signal line 3 can be made by crossing, at an approximately right angle between a scanning line 2 connecting the scanning line driving circuit 102 and a signal line 3 connecting the signal line driving circuit 101 . A TFT (Thin Film Transistor) is provided at each intersection point between a signal line and a scanning line for forming the grid shaped pixel. Numeral 103 denotes a circuit for common lines. This condition is shown by an equivalent circuit in FIG. 44 . The TFT 4 is a semiconductor element having three electrodes of a gate electrode, a source electrode 15 and a drain electrode 16 . The gate electrode is connected with a scanning line 2 extended from the scanning line driving circuit. The source electrode 15 is connected with the signal line 3 connected with the signal line driving circuit. The remaining drain electrode 16 , connected with the driving electrode 5 , drives the liquid crystal by an electric field caused between the driving electrode 5 and the opposite electrode 6 . Numeral 7 denotes a storage capacitor for storing the electric charge between the driving electrode 5 and the opposite electrode 6 . The construction of one pixel will be described in accordance with FIG. 43 a and FIG. 43 b . In a pixel formed through the crossing between the scanning line 2 and the signal line 3 are provided a driving electrode 5 for driving the liquid crystal layer, an opposite electrode 6 and a TFT 4 . In the TFT 4 there are three electrodes. The scanning line 2 connected with the scanning line driving circuit shown in FIG. 45 is connected with the gate electrode of the TFT 4 , so as to apply the scanning signal, the scanning line driving circuit outputs, upon the gate electrode of the TFT 4 . The signal line 3 connected with the signal line driving circuit is connected with the source electrode 15 of the TFT 4 to transmit the image signal the signal line driving circuit outputs. The drain electrode 16 of the TFT 4 is connected with the driving electrode 5 through a contact hole 14 as shown in FIG. 43 a . In the same pixel, an opposite electrode 6 is provided to be engaged face to face with the driving electrode 5 . The opposite electrode 6 is connected with the common line 8 . The common line 8 is connected with each opposite electrode 6 provided in each pixel on the TFT array substrate 20 . The sectional construction of the picture section will be described in accordance with FIG. 43 b . A driving electrode 5 and an opposite electrode 6 are respectively formed on the glass substrate 1 . Although not shown in FIG. 43 b , the scanning line 2 and the common line 8 are also formed in the same layer as that of the driving electrode 5 and the opposite electrode 6 . The gate insulating film 9 is laminated on a glass substrate by covering the driving electrode, the opposite electrode, the scanning line and the common line, and the signal line 3 is formed on the gate insulating film 9 . Although not shown in FIG. 43 b , the storage capacitor forming electrode 7 is also formed in the same layer as that of the signal line 3 . A passivation film 10 is laminated further on the signal line 3 , so as to form the TFT array substrate 20 . The TFT array substrate 20 and the opposite substrate 30 is superposed. The IPS liquid crystal displaying apparatus is made with a liquid crystal 11 being sealed between the TFT array substrate 20 and the opposite substrate 30 . The IPS liquid crystal displaying apparatus is a system where the electric filed field is caused along the surface of the TFT array substrate 20 between the driving electrode 5 and the opposite electrode 6 provided on the TFT array substrate 20 . Thus, the opposite substrate 30 is a no-electrode substrate having no electrode. On the opposite substrate 30 there is provided a BM 12 which is a light shielding film. Although not shown, the light leaked from a slit 40 of FIG. 43 a is to be shielded with a back light, provided on the under side of the TFT array substrate, as a light source in FIG. 43 b. An area surrounded by broken lines shown by 50 , defining an opening per pixel, functions as a role of a window through which light passes with the back light as a light source. But the light from the back light is shielded by a driving electrode 5 , an opposite electrode 6 , a black matrix 12 and so on, thereby influencing upon the picture quality of the liquid crystal display. Thus, a problem is to reduce the ratio, in area, of the driving electrode 5 , the opposite electrode 6 , the black matrix 12 and so on to be occupied in the area of the opening 50 . The above description is given about the construction of the pixel of the conventional IPS liquid crystal displaying apparatus about FIGS. 43 a and 43 b , FIG. 44 and FIG. 45 . The operation of the IPS liquid crystal displaying apparatus will be described. The gate electrode is provided in each pixel. The gate electrode of the TFT is connected with the scanning line 2 . The source electrode 15 is connected with the signal line 3 . The drain electrode 16 is connected with the driving electrode 5 . Such a TFT 4 is a semiconductor switching element, which controls the driving operation of the liquid crystal of each pixel. When a scanning signal is applied, through the scanning line 2 from the scanning line driving circuit, upon the gate electrode of the TFT 4 , all the TFT 4 of this horizontal line is respectively switched on. When the gate electrode is switched on, the image signal transmitted from the signal line driving circuit flows to the drain electrode 16 by way of the source electrode 15 and is stored in the driving electrode 5 connected with the drain electrode 16 . Electric charge applied in the driving electrode 5 is stored with respect to the opposite electrode 6 and the gate electrode is turned on again. The electric charge of that time is stored before the new image signal electric charge is applied. The driving electrode 5 and the opposite electrode 6 function as a capacitor in that the electric charge is stored while the gate electrode is on, and the stored electric charge is held as it is when the gate electrode is turned off. The storage capacitance 13 shown in FIG. 44 increases the accumulating force of the capacitance. The storage capacitance 13 is formed by the vertical lamination of the storage capacitance electrode 7 and the common line 8 through the gate insulating film 9 . In the conventional IPS liquid crystal displaying apparatus shown in FIGS. 43 a and 43 b , between the signal line 3 provided in the side end portion of one pixel and the opposite electrode 6 formed in parallel to the signal line 3 is caused an electric field due to the potential difference between the signal line 3 and the opposite electrode 6 . FIG. 46 is a view showing influences to be applied, upon the electric field to be caused between the driving electrode 5 and the opposite electrode 6 , by the electric field caused between the signal line 3 and the opposite electrode 6 of the conventional IPS liquid crystal displaying apparatus, which has the TFT array substrate where the driving electrode 5 and the opposite electrode 6 are formed in the layer lower than the signal line 3 . In FIG. 46 , changes in the potential caused between the driving electrode 5 and the opposite electrode 6 is obtained as a simulator. In FIG. 46 , the electric potential in the window upper portion or lower portion is calculated when a white window has been displayed in the half tone of the relative transmission factor 50%. It is desirable to correctly drive the liquid crystal to have the driving electrode 5 between two opposite electrodes 6 so that the potential distribution is symmetrical around the driving electrode 5 . It is found out from FIG. 46 that the potential distribution of an area near the signal line 3 of the opening 50 is subjected to the influences of the leakage of electric field caused between the signal line 3 and the opposite electrode 6 , thus resulting in asymmetric potential distribution. The electric field is caused along the surface of the glass substrate 1 , thus causing a problem like crosstalk. For example, when a white window is displayed in such black displaying as shown in FIG. 47 , there prises a problem on the display called “longitudinal crosstalk” where the vertical luminance of the window portion changes with respect to the other black displaying portion. An example in a case of a normally black mode (wherein the displaying becomes black with the voltage being not applied) will be described in FIG. 44 . When such a window pattern in FIG. 47 is displayed, the same voltage as that of the opposite electrode 6 is applied during the selecting period of the black displaying portion 111 upon the signal line 3 of the pixels of the window and its upper and lower portions during the picture face, and a voltage necessary to the white displaying 113 is applied during the selecting period of the white displaying portion 111 . The voltage of a value where the absolute value of the electric potential value between the electrodes has been averaged by hour is applied upon the liquid crystal 11 effectively. Therefore, for example, when the black displaying and the white displaying are equal in the selecting period, the effective potential equal to the half tone display 112 is applied upon these pixels between the signal line 3 and the opposite electrode 6 . At this time, the liquid crystal on the slit 40 between the signal line 3 and the opposite electrode 6 becomes a transmission mode by the electric field to horizontal to the glass substrate 1 to be caused between the signal line 3 and the opposite electrode 6 . The electric field to be caused by the electrical potential difference between the signal line 3 and the opposite electrode 6 gives influences even upon the electric field between the driving electrode 5 and the opposite electrode 6 , so as to change the liquid crystal of the black displaying portion into the transmission mode. As a result, the crosstalk is caused. In order to prevent such longitudinal crosstalk from being caused, the leaking light transmitting through the slit 40 between the signal line 3 and the opposite electrode 6 is required to be shielded by the BM 12 formed on the opposite substrate 30 and to prevent the electric field, caused between the signal line 3 and the opposite electrode 6 , from being interfered with the electric field between the driving electrode 5 and the opposite electrode 6 with the driving electrode 5 and the opposite electrode 6 spaced apart from the opposite electrode 6 of the side end portion on the side of the opening 50 , and the signal line 3 . When the driving electrode 5 and the opposite electrode 6 are separated from the signal line 3 to make larger the width of the opposite electrode 6 adjacent to the signal line 3 , and the aperture ratio of the opening 50 , namely, a portion to be occupied by an area where the area of the driving electrode 5 and the opposite electrode 6 and so on is subtracted from the area of the opening 50 with respect to the area of the opening 50 surrounded with broken lines in FIG. 43 a , becomes smaller to make the picture quality worse. In order to develop the high picture quality liquid crystal displaying apparatus, it is necessary to shield the light, without reducing the aperture ratio, the electric field to be caused between the signal line 3 and the opposite electrode 6 adjacent to the signal line 3 . As clear from FIG. 43 b , level of the surface of the passivation film 10 which is an upper layer film of the array substrate 20 is not flat (level difference), and the gap between the surface of the passivation film 10 and the opposite substrate 30 is not flat. Thus, uneven luminance is likely to be caused, causing the picture quality to worsen. The level difference provided makes not only the array substrate inferior due to crack, but also disconnects the wiring on the array substrate due to the level difference portion in the manufacturing operation with a problem in improving the yield factor and reliability of the product. Further, in accordance with the conventional IPS liquid crystal displaying apparatus, picture quality is deteriorated by light leaking transmitted from the slit 40 , the light being emitted by a back light serving as a light source. In order to shield the leaked light, the black matrix 12 is provided on the opposite substrate 30 . However, when the TFT array substrate 20 is superposed with the opposite substrate 30 , there might be generated error. Then, the black matrix 12 has been formed in such a manner as to be somewhat larger with some margin for the purpose of taking the error into consideration. However, there arises such a problem in which opening ratio is lowered when shieding effect is enhanced by making the black matrix 12 large. SUMMARY OF THE INVENTION The first object of the present invention is to solve the problems mentioned above, and to provide an IPS liquid crystal displaying apparatus causing electric field parallel to a glass substrate, the IPS liquid crystal displaying apparatus capable of improving shielding effect against electric field leaking from the signal line, making the opening wide (that is, making opening ratio high) by lowering the light shielding area. Further, the second object of the present invention is to provide a high quality IPS liquid crystal displaying apparatus in which cost for producing the apparatus is decreased by preventing the lines from disconnection thereby improving the yield factor. The IPS liquid crystal displaying apparatus of the present invention comprises: a TFT array substrate, an opposite substrate opposed to the TFT array substrate and liquid crystal interposed between the TFT array substrate and the opposite substrate, wherein the TFT array substrate is composed of a glass substrate, a gate insulating film formed on the glass substrate, a passivation film formed on the gate insulating film, a plurality of scanning lines for transmitting a scanning signal, the plurality of scanning lines being formed on the glass substrate, a plurality of signal lines for transmitting an image signal, the plurality of signal lines being formed on the gate insulating film, a plurality of pixels arranged in grid like pattern by crossing the plurality of scanning lines with the plurality of signal lines, a plurality of TFTs implementing switching operation of the image signal on the basis of the scanning signals, a plurality of driving electrodes connected with the TFT, a plurality of opposite electrodes arranged in such a manner that each of the plurality of opposite electrodes is opposed to each of the driving electrodes, and a plurality of common lines for mutually connecting each of the opposite electrode of one of the plurality of pixels with the other one of the plurality of pixels, wherein the TFT array substrate is formed on the passivation film, the passivation film being different from a layer provided with the driving electrode and the opposite electrode. The IPS liquid crystal displaying apparatus of the present invention is provided with a driving electrode for driving the liquid crystal layer by causing the electric field parallel to the TFT array substrate face, the driving electrode being connected with the TFT, and an opposite electrode connected with a common line. At least the opposite electrode has a TFT array substrate formed on the passivation film, different from a layer where the signal line is formed. The IPS liquid crystal displaying apparatus of the present invention has a TFT array substrate having an opposite electrode formed to cover one portion of the signal line or all the portion of the signal line. The IPS liquid crystal displaying apparatus of the present invention has a TFT array substrate having an opposite electrode formed to cover one portion of the scanning line or all the portion thereof, having at least an opposite electrode in a layer different from the scanning line. The IPS displaying apparatus of the present invention has a common line and a scanning line on the same layer, and a signal line provided on the gate insulating film. The IPS liquid crystal displaying apparatus of the present invention has a TFT array substrate with the surface of the passivation film being approximately flat in shape. The IPS liquid crystal displaying apparatus of the present invention has a light shielding means formed to have the signal line and the opposite electrode superposed. The IPS displaying apparatus of the present invention has a TFT array substrate formed, to have for superposition in different layers, a TFT for switching the picture image signal in accordance with the scanning signal, a driving electrode for accumulating, while the switch of the TFT is off, the electric load stored when the switch of the TFT is on, and a storage capacitance increasing electrode for reinforcing the capacitance of the driving electrode. BRIEF EXPLANATION OF THE DRAWINGS FIG. 1 is a sectional view showing the construction of one pixel of an IPS liquid crystal displaying apparatus of Embodiment 1 of the present invention; FIG. 2 is a plain view showing the construction of one pixel of an IPS switching type liquid crystal displaying apparatus of Embodiment 1 of the present invention; FIGS. 3 a and 3 b are a plain view and a sectional view showing the construction of one pixel of an IPS liquid crystal displaying apparatus of the embodiment 1 of the present invention; FIGS. 4 a , 4 b , 5 a , 5 b , 6 a , 6 b , 7 a , 7 b , 8 a and 8 b depict is a process flow of a TFT array substrate of an IPS liquid crystal displaying apparatus of Embodiment 1 of the present invention; FIGS. 9 a , 9 b , 10 a , 10 b , 11 a , 11 b , 12 a , 12 b , 13 a and 13 b depict is another process flow of a TFT array substrate of an IPS liquid crystal displaying apparatus of Embodiment 1 of the present invention; FIGS. 14 a , 14 b , 15 a , 15 b , 16 a , 16 b , 17 a , 17 b , 18 a and 18 b depict is a still another process flow of a TFT array substrate of an IPS liquid crystal displaying apparatus of Embodiment 1 of the present invention; FIGS. 19 a and 19 b are a plain view and a sectional view showing the construction of one pixel of an IPS liquid crystal displaying apparatus of Embodiment 2 of the present invention; FIGS. 20 a , 20 b , 21 a , 21 b , 22 a , 22 b , 23 a , 23 b , 24 a and 24 b depict a process flow of a TFT array substrate of an IPS liquid crystal displaying apparatus of Embodiment 2 of the present invention; FIGS. 25 a and 25 b are a plain view and a sectional view showing the construction of one pixel of an IPS liquid crystal displaying apparatus of Embodiment 3 of the present invention; FIGS. 26 a , 26 b , 27 a , 27 b , 28 a , 28 b , 29 a , 29 b , 30 a and 30 b depict a process flow of a TFT array substrate of an IPS liquid crystal displaying apparatus of Embodiment 3 of the present invention; FIGS. 31 a and 31 b are a plain view and a sectional view showing the construction of one pixel of an IPS liquid crystal displaying apparatus of Embodiment 4 of the present invention; FIGS. 32 a and 32 b are a plain view and a sectional view showing the construction of one pixel of an IPS liquid crystal displaying apparatus of Embodiment 5 of the present invention; FIG. 33 is a view showing the potential distribution when the driving electrode and the opposite electrode are in a layer higher than the upper layer; FIGS. 34 a and 34 b are a plain view and a sectional view showing the construction of one pixel of an IPS liquid crystal displaying apparatus of Embodiment 6 of the present invention; FIGS. 35 a and 35 b are a plain view and a sectional view showing the construction of one pixel of an IPS liquid crystal displaying apparatus of Embodiment 7 of the present invention; FIG. 36 is a sectional view showing the construction of one pixel of an IPS liquid crystal displaying apparatus of Embodiment 8 of the present invention; FIGS. 37 a , 37 b , 38 a , 38 b , 39 a , 39 b , 40 a , 40 b , 41 a , 41 b , 42 a and 42 b depict a process flow of a TFT array substrate of an IPS liquid crystal displaying apparatus of Embodiment 9 of the present invention; FIGS. 43 a and 43 b are a plain view and a sectional view showing the construction of one pixel of the conventional IPS liquid crystal displaying apparatus; FIG. 44 shows an equivalent circuit of one pixel of the conventional IPS liquid crystal displaying apparatus; FIG. 45 is a block diagram showing the construction of the conventional IPS liquid crystal displaying apparatus; FIG. 46 is an explanatory view showing the electric potential distribution when the driving electrode and the opposite electrode are in a layer lower than the signal line; and FIG. 47 an explanatory a view showing a crosstalk. DETAILED DESCRIPTION OF THE INVENTION Embodiment 1 One embodiment of the present invention will be described in accordance with drawings. The reference numerals in Embodiment 1 are the same as those of the conventional reference numerals. FIG. 1 is a sectional view showing the construction of one pixel of the IPS type liquid crystal displaying apparatus in Embodiment 1 of the present invention. FIG. 2 is its plain view. FIG. 1 is a sectional view taken along a line of A-A in FIG. 2 . Referring to the drawing, reference numeral 1 denotes a glass substrate, numeral 2 denotes a scanning line, numeral 3 denotes a signal line, numeral 4 denotes a TFT, numeral 5 denotes a driving electrode, numeral 6 denotes an opposite electrode, numeral 7 denotes an electrode for forming the storage capacitance, numeral 8 denotes a common line, numeral 9 denotes a gate insulating film, numeral 10 denotes a passivation film, numeral 11 denotes a liquid crystal, numeral 12 denotes a BM, numeral 14 denotes a contact hole, numeral 15 denotes a source electrode of the transistor, and numeral 16 denotes a drain electrode of the transistor. Numeral 20 denotes an array substrate comprising a glass substrate 1 , a signal line 3 , a driving electrode 5 , an opposite electrode 6 . Numeral 30 denotes an opposite substrate cerving as a displaying picture face arranged opposite to the array substrate 20 . Numeral 40 denotes a slit which is a gap between the signal line 3 and the opposite electrode 6 . Numeral 50 denotes an opening of a pixel. FIG. 3 depicts the construction of one pixel of the IPS type liquid crystal displaying apparatus when a channel passivation TFT 21 which is one type of a TFT 4 is provided as a TFT to be used in the IPS type liquid crystal displaying apparatus shown in FIG. 2 . FIG. 3 a is its plain view. FIG. 3 b is a sectional view. The construction of the pixel of the IPS type liquid crystal displaying apparatus will be described in accordance with FIG. 1 and FIG. 2 . Referring to the drawings, numeral 1 denotes a glass substrate with a scanning line 2 being formed on the glass substrate 1 . A gate insulating film 9 is laminated to cover the scanning line 2 and a signal line 3 is provided on the gate insulating film 9 . A passivation film 10 is laminated on the signal line 3 . A driving electrode 5 and an opposite electrode 6 are provided on the passivation film 10 . The TFT array substrate 20 is made as described above. A substrate 30 which is provided to be opposed to the TFT array substrate 20 is an opposite substrate for grasping a liquid crystal 11 with respect to the TFT array substrate 20 . The IPS liquid crystal displaying apparatus of the present invention causes an electric field along the surface of the TFT array substrate, and thereby to drive the liquid crystal 11 by controlling the direction of the electric field. FIG. 2 is a plain view of an IPS liquid crystal displaying apparatus shown in FIG. 1 . Referring to FIG. 2 , numeral 2 denotes a scanning line and numeral 3 denotes a signal line. An area surrounded by the scanning line 2 and the signal line 3 becomes one pixel. Numeral 4 denotes a TFT provided in the intersection point between the scanning line 2 and the signal line 3 . The gate electrode of three electrodes having the TFT 4 is connected with the scanning line 2 , and the source electrode 15 is connected with the signal line 3 . The drain electrode 16 of three electrodes having the TFT 4 is connected with the driving electrode 5 by a contact hole 14 in an upper layer through a passivation film 10 (not shown). An opposite electrode 6 which is provided opposite to be engaged with the driving electrode 5 is connected with the common line 8 of the same layer. The common line 8 not shown is connected with the opposite electrode 6 of the other adjacent pixel. The driving electrode 5 , the opposite electrode 6 , and the common line 8 are formed at the same time in a layer upper than the signal line 3 . Numeral 7 denotes storage capacitance for keeping the potential of the driving electrode 5 . The opposite electrode 6 and the drain electrode 16 are laminated vertically. Numeral 40 denotes a slit between the signal line 3 and the opposite electrode 6 . The BM 12 provided in the opposite substrate 30 shown in FIG. 1 shields the leakage light which transmits through the slit 40 with the back light as a light source. Numeral 50 denotes an opening. The larger the area of the opening becomes, the higher picture quality the liquid display can obtain. As the IPS liquid crystal displaying apparatus retains the electric charge stored in the driving electrode 5 connected with the drain electrode 16 of the TFT 4 and drives the liquid crystal 11 by causing the electric field along the surface of the glass substrate 1 , the opposite substrate 30 is a no-electrode substrate not provided with an electrode. One example of the process flow of the TFT array substrate for composing the pixel of the IPS liquid crystal displaying apparatus in Embodiment 1 will be described. FIGS. 4 a , 4 b , 5 a , 5 b , 6 a , 6 b , 7 a , 7 b , 8 a and 8 b depict a process flow of a TFT array substrate. FIGS. 9 a , 9 b , 10 a , 10 b , 11 a , 11 b , 12 a , 12 b , 13 a and 13 b depict another process flow of a TFT array substrate. FIGS. 14 a , 14 b , 15 a , 15 b , 16 a , 16 b , 17 a , 17 b , 18 a and 18 b depict still another process flow of a TFT array substrate. The left-hand side views of FIG. 4 a through FIG. 18 a show the TFT array substrate and the right-hand side views thereof show the terminal portions for embodying the scanning line 2 into the scanning line driving circuit. Referring to FIGS. 4 a , 4 b , 5 a , 5 b , 6 a , 6 b , 7 a , 7 b , 8 a and 8 b a step 1 ( FIGS. 4 a and 4 b ) forms a scanning line 2 , of approximately 50 nm through 800 nm in film thickness, under the construction of any one of Cr, Al, Mo, Ta, Cu, Al—Cu, Al—Si—Cu, Ti, W, or of their alloy, or transparent materials such as ITO (Indium Tin Oxide) or the like or the laminated thereof. The scanning line 2 functions even as the gate electrode of the TFT 4 . As an etching method in forming the scanning line 2 may be used an etching method as the section becomes rectangular although the taper etching which becomes trapezoidal in section is shown in FIGS. 4 a , 4 b , 5 a , 5 b , 6 a , 6 b , 7 a , 7 b , 8 a and 8 b. In step 2 ( FIGS. 5 a and 5 b ), a gate insulating film 9 is accumulated to cover the scanning line 2 , amorphous silicon with impurities such as amorphous silicon, phosphorus and so on being doped in it is continuously accommodated, then amorphous silicon is patterned and the TFT 4 is formed with a channel etch type. A gate insulating film 9 is proper to have approximately 200 nm through 600 nm in thickness by using a transparent insulating film such as silicon nitride, silicon oxide or the like, film oxide of a gate electrode material (namely, a material of the scanning line 2 ) or their laminated films. Also, a micro crystal silicon with impurities such as phosphorus or the like being doped in it can be used as a material instead of amorphous silicon with impurities such as phosphorus or the like being doped in it. In step 3 ( FIGS. 6 a and 6 b ) there is formed a signal line 3 simultaneously with a source electrode 15 and a drain electrode 16 of the TFT 4 . The signal line 3 functions as a source electrode 15 . The signal line 3 is formed of any one of Cr, Al, Mo, Ta, Cu, Al—Cu, Al—Si—Cu, Ti, W or alloy mainly made of them, or alloy made chiefly of them, or a transparent material of such as ITO or the like or their laminated construction. In step 4 ( FIGS. 7 a and 7 b ) there is formed a passivation film 10 with a transparent insulating film of silicon nitride, silicon oxide and so on. In order to electrically connect the driving electrode 5 with the drain electrode 16 , the partial passivation film on the drain electrode 16 of the TFT 4 is removed to form a contact hole 14 . At this time, the gate insulating film 9 and the passivation film 10 are removed from the terminal portion of the scanning line 2 at the same time and the passivation film 10 is removed from the terminal portion of the signal line 3 so that the external terminal, the scanning line 2 and the signal line 3 can be connected electrically. In step 5 ( FIGS. 8 a and 8 b ) there is formed the driving electrode 5 and the opposite electrode 6 , as an electrode for forming the electric field in a horizontal direction to the substrate face, with any one of Cr, Al, Mo, Ta, Cu, Al—Cu, Al—Si—Cu, Ti, W or alloy mainly composed of at least two thereof, or a transparent material of such as ITO or the like or their laminated construction or their laminated construction including them. The driving electrode 5 is connected with the drain electrode 16 through the contact hole 14 . The opposite electrode 6 is connected with the common line 8 . The opposite electrodes 6 are superposed through the drain electrode 16 and the passivation film 10 to form the storage capacitance 7 for keeping the electric potential of the driving electrode. By the above five steps, the driving electrode 5 and the opposite electrode 6 are provided in the layer (namely, on the side of the opposite substrate 30 ) upper than the signal line 3 . The TFT array substrate 20 which can apply the horizontal electric field to the substrate face can be made by using a channel etch type TFT with five photo-lithography processes. Although the terminal 22 is formed by using the metal of the same layer as that of the scanning line 2 in the process flow of the above described TFT array substrate, a terminal can be formed by using the ITO. The ITO has only to be made of the same layer as that of the scanning line or the signal line 3 . Although the signal wiring has been straightly etched, it is desirable to conduct a taper etching operation. When the signal line is formed on Cr under the Al laminated construction, an over etching operation is conducted in Cr when the Cr has been patterned after the Al is patterned, the construction becomes protective in construction, causing disconnection. In order to prevent it, the etching of Al is conducted again after the patterning of the Cr. Retreat the Al from the Cr end face and the protecting construction can be prevented. This etching of the Al can use the taper etching. This method can be adapted when the signal line is formed under the laminated construction of different metals of two types or more of any one of Cr, Al, Mo, Ta, Cu, Al—Cu, Al—Si—Cu, Ti, W or alloy mainly composed of at least two thereof, or transparent materials such as ITO or their laminated construction. In FIGS. 4 a , 4 b , 5 a , 5 b , 6 a , 6 b , 7 a , 7 b , 8 a and 8 b the driving electrode 5 and the opposite electrode 6 can be formed on the same layer and the driving electrode 5 and the signal line 3 are formed at the same time as shown in FIGS. 9 a , 9 b , 10 a , 10 b , 11 a , 11 b , 12 a , 12 b , 13 a and 13 b . After forming the passivation film 10 by using the silicon nitride or the like, the opposite electrode 6 can be formed. In this case, the driving electrode 5 and the opposite electrode 6 are formed in a separate layer. A channel passivation film transistor 21 which is one type of TFT 4 can be used, instead of a TFT used for the TFT array substrate shown in FIGS. 4 a , 4 b , 5 a , 5 b , 6 a , 6 b , 7 a , 7 b , 8 a and 8 b . FIGS. 14 a , 14 b , 15 a , 15 b , 16 a , 16 b , 17 a , 17 b , 18 a and 18 b are views showing a process flow of the TFT array substrate formed by using a channel passivation film transistor 21 . The TFT array substrate shown in FIGS. 14 a , 14 b , 15 a , 15 b , 16 a , 16 b , 17 a , 17 b , 18 a and 18 b includes a pixel of the IPS liquid crystal displaying apparatus shown in FIG. 3 , and is formed much more in branch layer than the TFT array substrate shown in FIG. 5 . This is due to the difference of a producing step ( FIGS. 15 a and 15 b ) of forming a scanning line 2 , then successively depositing the gate insulating film 9 , the amorphous silicon 9 b , and the channel passivation film to cover the scanning line 2 , then forming the channel passivation film 21 , ion-injecting the impurities such as P and so on into the amorphous silicon with the channel passivation film 21 as a mask to form an n-layer, and forming the channel passivation film transistor. In the characteristic construction of the TFT array substrate 20 of the IPS liquid crystal displaying apparatus of Embodiment 1, the driving electrode 5 and the opposite electrode 6 on the array substrate 20 are arranged on a layer (namely, on the side of the opposite substrate 30 ) upper than the signal line 3 . This arrangement allows a step of forming the contact hole 14 and removing the passivation film 10 from the terminal portion of the signal line 3 , and a step of removing the insulating film 9 and the passivation film 10 from the terminal portion of the scanning line 2 to carry out at one time. Thus, the number of the masks can be reduced by one and thereby the manufacturing cost can be reduced. It has been found by forming the driving electrode 5 and the opposite electrode 6 on the layer of the side of the opposite substrate 30 with the signal line 3 and the layer being made different that the influences of the electric field caused by the electric potential difference between the opposite electrode 6 , provided adjacently to the signal line 3 on the end portion of the opening 50 shown in FIG. 2 , and the signal line 3 , as judged from the description to be mentioned later in Embodiment 5. Thus, the opposite electrode of the side end portion of the opening 50 can be made closer to the signal line 3 and the area of the opening 50 can be made larger. In FIG. 1 , the driving electrode 5 and the opposite electrode 6 are directly in contact with the liquid crystal interposed between the TFT array substrate 20 and the opposite substrate 30 , so that the liquid crystal can be efficiently driven, and the space between the driving electrode 5 and the opposite electrode 6 can be made wider. Thus, an effect of improving the aperture ratio can be obtained. Embodiment 2 FIGS. 19 a and 19 b show the construction of the pixel electrode of the liquid crystal displaying apparatus of the embodiment 2 of the present invention. FIG. 19 a is its plain view. FIG. 19 b is a sectional view taken along a line of A-A of FIG. 19 a . FIGS. 20 a , 20 b , 21 a , 21 b , 22 a , 22 b , 23 a , 23 b , 24 a and 24 b are views showing the process flow of the array substrate. Referring to the drawing, reference numeral 1 denotes a glass substrate, numeral 2 denotes a scanning line, numeral 3 denotes a signal line, numeral 4 denotes a thin film transistor (TFT), numeral 5 denotes a driving electrode, numeral 6 denotes an opposite electrode, numeral 7 denotes an electrode for forming the storage capacitance, numeral 8 denotes common line, numeral 9 denotes a gate insulating film, numeral 10 denotes a passivation film, numeral 11 denotes a liquid crystal, numeral 12 denotes a BM, numeral 14 denotes a contact hole, numeral 15 denotes a source electrode of a transistor, and numeral 16 denotes a drain electrode. Numeral 18 denotes a through-hole, numeral 20 denotes an array substrate comprising a glass substrate 1 , a signal line 3 , a driving electrode 5 , an opposite electrode 6 . Numeral 30 denotes an opposite substrate serving as a display picture face arranged opposite to the array substrate 20 . Numeral 40 denotes a slit which is a gap between the signal line 3 and the opposite electrode 6 . Numeral 50 denotes an opening of the pixel. In Embodiment 1, the common line 8 is formed on the same layer as that of the opposite electrode 6 . In the embodiment 2, the common line 8 is formed on the same layer as that of the scanning line 2 , namely, on the glass substrate 1 as shown in FIGS. 20 a , 20 b , 21 a , 21 b , 22 a , 22 b , 23 a , 23 b , 24 a and 24 b . The source electrode 15 is connected with the signal line 3 , which is laminated on the scanning line 2 and the common line 8 through the gate insulating film 9 . Furthermore, the driving electrode 5 and the opposite electrode 6 are formed through the passivation film 10 . The driving electrode 5 is connected with the drain electrode 16 through the contact hole 14 . The opposite electrode 6 is connected with the common line 8 through the through-hole 18 . The channel passivation film TFT can be used as the TFT 4 . In the IPS liquid crystal displaying apparatus of Embodiment 2, as in Embodiment 1, the driving electrode 5 and the opposite electrode 6 are formed in a layer close to the liquid crystal different from the signal line 3 . As the liquid crystal can be driven more efficiently, the space between the driving electrode 5 and the opposite electrode 6 can be made wider to improve the aperture ratio. Since the common line 8 and the scanning line 2 are formed in the same layer, the common line 8 can be formed on the flat glass substrate 1 together with the scanning line 2 . Thus, a problem of disconnecting the common line 8 with a level difference portion is prevented from being caused, so as to improve traction defective. Therefore, the reliability of the product is improved. In Embodiment 1, the opposite electrode 6 cannot be made thinner in film due to resistivity of the common line 8 , but in Embodiment 2, the film of the opposite electrode 6 can be made thinner. The dispersion of the electrode space is made smaller due to the thinner film of the opposite electrode 6 , so as to realize a liquid crystal displaying apparatus which is less in uneven luminance across the whole picture face. Embodiment 3 FIGS. 25 a and 25 b show the construction of one pixel of the liquid crystal displaying apparatus of the embodiment 2 of the present invention FIG. 25 a is its plain view. FIG. 25 b is a sectional view taken along a line of A-A of FIG. 25 a . FIGS. 26 a , 26 b , 27 a , 27 b , 28 a , 28 b , 29 a , 29 b , 30 a and 30 b are views showing the process flow of the array substrate. Referring to the drawing, reference numeral 1 denotes a glass substrate, numeral 2 denotes a scanning line, numeral 3 denotes a signal line, numeral 4 denotes a TFT, numeral 5 denotes a driving electrode, numeral 6 denotes an opposite electrode, numeral 7 denotes an electrode for forming the storage capacitance, numeral 8 denotes common line, numeral 9 denotes a gate insulating film, numeral 10 denotes a passivation film, numeral 11 denotes a liquid crystal, numeral 12 denotes a BM, numeral 14 denotes a contact hole, numeral 15 denotes a source electrode of a transistor, and numeral 16 denotes a drain electrode. Numeral 20 denotes an array substrate comprising a glass substrate 1 , a signal line 3 , a driving electrode 5 , an opposite electrode 6 . Numeral 30 is an opposite substrate serving as a displaying picture face arranged opposite to the array substrate 20 . Numeral 40 denotes a slit which is a gap between the signal line 3 and the opposite electrode 6 . Numeral 50 denotes an opening of the pixel. In forming the TFT array substrate 20 , the passivation film 10 is formed of a transparent insulation film such as silicon nitride, silicon oxide. The surface of the passivation film 10 is not flat and has a level difference. In Embodiment 3, the passivation film 10 is made flat by removing the level difference of the surface of the passivation film 10 , as shown in FIG. 25 b and FIGS. 26 a , 26 b , 27 a , 27 b , 28 a , 28 b , 29 a , 29 b , 30 a and 30 b , by forming with the use of a material such as acrylic melamine, acrylic epoxy or the like having a function of flattening the surface of the layer to be formed. The IPS liquid crystal displaying apparatus of Embodiment 3 can equally constitute with precision the gap between the surface of the array substrate across the whole displaying picture face and the opposite substrate 30 by flattening the surface of the passivation film 10 . A liquid crystal displaying apparatus which is less in uneven brilliance across the whole picture face can be made. The fraction defective which is caused due to cracks or the like in the level difference portion of the passivation film 10 can be made smaller to improve the yield. A high quality liquid crystal displaying apparatus can be realized which is applied equally in rubbing treatment necessary to the orientation of the liquid crystal by the flattening operation and is less in orientation disturbing. As in Embodiment 1, the driving electrode 5 and the opposite electrode 6 are provided closer to the liquid crystal than a formed layer of the signal line 3 , with an effect of improving the aperture ratio, because the liquid crystal can be driven efficiently, and the space between the driving electrode 5 and the opposite electrode 6 can be widened. Embodiment 4 FIGS. 31 a and 31 b show the construction of one pixel electrode of the liquid crystal displaying apparatus of Embodiment 4 of the present invention FIG. 31 a is its plain view. FIG. 31 b is a sectional view taken along a line of A-A of FIG. 31 a . Referring to the drawing, reference numeral 1 denotes a glass substrate, numeral 2 denotes a scanning line, numeral 3 denotes a signal line, numeral 4 denotes a TFT, numeral 5 denotes a driving electrode, numeral 6 denotes an opposite electrode, numeral 7 denotes an electrode for forming the storage capacitance, numeral 8 denotes common line, numeral 9 denotes a gate insulating film, numeral 10 denotes a passivation film, numeral 11 denotes a liquid crystal, numeral 14 denotes a contact hole, numeral 15 denotes a source electrode of a TFT 4 , and numeral 16 denotes a drain electrode of the TFT. Numeral 20 denotes an array substrate composing a glass substrate 1 , a signal line 3 , a driving electrode 5 , an opposite electrode 6 . Numeral 30 denotes an opposite substrate serving as a displaying picture face arranged opposite to the array substrate 20 . Numeral 60 denotes a light shielding film provided on the glass substrate 1 . Embodiment 4 is characterized by formation of a light shielding film 60 on a glass substrate 1 , which shields the leakage light from a slit 40 (see FIG. 43 a ) between the signal line 3 and the opposite electrode 6 in the pixel structure of the liquid crystal displaying apparatus of Embodiment 1 through Embodiment 3. The structure of the liquid crystal displaying apparatus of Embodiment 4 will be described in accordance with FIG. 31 a and FIG. 31 b. A light shielding film 60 is formed on the glass substrate 1 in FIG. 31 b . Although not shown in FIG. 31 b , the scanning line 2 is also formed on the same layer as that of the light shielding film 60 . The scanning line 2 functions as a gate electrode of the TFT 4 . A gate insulating film 9 is laminated on the scanning line 2 and the light shielding film 60 . A signal line 3 , in a position superposed on the light shielding film 60 , on the gate insulating film 9 . The TFT 4 is also formed on the gate insulating film 9 . The TFT 4 can use either of the channel etch TFT and the channel passivation film TFT. The source electrode 15 of the TFT 4 and the drain electrode 16 are also formed in the same layer as that of the signal line 3 , so as to laminate the passivation film 10 . Continuously a contact hole 14 is formed in the passivation film 10 . The driving electrode 5 provided on the passivation film 10 and the drain electrode of the TFT 4 provided on the gate insulating film 9 are connected with each other through the contact hole 14 . The opposite electrode 6 is formed on the passivation film 10 as in the driving electrode 5 . In a position where the opposite electrode 6 is superposed on the light shielding film 60 , it is superposed through the drain electrode 16 and the passivation film 10 to form the storage capacitance 7 for keeping the electric potential of the driving electrode 5 . The opposite electrode 6 is connected with the common line 8 provided on the same layer. Broken lines are shown on both the end portions of the pixel of FIG. 31 a . The broken lines show a position in FIG. 31 a of the light shielding film 60 provided on the glass substrate 1 shown in FIG. 31 b . As shown by the broken lines, it is found out that a slit 40 (see FIG. 43 a ) is covered between the signal line 3 and the opposite electrode 6 by formation of the opposite electrodes 6 at both the ends to be superposed on the light shielding film 60 . In Embodiment 4, the driving electrode 5 and the opposite electrode 6 are formed on the passivation film 10 . The driving electrode 5 and the signal line 3 are formed simultaneously on the gate insulating film 9 and the opposite electrode 6 can be formed after the passivation film has been formed by using silicon nitride or the like. In this case, the driving electrode 5 and the opposite electrode 6 are formed in a different layer. In Embodiment 4, the light leaking from the slit 40 (not shown) between the signal line 3 and the opposite electrode 6 is not caused by formation of the light shielding film 60 on the glass substrate 1 . Thus, the width of the BM 12 of the opposite substrate 30 can be made narrower and the light shielding in the direction of the signal line 3 do not have to be conducted by the BM 12 . Therefore, the BM 12 can be omitted so that the opening portion can be provided larger. The liquid crystal displaying apparatus is manufactured by superposed combination between the TFT array substrate and the opposite substrate with a color filter attached to it, including the liquid crystal 11 into between these substrates, and connecting the driving circuit. Superposed errors are sometimes caused by a step of superposing the TFT array substrate and the opposed substrate. Thus, in the BM, the light shielding area has to be provided larger (see FIG. 43 a ), considering the superposed errors, so as to positively shield the leakage light from the slit 40 of the TFT array substrate 20 . The transmission portion of the slit leakage light can be shielded in light positively by provision of the light shielding film 60 on the TFT array substrate 20 . The superposed error between the TFT array substrate and the opposite substrate is not necessary to be considered. Thus, the BM 12 can be provided into the size of a necessary minimum, and thereby the opening portion can be made larger. In the IPS liquid crystal displaying apparatus of Embodiment 4, the driving electrode 5 and the opposite electrode 6 are provided in a layer close to the liquid crystal as in the IPS liquid crystal displaying apparatus of Embodiment 1. The liquid crystal can be driven effectively and the space between the electrodes can be widened, with an effect of improving the aperture ratio. Embodiment 5 A construction of one pixel of the IPS liquid crystal displaying apparatus of Embodiment 5 is depicted in FIGS. 32 a and 32 b . The plain view thereof is depicted in FIG. 32 a . FIG. 32 b is a sectional view taken along a line A-A of FIG. 32 a . Referring to the drawing, reference numeral 1 denotes a glass substrate, numeral 2 denotes a scanning line, numeral 3 denotes a signal line, numeral 4 denotes a thin film transistor (TFT), numeral 5 denotes a driving electrode, numeral 6 denotes an opposite electrode, numeral 7 denotes an electrode for forming the storage capacitance, numeral 8 denotes common line, numeral 9 denotes a gate insulating film, numeral 10 denotes a passivation film, numeral 11 denotes a liquid crystal, numeral 12 denotes a BM, numeral 14 denotes a contact hole, numeral 15 denotes a source electrode of a transistor, and numeral 16 denotes a drain electrode of a transistor. Numeral 20 denotes an array substrate comprising glass substrate 1 , a signal line 3 , a driving electrode 5 , an opposite electrode 6 . Numeral 30 denotes an opposite substrate serving as a displaying picture face arranged opposite to the array substrate 20 . Embodiment 5 is characterized by formation of the driving electrode 5 and the opposite electrode 6 , as in Embodiment 1, in a layer upper than the signal line 3 , and furthermore, the formation of the opposite electrode 6 to cover the signal line 3 , so as to make it hard to receive the influences of the leakage electric field from the signal line 3 but further, not to cause the leakage light from the slit 40 (see FIG. 43 a ) between the signal line 3 and the opposite electrode 6 . FIG. 33 depicts the simulated results of changes in electric potential caused between the driving electrode 5 formed to cover the signal line 3 and the opposite electrode 6 formed in the same layer as that of the driving electrode 5 . FIG. 33 is the calculated electric potential in the window upper portion or lower portion when a white window has been displayed on the half tone of 50% in relative transmission factor. Between FIG. 46 and FIG. 33 there is shown the electric potential distribution in the TFT array substrate of the conventional IPS liquid crystal displaying apparatus having the driving electrode 5 and the opposite electrode 6 in the layer lower than the signal line 3 . In FIG. 33 , the electric field to be caused by the electric potential difference between the signal line 3 and the opposite electrode 6 is shielded by the opposite electrode 6 arranged on the upper portion to cover the signal line 3 . Thus, the electric potential distribution is approximately symmetrical in the area close to the signal line 3 of the opening 50 and the area separated from the signal line 3 . In this manner, the TFT array substrate 20 of the IPS liquid crystal displaying apparatus of Embodiment 5 can reduce remarkably the influences, of the electric field to be caused between the signal line 3 and the opposite electrode 6 , with respect to the electric field to be caused between the driving electrode 5 and the opposite electrode 6 by formation of the driving electrode 5 and the opposite electrode 6 in a layer upper than the signal line 3 , and formation of the opposite electrode 6 to cover the signal line 3 . The opposite electrode 6 of the end of the opening 50 can be made much closer to the signal line 3 , thus making it possible to widen the total area of the opening 50 wider. As the opposite electrode 6 is formed to cover the signal line 3 , the leakage light can be shield, thus making it possible to remove the BM 12 . As the area of the opening portion 50 can be widened, a liquid crystal displaying apparatus higher in brilliance can be provided. As a step of providing the BM 12 can be reduced, the productivity can be improved, and a liquid crystal displaying apparatus can be produced with lower cost. As in Embodiment 1, the driving electrode 5 and the opposite electrode 6 can be formed in a layer close to the liquid crystal. The liquid crystal can be driven efficiently and the space between the electrodes can be widened, thus improving the aperture ratio. Embodiment 6 FIGS. 34 a and 34 b show the construction of one pixel of the IPS liquid crystal displaying apparatus of Embodiment 6. FIG. 34 a is its plain view. FIG. 34 b is a sectional view taken along a line of A-A of FIG. 34 a The construction of the pixel of the IPS liquid crystal displaying apparatus of Embodiment 6 shown in FIGS. 34 a and 34 b are fundamentally similar to that of the pixel of the IPS displaying apparatus of Embodiment 5 shown in FIG. 12 , the description thereof is omitted. Although the opposite electrode 6 of the construction for completely covering the signal line 3 is provided in Embodiment 5, the opposite electrode 6 of the construction for covering one portion of the signal line 3 can be used as in the opposite electrode 6 of the pixel of the IPS liquid crystal displaying apparatus of Embodiment 6 shown in FIGS. 34 a and 34 b. According to Embodiment 6, the opposite electrode 6 is adapted to form one portion of the signal line 3 . Thus, the electric field for generating the electric potential difference between the signal line 3 and the opposite electrode 6 can reduce the influences for influencing the electric field between the driving electrode 5 and the opposite electrode 6 , and the leakage light passing through the slit 40 between the signal line 3 and the opposite electrode 6 can be shielded. It is possible to make the width of the BM 12 narrower or remove the BM 12 . A liquid crystal displaying apparatus which is wider in an opening and higher in luminance can be realized. Also, a process of providing the BM 12 can be reduced by removing the BM 12 , so as to improve the productivity. As a superposed area of the signal line 3 and the opposite electrode 6 becomes smaller, the short circuit defect between the signal line 3 and the opposite electrode 6 can be reduced. As the superposed area of the signal line 3 and the opposite electrode 6 becomes smaller, the capacitance between the signal line 3 and the opposite electrode 6 can be made smaller, so that the load of the wiring can be reduced, making it easier to do a driving operation. Embodiment 7 FIGS. 35 a and 35 b show the construction of one pixel of the IPS liquid crystal displaying apparatus of Embodiment 7. FIG. 35 a is its plain view. FIG. 35 b is a sectional view taken along a line of A-A of FIG. 35 a . As the construction of the pixel of the IPS liquid crystal displaying apparatus of Embodiment 7 shown in FIGS. 35 a and 35 b are fundamentally similar to that of the pixel of the IPS type displaying apparatus of the embodiment 5 shown in FIGS. 34 a and 34 b , the description thereof is omitted. Embodiment 7 is characterized by enlarging the opposite electrode 6 up to above the scanning line 2 , and connecting the opposite electrode 6 of the other pixel adjacent to the pixel by using the opposite electrode 6 , in the pixel construction of the liquid crystal displaying apparatus in, for example, Embodiment 6 as shown in FIGS. 34 a and 34 b. By using such a construction, the width of the opposite electrode 6 becomes thicker so that the resistivity of the opposite electrode 6 is lowered and the load is reduced, making it easier to conduct a driving operation. As the electric potential is supplied from the opposite electrode 6 on the scanning line 2 even when the common line 8 is disconnected, it does not become defective on display. The reliability of the product is improved. The construction of the opposite electrode 6 in Embodiment 7 can be adapted to not only to Embodiment 7, but also the other embodiments. Embodiment 8 FIG. 36 shows the sectional construction of the storage capacitance portion of one pixel of the liquid crystal displaying apparatus of Embodiment 8 of the present invention. Referring to the drawing, reference numeral 17 denotes an electrode for increasing the storage capacitance formed on the glass substrate 1 . Numeral 16 denotes a drain electrode of the TFT. The storage capacitance portion of the liquid crystal liquid displaying apparatus of Embodiment 8 as shown in the drawing is superposed and laminated on a layer (for example, the layer of the scanning line 2 ) separate from the drain electrode 16 of the TFT through the gate insulating film 9 . It can make the area of the electrode for forming the storage capacitance smaller by the laminating construction of the electrode of the storage capacitance portion. As a result, the opening 50 (not shown) of the pixel can be made wider. Embodiment 9 FIGS. 37 a , 37 b , 38 a , 38 b , 39 a , 39 b , 40 a , 40 b , 41 a , 41 b , 42 a and 42 b are views showing the process flow of the TFT array substrate of the Embodiment 9. Referring to FIGS. 37 a , 37 b , 38 a , 38 b , 39 a , 39 b , 40 a , 40 b , 41 a , 41 b , 42 a and 42 b , reference numeral 1 denotes a glass substrate, numeral 2 denotes a scanning line, numeral 3 is a signal line, numeral 4 denotes a TFT, numeral 5 denotes a driving electrode, numeral 6 denotes an opposite electrode, numeral 8 denotes common line, numeral 9 denotes a gate insulating film, numeral 10 denotes a passivation film, numeral 14 denotes a contact hole, numeral 15 denotes a source electrode of a transistor, and numeral 16 denotes a drain electrode of a transistor. Numeral 19 denotes a second passivation film. Numeral 20 denotes an array substrate comprising a glass substrate 1 , a signal line 3 , a driving electrode 5 , an opposite electrode 6 . In Embodiment 9, a second passivation film 19 is formed on the TFT array substrate shown in FIGS. 4 a through 18 a and FIGS. 4 b through 18 b . The construction of one pixel of the liquid crystal displaying apparatus of Embodiment 9 is similar to Embodiment 1. A method of manufacturing the liquid crystal displaying apparatus of the embodiment will be described hereinafter. The process flow of the TFT array substrate in Embodiment 9 is similar to Embodiment 1 up to a step for forming the opposite electrode 6 . In Embodiment 9, a second passivation film 19 is formed on the top layer of the opposite electrode 6 . By forming the second passivation film 19 between the driving electrode 5 and the opposite electrode 6 , the short circuit, between the driving electrode 5 and the opposite electrode 6 , due to foreign materials can be prevented to improve the yield. As the level difference between the driving electrode 5 and the opposite electrode 6 can be made flat, a high quality of liquid crystal displaying apparatus can be realized where the rubbing treatment necessary for the liquid crystal orientation is equally applied and is less in orientation disturbing. According to the IPS liquid crystal displaying apparatus of the present invention, the driving electrode and the opposite electrode are formed in a layer close to the liquid crystal different to the signal line. The driving electrode and the opposite electrode are formed in a layer close to the liquid crystal so that the liquid crystal can be driven more efficiently. Thus, the space between the driving electrode and the opposite electrode can be widened, so as to improve the aperture ratio. According to the IPS liquid crystal displaying apparatus of the present invention, at least the opposite electrode of the driving electrode and the opposite electrode is formed in a layer close to the liquid crystal different from a layer where the signal line is formed, so that influences given by the electric field to be caused by the electric potential difference between the signal line and the opposite electrode. According to the IPS liquid crystal displaying apparatus of the present invention, the opposite electrode is formed to cover one portion or all the portion of the signal line. The electric field to be caused by the electric potential difference between the signal line and the opposite electrode influences the electric field to be caused between the driving electrode of the opening and the opposite electrode, thereby restraining a problem of deteriorating the picture quality on the displaying from being caused. Thus, the liquid crystal display of high picture quality can be made and the leakage light from between the signal line for making the black light a light source, and the opposite electrode can be shielded accurately. The BM can be removed, so as to improve the aperture ratio. According to the IPS liquid crystal displaying apparatus of the present invention, at least the opposite electrode is provided in a layer different from the scanning line so as to cover one portion or all the portion of the scanning line. The opposite electrode of the other pixel can be connected by the opposite electrode, so that the width of the opposite electrode can be made thicker without reduction in the area of the opening. Accordingly, the resistivity of the opposite electrode can be lowered to reduce the load of the wiring. As the electric potential can be fed from the opposite electrode on the scanning line when the common line is disconnected, the reliability can be increased by restraining the defects on the displaying from being caused. According to the IPS liquid crystal displaying apparatus of the present invention, the common line and the scanning line are provided on the same layer and the single line is provided on a layer closer to the opposite substrate than to the common line and the scanning line. The defect to be caused in the stage difference portion can be restrained. According to the IPS liquid crystal apparatus of the present invention, a passivation film which formed approximately flat in surface where the TFT array substrate comes into contact with the liquid crystal. Thus, the gap between the array substrate surface and the opposite substrate across all the display picture surface is equally constructed with precision. The rubbing treatment necessary for the liquid crystal orientation is equally applied and the orientation disturbing can be reduced. The liquid crystal displaying apparatus which is less in uneven luminance across the whole picture face can be realized. The fraction defective which is caused by cracks in the stage difference portion of the passivation film becomes smaller, so as to improve the yield. In the IPS liquid crystal displaying apparatus of the present invention, a TFT array substrate is provided having a light shielding means formed to have the signal line and the opposite electrode superposed. The leakage light for transmitting through the slit can be shielded, and thus the BM provided on the opposite substrate becomes unnecessary. The superposed errors are not necessary to be considered in the superposition between the TFT array substrate and the opposite substrate in determining the size of the light shielding means. Thus, the size of the light shielding means can be made that of a necessary minimum, so as to improve the aperture ratio. According to the in plain switching type liquid crystal displaying apparatus of the present invention, a TFT array substrate formed to be superposed with a TFT, a driving electrode, and a storage capacitance increasing electrode being different in layer. The area of the electrode for forming the storage capacitance can be made smaller and the opening portion of the pixel can be made wider correspondingly, and the liquid crystal displaying apparatus higher in luminance can be realized. Though several embodiments of the present invention are described above, it is to be understood that the present invention is not limited only to the above-mentioned, various changes and modifications may be made in the invention without departing from the spirit and scope thereof.

An In Plane Switching (IPS) liquid crystal displaying apparatus includes a TFT array substrate, an opposite substrate opposed to the TFT array substrate and a liquid crystal interposed between the TFT array substrate and the opposite substrate. The TFT array substrate includes a plurality of driving electrodes formed on a passivation film and connected with the plurality of TFTs, a plurality of opposite electrodes formed on the passivation film, each of the plurality of opposite electrodes opposing the respective plurality of driving electrodes, and a plurality of common lines configured to connect each of the plurality of opposite electrodes with each of a plurality of pixels. The TFT array substrate provided with a light shielding formed in such a manner as to superpose one signal line of the plurality of signal lines and one opposite electrode of the plurality of opposite electrodes.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2007-038939 filed on Feb. 20, 2007, the entire contents of which are incorporated herein by reference. BACKGROUND [0002] 1. Field [0003] This application relates to a buffer circuit and a control method thereof. [0004] 2. Description of Related Art [0005] In general, output signal potential characteristic in a buffer circuit may greatly fluctuate due to fluctuations of a threshold value of MOS transistors caused by process fluctuation. Japanese Unexamined Patent Publication No. 9(1997)-93111 discloses a buffer circuit in which fluctuations of the output signal potential characteristic are suppressed. [0006] The buffer circuit is provided with a first slew rate circuit and a second slew rate circuit. The first slew rate circuit has an input/output characteristic according to which, if an input potential of a signal input node is changed from a high level to a low level, a potential of a first output node rises rapidly from a low level, until the input signal potential becomes near ½ of a power supply potential, and a potential of the first output node rises slowly to a high level from a vicinity where the output signal potential at the output node dropped below ½ of the power supply potential. Further, the first slew rate circuit has an input/output characteristic according to which, if the input potential at a signal input node is changed from a low level to a high level, the potential at a first output node drops sharply from a high level to a low level. [0007] The second slew rate circuit has an input/output characteristic according to which, if an input potential at a signal input node is changed from a high level to a low level, a potential at the second output node rises rapidly from a low level to a high level. Further, the second slew rate circuit has an input/output characteristic according to which, if an input potential at the signal input node is changed from a low level to a high level, a potential at the second output node drops rapidly from a high level until the input signal potential becomes near ½ of the power supply potential, and a potential at a second output node drops slowly approximately from where the output signal potential at the output node exceeds ½ of the power supply potential until it becomes a low level. [0008] The above-described buffer circuit rapidly raises or drops the input waveforms of the output buffer circuit connected to the first and the second slew rate circuits up to ½ of the power supply voltage, depending on the input/output characteristic of the first and second slew rate circuits, after which, it slowly changes the input waveforms. In this buffer circuit, since the input waveforms of the output buffer circuit are rapidly raised or dropped up to ½ of the power supply voltage, and the output signal potential of the output buffer circuit exceeds an inversion region, it is possible to suppress the delay of the output signal potential with respect to the input potential. [0009] An output buffer circuit 100 is known which is provided with a delay circuit 110 and an auxiliary driving circuit 120 , as shown in FIG. 7 , and in which a P-type channel transistor M 71 and an N-type channel transistor M 72 that constitute output switching elements are quickly changed from an OFF state to an ON state. [0010] If an input signal inputted from an input terminal (IN) is changed from a high level to a low level in the above-described output buffer circuit 100 , operation is carried out in the following manner. In this output buffer circuit 100 , right after the input signal is changed from a high level to a low level, the gate voltage of the N-type channel transistor M 74 is fixed to a low level voltage, so that the N-type channel transistor M 74 enters an OFF state. At this time, the gate voltage of the P-type channel transistor M 73 is fixed to a low level voltage, so that the P-type channel transistor M 73 enters an ON state. [0011] In addition, right after the input signal is changed from a high level to a low level, a delay circuit 110 A inputs a low level delay signal obtained by delaying a high level input signal to a gate of the P-type channel transistor M 75 in the auxiliary driving circuit 120 . As a result, the gate voltage of the P-type channel transistor M 75 is fixed to a low level voltage, so that the P-type channel transistor M 75 enters an ON state. When the P-type channel transistor M 73 and the P-type channel transistor M 75 enter an ON state, respectively, a source current path L 51 is formed as shown in the drawing. The source current path L 51 extends from a power supply voltage Vdd to a gate of the N-type channel transistor M 72 by passing through the P-type channel transistors M 75 and M 73 . [0012] Since the gate of the P-type channel transistor M 76 is connected to a ground, the gate voltage of the transistor M 76 is fixed to a low level voltage. As a result, the P-type channel transistor M 76 is fixed to an ON state. When the P-type channel transistor M 73 and the P-type channel transistor M 76 enter an ON state, respectively, a source current path L 52 is formed as shown in the drawing. The source current path L 52 extends from the power supply voltage Vdd to a gate of the N-type channel transistor M 72 by passing through the P-type channel transistors M 76 and M 73 . [0013] The forming of the source current path L 52 in addition to the source current path L 51 in the above-described output buffer circuit 100 helps increase the current driving capability of the source current path with respect to the N-type channel transistor M 72 . Consequently, the time required to approximate the gate voltage of the N-type channel transistor 72 to a threshold voltage is shortened. Thus, in the output buffer circuit 100 , the time until the N-type channel transistor M 72 is changed from an OFF state into an ON state, is shortened, with the threshold voltage set as a boundary. [0014] On the other hand, in the above-described output buffer circuit 100 , if the input signal is changed from a low level to a high level, a sink current path L 62 is formed separately from a sink current path L 61 , by using the delay circuit 110 B and the N-type channel transistor M 80 of the auxiliary driving circuit 120 . As a result, the current driving capability of the sink current path with respect to the P-type channel transistor M 71 is increased. Consequently, the time required by the gate voltage of the P-type channel transistor M 71 to approximate to a threshold voltage is shortened. Thus, similarly with the above-described N-type channel transistor M 72 , the time until the P-type channel transistor M 71 is changed from an OFF state into an ON state is shortened. The symbols M 78 , M 80 and M 81 in the drawing show N-type channel transistors, respectively. Symbol 79 shows a P-type channel transistor. [0015] However, in the above-described output buffer circuit 100 , there may be cases that process fluctuation may cause fluctuations in the delay time of the respective delay circuits 110 A and 110 B and fluctuations in the threshold voltage of both transistors M 75 and M 80 of the auxiliary driving circuit 120 . [0016] In such a case, the fact that the timing at which the delay signals are outputted from the delay circuits 110 and 110 B to respective gates of the transistors M 75 and M 80 differs, and the fact that the output timing of the respective delay signals differs may have an effect and may cause fluctuations in the time required to form the source current path L 51 and the sink current path L 62 . [0017] In the above-described output buffer circuit 100 , when the time required to form the source current path L 51 and the sink current path L 62 fluctuates, it is believed that the time required by the gate voltage of transistors M 71 and M 72 to approximate to the threshold voltage fluctuates. Accordingly, in the above-described output buffer circuit 100 , if the time required by the gate voltage of transistors M 71 and M 72 to approximate to the threshold voltage fluctuates, it is believed that the timing at which transistors M 71 and M 72 are changed from an OFF state to an ON state fluctuates, which may cause fluctuations in the slew rate. [0018] When the slew rate fluctuates, it is believed that a response delay occurs in the output signal to be outputted from the output terminal (OUT) of the output buffer circuit 100 , with respect to the input signal. Due to this, in the above-described output buffer circuit 100 , the response delay in the output signal may have an effect, which may make the output characteristic become unstable. SUMMARY [0019] According to a first aspect of the present embodiment, there is provided a buffer circuit comprising: a driving portion driving an output switching element; a detecting portion detecting that a voltage value of a control terminal of the output switching element has exceeded a threshold voltage value; and an auxiliary driving portion connected to the driving portion, the auxiliary driving portion changing driving capability of the output switching element in accordance with a result of detection by the detecting portion. [0020] According to the buffer circuit according to the first aspect of the present embodiment, if an auxiliary driving portion is provided which is connected to the driving portion that drives the output switching element and is adapted to change the driving capability of the output switching element in accordance with the detection results of the detecting portion, the voltage value of the control terminal of the output switching element can be increased or decreased in accordance with the detection results of the detecting portion, depending on the driving capability of the output switching element which are set by the auxiliary driving portion. [0021] According to the buffer circuit according to the first aspect of the present embodiment, if the voltage value of the control terminal of the output switching element is increased by the auxiliary driving portion, the output switching element can be quickly changed from a non-conductive state into a conductive state, which allows to increase the slew rate of the buffer circuit. If the voltage value of the control terminal of the output switching element is decreased by the auxiliary driving portion, the conductive state of the output switching element can be restricted, so that the slew rate of the buffer circuit can be returned to a standard value based on the driving capability of the output switching element set by the driving portion. [0022] According to a second aspect of the present embodiment, there is provided a control method of a buffer circuit, comprising the steps of: driving an output switching element; detecting that a voltage value of a control terminal of the output switching element has exceeded a threshold voltage value; and auxiliary driving to change driving capability of the output switching element in the step of driving, in accordance with a result of detection by the step of detecting. [0023] According to the control method of the buffer circuit according to the second aspect of the present embodiment, if the step of auxiliary driving is provided which changes the driving capability of the output switching element in the step of driving, the voltage value of the control terminal of the output switching element can be increased or decreased in accordance with the detection results of the step of detecting, depending on the driving capability of the output switching element which are set by the step of auxiliary driving. [0024] According to the control method of the buffer circuit according to the second aspect of the present embodiment, if the voltage value of the control terminal of the output switching element is increased by the step of auxiliary driving, the output switching element can be quickly changed from a non-conductive state into a conductive state, which allows to increase the slew rate of the buffer circuit. If the voltage value of the control terminal of the output switching element is decreased by the step of auxiliary driving, the conductive state of the output switching element can be restricted, so that the slew rate of the buffer circuit can be returned to a standard value based on the driving capability of the output switching element set by the step of driving. [0025] The present disclosure has been worked out in view of the above-described situation, and an object thereof is to provide a buffer circuit and a control method thereof capable of controlling the timing at which the output switching element is changed from an OFF state to an ON state, and preventing the output characteristic from becoming unstable. [0026] The above and further novel features of the disclosure will more fully appear from the following detailed description when the same is read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended as a definition of the limits of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS [0027] FIG. 1 is a circuit configuration diagram of an output buffer circuit directed to a first embodiment; [0028] FIG. 2 is a circuit configuration diagram of an output buffer circuit directed to a second embodiment; [0029] FIG. 3 is a circuit configuration diagram of an output buffer circuit directed to a third embodiment; [0030] FIG. 4 is a circuit configuration diagram of an output buffer circuit directed to a fourth embodiment; [0031] FIG. 5 is a circuit configuration diagram of an output buffer circuit directed to a fifth embodiment; [0032] FIG. 6 is a circuit configuration diagram of an output buffer circuit directed to a sixth embodiment; and [0033] FIG. 7 is a circuit configuration diagram of a conventional output buffer circuit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment [0034] A first embodiment of the present disclosure will be described while referring to FIG. 1 . Here, the buffer circuit of the present disclosure will be described by taking an output buffer circuit 10 as an example. FIG. 1 is a circuit configuration diagram of the output buffer circuit 10 . In FIG. 1 , devices, etc. which are the same as those of FIG. 7 are denoted by the same numerical symbols. The output buffer circuit 10 is provided with a P-type channel transistor M 1 , an N-type channel transistor M 2 , first gate voltage control circuits 20 A and 20 B, first gate voltage detecting circuits 30 A and 30 B, and a second gate voltage control circuit 40 . The P-type channel transistor M 1 and the N-type channel transistor M 2 correspond to the output switching elements of the present disclosure. The first gate voltage control circuits 20 A and 20 B correspond to the driving portions of the present disclosure. The first gate voltage detecting circuits 30 A and 30 B correspond to the detecting portions of the present disclosure. The second gate voltage control circuit 40 corresponds to the auxiliary driving portion of the present disclosure. [0035] A source of the P-type channel transistor M 1 is connected to a power supply voltage Vdd (power supply line) A drain of the P-type channel transistor M 1 is connected to a drain of the N-type channel transistor M 2 . A source of the N-type channel transistor M 2 is connected to a ground. Further, the drain of the P-type channel transistor M 1 and the drain of the N-type channel transistor M 2 are connected to an output terminal (OUT). [0036] The first gate voltage control circuit 20 A is provided with a P-type channel transistor M 3 , a P-type channel transistor M 4 and an N-type channel transistor M 5 . A source of the P-type channel transistor M 3 is connected to the power supply voltage Vdd (power supply line). A gate of the P-type channel transistor M 3 is connected to the ground. A drain of the P-type channel transistor M 3 is connected to a source of the P-type channel transistor M 4 . Symbol A 1 in the drawing shows a connection point between the drain of the P-type channel transistor M 3 and the source of the P-type channel transistor M 4 . [0037] A drain of the P-type channel transistor M 4 is connected to a drain of the N-type channel transistor M 5 . A connection point A 2 between the drain of the P-type channel transistor M 4 and the drain of the N-type channel transistor M 5 is connected to a gate of the N-type channel transistor M 2 . A source of the P-type channel transistor M 5 is connected to the ground. A gate of the P-type channel transistor M 4 and a gate of the N-type channel transistor M 5 are connected to an input terminal (IN). [0038] The first gate voltage control circuit 20 B is provided with an N-type channel transistor M 13 , an N-type channel transistor M 14 and a P-type channel transistor M 15 . A source of the N-type channel transistor M 13 is connected to the ground. A gate of the N-type channel transistor M 13 is connected to the power supply voltage Vdd (power supply line). The drain of the N-type channel transistor M 13 is connected to the source of the N-type channel transistor M 14 . Symbol B 1 in the drawing shows a connection point between the drain of the N-type channel transistor M 13 and the source of the N-type channel transistor M 14 . [0039] A drain of the N-type channel transistor M 14 is connected to a drain of the P-type channel transistor M 15 . A connection point B 2 between the drain of the N-type channel transistor M 14 and the drain of the P-type channel transistor M 15 is connected to a gate of the P-type channel transistor M 1 . A source of the P-type channel transistor M 15 is connected to the power supply voltage Vdd (power supply line). A gate of the N-type channel transistor M 14 and a gate of the P-type channel transistor M 15 are connected to the input terminal (IN). [0040] The first gate voltage detecting circuit 30 A is provided with an N-type channel transistor M 7 , a resistor R 1 and an inverter 31 . A gate of the N-type channel transistor M 7 is connected to the connection point A 2 between the gate of the N-type channel transistor M 2 and the first gate voltage control circuit 20 A. The N-type channel transistor M 7 corresponds to the first switching element of the present disclosure. The gate of the N-type channel transistor M 7 corresponds to the first control terminal of the first switching element of the present disclosure. The gate of the N-type channel transistor M 2 corresponds to the control terminal of the output switching element of the present disclosure. A source of the N-type channel transistor M 7 is connected to the ground. A drain of the N-type channel transistor M 7 is serially connected to one terminal of resistor R 1 . The other terminal of the resistor R 1 is serially connected to the power supply voltage Vdd (power supply line). The resistor R 1 corresponds to the first resistor element of the present disclosure. A connection point C between the drain of the N-type channel transistor M 7 and a terminal of the resistor R 1 is connected to an input of the inverter 31 . [0041] In the present embodiment, the N-type channel transistor M 7 is manufactured by using the same manufacturing process as that used for the N-type channel transistor M 2 . Because of this, the value of the threshold voltage of the N-type channel transistor M 7 is set to be the same as the value of the threshold voltage of the N-type channel transistor M 2 . [0042] The first gate voltage detecting circuit 30 B is provided with a P-type channel transistor M 17 , a resistor R 11 and an inverter 32 . A gate of the P-type channel transistor M 17 is connected to the connection point B 2 between the gate of the P-type channel transistor M 1 and the first gate voltage control circuit 20 B. The P-type channel transistor M 17 corresponds to the first switching element of the present disclosure. The gate of the P-type channel transistor M 17 corresponds to the first control terminal of the first switching element of the present disclosure. The gate of the P-type channel transistor M 1 corresponds to the control terminal of an output switching element of the present disclosure. A source of the P-type channel transistor M 17 is connected to the power supply voltage Vdd (power supply line). A drain of the P-type channel transistor M 17 is serially connected to one terminal of the resistor R 11 . The other terminal of the resistor R 11 is serially connected to the ground. The resistor R 11 corresponds to the first resistor element of the present disclosure. A connection point D between the drain of the P-type channel transistor M 17 and one terminal of the resistor R 11 is connected to the input of the inverter 32 . [0043] In the present embodiment, the P-type channel transistor M 17 is manufactured by using the same manufacturing process as that used for the P-type channel transistor M 1 . Because of this, the value of the threshold voltage of the P-type channel transistor M 17 is set to be the same as the value of the threshold voltage of the P-type channel transistor M 1 . [0044] The second gate voltage control circuit 40 is provided with a P-type channel transistor M 8 and an N-type channel transistor M 18 . A source of the P-type channel transistor M 8 is connected to the power supply voltage Vdd (power supply line). A gate of the P-type channel transistor M 8 is connected to an output of the inverter 31 which is provided in the first gate voltage detecting circuit 30 A. A drain of the P-type channel transistor M 8 is connected to a connection point A 1 of the first gate voltage control circuit 20 A. The P-type channel transistor M 8 corresponds to the second switching element of the present disclosure. The gate of the P-type channel transistor M 8 is connected to the connection point C through the inverter 31 , which means that this corresponds to the second control terminal of the second switching element of the present disclosure. [0045] A source of the N-type channel transistor M 18 is connected to the ground. A gate of the N-type channel transistor M 18 is connected to the output of the inverter 32 which is provided in the first gate voltage detecting circuit 30 B. The drain of the N-type channel transistor M 18 is connected to the connection point B 1 of the first gate voltage control circuit 20 B. The N-type channel transistor M 18 corresponds to the second switching element of the present disclosure. The gate of the N-type channel transistor M 18 is connected to the connection point D, through the inverter 32 , which means that this corresponds to the second control terminal of the second switching element of the present disclosure. [0046] Next, the operation of the output buffer circuit 10 according to the present embodiment will be described. If the data signal to be inputted from the input terminal (IN) is changed from a high level to a low level, the output buffer circuit 10 operates as will be described in the following text. Description on operation which is the same as that of the output buffer circuit 100 shown in FIG. 7 is hereby omitted. [0047] In the output buffer circuit 10 , if the input signal is maintained at a high level, the gate voltage of the P-type channel transistor M 4 is fixed to a high level voltage so that the P-type channel transistor M 4 enters an OFF state. At this time, the gate voltage of the N-type channel transistor M 5 is fixed to a high level voltage, so that the N-type channel transistor M 5 enters an ON state. As a result, a sink current path with respect to the N-type channel transistor M 2 is formed. The sink current path extends from the gate of the N-type channel transistor M 2 to the ground, by passing through the N-type channel transistor M 5 . As a result of forming the sink current path, the gate voltage of the N-type channel transistor M 2 is fixed to a low level voltage, so that the N-type channel transistor M 2 is maintained in an OFF state. [0048] Since the gate of the N-type channel transistor M 7 is connected to the gate of the N-type channel transistor M 2 , when the gate voltage of the N-type channel transistor M 2 is fixed to a low level voltage, the gate voltage of the N-type channel transistor M 7 is fixed to a low level voltage. As a result, the N-type channel transistor M 7 enters an OFF state. [0049] The input of the inverter 31 receives a high level signal, based on the potential occurring at the connection point C. The inverter 31 outputs a low level signal to the gate of the P-type channel transistor M 8 . As a result, the gate voltage of the P-type channel transistor M 8 is fixed to a low level voltage, so that the P-type channel transistor M 8 is maintained in an ON state. [0050] In addition, since the gate of the P-type channel transistor M 3 is connected to the ground, the gate voltage of the transistor M 3 is fixed to a low level voltage. Here, the P-type channel transistor M 3 is maintained in an ON state. [0051] Then, when the input signal is changed from a high level to a low level, the gate voltage of the P-type channel transistor M 4 is fixed to a low level voltage, so that the P-type channel transistor M 4 enters an ON state. At this time, the gate voltage of the N-type channel transistor M 5 is fixed to a low level voltage, so that the N-type channel transistor M 5 enters an OFF state. As a result, the P-type channel transistor M 3 and the P-type channel transistor M 4 enter an ON state, to form the source current path L 1 as shown in the drawing. The source current path L 1 extends from the power supply voltage Vdd to the gate of the N-type channel transistor M 2 , by passing through the P-type channel transistor M 3 and the P-type channel transistor M 4 . [0052] At the same time, since the P-type channel transistor M 8 is maintained in an ON state, the source current path L 2 shown in the drawing is formed by the transistor M 8 and the P-type channel transistor M 4 which is in an ON state. The source current path L 2 extends from the power supply line to the gate of the N-type channel transistor M 2 , by passing through the P-type channel transistor M 8 and the P-type channel transistor M 4 . [0053] As a result of forming, in the output buffer circuit 10 of the present embodiment, the source current path L 2 in addition to the source current path L 1 , the current driving capability of the source current path with respect to the N-type channel transistor M 2 is increased. Consequently, the speed at which the gate voltage of the N-type channel transistor M 2 is boosted is increased, which shortens the time required by the gate voltage to approximate to the threshold voltage. In addition, in the present embodiment, since the gate of the N-type channel transistor M 7 is connected to the gate of the N-type channel transistor M 2 , the time required by the gate voltage of the N-type channel transistor M 7 to approximate to the threshold voltage is shortened, in association with an increase in the current driving capability of the source current path with respect to the N-type channel transistor M 2 manufactured by using the same manufacturing process as that used for the transistor M 7 . [0054] Since the value of the threshold voltage of the N-type channel transistor M 7 is set to the same value as the value of the threshold voltage of the N-type channel transistor M 2 , when the gate voltage of the N-type channel transistor M 2 reaches the threshold voltage, the gate voltage of the N-type channel transistor M 7 also reaches the threshold voltage. [0055] When the gate voltage of the N-type channel transistor M 7 exceeds the threshold voltage, the N-type channel transistor M 7 enters an ON state. As a result, the current path extending from the power supply line to the ground through the resistor R 1 is formed so that the potential occurring at the connection point C drops. The input of the inverter 31 receives a low level signal based on the potential that dropped. The inverter 31 outputs a high level signal to the gate of the P-type channel transistor M 8 . As a result, the gate voltage of the P-type channel transistor M 8 is fixed to a high level voltage, so that the P-type channel transistor M 8 enters an OFF state. [0056] When the P-type channel transistor M 8 enters an OFF state, the source current path L 2 is blocked, and subsequently, the source current path L 1 is formed. In this case, the current driving capability of the source current path with respect to the N-type channel transistor M 2 is reduced as compared to the case that the source current path L 2 is formed, in addition the source current path L 1 . Here, the speed at which the gate voltage of the N-type channel transistor M 2 is boosted is delayed when using one source current path L 1 , as compared to the boost speed required by the gate voltage of the N-type channel transistor M 2 to reach the threshold voltage when using the two source current paths L 1 and L 2 . [0057] Also, in the output buffer circuit 10 , if the input signal is maintained at a high level, the gate voltage of the N-type channel transistor M 14 is fixed to the high level voltage, so that the N-type channel transistor M 14 enters an ON state. At this time, the gate voltage of the P-type channel transistor M 15 is fixed to a high level voltage, so that the P-type channel transistor M 15 enters an OFF state. [0058] Further, since the gate of the N-type channel transistor M 13 is connected to the power supply voltage Vdd, the gate voltage of the transistor M 13 is fixed to a high level voltage. Here, the N-type channel transistor M 13 is maintained in an ON state. When the N-type channel transistor M 14 and the N-type channel transistor M 13 enter an ON state, respectively, a sink current path with respect to the P-type channel transistor M 1 is formed. The sink current path extends from the gate of the P-type channel transistor M 1 to the ground, by passing through the N-type channel transistor M 14 and the N-type channel transistor M 13 . As a result of forming the sink current path, the gate voltage of the P-type channel transistor M 1 is fixed to a low level voltage, so that the P-type channel transistor M 1 is maintained in an ON state. [0059] On the other hand, if the data signal inputted from the input terminal (IN) is changed from a low level to a high level, the output buffer circuit 10 of the present embodiment operates in the following manner. In the output buffer circuit 10 , if the input signal is maintained at a low level, the gate voltage of the N-type channel transistor M 14 is fixed to a low level voltage, so that the N-type channel transistor M 14 enters an OFF state. At this time, the gate voltage of the P-type channel transistor M 15 is fixed to a low level voltage, so that the P-type channel transistor M 15 enters an ON state. As a result, a source current path with respect to the P-type channel transistor M 1 is formed. The source current path extends from the power supply line to the gate of the P-type channel transistor M 1 , by passing through the P-type channel transistor M 15 . As a result of forming this source current path, the gate voltage of the P-type channel transistor M 1 is fixed to a high level voltage, so that the P-type channel transistor M 1 is maintained in an OFF state. [0060] Since the gate of the P-type channel transistor M 17 is connected to the gate of the P-type channel transistor M 1 , when the gate voltage of the P-type channel transistor M 1 is fixed to a high level voltage, the gate voltage of the P-type channel transistor M 17 is fixed to a high level voltage. As a result, the P-type channel transistor M 17 enters an OFF state. [0061] The input of the inverter 32 receives a low level signal based on the potential at the connection point D (ground potential). The inverter 32 outputs a high level signal to the gate of the N-type channel transistor M 18 . As a result, the gate voltage of the N-type channel transistor M 18 is fixed to a high level voltage, so that the N-type channel transistor M 18 is maintained in an ON state. [0062] In addition, since the gate of the N-type channel transistor M 13 is connected to the power supply voltage Vdd, the gate voltage of the transistor M 13 is fixed to a high level voltage. Here, the N-type channel transistor M 13 is maintained in an ON state. [0063] Then, when the input signal is changed from a low level to a high level, the gate voltage of the N-type channel transistor M 14 is fixed to a high level voltage, so that the N-type channel transistor M 14 enters an ON state. At this time, the gate voltage of the P-type channel transistor M 15 is fixed to a high level voltage, so that the P-type channel transistor M 15 enters an OFF state. As a result, the N-type channel transistor M 14 and the N-type channel transistor M 13 enter an ON state, and a sink current path L 11 as shown in the drawing is formed. The sink voltage path L 11 extends from the gate of the P-type channel transistor M 1 to the ground, by passing through the N-type channel transistor M 14 and the N-type channel transistor M 13 . [0064] At the same time, since the N-type channel transistor M 18 is maintained in an ON state, a sink current path L 12 as shown in the drawing is formed by the transistor M 18 and the N-type channel transistor M 14 which is in an ON state. The sink current path L 12 extends from the gate of the P-type channel transistor M 1 to the ground, by passing through the N-type channel transistor M 18 , via the N-type channel transistor M 14 . [0065] In the output buffer circuit 10 of the present embodiment, as a result of forming the sink current path L 12 in addition to the sink current path L 11 , the current driving capability of the sink current path with respect to the P-type channel transistor M 1 is increased. As a result, the speed at which the gate voltage of the P-type channel transistor M 1 is stepped down is increased, which shortens the time required by the gate voltage to approximate to the threshold value. In addition, in the present embodiment, since the P-type channel transistor M 17 is connected to the gate of the P-type channel transistor M 1 , the time required by the gate voltage of the P-type channel transistor M 17 to approximate to the threshold voltage is shortened, in association with an increase in the current driving capability of the sink current path with respect to the P-type channel transistor M 1 manufactured using the same manufacturing process as that for the transistor M 17 . [0066] Since the value of the threshold voltage of the P-type channel transistor M 17 is set to the same value as the value of the threshold voltage of the P-type channel transistor M 1 , when the gate voltage of the P-type channel transistor M 1 reaches the threshold voltage, the gate voltage of the P-type channel transistor M 17 also reaches the threshold voltage. [0067] After the gate voltage of the P-type channel transistor M 17 reaches the threshold voltage, the P-type channel transistor M 17 enters an ON state. As a result, a current path extending from the power supply line to the ground, by passing through the P-type channel transistor M 17 , via the resistor R 11 is formed, so that the potential at the contact point D is boosted. The input of the inverter 32 receives a high level signal based on the potential at the connection point D. The inverter 32 outputs a low level signal to the gate of the N-type channel transistor M 18 . As a result, the gate voltage of the N-type channel transistor M 18 is fixed to a low level voltage, so that the N-type channel transistor M 18 enters an OFF state. [0068] When the N-type channel transistor M 18 enters an OFF state, the sink current path L 12 is blocked, and subsequently, the sink current path L 11 is formed. In this case, the current driving capability of the sink current path with respect to the P-type channel transistor M 1 decreases, as compared to the case that the sink current path L 12 is formed in addition to the sink current path L 1 . Here, the speed at which the gate voltage of the P-type channel transistor M 1 is stepped down is reduced when one sink current path L 11 is used, as compared to the step-down speed required by the gate voltage of the P-type channel transistor M 1 to reach the threshold voltage, when two sink current paths L 11 and L 12 are used. [0069] In the present embodiment, the entering of the P-type channel transistor M 3 and the P-type channel transistor M 4 in an ON state to form the source current path L 1 , and the entering of the N-type channel transistor M 14 and the N-type channel transistor M 13 in an ON state to form the sink current path L 11 correspond to the step of driving of the present disclosure. [0070] In the present embodiment, the exceeding of the threshold voltage by the gate voltage of the N-type channel transistor M 7 manufactured by using the same manufacturing process as that used for the N-type channel transistor M 2 corresponds to the detecting step of the present disclosure. Further, in the present embodiment, the reaching of the threshold voltage by the gate voltage of the P-type channel transistor M 17 manufactured by using the same manufacturing process as that used for the P-type channel transistor M 1 corresponds to the step of detecting of the present disclosure. [0071] In the present disclosure, the entering of the P-type channel transistor M 8 in an ON state or an OFF state in response to the output signal of the inverter 31 , to form or block the source current path L 2 , thereby changing the current driving capability of the source current path with respect to the N-type channel transistor M 2 corresponds to the step of auxiliary driving of the present disclosure. Further, in the present embodiment, the entering of the N-type channel transistor M 18 in an ON state or an OFF state in response to the output signal of the inverter 32 to form or block the sink current path L 12 and thereby change the current driving capability of the sink current path with respect to the P-type channel transistor M 1 corresponds to the step of auxiliary driving of the present disclosure. Effects of the First Embodiment [0072] The output buffer circuit 10 of the present embodiment is provided with the second gate voltage control circuit 40 that is connected to first gate voltage control circuits 20 A and 20 B that respectively form the source current path L 1 with respect to the N-type channel transistor M 2 , or the sink current path L 11 with respect to the P-type channel transistor M 1 , and is adapted to form or block the source current path L 2 with respect to the N-type channel transistor M 2 , or form or block the sink current path L 12 with respect to the P-type channel transistor M 1 depending on whether the gate voltage of the N-type channel transistor M 7 of the first gate voltage detecting circuit 30 A or the gate voltage of the P-type channel transistor M 17 of the first gate voltage detecting circuit 30 B exceeded the threshold voltage, to thereby respectively increase or decrease the current driving capability of the source current path with respect to the N-type channel transistor M 2 , or the current driving capability of the sink current path with respect to the P-type channel transistor M 1 . [0073] In the output buffer circuit 10 , the gate voltage of the N-type channel transistor M 2 and the gate voltage of the P-type channel transistor M 1 can be respectively boosted or stepped down in accordance with the current driving capability of the source current path with respect to the N-type channel transistor M 2 and the current driving capability of the sink current path with respect to the P-type channel transistor M 1 . Here, according to the output buffer circuit 10 , the source current path L 2 is formed by the second gate voltage control unit 40 in addition to the source current path L 1 , and the sink current path L 12 is formed by the second gate voltage control circuit 40 in addition to the sink current path L 11 , so that the time required by the gate voltage of the transistors M 2 and M 1 to reach the threshold voltage is shortened. As a result, in the output buffer circuit 10 , transistors M 2 and M 1 can be quickly changed from an OFF state to an ON state, which allows increasing the slew rate. In the output buffer circuit 10 , the response delay with respect to the data input signal can thus be suppressed, thereby making it possible to adjust the output characteristic of the output buffer circuit 10 . [0074] According to the output buffer circuit 10 , after the source current path L 2 has been blocked by the second gate voltage control circuit 40 , the source current path L 1 is subsequently formed by the first gate voltage control circuit 20 A, and after the sink current path L 12 is blocked by the second gate voltage control circuit 40 , the sink current path L 12 is subsequently formed by the first gate voltage control circuit 20 B. As a result, the current driving capability of the source current path with respect to the N-type channel transistor M 2 and the current driving capability of the sink current path with respect to the P-type channel transistor M 1 are respectively decreased as compared to the case that the two source current paths L 1 and L 2 and the two sink current paths L 11 and L 12 are respectively formed. The time required to boost the gate voltage of the N-type channel transistor M 2 and the time required to step down the gate voltage of the P-type channel transistor M 1 can be delayed, as compared to the case that the two source current paths L 1 and L 2 and the two sink current paths L 11 and L 12 are respectively formed, which makes it possible to return the slew rate of the output buffer circuit 10 to a standard value decided by the source current path L 1 or sink current path L 11 . [0075] According to a control method of the output buffer circuit 10 , the gate voltage of the N-type channel transistor M 2 and the gate voltage of the P-type channel transistor M 1 can be respectively boosted or stepped down in accordance with the current driving capability of the source current path with respect to the N-type channel transistor M 2 and current driving capability of the of the sink current path with respect to the P-type channel transistor M 1 . Here, according to the control method of the output buffer circuit 10 , the source current path L 2 is formed in addition to the source current path L 1 , and the sink current path L 12 is formed in addition to the sink current path L 11 , which helps shorten the time required by the gate voltages of the transistors M 2 and M 1 to reach the threshold voltage. As a result, the transistors M 2 and M 1 can be quickly changed from an OFF state to an ON state, which allows increasing the slew rate. According to the control method of the output buffer circuit 10 , the response delay with respect to the data input signal can thus be suppressed, thereby making it possible to adjust the output characteristic of the output buffer circuit 10 . [0076] Further, according to the control method of the output buffer circuit 10 , after the source current path L 2 is blocked, the source current path L 1 is subsequently formed, and after the sink current path L 12 is blocked, the sink current path L 11 is subsequently formed. As a result, the current driving capability of the source current path with respect to the N-type channel transistor M 2 and the current driving capability of the sink current path with respect to the P-type channel transistor M 1 are respectively decreased as compared to the case that two source current paths L 1 and L 2 and two sink current paths L 11 and L 12 are respectively formed. Here, the time required to boost the gate voltage of the N-type channel transistor M 2 and the time required to step down the gate voltage of the P-type channel transistor M 1 can be delayed as compared to the case that the two source current paths L 1 and L 2 and the two sink current paths L 11 and L 12 are respectively formed, which allows the slew rate of the output buffer circuit 10 to be returned to a standard value determined by the source current path L 1 or the sink current path L 11 . [0077] In the output buffer circuit 10 of the present embodiment, the first gate voltage detecting circuit 30 A is provided with an N-type channel transistor M 7 which has a gate connected to the gate of the N-type channel transistor M 2 , and the first gate voltage detecting circuit 30 B is provided with a P-type channel transistor M 17 which has a gate connected to the gate of the P-type channel transistor M 1 . Here, if the gate voltages of the transistors M 2 and M 1 reach the threshold voltage so that the transistors M 2 and M 1 enter an ON state, the N-type channel transistor M 7 in which the value of the threshold voltage is the same as the value of the threshold voltage of the N-type channel transistor M 2 , and the P-type channel transistor M 17 in which the value of the threshold voltage is the same as the value of the threshold voltage of the P-type channel transistor M 1 enter an ON state, respectively. When the transistors M 7 and M 17 in the output buffer circuit 10 have entered in an ON state, detection can be made that the gate voltages of transistors M 2 and M 1 have reached the threshold voltage. [0078] In the output buffer 10 of the present embodiment, the first gate voltage detecting circuit 30 A is provided with the resistor R 1 which is arranged between the power supply line and the ground and is serially connected to the drain of the N-type channel transistor M 7 , and the first gate voltage detecting circuit 30 B is provided with the resistor R 11 which is arranged between the power supply line and the ground and is serially connected to the drain of the P-type channel transistor M 17 . When the N-type channel transistor M 7 in the output buffer circuit 10 enters an ON state or an OFF state, the potential occurring at the connection point C between the transistor M 7 and the resistor R 1 is changed, and when the P-type channel transistor M 17 enters an ON state or an OFF state, the potential occurring at the connection point D between the transistor M 17 and the resistor R 11 is changed. Here, a detection can be made that the N-type channel transistor M 2 and the N-type channel transistor M 7 have entered an ON state or an OFF state, and a detection can be made that the P-type channel transistor M 1 and the P-type channel transistor M 17 have entered an ON state or an OFF state in accordance with the change in the potential occurring at the connection points C and D in the output buffer circuit 10 . Thus, a detection can be made in the output buffer circuit 10 as to whether the gate voltages of the transistors M 2 and M 1 have reached the threshold value, based on the result that a detection was made that the N-type channel transistor M 2 and the P-type channel transistor M 1 have entered an ON state or an OFF state. [0079] In the output buffer circuit 10 according to the present embodiment, the second gate voltage control circuit 40 is provided with the P-type channel transistor M 8 that has a gate connected to the connection point C through the inverter 31 , and is also provided with the N-type channel transistor M 18 that has a gate connected to the connection point D through the inverter 32 . The gate voltages of the transistors M 8 and M 18 in the output buffer circuit 10 can be changed in accordance with a change in the potentials occurring at the connection points C and D. Here, in the output buffer circuit 10 , the transistors M 8 and M 18 can be controlled to enter an ON state or an OFF state in accordance with the gate voltages of the transistors M 8 and M 18 , to thus allow the formation of source current path L 2 and sink current path L 12 , and the blocking of the source current path L 2 and the sink current path L 12 . As a result of forming or blocking the source current path L 2 in the output buffer circuit 10 , the current driving capability of the source current path with respect to the N-type channel transistor M 2 can be changed. Also, as a result of forming or blocking the sink current path L 12 , the current driving capability of the sink current path with respect to the P-type channel transistor M 11 can be changed. Second Embodiment [0080] The second embodiment of the present disclosure will be described while referring to FIG. 2 . FIG. 2 is a circuit configuration diagram of an output buffer circuit 10 A of the present embodiment. Here, elements which are the same as those in the first embodiment are denoted by the same numerical symbols, to thereby simplify the description. The output buffer circuit 10 A is provided with a P-type channel transistor M 1 , an N-type channel transistor M 2 , first gate voltage control circuits 20 A and 20 B, second gate voltage detecting circuits 30 C and 30 D, a third gate voltage control circuit 40 A, and gate bias circuits 50 A and 50 B. The second gate voltage detecting circuits 30 C and 30 D correspond to the detecting portions of the present disclosure. The third gate voltage control circuit 40 A corresponds to the auxiliary driving portion of the present disclosure. [0081] The second gate voltage detecting circuit 30 C is provided with the N-type channel transistor M 7 , the P-type channel transistor M 27 and an inverter 31 . A drain of the N-type channel transistor M 7 is serially connected to the drain of the P-type channel transistor M 27 . A source of the N-type channel transistor M 27 is connected to a power supply voltage Vdd (power supply line). A connection point C 1 between a drain of the N-type channel transistor M 7 and a drain of the P-type channel transistor M 27 is connected to the input of the inverter 31 . [0082] The second gate voltage detecting circuit 30 D is provided with a P-type channel transistor M 17 , an N-type channel transistor M 37 and an inverter 32 . A drain of the P-type channel transistor M 17 is serially connected to a drain of the N-type channel transistor M 37 . A source of the N-type channel transistor M 37 is serially connected to a ground. A connection point D 1 between a drain of the P-type channel transistor M 17 and a drain of the N-type channel transistor M 37 is connected to an input of the inverter 32 . [0083] The gate bias circuit 50 A is provided with a P-type channel transistor M 51 and a constant current source 51 . The source of the P-type channel transistor M 51 is connected to the power supply voltage Vdd (power supply line). A gate of the P-type channel transistor M 51 is connected to a gate of the P-type channel transistor M 27 which is provided in a second gate voltage detecting circuit 30 C. [0084] The gate and the drain in the P-type channel transistor M 51 are short-circuited. The drain of the P-type channel transistor M 51 is connected to the ground through the constant current source 51 . [0085] The gate bias circuit 50 B is provided with an N-type channel transistor M 52 and a constant current source 52 . A drain of the N-type channel transistor M 52 is connected to the power supply voltage Vdd (power supply line) through the constant current source 52 . The drain and the gate in the N-type channel transistor M 52 are short-circuited. A gate of the N-type channel transistor M 52 is connected to a gate of the N-type channel transistor M 37 which is provided in a second gate voltage detecting circuit 30 D. A source of the N-type channel transistor M 52 is connected to the ground. [0086] The third gate voltage control circuit 40 A is provided with a P-type channel transistor M 28 and an N-type channel transistor M 38 . A source of the P-type channel transistor M 28 is connected to the power supply voltage Vdd (power supply line). A gate of the P-type channel transistor M 28 is connected to the output of the inverter 31 which is provided in the second gate voltage detecting circuit 30 C. A drain of the P-type channel transistor M 28 is connected to a connection point A 1 of the first gate voltage control circuit 20 A. The P-type channel transistor M 28 corresponds to the third switching element of the present disclosure. A gate of the P-type channel transistor M 28 is connected to the connection point C 1 through the inverter 31 , which means that this corresponds to the third control terminal of the third switching element according to the present disclosure. [0087] A source of the N-type channel transistor M 38 is connected to the ground. A gate of the N-type channel transistor M 38 is connected to an output of the inverter 32 which is provided in the second gate voltage detecting circuit 30 D. A drain of the N-type channel transistor M 38 is connected to a connection point B 1 of the first gate voltage control circuit 20 B. The N-type channel transistor M 38 corresponds to the third switching element of the present disclosure. The gate of the N-type channel transistor M 38 is connected to the connection point D 1 through the inverter 32 , which means that this corresponds to the third control terminal of the third switching element according to the present disclosure. [0088] Next, the operation of the output buffer circuit 10 A according to the present embodiment will be described. If the data signal inputted from the input terminal (IN) is changed from a high level to a low level, the output buffer circuit 10 A operates in the following manner. [0089] Right after the data input signal is changed from a high level to a low level, the gate voltage of the N-type channel transistor M 7 does not reach the threshold voltage. Thus, the OFF state of the N-type channel transistor M 7 is maintained. [0090] In the present embodiment, the P-channel transistor M 51 of the gate bias circuit 50 A and the P-type channel transistor M 27 of the second gate voltage detecting circuit 30 C constitute a current mirror circuit. The P-type channel transistor M 27 functions as a constant current source and runs a current corresponding to the output current of the constant current source 51 from the power supply line into the connection point C 1 . The P-type channel transistor M 27 corresponds to the current source of the present disclosure. [0091] The input of the inverter 31 receives a high level signal based on the potential occurring at the connection point C 1 . The inverter 31 outputs a low level signal to the gate of the P-type channel transistor M 28 . As a result, the gate voltage of the P-type channel transistor M 28 is fixed to a low level voltage, so that the P-type channel transistor M 28 is maintained in an ON state. [0092] Then, the output buffer circuit 10 A operates in the same manner as the output buffer circuit 10 of the first embodiment. In the output buffer circuit 10 A, a source current path L 2 A is formed as shown in the drawing, in addition to the source current path L 1 , in a manner similar to that in the first embodiment. As a result, similarly with the first embodiment, the current driving capability of the source current path with respect to the N-type channel transistor M 2 is increased, so that the time required by the gate voltage of the N-type channel transistor M 2 to approximate to the threshold voltage is shortened. The source current path L 2 A extends from the power supply line to the gate of the N-type channel transistor M 2 , by passing through the P-type channel transistor M 28 and further, through the P-type channel transistor M 4 . [0093] As a result of the gate voltage of the N-type channel transistor M 2 exceeding the threshold voltage, when the gate voltage of the N-type channel transistor M 7 exceeds the threshold voltage, the inverter 31 outputs a high level signal to the gate of the P-type channel transistor M 28 , similarly with the first embodiment. As a result, the P-type channel transistor M 28 enters an OFF state, and the source current path L 2 A is blocked. Thus, similarly with the first embodiment, the current driving capability of the source current path with respect to the N-type channel transistor M 2 is decreased, and the speed at which the gate voltage is boosted is delayed in comparison with the boost speed required by the gate voltage of the N-type channel transistor M 2 to reach the threshold voltage. [0094] On the other hand, right after the data input signal is changed from a low level to a high level, the gate voltage of the P-type channel transistor M 17 does not reach the threshold voltage. Thus, the P-type channel transistor M 17 is maintained in an OFF state. [0095] In the present embodiment, the N-type channel transistor M 52 of the gate bias circuit 50 B and the N-type channel transistor M 37 of the second gate voltage detecting circuit 30 D constitute a current mirror circuit. The N-type channel transistor M 37 functions as a constant current source, and flows a current corresponding to the output current of the constant current source 52 into the transistor M 37 . The N-type channel transistor M 37 corresponds to the current source of the present disclosure. [0096] The input of the inverter 32 receives a low level signal based on the potential (ground potential) at the connection point D 1 . The inverter 32 outputs a high level signal to the gate of the N-type channel transistor M 38 . As a result, the gate voltage of the N-type channel transistor M 38 is fixed to a high level voltage, so that the N-type channel transistor M 38 is maintained in an ON state. [0097] Then, the output buffer circuit 11 A operates in the same manner as the output buffer circuit 10 of the first embodiment. Thus, similarly with the first embodiment, a sink current path L 12 A as illustrated is formed in the output buffer circuit 10 A, in addition to the sink current path L 11 . As a result, similarly with the first embodiment, the current driving capability of the sink current path with respect to the P-type channel transistor M 1 is increased, which shortens the time required by the gate of the P-type channel transistor M 1 to approximate to the threshold voltage. The sink current path L 12 A extends from the gate of the P-type channel transistor M 1 to the ground, by passing through the N-type channel transistor M 38 via the N-type channel transistor M 14 . [0098] Further, as a result of the gate voltage of the P-type channel transistor M 1 reaching the threshold voltage, when the gate voltage of the P-type channel transistor M 17 reaches the threshold value, the P-type channel transistor M 17 enters an ON state. When the P-type channel transistor M 17 enters an ON state, the potential at the connection point D 1 is changed. The input of the inverter 32 receives a high level signal based on the potential at the connection point D 1 . [0099] The inverter 32 outputs a low level signal to the gate of the N-type channel transistor M 38 . As a result, the N-type channel transistor M 38 enters an OFF state, so that the sink current path L 12 A is blocked. Thus, similarly with the first embodiment, the current driving capability of the sink current path with respect to the P-type channel transistor M 1 is decreased, and the speed at which the gate voltage is stepped down is delayed as compared to the step down speed at which the gate voltage of the P-type channel transistor M 1 reaches the threshold voltage. Effects of the Second Embodiment [0100] In the output buffer circuit 10 A according to the present embodiment, the second gate voltage detecting circuit 30 C is provided with a P-type channel transistor M 27 which is connected to the N-type channel transistor M 7 and functions as a constant current source, and the second gate voltage detecting circuit 30 D is provided with an N-type channel transistor M 37 which is connected to the P-type channel transistor M 17 and functions as a constant current source. In the output buffer circuit 10 A, when the N-type channel transistor M 7 enters an ON state or an OFF state, the potential occurring at the connection point C 1 between the transistor M 7 and the P-type channel transistor M 27 is changed, and when the P-type channel transistor M 17 enters an ON state or an OFF state, the potential occurring at the connection point D 1 between the transistor M 17 and the N-type channel transistor M 37 is changed. Here, in the output buffer circuit 10 A, a detection can be made that the N-type channel transistor M 2 and the N-type channel transistor M 7 have entered an ON state or an OFF state, and a detection can be made that the P-type channel transistor M 1 and the P-type channel transistor M 17 have entered an ON state or an OFF state, depending on the change in the potential occurring at connection C 1 and D 1 . Thus, in the output buffer circuit 10 A, a detection can be made as to whether the gate voltages of the transistors M 2 and M 1 have reached the threshold voltage based on the result that a detection is made that the N-type channel transistor M 2 and the P-type channel transistor M 1 have entered in an ON state or an OFF state. [0101] In the output buffer circuit 10 A of the present embodiment, the third gate voltage control circuit 40 A is provided with a P-type channel transistor M 28 that has a gate connected to the connection point C 1 through the inverter 31 , and is also provided with the N-type channel transistor M 38 which has a gate connected to the connection point D 1 through the inverter 32 . In the output buffer circuit 10 A, the gate voltages of the transistors M 28 and M 38 can be changed in accordance with a change in the potentials occurring at the connection points C 1 and D 1 . Here, in the output buffer circuit 10 A, the transistors M 28 and M 38 can be controlled to enter an ON state or an OFF state in accordance with the gate voltages of the transistors M 28 and M 38 , so as to form the source current path L 2 A and the sink current path L 12 A, or block the source current path L 2 A and the sink current path L 12 A. Therefore, as a result of forming or blocking the source current path L 2 A in the output buffer circuit 10 A, the current driving capability of the source current path with respect to the N-type channel transistor M 2 can be changed. Also, as a result of forming or blocking the sink current path L 12 A, the current driving capability of the sink current path with respect to the P-type channel transistor M 1 can be changed. Third Embodiment [0102] The third embodiment of the present disclosure will be described while referring to FIG. 3 . FIG. 3 is a circuit configuration diagram of an output buffer circuit 10 B of the present embodiment. Here, elements which are the same as those in the first and second embodiments are denoted by the same numerical symbols, to thereby simplify the description. The output buffer circuit 10 B is provided with a fourth gate voltage control circuit 40 B instead of the third gate voltage control circuit 40 A of the second embodiment. The fourth gate voltage control circuit 40 B corresponds to the auxiliary driving portion of the present disclosure. [0103] The fourth gate voltage control circuit 40 B is provided with a P-type channel transistor M 28 , a P-type channel transistor M 29 , an N-type channel transistor M 38 , and an N-type channel transistor M 39 . [0104] A source of the P-type channel transistor M 29 is connected to a power supply voltage Vdd (power supply line). A gate of the P-type channel transistor M 29 is connected to a gate of a P-type channel transistor M 51 which is provided in a gate bias circuit 50 A and a gate of a P-type channel transistor M 27 in a second gate voltage detecting circuit 30 C. A drain of the P-type channel transistor M 29 is connected to a source of a P-type channel transistor M 28 . A gate of the P-type channel transistor M 28 is connected to an output of an inverter 31 which is provided in the second gate voltage detecting circuit 30 C. A drain of the P-type channel transistor M 28 is connected to a connection point A 1 of a first gate voltage control circuit 20 A. The P-type channel transistor M 29 corresponds to the fourth switching element of the present disclosure. [0105] A source of the N-type channel transistor M 39 is connected to a ground (low potential power supply) A gate of the N-type channel transistor M 39 is connected to a gate of an N-type channel transistor M 52 which is provided in a gate bias circuit 50 B and a gate of an N-type channel transistor M 37 in a second gate voltage detecting circuit 30 D. A drain of the N-type channel transistor M 39 is connected to a source of the N-type channel transistor M 38 . The N-type channel transistor M 39 corresponds to the fourth switching element of the present disclosure. [0106] A gate of the N-type channel transistor M 38 is connected to an output of an inverter 32 which is provided in the second gate voltage detecting circuit 30 D. A drain of the N-type channel transistor M 38 is connected to a connection point B 1 of a first gate voltage control circuit 20 B. [0107] Next, the operation of the output buffer circuit 10 B according to the present embodiment will be described. If the data signal inputted from the input terminal (IN) is changed from a high level to a low level, the output buffer circuit 10 B operates in the following manner. [0108] Similarly with the second embodiment, right after the data input signal is changed from a high level to a low level, the OFF state of an N-type channel transistor M 7 is maintained. As described above, the P-type channel transistor M 27 functions as a constant current source. An input of the inverter 31 receives a high level signal, based on the potential occurring at the connection point C 1 . The inverter 31 outputs a low level signal to the gate of the P-type channel transistor M 28 . As a result, the P-type channel transistor M 28 enters an ON state. [0109] In addition, the gate of the P-type channel transistor M 29 is connected to the gate of the P-type channel transistor M 51 and the gate of the P-type channel transistor M 27 . The current vale of the constant current source 51 is set so that the gate voltages of the transistors M 29 , M 51 and M 27 become near the threshold voltage. Here, when the P-type channel transistor M 51 and the P-type channel transistor M 27 enter an ON state, the P-type transistor M 29 also enters an ON state. The gate of the P-type channel transistor M 29 is connected to the gate of the P-type channel transistor M 27 which functions as a constant current source, which means that this corresponds to the fourth control terminal of the fourth switching element according to the present disclosure. [0110] At this time, a P-type channel transistor M 4 which is provided in the first gate voltage control circuit 20 A is in an ON state and hence the transistors M 29 , M 28 and M 4 simultaneously enter in an ON state. Thus, a source current path L 2 B is formed as shown in the drawing. The source current path L 2 B extends from the power supply line to a gate of an N-type channel transistor M 2 , by passing through the P-type channel transistors M 28 and M 29 and further, through the connection point A 1 , the P-type channel transistor M 4 and a connection point A 2 . In the output buffer circuit 10 B, a source current path L 1 is formed in addition to the source current path L 2 B, in a manner similar to that in the second embodiment. [0111] On the other hand, right after the data input signal is changed from a low level to a high level, the OFF state of a P-type channel transistor M 17 is maintained. As described above, the N-type channel transistor M 37 functions as a constant current source. An input of the inverter 32 receives a low level signal based on the potential (ground potential) at the connection point D 1 . The inverter 32 outputs a high level signal to the gate of the N-type channel transistor M 38 . As a result, the N-type channel transistor M 38 enters an ON state. [0112] In addition, in the present embodiment, the gate of the N-type channel transistor M 39 is connected to the gate of the N-type channel transistor M 52 and the gate of the N-type channel transistor M 37 . The current value of the constant current source 52 is set so that the gate voltages of the transistors M 39 , M 52 and M 37 become near the threshold voltage. Here, when the N-type channel transistor M 52 and the N-type channel transistor M 37 enter an ON state, the N-type channel transistor M 39 also enters an ON state. The gate of the N-type channel transistor M 39 is connected to the gate of the N-type channel transistor M 37 which functions as a constant current source, which means that this corresponds to the fourth control terminal of the fourth switching element of the present disclosure. [0113] At this time, the N-type channel transistor M 14 is in an ON state and hence the transistors M 14 , M 38 and M 39 simultaneously in an ON state. As a result, a sink current path L 12 B is formed as shown in the drawing. The sink current path L 12 B extends from the gate of a P-type channel transistor M 1 to the ground, by passing through a connection point B 2 , the N-type channel transistor M 14 and a connection point B 1 , and further through the N-type channel transistors M 38 and M 39 . In the output buffer circuit 10 B, a sink current path L 11 is formed in addition to the sink current path L 12 B, similarly with the second embodiment. Effects of the Third Embodiment [0114] In the output buffer circuit 10 B according to the present embodiment, the fourth gate voltage control circuit 40 B is provided with a P-type channel transistor M 29 which is connected between the P-type channel transistor M 28 and the power supply line and is provided with a gate which is connected to the P-type channel transistor M 27 which functions as a constant current source. The fourth gate voltage control circuit 40 B is further provided with the N-type channel transistor M 39 which is connected between the N-type channel transistor M 38 and the ground and is provided with a gate which is connected to the N-type channel transistor M 37 which functions as a constant current source. In the output buffer circuit 10 B, a constant current to be drawn from the power supply line through the P-type channel transistor can control a gate voltage of the P-type channel transistor M 29 . At the same time, a constant current flowing into the N-type channel transistor M 37 can control a gate voltage of the N-type channel transistor M 39 . As a result, in the output buffer circuit 10 B, the constant current can control gate voltages of the transistors M 29 and M 39 and keep constant the time required by the gate voltages of the transistors M 2 and M 1 to reach the threshold voltage, based on the current driving capability of the source current path L 2 B and the current driving capability of the sink current path L 12 B. Fourth Embodiment [0115] The fourth embodiment of the present disclosure will be described while referring to FIG. 4 . FIG. 4 is a circuit configuration diagram of an output buffer circuit 10 C of the present embodiment. Here, elements which are the same as those in the first to third embodiments are denoted by the same numerical symbols, to thereby simplify the description. The output buffer circuit 10 C is provided with a fifth gate voltage control circuit 40 C instead of the third gate voltage control circuit 40 A of the second embodiment. The fifth gate voltage control circuit 40 C corresponds to the auxiliary driving portion of the present disclosure. [0116] The fifth gate voltage control circuit 40 C is provided with a resistor R 2 , a P-type channel transistor M 28 , an N-type channel transistor M 38 and a resistor R 12 . One terminal of the resistor R 2 is connected to a power supply voltage Vdd (power supply line). The other terminal of the resistor R 2 is connected to a source of the P-type channel transistor M 28 . Agate of the P-type channel transistor M 28 is connected to an output of an inverter 31 of a second gate voltage detecting circuit 30 C in a manner similar to that in the second and third embodiments. A drain of the P-type channel transistor M 28 is connected to a connection point A 1 of a first gate voltage control circuit 20 A. The resistor R 2 corresponds to the second resistor element of the present disclosure. [0117] One terminal of the resistor R 12 is connected a ground (low potential power supply). The other terminal of the resistor R 12 is connected to a source of the N-type channel transistor M 38 . A gate of the N-type channel transistor M 38 is connected to an output of an inverter 32 of a second gate voltage detecting circuit 30 D. A drain of the N-type channel transistor M 38 is connected to a connection point B 1 of a first gate voltage control circuit 20 B. The resistor R 12 corresponds to the second resistor element of the present disclosure. [0118] Next, the operation of the output buffer circuit 10 C according to the present embodiment will be described. If the data signal to be inputted from the input terminal (IN) is changed from a high level to a low level, the output buffer circuit 10 C operates as will be described in the following text. [0119] Right after the data input signal is changed from a high level to a low level, the inverter 31 outputs a low level signal to the gate of the P-type channel transistor M 28 in a manner similar to that in the second and third embodiments. As a result, the P-type channel transistor M 28 enters an ON state. [0120] At this time, a P-type channel transistor M 4 which is provided in the first gate voltage control circuit 20 A is in an ON state, similarly with the second and third embodiments, and hence the transistors M 28 and M 4 simultaneously enter in an ON state. As a result, a source current path L 2 C is formed as shown in the drawing. The source current path L 2 C extends from the power supply line to a gate of an N-type channel transistor M 2 by passing through the resistor R 2 and the P-type channel transistor M 28 and further, through the connection point A 1 , the P-type channel transistor M 4 and a connection point A 2 . [0121] The current to be supplied from the power supply line to the source current path L 2 C is restricted by the resistor R 2 and the current value in the source current path L 2 C is suppressed. In the output buffer circuit 10 C, a source current path L 1 is formed in addition to the source current path L 2 C in a similar manner to that in the second and third embodiments. [0122] On the other hand, right after the data input signal is changed from a low level to a high level, similarly with the second and third embodiments, the inverter 32 outputs a high level signal to the gate of the N-type channel transistor M 38 . As a result, the N-type channel transistor M 38 enters an ON state. [0123] At this time, similarly with the second and third embodiments, the N-type channel transistor M 14 which is provided in the first gate voltage control circuit 20 B is in an ON state and hence the transistors M 14 and M 38 simultaneously enter in an ON state. Thus, a sink current path L 12 C is formed as shown in the drawing. The sink current path L 12 C extends from a gate of a P-type channel transistor M 1 to the ground by passing through a connection point B 2 , the N-type channel transistor M 14 and the connection point B 1 and further, through the N-type channel transistor M 38 and the resistor R 12 . [0124] In the present embodiment, the resistor R 12 restricts the current to be drawn to the ground. In the output buffer circuit 10 C, a sink current path L 11 is formed in addition to the sink current path L 12 C. Effects of the Fourth Embodiment [0125] In the output buffer circuit 10 C according to the present embodiment, the fifth gate voltage control circuit 40 C is provided with the resistor R 2 which is connected between the source of the P-type channel transistor M 28 and the power supply line and the resistor R 12 which is connected between the ground and the source of the N-type channel transistor M 38 . Here, in the output buffer circuit 10 C, adjusting of the resistance value of the resistors R 2 and R 12 can restrict the current value to be supplied from the power supply line to the source current path L 2 C within a certain range, or the current value to be drawn to the ground of the sink current path L 12 C within a certain range. Thus, in the output buffer circuit 10 C, the current driving capability of the sink current path L 2 C with respect to the N-type channel transistor M 2 and the current driving capability of the sink current path L 12 C with respect to the P-type channel transistor M 1 can be respectively set within a certain range. As a result, the time required by the gate voltages of the transistors M 2 and M 1 to reach the threshold voltage can be set within a certain range. Fifth Embodiment [0126] The fifth embodiment of the present disclosure will described while referring to FIG. 5 . FIG. 5 is a circuit configuration diagram of an output buffer circuit 10 D of the present embodiment. Here, elements which are the same those in the first to fourth embodiments are denoted by the same numeric symbols, to thereby simplify the description. The output buffer circuit 10 D is provided with sixth gate voltage control circuits 20 C and 20 D instead of the first gate voltage control circuits 20 A and 20 B of the output buffer circuit 10 B of the third embodiment. The sixth gate voltage control circuits 20 C and 20 D correspond to the driving portions of the present disclosure. [0127] The sixth voltage control circuit 20 C is provided with a P-type channel transistor M 3 A, a P-type channel transistor M 4 and an N-type channel transistor M 5 . The P-type channel transistor M 3 A corresponds to the fifth switching element of the present disclosure. A gate of the P-type channel transistor M 3 A is connected to a gate of a P-type channel transistor M 27 which is provided in a second gate voltage detecting circuit 30 C and a gate of a P-type channel transistor M 51 in a gate bias circuit 50 A. [0128] A drain of the P-type channel transistor M 3 A is connected to a source of the P-type channel transistor M 4 . A connection point A 3 between the drain of the P-type channel transistor M 3 A and the source of the P-type channel transistor M 4 is connected to a drain of a P-type channel transistor M 28 which is provided in a fourth gate voltage control circuit 40 B. [0129] The sixth gate voltage control circuit 20 D is provided with an N-type channel transistor M 13 A, an N-type channel transistor M 14 and a P-type channel transistor M 15 . The P-type channel transistor M 13 A corresponds to the fifth switching element of the present embodiment. A gate of the N-type channel transistor M 13 A is connected to a gate of an N-type channel transistor M 37 which is provided in a second gate voltage detecting circuit 30 D and a gate of an N-type channel transistor M 52 in a gate bias circuit 50 B. A drain of the N-type channel transistor M 13 A is connected to a source of the N-type channel transistor M 14 . A connection point B 3 between the drain of the N-type channel transistor M 13 A and the source of the N-type channel transistor M 14 is connected to a drain of an N-type channel transistor M 38 which is provided in the fourth gate voltage control circuit 40 B. [0130] Next, the operation of an output buffer circuit 10 D according to the present embodiment will be described. If the data signal to be inputted from the input terminal (IN) is changed from a high level to a low level, the output buffer circuit 10 D operates as will be described in the following text. [0131] In the present embodiment, the current value of a constant current source 51 is set so that the gate voltages of the transistors M 3 A, M 51 and M 27 become near the threshold voltage. When the P-type channel transistors M 51 and M 27 enter an ON state, the P-type transistor M 3 A also enters an ON state. [0132] In the present embodiment, a gate voltage of the P-type channel transistor M 3 A is set based on the current of the constant current source 51 . As a result, in the present embodiment, the time required by the gate voltage of the P-type channel transistor M 3 A to reach the threshold voltage is controlled to be kept constant based on the current of the constant current source 51 . The gate of the P-type channel transistor M 3 A is connected to the gate of the P-type channel transistor M 27 which functions as a constant current source, which means that this corresponds to the fifth control terminal of the fifth switching element of the present disclosure. [0133] When the data input signal is changed from a high level to a low level, the P-type channel transistor M 4 which is provided in the sixth gate voltage control circuit 20 C enters an ON state and hence the transistors M 3 A and M 4 simultaneously enter in an ON state. Thus, a source current path L 1 A is formed as shown in the drawing. The source current path L 1 A extends from the power supply line to a gate of an N-type channel transistor M 2 , by passing through the transistors M 3 A and M 4 and further, through a connection point A 2 . [0134] In the output buffer circuit 10 D, a source current path L 2 B is formed in addition to the source current path L 1 A in a manner similar to that in the third embodiment. In the present embodiment, the gate voltage of a P-type channel transistor M 29 is also set based on the current from the constant current source 51 . As a result, in a manner similar to that in the P-type channel transistor M 3 A, the time required by the gate voltage of the P-type channel transistor M 29 to reach the threshold voltage is controlled to be kept constant. [0135] On the other hand, if the data input signal is changed from a low level to a high level, the output buffer circuit 10 D of the present embodiment operates in the following manner. In the present embodiment, the current value of a constant current source 52 is set so that the gate voltages of the transistors M 13 A, M 52 and M 37 become near the threshold voltage. When the N-type channel transistor M 52 and the N-type channel transistor M 37 enter an ON state, the N-type transistor 13 A also enters an ON state. [0136] In the present embodiment, the gate voltage of the N-type channel transistor 13 A is set based on the current of the constant current source 52 . As a result, the time required by the gate voltage of the N-type channel transistor M 13 A to reach the threshold voltage is controlled to be kept constant based on the current of the constant current source 52 in the present embodiment. The gate of the N-type channel transistor M 13 A is connected to the gate of the N-type channel transistor M 37 which functions as a constant current source, which means that this corresponds to the fifth control terminal of the fifth switching element of the present disclosure. [0137] When the data input signal is changed from a high level to a low level, the N-type channel transistor M 14 which is provided in the sixth gate voltage control circuit 20 D enters an ON state and hence the transistors M 14 and M 13 A simultaneously enter in an ON state. Thus, a sink current path L 11 A is formed as shown in the drawing. The sink current path L 11 A extends from a gate of a P-type channel transistor M 1 to the ground, by passing through the N-type channel transistor M 14 and the N-type channel transistor M 13 A. [0138] In the output buffer circuit 10 D, a sink current path L 12 B is formed in addition to the sink current path L 11 A in a manner similar to that in the third embodiment. In the present embodiment, the gate voltage of an N-type channel transistor M 39 is also set based on the current from the constant current source 52 . As a result, in a manner similar to that in the N-type channel transistor M 13 A, the time required by the gate voltage of the N-type channel transistor M 39 to reach the threshold voltage is controlled to be kept constant. Effects of the Fifth Embodiment [0139] In the output buffer circuit 10 D according to the present embodiment, the sixth gate voltage control circuit 20 C is provided with the P-type channel transistor M 3 A which has a gate which is connected to the P-type channel transistor M 27 which functions as a constant current source, and the sixth gate voltage control circuit 20 D is provided with the N-type channel transistor M 13 A which has a gate which is connected to the N-type channel transistor power M 37 which functions as a constant current source. In the output buffer circuit 10 D, a constant current to be drawn from the power supply line through the P-type channel transistor M 27 can control a gate voltage of the N-type channel transistor M 3 A. At the same time, a constant current which flows into the N-type channel transistor M 37 can control a gate voltage of the N-type channel transistor M 13 A. As a result, in the output buffer circuit 10 D, the constant current can control gate voltages of the transistors M 3 A and M 13 A and keep the time required by the gate voltages of the transistors M 2 and M 1 to reach the threshold voltage constant, based on the current driving capability of the source current path L 1 A and the current driving capability of the sink current path L 11 A. Consequently, the delay in responding to the data input signal can be prevented. Sixth Embodiment [0140] The sixth embodiment of the present disclosure will be described while referring to FIG. 6 . FIG. 6 is a circuit configuration diagram of an output buffer circuit 10 E of the present embodiment. Here, elements which are the same as those in the first to fifth embodiments are denoted by the same numerical symbols, to thereby simplify the description. The output buffer circuit 10 E is provided with seventh gate voltage control circuits 20 E and 20 F instead of the sixth gate voltage control circuits 20 C and 20 D of the output buffer circuit 10 D of the fifth embodiment. The seventh gate voltage control circuits 20 E and 20 F correspond to the driving portions of the present disclosure. [0141] The seventh gate voltage control circuit 20 E is provided with a resistor R 3 , a P-type channel transistor M 4 , and an N-type channel transistor M 5 . The resistor R 3 corresponds to the third resistor element of the present disclosure. The P-type channel transistor M 4 corresponds to the sixth switching element of the present disclosure. [0142] One terminal of the resistor R 3 is connected to a power supply voltage Vdd (power supply line). The other terminal of the resistor R 3 is connected to a source of the P-type channel transistor M 4 . A connection point A 5 between the other terminal of the resistor R 3 and the source of the P-type channel transistor M 4 is connected to a drain of a P-type channel transistor M 28 which is provided in a fourth gate voltage control circuit 40 B. [0143] The seventh gate voltage control circuit 20 F is provided with a resistor R 13 , an N-type channel transistor M 14 , and a P-type channel transistor M 15 . The resistor R 13 corresponds to the third resistor element of the present disclosure. The N-type channel transistor M 14 corresponds to the sixth switching element of the present disclosure. [0144] One terminal of the resistor R 13 is connected to a ground (low potential power supply). The other terminal of the resistor R 13 is connected to a source of the N-type channel transistor M 14 . A connection point B 5 between the other terminal of the resistor R 13 and the source of the N-type channel transistor M 14 is connected to a drain of an N-type channel transistor M 38 which is provided in the fourth gate voltage control circuit 40 B. [0145] Next, the operation of the output buffer circuit 10 E according to the present embodiment will be described. If the data input signal to be inputted from the input terminal (IN) is changed from a high level to a low level, the output buffer circuit 10 E operates as will be described in the following text. [0146] When the data input signal is changed from a high level to a low level, the P-type channel transistor M 4 which is provided in the seventh gate voltage control circuit 20 E enters an ON state. Thus, a source current path L 1 B is formed as shown in the drawing. The source current path L 1 B extends from the power supply line to a gate of an N-type channel transistor M 2 , by passing through the resistor R 3 and the P-type channel transistor M 4 and further, through a connection point A 2 . [0147] The current to be supplied from the power supply line to the source current path L 1 B is restricted by the resistor R 3 and the current value in the source current path L 1 B is suppressed. In the present embodiment, the value of the current to be supplied to the gate of the N-type channel transistor M 2 is kept constant in accordance with the difference of the resistance value of the resistor R 3 . [0148] On the other hand, if the data input signal is changed from a low level to a high level, the output buffer circuit 10 E operates in the following manner. If the data input signal is changed from a low level to a high level, the P-type channel transistor M 14 which is provided in the seventh gate voltage control circuit 20 F enters an ON state. As a result, a sink current path L 11 B is formed as shown in the drawing. The sink current path L 11 B extends from a gate of a P-type channel transistor M 1 to the ground, by passing through a connection point B 2 and the N-type channel transistor M 14 . [0149] In the present embodiment, the resistor R 13 restricts the current to be drawn to the ground. As a result, in the present embodiment, the value of the current to be drawn to the ground is kept constant in accordance with the difference of the resistance value of the resistor R 13 . Effects of the Sixth Embodiment [0150] In the output buffer circuit 10 E according to the present embodiment, the seventh gate voltage control circuit 20 E is provided with the resistor R 3 which is connected between the P-type channel transistor M 4 which is connected to the gate of the N-type channel transistor M 2 and the power supply line. Further, the seventh gate voltage control circuit 20 F is provided with the resistor R 13 which is connected between the N-type channel transistor M 14 which is connected to the gate of the P-type channel transistor M 1 and the ground. The adjusting of the resistance values of the resistors R 3 and R 13 in the output buffer circuit 10 E helps restrict the value of the current to be supplied from the power supply line to the source current path L 1 B within a constant range or restrict the value of the current to, which the sink current path L 11 B draws to the ground, within a constant range. As a result, in the output buffer circuit 10 E, the current restricted within a constant range makes it possible to control the gate voltages of the transistors M 2 and M 1 and to restrict the time required by the gate voltages of the transistors M 2 and M 1 to reach the threshold value within a constant range, based on the current driving capability of the source current path L 1 B and the current driving capability of the sink current path L 11 B. Consequently, the delay in responding to the data input signal can be prevented. [0151] It is to be noted that the present disclosure is not limited to the embodiments described above, and is possible various improvements and modifications by the range in which it does not deviate from the scope of the disclosure. [0152] According to the buffer circuit and the control method thereof according to the present disclosure, if the driving capability of the output switching element is changed in accordance with a detection result if the voltage value of the control terminal of the output switching element exceeds the threshold voltage or not, the voltage value of the control terminal of the output switching element can be increased or decreased, depending on the driving capability of the output switching element which is set in accordance with the detection result. According to the buffer circuit and the control method thereof according to the present disclosure, if the voltage value of the control terminal of the output switching element is increased, the output switching element can be quickly changed from a non-conductive state into a conductive state, which allows increasing the slew rate of the buffer circuit. If the voltage value of the control terminal of the output switching element is decreased, the conductive state of the output switching element can be restricted, so that the slew rate of the buffer circuit can be returned to a standard value based on the driving capability of the output switching element set in advance.

The present disclosure has been worked out to provide a buffer circuit and a control method thereof capable of controlling the timing at which the output switching element is changed from an OFF state to an ON state, and preventing the output characteristic from becoming unstable. The buffer circuit includes: a driving portion 20 driving output switching elements M 1 and M 2; a detecting portion 30 detecting that the voltage values of control terminals of the output switching elements M 1 and M 2 have exceeded the threshold voltage value; an auxiliary driving portion 40 being connected to the driving portion 20 and changing driving capability of the output switching elements M 1 and M 2 in accordance with the result of detection by the detecting portion 30.

This is a continuation of application Ser. No. 06/720,930, filed Apr. 8, 1985, now abandoned. BACKGROUND OF THE INVENTION The present invention relates to an apparatus for retrieving character strings, and particularly to an apparatus for retrieving or finding out necessary and/or significant character strings or messages from a group of sentences, data and text. Character string retrieval apparatuses have important roles in achieving word-processing and inter-translation of languages, searching key words included in records of a data base, and performing pattern recognition in video data processing. Conventional data retrieval processing has been performed by software in computers, and in such cases, a character string input is sequentially compared to all the standard character strings registered. Accordingly, if there is an error in inputting character strings such as omission of some characters in the input character strings or input of unnecessary characters, then satisfactory search or retrieval cannot be expected. If the system is designed to avoid the effect of such errors in the input data, then the number of the registered standard character strings becomes too large, resulting in too lengthy a processing time. As described above, the conventional technique for retrieving or searching character strings by computers has bee disadvantageous in that the processing time of character strings is too slow and in that flexibility in treating errors included in input character strings is poor. SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus for retrieving character strings at a high speed. It is another object of the present invention to provide such an apparatus fabricated in the form of integrated circuits. The character string retrieving apparatus according to the present invention includes a memory circuit for storing characters. The memory circuit has a plurality of input lines and a plurality of output lines. Each of the input lines corresponds to one character, and When a memory cell coupled to one of the input lines stores a logic "1", the output line coupled to that memory cell is activated in response to the activation of the one input line to which it is connected. A sequential logic circuit is coupled to the output lines of the memory in such a manner that the output lines are coupled to the sequential logic circuit in the order of the characters of the character string to be detected, to thereby make the logic states of the respective stages of the sequential logic circuit true in sequence towards the output thereof. For example, the output line corresponding to a first character in the character string is coupled to a first stage of the sequential logic circuit and the output line corresponding to the i-th (i being an integer of at least 2) character of the character string is coupled to the i-th logic stage of the sequential logic circuit. Thus, when all of the characters to be detected are sequentially inputted, a "1" level output is generated from the sequential logic circuit. As the sequential logic circuit, a shift register or a charge transfer device can be effectively utilized. According to the present invention, the memory and the sequential logic circuit can be formed on the same semiconductor substrate. Also, the retrieving operation can be achieved during the transition time of the sequential logic circuit. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing inter-translation relations between English and Japanese; FIG. 2 a diagram showing state-transition diagrams in retrieving character strings; FIG. 3 is a diagram showing a flow chart of character string retrieval according to the prior art; FIG. 4 is a diagram showing shortened state-transition tables; FIG. 5 is a schematic block diagram showing a first embodiment of the present invention; FIG. 6 is a schematic block diagram showing a second embodiment of the invention; FIG. 7 is a diagram explaining operations of the embodiment of FIG. 6; and FIG. 8 is a schematic block diagram showing a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows task examples of inter-translations of character strings between Japanese and English, in which Japanese words are listed in the left side column while corresponding English words are shown in the right side column. This inter-translation function is the same as that of a Japanese-English dictionary and is called a dictionary function. In order to perform the dictionary function, the following steps are necessitated: (1) associating each Japanese word in a memory with a class number shown at the center column; (2) associating each English word corresponding to a Japanese word with the same class number; (3) comparing each input Japanese word with the registered English words to output the corresponding class number; and (4) outputting one of the registered English words in response to the output class number. Among the above four steps, the third step (3) is the most difficult one because this step must be conducted by comparing an unknown input word with all of the standard words stored in the memory. FIG. 2 shows state-transitions in sequential logic for retrieving input words. Here, the input words correspond to character strings. A word delimiting character is provided at the beginning or end of each word. As the components of the character strings, the letters A, B, C, E, H, K, N, O, R, S, T, V, Y are considered, and φ is employed as the word delimiting character. The state transition tables of FIG. 2 illustrate the processes of movement of the input characters by nodes indicated by circles and paths therebetween. Start nodes 210, 220, 230 and 240 denoted by two co-axial circles correspond to the step where the states are set prior to the input of a character string. Termination nodes 218, 227, 237 and 247 correspond to the step where the presence of the states of character strings is checked after the input of the character strings. When characters T, A, N, S, A, K, U, φ are input sequentially, a pointer which shows the position of the states moves from the beginning node 210 to the termination node 218 through nodes 211, 212, 213, 214, 215, 216 and 217. There is no case where the pointer moves to another termination node such as 227, 237 or 247. As a result, the above character string "T A N S A K U" is judged as belonging to the class "1". Similarly, when characters "R, Y, O, K, O, U φ are sequentially input, a pointer at the beginning node 220 moves only to the termination node 227. The other two character strings are detected in the same manner. Here, assuming the i-th node from the beginning in the state-transition for the j-th class character string as (i, j), the path for allowing the state-transition from the node (i, j) to the node (vi+1, j) is shown by transition paths 201 and is stored in the memory for the standard character string. Return paths 202 attached to the respective nodes (i, j) describe that characters other than the characters defined by the respective state-transition paths result in a return to their previous node (i, j). Accordingly, the pointer set at the beginning node 210 cannot reach the termination node when a character string other than the registered character string is received. Thus, the judgement of the class will not be performed for a non-registered character string. The judgement of character strings by the state-transition tables in sequential logic have heretofore been conducted by judgement processing programs in computers having a CPU and memory. However, input character strings are sequentially checked by reading algorithms for the respective classes of character strings, and hence processing time cannot be shortened. FIG. 3 shows a flow chart of character string retrieval according to the prior art. Alphabetic characters forming the character strings of FIG. 1 are sequentially accepted at a processing step 311 until the end of a word is detected, the input character string is transmitted to a class judging step 313-1. If it is accepted at the step 313-1, the processing moves to an output step 316. If it is not accepted at the step 313-1, the character string input is subjected to another class judging step 313-2. When the character string is not accepted by any one of the steps 313-1 to 313-4, then the processing moves to a step 314 and an output is provided indicating that the input character string is not classified into any one of the registered classes. After this, the processing moves to a step 315 which judges whether the next input character string is present or not. If. "Yes", the cycle returns to "START", otherwise the cycle ends. An algorithm which compares an unknown character string input with the registered character strings on a word-by-word basis may be utilized for the class judging steps 313. In this case, a minor error such as the omission or addition of a character in the input character string makes the class judging of the input character string difficult. From this point of view, the state-transition tables shown in FIG. 4 may be utilized to avoid the above shortening. Namely, in FIG. 4, pointers set at the beginning nodes 410, 420, 430, and 440 are adapted to recognize not only one character but also two or more characters and to then introduce the subsequent step. Also, the paths of state-transitions are shortened. Accordingly, in addition to the character string "T A N S A K U φ", many similar character strings such as "T A S A K φ", "A N S A K U φ" caused by input error are accepted only through the nodes 410, 411, 412, 413 and 414. The same thing is true for the other nodes. If the number of the nodes in the state-transition paths is further reduced, then erroneous judgement of character strings would occur. Therefore, the state-transition path must be determined in view of groups of standard character strings to be registered. However, it has been difficult to perform the above modified state-transitions according to the flow chart of FIG. 3, because the amount of CPU processing is increased. Thus, it has been disadvantageous in that the judging time of character strings is long and flexibility in avoiding input error is poor according to the conventional systems. With reference to FIG. 5, an apparatus for retrieving character strings according to a first embodiment of the present invention will now be described. Characters are sequentially input to an address register 510 provided for a memory and are used by an address decoder 520 to select word lines 525 corresponding to the respective characters. A plurality of read/write (R/W) circuits 530-1 to 530-3 are provided for bit lines 535 intersecting with the word lines 525. Outputs of the R/W circuits are used to control switches 545-1 to 545-3 which are used to serially connect registers 541, 542, 543, and 544. In the memory 500, among the intersections of the word lines 525 and bit lines 535, those with a circle store logic "1" while others without a circle store logic "0". Also, the word lines 525 correspond to A, B, C, E, H, K, N, O, R, S, T, U, Y from the right side towards the left side, respectively, as illustrated in FIG. 5. A shift register 540 has the registers 541, 542. 543 and 544 in correspondence to the nodes 410, 411, 412, and 413 in the state-transition of FIG. 4, and the switches 545 are used as the transition paths 201. Each of the bit lines is adapted to produce a "1" level when one of the word lines intersecting with that bit line at the intersection with the circle mark is selected. An initialize control circuit 550 detects the word delimiting character φ to set the content of the register 544 in a latch circuit 560 and then reset all of the registers 541, 542, 543 and 544. Thereafter, the circuit 550 sets a signal of "1" corresponding to the pointer in the register 541, which thus acts as a start node for the propagation of the "1" value through the registers. The switches 545 function to transmit the outputs of the registers to their subsequent registers. When at least one of the characters T, A and N is first inputted to the register 510, the R/W circuit 530-1 coupled to the first bit line 535 from the decoder 520 produces a "1" level output so that the "1" content of the register 541 is written to the second register 542 via the switch 545-1. In this instance, the second bit line coupled to the R/W circuit 530-2 generates a "0" level output, so that one content of the register 542 is not written to the subsequent register 543 in the case where the character T or N is inputted. When the characters A or S are inputted to the address register 510, the output of the R/W circuit 530-2 assumes a "1" level so that the content of the register 542 is written to the subsequent register 543 via the switch 545-2. Here, each of the registers 541 to 544 has the structure that, after it has assumed a "1" level, it continues to hold the "1" level until it is reset by the circuit 550. In this respect, the shift register 540 does not correspond to the state-transition table of FIG. 1 in one by one relation, but the important point is to transmit a "1" level to the last register 544 in response to the state of the bit lines, and the above feature of the register is not a problem. In the shift register 540, when the character string "T A S A K U" is inputted in sequence, the internal "1" level signal set in the first register 541 is written sequentially to the registers 542, 543 and 544. Therefore, when the word delimiting character φ is detected, the signal "1" is set in the latch circuit 560 under control of the circuit 550. The content of the latch circuit 560 assumes a "0" level when the last register 544 assumes a "0" level after next character string is inputted. Until the completion of the input of the next character string, the latch circuit 560 holds the judging result of the previous character string. The output of the latch circuit 560 shows whether the input character string is accepted or not. The circuit of FIG. 5 is required to perform the state-transitions shown in FIG. 4. Therefore, the capacity of the memory 500 will be the product of the number of characters N, the number of nodes M and the number of classes K, i.e., "N×M×K". The number of nodes M may be smaller than the length of a character string. The processing time is determined by the product of the respective read-out time for the respective characters (about 200 nsec) and the length of the character string, but is not affected by the number of classes K. Referring to FIG. 6, a second embodiment of the present invention will now be described. This embodiment is designed to retrieve the four classes of character strings shown in FIG. 4 simultaneously. In the memory 500, four groups of bit lines 535-1 to 535-4 are provided intersecting with the word lines 525. Each of the bit line groups is associated with the character string to be searched. Also, four sets of shift registers 540 and four latch circuits 561 to 564 are provided corresponding to four groups of bit lines 535-1 to 535-4, respectively. The outputs of the latch circuits 561 to 564 are provided to an encoder circuit 610 so that, after the input of character string, the retrieval output from one of the latch circuits 561 to 564 is decoded by the encoder 610 in the form of three-bit digital outputs O 1 to O 3 . Also in the memory 500, the word line corresponding to the word delimiting signal φ is provided and the bit line 535-0 is provided to detect φ. The bit line 535-0 is connected to the R/W circuit 530 to control the control circuit 550, so that the setting of the latch circuits 561 to 564, the resetting of the registers other than the first registers 541, and the setting of the first registers 541 are performed. A dummy latch circuit 565 is provided in order to set the outputs O 1 to O 3 at "0" when the character input string is not classified into any one of the classes. Namely, the dummy latch circuit 565 assumes a "1" level when the input character string is not classified and a "0" level when the input character string is classified and any one of the latches 561 to 564 assumes a "1" level. Thus, the encoder 610 produces an output indicating that the input character string is not classified. As the encoder 610, a priority encoder (e.g., SN 7414S produced by Texas Instruments, Inc.) can be utilized. FIG. 7 shows examples of operations of the circuit in FIG. 6. A Japanese sentence "C H 0 U S A R Y 0 K U D E --- ---" is composed of a plurality of words. i.e.. character strings as shown in FIG. 7, in which the characters φ are imaginarily indicated. To the address decoder 510 in FIG. 6. characters C H O U S A φ R Y O K O U D E φ C H I H O U N O φ --- are sequentially inputted. and from the encoder 610 the retrieval outputs "3", "2", "?", "4" and "1" are generated as illustrated in FIG. 7. If a RAM (random access memory) is connected to the output of the encoder 610, the English words listed in the right column of FIG. are produced in response to the detected retrieval outputs. Thus, the translation from Japanese to English can be achieved. FIG. 8 shows a third embodiment of the present invention. This embodiment is achieved by employing a charge transfer device 120 as one detailed example of the shift register 540 of FIG. 5. The memory section 500' has the same structure as the memory 500 of FIG. 5. The charge transfer device 120 is composed of an array 121 of capacitors C 0 to C 8 , and a plurality sets of transfer gates 122 with each set including transfer gates G 1 and G 2 controlled by clock pluses φ 1 and φ 2 from a pulse generator 124. When the output of the R/W circuit 530 is active, the charge of C 0 is transferred to the subsequent C 1 in response to φ 1 . Then, the charge of C 1 is transferred to C 2 in response to φ 2 . The charge stored in C 2 is transferred to C 3 in response to the output of the corresponding AND gate. However, if the output of the corresponding AND gate does not become active within a predetermined time corresponding to a time constant of a resistor 126 and a capacitance of C 2 , the charge stored in C 2 is discharged. Therefore, if an inconsistent character is included in the input character string, then the potential detected by an output circuit 130 becomes smaller. This function allows an indication of the degree of consistency between the input character string and the standard registered character string.

An apparatus for retrieving or searching character strings which can be fabricated with a simplified structure and operate at a high speed. A memory circuit storing a standard character string is employed. The memory circuit includes a plurality of input lines each corresponding to one of the characters in the standard character string, a plurality of output lines and memory cells. Each of output lines of the memory circuit is used to enable transfer operation of one stage of a sequential logic circuit, and a detection output is derived from the sequential logic circuit when all the stages are enabled in a predetermined order.

RELATED APPLICATION [0001] This application is a continuation of U.S. patent application Ser. No. 10/218,989, filed Aug. 14, 2002, now pending. FIELD OF THE INVENTION [0002] The present invention relates to pharmaceutical formulations, and more particularly to formulations containing cannabinoids for administration via a pump action spray. BACKGROUND OF THE INVENTION [0003] It has long been known to introduce drugs into the systemic circulation system via a contiguous mucous membrane to increase onset of activity, potency etc. [0004] For example, U.S. Pat. No. 3,560,625 disclose aerosol formulations for introducing an alkoxybenzamide into the systemic circulatory system. Two different types of aerosol formulations are disclosed: [0000] a) fluorinated hydrocarbon type comprising 2% by weight alkoxybenzamide, 18% ethanol, and 80% propellant; and b) nebuliser type comprising 0.5% by weight alkoxybenzamide, a mixed solvent system comprising 10.3% ethanol and 31.4% propylene glycol and 57.8% deionised water. [0005] U.S. Pat. No. 3,560,625 identifies a problem in finding a suitable solvent system to produce an aerosol spray for inhalation of the ortho-ethoxybenzamide, due to the fact that whilst ethanol was undoubtedly the best solvent, a mixture containing more than 18% of ethanol by weight produced an unpleasant oral reaction which more than counterbalanced the efficacy of the oral route. [0006] When the present applicant set out to produce spray formulations for a botanical drug substance comprising one or more cannabinoids they were aware that the highly lipophylic nature of the cannabinoids could present problems in formulating the active component(s). [0007] The present applicant first sought to develop a formulation for oromucosal, preferably sublingual, delivery in a pressurised aerosol or spray form, as disclosed in international patent application PCT/GB01/01027. Their initial focus was on propellant driven systems with HFC-123a and HFC-227 but these proved to be unsuitable as solvents for the cannabinoids. The formulations comprised synthetic Δ9-THC in amounts from 0.164 to 0.7% wt/wt, with ethanol as the primary solvent in amounts up to 20.51% by weight. One particular composition comprised 0.164% synthetic Δ9-THC, 4.992% ethanol, 4.992% propylene glycol and 89.582% p134a (propellant). [0008] The applicant found that even at ethanol levels of 20% by volume of the total formulation volume they were unable to dissolve sufficient levels of Δ9-THC in a standard spray dose to meet clinical needs, because of the cannabinoids poor solubility in the propellant. They also found that the ethanol level could not be increased, as the delivery characteristics of the device nozzle altered substantially when the lower volatility solvents were increased above a critical ratio. The HFC-123a and HFC-227 propellant sprays delivered a maximum of 7 mg/ml, whereas initial clinical studies suggested the formulations would be required to contain up to 50 mg cannabinoids/ml. [0009] Thus, the present applicants focussed on self-emulsifying drug delivery systems, as are discussed in detail in a review article European Journal of Pharmaceutics and Biopharmaceutics 50 (2000) 179-188, which concluded that the poor aqueous solubility of many chemical entities represents a real challenge for the design of appropriate formulations aimed at enhancing oral bioavailability. [0010] In their co-pending International application PCT/GB02/00620 the applicant discloses a wide range of cannabinoid-containing formulations containing at least one self-emulsifying agent. The inclusion of at least one self-emulsifying agent was thought necessary to get the formulation to adhere to the mucosal surface in order to achieve sufficient absorption of the cannabinoids. One particular formulation comprised 2% by wt glycerol mono-oleate, 5% CBME of G1 cannabis to give THC, 5% CBME of G5 cannabis to give CBD, 44% ethanol BP and 44% propylene glycol. SUMMARY OF THE INVENTION [0011] Surprisingly, the applicant has found that they do not absolutely require the presence of a self-emulsifying agent in a liquid formulation to achieve a satisfactory dosage level by oromucosal, and specifically sub-lingual or buccal, application. [0012] Indeed, contrary to the teachings of U.S. Pat. No. 3,560,625 and the European Journal of Pharmaceutics and Biopharmaceutics 50 (2000) 179-188, they have been able to produce a simple and effective vehicle for delivering a lipophilic medicament in a liquid spray. [0013] According to a specific aspect of the present invention there is provided a pharmaceutical formulation consisting essentially of one or more cannabinoids, ethanol and propylene glycol. [0014] Preferably the one or more cannabinoids are present in the form of at least one extract from at least one cannabis plant. The cannabis plant(s) preferably include at least one cannabis chemovar. Most preferably the plant extract will be a botanical drug substance (BDS), as defined herein. [0015] Optionally, the formulation may additionally contain a flavour, such as, for example, peppermint oil. [0016] The formulation may also contain, in addition to the cannabinoid(s), a further active agent, which is preferably an opiate, for example morphine. Thus, it is contemplated to provide a formulation consisting essentially of one or more cannabinoids, ethanol, propylene glycol and an opiate, preferably morphine. [0017] A typical liquid pharmaceutical formulation according to this specific aspect of the invention, given by way of example and not intended to be limiting to the invention, may contain in a 1 ml vol: THC 25-50 mg/ml, preferably 25 mg/ml (based on amount of cannabinoid in a botanical drug substance), CBD 25-50 mg/ml, preferably 25 mg/ml (based on amount of cannabinoid in a botanical drug substance), propylene glycol 0.5 ml/ml, peppermint oil 0.0005 ml/ml, and ethanol (anhydrous) qs to 1 ml. [0018] Other preferred formulations include a “high THC” formulation comprising in a 1 ml vol: THC 25 mg/ml (based on amount of cannabinoid in a botanical drug substance), propylene glycol 0.5 ml/ml, peppermint oil 0.0005 ml/ml, and ethanol (anhydrous) qs to 1 ml; and a “high CBD” formulation comprising in a 1 ml vol: CBD 25 mg/ml (based on amount of cannabinoid in a botanical drug substance), propylene glycol 0.5 ml/ml, peppermint oil 0.0005 ml/ml, and ethanol (anhydrous) qs to 1 ml. [0019] In these formulations the cannabinoids are added as botanical drug substances derived from cannabis plants, quoted amounts of cannabinoids correspond to total amount (weight) of cannabinoid present in 1 ml of the final formulation. The skilled reader will appreciate that the total amount of BDS which must be added in order to achieve the desired amount of cannabinoid in the final formulation will be dependent on the concentration of cannabinoid present in the BDS, which will vary between different batches of BDS. [0020] The finding that such a simple combination of one or more cannabinoids, ethanol and propylene glycol can be used effectively in a pump action spray was unexpected. [0021] The applicant has found that, where the solvent/co-solvent system is ethanol/propylene glycol and the lipophilic medicament comprises one or more cannabinoids in the form of a botanical drug substance (BDS), the limits in which the solvent/co-solvent will work effectively are quite narrow, as discussed below. [0022] More broadly speaking, and according to a general aspect of the invention, there is provided a liquid pharmaceutical formulation, for use in administration of a lipophilic medicament via a mucosal surface, comprising at least one lipophilic medicament, a solvent and a co-solvent, wherein the total amount of solvent and co-solvent present in the formulation is greater than 55% wt/wt of the formulation and the formulation is absent of a self-emulsifying agent and/or a fluorinated propellant. [0023] Preferably the amount of solvent/co-solvent is greater than 80%, more preferably in the order 90-98%. [0024] Preferably the formulation has a water content of less than 5%. [0025] Preferably the formulation does not contain any type of propellant. [0026] The formulation also lacks any self-emulsifying agent. Self-emulsifying agents are defined herein as an agent which will form an emulsion when presented with an alternate phase with a minimum energy requirement. In contrast, an emulsifying agent, as opposed to a self-emulsifying agent, is one requiring additional energy to form an emulsion. Generally a self-emulsifying agent will be a soluble soap, a salt or a sulphated alcohol, especially a non-ionic surfactant or a quaternary compound. Exemplary self-emulsifying agents include, but are not limited to, glyceryl mono oleate (esp. SE grade), glyceryl monostearate (esp. SE grade), macrogols (polyethylene glycols), and polyoxyhydrogenated castor oils e.g. cremophor. [0027] The formulation may additionally comprise a flavouring. The preferred flavouring is peppermint oil, preferably in an amount by volume of up to 0.1%, typically 0.05% v/v. [0028] Preferably the solvent is selected from C1-C4 alcohols. The preferred solvent is ethanol. [0029] Preferably the co-solvent is a solvent which allows a lower amount of the “primary” solvent to be used. In combination with the “primary” solvent it should solubilise the lipophylic medicament sufficiently that a medically useful amount of the lipophylic medicament is solubilised. A medically useful amount will vary with the medicament, but for cannabinoids will be an amount of at least 1.0 mg/0.1 ml of solvent/co-solvent. [0030] Preferred co-solvents are selected from glycols, sugar alcohols, carbonate esters and chlorinated hydrocarbons. [0031] The glycols are preferably selected from propylene glycol and glycerol, with propylene glycol being most preferred. The carbonate ester is preferably propylene carbonate. [0032] The most preferred combination is ethanol as the solvent and propylene glycol as the co-solvent. [0033] The preparation of liquid formulations for oropharangeal delivery of cannabinoids poses a number of problems. First, it is necessary to deliver at least 1.0 mg, more preferably at least 2.5 mg and even more preferably at least 5 mg of cannabinoids per 0.1 ml of liquid formulation to achieve a therapeutic effect in a unit dose. In this regard a patient may require up to 120 mg cannabinoid/day, on average around 40 mg/day to be taken in a maximum of six doses. [0034] In the case of a sublingual or buccal delivery, this means delivering this quantity of the active ingredient in an amount of formulation which will not be swallowed by the patient, if the active ingredient is to be absorbed transmucosally. [0035] Whilst such amounts can be achieved by dissolving the cannabinoid in ethanol as the solvent, high concentrations of ethanol provoke a stinging sensation and are beyond the limit of tolerability. [0036] There is thus a need to use a co-solvent in order to reduce the amount of ethanol, whilst still enabling sufficient quantities of cannabinoid to be solubilised. [0037] The applicant has discovered that the choice of co-solvent is limited. Preferred co-solvents should have a solubilizing effect sufficient to allow enough cannabinoid to be solubilised in a unit dose, namely at least 1.0 mg/0.1 ml of formulation, and which allows the amount of solvent present to be reduced to a level which is within the limits of patient tolerability. Particularly suitable co-solvents which fulfil these criteria are propylene glycol and glycerol. [0038] In a preferred embodiment the total amount of solvent and co-solvent present in the formulation, is greater than about 65% w/w, more preferably greater than about 70% w/w, more preferably greater than about 75% w/w, more preferably greater than about 80% w/w, more preferably greater than about 85% w/w of the formulation. Most preferably the total amount of solvent and co-solvent present in the formulation is in the range from about 80% w/w to about 98% w/w of the formulation. [0039] In a preferred embodiment the formulations according to the invention are liquid formulation administered via a pump-action spray. Pump-action sprays are characterised in requiring the application of external pressure for actuation, for example external manual, mechanical or electrically initiated pressure. This is in contrast to pressurized systems, e.g. propellant-driven aerosol sprays, where actuation is typically achieved by controlled release of pressure e.g. by controlled opening of a valve. [0040] Pump-action sprays are found to be particularly beneficial when it comes to delivering cannabinoids. Indeed, previously people have focussed their attention on solvent systems including a propellant. [0041] Whilst it has been recognised that there are disadvantages with such systems, including the speed of delivery, those skilled in the art have tried to address this by slowing the propellant or by altering the nozzle. The applicants have found that by using a pump spray with their formulations they are able to produce a spray in which the particles have a mean aerodynamic particle size of between 15 and 45 microns, more particularly between 20 and 40 microns and an average of about 33 microns. These contrast with particles having a mean aerodynamic particle size of between 5 and 10 microns when delivered using a pressurised system. [0042] In fact, comparative tests by the applicant have shown such a pump-action spray system to have advantages in being able to deliver the active components to a larger surface area within the target area. This is illustrated with reference to the accompanying Example 3. [0043] The variation in particle distribution and sprayed area has been demonstrated by direct experiment. A formulation as described in the accompanying Example 4 was filled into a pump action spray assembly (Valois vial type VP7100 actuated). The same formulation was filled into a pressurised container powered by HFA 134a. [0044] Both containers were discharged at a distance of 50 mm from a sheet of thin paper held at right angles to the direction of travel of the jet. The pattern of spray produced in both cases by discharge of 100 μl was then visualised against the light. In both cases the pattern of discharge was circular and measurements were as follows: [0000] Mean Diameter (mm) Mean Area (mm 2 ) Pump Action Spray 23 425.5 Pressurised Spray 16 201.1 [0045] The pressurised spray produced pooling of liquid at the centre of the area. The pump action spray gave a more even spray pattern and less “bounce back”. There was also a significantly greater area covered by the pump action spray. The conditions under which this test was carried out are relevant to the in-practice use of the device. A wider area of buccal mucosa can be reached by the pump action spray compared with the pressurised spray. [0046] For pump spray applications the solvent/co-solvent combination must have a viscosity within the viscosity range defined by the preferred solvent/co-solvent combination. Thus it should be a viscosity ranging between that for an ethanol/propylene glycol combination where the ethanol/propylene glycol are present in the relative proportions by volume of 60/40 and 40/60, more preferably still 55/45 to 45/55 and most preferably about 50/50. [0047] The viscosity of the resulting formulation when packaged for delivery by pump action through a mechanical pump such as, for example, a VP7 actuator valve (Valois), allows the resulting aerosol to deliver a spray having a mean aerodynamic particle size of from 20-40 microns, more preferably 25-35 and most preferably with an average particle size of from 30-35 microns. This maximises contact with the target mucosal membrane for sublingual/buccal delivery. [0048] Preferably the formulations according to the general and specific aspects of the invention comprises as the lipophilic medicament one or more cannabinoids. [0049] Preferably the lipophilic medicament is at least one extract from at least one cannabis plant. The cannabis plant(s) preferably include at least one cannabis chemovar. Most preferably the plant extract will be a botanical drug substance (BDS), as defined herein. [0050] A “plant extract” is an extract from a plant material as defined in the Guidance for Industry Botanical Drug Products Draft Guidance, August 2000, US Department of Health and Human Services, Food and Drug Administration Center for Drug Evaluation and Research. [0051] “Plant material” is defined as a plant or plant part (e.g. bark, wood, leaves, stems, roots, flowers, fruits, seeds, berries or parts thereof) as well as exudates. [0052] The term “ Cannabis plant(s)” encompasses wild type Cannabis sativa and also variants thereof, including cannabis chemovars which naturally contain different amounts of the individual cannabinoids, Cannabis sativa subspecies indica including the variants var. indica and var. kafiristanica, Cannabis indica and also plants which are the result of genetic crosses, self-crosses or hybrids thereof. The term “ Cannabis plant material” is to be interpreted accordingly as encompassing plant material derived from one or more cannabis plants. For the avoidance of doubt it is hereby stated that “ cannabis plant material” includes dried cannabis biomass. [0053] In the context of this application the terms “ cannabis extract” or “extract from a cannabis plant”, which are used interchangeably, encompass “Botanical Drug Substances” derived from cannabis plant material. A Botanical Drug Substance is defined in the Guidance for Industry Botanical Drug Products Draft Guidance, August 2000, US Department of Health and Human Services, Food and Drug Administration Center for Drug Evaluation and Research as: “A drug substance derived from one or more plants, algae, or macroscopic fungi. It is prepared from botanical raw materials by one or more of the following processes: pulverisation, decoction, expression, aqueous extraction, ethanolic extraction, or other similar processes.” A botanical drug substance does not include a highly purified or chemically modified substance derived from natural sources. Thus, in the case of cannabis , “botanical drug substances” derived from cannabis plants do not include highly purified, Pharmacopoeial grade cannabinoids. [0054] “ Cannabis based medicine extracts (CBMEs)”, such as the CBMEs prepared using processes described in the accompanying examples, are classified as “botanical drug substances”, according to the definition given in the Guidance for Industry Botanical Drug Products Draft Guidance, August 2000, US Department of Health and Human Services, Food and Drug Administration Center for Drug Evaluation and Research. [0055] “Botanical drug substances” derived from cannabis plants include primary extracts prepared by such processes as, for example, maceration, percolation, extraction with solvents such as C1 to C5 alcohols (e.g. ethanol), Norflurane (HFA134a), HFA227 and liquid carbon dioxide under sub-critical or super-critical conditions. The primary extract may be further purified for example by super-critical or sub-critical solvent extraction, vaporisation or chromatography. When solvents such as those listed above are used, the resultant extract contains non-specific lipid-soluble material. This can be removed by a variety of processes including “winterisation”, which involves chilling to −20° C. followed by filtration to remove waxy ballast, extraction with liquid carbon dioxide and by distillation. [0056] In the case where the cannabinoids are provided as a BDS, the BDS is preferably obtained by CO 2 extraction, under sub-critical or super-critical conditions, followed by a secondary extraction, e.g. an ethanolic precipitation, to remove a substantial proportion of waxes and other ballast. This is because the ballast includes wax esters and glycerides, unsatutrated fatty acid residues, terpenes, carotenes, and flavenoids which are not very soluble in the chosen solvent/co-solvent, particularly the preferred co-solvent, propylene glycol, and will precipitate out. Most preferably the BDS is produced by a process comprising decarboxylation, extraction with liquid carbon dioxide and then a further extraction to remove significant amounts of ballast. Most preferably the ballast is substantially removed by an ethanolic precipitation. [0057] Most preferably, cannabis plant material is heated to a defined temperature for a defined period of time in order to decarboxylate cannabinoid acids to free cannabinoids prior to extraction of the BDS. [0058] Preferred “botanical drug substances” include those which are obtainable by using any of the methods or processes specifically disclosed herein for preparing extracts from cannabis plant material. The extracts are preferably substantially free of waxes and other non-specific lipid soluble material but preferably contain substantially all of the cannabinoids naturally present in the plant, most preferably in substantially the same ratios in which they occur in the intact cannabis plant. [0059] Botanical drug substances are formulated into “Botanical Drug Products” which are defined in the Guidance for Industry Botanical Drug Products Draft Guidance, August 2000, US Department of Health and Human Services, Food and Drug Administration Center for Drug Evaluation and Research as: “A botanical product that is intended for use as a drug; a drug product that is prepared from a botanical drug substance.” [0060] “ Cannabis plants” includes wild type Cannabis sativa and variants thereof, including cannabis chemovars which naturally contain different amounts of the individual cannabinoids. [0061] The term “cannabinoids” also encompasses highly purified, Pharmacopoeial Grade substances, which may be obtained by purification from a natural source or via synthetic means. Thus, the formulations according to the invention may be used for delivery of extracts of cannabis plants and also individual cannabinoids, or synthetic analogues thereof, whether or not derived from cannabis plants, and also combinations of cannabinoids. [0062] Preferred cannabinoids include, but are not limited to, tetrahydrocannabinoids, their precursors, alkyl (particularly propyl) analogues, cannabidiols, their precursors, alkyl (particularly propyl) analogues, and cannabinol. In a preferred embodiment the formulations may comprise any cannabinoids selected from tetrahydrocannabinol, g-tetrahydrocannabinol (THC), Δ 8 -tetrahydrocannabinol, Δ 9 -tetrahydrocannabinol propyl analogue (THCV), cannabidiol (CBD), cannabidiol propyl analogue (CBDV), cannabinol (CBN), cannabichromene, cannabichromene propyl analogue and cannabigerol, or any combination of two or more of these cannabinoids. THCV and CBDV (propyl analogues of THC and CBD, respectively) are known cannabinoids which are predominantly expressed in particular Cannabis plant varieties and it has been found that THCV has qualitative advantageous properties compared with THC and CBD respectively. Subjects taking THCV report that the mood enhancement produced by THCV is less disturbing than that produced by THC. It also produces a less severe hangover. [0063] Most preferably the formulations will contain THC and/or CBD. [0064] In a preferred embodiment the formulations may contain specific, pre-defined ratios by weight of different cannbinoids, e.g. specific ratios of CBD to THC, or tetrahydrocannabinovarin (THCV) to cannabidivarin (CBDV), or THCV to THC. Certain specific ratios of cannabinoids have been found to be clinically useful in the treatment or management of specific diseases or medical conditions. In particular, certain of such formulations have been found to be particularly useful in the field of pain relief and appetite stimulation. [0065] It has particularly been observed by the present applicant that combinations of specific cannabinoids are more beneficial than any one of the individual cannabinoids alone. Preferred embodiments are those formulations in which the amount of CBD is in a greater amount by weight than the amount of THC. Such formulations are designated as “reverse-ratio” formulations and are novel and unusual since, in the various varieties of medicinal and recreational Cannabis plant available world-wide, CBD is the minor cannabinoid component compared to THC. In other embodiments THC and CBD or THCV and CBDV are present in approximately equal amounts or THC or THCV are the major component and may be up to 95.5% of the total cannabinoids present. [0066] Preferred formulations contain THC and CBD in defined ratios by weight. The most preferred formulations contain THC and CBD in a ratio by weight in the range from 0.9:1.1 to 1.1:0.9 THC:CBD, even more preferably the THC:CBD ratio is substantially 1:1. Other preferred formulations contain the following ratios by weight of THC and CBD:—greater than or equal to 19:1 THC:CBD, greater than or equal to 19:1 CBD:THC, 4.5:1 THC:CBD, 1:4 THC:CBD and 1:2.7 THC:CBD. For formulations wherein the THC:CBD ratio is substantially 1:1 it is preferred that the formulation includes about 2.5 g/ml of each of THC and CBD. [0067] Cannabis has been used medicinally for many years, and in Victorian times was a widely used component of prescription medicines. It was used as a hypnotic sedative for the treatment of “hysteria, delirium, epilepsy, nervous insomnia, migraine, pain and dysmenorrhoea”. The use of cannabis continued until the middle of the twentieth century, and its usefulness as a prescription medicine is now being re-evaluated. The discovery of specific cannabinoid receptors and new methods of administration have made it possible to extend the use of cannabis -based medicines to historic and novel indications. [0068] The recreational use of cannabis prompted legislation which resulted in the prohibition of its use. Historically, cannabis was regarded by many physicians as unique; having the ability to counteract pain resistant to opioid analgesics, in conditions such as spinal cord injury, and other forms of neuropathic pain including pain and spasm in multiple sclerosis. [0069] In the United States and Caribbean, cannabis grown for recreational use has been selected so that it contains a high content of tetrahydrocannabinol (THC), at the expense of other cannabinoids. In the Merck Index (1996) other cannabinoids known to occur in cannabis such as cannabidiol and cannabinol were regarded as inactive substances. Although cannabidiol was formerly regarded as an inactive constituent there is emerging evidence that it has pharmacological activity, which is different from that of THC in several respects. The therapeutic effects of cannabis cannot be satisfactorily explained just in terms of one or the other “active” constituents. [0070] It has been shown that tetrahydrocannabinol (THC) alone produces a lower degree of pain relief than the same quantity of THC given as an extract of cannabis . The pharmacological basis underlying this phenomenon has been investigated. In some cases, THC and cannabidiol (CBD) have pharmacological properties of opposite effect in the same preclinical tests, and the same effect in others. For example, in some clinical studies and from anecdotal reports there is a perception that CBD modifies the psychoactive effects of THC. This spectrum of activity of the two cannabinoids may help to explain some of the therapeutic benefits of cannabis grown in different regions of the world. It also points to useful effects arising from combinations of THC and CBD. These have been investigated by the applicant. Table 1 below shows the difference in pharmacological properties of the two cannabinoids. [0000] TABLE 1 Effect THC THCV CBD CBDV Reference CB 1 (Brain receptors) ++ ± Pertwee et al, 1998 CB 2 (Peripheral receptors) + − CNS Effects Anticonvulsant† −− ++ Carlini et al, 1973 Antimetrazol − − GW Data Anti-electroshock − ++ GW data Muscle Relaxant −− ++ Petro, 1980 Antinociceptive ++ + GW data Catalepsy ++ ++ GW data Psychoactive ++ − GW data Antipsychotic − ++ Zuardi et al, 1991 Neuroprotective antioxidant + ++ Hampson A J et al, activity* ++ − 1998 Antiemetic + + Sedation (reduced ++ Zuardi et al, 1991 spontaneous activity) Appetite stimulation ++ Appetite suppression − ++ Anxiolytic GW data Cardiovascular Effects Bradycardia − + Smiley et al, 1976 Tachycardia + − Hypertension§ + − Hypotension§ − + Adams et al, 1977 Anti-inflammatory ± ± Brown, 1998 Immunomodulatory/anti- inflammatory activity Raw Paw Oedema Test − ++ GW data Cox 1 GW data Cox 2 GW data TNFα Antagonism + + ++ ++ Glaucoma ++ + *Effect is CB1 receptor independent. †THC is pro convulsant §THC has a biphasic effect on blood pressure; in naive patients it may produce postural hypotension and it has also been reported to produce hypertension on prolonged usage. [0071] From these pharmacological characteristics and from direct experiments carried out by the applicant it has been shown, surprisingly, that combinations of THC and CBD in varying proportions are particularly useful in the treatment of certain therapeutic conditions. It has further been found clinically that the toxicity of a mixture of THC and CBD is less than that of THC alone. [0072] Accordingly, the invention provides pharmaceutical formulations, having all the essential features described above, which comprise cannabinoids as the active agents and which have specific ratios of CBD to THC, which have been found to be clinically useful in the treatment or management of specific diseases or medical conditions. [0073] In a further aspect the invention also relates to pharmaceutical formulations having all the essential features defined above, and which have specific ratios of tetrahydrocannabinovarin (THCV) or cannabidivarin (CBDV). THCV and CBDV (propyl analogues of THC and CBD, respectively) are known cannabinoids which are predominantly expressed in particular Cannabis plant varieties and it has been found that THCV has qualitative advantageous properties compared with THC and CBD respectively. Subjects taking THCV report that the mood enhancement produced by THCV is less disturbing than that produced by THC. It also produces a less severe hangover. [0074] The invention still further relates to pharmaceutical formulations, having all the essential features as defined above, which have specific ratios of THCV to THC. Such formulations have been found to be particularly useful in the field of pain relief and appetite stimulation. [0075] It has particularly been observed by the present applicants that the combinations of the specific cannabinoids are more beneficial than any one of the individual cannabinoids alone. Preferred embodiments are those formulations in which the amount of CBD is in a greater amount by weight than the amount of THC. Such formulations are designated as “reverse-ratio” formulations and are novel and unusual since, in the various varieties of medicinal and recreational Cannabis plant available world-wide, CBD is the minor cannabinoid component compared to THC. In other embodiments THC and CBD or THCV and CBDV are present in approximately equal amounts or THC or THCV are the major component and may be up to 95.5% of the total cannabinoids present. [0076] Particularly preferred ratios of cannabinoids and the target medical conditions for which they are suitable are shown in Table 2 below. Other preferred ratios of THC:CBD, THCV:CBDV and THC:TCHV and preferred therapeutic uses of such formulations are set out in the accompanying claims. [0000] TABLE 2 Target Therapeutic Groups for Different Ratios of Cannabinoid Product group Ratio THC:CBD Target Therapeutic Area High THC >95:5  Cancer pain, migraine, appetite stimulation Even ratio   50:50 Multiple sclerosis, spinal cord injury, peripheral neuropathy, other neurogenic pain. Reverse/Broad <25:75 Rheumatoid arthritis, Inflammatory ratio CBD bowel diseases. High CBD  <5:95 Psychotic disorders (schizophrenia), Epilepsy & movement disorders Stroke, head injury, Disease modification in RA and other inflammatory conditions Appetite suppression [0077] Formulations containing specific, defined ratios of cannabinoids may be formulated from pure cannabinoids in combination with pharmaceutical carriers and excipients which are well-known to those skilled in the art. Pharmaceutical grade “pure” cannabinoids may be purchased from commercial suppliers, for example CBD and THC can be purchased from Sigma-Aldrich Company Ltd, Fancy Road, Poole Dorset, BH12 4QH, or may be chemically synthesised. Alternatively, cannabinoids may be extracted from Cannabis plants using techniques well-known to those skilled in the art. [0078] In preferred embodiments of the invention the formulations comprise extracts of one or more varieties of whole Cannabis plants, particularly Cannabis sativa, Cannabis indica or plants which are the result of genetic crosses, self-crosses or hybrids thereof. The precise cannabinoid content of any particular cannabis variety may be qualitatively and quantitatively determined using methods well known to those skilled in the art, such as TLC or HPLC. Thus, one may chose a Cannabis variety from which to prepare an extract which will produce the desired ratio of CBD to THC or CBDV to THCV or THCV to THC. Alternatively, extracts from two of more different varieties may be mixed or blended to produce a material with the preferred cannabinoid ratio for formulating into a pharmaceutical formulation. [0079] The preparation of convenient ratios of THC- and CBD-containing medicines is made possible by the cultivation of specific chemovars of cannabis . These chemovars (plants distinguished by the cannabinoids produced, rather than the morphological characteristics of the plant) can be been bred by a variety of plant breeding techniques which will be familiar to a person skilled in the art. Propagation of the plants by cuttings for production material ensures that the genotype is fixed and that each crop of plants contains the cannabinoids in substantially the same ratio. [0080] Furthermore, it has been found that by a process of horticultural selection, other chemovars expressing their cannabinoid content as predominantly tetrahydrocannabinovarin (THCV) or cannabidivarin (CBDV) can also be achieved. [0081] Horticulturally, it is convenient to grow chemovars producing THC, THCV, CBD and CBDV as the predominant cannabinoid from cuttings. This ensures that the genotype in each crop is identical and the qualitative formulation (the proportion of each cannabinoid in the biomass) is the same. From these chemovars, extracts can be prepared by the similar method of extraction. Convenient methods of preparing primary extracts include maceration, percolation, extraction with solvents such as C1 to C5 alcohols (ethanol), Norflurane (HFA134a), HFA227 and liquid carbon dioxide under pressure. The primary extract may be further purified for example by supercritical or subcritical extraction, vaporisation and chromatography. When solvents such as those listed above are used, the resultant extract contains non-specific lipid-soluble material or “ballast”. This can be removed by a variety of processes including chilling to −20° C. followed by filtration to remove waxy ballast, extraction with liquid carbon dioxide and by distillation. Preferred plant cultivation and extract preparation methods are shown in the Examples. The resulting extract is suitable for incorporation into pharmaceutical preparations. [0082] There are a number of therapeutic conditions which may be treated effectively by cannabis , including, for example, cancer pain, migraine, appetite stimulation, multiple sclerosis, spinal cord injury, peripheral neuropathy, other neurogenic pain, rheumatoid arthritis, inflammatory bowel diseases, psychotic disorders (schizophrenia), epilepsy & movement disorders, stroke, head injury, appetite suppression. The proportion of different cannabinoids in a given formulation determines the specific therapeutic conditions which are best treated (as summarised in Table 2, and stated in the accompanying claims). [0083] The principles of formulation suitable for administration of cannabis extracts and cannabinoids can also be applied to other medicaments such as alkaloids, bases and acids. The requirements are that, if the medicament is insoluble in saliva, it should be solubilised and/or brought into the appropriate unionised form by addition of buffering salts and pH adjustment. [0084] Other lipophilic medicaments which may be included in the general formulations of the invention may include, but are not limited to, morphine, pethidine, codeine, methadone, diamorphine, fentanyl, alfentanil, buprenorphine, temazepam, lipophilic analgesics and drugs of abuse. The term “drugs of abuse” encompasses compounds which may produce dependence in a human subject, typically such compounds will be analgesics, usually opiates or synthetic derivatives thereof. [0085] The formulation is preferably packaged in a glass vial. It is preferably filled to a slight over-pressure in an inert atmosphere e.g. nitrogen to prevent/slow oxidative breakdown of the cannabinoids, and is contained in a form such that ingress of light is prevented, thereby preventing photochemical degradation of the cannabinoids. This is most effectively achieved using an amber vial, since the applicant has determined that it is UV and light in the blue spectrum, typically in the wavelength range 200-500 nm, that is responsible for photodegradation. [0086] The invention will be further described, by way of example only, with reference to the following experimental data and exemplary formulations, together with the accompanying Figures: BRIEF DESCRIPTION OF THE DRAWINGS [0087] FIGS. 1 a and 1 b illustrate mean plasma concentrations of cannabinoids CBD, THC and 11-hydroxy THC following administration of high CBD ( FIG. 1 a ) and high THC ( FIG. 1 b ) cannabis extracts to human subjects. [0088] FIG. 2 illustrates mean plasma concentrations of cannabinoids CBD, THC and 11-hydroxy THC following administration of a cannabis extract containing a 1:1 ratio of THC:CBD to a human subject. [0089] FIG. 3 illustrates cross-sectional area of aerosol plume vs % propylene glycol in propylene glycol/ethanol liquid spray formulations. [0090] FIG. 4 illustrates viscosity as a function of propylene glycol content in propylene glycol/ethanol liquid spray formulations. [0091] FIG. 5 illustrates cross-sectional area of aerosol plume vs viscosity for propylene glycol/ethanol liquid spray formulations. [0092] FIGS. 6 and 6 a show results of HPLC analysis of samples drawn from stored, light exposed solutions of THC, before and after charcoal treatment. [0093] FIGS. 7 and 7 a show results of HPLC analysis of samples drawn from stored, light exposed solutions of CBD, before and after charcoal treatment. DETAILED DESCRIPTION OF THE INVENTION Development of Pump-Action Spray Formulations [0094] Initially the applicant looked at cannabinoid uptake in patients by applying drops sublingually (BDS dissolved in a mixture of a glycerol/propylene glycol and ethanol) THC 5 mg/ml, CBD 5 mg/ml and THC/CBD 5 mg/ml plus 5 mg/ml. [0095] The results are noted in Table 3 below: [0000] TABLE 3 Initial absorption: 20 min T max: approx 2 hours C max: 6 ng/ml THC, 2 ng/ml CBD AUC 0-12: approx 16 ng · h/mlTHC, 8 ng · h/mlCBD following a dose of approx 20 mg of each cannabinoids Plasma levels after 6 hours were about 1 ng/ml THC and 0.5 ng/ml CBD [0096] The proportion of 11 hydroxy tetrahydro cannabinol to THC (AUC0-12) was about 1.9 indicating a significant amount of oral ingestion may have occurred. [0097] On moving to a pump action sublingual spray (following problems solubilising cannabinoids with hydrofluorocabon propellant systems) the applicant obtained the results noted in Table 4. The solvent system comprised 50:50 ethanol to propylene glycol (v/v ratio) with THC 25 mg/ml; CBD 50 mg/ml and THC/CBD 25 mg/ml plus 50 mg/ml respectively. [0000] TABLE 4 Initial absorption: 60 min T max: approx 3 hours C max: 6 ng/ml THC, 8 ng/ml CBD AUC 0-12: approx 16 ng · h/ml THC, 22 ng · h/ml CBD following a dose of approx 21 mg of THC and 35 mg CBD Plasma levels after 6 hours were about 1 ng/ml THC and 1 ng/ml CBD [0098] The proportion of 11 hydroxy tetrahydro cannabinol to THC (AUC0-12) was about 1.6. The profile for each cannabinoid was similar irrespective of the formulation (THC, CBD, THC plus CBD). [0099] After accounting for the different dosages, whilst the extent of absorption was comparable to the drops, the rate of absorption was slower and the proportion metabolised reduced. [0100] Despite the slower rate of absorption the pump spray mechanism and the ethanol/propylene glycol carrier system provided the opportunity to administer sufficient cannabinoids, in a flexible dose form with accuracy and advantageously with reduced metabolism. [0101] The data obtained is illustrated in FIGS. 1 a , 1 b and 2 , which show the mean plasma concentrations for the formulations identified with reference to Tables 3 and 4. [0102] That effective delivery of the cannabinoids can be achieved in a vehicle consisting of ethanol and propylene glycol is illustrated by the plasma levels shown in FIGS. 1 a , 1 b and 2 . These show, respectively, formulations containing the high THC and high CBD formulations in FIGS. 1 a and 1 b . Similarly, the effectiveness of a defined ratio formulation THC:CBD 1:1 is illustrated in FIG. 2 . [0103] Significantly the ethanol/propylene glycol system was found to only work with a pump action spray within quite narrow limits. [0104] The findings giving rise to the development of pump spray formulations, as exemplified in formulations 1-4 below, are set out below: Example 1 Significance of Particle Size [0105] Applicant observed that the propellant aerosols that were developed suffered from “bounce back” and this appeared to be a function of delivery speed and particle size. [0106] Applicant determined that, in contrast to the propellant driven system, a pump spray could deliver an aerosol plume in which the particle size could be controlled to generate a particle size of between 20 and 40 microns (thus maximising the amount of material hitting the sublingual/buccal mucosa and thus the amount of cannabinoids that can be absorbed). To produce particles of the appropriate size the viscosity of the formulation needed to be carefully controlled. If the formulation was too viscous droplet formation was hindered, a jet formed and the valve blocked; If the formulation was not viscous enough they got excessive nebulisation, a plume of broad cross sectional area formed, and the spray was no longer directed solely onto the sublingual/buccal mucosa. This could result in the formulation pooling and some of the formulation being swallowed. In both cases the result is unsatisfactory. [0107] In fact, it turned out that for the solvent of preferred choice, ethanol, and the co-solvent of preferred choice, propylene glycol, the working range was fairly narrow as demonstrated below: [0108] The viscosity of different combinations of ethanol/propylene glycol were studied and their spray performance with a vp7/100 valve (Valois) compared. The results are tabulated in Table 5 below: [0000] TABLE 5 Propylene glycol/ Relative viscosity ethanol (run time in sec) Spray performance 100/0  442 Jet formed 80/20 160 Jet formed 60/40 80 Some jetting 50/50 62 Good aerosol plume 40/60 44 Good aerosol plume 20/80 26 Good aerosol plume  0/100 16 Good aerosol plume [0109] From this data it appeared that addition of propylene glycol at greater than 60/40 would not be acceptable. These result, when read alongside U.S. Pat. No. 3,560,625, could have suggested that the said solvent/co-solvent combination would be no good. However, applicant found that patients could tolerate ethanol levels of this order when presented in the given formulations. [0110] The effect of viscosity on aerosol plume was quantified by spraying the various formulations at a standard distance of 0.5 cm onto disclosing paper. The distance represents the typical distance between the nozzle of the pump action spray unit and the sub lingual cavity in normal use. The paper was photocopied and the image of the plume excised and weighed to give a relative cross sectional area. The relative value was then converted into a real cross sectional area by dividing this value by the weight per cm 2 of the photocopier paper (determined by weighing a known area of paper). The results are given in Table 6 below: [0000] TABLE 6 Propylene glycol/ Area of cross section ethanol of spray plume 100/0  3.5 cm 2 80/20 14.2 cm 2 60/40 17.9 cm 2 50/50 20.7 cm 2 40/60 29.4 cm 2 20/80 54.4 cm 2  0/100 93.8 cm 2 This data is illustrated in FIG. 3 . [0111] Additionally plots of viscosity of mixtures of ethanol and propylene glycol content FIG. 4 and plume cross section as a function of viscosity FIG. 5 are given. [0112] The figures emphasise the dramatic and undesirable changes in properties which occur outside the narrow range of ethanol/propylene glycol wt/wt of 60/40 and 40/60, and more particularly still 55/45 to 45/55, most preferably about 50/50. [0113] Other factors are also significant in ensuring the combination is used in a narrow range. Increasing the ethanol levels beyond 60 vol % gives rise to irritation and at propylene glycol levels approaching 60% and as low as 55%, in the case of BDS, non polar derivatives present in the BDS begin to precipitate out on prolonged ambient storage. [0114] Other co-solvents which might be used would be expected to have similar limitations. The more viscous the co-solvent the greater the problem of producing a plume forming spray, and the more polar, the greater the risk that precipitation will be exacerbated. [0115] However, because the combination of ethanol/propylene glycol is able to dissolve up to 50 mg/ml (i.e. therapeutically desirable levels of cannabinoids), is non irritating, pharmaceutically acceptable, and the propylene glycol also acts as a penetration enhancer maximising bioavailability of the cannabinoids it is particularly advantageous. [0116] The mean particle size of the preferred compositions have been shown to be 33 μm when tested using a Malvern Marsteriser. The droplets, which are considerably greater than 5 μm, therefore minimise the risk of inhalation of aerosol. Example 2 Effect of Water when the Cannabinoids are Present in a BDS [0117] The presence of greater than 5% water in the formulation was shown to cause precipitation of the BDS as illustrated by the investigation described in Table 7 below: [0118] Table 7-Sequential addition of water was made to 5 ml 25 mg/ml THC and 5 ml 25 mg/ml CBD in an ethanol/propylene glycol formulate (50/50). [0000] Approx final solvent Vol of water Final vol ratio % vol Water/ added ml ml propylene glycol/ethanol observation 0 5 0/50/50 Solution 0.05 5.05 1/49.5/49.5 Ppt forms but redissolves on mixing 0.21 5.26 5/47.5/47.5 Ppt forms. Solution remains cloudy after mixing [0119] Indeed because of this observation the use of anhydrous ethanol is preferred. [0120] Example formulations (non-limiting) according to the invention are as follows: [0000] COMPOSITION 1 (General) COMPONENT AMOUNT PER UNIT (1 ml) FUNCTION Active THC (BDS) 25-50 mg/ml Active CBD (BDS) 25-50 mg/ml Excipient Propylene Glycol 0.5 ml/ml Co solvent Peppermint oil 0.0005 ml/ml Flavour Ethanol (anhydrous) qs to 1 ml Solvent [0000] COMPOSITION 2 (High THC) COMPONENT AMOUNT PER UNIT (1 ml) FUNCTION Active THC (BDS) 25 mg/ml Active Excipient Propylene Glycol 0.5 ml/ml Co solvent Peppermint oil 0.0005 ml/ml Flavour Ethanol (anhydrous) qs to 1 ml Solvent [0000] COMPOSITION 3 (High CBD) COMPONENT AMOUNT PER UNIT (1 ml) FUNCTION Active CBD (BDS) 25 mg/ml Active Excipient Propylene Glycol 0.5 ml/ml Co solvent Peppermint oil 0.0005 ml/ml Flavour Ethanol (anhydrous) qs to 1 ml Solvent [0000] COMPOSITION 4 (THC/CBD substantially 1:1) COMPONENT AMOUNT PER UNIT (1 ml) FUNCTION Active THC (BDS) 25 mg/ml Active CBD (BDS) 25 mg/ml Active Excipient Propylene Glycol 0.5 ml/ml Co solvent Peppermint oil 0.0005 ml/ml Flavour Ethanol (anhydrous) qs to 1 ml Solvent Example 3 [0121] The following example illustrates the application of liquid spray formulations to the buccal mucosae and the blood levels produced by buccal absorption in comparison with sublingual administration. [0122] The following liquid formulations suitable for buccal administration contain self-emulsifying agents, and hence do not fall within the scope of the present invention. Nevertheless, the general principles illustrated by use of these compositions applies equally to the delivery formulations according to the invention. Solutions were produced by dissolving (at a temperature not exceeding 50° C.) the following ingredients (quantitative details are expressed as parts by weight):— [0000] A B C D E Glyceryl monostearate (self- 2 — 2 — 2 emulsifying) Glyceryl monooleate — 2 — 2 — (self-emulsifying) Cremophor RH40 20 30 30 20 30 CBME-G1 to give THC 5 10 — — — CBME-G5 to give CBD — — 5 10 — CBME-G1 and G5 to give THC & — — — — 10 each CBD α-Tocopherol 0.1 0.1 0.1 0.1 0.1 Ascorbyl palmitate 0.1 0.1 0.1 0.1 0.1 Ethanol BP to produce 100 100 100 100 100 [0123] Cannabis Based Medicine Extract (CBME) is an extract of cannabis which may be prepared by, for example, percolation with liquid carbon dioxide, with the removal of ballast by cooling a concentrated ethanolic solution to a temperature of −20° C. and removing precipitated inert plant constituents by filtration or centrifugation. [0124] The product formed by mixing these ingredients is dispensed in 6 ml quantities into a glass vial and closed with a pump action spray. In use, the dose is discharged through a break-up button or conventional design. Proprietary devices that are suitable for this purpose are Type VP7 produced by Valois, but similar designs are available from other manufacturers. The vial may be enclosed in secondary packaging to allow the spray to be directed to a particular area of buccal mucosa. Alternatively, a proprietary button with an extension may be used to direct the spray to a preferred area of buccal mucosa. [0125] Each 1 ml of product contains 50-100 mg of Δ 9 -tetrahydrocannabinol (THC) and/or cannabidiol (CBD). Each actuation of the pump delivers a spray which can be directed to the buccal mucosae. In the above formulations CBMEs of known cannabinoid strength are used. CBME-G1 is an extract from a high THC-yielding strain of cannabis , and CBME-G5 is from a high CBD-yielding variety. It will be clear to a person skilled in the art that purified cannabinoids, and extracts containing the cannabinoids, can be made formulated as described above by quantitative adjustment. [0126] Although solutions of CBME in ethanol alone can be used as a spray, the quantity of cannabinoid that can be delivered is limited by the aggressive nature of pure ethanol in high concentration as a solvent. This limits the amount that can be applied to the mucosae without producing discomfort to the patient. When a group of patients received THC or CBD in a solution of the type described above, directing the spray either sublingually or against the buccal mucosa, the patients uniformly reported a stinging sensation with the sublingual application, but mild or no discomfort when the same solution was sprayed onto the buccal mucosa. Spraying small quantities of this type of formulation onto the buccal mucosa does not appreciably stimulate the swallowing reflex. This provides greater dwell time for the formulation to be in contact with the buccal surface. [0127] Formulations were administered to a group of 13 human subjects so that they received 4 mg THC, 4 mg of CBD or placebo (vehicle alone) via a sublingual tablet, sublingual pump-action spray or buccal route. [0128] Absorption [area under the absorption curve (AUC)] of cannabinoid and primary metabolite were determined in samples of blood taken after dosing. The following Table 8 gives these as normalised mean values. [0000] TABLE 8 Route of Administration Analyte in PAS sublingual Sublingual tablet Oropharyngeal Plasma AUC AUC AUC THC 2158.1 1648.4 1575 11-OH THC 3097.6 3560.5 2601.1 CBD 912 886.1 858 [0129] These results show that the total amounts of cannabinoid absorbed by sublingual and buccal (oropharyngeal) routes are similar but that there is a substantial (approximately 25%) reduction in the amount of 11-hydroxy (11-OH) metabolite detected after oropharyngeal (buccal) administration. This finding is not inconsistent with reduced swallowing (and subsequent reduced hepatic) metabolism of the buccal formulation. [0130] It is known that the 11-hydroxy metabolite of THC (11-OH THC) is possibly more psychoactive than the parent compound. It is therefore desirable to minimise the amount of this metabolite during administration, and this is likely to be achieved by using a formulation and method of application which reduces the amount of a buccal or sublingual dose that is swallowed. The pump action spray appears to offer a simple means of reducing the amount of material that is swallowed and metabolised by absorption from the intestinal tract below the level of the oropharynx. Example 4 Growing of Medicinal Cannabis [0131] Plants are grown as clones from germinated seed, under glass at a temperature of 25° C.±1.5° C. for 3 weeks in 24 hour daylight; this keeps the plants in a vegetative state. Flowering is induced by exposure to 12 hour day length for 8-9 weeks. No artificial pesticides, herbicides, insecticides or fumigants are used. Plants are grown organically, with biological control of insect pests. [0132] The essential steps in production from seed accession to dried Medicinal Cannabis are summarised as follows: [0000] Example 5 Determination of Cannabinoid Content in Plants and Extracts Identity by TLC a) Materials and Methods [0000] Equipment Application device capable of delivering an accurately controlled volume of solution i.e., 1 μl capillary pipette or micro litre syringe. TLC development tank with lid Hot air blower Silica gel G TLC plates (SIL N—HR/UV254), 200 μm layer with fluorescent indicator on polyester support. Dipping tank for visualisation reagent. Mobile phase 80% petroleum ether 60:80/20% Diethyl ether. Visualisation reagent 0.1% w/v aqueous Fast Blue B (100 mg in 100 ml de-ionised water). An optional method is to scan at UV 254 and 365 nm. b) Sample preparation i) Herbal raw material Approximately 200 mg of finely ground, dried cannabis is weighed into a 10 ml volumetric flask. Make up to volume using methanol:chloroform (9:1) extraction solvent. Extract by ultrasound for 15 minutes. Decant supernatant and use directly for chromatography. ii) Herbal drug Extract Approximately 50 mg of extract is weighed into a 25 ml volumetric flask. Make up to volume using methanol solvent. Shake vigorously to dissolve and then use directly for chromatography. c) Standards [0145] 0.1 mg/ml delta-9-THC in methanol. 0.1 mg/m1 CBD in methanol. [0146] The standard solutions are stored frozen at −20° C. between uses and are used for up to 12 months after initial preparation. [0000] d) Test solutions and method [0147] Apply to points separated by a minimum of 1 Omm. i) either 5 μl of herb extract or 1 μl of herbal extract solution as appropriate, ii) 10W of 0.1 mg/ml delta-9-THC in methanol standard solution, iii) 10 μl of 0.1 mg/ml CBD in methanol standard solution. Elute the TLC plate through a distance of 8 cm, then remove the plate. Allow solvent to evaporate from the plate and then repeat the elution for a second time (double development). The plate is briefly immersed in the Fast Blue B reagent until the characteristic re/orange colour of cannabinoids begins to develop. The plate is removed and allowed to dry under ambient conditions in the dark. A permanent record of the result is made either by reproduction of the image by digital scanner (preferred option) or by noting spot positions and colours on a tracing paper. Assay THC, THCA, CBD, CBDA and CBN by HPLC [0154] a) Materials and methods Equipment: HP 1100 HPLC with diode array detector and autosampler. The equipment is set up and operated in accordance with in-house standard operating procedures (SOPlab037) HPLC column Discovery C8 5 μm, 15×0.46 cm plus Kingsorb ODS2 precolumn 5 μm 3×0.46 cm. Mobile Phase Acetonotrile:methano1:0.25% aqueous acetic acid (16:7:6 by volume) [0000] Column Operating 25° C. Temperature Flow Rate 1.0 ml/min Injection 10 μl Volume Run time 25 mins Detection Neutral and acid cannabinoids 220 nm (band width 16 nm) Reference wavelength 400 nm/ bandwidth 16 nm Slit 4 nm Acid cannabinoids are routinely monitored at 310 nm (band width 16 nm) for qualitative confirmatory and identification purposes only. Data capture HP Chemistation with Version A7.01 software b) Sample preparation Approximately 40 mg of Cannabis Based Medicinal Extract is dissolved in 25 ml methanol and this solution is diluted to 1 to 10 in methanol. This dilution is used for chromatography. 0.5 ml of the fill solution, contained within the Pump Action Sublingual Spray unit, is sampled by glass pipette. The solution is diluted into a 25 ml flask and made to the mark with methanol. 200 μl of this solution is diluted with 800 μl of methanol. Herb or resin samples are prepared by taking a 100 mg sample and treating this with 5 or 10 ml of Methanol/Chloroform (9/1 w/v). The dispersion is sonicated in a sealed tube for 10 minutes, allowed to cool and an aliquot is centrifuged and suitably diluted with methanol prior to chromatography. c) Standards [0161] External standardisation is used for this method. Dilution of stock standards of THC, CBD and CBN in methanol or ethanol are made to give final working standards of approximately accurately 0.1 mg/ml. The working standards are stored at −20° C. and are used for up to 12 months after initial preparation. Injection of each standard is made in triplicate prior to the injection of any test solution. At suitable intervals during the processing of test solutions, repeat injections of standards are made. In the absence of reliable CBDA and THCA standards, these compounds are analysed using respectively the CBD and THC standard response factors. The elution order has been determined as CBD, CBDA, CBN, THC and THCA. Other cannabinoids are detected using this method and may be identified and determined as necessary. d) Test solutions Diluted test solutions are made up in methanol and should contain analytes in the linear working range of 0.02-0.2 mg/ml. e) Chromatography Acceptance Criteria: [0162] The following acceptance criteria are applied to the results of each sequence as they have been found to result in adequate resolution of all analytes (including the two most closely eluting analytes CBD and CBDA) i) Retention time windows for each analyte: [0000] CBD 5.4-5.9 minutes CBN 7.9-8.7 minutes THC 9.6-10.6 minutes ii) Peak shape (symmetry factor according to BP method) CBD<1.30 CBN<1.25 THC<1.35 iii) A number of modifications to the standard method have been developed to deal with those samples which contain late eluting impurity peaks e.g., method CBD2A extends the run time to 50 minutes. All solutions should be clarified by centrifugation before being transferred into autosampler vials sealed with teflon faced septum seal and cap. iv) The precolumn is critical to the quality of the chromatography and should be changed when the back pressure rises above 71 bar and/or acceptance criteria regarding retention time and resolution, fall outside their specified limits. f) Data Processing [0170] Cannabinoids can be subdivided into neutral and acidic—the qualitative identification can be performed using the DAD dual wavelength mode. Acidic cannabinoids absorb strongly in the region of 220 nm-310 nm. Neutral cannabinoids only absorb strongly in the region of 220 nm. Routinely, only the data recorded at 220 nm is used for quantitative analysis. The DAD can also be set up to take UV spectral scans of each peak, which can then be stored in a spectral library and used for identification purposes. Data processing for quantitation utilises batch processing software on the Hewlett Packard Chemstation. a) Sample Chromatograms [0171] HPLC sample chromatograms for THC and CBD Herbal Drug extracts are provided in the accompanying Figures. Example 6 Preparation of the Herbal Drug Extract [0172] A flow chart showing the process of manufacture of extract from the High-THC and High-CBD chemovars is given below: [0000] [0173] The resulting extract is referred to as a Cannabis Based Medicine Extract and is also classified as a Botanic Drug Substance, according to the US Food and Drug Administration Guidance for Industry Botanical Drug Products. Example 7 [0174] High THC cannabis was grown under glass at a mean temperature of 21+2° C., RH 50-60%. Herb was harvested and dried at ambient room temperature at a RH of 40-45% in the dark. When dry, the leaf and flower head were stripped from stem and this dried biomass is referred to as “medicinal cannabis”. [0175] Medicinal cannabis was reduced to a coarse powder (particles passing through a 3 mm mesh) and packed into the chamber of a Supercritical Fluid Extractor. Packing density was 0.3 and liquid carbon dioxide at a pressure of 600 bar was passed through the mass at a temperature of 35° C. Supercritical extraction is carried out for 4 hours and the extract was recovered by stepwise decompression into a collection vessel. The resulting green-brown oily resinous extract is further purified. When dissolved in ethanol BP (2 parts) and subjected to a temperature of −20° C. for 24 hours a deposit (consisting of fat-soluble, waxy material) was thrown out of solution and was removed by filtration. Solvent was removed at low pressure in a rotary evaporator. The resulting extract is a soft extract which contains approximately 60% THC and approximately 6% of other cannabinoids of which 1-2% is cannabidiol and the remainder is minor cannabinoids including cannabinol. Quantitative yield was 9% w/w based on weight of dry medicinal cannabis. [0176] A high CBD chemovar was similarly treated and yielded an extract containing approximately 60% CBD with up to 4% tetrahydrocannabinol, within a total of other cannabinoids of 6%. Extracts were made using THCV and CBDV chemovars using the general method described above. [0177] A person skilled in the art will appreciate that other combinations of temperature and pressure (e.g. in the range +10° C. to 35° C. and 60-600 bar) can be used to prepare extracts under supercritical and subcritical conditions. Example 8 The Effects of Light on the Stability of the Alcoholic Solutions of THC,CBD or THCV [0178] The following example includes data to support the packaging of liquid dosage forms in amber glass, to provide some protection from the degradative effects of light on cannabinoids. [0179] Further credence is also given to the selection of the lowest possible storage temperature for the solutions containing cannabinoid active ingredients. Background and Overview: [0180] Light is known to be an initiator of degradation reactions in many substances, including cannabinoids. This knowledge has been used in the selection of the packaging for liquid formulations, amber glass being widely used in pharmaceutical presentations as a light exclusive barrier. [0181] Experiments were set up to follow the effects of white light on the stability of methanolic solutions of THC, CBD or THCV. Following preliminary knowledge that light of different wavelengths may have differing effects on compound stability (viz. tretinoin is stable only in red light or darkness), samples were wrapped in coloured acetate films or in light exclusive foil. A concurrent experiment used charcoal treated CBME to study the effects of the removal of plant pigments on the degradation process. Materials and Methods: [0182] Cannabinoids: 1 mg/ml solutions of CBME were made up in AR methanol. Methanolic solutions of CBME (100 mg/ml) were passed through charcoal columns (Biotage Flash 12AC 7.5 cm cartridges, b/no. 2730125) and were then diluted to 1 mg/ml. Solutions were stored in soda-glass vials, which were tightly screw capped and oversealed with stretch film. Tubes were wrapped in coloured acetate films as follows: Red, Yellow, Green, and Cyan [0183] Solutions were also filled into the amber glass U-save vials; these were sealed with a septum and oversealed. One tube of each series of samples was tightly wrapped in aluminium foil in order to completely exclude light. This served as a “dark” control to monitor the contribution of ambient temperature to the degradation behaviour. All of the above tubes were placed in a box fitted with 2×40 watt white Osram fluorescent tubes. The walls of the box were lined with reflective foil and the internal temperature was monitored at frequent intervals. [0184] A further tube of each series was stored at −20° C. to act as a pseudo to the reference sample; in addition, one tube was exposed directly to light without protection. Samples were withdrawn for chromatographic analysis at intervals up to 112 days following the start of the study. The study was designated AS01201/AX282. [0185] Samples of the test solutions were withdrawn and diluted as appropriate for HPLC and TLC analysis. HPLC was carried out in accordance with TM GE.004.V1 (SOPam058). TLC was performed on layers on Silica gel (MN SilG/UV) in accordance with TM GE.002.V1 (SOPam056). [0186] Two further TLC systems were utilised in order to separate degradation products: [0000] a) SilG/UV, stationary phase, hexane/acetone 8/2 v/v mobile phase b) RPC18 stationary phase, acetonitrile/methanol/0.25% aqueous acetic acid 16/7/6 by volume Visualisation of cannabinoids was by Fast Blue B salt. Results and Discussion: [0187] HPLC quantitative analysis: [0188] The results from the HPLC analysis of samples drawn from the stored, light exposed solutions, are plotted and presented as FIGS. 6 and 6 a (THC before and after charcoal treatment), and FIGS. 7 and 7 a (CBI) before and after charcoal treatment). [0189] It can be seen from FIGS. 6 and 6 a that there are significant improvements to the stability of THC in all solutions, except those stored in the dark (at ambient temperature) and at −20° C. (and hence which are not under photochemical stress). Even storage in amber glass shows an improvement when un-treated extract is compared with charcoal treated extract. This, however, may reflect in an improvement of the thermal stability of the charcoal treated extract. [0190] FIGS. 7 and 7 a present similar data for CBD containing extracts, from which it can be seen that this cannabinoid is significantly more sensitive to the effects of light than is THC. In the absence of charcoal, all exposures, except in amber glass, light excluded (foil) and −20° storage, had degraded to non-detectable levels of CBD before 40 days. This improved to figures of between 42 and 62 days following charcoal treatment. Amber glass protected CBD showed an improvement from ˜38% residual compound at 112 days without charcoal clean up, to approximately 64% at the same time after charcoal treatment. There was also an improvement in the stability of CBD in light excluded solution after charcoal treatment. This can only reflect a reduction in either thermo-oxidative degradation, or a residual photochemical degradation initiated by light (and/or air) during CBME and solution preparation. Thin Layer Chromatography Qualitative Analysis: [0191] The evaluation of the light degraded solutions using thin layer chromatography, used both the existing normal phase system (i.e. Silica stationary phase and hexane/diethyl ether as mobile phase) and two additional systems, capable of resolving more polar or polymeric products formed during the degradation processes. [0192] Thus, chromatography using the hexane/diethyl ether system, showed that for THC by day 112, there was a reduction in the intensity of the THC and secondary CBD spots with all of the colour filtered lights (data not shown). At the same time, there was an increase in the intensity of Fast Blue B staining material running at, or close to, the origin. Foil protected solution exhibited none of these effects. CONCLUSIONS AND RECOMMENDATIONS [0193] Cannabinoids are known to be degraded by a number of natural challenges, viz. light, heat, oxygen, enzymes etc. It is most likely that in an extract of herbal plant material, which has not been subjected to extensive clean-up procedures, that some of these processes may still be able to continue. Paradoxically, it is also likely that the removal of cannabinoids from the presence of any protection agents within the plant tissue, may render the extract more likely to suffer from particular degradation pathways. [0194] Packaging into amber glass vials, conducting formulation manufacture in amber filtered light, and the storage of plant extracts and pharmaceutical formulations at temperatures as low as possible compatible with manufacturing and distribution requirements and patient compliance eliminates, or at least reduces, the effect of light on degradation of cannabinoids. These actions dramatically improved the storage stability of both plant extracts and finished products. [0195] It was interesting to note that CBD appeared to be markedly less stable than THC, when subjected to photochemical stress. This is the opposite of the finding for the relative thermo-oxidative stabilities, in which THC is the less stable. This seems to indicate that, although polymeric degradation products may be the common result of both photochemical and thermo-oxidative degradation, the exact details of the mechanism are not identical for the two processes. [0196] Among the conclusions that can be drawn are the following: [0000] 1] The choice of amber glass for the packaging of the dose solutions provides improved stability, but minor improvements can be made by additional light exclusion measures. 2] The drying process and subsequent extraction and formulation of cannabis extracts should indeed be carried out in low intensity, amber filtered light. 3] Consideration should be given to the blanketing of extracts under an inert atmosphere (e.g. Nitrogen). 4] Clean-up of cannabis extracts by simple charcoal filtration after winterisation, may yield substantial improvements to product shelf-life. [0197] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims. [0198] All references disclosed herein are incorporated by reference in their entirety.

The invention relates to pharmaceutical formulations, and more particularly to formulations containing cannabinoids for administration via a pump action spray. In particular, the invention relates to pharmaceutical formulations, for use in administration of lipophilic medicaments via mucosal surfaces, comprising: at least one lipophilic medicament, a solvent and a co-solvent, wherein the total amount of solvent and co-solvent present in the formulation is greater than 55% wt/wt of the formulation and the formulation is absent of a self emulsifying agent and/or a fluorinated propellant.

RELATED APPLICATIONS [0001] This application claims priority from U.S. provisional application Ser. No. 60/527,737, filed Dec. 8, 2003. FIELD OF THE INVENTION [0002] The present invention relates generally to home entertainment networks. BACKGROUND OF THE INVENTION [0003] Home entertainment systems enable viewers to access entertainment content from several sources, including TV content from cable or satellite, music from CDs, and movies on DVDs and videotape. Also, many systems include personal video recorders (PVR), which enable users to record televised content onto hard disk drives (HDD) for later viewing. [0004] The present invention recognizes that home entertainment systems which provide the above capabilities open avenues to increased functionality, enabling users to do more things than simply view whatever content happens to be broadcast. For instance, PVRs enable viewers to record television programs for later viewing at convenient times, without having to sit through commercials. Advanced digital systems such as DVDs can enable viewers to view non-public content such as home videos and digital pictures. In short, viewers can now select a variety of content from many sources for viewing and copying. [0005] But the variety in content and media type, while opening avenues for more entertainment options, also poses content management challenges. Currently, content in a home entertainment system must be managed media type-by-media type, but this is inconvenient because it forces the user to manage DVD content separately from PVR content, etc. Also, it may be desirable for access speed and convenience reasons to play or store content that is stored on one type of media using a component that is associated with another type of media. For example, as recognized herein it might be desirable to offload content that has been recorded in a PVR to DVD, to free up space on the HDD of the PVR. Or, it might be desirable to transfer music to a PVR HDD from a CD for quick access and vice-versa for storage capacity reasons. Still farther, it might be desired to make several copies of home movies or photographs for friends and family without repeating the copying process for each and every copy sought to be made. SUMMARY OF THE INVENTION [0006] A home entertainment system can include a video monitor and a computer communicating with the video monitor. The system also has a disk changer which holds multiple optical disks. A hard disk drive (HDD) is associated with the computer. Content from the HDD is automatically transferred to at least one optical disk in the disk changer if a predetermined data storage condition in the HDD has been met. [0007] The video monitor can be a TV monitor such as a HDTV monitor, and the computer can include a computer monitor. The optical disks can include CDs and/or DVDs. The computer may be controlled to cause content from plural optical disks to be substantially simultaneously copied onto the HDD, and also to copy content on the HDD onto plural optical disks substantially simultaneously. [0008] In some embodiments the monitor displays a browse disks screen that can be used by a person manipulating a remote control device to scroll through titles of content stored on optical disks in the disk changer. The computer may be connected to the Internet to facilitate (using, e.g., disk IDs) accessing the Internet to download metadata pertaining titles in the disk changer. Also, the monitor can display an index disks screen usable by a person manipulating a remote control device to automatically index content contained in the optical disks in the disk changer. [0009] In another aspect, a home entertainment system includes a TV and a portable computer communicating with the TV and with a disk changer. The system includes means for automatically downloading, from the Internet to the system, metadata pertaining to at least one video content stored on at least one optical disk in the disk changer. [0010] In still another aspect, an entertainment system includes a portable computer and a HDTV wirelessly communicating with the computer. A disk changer also communicates with the computer. The disk changer is configured to hold plural optical disks, at least some of which can be DVDs. A hard disk drive (HDD) also communicates with the computer. [0011] The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which: BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIG. 1 is a block diagram of the present system; [0013] FIG. 2 is a screen shot of the start screen; [0014] FIG. 3 is a screen shot of the browse disk screen; [0015] FIG. 4 is a screen shot of the play DVD screen; [0016] FIG. 5 is a screen shot of the changer utility screen; [0017] FIG. 6 is a screen shot of the index disks screen; [0018] FIG. 7 is a flow chart of overall management logic; [0019] FIG. 8 is a flow chair of the logic for copying optical disk content to HDD; and [0020] FIG. 9 is a flow chart of the logic for copying HDD content to optical disk. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0021] Referring initially to FIG. 1 , a system is shown, generally designated 10 , that includes a television (TV) 12 such as but not limited to a high definition television (HDTV) and a computer 14 . The computer 14 accesses one or more hard disk drives (HDD) 16 . The computer 14 also accesses a disk changer 18 that can include a DVD player and a disk burner 19 and that can hold multiple (e.g., four hundred) optical disks 20 including compact disks (CDs), digital video disks (DVDs), and other types of disks such as Blue Ray disks and super-audio CDs. Input can be provided to the computer 14 by a keyboard 22 and/or a mouse 24 and/or other input device such as a voice recognition device. Also, a remote control device 26 can input commands to the computer 14 and preferably to the TV 12 . The computer 14 can output the display screens. shown below to a computer monitor 28 and to the TV 12 if desired. [0022] As shown in FIG. 1 , the computer 14 can communicate with the Internet 32 , for purposes to be shortly disclosed. The computer 14 can also communicate with a TV content receiver 34 , such as a set-top box or a satellite receiver or a terrestrial TV signal antenna. [0023] In accordance with the present invention, the communication paths can be wired, but more preferably are wireless and more preferably still are radiofrequency (rf) such as Bluetooth paths, so that line-of-sight is not required, although infrared (IR) communication can be used if desired. Accordingly, the computer 14 can include a wireless rf communication module 36 , and both the mouse 24 and keyboard 22 can be wireless. The remote control device 26 also can be wireless, preferably rf wireless. Moreover, the link between the computer 14 and TV 12 can be wireless and can use conventional red-green-blue (RGB) protocols, or the link can use S-video protocols or component connections, or the link can use High Definition Multimedia Interface (HDMI)/Digital Visual Interface (DVI) protocols. While FIG. 1 shows that the computer 14 communicates directly with the TV 12 , it is to be understood that the communication path between the computer 14 and TV 12 alternatively can go through the content receiver 34 , particularly if the content receiver 34 is a set-top box. [0024] While the non-limiting illustration in FIG. 1 shows that the computer 14 can be housed with the disk changer 18 and various other components, it is to be understood that the computer 14 may be housed separately from the disk changer 18 and some of the other components shown in FIG. 1 and still communicate with the disk changer 18 and the other components. In one embodiment, for instance, the computer 14 can be a portable computer such as a PC or laptop computer, and can incorporate the HDD 16 . Or, the HDD 16 may be implemented in a personal video recorder (PVR) that is separate from the computer 14 . As a non-limiting example, the computer 14 can be a Vaio® laptop computer made by Sony Corp. and programmed to undertake the inventive aspects disclosed herein. [0025] Now referring to FIG. 2 , a non-limiting exemplary start-up screen 38 which may be presented upon power-on of the system 10 can be seen. The screen 38 shown in FIG. 2 , like the other screens described further below, can be presented on the TV 12 , or on the monitor 28 , or both. As shown, the start up screen 38 may include a menu of choices from which the user can select by, e.g., manipulating up and down arrows on the remote control device 26 and, when the desired selection is highlighted, depressing an “enter” button on the remote control device 26 . Or, the keyboard 22 and/or mouse 24 of the computer 14 can be used. In either case, the actions discussed below can be controlled by the computer 14 in response to user selections on the screens. [0026] The non-limiting start up screen menu can include a “my TV” selection, which, if selected, causes a TV channel list such as an electronic program guide (EPG) to be displayed from which a user can select a channel for display on the TV 12 . Also, using the “my TV”. selection a user can select a particular program for automatic recording on the HDD 14 for later viewing, i.e., the system 10 can be used to time-shift televised content. [0027] The start up screen 38 shown in FIG. 2 can also include a “my music” selection, which, if selected, causes a list of CDs that might be present in the disk changer 18 to be displayed. Also, music titles that might be stored on the HDD as well as TV channels that play only music can be displayed on the list, so that a user can scroll through both recorded music titles and TV music channels to select a desired title to be played on, e.g., the audio speakers of the TV 12 . If a CD is selected, the DVD player associated with the disk changer 18 can play the selected CD. [0028] Additionally, the start up screen 38 can include a selection to enable the user to select a blank CD or DVD in the changer 18 and create an audio CD or a CD-ROM (or a video DVD or DVD-ROM) and, if desired, define a ROM-defined disk as a drive of the computer 14 . Further, the start up menu can include a “browse disks” selection, described further below in reference to FIG. 3 , a “play disk” selection, described further below in reference to FIG. 4 , a “changer utilities” selection, described further below in reference to FIG. 5 , and an “index disks” selection, described further below in reference to FIG. 6 . System settings can be reviewed by selecting the “settings” selection on the start up screen 38 . [0029] FIG. 3 shows the “browse disks” screen 40 that is displayed when the “browse disks” selection on the start up screen 38 shown in FIG. 2 is selected. As shown, a list of movie titles that are recorded on the DVDs in the disk changer 18 is displayed. For example, the movie “Spiderman” is indicated as being on a DVD in slot # 232 of the DVD changer. Slot # 233 is indicated as being empty, and a DVD bearing the movie “Men in Black” is in slot # 234 . A blank DVD is indicated as being in slot # 235 . FIG. 3 indicates that the user has currently placed the cursor on the line indicating “Men in Black”, slot # 234 . In any case, using the browse disks screen a user can review the contents of each slot in the disk changer 18 . [0030] A play window 42 may also be superimposed on the browse screen 40 . As shown, the play window 42 can include an option to “play”, which if selected causes the highlighted selection in the browse screen 40 to be played by the DVD player of the disk changer 18 for presentation on the TV 12 . Also, an “update” selection can be selected to cause the computer 14 to automatically access metadata from the Internet pertaining to the highlighted title and to store the metadata on the associated DVD using, e.g., the DVD burner 19 . This metadata can include the year and director of the movie, background content/videos, etc. To update the DVD the computer 14 uses the ID of the selected disk and connects to a content provider Web site using, as entering argument, the disk ID. In the case of a selected disk that is a CD, the user can also be presented with a menu choice to copy the content to the HDD 14 . [0031] When the “play DVD” selection is made from the start up screen 38 shown in FIG. 2 , the screen 44 shown in FIG. 4 can be presented. As shown, the screen 44 can include a menu of movie titles on DVDs in the disk changer 18 . No unused changer slots or blank DVDs are shown. A user can scroll through the list (or input the first letter or two of a title to cause the list to jump to that title) and select a title for play. [0032] FIG. 5 shows a non-limiting “changer utility” screen 46 . Using the screen 46 , a user can select “auto rip CD”, which in turn causes a window 48 to be presented from which the user can select a particular audio file format, e.g., ATRAC or MP3. Upon selection of the format and the auto rip function, music files from CDs or DVDs in the disk changer 18 are encoded in the selected format and automatically copied onto the HDD 16 shown in FIG. 1 . If desired, all music files stored on disks in the disk changer 18 can be ripped to the HDD 16 , or only selected files as desired by the user. The “detail settings” selection can be used to define bit rates, folder locations, and other settings. Selecting the “blank disk” selection enables a user to view the format and other settings of blank disks in the disk changer 18 . [0033] An exemplary index disks screen 50 is shown in FIG. 6 . As shown, an auto detect function can be selected, in which the system 10 scans all disks for type (e.g., audio CD, CD-ROM, ATRAC3 CD, MP3 CD, DVD video, DVD-ROM, writable CD, writable DVD) and disk ID. The system 10 correlates the titles and/or disk IDs to the appropriate changer slot numbers. This is recommended for the first time use after the disk changer has been loaded with disks. Also, the system 10 can scan each disk for additional metadata to determine, based on the disk ID, whether any metadata is different from what is indicated by the latest index database as might be accessible on a content provider site on the Internet. If it is, the computer 14 can automatically obtain new metadata, if any, from the Internet in accordance with principles discussed above. Alternatively, the user can select the “manual detect” function, which requires the user to manually enter the slot number and disk ID for each disk that has been loaded into the disk changer 18 . The user can be prompted to make this selection if, for instance, metadata cannot be detected by the system 10 . The detection process may be canceled at any time by the user if the user wants to immediately play content, and periodically the user can be prompted to resume the detection process. [0034] FIG. 7 shows further operational logic of the system 10 in non-limiting flow chart format. Commencing at block 52 the disks 20 are loaded into the disk changer 18 . At block 54 the Internet can be accessed automatically by the computer 14 to obtain disk metadata using, e.g., disk IDs in accordance with principles set forth above. The computer 14 can not only respond to an “auto detect” command from the screen 50 shown in FIG. 6 to do this, but can also periodically obtain metadata from the Internet without any user command. [0035] Block 56 indicates that content, such as televised content, digital photographs, digital home videos, etc. can be received on the HDD 16 . Periodically the computer 14 determines, at decision diamond 58 , whether a predetermined data storage condition in the HDD 14 has been met, and if so the logic moves to block 60 to automatically offload content from the HDD 14 to one or more disks in the disk changer 18 . The data storage condition can be, without limitation, reaching a predetermined fraction of the total capacity of the HDD 14 . [0036] FIGS. 8 and 9 represent some of the functions discussed above. Specifically, block 62 of FIG. 8 indicates that the user can input a command to copy disk content such as audio files to the HDD 14 , with the command being carried out at block 64 for all relevant disks 20 substantially simultaneously. By “substantially simultaneously” is meant that in a single seamless process, all music on all CDs or just those selected by the user can be copied to the HDD 14 by, e.g., multiplexing among the disks 20 . [0037] Block 66 of FIG. 9 indicates that a user can enter a command to offload or to copy content from the HDD 14 to one or more disks 20 . At block 68 the selected HDD files can be copied to any number of disks 20 in the changer 18 substantially simultaneously. For instance, the system 10 permits a user to select a home video file on the HDD 14 , then select a number of disks the user wishes to copy the video to. The video would then be copied to the selected number of disks in the changer 18 . [0038] While the particular MULTIMEDIA HOME NETWORK COMPUTER as herein shown and described in detail is fully capable of attaining the above-described objects of the invention, it is to be understood that it is the presently preferred embodiment of the present invention and is thus representative of the subject matter which is broadly contemplated by the present invention, that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more”. It is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. Absent express definitions herein, claim terms are to be given all ordinary and accustomed meanings that are not irreconcilable with the present specification and file history.

A home entertainment network has a computer with a multi-DVD changer which holds plural DVDs onto which content from an hard disk drive (HDD) can be transferred for storage. Also, DVD content can be ripped to the HDD, and multiple copies of home videos and photographs on the HDD can be made onto several disks simultaneously.

RELATED APPLICATION [0001] This application claims the benefit of priority to U.S. Provisional Application Ser. No. 62/013,131 filed Jun. 17, 2014, which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION [0002] Embodiments of the invention relate generally to semiconductor structures, and particularly to high mobility semiconductor heterostructures. BACKGROUND OF THE INVENTION [0003] Two-dimensional electron gas systems such as quantum wells exhibit quantized electronic states in one dimension and have a step-like density of states. The charge carriers are thus localized in one dimension (i.e., growth direction) and can freely move in the in-plane directions. See U.S. Pat. No. 5,442,221, incorporated herein by reference in its entirety. [0004] Localized charge carriers exhibit high in-plane mobility in a wide charge carrier concentration range, which can be precisely controlled by conventional epitaxial crystal growth. Carrier mobility is limited by carrier scattering mechanisms that are typically dominated by optical phonon scattering, ionized impurity scattering and alloy scattering when alloys containing more than 2 atoms are used—i.e., ternary (3 atoms), quaternary (4 atoms) and quinternary (5 atoms) alloys. See M. Hayne et al. “Remote impurity scattering in modulation-doped GaAs/Al x Ga 1-x As heterojunctions”, Phys. Rev. B ., Vol. 57, No. 23, 1998; and A. K. Saxena, A. R. Adams, “Determination of alloy scattering potential in Ga 1-x Al x As alloys,” J. Appl. Phys ., Vol. 58, 2640, 1985, incorporated herein by reference in their entireties. [0005] Increasing carrier mobilities is a key challenge in semiconductor device fabrication processes. See, e.g., K.-J. Friedland, R. Hey, H. Kostial, R. Klann, and K. Ploog, “New Concept for the reduction of impurity scattering in remotely doped GaAs quantum wells,” Phys. Rev. Lett ., Vol. 77, No. 22, 1996, and U.S. Pat. Nos. 4,912,451; 5,657,189; 7,388,235; and 6,316,124, incorporated herein by reference in their entireties. SUMMARY [0006] In an aspect, some embodiments of the invention include a semiconductor heterostructure including a layer structure. The layer structure has a first charge reservoir layer, a second charge reservoir layer, a third charge reservoir layer, and a fourth charge reservoir layer disposed over a substrate, each charge reservoir layer including a dopant type of, e.g., donors or acceptors. An undoped quantum well layer is disposed between the second and third charge reservoir layers. The first charge reservoir layer is disposed over the substrate, the second charge reservoir layer is disposed over the first charge reservoir layer, the third charge reservoir layer is disposed over the second reservoir layer, and the fourth charge reservoir layer is disposed over the third charge reservoir layer. The first and fourth charge reservoir layers are remote from the quantum well layer, and the second and third charge reservoir layers are proximate the quantum well layer. [0007] One or more of the following features may be included. The second and third charge reservoir layers between which the quantum well layer is disposed include a first type of dopant, an interface between a top surface of the layer structure and air includes a second type of surface states, and the first and second types are different. [0008] A sheet doping density of at least one of the charge reservoir layers remote from the quantum well layer is substantially equal to a surface state sheet density of the layer structure. [0009] At least one of the charge reservoir layers remote from the quantum well layer may include a first type of dopant, an interface between the substrate and the layer structure may include a second type of interface states, and the first type may be different from the second type. A sheet carrier density of the charge reservoir layer disposed closest to the substrate is substantially equal to an interface state sheet density of the interface. [0010] The substrate may be lattice-matched to the layer structure, e.g., the layer structure may include at least one of (AlGaIn)(As)-containing layers disposed on a GaAs substrate and (AlGaIn)(AsP)-containing layers disposed on an InP substrate. [0011] The substrate may not be lattice-matched to the layer structure. The layer structure may include (AlGaIn)(AsSb)-containing layers disposed on a GaAs substrate. [0012] The two charge reservoir layers proximate the quantum well layer may include dopants of the same type at substantially equal concentrations. [0013] The charge reservoir layers remote from the quantum well layer may have a dopant type and concentration that enables the incorporation of a reduced dopant concentration in the two charge reservoir layers proximate the quantum well layer in comparison to a heterostructure without the remote charge reservoir layers, while maintaining constant a carrier concentration in the quantum well layer. [0014] A plurality of layers may be disposed between one of the charge reservoir layers proximate the quantum layer and the charge reservoir layers remote from the quantum well layer. A spacer layer including, e.g., aluminum, may be disposed between one of the charge reservoir layers proximate the quantum well layer and one of the charge reservoir layer remote from the quantum well layer. An upper barrier layer and/or a cap layer may be disposed over the fourth charge reservoir layer. The upper barrier layer comprises aluminum. The cap layer may be substantially free of aluminum. [0015] The quantum well layer may include at least a ternary composition, with the layer structure further including a first binary material layer disposed between the quantum well layer and one of the two proximate charge reservoir layers. A second binary material layer may be disposed between the quantum well layer and the second of the two proximate charge reservoir layers. [0016] An electronic device may include the semiconductor heterostructure. The electronic device may include a magnetic sensor, e.g., a galvano-magnetic sensor. The electronic device may be a transistor, such as a high-electron-mobility transistor, a pseudomorphic high-electron-mobility transistor, or a metal-oxide-semiconductor field effect transistor. [0017] In another aspect, embodiments of the invention include a method for manufacturing a semiconductor heterostructure, the method including forming sequentially a first, a second, a third, and a fourth charge reservoir layer over a substrate, each charge reservoir layer comprising a dopant type, e.g., donors or acceptors. An undoped quantum well layer is formed between the second and third charge reservoir layers. [0018] One or more of the following features may be included. Forming at least one of the charge reservoir layers may include forming a delta-doped layer, e.g., by molecular beam epitaxy or metalorganic chemical vapor deposition. [0019] Forming at least one of the charge reservoir layers may include growing an undoped layer and subsequently doping the undoped layer. The undoped layer may be formed by molecular beam epitaxy or metalorganic chemical vapor deposition. The undoped layer may be doped by ion implantation and/or diffusion. [0020] Forming at least one of the charge reservoir layers may include forming a doped layer by molecular beam epitaxy or metalorganic chemical vapor deposition. [0021] The quantum well layer may be formed between the second and third charge reservoir layers. [0022] A spacer layer may be formed between one of the charge reservoir layers proximate the quantum well layer and one of the charge reservoir layers remote from the quantum well layer. [0023] An upper barrier layer and/or a cap layer is formed over the fourth charge reservoir layer. [0024] In another aspect, embodiments of the invention include a semiconductor heterostructure having a layer structure. The layer structure has a second charge reservoir layer disposed over a substrate, and a third charge reservoir layer disposed over the second charge reservoir layer. A first charge reservoir layer is disposed between the second charge reservoir layer and the substrate; and/or a fourth charge reservoir layer is disposed over the third charge reservoir layer. Each charge reservoir layer includes a dopant type of, e.g., donors or acceptors. An undoped quantum well layer is disposed between the second and third charge reservoir layers. [0025] In another aspect, embodiments of the invention include a semiconductor heterostructure having a layer structure. The layer structure has a first charge reservoir layer, a second charge reservoir layer and a third charge reservoir layer disposed over a substrate, each charge reservoir layer including a dopant type of, e.g., donors and acceptors. An undoped quantum well layer is disposed between two of the charge reservoir layers. [0026] One or more of the following features may be included. The two charge reservoir layers between which the quantum well layer is disposed include a first type of dopant, an interface between a top surface of the layer structure and air include a second type of surface states, and the first and second types are different. [0027] A sheet doping density of the charge reservoir layer remote from the quantum well layer is substantially equal to a surface state sheet density of the layer structure. [0028] The charge reservoir layer remote from the quantum well layer may include a first type of dopant, an interface between the substrate and the layer structure may include a second type of interface states, and the first type may be different from the second type. A sheet carrier density of the charge reserve layer disposed closest to the substrate is substantially equal to an interface state sheet density of the interface. [0029] The substrate may be lattice-matched to the layer structure, e.g., the layer structure may include (AlGaIn)(As)-containing layers disposed on a GaAs substrate or (AlGaIn) (AsP)-containing layers disposed on an InP substrate. [0030] The substrate may not be lattice-matched to the layer structure. The layer structure may include (AlGaIn)(AsSb)-containing layers disposed on a GaAs substrate. [0031] The two charge reservoir layers proximate the quantum well layer may include dopants of the same type at substantially equal concentrations. [0032] The charge reservoir layer remote from the quantum well layer may have a dopant type and concentration that enables the incorporation of a reduced dopant concentration in the two charge reservoir layers proximate the quantum well layer in comparison to a heterostructure without the remote charge reservoir layer, while maintaining constant a carrier concentration in the quantum well layer. [0033] A plurality of layers may be disposed between one of the charge reservoir layers proximate the quantum layer and the charge reservoir layer remote from the quantum well layer. A spacer layer including, e.g., aluminum, may be disposed between one of the charge reservoir layers proximate the quantum well layer and the charge reservoir layer remote from the quantum well layer. An upper barrier layer and/or a cap layer may be disposed over the third charge reservoir layer. The upper barrier layer may include aluminum. The cap layer may be substantially free of aluminum. [0034] The quantum well layer may include at least a ternary composition, with the layer structure further including a first binary material layer disposed between the quantum well layer and one of the two proximate charge reservoir layers. A second binary material layer may be disposed between the quantum well layer and the second of the two proximate charge layers. [0035] An electronic device may include the semiconductor heterostructure. The electronic device may include a magnetic sensor, e.g., a galvano-magnetic sensor. The electronic device may be a transistor, such as a high-electron-mobility transistor, a pseudomorphic high-electron-mobility transistor, or a metal-oxide-semiconductor field effect transistor. [0036] In another aspect, embodiments of the invention include a method for manufacturing a semiconductor heterostructure, the method including forming sequentially a first, a second, and a third charge reservoir layer over a substrate, each charge reservoir layer comprising a dopant type, e.g., donors or acceptors. An undoped quantum well layer is formed between two of the charge reservoir layers. [0037] One or more of the following features may be included. Forming at least one of the charge reservoir layers may include forming a delta-doped layer, e.g., by molecular beam epitaxy or metalorganic chemical vapor deposition. [0038] Forming at least one of the charge reservoir layers may include growing an undoped layer and subsequently doping the undoped layer. The undoped layer may be formed by molecular beam epitaxy or metalorganic chemical vapor deposition, and the undoped layer may be formed by ion implantation and/or diffusion. [0039] Forming at least one of the charge reservoir layers may include forming a doped layer by molecular beam epitaxy or metalorganic chemical vapor deposition. [0040] The quantum well layer may be formed between the first and second charge reservoir layers. Alternatively, the quantum well layer may be formed between the second and third charge reservoir layers. [0041] A spacer layer may be formed between one of the charge reservoir layers proximate the quantum well layer and the charge reservoir layer remote from the quantum well layer. [0042] An upper barrier layer and/or a cap layer may be formed over the third charge reservoir layer. BRIEF DESCRIPTION OF DRAWINGS [0043] FIGS. 1 , 2 , and 5 are schematic cross-sectional diagrams illustrating exemplary heterostructures having four charge reservoir layers in accordance with embodiments of the invention; [0044] FIGS. 3 a and 3 b are graphs illustrating band structures for a structure with two charge layers in accordance with the prior art, and the structure of FIG. 2 with four charge layers, respectively; [0045] FIG. 4 is a graph illustrating experimental room-temperature electron mobilities attained in accordance with an embodiment of the invention having four charge reservoir layers and with a prior art structure with two charge reservoir layers; [0046] FIGS. 6 a and 6 b are graphs of experimental data obtained for a metamorphic high-mobility structure, in which FIG. 6 a is a plot of carrier mobility vs. carrier concentration in the remote first charge reservoir layer and FIG. 6 b is a plot of carrier concentration in the quantum well vs. carrier concentration in the remote first charge layer, with trap states at the substrate interface being dominant; and [0047] FIGS. 7 a and 7 b are schematic diagrams, top view and cross section respectively, illustrating a Hall effect sensor incorporating a high-mobility semiconductor heterostructure in accordance with an embodiment of the invention. DETAILED DESCRIPTION [0048] Embodiments of the invention include a structure that reduces the effect of ionized impurity scattering and, in certain cases, alloy scattering mechanisms. The described structure and method of manufacturing enable the achievement of high charge carrier mobility in a wide carrier concentration range in a reproducible and controlled way in both lattice-matched material systems as well as strongly mismatched systems, i.e., metamorphic systems in which thick buffer layers act as virtual substrates. [0049] High-mobility semiconductor heterostructures typically include at least one low-bandgap layer embedded between two higher bandgap materials, forming a quantum well with a two-dimensional electron gas (2DEG), a two-dimensional hole gas (2DHG), or a type I quantum well with two-dimensional electron/hole carrier gas. For maximum performance in terms of mobility, the charge carriers are supplied by introducing impurities into one or both of the surrounding high-bandgap layers to reduce the 2DEG scattering by ionized impurity atoms. For optimal performance, the 2DEG resides in the ground state of the quantum well. The wavefunction is preferably kept symmetric to reduce the overlap with the surrounding materials and remote ionized impurities. However, due to interface effects, such as surface depletion or carrier enrichment due to a relaxed substrate/layer stack interface, or trap states associated with the substrate/epitaxial layer interface, attaining a symmetric wavefunction may be difficult to achieve. [0050] Some embodiments of the invention include charge layers that are remote from the quantum well and are doped to compensate the interface effect. In the case of surface depletion, one charge layer is preferably positioned remote from the quantum well and closer to the top surface of the semiconductor/air interface. [0051] In particular, referring to FIG. 1 , a semiconductor heterostructure 5 may include a layer structure 7 disposed over a substrate 10 . A first charge reservoir layer 15 , which is a remote charge layer, may be disposed over the substrate 10 . A second charge reservoir layer 25 may be separated from the first charge reservoir layer by a undoped spacer or buffer layer 20 . An undoped quantum well layer 30 may be disposed over the second charge reservoir layer 25 and below third and fourth charge reservoir layers 35 and 45 respectively. [0052] The third charge reservoir layer 35 is disposed over the second charge reservoir layer 25 . The remote charge layers are the first and fourth charge reservoir layers 15 and 45 , i.e., the charge reservoir layers closest to and farthest from the substrate. The presence of the remote charge reservoir layers, i.e., first and fourth charge reservoir layers 15 and 45 , which are doped with impurity atoms (donors or acceptors, typically donors) to a certain concentration (e.g., to at least 10 11 cm −2 ), allows reducing the impurity ion concentration, i.e., donors or acceptors, in the two charge reservoir layers surrounding the quantum well, e.g., the second and third charge reservoir layers 25 and 35 , while maintaining the 2DEG sheet carrier concentration in the quantum well constant. [0053] A specific exemplary structure with four charge layers is shown in FIG. 2 , which depicts an AlGaAs/GaInAs/GaAs lattice-matched high-mobility heterostructure. A comparison of carrier mobilities attained with an experimental structure to mobilities attained with a prior art structure is shown in FIG. 4 . [0054] The high-mobility semiconductor heterostructure can be, for example, realized in a III-V lattice-matched material system, such as (AlGaIn) 1 (As) 1 on a GaAs substrate ( FIG. 2 ), (AlGaIn) 1 (AsP) 1 on an InP substrate or in III-V lattice-mismatched, or a pseudomorphic heterostructure such as (AlGaIn) 1 (AsSb) 1 on a GaAs substrate. In an embodiment in which the epitaxial structure is grown lattice-matched on a GaAs substrate, the Al concentration in the barrier AlGaAs material may be below 40%. For an embodiment lattice-matched with an InP substrate, the Al concentration in the barrier material may not exceed 60%. [0055] A high-mobility semiconductor heterostructure such as the structure depicted in FIG. 2 may be manufactured by conventional epitaxial growth techniques such as molecular beam epitaxy (MBE) or metal-organic chemical vapor deposition (MOCVD)(MOVPE). The growth is carried out on a semi-insulating substrate 10 , including a suitable material, such as II-VI or III-V compounds or group IV elements. In the illustrated example, substrate 10 may be composed of GaAs. A superlattice 12 including a periodic repetition of thin high bandgap and low band gap material pairs is formed over the substrate 10 . The superlattice is preferably sufficiently thick to suppress the propagation of threading dislocations from imperfections in the semi-insulating substrate 10 . A suitable choice of materials for the superlattice may be AlAs as a high bandgap material and GaAs as a low bandgap material, as shown in FIG. 2 . Typically, a superlattice thickness in the range of at least 10-50 nm is sufficient to suppress threading dislocation propagation. [0056] The superlattice layer 12 is followed by a bulk buffer layer 13 , typically composed of a high quality epitaxial material with a bandgap energy higher than that of the quantum well layer 30 . In the exemplary structure illustrated in FIG. 2 , the buffer layer 13 is formed of GaAs. The bulk buffer layer 13 is preferably sufficiently thick to allow a dislocation-free surface, and as thin as possible (to reduce growth time) while allowing a dislocation-free surface, e.g., between 50 nm-1000 nm. The lower buffer layer 13 is followed by growth of high-bandgap material lower barrier layer 14 , typically Al-containing alloy (AlGaIn) 1 (AsSb) 1 , with the Al concentration in the alloy being non-zero and chosen to facilitate proper electron confinement in the narrow bandgap quantum well. This layer may be AlGaAs, lattice matched to the GaAs substrate 10 . In an embodiment, a thickness of this layer is at least 1 nm, e.g., about 10 nm. [0057] After the desired thickness of lower barrier layer 14 is attained, growth is interrupted and the wafer surface is exposed only to the dopant atoms, forming a 2D layer of impurity atoms of the desired type, typically n-type, to form the first remote charge reservoir layer 15 . In some embodiments, a thickness of this 2D delta-doping layer is less than 1 monolayer. For example, the first charge reservoir layer 15 may be delta-doped with silicon atoms, acting as a donor type impurity Since electrons have a greater mobility than holes, n-type material is typically preferable for high-mobility structures, with donor-type impurities. Alternatively, the first charge reservoir layer 15 may be formed by depositing a suitable compound layer, e.g., a III-V layer such as GaAs, and then implanting impurity atoms, e.g., n-type dopants such as silicon. In embodiments in which the first charge reservoir layer is formed of a bulk layer, a thickness of this layer is preferably greater than 1 monolayer, e.g., several nanometers. [0058] Formation of first charge reservoir layer 15 may be followed by growth of a high bandgap spacer layer 20 , which typically has the same composition as the lower barrier layer 14 . The purpose of spacer layer 16 is to physically separate the first charge reservoir layer 15 from the second charge reservoir layer 25 , which acts as a charge supply layer to the quantum well layer 30 . The second charge reservoir layer is again physically separated from the quantum well by including a high bandgap spacer layer 26 , which in this example is again AlGaAs. This minimizes electron wavefunction overlap with ionized impurity atoms, resulting in less scattering. A quantum well thickness may be selected from a range of at least a few monolayers (at least 1 nm), up to 30 nm. A thickness of the spacer layer may be at least 1 nm, e.g., 5 nm. [0059] In the exemplary structure depicted in FIG. 2 , the undoped quantum well layer 30 may be composed of a ternary material such as (GaIn) 1 As 1 . In case of use of ternary quantum well material, in which both gallium and indium concentrations are non-zero, alloy scattering may be present and limit the maximum carrier mobility, and is enhanced at the interface between the high-bandgap Al-containing layer 26 , where a quaternary AlGaInAs interface is present. [0060] To avoid excess scattering at the interfaces, first and second binary material insert layers 27 a , 27 b , for example GaAs, can be embedded between spacer layer 26 and quantum well layer 30 and between quantum well layer 30 and spacer layer 31 , respectively. The thicknesses of the lattice matched first and second binary insert 27 a , 27 b and the spacer layer 26 together are preferably sufficient to confine the exponential tail of the electronic wavefunction in the ground state of the quantum well. A combined thickness of these layers of a few to ten monolayers may be sufficient [0061] After the quantum well layer 30 is grown, a second binary material insert layer 27 b is formed, followed by the growth of a high bandgap spacer layer 31 . The spacer layer 21 may be formed from a group III-containing material, such as an Al-containing material. For improved performance the thickness of the first binary material insert layer 27 a is preferably the same as that of binary insert layer 27 b , and the spacer layer 26 thickness is preferably the same as that of spacer layer 31 . [0062] A symmetric potential is desired due to the symmetric nature of the electronic wavefunction in the ground state of the quantum well. Accordingly, the growth of the second spacer layer 31 is followed by the addition of a third delta-doped charge reservoir layer 35 , which, ideally has the same impurity (i.e., dopant) type and concentration as the second charge reservoir layer 25 to induce a symmetric potential. Both of these charge layers serve as charge supply layer for the quantum well. In some embodiments, doping concentrations of the two charge supply layers may be selected from a range of 10 11 cm −2 -10 13 cm −2 . [0063] To counteract the surface depletion effect and to avoid the addition of excess donor atoms, additional functional layers may be added to the conventional high-mobility heterostructure, i.e., structures with only two charge reservoir layers. In particular, after the third charge reservoir layer 35 is formed, the high-bandgap material layer 40 , e.g., an Al-containing material such as AlGaAs, may continue to be grown, followed by a fourth charge reservoir layer 45 , which may be a Si-delta doped charge layer, with sheet donor concentration subsequently equal to the surface trap state sheet density. The intermediate spacer layer 40 may be sufficiently thick to decouple the third charge reservoir layer 35 and fourth charge reservoir layer 45 . Typically, a thickness in the range of 10-1000 nm is sufficient. The fourth charge reservoir layer may be capped with a high-bandgap Al-containing upper barrier layer 46 , followed by an Al-free capping layer 47 , typically binary GaAs or ternary InGaAs, to avoid surface oxidation. The upper barrier layer 46 typically has a thickness of 10-50 nm, and a thickness of the capping layer 47 can range from few nm to 10 nm. [0064] The structure with four charge reservoir layers described herein allows decoupling the inclusion of a desired carrier density in the quantum well layer and the compensation of the surface and substrate trap states to avoid the surface/epitaxial layer or substrate/epitaxial layer interface depletion or carrier enrichment. [0065] FIG. 3 a is a graph of a simulated conduction band structure for a conventional high-mobility semiconductor heterostructure with two charge layers, and FIG. 3 b is a graph of a simulated conduction band structure for a high-mobility semiconductor heterostructure having four charge reservoir layers, in accordance with embodiments of the invention. For band diagram simulations, material parameters, bandgap energies and conduction and valence band offsets together with doping concentration were used as input parameters. Both type of structures were realized experimentally with different 2D electron densities in the quantum wells. Mobility data for experimental structures is presented in FIG. 4 . [0066] In fabricated structures, surface depletion, which is a result of Fermi level pinning at the surface layer of the structure, may lead to a carrier depletion in the quantum well layer. In the (AlGaIn) 1 (As) 1 case illustrated in FIG. 2 , the surface states are acceptor type. Thus an increase in the donor concentration in the third charge reservoir layer 35 is necessary to compensate for carrier depletion in the quantum well layer. However, the addition of donor atoms may lead to an increase in ionized impurity ion concentration, which in turn increases the rate of carrier scattering by ionized impurities and limits the maximum mobility. Moreover, the potential becomes asymmetric and induces the asymmetry in the wavefunction of the ground state, leading to a larger penetration of the wavefunction into the spacer layer 31 ( FIG. 3 a ) where excess scattering by ionized impurity atoms in layer 35 occurs and limits the maximum carrier mobility. To counteract the asymmetry of the potential and the excess donor ions, embodiments of the invention include a fourth charge reservoir layer 45 , positioned remote from the quantum well layer and closer to the surface interface ( FIG. 3 b ). [0067] The impurity sheet carrier concentration of the remote charge layer is preferably kept substantially equal to the sheet density of the surface states at the top layer/air interface. The presence of the remote charge reservoir layer allows the realization of a symmetric charge supply from the two charge layers surrounding the quantum well layer and a more symmetric potential of the 2DEG ground state ( FIG. 3 b ), compared to a typical prior art structure in which only two charge layers are used ( FIG. 3 a ). In the prior art case, to compensate for the surface depletion, the second charge layer 35 grown above the quantum well layer is typically doped much more (e.g., 2-4 times more) than the first charge reservoir layer 25 . Moreover, the third and fourth remote charge layers 15 and 45 , disclosed herein, are not present in conventional heterostructures. This leads to asymmetric potential of the quantum well and larger overlap of the 2DEG wavefunction with the barrier material and the ionized impurity atoms in the surrounding charge layers ( FIG. 3 a ). This results in increased 2DEG scattering rate and lower mobility. [0068] In summary, ideally, in a semiconductor heterostructure containing a quantum well, the lowest energy state for the charge carriers is the ground state of the quantum well. Thus, if one were to aim for a structure with a desired carrier concentration N in the quantum well, it would be reasonable to dope the two surrounding charge layers with dopant ion concentration of N/2 each for a symmetric charge supply and potential around the quantum well. [0069] However, in actually fabricated devices, interface effects play a role. Accordingly, in the case of surface depletion, the Fermi level becomes pinned close to midgap due to surface states, leading to charge extraction from the two charge supply layers surrounding the quantum well, and in turn, to an asymmetric potential for the ground state in the quantum well. At the same time, substrate/heterostructure interface trap states can either deplete or enrich the quantum well with carriers, depending on the trap state type. This results in a carrier concentration in the quantum well being less or more than the desired N. In prior art cases, to overcome surface depletion, one of the two charge supply layers are doped substantially higher to compensate for the carrier extraction, while maintaining a constant carrier concentration in the quantum well (desired N). However, this may lead to excess impurity ions, with excess scattering and lower mobility. [0070] If, in accordance with embodiments of the invention, one or more remote charge layer are present (i.e., formed during the crystal growth process), they immediately compensate for the Fermi level pinning, maintain a symmetric potential for the quantum well, and allow doping of the two charge supply layers to N/2 each and compensate for surface and substrate interface trap induced effects. EXAMPLES Example 1 [0071] if the surface state sheet density is 10 12 cm −2 , then to achieve the carrier concentration of 10 12 cm −2 in the quantum well, the second charge reservoir layer 25 is preferably doped 5×10 11 cm −2 and the third charge reservoir layer 35 is preferably intentionally doped at least 1.5×10 12 cm −2 , which is a factor of 3 higher than the required nominal doping, meaning that also the number of ionized impurity scattering centers is a factor of 3 higher. Example 2 [0072] If this concept is applied to the example discussed for the dual charge reservoir structure, then to achieve the 2D carrier density in the quantum well of 10 12 cm −2 , it is sufficient to dope the second charge reservoir layer 25 and the third charge reservoir layer 35 with donor concentration of 0.5×10 12 cm −2 each, and dope the fourth charge reservoir layer 45 with donor concentration of 10 12 cm −2 to fully compensate the surface states. This allows the achievement of a fully symmetric potential as well as the reduction in scattering centers due to ionized impurity ions by a factor of 3. In turn, once the surface states are fully compensated by the inclusion of third charge reservoir layer 35 , the carrier concentration in the quantum well layer can be precisely controlled by adjusting the doping level in the second and third charge reservoir layers 25 , 35 . Depending on the materials used for the fabricated semiconductor heterostructure and the quality of the substrate/heterostructure interface, the first remote charge reservoir layer is doped in accordance with the trap state density resulting from the interface. This can be adjusted experimentally, and can be as low as 0.5×10 11 cm −2 for a good quality interface and as high as 5×10 12 cm −2 for a pseudomorphic relaxed interface. [0073] FIG. 4 illustrates experimental room-temperature mobility data as a function of 2D electron density in the quantum well for a prior art structure with two charge layers, and for a structure having additional remote charge layers, i.e., a total of four charge layers, in accordance with embodiments of the invention. Here, the experimental high-mobility heterostructure with four charge layers was formed from lattice-matched GaAs/AlGaAs/GaInAs materials, and the predominant interface effect is carrier depletion due to surface trap states that are compensated with the top remote charge reservoir layer. The remote bottom charge reservoir layer is kept at an order of magnitude lower doping density. However, a completely opposite behavior can be observed with pseudomorphic high-mobility heterostructures. In structures where a quantum well material has a lattice constant different from the lattice constant of the substrate material and lattice-matched growth is not possible, strongly mismatched metamorphic growth can be used. Such growth conditions lead to a completely relaxed interface between the substrate and the layer structure. An example of a metamorphic structure is a layer structure with an InAs or InSb quantum well grown on a GaAs substrate. Metamorphic structures may provide the advantage of using very high-mobility materials such as for example InAs or InSb on commercially available, low-cost substrates such as GaAs. [0074] It is clearly demonstrated that once the symmetry of the potential is maintained, and the number of ionized donor atoms is kept low, the carrier mobility is kept high regardless of carrier concentration in the quantum well for a wide concentration range. In particular, as can be seen from FIG. 4 , a structure with four charge reservoir layers provides a carrier mobility nearly twice the value attained with a conventional two charge reservoir layer high-mobility structure. The structures in which the carrier mobilities in FIG. 4 were measured are experimental versions of the simulated structures having the conduction band structures shown in FIGS. 3 a and 3 b . The experimental four charge reservoir layer structure is identical to the structure shown in FIG. 2 and the conventional two charge layer structure is also identical to the structure of FIG. 2 , other than for the fact that the remote charge layers 15 and 45 are omitted. The advantage of four charge reservoir layer structure is that the electron density in the quantum well is defined only by the doping density in the two surrounding charge layers, which, when doped with an equal impurity concentration, maintain a symmetric wavefunction and minimize excess scattering by ionized impurities in the barrier layers due to minimal wavefunction penetration. [0075] FIG. 5 illustrates an exemplary embodiment of the invention in which metamorphic growth is used. Referring also to the general schematic of a semiconductor heterostructure of FIG. 1 , relaxed interface 101 b is defined between substrate 10 and the layer structure 7 . In this embodiment, the lattice constant of the layer structure 7 differs significantly from the lattice constant of the substrate 10 . Accordingly, the large lattice mismatch may lead to the formation of threading dislocations that may propagate into the layer structure. Depending on the material of layer structure 7 , threading dislocations at the interface 101 b result in interface trap states due to antisite defects that can be acceptor-like (for example when the layers above the interface 101 b are gallium-rich, aluminum-rich or both gallium and aluminum-rich, i.e. gallium antimonide, aluminum antimonide, aluminum gallium antimonide) or donor-like (indium-rich layer structure 7 , for example InGaAs, InAs, etc.). Such interface states modify the carrier concentration in the quantum well layer by either depleting or enriching with carriers, depending on the interface state type. [0076] To improve the layer quality by reducing threading dislocation densities, a buffer layer thicker than typically used in lattice-matched structures may be preferred. [0077] A typical example of a metamorphic high-mobility semiconductor heterostructure is given in FIG. 5 and experimental data for carrier mobility and carrier concentration in the quantum well as a function of charge concentration in the remote bottom charge layer is given in FIGS. 6 a and 6 b . The structure in FIG. 5 may be manufactured by conventional epitaxial crystal growth technique such as molecular beam epitaxy or metal-organic vapor phase epitaxy. A plurality of buffer layers may be formed on a semi-insulating substrate 10 , such as GaAs. The thickness and composition of the buffer layers may be determined by one skilled in the art. In this particular example, the first buffer layer 11 is lattice-matched to the substrate, and may be, for example, GaAs, with a thickness selected from a range of at least 10 nm-several 100s nm, followed by the formation of a high-bandgap lattice-matched material 12, such as AlAs, which may be at least 10 nm thick, e.g., 100 nm. The high-bandgap buffer layer 12 is used as nucleation layer for the following high-bandgap, lattice-mismatched buffer layer 13 , for example AlSb. AlSb grows favorably on AlAs and metamorphic interface results in lower density of dislocations. See, e.g., G. Tuttle, H. Kroemer, J. H. English, “Effects of interface layer sequencing on the transport properties of InAs/AlSb quantum wells: evidence for antisite donors at the InAs/AlSb interface,” J. Appl. Phys., 67, 3032 (1990), incorporated herein by reference in its entirety. [0078] A thick buffer layer 14 is grown on lattice-mismatched buffer layer 13 . The thick buffer layer 14 has a lattice constant of the desired virtual substrate, for instance GaSb as in FIG. 5 . This layer is preferably sufficiently thick to minimize threading dislocation propagation but at the same time as thin as possible to minimize growth time. An appropriate thickness of the virtual substrate, i.e., of the thick buffer layer, depends on exact growth conditions, and may range from at least 50 nm to a several hundred nm. [0079] Due to a metamorphic nature of the structure, the antisite defects created by threading dislocations result in p-type background impurities in the GaSb buffer layer 14 and n-type impurities in the InAs quantum well layer 30 as shown in the exemplary structure of FIG. 5 . This leads to excess carrier concentration in the quantum well layer and, in turn, a decrease in mobility. To counteract this effect, a first remote charge reservoir layer 15 is included, which can be either bulk or delta-doped with impurities of the type opposite to that of the interface states due to antisite defect formation. In the structure shown in FIG. 5 the remote charge reservoir layer 15 is delta-doped with tellurium, acting as a donor in GaSb and AlSb. The impurity concentration in remote charge reservoir layer 15 is preferably substantially equal to the interface trap state density. An exact carrier density resulting from the interface strongly depends on actual growth conditions. In some embodiments, the carrier density is at least 10 15 cm −3 and may be as high as 10 18 cm −3 . [0080] Formation of the first charge reservoir layer 15 is followed by growth of a high-bandgap spacer layer 20 , which physically separates the remote bottom charge reservoir layer 15 from the second charge reservoir layer 25 . The second charge reservoir layer is grown on top of the spacer layer and is delta-doped with impurities and acts as a charge supply layer to the quantum well layer 30 . For highest carrier mobility, donor type of impurities are preferred, for example Te. The thickness of the high-bandgap spacer layer 20 may be selected from a range of 1 nm-several hundred nm; a few tens of nm is typically sufficient. In between the quantum well and the second charge layer 25 , a thin high bandgap spacer layer 26 may be formed that acts as a barrier to the quantum well and physically separates the electrons from ionized impurity atoms in the charge reservoir layer 25 . The spacer layer 26 is preferably sufficiently thick to minimize the 2DEG wavefunction overlap with the donor ions in layer 25 . Depending on the structure, the spacer may be at least 1 nm thick, e.g., 5-10 nm. An example of a suitable high-bandgap material for both spacer and barrier layers is AlSb. [0081] The quantum well layer 30 may be formed from low-bandgap material with a low-effective mass and as high a carrier mobility as possible, e.g., a binary or a ternary material. A good choice for the quantum well is indium arsenide. Since the ground state of the quantum well has a symmetric wavefunction, a symmetric potential of the quantum well is desirable. For this purpose the growth of the quantum well is followed by growing an upper spacer layer 31 , identical to the spacer layer 26 , which is then followed by adding a third charge reservoir layer 35 , which acts as a second charge supply layer to the quantum well layer 30 . The thickness of the quantum well may be chosen such that the wavefunction of the 2DEG ground state does not penetrate the surrounding barrier materials of the spacer layer 26 and upper spacer layer 31 . If the substrate interface trap states are compensated by the remote first charge reservoir layer 15 , the donor concentration in the third charge reservoir layer 35 is kept substantially the same as in second charge layer 25 , providing symmetric potential and charge supply in the same manner as in the lattice-matched case. [0082] Formation of the third charge reservoir layer 35 may be followed by growth of the high-bandgap spacer layer 40 , which typically includes a high bandgap material, preferably of the same composition as the spacer layers 26 , 31 , e.g., AlSb. The upper spacer layer 40 acts as a barrier to the quantum well, i.e., provides confinement in the growth direction for the 2 dimensional electron gas (2DEG) carriers. Keeping the composition of the upper barrier layer 40 the same as that of the high-bandgap first barrier layer 20 is simpler from a manufacturing standpoint, as well as also ensuring a symmetric potential for the 2DEG. The upper spacer layer is followed by growth of the fourth charge reservoir layer 45 , which is the top remote charge layer. The role of the fourth charge reservoir layer 45 is to compensate the surface (typically, air)-semiconductor interface trap states in the same way as is explained in the lattice-matched high-mobility semiconductor heterostructure case. [0083] The structure may be finalized with a layer of high bandgap cladding material such as AlSb 46 , followed by a lower bandgap, aluminum-free cap layer 47 , which is preferably thick enough to provide proper passivation of the layer structure to avoid oxidation, e.g., at least 1 nm thick. To avoid rapid oxidation, the cap layer 47 may be made from an aluminum-free material, such as GaSb. [0084] Referring to FIGS. 6 a and 6 b , a maximum mobility is reached when the remote charge reservoir layer carrier concentration is substantially equal to the carrier density produced by the interface states. The presence of the interface states and the effect of compensation is clearly seen in FIG. 6 b , where carrier concentration in the quantum well is plotted as a function of carrier concentration in the remote charge reservoir layer, e.g., first charge reservoir layer 15 . A clear minimum can be seen at N remote ˜2.8e17 cm −3 . This minimum corresponds to the carrier concentration substantially equal to the substrate/heterostructure interface trap state density due to antisite defect formation by threading dislocations. The doping density of the top remote charge layer was kept at 10e16 cm −3 to take care of the surface effects. Once this situation is reached, a maximum in the carrier mobility is observed ( FIG. 6 a ) and a minimum in the quantum well carrier concentration ( FIG. 6 b ). Further increasing the doping level in the first charge reservoir layer 15 leads to an increase in quantum well carrier concentration and a reduction in mobility due to excess carrier-carrier scattering. In the case where no interface states exist, a monotonic increase of carrier concentration in the quantum well is seen as the doping level in the remote charge reservoir layer 15 increases. In the illustrated case, the interface states resulted in a carrier concentration of ˜2.8e17 cm −3 , corresponding to a carrier mobility of 14 000 cm 2 /Vs. This carrier mobility value is 30% higher in comparison to a prior art case, when the remote charge layer is absent (corresponds to N remote =0 cm −3 in FIG. 6 ). [0085] The heterostructures described above can be used for a variety of device applications such as galvanomagnetic sensors, high-electron-mobility transistors (“HEMTs”), metal-semiconductor field effect transistors (“MESFETs”), and pseudomorphic high-electron-mobility transistors (“pHEMTs”). [0086] An example of a simple galvanomagnetic device, also referred to as a Hall effect sensor, is shown in FIGS. 7 a and 7 b . Here, a planar configuration Hall cross structure with four contacts is realized. A voltage is applied between two diagonally disposed contacts, for example contacts 701 and 703 . In case magnetic field B, perpendicular to the quantum well plane is present, it will result in a voltage drop between the other contact pair, for example contacts 702 and 704 , due to a Hall effect. This voltage drop is typically called the Hall voltage. The magnitude of this voltage is proportional to the strength of the magnetic field, carrier mobility, and carrier concentration. The important device parameter for Hall sensors is the current and voltage sensitivity, which reflects the change in the Hall voltage as a function of the change of the magnetic field strength at a fixed bias voltage or current point. Voltage sensitivity is directly proportional to carrier mobility, whereas current sensitivity is inversely proportional to the carrier concentration. Therefore heterostructures with high-mobility in a wide carrier concentration range are desired for high-sensitivity Hall sensors. [0087] Hall sensors, such as the device shown in FIGS. 7 a (top view) and 7 b (cross section), can be fabricated by realizing a lattice-matched or metamorphic semiconductor heterostructure by epitaxial growth as described in detail above. The epitaxial wafer, including the substrate and layer structure, is then passivated with a dielectric material, for example silicon dioxide or silicon nitride and spin-coated with photoresist, and contact holes are developed in the photoresist. Using the photoresist layer as a mask, the contact holes are etched into the semiconductor layer structure by wet-chemical or dry etching. The etching preferably stops at the quantum well layer 30 . The etching step is followed with contact hole sidewall passivation, keeping an open area at the bottom of the contact hole by use of photolithography and dielectric etching. Then, non-blocking ohmic contact pads are defined over a dielectric layer with appropriate materials, such as metal, for example TiPtAu or GeAuNiAu, etc. The processing of lattice-matched and metamorphic structure is identical. [0088] The described embodiments of the invention are intended to be merely exemplary and numerous variations and modifications will be apparent to those skilled in the art. For example, many of the illustrative embodiments of charge reservoir layers include n-type dopants, i.e., donors. Other embodiments of the invention may include p-type dopants, i.e., acceptors. A heterostructure may have a single remote charge reservoir layer. All such variations and modifications are intended to be within the scope of the present invention as defined in the appended claims.

A layer structure and method of fabrication of a semiconductor heterostructure containing a two-dimensional electron gas (2DEG), two-dimensional hole gas (2DHG), or a two-dimensional electron/hole gas (2DEHG). The heterostructure contains a quantum well layer with 2DEG, 2DHG, or 2DEHG embedded between two doped charge reservoir layers and at least two remote charge reservoir layers. Such scheme allows reducing the number of scattering ions in the proximity of the quantum well as well a possibility for a symmetric potential for the electron or hole wavefunction in the quantum well, leading to significant improvement in carrier mobility in a broad range of 2DEG or 2DHG concentration in the quantum well. Embodiments of the invention may be applied to the fabrication of galvano-magnetic sensors, HEMT, pHEMT, and MESFET devices.

BACKGROUND OF THE INVENTION I. Field of the Invention This invention relates to monitoring a patient's metabolic need over time, and more particularly to measuring metabolic equivalent (NETS) levels from sensors used in adaptive rate cardiac stimulators including, but not limited to, minute ventilation sensors and accelerometers, whereby patient metabolic equivalent rates and exercise events can be tracked and monitored. II. Description of the Related Art In order to measure metabolic equivalents it has been necessary in the past to measure the oxygen uptake (VO 2 ) of a patient. This is difficult to do, particularly outside of a laboratory setting, in that it is necessary to have the patient equipped with respiratory monitoring devices, such as a breathing mask and sample tube, a gas analyzer, ekg leads, an electronics module for processing the parameters being monitored, etc. Some models of calculating metabolic equivalents are based on the patient's intrinsic heart rate, but chronotropically incompetent pacemaker patients, of course, need a different model. A method is therefore needed to monitor a patient in order to provide a physician with METS data and exertion levels, during the patient's normal living activity, without performing difficult exercise-based, oxygen uptake measurements. The measurements taken are needed to assess the lifestyle, exertion level, exercise capacity, cardiovascular functional capacity, quality of life and wellness of a patient for overall therapy management. A method is also needed for changing the pacing parameters of a pacemaker based on current METS. SUMMARY OF THE INVENTION The invention provides metabolic equivalents data (METS) derived from an accelerometer (XL) and/or minute ventilation sensor (MV) used in rate-responsive pacemakers implanted in patients. Pacemakers commonly used today already have these sensors for providing rate adaption so patients need not be subjected to wearing a breathing mask or other devices to obtain the exertion level data needed to assess their well being. The data collected is presented to a physician to show rates of excursion and exertion levels experienced by a patient using the pacemaker. The physician can then vary the therapy being provided by, for example, adjusting the pacemaker's rate, AV delay or other programmable quantity accordingly. The accelerometer and minute ventilation sensor data obtained by the pacemaker can be stored in memory and a microprocessor can be programmed to manipulate the data into forms useful for the physician. Such useful forms include daily maximum exertion levels, average daily exertion levels, moving average exertion levels, exertion levels above a certain threshold, the number of times per day that the exertion levels are above the threshold and the duration of time above a threshold. The diagnostic reports to the physician can be transmitted to the physician and presented as daily, weekly, monthly or yearly data in graphic or tabular form. The method employed for assessing patient well-being in accordance with the present invention is carried out by implanting in the patient a cardiac rhythm management device having a cardiac depolarization sensor, a physiologic sensor that produces electrical signals proportional to patient activity, a pulse generator for applying stimulating pulses to the heart and a microprocessor-based controller that is coupled to receive the output from the cardiac depolarization sensor along with the electrical signals from the physiologic sensor for producing delta rate signals for the pulse generator. The microprocessor-based controller is equipped with a memory whereby the delta rate signals may be stored for later readout. The microprocessor in the microprocessor based controller, is programmed to compute an average of the stored delta rate signals over a first pre-determined time interval. This average is used as an operand in a linear regression formula whereby a metabolic equivalent (METS) may be computed. In accordance with a further feature of the invention, the physiologic sensor may be one or both of an accelerometer for sensing body motion and a transthoracic impedance sensor from which a minute ventilation signal can be derived. On a daily or weekly basis the maximum METS value and the average MET value for the interval in question can be computed and stored. OBJECTS OF THE INVENTION It is a principal object of the invention to provide a physician with metabolic need, physical activity and lifestyle information about a patient to evaluate the pacing parameters for the patient. It is another object of the invention to measure and record maximal and average METS for various time periods. It is yet another object of the invention to provide a method and apparatus for recording maximal MET, average MET, exercise frequency, and duration for storage whereby trended daily or weekly variations can be followed. It is a further object of the invention to provide ambulatory activity monitoring and assessment in pacemaker patients, especially those suffering from CHF. It is an object of the invention to improve management of pacing therapy. It is an object of the invention to optimize rate responsive pacing. It is still another object of the invention to change pacing therapy based on the MET measurements automatically. It is an object of the invention to determine a patient's exertion level and exercise capacity. It is also an object of the invention to monitor a patient to improve his quality of life and wellness. DESCRIPTION OF THE DRAWINGS Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing in which FIG. 1 is a block diagram of an implantable cardiac rhythm management device in which the present invention may be implemented. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 there is illustrated by means of an electrical schematic block diagram the hardware platform whereby the method of the present invention can be carried out. Shown enclosed by a broken line box 10 is an implantable CRM device having dual indifferent electrodes 12 and 14 disposed thereon. The electrode 12 may comprise an uninsulated portion of the metal (titanium) hermetically sealed housing while electrode 14 may be disposed on the device's header. The CRM device 10 is adapted to be coupled to a patient's heart via an electrical lead assembly 16 comprising an elongated flexible plastic tubular body member 18 having a distal tip electrode 20 and a ring electrode 22 affixed to the surface thereof. Extending the length of the lead are electrical conductors 24 that connect through electrical contacts in the lead barrel to the internal circuitry of the CRM device. Contained within the hermetically sealed housing is a R-wave sensing amplifier 26 which picks up and amplifies ventricular depolarization signals picked up by the electrode 20 . The output from the sense amplifier is applied as an input to a microprocessor circuit 28 by way of conductor 30 . The microprocessor, following a stored program, provides a control signal on line 32 to a pulse generator 34 whose output signal is applied over one of the conductors 24 to the tip electrode 20 for stimulating and thereby evoking a paced response from the heart. In accordance with the present invention, circuitry is also provided for measuring impedance changes within at least one chamber of the heart due to the influx and outflow of blood. In this regard, there is provided an oscillator 36 which, when activated, produces an alternating current of a predetermined frequency, typically in a range of from about 2000 Hz to 5000 Hz and of an amplitude below about 10 microamperes, which insures that the output from the oscillator will not stimulate heart tissue. This signal is preferably applied between the indifferent electrode 12 on the implanted CRM device and the tip electrode 20 on the lead and comprises an AC carrier signal that is modulated by the influx and outflow blood from the right ventricle. The modulated carrier signal is developed between the ring electrode 22 and the indifferent electrode 14 on the device's header and is amplified by sense amplifier 38 and then demodulated by demodulator circuit 40 to remove the modulating envelope from the carrier. The envelope signal is a measure of instantaneous impedance as a function of time. The impedance vs. time (Z vs. t) is then applied to a signal processing circuit 42 which comprises a peak/valley/zero cross detector. When a zero cross is detected, the circuit 42 calculates the preceding peak-to-valley amplitude and issues an interrupt signal to the microprocessor 28 . Upon receiving this interrupt, the microprocessor fetches the peak-to-valley amplitude from the signal processing circuit 42 and sums the absolute values of the peak-to-valley amplitudes over an eight-second interval. This eight-second sum of the peak-to-valley amplitudes comprises the sensor input that is used in establishing the minute ventilation delta signal fed over line 32 to the pulse generator 34 for adjusting the rate at which the pulse generator issues cardiac stimulating pulses to the heart. The pacemaker 10 also includes an activity sensor in the form of an integrated silicon accelerometer 44 that is bonded to a ceramic circuit board contained within the housing of the CRM device. The accelerometer includes a mass suspended by four leaf spring elements from a frame. The springs each include a piezoresistive element forming the four legs of a Wheatstone bridge which becomes unbalanced from displacement of the mass due to acceleration forces in a direction perpendicular to the frame. To conserve battery power, the Wheatstone bridge is energized in a pulse mode where a predetermined voltage is applied across it for only a short period of time, typically 15 microseconds, and at a repetition rate of about 146 Hz. The raw accelerometer output from device 44 is then amplified by amplifier 46 before being applied to a switched capacitor bandpass filter 48 . The pass band of the filter 48 effectively excludes motion artifacts due to external noise while allowing passage of signal components whose frequencies are related to body motion due to exercise. The output from the bandpass filter 48 is further signal processed by circuit 50 and then converted to a digital quantity by A/D converter 52 before being applied to the microprocessor 28 . The CRM device 10 further includes a telemetry circuit 54 of known construction which allows information stored in the microprocessor's RAM memory banks to be read out transcutaneously to an external monitor 56 for viewing by a medical professional. Moreover, the telemetry link 58 allows programmable operands of the pacemaker to be altered following implantation of the CRM device. One way to measure the activity level of a person is to measure the amount of oxygen the person is consuming. However, as explained above it is difficult to obtain accurate measurement of the amount of oxygen a person consumes unless the person is evaluated with somewhat cumbersome metabolic rate measuring equipment. For people going about their normal activities in a non-laboratory setting, a different method of measuring the person's activity level is required. Metabolic equivalents (METS) are a unit of energy expenditure that is proportional to work load or oxygen uptake (VO 2 ).1METS=3.5 ml/(kg min). At rest, a person uses approximately 1 MET. Walking at 3 miles per hour, a person uses approximately 3.3 METS. Although METS are used in this application for the units of energy expenditure, any units measuring the energy used by the body may be applicable. A pacemaker having an accelerometer and/or a minute ventilation sensor such as that described above, when installed in a patient, can conveniently be used to gather data which can then be used to calculate the metabolic equivalent (MET) in the patient due to patient activity. The data collected by the sensors may be averaged over a period of from about 8 seconds to about 16 seconds. Then the data is converted into MET data using a formula which accurately correlates the minute ventilation and/or the accelerometer data to MET data. Time averaged data over a period of 1 to 5 minutes, or over other time periods, may also be used to provide a running time change comparing MET data in a given time period to the pervious ones. In the present invention the MET level is calculated by the microprocessor solving the following linear equation: MET=ax+b Where a is a conversion factor, b is the resting MET level, which is usually defined as 1, and x is the averaged sensor signal from either the accelerometer sensor XL or from the minute ventilation sensor MV or from a blended or weighted value of these two sensors. In studies conducted on a significant number of patients we have empirically determined that for an accelerometer based rate responsive pacer, the values of a and b should be about 0.0576 and 1 respectively. Hence, the formula for accelerometerbased METS is: XL METS=0.0576 * XL+1 For a pacemaker having a minute ventilation sensor it was found to be preferred to use the value of a as a=0.0172 and the value for b of b=1 to calculate METS such that the formula for minute ventilation derived METS is: MV METS=0.0172 * XL+1 The values used for a and b in the above formulas may change with the type of sensor used, the amplification of the sensor and the placement of the sensor in the body; however, the principle of operation will remain the same. If the patient is on a treadmill, or otherwise has a known walking speed, V, then METS may be calculated as follows: METS=a * XL *V+b In one test sequence performed on a selected number of patients METS was found to be: METS=0.0123* XL * V+1. If the average sensor signal is sampled, for example, every 10 seconds, then there are 6 MET calculations per minute using the above formula. The data from each calculation can be stored for future reference. Of particular interest is data showing the daily maximum MET level, which comprises the maximum activity level sustained by the patient during the day. This information is useful to a physician for setting pacing parameters of the pacemaker for the patient. Also of interest is a daily moving average of MET levels of the patient. This information may also be calculated and stored. The moving average is calculated as the average over the last n number of measurements. For example n may be 50 or 100 to provide a moving average over recent measurements. In order to record exercise events, a 1 to 8 minute moving average and an amplitude threshold may be applied to the sensor signal, such that exercise events are counted and stored. In accordance with the invention, the daily maximum data, daily moving average, 1-8 minute moving average, and exercise events totals and times may be compiled in any combination of useful statistical manner, for daily, weekly, monthly or yearly reports, or for whatever need there is for MET data to aid in the treatment of the patient. The data can be programmed to be reported to the physician or other health care provider in any manner desired to give useful information about the patient's activity levels. The data may be displayed or printed in tabular form, as a graph, a histogram chart, or as a simple listing or data as collected chronologically. The long term history of the MET levels show the patient's activity patterns and the physician may use the data as a diagnostic tool to assess the efficacy of a treatment protocol. The MET data may also be used in a rate adaptive CRM device to automatically adjust the rate of pacing in a pacemaker. The accelerometer data and the minute ventilation data may be combined in a blending algorithm to provide METS values. The microprocessor 10 may be programmed to average received signals from the sensors over a time period of on the order of 8 to 16 seconds, and then to calculate the METS from the signals received, according to the above conversion formula e programmed into the microprocessor. The microprocessor is further programmed to store the data from each MET time period calculation along with the time it occurred and can compare the MET for each time period to determine the daily maximal MET level and then store the value and time thereof in a memory register for later readout. The microprocessor is also preferably programmed to calculate a daily 24 hour moving average MET value and to store that value and the date thereof in a predetermined memory register. For example, the microprocessor may be programmed to calculate a 1 to 8 minute moving average MET value and further, an amplitude threshold can be applied to the XL and/or MV sensor signals to detect when the threshold is exceeded, indicative of exercise events of a given intensity. The microprocessor can also be programmed to count and store the total number of exercise events and the time of occurrence and MET values of each such exercise event. The microprocessor can also be programmed to provide daily, weekly, monthly or yearly reports and average the MET values over any time periods to suit the report data desired by the physician or health care provider to better monitor the patient. The microprocessor may determine minimum averages of exertion during rest periods, and average exertion for the entire day or portions of the day. The maximum and averaged MET levels and exercise frequency data can be retrieved from the pacemaker by telemetry methods well known in the art. The METS data can be presented to the physician or health care provider in various forms including, but not limited to, time charting, graphs and tables. The physician can then use the data to determine what the patient's activity patterns are and to what degree of exertion the patient has reached during an exercise regimen and how frequently the exercise events take place. From this, the physician can then readily determine the degree of wellness of the patient and change the treatment of the patient accordingly. Such treatment may include changes in pacemaker pacing setting, drug delivery, etc. Alternatively the moving average MET values calculated by the pacemaker may be used to adaptively adjust the pacemaker automatically for the activity level currently being experienced by the patient. Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Exertion levels of a patient are measured by monitoring signals from adaptive-rate sensors such as an accelerometer and or a minute ventilation sensor; sensor data is collected for conversion into metabolic equivalent measurements. The data obtained can be used to evaluate patient physical activity levels and can be used to assess the patient's condition and change pacing therapy or other treatments accordingly. An automatic adjustment of the adaptive-rate pacing therapy may be based on the activity levels detected by the metabolic equivalent measurements made by the pacemaker.

FIELD OF THE INVENTION This invention relates generally to image editing, and more particularly to matting. BACKGROUND OF THE INVENTION Matting and compositing are frequently used in image editing, 3D photography, and film production. Matting separates a foreground region from an input image by estimating a color F and an opacity α for each pixel in the image. Compositing blends the extracted foreground into an output image, using the matte, to represent a novel scene. The opacity measures a ‘coverage’ of the foreground region, due to either partial spatial coverage or partial temporal coverage, i.e., motion blur. The set of all opacity values is called the alpha matte, the alpha channel, simply a matte. Matting is described generally by Smith et al., “Blue screen matting, “Proceedings of the 23rd annual conference on Computer graphics and interactive techniques,” ACM Press, pp. 259-268, and U.S. Pat. No. 4,100,569, “Comprehensive electronic compositing system,” issued to Vlahos on Jul. 11, 1978. Conventional matting requires a background with known, constant color, which is referred to as blue screen matting. If a digital camera is used, then a green matte is preferred. Blue screen matting is the predominant technique in the film and broadcast industry. For example, broadcast studios use blue matting for presenting weather reports. The background is a blue screen, and the foreground region includes the weatherman standing in front of the blue screen. The foreground is extracted, and then superimposed onto a weather map so that it appears that the weatherman is actually standing in front of the map. However, blue screen matting is costly and not readily available to casual users. Even production studios would prefer a lower-cost and less intrusive alternative. Rotoscoping permits non-intrusive matting, Fleischer 1917, “Method of producing moving picture cartoons,” U.S. Pat. No. 1,242,674. Rotoscoping involves the manual drawing of a matte boundary on individual frames of a movie. Ideally, one would like to extract a high-quality matte from an image or video with an arbitrary, i.e., unknown, background. This process is known as natural image matting. Recently, there has been substantial progress in this area, Ruzon et al., “Alpha estimation in natural images,” CVPR, vol. 1, pp. 18-25, 2000, Hillman et al., “Alpha channel estimation in high resolution images and image sequences,” Proceedings of IEEE CVPR 2001, IEEE Computer Society, vol. 1, pp. 1063-1068, 2001, Chuang et al., “A bayesian approach to digital matting,” Proceedings of IEEE CVPR 2001, IEEE Computer Society, vol. 2, pp. 264-271, 2001, Chuang et al., “Video matting of complex scenes,” ACM Trans. on Graphics 21, 3, pp. 243-248, July, 2002, and Sun et al, “Poisson matting,” ACM Trans. on Graphics, August 2004. Unfortunately, all of those methods require substantial manual intervention, which becomes prohibitive for long image sequences and for non-professional users. The difficulty arises because matting from a single image is fundamentally under-constrained. The matting problem considers the input image as a composite of a foreground layer F and a background layer B, combined using linear blending of radiance values for a pinhole camera: I p [x,y]=αF +(1−α) B,   (1) where αF is the pre-multiplied image of the foreground regions against a black background, and B is the image of the opaque background in the absence of the foreground. Matting is the inverse problem of solving for the unknown values of variables (α, F r , F g , F b , B r , B g , B b ) given the composite image pixel values (I Pr , I Pg , I Pb ). The ‘P’ subscript denotes that Equation (1) holds only for a pinhole camera, i.e., where the entire scene is in focus. One can approximate a pinhole camera with a very small aperture. Blue screen matting is easier to solve because the background color B is known. It desired to perform matting using non-intrusive techniques. That is, the scene does not need to be modified. It is also desired to perform the matting automatically. Furthermore, it is desired to provided matting for ‘rich’ natural image, i.e., images with a lot of fine, detailed structure, such as outdoor scenes. Most natural image matting methods require manually defined trimaps to determine the distribution of color in the foreground and background regions. A trimap segments an image into background, foreground and unknown pixels. Using the trimaps, those methods estimate likely values of the foreground and background colors of unknown pixels, and use the colors to solve the matting Equation (1). Bayesian matting, and its extension to image sequences, produce the best results in many applications. However, those methods require manually defined trimaps for key frames. This is tedious for a long image sequences. It is desired to provide a method that does not require user intervention, and that can operate in real-time as an image sequence is acquired. The prior art estimation of the color distributions works only when the foreground and background are sufficiently different in a neighborhood of an unknown pixel. It is desired to provide a method that can extract a matte where the foreground and background pixels have substantially similar color distributions. The Poisson matting of Sun et al. 2004 solves a Poisson equation for the matte by assuming that the foreground and background are slowly varying. Their method interacts closely with the user by beginning from a manually constructed trimap. They also provide ‘painting’ tools to correct errors in the matte. A method that acquires pixel-aligned images has been successfully used in other computer graphics and computer vision applications, such as high-dynamic range (HDR) imaging, Debevec and Malik, “Recovering high dynamic range radiance maps from photographs,” Proceedings of the 24th annual conference on Computer graphics and interactive techniques, ACM Press/Addison-Wesley Publishing Co., pp. 369-378, and Branzoi, “Adaptive dynamic range imaging: Optical control of pixel exposures over space and time,” Proceedings of the International Conference on Computer Vision (ICCV), 2003. Another system illuminates a scene with visible light and infrared light. Images of the scene are acquired via a beam splitter. The beam splitter directs the visible to a visible light camera and the infrared light to an infrared camera. That system extracts high-quality mattes from an environment with controlled illumination, Debevec et al., “A lighting reproduction approach to live action compositing,” ACM Trans. on Graphics 21, 3, pp. 547-556, July 2002. Similar systems have been used in film production. However, flooding the background with artificial light is impossible for large natural outdoor scenes illuminated by ambient light. An unassisted, natural video matting system is described by Zitnick et al., “High-quality video view interpolation using a layered representation,” ACM Trans. on Graphics 23, 3, pp. 600-608, 2004. They acquire videos with a horizontal row of eight cameras spaced over about two meters. They measure depth discrepancies from stereo disparity using sophisticated region processing, and then construct a trimap from the depth discrepancies. The actual matting is determined by the Bayesian matting of Chuang et al. However, that method has the view dependent problems that are unavoidable with stereo cameras, e.g., reflections, specular highlights, and occlusions. It is desired to avoid view dependent problems. SUMMARY OF THE INVENTION Matting is a process for extracting a high-quality alpha matte and foreground from an image or a video sequence. Conventional techniques require either a known background, e.g., a blue screen, or extensive manual interaction, e.g., manually specified foreground and background regions. Matting is generally under-constrained, because not enough information is obtained when the images are acquired. The invention provides a system and method for extracting a matte automatically from images of rich, natural scenes illuminated only by ambient light. The invention uses multiple synchronized cameras that are aligned on a single optical axis with a single center of projection. Each camera has the identical view of the scene, but a different depth of field. Alternatively, a single camera can be used to acquire images sequentially at different depths of field. A first image or video, has the camera focused on the background, a second image or video has the camera focused on the foreground, and a third image or video is acquired by a pinhole camera so that the entire scene is in focus. The images are analyzed according to Fourier image formation equations, which are over-constrained and share a single point of view but differ in their plane of focus. We minimize an error in the Fourier image equations. The invention solves the fully dynamic matting problem without manual intervention. Both the foreground and background can have high frequency components and dynamic content. The foreground can resemble the background. The scene can be illuminated only by ambient light. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a system for extracting a matte from images according to the invention; FIG. 2 is a flow diagram of a method for extracting a matte from images according to the invention; and FIG. 3 is a schematic of an optical geometry with different depths of field according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT System Overview FIGS. 1 and 2 shows a system 100 and method 200 according to our invention for automatically extracting a matte 141 from images acquired of a scene 110 including a background region (B) 111 having a background depth of field 131 , and a foreground region (F) 112 having a foreground depth of field 132 . These can be a natural, real word indoor or outdoor scene illuminated only by ambient light. Cameras The images are acquired 210 by a background camera 101 , a foreground camera 102 , and a pinhole camera (P) 103 . The three cameras 101 - 103 are aligned on a single optical axis 160 , sharing a single virtual center of projection, using first and second beam splitters 151 - 152 . Therefore, all cameras have an identical point of view of the scene 110 . The cameras are synchronized and connected to a processor 140 . The foreground and background cameras have relatively large apertures, resulting in small, non-overlapping depths of fields 131 and 132 . That is, the depths of field are substantially disjoint. The pinhole camera has a very small aperture resulting in a large depth of field 133 with the entire scene in focus. The foreground camera produces sharp images for the foreground region within about ½ meter of depth z F of a foreground image plane 162 and defocuses regions farther away. The background camera produces sharp images for the background region with a background plane 161 at a depth z B from about four meters to infinity and defocuses the foreground region, see FIG. 2 . The pinhole camera is nominally focused on the foreground region. It should be noted that other depth of field setting can be used for the foreground and background cameras, depending on the structure of the scene. Alternatively, a single camera can be used to acquire three images sequentially with the different aperture settings. This works for relatively static scenes, or for slowly varying scenes if the frame rate is relatively high or the exposure time is relatively short. In this, the camera is the foreground, background, and pinhole camera as the camera settings are changed in turn. Our cameras respond linearly to incident radiance. We connect each camera to the processor 140 with a separate FireWire bus 142 . The cameras acquire images at 30 frames per second. We equip each camera with a 50 mm lens 104 . The pinhole camera is positioned after the first beam splitter 151 . The aperture of the pinhole camera is f=12. The pinhole camera 103 is focused on the foreground plane 162 , because acquiring a correct matte is more important than correctly reconstructing the background. The foreground and background cameras have f=1.6 apertures and are positioned after the second beam splitter 152 . Although, each camera receive only half the light of the pinhole camera, the relative large apertures acquire a relatively large amount of illumination. Therefore, the exposure for these two cameras 101 - 102 is shorter than the exposure for the pinhole camera. As long as the acquired images are not under-exposed or over-exposed, the color calibration process corrects remaining intensity differences between cameras. Calibration The cameras are calibrated to within a few pixels. Calibration is maintained by software. The optical axes are aligned to eliminate parallax between cameras. Because the focus is different for the different cameras, the acquired images are of different sizes. We correct for this with an affine transformation. We color correct the images by solving a similar problem in color space. Here, the feature points are the colors of an image of a color chart and the affine transformation is a color matrix. We apply color and position correction in real-time to all image sequences. Image Sequences For videos, each camera produces a 640×480×30 fps encoded image sequence. The sequences of images are processed by the processor 140 performing a matte extraction method 200 according to our invention. Method Overview FIG. 2 shows a method 200 for automatically extracting a matte according to the invention. Background, foreground, and pinhole sequence of images (videos) 201 , 202 , 203 , respectively, 303 are acquired 310 of the scene 110 by the cameras 101 - 103 . It should be understood that a single camera can be used as well, acquiring images sequentially at the appropriate different depths of field. The pixels in each pinhole image are classified as either background, foreground, or unknown by matching neighborhoods around the pixel with corresponding neighborhood of pixels in the background and foreground images. The classification constructs 220 a trimap 221 for each pinhole image. An optimization process 230 is applied to the unknown pixels. The optimizer minimizes an error in classifying the unknown pixels as either background or foreground pixels. This produces the matte 104 . Scene Model We model the scene 110 as a textured foreground plane 162 with partial coverage, and an opaque textured background plane 161 . Because the background depth of field is larger than the foreground depth of field, and because there is no parallax between our cameras, the background region with varying depths can still be approximated as a plane for the purpose of matting. We pose matting as an over-constrained optimization problem. For each pixel, there are the seven unknown “scene” values, α, F {r,g,b} , and B {r,g,b} , and nine constraint values I P{r,g,b} , I F{r,g,b} , and I B{r,g,b} from the images I acquired by the cameras. The ‘P’ subscript denotes the pinhole images, the ‘F’ subscript the foreground-focused images, and the ‘B’ subscript the background-focused images. Optimizer We solve Fourier image formation equations by minimizing an error in classifying unknown pixels using the optimizer. To accelerate convergence for our optimizer, we construct 220 the trimaps 221 automatically using depth-from-defocus information, and select initial values that are likely near a true solution for the unknowns of the equations. Initial foreground values F 0 for the optimizer are determined by automatically assigning known foreground colors to unknown regions. Initial background values B 0 are determined by reconstructing occluded areas from neighboring images, and then ‘painting’ into always occluded regions. Initial alpha coverage values α 0 are determined by solving a pinhole compositing equation using F 0 and B 0 . Defocus matting is poorly conditioned when the foreground and background have the same color, when the scene lacks high frequency components, or when the images are under-exposed or over-exposed. To avoid local minima and to stabilize the optimizer in these poorly conditioned areas, we add regularization terms to our optimizer. The core of our optimizer 230 is the error function, which is invoked a few hundred times per image. Therefore, the challenge in solving the defocus matting by optimization is selecting an error function that is efficient to evaluate and easy to differentiate. Our error function is a sum-squared pixel value error between the acquired images and composite images rendered from the unknowns. Evaluating and differentiating the error function naively make the problem intractable. To move towards a global minimum, the optimizer must find the gradient of the error function, i.e., the partial derivatives with respect to each unknown variable. For a 320×240 pixel color image sequence at 30 fps, we need to solve for over 13 million unknowns per second. For instance, numerically evaluating the gradient invokes the error function once for each variable. For our method, this involves rendering three full-resolution images. A very fast ray tracer may be able to render the images in three seconds. That means a single call to the error function also takes three seconds. Therefore, it would take years to optimize a few seconds of video using conventional techniques. Therefore, we approach the minimization as a graphics-specific problem. We symbolically manipulate expressions to avoid numerical computations. Thus, we provide a very fast approximation to the image synthesis problem, which enables us to evaluate the error function in milliseconds. We replace numerical evaluation of the error derivative with a symbolic derivative based on our synthesis equations, described below. Notation We use the following notation to compactly express discrete imaging operations. Monochrome images are 2D matrices that have matching dimensions. Image matrices are multiplied component wise, without a matrix multiplication. A multi-parameter image is sampled across camera parameters, such as, wavelength λ, focus, and time t, as well as pixel location. We represent the multi-parameter image with a 3D or larger matrix, e.g., C[x, y, λ, z, t]. This notation and our matting method extend to images with more than three color samples and to other parameters, such as polarization, sub-pixel position, and exposure. Expressions, such as C[λ, z], where some parameters are missing, denote a sub-matrix containing elements corresponding to all possible values of the unspecified parameters, i.e., x, y, and t. Generally, our equations have the same form in the x and y dimension, so we frequently omit the parameter y. We also omit the z, λ, and t parameters when these parameters do not for a particular equation. A convolution F{circle around (×)}G of an image F and a matrix G has the same size as F. The convolution can be determined by extending edge values of F by half the size of G, so that F is well defined near the edges of F. A disk(r)[x, y] is 1/πr 2 times the partial coverage of the pixel [x, y] by a disk of radius r centered on pixel [0, 0]. If the radius r<½, then the disk becomes a discrete impulse δ[x, y] that is one at [0, 0], and zero elsewhere. Convolution with an impulse is the identity operation, and convolution with a disk is a ‘blur’ of the input image. A vector ‘hat’ (→) above a variable denotes a multi-parameter image ‘unraveled’ into a column vector along its dimensions in order, e.g., {right arrow over (F)}[x+W (( y− 1)+ H (λ−1))]= F[x, y, λ], for an image with W×H pixels and 1-based indexing. This is equivalent to a raster scan order. To distinguish the multi-parameter image vectors from image matrices, elements of the unraveled vectors are referenced by subscripts. Linear algebra operators, such as matrix-vector multiplication, inverse, and transpose operate normally on these vectors. Defocus Composites Equation 1 is the discrete compositing equation for a pinhole camera. We derive an approximate compositing equation for a camera with a non-zero aperture, which differs from a pinhole because some locations appear defocused. In computer graphics, cameras are traditionally simulated with distributed ray tracing. Instead, we instead use Fourier optics, which are well suited to our image-based matting problem. Defocus occurs because the cone of rays from a point in the scene intersects the image plane at a disk called the point spread function (PSF). FIG. 3 shows the optical geometry of the situation giving rise to a PSF with pixel radius r = f 2 ⁢ σ ⁢ # ⁢  z R ⁡ ( z F - f ) z F ⁡ ( z R - f ) - 1  , ( 2 ) where the camera is focused at depth z F , a pixel at a depth z R , # is the f-stop number, f is the focal length, and σ is the width of a pixel. Depths z 300 are positive distances in front of the lens 104 . A single plane of points perpendicular to the lens axis with pinhole image αF has a defocused lens image given by the convolution α{circle around (×)}F disk(r). Adding the background to the scene complicates matters because the background is partly occluded near foreground object borders. Consider a bundle of rays emanating from a partly occluded background to the lens. The light transport along each ray is modulated by the α value, where the ray intersects the foreground plane. Instead of a cone of light reaching the lens from each background point, a cone cut by the image αF reaches the aperture. Therefore, the PSF varies for each point on the background. The PSF is zero for occluded points, a disk for unoccluded points, and a small cut-out of the a image for partly occluded points. We express the PSF values for the following cases. Pinhole When fσ is very small, or # is very large, r is less than half a pixel at both planes and Equation 1 holds. Focused on Background When the background 161 is in focus, the PSF is an impulse, i.e., a zero radius disk with finite integral. Rays in a cone from the background B are still modulated by a disk of (1−α) at the foreground plane, but that disk projects to a single pixel in the final image. Only the average value, and not the shape of the α disk intersected affects the final image. The composition equation is: I B =(α F ){circle around (×)}disk( r F )+(1−α{circle around (×)}disk( r F )) B.   (3) Focused on Foreground When the background is defocused and only the foreground is in focus, the PSF varies along the border of the foreground. Here, the correct image expression is complicated and slow to evaluate, therefore, we use the following approximation: I F ≈αF +(1−α)( B{circle around (×)} disk( r B )),   (4) which blurs the background slightly at foreground borders. A matte is a 2D matrix α[x, y], and the foreground and background images are respectively 3D matrices F[x, y, α] and B[x, y, α]. We generalize the two-plane compositing expression with a function of the scene that varies over two discrete spatial parameters, a discrete wavelength (color channel) parameter λ, and a discrete focus parameter zε{1, 2, 3 }: C(α,F,B)[x,y,λ,z]= ( αF [λ]) {circle around (×)}h[z ]+(1−α{circle around (×)} h[z ])( B[λ]{circle around (×)}g[z ])| [x,y] ,   (5) where 3D matrices h and g encode the PSFs: h ⁡ [ x , y , z ] = { δ ⁡ [ x , y ] , z = 1 disk ( r F ) ⁡ [ x , y ] , z = 2 δ ⁡ [ x , y ] , z = 3 ⁢ ⁢ g ⁡ [ x , y , z ] = { δ ⁡ [ x , y ] , z = 1 δ ⁡ [ x , y ] , z = 2 disk ⁡ ( r B ) ⁡ [ x , y ] , z = 3 . ( 6 , 7 ) Constants r F and r B are the PSF radii for the foreground and background planes when the camera is focused on the opposite plane. Trimap From Defocus The trimap 221 segments the pinhole image into three mutually exclusive and collectively exhaustive regions expressed as sets of pixels. These sets of pixels limit the number of unknown pixels and provide initial estimates for our optimizer 230 . In contrast with the prior art, we construct 220 the trimaps 221 automatically as follows. Areas in the scene that have high-frequency texture produce high-frequency image content in the pinhole image I P , and either in the foreground image I F or the background image I B , but not both. We use this observation to classify pixels into sets of pixels with high-frequency neighborhoods into three regions based on the z values, which appear ‘sharp’. Sets ΩB and ΩF contain pixels that are respectively “definitely background” (α=0) and “definitely foreground” (α=1). Set Ω contains “unknown” pixels that may be either foreground, background, or some blend of foreground and background. This is the set over which we solve for extracting the matte using our optimizer. Many surfaces with uniform macro appearance actually have fine structural elements like the pores and hair on human skin, the grain of wood, and the rough surface of brick. This allows us to detect defocus for many foreground objects even in the absence of strong macro texture. We use lower thresholds to detect high frequency components in the background, where only macro texture is visible. We determine a first classification of the foreground and background regions by measuring a relative strength of the spatial gradients: Let D= disk(max( r F , r B )) Ω F1 =erode(close((|∇ I F |>|∇I B |){circle around (×)} D> 0.6, D )), D ) Ω B1 =erode(close((|∇ I F |<|∇I B |){circle around (×)} D> 0.4, D )), D )   (8,9) where erode and close are morphological operators used to improve accuracy. The disk is approximately the size of the PSFs. Then, we classify the ambiguous locations either in both ′Ω F1 and ′Ω B1 or in neither: Ω={tilde over (Ω)} F1 ∪{tilde over (Ω)} B1 ∪(Ω F1 ∩Ω B1 ).   (10) Finally, we enforce the mutual exclusion property: Ω F =Ω F1 ∩{tilde over (Ω)} Ω B =Ω B1 ∩{tilde over (Ω)}.   (11,12) Minimization Errors in Classifying Unknown Pixels We pose matting as an error minimization problem for each image, and solve the problem independently for each image. Assume we know the approximate depths of the foreground and background planes and all camera parameters. These are reasonable assumptions because digital cameras directly measure their parameters. From the lens to sensor distance we can derive the depths to the planes, if otherwise unknown. The foreground and background need not be perfect planes, they just need to lie within the foreground and background depth fields. Because the depth of field is related hyperbolically to depth, the background depth field can stretch to infinity. Let u=[{right arrow over (α)} T {right arrow over (B)} T {right arrow over (F)} T ] T be the column vector describing the entire scene, i.e., the unknown pixels in the matting problem, and {right arrow over (C)}(u) be the unraveled composition function from Equation 5. The unraveled constraints are {right arrow over (I)}=[{right arrow over (I)} P T {right arrow over (I)} B T {right arrow over (I)} F T ] T . The solution to the matting problem is a scene u* for which the norm of the error vector {right arrow over (E)}(u)={right arrow over (C)}(u)−{right arrow over (I)} is minimized according: Let ⁢ ⁢ Q ⁡ ( u ) = ∑ k ⁢ 1 2 ⁢ E → k 2 ⁡ ( u ) ⁢ ⁢ u * = arg ⁢ ⁢ min u ⁢ ⁢ Q ⁡ ( u ) . ( 13 , 14 ) Note that the scalar-valued function Q is quadratic because the function Q contains the terms of the form (α[x]F[i]) 2 . Iterative solvers appropriate for minimizing such a large system evaluate a given scene u and select a new scene u+Δu as a function of the vector {right arrow over (E)}(u), and a Jacobian matrix J(u). The Jacobian matrix contains the partial derivative of each element of the vector with respect to each element of u, J k , n ⁡ ( u ) = ∂ E → k ⁡ ( u ) ∂ u n . ( 15 ) The value k is an index into the unraveled constraints, and the value n is an index into the unraveled unknown array. Henceforth, we write {right arrow over (E)} rather than {right arrow over (E)}(u), and so on, for the other functions of u to simplify the notation in the presence of subscripts. A gradient descent solver moves opposite the gradient of Q: Δ ⁢ ⁢ u = - ∇ Q = - ∇ ⁢ ∑ k ⁢ 1 2 ⁢ E → k 2 ⁢ ⁢ so ⁢ ⁢ Δ ⁢ ⁢ u n = - ∂ ∑ k ⁢ 1 2 ⁢ E → k 2 ∂ u n = - ∑ k ⁢ ( E → k ⁢ ∂ E → k ∂ u n ) ⁢ ⁢ hence ( 16 , 17 ) Δ ⁢ ⁢ u = - E → T ⁢ J . ( 18 ) The gradient descent solver has a space advantage over other methods like Gauss-Newton and Levenberg-Marquardt because the gradient function does not need to determine the pseudo-inverse of the Jacobian matrix J. This is important because the vectors and matrices involved are very large. Let N be the number of unknown pixels and K be the number of constrained pixels. For 320×240 images, the matrix J has about 6×10 9 elements. We now derive a simple expression for the elements of the Jacobian matrix and determine that the matrix is sparse, so determining Δu is feasible when we do not need the non-sparse inverse of the matrix J. By definition, the elements are: J k , n = ∂ ( C → k ⁡ ( u ) - I → k ) ∂ u n = ∂ C → k ⁡ ( u ) ∂ u n . ( 19 ) To evaluate Equation 19, we expand the convolution from Equation 5. We change variables from packed 1D vectors indexed by k to images indexed by C ⁡ [ x , z , λ ] ⁢ ∑ s ⁢ α ⁡ [ s ] ⁢ F ⁡ [ s , λ ] ⁢ h ⁡ [ x - s , z ] + ( 1 - ∑ s ⁢ α ⁡ [ s ] ⁢ h ⁡ [ x - s , z ] ) ⁢ ∑ s ⁢ B ⁡ [ s , λ ] ⁢ g ⁡ [ x - s , z ] . ( 20 ) An examination of this expansion shows that the matrix J is both sparse and simple. For example, consider the case where unknown pixel u n corresponds to F[i,λ]. In a full expansion of Equation 20, only one term contains F[i, λ], so the partial derivative contains only one term: ∂ C ⁡ [ x , λ , z ] ∂ F ⁡ [ i , λ ] = α ⁡ [ i ] ⁢ h ⁡ [ x - i , z ] . ( 21 ) The expressions for the α and B derivatives are only slightly more complicated, with potentially non-zero elements only at: ∂ C ⁡ [ x , λ , z ] ∂ α ⁡ [ i ] = h ⁡ [ x - i , z ] ⁢ ⁢ ( F ⁡ [ i , λ ] - ∑ s ⁢ B ⁡ [ λ , s ] ⁢ ⁢ g ⁡ [ x - s , z ] ) = h ⁡ [ x - i , z ] ⁢ ⁢ ( F ⁡ [ i , λ ] - ( B ⁡ [ λ ] ⊗ g ⁡ [ z ] ) ⁡ [ x ] ) ⁢ ⁢ ∂ C ⁡ [ x , λ , z ] ∂ B ⁡ [ i , λ ] = g ⁡ [ x - i , z ] ⁢ ⁢ ( 1 - ∑ s ⁢ α ⁡ [ s ] ⁢ ⁢ h ⁡ [ x - s , z ] ) ⁢ = g ⁡ [ x - i , z ] ⁢ ⁢ ( 1 - ( α ⊗ h ⁡ [ z ] ) ⁡ [ x ] ) . ( 22 , 23 ) The summations in the last two cases are just elements of convolution terms that appear in {right arrow over (E)}, so there is no additional cost for computing these values. Trust Region and Weights The gradient indicate a direction to change u to reduce the error. We use a so-called dogleg trust region scheme to select the magnitude, see Nocedal and Wright, IEEE PAMI 18, 12, pp. 1186-1198, Springer Verlag. The idea is to take the largest step that decreases the error. We begin with a trust region of radius S=1. Let u′=max(0, min(1, u+(SΔu/|Δu|)). If |{right arrow over (E)}(u′)|<{right arrow over (E)}(u), then, we assume we have not overshot the minimum and repeatedly double S until the error increases above the lowest level seen this iteration. If |{right arrow over (E)}(u′)|<{right arrow over (E)}(u), then we assume we have overshot and take the opposite action, repeatedly halving S until we pass the lowest error in this iteration. If S becomes very small, e.g., 10 −10 or the error norm decreases by less than 0.1%, then we assume that we are at the local minimum and terminate the optimization process. Because our initial estimates are frequently good, we weigh the first N elements of Δu by constant β α =3 to influence the optimizer to take larger steps in α. This speeds convergence without shifting the global minimum. The narrow aperture and long exposure used to acquire the pinhole images produce more noise and motion blur than in the foreground and background images I F and I B . This prevents over-fitting the noise. This also reduces the over-representation in {right arrow over (E)} of in-focus pixels that occurs because image F and B are in focus in two of the constraint images and defocused in one each. Regularization In foreground regions that are low frequency or visually similar to the background, there are many values of u that satisfy the constraints. We bias the optimizer towards likely solutions. This is regularization of the optimization problem, which corresponds to having a different prior probability for a maximum likelihood problem. Regularization also to avoid local minima in the error function and stabilizes the optimizer in regions where the global minimum is in a ‘flat’ region that has many possible solutions. We extend the error vector {right arrow over (E)} with p new entries, each entry corresponding to the magnitude of a 7N-component regularization vector. Calling these regularization vectors ε, φ, γ, . . . , the error function Q now has the form: Q ⁢ ( u ) = ∑ k ⁢ ⁢ E → k ⁢ 2 = [ ∑ k = 1 9 ⁢ K ⁢ E → k 2 ] + E → 9 ⁢ K + 1 2 + E → 9 ⁢ K + 2 2 + … = ∑ k = 1 9 ⁢ K ⁢ E → k 2 + β 1 ⁢ 9 ⁢ K 7 ⁢ N ⁢ ∑ n 7 ⁢ N ⁢ ɛ n 2 + β 2 ⁢ 9 ⁢ K 7 ⁢ N ⁢ ∑ n 7 ⁢ N ⁢ ϕ n 2 + … ( 24 ) The regularization vectors are e. Each summation over n appears as a new row in the error vector {right arrow over (E)} and the matrix J for some k>9K: E -> k = ( β ⁢ 9 ⁢ K 7 ⁢ N ⁢ ∑ n ⁢ e n 2 ) 1 2 ⁢ ⁢ J k , n = ∂ E -> k ∂ u n = β E -> k ⁢ 9 ⁢ K 7 ⁢ N ⁢ ∑ i ⁢ [ e i ⁢ ∂ e i ∂ u n ] . ( 25 , 26 ) The factor 9 ⁢ K 7 ⁢ N makes the regularization magnitude invariant to the ratio of constraints to unknown pixels, and the scaling factor β allows us to control its significance. We select regularization vectors that are both easy to differentiate and efficient to evaluate, i.e., the summations over i generally contain only one non-zero term. Regularization influences the optimizer to the most likely of many solutions supported by the image data, but rarely leads to an unsupported solution. We use small weights on the order of β=0.05 for each term to avoid shifting the global minimum. Coherence The spatial gradients are small, e n = ∂ u n ∂ x ; ( E → T ⁢ J ) n = - ∂ 2 ⁢ u n ∂ x 2 . T ( 27 ) We apply separate coherence terms to α, F, and B, for each color channel and for directions x and y. The alpha gradient constraints are relaxed at edges in the image. The F gradient constraints are increased by a factor of ten, where |∇α| is large. These constraints allow sharp foreground edges and prevent noise in the foreground image F where it is ill-defined. Discrimination The value α is distributed mostly at 0 and 1, e n =u n −u n 2 ;( {right arrow over (E)} T J) n =( u n −u n 2 )(1−2 u n )|1≦ n≦N.   (28) Background Frequencies Should Appear in B: Let ⁢ ⁢ G = I B - I F ⊗ disk ⁡ ( r F ) ⁢ ⁢ e n = ∂ u n ∂ x - ∂ G -> n ∂ x ; ( E -> T ⁢ J ) n = - ∂ 2 ⁢ u n ∂ x 2 ❘ 4 ⁢ N + 1 ≤ 7 ⁢ N . ( 29 ) Other Applications Artificial Depth of Field We can matte a new foreground onto the reconstructed background, but select the point spread functions and transformations arbitrarily. This enables us to render images with virtual depth of field, and even slight translation and zoom. Image Filtering Defocus is not the only effect we can apply when recompositing against the original background image. Any filter can be used to process the foreground and background separately using the matte as a selection region, e.g., hue adjustment, painterly rendering, motion blur, or deblur. Although the invention has been described by way of examples of preferred embodiments, it is to be understood that various other adaptations and modifications may be made within the spirit and scope of the invention. Therefore, it is the object of the appended claims to cover all such variations and modifications as come within the true spirit and scope of the invention.

A method compresses a set of correlated signals by first converting each signal to a sequence of integers, which are further organized as a set of bit-planes. An inverse accumulator is applied to each bit-plane to produce a bit-plane of shifted bits, which are permuted according to a predetermined permutation to produce bit-planes of permuted bits. Each bit-plane of permuted bits is partitioned into a set of blocks of bits. Syndrome bits are generated for each block of bits according to a rate-adaptive base code. Subsequently, the syndrome bits are decompressed in a decoder to recover the original correlated signals.

CROSS REFERENCES TO RELATED APPLICATIONS Not applicable. STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT Not applicable. BACKGROUND OF THE INVENTION The present invention relates to winders in general and to guards to increase the safety of threading or splicing a broken web in particular. Papermaking is a continuous process which can be stopped and started only at considerable expense in time and material which must be recycled. Paper on the other hand is used in rolls often referred to as offsets. As paper is manufactured, it is wound onto a single large roll, sometimes referred to as a jumbo roll. The jumbo roll extends the full width of the papermaking machine, which can be 300 or 400 inches, and can be six to ten or more feet in diameter. These larger rolls are broken down into the smaller rolls used by the printing industry, on a machine referred to as a winder. Large moving rolls of any type have certain inherent dangers, particularly where one roll rides against another to form a nip. An operator's hand can be caught in such a nip drawing the operator into the nip with highly undesirable consequences. To avoid such hazards, the winding of paper into offset rolls is typically effected automatically or semiautomatically by machinery which usually does not require the operator's presence immediately adjacent to the moving rolls which form the winder. However, if a paper break occurs during the winding process, an operator is necessary to remedy the break. Repairing an offset reel of paper involves cutting or slabbing off the outer layers of loosely wound paper, taping a new start to a clean tail formed by the slabbing off process, and restarting the winding process. During the repair of a paper break the operator is working on the paper roll itself and is thus in a position near where the forming paper roll and a winder drum of the winder form a nip. The nip is rendered more hazardous by the fact that the winder drum has an aggressive high friction surface to better engage and cause the paper roll to rotate. This aggressive surface can make it difficult to withdraw an extremity once it enters the nip formed between the winder drum and the offset roll. What is needed is a system which creates a physical barrier between the nip and the operator to provide an additional margin of safety. SUMMARY OF THE INVENTION The winder of this invention has two spaced apart winder drums which support a paper roll. A paper web from a parent roll partially wraps the upstream winder drum and then wraps a roll core to form the paper roll. Both winder drums are driven to cause the paper roll to rotate. The downstream winder drum rotates about a drum axis on drum bearings. A guard is mounted for rotation about the downstream winder drum axis. The guard has two radially extending sector shaped flanges which are spaced inwardly of the drum bearings and to which is mounted a substantially cylindrical shell which forms the body of the guard. Each radially extending flange has a bearing ring, and extends beyond the cylindrical shell. The cylindrical shell has a D-shaped leading edge which approaches the paper roll, the leading edge is articulated so that if the operator's hand becomes wedged between the leading edge and the paper roll articulation on the leading-edge closes the switch which brings the winder to a stop. A hydraulic actuator extends between a lowermost radial edge of each sector shaped extension, and a fixed support. Operation of the hydraulic actuator causes the guard to rotate about the axis of the downstream winder drum so as to be between an operator and the downstream side of the winder drum. The leading edge of the the guard is positioned to limit operator access to the nip formed between the paper roll and the downstream winder drum. Spring loaded disk brakes are positioned to brake upon lower portions of the sector shaped extensions. The brakes can be opened by a hydraulic mechanism but are failsafe in the spring loaded braking configuration. Movement of the guard is controlled from the operator's control booth, or from dual switches positioned on either side of the winder and spaced sufficiently far from the winder so that the operator cannot come in contact with the winder while controlling the position of the guard. A light curtain is positioned so that the operator's hands passes through the light curtain to contact the paper roll. So long as the operator's hands are passing through the light curtain movement of the guard is inhibited. A long linear switch is positioned on the long leg of the a sector shaped member adjacent the blunt leading edge. Actuation of the linear switch causes all motion of the downstream winder drum and the paper roll to stop. The guard's leading edge is positioned approximately 12 to 14 inches from the nip formed between the driven downstream winder drum and the paper roll, after the paper roll reaches a selected diameter. It is a feature of the present invention to provide a winder with a movable guard to increase operator safety while performing a splice. It is a further feature of the present invention to provide a winder with a movable guard which prevents the operator from coming in contact with a nip formed between the downstream winder drum and the paper roll. It is another feature of the present invention to provide a winder with a movable guard which supports a work area for preparing a paper splice. It is a yet further feature of the present invention to provide a winder with a movable guard capable of incorporating a core loader. It is a still further feature of the present invention to provide a winder with a movable guard which can support a bridge for the removal of a wound paper roll. Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of the winder and winder guard of this invention. FIG. 2 is a side elevational view of the winder and winder guard of FIG. 1 with the guard in the full raised position. FIG. 3 is a side elevational view of the winder and winder guard of FIG. 1 with the guard in the fully lowered position. FIG. 4 is a schematic view of the winder of FIG. 1 together with associated control panels. FIG. 5 is an exploded isometric view of the winder guard and downstream winder drum of FIG. 1 . FIG. 6 is a enlarge partial side elevational view of the winder and winder guard of FIG. 1 with the flange extension shown in phantom. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring more particularly to FIGS. 1-5, wherein like numbers refer to similar parts, a winder 20 of the double drum type is shown in FIG. 1 . The winder has a first upstream winder drum 22 , and a second downstream winder drum 24 which support a paper roll 26 . The paper roll 26 forms a first nip 28 with the upstream winder drum 22 and a second downstream nip 30 with the downstream winder drum 24 . A paper web 32 from a jumbo roll or the like (not shown) wraps around the upstream winder drum 22 and onto a roll core 34 about which is formed the paper roll 26 . The downstream winder drum 24 is mounted between drum bearings 36 and is driven through a drive, not shown, about a drum axis 37 . The winder drum 24 has an aggressive surface 38 in order to grip and turn the paper roll 26 . The winder drum 24 may be divided by an imaginary vertical plane 40 passing through the drum axis 37 to define an upstream sector 42 encompassing the upstream half of the drum 24 , and a downstream sector 44 encompassing the downstream half of the drum 24 . When it is necessary to gain access to the forming paper roll 26 for the purpose of repairing a paper break an operator 46 stands downstream of the downstream sector 44 of the downstream winder drum 24 . As indicated by the arrow 48 , the downstream winder drum 24 rotates towards the nip 30 and, because of its aggressive surface 38 , has the potential of drawing the operator's hand 95 into the nip 30 . In order to prevent the operator's hand 95 from being drawn into the nip 30 , the winder 20 employees a guard 50 . As best shown in FIG. 5, the guard 50 comprises a first radially extending sector shaped flange 52 and a second radially extending sector shaped flange 54 which are connected by a substantially semicylindrical shell 56 which blocks operator access to the surface 38 of the downstream winder drum 24 . The first sector shaped flange 52 is mounted to a split ring bearing 58 comprised of a guard side 60 and a mounting side 62 which are joined by bolts 64 . The radially extending sector shaped flange 52 is bolted to the guard side 60 of the split ring bearing 58 . The second radially extending sector shaped flange 54 similarity is mounted to a split ring bearing (not shown). The cylindrical shell 56 extends around approximately one hundred twenty-six degrees of the circumference of the downstream winder drum 24 , the shell 56 is not perfectly cylindrical but spirals inwardly towards the axis 37 about one inch in the lowermost fifty degrees of the semicylindrical shell. The semicylindrical shell 56 is spaced inwardly of the outer edge 70 of the flanges 52 , 54 about 3½ inches, and spaced two to three inches outwardly from the surface 38 of the downstream winder drum 24 . A hinged guard extension 71 constructed of heavy rubber is attached to the trailing edge of the shell 56 . A second outer shell 72 extends from the radially outwardly extending plate 74 and is mounted between and perpendicular to the flanges 52 , 54 . The outer shell 72 wraps approximately eighty degrees of the drum circumference gradually spiraling inwardly to join the shell 56 as shown in FIG. 1 and FIG. 6 . As shown in FIG. 6, a blunt leading edge 76 of about four inches in radial extent, is hingedly mounted to the upper edge 73 of the outer shell 72 by a hinge 75 . The blunt leading edge 76 is semi-cylindrical in shape, and has a backplate 77 which is positioned substantially parallel to the radially outwardly extending plate 74 . The blunt leading edge 76 is arranged to hinge inwardly toward the backplate 77 if the operator's hand 95 or other object gets caught in the gap 92 between the guard 50 and the surface 81 of the paper roll 26 . The articulated motion of the leading edge 76 closes a switch 83 which causes the winder to come to a abrupt stop wherein the guard 50 can be retracted to release the operator's hand 95 . The leading edge 76 is biased and away from the plates 74 by a spring 85 which extends between the backplate 77 through an aperture in the plates 74 to a stop 87 . A bolt 89 is mounted to the backplate 77 through the aperture in the plate 74 and extends through an aperture in the stop 87 . The head 91 of the bolt 89 is held against the stop by the biasing spring 85 . If the leading edge 76 is caused to hinge inwardly, the bolt head 91 moves towards the switch 83 . The switch 83 is mounted to a bracket 93 which is spaced from the stop 87 . The switch 83 is of the magnetic field sensing type and detects the approach of the bolt head 91 and stops all the motion of the winder. The guard 50 is rotated about the drum axis 37 by hydraulic actuators 78 which extend from attachment points 79 on the trailing edges 80 of the flanges 52 , 54 to two fixed supports 82 positioned upstream of the winder drum 24 and below the attachment points 79 . The hydraulic actuators 78 move the guard over a travel range of seventy-five degrees as shown in FIGS. 1, 2 , and 3 , while at all times the guard 50 substantially occupies the downstream sector 44 which presents the possible hazard to the operator 46 . In other words more than half of the downstream sector 44 is always occupied by the guard 50 , and at the same time this means at least 90 degrees of the guard's circumferential extent always remains within the downstream sector 44 . The guard 50 is used when a paper break occurs. While the winder 20 is operating normally, the operator 46 is positioned in front of a control panel 86 which is located a distance from the winder 20 . Upon the detection of a paper break, the operator raises the guard 50 by pressing a switch 88 on the control panel 86 . The blunt leading edge 76 is positioned by the hydraulic actuators 78 one to one-half inches from the paper roll 26 when an operator is present. The position of the guard 50 may be controlled by the controller 84 , which may be contained within the control panel 86 . The controller 84 receives input from a paper roll height measuring instrument (not shown), which allows proper positioning of the guard 50 . The operator may now approach the winder 20 where the process of effecting a splice is performed. This process normally involves cutting away, or slabbing off, the outermost layers of the paper roll 26 and rotating the paper roll to remove the cutaway layers. A splice is prepared typically by taping the free end of the web 32 to the paper roll 26 . These operations require the operator to place his hands near the roll, and possibly to engage the paper roll 26 . The safety of this operation is enhanced by the presence of the guard 50 which is positioned to be closely spaced from the surface 81 of the paper roll 26 . The upper surface of the shell 72 is spaced radially outwardly of the surface 38 of this downstream winder drum 24 which causes the blunt leading edge 76 of the guard 50 to be distant approximately 10 to 14 inches from the nip 30 between the paper roll 26 and the downstream winder drum 24 . The narrow width of the gap 92 prevents the operator from extending a hand more than about five or six inches inward in the gap 92 . In addition, the guard 50 completely prevents a hand from engaging the aggressive surfaces 38 of the winder drum 24 . Motion of the guard 50 while the operator 46 is present is prevented by spring loaded brakes 94 which are similar to disc brakes and which grip the flange extensions 52 , 54 as shown in FIGS. 1-3, and 5 . The brakes 94 are of a type known in the art where spring force is used to apply the braking force and a hydraulic mechanism is used to release the brakes, such that the brakes fail in the engaged position. The guard 50 can be raised and lowered from the control panel 86 , and can also be controlled from switches 96 on either side of the winder 20 . To prevent the guard from being moved while an operator 46 is positioned near the guard, the switches 96 are positioned sufficiently far from the winder 20 so that the person operating the switches 96 cannot come into contact with the winder. Further, the switches are wired so that the guard can be raised and lower only by the simultaneous operation of both switches 96 so that two operators are required. When the guard 50 is lowered to gain access to the drum 24 , the winder is not driven. When the guard 50 is in the up position closely spaced from the paper roll 26 the winder may be jogged. A light curtain 98 , which extends the width of the paper roll 26 , projects light 100 between an upper member 102 and a lower member 104 so that the operator's arm 106 passes through the light curtain 98 in order to access the paper roll 26 or the guard 50 . Movement of the guard 50 is interlocked with the light curtain 98 so that the guard 50 cannot be moved when the light curtain detects the operator's arm 106 . Because it may be necessary to jog, i.e. operate the winder at slow speed, while the operator is present, a tape switch 108 which is one continuous switch is positioned along the top of the guard shells 72 adjacent to the blunt leading-edge 76 . The safety tape 108 is connected to the winder drives so the operation of the switch 108 by pressing or leaning against the switch stops all motion of the winder 20 . The light curtain 98 and tape switch 108 are available from Tapeswitch Corporation (www.tapeswitch.com). After the splicing operation is completed the operator 46 returns to the control panel 86 and operates a switch 110 which lowers the guard 50 to the position shown in FIG. 3 . It should be understood that the guard 50 may be positioned based on the size of the roll 26 , or a contact switch could be mounted on the portion of the leading edge 76 and spaced one to one-half inches outwardly from the leading edge to contact the roll and thus positioned the guard 50 . It should be understood that the hydraulic actuators 78 could be replaced by a chain drive driven by a hydraulic motor and brake system, or other comparable mechanical systems for positioning the guard 50 . It should be understood that hydraulic system used with the hydraulic actuators 78 includes design features to prevent rapid movement of the actuator due to a break in the hydraulic supply lines. It should further be understood that the guard could incorporate a core loader, or a core loader could be rebuilt to incorporate a guard 50 . The guard 50 could also function with a bridge to assist the removal of the completed paper roll 26 with or without an additional support positioned to engage the cylindrical shell 56 between the sector shaped flanges 54 , 56 to increase the load bearing capabilities of the guard 50 . It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces all such modified forms thereof as come within the scope of the following claims.

A guard is mounted for rotation about the downstream drum of a winder having two spaced apart winder drums which support a paper roll. The guard has a D-shaped leading-edge which approaches the paper roll. The leading-edge is articulated so that if an operator's hand becomes wedged between the leading-edge and the paper roll, articulation on the leading-edge closes a switch which brings the winder to a stop. A hydraulic actuator extends between a lowermost radial edge of each sector shaped extension and a fixed support. Operation of the hydraulic actuator causes the guard to rotate about the axis of the downstream winder drum so as to be between an operator and the downstream side of the winder drum. The leading edge of the the guard is positioned to limit operator access to the nip formed between the paper roll and the downstream winder drum.

PRIORITY The present application is a continuation-in-part of U.S. patent application Ser. No. 09/335,392, filed Jun. 17, 1999, which is herein incorporated by reference. TECHNICAL FIELD The present invention pertains to improvements to an engine and more particularly to improvements relating to mechanical components of a Stirling cycle heat engine or refrigerator which contribute to increased engine operating efficiency and lifetime. BACKGROUND OF THE INVENTION Stirling cycle machines, including engines and refrigerators, have a long technological heritage, described in detail in Walker, Stirling Engines , Oxford University Press (1980), herein incorporated by reference. The principle underlying the Stirling cycle engine is the mechanical realization of the Stirling thermodynamic cycle: isovolumetric heating of a gas within a cylinder, isothermal expansion of the gas (during which work is performed by driving a piston), isovolumetric cooling, and isothermal compression. The Stirling cycle refrigerator is also the mechanical realization of a thermodynamic cycle which approximates the ideal Stirling thermodynamic cycle. In an ideal Stirling thermodynamic cycle, the working fluid undergoes successive cycles of isovolumetric heating, isothermal expansion, isovolumetric cooling and isothermal compression. Practical realizations of the cycle, wherein the stages are neither isovolumetric nor isothermal, are within the scope of the present invention and may be referred to within the present description in the language of the ideal case without limitation of the scope of the invention as claimed. Various aspects of the present invention apply to both Stirling cycle engines and Stirling cycle refrigerators, which are referred to collectively as Stirling cycle machines in the present description and in any appended claims. The principle of operation of a Stirling engine is readily described with reference to FIGS. 1 a - 1 e , wherein identical numerals are used to identify the same or similar parts. Many mechanical layouts of Stirling cycle machines are known in the art, and the particular Stirling engine designated generally by numeral 10 is shown merely for illustrative purposes. In FIGS. 1 a to 1 d , piston 12 and a displacer 14 move in phased reciprocating motion within cylinders 16 which, in some embodiments of the Stirling engine, may be a single cylinder. Typically, a displacer 14 does not have a seal. However, a displacer 14 with a seal (commonly known as an expansion piston) may be used. Both a displacer without a seal or an expansion piston will work in a Stirling engine in an “expansion” cylinder. A working fluid contained within cylinders 16 is constrained by seals from escaping around piston 12 and displacer 14 . The working fluid is chosen for its thermodynamic properties, as discussed in the description below, and is typically helium at a pressure of several atmospheres. The position of displacer 14 governs whether the working fluid is in contact with hot interface 18 or cold interface 20 , corresponding, respectively, to the interfaces at which heat is supplied to and extracted from the working fluid. The supply and extraction of heat is discussed in further detail below. The volume of working fluid governed by the position of the piston 12 is referred to as compression space 22 . During the first phase of the engine cycle, the starting condition of which is depicted in FIG. 1 a , piston 12 compresses the fluid in compression space 22 . The compression occurs at a substantially constant temperature because heat is extracted from the fluid to the ambient environment. In practice, a cooler (not shown) is provided. The condition of engine 10 after compression is depicted in FIG. 1 b . During the second phase of the cycle, displacer 14 moves in the direction of cold interface 20 , with the working fluid displaced from the region of cold interface 20 to the region of hot interface 18 . This phase may be referred to as the transfer phase. At the end of the transfer phase, the fluid is at a higher pressure since the working fluid has been heated at constant volume. The increased pressure is depicted symbolically in FIG. 1 c by the reading of pressure gauge 24 . During the third phase (the expansion stroke) of the engine cycle, the volume of compression space 22 increases as heat is drawn in from outside engine 10 , thereby converting heat to work. In practice, heat is provided to the fluid by means of a heater (not shown). At the end of the expansion phase, compression space 22 is full of cold fluid, as depicted in FIG. 1 d . During the fourth phase of the engine cycle, fluid is transferred from the region of hot interface 18 to the region of cold interface 20 by motion of displacer 14 in the opposing sense. At the end of this second transfer phase, the fluid fills compression space 22 and cold interface 20 , as depicted in FIG. 1 a , and is ready for a repetition of the compression phase. The Stirling cycle is depicted in a P-V (pressure-volume) diagram as shown in FIG. 1 e. Additionally, on passing from the region of hot interface 18 to the region of cold interface 20 , the fluid may pass through a regenerator (not shown). The regenerator may be a matrix of material having a large ratio of surface area to volume which serves to absorb heat from the fluid when it enters hot from the region of hot interface 18 and to heat the fluid when it passes from the region of cold interface 20 . The principle of operation of a Stirling cycle refrigerator can also be described with reference to FIGS. 1 a - 1 e , wherein identical numerals are used to identify the same or similar parts. The differences between the engine described above and a Stirling machine employed as a refrigerator are that compression volume 22 is typically in thermal communication with ambient temperature and expansion volume 24 is connected to an external cooling load (not shown). Refrigerator operation requires net work input. Stirling cycle engines have not generally been used in practical applications, and Stirling cycle refrigerators have been limited to the specialty field of cryogenics, due to several daunting engineering challenges to their development. These involve such practical considerations as efficiency, vibration, lifetime, and cost. The instant invention addresses these considerations. A major problem encountered in the design of certain engines, including the compact Stirling engine, is that of the friction generated by a sliding piston resulting from misalignment of the piston in the cylinder and lateral forces exerted on the piston by the linkage of the piston to a rotating crankshaft. In a typical prior art piston-crankshaft configuration such as that depicted in FIG. 2, a piston 10 executes reciprocating motion along longitudinal direction 12 within cylinder 14 . Piston 10 is coupled to an end of connecting rod 16 at a pivot such as a pin 18 . The other end 20 of connecting rod 16 is coupled to a crankshaft 22 at a fixed distance 24 from the axis of rotation 26 of the crankshaft. As crankshaft 22 rotates about the axis of rotation 26 , the connecting rod end 20 connected to the crankshaft traces a circular path while the connecting rod end 28 connected to the piston 10 traces a linear path 30 . The connecting rod angle 32 , defined by the connecting rod longitudinal axis 34 and the axis 30 of the piston, will vary as the crankshaft rotates. The maximum connecting rod angle will depend on the connecting rod offset on the crankshaft and on the length of the connecting rod. The force transmitted by the connecting rod may be decomposed into a longitudinal component 38 and a lateral component 40 , each acting through pin 18 on piston 10 . Minimizing the maximum connecting rod angle 32 will decrease the lateral forces 40 on the piston and thereby reduce friction and increase the mechanical efficiency of the engine. The maximum connecting rod angle can be minimized by decreasing the connecting rod offset 24 on the crankshaft 22 or by increasing the connecting rod length. However, decreasing the connecting rod offset on the crankshaft will decrease the stroke length of the piston and result in less Δ (pV) work per piston cycle. Increasing the connecting rod length can not reduce the connecting rod angle to zero but does increase the size of the crankcase resulting in a less portable and compact engine. Referring now to the prior art engine configuration of FIG. 3, it is known that in order to reduce the lateral forces on the piston, a guide link 42 may be used as a guidance system to take up lateral forces while keeping the motion of piston 10 constrained to linear motion. In a guide link design, the connecting rod 16 is replaced by the combination of guide link 42 and a connecting rod 16 . Guide link 42 is aligned with the wall 44 of piston cylinder 14 and is constrained to follow linear motion by two sets of rollers or guides, forward rollers 46 and rear rollers 48 . The end 50 of guide link 42 is connected to connecting rod 16 which is, in turn, connected to crankshaft 22 at a distance offset from the rotational axis 26 of the crankshaft. Guide link 42 acts as an extension of piston 10 and the lateral forces on the piston that would normally be transmitted to cylinder walls 44 are instead taken up by the two sets of rollers 46 and 48 . Both sets of rollers 46 and 48 are required to maintain the alignment of guide link 42 and to take up the lateral forces being transmitted to the guide link by the connecting rod. The distance d between the forward set of rollers and the rear set of rollers may be reduced to decrease the size of the crankcase (not shown). However, reducing the distance between the rollers will increase the lateral load 54 on the forward set of rollers since the rear roller set acts as a fulcrum 56 to a lever 58 defined by the connection point 52 of the guide link and connecting rod 16 . The guide link will generally increase the size of the crankcase because the guide link must be of sufficient length that when the piston is at its maximum extension into the piston cylinder, the guide link extends beyond the piston cylinder so that the two sets of rollers maintain contact and alignment with the guide link. SUMMARY OF THE INVENTION In accordance with one aspect of the invention, a system for supporting lateral loads on a piston undergoing reciprocating motion along a longitudinal axis in a cylinder includes a guide link coupling the piston to a crankshaft undergoing rotary motion about a rotation axis of the crankshaft. A first guide element is located along the length of the guide link and includes a spring mechanism for urging the first guide element into contact with the guide link. The spring mechanism includes a first spring with a first natural frequency of oscillation and a second spring with a second natural frequency of oscillation. A second guide element is in opposition to the first guide element. In one embodiment, the first guide element is a roller having a rim in rolling contact with the guide link and the second guide element is a roller with a rim in rolling contact with the guide link. In a further embodiment, the second guide element includes a precision positioner for positioning the second guide element with respect to the longitudinal axis. The precision positioner may be a vernier mechanism having an eccentric shaft for varying a distance between the second guide element and the longitudinal axis. In accordance with another aspect of the invention, a linkage for coupling a piston undergoing reciprocating linear motion along a longitudinal axis to a crankshaft undergoing rotary motion about a rotation axis of the crankshaft includes a guide link having a first end proximal to the piston and coupled to the piston and a second end distal to the piston such that the rotation axis is disposed between the proximal end and the distal end of the guide link. A connecting rod is rotably connected to the end of the guide link distal to the piston at a rod connection point at a connecting end of the connecting rod. The connecting rod is coupled to the crankshaft at a crankshaft connection point on a crankshaft end of the connecting rod, where the crankshaft connection point is offset from the rotation axis of the crankshaft. A guide link guide assembly supports lateral loads at the distal end of the guide link and includes a first roller having a center of rotation fixed with respect to the rotation axis of the crankshaft and a rim in rolling contact with the distal end of the guide link. A spring mechanism is used to urge the rim of the first roller into contact with the distal end of the guide link. The spring mechanism includes a first spring with a first natural frequency of oscillation and a second spring with a second natural frequency of oscillation. In one embodiment, the guide link guide assembly further includes a second roller in opposition to the first roller and having a center of rotation and a rim in rolling contact with the distal end of the piston. The second roller may include a precision positioner to position the center of rotation of the second roller with respect to the longitudinal axis. In a further embodiment, the precision positioner is a vernier mechanism having an eccentric shaft for varying the distance between the center of rotation of the second roller and the longitudinal axis. In accordance with yet another aspect of the invention, an improvement is provided to a Stirling cycle machine of the type where at least one piston undergoes reciprocating motion along a longitudinal axis in a cylinder. The piston is coupled to a crankshaft undergoing rotary motion about a rotation axis using a guide link having a first end proximal to the piston and coupled to the piston and a second end distal to the piston. The improvement has a guide link guide assembly including a spring mechanism for urging the rim of a first roller into contact with the distal end of the guide link where the spring mechanism includes a first spring with a first natural frequency of oscillation and a second spring with a second natural frequency of oscillation. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more readily understood by reference to the following description, taken with the accompanying drawings, in which: FIGS 1 a - 1 e depict the principle of operation of a prior art Stirling cycle machine. FIG. 2 is a cross-sectional view of a prior art linkage for an engine. FIG. 3 is a cross-sectional view of a second prior art linkage for an engine, the linkage having a guide link. FIG. 4 is a cross-sectional view of a folded guide link linkage for an engine in accordance with a preferred embodiment of the present invention. FIG. 5 is a perspective view of a guide link and guide wheel assembly in accordance with an embodiment of the invention. FIG. 6 a is a cross-sectional view of a piston and guide assembly for allowing the precision alignment of piston motion using vernier alignment in accordance with a preferred embodiment of the invention. FIG. 6 b is a side view of the precision alignment mechanism in accordance with an embodiment of the invention. FIG. 6 c is a perspective view of the precision alignment mechanism of FIG. 6 b in accordance with an embodiment of the invention. FIG. 6 d is a top view of the precision alignment mechanism of FIG. 6 b in accordance with an embodiment of the invention. FIG. 6 e is a top view of the precision alignment mechanism of FIG. 6 b with both the locking holes and the bracket holes showing in accordance with an embodiment of the invention. FIG. 7 is a cross-sectional view of a folded guide link linkage for a two-piston machine such as a Stirling cycle machine in accordance with a preferred embodiment of the present invention. FIG. 8 is a perspective view of one embodiment of the dual folded guide link linkage of FIG. 7 . DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to FIG. 4, a schematic diagram is shown of a folded guide link linkage designated generally by numeral 400 . A piston 401 is rigidly coupled to the piston end of a guide link 403 at a piston connection point 402 . Guide link 403 is rotatably connected to a connecting rod 405 at a rod connection point 404 . The piston connection point 402 and the rod connection point 404 define the longitudinal axis 420 of guide link 403 . Connecting rod 405 is rotatably connected to a crankshaft 406 at a crankshaft connection point 408 which is offset a fixed distance from the crankshaft axis of rotation 407 . The crankshaft axis of rotation 407 is orthogonal to the longitudinal axis 420 of the guide link 403 and the crankshaft axis of rotation 407 is disposed between the rod connection point 404 and the piston connection point 402 . In a preferred embodiment, the crankshaft axis of rotation 407 intersects the longitudinal axis 420 . An end 414 of guide link 403 is constrained between a first roller 409 and an opposing second roller 411 . The centers of roller 409 and roller 411 are designated respectively by numerals 410 and 412 . The position of guide link piston linkage 400 depicted in FIG. 4 is that of mid-stroke point in the cycle. This occurs when the radius 416 between the crankshaft connection point 408 and the crankshaft axis of rotation 407 is orthogonal to the plane defined by the crankshaft axis of rotation 407 and the longitudinal axis of the guide link 403 . In a preferred embodiment, the rollers 409 , 411 are placed with respect to the guide link 403 in such a manner that the rod connection point 404 is in the line defined by the centers 410 , 412 of the rollers 409 , 411 at mid-stroke. As rollers 409 , 411 wear during use, the misalignment of the guide link will increase. In a preferred embodiment, the first roller 409 is spring loaded to maintain rolling contact with the guide link 403 . In accordance with embodiments of the invention, guide link 403 may comprise subcomponents such that the portion 413 of the guide link proximal to the piston may be a lightweight material such as aluminum, whereas the “tail” portion 414 of the guide link distal to the piston may be a durable material such as steel to reduce wear due to friction at rollers 409 and 411 . Alignment of the longitudinal axis 420 of the guide link 403 with respect to piston cylinder 14 is maintained by the rollers 409 , 411 and by the piston 401 . As crankshaft 406 rotates about the crankshaft axis of rotation 407 , the rod connection point 404 traces a linear path along the longitudinal axis 420 of the guide link 403 . Piston 401 and guide link 403 form a lever with the piston 401 at one end of the lever and the rod end 414 of the guide link 403 at the other end of the lever. The fulcrum of the lever is on the line defined by the centers 410 , 412 of the rollers 409 , 411 . The lever is loaded by a force applied at the rod connection point 404 . As rod connection point 404 traces a path along the longitudinal axis of the guide link 403 , the distance between the rod connection point 404 and the fulcrum, the first lever arm, will vary from zero to one-half the stroke distance of the piston 401 . The second lever arm is the distance from the fulcrum to the piston 401 . The lever ratio of the second lever arm to the first lever arm will always be greater than one, preferably in the range from 5 to 15. The lateral force at the piston 401 will be the forced applied at the rod connection point 404 scaled by the lever ratio; the larger the lever ratio, the smaller the lateral force at the piston 401 . By moving the connection point to the side of the crankshaft axis distal to that of the piston, the distance between the crankshaft axis and the piston cylinder does not have to be increased to accommodate the roller housing. Additionally, only one set of rollers is required for aligning the piston, thereby advantageously reducing the size of the roller housing and the overall size of the engine. In accordance with the invention, while the piston experiences a non-zero lateral force (unlike a standard guide link design where the lateral force of a perfectly aligned piston is zero), the lateral force can be at least an order of magnitude less than that experienced by a simple connecting rod crankshaft arrangement due to the large lever arm created by the guide link. Lateral forces on a piston can give rise to noise and to wear. As mentioned above, roller 409 and roller 411 are used to align the piston 401 and to take up lateral forces being transmitted to the guide link 403 by the connecting rod 405 . Preferably, one of the rollers 409 is spring loaded to maintain rolling contact with the guide link 403 . At least one spring may be used to force the roller 409 (otherwise referred to herein as a guide wheel) against the guide link 403 surface. During operation of an engine, the guide wheel 409 and spring mechanism will typically reciprocate or bounce on the surface of the guide link 403 at or near the natural resonant frequency of the guide wheel and spring combination. This oscillation may result in significant fluctuations in the force supporting the guide link 403 as well as intermittent contact between the guide link 403 and the guide wheel 409 . This, in turn, results in excessive noise, increased wear and decreased efficiency and power output. FIG. 5 is a perspective view of a guide link and guide wheel assembly in accordance with an embodiment of the invention. In FIG. 5, a guide link 500 is supported at its free end by a fixed guide wheel 501 and a spring loaded guide wheel assembly 502 . The guide wheel assembly 502 includes two springs 504 , 505 and a guide wheel 506 . Springs 504 and 505 force the guide wheel 506 against the guide link 500 . Springs 504 and 505 have the combined force necessary to hold the guide wheel assembly 502 in contact with guide link 500 . In addition, spring 504 and spring 505 each have a different natural frequency of oscillation (i.e., each has a different spring rate). By selecting springs with non-overlapping natural frequencies, at least one spring will advantageously not be in resonance at all times during operation. As mentioned above, the guide wheel assembly 502 will typically reciprocate on the surface of the guide link 500 at or near the natural resonant frequency of the guide wheel and springs. By using two springs with different natural frequencies of oscillation, the resonance of the guide wheel assembly 502 should be eliminated since at least one spring will not be in resonance. Additional friction may be generated by the misalignment of the piston in the cylinder. A solution to the alignment problem is now discussed with reference to FIGS. 6 a - 6 e . FIG. 6 a shows a schematic diagram of a piston 601 and a guide assembly 609 for allowing precision alignment of piston motion using vernier alignment in accordance with a preferred embodiment of the invention. The piston 601 executes a reciprocating motion along a longitudinal axis 602 in cylinder 600 . A guide link 604 is coupled to the piston 601 . An end of the guide link 604 is constrained between a first roller 605 and an opposing second roller 607 . The centers of roller 605 and roller 607 are designated respectively by numerals 606 and 608 . A piston guide ring 603 may be used at one end of the piston 601 to prevent piston 601 from touching the cylinder 600 . However, if piston 601 is not aligned to move in a straight line along longitudinal axis 602 , it is possible other points along the length of piston 601 not coupled to the guide ring may contact the cylinder 600 . In a preferred embodiment, piston 601 is aligned using rollers 605 and 607 and guide link 604 such that piston 601 moves along the longitudinal axis 602 in a straight line and is substantially centered with respect to cylinder 600 . In accordance with a preferred embodiment of the invention, the piston 601 may be aligned with respect to the piston cylinder 600 by adjusting the position of the center 608 of the second roller 607 . The first roller 605 is spring loaded to maintain rolling contact with the guide link 604 . The second roller 607 is mounted on an eccentric flange such that rotation of the flange causes the second roller 607 to move laterally with respect to longitudinal axis 602 . A single pin (not shown) may be used to secure the second roller 607 into a position. The movement of the second roller 607 will cause the guide link 604 and the piston 601 to also move laterally with respect to the longitudinal axis 602 . In this manner, the piston 601 may be aligned so as to move in cylinder 600 in a straight line that is substantially centered with respect to cylinder 600 . FIG. 6 b shows a side view of one embodiment of a precision alignment mechanism. A roller 607 is rotatably mounted on a locking eccentric 611 having a lower end 612 and an upper end 613 . The roller is mounted on a portion 610 of the locking eccentric 611 having a roller axis of rotation that is offset from the axis of rotation of the locking eccentric 611 . The lower end 612 is rotatably mounted in a lower bracket (not shown). The upper end 613 is rotatably mounted on an upper bracket 614 . FIG. 6 c shows a perspective view of the embodiment shown in FIG. 6 b . The upper bracket 614 has a plurality of bracket holes 620 drilled through the upper bracket 614 . In a preferred embodiment, eighteen bracket holes are drilled through the upper bracket 614 . The bracket holes 620 are offset a distance from the axis of rotation of the locking eccentric 611 and are evenly spaced around the circumference defined by the offset distance. FIG. 6 d shows a top view of the embodiment shown in FIG. 6 b . The upper end 613 of the locking eccentric 611 has a plurality of locking holes 615 . The number of locking holes 615 should not be identical to the number of bracket holes 620 . In a preferred embodiment, the number of locking holes 615 is nineteen. The locking holes 615 are offset from the axis of rotation of the locking eccentric 611 by the same distance used to offset the bracket holes 620 . The locking holes 615 are evenly spaced around the circumference defined by the offset distance. FIG. 6 d also shows a locking nut 616 that allows the locking eccentric 611 to rotate when the locking nut 616 is loose. When the locking nut 616 is tightened, the locking nut 616 makes a rigid connection between the locking eccentric 611 and the upper bracket 614 . FIG. 6 e is the same view as shown in FIG. 6 d but with the locking holes 615 shown. During assembly, the piston is aligned in the following manner. The folded guide link is assembled with the locking nut 616 in a loosened state. The piston 601 (FIG. 6 a ) is aligned within the piston cylinder 600 (FIG. 6 a ) visually by rotating the locking eccentric 611 . As the locking eccentric 611 is rotated, the roller axis of rotation 608 (FIG. 6 a ) will be displaced both laterally and longitudinally to the guide link longitudinal axis 602 (FIG. 6 a ). The large lever ratio of the present invention requires only a very small displacement of the roller axis of rotation 608 (FIG. 6 a ) with respect to the longitudinal axis 602 (FIG. 6 a ) to align the piston 601 (FIG. 6 a ) within the piston cylinder 600 (FIG. 6 a ). In accordance with an embodiment of the invention, the maximum displacement range may be from 0.000 inches to 0.050 inches. In a preferred embodiment, the maximum displacement is between 0.010 inches and 0.030 inches. As the locking eccentric 611 is rotated, one of the locking holes 615 will align with a bracket hole 620 . FIG. 6 d indicates such an alignment 630 . Once the piston 601 (FIG. 6 a ) is aligned in the piston cylinder 600 (FIG. 6 a ), a pin (not shown) is inserted through the aligned bracket hole and into the aligned locking hole thereby locking the locking eccentric 611 . The locking nut 616 is then tightened to rigidly connect the upper bracket 614 to the locking eccentric 611 . In accordance with a preferred embodiment of the invention, a dual folded guide link piston linkage such as shown in cross-section in FIG. 7 and designated there generally by numeral 700 may be incorporated into a compact Stirling engine. Referring now to FIG. 7, pistons 701 and 711 are the displacer and compression pistons, respectively, of a Stirling cycle engine. As used in this description and the following claims, a displacer piston is either a piston without a seal or a piston with a seal (commonly known as an “expansion” piston). The Stirling cycle is based on two pistons executing reciprocating linear motion about 90° out of phase with one another. This phasing is achieved when the pistons are oriented at right angles and the respective connecting rods share a common pin of a crankshaft. Additional advantages of this orientation include reduction of vibration and noise. Additionally, the two pistons may advantageously lie in the same plane to eliminate shaking vibrations orthogonal to the plane of the pistons. While the invention is described generally with reference to the Stirling engine shown in FIG. 7, it is to be understood that many engines as well as refrigerators may similarly benefit from various embodiments and improvements which are subjects of the present invention. The configuration of a Stirling engine shown in FIG. 7 in cross-section, and in perspective in FIG. 8, is referred to as an alpha configuration, characterized in that compression piston 711 and displacer piston 701 undergo linear motion within respective and distinct cylinders: compression piston 711 in compression cylinder 720 and displacer piston 701 in expansion cylinder 722 . Guide link 703 and guide link 713 are rigidly coupled to displacer piston 701 and compression piston 711 at piston connection points 702 and 712 respectively. Connecting rods 706 and 716 are rotationally coupled at connection points 705 and 715 of the distal ends of guide links 703 and 713 and to crankshaft 708 at crankshaft connection points 707 and 717 . Lateral loads on guide links 703 and 713 are substantially taken up by roller pairs 704 and 714 . As discussed above with respect to FIGS. 4 and 6, the pistons 701 and 711 may be aligned within the cylinders 720 and 722 respectively such using precision alignment of roller pairs 704 and 714 . The devices and methods described herein may be applied in other applications besides the Stirling engine in terms of which the invention has been described. The described embodiments of the invention are intended to be merely exemplary and numerous variations and modifications will be apparent to those skilled in the art. All such variations and modifications are intended to be within the scope of the present invention as defined in the appended claims.

A system for supporting lateral loads on a piston undergoing reciprocating motion along a longitudinal axis in a cylinder includes a guide link for coupling the piston to a crankshaft undergoing rotary motion about a rotation axis of the crankshaft where the longitudinal axis and the rotation axis are substantially orthogonal to each other. A first guide element is located along the length of the guide link and includes a spring mechanism for urging the first guide element into contact with the guide link. The spring mechanism includes a first spring with a first natural frequency of oscillation and a second spring with a second natural frequency of oscillation. A second guide element is in opposition to the first guide element.

This invention was made with support by the U.S. Army Medical Research and Development Command under Contract No. DAMD 17-87 C 7169 to Hermona Soreq. The U.S. Army has certain rights in the invention. This is a continuation of application Ser. No. 07/496,554, filed Mar. 20, 1990, now abandoned. FIELD OF THE INVENTION The invention relates to genetically engineered human acetylcholinesterase. The invention is also directed to the cloning and production of human acetylcholinesterase. The invention is further directed to the production of antibodies interacting with said protein. The invention also relates to pharmaceutical compositions comprising acetylcholinesterase for treatment and prophylaxis of organo-phosphorous compounds poisoning. The compositions of the present invention may also be used to relieve post-surgery apnea. Methods of treating or preventing organophosphorous poisoning or post-operative apnea by employing the pharmaceutical compositions of the invention are also within the scope of the application. The invention further relates to human cholinesterase probes which may be employed for diagnosing progressing ovarian carcinomas and hemocytopoietic disorders. Methods of diagnosing such tumors or hemocytopoietic disorders are also envisaged within this application. Furthermore, methods of treating hemocytopoietic disorders are also considered. Throughout this application, various publications are referenced by Arabic numerals within parentheses. Full citations for these references may be found at the end of the specifition immediately preceding the claims. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art as known to those skilled therein as of the date of the invention described and claimed herein. BACKGROUND OF THE INVENTION Properties of Cholinesterases Cholinesterases (ChEs) are highly polymorphic carboxylesterases of broad substrate specificity, involved in the termination of neurotransmission in cholinergic synapses and neuromuscular junctions. ChEs terminate the electrophysiological response to the neurotransmitter acetycholine (ACh) by degrading it very rapidly (1). ChEs belong to the B type carboxylesterases on the basis of their sensitivity to inhibition by organophosphorous (OP) poisons (2) and are primarily classified according to their substrate specificity and sensitivity to selective inhibitors into acetylcholinesterase (ACHE, acetylcholine acetylhydrolase, EC 3.1.1.7) and butyrylcholinesterase (BuChE, acylcholine acylhydrolase, EC 3.1.1.8) (3). Further classifications of ChEs are based on their charge, hydrophobicity, interaction with membrane or extracellular structures and multisubunit association of catalytic and non-catalytic "tail" subunits (4,5). The severe clinical symptoms resulting from OP intoxication (6) are generally attributed to their inhibitory interaction on AChE (7). OPs are substrate analogues to ChEs. The labeled OP diisopropylfluorophosphate (DFP) was shown to bind convalently to the serine residue at the active esteratic site region of ChEs, that is common to all of the carboxyl-esterases (8,9). However, the binding and inactivation capacity of OPs on ChEs is considerably higher than their effect on other serine hydrolases. Furthermore, even within species the inhibition of ChEs by different OPs tends to be highly specific to particular ChE types (10). In order to improve the designing of therapeutic and/or prophylactic drugs to OP intoxication, it was therefore desirable to reveal the primary amino acid sequence and three dimensional structure of human ACHE, and to compare them to those of human BuChE, as well as to the homologous domains in other serine hydrolases. AChE may be distinguished from the closely related enzyme BuChE by its high substrate specificity and sensitivity to selective inhibitors (11). Both enzymes exist in parallel arrays of multiple molecular forms, composed of different numbers of catalytic and non-catalytic subunits (12). However, in humans, as in other species, they display a tissue-specific mode of expression. BuChE, assumed to be produced in the liver, is the principal species in serum (13). In contrast, AChE is the major cholinesterease in various human brain regions (14), including the cholinoceptive basal brain ganglia (15). Extensive research efforts by several groups resulted in recent years in the isolation of cDNA clones encoding the electric fish AChE (16,17), Drosophila AChE (18,19) and human BuChE (20,21). However, the primary structure of mammalian, and more particularly, human AChE remained unknown. Interaction of Cholinesterases with Organophosphorous Insecticides and War Gases The use of organophosphorous (OP) anticholinesterase compounds in war (22) and as agricultural insecticides (23) resulted, over the last 40 years, in an interesting number of cases of acute and delayed intoxication. These included damage to the peripheral and central nervous system, myopathy, psychosis, general paralysis and death (24). Estimations are that 19,000 deaths occur out of the 500,000 to 1 million annual pesticide-associated poisonings (25). Previous animal studies demonstrated that methyl parathion administration suppressed growth and induced ossification in both mice and rats, as well as high mortality and cleft palate in the mouse (26). In humans, malformations of the extremities and fetal death were correlated with exposure to methyl parathion in 18 cases (27). In addition, a neonatal lethal syndrome of multiple malformations was reported in women exposed to unspecific insecticides during early pregnancy (28). Complete inhibition of ChEs by the administration of OP poisons is lethal (6). This inhibition is achieved by formation of a stable stoichiometric (1:1) covalent conjugate with the active site serine (7), followed by a parallel competing reaction, termed "aging", which transforms the inhibited ChE into a form that cannot be generated by the commonly used reactivators (7) such as active-site directed nucleophiles (e.g., quaternary oximes) which detach the phosphoryl moiety from the hydroxyl group of the active site serine (70). The aging process is believed to involve dealkylation of the covalently bound OP group (7), and renders therapy of intoxication by certain organophosphates such as Sarin, DFP and Soman, exceedingly difficult (29). Use of preparations comprising ChEs for therapeutical purposes has been demonstrated to be effective at laboratory level: purified AChE from fetal calf serum has been shown to protect rats from 2 lethal doses of Soman (a war OP poison) with half life of 5-6 days (37,38). Purified BuChE from human serum has been shown to improve the symptoms of OP-intoxicated patients (31). Interaction of Cholinesterases with Succinylcholine--Post-Operative Apnea Succinylcholine which acts as a competitive analogue of acetylcholine, is often used in surgery as a short-term muscle relaxant. Since the drug is hydrolyzed by BuChE, its administration into individuals carrying genetically abnormal BuChE causes prolonged apnea (32). The most common variant with this problem is the atypical variant E s , for which 3-6% of the Caucasian population is heterozygous and about 0.05% is homozygous (33). This enzyme hydrolyzes acetylcholine but not succinylcholine (34). Another variant, E 1 , which causes the complete absence of catalytically active serum BuChE in homozygotes, is also associated with this clinical problem (35). This type of "silent" enzyme cannot hydrolyze any ChE substrate, nor can it bind organophosphate compounds (9). High frequency of atypical and silent BuChE genes was reported among Iraqui and Iranian Jews (11.3% for heterozygotes and 0.08% for homozygotes, respectively) (36-38). This could explain the high frequency of reports of prolonged apnea following surgery in Israel, and apparently in many other countries. It is likely that AChE could be administered to patients to rid the body of the succinylcholine in cases of prolonged apnea. Alterations in the Level and Properties of Cholinesterases In several neurological or genetic disorders, such as Senile Dementia of the Alzheimer's type or Down's syndrome, modification in both the level (39) and the composition of molecular forms (40) of human brain acetylcholinesterase have been reported. In the Alzheimer's disease, the levels of AChE in cholinergic brain areas drops by about 50% and the tetrameric form of the enzyme dissappears completely. Individuals with Down's syndrome invariably develop manifestations of the Alzheimer's disease before the age of 40. In addition, it has been observed that neural tube defects in human embryos are clinically characterized by secretion of AChE tetramers into the amniotic fluid. These phenomenae are currently tested for by sucrose gradient fractionation, followed by enzymatic assays of substrate hydrolysis or gel electrophoresis and AChE activity staining. Simple and selective quantitative assays for specific AChE forms have not yet been developed. Furthermore, death at very early stages of development has been observed in Homozygote Drosophila mutants lacking the Ace locus which controls AChE biosynthesis and in nematode mutants defective in the expression of their four ChE genes. It is very likely that homozygous mutations in AChE genes in humans will result in early abortion or in severe neurological and possibly other malformations in the fetus. No methods to determine whether specific individuals carry such mutations have been disclosed so far. Relationship between Cholinesterases and Hematopoiesis and Blood Cells Differentiation Biochemical and histochemical analyses indicate that both acetylcholinesterase and butyrylcholinesterase are expressed in high levels in various fetal tissues of multiple eukaryotic organisms (41), where ChE are coordinately regulated with respect to cell proliferation and differentiation (42). However, no specific role could be attributed to ChE in embryonic development and their biological function(s) in these tissues remained essentially unknown (71). In addition to its presence in the membrane of mature erythrocytes, AChE is also intensively produced in developing blood cells in vivo (43) and in vitro (44) and its activity serves as an accepted marker for developing mouse megakaryocytes (45). Furthermore, administration of acetylcholine analogues as well as ChE inhibitors has been shown to induce megakaryocytopoiesis and increased platelet counts in the mouse (46), implicating this enzyme in the commitment and development of these hematopoietic cells. Recently, the cDNA coding for BuChE has been cloned (20) and BuChEcDNA hybridizing sequences have been localized to chromosome sites 3q21,26 and 16q12 (47). It is of importance to emphasize that the chromosome 3q21,26 region includes breakpoints that were repeatedly observed in peripheral blood chromosomes of patients with acute myelodisplastic leukemia (AML) (48,49). These cases all featured enhanced megakaryocytopoiesis, high platelet count and rapid progress of the disease (15). Accumulating evidence in recent reports implicates chromosomal breakpoints with molecular changes in the structure of DNA and the induction of malignancies (51). Therefore, the connection between: (a) abnormal control of megakaryocytopoiesis in AML as well as in mouse bone-marrow cells subjected to ChE inhibition; (b) cholinesterase genes location on the long arm of chromosome 3; and (c) chromosomal aberrations in that same region in AML, appeared more than coincidental (for discussion see (47)). The putative correlation between the human genes coding for ChEs and the regulation of megakaryocytopoiesis has been examined by searching for structural changes in the human AChE and ChE genes from peripheral blood DNA in patients with leukemia, platelet count abnormalities, or both. Proof of the active role of these enzymes in the progress of human hematopoiesis had to be established. Relationship between Cholinesterases and Ovarian Carcinomas High level of expression of AChE and ChE in tumors was reported in the past (66,67), however, it was still to be elucidated whether this high expression level is effected by gene amplification. The rapidly progressing carcinomas of the ovary (68) may offer a promising model in which to test said possibility since sections from these tumors exhibit pronounced diffuse cytochemical staining of ChE activities (66), whereas ChE expression in normal ovarian tissue appears to be confined to maturing oocytes (47). The possible amplification of the human AChE and ChE genes in primary ovarian carcinomas, and their expression in dividing cells within tumor loci, implicating involvement of cholinesterase in tumor growth and development, had to be established. SUMMARY OF THE INVENTION The invention is directed to human acetylcholinesterase, a neurotransmitter hydrolyzing enzyme, which has a major role in the termination of neurotransmission in cholinergic synapses and neuromuscular junctions. The invention provides for a molecule, as well as DNA and mRNA sequences which code for human acetylcholinesterase. Sources for large scale production of human acetylcholinesterase may be prepared by genetic engineering. The invention therefore provides a molecule encoding human acetylcholinesterase. Contrary to previous expectations it was found that the gene encoding acetylcholinesterase is completely not homologous to the previously isolated gene encoding the related enzyme butyrylcholinesterase, notwithstanding the apparent similarity between these two proteins. This non-obvious finding distinguishes the probes of the present invention from those of near inventions in this field. The invention also provides genetic sequences encoding human acetylcholinesterase or biologically active essential fragments thereof or polypeptides having human acetylcholinesterase activity. Expression vectors containing such molecule or genetic sequences are also provided, as well as hosts transformed with the expression vectors, and methods of producing the genetically engineered human acetylcholinesterase or biologically active essential fragments thereof or the polypeptides having human acetylcholinesterase activity. Human acetylcholinesterase or the biologically active essential fragments thereof or the polypeptides having human acetylcholinesterase activity, produced by the methods of the invention are useful in the treatment of organophosphorous poisoning, as an antidote for the treatment of patients suffering from such organophosphorous intoxication, and also in the prophylaxis of such poisonings. Additionally, the acetylcholinesterase of the present invention, or the biologically active essential fragments thereof or the polypeptides having human acetylcholinesterase activity, may be useful in relieving post-surgery apnea, resulting from prior administration of succinylcholine. Thus, the invention relates to pharmaceutical compositions comprising as active ingredient human acetylcholinesterase or biologically active essential fragments thereof or the polypeptides having human acetylcholinesterase activity, produced by the methods of the invention and to methods of treating or preventing organophosphorous poisoning or post-surgery apnea. The human acetylocholinesterase or its biologically active fragments or the polypeptides having human acetylcholinesterase activity produced by the methods of the invention can also be used to elicit antibodies raised thereagainst. These antibodies, which specifically interact with said protein or polypeptides, may be used for the detection of disease-related changes of acetylcholinesterase in patients. Assays for detecting the presence or absence of acetylcholinesterase altered by a disease or congenital disorder in a patient are also provided. Furthermore, fragments of cDNAs encoding for cholinesterases, for example cDNA of human acetylocholinesterase, may be suitably labeled and used as probes in hybridizaton tests for the detection of alterations in the respective cholinesterase genes. Such alterations appear in patients suffering from leukemia, platelet count abnormalities and possibly other blood cells disorders. Additionally, such alterations have been shown to also appear in patients with primary ovarian, and possibly other, carcinomas. The invention thus provides methods of diagnosing the above pathological conditions. Therapeutic compositions for, and methods of treating said pathological conditions, employing cDNA sequences encoding for human cholinesterases or fragments thereof may also be contemplated. Specific oligonucleotide preparations based on said cDNA sequence may be used as "antisense" compounds, aimed at blocking the expression of said genes in leukemic patients, providing a novel chemotherapeutic approach based on the early diagnosis of a previously unclassified syndrome. DESCRIPTION OF THE FIGURES FIG. 1a shows the sequencing strategy for AChEcDNA clones BG8A and FL2B from newborn brain basal nuclei and fetal liver and brain. FIG. 1b shows the sequencing strategy for AChEcDNA clones ABGACHE and FEMACHE from adult brain basal nuclei and fetal muscle and the GNACHE genomic clone. FIGS. 1c-1e shows the cDNA sequence of clones BGSA and FL2B, encoding for fetal human ACHE, with the oligonucleotides referred to in FIG. 1a marked by boxes. FIGS. 1f-1g shows the composite DNA sequence of the clones presented in FIG. 1c, encoding for the complete human ACHE, with some of the oligonucleotides referred to in FIG. 1b overlined. FIGS. 1h, 1i, 1j show the primary structure of fetal human AChE encoded by the cDNA given in FIGS. 1c, 1d, 1e. FIGS. 1k, 1l shows the primary structure of the full-length human AChE encoded by the cDNA sequence given in FIGS. 1f, 1g. FIGS. 2, 2a, 2b shows amino acid sequences of human AChE and BuChE as compared with Drosophila melanogaster, bovine and Torpedo californica AChEs and with bovine thyroglobulin and Esterase 6 from Drosophila. FIG. 3 shows a comparison of ChE active site region sequences with other serine hydrolases. The star indicates [ 3 H]-DFP-labeled or active site serine. FIG. 4 shows amino acids (up) and nucleotide (down) similarities between the coding regions in most of the human AChEcDNA sequence and parallel regions in the cDNAs encoding for human BuChE (HB), Torpedo AChE (TA) and Drosophila AChE (DA). FIG. 5 shows comparative hydrophobicity patterns of members of the ChE family, human AChE (HA), human BuChE (HB), Torpedo AChE (TA) and Drosophila AChE (DA). FIG. 6 shows the pronounced synthesis of ACHE, but not BuChE, mRNA transcripts in human fetal brain basal nuclei revealed by in situ hybridization with [ 35 S]-labeled ChEcDNA probes. FIG. 7a shows DNA blot hybridization with [ 32 P]-labeled AChEcDNA (there is no cross-interaction with BuChEase genes). FIG. 8 shows DNA blot hybridization of leukemic DNA samples. FIG. 9 shows the amplification of AChE and ChE genes in DNA from patients with hematopoietic disorders. FIG. 10 shows intensified gene amplification, accompanied by structural differences between the amplified DNA regions. FIG. 11 shows the quantification of the amplification levels in diseased DNA samples by slot-blot hybridization. FIG. 12 shows the co-amplification of the AChE and ChE genes in primary ovarian carcinomas. FIG. 13 shows DNA blot hybridization of ovarian carcinomas samples with BuChEcDNA. FIG. 14 shows the co-amplification of the AChE and ChE genes with C-RAFI and V-SIS oncogenes, demonstrated by dot-blot hybridization. FIGS. 15a, FIG. 15b shows the expression of full length ChEmRNA (by RNA hybridization) and the translatable ChEmRNA in ovarian carcinomas (by Xenopus oocyte microinjection). FIG. 16 shows the focal expression of the amplified AChE and ChE genes as demonstrated by in situ hybridization and immunochemical and cytochemical staining. DETAILED DESCRIPTION OF THE INVENTION The human acetylcholinesterase, its biologocally active essential fragments or the polypeptides having acetylcholinesterase activity of the invention may be prepared by cloning the cDNA encoding the protein or polypeptide and expressing the cloned DNA sequence. cDNA encoding human acetylcholinesterase or its said fragments or said polypeptides may be derived from various tissues. Brain cells, and particularly cells from adult brain basal ganglia, that are highly enriched with cholinoceptive cell bodies, may be preferred. The cDNA may be cloned, and the resulting clone screened with an appropriate probe for the cDNA coding for the desired sequence. Further, the gene of human acetylcholinesterase may be synthesized according to techniques known in the art and cloned for use in preparing the active enzyme in large scale and for producing antibodies thereagainst. The cloned cDNA may then be inserted into appropriate expression vector(s) to be transfected into heterologous cells. In the present case eukaryotic cells, possibly of embryonic or nervous system origin, may be preferable as hosts. Alternatively, non-mammalian cells such as microinjected Xenopus oocytes or yeast may be employed to produce the authentic recombinant AChE protein. The expressed protein may be isolated and purified in accordance with conventional methods such as extraction, precipitation, chromotography, affinity chromotography, electrophoresis, or the like. The recombinant acetylcholinesterase or its said fragments or said polypeptides produced according to the method of the invention, may be used as active ingredients in pharmaceutical compositions for the prophylaxis or treatment of organophosphorus poisoning. Pharmaceutical compositions of the invention may also be used to relieve post-surgery apnea resulting from administration of succinylcholine. The pharmaceutical compositions of the invention may also contain pharmaceutically acceptable carriers and diluents, which are well known in the art. In view of the high Kd value of AChE to OP's (16) it promises to be far more efficient for both said applications than other therapeutic agents, mostly aimed to prevent the "aging" process (i.e. oximes) or to improve the dynamic equilibrium between the neurotransmitter, receptor and enzyme by partially blocking the receptor (i.e., atropine). Moreover, being a human authentic protein it is expected, under normal circumstances not to induce toxic or immunological complications, and may therefore be highly advantageous over the currently available drugs such as oximes and atropin. In the case of prolonged apnea, it can save considerable intensive care expenses and (in some cases) brain damage and even death. AChE is the original target for both OP agents (particularly war ones) and succinylcholine, and as such, it carries the best-adapted binding sites for both types of agents. It is a highly stable protein, that will be available in large quantities and may be stored for prolonged periods, and due to its high stability it also promises to be effective in relatively small doses and for a long time (days). The invention also enables to clinically detect cholinesterase deficiencies or abnormalities in the cholinesterase genes, by using oligonucleotide hybridization to a patient's genomic DNA. Such detection techniques are known in the art, for example, the detection of abnormalities in the gene coding for sickle cell β-s globin (52). Detection of such abnormalities may be of importance in preventing post-surgery apnea, described above. In addition, it may be of marked importance in diagnosing various leukemias and abnormal megakaryocytopoiesis for which significant correlation between the disease and cholinesterases genes has now been found. It may be mentioned that treatment of such blood disorders by employing direct derivatives of recombinant cholinesterases is envisaged within the scope of the present invention. The invention thus provides for assays adapted to distinguish between normal and defective sequences in minute samples of the genomic DNA and in a single hybridization step. Specific antibodies may be elicited against the acetylcholinesterase, or biologically active essential fragments thereof. These antibodies may be used, for example by radioimmunoassay, to rapidly and simply detect poisoning or disease related changes in cholinesterases. Preliminary observations which will be described in the following EXAMPLES, show that mutations in the ChE gene(s) are found in patients suffering various blood disorders and also in certain individuals exposed to chronic doses of parathion, which is a potent precursor of the cholinesterase inhibitor paraoxon. The defective genes can be identified for diagnostic purposes and also at very early gestational stage, by hybridization, by using DNA from patients or from chronic villi or amniotic fibroblasts and well-characterized probes from AChE and/or ChE gene(s). Further recent observations which will also be described in the following EXAMPLES, show that the genes coding for the AChE and ChE enzymes are intensively expressed in multiple types of tumor tissues, including ovarian carcinomas. As will be shown hereafter, presence of translatable AChEmRNA and ChEmRNA, as well as their active protein products, was revealed in discrete tumor foci. The frequent co-amplification in these tumors of AChE and ChE genes implicates cholinesterases with neoplastic growth and/or proliferation. The defective genes can be identified by the techniques mentioned above, and this identification may be of considerable diagnostic value, enabling treatment at very early stages of the disease. The invention thus further provides an assay for the determination in mammals, including humans, of genetically altered cholinesterase-producing genes, essentially comprising the steps of: (a) obtaining DNA samples from the patient; (b) enzymatically restricting the DNA; (c) electrophoretically separating fragments of the DNA and blotting the fragments on a suitable support; (d) providing a labeled DNA or RNA probe of pre-determined sequence from cholinesterase or essential fragments thereof or polypeptides having human cholinesterase activity; (e) hybridizing the fragments obtained by step (c) with the probe (d); and (f) detecting the presence or absence of altered genes according to the hybridization pattern. The invention will now be described in more detail on hand of the following EXAMPLES, which are illustrative and do not limit the invention unless otherwise specified. EXAMPLES Example 1 General Methods To search for cDNA clones encoding human ACHE, oligodeoxynucleotide probes were synthesized according to the amino acid sequences in evolutionarily conserved and divergent peptides from electric fish AChE (17) as compared with human serum BuChE (53,20,9). These synthetic oligodeoxynucleotide probes were used for a comparative screening of cDNA libraries from several human tissue origins. Previous biochemical analyses revealed that in the fetal human brain, the ratio AChE:BuChE is close to 20:1 (14) In contrast, the cDNA library from fetal human liver was found to be relatively rich in BuChEcDNA clones (20). Therefore, cDNA clones were searched for, that would interact with selective oligodeoxynucleotide probes, designed according to AChE-specific peptide sequences in cDNA libraries from fetal and adult brain origin, and particularly from brain basal ganglia that are highly enriched with cholinoceptive cell bodies. Positive clones were then examined for their relative abundance in brain-originated cDNA libraries, as compared with liver. Brain-enriched cDNAs were further tested for their capacity to hybridize with the OPSYN oligodeoxynucleotide probes, previously designed according to the concensus amino acid sequence at the active esteratic site of ChEs (53). Finally, the confirmed clones were hybridized with BuChEcDNA and found to be not homologous to it. Use of Oligodeoxynucleotides in Hybridization Reactions and Isolation of cDNA Clones In detail, differential screening of various cDNA libraries from fetal human tissues was performed using two different oligodeoxynucleotide probes, designed to complement the predicted mRNA sequence as follows. Probe CTACHE, d[3'- ATG.TAC.TAC.GTG.ACC.TTC.TTG.GTC.AAG.CTG-GTG-AT], a 35-mer that represents the peptide sequence Tyr-Met-Met-His-Trp-Lys-Asn-Gln-Phe-Asp-His-Tyr, present in the c'-terminal region of Torpedo AChE (17), and in which G or C residues were inserted in positions where codon ambiguity presented a choice between G or T or between C or A, respectively. This probe was designed so that it would not hybridize with BuChE, since 3 out of the 12 amino acids are different in the parallel peptide of human BuChE (20). Probe OPSYNO, d[3'-AA.CCI.CT(CorT).(TC(A or G).AGI)CGI.CCI. CGI.CGI.(TC(A or G).AGI).CA], a 29-mer with a 36-fold degeneracy in which deoxyinosine was inserted in positions where codon ambiguity permits all four nucleotides (20), and where only one or the other of the two triplets in parentheses is present. This probe was expected to hybridize with both BuChEcDNA and AChEcDNA since it codes for the peptide Phe-Gly-Glu-Ser-Ala-Gly-Ala-Ala-Ser-Val found in the active esteratic site of human serum BuChE and that differs from the parallel peptide of Torpedo AChE by one amino acid only (No. 7 in this peptide, Gly in Torpedo). Oligodeoxynucleotides were 5'-end-labeled and screening was performed as previously described (53,20), using cDNA libraries from basal brain nuclei of 1 day old newborn (donated to the American Type Culture Collection by R. A. Lazzarini) and from fetal liver [21 weeks gestation (20)]. Two clones with 1.5 Kb inserts from the basal nuclei library, later found to be identical, were found positive first with the selective and then with the common active site probe and were designated BGSA (FIG. 1a refers) and ABGACHE (FIG. 1aa refers). Rescreening of the basal nuclei and the fetal liver libraries with [ 32 P]-labeled BG8AcDNA resulted in the isolation of 40 and 19 positive clones, respectively, and DNA sequencing revealed that they all encoded polypeptides having the same active site sequence. One of the liver clones, designated FL2B (FIG. 1a) and another from fetal muscle, designated FEMACHE (FIG. 1aa) were found to also include complete 3'-non-translated regions of 500 bp, ended with a polyadenylation site and a poly(A) tail. To reveal the full length of the AChE coding sequence, probe k-153, a 17-mer d[5'-CG°GCC°ATC°GTA°CAC°GTC], was designed according to the nucleotide sequence at the 5'-end of clone ABGACHE. It is complementary to the sequence encoding the peptide Asp-Val-Tyr-Asp-Gly-Arg that is highly specific for ACHE, and was used to screen a human genomic DNA library (BRL, Gaithersburg). The resultant genomic DNA clones were further characterized by hybridization with ABGACHEcDNA followed by double-strand DNA sequencing with the Sequenase kit (USB, Ohio). One of these clones, GNACHE, included the complete 5'-region of the AChE coding sequence, which was ligated with the cDNA clone to construct a pGEM transcription vector having the SP 6 RNA polymerase binding site (Promega, Madison). Transcription in vitro of this construct, Xenopus oocyte microinjection and acetylthiocholine hydrolysis were performed as recently described (77). Spontaneous substrate hydrolysis values were subtracted. The authentic nature of the recombinant AChE produced in the oocytes provided proof that this was indeed the correct sequence. Example 2 Sequencing the AChEcDNA Clones A. Sequencing strategy (i) The differential screening procedure described in Example 1 preliminarily resulted in the isolation of several brain, muscle and liver cDNA clones that included the regions complementary to probes CTACHE and OPSYNO (FIG. 1a) and which corresponded exactly to the peptide sequences used to design these oligodeoxynucleotide probes [FIG. 1c, FIG. 1d, FIG. 1e, amino acid residues encoded by nucleotides CTACHE (1440-1472) and OPSYNO (334-362), respectively]. All of the isolated clones contained large overlapping identical fragments, suggesting that they were derived from similar mRNA trancripts. Rescreening of cDNA libraries using these clones as probes further resulted in the isolation and characterization of fetal brain and liver cDNAs encoding the 3'-region of these cDNAs. A 400 nucleotide sequence from the 5'-region of AChEcDNA remained apparently missing because of the G,C-rich nature of this sequence, preventing reverse transcriptase from completing its synthesis. According to the strategy schematically illustrated in FIG. 1a, the entire DNA inserts of BG8A and FL2B and their restriction endonuclease EcoRI fragments were isolated and subcloned in the sequencing vectors M13mP18, M13mP19 and pUC118 (Amersham, Stratagene). DNA sequencing of the resulting recombinants was done by the dideoxynucleaside procedure, using the universal 17-mer primer (Amersham, No. 4511, indicated by filled circles at the beginning of arrows) or unique 17-mer primers synthesized from confirmed cDNA sequences (indicated by arrows beginning with empty circles). Confirmed sequences were obtained from both strands of the cDNA as indicated by arrow length and direction. Sequence data were managed as detailed previously (5). Restriction sites for several nucleases were located by computer analysis of the sequence data and confirmed experimentally. (ii) Further experiments of the differential screening described above resulted in the isolation of several additional brain, muscle and liver cDNA clones that included regions complementary to probes CTACHE and OPSYNO (FIG. 1b) and which correspond exactly to the peptide sequences used to design these oligodeoxynucleotide probes [FIG. 1f, FIG. g amino acid residues encoded by nucleotides CTACHE (1939-1947) and OPSYNO (847-876), respectively]. All of the isolated clones contained large overlapping identical fragments, suggesting that they were derived from similar mRNA trancripts and they were all terminated downstream of the region encoding the persued N-terminus of the AChE protein. A genomic DNA clone overlapping this region was then isolated which included the missing upstream sequence preceded by an AUG codon that was embedded in an appropriate concensus sequence for initiation of translation (21). According to the strategy schematically illustrated in FIG. 1aa, the entire DNA inserts of ABGACHE, FEMACHE and GNACHE and their restriction endonuclease EcoRI fragments were isolated and subcloned in the sequencing vectors M13mP18, M13mP19 and pUC118 (Amersham, Stratagene). DNA sequencing of the resulting recombinants was done by the dideoxynucleaside procedure, using the universal 17-mer primer (Amersham, No. 4511, indicated by filled rectangles at the beginning of arrows) or unique 17-mer primers synthesized from confirmed cDNA sequences (indicated by arrows beginning with circles). Confirmed sequences were obtained from both strands of the cDNA as indicated by arrow length and direction. Sequence data were managed as detailed previously (5). Restriction sites for several nucleases were located by computer analysis of the sequence data and confirmed experimentally. B. Primary structure of the fetal human AChE encoded by the brain and liver cDNA clones BG8A, F12B and FB5. (i) As may be seen in FIG. 1b, FIG. 1i, the 1.8-Kb composite nucleotide sequence of clones BG8A and FL2B was translated into its encoded amino acid sequence. Nucleotides are numbered in the 5'-to-3' direction, and the predicted amino acids are shown below the corresponding nucleotide sequence. Boxing indicates the esteratic site 14 amino acid residues that was found to exactly match the parallel peptide present in human serum BuChE (14,15) and was encoded, as expected, by the synthetic OPSYNO concensus oligodeoxynucleotide probe. Also boxed is the c-terminal selective 12 amino acid residues sequence which matched with a single nucloetide mismatch the ACh-specific probe CTACHE (see Example 1) and which was expected and found to be completely different from the parallel peptide in BuChE. Three putative sites for potential N-linked glycosylation, predicted by the sequence AsnXaa-Thr/Ser, in which Xaa represents any amino acid except proline (14), are doubly underlined. Eight Cys residues are enclosed in hexagons. 3' untranslated region is marked. The primary structure of the various oligonucleotide probes used to sequence fetal human AChE is shown in FIG. 1c-1e. (ii) In subsequent experiments, as may be seen in FIG. 1f-1g, the 2.2-Kb composite nucleotide sequence of clones GNACHE, ABGACHE and FEMACHE was translated into its encoded amino acid sequence. Nucleotides are numbered in the 5'-to-3' direction, and the predicted amino acids are shown below the corresponding nucleotide sequence. Overlining indicates the esteratic site 14 amino acid residues that was found to exactly match the parallel peptide present in human serum BuChE (14,15) and was encoded, as expected, by the synthetic OPSYNO concensus oligodeoxynucleotide probe. Also overlined is the c-terminal selective 12 amino acid residues sequence which matched with a single nucloetide mismatch (notched) the ACh-specific probe CTACHE (see Example 1) and which was expected and found to be completely different from the parallel peptide in BuChE. Three putative sites for potential N-linked glycosylation, predicted by the sequence AsnXaa-Thr/Ser, in which Xaa represents any amino acid except proline (14), are ovally circled. Nine Cys residues, as well as the first and last amino acids in the mature protein and the initiator methionine, are enclosed in circles. 5' and 3' untranslated regions are marked by no space between lines. The primary structure of the various oligonucleotide probes used to sequence fetal human AChE is shown in FIGS. 1f-1g. Example 3 Expression of Cloned Composite ACbEDNA in Microinjected Xenopus Oocytes In experiments for proving the identity and authenticity of the cloned AChEcDNA, the expression of its biologically active protein product was analyzed in Xenopus oocytes microinjected with synthetic AChEmRNA. For expression studies, consecutive DNA fragments from clones ABGACHE and GNACHE (FIG. 1aa) were prepared by digestion with the restriction enzymes Hind III and Sph I, ligated and subcloned into the pGEM-7ZF (Promega) transcription vector, linearized with EcoRI. EcoRI was heat inactivated (15 min, 68° C.) in both DNA samples and ligation was performed overnight at 4° C., in a reaction mixture containing 1 mM ATP, ligase buffer (according to the instructions of New England Biolabs) and 800 units of T 4 DNA ligase from the same source (NEB). Ligated DNA constructs were used to transform competent E. coli MV 1190 cells. Recombinant clones were detected by creating white colonies in the presence of IPTG and x-gal, indicating the inactivation of their β-galactosidase gene. Plasmid DNA was prepared from these colonies and employed for transcription in vitro using T 3 and T 7 RNA polymerase and cap analogue (Pharmacia). Synthetic mRNA transcripts were injected into Xenopus oocytes and AChE biosynthesis analyzed as previously detailed (77) for BuChEmRNA expression. One ng. samples of full-length recombinant AChEmRNA transcribed from this construct (in three independent transcription experiments) reproducibly induced in microinjected Xenopus oocytes the biosynthesis of catalytically active AChE capable of hydrolyzing 0.3±0.05 nmol of acetylthiocholine per hr., about 1000-fold higher efficiency as compared with the production of AChE from poly(A) + brain mRNA (61). In contrast, the recombinant enzyme appeared to be much less (50-fold less) efficient in its ability to hydrolyze butyrylthiocholine. Furthermore, the oocyte-produced enzyme was markedly (100%) sensitive to inhibition by 10 -5 M of the selective AChE inhibitor 1,5-bis-(4-allyldimethylammoniumphenyl)-pentan-3-one dibromide (BW284C51) but totally insensitive to 10 -5 M of the selective organophosphorous BuChE inhibitor tetraisopropylpyrophosphoramide (iso-OMPA) in the same concentration (Table I). Altogether, these experiments demonstrated that the combined sequence encoded for authentic human ACHE. TABLE I______________________________________Inhibition of Recombinant Human AChE Produced byMicroinjected Xenopus Oocytes by Cholinesterase Inhibitors AcThCho degraded % remainingInhibitor pmol/hr per ng mRNA activity______________________________________1. None 300 ± 5 1002. BW284C51 3 ± 1 1 ± 0.33. iso-OMPA 280 ± 10 98 ± 3______________________________________ a. Microinjection was performed using synthetic mRNA encoding AChE from 3 separate in vitro transcription reactions. Total AChE-mediated hydrolysis of acetylthiocholine (AcThCho, 1 mM) as a substarte was determined spectrophotometrically within oocyte homogenates over a period of 8-10 hrs. from 3 separate microinjection experiments repeated in quadruplicate per assay. b. In order to ascertain sensitivity to inhibitors, either BW284C51 (10 μM) or iso-OMPA (10 μM) were added to reaction mixtures 40 min. prior to the addition of the substrate. Net activities and percent inhibition values of recombinant AChE enzyme are shown, following subtraction of the endogenous AChE residing within Xenopus oocytes. Data shown represent mean values ±SEM. Example 4 Amino Acid Homologies Between ChEases from Different Origins When the amino acids predicted from the above cDNA sequences were aligned with the available complete sequence data published for human BuChE (20), Torpedo AChE (17) and Drosophila AChE (18) and esterase 6 (19) and with the incomplete sequence of bovine AChE and thyroglobulin (55), the entire coding region for a highly homologous protein was defined. This sequence includes the concensus active site which contains a serine residue that can be labeled by diisopropylfluorophosphate (FIGS. 2, 2a, 2b, indicated by a star). The pronounced homology at the N-terminal part that is considerably higher between cholinesterases as compared with the esterase 6 and the thyroglobulin sequences should be noted. The general amino acid composition of the protein encoded by these cDNAs was very similar to that reported for human erythrocyte AChE (56). Example 5 A. Comparison of ChEs Active Site Region Sequences with other Serine Hydrolases Active site region sequences of ChE were compared with those of other serine hydrolases. Results are shown in FIG. 3, in which the star indicates [ 3 H]-DFP-labeled or active site serine. DNA sequence analysis followed by computerized alignment of the encoded primary amino acid sequences of human AChE and BuChE demonstrated, as expected, that the functional similarity among ChEs reflects genetic relatedness. The active site peptide of human ACHE, as deduced from the AChEcDNA clones, revealed 17 out of 21 amino acid residues identical to those of either human BuChE or Torpedo AChE (FIG. 3). Lower level of similarity (12 out of 21 amino acid residues) was observed in comparison with Drosophila AChE (18). Esterase 6 from Drosophila (19) displayed 10 identical residues out of these 21, and several serine preoteases--3 or 4 identical residues only (FIGS. 2, 2a, 2b). This comparison draws a distinct line between serine proteases and the family of carboxylesterases, and more particularly--the highly conserved ChEs. B. Comparison of the Coding Region in Human AChEcDNA and the Inferred Amino Acid Sequence of the Human AChE Protein with the Parallel Sequences of other ChEs. The coding region in human AChEcDNA and the inferred amino acid sequence of the human AChE protein were compared with the parallel sequences of human BuChEcDNA (53,20,21), of AChEcDNA from Torpedo (17) and of the more evolutionarily remote AChEcDNA from Drosophila (18). Results are shown in FIG. 4. Regions of homology were searched for by the dot matrix approach (57). Match values that yielded clear homology regions and minimal background noise are presented: 12 out of 15 conservative matches for nucleotide sequence and 4 out of 5 conservative matches for amino acid residues. Nucleotides are numbered in the 5'-to-3' direction and amino acids in the N-to-C' direction for all of the sequences. This analysis revealed several peptide regions and DNA sequence domains that are highly conserved in all of the ChEs and displayed clearly the higher level of divergence between human and Drosophila AChEs, as opposed to the extensive similarities between human AChE and BuChE and Torpedo ACHE. A higher level of conservation was found at the amino acid level (FIG. 4, up) than at the nucleotide level (FIG. 4, down) in complete agreement with previous observations (20,5). Significant homology was also observed with the DNA and the amino acid sequence of bovine thyroglobulin, in corroboration of previous findings (17,5). Notwithstanding this homology, the AChEcDNA sequence does not hybridize at all with the previously isolated BuChEcDNA. This is due to its G,C-rich nature, opposing the A,T-rich nature of BuChEcDNA. C.Hydrophobicity Analysis of Human AChE and other ChE To further examine the molecular properties of the human AChE protein encoded by the newly isolated cDNA clones, it was subjected to hydrophobicity analysis according to (58). The results of this analysis are presented in FIG. 5, together with parallel analyses of the homologous sequences of human BuChE, Torpedo AChE and Drosophila ACHE. In FIG. 5, the dotted vertical baseline in each box represents a hydrophylicity value of --o--; increasing hydrophylicity is in the right-hand direction and increased hydrophobicity is in the left-hand direction. The human AChE inferred from this sequence has three potential sites for asparagine-linked carbohydrate chains, less sites than Torpedo AChE (17) and human BuChE (20,21). Its hydropathy index and putative charge relay system, as well as lack of sequence homology to serine proteases distinguish this protein as a type B carboxylesterase of the cholinesterases family (8) with a c-terminal peptide that is characteristic of the soluble AChE forms (16,17). It includes 9 cysteine residues, as compared with 7 residues for Torpedo AChE (17) and with 8 for human BuChE (20,21). Six intrachain disulfide bonds would be predicted to be at Cys 68 -Cys 95 , Cys 256 -Cys 271 and Cys 408 -Cys 529 . A fourth predicted disulfide bridge involves Cys 580 which, in all soluble cholinesterases, appears to be covalently attached to the parallel cysteine residue of an identical catalytic subunit (16,17). This leaves two additional cysteine residues at positions 419 and 422, that are particular to human ACHE. Comparative analysis of the amino acid sequence inferred for human ACHE, human BuChE, Torpedo and Drosophila ACHE, Drosophila esterase 6 and bovine thyroglobulin revealed 5 clear domains of sequence similarities with a decreasing homology, and with higher sequence conservation at the N-terminal part of cholinesterease. Conserved cysteine residues appeared at the borders of these homologous domains, in parallel with a similar phenomenon in the insulin receptor protein family. The level of conservation at the amino acid level was found to be considerably higher than at the nucleotide level for all of these sequences. Example 6 Pronounced Synthesis of AChEmRNA Transcripts in Human Fetal Brain Basal Nuclei Human AChEcDNA and BuChEcDNA probes were purified by enzymatic restriction, agarose gel electrophoresis and electroelution and were labeled with [ 35 S]-deoxyadenosine and deoxycytosine by multi-primed synthesis (Amersham) to specific activities of 5×10 9 cpm/μg. Frozen 10 μm thick sections from the brain basal nuclei of 21 weeks human fetuses were employed for hybridization with these probes as previously described. Exposure under Kodak NTB-2 emulsion was for 5 days at 4° C. Counter-staining was with hematoxilin-eosine. FIG. 6 displays photographs of sections hybridized with AChEcDNA (A,B) and BuChEcDNA (C,D). Pre-treatment with ribonuclease A abolished most labeling (B,D) in both cases. Level of AChEmRNA in multiple brain cells (A) was high as compared with low level of BuChEmRNA transcripts (C). Intensively labeled round large neuronal cells are marked by arrows. Thus, dot-blot hybridization of fetal brain poly (A)+RNA using 32 [P]-labeled AChEcDNA and BuChEcDNA, indicated low levels (about 0.01% and 0.001% of total mRNA, respectively) for both cholinesterase mRNA transcripts (not shown), in complete agreement with previous oocyte microinjection studies (61). In situ hybridization of these two cDNA probes, labeled with [ 35 S], to frozen sections from fetal brain basal nuclei revealed pronounced synthesis of AChEmRNA transcripts in multiple neuronal cell bodies within this brain area, noted for being enriched in cholinoceptive cell bodies (15). In contrast, labeling with BuChEcDNA was considerably lower in basal nuclei sections (FIG. 6), in agreement with previous cytochemical staining studies (62), and pre-treatment with pancreatic RNase abolished labeling with both probes (FIG. 6). Average number of grains per 100μ 2 was 160±10 (n=20) and 10±3 (n=20) for the AChE and BuChEcDNA probes, respectively. The ratio between the mRNA transcripts encoding these two enzymes in cholinoceptive brain cells is hence 16:1, close to the 20:1 ratio between their catalytic enzymatic activities (14) and suggesting that the level of active ChEs in human tissues reflects the level of transcription in their corrsponding genes. Example 7 DNA Blot Hybridization with Labeled ChEcDNA Probes Samples of 10 μg of human genomic DNA were enzymatically restricted with EcoRI (RI) or with PvuII (PV) and separated on 0.8% agarose gels. Agarose gel electrophoresis and filter hybridization were as previously described, using AChEcDNA (Ac) or BuChEcDNA (Bt) probes labeled with [ 32 P] by multiprime labeling to specific activities of 5×10 9 cpm/μg. Exposure was for 10 days with an intensifying screen. Results are shown in FIG. 7a. Lambda phage DNA cut with Hind III served for molecular weight markers (arrows). The genomic DNA blot hybridized with [ 32 P]-labeled probes of AChEcDNA and then BuChEcDNA reveals clear differences between the hybridization patterns obtained with the human genomic DNA sequences encoding BuChE and ACHE, respectively. Although this analysis does not completely exclude the possibility that alteranative splicing from a single gene is responsible to these different patterns, it certainly makes it highly unlikely. New information based on cosmid recombination cloning has now revealed that the gene encoding BuChE does not contain AChE coding sequences (80). Taking into account that there are three sites on human chromosomes that carry DNA sequences encoding BuChE (63,47), this implies the existence of a fourth cholinesterase gene (and perhaps more, although not many, as inferred from the intensity of hybridization) in the human genome. The presence of several EcoRI and PvuII sites in this gene indicates that it includes intervening sequences in addition to the regions represented in the cDNA. Parallel hybridization experiments with genomic DNA from several other species [bovine, rat, chicken and Torpedo (not shown)] revealed a high evolutionary conservation for the AChE genes. Mapping of the Human Genes Coding for ChEs on Chromosome No. 3 Using in situ chromosomal hybridization, inventors demonstrated that chromosome 3 carries sequences hybridizing with and BuChEcDNA. In situ hybridization experiments were performed using Q-banded and R-banded chromosome preparations from peripheral blood lymphcytes and the above BuChEcDNA probe labeled with [ 35 S]. Chromosome spreads from peripheral blood lymphcytes treated with 5-bromodeoxy Uracil were pre-incubated in 2×SSC (1×SSC=0.15M NaCl and 0.015M sodium citrate), for 30 min. at 70° C. RNA was hydrolyzed by 60 min. incubation at 37° C. in 0.1 mg/ml of pancreatic ribonuclease (Sigma), followed by successive washes of 5 min. in 2×SSC and 70, 80 and 100% ethanol. DNA was denatured by 4 min. incubation at 70° C. in 70% formamide, 2×SSC and 10 mM potassium phaphate buffer at a final pH of 7.0. The chromosome spreads were immediately transferred to frozen ethanol at 100, 80 and 70% concentrations for successive washes of 5 min. and were air-dried. Each spread was then covered by a 25 μl drop of hybridization solution, containing 50% formamide, 10% dextran sulfate, 1×Denhardt's solution (1×Denhardt's solution is 0.02% Ficoll, 0.02% polyvinylpyrrolidone and 0.02% bovine serum albumin) and 8 ng of the preboiled BuChE-cDNA probe, labeled by nick-translation with [ 35 S]-adenosine and [ 35 S]-cytosine to a specific activity of 1×10 8 cpm/μg and purified by three successive precipitations in ethanol, in the presence of 10 W:W Salmon sperm DNA as a carrier. Hybridization was for 18 hrs. at 37° C., in a humid chamber and under cover slides. The chromosomes were washed with 50% formamide and 2×SSC (1HR, 37° C.), 2×SSC (15 min., 37° C.), 2×SSC and 20 mM β-mercaptoethanol (15 min., 37° C.), 2×SSC (15 min., 37° C.), 2×SSC and 20 mM 5-mercaptoethanol (15 min., 37° C.), 2×SSC (15 min., 50° C.) and 0.15×SSC (15 min., 50° C.), dehydrated by successive 5 min. incubations in 70, 80 and 100% ethanol at room temperature and air-dried. Exposure was under photography emulsion (Kodak NTB-2 diluted 1:1 in H 2 O at 45° C.) in a dry chamber at 4° C. for 12-15 days and development was for 0.5-1.5 min. in D-19 Kodak developer. Slides were then stained for 15 min. in 150 mg/ml Hoechst 33258 Stain (Aldrich), rinsed in distilled water and dried. To create the R-bands, stained slides were mounted in 2×SSC under coverslips and were illuminated for 30 min. by a mercury vapor lamp at a distance maintaining a temperature of 47°-50° C., rinsed in distilled water and restained in 4% buffered Giemsa (Gurr-R-66) at pH 6.8. The cumulative distribution of autoradiographic silver grains observed over photographed chromosome spreads were statistically analyzed. The analysis of silver grain distributions from 52 karyotypes indicates BuChE is located in the q21-q26 region of chromosome 3. Example 8 Detection of Changes of Human ChE Genes Associated with Leukemia and/or Abnormal Megakaryocytopoiesis A. Methods Blood samples were drawn with 5 mM EDTA (pH7.5) from 7 patients (Department of Obstetrics and Gynecology, The Edith Wolfson Medical Center, Holon, Israel) suffering from abnormal platelet counts and leukemias. Blood DNA from 30 apparently healthy individuals served as controls. In addition, DNA from 14 patients with various leukemias was gratefully received from Prof. E. Canaani, The Weizmann Institute of Science. For hybridization experiments, 10 μg samples of purified DNA from peripheral blood were digested to completion with various restriction endonucleases (Boehringer Mannheim), and electrophoretically separated on 1.2% horizontal agarose gels (1.2 mA/cm, 18 hr). DNA was transferred onto GeneScreen membranes (NEN, Du Pont) according to the company's instructions. Filters were subjected to hybridization with electrophoretically purified fragments from AChEcDNA (64) and BChEcDNA (20), 1500 and 2400 nucleotides long, respectively, labeled by "multiprime" DNA polymerase reaction (Boehringer, Mannheim) with [ 32 P]-ATP to 5×10 9 dpm/μg. The hybridization condition used for detecting human ChE gene sequences was that described in reference 20. Specifically, the blot was incubated at 42° C. for 48 hr with 3×10 7 dpm of 32 P labeled DNA probe at a specific activity of 2×10 9 dpm/μg, in 50% (vol/vol) formamide/10% dextran sulfate/0.1% bovine serum albumin/0.1% Ficoll/0.1% polyvinylpyrrolidone/50 mM sodium phosphate buffer at pH 6.5/750 mM NaCl/75 mM sodium citrate/75 μg of herring sperm DNA per ml, adjusted with HCl to a final pH of 6.5. The blot was washed in 15 mM NaCl/1.5 mM sodium citrate at 50° C. (four times, 30 mins. each). DNA preparation, hybridization, x-ray film autoradiography and optical densitometry were performed as previously described (66) using the isolated cDNA fragments for quantitative analysis. B. Amplification of ACHE and CHE Genes (1) Appearance of Amplified ChE Genes in Various Types Leukemia In order to search for putative structural changes within the human ACHE and CHE genes encoding AChE and BuChE, the restriction fragment patterns in peripheral blood DNA from 16 patients with various leukemias as compared with DNA from 30 healthy individuals was first examined. For this purpose DNA blot hybridization was performed with equal amounts of patients' DNA following complete digestion with the restriction endonucleases PvulI and EcoRI and gel electrophoresis (see Methods). Hybridization with [ 32 P]-labeled AChEcDNA and BuChEcDNA repeatedly revealed invariant restriction patterns and signal intensities for DNA from all of the healthy individuals. The same restriction patterns and signal intensities were observed in DNA from 12 of the leukemic patients. In contrast, the hybridization patterns in the 4 remaining samples displayed both qualitative alterations and a clear signal enhancement with both cDNA probes. These observations are summarized in Table II hereafter [under (A)]. (2) DNA Blot Hybridization of Leukemic DNA Samples. FIG. 8 presents the DNA blot hybridization results obtained with three of the four latter leukemia DNA samples [see under (1)] and with one of the controls. In this experiment 10 μg of peripheral blood DNA from 3 AML cases and one healthy control (L10, L62, L70 and C1, see Table I for details) were subjected to complete enzymatic digestion with the restriction endonucleases PvuII and EcoRI, followed by agarose gel electrophoresis and DNA blot hybridization with [ 32 P]-labeled AChEcDNA and BuChEcDNA probes (see Methods). The experimental conditions were as detailed under Methods and in previous publications (5,20,65,47). Ethidium Bromide staining of the agarose gels was employed to ascertain that equal amounts of DNA were loaded and electrophoretically separated in each of the lanes. Exposure was for 10 days at -70° C. with an intensifying screen. Hind III digested DNA from Lambda and φ×174 phages served as molecular weight markers. Results are presented in FIG. 8, revealing intensified labeling signals appeared in bands that are also present in the control bands. Also, in leukemic DNAs novel labeled bands appeared, which are absent from the control lanes. (3) Appearance of Amplified CHE Genes in Patients with Platelet Disorders In view of the promising results described under (2) and the previous reports correlating ChE with megakaryocytopoiesis and platelet production (43,44,45,46), DNA from additional patients with platelet disorders, whether or not defined as leukemic was examined. Results are presented in TABLE II hereafter [under (B)]. Significantly enhanced hybridization signals with both cDNA probes were found in 3 out of 5 such patients examined, one of them leukemic. Interestingly, the intensity of hybridization in 2 of these samples was much higher than it was in any of the previously tested leukemic DNA samples. (4) DNA Blot Hybridization of DNA Samples from patients with Hematopoietic Disorders. FIG. 9 presents the DNA blot hybridization results obtained from one patient with highly increased platelet counts (ETG), from a leukemic patient with decreased platelet counts (ADS) and from a healthy donor (C2). Experimental details and conditions were identical with those of the experiment shown in FIG. 8. As may be seen in FIG. 9, there was pronounced enhancement of hybridization signals with both probes. Furthermore, the amplification events in these two samples appeared to involve many additional PvuII-cut DNA fragments, due to either nucleotide changes producing novel PvuII restriction sites, or different regions of DNA having been amplified. This may also be seen in FIG. 10a, described hereafter. (5) Comparative Analysis of DNA Samples from a Healthy Control, a Leukemic AML Case and a Non-Leukemic Case with Platelet Disorder. (i) Comparative analysis was performed with representative DNA samples from a healthy control (C1), a leukemic AML case with moderate amplification (ADS) and a non-leuklemic case with pronounced decrease in platelet counts (YED), by DNA blot hybridization using [ 32 P]-labeled probes. FIG. 10a illustrates blot hybridization patterns with PvuII cut genomic DNA and AChEcDNA probe (Ac) and with EcoRI cut genomic DNA and BuChEcDNA probe (Bt). Conditions were same as those employed in FIG. 8, with exposure for 6 days. (ii) To further compare the restriction fragment patterns of the amplified genes, the relevant lanes from the above described autoradiograms were subjected to optical densitometry. Results are shown is FIG. 10b. In this experiment, optical densitometry of individual lanes from the PvulI-treated, AChEcDNA-hybridized blot was performed at 545 mμ [details may be found in (72)]. This analysis clearly demonstrates the appearance of slightly enhanced hybridization signals at equal migration positions to those observed in control DNA from a representative leukemic DNA sample, marked L70 (FIG. 10b), with a moderate amplification. In another leukemic DNA sample, marked ADS, and taken from a patient with reduced platelet counts, the densitometry signals were higher by an order of magnitude and presented several additional short PvuII-cut fragments. Yet much higher signals and more novel bands of various sizes were observed with the YED sample, derived from a non-leukemic patient with a pronounced decrease in platelet count (thrombocytopenia). This may also be seen in FIG. 10c, which shows restriction sites for PvulI and EcoRI on the cDNA probes. This Figure shows that the number of PvuII-cut DNA fragments in YED that were labeled with AChEcDNA exceeds their expected number of three fragments based on the PvuII restriction pattern of AChEcDNA, which may either indicate the extension of amplification into intron regions or reflect structural changes and appearance of novel PvuII restriction sites within the amplified DNA sequence. (6) Quantification of the Amplification Levels in Diseased DNA Samples by Slot-Blot Hybridization The variable degrees of amplification occurring in the genes coding for AChE and BuChE in said individuals were quantified by slot-blot hybridization, using a 5-fold dilution pattern. In this experiment, denatured genomic DNA from the same 5 individuals that were analyzed in FIGS. 10 was spotted onto a GeneScreen filter using slot-blot applicator (Bio-Rad). Electroeluted AChEcDNA (Ac) and BuChEcDNA (Bt) inserts (FIG. 10c) were spotted in parallel for calibration. Herring testes DNA (Co) served as a negative control. All samples contained the noted quantities of genomic or insert DNAs supplemented with denatured Herring testes DNA to yield a total of 2 μg-DNA per slot. Hybridization, wash and exposure were done with [ 32 P]-labeled AChEcDNA or BuChEcDNA [for details see (66]. Results are shown in FIG. 11. Cross hybridization between AChE and BuChE cDNA probes was exceedingly low (less than 0.01), demonstrating that the observed amplification events indeed occurred in each of these genes and did not merely reflect similarity in their sequences. As may be seen in FIG. 11, 1 μg of YED DNA included genomic sequences equivalent to at least 1 ng of each purified DNA sequence. Taking the total complexity of human genomic DNA as 4×10 9 bp, this implies that more than 1000 copies of these sequences are present in YED's DNA. ADS'and ETG's DNAs featured about 20- and 40-fold lower signals, respectively, with BuChEcDNA and, in the case of ADS, somewhat weaker signals with the AChEcDNA, reflecting more modest amplifications in an order of up to 100 copies per genome, in itself a remarkable level. A summary of the appearance of amplified CHE genes in patients with hematocytopoietic disorders is given in TABLE II. Footnotes to TABLE II: 1. Peripheral blood DNA from 14 leukemic patients was received, together with clinical classification of the disease type, from Dr.E. Canaani, The Weizmann Institute of Science. Two other patients (LO3 and ADS) were diagnosed and classified in the Department of Obstetrics and Gynecology, The Edith Wolfson Medical Center, Holon, Israel. (AMegL: Acute megakaryocytic leukemia; AMoL: Acute monocytic leukemia; AMML: Acute monocytic/myeloid leukemia; AMLM2: FAB sub-classification of AML). 2. The characteristic types of hematopoietic progenitor cells which appear to be defective in each class of the screened leukemias are noted (50). 3. The approximate extent of amplification was separately determined for the ACHE and CHE genes by slot-blot DNA hybridization and optical densitometry. Numbers reflect the fold increase in number of copies as compared with control DNA. N=normal. 4. Peripheral blood DNA from 5 patients from said Department of Obstetrics and Gynecology, suffering from abnormal platelet counts, was analyzed as detailed above. Abnormalities in platelet counts are noted, where "low" implies<80,000/mm 3 and "high"→500,000/mm 3 (normal counts are considered 150,000-400,000 platelets/mm 3 ). Note that ADS (No. 16) appears twice. 5. DNA samples from apparently healthy individuals with normal platelet counts of blood ChE activities served as controls and were analyzed as detailed above. C1 and C2 correspond to representative control DNAs, shown in FIGS. 8-11. Similar results ware obtained in 28 more controls (not shown). TABLE II______________________________________A. Leukemias.sup.1 defectiveNo. type progenitors.sup.2 Approx. Amplification.sup.3______________________________________ AcChoEase BChoEase 1 L23 AML myeloid N N 2 L38 AMegL promegakaryocytes N N 3 L26 AMOL monocytes N N 4 L10 AML myeloid 30-60 30-60 5 L41 AMML myeloid/monocytes N N 6 L42 AML myeloid N N 7 L79 AML " N N 8 L70 AML " 25-50 25-50 9 L20 AML " N N10 L96 AML " N N11 L62 AMML myeloid/monocytes 25-50 25-5012 L59 AMML " N N13 L15 AML myeloid N N14 L12 AML " N N15 L03 AMLM.sub.2 " N N16 ADS AMLM.sub.2 " 50-100 30-60______________________________________B. Megakaryocytopoietic disorders.sup.4 platelet defectiveNo count progenitors.sup.2 Approx. Amplification.sup.3______________________________________ AcChoEase BChoEase16 ADS low promegakaryocytes 50-100 30-6017 ETG high " 20-40 20-4018 RLI low " N N19 YED " " 500-1000 350-75020 TLK " " N N______________________________________C. Controls.sup.5 platelet defectiveNo count progenitors.sup.2 Approx. Amplification.sup.3______________________________________ AcChoEase BChoEase21 C1 normal none N N22 C2 " " N N______________________________________ SUMMARY Altogether, 6 cases of co-amplification within the ACHE and CHE genes were observed in DNA samples from 20 patients with abnormal hematocytopoiesis, while DNA from 30 healthy individuals showed no amplification or polymorphism with respect to the restriction patterns obtained with these probes. The DNA samples presenting these amplifications were derived from 4 cases of AML with 20-100 copies of both ACHE and CHE genes, and 3 cases of platelet count abnormalities, one with excess platelets count, and 20-40 copies of ACHE and CHE genes, and two others with reduction of platelets count featuring up to 1000 copies of the same genes. These striking concomitant multiplications, summarized in TABLE II, present a highly significant correlation (p<0.01) between amplifications of ChE-encoding genes and the occurrence of abnormal myeloid progenitor cells or promegakaryocytes in the examined individuals. It has thus been shown that the cDNA of the present invention may be used for preparation of probes which may be used to diagnose abnormalities in the human ACHE and CHE genes, associated with various hematopoietic disorders. It has been shown herein that said cDNA probes detected the presence of multiple copies of the genes coding of ChEs in a considerable fraction of the leukemic DNA samples examined. Apart from their diagnostic value, the therapeutic potential of the genetic sequences and proteins of the invention, in treatment of blood cells disorders is also contemplated. Of particular importance is the non-balanced amplification of the AChE gene, which may predict abnormal expression patterns. Example 9 Detection of Changes in AChE and ChE Genes in Primary Ovarian Carcinomas Materials and Methods Primary tumor samples. Specimens of primary tumors were obtained at surgery, frozen immediately in liquid nitrogen and stored at -70° C. until used. Tumor subclassification was performed by standard pathological techniques. DNA and poly (A)+RNA were prepared as previously detailed (47 and 61, respectively). cDNA and plasmid probes. AChEcDNA and ChEcDNA were prepared as previously reported (73). The C-RAFI plasmid was from Amersham. V-SIS, C-FES and C-MYC (third exon) DNA probes were gratefully received from Opher Gileadi (Jerusalem). Blot and in situ hybridization. [ 32 P]- and [ 35 S]-labeled cDNA plasmid probes were prepared by the multi-prime labeling method (Boehringer Mannheim) using enzymatically restricted and gel electroeluted DNA fragments (see (20) and (69) for details). DNA and RNA blot hybridizations were performed as previously described (20,73). In situ hybridization was done with consecutive 10 μm thick Cryostat sections from the above tumor samples as detailed (71). Immunocytochemical staining cytochemical staining of cholinesterase were performed as described (70). Xenopus oocytes microinjection. Oocytes were injected, homogenized and assayed as detailed (61,77) with 50 ng of poly(A)+RNA from primary ovarian carcinomas or with Barth medium for controls. Oocyte incubation was 18 hrs at 19° C. and further enzymatic assays were performed for 48 hrs at 21° C. Data represent average values of 3 determinations with up to 20% deviation. Enzymatic activity measurements. Cholinesterase activities were measured spectrometrically by monitoring the hydrolysis of acetyl- or butyrylthiocholine in the presence of 5,5'-dithionitrobenzoic acid as previously described (70,71) or radioactively by measuring the release of [ 3 H]-acetate from acetylcholine (61). 5-10 μl samples of 1:10 (w:v) tissue or oocyte homogenates in PBS (the equivalent of approximately 1 μg tissue or one half oocyte) were assayed at room temperature. Rates of spontaneous substrate hydrolysis were calculated, averaged and subtracted in both cases. Either 10-5M 1,5-bis (allyldimethylammoniumphenyl)-pentan-3-one dibromide (BW284C51, AChE-specific) or 10-5M tetra isopropylpyrophosphoramide (iso-OMPA, ChE-specific) were used for selective inhibition experiments. iso-OMPA was pre-incubated with the samples 40 min prior to the addition of substrate to ensure complete irreversible binding. (1) Co-amplification of the AChE and ChE genes in primary ovarian carcinomas. 10 μg samples of DNA from 3 primary ovarian carcinomas (Nos. 1,5 and 8, TABLE III), 1 benign ovary (No. 19, TABLE III) from a patient with a unilateral ovarian tumor and 1 brain DNA sample from an apparently normal individual (B) were subjected to complete enzymatic digestion with the enzymes EcoRI or RsaI, followed by agarose gel electrophoresis and DNA blot hybridization with 1.5 Kb long [ 32 P]-AChEcDNA probe (64) or with a 2.4 Kb long [ 32 P]-ChEcDNA probe (20). Experimental details were according to previous publications ((69) and (73)). Ethidiumbromide staining of the agarose gels was employed to ascertain that equal amounts of DNA were loaded and electrophoretically separated in each of the lanes. Exposure was for 10 days at -70° C. with an intensifying screen. Hind III digested DNA from lambda phage and Hae III digested DNA from Φ×174 phage served as molecular weight markers. Internal RsaI restriction sites were found in both of these probes, whereas an EcoRI site exists in ChEcDNA but not in the AChEcDNA probe employed. Intense hybridization signals, reflecting gene amplification, with both these probes, which were shown to be non-cross reactive with each other (73), may be seen in FIG. 1. It should also be noted that the probes used apper to co-label the same genomic DNA fragments in all tumors analyzed. It may be seen from this Example that when DNA from untreated ovarian carcinomas was subjected to enzymatic restriction and blot hybridization with [ 32 P]-ChEcDNA, amplified hybridization signals were clearly observed with both probes in 6 out of 11 malignant tumors, but not in benign ovarian tissues (FIG. 12). In each case of amplification, novel bands were observed in addition to those representing the normal AChE and ChE genes. Moreover, the two non-homologous cDNA probes, which were previously shown not to cross-hybridize (73) appeared to co-label novel restriction fragments of similar sizes, cut with both EcoRI and RsaI, in DNA samples having the co-amplification and under exposure conditions where the normal genes were hardly detectable. In contrast, no such co-labeled fragments were found in DNA samples with normal AChE and ChE genes (FIG. 12). (2) Structural alterations in the amplified ChE genes in ovarian carcinomas (A) Ten microgram samples of DNA from 5 ovarian carcinomas (Nos. 1, 4, 5, 8 and 9, TABLE III) and 1 peripheral blood sample from a healthy individual (see No. 20, TABLE III and (69) for details) were subjected to complete enzymatic digestion with the enzymes Hind III, EcoRI and TaqI, followed by agarose gel electrophoresis and DNA blot hybridization with [ 32 P]-ChEcDNA (20). Experimental conditions were similar to those of FIG. 12. The low intensity signal obtained with the normal ChE gene (No. 20) and the reproducibly altered structure of the amplified ChEDNA fragments should be noted. (B) Restriction site mapping of ChEcDNA (20), which reflects that of the amplified genes in ovarian tumors (FIG. 13A) was performed with enzymes EcoRI (E), TaqI (T) and RsaI (R). Results suggest similar structural properties. Initiation (AUG) and Termination (UAA) sites are noted. The position of the three introns (i1-3) in the human ChE gene was determined by analysis of genomic clones (73, 74). (A)n=3'-poly(A) tail. The coding sequence is represented by shaded areas. (C) To ascertain the specificity of hybridization, used DNA blots were re-hybridized with a plasmid DNA probe from C-RAFI protoncogene (Amersham), wich also detected amplified DNA sequences in these primary tumors (TABLE 3). This probe labeled a single, different band in all of the tumors, confirming that hybridization signals with the AChEcDNA and ChEcDNA probe indeed reflected the true amplification of genuine genomic sequences and were not due to plasmid DNA contaminations (not shown). It is of interest that the amplified ChEcDNA sequences appeared not to include the internal Hind III restriction site characteristic of the normal, intron-containing ChE gene (FIG. 13, (74)(75)). Furthermore, TaqI generated the major fragments of 1400 and 1600 base pairs from amplified ChE genes in each of these tumors, which could hace indicated that the core amplification unit was composed of processed, intron-less ChEcDNA that includes such TaqI sites (20,21) (FIGS. 13A and 13B). However, PCR amplification data have shown that introns were present in the amplified gene. (3) Co-amplification of the AChE and ChE genes with C-RAFI and V-SIS oncogenes demonstrated by dot-blot hybridization. Quantification of the AChE and ChE genes co-amplification in DNA samples from malignant and benign tumor issues (TABLE III) was performed by dot-blot DNA hybridizations followed by optical densitometry of blot autoradiograms in comparison with the purified ChEcDNA and AChEcDNA inserts (for details see (69),(72)). Parallel blots were hybridized with DNA probes for the oncogenes C-RAFI (Amersham) and V-SIS (gratefully received from Opher Gileadi). Blots presented include series of 2-fold dilutions of μg quantities of genomic DNA preparations. The amplified signals in several of the examined samples and the co-amplification of the C-RAFI and V-SIS oncogenes in part, although not all of these samples should be noted. Representative calibration blots with pg quantities of the relevant purified cDNA inserts are included (center). Examples for the blot hybridization analyses and a summary of the data are presented in FIG. 14 and TABLE III. The aforementioned DNA samples from 6 malignant ovarian tumors included 7-23 pg of ACheDNA and 20-60 pg of ChEDNA per μg genomic DNA whereas DNA samples from four healthy control tissues and five benign tumors that were thus examined were found to include AChEDNA and ChEDNA sequences equivalent to 1-7 pg of AChEcDNA and ChEcDNA per μg (FIG. 14, TABLE I). These data reflect up to 10- or more fold ampilfication of the AChE and the ChE genes in those ovarian tumors. Hybridization with regional ChEcDNA probes (69) indicated that the amplified DNA included the entire ChE coding sequences (not shown). Parallel hybridizations with cDNA probes from four different oncogenes revealed pronounced amplifications of the protein kinase oncogenes C-RAFI and C-FES as well as the growth-factor oncogene V-SIS in three of the six tumors having AChE and/or ChE gene amplifications. Interestingly, these were the tumors with higher levels of amplified AChEDNA and ChEDNA sequences and higher ratios between ChE:AChE gene amplifications. No amplification in the third exon from C-MYC, a nuclear protein oncogene, was observed in any of these primary tumors. There was no apparent correlation between any of these gene amplifications and patient age. (4) Expression of full-length ChEmRNA and existence of translatable ChEmRNA in ovarian carcinomas. (A) Ten microgram sample of poly(A)+RNA from a representative ovarian carcinoma tumor (Oc, No. 8 in TABLE 1 and FIGS. 12 and 13) and from fetal human adrenal (Ad), kidney (Ki), liver (Li) and heart (He) (17 weeks gestation) were subjected to gel electrophoresis and RNA blot hybridization with [ 32 P]-ChEcDNA (for details see Prody et al., 1987). Repeated hybridization of the same blot with another cDNA probe, termed TH 14, revealed low intensity signal in all lanes (not shown), implying that the intensified labeling of 2.4 Kb ChEmRNA in the tumor tissue was specific and was not due to RNA overloading. Ribosomal RNA (28S, 5 Kb and 18S, 2 Kb) served for size markers. Exposure was for 5 days at -70° C. with an intensifying screen. RNA blot hybridization of poly(A)+RNA from normal ovary revealed no signal at all (79). (B) Fifty nanogram samples of poly(A)+RNA from the same primary tumor referred to under A were injected into Xenopus laevis oocytes and the resultant acetylcholine (ACh) hydrolyzing activities (+) were measured (for details see (61),(77)). Barth-medium injected oocytes served as controls (-). The selective inhibitors 1,5-bis (4-allyl-dimethyl-ammoniumphenyl)-pentan-3-one (BW284C51) and tetraisopropylpyrophosphoramide (iso-OMPA) were both employed in final concentrations of 1.10-5M to specifically block the activities of AChE and ChE, respectively. The intensive production of ChE activity in the tumor mRNA-injected oocytes should be noted (for comparison, fetal brain mRNA induces 1.4 nmol ACh hydrolyzed per μg RNA). As may be seen from this Example (Table III), measurements of AChE and ChE catalytic activities in soluble and membrane associated fractions from tumor homogenates revealed variable levels of both enzymes, in the range of 100-1000 nmol acetylthiocholine and butyrylthiocholine hydrolyzed per min. per gram tissue. There was no correlation between the level of soluble or membrane-associated enzyme activities and the extent of AChEDNA and/or ChEDNA amplifications (TABLE III). However, the ChE activities in tumor homogenates could be accounted for by residual blood contaminations, capable of contributing ChE activities in the range of several μmol/min/ml (76). Similarly, residual erythrocyte contaminations could explain the measured AChE activities. Therefore, the question of whether the amplified AChEDNA and ChEDNA sequences were expressed as active hydrolytic enzymes could not be resolved by enzyme activity measurements. The presence of ChEmRNA transcripts in the ovarian tumors was first persued by RNA blot hybridization. This analysis revealed, in three of the tumors bearing amplified ChEDNA, significantly enhanced labeling of a full-length 2.4 KB ChEmRNA relative to that observed in normal ovarian tissue (5) and in other normal developing tissues (FIG. 15A). The G,C-rich AChEcDNA probe tends to bind non-specifically to multiple RNA bands and gave inconclusive results. However, when poly(A)+RNA from such ovarian tumors was microinjected into Xenopus oocytes, it directed the synthesis of both AChE and ChE activities, sensitive to the selective inhibitors BW284C51 and iso-OMPA, respectively. The levels of induced activities were about twice as high as those measured for brain AChEmRNA ((61)(77, FIG. 15B). (5) Focal expression of the amplified AChE and ChE genes as demonstrated by in situ hybridization and immunochemical and cytochemical staining. As may be seen in FIG. 16, consecutive 10 μm thick cryostat sections from a representative ovarian tumor(No. 3, see TABLE 3 and FIG. 12 and 13) were subjected to in situ hybridization with [ 35 S]-ChEcDNA (A) or [ 35 S]-AChEcDNA (B), cytochemical staining with acetylthiocholine complexes (C) or fluorescence labeling with monoclonal antibodies to AChE (D), all performed as previously detailed (77,78,70, respectively). Haematoxin-eosin served for counterstain. The sections presented were 100 μm apart. The following should be noted: (a) the central position of the four types of labeling within the tumor tissue; (b) the focal nature of the labeled cells and (c) the presence of small rapidly dividing cells at the center of the labeled area. Thus, the expression of the mRNA transcripts produced from the amplified AChE and ChE genes was further assessed in frozen tissue sections, where the presence of mRNA transcripts could be demonstrated by in situ hybridization, their protein product by immunocytochemical staining with monoclonal anti-AChE antibodies (78), which cross-react with ChE (70), and enzymatic activity by cytochemical staining with acetylthiocholine compexes (70). When consecutive sections from single tumors were subjected to these three analyses, tumor foci were revealed in which the AChE and ChE genes were highly expressed, with clear colocalized labeling by the three techniques (FIG. 16). These loci were limited to malignant tumors bearing the amplified AChE and ChE genes, and were not observed in any of the other tissue types that were examined. Labeled areas were localized deep within the tumor tissue and contained primarily small, rapidly dividing cells. Semi-quantitative analysis of the in situ hybridization results demonstrated that only 8-12% of the examined areas were significantly labeled with the ChEcDNA probe (100±15 grains/100μ 2 as compared with 6±3 grains/100μ 2 in unlabeled areas (n=25 fields)). Parallel analysis with the AChEcDNA probe on sequential sections from the same tumors revealed that 9-14% of the analyzed cells were significantly labeled (85±14 grains/100μ 2 over 7±2 grains/100μ 2 in unlabeled areas (n=25 fields)). Labeling was sensitive to RNase treatment reproducibly focal in nature. FOOTNOTES TO TABLE III a. DNA was extracted from (A) 11 primary ovarian carcinoma tumors clinically classified as noted, prior to any treatment (ad.ca: adenocarcinoma); (B) from 5 benign ovarian tumors and (C) from 4 other tissue sources, as noted. (See (68) for detailed classification of ovarian carcinomas). b. ACHE and CHE activities, in nmol of acetylthiocholine and butyrylthiocholine hydrolized per min per g of tissue, were determined radiometrically or spectrophotometrically as detailed elsewhere (61,77). Subcellular fractionation to soluble and membrane-associated fractions was performed as described (70). Spectrophotometric assays were performed in multiwell plates 5-6 time points were measured in a Bio-Tek EL-309 microplate reader. Radioactivity measurements were performed in triplicates. Spontaneous hydrolysis of substrate was subtracted in both cases, and rates of enzymatic activity were calculated by linear regression analysis. The selective ACHE inhibitor BW284C51 and the CHE inhibitor iso-OMPA were both used in final concentration of 10 -5 M to distinguish between ACHE and CHE activities, as detailed previously 161,70,77). c. The approximate extent of ACHE and CHE gene amplification, as well as the amplification of C-RAFI, C-FES, V-SIS and C-MYC oncogenes was determined by dot-blot DNA hybridization followed by optical densitometry. Quantities of the labeled AChEcDNA and ChEcDNA or oncogene DNA probes that hybridized with genomic corresponding DNA sequences in each tissue sample are presented in value equivalent to pg of the relevant cDNA per μg of genomic DNA. Measurements of ACHE and CHE gene quantification in peripheral blood DNA samples were performed as described (72) and compared to parallel levels determined in a healthy control (Sample No. 20). Both the level and the DNA blot hybridization patterns of the ACHE and the CHE genes were similar in control blood DNA to those observed for DNA from normal ovary (sample 17 and Ref. (71)). N.A.--not applicable, N.D.--not determined. TABLE III__________________________________________________________________________Quantitation of CHE gene amplification and enzyme activities in ovariantissue homogenates Enzyme activities.sup.b nmol/min/gr ACHE CHETumor classification Membrane Membrane Amplified Genes, pg/μg DNA.sup.cNo and age Soluble associated Soluble associated CHE ACHE RAF1 SIS FES MYC__________________________________________________________________________A. Malignant ovarian tumors.sup.a 1 Serous Papillary ad.ca (57) 657 251 381 28 32-38 4-6 40-50 20-30 10-12 1-2 2 Serous Papillary ad.ca (54) 105 27 119 17 21-26 10-13 2-3 1-2 1-2 1-2 3 Serous Papillary ad.ca (22) 980 183 412 33 20-24 8-12 2-3 1-2 1-2 1-2 4 Serous Papillary ad.ca (55) 607 218 397 31 7-11 N.D N.D N.D N.D N.D 5 Non-differentiated ad.ca (44) 1005 124 192 14 50-60 7-11 60-80 40-50 40-60 2-3 6 Non-differentiated ad.ca (49) 283 85 203 13 6-8 4-6 3-4 1-2 1-2 1-2 7 Non-differentiated ad.ca (67) 207 58 183 11 4-6 6-8 5-8 20-30 1-2 1-2 8 Endometrioid ad.ca (43) 451 18 219 10 30-40 9-12 60-80 40-50 10-12 2-3 9 Endometrioid ad.ca (52) 311 85 197 11 6-9 N.D N.D N.D N.D N.D10 Moucinous ad.ca (87) 193 81 128 7 5-10 N.D N.D N.D N.D N.D11 Granulosa cell tumor (42) 428 203 212 5 40.50 18-23 5-8 1-3 1-2 1-2B. Benign ovarian tumors12 Follicular cyst (47) 208 53 211 6 5-7 N.D N.D N.D N.D N.D13 Follicular cyst (48) 412 183 222 5 N.D N.D N.D N.D N.D N.D14 Follicular cyst (46) 298 89 232 4 5-7 N.D N.D N.D N.D N.D15 Follicular cyst (36) 753 412 361 6 5-7 N.D N.D N.D N.D N.D16 Dermoid cyst (35) 818 453 377 37 5-7 N.D N.D N.D N.D N.DC. Others17 Normal ovary (48) 213 89 106 4 2-5 N.D N.D N.D N.D N.D (Uterine myoma)18 Normal ovary (47) 187 45 123 4 1-3 N.D N.D N.D N.D N.D (Uterine myoma)19 Benign ovary of No. 6 (49) 192 35 138 5 3-7 4-6 5-8 5-10 3-4 1-220 Peripheral Blood, (37) N.A. N.A. N.A. N.A 1-3 1-3 N.D N.D N.D N.A (no pathologies)__________________________________________________________________________ LIST OF REFERENCES 1. Silver, A., The Biology of Cholinesterases. North-Holland Pub. Co., Amsterdam (1974). 2. Heymann, E., Carboxylesterases and Amidases. In: W. Jackoby, Ed., Enzymatic Basis of Detoxification, Vol. 2, Acad. Press, N.Y. pp. 291-323 (1980). 3. Massoulie, J. and Bon, S., Ann. 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T. et al., Science 219: 1184-1190 (1983). 16. Sikorav, J. L., et al., EMBO J. 6: 1865-1873 (1987). 17. Schumacher M. et al., Nature 319: 407-409 (1986). 18. Hall, L. M. and Spierer, P., EMBO J. 5: 2949-2954 (1987). 19. Oakeshott, J. G., et al., Proc. Natl. Acad. Sci. U.S.A. 84: 3359-3363 (1987). 20. Prody, C. et al., Proc. Natl. Acad. Sci. U.S.A. 84: 3555-3559 (1987). 21. McTiernan, C. et al., Proc. Natl. Acad. Sci. U.S.A. 84: 6682-6686 (1987). 22. UN Security Council, Report of Specialists Appointed by the Secretary General, Paper No. S/16433 (1984). 23. Bidstrup, P. L., British Med. J. Sept. 2, 548-551 (1950). 24. Namba, T. et al., The Am. J. Med. 50: 475-492 (1971). 25. Bull, D., The Growing Problem: Pesticides and the Third World Poor, Oxford, U.K.: OXFAM, 38-45 (1982). 26. Tanimura, T. et al., Arch. Environ. Health 15: 609-613 (1967). 27. Ogi, D. and Hamada, A., J. Jpn. Obstet. Gynecol. Soc. 17: 569 (1965). 28. Hall, J. G. et al., Am. J. Med. Genet. 7: 47-74 (1980). 29. 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Burstein, S. A., et al., J. Cell Physiol. 103: 201-208 (1980). 45. Burstein, S. A., et al., J. Cell Physiol. 122: 159-165 (1985). 46. Burstein, S. A., et al., Clin. Haematol. 12: 3-27 (1983). 47. Soreq, H., et al., Hum. Genet. 77: 325-328 (1987). 48. Bernstein, R., et al., Blood 60: 613-617 (1982). 49. Turchini, M. F., et al., Cancer Genet. Cytogenet. 20: 1-4 (1986). 50. Pintado, T., et al., Cancer 55: 535-541 (1985). 51. Bishop, J. M., Science 235: 305-311 (1987). 52. Corner et al., Proc. Natl. Acad. Sci. U.S.A. 80: 278-282 (1983). 53. Prody, C., et al., J. Neurosci. Res. 16: 25-35 (1986). 54. Lockridge, O., et al., J. Biol. Chem. 262: 549-557 (1987). 55. Merken, L., et al., Nature 316: 647-651 (1985). 56. Hass and Rosenberrry, T. L., Anal. Bio. Chem. 148: 74-77 (1985). 57. Maizel, J. V., et al., Proc. Natl. Acad. Sci. U.S.A. 78: 7665-7669 (1981). 58. Hopp, T. P. and Woods, K. R., Proc. Natl. Acad. Sci. U.S.A. 78: 3824-3828 (1981). 59. McPhee-Quigley, K. et al., J. Biol. Chem. 260: 12185-12189 (1986). 60. Lockridge, O. et al.,. J. Biol. Chem. 262: 549-557 (1987). 61. Soreq, H., et al., EMBO J. 3: 1371-1375 (1984). 62. Kostovic, I. and Rakic, P., J. Neurosci. 4: 25-42 (1984). 63. Zakut, H., et al., Hum. Rep. (1990), in press. 64. Soreq, H. and Prody, C. A., In: Computer-Assisted Modeling of Receptor-Ligand Interactions, Theoretic Aspects and Application to Drug Design, Golombek A. and Rein, R., Eds., Alan & Liss, N.Y. (1989), 347-359. 65. Soreq, H. and Zakut, H. (1989), Expression and in vivo amplification of the human cholinesterase genes, Progress in Brain Research, (in press). 66. Drews, E., Prog. Histochem. 7: 1-52 (1975). 67. Razon, N., et al., Exp. Neurol. 84: 681-695 (1984). 68. Slotman, B. J. and Ramanath, R. B. Anticancer Res. 8: 417-434 (1988). 69. Prody, C. A., et al., Proc. Natl. Acad. Sci. U.S.A., 86: 690-694 (1989). 70. Dreyfus, P., et al., J. Neurochem. 51: 1858-1867 (1988). 71. Malinger, G., et al., J. Molec. Neurosci. 1: 77-84 (1989). 72. Lapidot-Lifson, Y., et al., Proc. Natl. Acad. Sci. U.S.A. 86: 4715-4719 (1989). 73. Gnatt, A. and Soreq, H. (1987) Molecular Cloning of Human Cholinesterase Genes: Potential Applications in Neurotoxicology. In: Model Systems in Neurotoxicology: Alternative Approaches to Animal Testing. Eds. A. Shaher and A. M. Goldberg, Alan R. Liss, Inc., New York, 111-119. 74. McGuire, M. C., et al., Proc. Natl. Acad. Sci. U.S.A. 86: 953-957 (1989). 75. Chatonnet, A. and Lockridge, O., Biochem. J. 260: 625-634 (1989). 76. Zakut, H., et al., Cancer 61: 727-739 (1988). 77. Soreq, H., et al., J. Biol. Chem. 264: 10608-10613 (1989). 78. Mollgard, K., et al., Dev. Biol. 128: 207-221 (1988). 79. Soreq, H., et al., Human Reprod. 2: 689-693 (1987). 80. Gnatt, A. et al., Human Acetylcholinesterase and Butyrylcholinesterase are Encoded by Two Distinct Enzymes, Cell. Molec. Neurobiol. (1990, in press).

Genetically engineered human acetylcholinesterase and antibodies that def the protein are described. These composition may be used in pharmaceutical preparations for treatment and prophylaxis of organo-phosphorous compound poisoning or post-operative apnea. Also described are human cholinesterase DNA probes which may be employed for diagnosing progressing ovarian carcinomas and hemocytopoietic disorders.

CROSS-REFERENCE TO RELATED APPLICATION This is a continuation-in-part of the present inventor's co-pending patent application Ser. No. 07/345,084, filed Apr. 28, 1989, INFLAMMATORY DISEASE TREATMENT, now U.S. Pat. No. 4,874,794, to which priority is claimed. FIELD OF THE INVENTION This invention relates to alcohol-containing compositions which are useful in the systemic treatment of various virus infections. More specifically, the present invention relates to a systemic antiviral treatment using a narrow class of aliphatic straight-chain saturated monohydric alcohols which have from 27 to 32 carbons in the chain. BACKGROUND OF THE INVENTION It is well known that certain selected alcohols have some physiological activity. It is known, for example, that 1-triacontanol stimulates the growth of plants, see, e.g. Ries, Stanley K. and Sweeney, Charles C., U.S. Pat. No. 4,150,970. Interestingly, the C-30 alcohol triacontanol appears to possess this physiological activity, and the C-28 and C-32 do not possess such physiological activity, or at least have very much less physiological activity in plant growth, see, e.g., the patents and publications of Ries et al., ibid, and of Ashmead, Harvey H., Weleber, Andrew J., Laughlin, Robert G., Nickey, Donald O. & Parker, Dane. K, and Ohorogge, Alvin J. Triacontanol has also been reported to accelerate the decomposition of sewage and reduce H 2 S, Starr, Jerry, U.S. Pat. No. 4,246,100. Beeswax comprises, inter alia, esters of long-chain aliphatic alcohols having chain lengths in the area of interest, and it is known to obtain such alcohols by hydrolysis of beeswax. Beeswax has been used since antiquity in a great variety of cosmetic and therapeutic applications, as a base for lipstick, in lotions and creams, as an emollient and as a constituent in therapeutic products for topical and membrane application. Various constituents of beeswax and products derived from beeswax have also been used in cosmetic and therapeutic applications. For example, Slimak, Karen M., U.S. Pat. No. 4,793,991, describes a hypoallergenic cosmetic comprising single plant source beeswax. Gans, Eugen, Nacht, Sergio and Yeung, David have described the use of the non-polar saturated straight chain C-21 to C-33 hydrocarbon fraction of beeswax in the treatment of inflammatory skin disorders, U.S. Pat. No. 4,623,667. The mechanism of the rather diverse and unpredictable physiological effects of the various alcohols are, at best, poorly understood and studies are not generally definitive. There appears to some interaction of certain n-alkanols with lipid bilayer membranes, Westerman, P. W., Pope, J. M., Phonphok, N., Dan, J. W., Dubro, D. W., Biochim Biophys Acta(NETHERLANDS) 939, 64-78 (1988), and studies have been conducted respecting the partitioning of long-chain alcohols into lipid bilayers, Franks N. P. & Lieb W. R., Proc. Natl. Acad. Sci. USA 83 5116-20 (1986); cholesterol solubility of n-alkanols, Pal S. & Moulik S. P., Indian J Biochem Biophys 24-8 (1987); neurological effects of certain long-chain alcohols, Natarajan V. & Schmid H. H., Lipids 12 128-30 (1977); Snider S. R., Ann Neurol 16 723 (1984); Borg J., Toazara J., Hietter H., Henry M., Schmitt G., Luu B., FEBS Lett 213 406-10 (1987). Levin, Ezra reported that tetracosanol, hexacosanol, octacosanol and triacontanol and their esters improved physical performance of athletes and disclosed compositions comprising such alcohols and esters in vegetable oil bases for oral ingestion, U.S. Pat. No. 3,031,376. An incidental disclosure of a composition intended for topical application comprising a major portion liquified gaseous propellant and a minor portion of a mixture of C-12 to C-30 fatty alcohols which were used simply to mark the areas of application of the aerosol is contained in U.S. Pat. No. 3,584,115 to Gebhart. Clark, U.S. Pat. No. 4,670,471 discloses the use of triacontanol, in a suitable carrier, as a treatment for inflammatory disorders such as herpes simplex, eczema, shingles, atopic dermatitis, psoriasis, etc. Clark performed experiments with the compositions of the type disclosed by Gebhart, U.S. Pat. No. 3,584,115 comprising an aerosol and a mixture of triacontanol and palmitic acid, which Clark indicates to be as effective as pure triacontanol, and concluded that the aerosol carrier destroyed the effect of triacontanol and that a hydrophilic carrier for triacontanol was necessary to achieve the desired anti-inflammatory effect. There is some reason to believe that Clark's composition was simply saponified beeswax which would contain triacontanol and palmitic acid, as Clark indicates, but which would also contain, as substantial constituents, hexacosanolic acid and various hydrocarbons. Results gas chromatographic-mass spectrum analysis of various compositions believed to have been used by Clark were not definitive, but suggested that at least some such compositions were very complex mixtures, some of which may be lower alkanes, esters, acids or alcohols. Whether or not these were found by Clark to be effective anti-inflammatory compositions is not known. McKeough, Mark & Spruance, S. L. evaluated the efficacy of 5% triacontanol in a branch chain ester base in the treatment of HSV-1 dorsal cutaneous infection in guinea pigs and concluded that the active ingredient in triacontanol is the long chain hydrocarbon (unpublished report in the file of U.S. Pat. No. 4,670,471). Revici, Emanuel, Sherwood, Bob E., Benecke, Herman P., Rice, John M., and Geisler, Richard W., U.S. Pat. No. 4,513,008, disclose a method of inactivating enveloped virus using C-20 to C-24 polyunsaturated acids, aldehydes or alcohols having 5-7 double bonds, and references disclosures by Sands et al. Antimicrobial Agents and Chemotherapy 15, 67-73 (1979) (antiviral activity of C-14 to C-20 unsaturated alcohols having 1-4 double bonds), Snipes et al., Antimicrobial Agents and Chemotherapy 11, 98-104 (1977) (C-20 tetraenyl alcohol having low activity), and Symp. Pharm. Effects Lipids (AOCS Monograph No. 5) 63-74 (1978) (even suggesting lower antiviral activity for saturated long-chain alcohols). Katz, Martin & Neiman, Herbert M., U.S. Pat. No. 3,592,930 disclose a medicant vehicle containing from 15 to 45 parts of saturated fatty alcohol from 16 to 24 carbons, along with glycol solvent, plasticizer, penetrant and adjuvant which is used as a carrier for antibiotics, steroids, antihistamines, etc. Ryde, Emma Marta & Ekstedt, Jan Erik, U.S. Pat. No. 3,863,633 disclose a composition for topical treatment of the eye which comprises a lipophilic substance, a hydrophilic swellable polymer and from 10 to 80% C-12 to C-22 surface active alcohols such as 1-docosanol, 1-hexadecanol, 1-octadecanol and 1-eicosanol which serve as a stabilizer for the mixture. The content of the prior art and the corresponding skill of the art, relative to topically administered compositions, may be summarized as follows: short-chain alcohols, i.e. under about 16 carbons, tend to be irritants while longer chain alcohols, particularly the aliphatic alcohols tend to be non-irritating (Katz et al., supra). 1-Triacontanol, a 30-carbon unsaturated aliphatic alcohol, in a suitable hydrophilic carrier has (or, may have, depending upon the precise compositions used by Clark) value in treating inflammatory conditions of the skin (Clark, supra). Shorter chain C-10 to C-14 aliphatic alcohols demonstrate low level in vitro virucidal characteristics, while C-18 alcohols show no discernable virucidal activity in vitro (Snipes, supra). Polyunsaturated C-20 to C-24 alcohols inactivate enveloped virus (Revici et al., supra). C-16 to C-24 aliphatic alcohols are useful as stabilizers in carrier compositions for drugs having diverse physiological activity. Respecting aliphatic alcohols, one would predict from the studies of Snipes and Clark that, in the continuum of aliphatic alcohols from C-10 to C-30 virucidal activity, at a very low level, may appear (if in vitro studies may be used to predict in vivo results) in C-10 to C-14 alcohols (which would also be irritants as reported by Katz), that virucidal activity disappears in the C-16 to C-28 range and then appears uniquely (if Clark's compositions were pure triacontanol or mixtures of triacontanol with palmitic acid as he indicates) with the C-30 alcohol 1-triacontanol, which has been shown to have unique physiological effects in plant treatment. Even considering the possible ambiguity of Clark's compositions, one would not predict any significant virucidal activity for aliphatic alcohols in the C-20 through C-28 chain length. Notwithstanding the negative teachings of the prior art, the inventor has previously discovered that a composition, in which the active constitute consists essentially of C-27 to C-32 aliphatic alcohols, e.g. docosanol, tetracosanol and hexacosanol, is an effecting topical anti-inflammatory, (see the present inventor's co-pending patent application Ser. No. 07/345,084, filed Apr. 24, 1989, INFLAMMATORY DISEASE TREATMENT, to which priority is claimed to the extent of the disclosure therein), and has now determined that this class of compounds may be used, in suitable carrier compositions, in the systemic treatment of virus-induced disease and in the prevention or inhibition of infection by disease-causing virus. SUMMARY OF THE INVENTION The present invention is embodied in methods for preventing, inhibiting and treating virus diseases in humans or other mammals, comprising intravenous, intramuscular, transdermal or oral introduction into the human or other mammal to be treated of a composition consisting of one or more of C-27 to C-32 aliphatic alcohols in a physiologically compatible carrier, and to compositions suitable for carrying out such methods. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 depicts data showing the inhibition of Friend virus-induced erythroleukemia. DESCRIPTION OF THE PREFERRED EMBODIMENTS The method may be carried out using compositions in which the sole physiologically active agent(s) is the C-27 to C-32 aliphatic alcohol, or comparable compositions which may also include other physiologically active constituents which do not interfere with the efficacy of the C-27 to C-32 alcohols. Corresponding low-molecular-weight ethers of these alcohols, e.g. methyl-, ethyl-, propyl-, etc., ether derivatives of these alcohols, and corresponding low molecular weight ester derivatives, e.g. formyl-, acetyl-, propyl-, etc., ether derivatives of these alcohols are regarded as less preferred possible equivalents of the alcohols of this invention. The composition of the carrier is not critical so long as the carrier is physiologically compatible with the blood and tissues of the human or other mammal to be treated and is substantially free from any interfering physiological effect. Compositions suitable for intravenous or intramuscular injection into the human or mammal patient consist essentially of one or more aliphatic alcohols having from 27 to 32 carbons in the aliphatic chain of the alcohol(s) in a suitable carrier. For example, a suspension of from 0.1 mg/ml to 300 mg/ml of the indicated alcohol(s) suspended in a carrier solution of isotonic sodium chloride solution containing a suitable preservative, such as 0.1 to 1.5% benzyl alcohol, stabilizers such as from 0.25 to 1% carboxymethylcellulose sodium and 0.005 to 0.1% polysorbate 80, and sufficient sodium hydroxide or hydrochloric acid to adjust the pH to 5.0 to 7.5, all percentages by weight, may be used for either intravenous or intramuscular injection. Another composition suitable for intravenous or intramuscular injection into the human or mammal patient may consist essentially of one or more aliphatic alcohols having from 27 to 32 carbons in the aliphatic chain of the alcohol(s) in a suitable carrier in suspension of from 0.1 mg/ml to 300 mg/ml of such alcohol(s) suspended in a carrier solution of alcohol (1-10%), glycerin (10-20%) and water (balance 70-89%), along with suitable preservative. Such compositions may be injected in suitable amounts to provide a dose to the patient of from 0.1 mg/50 kg body weight to 2 gm/50 kg body weight. It is desirable to achieve and maintain a level of the specified alcohol(s) in the body in the range of at least about 0.1 mg/kg of body weight. The alcohol(s) to which this invention is directed may effectively be introduced through the mucus membrane system of the human or mammal patient. Such introduction may be, for example, through the vaginal, anal, or nasal membranes. The above liquid compositions which consist essentially of one or more aliphatic alcohols having from 27 to 32 carbons in the aliphatic chain of such alcohol(s) in a suitable liquid carrier may, for example, be used for trans-mucus membranal introduction of such alcohol(s) into the circulatory system of the human or mammal to be treated by, for example, introducing such liquid as an aerosol into the oral or nasal passages or as liquid into the vaginal or anal passages of the body where these compounds inactivate virus locally, inhibit the passage of virus into the membrane, and pass through the membrane into the circulatory system of the patient where the compounds act as inhibitors of viral activity and infectivity and inactivate virus. In the latter applications, however, gels, creams or suppositories are more conveniently used. In one convenient embodiment, the method of the invention comprises a composition consisting essentially of one or more aliphatic alcohols having from 27 to 32 carbons in the aliphatic chain of such alcohol(s) into the vagina, where it will inhibit the activity of the sperm and interfere with fusion of the sperm cell with the female egg cell. The alcohol composition of interest may, of course, be used in connection with a diaphragm or other contraceptive device if desired. As indicated above, the alcohols of interest here will serve as contraceptive compositions. The mode of action has not been fully explored, but it is believed that these alcohols reduce the activity and viability of sperm and inhibit or prevent the sperm from attaching to and penetrating the egg, thus preventing fertilization. Likewise, the alcohol-containing composition may be introduced through the anus where it also inactivates virus, inhibits the passage of virus into the membrane, and passes through the membrane into the circulatory system of the patient where it acts as an inhibitor of viral activity and infectivity and inactivates virus in the circulatory system and cells nourished by the circulatory system. The specified alcohol(s) may be in any physiological acceptable form such as in cream or suppository compositions. An exemplary suppository may consist essentially of a composition consisting essentially of one or more aliphatic alcohols having from 27 to 32 carbons in the aliphatic chain of such alcohol(s) alone or in a concentration of from 0.05 mg alcohol(s)/gm of carrier to 400 (or higher) mg alcohol(s)/gm of carrier. Cocoa butter is a commonly used suppository carrier component, alone or in mixture with, for example, tartaric acid and malic acid. Polyethylene glycols of suitable molecular weight are also suitable suppository carriers. Suppositories may also include a preservative such as methylparaben or benzethonium chloride, and such acid or base components as are desired to adjust the pH to the range of about pH 5 to pH 7.5. Any of the above, or other, suitable suppository carrier compositions may be used with composition consisting essentially of one or more aliphatic alcohols having from 27 to 32 carbons in the aliphatic chain of such alcohol(s) to form a suitable contraceptive and/or anti-viral suppository. The suppository, to be commercially and aesthetically acceptable, must be a solid at ambient room temperature, i.e. generally in the range of about 27° C., and must melt at or slightly below normal body temperature, i.e. in the general range of about 37° C. These temperatures are, of course, only general ranges, and the precise melting point is not critical. Trans-membranal introduction of such alcohol(s) may be accomplished by introducing small amounts of such alcohols neat, but such introduction is difficult to control and not efficient. Cream and gel compositions consisting essentially of one or more aliphatic alcohols having from 27 to 32 carbons in the aliphatic chain of such alcohol(s) in concentrations of from about 0.1 mg/ml to 300 mg/ml (or higher) in a suitable cream or gel carrier may also be used effectively. Such a gel may, for example, comprise a suspension agent such as Carbomer® polyacrylic acid cross-linked with allyl sucrose, polyethylene glycol, water and suitable preservatives. A suitable cream base may, for example, comprise white petrolatum, polyoxyethylene stearate, cetyl alcohol, stearyl alcohol, propylene glycol, isopropyl myristate, sorbitan monooleate and water along with suitable preservatives adjusted to a pH of from pH 5 to pH 7.5. The alcohols of interest here may also be introduced for trans-membranal passage into the human or mammal patient's circulatory system, as well as a prophylaxis against infection from airborne virus, through inhalation of a composition consisting essentially of one or more aliphatic alcohols having from 27 to 32 carbons in the aliphatic chain of such alcohol(s) in a suitable physiologically acceptable carrier. The liquid compositions mentioned before may, for example, be packaged in a nebulizer and introduced through nasal or oral passages in the customary manner. An exemplary composition consisting essentially of one or more aliphatic alcohols having from 27 to 32 carbons in the aliphatic chain of such alcohol(s) suspended in aerosol propellant such as trichloromonofluoromethane and/or dichlorodifluoromethane, along with diluents, preservatives, pH adjusting reagents, etc. The exemplary aerosol composition delivers essentially neat alcohol(s) to the mucus membrane. An exemplary ear drop composition delivers essentially neat alcohol(s) to the tympanic membrane. Comparable liquid drops may be applied using appropriate droppers to the eyes, ears and mouth for application to and passage through the membranes in these respective organs. All trans-membranal compositions may, in addition to other ingredients, may also include penetration enhancers. A number of such enhancers are known as penetration enhancers and may be used in the compositions of this invention. One such vehicle is dimethyl sulfoxide, which is described in U.S. Pat. No. 3,551,554. Other such penetration enhancers are disclosed in U.S. Pat. Nos. 3,989,816; 3,991,203; 4,112,170; 4,316,893; 4,415,563; 4,423,040; 4,424,210; 4,444,762, sometimes referred to as Azone®. The discovery that these alcohols, which are naturally occurring and are essentially non-toxic in concentration ranges of interest have significant anti-viral effect is considered to be of major import inasmuch as the way is open to providing a safe and effective method for the treatment for virus diseases and for preventing or at least significantly reducing the likelihood of virus infection to the human or other mammal patient, without any significant side effects and without the need for as intense monitoring by the treating physician as is required with inherently toxic compounds. As a treatment for acquired immunodeficiency syndrome (AIDS), as a method for prophylatic treatment of persons exposed to AIDS and/or carrying AIDS virus but without demonstrating, AIDS symptoms, and as methods and compositions for preventing or reducing the risk of infection by AIDS and virus-induced diseases, the present invention is regarded as a significant improvement. Another important aspect of the invention is that it may provided a safe and effective mode of treatment of diseases resulting from infection of the patient with such lipid-containing virus as HTLV-1, HSV-1, HSV-2, cytomegalovirus (CMV), Epstein-Bar (EBV), and influenza viruses. The risk of infection by such viruses as HIV, HSV-1, HSV-2, CMV, EBV, influenza viruses and other viruses which are communicated by personal contact, contact with contaminated blood or tissue or laboratory instruments or devices, aerosol transmission, etc., may be substantially reduced by the methods and compositions of the present invention. It is believed that another mode of action of the alcohols of this invention is in the inhibition or prevention of malignant growth and/or metastasis. If, for example, cancer cells cannot metastasize, or the rate of metastasis is reduced, then the spread of cancer may be blocked or reduced. Significant inhibition of cancer cell metastasis coupled with natural or drug-induced death or destruction of existing cancerous cells will lead to partial or total remission of the disease. The same principle applies, of course, to any disease which is propagated by cell metastasis. Accordingly, the present invention is considered useful in the treatment of nonvirus-induced disease and diseases which are not dependent upon viral replication but which are spread by metastasis. It will be readily understood from the foregoing that the essential constituent(s) of the compositions useful in the present method is one or more aliphatic alcohols having from 27 to 32 carbons in the aliphatic chain of the alcohol(s), and that the composition of the carrier is non-critical and subject to great variation. INDUSTRIAL APPLICATION This invention is useful in treating and suppressing virus-induced diseases of humans and other mammals.

Systemic antiviral treatment using a narrow class of aliphatic straight-chain saturated monohydric alcohols which have from 27 to 32 carbons in the chain in physiologically compatible compositions for injection or trans-mucus membrance introduction into humans and other mammals is disclosed.

FIELD OF APPLICATION [0001] The present invention relates to the field of chemical industry, notably to the chemical preparations industry for medical, dental and hygienic purposes. INTRODUCTION [0002] The present invention relates to a disinfection composition based on chlorhexidine, cationic and/or non-ionic surfactants and xylitol, for lasting disinfection of synthetic fibers, synthetic surfaces, metal surfaces and composite surfaces, and the like. In addition, the present invention relates to a disinfection method of surfaces, a disinfection protocol of toothbrushes and, finally, to a disinfection product. STATE OF THE ART [0003] The use of chlorhexidine in disinfection liquid compositions is long known in the state of the art, as demonstrated by, for example, the German patent document DE 203 04 504, disclosing a toothbrush-cleaning composition wherein it comprises cetylpyridinium chloride and/or a mixture of chlorhexidine (including derivatives), optionally comprising dyes and various fragrances and/or plant extracts. Said German document, even though describing a chlorhexidine-based product for cleaning bristles of toothbrushes, neither mentions the time of residual action of the product on the toothbrush after separating it from the bristles, nor refers to the intended disinfection characteristics. There is no mention as to how the proposed composition acts, or to the success of the removal of various residues to which toothbrushes, for instance, are exposed to daily. [0004] Patent document CH 700 343 discloses a care solution for toothbrushes, specifically intended for the cleaning of bristles of toothbrushes by dipping them in the solution. Said composition can comprise from 80 to 90 wt % vegetable glycerin, from 4 to 10 wt % demineralized water, from 1.00 to 1.40 wt % chlorhexidine digluconate, from 2.0 to 5.0 wt % rosemary extract, from 2.0 to 5.0 wt % mint extract. Just like said German document, CH 700 343 neither mentions the time of residual action of the product on the toothbrush after the separation from the bristles, nor refers to the intended disinfection characteristics. There is no mention as to how the proposed composition acts, or to the success of the removal of various residues to which toothbrushes, for instance, are exposed to daily. [0005] As for Brazilian patent document PI 0702469-0, it discloses formulation of antiseptic solution for application in dentistry to prevent dental caries and further oral diseases. Even though said formulation exhibits antiseptic solutions containing, among other things, guanidines and biguanidines, surfactants, solvents etc., it is intended specifically to the hygiene of the oral cavity, thus having no reference to its use as a disinfection agent for bristles or other external elements. Again, there is a lack of references as to the time of residual action of the product on the toothbrush after the separation from the bristles and to intended disinfection characteristics. Also, since it is a mouthwash, there is no mention as to how the proposed composition acts, or to the success of the removal of various residues to which toothbrushes, for instance, are exposed to daily. [0006] The combined use of chlorhexidine and alkylpolyglycosides in antimicrobial compositions is also known in the state of the art, as demonstrated by document WO 2012/034032, which discloses antimicrobial solutions that in certain cases comprise a biguanide and at least one alkylpolyglucoside. The solutions and methods proposed by this document are intended for the elimination or reduction of bacteria, fungi and viruses from the surfaces, for example, of medical equipment, organic surfaces like the skin and sutures, and other inorganic surfaces. There is no mention to the specific treatment of surfaces with the characteristics of toothbrush bristles, as well as there is no mention to the time of residual action of the product on toothbrush bristles, for example, after it is separated from the bristles. [0007] Another example of the combined use of chlorhexidine and cationic detergents such as alkylpolyglucosides is given by the sanitizing compositions and methods of WO/010345 2010, which discloses sanitizing compositions for use in combination with specific cleaning compositions. In addition to requiring specific protocols for each type of surface to be disinfected, said document does not mention the specific treatment of surfaces with characteristics similar to those of toothbrush bristles. [0008] Document WO 2009/117299 discloses chlorhexidine-based cleaning, disinfecting, sanitizing and sterilizing preparations and non-ionic surfactants, however, exhibiting the same deficiencies of above-mentioned document WO 2010/010345. The same deficiency occurs with the composition of personal and domestic hygiene disclosed by document PI 0514935-5. [0009] As can be inferred from the above description, there is room for improvements in formulations of disinfection compositions for lasting disinfecting of synthetic fibers, synthetic surfaces, metal surfaces, composite surfaces, similar surfaces and the like. [0010] In addition to the compositions and combinations disclosed by the above-mentioned documents, it is also worth mentioning some products that are known in the state of the art and that are also used, both alone and in compositions, as main active principle or as a complement, as compositions for oral hygiene and, eventually, cited for disinfection of surfaces. [0011] One such product that is worth mentioning is triclosan (in Portuguese, also known as triclosano), also widely used in dentrif ices, which disrupts the bacterial cell membrane, inhibiting its enzymatic function (Torres C R G, Kubo C H, Anido A A, Rodrigues J R. Agentes antimicrobianos e seu potencial de use na Odontologia. Pós Grad Rev Fac Odontol São José dos Campos 2000:3:43-52.). At low concentrations, there is adsorption of microorganisms in the lipid moiety, which causes a drastic change in cellular transport and thereby prevents proper metabolism and cell reproduction, and, accordingly, providing a broad spectrum antimicrobial effect. Despite being a chemical agent capable of providing bacteriostatic action, its anionic charge causes it to have a low substantiality. Its main drawback is the fact that it is anionic, unlike, for example, chlorhexidine and cetylpyridinium chloride, which are cationic. This feature also impairs a synergy action with a cationic surfactant. In addition to being highly toxic to the human body, as well as carcinogenic and also highly polluting to the environment. [0012] Another product widely used for disinfection is sodium hypochlorite, also known as bleach or javel water. Sodium hypochlorite is a chemical compound with the formula NaClO, typically found in liquid form, in slightly greenish-yellow color, of pungent odor, water soluble, non-flammable, photosensitive (it decomposes when in direct contact with the light), corrosive to metals, having easy oxidation and decomposition, that releases toxic gases when in contact with acids obtained from the reaction of chlorine with a diluted solution of sodium hydroxide (caustic soda). Sodium hypochlorite has germicidal properties and it is widely used for the treatment and purification of water, for disinfection of vegetables and fruits, in the production of industrial disinfectants, in the treatment of swimming pools (disinfection of water), in the composition of conventional pesticides and as an agent of sterilization in the industries of beverages such as beer, wine and cola soft drinks. It is very suitable for sterilization of domestic environments such as bathrooms and kitchens (usually more susceptible to the spread of germs). It can also be used in dental care as an irrigating solution (this use is still not widespread in Brazil, and therefore many dentists use bleach). For being a strong oxidant, it must be handled with care, since the products of its oxidation are corrosive and can cause burns to the skin and eyes, especially when at high concentrations. The reaction of sodium hypochlorite with organic compounds is violent and gives rise to toxic and even carcinogenic substances. For instance, mixtures of hypochlorite and urine should be avoided, since the reaction of this compound with ammonia leads to chloramine, which is toxic to the human body. Accidents involving sodium hypochlorite can result in harmful effects to health. If inhaled, it can cause irritation to the respiratory system, causing cough and dyspnea. If ingested, it causes bloody vomiting, nausea and diarrhea, ulcerations in the esophagus and stomach, in addition to the fact that high concentrations of sodium in the body can lead to dehydration. [0013] On the other hand, glutaraldehyde has an environmental toxicity above 0.2 ppm/m 3 , also being a carcinogen. It is widely used as a sterilizer and disinfectant for surgical and dental instruments, thermometers, plastic or rubber equipment, veterinary clinics and hospitals (place of consultations and surgeries); various facilities and other materials that cannot be heat sterilized, vehicles for transporting animals, feeders, waterers and eggs. Glutaraldehyde has been widely used for disinfection of certain pieces of equipment such as endoscopes, connections of medical ventilators, respiratory therapy equipment, dialyzers, spirometry tubes and others; to this end the exposure time is 30 minutes. It is not used as a surface disinfectant since it is costly and very toxic. [0014] Finally, peracetic acid is fairly used in disinfection/sterilization of plastic, polyurethane, polyethylene, PVC, ABS, nylon 6 and 66, optical fiber, viton, silicone, natural and nitrilic rubbers, natural and synthetic fabrics. Plastics, rubber or silicone may experience dryness and/or rigidity depending on their porosity, it is highly flammable and has a strong odor. Peracetic acid (acetyl hydroperoxide or peroxyacetic acid) is a chemical product that presents itself as a colorless liquid, non-colorant, and powerful oxidizing agent with acidic pH, a density close to that of the water and slightly vinegary odor, corrosive to metals (brass, copper, galvanized iron, tin) that, at low concentration, has a fast action against all microorganisms, including bacterial spores. 0.2% peracetic acid can cause respiratory distress, its vapors are irritating, and it requires careful handling. It has low storage stability and low residual effect. [0015] The other existing antiseptics on the market are indicated (and used), in their overwhelming majority, just as mouthwashes. The products presented and commonly used in the state of the art, either lack a disinfection power strong enough to provide an efficient hygiene of surfaces; or have said disinfection power based on highly toxic products, therefore, inappropriate for application on objects of personal use and hygiene. [0016] Therefore, as can be inferred from the above description, there is room for improvements in formulations of disinfection compositions for lasting disinfecting of synthetic fibers, synthetic surfaces, metal surfaces, composite surfaces, similar surfaces and the like. [0017] More specifically, there is room for sanitizing and/or hygiene compositions for objects of personal use having both combined and simultaneous antibacterial, antiseptic and deep cleaning activity with extended action especially for continuous use in toothbrush bristles, but also effective for the disinfection of other synthetic or metallic surfaces (such as, for example, oral hygiene instruments such as tongue scrapers, dental floss bow, among others, in addition to surfaces of oral devices (braces and retainers for instance), prostheses, and even hearing aids, combining minimal toxicity (to the human body) to maximum effectiveness. [0018] The effectiveness of these compositions still lacking in the state of the art must also be extended to the complementary residues that can be found on the surfaces of objects to be disinfected, for example, fat, dentifrice debris, food debris, organic tissue, saliva, soaps, shampoos, rinses and the like, their continuous and daily use being guaranteed, without restrictions due to a toxic component or which results in human rejection. [0019] In addition, there is room for a composition having a lasting action on the disinfected surfaces as above-mentioned and which can additionally be beneficial to the health of the user, in a complementary manner. Said composition containing, for instance, compounds having anti-caries efficacy and the like, presenting antimicrobial and also dental plaque inhibiting action, thus achieving a reduction of oral diseases and halitosis, in addition to various conditions related to medical and hearing aids. OBJECTIVES OF THE INVENTION [0020] One of the objectives of the present invention is the provision of a disinfection composition according to the features of claim 1 . Another objective of the present invention is the provision of a disinfection method according to the features of claim 9 . Another objective of the present invention is the provision of a disinfection protocol for toothbrushes according to the features of claim 10 . Yet another objective of the present invention is the provision of a disinfection product according to the features of claim 11 . DETAILED DESCRIPTION OF THE INVENTION [0021] A disinfection composition according to the invention must meet three main functions, namely: disinfection; removal of fat and residues; and additional protection. [0025] Disinfection [0026] In a preferred embodiment of the invention, the composition according to the invention has a chlorhexidine gluconate based or chlorhexidine digluconate based disinfection component or simply chlorhexidine. [0027] Chlorhexidine has antifungal and antibacterial action, in addition to an extremely high capacity of disinfection, bacterial destruction and bacteriostatic action, thus inhibiting bacterial growth (colonies). [0028] In the form of digluconate, it is an antimicrobial agent exhibiting disinfecting and sanitizing features. It is effective against Salmonella spp., Listeria spp., Clostridium spp., E. Coli, Staphylococcus spp. and Pseudomonas spp. (Chlorhexidine, Technical report, NEOBRAX). [0029] Its antibacterial mechanism of action is explained by the fact that the cationic molecule of chlorhexidine is quickly attracted to the negatively charged bacterial surface and is adsorbed to the cell membrane by electrostatic interactions, presumably by hydrophobic bonds or hydrogen bridges, this adsorption being concentration-dependent. Thus, at high dosages, it causes precipitation and coagulation of cytoplasmic proteins and bacterial death; and, at lower dosages, the integrity of the cell membrane is altered, resulting in leakage of the bacterial components having low molecular weight (Hjeljord et al. 37 1973; Hugo and Longworth 38 1964; Rolla and Melsen 60 1975). [0030] In addition, chlorhexidine is stable, is not toxic to tissues, its absorption by the mucosa and skin is minimal and it does not provoke systemic toxic side effects with extended use as well as alterations in the oral microbiota (Davies and Hull 23 1973; Case 15 1977; Rush-ton 62 1977; Winrow 73 1973; Löe et al. 45 1976). [0031] Chlorhexidine has a substantivity (i.e., active residence time) of approximately 12 hours which is explained by its dicationic nature. Thus, a cationic end of the molecule is attached to the film, which is negatively charged, and the other cationic end is free to interact with bacteria. In this manner, it shall perform an initial bactericidal action, combined with an extended bacteriostatic action (Zanatta F B, Rösing C K. Clorexidina: Mecanismo de ação e Evidências atuais de sua eficácia no contexto do biofilme supragengival , Scientific-A 2007). [0032] In addition, chlorhexidine is characterized by not developing bacterial resistance, by being non-toxic, non-corrosive and biodegradable (Chlorhexidine, Technical report, NEOBRAX). [0033] In a preferred embodiment of the invention, the chlorhexidine content of the composition according to the invention is from 0.1 vol % to 20 vol %, preferably from 0.2 vol % to 7 vol %, more preferably from 4 vol % to 6 vol %. [0034] Removal of Fat and Residues [0035] Within the scope of the present invention, removal of fat and residues should be understood as the removal of complementary residues that can be found on the surfaces of objects to be disinfected, such as, for example, fat, dentifrice debris, food debris, organic tissue, saliva, soaps, shampoos, rinses and the like. [0036] In a preferred embodiment of the invention, the composition according to the invention has a cationic surfactant as a component for fat and residues removal. [0037] Surfactant is a substance or compound capable of reducing the surface tension of the fluid in which it is dissolved; or capable of reducing interfacial tension by preferential adsorption of a vapor-liquid interphase and another interphase. [0038] The cationic surfactant is the one that, in aqueous solution, is ionized, thus producing positive organic ions which are responsible for the surface activity, having a positively charged radical as the hydrophilic part of the chain. That is, in this type of surfactant, it is one part of the molecule having a positive character that interacts with water, unlike the anionic surfactants. They are not compatible with anionic surfactants, forming an insoluble precipitate with them. [0039] Cationic surfactants have germicidal properties, are provided with high bactericide power against gram-negative bacteria, as well as being fungicides, acting on certain pathogenic protozoa. They exhibit relatively low toxicity, with the absence of corrosive power (see Technical report: Amaral L et al, Detergente doméstico, Instituto de Tecnologia do Paraná , December 2007). [0040] In a preferred embodiment of the invention, the composition according to the invention has a non-ionic surfactant as a component for fat and residues removal. [0041] Non-ionic surfactants are characterized by hydrophilic groups without charges linked to the fat chain. They have as their characteristics the compatibility with most raw materials used in cosmetics, the low irritability to skin and eyes, a high power of surface and interfacial tension reduction, and low detergency and foaming powers. [0042] In short, the surfactant decreases the surface tension of the liquid, increasing its penetration capability. It binds to and captures fat particles having lipophilic capacity and, at the other molecular end, having hydrophilicity. [0043] In a preferred embodiment of the invention, the composition according to the invention has an alkylpolyglycoside-based fat removal component. [0044] Alkylpolyglycosides are a family of relatively new surfactants, synthesized by reacting cornstarch glucose with a fatty alcohol. The resulting molecule is a non-ionic surfactant having good water solubility due to hydroxyl groups. Those are good detergents and have a very high degree of biodegradability. The main surfactants of this class are decyl- and lauryl-polyglucoside with a high degree of polymerization (average number of glucose units per alcohol unit). [0045] In a preferred embodiment of the invention, the alkylpolyglycosides content of the composition according to the invention is from 0.5 vol % to 12 vol %, preferably 4 vol %. [0046] In a preferred embodiment of the invention, said alkylpolyglycosides are decylpolyglycosides. [0047] In another preferred embodiment of the invention, said alkylpolyglycosides are laurylpolyglycosides. [0048] In yet another preferred embodiment of the invention, said alkylpolyglycosides are decylpolyglycosides mixed with laurylpolyglycosides. [0049] Additional Protection [0050] Within the scope of the present invention, additional protection should be understood as the additional protection the user is provided with against caries and oral diseases, various oral conditions and halitosis and various conditions related to medical and hearing aids. [0051] In a preferred embodiment of the invention, the composition according to the invention has a xylitol-based additional protection component. [0052] Xylitol is a polyalcohol having as molecular formula C 5 H 12 O 5 (1, 2, 3, 4, 5-pentahydroxypentane), with both inhibition and anti-adhesion actions over certain bacteria. Xylitol is transported via fructose-phosphotransferase system, resulting in intracellular accumulation of xylitol-5-phosphate. This intermediate metabolite is dephosphorylated and excreted as xylitol, without resulting in ATP production. This ‘futile cycle’ consumes energy and results in inhibition of bacterial growth and metabolism, particularly in some bacteria like Streptococcus mutans, Streptococcus pneumoniae, Haemophilus influenzae . (Pereira AFF, 2009) (Almeida LMAG). [0053] One of the advantages of xylitol, for example over sucrose, is that, due to its high chemical and microbiological stability, it acts as a preservative of food products even at low concentrations, offering resistance to the growth of microorganisms and extending the shelf life of these products (Bar, 1991). [0054] Since xylitol is a non-toxic substance, as classified by Food and Drug Administration (FDA) as a GRAS-type additive (Generally Regarded as Safe), its incorporation in food is legally permitted. [0055] Acute otitis media is the second most common infection in children. It is caused by bacteria from the nasopharynx that enter the middle ear via the Eustachian tube (Erramouspe, Heyneman, 2000). According to Kontiokari et al. (1995), xylitol acts to prevent or to combat this disease, inhibiting the growth of Streptococcus pneumoniae bacteria, the main cause of sinusitis and middle ear infections. [0056] When compared to other sweeteners, xylitol brings about greater benefits for oral health, preventing the incidence of cavities or reducing their formation (Mussatto S I, Roberto I C. Xilitol: Edulcorante com efeitos benéficos para a saúde humana, Revista Brasileira de Ciências Farmacêuticas , vol. 2002). [0057] In a preferred embodiment of the invention, the xylitol content of the composition according to the invention is from 0.1 vol % to 30 vol %, preferably 10 vol %. [0058] Other Components [0059] In a preferred embodiment of the invention, the composition according to the invention comprises various additional components. [0060] One of the additional components can be, for example, a solution of citric acid, containing 0.01 vol % to 10 vol % qs. [0061] Other additional component can be, for example, purified water or deionized water, qsp. [0062] Another additional component can be, for example, a pH stabilizer, in order to maintain the pH between 6.0 and 7.0 composition, in sufficient amount to meet the conditions of the composition according to the invention. [0063] In addition to these components, preservatives, flavorings, colorings and alcohol may be part of the formulation of the composition according to the invention. [0064] Application Forms/Pharmaceutical Forms [0065] In a preferred embodiment of the invention, the compositions according to the invention are used in liquid form and preferably applied in the form of a immersion bath. [0066] In another preferred embodiment of the invention, the compositions according to the invention can be used and applied respectively in the form of effervescent material (pill, tablet, powder or similar), in the form of aerosol, misting fluid, infusion fluid, vapor and other forms that are suitable for application to surfaces. [0067] New Technical Effect [0068] The disinfection composition according to the invention provides a unique synergy that results in a new and unique technical effect. [0069] Initially, the composition according to the invention has high penetration power in synthetic bristles, especially toothbrush bristles. The penetration occurs even among the tufts, an effect which is primordial to the effective action of the remaining components of the formula. [0070] As described above, this action occurs due to the reduction of the surface tension of the liquid obtained by surfactant component, being an advantage over all the liquid antiseptics on the market. [0071] The composition according to the invention eliminates the culture existing in toothbrushes, for example, having an effective action on saliva, fat, dentifrice debris and microorganisms—components which are known to initiate the formation of a biofilm which is responsible for the culture medium. [0072] Therefore, the composition according to the invention provides the elimination of growth and formation of colonies of microorganisms, the elimination of the medium responsible for the formation of bacterial resistance (resistant bacteria), the elimination of the potential for recontamination and/or transmission of microorganisms to the user, wherein this action is due to the combination of the ability of fat particles sequestration performed by the surfactant plus the chlorhexidine action of disinfection. [0073] As previously mentioned, the composition according to the invention acts preventively on the inhibition of biofilm formation. [0074] This effect is due to the action on all the components forming the biofilm and on the entire toothbrush because of the excellent penetration provided by the surfactant that, added to chlorhexidine disinfection capacity, is enhanced by the action of xylitol in inhibiting the growth and metabolism of bacteria. [0075] The composition according to the invention acts with a disinfectant action, eliminating bacteria, fungi and viruses. The action of chlorhexidine is enhanced for the main etiological agent of dental caries, Estreptococcus mutans , due to combination with xylitol. [0076] The composition according to the invention has an extended effect (continued disinfection) of at least 7 (seven) days, as a result of the combination of the effects of (i) surfactant provided with excellent penetration in the bristles and the preventive effect against the formation of biofilm, (ii) chlorhexidine disinfection capacity for bacteria, fungi and viruses, wherein chlorhexidine has its residual action of up to 12 hours (Perionews 2011) extended for at least 7 (seven) days within the composition according to the invention. [0077] The composition according to the invention fights the action of E. mutans through the action enhanced by xylitol. [0078] Therefore, it is concluded that the actions of disinfection are effective on the entire toothbrush, because of the effective permeability of liquid in addition to the capacity of deep cleaning with dissolution of the fat existing in saliva and residual organic matter. [0079] As a result of the effects described, in addition to having a disinfected surface, there will be no residual or remaining substrate for the new formation of biofilm and proliferation of bacteria—essential and indispensable condition for high hygiene requirements. [0080] Composition [0081] Therefore, one objective of the present invention is the provision of a disinfection composition comprising at least one disinfection component, at least one fat removal component, at least one additional protection component and various additional components. [0082] In a preferred embodiment of the invention, the composition according to the invention comprises: at least one chlorhexidine-based disinfection component; at least one alkylpolyglycoside-based fat removal component; at least one xylitol-based additional protection component; and one or more additional components selected from the group consisting of citric acid solution, purified or deionized water qsp, pH stabilizer, preservatives, flavorings, dyes and alcohol. [0087] In a preferred embodiment of the invention, the composition according to the invention comprises: a chlorhexidine content from 0.1 vol % to 20 vol %, preferably 0.2 vol %; an alkylpolyglycoside content of 0.5 vol % to 12 vol %, preferably 4 vol %; a xylitol content from 0.1 vol % to 30 vol %, preferably 10 vol %; additional components that can properly complete the formula. [0092] Disinfection Method [0093] Another objective of this invention is the provision of a disinfection method, especially for lasting disinfection of synthetic fibers, synthetic surfaces, metallic surfaces, composite surfaces and the like. [0094] The method according to the invention comprises the following steps: a) washing the surface to be disinfected with running water; b) washing the surface to be disinfected with saline (optional); c) immersing the surface to be disinfected in the disinfection composition and/or applying the disinfection composition on the surface to be disinfected; d) allowing the action of the disinfection composition during 5 to 15 minutes, preferably 10 minutes; e) emerging the surface to be disinfected in the disinfection composition (considering the immersion of step ‘c’); f) washing the surface to be disinfected with running water; and g) washing the surface to be disinfected with saline (optional). [0102] Disinfection Protocol for Toothbrushes [0103] Another objective of this invention is the provision of a disinfection protocol, notably for the lasting disinfection of bristles of toothbrushes. [0104] The disinfection protocol comprises the following steps: a) washing hands; b) performing oral hygiene with a toothbrush and a dentifrice or appropriate oral hygiene product; c) washing the toothbrush with running water; d) inserting a disinfection composition according to the invention into a suitable container for partial immersion of the toothbrush; e) immersing the bristles head of the toothbrush in the disinfection composition; f) allowing the action of the disinfection composition during 5 to 15 minutes, preferably 10 minutes or removing the toothbrush only at the time of the next oral hygiene procedure; g) disposing said used disinfection composition after a maximum of 7 days; h) washing the bristles of the toothbrush with running water before the next oral hygiene procedure. [0113] Product [0114] Another objective of this invention is the provision of a disinfection product, especially for lasting disinfection of synthetic fibers, synthetic surfaces, metallic surfaces, composite surfaces and the like, comprising a disinfection composition according to the invention. [0115] In a preferred embodiment of the invention, the product according to the invention is a liquid or fluid for immersion. [0116] In another preferred embodiment of the invention, the product according to the invention is an effervescent material (pill, tablet, powder or similar) or aerosol, or a misting or infusion fluid, or vapor, or any other form that is suitable for application to surfaces. [0117] Tests/Results [0118] In order to test the effectiveness of the disinfection composition according to the invention and its extended action, numerous laboratory tests were conducted, two of which have their results briefly presented below. [0119] One of the tests performed was the verification of the minimum extended action time of the disinfection composition according to the invention, by dipping toothbrushes infected with Escherichia coli and Pseudomonas aeruginosa separately in a vessel containing the composition according to the invention. [0120] Contamination of two separate solutions with each of the bacteria was performed, the bristles of a toothbrush being, then, immersed in said contaminated solutions, contaminating them completely. [0121] Two toothbrushes were infected, each with one of the types of bacteria. Bacteria continued to be inoculated daily and the toothbrushes were kept in their respective fluids kept in an oven at 37° C. [0122] Said contaminated brushes were then immersed in a disinfection composition according to the invention. The following table (Table 1) shows the result of the presence of bacteria in the infected brushes immersed in those test liquids, for 7 (seven) days, for each bacteria. [0000] TABLE 1 7 days laboratory test DAY 1 DAY 2 DAY 3 DAY 4 DAY 5 DAY 6 DAY 7 Bacterium: Escherichia Coli TOOTHBRUSH 1 NEGATIVE NEGATIVE NEGATIVE NEGATIVE NEGATIVE NEGATIVE NEGATIVE TOOTHBRUSH 2 NEGATIVE NEGATIVE NEGATIVE NEGATIVE NEGATIVE NEGATIVE NEGATIVE Bacterium: Pseudomonas Aeruginosa TOOTHBRUSH 1 NEGATIVE NEGATIVE NEGATIVE NEGATIVE NEGATIVE NEGATIVE NEGATIVE TOOTHBRUSH 2 NEGATIVE NEGATIVE NEGATIVE NEGATIVE NEGATIVE NEGATIVE NEGATIVE [0123] Taking into consideration Table 1 above, one concludes that the qualitatively tested disinfection composition has an extended action during at least seven days, without being replaced or replenished throughout the testing period. The composition according to the invention was successful considering the extended period criterion, even with daily inoculation of bacteria. [0124] Another test performed was the one for efficacy of elimination of microorganisms strains added to different liquids, including the composition according to the invention, by measuring the residual content of the strains in those fluids. [0125] The microorganism strains used are recited in the results table below (Table 2). [0126] The disinfection liquids prepared and tested are also recited in the results table below (Table 2). [0127] Antimicrobial activities of three liquids were analyzed, namely: (i) Purified water (reference) (ii) Solution A (1 vol % chlorhexidine, 4 vol % alkylpolyglycosides, 10 vol % xylitol and purified water qsp pH 6.0) and Solution B (5 vol % chlorhexidine, 4 vol % alkylpolyglycosides, 10 vol % xylitol and purified water qsp pH 6.0). [0128] Methodology: inoculation of each microorganism at 10 6 in each respective disinfection liquid, individually. Keeping it in each liquid for a disinfection action for 10 minutes. Then, the respective cultures were carried out in which there was quantitative analysis with a counting method after 48 hours in an oven. [0129] Table 2 results, referring to residual activity, prove the effectiveness of compositions according to the invention. [0000] TABLE 2 antimicrobial activity by contact time Candida Klebsiella E. Coli Samonella S. Mutans S. aureus P. Aeruginosa Lactobacillus Decimal Inoculum Inoculum Inoculum Inoculum Inoculum Inoculum Inoculum Inoculum Reduction 5.3 × 10 5 1.1 × 10 6 5.0 × 10 6 4.6 × 10 6 2.1 × 10 6 4.0 × 10 6 4.7 × 10 6 4.5 × 10 5 (% DR) Product CFU CFU CFU CFU CFU CFU CFU CFU Bacteria Purified 2.2 × 10 5 6.7 × 10 5 3.4 × 10 6 2.9 × 10 6 2.1 × 10 6 4.7 × 10 6 4.0 × 10 6 2.8 × 10 5 No water reduction Solution A <10 <10 <10 <10 <10 <10 <10 <10 99.99 Solution B <10 <10 <10 <10 <10 <10 <10 <10 99.99 [0130] Final Considerations [0131] As can be inferred from the description above, the composition according to the invention provides lasting disinfection of synthetic fibers, synthetic surfaces, metal surfaces, composite and similar surfaces, and the like, avoiding contamination and re-contamination of said elements. [0132] More specifically, the composition according to the invention exhibits both combined and simultaneous antibacterial, antiseptic and deep cleaning activity with extended action (of at least seven days) especially for continuous use in toothbrush bristles, but also effective for the disinfection of other synthetic or metallic surfaces (such as, for example, oral hygiene instruments such as tongue scrapers, dental floss bow, among others), in addition to surfaces of oral devices (braces and retainers for instance), prostheses, and even hearing aids, combining minimal toxicity (to the human body) to maximum effectiveness. [0133] The effectiveness of the composition according to the invention also extends to the complementary residues that can be found on the surfaces of objects to be disinfected, for example, fat, dentifrice debris, food debris, organic tissue, saliva, soaps, shampoos, rinses and the like, their continuous and daily use being guaranteed, without restrictions due to its non-toxic components. [0134] In addition, there is room for a composition having a lasting action on the disinfected surfaces as above-mentioned and which can additionally be beneficial to the health of the user, in a complementary manner. Said composition containing, for instance, compounds that have anti-caries efficacy and the like, presenting antimicrobial and also dental plaque inhibiting action, thus achieving a reduction of oral diseases and halitosis, in addition to various conditions related to medical and hearing aids. CONCLUSION [0135] Those skilled in the art will easily understand that modifications can be made to the present invention without straying from the concepts exposed in the above description. These modifications are to be considered comprised by the scope of the present invention. Consequently, the particular embodiments previously described in detail are only illustrative and exemplary as well as non-restrictive with regards to the scope of the present invention, to which the full extent of the appended claims and of each and every equivalent should be given.

The present invention relates to a disinfection composition, particularly for lasting disinfection of synthetic fibres, synthetic surfaces, metallic surfaces and composite surfaces, and similar surfaces, said disinfection composition comprising at least one disinfectant, at least one fat- and residue-removing component, at least one additional protection component and additional components which are compatible with the above components and have low or no toxicity. The invention further relates to a disinfection method, to a specific tooth brush disinfection protocol and finally, to a corresponding disinfection product.

BACKGROUND OF THE INVENTION [0001] a) Field of the Invention [0002] This invention relates to the preparation of a solid product in the form of a cake, a powder, or the like, by mixing a solvent comprising water, an aqueous solution, at least one non-aqueous organic solvent, or combinations thereof, with at least one stabilizing agent, and subsequently adding at least one liquid biologically active agent to the above mixture; and treating the whole under conditions to give the above solid product which is substantially solvent free. More particularly, the invention relates to the above solid product and a method for rapid reconstitution thereof in an aqueous media, whereby an essentially clear, lipid free, sterile, stable aqueous product is formed containing nano-dispersions or micelles of the aforementioned stabilizing and biologically active agents; and to a method of treating a patient in need of said biologically active agent by administration of said stable aqueous product thereto. In a preferred embodiment, the biologically active agent is water immiscible and may be selected from 2,6-bis-(1-methylethyl)phenol or 2,6-diisopropylphenol commonly known as propofol, 2-phenoxyethanol, quinaldine, methoxyflurane and the like and combinations thereof. The most preferred biologically active agent is propofol. [0003] b) Description of the Prior Art [0004] Propofol (known as 2,6-bis-(1-methylethyl)phenol, also known as 2,6-diisopropylphenol) is currently the most popular anaesthetic in the world. It is used for the induction and maintenance of anaesthesia or sedation upon administrations to humans or animals. Intravenous injection of a therapeutic dose of propofol produces hypnosis rapidly and with minimal excitation, usually within 40 seconds from the start of an administration. Fast onset and short half life (10-15 minutes) allows for a clinically useful profile with prompt recovery. Due to the rising cost of health care, this quick recovery time is especially advantageous for increasingly common outpatient procedures. [0005] At room temperature, propofol is an oil that is immiscible with water (aqueous solubility of approximately, 0.154 mg/mL) and is supplied in a emulsion, at concentrations of 1% or 2% (w/w) (2% is used for longer sedation). Propofol oil-in-water emulsions currently on the market are DIPRIVAN® (manufactured by AstraZeneca Pharmaceuticals, Inc.,), BAXTER® IPP (manufactured by Gensia Sicor, Inc), and Propofol injectable emulsion (Manuf. Bedford Laboratories). [0006] Extreme care must be taken during manufacture to thoroughly distribute the propofol in the emulsion, as large droplet sizes of propofol in the blood stream have been linked to embolism in humans. These emulsions typically contain: soybean oil (100 mg/mL), glycerol (22.5 mg/mL) and egg lecithin (12 mg/mL). Emulsions are defined by a large particle size, generally of more than 200 nm, thereby creating a milky white opaque formulation. This causes visual inspection for foreign particles in the formulation by the anesthesiologist, to be more difficult. The high lipid content of these emulsions has been linked to hyperlipidaemia. [0007] The presence of the egg lecithin and soybean oil in these emulsions also makes them highly susceptible to microorganism growth and allergic reactions. In order to suppress bacterial growth, manufacturers have added the preservative EDTA (ethylene diamine tetraacetic acid) at 0.05 mg/mL to DIPRIVAN® and sodium metabisulfite at 0.25 mg/mL, to BAXTER® PPI propofol, and benzyl alcohol at 1 mg/ml to propofol injectable emulsion of Bedford Laboratories. [0008] Some of these preservatives have been known to cause adverse reactions in humans. Sodium metabisulfite is a sulfite known to cause allergic-type reactions including anaphylactic symptoms and life-threatening or asthmatic episodes in certain sulfite sensitive individuals. Sodium bisulfite has also been shown to catalyze propofol degradation. Similarly, the chelating properties of EDTA are of concern to the FDA due to their unfavorable effects on cardiac and renal function. Moreover, these emulsions cannot be effectively sterilized using standard sterilizing filters, as they are too thermodynamically unstable and tend to separate under the shear force required. Such emulsions are also unstable versus dilution and/or mixing with saline, dextrose or other medication containing solutions. Furthermore, the presence of egg lecithin as an emulsifier and soybean oil as a solubilizer may produce anaphylactic and anaphylactoid reactions in persons allergic to eggs and/or soybeans. [0009] Propofol emulsions are known to be thermodynamically unstable, that is, the oil and water components have a tendency to separate when diluted, sheared, cooled, heated, or mixed with other solutions. Furthermore, this separation is accelerated when the formulation is stored at low temperatures, i.e. below 2° C., or at elevated temperatures, i.e. above 25° C. In addition, these lipid-based emulsions have been associated with pain at the injection site, often causing the concomitant use of a topical anaesthetic upon injection. [0010] A variety of methods and procedures have been described in the prior art for preparing stable formulations for the effective delivery of at least one hydrophobic compound, particularly pharmaceutical drugs, to a desired location in the body. A number of these methods are based on the use of auxiliary solvents; surfactants; soluble forms of the drug, e.g., salts and solvates; chemically modified forms of the drug, e.g., prodrugs; soluble polymer-drug complexes; special drug carriers such as liposomes; and others. [0011] Indeed, the use of surfactant based micelles has attracted a great deal of interest as a potentially effective drug carrier that is capable of solubilizing a hydrophobic drug in an aqueous environment. Typically, micelles and nanodispersions have been shown to alter the pharmacokinetics (and usually the pharmacodynamics) of the biological agent to be delivered. Thus, by sequestering the drug within them, they may prolong the circulation time, may allow more drug to be delivered to a specific location, and/or may allow a different biodistribution when compared to administration of the drug alone. [0012] However, each of the above procedures is associated with certain drawbacks, especially when considering the delivery of “on/off” type anaesthetics, such as propofol. For example, the method based on the use of surfactant micelles to solubilize hydrophobic drugs can be inherently problematic in that some of the surfactants are relatively toxic (e.g. Cremophor EL®) and that precipitation of hydrophobic drugs may occur when subjected to dilution. Other methods of preparation yield poor entrapment efficiencies (e.g. equilibration methods), relatively large particle sizes (emulsions), or are time-consuming. [0013] Finally, the prolonged circulation time associated with micellar or liposomal delivery can detrimentally affect the “on/off” properties required of an anaesthetic drug such as propofol [0014] Likewise, there have been studies based on the use of cyclodextrin derivates, which are water-soluble cyclic carbohydrate compounds with hydrophobic interior cavities that complex with propofol allowing dissolution of the drug in water to form a clear solution. However, cyclodextrins are expensive and have been associated with hemodynamic adverse events. Also, long-term stability of cyclodextrin formulations has been an issue with formulators. More importantly, cyclodextrins have been linked with renal toxicity at high doses. [0015] There have also been various attempts investigating the use of water-soluble prodrugs comprising a propofol phosphate. However, usually prodrugs require much higher doses (up to ten times and more) for the same response as the instant invention and usually demonstrate a slower onset of action and slower clearance. Moreover, in some propofol prodrugs one of the bi-products is formaldehyde, a probable carcinogen. Prodrugs are also notably unstable resulting in short shelf lives or low storage temperatures to maintain their stability. The beneficial pharmacokinetics are changed due to the use of prodrugs. [0016] Furthermore, when a liquid biologically active agent such as propofol is formulated with the technologies discussed above, a liquid dosage form is produced. However, the stability of such liquid formulations is always a concern with respect to duration and storage conditions. [0017] Thus, what is lacking in the art is a light-weight, dry powder or cake formed from a water immiscible liquid drug, such as propofol, that is stable in several different temperature and dilution conditions for prolonged periods, that is readily reconstituted using aqueous media to produce essentially clear, sterile liquids which do not support bacterial growth, comprising drug-loaded micelles or nanodispersions in an aqueous medium. The micelles or nanodispersions, which are produced directly and spontaneously after addition of the aqueous reconstitution medium, allows high loading levels of propofol or other biologically active liquids to be achieved with substantially no effect on stability. [0018] Many studies, literature articles and patents have been directed toward forming stable anaesthetic compositions suitable for parenteral administration, particularly the administration of propofol and other drugs in liquid form. [0019] For example, WO 02/45709 A1 discloses a stable, clear and sterile aqueous composition comprising propofol, a water-soluble emulsifier (TPGS) and water, suitable for parenteral administration and a process for making the same. However, the final product is a liquid and the process of manufacturing requires both the filtration of the composition through a micron-sized filter and autoclaving the sealed container filled with the filtrate in order to achieve effective sterilization. [0020] WO 03/030862 A2, discloses inhalation anaesthetic compositions and methods comprising a suspension of the anaesthetic in an aqueous solution. The reference teaches the use of surfactant poloxamers, (known as Pluronics® in the United States and Lutrols® in Europe) to encapsulate the anaesthetic (i.e. propofol) within the micelles. The preferred embodiments require the presence of propylene glycol in order to achieve adequate solubilization of propofol. However, the product is supplied as a liquid and the presence of water in the inhaled anaesthetic is not always beneficial to patients with pulmonary disorders, such as plural effusion. It will be noted that the composition disclosed in this reference is prepared using a mixture of liquids to constitute a liquid composition. [0021] WO 01/64187 A2 and corresponding U.S. PGPUB No. 2003/0138489 A1, on the other hand, disclose propofol solubilized in aqueous micellar preparations using combinations of poloxamers to form a clear, injectable solution without inclusion of water-miscible co-solvents, such as propylene glycol. According to WO 01/64187 A2, the use of water-miscible co-solvents can have undesirable medical effects, such as superficial thrombophlebitis, intravasal, haemolytic reactions, and possible increase in formation of free propofol. Moreover, WO 01/64187 A2 indicates that autoclaving may be undesirable when the formulation is filtered to sterility since autoclaving has been known to disrupt the micelles, to the extent of requiring re-emulsification. In addition, poloxamers are detergent-like surfactants that are not readily degradable and may open-up tight junctions. Moreover, detergent surfactants may be a source of pain upon injection and require the addition of lidocaine to reduce local pain. The final product is a liquid. [0022] U.S. Pat. No. 6,322,805 discloses a biodegradable polymeric drug carrier micelle composition capable of solubilizing a solid hydrophobic drug in a hydrophilic environment. The patent discloses a biodegradable polymeric drug carrier micelle and a hydrophobic drug wherein the drug is physically trapped within and not covalently bonded to the polymeric drug carrier micelle. The drug carrying micelle is capable of dissolving in water to form a solution thereof, and the drug carrier comprises an amphiphilic block copolymer having a hydrophilic poly(alkylene oxide) component, and a biodegradable hydrophobic polymer component selected from the group consisting of poly(lactic acid), poly(glycolic acid), poly(lactic-co-glycolic acid), poly(ε-caprolactone), a derivative thereof or a mixture thereof. The disclosed micelle is characterized as a solubilizing agent for a hydrophobic drug. The hydrophobic drug is mixed with the polymeric drug carrier micellar solution and the mixture is either stirred, heated, subjected to ultrasonic treatment, solvent evaporation or dialysis so as to incorporate it into the hydrophobic polymer core, after which it is formed into an aqueous solution. [0023] U.S. Pat. No. 5,543,158 discloses nanoparticles or microparticles formed of a block copolymer consisting essentially of poly(alkylene glycol) and a biodegradable polymer, poly(lactic acid). In the nanoparticle or microparticle, the biodegradable moieties of the copolymer are in the core of the nanoparticle or microparticle and the poly(alkylene glycol) moieties are on the surface of the nanoparticle or microparticle in an amount effective to decrease uptake of the nanoparticle or microparticle by the reticuloendothelial system. Thus, the nanoparticles or microparticles are designed to circulate for prolonged periods within the blood fluids. In this patent, the molecular weight of the block copolymer is too high to be soluble in water, and a nanoparticle can only be prepared by first dissolving the block copolymer and a drug in an organic solvent, forming an o/w emulsion by sonication or stirring, and then collecting the precipitated nanoparticles containing the drug. The patent fails to provide the concept of solubilization of hydrophobic drugs, nor does it teach or suggest the formation of a clear, sterilizable solution containing the polymer/drug blend and subsequent lyophilization thereof, resulting in a readily dispersible micelle or nanodispersion, formed upon reconstitution. [0024] EP 0520888 A1 discloses nanoparticles made of a poly(lactic acid) and poly(alkylene oxide) block copolymer. A high molecular weight poly(lactic acid) is used and a surfactant is employed in preparing a colloidal suspension of the nanoparticles. In this patent, nanoparticles are prepared by dissolving the block copolymer and a drug in an organic solvent, emulsifying the organic solution in water, and evaporating the organic solvent to precipitate the nanoparticles containing the drug. The resulting nanoparticles are fine particles having both hydrophilic and hydrophobic components and they cannot form clear stable aqueous liquids. [0025] U.S. Pat. No. 4,997,454 teaches a method for making uniformly sized particles from solid compounds for intravenous administration as suspensions of particles of three microns in diameter, or less. A suitable solid compound is dissolved in a suitable solvent, and a precipitating liquid is infused to form non-aggregated particles which are separated from the liquid mixture. The product is a liquid comprising a suspension of solid microspheres. [0026] U.S. Pat. Nos. 4,370,349 and 4,311,712 disclose a process for preparing a freeze-dried, liposomal, mixture which comprises either (a) dissolving at least one liposome-forming amphiphilic lipid, at least one biologically-active compound, and optionally one or more adjuvants, in a suitable solvent, and then freeze-drying the solution, or (b) preparing by any known method an aqueous liposome composition containing at least one biologically-active compound, and then freeze-drying the said aqueous liposome composition. The patents are particularly directed toward a process for preparing an aqueous liposome composition which comprises dispersing said freeze-dried, potential liposomal, mixture, obtained by procedure (a) or (b), in a suitable aqueous medium. The process of the instant invention is not directed toward liposome production. [0027] U.S. Pat. No. 6,780,324 teaches a unique process wherein a solution is formed from a hydrophobic biologically active agent, in combination with a dispersing agent and a suitable solvent or solvent blend (which may further include water), the mixture being lyophilized and thereafter rehydrated to form a biologically active agent loaded micelle or nanodispersion. The instant invention provides an improved method for forming a biologically active agent loaded micelle or nanodispersion from a liquid hydrophobic biologically active agent by first forming a solution of a stabilizing agent and solvent (which solvent may solely comprise water), to which is added a liquid hydrophobic biologically active agent. This is followed by lyophilization and/or any treatment that will result in a solid product that is substantially free of solvent. [0028] U.S. Pat. No. 6,835,396 discloses the preparation of submicron sized particles by mixing a pharmacologically active compound with a water immiscible solvent to form an organic phase. On the other hand there is provided an aqueous phase containing a surface active compound. The organic phase and the aqueous phase are combined to form a crude dispersion and the latter is treated with a sonication device allowing cavitation to occur. The dispersion is then frozen and lyophilized to provide particles having a mean particle size of less than 500 nm. [0029] Ideally therefore, propofol should be available as a solid product that can instantaneously be hydrated to form a clear stable solution ready for injection. For this purpose, a test was made by lyophilizing a mixture of water and propofol. The result is that water and propofol had all evaporated and nothing remained. This is an indication that other avenues must be investigated. [0030] Accordingly, it is a main objective of the instant invention to provide a process for the formation of a sterile, solid loaded micelle or nanodispersion comprising a liquid biologically active agent in an amphiphilic biodegradable polymer. [0031] An additional objective of the invention is to produce a stable cake or powder that is readily reconstituted to form an essentially clear aqueous liquid containing a stabilized drug nanodispersion or loaded micelle. [0032] It is still a further objective of the instant invention to provide a process whereby a clear liquid comprising a biologically active agent, polymer and optionally an additive (e.g. a bulk forming agent, a cryoprotectant, a lyoprotectant) and/or stabilizer is formed using any suitable solvent prior to a treatment such as freeze-drying, spray drying, and the like. [0033] Another objective of the present invention is to provide a storable powder that is instantaneously reconstituted before administration to a patient for long-term infusions as well as bolus (highly concentrated) injections. [0034] Another objective of the present invention is to provide micelles or nanodispersions loaded with liquid biologically active agents that release quickly into body fluids and tissues post administration. [0035] Yet another objective of the instant invention is the formation of a powder that yields a longer shelf life and lighter product. [0036] It is still a further objective of the invention to provide a sterile formulation without the need for preservatives. [0037] Another objective of the invention is to provide a formulation that reduces or eliminates any sensation of pain upon administration commonly, which has been associated with currently marketed formulations. [0038] It is a further objective of the instant invention to provide, once reconstituted, a liquid medical formulation that is stable for more than 24 hours at high drug loading levels at room temperatures. [0039] Another objective of the present invention is to provide a formulation that is stable after dilution, when subjected to shear forces, or when mixed with saline, dextrose or other medication containing solutions (e.g. injectable lidocaine solutions). [0040] Another objective of the present invention is to provide a solid formulation that, upon reconstitution, does not support bacterial growth. [0041] Another objective of the present invention is to provide a formulation that is lipid free. DEFINITIONS [0042] The term “stabilizing agent” as used in the present specification and claims, is intended to mean a vehicle or material which allows aqueous preparations of water insoluble drugs. [0043] The term “essentially clear” as used in the present specification and claims, is intended to mean a stable solution of a reconstitution solvent and a reconstituted solid, wherein a solid product comprising an intimate mixture of at least one stabilizing agent and at least one liquid biologically active agent loaded within the stabilizing agent, upon reconstitution, forms a clear stable reconstituted solution in which said at least one biologically active agent is present as stabilized nanodispersions or loaded micelles up to about 13% drug loading level, an increasingly opalescent solution at about 13% to about 20% drug loading level, and a transparent, cloudy suspension at greater than about 20% drug loading level. Nevertheless, all of these formulations of the instant invention are stable for more than 24 hours, i.e. they do not precipitate upon dilution in water and/or albumin 35 g/L solution. PPF-PM means propofol-polymeric micelle SUMMARY OF THE INVENTION [0044] In order to overcome the problems encountered by the prior art, the instantly disclosed invention relies on a treatment, such as lyophilization, spray drying, or the like well known to those skilled in the art, which is obtained by mixing a solvent selected from water, an aqueous solution, at least one non-aqueous organic solvent, or combinations thereof with at least one stabilizing agent under conditions to provide a first solution, to which is subsequently added at least one liquid biologically active agent such as propofol or the like, to give a second solution. The latter is lyophilized, spray-dried, or the like under conditions which yield a solid product, in which the liquid biologically active agent is intimately associated, and from which substantially all the solvent or solvents have been removed and where virtually no loss of drug occurs during the treatment; optionally an additive, non-limiting examples of which include a buffer, a bulk forming additive, a cryoprotectant, and a lyoprotectant may be added at any stage during the treatment. [0045] Such a liquid can be subjected to a sterilizing filtration step prior to the above treatment to form a powder, a cake or the like. The solid product resulting from the above treatment is a light-weight, lipid free material that can be stored, transported and then reconstituted prior to use by the addition of an aqueous solution e.g. water, saline, dextrose or the like to form essentially clear, stable, sterile, liquids comprising nanodispersions or micelles in aqueous medium. [0046] The instant process illustrates a simple and elegant procedure for forming a solid product from a liquid containing an intimate association of an insoluble liquid drug and a stabilizing agent. The liquid, comprising an intimate association of the solvent, insoluble liquid drug and stabilizing agent, may be dried by a process, whereby the insoluble liquid drug remains in close association with the stabilizing agent such that virtually all drug is retained during the process. The product is a dry, solid as mentioned above. The dry solid product upon addition of water or an aqueous solution spontaneously reconstitutes to form an essentially clear stable liquid comprising drug micelle or drug nanodispersions loaded with a liquid biologically active agent. [0047] Broadly, the invention relates to a solid product suitable for reconstitution to a clear, stable solution upon addition of an aqueous solvent thereto, the solid product comprising an intimate mixture of at least one stabilizing agent, and at least one liquid biologically active agent, non-limiting examples of which are propofol, 2-phenoxyethanol, quinaldine, methoxyflurane, and the like, loaded within the stabilizing agent, in such a manner that the liquid biologically active agent is intimately associated with the stabilizing agent in a substantially solid product. The substantially solid product upon rehydration with a reconstituting aqueous solvent or solution, is capable of forming the essentially clear stable solution in which at least one biologically active agent is present as nanodispersions or micelles loaded with the at least one biologically active agent. [0048] The invention also relates to a process for the production of a solid product suitable for reconstitution to a clear stable solution upon addition of an aqueous solution thereto, which is produced by forming a first mixture comprising a solution of at least one stabilizing agent, and at least one solvent, under conditions to achieve micelle or nanodispersion formation, subsequently adding at least one liquid biologically active agent, such as propofol, 2-phenoxyethanol, quinaldine, methoxyflurane, and the like, to the first mixture in such a manner to load the micelle or nanodispersion therewith and form a second mixture, and treating the second mixture under conditions effective to remove the solvent therefrom while forming a substantially solid product that contains the liquid biologically active agent intimately associated with the stabilizing agent, the solid product upon rehydration being capable of forming an essentially clear stable solution in which the at least one biologically active agent is present as a nonodispersion or micelle loaded with the at least one biologically active agent. [0049] The invention also comprises a process for the production of a stabilized nanodispersion or loaded micelle containing a liquid biologically active agent by hydrating the above solid product under conditions to provide a stabilized nanodispersion or loaded micelle containing the liquid biologically active agent. [0050] The invention also comprises the essentially clear liquid product obtained by reconstituting the solid product defined above, and a method of medical treatment which comprises administering to a patient the above essentially clear liquid comprising a stabilized nanodispersion or loaded micelle of the liquid biologically active agent. [0051] The invention additionally comprises a device for producing solid formulations of liquid biologically active agents comprising a container, means for adding at less one stabilizing agent and at least one solvent into the container, mixing means operable with the container to form a first mixture of the stabilizing agent and the solvent under conditions to achieve micelle or nanodispersion therein, means for subsequently adding a liquid biologically active agent to the first mixture and to form a second mixture, means operating the mixing means under conditions to treat the second mixture to load the micelle or nanodispersion with the biologically active agent, and means for treating the loaded micelle or nanodispersion to form a solid product containing the liquid biologically active agent intimately associated with the stabilizing agent and substantially free of the solvent. [0058] Examples of suitable stabilizing agents include, but are not limited to amphiphilic polymers such as linear, branched or star-shaped block amphiphilic copolymers where the hydrophilic part may include at least one member selected from a group consisting of poly(ethylene oxide), poly(N-vinylpyrrolidone), poly(N-2-hydroxypropyl methacrylamide), poly(2-ethyl-2-oxazoline), poly(glycidol), poly(2-hydroxyethylmethacrylate), poly(vinylalcohol), polymethacrylic acid derivatives, poly(vinylpyridinium), poly((ammoniumalkyl)methacrylate), poly((aminoalkyl)methacrylate) and combinations and derivatives thereof; and wherein the hydrophobic segment may include at least one member which is selected from a group consisting of a poly(ester), poly(ortho ester), poly(amide), poly(ester-amide), poly(anhydride), poly(propylene oxide), poly(tetrahydrofuran) and combinations thereof. [0059] The poly(ester) may be at least one member selected from a group consisting of poly(ε-caprolactone), poly(lactide), poly(glycolide), poly(lactide-co-glycolide), poly(hydroxy alkanoates) (e.g. poly (γ-hydroxybutyrate)), poly(δ-hydroxy valerate)), poly (β-malic acid), and derivatives thereof. [0060] Other non-limiting illustrative examples of stabilizing agents may include at least one member selected from the group consisting of sodium lauryl sulfate, hexadecyl pyridinium chloride, polysorbates, sorbitans, poly(oxy ethylene) alkyl ethers, poly(oxyethylene) alkyl esters and the like, including various combinations thereof. [0061] Without limiting the scope of the present invention, suitable agents for incorporation into the nanodispersion or micelles produced in accordance with the teachings of the instant invention may include at least one anaesthetic agent, such as propofol, at a physiologically effective amount, preferably provided at a concentration of about 0.1% to 15%, preferably 1% to 10% (w/v), of propofol. Typically personal characteristics, including but not limited to age, weight and/or health dictate the physiologically effective amount, or dosage, necessary. [0062] Suitable solvents or mixtures thereof will have the ability to solubilize appropriate amounts of the stabilizing agent as well as appropriate amounts of liquid biological agent without denaturation or degradation of the liquid biological agent. Preferred solvents (or mixtures of solvents) should be removed during the lyophilization, spray-drying or the like process. While numerous solvents are capable of functioning in accordance with the process of the instant invention, non-limiting illustrative examples of such solvents include water, dextrose solution in water, saline, DMSO, DMF, dioxane, pyridine, pyrimidine, and piperidine, alcohols such as methanol, ethanol, n-butanol and t-butanol, and acetone, which are useful either alone or in combination, and may be further admixed, e.g. with water, to form a binary mixture. Other solvents may be added in small amounts to facilitate the dissolution of the drug. [0063] Objectives and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and examples, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objectives and features thereof. BRIEF DESCRIPTION OF THE DRAWINGS [0064] FIG. 1 is a graphical representation of pharmacodynamic effects obtained in vivo 001 (example 3) of Diprivan® versus three propofol polymeric micelle formulations after iv administration at 10 mg/kg in female Sprague-Dawley rats. [0065] FIG. 2 is a graph showing the comparison of the time for righting reflex in pharmacodynamic study #1 (example 3) and #2 (example 9). [0066] FIG. 3 is a graph showing the mean concentration-time profiles of propofol in blood following the intravenous administration of Diprivan® and three PPF-PM formulations (10 mg/kg). [0067] FIG. 4 is a graph showing the mean concentration-time profiles of propofol in plasma following the intravenous administration of Diprivan® and three PPF-PM formulations. [0068] FIG. 5 is a graph showing the mean (±SD) withdrawal reflex time, time of first movement and time of righting following the intravenous administration of Diprivan® (1), PPF-PM 7%, PPF-PM 10% and PPF-PM 12% in male Sprague-Dawley rats obtained in vivo 003 study (example 10). [0069] FIG. 6 is a graph showing the mean (±SD) pay withdrawal reflex time following the intravenous administration of Diprivan® (1), PPF-PM 7% (2), PPF-PM 10% (3) and PPF-PM 12% (4) in male Sprague-Dawley rats obtained in vivo 003 study (example 10). [0070] FIG. 7 is a graph showing Staphylococcus Aureus growth in water, in polymer solution in water, propofol polymeric micelle (PPF-PM) solution in water for injection and Diprivan®. [0071] FIG. 8 is a graph showing Staphylococcus Aureus growth in dextrose, in polymer solution in dextrose (PVP-PLA), propofol polymeric micelle (PPF-PM) solution in dextrose and Diprivan®. [0072] FIG. 9 is a graph showing Staphylococcus Aureus growth in saline, in polymer solution in saline (PVP-PLA), propofol polymeric micelle (PPF-PM) solution in saline and Diprivan®. [0073] FIG. 10 is a graph showing E. Coli growth in water, in polymer solution in water (PVP-PLA), propofol polymeric micelle (PPF-PM) solution in water and Diprivan®. [0074] FIG. 11 is a graph showing E. Coli growth in dextrose, in polymer solution in dextrose (PVP-PLA), propofol polymeric micelle (PPF-PM) solution in dextrose and Diprivan®. [0075] FIG. 12 is a graph showing E. Coli growth in saline, in polymer solution in saline (PVP-PLA), propofol polymeric micelle (PPF-PM) solution in saline and Diprivan® . [0076] FIG. 13 is a graph showing Pseudomonas Aeruginosa growth in water, in polymer solution in water (PVP-PLA), propofol polymeric micelle (PPF-PM) solution in water and Diprivan®. [0077] FIG. 14 is a graph showing Pseudomonas Aeruginosa growth in dextrose, in polymer solution in dextrose (PVP-PLA), propofol polymeric micelle (PPF-PM) solution in dextrose and Diprivan® [0078] FIG. 15 is a graph showing Pseudomonas Aeruginosa growth in saline, in polymer solution in saline (PVP-PLA), propofol polymeric micelle (PPF-PM) solution in saline and Diprivan®. [0079] FIG. 16 is a graph showing Candida Albicans growth in water, in polymer solution in water (PVP-PLA), propofol polymeric micelle (PPF-PM) solution in water and Diprivan®. [0080] FIG. 17 is a graph showing Candida Albicans growth in dextrose, in polymer solution in dextrose (PVP-PLA), propofol polymeric micelle (PPF-PM) solution in dextrose and Diprivan®. [0081] FIG. 18 is a graph showing Candida Albicans growth in saline, in polymer solution in saline (PVP-PLA), propofol polymeric micelle (PPF-PM) solution in saline and Diprivian®. [0082] FIGS. 19 A-C illustrate colony counts after 24-hour incubation time of all strains and all reconstitution media, polymer solutions and formulations. [0083] FIG. 20 is a schematic representation of a drug loading procedure and preparation of an essentially clear solution thereof according to the invention. [0084] FIG. 21 is a schematic illustration of a device for producing a solid drug formulation according to the invention. DESCRIPTION OF PREFERRED EMBODIMENTS [0085] In accordance with the schematic representation set forth in FIG. 20 , predetermined amounts of a stabilizing agent, e.g. a suitable polymer, copolymer or a surfactant or a dispersing agent, and optionally, an additive, e.g. a buffer, a cryoprotectant/a lyoprotectant/a bulk forming agent or the like (e.g. commercially available poly (vinylpyrrolidone) Kollidon 12 PF® or 17 PF®, BASF) and/or additional stabilizing agents are dissolved in a solvent, e.g. water, an aqueous solution, at least one non-aqueous organic solvent, or combinations of water or an aqueous solution and said at least one non-aqueous organic solvent to form a first mixture in the form of a micellar solution. It has been realized that proper mixing achieves micelle or nanodispersion formation within the first mixture. [0086] Once the first mixture is well formed, a liquid drug, here propofol, although any other liquid biologically active agent may be used as will be appreciated by one skilled in the art, is added to the first mixture under conditions well known to those skilled in the art, whereby the micelle or nanodispersion will be loaded with the liquid drug in a second mixture in the form of a drug micellar clear solution. [0087] In either or both of the mixing steps described above, a suitable “additive” could be added for purposes well known to those skilled in the art. Non limiting examples of additives include, but are not limited to buffers, cryoprotectants, lyoprotectants, analgesics and bulk forming agents. Other suitable additives include, but are not limited to poly(vinylpyrrolidone), poly(ethylene glycol), sugars (lactose, trehalose), polyols (mannitol), saccharides and amino acids soluble in the solvent or solvent mixture. As broadly recited herein, the term “solvent” is understood to mean water alone, water with at least one non-aqueous organic solvent, or combinations of water and said at least one non-aqueous organic solvent. In one illustrative embodiment, additional dissolution enhancing means, here stirring, may be employed to aid in the forming of the liquid comprising a biologically active agent, a stabilizing agent and a solvent, prior to treatment to form a solid product. Illustrative, but non-limiting examples of said dissolution enhancing means may include a process, for example, wherein the mixture may be stirred, vortexed and sonicated, if needed. For some polymers, the solution may also need to be heated to speed up dissolution. [0088] In the illustrated embodiment, the solution is filtered through a sterilizing filter, e.g. through a 0.2 μm filter. Subsequently, the solution is freeze-dried to form a sterile dry cake or powder or the like. [0089] Lastly, for administration to a patient, the dried powder or cake is reconstituted with water, saline 0.9%, dextrose 5%, or other suitable solvent, or drug containing aqueous solutions, whereby a stable nanodispersion or loaded micelle is spontaneously produced. [0090] The reconstituted formulation comprising nanodispersions or micelles in a suitable (usually aqueous) solvent may be characterized by; 1. Particle size and particle size distribution of the nanodispersion or micelle e.g. as determined by dynamic light scattering; 2. Clarity of the liquid e.g. as determined by degree of light transmittance at 660 nm; 3—pH; 4—Drug content/dose/concentration; 5—Viscosity (not in examples though); 6—Osmolality [0097] In the present invention, the drug loading levels of 1 to 10% w/w were found to produce clear/stable solutions at any volume of reconstitution from 10 mg/mL, (found in commercially available propofol emulsions), to 100 mg/mL. However, at the latter concentration, the solution's viscosity becomes an issue for injection. Hence, the concentration of polymer in water is the limiting factor for reconstitution volume of formulations. [0098] Starting at around 12% drug loading level, reconstituted solutions, while remaining essentially clear, become increasingly opalescent, with a blue tint at 12% to a transparent, cloudy suspension at 20% and more. Nevertheless, all of these formulations of the instant invention were found to be stable for more than 24 hours, i.e. they do not precipitate upon dilution in water and/or albumin 35 g/L solutions. The opalescence suggests the swelling of the micelles to bigger sizes causing light diffraction observable by the naked eye. [0099] The presence of albumin does not affect the stability of the propofol formulation of the current invention. Dilutions of 10, 20, and 40 mg/mL formulations at 5% w/w, 7% w/w, 10% w/w, and 15% w/w drug loading levels in 35 g/L albumin solutions showed no significant turbidity or differences with reconstituted solutions in water, saline or dextrose. That is, the clear solutions stayed clear, with no visible precipitation of polymer and/or albumin and/or floating propofol (phase separation is not present). Similarly, the opalescent suspensions stayed opalescent, but less so after dilution, with no precipitation of polymer and/or albumin and/or floating propofol. [0100] With reference to FIG. 21 , a device for carrying out the preparation of a solid product according to the invention comprises a container 1 which is connected in known manner to a supply 3 of solvent, here water, and a supply 5 of a stabilizing agent, here PVP-PDLLA. A mixer 7 is provided in container 1 to stir the mixture of water and PVP-PDLLA under conditions for forming a micelle or nanodispersion. [0101] A supply 9 of propofol is also connected in known manner to container 1 to add propofol thereto once micelle or nanodispersion is achieved through stirrer 7 thereby forming a second mixture comprising a micelle or nanodispersion loaded with propofol. [0102] In the non limiting illustrated embodiment, there is provided a filter 11 allowing for sterilization of the micelle or nanodispersion, filter 11 being connected in known manner to container 1 through duct 13 . Vials 15 are provided at 15 downstream of filter 11 , to receive filtered quantities of sterilized micelle or nanodispersion. Vials 15 are connected in known manner through duct 17 to filter 11 . [0103] The device also comprises a lyophilizer 19 of known construction connected in known manner to vials 15 through duct 21 downstream of vials 15 . A recipient 23 is finally connected to vials 15 through duct 25 to collect the solid product 27 obtained through lyophilization. EXAMPLES [0104] The invention will now be illustrated but is not limited by means of the following examples. The stabilizing agents used are different types of commercially available poly(N-vinylpyrrolidone)-b-poly(d,l-lactide) copolymers, while the liquid biologically active agent is propofol. It is understood that other stabilizing agents and liquid biologically active agents could also be used with similar results as will be appreciated by one skilled in the art. [0105] Characteristics of PVP-PDLLA lots used in the following examples are given in Table 1. [0000] TABLE 1 Characteristics of PVP-PDLLA lots used in the following examples PDLLA PDLLA PVP-PDLLA Wt % 1 mol % 1 Mw 2 Mn 2 PDI POLYMER 1 36.7 47.2 3900 3500 1.1 POLYMER 2 38.1 48.8 4500 3900 1.2 POLYMER 3 35.7 46.4 4961 4177 1.2 POLYMER 4 36.7 47.2 4591 4012 1.1 POLYMER 5 33.6 43.8 4685 3872 1.2 1 Weight and molar percentages were measured from elemental analysis of polymer samples. 2 Absolute molecular weights were determined using a Gel Permeation Chromatography system equipped with a light scattering detector. Example 1 [0106] PVP-PDLLA (POLYMER 1 and POLYMER 2) samples were dissolved in mixtures of water and various amounts of tert-butyl alcohol (TBA). Propofol is then added to the PVP-PDLLA solution. Water is then added to the TBA/PVP-PDLLA/propofol solution to the desired final volume. Final TBA concentration in these solutions was 10-30%. Drug loading levels, % w/w of propofol/(propofol+PVP-PDLLA), were also varied from 5, 7, 8, 10, 12, 15 and 20%. Solutions were then frozen in a dry ice/acetone bath and lyophilized for at least 24 hours. Lyophilized cakes obtained were then reconstituted by adding water to obtain an aqueous solution of propofol 1% w/v in less than 30 seconds. Overall results indicated that at 10% w/w drug loading levels and below, solutions were 100% homogenous. At drug loading levels above 10% w/w, the solutions were gradually more and more opalescent (bluish tint caused by diffracted light). At 20%, solutions are cloudy, but stable (no precipitation for more than 8 hours). Example 2 [0107] PVP-PDLLA (POLYMER 1) is dissolved directly in water at concentrations between 100 to 350 mg/mL. Propofol is added to the PVP-PDLLA solution and mixed until a homogenous solution is obtained. The solution is then diluted to a concentration of 1% w/v of propofol. 7, 10 and 12% w/w drug loading levels were tested. All solutions were then filtered using 0.2 μm sterile filters and frozen in acetone/dry ice bath or in −80° C. freezer for at least 4 hours before being lyophilized for 48 hours. Solid lyophilized cakes of 7, 10 and 12% w/w were reconstituted by adding water for injection. 7 and 10% w/w drug loading levels yield homogenous solutions, while the 12% w/w yielded a slightly opalescent solution (bluish tint). All where stable for more than 8 hours, i.e. no precipitation or phase separation under visual observation. [0000] TABLE 2 Reconstituted formulation characteristics of example 1. Sample ID DLL theo DLL exp Osmolality Particle size 1 FR041124 (% w/w) (%) mOsm (nm) POLYMER 1 7 6.7 438 23 (99%)* POLYMER 1 10 9.6 355 26 (99%)* POLYMER 1 12 11.4 342 20 (99%)* *size of main peak (intensity signal) and volume percentage occupied by the main peak. All were reconstituted in 5% Dextrose Example 3 [0108] Formulations found in table 2 were tested in female Sprague-Dawley rats at a dose of 10 mg/kg. Injection time was 1 minute. All formulations prepared had a propofol concentration of 1% w/v, i.e. 10 mg/mL. [0000] TABLE 3 Pharmacodynamic parameters of Diprivan versus three propofol polymeric micelle formulations in Sprague-Dawley rats. Time of Time of Time Of First Righting Full Onset Movement Reflex Recovery Formulation of (min ± (min ± (min ± (n = 5) % DLL Sleep Std Dev) Std Dev) Std Dev) Diprivan ® ca. 7% <1 min   8 ± 3.4 10.4 ± 2.7 19.2 ± 3.3 FR041124-11  7% <1 min 8.7 ± 1.5  9.3 ± 1.5 17.7 ± 0.6 FR041124-21 10% <1 min 10.2 ± 2   10.4 ± 2.1 17.4 ± 2.7 FR041124-31 12% <1 min 9.8 ± 3.0 11.2 ± 1.9 18.2 ± 1.1 The results of the above study are illustrated in FIG. 1 which is a sleep/recovery study upon iv administration of 10 mg/kl of propofol formulation in rats (onset of sleep less than 1 min). Example 4 [0109] PVP-PDLLA (POLYMER 2) is dissolved in water at concentrations between 100 to 350 mg/mL. Propofol is added to the PVP-PDLLA solution and mixed until a homogenous solution is obtained. The solution is then diluted to a concentration of 1% w/v of propofol. 7, 10 and 12% w/w drug loading levels were tested. All solutions were then filtered using 0.2 μm sterile filters and frozen in acetone/dry ice bath before being lyophilized for 48 hours. Solid lyophilized cakes of 7, 10 and 12% w/w were reconstituted by adding water. 7 and 10% w/w drug loading levels yielded homogenous solutions, while the 12% w/w yielded a slightly opalescent solution (feeble blue tint). All where stable for more than 8 hours, i.e. no precipitation or phase separation under visual observation. Example 5 [0110] PVP-PDLLA (lot #POLYMER 3) is dissolved in water at concentrations between 100 to 350 mg/mL. Propofol is added to the PVP-PDLLA solution and mixed until a homogenous solution is obtained. The solution is then diluted to a concentration of 1% w/v of propofol. 7, 10 and 12% w/w drug loading levels were tested. All solutions were then filtered using 0.2 μm sterile filters and frozen in acetone/dry ice bath before being lyophilized for 48 hours. Solid lyophilized cakes of 7, 10 and 12% w/w were reconstituted by adding water. 7 and 10% w/w drug loading levels yielded homogenous solutions, while the 12% w/w yielded a slightly opalescent solution (feeble blue tint). All were stable for more than 8 hours, i.e. no precipitation or phase separation under visual observation. Example 6 [0111] PVP-PDLLA (lot #POLYMER 2) is dissolved in sodium phosphate buffer pH 7.4. Propofol is added to the PVP-PDLLA solution and mixed until a homogenous solution is obtained. 10% drug loading level is tested. Water is then added to obtain a 1% w/v propofol concentration and a sodium phosphate buffer concentration ranging from 10 to 100 mM. Osmolality, pH and particle size of reconstituted solutions were obtained (table 4). [0000] TABLE 4 pH, Osmolality and particle size as a function of sodium phosphate buffer concentration and time. Phosphate Time after buffer conc. reconstitution Osmolality Particle size (mM) hours pH (mOsm) (nm) ca. 100 0 7.4 356 41 ca. 24 7.1 369 36 75 0 7.3 323 35 ca. 24 7.1 336 32 50 0 7.2 232 32 ca. 24 6.9 241 36 10 0 6.5 105 29 ca. 24 5.9 110 30 Example 7 [0112] PVP-PDLLA (lot #POLYMER 1, POLYMER 2, POLYMER 3, POLYMER 4 and POLYMER 5) is dissolved directly in 100 mM sodium phosphate buffer, pH 7.4, at concentrations between 100 to 350 mg/mL. Propofol is added to the PVP-PDLLA solution and mixed until a homogenous solution is obtained. The solution is then diluted to a concentration of 1% w/v of propofol and 70 mM of sodium phosphate buffer concentration. 7, 10 and 12% w/w drug loading levels were tested. All solutions were then filtered using 0.2 μm sterile filters and frozen in acetone/dry ice bath or in −80° C. freezer for at least 4 hours before being lyophilized for 48 hours. Solid lyophilized cakes of 7, 10 and 12% w/w were reconstituted by adding water for injection. 7 and 10% w/w drug loading levels yield homogenous solutions, while the 12% w/w yielded a slightly opalescent solution (bluish tint). All reconstituted solutions were stable for more than 24 hours, i.e. no precipitation or phase separation under visual observation. Characteristics of samples can be found in tables 5, 6 and 7. [0000] TABLE 5 Formulation characteristics for lot # POLYMER 3 at 70 mM sodium phosphate buffer concentration DLL Particle Propofol (%) Osmolarity size 1 Conc 2 % T + w/w pH mOsm (nm) (mg/mL) (660 nm) POLYMER 3 7 6.96 370 42 (100%)  10.1 99.0 POLYMER 3 10 7.05 292 39 (99.9%) 9.9 98.6 POLYMER 3 12 7.1 283 50 (99.3%) 9.8 97.5 [0000] TABLE 6 Formulation characteristics for POLYMER 4 at 70 mM sodium phosphate buffer concentration DLL Particle Propofol Water Sample ID (%) Osmolarity size 1 Conc 2 % T content 3 MT050816 w/w pH mOsm (nm) (mg/mL) (660 nm) (% w/w) POLYMER 4 7 6.85 282 26.9 (100%) 10.1 99.6 0.7 POLYMER 4 10 6.94 243 26.1 (100%) 10.2 98.9 0.9 POLYMER 4 12 7.0 226 27.4 (100%) 10.0 99.1 0.9 [0000] TABLE 7 Formulation characteristics for POLYMER 5 at 70 mM sodium phosphate buffer concentration DLL Particle Propofol Water Sample ID (%) Osmolarity size 1 Conc 2 % T content 3 MT050809 w/w pH mOsm (nm) (mg/mL) (660 nm) (% w/w) POLYMER 5 7 6.83 292 28.1 (100%)  9.8 98.7 0.6 POLYMER 5 10 6.93 248 29.5 (99.8%) 9.4 98.8 0.8 POLYMER 5 12 6.96 230 30.0 (99.0%) 8.7 96.6 0.9 1 Particle size measured using Malvern zeta sizer. Size is selected from the main peak of the intensity signal. Percentages in brackets represent the volume fraction of micelles of that main peak. 2 Propofol concentration is determined by HPLC method. 3 Water content is determined by Karl Fisher titration. Example 8 [0113] PVP-PDLLA (POLYMER 4) is dissolved directly in 100 mM sodium phosphate buffer, pH 7.4, at concentrations between 140 to 300 mg/mL, depending on drug loading level. One of the two 10% w/w drug loading level formulations was dissolved in water. Propofol is added to the PVP-PDLLA solutions and mixed until homogenous solutions are obtained. The solutions are then diluted to a concentration of 1% w/v of propofol and 70 mM of sodium phosphate buffer concentration. 7, 10 and 12% w/w drug loading levels were tested. All solutions were then filtered using 0.2 μm sterile filters and frozen in −80° C. freezer for at least 4 hours before being lyophilized for 48 hours. Solid lyophilized cakes of 7, 10 and 12% w/w were reconstituted by adding water for injection, except for one formulation containing no phosphate buffer that was reconstituted in 5% dextrose w/w. All reconstituted solutions were stable for more than 24 hours, i.e. no precipitation or phase separation under visual observation. Example 9 [0114] In-vivo 002. Using propofol-PM formulations presented in Example 8, and Diprivan® (commercial propofol 1% w/v formulation), a pharmacodynamic study was performed. The objectives of this study were: 1. Evaluate the pharmacodynamic effect of changing PVP-PDLLA molecular weight in the formulation 2. Evaluate the changes in pharmacodynamic parameters when using a sodium phosphate buffer to control pH and Osmolality 3. Compare results [0118] Lyophilized solid formulations of propofoi-PM were reconstituted to a homogenous solution by adding water for injection (WFI) or dextrose 5% w/v for injection (sample MT050816-3). Final propofol concentration in solutions is 1%, equivalent to the commercial formulation Diprivan®. Female Sprague Dawley rats were injected a bolus dose of 10 mg/kg in 60 seconds. Pharmacodynamic parameters were then measured. Tables 8 and 9 present selected characteristics and parameters of interest. [0119] For a comparison of a time for righting reflex measured in in vivo 002 and in vivo 001 sleep/recovery study, reference is made to FIG. 2 . [0000] TABLE 8 In-house propofol-PM formulation compositions to be tested in second pharmacodynamic study. Final % concentration Reconstitution propofol Polymer w/w of Phosphate % T conc. Lot# batch# DLL* Buffer (mM) Medium Speed (660 nm) (mg/mL) MT050816-1 POLYMER 4  7% 70 WFI <1 min 99.6 10.2 MT050816-2 POLYMER 4 10% 70 WFI <1 min 98.9 10.46 MT050816-3 POLYMER 4 10% 0 Dextrose <1 min 98.9 9.9 5% MT050817-4 POLYMER 4 12% 70 WFI <1 min 99.1 10.26 *All parts percentages of drug loading reported herein are weight per unit weight (w/w), in which the weight in the denominator represents the total weight of the formulation (polymer and drug, excluding buffering excipients). [0000] TABLE 9 In-house propofol-PM formulation compositions to be tested in second pharmacodynamic study: Characteristics and results RESULTS % Micelle size* Time of Formulation DLL (nm) Osmolality % T Onset of Righting Reflex (n = 5) w/w (Volume %) pH mOsmol (660 nm) Sleep (min ± Std Dev) Diprivan ® Ca. 7% ND 7 311 ND <1 min 10.4 ± 3.3 MT050816-1  7% 30.3 (100) 6.86 284 99.6 <1 min 11.6 ± 1.7 MT050816-2 10% 31.5 (100) 6.95 240 98.9 <1 min 10.4 ± 2.9 MT050816-3 10%  37.6 (99.5) 3.32 315 98.9 <1 min 10.4 ± 1.7 (no PB) MT050817-4 12%   32.8 (99.95) 7.02 224 99.1 <1 min 10.3 ± 1.3 *Particle size measured using Malvern zeta sizer. Size is selected from the main peak of the intensity signal. Percentages in brackets represent the volume fraction of micelles of that main peak. Example 10 [0120] In-vivo 003. Using formulations prepared according to the protocol in example 8, pharmacokinetic and pharmacodynamic studies were performed in Male Sprague-Dawley rats. Formulations tested and pharmacokinetic study design, which included Diprivan®, are presented in the table below. [0000] TABLE 10 Pharmacokinetic groups and details Dose Injection Number Dose volume time of Group Formulation (mg/kg) (mL/kg) (sec) Animals Matrix 1 Diprivan ® 10 1 30 5 Blood 2 5 Plasma 3 Propofol-PM 10 1 30 5 Blood 4 (7% w/w) 5 Plasma 5 Propofol-PM 10 1 30 5 Blood 6 (10% w/w) 5 Plasma 7 Propofol-PM 10 1 30 5 Blood 8 (12% w/w) 5 Plasma Forty male Sprague-Dawley Rats (300-325 g) were used to determine the pharmacokinetic properties The animals were equally allotted into four groups (n=5) A, B, C and D corresponding to the four treatments Diprivan®, Propofol-PM 7%, 10% and 12% (w/w). [0000] TABLE 11 Summary of mean pharmacokinetic parameters for propofol in blood for Diprivan ® and PPF-PM formulations PK PPF-PM PPF-PM PPF-PM parameters Units Diprivan ® 7% w/w 10% w/w 12% w/w C max μg/mL 18.65   14.4 * 19.1 19.0 C 0 μg/mL 20.4 14.1 21.7 18.5 AUC t μg · 262.3 246.6  255.6 258.1 min/mL AUC inf μg · 301.1 271.5  272.8 282.9 min/mL CL mL/min/ 31.3 28.4 22.5 25.4 kg MRT Min 34.1 39.6 37.1 36.6 T ½ Min 28.6 22.5 20.0 22.9 T ½ {acute over (α)} Min 3.1  2.6 2.9 3.0 T ½ β Min 40.9 24.7 37.8 26.0 λ 1 /min 0.262   0.303 0.349 0.245 λ 2 mL/kg 0.024   0.032 0.027 0.028 V 1 μg/mL 447.8 608.5  400.1 452.6 Vss μg/mL 1347.9 1119.0  833.0 921.7 * p < 0.05 [0000] TABLE 12 Summary of mean plasmatic pharmacokinetic parameters for Diprivan and PPF-PM formulations PK PPF-PM PPF-PM PPF-PM parameters Units Diprivan ® 7% w/w 10% w/w 12% w/w C max μg/mL 11.7  6.0 *** 7.6 6.1 *** C 0 μg/mL 12.4 6.2   6.6 6.8    AUC t μg · 126.5  77.3 ****   84.2 *** 76.7 **** min/mL AUC inf μg · 132.8  87.2 ***    89.2 **** 85.4 ***  min/mL CL mL/min/ 19.2  27.2 *** 21.9  28.3    kg MRT Min 77.1 122.5 ***   113.0 **** 130.9 **   T ½ Min 17.5  23.8 **** 19.5  26.1    T ½ {acute over (α)} Min 1.4 3.5 * 2.0 3.1    T ½ β Min 16.6 38.7   20.3  32.2 *   λ 1 /min 0.508   0.243 ***  0.432 0.287 * λ 2 mL/kg 0.042   0.024 ***  0.038   0.024 **** V 1 μg/mL 626.0 1875.0 **** 1052.9 *   1622.0 ****  Vss μg/mL 1467.5 3293.3 ****  2481.9 *** 3632.1 ****  * p < 0.05 ** p < 0.03 *** p < 0.02 **** p < 0.01 [0000] TABLE 13 Mean partition coefficient (Kp RBC: Plasma) of propofol in blood following a single intravenous dose (target 10 mg/kg) of Diprivan ® and 3 PPF-PM formulations (7, 10 and 12%) Kp Kp Kp Time Kp PPF-PM PPF-PM PPF-PM (min) Diprivan ® 7% w/w 10% w/w 12% w/w 1 8.5 10.4 14.0 15.7 3 7.6 9.9 12.0 11.3 5 6.4 5.8 9.8 10.5 7.5 5.6 5.9 5.9 7.0 10 3.7 4.2 4.2 5.7 15 2.1 4.1 3.9 3.2 30 2.2 2.7 2.1 2.5 60 1.1 0.9 0.6 0.7 75 0.8 0.5 0.5 0.6 Example 11 [0121] PVP-PDLLA (POLYMER 1) was dissolved directly in water at concentrations between 140 to 350 mg/mL. Propofol is added to the PVP-PDLLA solution and mixed until a homogenous solution is obtained. The solution is then diluted to a concentration of 1% w/v of propofol (7%, 9%, 10% and 12% w/w drug loading levels). The solutions were then filtered using 0.2 m sterile filters and frozen in ethanol/dry ice bath before being lyophilized for 48 hours. Solid lyophilized cakes were reconstituted by adding sterile dextrose 5% for injection to yield a propofol concentration of 1% w/v (10 mg/mL). Micelle size distributions were then measured at 1% w/v and 0.1% w/v propofol concentrations to evaluate the effect of dilution. At 0.01% w/v (1/100 dilution), the light scattering signal was very weak for obvious reasons. The sample at 7% w/w drug loading level was the only one measured at 0.01% w/v-propofol concentration. All solutions were stable visually and no phase separation or precipitation was observed upon dilution. Characteristics of these formulations are presented in the table below. [0000] TABLE 14 Characteristics and, particle size and stability, of propofol polymeric micelle formulations upon dilution DLL Sample ID (%) Dilution Micelle Size (nm) POLYMER 1 w/w medium 1% w/v PPF 0.1% w/v 0.01% w/v FR041124 7 Dextrose 5% 23 (99.4%) 23 (99.4%) 18 (100%) DLG041123 9 Dextrose 5% 24 (99.6%) 24 (99.9%) ND DLG041123 10 Dextrose 5% 24 (99.5%) 25 (99.6%) ND DLG041123 12 Dextrose 5% 26 (97%) 30 (98.6%) ND Example 12 [0122] Microbial growth study. Formulations prepared as per example 2 were reconstituted in three different media (water for injection, dextrose 5% w/v and saline 0.9% w/v) inoculated with 4 different strains of bacteria. Furthermore, reconstitution media alone (saline, dextrose 5% and water for injection) and polymer solutions without any propofol in all three different reconstitution media were also inoculated for comparison. 1×10 cfu/mL were added to each articles tested (solutions, formulations, media). Dirpivan® emulsion was also inoculated for comparison. Characteristics of polymer solutions and formulations follow (table) and graphical results on microbial proliferation in different tests are presented below. [0000] TABLE 15 Characteristics of formulation and polymer solutions tested for microbial growth study. Propofol DLL Reconstitution Formulation (%) Conc. POLYMER 1 w/w Medium Time Clarity (mg/mL) PVP-PLA 0 WFI <30 sec Clear 0 PVP-PLA 0 Dextrose <30 sec Clear 0 PVP-PLA 0 0.9% Saline <30 sec Clear 0 w/v PPF-PM 10 WFI <30 sec Clear 9.56 PPF-PM 10 Dextrose <30 sec Clear 9.72 PPF-PM 10 0.9% Saline <30 sec Clear 9.89 w/v [0123] Results of the microbial growth study indicate that the PVP-PLA solutions of the invention (containing no propofol) are most of the time not significantly different than proliferation observed in the reconstitution media (water for injection, saline 0.9% w/v and dextrose 5% w/v) alone. The addition of propofol to form the propofol polymeric micelle (PPF-PM) formulations demonstrates that the intrinsic bactericidal property of propofol is active in killing all bacteria inoculated, independent on the reconstitution media or the polymer. Diprivan® as shown highest microbial growth support in all cases. [0124] FIGS. 7-18 : Microbial growth time profile of polymer solutions (PVP-PLA), propofol polymeric micelle formulations (PPF-PM), Diprivan® and reconstitution media of all 4 strains of bacteria tested. Example 12 [0125] PVP-PDLLA (POLYMER 4) is dissolved directly in 100 mM sodium phosphate buffer, pH 7.4. Propofol is added to the solution and mixed. Once the clear solution is obtained, the solution is diluted to 1% w/v propofol concentration and a final buffer concentration of 75 mM. The solutions were then lyophilized. The freeze dried cakes were then reconstituted directly with 2%, 1% and 0.2% w/v lidocaine solutions. Particle size and pH of solutions were measured daily over a period of 5 days. Results are presented below. [0000] TABLE 16 Propofol polymeric micelle stability in solution with different lidocaine concentration Propofol 1% Particle size (nm)/pH Lidocaine At concentration reconstitution Day 1 Day 2 Day 3 Day 4 0.2% (2 mg/mL)   35.1/6.35 35.8/6.4  36.8/6.20 39.2/6.36 39.9/6.26 1% (10 mg/mL) 33.9/6.53 34.5/6.38 33.0/6.39 37.5/6.49 37.0/6.43 2% (20 mg/mL) 31.9/6.87 34.5/6.56 33.2/6.60 32.4/6.71 31.1$6.65 Example 13 [0126] Two other liquid biologically active agents have also been successfully loaded in PVP-PLA micelles using the same procedure. 2-phenoxyethanol (50 mg/mL) and quinaldine (10 mg/mL) were added to aqueous PVP-PLA solutions (90 mg/mL) containing 75 mM (final concentration) of sodium phosphate buffer (pH 7.4). The clear solutions were then diluted to suitable concentration for UV absorbance measurements prior to freezing and lyophilization. The resulting lyophilizate was then reconstituted by addition of water to approximately the same concentration, i.e. 50 mg/mL for 2-phenoxyethanol and 10 mg/mL for quinaldine. Clear solutions were obtained. UV absorbance was then measured to assess the presence of the two drugs. Results below indicate that the two biologically active liquids were retained in the PVP-PLA micelles. [0000] TABLE 17 Formulation 1: 2-Phenoxyethanol (final concentration of drug = 50 mg/mL) Formulation 1 Abs (228 nm) Before freeze drying 0.76040 After reconstruction 0.62017 Formulation 1. was diluted with USP water to a 0.5 mg/mL concentration for UV measurement [0000] TABLE 18 Formulation 2: Quinaldine (final concentration of drug = 10/mL) Formulation 2 Abs (225 nm) Before freeze drying 2.08290 After reconstitution 1.72110 Formulation 2 was diluted with USP water to a 0.1 mg/mL concentration for UV measurement. [0127] It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and drawings/figures. [0128] One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. [0129] Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.

The instant invention relates to a solid product comprising a liquid biologically active agent which is intimately associated to a stabilizing agent; particularly a solid product that can be reconstituted to a clear, stable, stabilized nanodispersion or loaded micelles comprising a polymer as a stabilizing agent and a liquid, preferably water immiscible, biologically active agent. The instant invention is further directed toward a process for the production of the above solid product; particularly to micelles or nanodispersions produced by hydration of a cake or powder of the solid product, produced via an effective treatment of a stabilized solution comprising for example a polymer as a stabilizing agent, such as an amphiphilic block copolymer or a small molecular weight surfactant, loaded with a liquid biologically active agent, such as propofol, an optional additive, and a suitable solvent.

CROSS REFERENCE TO RELATED APPLICATIONS N/A STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT N/A COPYRIGHT NOTICE A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or patent disclosure as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyrights rights whatsoever. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to radial arm saws, and more particularly to a safety top for use in safe operation of radial arm saws while providing improved dust collection. 2. Description of Related Art Radial arm saws are routinely found in wood working environments for use us in various wood cutting applications. Over the past several years, the use of the radial arm saw has expanded significantly due largely to versatility and simplicity of use. Today, radial arm saws are in use in wood working shops, garages, even retail outlets, such as hardware and home improvement stores. A typical radial arm saw includes a work table having a horizontal flat top work surface with a vertically projecting backstop, commonly referred to as a fence. The material to be cut, such as a piece of wood, is supported on the work surface and against the fence. At the rear of the work table a vertical column extends upwardly. Extending horizontally from the top of the column is a radial arm, which is capable of rotation about the column, but which is generally positioned over the top of the table. A rotary power saw is suspended below the radial arm by a carriage adapted for travel along the length of the radial arm. In most operations, the saw is positioned over the work table and is moved along the radial arm to cut a workpiece positioned on the work surface. While the radial arm saw is an efficient and proven power tool, there remain a number of problems and shortcomings associated with the operation thereof that heretofore have not been adequately solved or addressed. One such problem associated with the radial saw operation relates to the substantial amount of sawdust created and dispersed when cutting. The sawdust generated by a radial arm saw ranges from very fine dust particles to larger wood chips. While this problem has been widely recognized for many years, radial arm saw manufacturers have failed to develop an effective dust collection system for use with these saws. One common, yet ineffective, solution has been to provide the saw blade with a protective guard or hood adapted with a suction port connected to a vacuum-generating dust collection system by a hose. That attempt, however, has proven unsatisfactory and generally ineffective. As a result of the persistent problems associated with saw dust, the background art reveals a number of attempts directed to dust collection systems for use with radial arm saws. For example, U.S. Pat. No. 2,839,102, issued to Kido, discloses a dust collecting attachment that mounts behind the guide fence of a radial arm saw. The attachment defines slotted openings aligned with kerfs in the guide fence, and is attached to a suction-generating dust collector apparatus. U.S. Pat. No. 3,322,169, issued to Hilliard, discloses a dust collector for a radial arm saw including a rectangular shroud having an inlet and a tapered tube extending rearwardly therefrom for connection to a vacuum hose. U.S. Pat. No. 3,401,724, issued to Kreitz, discloses a dust collector for a radial arm saw comprising generally funnel-shaped hood positioned at the rear of the work table. The wide hood inlet opens toward the front of the work table and a narrow outlet is connected to a dust collector apparatus. U.S. Pat. No. 4,144,781, issued to Kreitz, discloses a dust collector for a radial arm saw including a generally funnel-shaped flat-bottomed shroud connected to a vacuum hose. The top and bottom of the shroud are contoured so that the shroud partially surrounds the column which supports the radial arm saw. U.S. Pat. No. 4,742,743, issued to Scarpone, discloses a radial arm saw accessory comprising a grid structure formed in the table surface in proximity to the fence to permit passage of sawdust therethrough. It appears, however, that the above-referenced advances in the art of radial arm saw dust collection have not been successful in substantially containing and collecting sawdust generated by the radial arm saw. Accordingly, those devices have not gained widespread acceptance. Thus, there exists a need for improvements in radial arm saw design. More particularly, there exists a need for an improved dust collection system for use with radial arm saws. Another serious problem present with the widespread use of radial arm saws relates to operator safety. More particularly, during normal use the rotating saw blade often comes in close proximity to the operators hands and fingers. As a result, numerous individuals have been seriously injured by inadvertent contact with the rotating saw blade while operating the radial arm saw. The problem is complicated since operation of the saw requires the user to move the saw/blade across the work surface while cutting thereby increasing the risk of injury. The risk of injury increases when the saw is used by inexperienced operators in garage shops or employees in retail locations. Despite the serious risk of injury inherent with conventional radial arm saw designs, manufacturers have failed to provide adequate measures intended to prevent injury. The background art reveals a number of attempts directed to protecting operators from injury while operating radial arm saws. These attempts include blade guards intended to prevent the operator's hand from contacting the rotating blade. Blade guards, however, have proven ineffective. Other attempts include providing work piece guides and push devices designed to assist the operator in positioning the work piece. U.S. Pat. No. 5,678,467, issued to Aigner, discloses a handle adapted for holding or pushing wood during the sawing process. The Aigner device, and others in the art, provide handle-like structures that engage the wooden workpiece such that the user's hand is positioned away from the cutting plane. The prior art further reveals a number of work piece guides, primarily for use with table saws. Representative disclosures of such devices are found in U.S. Pat. Nos. 4,026,173 (Livick), 4,469,318 (Slavic), and 4,485,711 (Schnell). These devices, however, are adapted for pushing and guiding the workpiece though the cutting area, and are generally not suitable for use with a radial arm saw wherein the saw blade is moved through the workpiece. Accordingly, there exists a need for improvements directed to radial arm saws directed to protecting operators from injury by securing the workpiece. BRIEF SUMMARY OF THE INVENTION The present invention overcomes the disadvantages and shortcomings in the art by adapting a radial arm saw with a safety top configured with a cutting box enclosure for containing and collecting substantially all of the sawdust generated when in use. The safety top further includes spring biased push blocks that function to hold the work piece in place during the sawing process while maintaining the user's hands safely away from the saw blade. In accordance with the present invention, a radial arm saw is adapted with a safety top providing an improved work surface, a fully integrated structure that contains and captures substantially all of the sawdust and particles generated by the saw, and integrated push blocks that are mechanically biased to secure the workpiece in engagement with the fence. Accordingly, it is an object of the present invention to provide an improved safety top for use with radial arm saws. Another object of the present invention is to provide an improved dust collection system for use with radial arm saws. Still another object of the present invention is to provide advancements in control systems for radial arm saws. In accordance with these and other objects, which will become apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS FIG. 1 depicts a typical radial arm saw of the prior art; FIG. 2 depicts a radial arm saw adapted with a safety top in accordance with the present invention; FIG. 3 illustrates cutting of a wood work piece using a radial arm saw adapted with a safety top in accordance with the present invention; FIG. 4 is a bottom view of the safety top showing alternate mechanical biasing systems for the push handles; FIG. 5 is a top view of the safety top wherein the saw is positioned to cut a wood work piece; FIG. 6 is a top view of the safety top wherein the work piece has been cut; and FIG. 7 depicts a control panel for use with the present invention. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 depicts a radial arm saw 10 typical of prior art saws to which the present invention most directly pertains. The typical radial arm saw 10 includes a work table 20 having a horizontal flat top work surface 22 with a vertically projecting backstop 24 , commonly referred to as a rip fence. The material to be cut, such as a piece of wood, is supported on work surface 22 in abutting relation with fence 24 . A vertical column 30 extends upwardly from the back of work table 20 . Extending horizontally from the top of column 30 is a radial arm 32 , which is capable of rotation about the column, but which is generally positioned over the top of the table. A rotary power saw 40 is suspended below the radial arm by a carriage adapted for travel along the length of radial arm 32 . Power saw 40 includes a rotating blade 42 , a protective blade shroud 44 , a motor housing 46 , and a handle 48 . As noted above, blade shroud 44 is often configured to function as a dust collecting shroud by attachment of a shop vac dust collector thereto. In most operations, the saw is positioned over the work table and is moved along the radial arm to cut a workpiece positioned on the work surface when pulled by the user such that the saw moves from behind the fence through the workpiece to be cut. FIG. 2 depicts a radial arm saw adapted with a safety top assembly, generally referenced as 100 , an improved control system, which includes a control panel 200 , according to the present invention. Safety top 100 is preferably fabricated from a durable material. In a preferred embodiment, safety top 100 is fabricated from sheets phynolic material, which sheets are known for their strength, high heat resistance and flame retardancy. It should be noted, however, that any suitable material is considered within the scope of the present invention. Safety top 100 is preferably a fully assembled structure adapted for mounting directly on to a radial arm saw with minimal if any modification required. Safety top 100 includes a generally planar work surface 102 and a backstop or rip fence 104 (hereinafter “fence”) vertically projecting therefrom. Work surface 102 defines a pair of slotted apertures 106 that function as guide slots for push handles 108 . Each push handle 108 includes a base 108 A, a vertical end wall 108 B for engaging a workpiece, and a cutout portion 108 C to facilitate grasping thereof by the user. Base 108 A includes a downwardly projecting tongue sized for slidable inserted engagement with slotted aperture 106 . FIG. 3 depicts a wood workpiece, such as a two-by-four disposed between push handles 108 and rip fence 104 . Each push handle 108 is mechanically biased toward fence 104 by a spring loaded biasing mechanism preferably disposed on the bottom surface of work surface 102 . FIG. 4 shows a bottom view of safety top 100 and discloses a preferred helical spring loaded embodiment of the mechanical biasing system depicted on the right hand side of FIG. 4B , which embodiment is generally referenced as 110 , and an alternate auto-retracting embodiment mechanical biasing system depicted on the left hand side of FIG. 4B , which embodiment is generally referenced as 120 . The helical spring mechanical biasing system 110 includes a plurality of anchors 112 fastened to the underside of work surface, and an anchor 114 fastened to the lower portion of push handle 108 . A spring biased cable and pulley system is connected to anchors 112 and 114 . More particularly, the spring biased cable and pulley system includes a chain section 116 connected at one end thereof to an anchor 112 , a helical spring 117 connected on one end thereof to chain 116 and connected at the opposite end thereof to a first pulley 118 . A cable 119 is routed in a two pulley configuration with opposing cable ends connected to a fixed anchor 112 and anchor 114 respectively thereby realizing a mechanical advantage. The provision of chain section 116 allows for adjustment of the tension by adjustable connection of individual links to anchor 112 . The alternate embodiment mechanical biasing system 120 includes an automatic retraction apparatus 122 connected to the lower portion of push handle 108 by a cable 124 . Automatic retraction apparatus 122 is generally characterized as providing a retraction force of a substantially constant level by use of internal spring mechanisms. It should be noted, however, that any suitable biasing system, whether mechanical or electrical is considered within the scope of the present invention. As should be apparent, the mechanical biasing systems function to urge push handles 108 toward rip fence 104 so as to secure a piece of wood in place for the sawing process. Safety top 100 further includes dust collecting cutting box 130 mounted on and projecting above work surface 102 . Cutting box 130 is preferably mounted in alignment with power saw 40 , and particularly saw blade 42 for reasons more fully discussed hereinbelow. Cutting box 130 is bounded by a floor formed by the work surface 102 , and further includes a top 132 , opposing sides 134 , and front and rear walls 136 . Top 132 defines a plurality of slotted apertures (“slots”), including a saw blade slot 137 aligned with saw blade 42 , and left and right slotted apertures 137 disposed on opposing sides of blade slot 137 and in parallel relation therewith. Saw blade slot 137 allows saw blade 42 to pass below cutting box top 132 during the sawing process. Left and right slotted apertures 138 function to provide the user with a line of sight through cutting box top 132 to the cutting area disposed below. Cutting box sides 134 include portions thereof formed by brush bristles 135 connected to and projecting downwardly from top 132 , extending forward from fence 104 . Brush bristles 135 allow a work piece to be inserted into cutting box 130 and automatically form a seal to contain saw dust within cutting box 130 . The present invention further contemplates providing the saw portion with a specially adapted semi-circular shroud 150 in partial covering relation with the saw blade. Shroud 150 defines a bottom opening having a generally rectangular cross-section, which opening includes brush bristles 152 attached to the peripheral edge thereof. Shroud bristles 152 project downwardly from shroud 150 and are in sweeping contact with the cutting box top 132 thereby forming a dust seal between shroud 150 and top 132 as the saw moves back and forth while cutting the work piece. Cutting box 130 thus defines an internal chamber wherein the rotating saw blade meets the work piece during the cutting process and functions to contain the sawdust and wood chips generated as the blade cuts through the wood. Accordingly, cutting box 130 is further adapted for connection to an external dust collection system. More particularly, cutting box 130 is adapted with first and second dust collection outlet ports, referenced as 160 and 162 respectively. Each outlet port provides a connection point for attachment of a hose from a vacuum generating external dust collection system. Since vacuum type dust collection systems are well known, those systems shall not be further detailed. Outlet port 160 is preferably located rearward along cutting box side 134 and thus places the interior of cutting box 130 in fluid communication with the external dust collection system. As best depicted in FIG. 4 , second outlet port 162 is defined by a dust collecting tray 164 disposed beneath work surface 102 in alignment with a slotted aperture 166 defined bottom of work surface 102 . First and second outlet ports are preferably connected to a common dust collection system by a vacuum hose adapted with a Y-fitting. As best depicted in FIG. 3 , safety top 100 further includes a flexible, generally flat, strip of sealing material 170 having a first end thereof attached to shroud 150 and a second end thereof 172 hanging or draping down the back side of safety top 100 . Sealing strip 170 further includes opposing edges thereof riding within grooves formed on opposing sides of saw blade slot 137 . Accordingly, as the saw is moved forward during the cutting process, sealing strip 170 is pulled in trailing relation with shroud 150 so as to cover or seal that portion of saw blade slot 137 behind the saw thereby providing a seal and preventing saw dust from escaping. As the saw is moved rearward during the cutting process sealing strip 170 is pushed rearward while traveling within grooves formed on opposing sides of saw blade slot 137 . As should be apparent, any sawdust generated during operation of the radial arm saw adapted with a safety top 100 in accordance with the present invention will be contained within cutting box 130 and will be removed therefrom via dust collection outlet ports 160 and 162 . As best depicted in FIGS. 5 and 6 , radial arm saw safety top 102 further includes a laser alignment device 180 for projecting a light beam 182 over the work piece to insure proper alignment and precise cutting. In a preferred embodiment, laser alignment device 180 is mounted within cutting box 130 and oriented so as to project a light beam over the work piece and along the cutting plane formed by the edge of the saw blade. Light beam 182 thus provides visible indication as to exactly where the saw blade will intersect the work piece. Light beam 182 may be visible to the operator through any of cutting box top slots 137 or 138 . As further illustrated in FIG. 2 , the present invention may further include a control panel, referenced as 200 which functions to provide safe and efficient operation of the radial arm saw, particularly for saws operating in retail store environments, such as saws operating in home improvement and hardware stores. Control panel 200 provides a primary connection to electrical power, such as 208VAC, 230 VAC, or 460VAC electrical power and includes a step-down electrical transformer capable of 24 VAC output. The ability of control panel 200 to operate using a range of voltages is considered important since the power available at different locations often varies. Control panel 200 includes a keypad 202 that provides an input device to restrict operation to authorized users who enter an appropriate authorization code. A power supply is connected to the 24 VAC output for providing DC power to keypad 202 . Control panel 200 further includes a main disconnect switch 204 that enables quick disconnection of power to the saw and various components. In addition, a push-start/pull-stop control button 206 is provided to initiate or discontinue operation. Further, control panel 200 includes a visual alarm beacon 208 that is configured to flash when power is supplied to the radial arm saw systems, and an alarm horn 210 that is configured to generate an audible sound after a predetermined time period to indicate that the radial arm saw is about to shut down. The operating sequence for a radial arm saw adapted with a control panel according to the present invention is a follows. A red indicator light 202 A on the keypad indicates that power is being supplied to the radial arm saw control panel. The user enters the appropriate security code on the keypad to initiate operation. As should be apparent, any suitable code may be used. Upon entry of the appropriate code, a light 206 A on control button 206 illuminates indicating that a predetermined operation period, such as five minutes, has begun. The user then must pull control button 206 to automatically supply power from the control panel to the radial arm saw and dust collection system, at which time beacon 208 is activated thus providing a visual signal/warning that power has been supplied and the systems are operational. Shortly before expiration of the predetermined operation period (e.g. 30 seconds prior to expiration) alarm horn 210 sounds as a signal that the saw will automatically shut down shortly. While the system is programmed to allow operation for a predetermined period of time before automatically shutting down, the period of operation may be extended by re-entering the authorization code. If, at any time, the operator wishes to manually shut the systems down he simply must push control button 206 . The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art.

A radial arm saw is adapted with a safety top configured with cutting box enclosure that contains and collects substantially all of the sawdust generated during use. A dust collection system is in fluid communication with the cutting box for removing the sawdust contained therein. Spring biased push blocks function to hold the work piece in place during the sawing process while maintaining the user's hands safely away from the saw blade. A laser alignment device projects a beam within the cutting box along the cutting plane. A control panel is provided to allow use by authorized users upon entry of an authorization code.

RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Patent Application No. 62/191,074, filed Jul. 10, 2015 and U.S. Provisional Patent Application No. 62/246,706 filed Oct. 27, 2015, both of which are incorporated by reference herein in their entireties. BACKGROUND OF THE INVENTION [0002] Field of the Invention [0003] The present invention is broadly concerned with dough relaxers made up of natural ingredients, as well as methods of use thereof and resultant dough formulations. More particularly, the invention is concerned with dough relaxers produced by pre-treating or pre-reacting wheat protein with non-leavening yeast and/or yeast extract; such relaxers may then be used in conventional dough formulations to obtain desirable relaxation properties. [0004] Description of the Prior Art [0005] It is known that redox (reduction-oxidation) reactions involving wheat flour sulfhydryl (SH) groups and disulfide bonds have a significant effect on structure of gluten proteins, and are considered crucial to dough rheology and bread-making performance (Fitchett and Frazier 1986; Grosch 1986). In the past, dough relaxers or reducing agents have been added to wheat-based doughs to improve the extensibility, sheeting properties, and overall machinability of the doughs. In flour tortillas, for example, reducing agents are commonly used to shorten resting times before pressing by increasing the extensibility and decreasing elasticity of gluten proteins within the tortilla doughs. This is achieved using compounds such as L-cysteine, sodium metabisulfite, sorbic acid or fumaric acid, which break disulfide bonds (Van Eijk and Legel 1996). While L-cysteine is quite effective, it is derived from animal sources (hair or feathers). Sodium metabisulfite is also chemically derived and is considered an allergen. [0006] The resistance of consumers to chemical additives and their propensity to desire more natural additives is growing. Therefore, commercial suppliers of wheat-based products would like to be able to offer “natural” additives to meet consumer preferences. [0007] Heretofore, materials such as soy flour, wheat germ, garlic, and inactivated dry yeast have been proposed as dough relaxing agents or mix time reducers, because they are a good source of low molecular weight SH compounds such as L-cysteine and/or glutathione. However, these materials are not as effective as animal-derived or synthetic chemical relaxers. There is therefore a need in the art for improved dough relaxers which are fully effective while avoiding the use of traditional dough relaxing ingredients. [0008] The following references describe the prior research on wheat proteins, dough relaxers, and dough formulations containing conventional relaxers: U.S. Pat. Nos. 4,643,900; 5,510,126, 5,576,036; 5,763,741; 5,792,499; 5,859,315; 6,436,459; and 8,309,152; US Patent Applications Nos. 2004/0146601; 2008/0254200; PCT Publication Nos. WO 2006009447 A1 and WO 2013092731 A1. Cha, J.-Y., Park, J.-C., Jeon, B.-S., Lee, Y.-C. and Cho, Y.-S. 2004. Optimal fermentation conditions for enhanced glutathione production by Saccharomyces cerevisiae FF-8. J. Microbiol. 42(1):51-55. Chen, X. and Schofield, J. D. 1996. Changes in glutathione content and bread-making performance of white wheat flour during short-term storage. Cereal Chem. 73(1):1-4. Fitchett, C.S. and Frazier, P.J. 1986. Action of oxidants and other improvers. Pages 179-198 In: Chemistry and Physics of Baking, J. M. V. Blanshard, P. J. Frazier and T. Galliard, eds., Royal Society of Chemistry: London. Frater, R. and Hird, F. J. R. 1963. The reaction of glutathione with serum albumin, gluten and flour proteins. Biochem. J. 88:100-105. Grosch, W. 1986. Redox systems in dough. Pages 155-169 In: Chemistry and Physics of Baking. J. M. V. Blanshard, P.J. Frazier and T. Galliard, eds., Royal Society of Chemistry: London. Sakato, K. and Tanaka, H. 1992. Advanced control of glutathione fermentation process. Biotechnol. Bioeng. 40:904-912. Wei, G., Li, Y., and Chen, J. 2003a. Effect of surfactants on extracellular accumulation of glutathione by Saccharomyces cerevisieae . Process Biochem. 38:1133-1138. Wei, G., Li, Y., and Chen, J. 2003b. Application of a two-stage temperature control strategy for enhanced glutathione production in the batch fermentation by Candida utilis. Biotechnol. Lett. 25:887-890. SUMMARY OF THE INVENTION [0009] The present invention overcomes the problems outlined above and provides a new class of dough relaxers which comprise high-concentration wheat protein products pre-reacted with non-leavening yeasts and/or yeast extracts. These dough relaxers can then be used in a wide variety of dough formulations to give the formulations beneficial properties, particularly in the context of commercial processing. As used herein, “dough relaxers” refers to compositions having the ability to improve at least one of the extensibility, sheeting, machinability, and lowered mixing time properties of doughs prior to baking or frying thereof; dough relaxers are not associated with end properties of such baked or fried products derived from the doughs, e.g., bread loaf volumes or cookie spreads. [0010] In more detail, the highly concentrated wheat protein products used in the invention are advantageously selected from the group consisting of products containing at least about 50% by weight gluten proteins. Such products are typically produced by wet-processing of wheat flour to remove a substantial fraction of the native starch of the flour. Two types of commercially available products are particularly useful, namely vital wheat glutens and wheat protein isolates. Vital wheat glutens usually contain about 75% by weight protein (dry basis) and are classified as wheat protein concentrates. Further processing of these products, either by mechanical means or solubilization followed by centrifugation or filtration, yields products having protein levels of around 85-90% by weight (dry basis), using a nitrogen conversion factor of 6.25. These products are normally referred to in the art as wheat protein isolates. [0011] The non-leavening or inactivated yeasts, as well as the yeast extracts, include naturally occurring glutathione, a tripeptide composed of glutamic acid, cysteine, and glycine (γ-L-glutamyl-L-cysteinylglycine) having CAS# 70-18-8. Preferably, these yeasts contain from about 10-30 mg glutathione per gram of yeast [0012] The high-protein products are advantageously pre-reacted with non-leavening yeasts and/or yeast extracts in aqueous slurries with agitation and mild heating. Such slurries generally include from about 20-85% by weight water (more preferably from about 40-75% by weight, and most preferably from about 55-70% by weight), from about 15-60% by weight high-concentration gluten product(s) (more preferably from about 25-50% by weight and most preferably from about 28-40% by weight), and from about 0.01-20% by weight of suitable yeast product(s) (more preferably from about 1-10% by weight, and most preferably from about 1-5% by weight). The foregoing ranges are based upon the total weight of the slurries taken as 100% by weight. The weight ratio of high-concentration gluten products: yeast in the slurries (and thus also in the final dough relaxers) is usually from about 10:1 to 100:1, more preferably from about 35:1 to 70:1. [0013] The slurries are preferably agitated in a water bath for a period of from about 30 minutes—2 hours, more preferably from about 45 minutes—1.5 hours, and most preferably about 1 hour. The water fraction of the slurries is normally heated to a level of from about 90-140° F., more preferably from about 100-130° F., and most preferably around 122° F. and the water bath temperature is normally kept from about 90-140° F., more preferably from about 100-130° F., and most preferably around 122° F. [0014] In another embodiment of the invention, the high-protein products are pre-reacted with non-leavening yeasts and/or yeast extracts in dough states under static conditions and with mild heating. The doughs are preferably agitated for a period of from about 30 seconds—5 minutes, more preferably from about 60 seconds—3 minutes, and most preferably about 90 seconds. The water fraction of the doughs is normally heated to a level of from about 80-125° F., more preferably from about 95-110° F., and most preferably around 104° F. The moist doughs are allowed to sit in a static condition for a period of from about 30 minutes—3 hours, more preferably from about 45 minutes—2 hours, and most preferably about 1 hour. [0015] After such pre-treatments, the moist doughs or slurries may be dried by any convenient means to form solids. In preferred forms, the moist doughs or slurries are placed in a deep freezer for at least about 24 hours whereupon the frozen product may be dried in a freeze dryer followed by grinding to create a particulate material, e.g., a powder. [0016] The pre-reacted dough relaxers in powder form can be added to wheat flour-based doughs, which can be baked or fried to yield a wide variety of end products. The dough relaxers are generally added to wheat flour at a level of from about 0.1-10% by weight (more preferably from about 0.5-8% by weight, and most preferably from about 1-5% by weight), based upon the total weight of the mixture taken as 100% by weight. The relaxers may be incorporated by any convenient means. Inasmuch as the preferred relaxers are dried, particulate form, they can be readily added with the other dough ingredients without difficulty. BRIEF DESCRIPTION OF THE DRAWINGS [0017] FIG. 1 is a mixograph profile of one treated vital wheat gluten A at 85.7% absorption; [0018] FIG. 2 is a mixograph profile at 85.7% absorption of vital wheat gluten A treated with 2% yeast extract 4101 at neutral pH; [0019] FIG. 3 is a mixograph profile at 85.7% absorption of vital wheat gluten A treated with 3% yeast extract 4101 at neutral pH; [0020] FIG. 4 is a mixograph profile at 85.7% absorption of vital wheat gluten A treated with 3% non-leavening yeast RS 190 at neutral pH; FIG. 5 is a mixograph profile at 85.7% absorption of vital wheat gluten A treated with 3% non-leavening yeast SuperRelax at neutral pH; and [0021] FIG. 6 is a mixograph profile at 85.7% absorption of vital wheat gluten A treated with 3% yeast extract 4101 at acidic pH. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT EXAMPLES 1-9 [0022] The following examples set forth techniques for the preparation of representative dough relaxers of the invention, and the effect thereof on dough formulations. It is to be understood, however, that these examples are provided by way of illustration only, and nothing therein should be taken as a limitation upon the overall scope of the invention. [0023] Materials [0024] Five wheat protein samples were used in this series, of tests, namely Vital Wheat Gluten (Lot N070614), Vital Wheat Gluten (Lot N070414), Vital Wheat Gluten (Lot H082714), Wheat Protein Isolate (Lot N082714) and Wheat Protein Isolate (Lot H120214). These products were all manufactured by Manildra Milling Corporation (Bomaderry, NSW, Australia and Hamburg, Iowa) and will be referred to herein as Vital Wheat Gluten A, Vital Wheat Gluten B, Vital Wheat Gluten C, Wheat Protein Isolate D and Wheat Protein Isolate E, respectively. All wheat protein samples were sent to Medallion Laboratories (Plymouth, Minnesota) for analysis of moisture and protein. [0025] The non-leavening yeasts or yeast extracts used in this series of tests were: 1. Springer® 4101/0-PW-L, a yeast extract produced by controlled autolysis process by Bio Springer (a Lesaffre Company) in Cedar Rapids, Iowa, 2. SAF Pro® Relax RS 190, a deactivated (non-leavening) yeast ( Saccharomyces cerevisiae ) produced by Lesaffre Yeast Corporation (Milwaukee, Wisconsin) and 3. Fermaid® SuperRelax, produced by fermenting a specific baker's yeast strain ( Saccharomyces cerevisiae ), followed by drying and deactivation by Lallemand Baking Solutions (Montreal, Quebec, Canada). For convenience, these yeast products will be referred to herein as 4101, RS 190 and SuperRelax, respectively. The following glutathione content of the yeast products was provided by the respective manufacturers. SuperRelax contains 15-19 milligrams glutathione per gram (or 1.5-1.9%) and 4101 contains 1.0-3.0% glutathione. [0026] All chemicals used were either reagent grade or commercial grade. Citric acid (anhydrous) and lactic acid (88%) were obtained from ADM (Decatur, IL), DL-malic acid (FCC) was obtained from Bartek Ingredients (Stoney Creek, Ontario, Canada), and tartaric acid (USP/FCC) was obtained from American Tartaric Products, Inc. (Windsor, Calif.). Glacial acetic acid (USP) was obtained from Spectrum Chemical Mfg. Corp. (Gardena, Calif.). [0027] Methods [0028] Mixograph Procedure A [0029] Ten grams of wheat protein treated with non-leavening yeast or yeast extract was added to 25 grams of native wheat starch (GemStar™ 200 Wheat Starch, Manildra Milling Corporation, Hamburg, Iowa) followed by blending into a homogeneous mixture. The mixture was transferred into the 35-gram bowl of the Mixograph (National Manufacturing Company, Lincoln, Neb.) and 30 grams of water was added. The Mixograph instrument was turned on immediately and allowed to run for 10 minutes. After 10 minutes, the parameters in the Mixograph curve generated using MIXSMART® for Windows for computerized data acquisition and analysis were recorded using mid-line analysis: peak time (min), peak height (%), peak width (%), mixing stability or tolerance (%/min) and work input (% torque x min). Peak time represents the time for the curve to reach a peak. Peak height signifies the maximum mixing resistance. The sum of the absolute values for the left of peak and right of peak slopes is a measure of mixing stability or tolerance. A small value indicates a flat, stable curve, which is desirable. A large value indicates a rapid rise and/or breakdown, which is undesirable. Work input represents the work put into the flour and water dough in order to develop it, and is calculated as the integral value of the area beneath the mid-line from time zero to the peak time. Peak width at mid-line is calculated by subtracting the height of the bottom envelope from the height of the top envelope or in other words it represents the distance between the top and bottom envelopes. [0030] Mixograph Procedure B [0031] In order to evaluate the rheological effect on wheat flour, pre-reacted dough relaxers in accordance with the invention were added at 2% or 4% levels to hard red winter wheat flour (Bay [0032] State Milling Company, Mooresville, NC). The Certificate of Analysis for this wheat flour showed the following analysis results: moisture, 13.7%; protein, 11.5%; ash, 0.5%; and Falling Number, 390. The water absorption of the flour by itself is 63% as determined in the Mixograph. The mixing properties of the blended flour were examined in a Mixograph instrument by weighing 35 grams of the flour and adding to it 23.05 grams of water plus extra water to compensate for the presence of wheat proteins (1.5 or 2 grams of water for every gram of wheat protein added). Mid-line Mixograph parameters were recorded as described above in Procedure A. EXAMPLE 1 [0033] Vital Wheat Gluten A was treated with 2-3% of non-leavening yeast or yeast extract in a hydrated dough state for 1 hour at room temperature and the gluten dough was subsequently frozen. The frozen dough was then dried in a freeze-drier and ground into a powder. Specifically, 1.8 grams of yeast extract (4101) was dispersed with stirring in 180 ml of tap water (104° F.) and then added to a 500-ml plastic container containing 90 grams of Vital Wheat Gluten A. The lid was placed on the container and then shaken violently by hand for immediate hydration and formation of dough. The dough was allowed to remain in static condition for 1 hour after which it was placed in a deep freezer for at least 24 hours. The frozen dough of gluten was shipped overnight to the [0034] Food Processing Center of the University of Nebraska, Lincoln where it was dried in a ThermoVac freeze-drier and then ground into a powder using a Thomas Wiley mini-mill. EXAMPLE 2 [0035] The procedure of Example 1 was repeated using 2.7 grams of yeast extract (4101) instead of 1.8 grams of yeast extract (4101). EXAMPLE 3 [0036] The procedure of Example 1 was repeated using 2.7 grams of non-leavening yeast (SuperRelax) instead of 1.8 grams of yeast extract (4101). EXAMPLE 4 [0037] The procedure of Example 1 was repeated using 2.7 grams of non-leavening yeast (RS 190) instead of 1.8 grams of yeast extract (4101). EXAMPLE 5 [0038] In order to evaluate the effect of lower pH, the procedure of Example 1 was modified using natural acidulants to acidify the slurry. A mixture of 510 grams of tap water (122° F.) was added to a 1-liter beaker along with 2.7 grams of acetic acid, followed by slow addition of 90 grams of Vital Wheat Gluten A. Then, 2.7 grams of yeast extract (4101) was added to the mixture and the resulting slurry was stirred for 1 hour, with the beaker placed in a water bath maintained at 122° F. After 1 hour, the beaker containing the slurry was removed from the water bath and allowed to cool to room temperature. The slurry was placed in a deep freezer for at least 24 hours and then freeze-dried and ground into a powder at University of Nebraska as described in Example 1. EXAMPLE 6 [0039] This procedure is a repeat of Example 5 except the treatment used 3% non-leavening yeast (SuperRelax) and 3% of other natural acidulants (for example citric acid, malic acid, lactic acid or tartaric acid). EXAMPLE 7 [0040] In order to evaluate the effect of other wheat protein sources, the procedure of Example 5 was repeated using 2% 4101 and 3% lactic acid. EXAMPLE 8 [0041] The above procedure of Example 7 was repeated using 3% RS 190 instead of 2% 4101. EXAMPLE 9 [0042] Wheat Protein Isolate D and Wheat Protein Isolate E were compared by treating with 3% RS 190 using three different natural acidulants (malic, citric or tartaric acid) to acidify the slurry. [0043] The pH levels of 10% aqueous slurry in distilled water of untreated and yeast-treated wheat protein samples was measured. [0044] The mixing properties of the above samples from Examples 1-9 were measured in a Mixograph using Procedure A. [0045] Selected samples of the pre-reacted dough relaxers prepared in Examples 1-9 were evaluated for their effects on rheology of hard red winter wheat flour (Bay State Milling Company, Mooresville, North Carolina). The level of addition to wheat flour is 2-4% and the Mixograph characteristics were measured at two levels of water absorption using Procedure B. [0046] Results [0047] The moisture, protein, pH and mixing properties of five wheat protein samples used in this invention are shown in Table 1. Moisture varies from 4.3-6.3% and pH ranges from 5.30-5.89. The three vital wheat gluten samples with 75.6-76.0% protein exhibited varying properties with both Vital Wheat Gluten A and B possessing higher mixing strength (elevated peak height) and higher work input compared to Vital Wheat Gluten C. In contrast, Vital Wheat Gluten C demonstrated a longer mixing time but increased mixing stability or tolerance compared to the other wheat gluten samples. Wheat Protein Isolate D (89.0% protein) displayed a higher mixing strength and higher work input compared to Wheat Protein Isolate E (97.3% protein). [0000] TABLE 1 Properties of Wheat Proteins Used as Base Materials for Treatment with Non-Leavening Yeast or Yeast Extract Vital Vital Vital Wheat Wheat Wheat Wheat Wheat Protein Protein Gluten Gluten Gluten Isolate Isolate Parameters A B C D E Moisture, % 6.1 6.2 4.4 6.3 4.3 Protein, % d.b. 76.0 a 75.6 a 75.6 a 89.0 b 97.3 b pH 5.70 5.66 5.64 5.30 5.89 Peak Time, min 6.9 6.4 10.0 9.7 9.9 Peak Height, % 68.6 61.2 17.8 65.4 32.9 Peak Width, % 41.6 36.9 5.6 45.4 41.6 Mixing Stability or 6.1 10.0 0.5 4.1 2.4 Tolerance, %/min Work Input, % 249.2 209.0 153.4 323.0 243.3 torque × min a Calculated as N × 5.7, dry basis b Calculated as N × 6.25, dry basis [0048] The appearance of the Mixograph curves of untreated and yeast-treated Vital Wheat Gluten A is shown in FIGS. 1-5 . The Mixograph data in Table 2 generally shows that the parameters of peak time, peak height, peak width, work input and mixing stability or tolerance decreased as a result of treating wheat gluten with 2-3% non-leavening yeast or yeast extract. Treatment with 3% yeast extract (4101) exhibited the largest lowering effect of those five parameters whereas 3% SuperRelax showed the smallest lowering effect. These results can possibly be explained by the level of glutathione in the yeast samples. Glutathione is a reducing agent capable of cleaving disulfide bonds in the wheat protein polymer, which consequently results in the observed Mixograph data. In the hydrated state, the gluten dough treated with 2-3% non-leavening yeast or yeast extract yielded more extensible, less elastic doughs compared to the untreated wheat gluten, with 4101 treatment showing the most extensible property. Overall, these reduced forms of wheat proteins display varying levels of dough extensibility depending on the level and type of yeast product used. [0000] TABLE 2 Mixing Properties of Vital Wheat Gluten A after Treatment with Non-Leavening Yeast or Yeast Extract Level of Non-Leavening Yeast or Yeast Extract, % 2% 3% 3% 3% Parameters 0 4101 4101 RS 190 SuperRelax pH 5.70 5.98 5.91 5.77 5.71 Peak Time, min 6.9 3.8 3.2 5.9 6.5 Peak Height, % 68.6 52.6 45.2 56.2 55.8 Peak Width, % 41.6 18.2 14.8 27.8 25.2 Mixing Stability or 6.1 7.2 8.1 13.2 11.4 Tolerance, %/min Work Input, % 249.2 106.3 85.1 170.2 189.1 torque × min [0049] Reaction of Vital Wheat Gluten A with 4101 under neutral or acidic pH was evaluated for the effects on mixing properties. The Mixograph data in Table 3 and the Mixograph curves ( FIGS. 1 and 3 compared to FIG. 6 ) confirm the decline of peak time, peak height, peak width and work input upon treatment with 4101 under neutral pH conditions (pH 5.91), and a further lowering of the four mixing parameters when 4101 treatment was conducted at acidic conditions (pH 4.39). [0000] TABLE 3 Effect on Mixograph Properties of Treating Vital Wheat Gluten A with 3% 4101 at Neutral or Acidic Conditions Vital Wheat Gluten A Treated with 3% Treated with 3% 4101 at Neutral 4101 at Acidic Parameters Untreated pH a pH b pH 5.70 5.91 4.39 Peak Time, min 6.9 3.2 2.4 Peak Height, % 68.6 45.2 30.5 Peak Width, % 41.6 14.8 6.4 Mixing Stability or 6.1 8.1 6.1 Tolerance, %/min Work Input, % 249.2 85.1 50.5 Torque × min a Neutral pH means that there were no added acidic or alkaline chemicals during treatment with 4101 b With 3% acetic acid [0050] Using different types of natural acidulants to lower the pH during reaction of Vital Wheat Gluten A with SuperRelax, the pH ranged from 3.59-4.25 and the Mixograph parameters of peak time, peak height, peak width and work input generally declined whereas mixing stability or tolerance improved (Table 4). Among the five natural acidulants, tartaric acid tended to have the largest lowering effect on Mixograph parameters while citric acid has the smallest lowering effect. It appears that varying levels of extensibility of the reduced form of wheat protein can be attained depending on the type of acidulant used. [0000] TABLE 4 Effect of Acidic pH on mixing properties of Vital Wheat Gluten A Treated with 3% SuperRelax Level of Natural Acidulant to Lower pH 3% 3% 3% 3% 3% Acetic Citric Lactic Malic Tartaric Parameters 0 Acid Acid Acid Acid Acid pH 5.70 4.25 3.85 3.95 3.79 3.59 Peak Time, min 6.5 2.8 3.7 2.1 2.9 2.1 Peak Height, % 55.8 38.2 38.9 35.2 33.2 31.5 Peak Width, % 25.2 11.0 12.1 9.7 8.7 8.2 Mixing Stability or 11.4 4.5 4.5 5.7 4.3 5.5 Tolerance, %/min Work Input, 189.1 73.8 92.5 55.3 66.9 50.4 % Torque x min [0051] The mixing properties of four wheat protein samples treated with 2% 4101 at acidic conditions (pH 4.00-4.12) were determined. Compared to the Mixograph data of native wheat proteins shown on Table 1, there is again a general lowering trend of mixing parameters (Table 5). [0052] The magnitude of the effect appears to show more variability with vital wheat gluten samples than with wheat protein isolate samples. The hydrated, reduced form of wheat proteins exhibits more extensibility than the untreated, native wheat proteins. [0000] TABLE 5 Effect on Mixing Properties of Different Sources of Wheat Protein Treated with 2% 4101 at Acidic pH a Source of Wheat Protein Vital Vital Wheat Wheat Wheat Wheat Protein Protein Gluten Gluten Isolate Isolate Parameters B C D E pH 4.07 4.10 4.00 4.12 Peak Time, min 2.1 4.7 1.5 1.8 Peak Height, % 31.8 32.9 35.2 30.2 Peak Width, % 6.6 7.4 9.1 10.2 Mixing Stability or 6.5 0.5 15.2 9.0 Tolerance, %/min Work Input, % 48.2 113.1 40.2 41.7 torque × min a With 3% lactic acid [0053] The Mixograph data in Table 6 using four different wheat proteins treated with 3% RS 190 at acidic conditions (pH 3.96-4.06) appears to be consistent with the data shown in Table 5 obtained from wheat proteins treated with 2% 4101 also at acidic conditions. The differential effect was again more evident with wheat gluten, specifically Vital Wheat Gluten C. A common characteristic of these RS 190-treated wheat proteins is the increased dough extensibility compared to their respective untreated, native wheat protein counterparts. [0000] TABLE 6 Effect on Mixing Properties of Different Sources of Wheat Protein Treated with 3% RS 190 at Acidic pH a Source of Wheat Protein Vital Vital Wheat Wheat Wheat Wheat Protein Protein Gluten Gluten Isolate Isolate Parameters B C D E pH 3.97 4.02 3.96 4.06 Peak Time, min 2.1 5.2 1.5 1.3 Peak Height, % 32.9 32.5 34.6 35.0 Peak Width, % 10.1 7.2 10.1 6.8 Mixing Stability or 4.9 0.5 12.9 25.0 Tolerance, %/min Work Input, % 52.2 130.4 42.7 39.3 torque × min a With 3% lactic acid [0054] Citric acid tends to have a lesser lowering effect on Mixograph parameters compared to malic and tartaric acids (Table 7). Both samples of wheat protein isolates, in general, behaved similarly with respect to their mixing properties as affected by RS 190 treatment at acidic pH conditions (pH 3.60-3.96). [0000] TABLE 7 Effect on Mixing Properties of Two Wheat Protein Isolates Treated with 3% RS 190 at Acidic pH Wheat Protein Isolate D Wheat Protein Isolate E 3% 3% 3% 3% 3% 3% Parameters Malic Citric Tartaric Malic Citric Tartaric Natural Acidulant Acid Acid Acid Acid Acid Acid pH 3.77 3.83 3.60 3.89 3.96 3.69 Peak Time, min 1.8 3.1 2.3 2.0 3.6 2.0 Peak Height, % 35.0 40.0 30.9 36.6 39.4 32.5 Peak Width, % 9.5 12.8 7.8 10.1 12.5 11.8 Mixing Stability or 10.0 3.8 5.5 7.2 2.8 8.0 Tolerance, %/min Work Input, % torque 48.8 82.8 53.2 58.0 99.4 51.1 x min [0055] Table 8 shows the effect on Mixograph properties of hard red winter wheat flour containing 0% (Control), 2%, or 4% of wheat gluten. Vital Wheat Gluten A tended to increase peak time, peak height and work input with the larger effect exhibited at 4% level of addition. The same trend is true for Vital Wheat Gluten B, except that, in addition, it tends to have higher peak width compared to the control wheat flour. Vital Wheat Gluten C behaved differently than the other two gluten samples. It has higher peak time and much elevated work input compared to the control wheat flour. [0000] TABLE 8 Effect on Mixing Properties of Wheat Flour by Adding Vital Wheat Gluten at 2% or 4% Level 0% Parameters (Control) 2% 2% 4% 4% Level of Addition of Vital Wheat Gluten A Absorption, % 63 66 67 69 71 Peak Time, min 3.3 3.3 3.5 3.5 3.7 Peak Height, % 53.2 54.5 55.6 55.6 54.3 Peak Width, % 24.9 29.6 27.8 23.4 24.8 Mixing Stability or 4.9 5.8 6.4 5.0 5.2 Tolerance, %/min Work Input, % 145.3 143.2 149.5 151.6 152.0 torque × min Level of Addition of Wheat Gluten B Absorption, % 63 66 67 69 71 Peak Time, min 3.3 3.4 3.6 3.5 3.6 Peak Height, % 53.2 55.9 56.5 55.5 55.0 Peak Width, % 24.9 27.7 26.6 27.5 26.6 Mixing Stability or 4.9 5.0 6.0 5.1 4.8 Tolerance, %/min Work Input, % 145.3 153.6 159.3 152.6 150.4 torque × min Level of Addition of Vital Wheat Gluten C Absorption, % 63 66 67 69 71 Peak Time, min 3.3 4.0 4.2 4.7 4.9 Peak Height, % 53.2 50.3 50.0 53.8 53.8 Peak Width, % 24.9 25.6 22.7 26.2 22.2 Mixing Stability or 4.9 2.4 0.6 1.1 3.3 Tolerance, %/min Work Input, % 145.3 167.6 174.5 202.5 202.7 torque × min [0056] Table 9 shows the effects on Mixograph properties of hard red winter wheat flour containing 0% (Control), 2%, and 4% of Wheat Protein Isolate D. Isolate D tended to increase peak time, peak height and work input of wheat flour, whereas Isolate E tended to increase peak time, peak height, peak width, and work input. In addition, Isolate E improved the mixing stability or tolerance of flour. The 4% level of addition of Wheat Protein Isolate E exhibited higher work input compared to 2% level of addition. [0000] TABLE 9 Effect on Mixing Properties of Wheat Flour by Adding Wheat Protein Isolate at 2% or 4% Level 0% Parameters (Control) 2% 2% 4% 4% Level of Addition of Wheat Protein Isolate D Absorption, % 63 66 67 69 71 Peak Time, min 3.3 3.5 3.6 3.6 3.7 Peak Height, % 53.2 55.1 53.5 55.8 53.4 Peak Width, % 24.9 23.8 27.3 23.2 25.0 Mixing Stability or 4.9 4.4 5.1 4.3 5.6 Tolerance, %/min Work Input, % 145.3 153.3 153.0 155.6 153.0 torque × min Level of Addition of Wheat Protein Isolate E Absorption, % 63 66 67 69 71 Peak Time, min 3.3 4.0 4.0 4.2 4.4 Peak Height, % 53.2 53.3 53.5 55.4 53.7 Peak Width, % 24.9 27.6 29.6 25.2 27.6 Mixing Stability or 4.9 2.3 3.4 2.6 3.4 Tolerance, %/min Work Input, % 145.3 170.1 171.2 179.8 186.2 torque × min [0057] The type and level of non-leavening yeast or yeast extract used to treat Vital Wheat Gluten A to produce a dough relaxer affected the Mixograph properties of wheat flour. For example, 2% level of addition of 3% 4101-treated wheat gluten resulted in a general decrease of peak time and work input compared to wheat flour and untreated wheat gluten. The lowering effect of both parameters was exhibited more after 3% 4101 treatment than after 2% 4101 treatment (Table 10a). At 4% level of addition, the above same effect on peak time and work input was observed except that the magnitude of decrease was more substantial (Table 10b). In contrast, a dough relaxer made using RS 190-treated wheat gluten did not have a significant effect on Mixograph properties, but a SuperRelax-treated wheat gluten relaxer caused a general decrease in peak width at 2 and 4% levels of addition. Furthermore, there is a decrease in peak height, an improvement in mixing stability or tolerance and an increase in peak time and work input at 2% level of addition of SuperRelax-treated wheat gluten. [0000] TABLE 10a Effect on Mixograph Properties of Wheat Flour by Adding 2% of Untreated, 4101-, RS 190- or SuperRelax-Treated Vital Wheat Gluten A Prepared under Neutral pH Conditions Wheat Vital Wheat Gluten A (2% Level) Parameters Flour Untreated 2% 4101 a 3% 4101 a Absorption, % 63 66 67 66 67 66 67 Peak Time, min 3.3 3.3 3.5 3.4 3.4 3.1 3.1 Peak Height, % 53.2 54.5 55.6 53.2 51.6 53.9 55.0 Peak Width, % 24.9 29.6 27.8 24.3 20.7 22.6 29.8 Mixing Stability or 4.9 5.8 6.4 4.3 4.3 3.2 5.9 Tolerance, %/min Work Input, % 145.3 143.2 149.5 142.4 137.0 132.8 132.5 Torque x min Vital Wheat Gluten A (2% Level) Wheat 3% 3% Parameters Flour Untreated RS 190 a SuperRelax a Absorption, % 63 66 67 66 67 66 67 Peak Time, min 3.3 3.3 3.5 3.5 3.4 3.6 3.7 Peak Height, % 53.2 54.5 55.6 55.8 53.6 52.7 51.2 Peak Width, % 24.9 29.6 27.8 25.4 30.8 23.4 22.3 Mixing Stability or 4.9 5.8 6.4 4.8 4.7 2.9 3.2 Tolerance, %/min Work Input, % 145.3 143.2 149.5 153.3 145.4 151.4 151.8 Torque x min a Prepared under neutral pH conditions (no added acidic or alkaline chemicals) [0000] TABLE 10b Effect on Mixograph Properties of Wheat Flour by Adding 4% of Untreated, 4101-, RS 190- or SuperRelax-Treated Vital Wheat Gluten A Prepared under Neutral pH Conditions Wheat Vital Wheat Gluten A (4% Level) Parameters Flour Untreated 2% 4101 a 3% 4101 a Absorption, % 63 69 71 69 71 69 71 Peak Time, min 3.3 3.5 3.7 3.1 3.3 2.8 3.0 Peak Height, % 53.2 55.6 54.3 54.5 52.3 54.5 54.1 Peak Width, % 24.9 23.4 24.8 22.7 21.5 23.7 21.0 Mixing Stability or 4.9 5.0 5.2 5.2 5.1 3.9 5.6 Tolerance, %/min Work Input, 145.3 151.6 152.0 129.2 132.4 116.4 121.2 % Torque x min Vital Wheat Gluten A (4% Level) Wheat 3% 3% Parameters Flour Untreated RS 190 SuperRelax a Absorption, % 63 69 71 69 71 69 71 Peak Time, min 3.3 3.5 3.7 3.4 3.6 3.5 3.7 Peak Height, % 53.2 55.6 54.3 55.5 53.3 53.8 52.4 Peak Width, % 24.9 23.4 24.8 27.9 21.6 20.7 20.8 Mixing Stability or 4.9 5.0 5.2 5.6 5.1 4.0 5.2 Tolerance, %/min Work Input, 145.3 151.6 152.0 144.0 145.0 144.3 149.1 % Torque x min a Prepared under neutral pH conditions (no added acidic or alkaline chemicals) [0058] Addition of 4101-treated Vital Wheat Gluten A generally decreased peak time and work input, but increased peak height of wheat flour (Table 11). Addition of 4101-treated Vital Wheat Gluten A prepared under acidic conditions generally decreased peak time, peak width and work input, but increased peak height of wheat flour. The lowering effect on peak time, peak width and work input was enhanced under acid pH conditions. Higher level of addition of 4101-treated Vital Wheat Gluten A produced a greater reduction in work input whether under neutral or acid pH conditions. The results indicate a dough relaxing effect of 4101-treated Vital Wheat Gluten A prepared under neutral or acidic pH conditions. [0000] TABLE 11 Effect on Mixograph Properties of Wheat Flour by Adding 4101 a -Treated Vital Wheat Gluten A Prepared under Neutral or Acidic Conditions 0% Parameters (Control) 2% 2% 4% 4% Level of Addition of 4101 a -Treated Vital Wheat Gluten A (Acidic pH b ) Absorption, % 63 66 67 69 71 Peak Time, min 3.3 2.7 2.9 2.4 2.6 Peak Height, % 53.2 54.8 55.8 55.5 53.2 Peak Width, % 24.9 21.5 24.6 20.3 19.3 Mixing Stability or 4.9 4.2 5.6 5.0 3.7 Tolerance, %/min Work Input, % 145.3 115.0 122.8 103.7 102.4 torque × min Level of Addition of 4101 a -Treated Vital Wheat Gluten A (Neutral pH c ) Absorption, % 63 66 67 69 71 Peak Time, min 3.3 3.1 3.1 2.8 3.0 Peak Height, % 53.2 53.9 55.0 54.5 54.1 Peak Width, % 24.9 22.6 29.8 23.7 21.0 Mixing Stability or 4.9 3.2 5.9 3.9 5.6 Tolerance, %/min Work Input, % 145.3 132.8 132.5 116.4 121.2 torque × min a Treated with 3% 4101 b With 3% Acetic Acid c Neutral pH means that there were no added acidic or alkaline chemicals during treatment with 4101 [0059] Addition of 4101-Treated Vital Wheat Gluten B generally decreased peak time and work input, but increased peak height of wheat flour (Table 12). With RS 190 treatment, there is a general reduction in peak time and work input, but improvement in mixing stability or tolerance. In both treatments, 4% level of addition has greater reducing effect on peak time and work input. [0000] TABLE 12 Effect on Mixograph Properties of Wheat Flour by Adding 4101- or RS 190-Treated Vital Wheat Gluten B 0% Parameters (Control) 2% 2% 4% 4% Level of Addition of 4101 a -Treated Vital Wheat Gluten B (Acidic pH c ) Absorption, % 63 66 67 69 71 Peak Time, min 3.3 2.9 2.9 2.6 2.7 Peak Height, % 53.2 57.0 53.8 56.2 54.0 Peak Width, % 24.9 31.1 20.1 23.8 19.7 Mixing Stability or 4.9 5.0 3.2 4.5 4.6 Tolerance, %/min Work Input, % 145.3 128.7 121.8 109.0 109.0 torque × min Level of Addition of RS 190 b -Treated Vital Wheat Gluten B (Acidic pH c ) Absorption, % 63 66 67 69 71 Peak Time, min 3.3 3.0 3.1 2.7 2.8 Peak Height, % 53.2 53.7 53.5 54.0 52.4 Peak Width, % 24.9 26.2 22.6 21.9 21.9 Mixing Stability or 4.9 3.6 3.7 3.2 3.7 Tolerance, %/min Work Input, % 145.3 126.8 131.4 113.4 113.6 torque × min a Treated with 2% 4101 b Treated with 3% RS 190 c With 3% lactic acid [0060] Addition of Vital Wheat Gluten C treated with 2% 4101 or 3% lactic acid generally results in a decline in peak time, peak height, peak width and work input but an improvement in mixing stability or tolerance (Table 13). The magnitude of peak time and work input reduction was higher at 4% addition level compared to 2% level. With 3% RS 190 and 3% lactic acid, there is a general reduction in peak height, peak width and work input, but an improvement in mixing stability or tolerance. Addition of Vital Wheat Gluten C treated with only 3% lactic acid did not show any general trend except for an improvement of mixing stability or tolerance. [0000] TABLE 13 Effect on Mixograph Properties of Wheat Flour by Adding 4101- or RS 190-Treated Vital Wheat Gluten C 0% Parameters (Control) 2% 2% 4% 4% Level of Addition of 4101 a -Treated Vital Wheat Gluten C (Acidic pH c ) Absorption, % 63 66 67 69 71 Peak Time, min 3.3 3.2 3.1 2.8 3.0 Peak Height, % 53.2 53.0 52.7 52.2 50.5 Peak Width, % 24.9 21.7 23.4 20.6 23.7 Mixing Stability or 4.9 3.7 3.9 3.8 3.1 Tolerance, %/min Work Input, % 145.3 134.3 130.2 117.4 119.2 torque × min Level of Addition of Acidified Vital Wheat Gluten C (Acidic pH c ) Absorption, % 63 66 67 69 71 Peak Time, min 3.3 3.2 3.4 3.3 3.6 Peak Height, % 53.2 53.6 54.1 51.6 49.8 Peak Width, % 24.9 28.7 22.6 23.2 22.8 Mixing Stability or 4.9 3.7 3.1 2.8 2.3 Tolerance, %/min Work Input, % 145.3 140.6 149.7 137.2 147.5 torque × min Level of Addition of RS 190 b -Treated Vital Wheat Gluten C (Acidic pH c ) Absorption, % 63 66 67 69 71 Peak Time, min 3.3 3.2 3.3 3.1 3.2 Peak Height, % 53.2 52.2 52.3 51.7 51.3 Peak Width, % 24.9 24.3 20.3 21.1 21.9 Mixing Stability or 4.9 3.5 3.6 2.5 3.0 Tolerance, %/min Work Input, % 145.3 137.8 138.0 129.4 130.3 torque × min a Treated with 2% 4101 b Treated with 3% RS 190 c With 3% lactic acid [0061] Adding 2-4% of 4101-treated Wheat Protein Isolate E tended to reduce peak time and work input but increase peak height of wheat flour (Table 14). This signifies a dough relaxing effect of the reduced form of wheat protein. The magnitude of reduction in work input is larger at 4% level of addition. A reduction in peak time, peak width and work input was observed after adding 2-4% of RS 190-treated Wheat Protein Isolate E to wheat flour. The addition of acidified Wheat Protein Isolate E (no treatment with 4101 or RS 190) improved mixing stability or tolerance with a decline in work input, but the magnitude of the change is not as substantial when compared to addition of 4101-treated or RS 190-treated wheat protein isolate. In general, the 4% level of addition of the three wheat protein isolates has a larger lowering effect of work input of wheat flour compared to 2% level of addition. [0000] TABLE 14 Effect on Mixograph Properties of Wheat Flour by Adding Acidified, 4101-Treated or RS 190-Treated Wheat Protein Isolate E 0% Parameters (Control) 2% 2% 4% 4% Level of Addition of 4101 a -Treated Wheat Protein Isolate E (Acidic pH c ) Absorption, % 63 66 67 69 71 Peak Time, min 3.3 2.9 3.1 2.6 2.7 Peak Height, % 53.2 57.2 57.0 56.2 54.6 Peak Width, % 24.9 28.1 22.7 23.4 23.8 Mixing Stability or 4.9 5.3 6.0 5.3 4.4 Tolerance, %/min Work Input, % 145.3 132.1 138.1 115.1 114.8 torque x min Level of Addition of Acidified Wheat Protein Isolate E (Acidic pH c ) Absorption, % 63 66 67 69 71 Peak Time, min 3.3 3.4 3.3 3.1 3.2 Peak Height, % 53.2 53.4 52.8 53.9 52.5 Peak Width, % 24.9 25.8 24.7 20.7 21.4 Mixing Stability or 4.9 2.9 3.2 2.1 3.7 Tolerance, %/min Work Input, % 145.3 145.0 139.4 134.7 133.5 torque x min Level of Addition of RS 190 b -Treated Wheat Protein Isolate E (Acidic pH c ) Absorption, % 63 66 67 69 71 Peak Time, min 3.3 3.1 3.1 2.8 3.0 Peak Height, % 53.2 53.3 53.1 53.2 52.6 Peak Width, % 24.9 23.7 22.2 21.3 22.8 Mixing Stability or 4.9 3.8 2.5 3.1 4.2 Tolerance, %/min Work Input, % 145.3 134.4 131.8 119.5 121.9 torque x min a Treated with 2% 4101 b Treated with 3% RS 190 c With 3% lactic acid [0062] Further details regarding the above examples are set forth in an attachment hereto. EXAMPLE 10 [0063] In this example, a series of thirteen samples (ca. 10 mg) were tested to determine the ratio of polymeric (P) to monomeric (M) proteins therein. The vital wheat gluten A, yeast extract 4101, RS 190, and SuperRelax products are defined above. [0064] In the preparation of the samples, SDS SE-HPLC buffer was employed containing 7.1 g Na 2 HPO 4 plus 5 g SDS (sodium dodecyl sulfate) dissolved in 1 L water, followed by pH adjustment to 6.9 with HC1. Ten grams of each sample was weighed and an appropriate volume of the SDS buffer was added to obtain a 10 mg/mL solution. The solution was then mixed using a vortex mixer on setting 5 for 5 minutes, followed by sonication for 15 seconds with an output of 6 W. The sonicator probe chip was placed in the tube center at ⅓ of the distance up from the tube bottom. The sample was then centrifuged at 12,000 rpm for 10 minutes, followed by additional centrifugation at 14,000 rpm for 5 minutes. The supernatant was then filtered and placed into a HPLC vial. [0065] The samples were then analyzed by size exclusion chromatography (SEC) using an Agilent HP 1100 HPLC with a Phenomenex Biosep-SEC-s4000, 300 mm×7.8 mm, 5 μm. Isolated bovine serum albumin, egg albumin, trypsinogen, and lysozyme purchased from Sigma Chemical were used to calibrate the instruments. The mobile phase used in the tests was acetonitrile/water (50/50) plus 0.1% Ormic acid, isocratic elution. The UV detector was a UV-Vis detector set at 210 nm. A retention time of 8 minutes was used as a cutoff for the P and M proteins. To calculate the ratio of P/M, the sum of the peak areas before 8 minutes was divided by the sum of the positive peaks between 8-13 minutes. Duplicates were averaged for each sample. [0066] The samples and the P/M ratios are set forth in the following table. [0000] TABLE 15 Summary of the Ratio of Polymeric (P) to Monomeric (M) Protein in 13 Samples as Determined by SEC Sample P/M Standard Code Sample Identity Ratio Deviation 1 Vital Wheat Gluten A Untreated 1.21 0.04 2 Vital Wheat Gluten A Treated (Pre-Reacted) 1.11 0.01 with 2% Yeast Extract 4101 at Neutral pH 3 Vital Wheat Gluten A Treated (Pre-Reacted) 1.10 0.04 with 3% Yeast Extract 4101 at Neutral pH 4 Vital Wheat Gluten A Treated (Pre-Reacted) 1.11 0.03 with 3% Non-Leavening Yeast RS 190 at Neutral pH 5 Vital Wheat Gluten A Treated (Pre-Reacted) 1.16 0.01 with 3% Non-Leavening Yeast SuperRelax at Neutral pH 6 Vital Wheat Gluten A Treated (Pre-Reacted) 1.03 0.02 with 3% Yeast Extract 4101 at Acidic pH (3% Acetic Acid) 7 Vital Wheat Gluten A Dry Blended with 1.20 0.02 2% Yeast Extract 4101 8 Vital Wheat Gluten A Dry Blended with 1.16 0.04 3% Yeast Extract 4101 9 Vital Wheat Gluten A Dry Blended with 1.25 0.03 3% Non-Leavening Yeast RS 190 10 Vital Wheat Gluten A Dry Blended with 1.18 0.06 3% Non-Leavening Yeast SuperRelax 11 Yeast Extract 4101 0.00 0.00 12 Non-Leavening Yeast RS 190 2.14 0.18 13 Non-Leavening Yeast SuperRelax 2.43 0.07 [0067] As can be seen in the above table, the P/M ratios were reduced for the pre-reacted products of the invention (Samples 2-6), as compared with untreated vital wheat gluten A (Sample 1). Moreover, the simple gluten/yeast extract mixtures without pre-reaction had P/M ratios very similar to that of the untreated vital wheat gluten A.

Wheat protein-based dough relaxers are prepared by pre-reacting a high-concentration wheat protein product (e.g., vital wheat gluten, wheat protein isolate, and mixtures thereof) with a yeast product selected from inactivated non-leavening yeast, yeast extract, and mixtures thereof. The pre-reaction is preferably carried out using an aqueous slurry containing the protein and yeast products, followed by drying. The resultant dough relaxers may be incorporated into a wide variety of wheat protein-based dough formulations to enhance the handling properties thereof, especially dough extensibility and machinability, and reduced dough mixing times.

FIELD OF THE INVENTION The present invention relates to semiconductor light emitting devices with increased operating speed and near linear light output versus current input characteristics, and lasing suppression mechanisms. BACKGROUND OF THE INVENTION The invention of the instant application is related to U.S. Ser. 08/276,131, filed Jul. 15, 1994 and U.S. patent application Ser. No. 08/339,053 (TWC Docket No. 16031), filed concurrently herewith. The advent of heterostructure semiconductor devices has lead to the ease in fabrication and improved characteristics of many types of semiconductor devices. The light emitting diode (LED) the subject of the present invention, is an example of a device that benefits greatly from the use of heterostructure device design. Generally, the heterostructure employed in the fabrication of an LED is a double heterostructure, in which an active region III-V semiconductor (ternary or quaternary) is sandwiched between two oppositely doped II-IV compounds. By choosing appropriate materials of the outer layers, the band gaps are made to be larger than that of the active layer. This procedure, well known to the skilled artisan, produces a device that permits light emission due to recombination in the active region, but prevents the flow of electrons or holes between the active layer and the higher band gap sandwiching layers due to the differences between the conduction band energies and the valence band energies, respectively. An example of this is shown in FIG. 1, which is an energy band diagram of an N-n-P (where N,P are indicative of materials with greater band gaps than the n-doped active region) double semiconductor heterostructure, which shows the discontinuities 2,3 in energy levels of the conduction band energy (E c ) and the valence band energy (E v ) at the depletion regions that create the confinement of electrons and holes in the active region 1 (The Fermi level E f , is aligned at all three materials). The minority carrier concentration (holes) in the sandwiched region can have a magnitude comparable to the majority carrier concentration in the p-doped region. Accordingly, upon application of a junction forward bias, recombination takes place in and is essentially restricted to the central region, a feature of great advantage in the LED. A further advantage stems from a structure such as that shown, is that the dielectric constant of the higher bandgap layers is lower than that of the central lower bandgap region. Accordingly, the index of refraction of the lower bandgap region is higher than that of the lower bandgap regions, an a natural dielectric slab (assuming a rectangular layer structure) waveguide is formed. Light emitting devices can be fabricated to emit light from an edge of the active layer, or as stated above from a surface. The devices can be either light emitting diodes or lasers. For the purposes of clarity of instruction, one particular design will be described in detail. The particular design shows an edge emitting LED on n-type substrate. However the same principles apply for these light emitting devices on a p-type substrate. Furthermore, the active layer composition for the these devices can be either of conventional bulk material or strained or unstrained quantum well type material. An Edge Emitting Light Emitting Diode (ELED), fabricated by conventional techniques is shown in FIGS. 2-4. Turning first to FIG. 2, an p-type indium phosphide (p-InP) layer 22 is grown on substrate 21. A n-InP cladding layer 23 is grown on the layer 22, and a v-groove is etched as shown with an active region of InGaAsP grown thereafter. Then a p-cladding layer of InP 24 followed by a p + layer of InGaAsP contact 25 or cap layer. Then a metal contact layer 26 is deposited on layer 25. With the exception the metal contact layer of these layers are grown on the substrate epitaxially. In the structure as shown, distinct advantages are realized. First, as with other conventional devices, the natural waveguide is formed by choosing the appropriate cladding and active layers. Also, a buried structure is formed which enables current confinement which results in a lower current threshold level, and reduced operating temperatures. This current confinement comes about by selective junction biasing. To be specific to the example shown, a forward bias at the active/cladding region results in emission through recombination. However, as can be appreciated, application of an electric potential to effect a forward bias from active to cladding will result in a reverse bias in the lateral pn junctions, thus electrically burying the active region and resulting in current confinement. Optical confinement is also effected by the fact that the lateral regions are of lower index of refraction than that of the active region, resulting in a guided optical wave. FIG. 3 shows a p-type substrate of InP 31 having a buried crescent active region of p-GaInAsP 33 and cladding layers of n-InP 32 and p-InP 34 respectively. In the particular device shown, there is shown the interface of the cladding and substrate regions at 36 which is angled to reduce reflections thereby reducing the probability of lasing. In a device designed to be an LED, it is undesirable to have a resonant cavity capable of supporting lasing action, and this is one method used to prevent this. Finally, turning to FIG. 4, the basic structure as shown in FIG. 3 is found, however, at 47 is shown a region that separates the active region 43 from an absorption region of material identical to that of the active region. In purpose and effect, such a structure is designed to absorb any light that is refracted at the interface 46 and propagates through the semi-insulating region. Potentially, this could effect resonating and thereby result in undesired lasing. The device shown in FIG. 4 also has a dielectric cap of SiO 2 which is supposed to reduce leakage current in the absorption region from the ohmic metal contact for the device which is deposited onto the top surface. The shortcoming of this approach is that there is still current leakage through the heavily doped cap layer of n-InGaAsP. This leakage current will result in electrical pumping of the absorption region of the LED, and accordingly, lasing effects could result. In addition, this leakage current (current flow from the absorption region) reduces the actual current needed to pump the active region. Furthermore, this structure, while effective in DC applications has great shortcomings in the ever increasing switching speeds required for example in communications applications. This is due intrinsic capacitance between the layers that make up the device. Furthermore, the layer of dielectric which is used to decrease leakage current has the adverse affect of preventing heat dissipation as well as increasing device capacitance. It is desirable to reduce the area of the layers which reduces the capacitance, as well as to increase the ability to dissipate joule heating of the device. With the desire for higher switching speeds, particularly the desire to reduce the rise and fall times of a digital optical signal, the ill-effects of parasitic capacitance must be reduced. Examples of attempts to curb the ill-effects of parasitic capacitance can be found in related U.S. Pat. Nos. 5,003,358; 5,100,833; 5,194,399 and 5,275,968 to Takahashi, et al. incorporated herein by reference. As is disclosed in the '358 reference, a semi-insulating or insulating substrate has deposited thereon a semi-insulating layer of InP which is etched to accommodate the p and n side electrodes as well as an vertical aperture in which an active layer is grown between p and n type cladding layers. Thereby, a light emitting device is formed in the aperture. Connecting the n-type cladding to the n side electrode is a conducting n-type InP layer which is buried in a groove etched in the semi-insulating layer. This structure having the light emitting device in a relatively small and confined region reduces the intrinsic parasitic capacitance by reducing the area of the p-n junctions of the device, and thereby the capacitance which is directly proportional to the area of the p-n junction. A good understanding of the ill-effects of this parasitic peripheral pn junction capacitance is found by a review of the prior art disclosed in FIG. 5 of the '358 reference. U.S. Pat. 5,309,467 to Terakado, the disclosure of which is specifically incorporated herein by reference, discloses a buried stripe semiconductor laser with a semi-insulating layer on either side of the buried mesa structure. This structure enables the operation of a laser with high luminous efficiency at elevated temperatures. This reference teaches the structure to effect lasing. What is desired is an LED which is capable of operating at high frequencies and at elevated temperatures. SUMMARY OF THE INVENTION The present invention provides for an edge emitting LED which is capable of operating at high frequencies, and thereby with a greater operational bandwidth. The invention effects light emission without the adverse affects of lasing with light diffusion surfaces and a nearly unpumped absorption region. OBJECTS, FEATURES AND ADVANTAGES It is an object of the present invention to enable an LED to operate with high switching speed, thereby with greater bandwidth capabilities. It is a feature of the present advantage to fabricate a buried heterostructure device with greatly reduced intrinsic capacitance, thereby having a lower intrinsic RC time constant. It is a further feature to reduce the lateral pn junction capacitance through the use of a semi-insulating material deposited on either side of the buried heterostructure. It is a further feature of the present invention to prevent lasing by removal of portions of the cap, cladding and semi-insulating layers. It is a further feature of the present invention to dissipate joule heat through the semi-insulating layer that reduces the intrinsic capacitance. It is an object of the present invention to fabricate a high switching speed light emitting device that is not prone to lasing. It is a further feature of the present invention to reduce the ill-effects of joule heating, and the subsequent non-linear light versus current characteristics. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an example of an energy band diagram of a double heterostructure junction with an active layer having a lower band gap than the outer layers. FIG. 2 is a schematic cross sectional view of a conventional ELED with a thyristor blocking layer. FIG. 3 is a cross sectional view of a conventional ELED with a thyristor blocking layer and a light diffusion surface. FIG. 4 is a cross-sectional view of a conventional ELED with a thyristor blocking layer, light diffusion surface and absorption layer. FIGS. 5a-5f show cross sectional views of the present invention based on a buried crescent structure. FIGS. 6a-6f show cross sectional views of the present invention based on a buried mesa heterostructure. FIGS. 7a-7b show an alternative fabrication step. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning to FIGS. 5a through 5d, we see the schematic cross section of the device fabrication of a buried crescent heterostructure ELED preferably employed to fabricate the present invention. The device is fabricated as follows. First we see in FIG. 5a, a substrate 51 which is preferably n-InP wafer that is doped to a degree that it is conductive, for preferably having doping levels of approximately 10 17 to 10 19 cm -3 . A layer of high thermal conductivity semi-insulating material 52 (for example Fe doped InP) is epitaxially grown on the substrate 51 preferably by Metal Oxide Chemical Vapor Deposition (MOCVD), however techniques such as Liquid Phase Epitaxy (LPE), Molecular Beam Epitaxy (MBE) and Chemical Beam Epitaxy (CBE) are also possible techniques. Turning now to FIG. 5b, we see the etched layers of the semi-insulating layer in order to effect the groove structure which advantageously divides the device into first and second regions with attendant advantages. The etching of the semi-insulating layer and the substrate as shown in FIG. 5b is effected preferably by masking with an appropriate mask such as SiO 2 or silicon nitride followed by an wet chemical etchant, however a dry etching method such as Reactive Ion Etching (RIE) is within the purview of the present invention. The epitaxial materials are grown first in a planar structure and then masked with dielectric or photoresist. The mask is patterned and partially removed. The exposed area is then etched by an etchant to leave a groove structure in the semi-insulating layer and substrate. The unetched semi-insulating portion 53 divides the device into a first and second region for discussion purposes. In any event, the grooves 54 are preferably in the dimension of a few microns in depth and a few hundred microns in length. It is critical that in the lateral dimension (the width) the grooves have an arrowhead or v-shape as at 55 to pinch off the active region in the ensuing regrowth. In the longitudinal direction the v-shape of the grooves facilitates the light diffusion as at 56. The desired orientations of the arrowhead 55 and the light diffusion surface 56 are effected by etching to reveal selected crystalline planes of the monocrystalline layers of the semi-insulating and substrate layers. By way of example, by choosing a (001) substrate, a 54.7 degree angle relative to the substrate is achieved with a (111) surface etch of the face 56 in the semi-insulating layer. The orientations described are merely exemplary, and it is clearly understood that other materials with other crystalline orientations are considered within the purview of the skilled artisan. Details of selective crystalline etching are found in U.S. Pat. No. 4,210,923 to North, et al., the disclosure of which is specifically incorporated herein by reference. The buried crescent heterostructure as shown in FIG. 5c is fabricated preferably as follows. The first cladding layer which is preferably of InP is grown by preferably LPE and effects a concave surface in the region of the etched grooves at an increased growth rate over that of convex growth. Accordingly, the LPE is carried out for preferably 10-90 seconds along with the growth of the active/absorption layer of n-InGaAsP in the first and second regions of the device 511 and 512, respectively, to form a concave structure as shown in a single high growth rate step. At this point, the second cladding layer of InP is grown by a long LPE step, generally of a few minutes. This enables relatively planar growth of this layer as is desired. Finally, a cap layer of n-InGaAsP is grown in a relatively fast planar growth step of about 20-30 seconds of LPE to form the planar layer as shown. It is of course possible to have differently doped materials for the differing materials. As the important factor being that the basic physics of an ELED be employed, it is considered within the purview of the skilled artisan to effect a device by differently doped materials as well as different III-V compounds. Finally, turning to FIG. 5d, we see the final version of a preferred embodiment of the instant invention. Partial etching of the cap, second cladding and the semi-insulating layers is carried out for reasons explained herein. The etching is achieved by masking selected regions of the structure with a dielectric or photoresist followed by a wet etch of isotropical etchant. The mask is then removed with a solution of HF, for example. The removal of these layers selectively enables operation of the device with the attendant advantage of preventing current flow to the absorption region. Thereby, any light which is transmitted through the diffusion surface from the active region will be absorbed more readily in this electrically unpumped region. Accordingly, the tendency of the device to lase is suppressed, and the device functions as a high speed ELED. A further preferred embodiment is as shown in FIG. 5d. To be specific, after the selective etching of the cap, second cladding and semi-insulating layers, a double channel 510 is revealed. The channel is etched via photolithographic techniques above described, using a dielectric or photoresist as a mask in the etching of the double channel in the first region 512 of the device and to etch the entire second region 513 of the device, as shown. Note the first and second regions are the imaginary division of the device with the semi-insulating mesa as the division between the first and second regions (this terminology pertains throughout the disclosure with reference to the first and second regions). The double channel could be etched in the first region deeper than in the second region, and thereby to be within about two microns of the active layer. Choosing the channel to be etched to within about two microns of the active layer allows for the heat generated in the active layer to be dissipated through the channel without any appreciable absorption of the optical field of the device as a metal layer (for example) in contact with the active layer would. Since the evanescent optical field tails off exponentially with distance at the semi-insulating layer/active layer interface, by having the channel at about two microns from the active layer, there is no appreciable absorption of the optical field. The heat generated in the active layer could be readily dissipated through the two microns of semi-insulating InP, and readily through a thermally conductive material deposited (described below in connection with FIG. 5e, below) in the channel and across the first region as shown. Turning now to FIG. 5e, we see a deposited metal layer as the heat sink. The metal layer is preferably an alloy of Ti-Pt-Au or Au-Zn-Au for a p-type cap layer. For an n-cap layer it is preferred to use an alloy of AuGe-Ni-Au or Ge-Au-Ni-Au. The layers are deposited by standard plating or evaporation techniques. The heat generated in the active layer is dissipated across the semi-insulating layer and through the thermally conductive layer enabling the device to operate at nearly linear light output versus current input characteristic. This method of heat dissipation is not possible with the structure of the prior art as for example an n-cap, p-n-p-n blocking layer, the thermally conductive layer would short the n-cap and the n blocking layers. Finally, the device as shown in FIG. 5f has no heat dissipating channel and is fabricated above with the steps toward the channel fabrication eliminated. The benefits of such a structure are as described presently. First, this structure minimizes the area of the pn junctions through mesa structure, and has the benefit thereby of reducing the ill-effects of pn junction capacitance. Secondly, the deposition of a semi-insulating layer as the isolating layer serves as well to decrease the capacitance between the p-electrode and the n-electrode, outside the mesa region. The advantage of having a reduction in the overall intrinsic capacitance of the ELED is the great reduction in rise and fall time of the device due to a reduction in the device RC time constant. Reducing the RC time constant increases the switching speed, and in the realm of nearly square-wave digital signals faster rise and fall response times will result in higher frequency devices with greatly enhanced communication bandwidths. This ELED as designed experiences rise and fall times on the order of 0.5 nanoseconds. This rapid switching capability has resulted in a bandwidth of over 700 MHz. Another benefit of the present device design is its capability to dissipate the joule heat generated in operation. Joule heating in conventional light emitting devices results in non-linear light output power versus bias currents. The structure of the present invention has the ability to dissipate heat through two paths. Turning to FIGS. 5 and 6, the layer of semi-insulating InP which has a thermal conductivity of approximately 0.68 watt-cm -1 -K -1 forms one path. The layer 65 has the same thermal expansion coefficient and lattice constant as the n-doped InP substrate, and can thereby be grown to any desired thickness, which has obvious ramifications relative to the degree of electrical isolation as well as the ability of the device to dissipate heat. For example, this could be a layer of Fe-doped InP exhibiting a resistivity in the range 10 6 -10 10 Ohm-cm, however other materials could be used in keeping with the theme and spirit of the invention. The dissipation of heat away from the pn junctions of the mesa structure allows the device to operate at high injection current levels without significant heating of the pn junctions, thereby improving the light output power linearity with respect to bias current. Turning now to FIGS. 6a-6f, we see the fabrication steps of the present invention in a buried mesa heterostructure. There are two methods preferred to fabricate the buried mesa structure device, and each will be discussed separately. Turning first to FIG. 6a, we see the planar layers of substrate 61, first cladding layer 67, active layer 68 and second cladding layer 69 which are preferably deposited by MOCVD, however LPE, MBE or CBE will work. The layers are identical in materials doping types and doping levels as were stated above relative to the buried crescent device. Succinctly, for an InP n-substrate, an n-InP first cladding layer, an InGaAsP active layer and a p-InP second cladding layer, the first cladding layer is doped with S,Si or Sn as described above. The active layer is undoped/unintentionally doped or intentionally doped with Zn which serves to decrease carrier lifetime and increase the bandwidth of the device. Accordingly, bandwidth is increased by decreasing intrinsic capacitance as well as by selective doping of the active layer. However, care must be taken to not dope the active layer too greatly, as light intensity is adversely affected by too high of doping levels. The present invention enables increasing bandwidth even with an undoped/unintentionally doped active layer by virtue of the reduced capacitance. Finally, the second cladding layer is doped p-type with Zn as described above. Turning now to FIG. 6b, we see the etched structure. Etching is effected by photolithography preferably using patterned dielectric to mask the desired regions of the layers. The preferred etchant is HCl, however mixtures of HCl and H 3 PO 4 are also possible. The etching again makes use of the characteristic planes of monocrystalline material, and the light diffusion surfaces are readily effected by etching to reveal the (111) planes. The dielectric is removed by HF solution. Turning now to FIG. 6c, we see the growth of the various layers of the device. The preferred technique is LPE, however, MOCVD,MBE or CBE are also possible. By the very nature of LPE, the growth rate in a concave surface is much faster than in a planar or convex surface, the semi-insulating layer could be grown in the non-mesa region with no growth at the top of the mesa. After the semi-insulating layer is grown to result in a nearly planar wafer, the p-cladding and p-cap layers are grown in planar form thereon. The semi-insulating layer is doped preferably with Co at a concentration of 10 19 /cm 3 . The preferred dopant for the p-cap layer is Zn in concentration of 10 19 /cm 3 . FIGS. 6d and 6e show the etching to effect the double channel heat sink. As the etching and deposition of a thermally conductive layer is identical to the description associated with FIGS. 5d and 5e, it will not be repeated. Turning now to FIGS. 7a and 7b, we see alternative steps to that shown in the fabrication steps shown and described relative to FIG. 6b. Clearly, the same etching is performed in FIG. 7a, with a dielectric layer as a mask in the etching of the mesas. However, instead of removing the dielectric the layer is left on during epitaxial growth of the semi-insulating layer so as to serve as a growth inhibitor. The layer of dielectric is deposited so that after etching, it overhangs the mesas as at 71. This structure will allow epitaxial growth of the semi-insulating layer on the substrate, but will prevent its growth on the second cladding layer. The structure that results is as shown in FIG. 7b. The preferred technique is growth of the semi-insulating layer, preferably Fe-doped InP, by MOCVD, however LPE, MBE and CBE. Also, as described previously, other dopants are possible if not necessary given the desired substrate for a given structure. The doping concentrations are as stated previously. The growth of the semi-insulating layer is grown to planarize the wafer. After the growth of the semi-insulating layer the structure results as is shown in FIG. 7b, and the layer of dielectric layer is removed by HF. The cladding layers, active layer, cap layer are as described previously, and the structure can be further processed to effect the heat sink as described above. Having described the preferred embodiments, it is clear that there are various techniques for fabrication as well as materials and dopants that are considered within the purview of the artisan of ordinary skill. Such variations of the instant teachings contained herein are considered within the theme and spirit of the invention.

Light emitting devices are requiring greater switching speeds to achieve greater modulation bandwidths. The problems of intrinsic capacitance associated with conventional semiconductor heterojunction devices are reduced by the reduction of pn junction capacitance as well as the use of a semi-insulating blocking layer and a conductive substrate. Furthermore, a light absorbing layer is disposed on one side of an unetched portion of the semi-insulating material and an active layer disposed on opposite side. Also, the interface of the semi-insulating material and the active and absorbing layers are at prescribed angles that reduce back reflections to the absorbing and active layers. This arrangement reduces pumping in the absorbing region and thus reduces the lasing effect, allowing for a stable LED. The angle at the interface is determined by having the structure at a predetermined crystallographic direction and having the semi-insulating mesa etched to reveal a predetermined crystalline plane. Finally, in one embodiment of the invention, a channel is etched and filled with thermally conductive material to dissipate heat. This channel, in addition to the heat dissipation effected by the semi-insulating material enables a near linear light output versus current input characteristic for the device.

RELATED APPLICATIONS [0001] This Application claims priority to U.S. provisional Application No. 60/472,192 filed on May 21, 2003. U.S. provisional Application No. 60/472,192 is incorporated by reference as if set forth fully herein. FIELD OF THE INVENTION [0002] The field of the invention generally relates to chemical methods used to produce anthracyclines. More specifically, the field of the invention relates to methods and processes used to produce 4-R-substituted 4-demethoxydaunorubicin having the formula (I) described more fully herein from 4-demethyldaunorubicin. In the case where R=H, the present invention relates to chemical methods and processes used to produce idarubicin from 4-demethyldaunorubicin. BACKGROUND OF THE INVENTION [0003] Anthracyclines form one of the largest families of naturally occurring bioactive compounds. Several members of this family have shown to be clinically effective anti-neoplastic agents. These include, for example, daunorubicin, doxorubicin, idarubicin, epirubicin, pirarubicin, zorubicin, aclarubicin, and carminomycin. For instance, these compounds have shown to be useful in bone marrow transplants, stem cell transplantation, treatment of breast carcinoma, acute lymphocytic and non-lymphocytic leukemia, chronic lymphocytic leukemia, non-Hodgkin's lymphoma, and other solid cancerous tumors. [0004] Currently known methods used to prepare 4-demethoxy-4-R-daunorubicin-type anthracyclines (where R=H the anthracycline is known as idarubicin) are based on coupling of the aglycone (synthesized by any of the known methods) and protected and activated daunosamine in the presence of silver triflate (AgOSO 2 CF 3 ), trimethylsilyltriflate ((CH 3 ) 3 SiOSO 2 CF 3 ), or a mercuric oxide—mercuric bromide system (HgO—HgBr 2 ). For example, it is currently known to synthesize aglycone using either anthracenetetrone or isobenzofurane as the starting substance. Unfortunately, these methods of aglycone synthesis are complicated by the creation of optically active centers at carbons C7 and C9. [0005] An alternative method of synthesis of 4-demethoxydaunorubicin (idarubicin) utilizes daunorubicin aglycone which is prepared by the acidic hydrolysis of daunorubicin starting material. In this method, at the same time daunosamine is synthesized, with chemical modification, the daunosamine can be further used for glycosylation of the modified aglycone. Earlier methods involved the substitution of 4-MeO aglycone substituent for hydrogen, NH 2 , or other chemical groups involved demethylation of daunorubicinone, sulfonation of the resulting 4-demethoxydaunorubicinone and substitution of the 4-ArSO 2 O radical for a 4-ArCH 2 NH with further reduction of the benzyl radical leading to formation of 4-NH 2 − radical. See U.S. Pat. No. 4,085,548 entitled 4-DEMETHOXY-4-AMINO-ANTHRACYCLINES, issued Jan. 15, 1991, to Caruso et al., the disclosure of which is incorporated by reference as if set forth fully herein. Further reductive deamination results in production of 4-demethoxydaunorubicin (idarubicin). See EP Application No. 0328399, published Aug. 16, 1989, the disclosure of which is incorporated by reference as if set forth fully herein. [0006] There also has been described a reductive cross-condensation reaction of 4-demethyl-4-Tf-daunorubicinone on the phosphorous hydride—Pd 0 catalyzing complexes. See U.S. Pat. No. 5,587,495. In these reactions, 4-R substituted daunorubicinones are produced wherein R= [0007] Similarly, reductive carbonylation of 4-Tf-daunorubicinone on the same catalysts described above results in 4-COOR substituted daunorubicinones. See U.S. Pat. No. 5,218,130. When formate is utilized as a ligand, substitution of 4-O-Tf radical for hydrogen takes place resulting in formation of 4-demethoxydaunorubicinone. See U.S. Pat. No. 5,103,029. SUMMARY OF THE INVENTION [0008] The present invention relates to processes used to prepare 4-R-substituted anthracyclines and their corresponding salts of formula (I) shown below from 4-demethyldaunorubicin: [0009] Wherein R is defined as hydrogen, a linear or branched oxy[alkyl, alkenyl or alkynyl] group comprised of one to sixteen carbon atoms, or a complex ester group COOR 1 ′, wherein R 1 ′ is a linear or branched alkyl, alkenyl or alkyne group of up to ten carbon atoms, comprising the steps of: [0010] (1) providing 4-demethyldaunorubicin or a derivative of 4-demethyldaunorubicin of formula (II) [0011] wherein R 1 comprises H, acyl or acyl halide and R 2 comprises H, acyl or acyl halide, carbonate, or Schiff's base [0012] (2) treating the 4-demethyldaunorubicin or the derivative of 4-demethyldaunorubicin of formula (II) with a sulfonylating agent having a chemical formula R 3 —SO 2 —X, wherein R 3 is an alkyl group, an alkyl halide group or an aryl group, X is a halide group or —O—SO 2 —R 3 to form 4-demethyl-4-sulfonyl-daunorubicin having formula (III) [0013] wherein R 3 comprises an alkyl group having from 1 to 4 carbon atoms optionally substituted by one or more halogen atoms or an aryl group optionally substituted by halogen, alkyl, aloxy or nitro, R 1 comprises hydrogen, acyl, or acyl halide, and R 2 comprises hydrogen, acyl, acyl halide, carbonate, or Schiff's base; [0014] (3) reacting the 4-demethyl-4-sulfonyl-daunorubicin of formula (III) with a reducing agent in the presence of catalytic quantities of a compound having formula (IV) ML p L′ q   (IV) [0015] wherein M represent a transition metal atom; L and L′, wherein L and L′ represent the same or different anions or a neutral molecule, and p and q may vary from zero to four, to produce protected 4-demethoxydaunomycin having a formula (V), [0016] (4) hydrolyzing the protected 4-demethoxydaunomycin in a basic solution to produce a 4-R-substituted anthracycline of formula (I). [0017] The present invention uses a novel method of synthesis which lacks the step of forming a stereospecific glycoside bond between aglycone and aminoglycoside. The inventors have found that the novel method of synthesis increases the yield of the final product to up to 30-40% from (II). It thus is an object of the invention to provide a method of synthesis which reduces the number of steps involved to produce 4-R-substituted 4-demethoxydaunorubicin. It is a further object of the invention to provide a method of synthesis which increases the yield of the process. DETAILED DESCRIPTION OF THE INVENTION [0018] The present invention is directed to methods used to prepare 4-R-substituted anthracyclines and their corresponding salts of formula (I) shown below [0019] Formula (I) illustrates a salt of a 4-R-substituted anthracyclines. It should be understood, however, that the present method contemplates the synthesis of 4-R-substituted anthracyclines of formula (I) in both the salt and non-salt forms. With respect to the salt form shown in Formula (I), An − is preferably a anion of a strong acid, for example, hydrochloric or hydrobromic acid. In Formula (I), R may comprise hydrogen (for example, in the case of idarubicin), a linear or branched oxy[alkyl, alkenyl, or alkynyl] group comprised of between one to sixteen carbon atoms. In the case of a linear or branched oxy [alkyl, alkenyl, or alkynyl] group, R preferably has less than or equal to four carbon atoms. [0020] The linear or branched oxy[alkyl, alkenyl, or alkynyl] group may be partially substituted for an aryl group (both unsubstituted and substituted) for any inert group such as, for example, an alkyl group, an alkoxy group, or a nitro group. In addition, the linear or branched oxy group may be partially substituted for an alkoxy group, a trialkylsilyl group, ester group, or amide group. [0021] R may also comprise a complex ester group, COOR 1 ′, where R 1 ′ is a linear or branched alkyl, alkenyl or alkyne group of up to ten carbon atoms. [0022] The synthesis of the 4-R-substituted anthracycline of formula (I) begins by providing a starting compound, preferably 4-demethyldaunorubicin or a derivative of 4-demethyldaunorubicin of formula (II) [0023] wherein R 1 comprises H, acyl or acyl halide and R 2 comprises H, acyl or acyl halide, carbonate, or Schiff's base; (preferably COCF 3 ). [0024] Next, the compound of formula (II) is treated with a sufonylating agent having the chemical formula R 3 —SO 2 —X, where R 3 comprises an alkyl group, alkyl halide group or an aryl group and X comprises a halide or —O—SO 2 —R 3 . The reaction is preferably conducted in pyridine in the presence of sterically hindered tertiary amine, for example, N, N-diisoprolylethylamine, and catalytic quantities of N, N-dimethylaminopyridine. The reaction involves mostly C4-OH. In addition, hydroxyl groups at C6, C11 and C9 react principally in special conditions allowing utilization of unprotected derivatives of the 4-demethyldaunorubicin at these carbon positions. The above steps produce 4-demethyl-4-sulfonyl-daunorubicin having formula (III) [0025] wherein R 3 comprises an alkyl group having one to four carbon atoms optionally substituted by one or more halogen atoms or an aryl group optionally substituted by a halogen group, alkyl group, aloxy group, or nitro group. Preferred groups for R 3 include trifluoromethyl, 4-fluorophenyl, and 4-tolyl. R 1 preferably comprises hydrogen, acyl, or acyl halide. R 2 preferably comprises hydrogen, acyl, acyl halide, carbonate, or Schiff's base (i.e., a compound formed by a condensation reaction between an aromatic amine and an aldehyde or ketone). [0026] The 4-demethyl-4-sulfonyl-daunorubicin of formula (III) us then reacted with a reducing agent in the presence of catalytic quantities (10 4 :1 to 1:1 and preferably 20:1 to 100:1 (in a molar ratio) of a compound having formula (IV) to produce protected 4-demethoxydaunomycin having a formula (V). ML p L′ q   (IV) [0027] wherein M represent a transition metal atom, preferably palladium or nickel. L and L′, which are the same or different molecules, represent the same or different anions or a neutral molecule. Anions for L and L′ include anions such as HCOO − , CH 3 COO − , Cl − . Examples of a neutral molecule include neutral solvent molecules, mono or di-phosphine, phosphate or diamine, and preferably a chelating diphosphine such as 1,3-diphenylphosphinopropane, 1,1′-bis(diphenylphosphino)ferrocene, and 1,2-bis[N-(1-phenylethyl),N-(diphenylphosphino)amino]ethane. In formula (IV), p and q may vary from zero to four. [0028] Preferably, the reducing agent is a formiate anion (e.g., formic acids or salts of formic acid) or unsaturated compound such as CO or substituted alkenyl and alkynyl groups in a reducing environment. [0029] Preferably, the reaction is conducted at temperatures in the range from about 30° C. to about 100° C. in a polar aprotic solvent, preferably in alkylamides in an inert atmosphere. Protected 4-demethoxydaunomycin having a formula (V) is shown below. [0030] The protected 4-demethoxydaunomycin (R 1 or R 2 ≠H) is then hydrolyzed to remove the protecting group in a basic solution to produce 4-R-substituted anthracycline of formula (I). Preferably the basic solution is formed in water or alcohol, preferably water or methanol. [0031] The following examples set forth below illustrate a preferred method of preparing a 4-R-substituted anthracycline (idarubicin) of formula (I) from 4-demethyldaunorubicin. EXAMPLE 1 [0032] a) First, 2 g of 3′-trifluoroacetamido-4-demethyldaunorubicin (R 1 =H, R 2 =trifluoroacetyl) are dissolved in 0.2 L of pyridine. [0033] b) Next, 4 ml of diisopropylethylamine and 0.5 g of 4-dimethylaminopyridine are added to the solution of step (a) of Example 1. [0034] c) Next, the solution in step (b) of Example 1 is chilled to 0° C. and 2.5 ml of freshly distilled trifluoromethanesulfonic anhydride is added. [0035] d) Next, the solution in step (c) of Example 1 is incubated for 1 hour at room temperature. [0036] e) After incubation, 0.15 L of concentrated hydrochloric acid, 0.2 kg of ice, and 0.2 L of dichloromethane is added to the incubated solution. [0037] f) Next, the organic layer is washed in 0.2 L of distilled water and dichloromethane is removed by evaporation at partial vacuum pressure. [0038] g) After evaporation, 1.5 g of 4-trifluoromethanesulfonyl-3′-trifluoroacetamido-4-demethyldaunorubicin is produced with a purity 85% (Confirmed by HPLC). [0039] h) The 4-trifluoromethanesulfonyl-3′-trifluoroacetamido-4-demethyldaunorubicin from step (g) of Example 1 is used in the next synthetic step in Example 2 with or without additional purification. EXAMPLE 2 [0040] a) 1.5 g of 4-trifluoromethanesulfonyl-3′-trifluoroacetamido-4-demethyldaunorubicin (R 1 =H, R 2 =trifluoroacetyl, R 3 =trifluoromethyl), yielded from synthesis in Example 1, is dissolved in 0.1 L of dimethylformamide. [0041] b) While stirring, 2 g of triethylamine formate and 50 mg of palladium acetate are added to the mixture of step (a) in Example 2 and an argon stream is passed through the mixture. [0042] c) The mixture of step (b) of Example 2 is then heated to 50° C. and 200 mg of 1,1′-bis(diphenylphosphino)ferrocene is added. [0043] d) The mixture of step (c) of Example 2 is heated at 50° C. for 8 hours. [0044] e) The mixture of step (d) of Example 2 is then poured into water with intense stirring with resulting sediment formation (4-demethoxy-3′-trifluoroacetamidodaunomycin). [0045] f) The sediment (4-demethoxy-3′-trifluoroacetamidodaunomycin) is filtered, and then purified by preparative chromatography. [0046] g) The yield of this process is 0.8-0.85 g of 4-demethoxy-3′-trifluoroacetamidodaunomycin of 98% purity (Confirmed by HPLC). EXAMPLE 3 [0047] a) 0.85 g of 4-demethoxy-3′-trifluoroacetamidodaunomycin are added to the stirred water solution of 0.1 N NaOH (0.06 L) and incubated at 30° C. for 30 minutes. The color of the solution turns deep blue-violet. [0048] b) The reactive mixture is then poured with intense stirring into 0.5 L of 10-12% chloroform-in-butanol solution heated to 40° C. [0049] c) Next, while intensely stirring, hydrochloric acid (1:3) is added to the mixture to titrate to a pH of 8.8-9.0. [0050] d) The resulting organic layer is then washed in distilled water. [0051] e) 0.1 L of distilled water is then added to washed organic layer in step (d) of Example 3, and 0.8 N hydrochloric acid is added (0.1 L) to titrate to a pH of 3.5. [0052] f) The solution in step (e) in Example 3 is intensely stirred, and the water layer containing 4-demethoxydaunomycin hydrochloride (idarubicin) is separated. [0053] g) The solution of idarubicin hydrochloride is evaporated to 50% of its original volume and was subjected to chromatographic purification. [0054] h) The eluate was subjected to evaporation and crystallization using hydrophilic solvents, preferably low-molecular-weight aliphatic alcohols. [0055] i) The yield of this process is 0.6 g of 4-demethoxydaunomycin hydrochloride (idarubicin hydrochloride) of 99% purity (Confirmed by HPLC). [0056] While embodiments of the present invention have been shown and described, various modifications may be made without departing from the scope of the present invention. The invention, therefore, should not be limited, except to the following claims, and their equivalents.

A method of synthesizing 4-R-substituted anthracyclines and their corresponding salts from 4-demethyldaunorubicin includes the steps of treating 4-demethyldaunorubicin with a sulfonylating agent to form 4-demethyl-4-sulfonyl-R 3 -daunorubicin. 4-Demethyl-4-R 3 -sulfonyl-daunorubicin is then subject to a reducing agent in the presence of a transition metal catalyst in a temperature range of about 30° C. to about 100° C. in a polar aprotic solvent in an inert atmosphere. Protected 4-demethoxy-4-R-daunomycin then undergoes hydrolysis in a basic solution to form the 4-R-substituted anthracyclines. The novel method lacks the step of forming a stereospecific glycoside bond between aglycone and aminoglycoside. The method also increases the yield of the final product up to 30 to 40%.

BACKGROUND OF THE INVENTION (1) Field of the Invention The present invention relates to chemiluminescent 1,2-dioxetane compounds that can be triggered by reagents including enzymes and other chemicals to generate light. In particular, the present invention relates to stable aryl group-substituted 1,2-dioxetanes that contain a triggerable X-oxy group (OX) which is a substituent of the aryl group, in which the stable 1,2-dioxetane forms an unstable dioxetane compound by removal of X, which decomposes to produce light and two carbonyl compounds. (2) Description of Related Art a. Preparation of 1,2-Dioxetanes. Kopecky and Mumford reported the first synthesis of a dioxetane (3,3,4-trimethyl-1,2-dioxetane by the base-catalyzed cyclization of a β-bromohydroperoxide, which, in turn, is prepared from the corresponding alkene (K. R. Kopecky and C. Mumford, Can. J. Chem., 47, 709 (1969)). Although this method has been used to produce a variety of alkyl and aryl-substituted 1,2-dioxetanes, it can not be used for the preparation of dioxetanes derived from vinyl ethers, vinyl sulfides and enamines. An alternate synthetic route to 1,2-dioxetanes, especially those derived from vinyl ethers, vinyl sulfides and enamines was independently reported by Bartlett and Schaap (P. D. Bartlett and A. P. Schaap, J. Am. Chem. Soc., 92, 3223 (1970)) and Mazur and Foote (S. Mazur and C. S. Foote, J. Am. Chem. Soc., 92, 3225 (1970)). Photochemical addition of a molecule of oxygen to the appropriate alkene compound in the presence of a photosensitizer produces 1,2-dioxetanes in high yield. This method has been used to produce a large number of dioxetane compounds (K. R. Kopecky in Chemical and Biological Generation of Excited States, W. Adam and G. Cilento, (Eds.), Academic Press, New York, p. 85, 1982). Two limitations of this method have been reported. Certain alkenes with aromatic substituents were found to produce six membered ring peroxides known as endoperoxides on photooxygenation (A. P. Schaap, P. A. Burns and K. A. Zaklika, J. Am. Chem. Soc., 99, 1270 (1977)). Alkenes with reactive allylic hydrogens frequently undergo an alternate reaction, the "ene" reaction, producing an allylic hydroperoxide instead of a dioxetane (A. Baumstark in Advances In Oxygenated Processes, JAI Press, Greenwich, Conn., 1988; Vol.1, pp 31-84). b. Thermally Stable Dioxetanes from Sterically Hindered Alkenes. The dioxetane derived from the hindered alkene adamantylideneadamantane which was discovered by Wynberg (J. H. Wieringa, J. Strating, H. Wynberg and W. Adam, Tetrahedron Lett., 169 (1972) was shown to have an activation energy for decomposition of 37 kcal/mol and a half life (t 1/2 ) at 25° C. of several years (N. J. Turro, G. Schuster, H. C. Steinmetzer, G. R. Faler and A. P. Schaap, J. Amer. Chem. Soc., 97, 7110 (1975)). Others have shown that a spiro-fused polycyclic group such as the adamantyl group can help to increase the stability of dioxetanes derived from amino-substituted alkenes (F. McCapra, I. Beheshti, A. Burford, R. A. Hann and K. A. Zaklika, J. Chem. Soc., Chem. Comm., 944 (1977)), vinyl ethers (W. Adam, L. A. Encarnacion and K. Zinner, Chem. Ber., 116, 839 (1983)) and vinyl sulfides (G. G. Geller, C. S. Foote and D. B. Pechman, Tetrahedron Lett., 673 (1983); W. Adam, L. A. Arias and D. Schuetzow, Tetrahedron Lett., 2835 (1982)) which would be unstable without this group. c. Chemical Triggering of Dioxetanes. The first example in the literature is described in relation to the hydroxy-substituted dioxetane derived from the 2,3-diaryl-1,4-dioxene (A. P. Schaap and S. Gagnon, J. Amer. Chem. Soc., 104, 3504 (1982)). However, the hydroxy-substituted dioxetane and any other examples of the dioxetanes derived from the diaryl-1,4-dioxenes are relatively unstable having half-lives at 25° C. of only a few hours. Further, these non-stabilized dioxetanes are destroyed by small quantities of amines (T. Wilson, Int. Rev. Sci.: Chem., Ser. Two, 9, 265 (1976)) and metal ions (T. Wilson, M. E. Landis, A. L. Baumstark, and P. D. Bartlett, J. Amer. Chem. Soc., 95, 4765 (1973); P. D. Bartlett, A. L. Baumstark, and M. E. Landis, J. Amer. Chem. Soc., 96, 5557 (1974)), both components used in the aqueous buffers for biological assays. Examples of the chemical triggering of adamantyl-stabilized dioxetanes were first reported in U.S. patent application (A. P. Schaap, patent application Ser. No. 887,139, filed Jul. 17, 1986) and a paper (A. P. Schaap, T. S. Chen, R. S. Handley, R. DeSilva, and B. P. Giri, Tetrahedron Lett., 1155 (1987)). These dioxetanes exhibit thermal half-lives of years but can be triggered to produce efficient chemiluminescence on demand. Moderately stable benzofuranyl dioxetanes substituted with trialkylsilyl and acetyl-protected phenolic groups which produce weak chemiluminescence have also been reported (W. Adam, R. Fell, M. H. Schulz, Tetrahedron, 49(11), 2227-38 (1993); W. Adam, M. H. Schulz, Chem. Ber., 125, 2455-61 (1992)). The stabilizing effect of other rigid polycyclic groups has also been reported (P. D. Bartlett and M. Ho, J. Am. Chem. Soc., 96, 627 (1975); P. Lechtken, Chem. Ber., 109, 2862 (1976)). A PCT application, WO 94/10258 discloses chemical triggering of dioxetanes bearing various rigid polycyclic substituents. d. Enzymatic Triggering of Adamantyl Dioxetanes. Dioxetanes which can be triggered by an enzyme to undergo chemiluminescent decomposition are disclosed in U.S. patent application (A. P. Schaap, patent application Ser. No. 887,139) and a series of papers (A. P. Schaap, R. S. Handley, and B. P. Giri, Tetrahedron Lett., 935 (1987); A. P. Schaap, M. D. Sandison, and R. S. Handley, Tetrahedron Lett., 1159 (1987) and A. P. Schaap, Photochem. Photobiol., 47S, 50S (1988)). The highly stable adamantyl-substituted dioxetanes bearing a protected aryloxide substituent are triggered to decompose with emission of light by the action of an enzyme in an aqueous buffer to give a strongly electron-donating aryloxide anion which dramatically increases the rate of decomposition of the dioxetane. As a result, chemiluminescence is emitted at intensities several orders of magnitude above that resulting from slow thermal decomposition of the protected form of the dioxetane. U.S. Pat. No. 5,068,339 to Schaap discloses enzymatically triggerable dioxetanes with covalently linked fluorescer groups. Decomposition of these dioxetanes results in enhanced and red-shifted chemiluminescence through intramolecular energy transfer to the fluorescer. U.S. Pat. No. 4,952,707 to Edwards discloses enzymatically triggerable dioxetanes bearing an adamantyl group and 2,5- or 2,7-disubstituted naphthyl groups. U.S. Pat. Nos. 5,112,960, 5,220,005, 5,326,882 and a PCT application (88 00695) to Bronstein disclose triggerable dioxetanes bearing adamantyl groups substituted with various groups including chlorine, bromine carboxyl, hydroxyl, methoxy and methylene groups. A publication (M. Ryan, J. C. Huang, O. H. Griffith, J. F. Keana, J. J. Volwerk, Anal. Biochem., 214(2), 548-56 (1993)) discloses a phosphodiester-substituted dioxetane which is triggered by the enzyme phospholipase. U.S. Pat. No. 5,132,204 to Urdea discloses dioxetanes which require two different enzymes to sequentially remove two linked protecting groups in order to trigger the chemiluminescent decomposition. U.S. Pat. No. 5,248,618 to Haces discloses dioxetanes which are enzymatically or chemically triggered to unmask a first protecting group generating an intermediate which spontaneously undergoes an intramolecular reaction to split off a second protecting group in order to trigger the chemiluminescent decomposition. e. Enhanced Chemiluminescence from Dioxetanes in the Presence of Surfactants. Enhancement of chemiluminescence from the enzyme-triggered decomposition of a stable 1,2-dioxetane in the presence of water-soluble substances including an ammonium surfactant and a fluorescer has been reported (A. P. Schaap, H. Akhavan and L. J. Romano, Clin. Chem., 35(9), 1863 (1989)). Fluorescent micelles consisting of cetyltrimethylammonium bromide (CTAB) and 5-(N-tetradecanoyl)aminofluorescein capture the intermediate hydroxy-substituted dioxetane and lead to a 400-fold increase in the chemiluminescence quantum yield by virtue of an efficient transfer of energy from the anionic form of the excited state ester to the fluorescein compound within the hydrophobic environment of the micelle. U.S. Pat. Nos. 4,959,182 and 5,004,565 to Schaap describe additional examples of enhancement of chemiluminescence from chemical and enzymatic triggering of stable dioxetanes in the presence of the quaternary ammonium surfactant CTAB and fluorescers. Fluorescent micelles formed from CTAB and either the fluorescein surfactant described above or 1-hexadecyl-6-hydroxybenzothiazamide enhance chemiluminescence from the base-triggered decomposition of hydroxy- and acetoxy-substituted dioxetanes. It was also reported that CTAB itself can enhance the chemiluminescence of a phosphate-substituted dioxetane. U.S. Pat. No. 5,145,772 to Voyta discloses enhancement of enzymatically generated chemiluminescence from 1,2-dioxetanes in the presence of polymers with pendant quaternary ammonium groups alone or admixed with fluorescein. Other substances reported to enhance chemiluminescence include globular proteins such as bovine albumin and quaternary ammonium surfactants. Other cationic polymer compounds were of modest effectiveness as chemiluminescence enhancers; nonionic polymeric compounds were generally ineffective and the only anionic polymer significantly decreased light emission. A PCT application WO 94/21821 discloses enhancement from the combination of a polymeric ammonium salt surfactant and an enhancement additive. European Patent Application No. 92113448.2 to Akhavan-Tafti published on Sep. 22, 1993 discloses enhancement of enzymatically generated chemiluminescence from 1,2-dioxetanes in the presence of polyvinyl phosphonium salts and polyvinyl phosphonium salts to which fluorescent energy acceptors are covalently attached. Co-pending application U.S. Ser. No. 08/082,091 to Akhavan-Tafti filed Jun. 24, 1993 discloses enhancement of enzymatically generated chemiluminescence from 1,2-dioxetanes in the presence of dicationic phosphonium salts. Triggerable stabilized dioxetanes known in the art incorporate a rigid spiro-fused polycyclic substituent or a substituted spiroadamantyl substituent. The ketone starting materials from which these dioxetanes are prepared are relatively expensive and are of limited availability or must be prepared from costly precursors. No examples of stable triggerable dioxetanes bearing two alkyl groups in place of rigid spirofused polycyclic organic groups are known. Such triggerable stabilized dioxetanes can be prepared from inexpensive, readily available starting materials and will therefore provide cost advantages facilitating their commercial potential. OBJECTS It is an object of the present invention to provide novel dialkyl and aryl OX-substituted triggerable 1,2-dioxetane compounds which are stable at room temperature over an extended period of time. It is also an object of the present invention to provide such stable 1,2-dioxetane compounds which can be triggered to decompose with the generation of chemiluminescence. It is also an object of the present invention to provide such stable 1,2-dioxetane compounds which can be prepared from inexpensive, readily available starting materials. It is an object of the present invention to provide a method and compositions containing a stable 1,2-dioxetane which can be triggered by reagents, including enzymes and other chemicals, to generate chemiluminescence. Further, it is an object of the present invention to provide a method and compositions for additionally enhancing the chemiluminescence through the use of enhancer substances. Further the present invention relates to a method and compositions for the detection of enzymes, and for use in immunoassays and the detection of enzyme-linked nucleic acids, antibodies and antigens such as are generally known in the art. Further, it is an object of the present invention to provide a method and compositions for chemical lighting applications. IN THE DRAWINGS FIG. 1 is a spectrum of the chemiluminescence emitted from a solution of dioxetane 2c in dimethyl sulfoxide (DMSO) when triggered by addition of a solution of potassium hydroxide in a mixture of methanol and dimethyl sulfoxide. The spectrum is corrected for the decay in chemiluminescence intensity occurring during the scan. FIG. 2 is a graph of chemiluminescence intensity as a function of time produced by triggering a 10 μL aliquot of a 10 -6 M solution of dioxetane 2g with 50 μL of 1M tetra-n-butylammonium fluoride in DMSO. FIG. 3 is a graph showing a comparison of the time profile of the chemiluminescence intensity emitted by 100 μL of solutions containing either dioxetane 2f of the present invention or 2k (LUMIGEN PPD, Lumigen, Inc., Southfield, Mich.) triggered at 37° C. by addition of 1.12×10 -17 mol of AP. The reagents consist of 1) a 0.33 mM solution of dioxetane 2f in 0.2M 2-amino-2-methyl-1-propanol buffer, pH 9.6, and 2) a 0.33 mM solution of dioxetane 2k in 0.2M 2-amino-2-methyl-1-propanol buffer, pH 9.6. Use of dioxetane 2f of the present invention advantageously achieves a higher maximum intensity compared to dioxetane 2k. FIG. 4 is a graph showing a comparison of the time profile of the chemiluminescence intensity emitted by 100 μL of solutions containing either dioxetane 2f or 2k triggered at 37° C. by addition of 1.12×10 -17 mol of AP. The reagents consist of 1) a 0.33 mM solution of dioxetane 2f in 0.2M 2-amino-2-methyl-1-propanol buffer, pH 9.6 containing 1.0 mg/mL of the enhancer 1-(tri-n-octylphosphoniummethyl)-4-(tri-n-butylphosphoniummethyl)benzene dichloride (Enhancer A), and 2) a 0.33 mM solution of dioxetane 2k in 0.2M 2-amino-2-methyl-1-propanol buffer, pH 9.6 containing 1.0 mg/mL of the same enhancer. Use of dioxetane 2f of the present invention advantageously achieves higher light intensities at all time points compared to dioxetane 2k. FIG. 5 is a graph showing a comparison of the time profile of the chemiluminescence intensity emitted by 100 μL of another pair of solutions containing either dioxetane 2f or 2k triggered at 37° C. by addition of 1.12×10 -17 mol of AP. The reagents consist of 1) a 0.33 mM solution of dioxetane 2f in 0.2M 2-amino-2-methyl-1-propanol buffer, pH 9.6 containing 0.5 mg/mL of polyvinylbenzyltributylphosphonium chloride (Enhancer B) and 2) a 0.33 mM solution of dioxetane 2k in 0.2M 2-amino-2-methyl-1-propanol buffer, pH 9.6 containing 0.5 mg/mL of the same enhancer. The preparation of Enhancer B is described in European Patent Application 561,033 published Sep. 22, 1993. Use of dioxetane 2f of the present invention advantageously achieves higher light intensities at all time points compared to dioxetane 2k. FIG. 6 is a graph showing a comparison of the time profile of the chemiluminescence intensity emitted by 100 μL of another pair of solutions containing either dioxetane 2f or 2k triggered at 37° C. by addition of 1.12×10 -17 mol of AP. The reagents consist of 1) a 0.33 mM solution of dioxetane 2f in 0.2M 2-amino-2-methyl-1-propanol buffer, pH 9.6 containing 0.5 mg/mL of polyvinylbenzyltributylphosphonium chloride co-polyvinylbenzyltrioctylphosphonium chloride (containing a 3:1 ratio of tributyl:trioctyl groups) (Enhancer C) and 2) a 0.33 mM solution of dioxetane 2k in 0.2M 2-amino-2-methyl-1-propanol buffer, pH 9.6 containing 0.5 mg/mL of the same enhancer. The preparation of Enhancer C is described in European Patent Application 561,033. Use of dioxetane 2f of the present invention advantageously achieves higher light intensities at all time points compared to dioxetane 2k. FIG. 7 is a graph relating the maximum chemiluminescence intensity emitted by 100 μL of a reagent containing dioxetane 2f triggered at 37° C. to the amount of AP. Chemiluminescence emission was initiated at 37° C. by addition of 3 μL of solutions of AP containing between 3.36×10 -16 mol and 3.36×10 -22 of enzyme to 100 μL of a 0.33 mM solution of dioxetane 2f in 2-amino-2-methyl-1-propanol buffer, 0.2M (pH 9.6) containing 1.0 mg/mL of Enhancer A. The term S-B refers to the chemiluminescence signal (S) in Relative Light Units (RLU) in the presence of AP corrected for background chemiluminescence (B) in the absence of AP. The graph shows the linear detection of alkaline phosphatase. The calculated detection limit (twice the standard deviation of the background) was determined to be 1.4×10 -22 mol or less than 100 molecules of alkaline phosphatase under these conditions. FIG. 8 is a digitally scanned image of an X-ray film from an experiment detecting alkaline phosphatase on a membrane with chemiluminescence. Solutions of alkaline phosphatase in water containing from 1.1×10 -15 to 1.1×10 -18 mol were applied to identical nylon membranes (Micron Separations Inc., Westboro, Mass.). The membranes were air dried for 5 min and soaked briefly with a reagent containing 1 mg/mL of Enhancer A in 0.2M 2-amino-2-methyl-1-propanol buffer, pH 9.6 containing 0.88 mM MgCl and either 0.33 mM dioxetane 2f or 0.33 mM dioxetane 2k. The membrane was placed between transparent plastic sheets and exposed to x-ray film (Kodak X-OMAT AR, Rochester, N.Y.). In a comparison of the two reagents, the light produced using dioxetane 2f of the present invention led equivalent images and detection sensitivity. These results illustrate the performance of dioxetane 2f which is to be expected in Western blotting, Southern blotting, DNA fingerprinting and other blotting applications. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to compositions containing a stable 1,2-dioxetane which can be triggered by reagents, including enzymes and other chemicals, to generate chemiluminescence. Stable dioxetanes useful in practicing the present invention may be of the formula: ##STR1## wherein R 3 and R 4 are nonspirofused organic groups, wherein R 1 is an organic group which may be combined with R 2 and wherein R 2 represents an aryl group substituted with an X-oxy group which forms an unstable oxide intermediate dioxetane compound when triggered to remove a chemically labile group X by a reagent, including enzymes and other chemicals. The unstable oxide intermediate dioxetane decomposes and releases electronic energy to form light and two carbonyl containing compounds of the formula ##STR2## A preferred method of practicing the present invention uses a stable dioxetane of the formula: ##STR3## wherein R 1 is selected from alkyl, cycloalkyl and aryl groups containing 1 to 12 carbon atoms which may additionally contain heteroatoms, R 3 and R 4 are selected from branched chain alkyl and cycloalkyl groups containing 3 to 8 carbon atoms and may additionally contain heteroatoms and which provide thermal stability, and wherein R 2 is selected from aryl, biaryl, heteroaryl, fused ring polycyclic aryl or heteroaryl groups which can be substituted or unsubstituted and wherein OX is an X-oxy group which forms an unstable oxide intermediate dioxetane compound when triggered to remove a chemically labile group X by a reagent including enzymes and other chemicals. The stable 1,2-dioxetane compounds have relatively long half-lives at room temperature (20°-30° C.) even though they can be triggered by chemical reagents. Previous examples of stable, triggerable 1,2-dioxetanes all made use of rigid spiro-fused polycyclic alkyl groups such as adamantyl and substituted adamantyl to confer thermal stability. It has now been discovered that 1,2-dioxetanes bearing a wider range of substituents corresponding to R 3 and R 4 in the structure above also exhibit substantial thermal stability at room temperature. Dioxetane compounds substituted with alkyl groups containing as few as 3 carbons (as substituents R 3 and R 4 in the structure above) have half-lives of approximately one year at room temperature and several years at 4° C. R 3 and R 4 groups whose carbon atom attached to the dioxetane ring carbon is substituted with zero or one hydrogen atoms (e.g. isopropyl, sec-butyl, t-butyl, cycloalkyl) provide enough thermal stability to the dioxetane compounds to render them useful for practical applications. R 3 and R 4 groups which are linked to the dioxetane ring through a CH 2 group but which are otherwise bulky, for example a neo-pentyl group, are considered to be within the scope of the invention. Further, these dioxetanes can be triggered by the removal of an X group to decompose with emission of light. The degree of rate enhancement upon triggering depends on such factors as the lability of the X group, the amount of the triggering reagent, choice of solvent, pH and temperature. By selecting appropriate conditions, a factor of 10 6 or greater rate enhancement can be achieved. The present invention relates to a process using readily available or inexpensive starting materials for preparing a stable 1,2-dioxetane of the formula: ##STR4## wherein R 3 and R 4 are nonspirofused organic groups, wherein R 1 is an organic group which may be combined with R 2 and wherein R 2 represents an aryl group substituted with an X-oxy group by addition of oxygen to the appropriate alkene. An unexpected finding of the present invention is that the alkenes reported here readily undergo photochemical addition of a molecule of oxygen (as singlet oxygen 1 O 2 ) to produce the corresponding 1,2-dioxetane. It is well known in the literature that alkenes bearing allylic hydrogens may preferentially undergo addition of singlet oxygen by a different reaction path to produce an allylic hydro-peroxide, dioxetane formation is a minor process at most. ##STR5## The requisite alkene compounds are synthesized through coupling arylcarboylate esters substituted with an X-oxy group and dialkyl ketones of the formula shown below: ##STR6## in the presence of lithium aluminum hydride, other metal hydride, zinc metal or zinc-copper couple in a polar aprotic organic solvent, preferably tetrahydrofuran, with a transition metal halide salt, preferably a titanium chloride compound, and a tertiary amine base. The reaction is generally conducted in refluxing tetrahydrofuran and usually goes to completion in about 2 to 24 hours. A significant advantage of the present process is the ability to conduct the reaction on a large scale due to the availability of the ketone starting materials in large quantity. Triggerable dioxetanes in commercial use are prepared from adamantanone or a substituted adamantanone compound. Adamantanone is relatively costly. Substituted adamantanones are even more expensive and of more limited supply. In comparison to the preparation of adamantanone, which involves a laborious procedure involving large quantities of dangerous oxidizing materials, alkyl and cycloalkyl ketones are readily prepared in large quantities by standard techniques. Another advantage is the reduced cost of certain of the ketone starting materials. Diisopropyl ketone, for example, is between 15 and 20 times less expensive than adamantanone on a molar basis. The triggering reagent may be a chemical which requires 1 equivalent (F-) or a catalyst such as an enzyme wherein only a small amount is used. Electron donors, organic and inorganic bases, nucleophilic reagents and reducing agents can be used to remove X. The triggering reagent may also be an enzyme selected from but not limited to phosphatase enzymes, esterase enzymes, cholinesterase enzymes, hydrolytic enzymes such as α- and β-galactosidase, α- and β-glucosidase, glucuronidase, trypsin and chymotrypsin. The OX group may include, without limitation, hydroxyl, OOCR 6 wherein R 6 is an alkyl or aryl group containing 2 to 20 carbon atoms either of which may contain heteroatoms, trialkylsilyloxy, triarylsilyloxy, aryldialkylsilyloxy, OPO 3 -2 salt, OSO 3 - salt, β-D-galactosidoxy and β-D-glucuronidyloxy groups. The present invention relates to a method for generating light which comprises providing a chemical reagent and a stable 1,2-dioxetane of the formula: ##STR7## wherein R 3 and R 4 are organic groups which are selected from lower alkyl or cycloalkyl containing 3 to 8 carbon atoms and which provide thermal stability, wherein R 1 is an organic group which may be combined with R 2 and wherein R 2 represents an aryl group substituted with an X-oxy group which forms an unstable oxide intermediate dioxetane compound when triggered to remove a chemically labile group X by a reagent including enzymes and other chemicals wherein the unstable oxide intermediate dioxetane decomposes and releases electronic energy to form light and two carbonyl containing compounds of the formula: ##STR8## The present invention also relates to a method for detecting triggering reagents selected from chemical reagents including enzymes. In this instance the dioxetane is used as the reagent. Further the present invention relates to a method and compositions for the detection of enzymes, in immunoassays, e.g. ELISA and the detection of enzyme-linked DNA or RNA probes. Detection of the light emitted may be readily performed using a luminometer, X-ray film or with a camera and photographic film. EXAMPLES Nuclear magnetic resonance (NMR) spectra were obtained on a GE QE300 or a Varian Gemini 300 spectrometer as solutions in CDCl 3 with tetramethylsilane as internal standard or as solutions in CD 3 OD or D 2 O. Mass spectra were obtained on an AEI MS-90™ spectrometer. EXAMPLE 1. Synthesis of 1-(3-t-Butyldimethylsilyloxyphenyl)-2,2-diisopropyl-1-methoxyethene (1a). ##STR9## A three neck flask was purged with argon and charged with 100 mL of anhydrous tetrahydrofuran (THF). The flask was cooled in an ice bath and titanium trichloride (18 g) was added with stirring. Lithium aluminum hydride (2.2 g) was added in small portions causing a brief exothermic reaction. After all of the lithium aluminum hydride was added the cooling bath was removed and triethylamine (16 ml) was added. The black mixture was refluxed for one hour under argon. A solution of 2,4-dimethyl-3-propanone (3.86 g) and methyl 3-t-butyl-dimethylsilyloxybenzoate (3.00 g) in 10 mL of dry THF was added dropwise over 2 hours. Reaction progress was monitored by TLC on silica plates eluting with 4% ethyl acetate/hexane. The crude reaction mixture was cooled to room temperature and diluted with hexane and decanted. The residue was washed several times using a total of ca. 700 mL of hexane. The combined hexane solutions were filtered and evaporated leaving an oil which was purified by column chromatography on silica gel, eluting with hexane yielding 2.12 g (54%) of 1a: 1 H NMR (CDCl 3 ) δ 7.3-6.7 (m, 4H), 3.18 (s, 3H), 2.45 (sept, 1H, J=7.2 Hz), 2.31 (sept, 1H, J=7.2 Hz), 1.24 (d, 6H, J=7.2 Hz), 0.99 (s, 3H), 0.91 (d, 6H, J=7.2 Hz), 0.19 (s, 3H); 13 C NMR (CDCl 3 ) δ 128.76, 122.84, 121.46, 119.28, 56.06, 30.32, 26.54, 25.56, 21.91, 20.86, -4.58; Mass spectrum (m/z): 348, 333, 306; exact mass, cald'd. 348.2484, found 348.2479. EXAMPLE 2. Synthesis of 2,2-Diisopropyl-1-(3-hydroxyphenyl)-1-methoxyethene (1b). ##STR10## To a solution of 0.97 g (2.78 mmol) of alkene 1a in 30 ml of dry THF was added 0.81 g (1.1 eq.) of tetra-n-butylammonium fluoride. After stirring for one hour TLC (silica, 20% ethyl acetate/hexane) showed complete conversion of starting material to a new compound. The THF was evaporated and the residue dissolved in ethyl acetate. The ethyl acetate solution was extracted four times with water and dried. Silica gel (2 g) was added and the solvent evaporated. The material was purified by column chromatography on silica gel, eluting with 10-20% ethyl acetate/hexane yielding 0.568 g (87%) of 1b: 1 H NMR (CDCl 3 ) δ 7.5-6.5 (m, 4H), 4.91 (s, 1H), 3.20 (s, 3H), 2.47 (sept, 1H), 2.33 (sept, 1H), 1.25 (d, 6H), 0.92 (d, 6H); 13 C NMR (CDCl 3 ) δ 129.25, 124.98, 122.60, 116.54, 114.98, 114.56, 56.38, 30.52, 26.80, 22.11, 21.08; Mass spectrum (m/z): 234, 219, 191; exact mass, cald'd. 234.1620, found 234.1620. EXAMPLE 3. Synthesis of 1-(3-Acetoxyphenyl)-2,2-diisopropyl-1-methoxyethene (1c). ##STR11## Alkene 1b (200 mg, 0.85 mmol) was dissolved in 20 mL of dry methylene chloride with 0.31mL of anhydrous pyridine. The flask was purged with argon and cooled in an ice bath. Acetyl chloride (0.115 g, 1.47 mmol) in 5 mL of dry methylene chloride was added dropwise over one hour. TLC analysis (silica, 20% ethyl acetate/hexane) indicated the reaction to be complete after 2.5 hours of stirring at 0° C. The solvents were evaporated and the residue dissolved in ethyl acetate. The solution was washed four times with water, dried over MgSO 4 and evaporated. The residue was purified by column chromatography on silica gel, eluting with 10-20% ethyl acetate/hexane yielding 220 mg (93%) of 1c: 1 H NMR (CDCl 3 ) δ 7.37-6.99 (m, 4H), 3.19 (s, 3H), 2.47 (sept, 1H, J=6.9 Hz), 2.33 (sept, 1H, J=6.9 Hz), 2.29 (s, 3H), 1.24 (d, 6 H, J=6.9 Hz), 0.93 (d, 6 H, J=6.9 Hz); 13 C NMR (CDCl 3 ) δ 169.46, 150.62, 149.03, 139.02, 133.64, 128.95, 127.24, 122.89, 120.72, 56.50, 30.49, 26.98, 22.06, 21.25, 21.05. EXAMPLE 4. Synthesis of 1-(3-Benzoyloxyphenyl)-2,2-diisopropyl-1-methoxyethene (1d). ##STR12## Alkene 1b (4.5 g, 1.9 mmol) was dissolved in 50 mL of dry CH 2 Cl 2 with 5.3 mL of anhydrous triethylamine. The flask was purged with argon and cooled in an ice bath. Benzoyl chloride (4.05 g, 2.9 mmol) was added dropwise. The cooling bath was removed and stirring continued for 1 hour at room temperature. The mixture was filtered and the solution was washed with water, dried over MgSO 4 and evaporated. The residue was suspended in hexane, the solid filtered away and the solution evaporated. The residue was purified by column chromatography on silica gel, eluting with 1% ethyl acetate in hexane yielding 3.7 g of dioxetane 1d: 1 H NMR (CDCl 3 ) δ 8.25-7.05 (m, 9H), 3.25 (s, 1H), 2.54 (sept, 1H, J=6.9 Hz), 2.40 (sept, 1H, J=6.9 Hz), 2.29 (s, 3H), 1.26 (d, 6 H, J=6.9 Hz), 0.95 (d, 6 H, J=6.9 Hz). EXAMPLE 5. Synthesis of 1-(3-Pivaloyloxyphenyl)-2,2-diisopropyl-1-methoxyethene (1e). ##STR13## Alkene 1b (2 g, 8.6 mmol) was dissolved in 50 mL of dry CH 2 Cl 2 with 2.4 mL of anhydrous triethylamine. The flask was purged with argon and cooled in an ice bath. Pivaloyl chloride (1.6 g, 2 eq.) was added dropwise over one hour. The cooling bath was removed and stirring continued for 3 hours at room temperature. The solution was washed with aq. K 2 CO 3 and then water, dried over MgSO 4 and evaporated. The residue was purified by column chromatography on silica gel, eluting with 5% triethylamine in hexane yielding 1.95 g of dioxetane 1e: 1 H NMR (CDCl 3 ) δ 7.34-6.98 (m, 4H), 3.198 (s, 3H), 2.47 (sept, 1H), 2.33 (sept, 1H), 1.36 (s, 9H), 1.24 (d, 6 H, J=6.9 Hz), 0.92 (d, 6 H, J=6.9 Hz). EXAMPLE 6. Synthesis of 2,2-Diisopropyl-1-methoxy-1 (3-phosphoryloxyphenyl)ethene, disodium salt (1f). ##STR14## (a) A solution of 9 mL of dry CH 2 Cl 2 and 0.7 mL of anhydrous pyridine (8.7 mmol) was purged with argon and cooled in an ice bath. Phosphorus oxychloride (0.40 g, 2.6 mmol) was added followed after 5 min by a solution of alkene 1b (209 mg, 0.87 mmol) in 0.4 mL of pyridine. The solution was stirred at room temperature for 1 hour. TLC analysis (silica, 30% ethyl acetate/hexane) indicated the reaction to be complete. The solvents were evaporated and the residue taken on to the nest step. (b) The product from step (a) was dissolved in CH 2 Cl 2 and 0.7 mL of pyridine added. The solution was cooled in an ice bath and treated with 618 mg of 2-cyanoethanol (8.7 mmol). The ice bath was removed and stirring continued at room temperature for two hours. The mixture was then concentrated and the residue was purified by column chromatography on silica gel, eluting with a gradient of 50% ethyl acetate in hexane to 100% ethyl acetate yielding of the bis(cyanoethyl phosphate) 1 H NMR (CDCl 3 ) δ 0.934 (d, 6H, J=9 Hz), 1.235 (d, 6H, J=9 Hz), 2.28-2.45 (m, 2H), 2.76-2.82 (m, 4H), 3.18 (s, 1H), 4.31-4.47 (m, 4H), 7.11-7.38 (m, 4H). (c) The bis(cyanoethyl phosphate) alkene (420 mg) was dissolved in 4 mL of acetone. Sodium hydroxide (65 mg) was dissolved in 1 mL of water and added to the acetone solution which was then stirred over night. The precipitate was collected and dried to a white powder. 1 H NMR (D 2 O) δ 0.907 (s, 3H), 0.929 (s, 3H), 1.20 (s, 3H), 1.22 (s, 3H), 2.35-2.46 (m, 2H), 3.23 (s, 1H), 6.96-7.37 (m, 4H); 13 C NMR (D 2 O) δ 155.15 (d), 149.56, 137.84, 136.08, 129.71, 124.55, 122.33 (d), 120.48, 57.16, 31.27, 27.21, 22.59, 21.10; 31 P NMR (D 2 O) (rel. To ext. H 3 PO 4 ) δ 0.345. EXAMPLE 7. Synthesis of 1-(3-t-Butyldimethylsilyloxyphenyl)-2,2-dicyclopropyl-1methoxyethene (1g). ##STR15## A three neck flask was purged with argon and charged with 50 mL of anhydrous THF. The flask was cooled in an ice bath and titanium trichloride (11.6 g) was added with stirring. Lithium aluminum hydride (1.4 g) was added in small portions causing a brief exothermic reaction. While the lithium aluminum hydride was being added, an additional 20 mL portion of anhydrous THF was added to aid stirring. The cooling bath was removed when the addition was complete and the black mixture was brought to reflux. Triethylamine (10.5 ml) was added and the black mixture was refluxed for one hour under argon. A solution of dicyclopropyl ketone (2.61 g) and methyl 3-t-butyldimethylsilyloxybenzoate (2.00 g) in 20 mL of dry THF was added dropwise over 75 min. The reaction was judged complete after an additional 1 hour reflux period as monitored by TLC on silica plates eluting with 5% ethyl acetate/hexane. The crude reaction mixture was cooled to room temperature and extracted with four 400 mL portions of hexane. The combined hexane solutions were filtered and evaporated leaving 1.42 g of a yellow oil which was purified by column chromatography on silica gel, eluting first with hexane and then with 20% ethyl acetate/hexane to elute the product alkene 1a. Further purification was achieved by preparative TLC on silica eluting with 5% ethyl acetate/hexane. 1 H NMR (CDCl 3 ) δ 7.3-6.7 (m, 4H), 3.36 (s, 3H), 1.80 (m, 1H), 1.13 (m, 1H), 0.988 (s, 9H), 0.78-0.67 (m, 4H), 0.43-0.37 (m, 2H), 0.19 (s, 6H), 0.11-0.05 (m, 2H). EXAMPLE 8. Synthesis of 1-(3-t-Butyldimethylsilyloxyphenyl)-2,2-dicyclohexyl-1-methoxyethene (1h). ##STR16## A mixture of 4.3 g of methyl 3-t-butyldimethylsilyloxybenzoate and 9.5 g of dicyclohexyl ketone in dry THF were coupled according to the procedure of Example 5 using the Ti reagent made from 25 g of TiCl 3 , 3.0 g of LiAlH 4 and 16.4 g of triethylamine in 150 mL of dry THF. The crude product mixture (10 g) obtained after hexane extraction was purified by column chromatography on silica gel, eluting first with hexane, followed by 1% ethyl acetate/hexane and then with 3% ethyl acetate/hexane. The yield was 3.5 g (51%) of alkene 1e: 1 H NMR (CDCl 3 ) δ 7.22-7.16 (m, 1H), 6.85-6.72 (m, 3H), 3.155 (s, 3H), 2.05-0.86 (m, 22H), 0.995 (s, 9H), 0.21 (s, 6H). EXAMPLE 9. Synthesis of 2,2-Dicyclohexyl-1-(3-hydroxyphenyl)-1-methoxyethene (1i). ##STR17## To a solution of 0.7 g of alkene 1f in dry THF was added 0.62 g (1.2 eq.) of tetra-n-butylammonium fluoride dropwise. After stirring for one hour TLC (silica, 20% ethyl acetate/hexane) showed complete conversion of starting material to a new compound. The THF was evaporated and the residue dissolved in ethyl acetate. The ethyl acetate solution was extracted with water and dried over MgSO 4 . The material was purified by column chromatography on silica gel, eluting with 0-10% ethyl acetate/hexane yielding 0.46 g (92%) of 1f. The alkene was further purified by crystallization in benzene/hexane (1:6) at 4° C.: 1 H NMR (CDCl 3 ) δ 7.20-6.72 (m, 4H), 4.72 (s, 1H), 3.174 (s, 3H), 2.06-1.04 (m, 22H); 13 C NMR (CDCl 3 ) δ 155.19, 138.20, 131.97, 129.05, 122.50, 116.36, 114.39, 56.48, 41.51, 39.34, 31.40, 30.92, 27.50, 26.37, 26.25, 25.99; Mass spectrum (m/z): 314, 231, 121; exact mass, cald'd. 314.2246, found 314.2246. TABLE 1______________________________________Dioxetane Compounds ##STR18##Dioxetane R.sub.3 R.sub.4 X______________________________________2a CH(CH.sub.3).sub.2 CH(CH.sub.3).sub.2 Si(CH.sub.3).sub.2 t-Bu2b CH(CH.sub.3).sub.2 CH(CH.sub.3).sub.2 H2c CH(CH.sub.3).sub.2 CH(CH.sub.3).sub.2 COCH.sub.32d CH(CH.sub.3).sub.2 CH(CH.sub.3).sub.2 COPh2e CH(CH.sub.3).sub.2 CH(CH.sub.3).sub.2 COC(CH.sub.3).sub.32f CH(CH.sub.3).sub.2 CH(CH.sub.3).sub.2 PO.sub.3 Na.sub.22g c-C.sub.3 H.sub.5 c-C.sub.3 H.sub.5 Si(CH.sub.3).sub.2 t-Bu2h c-C.sub.6 H.sub.11 c-C.sub.6 H.sub.11 Si(CH.sub.3).sub.2 t-Bu2i c-C.sub.6 H.sub.11 c-C.sub.6 H.sub.11 H2jadamantyl - Si(CH.sub.3).sub.2 t-Bu2kadamantyl - PO.sub.3 Na.sub.2______________________________________ EXAMPLE 10. Synthesis of 1,2-Dioxetanes Photooxygenation procedure. Method A. Typically a 100 mg sample of the alkene was dissolved in 20 mL of a 1:1 mixture of methanol and methylene chloride in a photooxygenation tube. Approximately 200 mg of polystyrene-bound Rose Bengal was added and an oxygen bubbler connected. Oxygen was passed slowly through the apparatus while immersed in a half-silvered Dewar flask containing either Dry Ice/2-propanol or ice water. The sample was irradiated with a 400 W sodium lamp (GE Lucalox) through a film of 5 mil Kapton (DuPont, Wilmington, Del.) as UV cutoff filter while continuously bubbling oxygen. Progress of the reaction was monitored by TLC or 1 H NMR. The dioxetane compound was isolated by filtering off the polymer-bound sensitizer and evaporating the solvent at room temperature. Further purification could be achieved by column chromatography on silica gel or crystallization from a suitable solvent as necessary. Method B. Alternatively, methylene blue was used in some cases as photosensitizer. Approximately 100 mg was dissolved in 10 mL of the reaction solvent and irradiation proceeded as described above. The dioxetanes prepared in this manner were purified by column chromatography on silica gel. EXAMPLE 11. Synthesis of 4-(3-t-Butyldimethylsilyloxyphenyl)-3,3-diisopropyl-4-methoxy-1,2-dioxetane (2a). ##STR19## A 102.8 mg sample of the alkene was photooxygenated for a total of 9 hours by method B at -78° C. The solvent was evaporated and the mixture purified by preparative TLC using 4% ethyl acetate/hexane to elute the plate. The yield of dioxetane 2a was 55.9 mg (50%). 1 H NMR (CDCl 3 ) δ 7.6-6.7 (m, 4H), 3.14 (s, 3H), 2.61 (sept, 1H), 2.46 (sept, 1H), 1.30 (d, 1H), 1.18 (d, 1.H), 1.00 (s, 3H),0.92 (d, 1H), 0.46 (d, 1H), 0.20 (s, 3H); 13 C NMR (CDCl 3 ) δ 155.88, 137.07, 129.41, 114.526, 98.57, 49.46, 33.51, 29.24, 25.79, 19.43, 18.51, 17.29, 16.69, -4.32. EXAMPLE 12. Synthesis of 3,3-Diisopropyl-4-(3-hydroxyphenyl)-4-methoxy-1,2-dioxetane (2b). ##STR20## Alkene 1b (83.2 mg) was photooxygenated for a total of 3 hours by method B at -78° C. The solvent was evaporated, the residue dissolved in ethyl acetate and the mixture purified by preparative TLC using 20% ethyl acetate/hexane to elute the plate. The yield of dioxetane 2b was 79 mg (84%). 1 H NMR (CDCl 3 ) δ 7.4-6.8 (m, 4H), 3.2 (s, 3H), 2.62 (sept, 1H), 2.48 (sept, 1H), 2.08 (s,1H), 1.30 (d, 3H), 1.17 (d, 3H), 0.90 (d, 3H), 0.47 (d, 3H); 13 C NMR (CDCl 3 ) δ 156.00, 137.21, 129.70, 116.41, 114.61, 98.97, 49.58, 33.55, 29.35, 19.46, 18.56, 17.31, 16.65. EXAMPLE 13. Synthesis of 4-(3-Acetoxyphenyl)-3,3-diisopropyl-4-methoxy-1,2-dioxetane (2c). ##STR21## A 63 mg sample of the alkene was photooxygenated for a total of 6.5 hours by method B at -78° C. The solvent was evaporated, the residue dissolved in ethyl acetate and the mixture purified by preparative TLC using 20% ethyl acetate/hexane to elute the plate. The yield of dioxetane 2c was 56 mg (80%). 1 H NMR (CDCl 3 ) δ 7.37-6.99 (m, 4H), 3.14 (s, 3H), 2.59-2.42 (m, 2H), 2.32 (s, 3H), 1.30 (d, 3H, J=7.2 Hz), 1.17 (d, 3H, J=7.2 Hz), 0.91 (d, 3H, J=7.2 Hz), 0.46 (d, 3H, J=7.2 Hz); 13 C NMR (CDCl 3 ) δ 150.89, 137.34, 129.39, 122.73, 114.07, 98.34, 49.60, 33.54, 29.31, 21.22, 19.44, 18.53, 17.17, 16.59. EXAMPLE 14. Synthesis of 4-(3-Benzoyloxyphenyl)-3,3-diisopropyl-4-methoxy-1,2-dioxetane (2d). ##STR22## A 3.7 g sample of the alkene was photooxygenated for a total of 19 hours by method B at -78° C. using 500 mL of a 1:1 mixture of acetone and CH 2 Cl 2 and 100 mg of methylene blue. Progress of the reaction was monitored by 1 H NMR. The solvent was evaporated, the residue dissolved in ethyl acetate and the mixture purified by column chromatography using hexane as eluent. 1 H NMR (CDCl 3 ) δ 8.22-7.0 (m, 9H), 3.184 (s, 3H), 2.62-2.46 (m, 2H), 1.30 (d, 3H, J=7.2 Hz), 1.20 (d, 3H, J=7.2 Hz), 0.94 (d, 3H, J=7.2 Hz), 0.52 (d, 3H, J=7.2 Hz ); 13 C NMR (CDCl 3 ) δ 151.09, 137.32, 133.72, 130.18, 129.33, 128.61, 122.66, 98.24, 49.48, 33.44, 29.22, 19.32, 18.42, 17.11, 16.48. EXAMPLE 15. Synthesis of 4-(3-Pivaloyloxyphenyl )-3,3-diisopropyl-4-methoxy-1,2-dioxetane (2e). ##STR23## A 1.95 g sample of the alkene was photooxygenated for a total of 2.5 hours by method B at 4° C. using 300 mL of a 1:1 mixture of acetone and CH 2 Cl 2 . Progress of the reaction was monitored by 1 H NMR. The solvent was evaporated, the residue dissolved in ethyl acetate and the mixture purified by column chromatography using hexane as eluent. 1 H NMR (CDCl 3 ) δ 7.43-7.07 (m, 4H), 3.14 (s, 3H), 2.59-2.42 (m, 2H), 1.37 (s, 9H), 1.31 (d, 3H, J=6.9 Hz), 1.17 (d, 3H, J=6.9 Hz), 0.92 (d, 3H, J=6.9 Hz), 0.47 (d, 3H, J=6.9 Hz). EXAMPLE 16. Synthesis of 4-(3-Phosphoryloxyphenyl)-3,3-diisopropyl-4-methoxy-1,2,dioxetane, disodium salt (2f). ##STR24## A 64 mg sample of the alkene was photooxygenated for a total of 1.5 hours in 3 mL of D 2 O at 0° C. according to Method B. The solution was stored at 4° C. to induce crystallization. The white crystals were filtered, washed with acetone and dried. 1 H NMR (D 2 O) δ 7.43-7.14 (m, 4H), 3.132 (s, 3H), 2.63-2.53 (m, 2H), 1.225 (d, 3H, J=7.5 Hz), 1.123 (d, 3H, J=7.5 Hz), 0.892 (d, 3H, J=6.6 Hz), 0.475 (d, 3H, J=6.6 Hz); 31 P NMR (D 2 O) (rel. To ext. H 3 PO 4 ) δ 0.248. It should be noted that all other solvent systems used including D 2 O/p-dioxane, methanol, methanol/CH 2 Cl 2 required reaction times of several hours and led to significant quantities of decomposition products. EXAMPLE 17. Synthesis of 4-(3-t-Butyldimethylsilyloxyphenyl)-3,3-dicyclopropyl-4-methoxy-1,2-dioxetane (2g). ##STR25## A 25 mg sample of the alkene was photooxygenated for a total of 1 hour by method A at -78° C. 1 H NMR indicated the solution to contain a 3:1 mixture of dioxetane to alkene and a small amount of the ester decomposition product. Irradiation was stopped at this point and the sensitizer filtered away. The solvent was evaporated and the mixture used as a solution in xylene for kinetic measurements. 1 H NMR (CDCl 3 ) peaks due to dioxetane: δ 7.6-6.7 (m, 4H), 3.14 (s, 3H), 1.80 (m, 1H), 1.2-1.0 (m, 9H), 0.991 (s, 9H), 0.221 (s, 6H). EXAMPLE 18. Synthesis of 4-(3-t-Butyldimethylsiloxyphenyl)-3,3-dicyclohexyl-4-methoxy-1,2-dioxetane (2h). ##STR26## A 2.0 g sample of alkene 1f was photooxygenated for a total of 8.5 hours by method B at -78° C. The solvent was evaporated, the residue dissolved in hexane and filtered. The organic solution was evaporated and the solid residue was purified by column chromatography. The yield of product was 2.0 g (93%). 1 H NMR (CDCl 3 ) δ 7.26-6.85 (m, 4H), 3.143 (s, 3H), 2.3-0.5 (m, 22H) 0.995 (s, 9H), 0.205 (s, 6H); 13 C NMR (CDCl 3 ) δ 155.57, 136.82, 129.10, 122-121 (several unresolved), 114.56, 104.39, 97.31, 49.49, 45.18, 41.79, 28.71, 28.07, 27.80, 27.17, 26.95, 26.83, 26.74, 26.30, 25.68, 18.24, -4.38. EXAMPLE 19. Synthesis of 3,3-Dicyclohexyl-4-(3-hydroxyphenyl)-4-methoxy-1,2-dioxetane (2i). ##STR27## A 150 mg sample of alkene 1g was photooxygenated for a total of 1.5 hours by method B at -78° C. The solvent was evaporated, the residue dissolved in hexane and filtered. The precipitate was washed with 10 ml of 20% ethyl acetate/hexane and the organic solution evaporated. The solid residue was purified by preparative TLC using 20% ethyl acetate/hexane to elute the plate. The yield of product was 120 mg (72%). 1 H NMR (CDCl 3 ) δ 7.34-6.93 (m, 4H), 5.30 (s, 1H), 3.163 (s, 3H), 2.23-0.56 (m, 22H); 13 C NMR (CDCl 3 ) δ 155.55, 137.02, 129.42, 116.23, 116.12, 114.62, 104.36, 97.88, 49.60, 45.28, 41.78, 28.70, 28.09, 27.75, 27.14, 26.90, 26.86, 26.72, 26.37. EXAMPLE 20. Synthesis of 1-(tri-n-octylphosphoniummethyl)-4-(tri-n-butylphosphoniummethyl)benzene dichloride, Enhancer A. ##STR28## (a) A mixture of tri-n-butylphosphine (7 g, 34.6 mmol) in toluene (50 mL) was added dropwise to a mixture of α,α'-dichloro-p-xylene (12.1 g, 69.2 mmol, 2 eq.) in toluene (200 mL) under argon. The reaction mixture was stirred for 12 hours at room temperature under argon, after which time 4-(chloromethyl) benzyl-tri-n-butylphosphonium chloride had crystallized out of solution. The crystals were filtered and washed with toluene and hexane and air dried: 1 H NMR (CDCl 3 ) δ 0.92 (t,9H), 1.44 (m, 12H), 2.39 (m, 6H), 4.35-4.40 (d, 2H), 4.56 (s, 2H), 7.36-7.39 (d, 2H), 7.47-7.51 (dd, 2H). (b) To a mixture of 4-(chloromethyl)benzyl-tri-n-butylphosphonium chloride (3 g, 7.9 mmol) in DMF at room temperature, under argon was added tri-n-octylphosphine (4.39 g, 12 mmol). The reaction mixture was allowed to stir for several days, after which time TLC examination showed the reaction to be complete. The DMF was removed under reduced pressure, the residue washed with hexanes and toluene several times and then dried to give 1-(tri-n-octylphosphoniummethyl)-4-(tri-n-butylphosphoniummethyl)benzene dichloride as white crystals: 1 H NMR (CDCl 3 ) δ 0.84 (t,9H), 0.89 (t, 9H), 1.22 (br s, 24H), 1.41 (m,24H), 2.34 (m, 12H), 4.35-4.40 (d, 4H), 7.58 (s, 4H); 13 C NMR (CDCl 3 ) δ 13.34, 13.94, 18.33, 18.62, 18.92, 19.21, 21.76, 21.81, 23.58, 23.64, 23.78, 23.98, 26.10, 26.65, 28.86, 30.68, 30.88, 31.53, 129.22, 131.22; 31 P NMR (D 2 O) δ 31.10. 31.94. EXAMPLE 21. Measurement of Chemiluminescence Kinetics. Chemiluminescence intensities and rate measurements were performed using either a Turner Designs (Sunnyvale, Calif.) model TD-20e luminometer or a luminometer built in house (Black Box) which uses a photon counting photomultiplier. Temperature control of samples analyzed in the luminometers was achieved by means of a circulating bath connected to the instrument. Quantitative measurement of light intensities on the Turner luminometer was extended beyond the 10 4 linear range of the detector by a neutral density filter. Data collection was controlled by an Apple Macintosh SE/30 computer using the LUMISOFT data reduction program (Lumigen, Inc., Southfield, Mich.). Activation energies for thermal decomposition of dioxetanes 2c, h and i were determined by measuring the first order rate constant k for decay of chemiluminescence of dilute solutions in xylene at several temperatures. TABLE 2______________________________________Thermal Stability of Stabilized Dioxetanes EaDioxetene (kcal/mol) log A t1/2 25° C. t1/2 4° C.______________________________________2c 28.1 12.85 1.2 yr 43.9 yr2h 29.4 13.7 1.7 yr 72.3 yr2i 28.5 13.2 1.1 yr 43.4 yr______________________________________ EXAMPLE 22. Chemiluminescence and Fluorescence Spectra Chemiluminescence and fluorescence spectra were measured using a Fluorolog II fluorimeter (Spex Ind., Edison, N.J.) with 1 cm quartz cuvettes. All measurements were performed at ambient temperature. The spectrum was either scanned when the light intensity reached a constant level or correction was made for the decay of light intensity during the scan. FIG. 1 shows a typical chemiluminescence spectrum from the decomposition of dioxetane 2c in DMSO triggered by addition of a small volume of a solution of KOH in 1:1 methanol/DMSO. The emission arises from the excited state of the anion of methyl 3-hydroxybenzoate. Triggered decomposition of each dioxetane of the present invention in DMSO generates this excited state. EXAMPLE 23. Chemical Triggering of the Chemiluminescent Decomposition of Dioxetanes 2c,g,i. Stock solutions of dioxetanes 2c, 2e, 2g and for comparison, 4-(3-t-butyldimethylsilyloxyphenyl)-4-methoxyspiro[1,2-dioxetane-3,2'-tricyclo[3.3.1.1 3 ,7 ]decane] (2j), (preparation described in U.S. Pat. No. 4,962,192) were made to a concentration of 10 -6 M in DMSO. Serial dilutions in DMSO were made as required. Ten μL aliquots were triggered in 7×50 mm polypropylene tubes in a Turner Designs TD-20e luminometer by injection of 50 μL of a solution of tetra-n-butylammonium fluoride (TBAF) in DMSO (1M-10 -4 M) in the appropriate solvent, typically DMSO. Light intensity was attenuated when needed by a neutral density filter. All experiments were conducted at ambient temperature. Peak light intensity and decay rate diminished as the fluoride concentration was decreased. At the lowest concentration of fluoride, decay kinetics were not cleanly first order. Other triggering reagents found to produce chemiluminescence from dioxetanes 2a-e and 2g-i in DMSO or DMF include hydrazine, potassium and tetraalkylammonium hydroxides, alkali metal and tetraalkylammonium alkoxides and sodium azide. Small amounts (<5%) of a protic co-solvent such as methanol, ethanol or water could be used to dissolve the triggering agent in DMSO. The duration and intensity of chemiluminescence may be altered by the choice of solvent, triggering agent and ratio of dioxetane/triggering agent. Suitable solvents for practicing the present invention include any aprotic solvent in which the reactants are soluble, especially polar solvents such as DMSO, dimethylformamide, acetonitrile, p-dioxane and the like. The reaction can also be conducted in, for example, a hydrocarbon solvent where only one of the reactants is dissolved and the other is supplied in the medium undissolved. In this case, light is emitted from the surface of the undissolved reactant. EXAMPLE 24. Rates of Triggered Decomposition of Dioxetanes 2c,h,i. FIG. 2 shows a typical chemiluminescence intensity profile upon triggering a 10 μL aliquot of a 10 -6 M solution of dioxetane 2h with 50 μL of 1M TBAF in DMSO. Triggering of serial ten-fold dilutions of the dioxetane solution showed that a 10 -9 M solution provided a signal 1.5 times that of background. All chemiluminescence decay curves showed pseudo-first order kinetics. The half lives for decay were essentially independent of dioxetane concentration. TABLE 3______________________________________Rates and Chemiluminescence Intensity fromFluoride-triggered Decomposition of Dioxetane 2h as aFunction of Concentration.[Dioxetane 2h] [F.sup.- ] t1/2 (sec) Total intensity______________________________________10.sup.-6 M 1M 7.2 1.9 × 10.sup.4 TLU10.sup.-7M 1 M 6.2 2.0 × 10.sup.3 TLU10.sup.-8M 1 M 6.2 2.1 × 10.sup.2 TLU10.sup.-9M 1 M 6.7 1.5 × 10.sup.1 TLU______________________________________ The rates of fluoride-triggered decomposition of dioxetanes 2c, h, i and j were compared in DMSO under identical conditions, i.e. 10 μL aliquot of a 10-6M solution of dioxetane with 50 μL of 1M TBAF in DMSO. All four dioxetanes were found to undergo reaction at essentially the same rate under these conditions. TABLE 4______________________________________Comparison of Thermal and Fluoride-triggeredDecomposition Rates.Dioxetene t1/2 trig. t1/2 thermal Rate acceleration______________________________________2c 7 sec 1.2 yr 5.5 × 10.sup.62h 7 sec 1.7 yr 7.0 × 10.sup.62i 6 sec 1.1 yr 5.7 × 10.sup.62j 7 sec 3.8 yr 1.4 × 10.sup.7______________________________________ EXAMPLE 25. Measurement of Relative Chemiluminescence Quantum Yields The total chemiluminescence intensity generated by fluoride-triggering of dioxetanes 2c, g, h and i were compared in DMSO under identical conditions, i.e. 10 μL aliquot of a 10 -6 M solution of dioxetane with 50 μL of 1M TBAF in DMSO. Precise values were difficult to reproduce; however, all four dioxetanes were found to generate the same chemiluminescence output within a factor of two under these conditions. Based on the reported chemiluminescence efficiency of 25% for dioxetane 2h (A. P. Schaap, T.-S. Chen, R. S. Handley, R. DeSilva and B. P. Giri, Tetrahedron Lett., 1155 (1987)) the dioxetanes of the present invention are found to produce chemiluminescence with high efficiency upon triggering in DMSO. EXAMPLE 26. Comparison of Chemiluminescence Intensities-Kinetic Profile of Solutions Containing Dioxetane 2f or 2k. In order to demonstrate the unexpected advantage of the phosphate dioxetane 2f of the present invention, a comparison was made of the time course of chemiluminescence from this dioxetane induced by alkaline phosphatase (AP) in alkaline buffer solutions to the commercially available dioxetane 4-methoxy-4-(3-phosphoryloxyphenyl)spiro [1,2-dioxetane-3,2'-tricyclo[3.3.1.1 3 ,7 ]decane], disodium salt, (LUMIGEN PPD, Lumigen, Inc., Southfield, Mich.), dioxetane 2k. FIG. 3 illustrates the time profile and relative chemiluminescence intensities at 37° C. from two compositions, one containing 0.33 mM dioxetane 2d of the present invention and the other containing 0.33 mM dioxetane 2k in the same buffer. Light emission was initiated by addition of 1.12×10 -17 moles of AP to 100 μL of the dioxetane solution. The reagent containing dioxetane 2f of the present invention reaches a significantly higher maximum intensity. EXAMPLE 27. Comparison of Chemiluminescence Intensities-Kinetic Profile of Solutions Containing Dioxetane 2f or 2k. FIG. 4 illustrates the time profile and relative chemiluminescence intensities at 37° C. from two compositions, one containing 0.33 mM dioxetane 2f of the present invention and 1.0 mg/mL of 1-(tri-n-octylphosphoniummethyl)-4-(tri-n-butylphosphoniummethyl)benzene dichloride (Enhancer A) and the other containing 0.33 mM dioxetane 2k and 1.0 mg/mL of the same enhancer. Light emission was initiated by addition of 1.12×10 -17 moles of AP to 100 μL of the dioxetane solution. The reagent containing dioxetane 2f of the present invention reaches achieves higher light intensities at all time points. EXAMPLE 28. Comparison of Chemiluminescence Intensities-Kinetic Profile of Solutions Containing Dioxetane 2f or 2k. FIG. 5 illustrates the time profile and relative chemiluminescence intensities at 37° C. from two compositions, one containing 0.33 mM dioxetane 2f of the present invention and 0.5 mg/mL of polyvinylbenzyltributylphosphonium chloride (Enhancer B) and the other containing 0.33 mM dioxetane 2k and 1.0 mg/mL of the same enhancer. Light emission was initiated by addition of 1.12×10 -17 moles of AP to 100 μL of the dioxetane solution. The reagent containing dioxetane 2f of the present invention reaches achieves higher light intensities at all time points. EXAMPLE 29. Comparison of Chemiluminescence Intensities-Kinetic Profile of Solutions Containing Dioxetane 2f or 2k. FIG. 6 illustrates the time profile and relative chemiluminescence intensities at 37° C. from two compositions, one containing 0.33 mM dioxetane 2f of the present invention and 0.5 mg/mL of polyvinylbenzyltributylphosphonium chloride co-polyvinylbenzyltrioctylphosphonium chloride (containing a 3:1 ratio of tributyl:trioctyl groups) (Enhancer C) and the other containing 0.33 mM dioxetane 2k and 0.5 mg/mL of the same enhancer. Light emission was initiated by addition of 1.12×10 -17 moles of AP to 100 μL of the dioxetane solution. The reagent containing dioxetane 2f of the present invention reaches achieves higher light intensities at all time points. EXAMPLE 30. Linearity and Sensitivity of Detection of Alkaline Phosphatase with Dioxetane 2f. The linearity of detection of AP using a reagent composition of the present invention containing dioxetane 2f was determined. To each of 48 wells in a 96-well microplate was added 100 μL of a 0.33 mM solution of 2f in 0.2M 2-methyl-2-amino-1-propanol buffer, pH 9.6 containing 0.88 mM Mg +2 and 1.0 mg/mL of Enhancer A. The plate was incubated at 37° C. and chemiluminescence emission initiated by addition of 3 μL of solutions of AP containing between 3.36×10 -16 mol and 3.36×10 -22 mol of enzyme. Light intensities were measured at 10 min. FIG. 7 shows the linear detection of alkaline phosphatase. The term S-B refers to the chemiluminescence signal (S) in RLU in the presence of alkaline phosphatase (AP) corrected for background chemiluminescence (B) in the absence of AP. The calculated detection limit (twice the standard deviation of the background) was determined to be 2.0×10 -22 mol, or 120 molecules of AP under these conditions. EXAMPLE 31. Comparison of Chemiluminescence Quantum Yields. The relative chemiluminescence quantum yields of dioxetanes 2f and 2k were determined in solutions containing 1 mg/mL of Enhancer C in 0.2M 2-amino-2-methyl-1-propanol buffer, pH 9.6 containing 0.88 mM Mg +2 and selected enhancers as described in Table 4. A 100 μL aliquot of each reagent was completely dephosphorylated by addition of 3.36×10 -13 mol of alkaline phosphatase. The total amount of light emitted in Relative Light Units (RLU) was integrated until light emission ceased. A similar comparison was also made with 500 μL portions of formulations without any enhancer using either 0.2M or 0.75M 2-amino-2-methyl-1-propanol buffer, pH 9.6 containing 0.88 mM Mg +2 . Dioxetane 2f produces more light than dioxetane 2k in buffer alone and in the presence of Enhancers A and C. TABLE 5______________________________________Total Light Intensity from Phosphate DioxetanesEnhancer Dioxetane 2f Dioxetane 2k______________________________________None (0.2M) 2.82 × 10.sup.5 1.55 × 10.sup.5None (0.75M) 5.55 × 10.sup.4 4.41 × 10.sup.4Enhancer A (1 mg/mL) 1.19 × 10.sup.7 9.0 × 10.sup.6Enhancer B (0.5 mg/mL) 1.65 × 10.sup.6 2.09 × 10.sup.6Enhancer C (0.5 mg/mL) 4.15 × 10.sup.7 3.65 × 10.sup.7______________________________________ EXAMPLE 32. Stability of Dioxetane 2f in Aqueous Solutions. The thermal and hydrolytic stability of a 0.33 mM solution of dioxetane 2f containing 1 mg/mL of Enhancer A in 0.2M 2-amino-2-methyl-1-propanol buffer, pH 9.6 and 0.88 mM Mg +2 was determined at 37° C. Solutions of the dioxetane were maintained at room temperature and 37° C. for 5 days. To each of 12 wells in a 96-well microplate was added 100 μL of each solution. The plate was incubated at 37° C. and chemiluminescence emission initiated by addition of 10 μL of solutions containing 1.1×10 -15 mol of AP. Light intensities were integrated for 2.5 hours. Stability of the dioxetane was assessed by comparing the average light yield of the sample incubated at 37° C. to the solution held at room temperature. A decrease in the amount of light emitted indicates decomposition of the dioxetane during the incubation period. The solution maintained at 37° C. was identical to the room temperature solution indicating the dioxetane to be stable under these conditions. EXAMPLE 33. Chemiluminescent Detection of Alkaline Phosphatase on Membrane. The utility of a composition of the present invention for the chemiluminescent detection of enzymes on the surface of blotting membranes is demonstrated in the following example. Solutions of alkaline phosphatase in water containing from 1.1 fmol to 1.1 amol were applied to identical nylon membranes (Micron Separations Inc., Westboro, Mass.). The membranes were air dried for 5 min and soaked briefly with a reagent containing 1 mg/mL of Enhancer A in 0.2M 2-amino-2-methyl-1-propanol buffer, pH 9.6 containing 0.88 mM MgCl and either 0.33 mM dioxetane 2f or 0.33 mM dioxetane 2k. The membranes were placed between transparency sheets and exposed to X-ray film (Kodak X-OMAT AR, Rochester, N.Y.). FIG. 8 shows that the light produced using the two dioxetanes led to equivalent images and detection sensitivity. These results illustrate the performance of dioxetane 2f which is to be expected in Western blotting, Southern blotting, DNA fingerprinting and other blotting applications.

A chemiluminescent assay method and compositions are described which use a dialkyl-substituted dioxetane which is deprotected to trigger a chemiluminescent reaction. Chemiluminescent 1,2-dioxetane compounds substituted on the dioxetane ring with two nonspirofused alkyl groups which can be triggered by a reagent to generate light are disclosed. Dialkyl-substituted dioxetanes are useful for the detection of triggering agents including enzymes. The enzyme may be present alone or linked to a member of a specific binding pair in an immunoassay, DNA probe assay or other assay where the enzyme is bound to a reporter molecule.

[0001] This application is a continuation in part of U.S. patent application Ser. No. 09/999,268 filed Oct. 31, 2001, the disclosures of which are incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The instant invention relates generally to disposable, highly absorbent sheets and pads having superior strength and more specifically it relates to disposable, absorbent, multilayer composite sheets and pads suitable for medical scientific, veterinarian, pet and other usage. [0004] 2. Description of the Prior Art [0005] Disposable, absorbent pads and sheets are known in the art. For example, U.S. Pat. No. 3,956,782 (Morrison, R. D., 18 May 1976) discloses a contour mattress cover comprising a fluid impervious foundation layer laminated to an absorbent layer. [0006] U.S. Pat. No. 3,989,867 (Sisson, B 2 November 1976) discloses an absorbent device having an absorbent body and liquid impervious backsheet underlying the absorbent body. [0007] U.S. Pat. No. 4,923,453 (Bullard, Jr M., 8 May 1990) discloses an absorbent utility cover comprising three layers, a bottom layer of waterproof plastic, a central absorbent layer and top semi-porous layer. [0008] U.S. Pat. No. 5,081,729 (Menday, E. C., 21 Jan. 1992) discloses disposable fitted birthing sheet comprising liquid impervious backing layer, a middle layer of absorbent material and a liquid permeable top layer. [0009] While these patents all disclose multi-layer absorbent articles, they do not teach multi-layer absorbent articles having high tensile strength which are suitable for heavy use, for example, lifting a patient. SUMMARY OF THE INVENTION [0010] The present invention is concerned with an article suitable for use in disposable, absorbent multilayer composite sheets and pads having a high tensile strength. More particularly, the present invention is directed to flexible multilayer sheet structures that are highly absorbent. These sheet structures may include one or more laminates, co-extruded layers and combinations thereof. [0011] A primary object of the present invention is to provide a disposable, absorbent article that will absorb a relatively large quantity of fluid in comparison to other absorbent structures. [0012] Another object of the present invention is to provide a disposable, absorbent article having an improved tensile strength such that the structures of the present invention do not tear easily when used. [0013] It is a further object of the invention to provide a disposable, absorbent article having improved puncture resistance. [0014] A still further object of the present invention is to provide a disposable, absorbent article that will not tear readily when a patient or other object is being transported by lifting the sheet. [0015] An additional object of the present invention is to provide a multi-layer disposable, absorbent article having a liquid-impervious layer, an absorbent layer, and a tensile strength-providing layer. Additional layers, such as a liquid-permeable top layer, may also be present. [0016] A further object of the present invention is to provide a disposable, absorbent article that is easy to use, economical to manufacture and safe and convenient to dispose. [0017] The foregoing and other objects, advantages and characterizing features will become apparent from the following description of certain illustrative embodiments of the invention. [0018] The novel features which are considered characteristic for the invention are set forth in the appended claims. The invention itself, however both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of the specific embodiments when read and understood in connection with the accompanying drawings. Attention is called to the fact however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated and described within the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWING FIGURES [0019] FIG. 1 is a cross-sectional view taken through an example of the article of the present invention [0020] FIG. 2 is an exploded cross-sectional view taken through an article of the present invention, wherein the major layers are shown individually. [0021] FIG. 3 is a further exploded cross-sectional view taken through an article of the present invention, wherein each layer is shown individually. [0022] FIG. 4 is a descriptive exploded view of the article of FIG. 3 , wherein the preferred characteristics of the various layers of the present invention, are illustrated. [0023] FIG. 5 is a cross sectional view of an alternative embodiment of the present invention. [0024] FIG. 6 is a cross sectional view of an additional alternative embodiment of the present invention. LIST OF REFERENCE NUMERALS UTILIZED IN THE DRAWINGS [0000] 10 —absorbent, multi-layer article that is preferably disposable 12 —cover layer that is preferably permeable 14 —core layer that is preferably absorbent 16 —optional high tensile strength-providing layer 18 —liquid-impermeable barrier layer 20 —fabric layer preferably a spunbond material 22 —polyester/polypropylene scrim 24 —high tensile strength fabric 26 —preferred permeable cover stock, having a weight of between about 10 and about 40 g/m 2 28 —preferred absorbent core, having a weigh t of between about 100 and about 400 g/m 2 30 —waterproof barrier 32 —polyester/polypropylene scrim 34 —preferred polypropylene fabric, having a weight of between about 20 and about 80 g/m 2 36 —preferred polypropylene fabric, having a weight of between about 20 and about 80 g/m 2 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0039] Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views, the Figures illustrate an absorbent, multi-layer article of the present invention. One of the advantages of the present invention is the relatively low cost of the article of the present invention that permits the article to be disposable if desired. Disposability is an important advantage in many applications particularly in the medical field where the spread of infection and other contagions is to be limited. Accordingly, the structures of the present invention will be described herein in relationship to their use in primarily as disposable absorbent articles. For the purpose of the present invention, a disposable absorbent article is an article which absorbs and contains liquids, such as body fluids and other liquids and prevents the fluids from spreading off of the sheet. Further, the term disposable is also intended to encompass sheets that will be discarded after a limited period of use. The articles are not typically intended to be laundered or otherwise restored for reuse while the present description will generally be made in the context of a disposable absorbent article particularly a disposable sheet for medical use, it should be understood that the various structures of the present invention are also applicable to other articles such as incontinence pads, lab spill wipes and counter top pads, industrial spill sheets, operating room drapes, ambulance stretcher sheets, bed and crib pads absorbent wipes and the like. It is also contemplated that the present invention have applicability as a drape over operating table in the operating room, in a sterile operating room pack, as well as a fenestrated drape, i.e., a sheet that is placed over a patient or that portion of a patient that is being operated on. The sheet has an opening through the sheet that permits operating room personnel to work through the opening in the sheet. The opening may be merely one or more slits in the sheet that may be spread apart to give the operating room personnel an area in which to work. Alternatively, the opening may be an enlarged opening for example, in the form of a square or circle or other shape that accomplishes the same purpose. The absorbent material may be places on either side of the sheet or both sides as desired by the nature of the operation. [0040] In dental offices, the sheet of the present invention may be used as a bib during dental procedures where the highly absorbent layer will permit the water, saliva and other fluids typically present to be absorbed. The sheet may also be a sheet or cover for the back board used to carry the patient. If made large enough the sheet can be wrapped about the patient and the sheet may be held in place by a suitable means such as a pin or by one or more Velcro fasteners. By weighing the sheet prior to use and comparing the weight of the sheet after use, medical personnel are given some idea as to the amount of blood lost by the patient. [0041] Outside of the medical field, the present invention also has applicability in the area of pet care particularly in the veterinary field. The sheet may be used as a stretcher for animals. For another example, when used as a cover for the operating table in a veterinary hospital, the sheet of the present invention may be used because of its strength to pick up the operated on animal and carry the animal to the recovery area. [0042] The subject matter of the present invention also has applicability in the area of highly absorbent undergarments as well. These undergarments may be used for children as well as adults who have problems with incontinence and can be in the form of a diaper or a preformed undergarment such as shorts. [0043] Another example of the applicability of the present invention is in the area of a protector for bedding table covers and the like. This bedding can be a hospital bed, for home care, an incubator or Stablete, etc. The sheet of the present invention may be part of a pouch. The sheet on the present invention may be formed into a pouch having one sheet of the present invention on one surface and another sheet of the same or a different material on the other surface. The absorbent side of the sheet is preferably on the outer surface of at least one side of the pouch. The pouch typically has a generally rectangular shape although other shapes are possible. Other shapes would include circles, squares and combinations thereof. When generally rectangular, three of the sides of the pouch may be sealed by any suitable means and the fourth side remains open to permit a mattress or other object to be inserted therein. Depending on the application, the absorbent surface may be either on one or more of the inside surfaces of the pouch or on one or more outer surfaces of the pouch or combinations thereof. In another embodiment, the pouch of the present invention may have a top surface, a bottom surface, a first sidewall, a second sidewall and an end wall with the remaining end wall being open for insertion of an object. Alternatively, the pouch may have only a single side wall and a pair of end walls. The present invention may also be used as the interior surface of a container so that any fluids in the container or that leak in the container may be absorbed by the present invention. In another application of the invention, the sheet may be a mattress cover that is placed over a mattress to prevent damage to the mattress when fluids leak. In another embodiment, the sheet may be in the form of a traditional mattress cover with sides that are fitted to the mattress. Either the entire mattress cover can be made of the material of the present invention or only a portion of the area of the cover may be made of the sheet material of the present invention. [0044] The material of the present invention may also be made into a glove. When made into a glove, either the entire glove may be made of the material of the present invention. Alternatively, either the palm surface or the opposite side of the glove may have the material of the present invention. [0045] In most operating rooms throughout the country, the operating room personnel wear booties to protect their feet and also to prevent bacteria and other infectious agents from spreading in the room. During an operation, it is not uncommon for fluids to contact the booties. Most of the currently used booties slough off the fluids onto the floor where the fluids can be a hazard. The booties can be made of the material of the present invention where the absorbent layer is on the outer surface, the inner surface of both. With booties made from the material of the present invention, any fluids that come into contact with the outer surface of the booties are absorbed. This reduces the risk of a fall in the operating room. [0046] In some forms of knee surgery, the knee is operated on by the surgeon with the leg in a non horizontal position, in these operations, it is very common for fluids to drip down the leg. A sleeve of the material of the present invention may be used to absorb the fluids that drip down the leg. The sleeve preferably has the absorbent material of the present invention on the interior surface of the sleeve although the absorbent surface can be on the inside surface or both surfaces as well. The sleeve may be either a tube open at each end so the leg can pass through or a sheet that releasably sealable along an edge and can be wrapped about the leg. [0047] With reference to FIG. 1 , an article of the present invention preferably includes at least four separate layers. In one preferred embodiment, the article of the present invention has only the four layers as shown in FIG. 1 . It has been found that the four layered structure of FIG. 1 has superior strength, absorbency and low cost. These layers include a topsheet layer 12 and an absorbent layer 14 which is preferably adjacent to the top sheet layer. There is a fabric layer 16 which provides the article 10 with its high tensile strength. This layer with high tensile strength can also be a scrim layer. The fourth layer can be the backsheet layer 18 . The fabric layer is preferably between the back sheet layer and the absorbent layer. The layers may be laminated together by any suitable means including the use of an adhesive to form a unitary structure 10 . In a preferred embodiment each of the layers is coextensive with the adjacent layers so that the composite structure has the attributes of each layer over its entire surface. The layers do not have to be adhered together across their entire surface. In some instances, they may be sealed together about their perimeter edges and the remainder of the surface is not adhered to the adjacent layer. Alternatively, layers may be adhered together at other locations on their surface such as for example a series or plurality of connecting points in a variety of patterns across the surface of the layers. The four preferred layers are a topsheet layer 12 , an absorbent layer 14 , a fabric layer 16 and a backsheet layer 18 . It will be appreciated that the surface layer 12 can be made of an absorbent material and the fabric layer may be eliminated so that the structure need only have one additional layer, the backsheet layer 18 . The layers are preferably coextensive with each adjacent layer so that the layer structure is preferably uniform in thickness across its entire surface. Every layer of the pad preferably reaches to the edge of the pad. This creates an equal amount of absorbency and strength across the surface of the pad. [0048] A preferred embodiment of the pad has a thickness no greater than approximately 0.5 inches. A more preferred embodiment has a thickness no greater than approximately 0.250 inches. The most preferred embodiment will be no greater than about 0.125 inches thick. In the preferred embodiment, all layers of the pad are coextensive, making the pad the same thickness across the surface. Every layer of the pad reaches to the edge of the pad. This provides generally an equal amount of absorbency throughout the surface of the pad [0049] The topsheet layer 12 a sheet of liquid permeable or semi-permeable material so that the liquid will pass through to the absorbent core which underlies the topsheet. The topsheet maybe composed of a substantially hydrophobic and substantially nonwettable material, and the hydrophobic material may optionally be treated with a surfactant or otherwise processed to impart a desired level of wettability and hydrophilicity. A suitable topsheet may be manufactured from a wide selection of web material. such as porous foams, reticulated foams, apertured plastic films, natural fibers (for example, wood or cotton fibers), synthetic fibers (for example. polyester or polypropylene fibers), or a combination of natural and synthetic fibers. Various woven and nonwoven fabrics can be used for the topsheet. For example, the topsheet may be composed or a meltblown or spunbonded web of polyolefin fibers. The topsheet may also be a bonded-carded-web composed of natural and/or synthetic fibers, such as, for example, the preferred nonwoven polypropylene, polyester, polyethylene or poly/acrylic blend fabric. With regard to the weight of the topsheet, it is preferred that it have a basis weight between about 10 and 40 grams per square meter (g/m 2 ) [0050] For medical applications, the topsheet should be made of a hypoallergenic material can be sterilized. Furthermore, in applications where the article is in contact with a person's skin, it is preferred that the topsheet remain dry to the touch after allowing the liquid to pass through to the absorbent core. This is readily accomplished by the aforementioned use of hydrophobic material and surface treatments. The use of absorbent materials that convert the liquid to a gel form further assists this goal. In a preferred embodiment, the material of the topsheet is selected not only for its wettability and hydrophilicity but also for its softness to any skin that comes into contact therewith. [0051] The backsheet 18 is composed of a material which is configured to be substantially impermeable to fluids including liquids and water vapor. The backsheet 18 has a top surface and a bottom surface and consists essentially of a plastic sheet material which does not have any added holes or orifices that extend from one surface of the sheet to the other surface of the sheet. The material is a thin sheet formed without any added holes or orifices therein that would permit water, water vapor or gas or any fluid to pass from one surface to the other surface through the added orifices or holes For example, a typical backsheet can be manufactured from a thin plastic film, or other flexible liquid-impermeable material. The backsheet typically helps to prevent the absorbed liquids contained in the absorbent layer from wetting articles or people in contact with the article. For example, the backsheet acts to protect bed linens, counter tops, lab benches floors and the like. Also, when used in the form of disposable cleaning pads/wipes, the backsheet acts to prevent contact of the user with the substance being cleaned. This is particularly crucial when infectious or toxic wastes are concerned. In such instances, the backsheet actually becomes an isolating wrap for disposal of the used article, allowing the user to touch the impervious backing layer and not the contaminated surface. When use for example in a medical setting either in a hospital doctors office or on an EMS board, the amount of blood or other fluid that the patient has lost can be roughly calculated by weighing the sheets after use and comparing the weight to the weight of an unused pad. In applications where sterility is needed the sheets of the present invention may be sterilized by gamma rays or a sterilizing gas. [0052] In particular embodiments, the backsheet 18 is a polypropylene, polyethylene or polyester film having a thickness of from about 0.012 millimeters (0.5 mil) to about 0.051 millimeters (2.0 mils), preferably about 0.025 millimeters (1.0 mil). The backsheet may be made from such polyethylenes as linear low density polyethylene, very low density polyethylene, ultra low density polyethylene. The backsheet 18 typically provides the outer cover of the article. Optionally, however, the article may have the fabric layer 16 over the back sheet as the outermost layer in the article. [0053] The flexible absorbent layer 14 is typically positioned between the topsheet 12 and the fabric layer 16 . Optionally, however, it can be disposed between the topsheet 12 and the backsheet 18 , when the fabric layer 16 is the outermost layer as discussed above. Various types of wettable, hydrophilic fibrous material can be used to form the absorbent layer. These fibers are preferably flexible and should not be treated with a chemical stiffener on their surface. Examples of suitable fibers include naturally occurring organic fibers composed of intrinsically wettable material such as cellulosic fibers, synthetic fibers composed of cellulose or cellulose derivatives, such as rayon fibers; inorganic fibers composed of an inherently wettable material, such as glass fibers; synthetic fibers made from wettable thermoplastic polymers, such as particular polyester or polyamide fibers; and synthetic fibers composed of a nonwettable thermoplastic polymer, such as polypropylene fibers, which have been hydrophilized by appropriate means. The fibers may be hydrophilized for example, by treatment with silica, treatment with a material which has a suitable hydrophilic moiety and is not readily removable from the fiber, or by sheathing the nonwettable, hydrophobic fiber with a hydrophilic polymer during or after the formation of the fiber. It is also contemplated that selected blends of the various types of fibers mentioned above may also be employed. Preferably, the absorbent core is made of a material which converts liquids to gel foam, as is well known in the art. The absorbent layer may also be provided with a deodorant material in the layer. [0054] The absorbent layer 14 preferably is a flexible material so that the sheet of the present invention may be used in a variety of applications. The absorbent layer preferably has a basis weight between about 100 and 400 g/m 2 , most preferably about 300 g/m 2 This will generally correspond to a thickness of between about 1 and 6 mm usually between about 3 and 5 mm. With regard to absorbency, it can readily be appreciated that the ability of the article to absorb liquid depends substantially on the nature of the liquid being absorbed. Speaking generally, however, the absorbent layer should have an absorbent capacity of at least about 15 grams of saline solution g/g during one minute and/or at least up 20 grams of water per gram of sorbent (g/g) during one minute, preferably at least 20 grams of saline solution g/g and/or at least 25 g/g water. More preferably, the absorbent layer should have an absorbent capacity of at least about 25 grams of saline solution g/g during one minute and/or at least up 30 grams of water per gram of sorbent (g/g) during one minute. Most preferably, the absorbent layer should have an absorbent capacity of at least about 30 grams of saline solution g/g during one minute and/or at least up 35 grams of water per gram of sorbent (g/g) during one minute. One material that can be used contains cellulosic fibers, e.g., wood pulp fluff made up of bleached sulphate wood pulp containing softwood fibers, such as that available from International Paper, Tuxedo, N.Y., co-mingled with hydrogel polymer particulates (known as Super Absorbent Polymer or “SAP”). The material used in the absorbent layer 14 does not have any stiffeners or means to increase stiffness added to the layer [0055] A preferred material for providing suitable absorption in the absorbent layer is material in the form of a powder or granules sold by Stockhusen. These granules are made up of a Super Absorbent Polymer such as Stockhausen Favor SXM 70 polymer and can be interspersed throughout the material that makes up the absorbent layer. [0056] In a preferred embodiment, the absorbent layer may have the following structure: 45-65% Long Staple Hardwood Fiber Pulp 15-25% Binding Fiber 20-30% Super Absorbent Polymer EXAMPLE 1 [0000] The absorbent layer is preferably: 57% Long Staple Hardwood Fiber Pulp 19% Binding Fiber 24% Super Absorbent Polymer [0064] Alternatively, the absorbent layer may be 45-65% Long Staple Hardwood Fiber Pulp 15-25% Binding Fiber 20-30% Super Absorbent Fiber EXAMPLE 2 [0000] 57% Long Staple Hardwood Fiber Pulp 18% Binding Fiber 25% Super Absorbent Polymer [0071] The fabric layer 16 provides the article 10 with its high tensile strength. This layer as described earlier can be disposed either between the absorbent layer 14 and the backsheet layer 18 or, optionally, could form the outer layer, that is the backsheet layer 18 is disposed between the absorbent layer 14 and the fabric layer 16 . This layer is composed of a flexible sheet with a high tensile strength. When the fabric layer is disposed adjacent to the absorbent layer, it is important that it retain its tensile strength when wet. The fabric layer 16 should have a tensile strength sufficient to provide the article with a tensile strength high enough to enable the article to lift, for example, a pet or other animal when used in veterinary applications or an adult person when used in many medical applications. The composite sheets made from the topsheet, absorbent layer, scrim layer and the backsheet have superior strength. The sheets of the present invention may be used to carry a patient or a pet weighing 100 pounds or more without tearing even when wet due to the presence of fluids that have been absorbed into the sheet. If desired, the sheets may be provided with hand holds to assist the medical personnel in moving a patient. [0072] With reference to FIGS. 2 and 3 , it can be seen that the fabric layer 16 itself can be composed of a plurality of separate layers laminated together. For example, as illustrated in the Figures, the fabric layer 16 can be made up of two fabric layers 20 and 24 . These layers can be laminated together or if desired they may be laminated to opposite sides of a support layer 22 . Such a structure provides the article with an even greater tensile strength, especially if each of the fabric layers has a tensile strength higher along one longitudinal axis than the other in which case the two fabric layers are oriented in opposite longitudinal directions. [0073] The fabric layer(s) can be made of any of a wide variety of materials, as long as adequate tensile strength is provided. Preferred materials include, for example a polymeric fabric including but not limited to a polyethylene, a polypropylene polyester or other fabric having a basis weight between about 20 and 80 g/m 2 . With regard to the support layer 22 , a flexible polypropylene or polyester scrim is preferred. The scrim is preferably in the form of a mesh or net to reduce cost while at the same time providing superior tensile strength. The precise nature of the support layer is not critical however, as long as it provides an appropriate surface for laminating the two fabric layers thereto. [0074] In one embodiment, the fabric layer 16 and the backsheet layer 18 may be laminated together by any suitable means such as an adhesive, a solvent weld or by co-extruding the layers. The remaining layers may be added subsequently to this base structure. Alternatively, the topsheet 12 and absorbent layer may be laminated together and the fabric layer or a composite of the fabric layer and the backsheet layer may be joined this substrate. Similarly, where the fabric layer has two fabric layers that are adjacent to each other or two fabric layers on either side of a support layer, these layers can be laminated together by any suitable means such as an adhesive, a solvent weld or by co-extruding the layers. To the so formed substrate may be added the remaining layers by any suitable means. [0075] FIGS. 5 and 6 show alternative embodiments of the present invention. In FIG. 5 there is a cover stock layer or top sheet 12 as the outer layer. Below and preferably adjacent to the top sheet is a layer of superabsorbent material 14 which may be a superabsorbent polymer containing layer, fiber or the other materials discussed above. The next layer is preferably a three layer composite of a scrim core layer 22 with a polymeric material 52 and 54 on either side. The polymeric material on either side preferably has a basis weight of between about 2 and about 10 g/m 2 . The scrim core layer 22 provides strength to the overall structure and is preferably a 12 by 4 mesh of a polymeric material. If the polymeric material 54 is a barrier material, no additional layers are necessarily present. If the polymeric material 54 is not a barrier material, it is preferred that there be an additional barrier layer 56 present. [0076] In FIG. 6 there is no barrier layer and the three layer composite having a scrim core layer has a material that allows fluids to pass through the layer 54 , the scrim 22 and the layer 52 . This structure allows absorbency from both sides of the structure. [0077] It will be appreciated by those skilled in the art that the present invention can be manufactured in a number of different ways. One preferred manner of manufacturing is be means of a process that employs a first heating area that brings the temperature of the materials to be fused to a first temperature of at least 50°. From the first heating area the materials to be fused enters a preheat zone where the fusing material that is heated to a fluidity temperature. From the preheat zone the material enters in succession a plurality of areas where heat is applied to one side of the material and then to the other side of the material so that the fusible resin is drawn toward the heat that is being applied. This permits the resin to penetrate the material to be assembled. Once the appropriate temperature is reached in the plurality of heating zones the material is fused together by at least one pair of rollers. After rolling the fused material is kept under slight pressure to retain the material together and permitted to gradually cool down without the application of additional heat. From this light pressure area, the material passes to a cooling area where the material is permitted to cool down without pressure on the material. [0078] It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of applications differing from the type described above. [0079] While the invention has been illustrated and described as embodied in a disposable absorbent article, it is not intended to be limited to the details shown, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the formulation illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention. [0080] Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that from the standpoint of prior art fairly, constitute essential characteristics of this invention. [0081] What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

The present invention relates to a disposable, absorbent article having a liquid impervious backsheet layer, a liquid permeable topsheet layer disposed in facing relation with the backsheet layer, an absorbent layer interposed between the backsheet layer and the topsheet layer, and a fabric layer interposed between the backsheet layer and the absorbent layer. Preferably, the article further contains a second fabric layer disposed in facing relation with the first fabric layer and a scrim support layer interposed between and laminated to each of the fabric layers. These articles are useful for containing liquids such as those commonly encountered in medical, nursing, health care, hospital, laboratory and industrial fields. Due to their high tensile strength these articles are particularly useful in moving medical patients.

PRIORITY CLAIM [0001] This application claims priority form U.S. Provisional Application Ser. No. 60/272,372 filed Feb. 27, 2001 and U.S. Provisional Application Ser. No. 60/275,587 filed Mar. 12, 2001. FIELD OF THE INVENTION [0002] This invention relates generally to lubricating systems. BACKGROUND OF THE INVENTION [0003] Two-cycle engines were developed as a lower cost, lightweight alternative to four-cycle engines. Two-cycle engines are commonly employed to power outboard engines, chainsaws, lawn mowers, motorcycles, weed eaters, hedge trimmers, portable blowers, power generators, hydraulic power units, or any other application where lightweight, high RPM power is required. Two-cycle gasoline engines, unlike four-cycle gasoline engines, do not have oil filled crankcases as a means of lubricating the moving parts of the engine. Rather, two-cycle engines use a blended mixture of fuel and lubricating oil as a means of powering the engine and simultaneously lubricating various parts of the engine. This blended fuel mixture requires one of two engine setups. One setup pre-blends the fuel and oil before putting it in the engine. Also, a more current trend in two-cycle engine design keeps the fuel and oil separate in their own reservoirs, and blends the fuel and oil during operation. In this second setup, the ratio of fuel to oil may depend upon power requirements. Both of these technologies have created a variety of problems common to any engine. [0004] In the instance where an engine design does not employ pre-blended fuel, rather employing separate fuel and oil reservoirs, additional problems have developed. First, the oil reservoir must be independently checked to make sure that it contains an adequate amount of oil. As the viewing area for checking the oil level is often located in an undesirable location, an operator is required to contort themselves in awkward positions to accomplish this task. Often times, this inconvenience means that the oil level goes unchecked, which potentially leads to running the engine on no oil. [0005] The filling of the oil reservoir requires additional tools, more specifically, funnels, spouts, rags or other such devices used to aid in filling the oil reservoir. The use of funnels to fill the oil reservoir creates a couple of problems. First, the portion of the funnel located within the reservoir at the time of filling displaces a significant volume of oil. Consequently, when the funnel is removed, the oil volume is reduced by a volume equivalent to the funnel, thus a true full reservoir is not attained. Further, the funnel's bulky shape makes it difficult to determine when the oil reservoir is nearing full, often yielding in overfilling the oil reservoir. Regardless of whether an under-filled or over-filled reservoir is attained, additional problems result from the current oil reservoir technology. [0006] An additional problem with current engine lubrication technology is the potential of harm to the engine itself. More specifically, in instances where a reservoir is over-filled, oil residue is left upon the surface of the engine around the entrance to the reservoir. Consequently, dust and other foreign material, hazardous to internal engine components, collects around the opening to the reservoir. This combination of foreign material and oil can be introduced into the oil reservoir upon opening the reservoir or working around an open reservoir. Likewise, funnels and other such devices employed in filling the reservoir also collect dust that is potentially passed into the oil reservoir during a subsequent use. Thus, the state of current lubrication technology actually serves to increase the potential for engine harm. This problem is magnified when the environment in which these engines are employed is considered. For example, chain saws being used in forests produce vast quantities of sawdust, or motorcycles traveling along dusty roads. [0007] Aside from the ease of use and potential damage to the engine, current engine lubrication technology is also potentially damaging to other assets around the engine. Primarily, any spilled oil or blended fuel/oil not only attaches itself to the engine, but also to anything else it happens to contact. The fuel/oil has a tendency to undesirably attach itself to other assets in the area of the engine. For example, in a marine environment oil may attach itself to fishing gear, water-skiing equipment, SCUBA gear or other such assets. The oil is often detrimental to the other assets in that it causes fouling or actual deterioration of the assets itself. [0008] Aside from just the physical or tangible assets in the area of which the engine is employed, there are environmental concerns as well. Spillage or oil remnants are often deposited in the environment. This oil spillage in a marine application creates oil slicks on the surface of the water, damaging both surface and subsurface marine plants and animals. Further, oil spillage on dry land is absorbed into the soil potentially harming both plants and animals. Further, oil spillage is potentially damaging to water reservoirs and aquifers. [0009] The various problems of lubrication discussed above are not limited to internal combustion engines. Rather, all machine parts or elements have similar lubrication problems or considerations. More specifically, machine parts, including milling machines, presses, drills, fabrication units, lathes, agricultural equipment, construction equipment, earth moving equipment and other mechanical devices all require sufficient lubrication in order to function properly, and all are subject to the above discussed lubrication concerns and problems. [0010] Therefore, there exists a need to provide a clean lubricating oil or machine element lubricating system. SUMMARY OF THE INVENTION [0011] The present invention comprises a disposable or reusable lubricating oil container system wherein the disposable/reusable oil container functions as the primary oil reservoir for engines or other machine parts. The container snaps, plugs into or attaches to a self-tapping repository chamber connected to a lubrication system of an engine or other machine part. The container has a neck portion defining an opening for transferring lubricating oil. The oil is transferred from the container to an engine or other machine part via a sealing unit attached to the neck. Additionally, the container can be an existing retail container for motor and engine lubricants or can be specifically designed for a given purpose. [0012] In accordance with further aspects of the invention, a safety seal and cap are employed over the neck. [0013] In accordance with other aspects of the invention, the container includes a graduated section or a viewing section at its surface. [0014] In accordance with still further aspects of the invention, a strap employed secures the container to the carrier. [0015] In accordance with yet other aspects of the invention, the sealing unit attaches to the container by a male or female coupling unit. [0016] In accordance with other aspects of the invention, an attachment ring secures the sealing unit to the container. [0017] In accordance with still further aspects of the invention, carrier attachments secure the carrier to an engine or machine part for damping vibration. [0018] In accordance with yet other aspects of the invention, the carrier is a heat shield for the container. [0019] As will be readily appreciated from the foregoing summary, the invention provides a unique disposable lubricating cartridge system. BRIEF DESCRIPTION OF THE DRAWINGS [0020] The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings. [0021] [0021]FIG. 1 is a cross-sectional view of a disposable lubricating container and reservoir formed in accordance with the present invention; [0022] [0022]FIG. 2 is a top view of a carrier for the container shown in FIG. 2; and [0023] [0023]FIGS. 3 and 4 are cross-sectional side views of sealing units formed in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0024] This invention preferably functions with engines employing either premixed fuel/oil or separate fuel and oil reservoir engine arrangements. However, this invention is employable with any machine part. For clarity, only the internal combustion engine with a separate reservoir arrangement is illustrated here. More specifically, FIG. 1 shows a disposable lubricating container system 20 that includes a disposable lubricating container 24 with a sealing unit 44 that is used in conjunction with an oil reservoir 70 of an internal combustion engine 22 . [0025] The overall size, shape, and design of the container system 20 is a function of the environment in which the system is employed. The container 24 can be an existing retail container for motor or engine lubricants or can be designed for a specific purpose. For example, a small container is likely to be employed with devices where space and weight are a factor, e.g., chainsaws and hand-held lawn equipment. Further, where the employment environment permits, larger, more typical container geometries may be implemented. Additionally, the container 24 can have a graduated section and/or a viewing section located on a surface of the container 24 . In this manner, a visual inspection of the container 24 gives an oil level reading. [0026] In the embodiment shown in FIG. 1, the container 24 includes a reducing area 36 , a neck 38 , and locking recesses 62 . In the preferred embodiment, the reducing area 36 and the neck 38 are located at one end of the container 24 . However, other geometries for the disposable lubricating container 24 are considered within the scope of this invention. For example, the oil container 24 may be cylindrical, rectangular, trapezoidal, square, circular or any other shape. In each physical arrangement, the location and shape of the reducing area 36 and neck 38 are controlled by the spatial limitations of the container's deployment. The neck 38 and reducing area 36 are typically employed at the lowest elevation point of the container 24 as it is oriented on the machine element. In this manner all of the lubricating oil is allowed to drain from the container 24 prior to removal of the container 24 . [0027] The neck 38 provides an opening to the inside of the container 24 . The neck 38 is capped by a seal 52 prior to operation. Also, the neck 38 is designed to receive the mated sealing unit 44 a. The sealing unit 44 a houses a penetrating tube 42 a and a vent 40 acting as a self-tapping fluid transfer system. The penetrating tube 42 a is designed such that upon insertion of the sealing unit 44 a into the container 24 , the seal 52 is broken. The penetrating tube 42 a further serves as the transfer structure for passing the lubricating oil from the container 24 to the reservoir 70 , directly into a fuel/oil blending structure (not shown) if no reservoir is employed, or lubrication site of another machine element. In the preferred embodiment, the sealing unit 44 a is preferably constructed from hardened rubber. However, other materials, such as polymer-based plastic and resin, are considered within the scope of this invention. When the sealing unit 44 a is inserted into the neck 38 , the vent 40 is in fluid communication with a cartridge vent tube 30 located on the inside of the container 24 . The cartridge vent tube 30 provides air to enter the container 24 in order to equalize pressure within the container 24 as the lubricating oil is used up. [0028] The container system 20 also includes a carrier 48 for securing the container 24 to the engine 22 . However, the container system 20 can also be attached to a device employing the engine 22 or any other machine part without a carrier if desired. The carrier 48 includes locking arms 32 , each with a locking arm point 60 a. The locking arm points 60 are received by respective locking recesses 62 in a manner that keeps the container 24 from moving excessively. The locking arm points 60 a are located on longitudinally disposed ends of the carrier 48 . For example, the container can slide, snap or plug into or otherwise attach itself to the carrier. The locking arm points 60 are located on longitudinally disposed ends of the carrier 48 . For example, the locking recesses 62 may run longitudinally along the sides of container 24 , in a direction parallel to the central access of the container 24 . The carrier 48 is designed to mate with the locking recesses 62 of the container 24 such that the carrier 48 securely holds the container 24 . [0029] Material choice for the carrier is variable. The carrier is constructed of material allowing the locking arms 32 to elastically deform while inserting the container 24 into the carrier 48 while maintaining substantially rigid characteristics. Additionally, as the carrier acts as a heat shield for the container, the material choice for the carrier preferably is thermally resistant. The carrier 48 , in the preferred embodiment, is constructed of a thermal-resistant, polymer-based material, such as a thermo-set plastic. However, any other material capable of elastic deformation while maintaining substantial rigidity and thermal resistance is considered within the scope of this invention. For example, metallic, nonmetallic, or carbon-based materials, ceramics, alloys or composites thereof are employable as carrier 48 material. However, other container-attaching methods are considered within the scope of this invention. [0030] The carrier 48 includes carrier attachments 34 for affixing the carrier 48 to another rigid body, for example, an engine 22 or a housing. The attachments 34 serve the additional purpose of damping any vibration. As such, any combination of frictional fastening devices such as bolts, screws, rivets, pins, or the like with any known damping structure such as rubber bushings, plastic bumpers, or spring dampers are examples of attachments 34 . [0031] The transfer tube 42 a is connected to the reservoir 70 or other machine element and is in fluid communication with reservoir tubes 72 . The reservoir 70 is illustrative of the remaining lubrication system of an engine. For clarity purposes, the specifics of any engine components have been left out of the illustration. This invention is employable with any engine arrangement or lubrication system structure. [0032] The safety seal 52 and a cap (not shown) are located at the end of the neck 38 . The cap is typically threaded on the neck and serves as a primary containment device for the lubricating oil. The seal 52 serves a secondary containment device for the oil. Typically the seal is a metallic foil that adheres to the terminal end of the neck 38 . However, other seal 52 materials can be used, for example, rubber or polymer based substances. [0033] [0033]FIG. 2 is a top view of the carrier 48 . The carrier 48 includes a tie strap 78 as an additional securing device for the container 24 (see FIG. 1). The tie strap 78 is preferably an elastic member designed to extend over the container 24 and further assist in securing the container 24 to the carrier 48 . One end of the strap 78 is secured to a first side of the carrier 48 . The tie strap 78 contains a fastener 80 attached to the end of the strap 78 not secured to the carrier 48 . In the preferred embodiment, the fastener 80 is a hook. The hook of the fastener 80 attaches to a loop 82 that is secured to a side of the carrier 48 opposite the first side. Other fasteners are considered within the scope of this invention, for example, clamps, hook and loop arrangements, snaps, buckles, or clasps. Further, only one tie strap 78 is illustrated, however any number of straps, applied in any arrangement is within the scope of this invention. [0034] [0034]FIG. 3 depicts an alternate embodiment sealing mechanism. A sealing unit 44 b is designed as male insert that fits inside the neck 38 (see FIG. 1). The unit 44 b includes a penetrating tube 42 b. The tube 42 b is hollow with a funnel-like shape capable of puncturing the safety seal 52 . Further, the unit 44 b includes a sealing ring 56 a that is annularly located around the outer surface of the sealing unit 44 b. The sealing ring 56 a increases the internal biasing force of sealing unit 44 b against the internal surface of neck 38 and further helps to maintain the sealing unit's positive connection with the container 24 . The sealing ring 56 a also serves to prevent leakage of the lubricating oil inside the container 24 to the outside environment. Additionally, an attachment ring 84 is used to further maintain the connection between the sealing unit 44 and the container 24 . The attachment ring 84 is designed to threadably, or otherwise attach itself to the container 24 /neck 38 . [0035] [0035]FIG. 4 shows an alternative embodiment sealing mechanism. A sealing unit 44 c serves as a female counterpart for the neck 38 . In this embodiment, the internal diameter of the sealing unit 44 c is slightly larger then the external diameter of the neck 38 . When sealing unit 44 c is connected to the neck 38 , neck 38 is encompassed by the sealing unit 44 c and is biased by a sealing ring 56 b located on the inner wall of the unit 44 c. The unit 44 c includes a penetrating tube 42 c for puncturing the foil seal 52 and for transferring the lubricating oil within the container 24 to the reservoir 70 . [0036] While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.

A disposable lubricating container system including a disposable container, a carrier, a sealing unit and transfer tubes. The carrier rigidly attaches itself to an engine or other machine part and the container attaches to the carrier. The container mates with the carrier to securely hold the container while being easily removed or inserted into the carrier. The sealing unit attaches to a neck portion of the container and serves to provide a fluid transfer system for the lubricating oil or fuel/oil mixture from the container to the engine. Lubricating oil in the container is transfered to an existing oil reservoir, directly to engine components or other machine parts.

FIELD OF THE INVENTION This application is a continuation in part, claiming priority upon U.S. Ser. No. 09/599,693 filed Jun. 22, 2000, and a continuation-in part of application Ser. No. 09/599,695, filed Jun. 22, 2000. The invention relates to coating compositions for use with metallic substrates and more particularly to automotive refinish coating compositions intended for use on metallic substrates, and especially to two component polyurethane primers which can be sanded and recoated and are intended for use on steel substrates. BACKGROUND OF THE INVENTION As used herein, “automotive refinish” refers to compositions and processes used in the repair of a damaged automotive finish, usually an OEM provided finish. Refinish operations may involve the repair of one or more outer coating layers, the repair or replacement of entire automotive body components, or a combination of both. The terms “refinish coating” or “repair coating” may be used interchangeably. Automotive refinishers must be prepared to paint a wide variety of materials. Examples of commonly encountered materials are one or more previously applied coatings, plastic substrates such as RIM, SMC and the like, and metal substrates such as aluminum, galvanized steel, and cold rolled steel. Bare metal and plastic substrates are often exposed as a result of the removal of the previously applied coating layers containing and/or surrounding the defect area. However, it is often difficult to obtain adequate adhesion of refinish coatings applied directly to exposed bare substrates. Among the many factors influencing the degree of refinish coating/substrate adhesion are the type of exposed substrate, the presence or absence of adhesion promoting pretreatments and/or primers, the size of the exposed area to be repaired, and whether previously applied “anchoring” coating layers surround the exposed repair area. For example, refinish adhesion is particularly challenging when the exposed substrate is a bare metal such as galvanized iron or steel, aluminum or cold rolled steel. It is especially hard to obtain adequate refinish adhesion to galvanized iron. “Galvanized iron or steel” as used herein refers to iron or steel coated with zinc. “Steel” as used herein refers to alloys of iron with carbon or metals such as manganese, nickel, copper, chromium, molybdenum, vanadium, tungsten and cobalt. Refinish operations have traditionally used adhesion pretreatments to overcome the adhesion problems associated with the coating of bare metal substrates. Pretreatment as used herein may refer to either mechanical or chemical alterations of the bare metal substrate. Mechanical alterations used to obtain improved adhesion include sanding, scuffing, and the like. Chemical alterations include treatment of the substrate with compositions such as chromic acid conversion coatings, acid etch primers and the like. Although such pretreatments have obtained improved refinish adhesion, they are undesirable for a number of reasons. Most importantly, pretreatments are inefficient and expensive to apply in terms of material, time, and/or labor costs. Some chemical pretreatments also present industrial hygiene and disposal issues. Finally, the use of some pretreatments such as acid etch primers may contribute to water sensitivity and/or coating failure under test conditions of extreme humidity. Accordingly, it is highly desirable to eliminate the need for substrate pretreatment as regards the refinish coating of bare metal substrates. In addition, adhesion to bare metal substrates is improved when the defect area to be repaired is relatively small and is surrounded by previously applied coating layers. Such previously applied coating layers act as an ‘adhesion anchor’ to the refinish coating. However, many refinish repairs are of a size such that they lack any surrounding adhesion anchors. Moreover, such anchoring adhesion may be completely absent when replacement body parts are painted with a refinish coating. Finally, improvements in refinish adhesion to bare exposed metal substrates must not be obtained at the expense of traditional refinish coating properties. Such properties include sandability, recoatability, corrosion resistance, durability, ambient or low temperature cure, application parameters such as pot life, sprayability, and clean up, and appearance. Performance properties such as sandability, recoatability and corrosion resistance are particularly important for coating compositions intended for use as primers over steel substrates. However, it has been difficult for the prior art to obtain the proper balance with regard to sandability, recoatability, corrosion resistance, and metal adhesion requirements. Failure to provide adequate corrosion resistance or salt spray resistance typically manifests as “scribe creep”. “Scribe creep” refers to the degree of corrosion and/or loss of adhesion which occurs along and underneath film adjacent to a scribe made in a cured film after the scribed film has been placed in a salt spray test apparatus. The scribe generally extends down through the film to the underlying metal substrate. As used herein, both ‘corrosion resistance’ and ‘salt spray resistance’ refer to the ability of a cured film to stop the progression of corrosion and/or loss of adhesion along a scribe line placed in a salt spray test apparatus for a specified time. Cured films that fail to provide adequate salt spray resistance are vulnerable to large scale film damage and/or loss of adhesion as a result of small or initially minor chips, cuts and scratches to the film and subsequent exposure to outdoor weathering elements. Although urethane coatings have been known to be useful as refinish primers, they have not achieved the desired balance of properties. In particular, for polyurethane films to provide desirable salt spray resistance, they have typically relied upon the use of corrosion protection components containing heavy metal pigments such as strontium chromate, lead silica chromate, and the like. Unfortunately, sanding such a film produces dust that is environmentally disfavored due to the presence of the heavy metal containing pigments. Since sanding is a necessity for automotive refinish primers, this disadvantage can render the coating unusable in most commercial refinish application facilities. Accordingly, it would be advantageous to provide a coating which can provide adequate salt spray resistance but which is substantially free of any heavy metal containing pigments. Aluminum pigments have traditionally been used to provide a desirable metallic or lustrous appearance. For example, the 1977 Federation Series on Coatings Technology teaches that aluminum pigment containing paints have no specific anti-corrosive effect, such as is afforded by rust-inhibitive pigments traditionally used in commercially acceptable metal primers. Indeed, it is further taught that strontium chromate should be used in combination with aluminum pigments to provide aluminum containing paints having an anti-corrosive effect. Aluminum pigments, especially leafing aluminums, are known to produce an apparently continuous film of aluminum metal. Barrier pigments, especially platy or platelet pigments have been known to provide anticorrosive effects. However, leafing aluminums and barrier pigments have traditionally been somewhat disfavored due to recoatability and/or sanding performance issues. Moreover, the anticorrosive effect of the coating post sanding can be impaired due to the removal of the barrier or leafing layer. As a result, the use of aluminum pigments in primers is to some extent disfavored. The prior art has thus failed to provide a coating composition intended for use as a direct to metal primer which has commercially acceptable performance properties with regard to salt spray resistance, sandability, recoatability and adhesion to metal substrates, especially iron and/or steel. Accordingly, it is an object of the invention to provide a curable coating composition that can be applied directly to a metal substrate and provides a commercially acceptable level of salt spray resistance. It is a further object of the invention to provide a curable coating composition which has commercially acceptable performance properties with regard to direct to metal adhesion and salt spray resistance and further can be sanded without the production of environmentally disfavored dust. It is a further object of the invention to provide a curable coating composition which has commercially acceptable performance properties with regard to direct to metal adhesion, salt spray resistance, sandability, and further can be recoated with a second application of the curable coating composition of the invention or another curable coating composition. Finally, it is an object of the invention to provide a curable coating composition which has commercially acceptable performance properties with regard to direct to metal adhesion, salt spray resistance, sandability, and recoatability, especially a curable coating composition having a film forming component selected from the group consisting of polyurethane systems and epoxy/amine systems. SUMMARY OF THE INVENTION It has been found that these and other objects of the invention have been achieved with the use of a curable coating composition comprising a film-forming component selected from the group consisting of polyurethane systems and epoxy/amine systems, and a corrosion protection component consisting of aluminum selected from the group consisting of nonleafing aluminum pigments and present in an amount effective to prevent corrosion of the substrate, wherein a cured film of the coating applied to a metallic substrate has a pass rating after 480 hours in salt spray per ASTM B117, and is both sandable and recoatable. In a preferred embodiment of the invention, the aluminum pigment will be a lamellar shaped aluminum pigment and will be present in an amount of from 0.011 to 0.051 P/B. In a particularly preferred embodiment of the invention, the film forming component of the invention will be a polyurethane based coating system comprising a film forming polymer which is an active hydrogen containing group polymer and an isocyanate functional crosslinking agent. In a most preferred embodiment of the invention, the polyurethane film forming component will further comprise a composition comprising (I) an effective amount of a first compound having an acid number of from 70 to 120 mg KOH/g, a hydroxyl number of from 200 to 400 mg KOH/g, a number average molecular weight of from 300 to 700, and which is the reaction product of (a) at least one difunctional carboxylic acid, (b) at least one trifunctional polyol, (c) at least one chain stopper, and (d) phosphoric acid, and (II) an effective amount of a second compound comprising a carboxy phosphate ester having the formula: wherein R is an C5-C40 aliphatic group in which one or more aliphatic carbon atoms are substituted with lateral or terminal —COOR1 groups, wherein R1 is H, metal, ammonium, C1-C6 alkyl, or C6-C10 aryl, M is hydrogen, metal or ammonium and x is a number from 0 to 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The methods of the invention utilize two-component coating compositions. As used herein, the term “two-component” refers to the number of solutions and/or dispersions which are mixed together to provide a curable coating composition. Up until the point of mixing, neither of the individual components alone provides a curable coating composition. Once mixed, the resulting curable coating composition is applied to a substrate as quickly as possible. Typically, “as quickly as possible” means immediately after the mixing of the separate components or within eight (8) hours from the time the separate components are mixed, preferably less than one (1) hour after mixing. In a typical two-component application process the components are mixed together either (i) at the nozzle of a sprayer by the joining of two separate carrier lines at the nozzle or (ii) immediately upstream of the nozzle of a sprayer and then delivered to the nozzle via a single carrier line. Once at the nozzle, the mixture is immediately atomized into a mist which is directed at a substrate which is being coated with a film of the mixture of the two-components. Unlike one-component compositions, two-component compositions will generally cure in the absence of elevated temperatures. The individual components (I) and (II) will react with each other upon admixture to provide a crosslinked product, most often at ambient temperatures, or more particularly at temperatures of from 15 to 60° C. and most preferably from 24 to 60° C. The coating compositions of the invention comprise a corrosion protection component that consists essentially of, and more preferably consists of, one or more aluminum pigments. Although the composition may contain other filler and/or extender pigments such as talc, barrites, silicas and the like, such are not generally considered to substantially contribute to the salt spray resistance of cured films made from the coating compositions of the invention. Aluminum pigments suitable for use in the instantly claimed compositions are those aluminum pigments defined as nonleafing aluminum pigments. Although the prior art has taught that the leafing aluminum pigments may be superior in regards to possible anti corrosive effects due to the formation of a barrier-like layer, it has been found that the use of nonleafing aluminum pigments is advantageous in the coating composition of the invention. Leafing aluminum pigments have a hydrophobic nature which causes the pigments to float on the surface of water. When placed in a coating, the flakes of leafing aluminum pigments will orientate at or near the surface of the cured film. The flakes are normally oriented in a parallel overlapping fashion and provide a continuous metallic sheath. In contrast, nonleafing aluminum pigments are distributed evenly throughout the entire cured film. This distribution is generally attributed to the lubricants used during the aluminum pigment manufacturing process. Typically used lubricants are unsaturated fatty acids such as oleic acid. Suitable nonleafing aluminum pigments will have flake thicknesses of from 0.1 μm to 2.0 μm and diameters of from 0.5 μm to 200 μm. Acid-resistant grades of nonleafing aluminum pigments are particularly preferred. In general, the corrosion protection component of the invention will be present in an amount of from 0.011 to 0.051, more preferably 0.015 to 0.045, and most preferably from 0.025 to 0.040, all being based on P/B, i.e., the % by weight based on the total nonvolatile of the film-forming component, i.e., the total nonvolatile weight of the film-forming polymer and the crosslinking agent. Coating compositions of the invention will generally have a pass rating for 480 hour salt spray tests per ASTM B117, incorporated herein by reference. A pass rating is scribe creep of less than 3 mils along the edge of the scribe. More preferably, the coating compositions of the invention will have no more than 2 mils of adhesion loss along the scribe and most preferably will have scribe creep of from 0.5 to 1.5 mils. The coating compositions of the invention will also be free of blistering and rust spots upon completion of salt spray tests per ASTM B117. The two-component coating composition typically comprises a film-forming component that in turn comprises a film-forming polymer or binder and a crosslinking agent. The film-forming polymer is typically in a polymer or binder component (I), while the crosslinking agent is typically in a hardener component (II). Coating compositions of the invention may comprise any of the film-forming components used in the refinish coatings industry. Such coating compositions may rely on air dry lacquer film formation, film formation via chemical crosslinking, or a combination thereof Thermosetting films produced by chemical crosslinking are most preferred. Thermosetting coatings of the invention will comprise at least one film-forming polymer and at least one crosslinking agent. The film-forming polymer will comprise one or more functional groups reactive with one or more functional groups on the crosslinking agent. Examples of functional group combinations useful for the production of crosslinked coatings include, but are not limited to, active-hydrogen and isocyanate, epoxide and carboxylic acid, hydroxyl/carboxylic acid and/or urea-formaldehyde/melamine-formaldehyde, epoxide and amine, and the like. Although the film-forming polymer may contain any functional group reactive with the functional group present on the crosslinking agent, preferably the functional group present on the film-forming polymer is at least one functional group selected from the group consisting of hydroxyl, amine, carboxylic acid, epoxy and mixtures thereof. Especially preferred functional groups for use on the film-forming polymer are hydroxyl groups and amine groups, with hydroxyl groups being most preferred. Examples of suitable film-forming polymers are acrylic polymers, polyurethane polymers, polyesters, alkyds, polyamides, epoxy group containing polymers, and the like. Particularly preferred film-forming polymers will be difunctional, generally having an average functionality of about two to eight, preferably about two to four. These compounds generally have a number average molecular weight of from about 400 to about 10,000, preferably from 400 to about 8,000. However, it is also possible to use low molecular weight compounds having molecular weights below 400. The only requirement is that the compounds used as film-forming polymers not be volatile under the heating conditions, if any, used to cure the compositions. More preferred compounds containing reactive hydrogen groups are the known polyester polyols, polyether polyols, polyhydroxyl polyacrylates, polycarbonates containing hydroxyl groups, and mixtures thereof In addition to these preferred polyhydroxyl compounds, it is also possible to use polyhydroxy polyacetals, polyhydroxy polyester amides, polythioether containing terminal hydroxyl groups or sulphydryl groups or at least difunctional compounds containing amino groups, thiol groups or carboxy groups. Mixtures of the compounds containing reactive hydrogen groups may also be used. In a most preferred embodiment of the invention, the film-forming polymer reactable with the crosslinking agent is an acrylic resin, which may be a polymer or oligomer. The acrylic polymer or oligomer preferably has a number average molecular weight of 500 to 1,000,000, and more preferably of 1000 to 20,000. Acrylic polymers and oligomers are well-known in the art, and can be prepared from monomers such as methyl acrylate, acrylic acid, methacrylic acid, methyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, and the like. The active hydrogen functional group, e.g., hydroxyl, can be incorporated into the ester portion of the acrylic monomer. For example, hydroxy-functional acrylic monomers that can be used to form such resins include hydroxyethyl acrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, hydroxypropyl acrylate, and the like. Amino-functional acrylic monomers would include t-butylaminoethyl methacrylate and t-butylamino-ethylacrylate. Other acrylic monomers having active hydrogen functional groups in the ester portion of the monomer are also within the skill of the art. Modified acrylics can also be used. Such acrylics may be polyester-modified acrylics or polyurethane-modified acrylics, as is well known in the art. Polyester-modified acrylics modified with e-caprolactone are described in U.S. Pat. No. 4,546,046 of Etzell et al, the disclosure of which is incorporated herein by reference. Polyurethane-modified acrylics are also well known in the art. They are described, for example, in U.S. Pat. No. 4,584,354, the disclosure of which is incorporated herein by reference. Polyesters having active hydrogen groups such as hydroxyl groups can also be used as the film-forming polymer in the composition according to the invention. Such polyesters are well-known in the art, and may be prepared by the polyesterification of organic polycarboxylic acids (e.g., phthalic acid, hexahydrophthalic acid, adipic acid, maleic acid) or their anhydrides with organic polyols containing primary or secondary hydroxyl groups (e.g., ethylene glycol, butylene glycol, neopentyl glycol). Polyurethanes having active hydrogen functional groups are also well known in the art. They are prepared by a chain extension reaction of a polyisocyanate (e.g., hexamethylene diisocyanate, isophorone diisocyanate, MDI, etc.) and a polyol (e.g., 1,6-hexanediol, 1,4-butanediol, neopentyl glycol, trimethylol propane). They can be provided with active hydrogen functional groups by capping the polyurethane chain with an excess of diol, polyamine, amino alcohol, or the like. Although polymeric or oligomeric active hydrogen components are often preferred, lower molecular weight non-polymeric active hydrogen components may also be used in some applications, for example aliphatic polyols (e.g., 1,6-hexane diol), hydroxylamines (e.g., monobutanolamine), and the like. Examples of suitable crosslinking agents include those compounds having one or more functional groups reactive with the functional groups of the film-forming polymer. Examples of suitable crosslinking agents include isocyanate functional compounds and aminoplast resins, epoxy functional compounds, acid functional compounds and the like. Most preferred crosslinkers for use in the coating compositions of the invention are isocyanate functional compounds. Suitable isocyanate functional compounds include polyisocyanates that are aliphatic, including cycloaliphatic polyisocyanates, or aromatic. Useful aliphatic polyisocyanates include aliphatic diisocyanates such as ethylene diisocyanate, 1,2-diisocyanatopropane, 1,3-diisocyanatopropane, 1,6-diisocyanatohexane, 1,4-butylene diisocyanate, lysine diisocyanate, hexamethylene diisocyanate (HDI), 1,4-methylene bis-(cyclohexylisocyanate) and isophorone diisocyanate. Useful aromatic diisocyanates include the various isomers of toluene diisocyanate, meta-xylenediioscyanate and para-xylenediisocyanate, also 4-chloro-1,3-phenylene diisocyanate, 1,5-tetrahydro-naphthalene diisocyanate, 4,4′-dibenzyl diisocyanate and 1,2,4-benzene triisocyanate can be used. In addition, the various isomers of alpha.,.alpha.,.alpha.′,.alpha.′-tetramethyl xylene diisocyanate can be used.. In a most preferred embodiment, the crosslinking agent will comprise one or more components selected from the group consisting of hexamethylene diisocyanate (HDI), the isocyanurates of HDI, the biurets of HDI, and mixtures thereof, with the isocyanurates and biurets of HDI being particularly preferred. Suitable isocyanate functional compounds may be unblocked, in which case the coating composition should be utilized as a two component system, i.e., the reactive components combined shortly before application, or they may be blocked. Any known blocking agents, such as alcohols or oximes, may be used. In a most preferred embodiment of the coating compositions of the invention, the coating composition will be a two-component system with the reactive film forming polymer and the crosslinking agent combined shortly before application. In such an embodiment, the most preferred coating composition of the invention comprising the mixture of compounds (I) and (II) will be preferably incorporated with the film-forming polymer containing component. Hardener component (II) may also comprise one or more solvents. In a preferred embodiment, component (II) will include one or more solvents. Suitable solvents and/or diluents include aromatics, napthas, acetates, ethers, esters, ketones, ether esters and mixtures thereof. Additives, such as catalysts, pigments, dyes, leveling agents, and the like may be added as required to the coating compositions of the invention. In a most preferred embodiment of the invention, the coating compositions of the invention will further comprise an adhesion enhancing composition comprising a mixture of a first compound (I) and a second compound (II), wherein compound (I) and compound (II) cannot be the same. It has unexpectedly been found that the combination of compounds (I) and (II) provides an improvement in refinish adhesion, i.e., the adhesion of a refinish coating to a bare exposed metal substrate, which is better than that obtained with the use of either compound (I) or compound (II) alone. Compound (I) is a low molecular weight polyester compound having both acid and hydroxyl functionality. It will generally have a number average molecular weight in the range of from 150 to 3000, preferably from 300 to 1000, and most preferably from 400 to 600. Compound (I) will generally have a polydispersity of from 1.00 to 2.00, with a polydispersity of 1.50 being most preferred. Suitable compounds (I) will also have an acid number in the range of from 70 to 120 mg KOH/g, preferably from 70 to 100 mg KOH/g, and most preferably from 70 to 80 mg KOH/g. In addition, suitable compounds (I) will have a hydroxyl number in the range of from 200 to 400 mg KOH/g, more preferably from 300 to 400 mg KOH/g and most preferably from 330 to 360 mg KOH/g. Compound (I) generally comprises the reaction product of the reaction of (a) at least one difunctional carboxylic acid, (b) at least one trifunctional polyol, (c) at least one chain stopper, and (d) phosphoric acid. Examples of suitable difunctional carboxylic acids (a) include adipic acid, azeleic acid, fumaric acid, phthalic acid, sebacic acid, maleic acid, succinic acid, isophthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, dimer fatty acids, itaconic acid, glutaric acid, cyclohexanedicarboxylic acid, and mixtures thereof. Preferred difunctional carboxylic acids (a) are adipic acid and azeleic acid. Adipic acid is most preferred for use as difunctional carboxylic acid (a). The at least one trifunctional polyol (b) may be branched or unbranched, but branched trifunctional polyols are preferred. Examples of suitable trifunctional polyols (b) are trimethylolpropane, trimethylol ethane, glycerin, 1,2,4-butanetriol, and mixtures thereof. Preferred trifunctional polyols (b) are trimethylolpropane and trimethylol ethane, with trimethylolpropane being a most preferred trifunctional polyol (b). The at least one chain stopper will generally be a carboxylic acid that is different from the at least one difunctional carboxylic acid (a). Monocarboxylic acids are preferred. Suitable carboxylic acids (c) will preferably contain one or more aromatic structures and will preferably contain some branched alkyl groups. Examples of suitable carboxylic acids (c) include para-t-butyl benzoic acid, benzoic acid, salicylic acid, 2-ethylhexanoic acid, pelargonic acid, isononanoic acid, C 18 fatty acids, stearic acid, lauric acid, palmitic acid, and mixtures thereof. Preferred carboxylic acids (c) include para-t-butyl benzoic acid, benzoic acid, and 2-ethylhexanoic acid, with para-t-butyl benzoic acid being most preferred. Phosphoric acid (d) should be added to the reaction mixture in an amount of from 0.03 to 0.20, preferably from 0.05 to 0.15, and most preferably from 0.07 to 0.10. It will be appreciated that while phosphoric acid is most preferred, phosphate esters such as butyl or phenyl acid phosphate and the like are suitable for use as component (d) in the preparation of compound (I). Polymerization of the reactants may occur at typical esterification conditions, i.e., 200-230° C. reaction temperature while continuously removing water as a reaction by-product. Solvents that facilitate the removal of water from the reaction system (those that form an azeotrope) such as xylenes, may be used. Reactants (a), (b), (c) and (d) will generally be used in a molar ratio of 4.2:4.9:0.01:0.0005 to 5.1:5.6:0.7:0.005, preferably from 4.4:5.0:0.02:0.0008 to 5.0:5.5:0.6:0.003, and most preferably from 4.8:5.2:0.02:0.0009 to 4.9:5.4:0.06:0.002. A commercially available and most preferred example of compound (I) is Borchigen HMP, commercially available from the Wolff Walsrode division of the Bayer Corporation of Burr Ridge, Ill., U.S.A. Compound (II) comprises a carboxy phosphate ester having the formula: wherein M is hydrogen, metal or ammonium, x is a number from 0 to 3, and R is a saturated or unsaturated C 5 -C 40 aliphatic group in which one or more of the aliphatic carbon atoms can be substituted or replaced with a halogen atom (such as fluorine or chlorine), a C 1 -C 6 alkyl group, a C 1 -C 6 alkoxy group, a C 6 -C 10 aromatic hydrocarbon group, preferably phenyl or naphthyl, or a C 6 -C 10 aromatic hydrocarbon group that is substituted with one or more (preferably 1 to 3) C 1 -C 6 alkyl groups or —COOR 1 groups wherein R 1 is H, metal, ammonium, C 1 -C 6 alkyl, or C 6 -C 10 aryl, or mixtures thereof. In preferred compounds (II), R will contain one or more C 6 -C 10 aromatic hydrocarbon groups, and most preferably, one or more C 6 -C 10 aromatic hydrocarbon groups which contain one or more, preferably at least two, —COOR 1 groups wherein R 1 is H, metal, ammonium, C 1 -C 6 alkyl, or C 6 -C 10 aryl. In a most preferred compound (II), R will contain at least one C 6 -C 10 aromatic hydrocarbon group and at least two —COOR 1 groups wherein R 1 is H, metal, ammonium, C 1 -C 6 alkyl, or C 6 -C 10 aryl. R 1 will most preferably be a C 1 -C 6 alkyl or a C 6 -C 10 aryl group. The —COOR 1 groups may be lateral or terminal. It will be appreciated that when R 1 is H, compound (II) will comprise one or more free carboxylic acid groups. Similarly, when R 1 is a metal or ammonium ion, compound (II) will have one or more carboxylic acid salt groups. Finally, when R 1 is a C 1 -C 6 alkyl or a C 6 -C 10 aryl, compound (II) will comprise one or more ester groups. It will be appreciated that suitable compounds (II) can and most preferably will comprise mixtures of compounds having the formula: wherein R, M, x, and R 1 are as described above. However, in a most preferred embodiment, such a mixture will contain one or more molecules having the above structure wherein x is 1 or 2, preferably 1, R has at least one C 6 -C 10 aromatic hydrocarbon group substituted with at least one, preferably two, —COOR 1 groups wherein R 1 is H or a C 1 -C 6 alkyl or C 6 -C 10 aryl, most preferably a C 1 -C 6 alkyl, and M is H. Compound (II) will generally have a number average molecular weight in the range of from 600 to 1200, preferably from 700 to 900, and most preferably from 750 to 850. Compound (II) will generally have a polydispersity of from 1.00 to 2.00, with a polydispersity of 1.00 to 1.50 being preferred and a polydispersity of 1.15 to 1.35 being most preferred. Suitable compounds (II) will also have an acid number in the range of from 50 to 200 mg KOH/g, preferably from 100 to 180 mg KOH/g, and most preferably from 120 to 160 mg KOH/g. In addition, suitable compounds (II) will have a hydroxyl number in the range of from 100 to 250 mg KOH/g, preferably from 120 to 230 mg KOH/g, and most preferably from 150 to 200 mg KOH/g. Suitable compounds (II) generally comprise the reaction product of (a) at least one difunctional polyol, (b) phosphoric acid, and (c) at least one trifunctional carboxylic acid. Examples of suitable difunctional polyols (a) include neopentanediol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, hydrogenated bisphenol A, 1,6-hexanediol, hydroxypivalylhydroxypivalate, cyclohexanedimethanol, 1,4-butanediol, 2-ethyl-1,3-hexandiol, 2,2,4-trimethyl-1,3-pentandiol, 2-ethyl-2-butyl-1,3-propanediol, 2-methyl-1,3-propanediol, and mixtures thereof. Preferred difunctional polyols (a) are neopentane diol and 2-ethyl-2-butyl-1,3-propanediol, with neopentane diol being most preferred. The at least one trifunctional carboxylic acid (c) may be aromatic or aliphatic in nature, but aromatic containing structures are most preferred. Examples of suitable trifunctional carboxylic acids are trimellitic acid, 1,3,5-benzenetricarboxylic acid, citric acid, and mixtures thereof. Preferred trifunctional carboxylic acids are 1,3,5-benzenetricarboxylic acid and trimellitic acid, with trimellitic acid being most preferred. Phosphoric acid (c) is as described above with respect to (I(d)). Polymerization of the reactants (a), (b), and (c) may occur at typical esterification conditions, i.e., 200-230° C. reaction temperature while continuously removing water as a reaction by-product. Solvents that facilitate the removal of water from the reaction system (those that form an azeotrope) such as xylenes, may be used. The reaction can also be subsequently admixed with suitable solvents. Reactants (a), (b), and (c) will generally be used in a ratio of 6.3:3.0:0.05 to 7.9:4.0:0.15, preferably from 6.7:3.2:0.07 to 7.6:3.8:0.12, and most preferably from 6.9:3.3:0.09 to 7.3:3.5:0.11. A commercially available and most preferred example of compound (II) is LUBRIZOL™ 2063, available from the Lubrizol Corp of Wickliffe, Ohio. Compound (I) will typically comprise from 50 to 80% by weight of the mixture of compound (I) and compound (II), preferably from 60 to 75% by weight, and most preferably from 65 to 70% by weight, based on the total weight of the mixture of compound (I) and compound (II). Compound (II) will comprise from 20 to 50% by weight of the mixture of compound (I) and compound (II), preferably from 25 to 40% by weight, and most preferably from 30 to 35% by weight, based on the total weight of the mixture of compound (I) and compound (II). The composition comprising the mixture of compound (I) and compound (II) will typically be present in a coating composition in an amount of from 0.10 to 1.00% by weight, preferably from 0.10 to 0.30%, and most preferably from 0.15 to 0.25% by weight, based on the total nonvolatile weight of the coating composition. The mixture of compound (I) and compound (II) may incorporated into finished coating compositions by conventional mixing techniques using mixing equipment such as a mechanical mixer, a cowles blade, and the like. Although the additives may be added during the manufacturing process or subsequently to a finished coating, those skilled in the art will appreciate that in a most preferred embodiment, the additives will be added post grind during the manufacturing process. Although the mixture of compound (I) and compound (II) may be used in single or two component systems, use in two-component systems is preferred, particularly where the mixture of compounds (I) and (II) is placed in the resin component of a two component system. Finally, although a variety of packaging options are suitable for containing the coating compositions of the invention, it is most preferred that coating compositions containing the mixture of compounds (I) and (II) be packaged in epoxy or phenolic lined cans. Packaging in such containers has been found to ensure the retention of optimum adhesion characteristics. The mixture of compound (I) and compound (II) when used in coating compositions provides improved adhesion of the coating composition to bare untreated metal substrates, including aluminum and galvanized steel substrates. The coating compositions of the invention may be stored as such for prolonged periods at room temperature without gel formation or undesirable changes. They may be diluted as required to a suitable concentration and applied by conventional methods, for example, spraying or spread coating, and cured by exposure to ambient temperatures of from 70 to 75° F. for a period of from 1 to 3 hours, preferably from 1.5 to 2 hours. However, sandable films of the coating compositions of the invention comprising mixtures of compounds (I) and (II) may also be obtained upon exposure of the applied coating to temperatures in the range of from at least 120° F., more preferably up to 140° F., for periods of from 30 to 50 minutes, preferably from 30 to 40 minutes.

The invention provides a coating composition for use with metallic substrates that provides a unique balance of required properties. In particular, the coating composition of the invention simultaneously provides desirable levels of adhesion to metal, sandability without the production of harmful dust, corrosion resistance, and recoatability. The coating composition of the invention comprises a polyurethane or epoxy/amine film-forming component, and a corrosion protection component consisting of aluminum selected from the group consisting of nonleafing aluminum pigments, the corrosion protection component being present in the composition in an amount effective to prevent corrosion of the substrate. A cured film of the coating applied to a steel substrate has a pass rating after 480 hours in salt spray per ASTM B117.

CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims the benefit of U.S. Provisional Application Nos. 61/285,684 filed Dec. 11, 2009, and 61/406,644 filed Oct. 26, 2010, both of which are incorporated herein by reference in their entireties. FIELD OF THE INVENTION The present invention relates generally to a system and method for detecting the position of an object within a touch screen or a position sensing system and a retroreflective or prismatic film used thereby. More specifically, the invention concerns a low profile position detecting system for use in touch screens or position sensing systems that employs a large spacing between source and detector in the plane of the screen, and a prismatic film that is brightly retroreflective at larger observation angles, and over a broad range of entrance angles. BACKGROUND OF THE INVENTION Some position detection systems related to touch screens sense the interruption of radiation (e.g., light) by an interposing opaque object (e.g., a finger, stylus, etc.). Such systems generally utilize radiation transmitters such as LEDs or IR emitters which are typically mounted in opposing corners of a same side of the touch screen. Each LED or IR emitter light source transmits a 90° fan-shaped pattern of light across the field of the touch screen, parallel to the viewing field surface. A retroreflective sheeting material may be positioned around the perimeter of the active field of the touch screen, as disclosed in U.S. Pat. No. 4,507,557. The retroreflective sheeting material is generally arranged to reflect light received from the LED light sources back toward the originating source. Light incident on the front surface of the sheeting impinges on retroreflective elements, and is reflected back out through the front surface in a direction nominally 180 degrees to the direction of incidence. Digital cameras are located in the same opposing corners where the LED light sources are mounted to detect the retroreflected light that passes across the field of the touch screen and sense the existence of any interruption in this radiation by an opaque object. One problem with the use of certain conventional retroreflective sheeting materials in touch screen applications and/or position detection systems is that dirt and/or moisture may penetrate the structure and adversely affect retro reflectivity of the retroreflective sheeting material. Another problem with conventional retroreflective sheeting material used in touch screen applications and/or position detection systems is difficulty in obtaining a uniform background throughout the area of interest (e.g., the detection area), against which the opaque object can be contrasted. Many conventional retroreflective sheeting material designs provide a non-uniform background and have portions, especially at or near the corner regions where the detected signal is very low. This makes it difficult to detect movement of the opaque object in such areas. In operation, the position of the interposing object is typically determined by triangulation. When an interposing object such as a finger tip interrupts the pattern of light beams radiated from the LED light sources or IR emitters, a discrete shadow is created along a horizontal axis in the pattern of retroreflected light received by the two digital cameras. The digital cameras each generate a signal in which the discrete shadow registers as a dip in light intensity along a point of the horizontal axis of the camera field of view. A digital control circuit receives these digital camera signals and converts the horizontal position of the shadow into angles θ 1 , θ 2 whose vertex originates with the digital cameras. Because the digital cameras are separated a known distance D at opposite ends of a same side of the touch screen, the y coordinate of the interposing object can be computed by the digital control circuit using the formula y=D/(1/tan θ 1 +1/tan θ 2 ), and the x coordinate may be computed as x=y(1/tan θ 1 ). BRIEF SUMMARY OF THE INVENTION The embodiments of the present invention described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present invention. While such prior touch-screen configurations are generally adequate for their intended purpose, the applicant has observed that such touch-screen configurations can only reliably detect a single touch at one time. A double touch will produce two dips in each camera signal, one for each object. Since it may not be clear which dip in the second camera signal corresponds to a given dip in the first camera signal, the resulting signal data may be ambiguous, making it impossible to determine with certainty the coordinate location of the two interposing objects. A first aspect of the invention is the collocation of both source and detector in the plane of the touch-screen. This allows the dimension of the camera perpendicular to the plane of the screen to be minimized. The location of the source along the horizontal axis of the camera also maximizes parallax effects. A second aspect of the invention relates to a position detection system having cameras that utilize parallax to unambiguously determine the position of an interposing object. To this end, the position detection system comprises a camera positioned to receive electromagnetic radiation traversing a detection area that generates a signal representative of an image; two spaced-apart sources of electromagnetic radiation positioned adjacent to said camera for outputting electromagnetic radiation that overlaps over at least a portion of a detection area, and a prismatic film positioned along a periphery of at least a portion of the detection area that retroreflects said electromagnetic radiation from said two sources to said camera. In such a configuration, the camera generates a double-image of any opaque, interposing object in the detection area which in turn allows a digital processor to make a parallax-based computation of the location of an object in the detection area based on the angle and distance of the object from the camera lens. If two cameras are mounted in opposing corners of a same side of the touch screen and two dual radiation sources are used in combination with these cameras, an unambiguous determination can be made of the location of two simultaneously interposing objects. Alternatively, if only a single touch capability is desired, then only a single camera in combination with a dual radiation source is necessary. The applicant further observed that retroreflective properties of prior art prismatic films limit the accuracy of the parallax-based location computation. The accuracy of such computations increases with the distance of separation between two sources of electromagnetic radiation. However, prior art prismatic films have a limited range of observation angles for efficient retroreflection. Consequently, the farther apart the two sources are spaced, the dimmer or darker one or the other or both of the parallax images becomes, and the smaller the signal-to-noise ratio becomes. Accordingly, a third aspect of the invention is the provision of a prismatic film that is brightly retroreflective over an unusually broad range of observation angles along the horizontal axis of the film. To this end, the prismatic film of the invention includes a plurality of triangular cube corner retroreflective elements having dihedral angle errors e 1 , e 2 , and e 3 such that e 1 ≈e 2 ≈0 and e 3 ≈0 Preferably, |e 1 | and |e 2 | are between about 0.02° and 0.20°. About half of the plurality of triangular cube corner retroreflective elements may have dihedral angle errors e 1 and e 2 between about 0.02° and 0.20°, and the remaining half of the plurality of triangular cube corner retroreflective elements have dihedral angle errors e 1 and e 2 between about −0.02° and −0.20°. Additionally, the triangular cube corner elements may be canted edge-more-parallel between about 8° and 20°. Finally, to further enhance retroreflectivity over a broad range of entrance angle, the prismatic film may include a metallized layer disposed over at least a portion of the retroreflective substrate. In a still further aspect of the present invention a prismatic film, is described and includes an unpinned prismatic film having a retroreflective substrate including a plurality of triangular cube corner retroreflective elements; and wherein the pattern of retroreflected light has a horizontal spread greater than a vertical spread at entrance angles of 0° and 60°. In addition, the spread in the horizontal direction is 1.5 times greater than in the vertical direction. A prismatic film in one or more of the foregoing embodiments wherein the triangular cube corners elements are canted between −10° and −6° and in a further embodiment between −15° and −6°. In a still further exemplary embodiment of the presently described invention, a prismatic film, includes an unpinned prismatic film having a retroreflective substrate including a plurality of triangular cube corner retroreflective elements. The retroreflective cube corner elements have dihedral angle errors e 1 , e 2 , and e 3 such that e 1 ≈e 2 0 and e 3 ≈0, where the plurality of triangular cube corner elements are canted between −10° and −6°. Other features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description. It is to be understood, however, that the detailed description of the various embodiments and specific examples, while indicating preferred and other embodiments of the present invention, are given by way of illustration and not limitation. Many changes and modifications within the scope of the present invention may be made without departing from the spirit thereof, and the invention includes all such modifications. BRIEF DESCRIPTION OF THE DRAWINGS These, as well as other objects and advantages of this invention, will be more completely understood and appreciated by referring to the following more detailed description of the presently preferred exemplary embodiments of the invention in conjunction with the accompanying drawings, of which: FIG. 1 is a schematic view of a touch screen system in accordance with aspects of the present invention; FIG. 2 is a cross-sectional view of the touch screen system of FIG. 1 in accordance with the present invention; FIGS. 3 and 4 are cross-sectional views of prismatic film embodiments in accordance with the present invention; FIG. 3 a is a cross sectional view of a prismatic film embodiment in accordance with the present invention; FIG. 5 is a plan view of prismatic film with an array of canted cube corner retroreflective elements as shown in FIGS. 3 and 4 ; FIG. 6 is a plan view of an exemplary canted cube corner retroreflective structure in accordance with aspects of the present invention; FIG. 7 is a plan view of unpinned prismatic film of canted cube corner retroreflective elements as shown in FIG. 6 ; FIG. 8 is a cross-sectional view of FIG. 5 taken along line 9 - 9 ; FIG. 9 illustrates the dihedral angle errors e 1 , e 2 , e 3 present on the faces of the cube corners of the invention; FIGS. 10A-10H are spot diagrams of conventional cube corners canted edge more parallel at 0°, 16° and −8° for entrance angles (beta) of 0° and 60°; FIGS. 11A-11D are spot diagrams of cube corners of the invention canted edge more parallel at 0° and 16° for entrance angles (beta) of 0° and 60°; FIGS. 12A , 12 C, 12 E, 13 A, 13 C, 13 E are simulated light return patterns generated by unaberrated conventional cube corners canted edge more parallel at 0° and 16° for entrance angles (beta) of 0°, 60° and −8°; FIGS. 12B , 12 D, 12 F, 13 B, 13 D, 13 F are simulated light return patterns generated by cube corners aberrated according to the instant of the invention canted edge more parallel at 0° and 16° for entrance angles (beta) of 0°, 60° and −8°; and FIG. 14 is an exemplary plot of camera signal for different screen sizes having a 16/9 aspect ratio. DETAILED DESCRIPTION OF THE INVENTION The present invention is now illustrated in greater detail by way of the following detailed description which represents the best presently known mode of carrying out the invention. However, it should be understood that this description is not to be used to limit the present invention, but rather, is provided for the purpose of illustrating the general features of the invention. One disadvantage of using arrays of prisms with positive cant in a touch-screen is the phenomenon of “sparkles.” At certain entrance angles, light from the LED can enter the prismatic film, bounce off of just two of the cube corner faces and return to the camera aperture. This creates a sharp “spike” in the camera signal at that particular angle. The presence of “spikes” in the camera signal is undesirable. So for many applications, it is desirable to choose a cant for which sparkles only occur at entrance angles not seen in the touch-screen geometry. Typical touch-screens see entrance angles ranging out to about 60°. The following graph shows the location of sparkles for touch-screens with the retroreflective strip perpendicular to the plane of the screen. For cants of +7° and +15.5°, one can read off the location of the sparkles: 45° and 30°, respectively. It can be seen that no sparkles occur for the entrance angles of interest (0°-60°, if the cant ranges from about −19° to −0.5°. In a similar manner, prisms with cant=+15.5° give a sparkle at an entrance angle of about 30°. If the retroreflective film is tilted slightly, so as to no longer be perpendicular to the plane of the touch-screen, the location of the sparkle can change somewhat. To illustrate this, the following graphs show the retroreflective efficiency of triangular cube corners with various cants, as a function of entrance angle (β) and orientation angle (ω s ). Overlaid in white are the angles at which a “sparkle” will occur. Overlaid in black are the angles encountered in the touch-screen geometry. The four black lines correspond to different tilts of the retroreflective film (−30°, −10, 10°, 30°. The graphs show that avoiding sparkles in the case of a tilted retroreflector requires a narrower range of cants. For example, a touch-screen with retroreflected film tilted 10° will avoid sparkles if the cant ranges from about −15° to about 0°. U.S. Pat. No. 4,588,258 to Hoopman discloses retroreflective articles having a generally negative cant producing wide angularity, when using sets of matched pairs with the cube axes of the cubes in each pair being tilted toward one another. For purposes of this application, certain terms are used in a particular sense as defined herein and other terms in accordance with industry accepted practice, such as current ASTM definitions, for example. U.S. patent application Ser. No. 12/351,913, entitled “Retroreflector for use in touch screen applications and position sensing systems” filed Jan. 12, 2009 (having a common inventor and assigned to the same assignee as the present application) is hereby incorporated by reference herein as is necessary for a complete understanding of the present invention. The term “cube” or “cube corner elements” (also “cube corner prisms” or “cube corners” or “cube corner retroreflective elements”) as used herein includes those elements consisting of three mutually intersecting faces, the dihedral angles of which are generally on the order of 90 degrees, but not necessarily exactly 90 degrees. The term “cube shape” as used herein means the two-dimensional geometric figure defined by the projection of the cube perimeter in the direction of the principal refracted ray. For example, a triangular cube has a cube shape that is a triangle. The term “dihedral angle error” as used herein refers to the difference between the actual dihedral angle and 90 degrees. Each cube corner element has three dihedral angle errors, e 1 , e 2 , and e 3 . For a canted cube corner with a cube shape that is an isosceles triangle, we adopt a convention whereby the label e 3 is assigned to the dihedral angle between the two faces with the same (but mirrored) shape. The term “retroreflective substrate” as used herein means a thickness of a material having an array of either male or female cube corner elements formed on a second surface thereof. The first surface can be flat, or can be somewhat uneven in a pattern generally corresponding to the array of cube corner elements on the back surface. For male cube corner elements, the expression “substrate thickness” means the thickness of material on which the cube corner elements rest. For female cube corner elements, the expression “retroreflective substrate thickness” means the total thickness of material into which the female cube corner elements form cavities. The term “cube axis” as used herein means a central axis that is the tri-sector of the internal space defined by the three intersecting faces of a cube corner element. The term “canted cube corner” as used herein means a cube corner having its axis not normal to the sheeting surface. Cant is measured as the angle between the cube axis and the sheeting surface normal. It is noted that when there is cant, a plan view normal to the sheeting surface shows the face angles at the apex not all 120 degrees. The term “entrance angularity” as used herein means the angle between the illumination axis and the optical axis (retroreflector axis). The entrance angle is measured between the incident ray and the retroreflector axis. Entrance angle is a measure only of the amount by which an incident ray is angled to the retroreflector axis and is not concerned with the normal. The term “face-more-parallel cant” (or “canted in a direction face-more-parallel or “canted in a face-more-parallel direction”) and “edge-more parallel cant” as used herein refer to the positioning of the cube relative to the principal refracted ray. When the angles between the cube faces and the principal refracted ray are not all equal to 35.26°, the cube is “face-more-parallel” or “edge-more-parallel” depending upon whether the face angle with respect to the principal refracted ray that is most different from 35.26° is respectively greater or less than 35.26°. In the case of sheeting or other retroreflectors for which the principal refracted ray is nominally perpendicular to the front surface of the retroreflector, then for face-more-parallel cubes the selected cube face will also be more parallel to the reflector front surface than will any face of an uncanted cube. An exemplary position detection system 100 in accordance with aspects of the present invention is illustrated in FIG. 1 . FIG. 1 illustrates a plan view of a display 102 (e.g., a computer display, a touch screen display, etc.) having a screen area or viewing field 104 surrounded by a raised frame or border 106 . While shown in the context of a computer display, the position detection system 100 may be used in any type of optical position detection system. The inner surface of the border 106 , which is generally substantially perpendicular to the viewing field 104 of the display screen 102 is provided with a prismatic film (also referred to herein as retroreflective film 108 ). The prismatic film 108 , which is discussed in detail below, provides a retroreflective surface around at least a portion of the viewing field 104 (also referred to herein as a detection field). That is, the prismatic film 108 provides a surface that reflects radiation from an originating radiation source back toward the originating source. The composition of the prismatic film 108 may be applied directly to the frame 106 through use of an adhesive or other attachment means, or it may be manufactured first in the form of an adhesive tape, which is subsequently applied to the inner surface of the border 106 . It is desirable to align the prismatic film in such a manner that a plane of maximum entrance angularity associated with the prismatic film is substantially parallel to the viewing field, the detection field and/or the display to optimize possible detection of an object in the area of interest. As discussed more fully below, the prismatic film 108 comprises a retroreflective film having multiple layers, wherein one of the layers includes a plurality of triangular cube corner retroreflective elements that reflect the incoming radiation. In an alternate embodiment, the film may include only a single layer that includes a plurality of triangular cube corner retroreflective elements. The triangular cube corners may have a negative cant ranging from between −10° and −6°. The embodiments of the present invention described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present invention. The position detection system 100 shown in FIG. 1 further includes two sources of dual radiation 110 , 112 , each of which includes two spaced-apart point sources (or substantially point sources) 111 a , 111 b and 113 a , 113 b . The first source of dual radiation 110 may be disposed at one corner of the viewing field 104 and the second source 112 may be disposed at another corner of the viewing field 104 . In a preferred embodiment, the first source and second sources of dual radiation 110 , 112 are mounted along a same side 114 . As shown in FIG. 1 , side 114 may not be provided with the prismatic film 108 , which is provided on the other three sides of the display 102 . One of ordinary skill in the art will readily appreciate that the precise location of the dual radiation sources 110 , 112 may vary depending a variety of design considerations, including environment, application, etc. Likewise, one of ordinary skill in the art will appreciate that the entire perimeter of the viewing field may be surrounded by prismatic film 108 . The sources of dual radiation 110 , 112 together illuminate the entire viewing field 104 with radiation, which extends in a direction parallel to the plane of the viewing field 104 . The sources of dual radiation may provide any desirable spectrum of electromagnetic radiation. That is, the sources of radiation may be selected to operate in any desired frequency range or at any desired wavelength. For example, the sources may be a source of infrared radiation, radio frequency radiation, visible light radiation, light emitting diode (LED), laser, IR emitter, etc. In a preferred embodiment, the point sources 111 a , 111 b and 113 a , 113 b of the dual radiation sources 110 , 112 are infrared light emitting diodes. The prismatic film 108 provided around the perimeter of the viewing field reflects the infrared radiation back toward the respective originating sources as is indicated by the arrows within the viewing field. Thus, for example, the dual rays of infrared radiation originating from the point sources 111 a , 111 b of source 110 extend outward to the side of the display screen and are reflected 180° to return to the source 110 , as shown in FIG. 1 . Electromagnetic radiation is reflected backward toward its source by the prismatic film 108 . One or more of the layers that overlie the triangular cube corner retroreflective elements of the prismatic film 108 function to allow most of the infrared radiation through (e.g., a double-pass transmission of about 74% to about 100%) and substantially block visible light, which gives the film an appearance of darkness. These aspects of the invention will be further discussed below. The point sources 111 a , 111 b and 113 a , 113 b of the dual radiation sources 110 , 112 are symmetrically disposed along a horizontal axis H 1 on either side of lenses 115 and 116 , respectively (as is shown in FIG. 2 ), for reasons which will become apparent hereinafter. The axis H 1 is coplanar with the longitudinal axis H 2 of the prismatic film 108 . Lenses 115 and 116 are further disposed in front of cameras 117 , 118 , respectively. The lenses 115 and 116 focus the retroreflected radiation onto an image capturing device of the cameras 117 and 118 . The point sources 111 a , 111 b and 113 a , 113 b are positioned a distance x away from the lenses 115 , 116 as indicated in FIG. 2 . In the preferred embodiment, the distance x is preferably between about 1 and 6 millimeters for touch screens whose longest side ranges from between about 17 to 30 inches for reasons discussed in detail hereinafter. More preferably, the distance x is between about 2 and 4 millimeters for touch screens of such sizes. The cameras 117 , 118 may be line-scan cameras and/or area-scan cameras. The image capturing device of the cameras 117 , 118 may include a charge coupled device (CCD) sensor that is formed by an array of photosensitive elements (e.g., pixels). A line scan camera generally acquires an image on a single line of pixels. An area scan camera, like a conventional camera, includes a CCD sensor (usually rectangular in form) of pixels that generates two dimensional frames corresponding to length and width of the acquired image. Reflected radiation passes through corresponding lenses (e.g., lens 115 or lens 116 , depending on the location of the radiation source) and forms an image of an object detected by CCD sensor. The CCD sensor converts the detected radiation on a photo diode array to an electrical signal and outputs the measured amount. One single scanning line of a line scan camera may generally be considered as a one-dimensional mapping of the brightness related to every single point of an observed line. A linear scanning generates a line, showing on the Y axis the brightness of each point given in grey levels (e.g., from 0 to 255 levels for an 8-bit CCD sensor or from 0 to 1023 for a 10-bit CCD sensor). The outputs from the cameras 117 , 118 can be processed by a control unit 119 . The control unit 119 includes a digital processor that processes the output signals received from the cameras into signals indicative of the X and Y coordinate position of the object 109 via a parallax algorithm. One of ordinary skill in the art will readily appreciate that a scan taken from an area camera will generate a two-dimensional mapping of the brightness related to every point of the observed area. The operation of the position detecting system 100 is best understood with reference to FIGS. 1 and 2 , which will be explained first with reference to dual radiation source 110 . Dual radiation source 110 emits two beams of infrared radiation from its pair of point sources 111 a , 111 b . The viewing field 104 has a prismatic film 108 along three sides of the frame 106 , wherein both the point sources 111 a , 111 b are directed. The two different beams of infrared radiation generated by the point sources 111 a , 111 b strike an object 109 interposed within the viewing field 104 at different angles due to their 2× displacement from one another, creating two shadows of the object 109 located on either side of the object 109 . The two beams of infrared radiation striking the prismatic film 108 are reflected back to the line scan camera 117 . The infrared radiation passes through the lens 115 to the line scan camera 117 , which in turn focuses an image on the CCD of the camera that includes an image of the interposing object 109 and the shadows flanking it. The amount separation between the object 109 and the flanking shadows along the horizontal axis H 1 is linearly proportional to the distance between the object 109 and the point light sources 111 a , 111 b , being largest when the object 109 is closest to the point light sources 111 a , 111 b and smallest when the object 109 is farthest away. The amount of distance separation of the flanking shadows is also proportional to the distance 2× between the point light sources 111 a , 111 b . The distance between the object 109 and the front of the lens 115 can be accurately computed if the distance 2× is known via a parallax algorithm from the amount of observed separation between the object 109 and its flanking shadows. The proportional line scan camera generates a corresponding line image corresponding to the image along the longitudinal axis H 2 of the prismatic film 108 , having a digitized brightness value that depends on the resolution of line scan camera for the various points along the line of the scanner. For any position in the line image that does not receive radiation a logical value 0 is generated. For example, if an opaque object 109 , such as a stylus or a human finger, enters the viewing field, a shadow is cast on the lens and the corresponding line scan camera, which results in very little or no charge being detected by the line scan camera for that particular pixel or area of pixels. In locations where radiation is detected, the radiation discharges a corresponding CCD sensor associated with the line scan camera, which generates a substantially higher signal value depending on the resolution of the line scan camera. The combination of the image of the object 109 and its flanking shadows generates a dip or trough in the image signal generated by the camera 117 (or even three discrete dips or troughs) whose breadth along the axis H 2 can be converted into a distance between the object 109 and the point radiation sources 111 a , 111 b by the digital processor of the control circuit 119 via a parallax algorithm (or a look-up table generated by such an algorithm). Additionally, the angle θ 1 can be determined by the digital processor of the control circuit 119 from the location of the midpoint of the dip (or group of dips) along the horizontal axis of the CCD of the camera 117 . Hence the location of a single interposing object 109 can be completely determined by a single camera 117 in combination with the dual radiation source 110 and the digital processor of the control circuit 119 . While the determination may initially be in polar coordinates, conversion to Cartesian X, Y coordinates is easily implemented. Moreover, if a combination of two dual radiation sources 110 , 112 and line scan cameras 117 , 118 are provided as are illustrated in FIG. 1 and operated simultaneously, then the X and Y position of two simultaneously interposing objects may be unambiguously determined, as only one combination of a camera and dual light source is necessary to determine the X, Y coordinates of a single interposing object. The prismatic film (also referred to herein as the retroreflective film) 108 will now be discussed. Referring to FIG. 3 , an exemplary prismatic film 108 in accordance with aspects of the present invention is illustrated in cross-sectional view. The prismatic film 108 includes a first substrate 120 having a first surface 122 and a second surface 124 . The first surface 122 (also referred to as the front surface) of the prismatic film 108 is generally flat (and typically smooth). The second surface 124 is also generally flat and is secured to a second substrate 126 . The second substrate 126 has a first surface 128 and a second surface 130 . As shown in FIG. 3 , the first surface 128 of the second substrate 126 is generally flat (and typically smooth) and generally confronts the second surface 124 of the first substrate 120 . The second surface 130 of the second substrate 126 is also generally flat and is secured to a retroreflective substrate 132 . The first and second substrates 120 , 126 can be comprised of a material, such as a polymer that has a high modulus of elasticity. The polymer may be selected from a wide variety of polymers, including, but not limited to, polycarbonates, polyesters, polystyrenes, polyarylates, styrene-acrylonitrile copolymers, urethane, acrylic acid esters, cellulose esters, ethylenically unsaturated nitrites, hard epoxy acrylates, acrylics and the like, acrylic and polycarbonate polymers being preferred. Preferably, the first and second substrates are colored and/or have a dye distributed uniformly throughout the first and second substrates. In one embodiment, the first substrate 120 has a red dye distributed throughout and the second substrate 126 has a blue dye distributed throughout. In another embodiment, the first substrate 120 has blue dye distributed throughout and the second substrate 126 has a red dye distributed throughout. Both first and second substrates 120 , 126 have dye distributed uniformly throughout. One of ordinary skill in the art will readily appreciate that aspects of the present invention include using any desirable color or combination of colors to obtain the desired functionality, aesthetic appearance, etc., discussed herein. For example, the substrates 120 , 126 may have different colored dyes distributed throughout. See for example US published applications 20030203211 and 20030203212 (assigned to the same assignee as the present application) which are hereby incorporated by reference herein as is necessary for a complete understanding of the present invention. The substrates are preferably chosen to be highly transparent in infrared wavelengths and non-transparent in visible light wavelengths, which will provide a substantially black appearance. The bright background provided by the film is preferably made to be as bright and uniform, as reasonably possible, to allow detection of an object 109 within the field of the prismatic film 108 (e.g., the viewing field 104 ). The retroreflective substrate 132 has a first surface 134 and a second surface 136 . As shown in FIG. 3 , first surface 134 is generally flat (and typically smooth) and generally confronts the second surface 130 of the second substrate 126 . The second surface 136 includes or otherwise defines a plurality of cube corner retroreflective elements 140 and may be confronted with an adhesive 143 for use in an application. The retroreflective substrate 132 , including the cube corner elements 140 formed therein, can be comprised of a transparent plastic material, such as a polymer that has a high modulus of elasticity. The polymer may be selected from a wide variety of polymers, including, but not limited to, polycarbonates, polyesters, polystyrenes, polyarylates, styrene-acrylonitrile copolymers, urethane, acrylic acid esters, cellulose esters, ethylenically unsaturated nitrites, hard epoxy acrylates, acrylics and the like, with acrylic and polycarbonate polymers being preferred. The prismatic film of FIG. 3 a , provides a signal layer film as opposed to the multiple layer film as provided in FIGS. 3 and 4 . For convenience, similar reference numerals are used in the description of the FIG. 3 a embodiment. An exemplary prismatic film 108 in accordance with aspects of the present invention is illustrated in cross-sectional view. The retroreflective substrate 132 has a first surface 134 and a second surface 136 . As shown in FIG. 3 a , first surface 134 is generally flat (and typically smooth). The second surface 136 includes or otherwise defines a plurality of cube corner retroreflective elements 140 and may be confronted with an adhesive 143 for use in an application. The retroreflective substrate 132 , including the cube corner elements 140 formed therein, can be comprised of a transparent plastic material, such as a polymer that has a high modulus of elasticity. In another embodiment illustrated in FIG. 4 , the first and second substrates 120 , 126 may be replaced by a single substrate 150 . The substrate 150 has a single dye layer film to absorb the visible light with a front surface 152 and an opposing back surface 154 . The back surface 154 confronts the retroreflective substrate 132 , as discussed above with respect to the second substrate. The front surface 152 is generally smooth. In one embodiment, the substrate 150 is colored black. Benefits associated with a single dye layer are to make the overall film structure thinner and increase uniformity of transmission through the single dye layer 150 . In one preferred embodiment, the retroreflective substrate 132 , including the cube corner elements formed therein, is made of acrylic, e.g., an acrylic material having an index of refraction of about 1.49. Of course, other suitable materials having a higher or lower index of refraction can be employed without departing from the scope of the present invention. The cube corner elements can be formed within or as an integral part of the substrate using, for example, any of the methods described in U.S. Pat. No. 6,015,214 (RE 40,700) and U.S. Pat. No. 6,767,102 (RE 40,455) (assigned to the same assignee as the present application) which are hereby incorporated by reference herein as is necessary for a complete understanding of the present invention. As is described more fully below, the refractive index of the substrate, the size and canting of the cube corner elements may be selected to provide a desired retroreflectivity and uniformity. While the present invention is being described with respect to cube corner elements that are formed integrally as part of the substrate, it is to be appreciated that the present invention is applicable to cube corner elements that are formed separately (e.g., by casting or molding) from the substrate and bonded to the substrate. The plurality of cube corner elements 140 are metallized 142 with a suitable metal, such as aluminum, silver, nickel, gold or the like. Such metallization can be provided by depositing (e.g., sputtering or vacuum depositing) a metal film over the surfaces of the cube corner elements. The metallized cube corner side of the substrate can be coated with or otherwise embedded in an adhesive 143 (forming, for example a product similar to conspicuity tape). The metallization of the cube corner elements allows the display to be cleaned and otherwise not susceptible to contaminants and/or moisture that may have deleterious effects on the retroreflectivity of the retroreflective film 108 . U.S. Pat. No. 7,445,347 (assigned to the same assignee as the present application) is hereby incorporated by reference herein as is necessary for a complete understanding of the present invention. With reference now to FIGS. 5-8 and continued reference to FIG. 3 , the retroreflective film 108 includes a plurality of individual cube corner elements 140 ( FIG. 3 ) that are arranged in or otherwise formed as an array 200 ( FIG. 5 ). Each cube corner element 140 is formed by three substantially, but not completely perpendicular faces 202 that meet at an apex 204 . The faces intersect one another at dihedral edges 206 . The angles at the dihedral edges 206 , between the mutually intersecting faces 202 are commonly referred to as dihedral angles. In a geometrically perfect cube corner element, each of the three dihedral angles is exactly 90°. However, in the present invention, a specific pattern of errors is deliberately incorporated into two of the three dihedral angles in order to enhance the brightness of detected radiation retroreflected along the longitudinal axis of the prismatic film 108 , as will be described in detail hereinafter. As depicted in FIG. 6 , each cube corner element 140 has a triangular cube shape with three base edges 210 . In the present embodiment, each cube corner element 140 has an isosceles triangle cube shape, where two of the base edges (e.g., base edges having lengths a and b) are approximately the same length. Alternatively, one or more of the cube corner elements 140 can have a non-isosceles triangle cube shape. Because base edges 210 of cube corner element 140 are linear and in a common plane, an array of such is defined by intersecting sets of grooves. As shown in FIG. 5 , each cube corner element 140 is defined by three V-shaped grooves 212 , 214 , 216 , which are each one member of three sets of grooves that cross the array 200 in an intersecting pattern to form matched pairs of cube corner elements. Normally all three sets of grooves are cut to the same depth (see, e.g., grooves 141 in FIG. 4 ), but one or more sets of grooves may be offset vertically (i.e., cut shallow or deep with respect to the others). Also, one of the groove sets can be offset horizontally, causing the cube shape to differ from a triangle. Such cubes are still considered triangular cube corners and are within the scope of this invention. In the embodiment illustrated in FIG. 6 , faces adjacent sides a and b have a half groove angle of about 38.5 degrees (e.g., 38.5211 degrees), while the face adjacent side c has a half groove angle of about 28.3 degrees (e.g., 28.2639 degrees). The array 200 may be replicated several times over, for example in approximately square tiles of a desired size. In the preferred embodiment, such tiles provided in a linear arrangement as illustrated in FIG. 7 whose longitudinal axis corresponds to the longitudinal axis of the strip of film 108 disposed around the border 106 of the position detection system 100 shown in FIG. 1 . Sheeting with one tile or multiple tiles all having the same cube corner orientation is referred to as unpinned sheeting. In prismatic films, a cube corner element is generally used with at least one other cube corner element as part of a matched pair and commonly is used with an array of such elements. Such an array is shown in FIGS. 5-7 , and such a matched pair is shown in cross-section in FIG. 8 . The cube corner elements illustrated in FIGS. 6 and 8 and repeated in the arrays of FIGS. 5 and 7 are preferably canted in the edge-more-parallel direction between about 8° and 24°, and are more preferably canted in the edge-more-parallel direction between about 12° and 20°. In a further exemplary embodiment the triangular cube corners elements are canted between −10° and −6° and in another embodiment between −15° and −6°. In the foregoing exemplary embodiments, each cube corner element is canted in the edge-more-parallel direction 15.5°. Additionally, each cube corner element preferably has a cube depth of between about 0.006 and 0.0055 and more preferably 0.002 and 0.0045 inches. In this exemplary embodiment, each cube corner element has a cube depth of 0.00325 inches. As discussed above, one aspect of the present invention is directed to providing a retroreflective film that has a high brightness value. Accordingly, highly reflective prismatic sheeting is utilized to achieve this goal. However, the choice of prismatic sheeting potentially compromises the desire for uniformity. The geometry of a typical touch screen display is such that entrance angles range from 0 to 60 degrees. One of ordinary skill in the art will readily appreciate that this is a very large range over which to maintain uniform brightness with prismatic sheeting. Because observation angles also vary, particular care should be made in the selection of the cube geometry and size to achieve a combination of high brightness and good uniformity. For prismatic sheeting applications, triangular cube corner prisms are most commonly used, because they can be directly machined into a substrate using conventional ruling or diamond turning techniques. An algorithm has been developed to simulate the signal brightness and uniformity as a function of geometry and size for isosceles triangular cube corners cut with equal groove depths. For these cube corners, the geometry and size are fully determined by two parameters: cube cant, and cube depth. One of ordinary skill in the art will readily appreciate that other types of triangular cube corners are possible, including for example, scalene triangles and bi-level or tri-level cutting of the groove sets. In these cases, it is not the cube cant/cube depth combination per se that determines signal brightness and uniformity, but rather the active aperture size for each direction of incident light. The applicant has discovered that the brightness of the image of an interposing member 109 and the flanking shadows generated by the dual radiation sources 110 , 112 can be enhanced if errors e 1 , e 2 , and e 3 of a particular pattern are deliberately incorporated into the normally 90° dihedral angles between the faces of the cube corners. The pattern of errors e 1 , e 2 , and e 3 that forms part of this invention is best understood with respect to FIG. 9 , which illustrates a single cube corner element having three triangular faces 202 a , 202 b and 202 c . As explained with respect to FIG. 6 , these faces 202 a , 202 b and 202 c intersect to form three substantially dihedral edges 206 and three substantially dihedral angles e 1 , e 2 , and e 3 which represent the angles between faces 202 b , 202 c ; 202 a , 202 c and 202 a , 202 b , respectively. In the cube corners of the invention, the dihedral angles each include a pattern of errors or departures e 1 , e 2 , and e 3 from the ideal 90° value such that e 1 ≈e 2 , and e 3 ≈0. Preferably, |e 1 | and |e 2 | are >0.033° (or 2 minutes) and |e 3 |<0.033° (or 2 minutes). More preferably, |e 1 | and |e 2 | are between about 0.035° and 0.10°, and between about 0.03° and 0.20° and |e 3 | is about 0°. In the preferred embodiment, |e 1 | and |e 2 | are both 0.063° (or 3.8 minutes) while |e 3 | is 0°. In a still further preferred embodiment, e 1 and e 2 ≈0; (e 1 +e 2 )/2>0.03° and still more preferably (e 1 +e 2 )/2>0.05°. In a further embodiment, e 3 <0.03° and more preferably, where e 3 <0.015°. In a further embodiment, |e 1 −e 2 <0.06° and more preferably |e 1 −e 2 |<0.03°. One way such an error set may be achieved is by cutting the vee-grooves that form the opposing faces 202 c of adjacent cube corner elements at an angle that has the effect of either increasing or decreasing the dihedral angles by 0.063°. These vee-grooves correspond to the horizontal vee-grooves of the cube corner array illustrated in FIGS. 5 and 7 . However, such a technique would provide all of the cube corners with an error pattern having the same sign, i.e. e 1 and e 2 would all be either positive or negative, and the applicant has observed that the inclusion of both positive and negative assets of errors would advantageously reduce the sensitivity of film performance to dihedral angle variations that may arise during the manufacturing process. One method of achieving both positive and negative sets of dihedral angle errors is as follows. The cutter used to cut the horizontal grooves along the short sides of the triangles illustrated in FIGS. 5 and 7 is tilted in one direction. This causes an increase in e 1 and e 2 in the cube corner elements on one side of the cutter, and a corresponding decrease in e 1 and e 2 in the cube corner elements on the other side of the cutter. This tilted cutter is used to cut every other groove. Then the substrate is rotated 180° and the missing grooves are cut. This provides the resulting cube corner array with alternating rows of cube corners where e 1 and e 2 are +0.063° and −0.063°, respectively. A comparison of the spot diagrams illustrated in FIGS. 10A-10H with those of FIGS. 11A-11D illustrate that an array of cube corners canted 0°, 16° and −8° edge-more-parallel and having the error pattern e 1 , e 2 , and e 3 of the invention advantageously contains the spread of light as much as possible within the plane of the touch-screen. When a cube corner is exposed to a point source of light, each of the three faces of the cube corner generates two retroreflected spots as a result of the fact that some of the light reflected off each face is in turn reflected off each of the other two cube faces. FIGS. 10A-10H are spot diagrams of conventional cube corners canted at 0° and 60° for entrance angles (beta) of 0° and 60°, wherein all of the dihedral angles are 90° (i.e. e 1 =e 2 =e 3 =0°). FIGS. 10A-10H illustrate that, for all combinations of cant and entrance angle, all six of the retroreflected spots of the cube corner surfaces are accurately retroreflected 180° back to the point source of light such that they all converge onto the same x, y coordinates. By contrast, as is illustrated by FIGS. 11A-11D , when a pattern of dihedral angle errors e 1 =6 min. e 2 =6 min. and e 3 =0 is introduced into the cube corners, the three faces of the cube corners do not retroreflect the six spots exactly 180° with respect to the point source, but instead retroreflect four of the six spots at divergent points (roughly 0.4°) along the x-axis. The remaining two spots are more compressed toward the x axis when the cube cant=16°. As the x-axis corresponds to the plane of the touch screen, FIGS. 11A-11D illustrate that cube corners incorporating the cant and dihedral angle error pattern of the invention advantageously contain the spread of light as much as possible within the plane of the touch-screen. FIGS. 12A-12F and 13 A- 13 F represent the anticipated retroreflected patterns of light when diffraction is taken into account. FIGS. 12A , 12 C, 12 E, 13 A, 13 C, 13 E are light pattern diagrams for conventional cube corners canted at 0° and 60° for entrance angles (beta) of 0° and 60°, wherein all of the dihedral angles are 90° (i.e. e 1 =e 2 =e 3 =0°). FIGS. 12B , 12 D, 12 F, 13 B, 13 D, 13 F illustrate the differences in the light pattern diagrams of such cube corners when a pattern of dihedral angle errors e 1 =6 min. e 2 =6 min. and e 3 =0 is introduced into them. In general, the retroreflected light is more concentrated along the x-axis, as is best seen with respect to FIGS. 13B , 13 D, 13 F. A comparison of these diagrams confirms the conclusions reached with respect to FIGS. 10A-11D and FIGS. 11A-11D , i.e. that cube corners incorporating the cant and dihedral angle error pattern of the invention advantageously contain the spread of light as much as possible within the plane of the touch-screen. As provided in FIGS. 13B , 13 D, 13 F the unpinned prismatic film includes a plurality of triangular cube corner retroreflective elements in which the light source when reflected produces a pattern of light having a horizontal spread greater than a vertical spread. The horizontal spread is at least 1.5 times greater at entrance angles of 0° and 60° and the total light return at 60° is at least 10% of light return at 0° and in certain cases greater than 30%. Finally, FIG. 14 is an exemplary plot of camera signal for different screen sizes having a 16/9 aspect ratio. As is evident in the graph, for screen sizes of 17 inches, 19 inches, 22 inches, 26 inches and 30 inches, the minimum signal strength at never falls below about 2.0 while the maximum signal strength may be as high as 30.0 over an observation angle of 90°. Hence the retroreflective material of the invention provides sufficient retroreflection over a 90° angle to generate an easily detectible signal in the cameras used in the preferred embodiment. It will thus be seen according to the present invention a highly advantageous prismatic film for use with touch screen and position sensing systems has been provided. While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it will be apparent to those of ordinary skill in the art that the invention is not to be limited to the disclosed embodiment, that many modifications and equivalent arrangements may be made thereof within the scope of the invention, which scope is to be accorded the broadest interpretation of the appended claims so as to encompass all equivalent structures and products. Publications, patents and patent applications are referred to throughout this disclosure. All references cited herein are hereby incorporated by reference.

A dual light-source position detecting system for use in touch screens is provided that utilizes parallax to determine the position of an interposing object, and a prismatic film that is brightly retroreflective over a broad entrance angle to enhance to accuracy of the parallax determination of position. The position detecting system includes at least one camera positioned to receive light radiation traversing a detection area and that generates a signal representative of an image; two spaced-apart sources of light radiation, which may be LEDs, or IR emitters positioned adjacent to the camera for outputting light radiation that overlaps over at least a portion of a detection area, and a prismatic film positioned along a periphery of at least a portion of the detection area that retroreflects the light radiation from the two sources to the camera.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This is a divisional of U.S. patent application Ser. No. 13/529,489, entitled “INFLATABLE BAG WITH BURST CONTROL ENVELOPE AND GAS GENERATOR”, filed Jun. 21, 2012, which is incorporated herein by reference. BACKGROUND [0002] 1. Technical Field [0003] The field relates to inflatable devices such as air bags and more particularly to an air bag having a burst point control envelope with particular application to stun grenades. [0004] 2. Description of the Technical Field [0005] U.S. Pat. No. 8,117,966 taught a non-pyrotechnic stun grenade for generating loud, explosive sound by inflation to rupture of an inflatable bag. To make the point of rupture consistent from bag to bag and to achieve target noise levels within a limited time period the '966 patent proposed to construct a single layer inflatable bag with a rupture seam. Upon inflation the rupture seam parted abruptly at a particular and predetermined degree of tension on the seam. The rupture seam parted at a design volume of the bag and pressure within the bag to produce an N-wave. The explosive sound produced consistently met a minimum target volume level. Although the '966 patent provided for a non-pyrotechnic, compressed air, inflation source the patent suggests that pyrotechnic gas generation more readily produced high gas flow rates than compressed gas sources. [0006] The use of chemical reactions to generate gas generators for inflation of automotive air bags is known. One issue addressed during the development of such air bags was the type of gas generator to use. Among the concerns was the byproducts produced by the chemical reactions or combustion of the fuel source used to generate the gas. [0007] A popular contemporary gas generator for automotive applications is a mixture of sodium azide (NaN 3 ), potassium nitrate (KNO 3 ) and silicon dioxide (SiO 2 ). An exothermic (heat producing) decomposition of sodium azide into nitrogen gas and sodium can be initiated by exposure of the compound to 300° C. The free nitrogen gas inflates the bag while the potassium nitrate reacts with the sodium in a second reaction to produce potassium oxide (K 2 O), sodium oxide (Na 2 O) and more free nitrogen (N 2 ). A final reaction translates the reactive potassium oxide and sodium oxide compounds into more stable byproducts by a reaction with the silicon dioxide to produce potassium silacate and sodium silicate (K 2 O 3 Si an Na 2 O 3 Si). These are chemically stable compounds which pose no known environmental and health threat. See Gas Laws Save Lives: The Chemistry Behind Airbags, Casiday, R. and Frey, R. (2000). In addition, the initiating materials are not hygroscopic as water absorption can slow or stop gas generating reactions limiting the shelf life of units. Alternative pyrotechnic formulations for a gas generator may make use of potassium nitrite (KNO 2 ). Such fuel sources result in reactions which are highly exothermic and can produce higher temperatures than the reaction based on sodium azide. [0008] Construction of an inflatable bag which ruptures at a consistent degree of inflation to produce predictable noise levels using an exothermic chemical reaction to produce the inflation gas poses issues not present when a compressed air source is used. In contrast, where a compressed gas source is used for inflation the temperature of compressed gas falls upon expansion. SUMMARY [0009] A rupturable bag assembly including a balloon, an outer wall, an inlet port, and a heat resistant shield. The balloon is fabricated from an elastic material. The outer wall is disposed around the balloon, the outer wall having a perimeter seam which parts abruptly at a predetermined tension. The inlet port passes through the outer wall into the balloon for inflating the balloon to produce the predetermined tension. The heat resistant shield is disposed within the balloon opposite the inlet port. The outer wall is constructed of a relatively inelastic material in comparison to the material used to construct the balloon. [0010] An inflation port is provided from outside into the rupturable bag through the first sections of the outer and inner walls to deliver gas into the rupturable bag and against the heat resistant shield. [0011] An inflation gas generator and flow arrester assembly is fitted to the inflation port outside of the rupturable bag. BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIG. 1 is a perspective view of a rupturable bag assembly for a stun grenade. [0013] FIG. 2 is a perspective view of a rupturable bag. [0014] FIG. 3 is a side elevation of the rupturable bag of FIG. 2 . [0015] FIG. 4 is a cross section view of the rupturable bag of FIGS. 2 and 3 . [0016] FIG. 5 is an exploded perspective view of the rupturable bag. [0017] FIG. 6 is an exploded side view of the rupturable bag. [0018] FIG. 7A is an cross sectional view of mating of an air inlet with the rupturable bag. [0019] FIG. 7B is a detail view of clamping the bag with the air inlet. [0020] FIG. 7C is detail of the rupturable bag upper wall. [0021] FIGS. 8A and 8B are exploded perspective and side views of the rupturable bag assembly. [0022] FIG. 9 is a perspective view of the pressurization gas arrester for the rupturable bag assembly. [0023] FIG. 10 is a top view of the gas arrester. [0024] FIG. 11 is a cross-sectional view of the gas arrester taken along section lines 11 - 11 of FIG. 10 . [0025] FIGS. 12A , B and C are detail views of a assembly washer for the gas arrester. DETAILED DESCRIPTION [0026] In the following detailed description, like reference numerals and characters may be used to designate identical, corresponding, or similar components in differing drawing figures. Furthermore, example sizes/models/values/ranges may be given with respect to specific embodiments but are not to be considered generally limiting. [0027] Referring now to the figures and in particular to FIG. 1 , a self-inflating rupturable bag assembly 10 is shown. Rupturable bag assembly 10 may conceptually be divided into two sections, a rupturable bag 12 and an inflation gas generator assembly 14 which is mounted to bag inflation port 16 . Rupturable bag 12 parts along a perimeter seam 18 upon inflation to a minimum pressure and tension on the seam. The rupturable bag assembly 10 may be used with a variety of stun grenades to generate an explosive sound. A pair of electrical studs 52 allow connection to an electrical circuit which may be used to ignite a fuel source located in the inflation gas generator assembly 14 . [0028] In FIG. 2 the rupturable bag 12 is shown with inflation gas generator assembly 14 detached to better show inflation port 16 . The upper portion of inflation port 16 is threaded for attachment to the inflation gas generator assembly 14 and provides an inlet 20 disposed through its center. Inflation gas is introduced to rupturable bag 12 via inlet 20 . [0029] The details of construction of rupturable bag 12 are shown in FIGS. 3-6 . Inflation port 16 is a multiple element assembly extending through an upper wall of rupturable bag 12 . The inflation port 16 incorporates a conduit 34 which is flattened and thickened at one end to form an inner bulkhead 26 . Conduit 34 extends through a first of two walls 13 , 15 of rupturable bag 12 which places inner bulkhead between the two walls, inside an assembled an assembled rupturable bag 12 . [0030] Located between the inner bulkhead 26 and the first wall 13 is an inner collar 30 . Outside of first wall 13 is an outer collar 28 . Adjacent the outer collar 28 moving along conduit 34 is a washer 42 . The collars 30 , 28 , clamp washer 22 and washer 42 are held in place by a nut 32 which is threaded onto the conduit 34 . [0031] The rupturable bag 12 comprises first and second walls 13 , 15 . The rupturable bag 12 also comprises an inner elastic balloon 38 and an outer reinforced envelope 36 . The material of the outer envelope 36 is less elastic than the material used to construct the inner balloon 38 . A nylon weave fabric would be suitable. Both the inner elastic balloon 38 and the outer reinforced envelop 36 are constructed from first and second layers, in the case of the inner elastic balloon, first and second layers 38 A and 38 B, and in the case of the outer reinforced envelope 36 , first and second layers 36 A and 36 B. The halves of inner elastic balloon 38 are closed along seam 19 . The halves of outer reinforced envelope 36 are closed along seam 18 . Seam 18 is constructed to part upon application of pressure from within. Failure of seam 18 results in a cascade failure of inner elastic balloon 38 . Seam 18 may be constructed in a number of ways. Where closed mesh, rip stop (a type of weave) nylon is used as a fabric from which outer reinforced envelop 36 is constructed. The seam 18 may be formed using braided nylon or polyester with a typical strength range of 20 to 50 lbs. tensile strength stitching the two halves together. A zig-zag stitch allows the use of lower tensile strength materials for the burst envelope and the seam than a straight stitch allows. The inner elastic balloon may be made with vinyl with the halves welded together. Welding may be done a number of ways, for example, sonically, chemically or radio frequency welded. Adhesives and heat bonding are also possible. In this way a volumetrically small envelope can be constructed which can be inflated to a target burst pressure of 375 psi. A bag having a diameter of 5 inches on inflation producing a 180 dB peak over pressure shock wave on rupture can be built. Such a bag can be inflated to rupture in 20 to 30 milliseconds using a sodium azide or similar gas source. [0032] Applied to the inner face of second layer 38 B of inner elastic balloon 38 is a heat shield layer 40 , which may be constructed of aluminum foil of mylar. Heat shield layer 40 is used to prevent premature failure of rupturable bag 12 due to ejection of hot gas from inlet 20 . [0033] FIGS. 7A-C illustrate of the juncture between inlet port assembly 16 and the first wall 13 of rupturable bag 12 and of the second wall 15 of the rupturable bag. The clamp washer 22 carries an annular dimple 44 on one face displaced outwardly from the conduit 24 . Annular dimple 44 aligns on and is shaped to conform to an annular depression 46 on the adjacent face of inner bulkhead 26 . The first wall 13 of the rupturable bag 12 is pinched between the inner bulkhead 26 and the clamp washer 22 . Adhesive layers may be used between wall elements in the area of the clamp washer 22 to improve sealing. [0034] FIGS. 8-12 illustrate construction of the inflation gas generator assembly 14 . Gas arrester assembly 14 includes a housing/body 50 which is essentially a tube which is open an one end, closed at the other. The open end of the body 50 is mated with a connector 48 fitted between the inflation gas generator assembly 14 and the inflation port 16 . Connecter 48 is fitted to conduit 24 outside nut 32 on the exposed end of the conduit relative to the rupture bag 12 . The remaining elements of the inflation gas generator assembly 14 , excluding a pair of electrical studs 52 , are located in the housing 50 . The electrical studs 52 pass through the housing to allow application of an electrical trigger signal from outside the housing to a fuel source 54 located in the housing 50 . [0035] Combustion of fuel source 54 , which may be a dry, packed blend of sodium azide, silicon dioxide and potassium nitrate, results in a jet of high temperature gas being ejected from the open end of the inflation gas generator assembly 14 into a connector 48 between the assembly 14 and the inlet 20 of the inflation port 16 . Fuel source 54 is shaped an a ring with a plurality of radial connecting rods 64 aimed inwardly on the ring for connection to the electrical studs 52 by wires (not shown). As an alternative to a fuel source including sodium azide, more conventional pyrotechnic fuel sources may be used, typically incorporating potassium nitrite. To protect the elastomeric and fabric layers of the rupturable bag 12 from the full force and heat of gas ejected from the gas generator assembly 14 the path from fuel source 54 to connector 48 , while axial, is not direct. A variety of trigger mechanisms may be used, particularly where an electronic trigger signal is provided. [0036] Upon assembly of inflation gas generator assembly 14 the fuel source 54 is located deepest in the housing 50 , proximate to the closed end of the housing and distal to its open end. Moving toward the open end of housing 50 a lower washer 58 B is located having a central annular opening through which gas is ejected. Next in line is a lower spacing washer 56 B which defines openings between its perimeter edge and the inner wall of the housing 58 B. Spacing elements are constructed into the lower spacing washer 56 B so that gas can pass from the central annular opening of washer 58 B to the perimeter openings. This cycle is repeated once with an upper washer 58 A and an upper spacing washer 56 A. The lower and upper spacing washers 56 B and 56 A are illustrated in detail in FIGS. 12A-C generally at reference numeral 56 . Washers 58 A, 58 B, 56 A and 56 B, along with top cap 60 , provide a flame arresting function the fuel source 54 and the inlet port 20 . A more extensive flame arresting system incorporating additional washers of alternating types may be employed for pyrotechnic devices as the target temperature range in the rupture envelope is below 100 to 125 degrees Celsius. [0037] Gas is ejected from housing 50 through a perforated top cap 60 . Top cap 60 is retained in housing 50 using a spring spacing ring 62 which fits in an annular slot 66 in the inner wall of the housing proximate to the open end of the housing.

A rupturable bag assembly including a balloon, an outer wall, an inlet port, and a heat resistant shield. The balloon is fabricated from an elastic material. The outer wall is disposed around the balloon, the outer wall having a perimeter seam which parts abruptly at a predetermined tension. The inlet port passes through the outer wall into the balloon for inflating the balloon to produce the predetermined tension. The heat resistant shield is disposed within the balloon opposite the inlet port. The outer wall is constructed of a relatively inelastic material in comparison to the material used to construct the balloon.

This application is a division of U.S. patent application Ser. No. 10/442,234, filed on May 21, 2003. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus and a fingerprint recognition apparatus, and in particular to an image pickup apparatus and a fingerprint recognition apparatus which have a light irradiation unit for irradiating light to a photographing object and an image pickup element for receiving reflected light or transmitted light from the photographing object and generating an electric signal corresponding to an amount of received light. 2. Related Background Art Conventionally, as a fingerprint collation apparatus, for example, Japanese Patent Application Laid-Open No. 5-81412 discloses one in which a microcomputer corrects a trapezoidal distortion of a fingerprint image for registration or collation according to a magnification representing a degree of distortion, which is determined from a trapezoidal distortion of a reference figure photographed image based upon a reference figure, and after setting this corrected fingerprint image as a registered fingerprint image or a collated fingerprint image, collates both the reference figure photographed image and the registered fingerprint image or the collated fingerprint image. In addition, Japanese Patent Application Laid-Open No. 10-105708 discloses an image collation apparatus which is applied to, for example, a fingerprint collation apparatus and, when converting a video signal into a binarization signal based upon a predetermined threshold value to judge conformity or non-conformity between first and second images, corrects a signal level of this threshold value to correct unevenness of an amount of light in an optical system. However, there is a problem in that the above-mentioned fingerprint collation apparatus needs a complicated arithmetic circuit and a large-scale memory in order to perform data correction, which leads to lengthening of processing time and increase in costs. SUMMARY OF THE INVENTION An image pickup apparatus according to the present invention includes: light irradiation means that irradiates light on an object of image pickup; and an image pickup element that receives reflected light or transmitted light from the object of image pickup to generate an electric signal corresponding to an amount of received light, and is characterized in that a light receiving condition of a pixel of the image pickup element is changed such that shading of a signal from the image pickup element is corrected. In the image pickup apparatus, it is desirable that the light receiving condition is determined by a pixel structure of the image pickup element, in particular, an area of an opening portion, a shape of a lens provided on the opening portion, or an impurity concentration in a photoelectric conversion region of the image pickup element. Further, it is desirable that the light receiving condition is a storage time, during a driving of the image pickup element. The storage time is controlled by, for example, controlling the image pickup element with an electronic shutter. A fingerprint recognition apparatus according to the present invention includes, as fingerprint image input means, the above-mentioned image pickup apparatus of the present invention. A fingerprint recognition apparatus according to the present invention includes an image sensor that irradiates light on a finger and receives the light transmitted through or reflected on the finger to convert the received light into an image signal, in which image signal shading due to unevenness of luminance and an illumination environment of a light source or a shape and a position of a finger can be corrected by controlling a light-receiving condition (sensor pixel structure, storage time control, etc.) in one frame scanning. For example, in a fingerprint recognition apparatus in which one LED for illumination is arranged in the vicinity of a center on each side in a vertical scanning direction of an image sensor, a longitudinal direction of a finger is aligned with the vertical scanning direction of the sensor to take in a fingerprint image. At this point, since light is transmitted through the inside of the finger to be incident on the sensor side in a central part in the vertical scanning direction, an amount of light is reduced in a part closer to the central part. Therefore, in a first preferred embodiment of the present invention, a pixel structure, for example, areas (shapes) of opening portions of sensor pixels are changed, and openings are made larger toward the vicinity of the central part in the vertical scanning direction where an amount of light is reduced and made smaller in the vicinity of a peripheral part in the vertical scanning direction where an amount of light is large, whereby shading in the plane is corrected. In addition, in a second preferred embodiment of the present invention, an electronic shutter pulse is controlled such that the storage time is long in the central part and short in the peripheral part, whereby shading in the sensor vertical scanning direction is corrected. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings: FIG. 1 is a diagram schematically showing a solid-state image pickup element used in a first embodiment; FIG. 2 is an equivalent circuit diagram of one pixel of a pixel portion of an image pickup element used in the first embodiment; FIG. 3 is a diagram schematically showing a solid-state image pickup element to be a comparative example in the first embodiment and also schematically showing a solid-state image pickup element of the present invention according to a second embodiment; FIG. 4A is a perspective view of a fingerprint image input device of a fingerprint recognition apparatus of the present invention; FIG. 4B is a plan view of a structure of the fingerprint image input device of the fingerprint recognition apparatus of the present invention and shows a shading tendency of a sensor signal in the case in which the present invention is not applied; FIG. 5 is a block diagram showing a structure of an image recognition apparatus having a fingerprint image input device used in the first embodiment; FIG. 6 is a diagram schematically showing a solid-state image pickup element used in the second embodiment; FIG. 7A is a partial schematic diagram of a solid-state image pickup element for explaining an operation of an electronic shutter pulse used in the second embodiment; FIGS. 7B and 7C are timing charts for explaining the operation of the electronic shutter pulse used in the second embodiment; FIG. 8 is a timing chart for explaining the operation of the electronic shutter pulse used in the second embodiment; and FIG. 9 is an operation flowchart for performing shading correction used in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be hereinafter described in detail with reference to the accompanying drawings. First Embodiment FIG. 4A is a perspective view of a fingerprint image input device of a fingerprint recognition apparatus of the present invention. FIG. 4B is a plan view of a structure of the fingerprint image input device of the fingerprint recognition apparatus of the present invention and shows a shading tendency of a sensor signal in the case in which the present invention is not applied. As shown in FIG. 4B , one LED 202 for illumination is arranged in the vicinity of a center on each side in a vertical scanning direction of a solid-state image pickup element 201 , such as a CMOS sensor, of a fingerprint image input device 200 . A finger 100 is placed on the solid-state image pickup element 201 , and light is irradiated on the finger 100 from the LEDs 202 . The irradiated light is transmitted through or scattered in the inside of the finger to be incident on the solid-state image pickup element 201 side. Then, the solid-state image pickup element 201 aligns a longitudinal direction of the finger with the vertical scanning direction of the sensor to take in a fingerprint image. At this point, in a central part in the vertical scanning direction and a horizontal scanning direction of the solid-state image pickup element, since light is transmitted through or scattered in the arrangement of the LEDs 202 and the inside of the finger to be incident on the solid-state image pickup element side, an amount of light is reduced in a part closer to the central part. When an image pickup element having a uniform opening shape of pixels as shown in FIG. 3 is used, a signal level of a sensor signal also falls in the central part. That is, in the solid-state image pickup element of FIG. 3 , since opening shapes of pixels 10 are uniform in the plane and opening areas are uniform for all the pixels, and a distribution of an amount of light is thinner in a part closer to the central part in the case in which this image pickup element is used for the fingerprint image input device of FIGS. 4A and 4B , an output of the sensor signal falls and shading of a pixel signal as shown in FIG. 4B occurs. Distortion of an image signal due to a shape and a position of a finger, unevenness of luminance and an illumination environment of a light source, or the like is called shading. In this embodiment, as described later, shading correction is performed by changing opening areas of pixels of the solid-state image pickup element 202 in accordance with the shading. FIG. 5 is a block diagram showing a structure of an image recognition apparatus having a fingerprint image input device. As shown in FIG. 5 , image data of a fingerprint image inputted from a picture image input unit 301 serving as the fingerprint image input device of FIGS. 4 A and 4 B is temporarily stored in a memory 302 . A unit extracting characteristic point 303 reads the picture image data from the memory 302 and processes it to extract a characteristic point, and stores the characteristic point in a unit storing characteristic data 304 as characteristic point data. The characteristic point data is represented by a coordinate position on rectangular coordinate axes in which an origin and coordinate axes of coordinates are determined arbitrarily every time the data is represented while keeping a scale of the coordinates identical (keeping a certain image of a fingerprint). Then, a distance between adjacent two characteristic points is calculated, which is simultaneously stored as characteristic point data. This characteristic point data and characteristic point data of a fingerprint image stored in the unit storing registered data 306 in advance are collated in a collating unit 307 . Authenticity of the characteristic data is displayed in a unit displaying authenticity 308 in a form of, for example, a graph. Reference numeral 305 denotes a control unit for sending a control signal to each unit. If a fingerprint image taken in by the fingerprint image input device has shading as shown in FIG. 4B , it becomes difficult to extract a characteristic point, which causes a deficiency such as decrease in an authenticity ratio or malfunction. In this embodiment, shading correction is performed by setting opening areas of pixels of the solid-state image pickup element in accordance with the shading. FIG. 1 is a diagram schematically showing a solid-state image pickup element used in this embodiment. FIG. 2 is an equivalent circuit diagram of one pixel of a pixel portion of the solid-state image pickup element. FIG. 3 is a diagram schematically showing a solid-state image pickup element to be a comparative example. In this embodiment, as shown in FIG. 1 , the pixel portion is constituted by pixels arranged in a matrix. A vertical shift register (VSR) 15 is operated to send a control signal to the pixel portion through horizontal signal lines 12 , a charge signal from the pixel portion is transferred to a storage unit 13 via vertical output lines 11 , and a pixel signal is sequentially outputted by a horizontal shift register (HSR) 14 . The storage unit 13 stores a noise signal and a sensor signal in storage capacitors CT N and CT S , respectively, which are provided for each vertical output line 11 . In addition, FIG. 2 is an equivalent circuit diagram of one pixel. Reference symbol PD denotes a photodiode serving as a photoelectric conversion portion for converting an optical signal into a charge; TX, a transfer transistor for transferring a charge signal from the photodiode PD; RES, a reset transistor for resetting a charge in a read path of the charge signal; SEL, a selection transistor for selecting a signal read line; and SF, a transistor for reading out the charge signal to the storage unit 13 with a source follower. A noise signal is read from the vertical output lines 11 in a state in which the transfer transistor TX is turned OFF and the reset transistor RES and the selection transistor SEL are turned ON. A sensor signal is read from the vertical output lines 11 after the noise signal is read in a state in which the transfer transistor TX is turned ON, the reset transistor RES is turned OFF, and the selection transistor SEL is turned ON. Then, a sensor signal having a noise component removed therefrom can be obtained by performing processing for subtracting the noise signal from the sensor signal. Opening shapes of pixels of the pixel portion shown in FIG. 1 are those of the case in which shading in the sensor horizontal scanning direction shown in FIG. 4B is corrected. In accordance with the shading, opening areas of pixels 10 - 5 in a central part of the pixel portion are set large and opening areas of pixels 10 - 4 , 10 - 3 , 10 - 2 , and 10 - 1 are sequentially set such that the opening areas become smaller toward a peripheral part of the pixel portion. In FIG. 1 , a left half of the pixel portion is shown in the case in which the opening areas of the pixels are made smaller from the central part to a left end side of the pixel portion. In a right half of the pixel portion, the opening areas of the pixels are made smaller from the central part to a right end side of the pixel portion in the same manner. Note that the shading in the sensor vertical scanning direction shown in FIG. 4B can also be corrected by, in accordance with the shading, setting opening areas of pixels such that the opening areas of pixels in the central part of the pixel portion are large and become smaller toward the peripheral part thereof. In this way, nonuniformity of distribution of an amount of light due to a shape and a position of a finger, unevenness of luminance and an illumination environment of a light source, or the like can be adjusted by manipulating opening areas, and shading correction can be performed without involving complicated image pickup conditions, change of drive timing, and a correction algorithm. Although the opening areas of pixels of the pixel portion are changed in this embodiment, for example, shading correction can also be performed by changing a shape of a microlens provided on each pixel (opening portion) to change a light condensing ratio, or changing an impurity concentration in a photoelectric conversion region of a pixel to change photoelectric conversion efficiency in a photodiode portion. It is mentioned, for example, in FIG. 4 of Japanese Patent Application Laid-Open No. 6-140612 that an amount of light is adjusted by changing a shape of a microlens. In the figure, a curvature of the microlens is changed so as to increase (such that a curvature radius decreases) from a central part toward an end side of the microlens. In this embodiment, to the contrary, a light condensing ratio can be changed by changing the curvature of the microlens so as to decrease (such that the curvature radius increases) from the central part toward the end side in accordance with shading. Second Embodiment In the first embodiment, shading correction is performed by changing an opening shape of a pixel portion. In this embodiment, shading correction is performed by controlling drive timing within a scanning time for one frame. Here, control of storage time of a pixel portion is performed by an electronic shutter (rolling shutter). FIG. 6 is a diagram schematically showing a solid-state image pickup element used in this embodiment. One pixel of the pixel portion has the same pixel structure as that shown in FIG. 2 . In addition, opening shapes of pixels of a pixel area 20 are uniform for all pixels. In FIG. 6 , reference numeral 20 denotes a pixel area constituted by arranging a plurality of pixels; 21 , a first vertical scanning circuit (Vs·SR) such as a shift register for sequentially selecting pixel rows to be read; 22 , a second vertical scanning circuit (Vc·SR) such as a shift register for sequentially resetting pixel rows in order to start storage; 23 , an entire pixel reset switch (V R ) for collectively resetting all pixels of the pixel area 20 ; 24 , a memory for storing a noise signal and a sensor signal from the pixel area 20 ; 25 , a horizontal scanning circuit for scanning the memory 24 for each pixel column in order to output the noise signal and the sensor signal from the memory 24 ; and 26 , a differential amplifier for subtracting the noise signal from the sensor signal to output an output signal Vout. Time from reset of a pixel to output of a signal, that is, storage time, can be controlled by providing the first vertical scanning circuit (Vs·SR) 21 such as a shift register for sequentially selecting pixel rows to be read and the second vertical scanning circuit (Vc·SR) such as a shift register for sequentially resetting pixel rows in order to start storage, and changing start time for a reset operation and a reading operation. This is called a rolling shutter. Each pulse name corresponds to the equivalent circuit diagram of the part of the pixel portion shown in FIG. 2 . An interval between reset and reading of a pixel becomes the storage time. Therefore, as shown in FIG. 4B , since light is transmitted through the inside of a finger to be incident on a sensor side in a central part in the vertical scanning direction of the pixel portion, in the case in which an amount of light is smaller toward the central part, scanning is performed with the first vertical scanning circuit 21 and the second vertical scanning circuit 22 such that the interval between reset and reading of a pixel is increased in the central part and decreased in a peripheral part of the pixel portion. FIGS. 7A to 7C show operations of an electronic shutter. Each pulse name corresponds to the equivalent circuit of a part of the pixel portion shown in FIG. 2 . First, in a pixel portion of a line selected by the second vertical scanning circuit (Vc·SR) 22 shown in FIG. 7A (in this case, this line becomes a shutter line), as indicated by an operation pulse shown in FIG. 7C , pixels are reset after pulses φRES and φTX are applied and noise read (N read) and signal read (S read) are performed in the same manner as the usual operation. However, since the selection pulse φSEL is in a low level, a noise signal and a sensor signal are not outputted to the vertical output line from the pixels. Next, the same line is selected by the first vertical scanning circuit (Vs·SR) 21 which performs scanning with a delay from the scanning performed by the second vertical scanning circuit 22 (in this case, this line becomes a read line). In a pixel portion of the selected line, as indicated by an operation pulse shown in FIG. 7B , pulses φRES and φTX are applied and noise read (N read) and signal read (S read) are performed by the usual operation. Here, since the selection pulse φSEL is in a high level, a noise signal N and a sensor signal S (including a noise component) are outputted to the vertical output line from the pixels, respectively. Finally, an S-N signal subjected to processing for subtracting the noise signal from the sensor signal is outputted from a differential amplifier. Therefore, time from pixel reset in the shutter line operation to transfer in the read line operation becomes the storage time. Thus, the storage time can be varied by controlling an interval from the time when each horizontal line is selected as a shutter line until the time when it is selected as a read line. Next, operations of the shift register to be the vertical scanning circuit will be described using FIG. 8 . The shift register starts the second vertical scanning circuit (Vc·SR) 22 for performing a reset operation according to a start pulse VcST, and resets pixel rows sequentially according to a pulse φVc. Next, with a delay from the start of the second vertical scanning circuit (Vc·SR) 22 , the shift register starts the first vertical scanning circuit (Vs·SR) 21 for performing a read operation according to a start pulse VsST to perform a read operation for each pixel row according to a pulse φVs. In this case, hatched parts of the pulse φVs in FIG. 8 indicate intervals in which storage time for other rows is intentionally made longer compared with an interval (storage time of a first row) between Vc 1 and Vs 1 . As shown in FIG. 8 , the interval is gradually increased from a start side in the vertical scanning direction toward a central part of the pixel portion and, on the contrary, the interval is made smaller from the central part toward a completion side in the vertical scanning direction. Storage time of each horizontal line is an interval from reset to reading, such as between Vc 1 and Vs 1 or Vc 2 and Vs 2 , and can be set such that a reset-reading interval in a pixel row in a peripheral part of the pixel portion is short and a reset-reading interval in a pixel row in the central part thereof is long. FIG. 9 shows an operation flowchart for performing the shading correction. First, it is detected that a finger is placed on an image pickup element and the image pickup element is turned on (step S 1 ) to take in a fingerprint image once (step S 2 ). The image thus taken in is projected in the vertical direction to obtain data, based upon which change in amplitude of a luminance signal is calculated. (step S 3 ) and it is judged whether shading has occurred (step S 4 ). Then, if it is judged that shading has occurred, vertical scanning is controlled such that an interval between reset and reading of a pixel is large in a part where a signal amplitude is small and the interval between reset and reading of a pixel is small in a part where the signal amplitude is large (step S 5 ), and the fingerprint image is installed again (step S 2 ). Upon taking in of an image of a level at which it is possible to determine that there is no shading, the operation proceeds to the next step, and extraction of a characteristic point is performed (step S 6 ). Then, the operation advances to an authenticity operation, and an authenticity of a fingerprint, that is, whether or not authenticity of a subject has been verified is displayed (step S 7 ). In this way, the interval between reset and reading of a pixel is controlled such that the storage time is long in the central part and is short in the peripheral part, whereby shading in the sensor vertical scanning direction can be corrected. In addition, it is also possible to combine the first embodiment and the second embodiment to correct shading in both the sensor horizontal scanning direction and the sensor vertical scanning direction, respectively, thereby obtaining a more optimized sensor signal. As described above in detail, according to the present invention, simplification of processing and reduction in costs can be realized without the need to perform correction of an image signal with a complicated algorithm or a large-scale correction circuit.

An image pickup apparatus is provided which performs correction of shading without performing correction of an image signal with a complicated algorithm or a large-scale correction circuit. The image pickup apparatus includes light irradiation unit that irradiates light on an object of image pickup and an image pickup element that receives reflected light or transmitted light from the object of image pickup to generate an electric signal corresponding to an amount of received light, in which a light receiving condition of a pixel of the image pickup element is changed such that shading of a signal from the image pickup element is corrected. The light receiving condition is changed by changing areas of opening portions of pixels 10 - 1 to 10 - 5 of the image pickup element, a shape of a lens provided on the opening parts, or an impurity concentration in a photoelectric conversion region of the image pickup element, or changing storage time, storing being performed through driving of the image pickup element.

BACKGROUND OF THE INVENTION This invention relates to novel 2-oxo-1-azetidine sulfonic acid derivatives which are of value for use in combination with β-lactam antibiotics to increase their effectiveness in infection caused by β-lactamase producing bacteria. Of the commercially available β-lactam antibiotics, penicillins and cephalosporins are best known and frequently used. Although widely used as useful chemotherapeutic agents, enzymatic inactivation of β-lactam antimicrobial agents has been an obstacle to the treatment of infection for as long as these agents have been used. The production of enzymes that degrade the β-lactam containing antimicrobial agents--penicillins and cephalosporins--is an important mechanism of bacterial resistance, thereby causing the antibiotic to lose it's antimicrobial activity. A novel approach to countering these bacterial enzymes is the delivery of a β-lactam antimicrobial agent together with an enzyme inhibitor. When a β-lactamase inhibitor is used in combination with a β-lactam antibiotic, it can increase or enhance the antibacterial effectiveness of the antibiotic against certain microorganisms. The present invention provides certain novel 2-oxo-1-azetidine sulfonic acid derivatives which are potent inhibitors of bacterial β-lactamases, particularly against class C β-lactamases (cephalosporinase). Aztreonam (U.S. Pat. No. 4,775,670) is a known monobactam antibiotic. Several publications (e.g., Antimicrobial Agents of Chemotherapy, vol. 22, pp. 414-420, 1982; Chemotherapy, vol. 30, pp. 398-407 (1984); J. Antibiotics, vol. 35, no. 5, pp. 589-593 (1982); J. Antibiotics, vol. 43, no. 4, pp. 403-410 (1990)! suggest that aztreonam possesses β-lactamase inhibitory properties. SUMMARY OF THE INVENTION It is an object of the present invention to provide novel and new 2-oxo-1-azetidine sulfonic acid derivatives having β-lactamase inhibitory activity, particularly against class C β-lactamases (cephalosporinase). It is a further object of the invention to provide pharmaceutical compositions comprising a β-lactamase inhibitor of this invention in combination with a β-lactam antibiotic and a pharmaceutically acceptable carrier or diluent. It is an additional object of the invention to provide an improved method for the treatment of bacterial infections caused by class C β-lactamase (cephalosporinase) producing bacteria in mammalian subjects, particularly in human. Accordingly, this invention provides novel 2-oxo-1-azetidinesulfonic acid derivatives having the formula (I): ##STR3## and the pharmaceutically acceptable salts thereof, wherein R 1 is a 5-membered heterocyclic ring and R 2 is selected from any one of the following groups: ______________________________________ ##STR4## ##STR5## ##STR6## ##STR7## ##STR8## ##STR9## ##STR10##______________________________________ M is hydrogen or a pharmaceutically acceptable salt forming cation. The present inventors found that the oxyimino group, i.e. ═N--OR 2 in the formula (I) while in the `anti` orinentation provides excellent synergy with a β-lactam antibiotic against class C β-lactamase (cephalosporinase) producing microorganisms. In particular, they show markedly superior synergy in combination with cephalosporins (e.g., ceftazidime) against Pseudomonas aeruginosa. The present inventors also found that the inhibitory activity against isolated β-lactamase (e.g., cephalosporinase from P. aeruginosa 46012) and the synergy with a β-lactam antibiotic e.g., ceftazidime is greatly influenced by the nature of the heterocyclic ring represented by R 1 and the nature of the substituent in the oxime fragment represented by R 2 . Thus, thiophene is the preferred 5-membered heterocyclic ring as R 1 and hydroxy pyridone including N-hydroxy pyridone is the preferred 6-membered heterocyclic ring attached through a spacer to the oxygen atom; items (a) to (g)! as one of the components represented by R 2 . DETAILED DESCRIPTION OF THE INVENTION The β-lactamase inhibitors of this invention are the compounds having the formula (I) ##STR11## The present β-lactamase inhibitors of the invention are effective in enhancing the antimicrobial activity of β-lactam antibiotics, when used in combination to treat a mammalian subject suffering from a bacterial infection caused by a β-lactamase producing microorganism. Examples of antibiotics which can be used in combination with the compounds of the present invention are commonly used penicillins such as amoxicillin, ampicillin, azlocillin, mezlocillin, apalcillin, hetacillin, bacampicillin, carbenicillin, sulbenicillin, ticarcillin, piperacillin, mecillinam, pivmecillinam, methicillin, ciclacillin, talampicillin, aspoxicillin, oxacillin, cloxacillin, dicloxacillin, flucloxacillin, nafcillin, pivampicillin; commonly used cephalosporins such as cephalothin, cephaloridine, cefaclor, cefadroxil, cefamandole, cefazolin, cephalexin, cephradine, ceftizoxime, cefoxitin, cephacetrile, cefotiam, cefotaxime, cefsulodin, cefoperazone, ceftizoxime, cefmenoxime, cefmetazole, cephaloglycin, cefonicid, cefodizime, cefpirome, ceftazidime, ceftriaxone, cefpiramide, cefbuperazone, cefozopran, cefepime, cefoselis, cefluprenam, cefuzonam, cefpimizole, cefclidin, cefixime, ceftibuten, cefdinir, cefpodoxime proxetil cefteram pivoxil, cefetamet pivoxil, cefcapene pivoxil, cefditoren pivoxil; commonly used carbapenem antibiotics such as imipenem, meropenem, biapenem, panipenem and the like; commonly used monobactams such as aztreonam and carumonam and salts thereof. Furthemore, the β-lactamase inhibitors of the present invention can be used in combination with another β-lactamase inhibitor to enhance the antimicrobial activity of any of the above mentioned β-lactam antibiotics. For example, the inhibitors of this invention can be combined with piperacillin/tazobactam combination; ampicillin/sulbactam combination; amoxycillin/clavulanic acid combination; ticarcillin/clavulanic acid combination, cefoperazone/sulbactam combination, and the like. R 1 in the formula (I) is a 5-membered heterocyclic ring containing from 1 to 4 heteroatoms independently selected from the group consisting of O, S and N. Preferred heterocyclic rings are: ##STR12## Preferably, R 1 in the formula (I) is thiophene and 2-aminothiazole; Even more preferably R 1 is thiophene. R 2 in the formula (I) is selected from any one of the following groups: ______________________________________ ##STR13## ##STR14## ##STR15## ##STR16## ##STR17## ##STR18## ##STR19##______________________________________ Examples of 5-membered heterocyclic ring represented by "Y" include oxadiazoles, isoxazoles, isothiazoles, thiazoles and thiadiazoles. Examples of the group for forming a pharmaceutically acceptable salt represented by M in the formula (I) include the inorganic base salts, ammonium salts, organic base salts, basic amino acid salts. Inorganic bases that can form the inorganic base salts include alkali metals (e.g., sodium, potassium, lithium) and alkaline earth metals (e.g., calcium, magnesium); organic bases that can form the organic base salts include cyclohexylamine, benzylamine, octylamine, ethanolamine, diethanolamine, diethylamine, triethylamine, procaine, morpholine, pyrrolidine, piperidine, N-ethylpiperidine, N-methylmorpholine; basic amino acids that can form the basic amino acid salts include lysine, arginine, ornithine and histidine. As will be appreciated by one skilled in the art, the compounds of formula (I) containing an acidic hydrogen atom other than the SO 3 H group at N-1 position are capable of forming salts with basic groups as mentioned earlier. Such salts with pharmaceutically acceptable bases are included in the invention. Moreover, when M is hydrogen in the formula (I) it can form a zwitterion (inner salt or internal salt) by interacting with a basic nitrogen atom present in the molecule of formula (I). A variety of protecting groups conventionally used in the β-lactam art to protect the OH groups present in the items (a) to (g) can be used. While it is difficult to determine which hydroxy-protecting group should be used, the major requirement for such a group is that it can be removed without cleaving the β-lactam ring and the protecting group must be sufficiently stable under the reaction conditions to permit easy access to the compound of formula (I). Examples of most commonly used hydroxy-protecting groups are: diphenylmethyl, 4-methoxybenzyl, allyl, etc. The compounds of this invention having the formula (I) can be prepared using a variety of well known procedures as shown below: ##STR20## Each procedure utilizes as a starting material the known azetidine of the formula ##STR21## Azetidines of the formula (III) are well known in the literature; see for example the United Kingdom patent application no. 2,071,650 published Sep. 23, 1981; J. Org. Chem., vol. 47, pp. 5160-5167, 1982. In a preferred procedure the compounds of the formula (I) can be prepared by reacting azetidines of the formula (III) with compounds of the formula ##STR22## in the presence of a coupling agent. R 1 and R 2 have the same meaning as described before. It is preferably to first treat the compound of formula III with one equivalent of a base, e.g. tributylamine or trioctylamine or sodium bicarbonate. Preferably the reaction is run in the presence of a substance capable of forming a reactive intermediate in situ, such as N-hydroxybenzotriazole and a catalyst such as dimethylaminopyridine, using a coupling agent such as dicyclohexylcarbodiimide. Exemlplary solvents which can be used for the reaction are dimethylformamide, tetrahydrofuran, dichloromethane or mixtures thereof. The reaction of an acid of formula (II) or a salt thereof, and a (3S)-3-amino-2-oxo-1-azetidinesulfonic acid salt of formula (III) proceeds most readily if the acid of formula (II) is in activated form. Activated forms of carboxylic acids are well known in the art and include acid halides, acid anhydrides (including mixed acid anhydrides), activated acid amides and activated acid esters. To be more concrete, such reactive derivatives are: (a) Acid anhydrides The acid anhydrides include, among others, mixed anhydride with a hydrohaloic acid e.g. hydrochloric acid, hydrobromic acid; mixed anhydrides with a monoalkyl carbonic acid; mixed anhydrides with an aliphatic carboxylic acid, e.g., acetic acid, pivalic acid, valeric acid, isopentanoic acid, trichloroacetic acid; mixed anhydrides with an aromatic carboxylic acid, e.g., benzoic acid; mixed anhydride with a substituted phosphoric acid e.g., dialkoxyphosphoric acid, dibenzyloxyphosphoric acid, diphenoxyphosphoric acid; mixed anhydride with a substituted phosphinic acid e.g., diphenylphosphinic acid, dialkylphosphinic acid; mixed anhydride with sulfurous acid, thiosulfuric acid, sulfuric acid, and the symmetric acid anhydride. (b) Activated amides The activated armides include amides with pyrazole, imidazole, 4-substituted imidazoles, dimethylpyrazole, triazole, benzotriazole, tetrazole, etc. (c) Activated esters The activated esters include, among others, such esters as methyl, ethyl, methoxymethyl, propargyl, 4-nitrophenyl, 2,4-dinitrophenyl, trichlorophenyl, pentachlorophenyl, mesylphenyl, pyranyl, pyridyl, piperidyl and 8-quinolylthio esters. Additional examples of activated esters are esters with an N-hydroxy compound e.g., N,N-dimethylhydroxylamine, 1-hydroxy-2(1H)pyridone, N-hydroxy succinimide, N-hydroxyphthalimide, 1-hydroxy-1H-benzotriazole, 1-hydroxy-6-chloro-1H-benzotriazole, 1,1'-bis 6-trifluoromethyl)benzotriazolyl!oxalate (BTBO), N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline, and the like. Appropriate reactive derivatives of organic carboxylic acids are selected from among such ones as mentioned above depending on the type of the acid used. When a free acid is used as the acylating agent, the reaction is preferably carried out in the presence of a condensing agent. Examples of the condensing agent are N,N'-dicyclohexylcarbodiimide, N-cyclohexyl-N'-morpholinoethylcarbodiimide, N-cyclohexyl-N'-(4-diethylaminocyclohexyl) carbodiimide and N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide. The acylation reaction is usually carried out in a solvent. The solvent includes water, acetone, dioxane, acetonitrile, methylene chloride, chloroform, dichloroethane, tetrahydrofuran, ethyl acetate, dimethylformamide, pyridine and other common organic solvents inert to the reaction. The acylation reaction can be carried out in the presence of an inorganic base such as sodium hydroxide, sodium carbonate, potassium carbonate or sodium hydrogen carbonate or an organic base such as trimethylamine, triethylamine, tributylamine, N-methylmorpholine, N-methylpiperidine, N,N-dialkylaniline, N,N-dialkylbenzylamine, pyridine, picoline, lutidine, 1,5-diazabicyclo 4.3.0!non-5-ene, 1,4-diazabicyclo 2.2.2!octane, 1,8-diazabicyclo 5.4.4!undecene-7, tetra-n-butylammonium hydroxide. The reaction is usually conducted under cooling or at room temperature. The amides of formula V, which result from the coupling of acid IV (or a salt thereof) and a (3S)-3-amino-2-oxo-1-azetidinesulfonic acid salt of formula (III) can be oxidized to the corresponding ketoamide of formula VI (Process B). A wide variety of oxidation procedures may be used e.g., potassium nitrosodisulfonate in water (or a mixed aqueous solvent), selenium dioxide in dioxane; use of metal catalysts in the presence of a suitable co-oxidant. Alternatively, the ketoamide (VI) can be prepared (Process C) by coupling the keto acid (VII) with (3S)-3-amino-2-oxo-1-azetidinesulfonic acid of formula III (or a salt thereof). The compounds of this invention of formula (I) can also be prepared by reacting a ketoamide (VI) (Process B or Process C) having the formula ##STR23## with a hydroxylamine derivative (or a salt thereof) of formula R.sub.2 --O--NH.sub.2 (IX) wherein R 1 and R 2 have the same meaning as described before. Alternatively, the ketoamide (VI) can be reacted with hydroxylamine hydrochloride to provide the hydroxyimino derivative (VIII) (Process D). Coupling of the hydroxyimino derivative of formula (VIII). ##STR24## with the alcohol (R 2 --OH, X) under Mitsunobu conditions (PPh 3 /DEAD/THF) will provide the compounds of formula (I). R 2 has the same meaning as described before. Alternatively, the compounds of formula (I) can be prepared by reacting the hydroxyimino derivative (VIII) (Process E) with a compound of the formula, R 2 --X (XI) wherein X is a leaving group such as halogen, trifluoroacetate, alkylsulfonate, arylsulfonate or other activated esters of alcohols. Wherein R 2 has hereinbefore been defined. The compounds of formula (I) which has a sulfo group (SO 3 H) at N-1 position can generally react with a base to form a salt thereof. Therefore, the compound (I) may be recovered in the form of a salt and such salt may be converted into the free form or to another salt. And, the compound (I) obtained in the free form may be converted into a salt. The present invention also covers the compound (I) in a pharmaceutically acceptable salt form. For conversion of the compound obtained in the salt form into the free form, the method using an acid can be used. Usable acids depend on the kind of protective group and other factors. The acids include, for example, hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, trifluoroacetic acid, p-toluenesulfonic acid, among others. Acid ion exchange resins can also be used. Solvents may be used include hydrophilic organic solvents such as acetone, tetrahydrofuran, methanol, ethanol, acetonitrile, dioxane, dimethylformamide, dimethyl sulfoxide, water and mixed solvents thereof. Compounds of formula (II) are novel compounds and as such form an integral part of this invention. The compounds of formula (II) can be prepared by reacting an intermediate of formula (XII). ##STR25## With the alcohol R 2 --OH (X) under standard Mitsunobu conditions (PPh 3 /DEAD/THF; D. L. Hughes, The Mitsunobu Reactions in Organic Reactions; P. Beak et al., Eds.; John Wiley & Sons, Inc.: New York, vol. 42, pp. 335-656, 1992). R 1 has the same definition as defined before. R 3 is a protective group for the carboxyl group. The protective groups for said carboxyl group include all groups generally usable as carboxyl-protecting groups in the field of β-lactam compound and organic chemistry, for example, methyl, ethyl, propyl, isopropyl, allyl, t-butyl, benzyl, p-methoxybenzyl, p-nitrobenzyl, benzhydryl, methoxymethyl, ethoxymethyl, acetoxymethyl, pivaloyloxymethyl, trityl, 2,2,2-trichloroethyl, β-iodoethyl, t-butyldimethylsilyl, dimethylsilyl, acetylmethyl, among others. The selection of the said protective group should be in such a way which at the end of the above described reaction sequence can be cleaved from the carboxyl group under conditions that do not alter the rest of the molecule. Preferred protective groups are methyl, ethyl, allyl. The removal of protective groups R 3 can be effected by selective application of a per se known method such as the method involving the use of an acid, one using a base, the method involving the use of palladium tetrakis. The method involving the use of an acid employs according to the type of protective group and other conditions, inorganic acid such as hydrochloric acid, phosphoric-acid; organic acid like formic acid, acetic acid, trifluoroacetic acid, acidic ion exchange resins and so on. The method involving the use of a base employs, according to the type of protective group and other conditions, inorganic bases such as the hydroxides or carbonates of alkali metals (e.g., sodium, potassium etc.) or of alkaline earth metals (e.g., calcium, magnesium, etc.) or organic bases such as metal alkoxides, organic amines, quarternary ammonium salts or basic ion exchange resins, etc. The reaction temperature is about 0° to 80° C., more preferably about 10° to 40° C. The reaction is usually carried out in a solvent. As the solvent, organic solvents such as ethers (e.g., dioxane, tetrahydrofuran, diethyl ether), esters (e.g., ethyl acetate, ethyl formate), halogenated hydrocarbons (e.g., chloroform, methylene chloride), hydrocarbons (e.g., benzene, toluene) and amides (e.g. dimethylformamide, dimethylacetamide) and a mixture thereof are used. Alternatively, the intermediate of formula (II) can be prepared by reacting the compound of formula (XII) with a compound of formula, R 2 --X (XI) wherein X is a leaving group such as halogen, trifluoroacetate, alkylsulfonate, arylsulfonate or other activated esters of alcohols. R 2 has the same meaning as defined before. In another approach, the intermediate (II) can be prepared by reacting a keto acid compound of formula (VII) with a hydroxylamine derivative (or it's salt) of formula, R 2 --O--NH 2 (IX) using conventional procedures; see for example, EP 0251,299 (Kaken); Tokkai Hei 6-263766 (Kyorin, Sep. 20, 1994). The acids useful for eliminating the hydroxy-protecting group present in the items (a) to (g) in the final step of the preparation of compound of the formula (I) are formic acid, trichloroacetic acid, trifluoroacetic acid, hydrochloric acid, trifluoromethanesulfonic acid or the like. When the acid is used in a liquid state, it can act also as a solvent or an organic solvent can be used as a co-solvent. Useful solvents are not particularly limited as far as they do not adversely affect the reaction. Examples of useful solvents are anisole, trifluoroethanol, dichloromethane and like solvents. The 2-oxo-1-azetidinesulfonic acid derivatives of the present invention having the formula (I) in which M is hydrogen can be purified by standard procedures well known in the art such as crystallization and chromatography over silica gel or HP-20 column. The present invention encompasses all the possible stereoisomers as well as their racemic or optically active mixtures. Typical solvates of the compounds of formula (I) may include water as water of crystallization and water miscible solvents like methanol, ethanol, acetone, dioxane or acetonitrile. Compounds containing variable amounts of water produced by a process such as lyophilization or crystallization from solvents containing water are also included under the scope of this invention. The β-lactamase inhibitors of this invention of formula (I) are acidic and they will form salts with basic agents. It is necessary to use a pharmaceutically acceptable non-toxic salt. However, when M is hydrogen and when there is an acidic hydrogen in the R 2 residue as exemplified by N--OH, the compound of the formula (I) is diacid and can form disalts. In the latter case, the two cationic counterions can be the same or different. Salts of the compounds of formula (I) can be prepared by standard methods known in the β-lactam literature. Typically, this involves contacting the acidic and basic components in the appropriate stoichiometric ratio in an inert solvent system which can be aqueous, non-aqueous or partially aqueous, as appropriate. Favourable pharmaceutically-acceptable salts of the compounds of formula (I) are sodium, potassium and calcium. The compounds of the present invention including the pharmaceutically-acceptable salts thereof are inhibitors of bacterial β-lactamases particularly of cephalosporinases (class C enzyme) and they increase the antibacterial effectiveness of β-lactamase susceptible β-lactam antibiotics--that is, they increase the effectiveness of the antibiotic against infections caused by β-lactamase (cephalosporinase) producing microorganisms, e.g. Pseudomonas aeruginosa, in particular. This makes the compounds of formula (I) and said pharmaceutically acceptable salts thereof valuable for co-administration with β-lactam antibiotics in the treatment of bacterial infections in mammalian subjects, particularly humans. In the treatment of a bacterial infection, said compound of the formula (I) or salt can be mixed with the β-lactam antibiotic, and the two agents thereby administered simultaneously. Alternatively, the said compound of formula (I) or salt can be administered as a separate agent during a course of treatment with the antibiotic. The compounds of the invention can be administered by the usual routes. For example, parenterally, e.g. by intravenous injection or infusion, intramuscularly, subcutaneously, orally, intraperitoneally; intravenous injection or infusion being the preferred. The dosage depends on the age, weight and condition of the patient and on the administration route. The pharmaceutical compositions of the invention may contain a compound of formula (I) or a pharmaceutically acceptable salt thereof, as the active substance mixed with a β-lactam antibiotic in association with one or more pharmaceutically acceptable excipients and/or carriers. Alternatively, the pharmaceutical compositions of the invention may contain a compound of formula (I) mixed with a β-lactam antibiotic in association with a salt forming basic agent, e.g. NaHCO 3 or Na 2 CO 3 in an appropriate ratio. The pharmaceutical compositions of the invention are usually prepared following conventional methods and are adminstered in a pharmaceutically suitable form. For instance, solutions for intravenous injection or infusion may contain a carrier, for example, sterile water or, preferably, they may be in the form of sterile aqueous isotonic saline solutions. Suspensions or solutions for intramuscular injections may contaim, together with the active compound and the antibiotic, a pharmaceutically acceptable carrier, e.g. sterile water, olive oil, ethyl oleate, glycols, e.g. propylene glycol. For oral mode of administration a compound of this invention can be used in the form of tablets, capsules, granules, powders, lozenges, troches, syrups, elixirs, suspensions and the like, in accordance with the standard pharmaceutical practice. The oral forms may contain together with the active compound of this present invention and a β-lactam antibiotic, diluents, e.g. lactose, dextrose, saccharose, cellulose, cornstarch, and potato starch; lubricants e.g. silica, talc, stearic acid, magnesium or calcium stearate, and/or polyethylene glycols; binding agents e.g. starches, arabic gums, gelatin, methylcellulose, carboxymethyl cellulose, disaggregating agents, e.g. a starch, alginic acid, alginates, sodium starch glycolate, effervescing mixtures; dyestuffs; sweetners; wetting agents e.g., lecithin, polysorbates, laurylsulphates and pharmacologically inactive substances used in pharmaceutical formulations. As already said, the oxyimino fragment i.e., ═N--OR 2 in the formula (I) in its `anti` orientation provides excellent synergy with a β-lactam antibiotic against class C β-lactamase (cephalosporinase) producing microorganisms, P. aeruginosa, in particular. Thus this invention includes only those compounds having the formula (I) in which the oxyimino group (═N--OR 2 ) is specifically in the `anti` orientation as shown in (I). Furthermore, the inhibitory activity against the isolated β-lactamase (e.g., cephalosporinase from P. aeruginosa 46012) and the synergy with a β-lactam antibiotic is greatly influenced by the nature of the heterocyclic ring represented by R 1 and the nature of the substituent in the oxime fragment represented by R 2 . Thus, thiophene and 2-aminothiazole are the preferred 5-membered heterocyclic rings as R 1 and hydroxypyridone including N-hydroxypyridone as represented by ##STR26## is the preferred 6-membered heterocyclic ring as one of the components represented by R 2 . Furthermore, in the above formula when X is N--OH the compounds of formula (I) may have the following keto and enol tautomeric isomers; keto--form being the preferred one. ##STR27## In most instances, an effective β-lactamase inhibiting dose of a compound of formula (I) or a pharmaceutically acceptable salt thereof, will be a daily dose in the range from about 1 to about 500 mg/kg of body weight orally, and from about 1 to about 500 mg/kg of body weight parenterally. However, in some cases it may be necessary to use dosages outside these ranges. The weight ratio of the β-lactamase inhibitor of the present invention and the β-lactam antibiotic with which it is being administered will normally be in the range of 1:20 to 20:1. Test for Antibacterial Activity The compounds of the present invention in combination with ceftazidime were tested for minimal inhibitory concentration (MIC) against the bacteria listed in Table 3, according to the microbroth dilution method described below. The MICs of the antibiotics (ceftazidime) alone, the MICs of ceftazidime in combination with reference compounds particularly aztreonam (ref. compd. I) and the MICs of the β-lactamase inhibitors (10 μg/ml) of the present invention in combination with ceftazidime were determined with the same β-lactamase producing bacteria. After incubation in Mueller-Hinton Broth (Difco) at 37° C. for 18 h, the bacterial suspension was diluted and about 10 5 CFU/ml was applied to the drug-containing Mueller-Hinton Broth in each well of 96 well plate. The MICs were recorded after 18 h of incubation at 37° C. on the lowest combinations of drug that inhibited visible growth of bacteria. Test for β-Lactamase Inhibitory Activity The inhibitory activities of present compounds (β-lactamase inhibitors) against cephalosporinase was measured by spectrophotometric rate assay using 490 nM and using nitrocefin as a substrate (J. Antimicrob. Chemother., vol. 28, pp 775-776, 1991). Table 1 shows the results. TABLE 1__________________________________________________________________________Compound R.sub.1 R.sub.2 /orientation of OR.sub.2 M IC.sub.50, μM__________________________________________________________________________Ref. compd. I (Aztreonam) ##STR28## ##STR29## H 0.13Ref. compd. II ##STR30## ##STR31## H 2.0Ref. compd. III ##STR32## ##STR33## K 0.04 1 ##STR34## ##STR35## H 0.06 2 ##STR36## ##STR37## K 0.04 3 ##STR38## ##STR39## Na 0.01 4 ##STR40## ##STR41## H 0.06 5 ##STR42## ##STR43## Na 0.05 6 ##STR44## ##STR45## Na 0.1 7 ##STR46## ##STR47## H 0.06 8 ##STR48## ##STR49## Na -- 9 ##STR50## ##STR51## K 0.00610 ##STR52## ##STR53## K 0.00111 ##STR54## ##STR55## K 0.0512 ##STR56## ##STR57## K 0.00613 ##STR58## ##STR59## K 0.0114 ##STR60## ##STR61## K 0.0415 ##STR62## ##STR63## K 0.916 ##STR64## ##STR65## -- 0.004517 ##STR66## ##STR67## H --18 ##STR68## ##STR69## H --__________________________________________________________________________ The following examples are provided to demonstrate the operability of the present invention. The structures of the compounds were established by the modes of synthesis and by extensive high field nuclear magnetic resonance spectral techniques. Preparation of Compound 1 (EXAMPLE 1) Step 1 Ethyl (E)-2-(2-thienyl)-2-(hydroxyimino) acetate To a solution of ethyl 2-oxo-2-(2-thienyl) acetate (41 gm, 0.223 moles) in ethanol (350 ml) was added hydroxylamine hydrochloride (23.2 gm, 0.334 moles) followed by pyridine (21.6 ml, 0.267 moles) and the mixture was heated at 40°-45° C. overnight. Solvent was removed under reduced pressure. Ethyl acetate (120 ml) was added and the mixture was cooled to 0° C.; the precipitated solid was collected by filtration (10 gm). The mother liquor was concentrated under reduced pressure and the residue was taken in ether (400 ml); a stream of hydrogen chloride gas was bubbled through the solution for 35 min, stirred at room temp. for 0.5 hr. After removal of the solvent, the precipitated solid was collected by filtration and washed thoroughly with ether to give an additional amount of the product. Ethyl (E)-2-(2-thienyl)-2-(hydroxyimino) acetate was obtained as white crystalline solid (38 gm, 92% yield). Step 2 Ethyl (E)-2-(2-thienyl)-2- (1,5-dibenzhydryloxy-4-pyridon-2-yl methoxy)imino!acetate A solution of 1,5-dibenzhydryloxy-2-hydroxymethyl-4-pyridone (EP 0251 299) (46.7 gm) in dimethylformamide (200 ml) was gently heated until the solution became clear. After cooling the solution to room temperature, 19.0 gm of ethyl (E)-2-(2-thienyl)-2-(hydroxyimino) acetate and 25.0 gm of triphenyl phosphine was added. To this mixture was added diethyl azodicarboxylate (15 ml) dropwise and the mixture was reacted at room temperature for 2 hours under stirring. DMF was removed under reduced pressure and the residue was taken in ethyl acetate (300 ml), washed successively with water and brine and dried to obtain 40 gm of the above identified compound. NMR (DMSO-d 6 ): δ 1.30 (t, 3H), 4.35 (q, 2H), 5.00 (br, s, 2H), 6.00 (s, 1H), 6.35 and 6.40 (2s, 2H), 7.20-7.45 (m, 11H), 7.72 (d, 1H), 7.77 (s, 1H), 7.98 (d, 1H). Step 3 (E)-2-(2-thienyl)-2- (1,5-dibenzhydryloxy-4-pyridon-2-yl methoxy)imino!acetic acid A mixture of ethyl (E)-2-(2-thienyl)-2- (1,5-dibenzhydryloxy-4-pyridon-2-yl methoxy)imino! acetate (from step 2, 17.74 gm) in methanol (350 ml) and THF (75 ml) was stirred at room temperature until the reaction mixture became clear. To this mixture an aqueous solution of NaOH (1.58 gm dissolved in 100 ml of water) was added dropwise over 20 min, and the mixture was stirred at room temp. for 5 hr. After completion of the reaction, solvent was removed under reduced pressure. The residue was diluted with water (350 ml), cooled in an ice-bath and carefully acidified by dropwise addition of dilute hydrochloric acid (3.5 ml of conc. HCl dissolved in 15 ml of water) with vigorous stirring. At pH 2˜3, fine white solid started to precipitate out. To the mixture chloroform (500 ml) was added and partitioned. The aqueous layer was separated out and reextracted with CHCl 3 (2×200 ml). The combined organic layer was concentrated to dryness. The solid thus obtained was suspended in ether (100 ml), stirred for 30 min, filtered off and washed thoroughly with ether (2×30 ml). The solid was dried over P 2 O 5 under vacuum to obtain 17.5 gm of the above identified product. NMR (DMSO-d 6 ): δ 4.96 (br, s, 2H), 6.01 (s, 1H), 6.37 and 6.40 (2s, 2H), 7.20-7.50 (m, 1H), 7.70 (d, 1H), 7.80 (s, 1H), 7.95 (d, 1H). Step 4 (3S)-trans-3- (E)-2-(2-thienyl)-2-{(1,5-dibenzhydryloxy-4-pyridon-2-yl methoxy)imino}acetamido!-4-methyl-2-oxoazetidine-1-sulfonic acid, potassium salt A mixture of (3S)-trans-3-amino-4-methyl-2-oxoazetidine-1-sulfonic acid 1.37 gm, J. Org. Chem., 47, 5160, (1982)!, (E)-2-(2-thienyl)-2- (1,5-dibenzhydryloxy-4-pyridon-2-ylmethoxy)imino!acetic acid (step 3, 4.89 gm), DCC (1.73 gm) and 1-hydroxybenzotriazole (1.13 gm) in DMF (50 ml) was stirred under N 2 at room temperature for 30 min, KHCO 3 (0.762 gm) was added in one portion and the mixture was stirred at room temperature for 24 hr. The solid was filtered off and the filtrate was evaporated under reduced pressure to remove DMF. The crude product was taken in THF (50 ml) and cooled to -30° C. The solid was filtered off and the filtrate was evaporated to dryness. The residue (7.5 gm) was dissolved in 10 ml of methanol and diluted with ether with stirring at room temperature. The separated fine solid was collected by filtration. The filtrate was concentrated again to give a foam which was dissolved in minimum amount of methanol and diluted with ether. The separated solid was collected by filtration and air dried. Total mass of the product was 6.0 gm, which was used for the next step. Step 5 (3S)-trans-3- (E)-2-(2-thienyl)-2-{(1,5-dihydroxy-4-pyridon-2-ylmethoxy)imino}acetamido!-4-methyl-2-oxoazetidine-1-sulfonic acid 25.0 gm of (3S)-trans-3- (E)-2-(2-thienyl)-2-{(5-benzhydryloxy-4-pyridon-2-yl methoxy)imino}acetamido!-4-methyl-2-oxoazetidine-1-sulfonic acid, potassium salt (from Step 4) was taken in 40 ml of dry methylene chloride and anisole mixture (1:1) and cooled to -10° C., trifluoroacetic acid (46 ml) was added dropwise over 10 min, an additional amount of methylene chloride (20 ml) was added and the mixture was stirred at -10° C. for 2 hr. All the volatile solvents were removed under reduced pressure and the residue was digested with ether and the solvent was decanted off. The residue was finally digested with ethyl acetate and the off-white precipitated solid was collected by filtration. The solid thus obtained was crystallized from methanol-water to provide 8.0 gm of the target compound as white powder; m.p. 170° C. (decomp.). C, H analysis: Calcd, C, 40.67; H, 3.41; N, 11.86 Found, C, 40.14; H, 3.46; N, 11.44 NMR (DMSO-d 6 ): δ 1.41 (d, 3H, J═6.15 Hz), 3.78-3.82 (m, 1H), 4.49 (dd, 1H, J=2.68 Hz and 8.25 Hz), 5.58 (s, 2H), 7.10 (s, 1H), 7.27 (dd, 1H, J=4.0 Hz and 5.0 HZ), 7.82 (dd, 1H, J=1.0 Hz and 4.0 Hz), 8.01 (dd, 1H, J=1.0 Hz and 5.0 Hz), 8.28 (s, 1H), 9.40 (d, J=8.25 Hz). Preparation of Compound 14 (EXAMPLE 2) Step 1 Allyl (E)-2-(2-thienyl)-2- (5-benzhydryloxy-4-pyranon-2-yl methoxy)imino!acetate To an ice cooled solution of allyl (E)-2-(2-thienyl)-2-(hydroxyimino)acetate (1.0 gm, 4.734 mmol), 5-benzhydryloxy-2-(hydroxymethyl) pyran-4-one (1.46 gm, 4.734 mmol) and triphenylphosphine (1.24 gm, 4.734 mmol) in dry THF (30 ml) under nitrogen was added dropwise diethyl azodicarboxylate (820 μl, 5.208 mmol). The reaction mixture was stirred at room temperature overnight and concentrated under reduced pressure to afford the crude as yellow gum (4.93 gm). The product was purified by silica gel column chromatography using hexane-ethyl acetate (2:1) as eluant to provide the title compound as a gummy foam in 47% yield (1.11 gm). 1 H NMR (DMSO-d 6 ): δ 8.15 (s, 1H); 8.01 (dd, 1H, J=0.85 Hz and 5.0 Hz); 7.76 (dd, 1H, J=1.0 Hz and 4.0 Hz); 7.23-7.46 (m, 11H); 6.48 (s, 1H); 6.47 (s, 1H); 5.91-6.11 (m, 1H); 5.28-5.43 (m, 2H); 5.25 (s, 2H); 4.84 (d, 2H, J=5.51 Hz). Step 2 Sodium (E)-2-(2-thienyl)-2- (5-benzhydryloxy-4-pyranon-2-yl methoxy)imino!acetate A solution of allyl (E)-2-(2-thienyl)-2- (5-benzhydryloxy-4-pyranon-2-yl methoxy)imino!acetate (from Step 1, Example 2, 2.09 gm, 4.17 mmol), in a mixture of methylene chloride and ethyl acetate (25 ml: 55 ml) was treated with sodium 2-ethylhexanoate (693 mg, 4.17 mmol), triphenylphosphine (109 mg, 0.417 mmol) and Pd (PPh 3 ) 4 (193 mg, 0.167 mmol) and the mixture was stirred at room temperature for 5 hrs. The resulting precipitate was filtered, washed with a mixture of ether-ethyl acetate (1:1) and dried in vacuo to afford a white solid (2.0 gm, 99% yield). 1 H NMR (DMSO-d 6 ): δ 8.10 (s, 1H); 7.72 (dd, 1H, J=0.9 Hz and 5.0 Hz); 7.61 (dd, 1H, J=1.0 Hz and 4.0 Hz); 7.24-7.45 (m, 10H); 7.10 (dd, 1H, J=4.0 Hz and 5.0 Hz); 6.47 (s, 1H); 6.34 (s, 1H); 4.96 (s, 2H). Step 3 (E)-2-(2-Thienyl)-2- (5-benzhydryloxy-4-pyridon-2-yl methoxy)imino!acetic acid A suspension of sodium (E)-2-(2-thienyl)-2- (5-benzhydryloxy-4-pyranon-2-yl methoxy) imino!acetate (from Step 2, Example 2, 1.07 gm, 2.07 mmol) in 30% NH 4 OH (25 ml) in a steel bomb was heated at 90° C. for 1 hr. On cooling to room temp. N 2 gas was bubbled through and the brown solution was cooled to 0° C. and the pH was carefully adjusted to ˜2.0 with 50% HCl. The precipitated solid was filtered off, washed with water, ethyl acetate, hexane and dried successively to give a beige solid in 60% yield (610 mg). 1 H NMR (DMSO-d 6 ): δ 7.89 (dd, 1H, J=0.8 and 5.0 Hz); 7.76 (dd, 1H, J=1.0 and 4.0 Hz); 7.69 (s, 1H); 7.16-7.61 (m, 11H); 6.61 (s, 1H); 6.58 (s, 1H); 5.16 (s, 2H). Step 4 (3S)-trans-3- (E)-2-(2-thienyl)-2-{5-benzhydryloxy-4pyridon-2-yl methoxy)imino}acetamido!-4-methyl-2-oxoazetidine-1-sulfonic acid, potassium salt A mixture of (3S)-trans-3-amino-4-methyl-2-oxoazetidine-1-sulfonic acid, potassium salt 373 mg, 1.71 mmol, J. Org. Chem., 47, 5160 (1982)!, (E)-2-(2-thienyl)-2- (5-benzhydryloxy-4-pyridon-2-yl methoxy)imino!acetic acid (Step 3, Example 2, 656 mg, 1.425 mmol), DCC (294 mg, 1.425 mmol) and 1-hydroxybenzotriazole (193 mg, 1.425 mmol) in dry DMF (40 ml) was stirred under N 2 at room temp. for 20 hrs, filtered and the filtrate was concentrated to dryness under reduced pressure to give a gum which was dissolved in a mixture of acetonitrile-water (7:3) and freeze dried to give a brown fluffy mass (1.21 gm). The product was purified over a HP-20 column using acetonitrile-water as eluant. The appropriate fractions were collected and freeze dried to afford the title compound as a light brown fluff solid in 63% yield (590 mg). 1 H NMR (DMSO-d 6 ): δ 9.34 (d, 1H, J=8.3 Hz); 8.12 (s, 1H); 7.97 (dd, 1H, J=1.0 Hz and 5.0 Hz); 7.78 (dd, 1H, J=1.0 Hz and 3.8 Hz); 7.21-7.52 (m, 11H); 7.06 (s, 1H); 6.76 (s, 1H); 5.37 (s, 2H); 4.47 (dd, 1H, J=2.7 Hz and 8.3 Hz); 3.76-3.81 (m, 1H); 1.40 (d, 3H, J=6.14 Hz). Step 5 (3S)-trans-3- (E)-2-(2-thienyl)-2{(5-hydroxy-4-pyridon-2-yl methoxy)imino}acetamido!-4-methyl-2-oxoazetidine-1-sulfonic acid, potassium salt A suspension of (3S)-trans-3 - (E)-2-(2-thienyl)-2-{(5-benzhydryloxy-4-pyridon-2-yl methoxy)imino}acetamido!-4-methyl-2-oxoazetidine-1-sulfonic acid, potassium salt (from Step 4, Example 2, 570 mg, 0.863 mmol) in dry anisole (1 ml) at -10° C. was treated with trifluoroacetic acid (1.33 ml) and stirred for 2 hr. The reaction mixture was concentrated under reduced pressure to give a gum which was triturated with diethyl ether followed by a mixture of ethyl acetate-ether (5:1) to give a light brown solid (440 mg). Purification over a HP-20 column using acetone-water (1:10) as eluant and after freeze-drying of the appropriate fractions, the title compound was obtained as a pale yellow fluffy solid, 226 mg (53% yield). 1 H NMR (DMSO-d 6 ): δ 9.36 (br, s, 1H); 7.93 (dd, 1H, J=0.9 Hz and 5.0 Hz); 7.77 (dd, 1H, J=0.9 Hz and 4.0 Hz); 7.53 (br, s, 1H); 7.21 (dd, 1H, J=4.0 Hz and 5.0 Hz); 6.46 (br, s, 1H); 5.20 (s, 2H); 4.49 (s, 1H); 3.81-3.86 (m, 1H); 1.41 (d, 3H, J=6.2 Hz). TABLE 2__________________________________________________________________________.sup.1 H NMR spectra of some representative compoundsCompd No. Solvent δ (ppm)__________________________________________________________________________ 3 D.sub.2 O 7.71-7.79 (m, 2H); 7.56 (s, 1H); 7.15 (s, 1H); 6.60 (s, 1H); 5.37 (s, 2H); 4.54 (d, 1H); 4.23- 4.34 (m, 1H); 1.53 (d, 3H, J=6.0 Hz). 4 DMSO-d.sub.6 9.32 (d, 1H, J=8.3 Hz); 8.18 (s, 1H); 8.02 (d, 1H, J=4.1 Hz); 7.70-7.80 (m, 1H); 7.26 (t, 1H, J=5.0 Hz); 6.95 (s, 1H); 5.83 (q, 1H, J=7.0 Hz); 4.40-4.48 (m, 1H); 3.70-3.80 (br, m, 1H); 1.66 (d, 3H, J=7.0 Hz); 1.38 (d, 3H, J=5.9 Hz). 5 DMSO-d.sub.6 9.33 (br, s, 1H); 7.95 (d, 1H, J=4.7 Hz); 7.78 (t, 1H, J=3.2 Hz); 7.50 (s, 1H); 7.22 (t, 1H, J= 4.5 Hz); 6.36 (d, 1H, J=2.0 Hz); 5.75-5.95 (m, 2H); 5.03-5.15 (m, 2H); 4.41 (br, s, 1H); 3.75- 3.83 (m, 1H); 2.55-2.85 (m, 2H); 1.37 (d, 3H, J=5.95 Hz). 6 DMSO-d.sub.6 9.41 (br, s, 1H); 7.92-7.98 (m, 1H); 7.73-7.80 (m, 1H); 7.40-7.58 (m, 2H); 7.10-7.30 (m, 4H); 6.93 (s, 1H); 6.31 (s, 1H); 4.40-4.48 (m, 1H); 3.75-3.90 (m, 1H); 1.39 (d, 3H, J=6.1 Hz). 7 DMSO-d.sub.6 9.35 (d, 1H, J=8.4 Hz); 7.97 (s, 1H); 7.88 (dd, 1H, J=1.0 Hz and 5.0 Hz); 7.80 (dd, 1H, J= 1.0 Hz and 4.0 Hz); 7.20 (dd, 1H, J=4.0 Hz and 5.0 Hz); 7.05 (s, 1H); 4.50 (dd, 1H, J=2.6 Hz and 8.2 Hz); 4.46 (t, 2H, J=6.0 Hz); 3.94 (s, 2H); 3.83 (m, 1H); 3.00 (t, 2H, J=6.0 Hz); 1.41 (d, 3H, J=6.0 Hz). 8 DMSO-d.sub.6 9.35-9.45 (m, 1H); 7.50-7.95 (m, 3H); 7.12-7.20 (m, 1H); 6.81 (s, 1H); 4.35-4.70 (m, 4H); 4.08-4.20 (m, 1H); 3.79-3.89 (m, 1H); 2.98-3.55 (m, 2H); 1.42 (d, 3H, J=6.1 Hz). 9 DMSO-d.sub.6 9.15 (br, s, 1H); 7.79-7.84 (m, 2H); 7.56-7.66 (m, 3H); 7.10-7.15 (m, 2H); 6.96-7.05 (m, 1H); 6.67 (s, 1H); 5.11 (s, 2H); 4.40-4.46 (m, 3H); 3.78-3.84 (m, 1H); 3.60-3.70 (br, m, 2H); 1.40 (d, 3H, J=6.2 Hz).10 DMSO-d.sub.6 8.75 (br, s, 1H); 7.75-7.90 (m, 5H); 7.58 (s, 1H); 7.10-7.18 (m, 2H); 6.52 (s, 1H); 6.33 (s, 2H); 4.36-4.50 (m, 3H); 3.53-3.85 (m, 3H); 1.40 (d, 3H, J=6.0 Hz).11 DMSO-d.sub.6 8.10 (br, s, 1H); 7.96 (d, 1H, J=5.0 Hz); 7.90 (br, s, 1H); 7.74 (d, 1H, J=3.2 Hz); 7.24 (s, 1H); 7.16 (t, 1H, J=5.0 Hz); 6.04 (s, 1H); 5.14 (s, 2H); 4.28-4.52 (m, 3H); 3.89-3.98 (m, 1H); 3.56 (br, s, 2H); 1.96 (s, 3H); 1.41 (d, 3H, J=6.1 Hz).12 DMSO-d.sub.6 9.30 (br, s, 1H); 8.89 (br, t, 1H); 7.84-7.90 (m, 2H); 7.68 (s, 1H); 7.05-7.30 (m, 3H); 6.70 (s, 1H); 6.65 (s, 1H); 5.08 (s, 2H0; 4.40-4.50 (m, 3H); 3.80-3.90 (m, 1H); 3.58-3.70 (m, 2H); 1.41 (d, 3H, J=6.2 Hz).13 DMSO-d.sub.6 9.30 (br, s, 1H); 8.58 (br, s, 1H); 7.83-7.88 (m, 2H); 7.76 (dd, 1H, J=1.0 Hz and 4.0 Hz); 7.38 (s, 1H); 7.15 (dd, 1H, J=4.0 Hz and 5.0 Hz); 4.47 (br, s, 1H); 4.39 (t, 2H, J=5.3 Hz); 3.80- 3.84 (m, 1H); 3.55-3.67 (m, 2H); 1.40 (d, 3H, J=6.2 Hz).15 DMSO-d.sub.6 9.28 (br, d, 1H); 7.68 (s, 1H); 6.90 (s, 1H); 6.59-6.66 (m, 2H); 6.10 (dd, 1H, J=1.0 Hz and 2.0 Hz); 5.19 (s, 2H); 4.42 (br, s, 1H); 3.80-3.85 (m, 1H); 3.50 (s, 3H); 1.39 (d, 3H, J=6.0 Hz).16 DMSO-d.sub.6 9.35 (d, 1H, J=8.0 Hz); 7.80-7.93 (m, 4H); 7.16-7.40 (m, 3H); 6.89 (s, 1H); 5.21 (s, 2H); 4.48-4.65 (m, 4H); 4.05-4.12 (m, 1H); 3.74-3.82 (m, 1H); 3.50-3.70 (m, 1H); 1.27 (d, 3H, J= 6.1 Hz).__________________________________________________________________________ TABLE 3__________________________________________________________________________ANTIBACTERIAL ACTIVITY OF CEFTADIZIME WITH COMPOUNDS (β-LACTAMASEINHIBITOR) MIC of ceftazidime (μg/ml) with Ref. Compd. I with with with with withOrganism alone (Aztreonam) Ref. Compd. II Ref. Compd. III Compd. 1 Compd. 2 Compd.__________________________________________________________________________ 3E. cloacae 40054 >32 >32 32 1.0 1.0 1.0 1.0E. cloacae MNH-2 >32 >32 >32 >32 2.0 4.0 2.0E. cloacae P99 >32 >32 16 >32 >32 >32 32E. aerogenes S-95 >32 32 8.0 4.0 1.0 4.0 0.5E. aerogenes 41006 >32 >32 >32 >32 -- >32 >32M. morganii 36014 32 -- <0.25 <0.25 <0.25 <0.25 <0.25M. morganii 36030 >32 <0.25 <0.25 <0.25 <0.25 <0.25 <0.25P. aeruginosa L46004 >32 >32 >32 >32 16 32 32P. aeruginosa 46012 (R) >32 >32 >32 32 4.0 16 8.0P. aeruginosa 46017 >32 >32 >32 32 4.0 16 4.0P. aeruginosa 46220 DR-2 32 8.0 16 <0.25 <0.25 <0.25 1.0P. aeruginosa 46220 DR-2-1 >32 >32 >32 16 <0.25 1.0 2.0P. aeruginosa CT-122 32 16 16 8.0 4.0 8.0 8.0P. aeruginosa CT-137 16 16 32 4.0 2.0 4.0 4.0P. aeruginosa CT-144 >32 >32 >32 8.0 1.0 2.0 4.0P. aeruginosa PAO 303 carb-4 32 32 32 4.0 4.0 4.0 2.0P. aeruginosa sp 2439 Wt. >32 >32 >32 32 4.0 8.0 4.0P. fluorescens sp 5953 >32 >32 >32 >32 4.0 8.0 8.0P. aeruginosa M 1405 >32 >32 >32 32 2.0 8.0 32P. aeruginosa M 2297 >32 >32 >32 32 32 16 32P. aeruginosa AU-1 >32 >32 -- 16 4.0 8.0 8.0P. aeruginosa AU-5 >32 <0.25 -- 8.0 2.0 2.0 8.0P. aeruginosa AU-7 >32 >32 -- 16 4.0 8.0 8.0P. aeruginosa AU-8 >32 >32 -- -- 8.0 8.0 8.0P. aeruginosa AU-10 32 16 -- 8.0 4.0 4.0 4.0__________________________________________________________________________ MIC of ceftazidime (μg/ml) with Ref. Compd. I with with with with Organism alone (Aztreonam) Compd. 7 Compd. 8 Compd. 9 Compd. 10__________________________________________________________________________ E. cloacae 40054 >32 >32 <0.25 0.5 1.0 <0.25 E. cloacae MNH-2 >32 >32 >32 >32 8.0 8.0 E. cloacae P 99 >32 >32 32 >32 >32 >32 E. aerogenes S-95 >32 32 1.0 0.5 1.0 1.0 E. aerogenes 41006 >32 >32 32 >32 -- -- M. morganii 36014 32 -- -- -- -- -- M. morganii 36030 >32 <0.25 <0.25 2.0 2.0 <0.25 P. aeruginosa L 46004 >32 >32 8.0 16 8.0 32 P. aeruginosa 46012 (R) >32 >32 8.0 32 1.0 1.0 P. aeruginosa 46017 >32 >32 8.0 32 1.0 0.5 P. aeruginosa 46220 DR-2 32 8.0 1.0 1.0 0.5 0.5 P. aeruginosa 46220 DR-2-1 >32 >32 0.5 2.0 <0.25 <0.25 P. aeruginosa CT-122 32 16 4.0 8.0 2.0 2.0 P. aeruginosa CT-137 16 16 2.0 2.0 1.0 1.0 P. aeruginosa CT-144 >32 >32 2.0 8.0 0.5 1.0 P. aeruginosa PAO 303 carb-4 32 32 2.0 -- 2.0 2.0 P. aeruginosa sp 2439 Wt. >32 >32 2.0 8.0 2.0 4.0 P. fluorescens sp 5953 >32 >32 8.0 8.0 1.0 1.0 P. aeruginosa M 1405 >32 >32 8.0 16 0.5 1.0 P. aeruginosa M 2297 >32 >32 8.0 32 32 32 P. aeruginosa AU-1 >32 >32 8.0 8.0 2.0 4.0 P. aeruginosa AU-5 >32 <0.25 -- -- 1.0 2.0 P. aeruginosa AU-7 >32 >32 8.0 8.0 2.0 4.0 P. aeruginosa AU-8 >32 >32 8.0 8.0 8.0 8.0 P. aeruginosa AU-10 32 16 4.0 8.0 2.0 2.0__________________________________________________________________________

A compound of formula (I) ##STR1## wherein R 1 is selected from the group consisting of 2-thienyl, 2-furyl, 2-pyrrolyl, 1-methyl-2-pyrrolyl, 2-amino-1-thiazolyl and 5-isothiazolyl; R 2 is selected from the group consisting of: ##STR2## and M is hydrogen or a pharmaceutically acceptable cation; wherein the oxyimino fragment (═N--OR 2 ) in formula (I) is in the `anti` orientation.

This is a National Phase Application in the United States of International Patent Application No. PCT/EP2004/008521 filed Jul. 29, 2004, which claims priority on European Patent Application No. 03017343.9, filed Jul. 31, 2003. The entire disclosures of the above patent applications are hereby incorporated by reference. This application incorporates by reference the Sequence Listing on the compact disc, namely the file “Sequence-listing.APP” created on Jan. 26, 2006 with a size of 4 kilobytes. BACKGROUND OF THE INVENTION The present invention relates to methods and materials for improving gene expression in eucaryotic cells, particularly in plant cells comprised in mosses, such as moss protonema cells. RELATED ART Gene amplification for improving the expression of recombinant proteins in mammalian cell cultures is a generally used strategy (Herlitschka et al. (1996) Protein Expr. Purif. 8, 358-364; Ringold et al. (1981) J. Mol. Appl.). In plants, effecting gene amplification strategies is problematic due to silencing events that can be triggered by multi-copy integrations of heterologous DNA (Asaad et al. (1993) Plant Mol. Biol. 22, 1067-1085). Recently, strategies for gene amplification in plants have been developed to overcome these limitations. The cis-acting genetic element aps was isolated from a non-transcribed spacer region of tobacco ribosomal DNA. This spacer element was fused to reporter genes of interest and resulted in in higher expression levels of heterologous proteins therefrom (Borisjuk et al. (2000) Nature Biotechnol. 18, 1303-1306). A further strategy has been described by Klimyuk et al. which involved the expression of heterologous proteins via trans-splicing (WO 02/097080). To date, little is known about the correlation of copy number and heterologous gene expression in transgenic moss plants. The use of mosses for the production of recombinant proteins is a well-established technology (EP1206561, Gorr et al. 2001 , Naunyn - Schmiedeberg's Arch. Pharmacol. 363 Suppl.: R 85). Typically, anything from 1 to about 50 copies of the transforming plasmid may be integrated into the genome of transformed moss tissue (Schaefer (2002) Annu. Rev. Plant Biol. 53, 477-501). Depending on the design of the transforming constructs employed, homologous recombination, that is, a targeted integration event and/or heterologous recombination, that is, a random or non-targeted integration event can occur. Thus, by using DNA sequences (i.e. comprised of coding or non-coding sequences) for transformation which are homologous to genomic DNA sequences of a moss can result in one or more homologous recombination events via integration of the introduced or transforming DNA into the genomic locus of the homologous DNA. Use of DNA sequences (i.e. comprised of coding or non-coding sequences) for transformation that lack any appreciable homology to a genomic DNA sequence of a moss can result in one or more heterologous recombination events via integration of the introduced DNA randomly into the genome. Moss is the only known plant system which displays a high frequency of homologous recombination (Strepp et al. (1998) Proc. Natl. Acad. Sci. USA 95, 4368-4373; Schaefer (2002) Annu. Rev. Plant Biol. 53, 477-501). This apparently unique attribute of mosses has been used for the targeted introduction of genes. However, the amplification of gene expression by increasing the copy number of plasmids of interest in order to generate greater levels of protein per unit mass of stably transformed moss tissue has not hitherto been described. Surprisingly, it has been found that by transforming, typically co-transforming cells (protoplasts) of moss tissue with at least two heterologous nucleic acid sequences comprising at least one set of recombination sequences results in an increase in the integrated copy number of heterologous nucleic acid constructs in regenerated tissue, such as cells comprised in moss protonema, which in turn is correlated with an increase of protein expression levels. It is therefore an object of the invention to provide an improved method for the production of proteins of interest in cells comprised in moss tissue. BRIEF SUMMARY OF THE INVENTION According to the present invention there is provided a method of amplifying gene expression in a moss plant cell comprising 1) providing at least a first heterologous nucleic acid construct comprising at least one heterologous nucleotide sequence operably linked to a promoter, wherein the said construct is flanked at the 5′ end thereof by a first recombination sequence and is flanked at the 3′ end of the said construct by a second recombination sequence in the same orientation as the first; 2) providing at least a second heterologous nucleic acid construct comprising at least one heterologous nucleotide sequence operably linked to a promoter, wherein the said construct is flanked at the 5′ end thereof by said second recombination sequence and is flanked at the 3′ end of the said construct by said first recombination sequence in the same orientation as the second; and 3) transforming into the moss plant cell at least said first and said second heterologous nucleic acid construct. The skilled addressee will appreciate that once the said at least two heterologous constructs are transformed into the moss plant cell, such as a moss protoplast, for example a Physcomitrella patens protoplast, which is then permitted to regenerate into moss protonema, for example of Physcomitrella patens , they will undergo recombination with each other many times over. This process, once initiated in the moss plant cell, increases the copy number of integrated transforming DNA constructs of the invention therein. Thus, as a further aspect of the invention there is provided a moss protonema, preferably protonema of Physcomitrella patens , comprised of cells stably transformed, more preferably co-transformed with at least two complementary constructs of the invention. Ultimately, significant increases in the level of heterologous protein of interest from the at least one heterologous gene of interest are measurable over and above the levels of protein that are measurable in moss protonema cells from conventional transforming constructs lacking the features of constructs of the invention. The at least first and the at least second recombination sequences form a complementary set that make it possible for the constructs of the invention to recombine with each other. Naturally, the skilled addressee will appreciate that constructs of the invention may be employed in which one or more complementary sets of recombination sequences may be used depending on how many of the same or different nucleotide sequences of interest are intended to be utilised for protein production, such as 1, 2, 3, 4, or 5 or more sets. Preferably a single complementary set of recombination sequences is used for ease of convenience. In a further aspect of the invention there is provided a heterologous DNA construct of the invention that comprises in the 5′ to 3′ direction: 1) an introduced first recombination sequence; 2) at least a heterologous nucleic acid sequence of interest comprising a promoter operably linked thereto and optionally a terminator therefor; and 3) an introduced second recombination sequence. In a further aspect of the invention there is provided a heterologous DNA construct of the invention that comprises in the 5′ to 3′ direction: 1) an introduced second recombination sequence; 2) at least a heterologous nucleic acid sequence of interest comprising a promoter operably linked thereto and optionally a terminator therefor; and 3) an introduced first recombination sequence. Thus the two constructs comprise similar complementary recombination sequences located at different sites therein that enable or permit the constructs to recombine with each other in situ in transformed moss protonema cells comprised in the moss protonema, for example protonema of Physcomitrella patens . Preferably, the constructs of the invention are in linear form. Such constructs may be used to transform moss protoplasts in at least two separate transformation events where a first transformation event is separated from a second transformation event in time or the constructs of the invention may be co-transformed into moss protoplasts which are then permitted or allowed to regenerate into moss protonema. Preferably, the transformation event comprises co-transforming moss protoplasts with at least two constructs of the invention as described above. The recombination sequence utilised in constructs of the invention may be any sequence selected from any organism, such as from plant genomic DNA, such as from genomic DNA, cDNA, intron or exon regions or non-coding regions or any combination thereof, for example, from Physcomitrella patens . Suitable genomic DNA for use as recombination sequence may comprise DNA from an exon or an intron or a hybrid of the two. Preferably the recombination sequence is formed of DNA from an intron or non-coding region of DNA. As discussed herein, the orientation of the two flanking recombination sequences is preferably in the same orientation, for example, in the 5′ to 3′ direction or in the 3′ to 5′ direction in both of the two transforming constructs albeit that the actual location of the recombination sequences within the two constructs is different one from the other as alluded to above. Naturally, the skilled addressee will appreciate that the heterologous constructs of the invention will comprise recombination sequences in appropriate position and orientation that enables recombination events to occur between the two. The recombination nucleotide sequences of constructs of the invention can be of any length provided that they are capable of causing or permitting recombination events to occur. Suitable lengths for the recombination sequences employed in constructs of the invention range from 25-1000 nucleotides in length or longer; from 25-650 nucleotides in length; from 50-650 nucleotides in length; from 100-400 nucleotides in length; or from 200-400 nucleotides in length, for example, of about 200+/−50 nucleotides in length. The skilled addressee will appreciate that the length of the recombination sequences of constructs of the invention may vary depending on design. As a further aspect of the invention, there is provided a moss cell comprised of constructs of the invention, moss protonema comprised of said moss cells, and/or moss plants comprising constructs of the invention, particularly a moss protonema cell, moss protonema comprised of protonema cells comprised of constructs of the invention, and/or moss plants comprised of constructs of the invention that are Physcomitrella patens. Particular aspects of the invention will now be discussed in more detail. DETAILED DESCRIPTION OF THE INVENTION Definitions The term “heterologous” is used broadly below to indicate that the gene/sequence of nucleotides in question have been introduced into moss protoplasts using genetic engineering, i.e. by human intervention. A heterologous gene may augment the expression of a protein of interest from an endogenous equivalent gene, i.e. one which normally performs the same or a similar function, or the inserted sequence may be additional to the endogenous gene or other sequence. Nucleic acid heterologous to a cell may be non-naturally occurring in moss protoplasts of that type, variety or species. Thus the heterologous nucleic acid may comprise a coding sequence of, or derived from, a particular type of organism, such as a mammalian species, e.g of human, ovine, bovine, equine, or porcine species, placed within the context of a moss protoplast, such as a protoplast derived from Physcomitrella patens . A further possibility is for a nucleic acid sequence to be placed within a moss protoplast in which it or a homologue is found naturally, but wherein the nucleic acid sequence is linked and/or adjacent to nucleic acid which does not occur naturally within the cell, or cells of that type or species or variety of plant, such as operably linked to one or more regulatory sequences, such as a promoter sequence, for control of expression. “Gene” unless context demands otherwise refers to any nucleic acid encoding genetic information for translation into a peptide, polypeptide or protein. “Vector” is defined to include, inter alia, any plasmid, cosmid, phage, or viral vector in double or single stranded linear or circular form which may or may not be self transmissible or mobilizable, and which can transform a prokaryotic or eukaryotic host and exists extrachromosomally (e.g. autonomous replicating plasmid with an origin of replication). Specifically included are shuttle vectors by which is meant a DNA vehicle capable, naturally or by design, of replication in two different host organisms, which may be selected from actinomycetes and related species, bacteria and eucaryotic (e.g. higher plant, mosses, mammalian, yeast or fungal) cells. “Expression vector” refers to a vector in which a nucleic acid is under the control of, and operably linked to, an appropriate promoter or other regulatory elements for transcription in a host cell such as a microbial cell or a moss protoplast. The vector may be a bi-functional expression vector which functions in multiple hosts. In the case of genomic or subgenomic DNA, this may contain its own promoter or other regulatory elements and in the case of cDNA this may be under the control of an appropriate promoter or other regulatory elements for expression in the host cell. A “promoter” is a sequence of nucleotides from which transcription may be initiated of DNA operably linked downstream (i.e. in the 3′ direction on the sense strand of double-stranded DNA). “Operably linked” means joined as part of the same nucleic acid molecule, suitably positioned and oriented for transcription to be initiated from the promoter. The term “inducible” as applied to a promoter is well understood by those skilled in the art. In essence, expression under the control of an inducible promoter is “switched on” or increased in response to an applied stimulus. The nature of the stimulus varies between promoters. Some inducible promoters cause little or undetectable levels of expression (or no expression) in the absence of the appropriate stimulus. Other inducible promoters cause detectable constitutive expression in the absence of the stimulus. Whatever the level of expression is in the absence of the stimulus, expression from any inducible promoter is increased in the presence of the correct stimulus. The invention also embraces use of a variant of any of these sequences. A variant protein shares homology with, or is identical to, all or part of the sequences discussed above. Generally speaking, wherever the term is used herein, variants may be: (i) naturally occurring homologous variants of the relevant protein, (ii) artificially generated homologous variants (derivatives) which can be prepared by the skilled person in the light of the present disclosure, for instance by site directed or random mutagenesis, or by direct synthesis. Preferably the variant nucleic acid, encoding the variant polypeptide, is generated either directly or indirectly (e.g. via one or more amplification or replication steps) from an original nucleic acid. Changes to the nucleic acid sequence may produce a derivative by way of one or more of addition, insertion, deletion or substitution of one or more nucleotides in the nucleic acid, leading to the addition, insertion, deletion or substitution of one or more amino acids in the encoded polypeptide. Desirable mutation may be random or site directed mutagenesis in order to alter the activity (e.g. specificity) or stability of the encoded polypeptide. Changes may be by way of conservative variation, i.e. substitution of one hydrophobic residue such as isoleucine, valine, leucine or methionine for another, or the substitution of one polar residue for another, such as arginine for lysine, glutamic for aspartic acid, or glutamine for asparagine. Also included are variants having non-conservative substitutions. In regions which are critical in determining the peptides conformation or activity such changes may confer advantageous properties on the polypeptide e.g. altered stability or specificity. Similarity or homology in the case of variants is preferably established via sequence comparisons made using FASTA and FASTP (see Pearson & Lipman, 1988. Methods in Enzymology 183: 63-98). Parameters are preferably set, using the default matrix, as follows: Gapopen (penalty for the first residue in a gap): −12 for proteins/−16 for DNA Gapext (penalty for additional residues in a gap): −2 for proteins/−4 for DNA KTUP word length: 2 for proteins/6 for DNA. Homology may be at the nucleotide sequence and/or encoded amino acid sequence level. Preferably, the nucleic acid and/or amino acid sequence shares at least about 75%, or 80% identity, most preferably at least about 90%, 95%, 96%, 97%, 98% or 99% identity. Homology may also be assessed by use of a probing methodology (Sambrook et al., 1989). One common formula for calculating the stringency conditions required to achieve hybridization between nucleic acid molecules of a specified sequence homology is: T m =81.5° C.+16.6 Log [Na+]+0.41 (% G+C)−0.63 (% formamide)−600/#bp in duplex. As an illustration of the above formula, using [Na+]=[0.368] and 50-% formamide, with GC content of 42% and an average probe size of 200 bases, the T m is 57° C. The T m of a DNA duplex decreases by 1-1.5° C. with every 1% decrease in homology. Thus, targets with greater than about 75% sequence identity would be observed using a hybridization temperature of 42° C. Use in Moss Plants As described below, in its various aspects, the invention will generally be employed on moss protoplasts, using nucleic acids encoding proteins of interest. Suitable promoters which operate in moss protoplasts include the Cauliflower Mosaic Virus 35S (CaMV 35 S). Other examples are disclosed at pg 120 of Lindsey & Jones (1989) Plant Biotechnology in Agriculture” Pub. OU Press, Milton Keynes, UK. The promoter may be selected to include one or more sequence motifs or elements conferring developmental and/or tissue-specific regulatory control of expression. Inducible plant promoters include the ethanol induced promoter of Caddick et al (1998) Nature Biotechnology 16: 177-180. A terminator is contemplated as a DNA sequence at the end of a transcriptional unit which signals termination of transcription. These elements are 3′-non-translated sequences containing polyadenylation signals, which act to cause the addition of polyadenylate sequences to the 3′ end of primary transcripts. For expression in plant cells the nopaline synthase transcriptional terminator (A. Depicker et al., 1982, J. of Mol. & Applied Gen. 1:561-573) sequence may serve as a transcriptional termination signal, as can the CaMV 35S terminator (Töpfer et al. (1987) NAR 15, 5890). If desired, selectable genetic markers may be included in further conventional constructs, such as circular plasmids or in further linearised DNA constructs that are co-transformed into a moss cell of the invention, such as those that confer selectable phenotypes such as resistance to antibiotics or herbicides (e.g. kanamycin, hygromycin, phosphinotricin, chlorsulfuron, methotrexate, gentamycin, spectinomycin, imidazolinones and glyphosate). The present invention also provides methods comprising the introduction of such constructs comprising appropriate heterologous sequences into a moss plant cell and/or induction of expression of a construct of the invention within a moss plant cell, by application of a suitable stimulus e.g. an effective exogenous inducer. Suitable moss plant cells include the moss protoplast, and cells comprised in the protonema, such as those derived from Physcomitrella patens. Nucleic acid can be introduced into moss protoplasts using any suitable technology, such as PEG-mediated DNA uptake as herein described, particle or microprojectile bombardment (U.S. Pat. No. 5,100,792, EP-A-444882, EP-A-434616) microinjection (WO 92/09696, WO 94/00583, EP 331083, EP 175966, Green et al. (1987) Plant Tissue and Cell Culture , Academic Press), electroporation (EP 290395, WO 8706614 Gelvin Debeyser) other forms of direct DNA uptake (DE 4005152, WO 9012096, U.S. Pat. No. 4,684,611), liposome mediated DNA uptake (e.g. Freeman et al. Plant Cell Physiol. 29: 1353 (1984)), or the vortexing method (e.g. Kindle, PNAS U.S.A. 87: 1228 (1990d) Physical methods for the transformation of plant cells are reviewed in Oard, 1991 , Biotech. Adv. 9: 1-11. Electroporation, PEG-mediated DNA uptake and direct DNA uptake are preferred. Especially preferred is the modified PEG mediated DNA uptake procedure as disclosed in the examples herein. The particular choice of a transformation technology will be determined by its efficiency to transform certain moss species as well as the experience and preference of the person practising the invention with a particular methodology of choice. It will be apparent to the skilled person that the particular choice of a transformation system to introduce nucleic acid into moss protoplasts is not essential to the invention. However, the use of the PEG-mediated DNA transformation system as described herein is preferred. Thus various aspects of the present invention provide a method of transforming a moss protoplast involving introduction of a heterologous nucleic acid-based construct of the invention as described herein into a moss protoplast and regeneration of the protoplast into protonema tissue and causing or allowing expression of protein from the constructs of the invention. Thus, the skilled addressee may expect that expression of protein targeted to the cytosol or other cellular compartments can be improved by using constructs and methods of the invention. Preferably, recombinant proteins produced by the methods of the invention are secreted into the medium from stably transformed protonemal tissue. Thus, by employing the at least two constructs of the invention as herein described production lines may be generated harbouring high copy numbers of the target gene which in turn results in high protein yields over the cultivation period in a suitable bioreactor. Choice of Genes to Enhance Genes of interest include those encoding proteins which are themselves, natural medicaments such as pharmaceuticals or veterinary products. Heterologous nucleic acids may encode, inter alia, genes of bacterial, fungal, plant or animal origin. Polypeptides produced may be utilised for producing polypeptides which can be purified therefrom for use elsewhere. Such proteins include, but are not limited to retinoblastoma protein, p53, angiostatin, and leptin. Likewise, the methods of the invention can be used to produce mammalian regulatory proteins. Other sequences of interest include proteins, hormones, such as follicle stimulating hormone, growth factors, cytokines, serum albumin, haemoglobin, collagen, thaumatin, thaumatin-like proteins, epidermal growth factors such as VEGF, heterodimers, antibodies, immunoglobulins, fusion antibodies and single chain antibodies. Expression of Target Genes Generally speaking, heterologous nucleic acids may be expressed by any appropriate process used in the art or they may be transcribed or expressed as follows: (i) expression of ‘naked’ DNA e.g. comprising a promoter operably linked to the heterologous sequence in a construct of the invention, (ii) expression from an expression vector, such as a replicating vector. Generally speaking, those skilled in the art are well able to construct vectors and design protocols for recombinant gene expression. Suitable vectors can be chosen or constructed, containing appropriate regulatory sequences, including promoter sequences, terminator fragments, polyadenylation sequences, enhancer sequences, marker genes and other sequences as appropriate. For further details see, for example, Molecular Cloning: a Laboratory Manual: 2nd edition, Sambrook et al, 1989, Cold Spring Harbor Laboratory Press or Current Protocols in Molecular Biology , Second Edition, Ausubel et al. eds., John Wiley & Sons, 1992. As discussed above, the present inventors show that enhanced expression from constructs of the invention introduced (preferably at high levels) into the protoplasts of a moss, preferably at high cell density, such as Physcomitrella patens , which constructs are integrated into the genome give rise to transcribed mRNA. Thus in one aspect of the invention there is disclosed use of a transformed moss protoplast capable of generating mRNA encoding a target protein generated by transcription from an introduced nucleic acid construct of the invention including the target nucleotide sequence operably linked to a promoter, which construct is introduced into the cell of an organism. The “introduced nucleic acid” will thus include the heterologous nucleic acid sequence as a DNA sequence provided in the form of a construct of the invention that is capable of giving rise to the production of extracellular protein at an elevated level relative to the level of protein production normally associated with stable transgene expression of the said DNA sequence. In one aspect of the invention, the heterologous nucleic acid sequence may encode a protein that is made up of a signal and/or a transit peptide coupled to the protein or polypeptide sequence of choice. The reporter can be any detectable protein, such as a marker gene, commonly used in the art such as GUS, GFP, luciferase etc. Preferably, the reporter is a non-invasive marker such as GFP or luciferase. Naturally, the man skilled in the art will recognise that more than one heterologous nucleic acid sequence may be used in the, or each, construct of the invention, although a single sequence in each case is preferred. Multiple vectors (each including one or more nucleotide sequences encoding heterologous protein of choice) may be introduced into the moss protoplasts via PEG-mediated DNA uptake methods as described herein. This may be useful for producing e.g. multiple subunits e.g. of an enzyme. In a further embodiment of the invention high levels of fully and correct assembled proteins consisting of multiple subunits can be achieved by influencing the stoichiometry of the different coding nucleic acid sequences integrated into the genome. The amount of proper assembled protein that consists of multiple subunits is dependent on the stoichiometry of the subunits on the protein level. In the case of subunits which have to be targeted to different compartments via signal peptides e.g. to the secretory pathway, the stoichiometry is not only influenced by the expression derived from e.g. promoter and transcriptional signals but also by the targeting signal and processing of targeting signal, e.g. proper cleavage of the signal peptide. In this aspect of the invention use of non-equimolar quantities of the nucleic acid sequences coding for the different subunits may be appropriate for multimeric proteins, e.g. for immunoglobulins. Non-equimolar quantities of coding nucleic acids resulting in proper stoichiometry of multiple subunits of a dimeric or multimeric protein can thus be achieved by providing appropriately designed constructs of the invention that enable correct assembly of the different subunits. As described in the Examples below, expression of heterologous sequences using methods of the invention when introduced in this way can give very high levels of target polypeptide over the course of the expression period, which will generally be several days, depending on the precise methods and materials employed. By using the methods of the invention as herein described, high levels of heterologous polypeptide production from stably incorporated constructs of the invention from regenerated transformed, preferably co-transformed protonema can be achieved. All references discussed herein, inasmuch as they may be required to supplement the present disclosure, are incorporated herein in their entirety by reference. The invention will now be further described with reference to the following non-limiting Figures and Examples. Other embodiments of the invention will occur to those skilled in the art in the light of these. EXAMPLES Methods and Materials Plant Material The wild-type strain of Physcomitrella patens (Hedw.) B. S. G. (Reski et al. 1994) is used. It is a subculture of strain 16/14 which was collected by H. L. K. Whitehouse in Gransden Wood, Huntingdonshire, UK and propagated by Engel (1968). Construction of Vectors Construction of pRT101VEGF C3 Human vascular endothelial growth factor 121 (VEGF 121 ) cDNA without leader sequence is excised as an NdeI-SalI fragment from pCYTEXP-VEGF 121 (GBF, Braunschweig, Germany). This fragment is blunted by the Klenow reaction and introduced into pRT101 (Töpfer et al. 1987) at the SmaI restriction site to form plasmid pRT101VEGF C3. In this construct, the VEGF 121 cDNA minus leader sequence was placed downstream of the CaMV 35 S promoter and behind the CaMV terminator (Gorr, 1999). Construction of pRT101TPVEGF C3 The sequence for VEGF signal peptide (sorting signal for secretion) is cloned into pRT101VEGF C3. The signal peptide cDNA is amplified from the plasmid pRT101 P21(Gorr, 1999) using the 5′ primer MoB323 (5′-ATA CTC GAG GAA GAT GAA CTT TTC TGC CTG TCT TGG-3′, SEQ ID NO 1) containing an XhoI restriction side and 3′ primer MoB349 (5′-CTG CCA TGG GTG CAG CCT GGG ACC AC-3′, SEQ ID NO 2) containing NcoI restriction side. The amplified DNA is digested with XhoI and NcoI and ligated into pRT101VEGF C3 (XhoI/NcoI digested) resulting in pRT101TPVEGF C3. The resulting plasmid contains the coding sequences for the VEGF signal peptide and VEGF 121 in frame under control of the CaMV 35 S promoter. Cloning Procedure for 5′ First Recombination Sequence into pRT99 The 250 bp 5′ sequence of the 5 th intron: (5′-GCGGAAATGTTCAGAGTTAAGCGAAATCACAACTAAAAGAGATTGGAAGCAGAAGAATT TTTGAGCAGCTGTTCTTAATTCACGCAACGACAACGCTATTAACTGTATGTGTAGACGAT GCACTTTCGTACTGAAGGGATCTAAATTTATTATATCCCTTCATAACTAGAGGCAAGGCG GAAATCACAAAACTATTGGTACCTACGTACTACAGCCTCCAGGATCAAACATAAGAGTGA AACACTGGACC-3′, SEQ ID NO 3) of the alpha 1,3-fucosyltransferase gene of Physcomitrella patens is amplified from genomic DNA of Physcomitrella patens by Pfu-proof-reading PCR (Promega, Germany) using the upstream primer Rec1_SalI_SacII (5′-GAG GTC GAC CCG CGG AAA TGT TCA GAG-3′, SEQ ID NO 4) and the downstream primer Rec1_SmaI (5′-CTC CCC GGG TCC AGT GTT TCA CTC-3′, SEQ ID NO 5). After restriction of the resulting amplification product with SalI and SmaI it is cloned into the vector pRT99 (Töpfer et al. 1988) (SalI and SmaI digested). The resulting plasmid pRT99Rec1 contains the 5′ first recombination sequence. Cloning Procedure for the 3′ Second Recombination Sequence into pRT99Rec1 The 208 bp 3′ sequence of the 5 th intron: (5′-GGGACCCAAGCGTAAGAAGTCTTATGAAAAAGTTACCTCACAGATTAAAACTAAACATAGGA AAATACCAATGCACTCCAATGTGTCAATGAGATTAACGCTTGACTAACATGAAAATATAA ATATTCACCGAATGAAAGAAATTAGAAAACAGGACCTGTAGATTGTAAGAGATAGATTCT TGAGTTAGAAACACAAATGATTGTCC-3′, SEQ ID NO 6) of the alpha 1,3-fucosyltransferase gene of Physcomitrella patens is amplified from genomic DNA of Physcomitrella patens by Pfu-proof-reading PCR (Promega, Germany) using the upstream primer Rec11_SmaI (5′-GAG CCC GGG ACC CAA GCG TAA GAA G-3′, SEQ ID NO 7) and the downstream primer Rec11_SacII_SsTII (5′-TCT GAG CTC CCG CGG ACA ATC ATT TGT GTT TC-3′, SEQ ID NO 8). After restriction of the resulting amplification product with SmaI and SstI it is cloned into the vector pRT99Rec1 (SmaI and SstI digested). The resulting plasmid pRT99Rec11 contains the 5′ first and the 3′ second recombination sequence. Construction of pRT99TPVEGFRec1 The expression cassette containing the CaMV 35S promoter, TPVEGF121 and CaMV 35S terminator is excised as a PstI fragment from pRT101TPVEGF C3. This fragment is blunted by the Klenow reaction and introduced into the SmaI digested and dephosphorylated plasmid pRT99Rec11 resulting in the plasmid pRT99TPVEGFRec1. Cloning Procedure for 5′ Second Recombination Sequence into pRT99 The 208 bp 3′ sequence of the 5 th intron: (5′-GGGACCCAAGCGTAAGAAGTCTTATGAAAAAGTTACCTCACAGATTAAAACTAAACATAGGA AAATACCAATGCACTCCAATGTGTCAATGAGATTAACGCTTGACTAACATGAAAATATAA ATATTCACCGAATGAAAGAAATTAGAAAACAGGACCTGTAGATTGTAAGAGATAGATTCT TGAGTTAGAAACACAAATGATTGTCC-3′, SEQ ID NO 6) of the alpha 1,3-fucosyltransferase gene of Physcomitrella patens is amplified from genomic DNA of Physcomitrella patens by Pfu-proof-reading PCR (Promega, Germany) using the upstream primer Rec2_SalI_SacII (5′-GAG GTC GAC CCG CGG ACC CAA GCG TAA GAA G-3′, SEQ ID NO 9) and the downstream primer Rec2_SmaI (5′-TCT CCC GGG ACA ATC ATT TGT GTT TC-3′, SEQ ID NO 10). After restriction of the resulting amplification product with SalI and SmaI it is cloned into the vector pRT99 (Töpfer et al. 1988) (SalI and SmaI digested). The resulting plasmid pRT99Rec2 contains the 5′ second recombination sequence. Cloning Procedure for 3′ First Recombination Sequence into pRT99Rec2 The 250 bp 51 sequence of the 5 th intron: (5′-GCGGAAATGTTCAGAGTTAAGCGAAATCACAACTAAAAGAGATTGGAAGCAGAAGAATT TTTGAGCAGCTGTTCTTAATTCACGCAACGACAACGCTATTAACTGTATGTGTAGACGAT GCACTTTCGTACTGAAGGGATCTAAATTTATTATATCCCTTCATAACTAGAGGCAAGGCG GAAATCACAAAACTATTGGTACCTACGTACTACAGCCTCCAGGATCAAACATAAGAGTGA AACACTGGACC-3′, SEQ ID NO 3) of the alpha 1,3-fucosyltransferase gene of Physcomitrella patens is amplified from genomic DNA of Physcomitrella patens by Pfu-proof-reading PCR (Promega, Germany) using the upstream primer Rec22_SmaI (5′-GAG CCC GGG AAA TGT TCA GAG TTA AGC G-3′, SEQ ID NO 11) and the downstream primer Rec22_SacII_SstI (5′-TCT GAG CTC CCG CGG TCC AGT GTT TCA CTC TTA TG-3′, SEQ ID NO 12). After restriction of the resulting amplification product with SmaI and SstI it is cloned into the vector pRT99Rec2 (SmaI and SstI digested). The resulting plasmid pRT99Rec22 contains the 5′ second and the 3′ first recombination sequences. Construction of pRT99TPVEGFRec2 The expression cassette containing CaMV 35S promoter, TPVEGF 121 and CaMV 35S terminator is excised as a PstI fragment from pRT101TPVEGF C3. This fragment is blunted by the Klenow reaction and introduced into the SmaI digested and dephosphorylated plasmid pRT99Rec22 resulting in the plasmid pRT99TPVEGFRec2. Restriction of pRT99TPVEGFRec1 and Rec2 with SacII or SalI and SstI results in linearisation of the first and the second heterologous nucleic acid sequences comprising the recombination sequences and the heterologous nucleic acid sequences of interest comprising a promoter operably linked thereto. The linearised heterologous nucleic acid sequences are used for transformation of moss cells. Standard Culture Conditions Plants are grown axenically under sterile conditions in plain inorganic liquid modified Knop medium (1000 mg/l Ca(NO 3 ) 2 ×4H 2 O 250 mg/l KCl, 250 mg/l KH 2 PO4, 250 mg/l MgSO 4 ×7H 2 O and 12.5 mg/l FeSO 4 ×7H 2 O; pH 5.8 (Reski and Abel 1985)). Plants are grown in 500 ml Erlenmeyer flasks containing 200 ml of culture medium and the flasks are shaken on a Certomat R shaker (B. Braun Biotech International, Germany) set at 120 rpm. Conditions in the growth chamber are 25+/−3° C. and a light:dark regime of 16:8 h. The flasks are illuminated from above by two fluorescent tubes (Osram L 58 W/25) providing 35 μmols −1 m −2 . The cultures are sub-cultured once a week via disintegration using an Ultra-Turrax homogenizer (IKA, Staufen, Germany) and inoculation of two new 500 ml Erlenmeyer flasks containing 100 ml fresh Knop medium. Protoplast Isolation Pre-culture of moss tissue for optimal protoplast isolation. Mosses (especially Physcomitrella patens ) can be pre-cultured under different conditions to obtain optimal protoplast yields: I. Rother et al. 1994 cultivated moss tissue for 7 days in Knop medium with reduced (10%) Ca(NO 3 ) 2 content. Cultures are filtered 3 or 4 days after disintegration and are transferred into fresh Knop medium with reduced (10%) Ca(NO 3 ) 2 content. II. Instead of reduction of Ca(NO 3 ) 2 the medium for pre-culture can be supplemented with 5 mM ammonium tartrate or the pH can be altered to 4.5 (in liquid cultures with uncontrolled pH-values an average pH of 5.8 is reached for modified Knop medium). Cultures are filtered 3 or 4 days after disaggregation of tissue and are transferred into fresh modified Knop medium (supplemented with 5 mM ammonium tartrate or altered to pH 4.5). III. Hohe and Reski (2002) optimised culture conditions in a semi-continuous bioreactor to obtain high yields of protoplasts. Isolated protoplasts of high yields are obtained either by supplementation of modified Knop medium (Reski and Abel 1985) with 460 mg/l ammonium tartrate or under controlled pH-values with a setpoint of 4.5 (in bioreactor cultures with uncontrolled pH-values an average pH of 5.8 is reached for modified Knop medium). Different protocols for the isolation of protoplasts (Grimsley et al. 1977; Schaefer et al. 1991; Rother et al. 1994; Zeidler et al. 1999; Hohe and Reski 2002, Protocol Schaefer 2001) and for transformation (Schaefer et al. 1991; Reutter and Reski 1996, Protocol Schaefer 2001) have been described for Physcomitrella patens. For the work presented herein, a modification/combination of the previously described methods is used: After filtration the moss protonemata are preincubated in 0.5 M mannitol. After 30 min, 4% Driselase (Sigma, Deisenhofen, Germany) is added to the suspension. Driselase is dissolved in 0.5 M mannitol (pH 5.6-5.8), centrifuged at 3600 rpm for 10 min and sterilised by passage through a 0.22 μm filter (Millex GP, Millipore Corporation, USA). The suspension, containing 1% Driselase (final concentration), is incubated in the dark at RT and agitated gently (best yields of protoplasts are achieved after 2 hours of incubation) (Protocol Schaefer 2001). The suspension is passed through sieves (Wilson, CLF, Germany) with pore sizes of 100 μm and 50 μm. The suspension is centrifuged in sterile centrifuge tubes and protoplasts are sedimented at RT for 10 min at 55 g (acceleration of 3; slow down at 3; Multifuge 3 S—R, Kendro, Germany) (Protocol Schaefer 2001). Protoplasts are gently re-suspended in W5 medium (125 mM CaCl 2 ×2H 2 O; 137 mM NaCl; 5.5 mM glucose; 10 mM KCl; pH 5.6; 660-680 mOsm; sterile filtered). The suspension is centrifuged again at RT for 10 min at 55 g (acceleration of 3; slow down at 3; Multifuge 3 S-R, Kendro, Germany). Protoplasts are gently re-suspended in W5 medium (Rother et al. 1994). For counting protoplasts a small volume of the suspension is transferred to a Fuchs-Rosenthal-chamber. Transformation Protocol For transformation protoplasts are incubated on ice in the dark for 30 minutes. Subsequently, protoplasts are sedimented by centrifugation at RT for 10 min at 55 g (acceleration of 3; slow down at 3; Multifuge 3 S-R, Kendro). Protoplasts are re-suspended in 3M medium (15 mM CaCl 2 ×2H 2 O; 0.1% MES; 0.48 M mannitol; pH 5.6; 540 mOsm; sterile filtered, Schaefer et al. 1991) at a concentration of 1.2×10 6 protoplasts/ml (Reutter and Reski 1996). 250 μl of this protoplast suspension are dispensed into a new sterile centrifuge tube, 50 μl DNA solution of both constructs, pRT99TPVEGFRec1 and pRT99VEGFRec2, and the vector containing the selection marker (column purified DNA in H 2 O (Qiagen, Hilden, Germany); 10-100 μl; DNA amount of 30 μg per construct; 10 μg of the vector containing the selection marker) is added and finally 250 μl PEG-solution (40% PEG 4000; 0.4 M mannitol; 0.1 M Ca(NO 3 ) 2 ; pH 6 after autoclaving) is added. The suspension is immediately but gently mixed and then incubated for 6 min at RT with occasional gentle mixing. The suspension is diluted progressively by adding 1, 2, 3 and 4 ml of 3M medium. The suspension is centrifuged at 20° C. for 10 minutes at 55 g (acceleration of 3; slow down at 3; Multifuge 3 S-R, Kendro). The pellet is re-suspended in 3 ml regeneration medium. Selection procedure is performed as described by Strepp et al. (1998). DNA Analysis DNA analysis of stably transformed plants is performed as described by Strepp et al. (1998). Estimation of copy number is performed by Southern blot analysis and comparison to a stably transformed plant containing one copy of the heterologous DNA. Assays Quantification of Recombinant VEGF 121 Recombinant VEGF 121 expressed by stably transformed moss plants is quantified by ELISA (R&D Systems, Wiesbaden, Germany). The ELISA is performed according to the instructions of the manufacturer. The samples can be diluted for quantification. Results For stably transformed plants the estimation of high copy numbers of integrated constructs correlates with high yields of recombinant protein. LITERATURE Engel P P (1968) The induction of biochemical and morphological mutants in the moss Physcomitrella patens . Am J Bot 55, 438-446. Gorr G (1999) Biotechnologische Nutzung von Physcomitrella patens (Hedw.) B. S. G. Dissertation, Universität Hamburg. Grimsley N H, Ashton N W and Cove D J (1977) The production of somatic hybrids by protoplast fusion in the moss, Physcomitrella patens. Mol Gen Genet. 154, 97-100. Hohe A, Reski R (2002) Optimisation of a bioreactor culture of the moss Physcomitrella patens for mass production of protoplasts. Plant Sci 163, 69-74. Reski R, Abel W O (1985) Induction of budding on chloronemata and caulonemata of the moss, Physcomitrella patens , using isopentenyladenine. Planta 165, 354-358. Reski R, Faust M, Wang X-H, Wehe M, Abel W O (1994) Genome analysis of the moss Physcomitrella patens (Hedw.) B. S. G. Mol Gen Genet. 244, 352-359. Rother S, Hadeler B, Orsini J M, Abel W O and Reski R (1994) Fate of a mutant macrochloroplast in somatic hybrids. J Plant Physiol 143, 72-77. Reutter K and Reski R (1996) Production of a heterologous protein in bioreactor cultures of fully differentiated moss plants. Plant Tissue Culture and Biotechnology 2, 142-147. Schaefer D, Zryd J-P, Knight C D and Cove D J (1991) Stable transformation of the moss Physcomitrella patens. Mol Gen Genet. 226, 418-424. Schaefer D G (2001) Principles and protocols for the moss Physcomitrella patens . http://www.unil.ch/lpc/docs/PPprotocols2001.pdf Strepp R, Scholz, S, Kruse, S, Speth V and Reski, R (1998) Plant nuclear gene knockout reveals a role in plastid division for the homologue of the bacterial cell division protein FtsZ, an ancestral tubulin. Proc Natl Acad Sci USA 95, 4368-4373. Töpfer R, Matzeit V, Gronenborn B, Schell J and Steinbiss H-H (1987) A set of plant expression vectors for transcriptional and translational fusions. NAR 15, 5890. Töpfer, R, Schell, J and Steinbiss, H-H (1988) Versatile cloning vectors for transient gene expression and direct gene transfer in plant cells. NAR 16, 8725.

A method of amplifying gene expression in a moss plant cell or moss tissue, DNA constructs therefor, moss plant cells and uses thereof for the production of protein.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional of U.S. patent application Ser. No. 13/204,194, filed on Aug. 5, 2011, which is continuation of U.S. patent application Ser. No. 11/076,293 filed on Mar. 9, 2005, issued as U.S. Pat. No. 8,052,758. The entire disclosures of the above applications are incorporated herein by reference. FIELD [0002] The present disclosure relates to a prosthesis for replacing and reconstructing a portion of the humerus and more specifically to a trialing system for a modular humeral prosthesis which allows for shoulder joint replacement. BACKGROUND [0003] The present disclosure relates to a prosthesis for replacing and reconstructing a portion of the humerus and more specifically to a modular humeral prosthesis which allows for shoulder joint replacement. [0004] The shoulder joint is considered to be one of the most complex joints in the body. The scapula, the clavicle and the humerus all meet at the shoulder joint. The head of the humerus fits into a shallow socket of the scapula called the glenoid fossa to form a mobile joint. When the joint is articulated, the humeral head moves in the glenoid fossa to provide a wide range of motion. The shoulder joint may suffer from various maladies including rheumatoid arthritis, osteoarthritis, rotator cuff arthropathy, avascular necrosis, bone fracture or failure of previous joint implants. If severe joint damage occurs and no other means of treatment is found to be effective, then shoulder reconstruction may be necessary. [0005] A shoulder joint prosthesis generally includes the replacement of the ball of the humerus and, optionally, the socket of the shoulder blade with specially designed artificial components. The bio-kinematics, and thus the range of motion in the shoulder vary greatly among prospective patients for reconstruction shoulder surgery. The humeral component typically has a metal shaft or stem with a body portion that is embedded in the resected humerus and a generally hemispherical head portion supported on the stem. The head slidingly engages a glenoid implant on the glenoid fossa. During reconstructive surgery, the components of the prosthesis are matched with the bio-kinematics of the patient in an effort to maintain the natural range of motion of a healthy shoulder joint. Thus, a shoulder prosthesis design must be readily adaptable to a wide range of bio-kinematics for prospective patients. [0006] In this regard, shoulder prostheses are generally available as either unitary structures or modular components. With unitary shoulder prosthesis, a large inventory of differently sized prostheses must be maintained to accommodate the different bone sizes and joint configurations of the prospective patients. With such unitary shoulder prosthesis, the patient is typically evaluated by x-ray to determine the approximate prostheses size needed for reconstruction. A number of differently sized prostheses are selected as possible candidates based upon this preliminary evaluation. Final selection of the appropriately sized prosthesis is made during the surgery. With unitary shoulder prosthesis, each design may represent a compromise that is unable to achieve all of the natural range of motion of a healthy shoulder joint because of the fixed geometric configuration in their design. [0007] Modular prostheses systems which reduce the need to maintain large inventories of various sized components are well known in the art. Conventionally, the humeral prosthesis includes two components—a humeral stem component and a spherical head releasably coupled to the stem. Alternately, a three component design is known in which the stem and shoulder are interconnected with an adapter. In either of the two-piece or three-piece designs, a radial offset or angulator inclination of the head relative to the stem is provided in individual components. Different radial offsets or angular inclinations are achieved through the use of different adapters or heads. In this regard, conventional modular shoulder prosthesis kits include multiple redundant components such as adapters and heads to achieve a range of prosthetic options. [0008] While providing an advantage over the unitary design in reducing the number of components needed, a rather large inventory of head components and/or adapter components must be maintained to provide the desired range of geometric configurations with the conventional modular shoulder prostheses. These components are readily adaptable to provide a range of geometric configurations, i.e. radial offsets of angular inclination while minimizing the number of components required. There is, therefore, a need for a trialing system and method for determining which of these components are needed and their specific orientation. SUMMARY [0009] In accordance with the teachings of the present disclosure a modular joint prosthesis system is provided. Specifically, a humeral component for a shoulder prosthesis includes an adapter and a head component which cooperate to provide a range of radial offsets and/or angular inclinations and which are adapted to be used in conjunction with a stem. [0010] According to one exemplary embodiment, a measuring instrument for humeral component for a shoulder prosthesis is provided for determining the needed adjustable radial offset of the head with respect to the stem. The present disclosure includes an adapter interposed between a stem and a head. The adapter is slidably coupled to the head such that relative linear positioning of the adapter on the head will effect a first adjustment in the radial offset. Likewise, the adapter component is rotationally coupled to the stem as such that relative angular position of the adapter will effect a rotational offset adjustment. By selectively positioning the adapter with respect to the head, an infinite adjustment of the radial offset within a given range may be achieved. Indicia are provided at the interface between the adapter and the head to indicate the offset vector (i.e., offset amount and direction). [0011] According to another exemplary embodiment, a measuring instrument for a humeral component for a shoulder prosthesis is provided for determining the adjustable radial offset of the head with respect to the stem. The present disclosure includes an adapter interposed between a stem and a head. The adapter is slidably coupled to a cavity formed in the head such that relative linear positioning of the adapter on the head will effect a first adjustment in the radial offset of the head. Likewise, the adapter component is rotationally coupled to the stem as such that relative angular position of the stem on the adapter will effect a rotational offset adjustment. A fastener is provided to fix the location of the head to the adapter. In one example, indicia are provided on the adapter and the head to indicate the offset vector. [0012] The joint prosthesis measurement system of the present disclosure provides great flexibility in the adjustment of important bio-kinematic parameters for the prosthesis systems while allowing for the minimizing the number of components required for the modular system. These and other features of the present disclosure will become apparent from the description and especially taken in conjunction with the accompanying drawings. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS [0013] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: [0014] FIG. 1 is an exploded front view of a modular shoulder prosthesis measurement system in accordance with the present teachings; [0015] FIG. 2 is a perspective view of the adapter and head components of the device illustrated in FIG. 1 shown in an assembled state; [0016] FIG. 3 is a bottom view of the embodiment of the present teachings illustrated in FIG. 1 ; [0017] FIGS. 4A-4C are views of the adapter shown in FIG. 1 ; [0018] FIGS. 5A-5D are views of the head shown in FIG. 1 ; [0019] FIG. 6 represents the implantation of the measurement head into a stem component; [0020] FIG. 7 is cross-sectional view of the trial head coupled to an implanted stem; [0021] FIG. 8 is cross-sectional view of the trial head coupled to an implanted stem and being positioned into a glenoid; [0022] FIGS. 9 and 10 represent the adjustment of the head with respect to the adapter; and [0023] FIG. 11 represents a kit of components. DETAILED DESCRIPTION [0024] The following description is merely exemplary in nature and is in no way intended to limit the present disclosure, its application, or uses. [0025] FIG. 1 is an exploded front view of a modular shoulder prosthesis measurement system according to the present teachings. The measuring device 10 is formed of an adapter 12 , a head 14 , and a coupling member 16 . The adapter 12 is preferably formed of a polymer material, which allow its relative rotation with respect to a fixation member or stem 18 . The measuring device 10 is configured to determine both the needed radial offset of an implant head with respect to an implanted fixation member, and also the rotational offset of the head with respect to the fixation member. As further described below, the adapter 12 is slidably coupled to the head 14 such that relative linear positioning of the adapter 12 with the head 14 will affect a first adjustment in the radial offset. Selected positioning of the adapter 12 with respect to the head 14 gives an infinite adjustment of the radial offset within a given range. [0026] Referring generally to FIG. 1 , FIGS. 4A-4C and FIG. 6 , the adapter 12 has a body portion 24 , having a first pair of bearing surfaces 26 and 28 . The first pair of bearing surfaces 26 and 28 are slidably coupled to a second pair of bearing surfaces 30 and 32 defined on the head 14 . The body portion 24 further has a flat stop surface 35 and a circular stop surface 36 which function to limit the movement of the adapter 12 with respect to the head 14 . The adapter 12 further defines a coupling member accepting bore 38 which is optionally threaded. A tapered coupling portion 40 is configured to interface with a Morse taper coupling feature on the stem 18 . This tapered coupling portion 40 , while shown as a male taper, may optionally be a female taper configured to interface with a male Morse taper formed on the stem 18 or any other connection member. [0027] As shown in FIGS. 2 and 3 , the bottom surface 34 of the adapter 12 and a bottom surface 22 of the head 14 each have indicia 46 and 48 which indicate the relative positioning of the head 14 with respect to the adapter 12 . Additionally, the outer spherical surface 20 has the rotational indicia 43 which is used to determine the relative rotation of the head 14 with respect to the stem 18 . [0028] FIGS. 5A-5D represent the head 14 shown in FIG. 1 . Defined on the bottom surface 22 is an adapter accepting cavity 50 . The cavity 50 has the second pair of bearing surfaces 30 and 32 . Additionally, the cavity 50 has flat and curved bearing surfaces 52 and 55 which are configured to interface with the flat and circular bearing surfaces 35 and 36 of the adapter. [0029] The head 14 further defines a through bore 54 . The through bore 54 passes through the outer spherical surface 20 and the adapter accepting cavity 50 . The through bore 54 has a defined shelf 56 which is configured to support a head portion 57 of the coupling member 16 . The through bore 54 further has a slot portion 58 and a circular portion 60 which facilitate transverse movement of the coupling member 16 within the through bore 54 . As the cavity 50 has a length L 1 which is longer than the length L 2 of the adapter 12 , the adapter 12 is configured to move transversely within the head 14 . The difference in L 1 and L 2 is the distance of the linear offset of the system. The first pair of bearing surfaces 26 and 28 and second pair of bearing surfaces 30 and 32 are configured so as to prevent relative rotational movement between the adapter 12 and the head 14 . [0030] FIGS. 6-8 show views of the relationship of the measuring device 10 in its environmental surroundings. The tapered coupling portion 40 of the adapter 12 is positioned within the taper 42 of the stem 18 . Coupling member 16 passes through the through bore 54 of the head 14 to loosely couple the head 14 to the adapter 12 . After, the head 14 is then positioned against a glenoid 62 which can be natural or an implant, and the kinematic action of the head is then tested. [0031] As seen in FIGS. 8 and 9 , should a physician determine that adjustment is necessary, the radial offset 49 of the head 14 can be accomplished by moving it in a first degree of freedom relative to the adapter 12 . After this adjustment is made, the physician will then tighten the coupling member 16 to fix the radial position of the head 14 with respect to the adapter 12 . The physician can then use the indicia 46 and 48 on the lower stem engaging surface or bottom surface 34 of the adapter 12 and bottom surface 22 of the head 14 to determine the appropriate implant to use. [0032] As seen in FIG. 9 , the adapter 12 and head 14 can be rotated 51 in a second degree of freedom with respect to the stem 18 . The rotational indicia 43 on the outer spherical surface 20 can be used to mark the relative location of the implant measuring device 10 with respect to the stem 18 . This marking can optionally be made on the biologic tissue surrounding the stem 18 . This relative rotation marking is then used by the physician to determine the rotational alignment of the offset implant prior to implantation. [0033] The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the gist of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.

The present disclosure is directed to a modular shoulder prosthesis measuring device having an adjustable radial offset provided by relative rotation of an adapter interdisposed between the stem and the head. Specifically, the interface configuration between the stem and the adapter, as well as between the adapter and the head are designed such that relative positioning of these components provides a continuous adjustment in the radial offset. Indicia are provided to precisely determine the magnitude and direction of the adjustment being made.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of International Application No. PCT/JP2011/069083, filed on Aug. 24, 2011, the entire contents of which are incorporated herein by reference. FIELD [0002] The embodiments discussed herein are related to a casing mounting rail, a blank plate, and a rack mount system. BACKGROUND [0003] In a computer system, as the scale of the system increases, the number of electronic devices in the system such as servers, storages, and network devices increases. For the increased number of electronic devices, a storage frame called a rack is used to store the electronic devices efficiently and achieve space saving. To mount the electronic devices in the rack, casing mounting rails for mounting the casing of the electronic devices are laid from the front side to the rear side of the rack. The electronic devices are mounted in the rack in a stacked manner with their casing mounted on the casing mounting rails. [0004] This casing mounting rail is fixed to a support on the front side of the rack and another support on the rear side of the rack. Processes for fixing the casing mounting rail to the rack thus include a fixation process on the front side of the rack and a fixation process on the rear side of the rack. [0005] When mounted to a rack, the electronic devices do not necessarily fill the rack. When the electronic devices thus mounted do not fill the rack, a part with no electronic device mounted results in space within the rack. In this case, when such space is given on the front face of the rack, the exhaust air of the electronic devices is returned and sucked back into the electronic devices. This state interferes with appropriate cooling of the electronic devices and accumulates heat in the electronic devices, which causes a failure. In view of these circumstances, a blank plate is attached to fill the space on the front face in racks. [0006] As such a filling blank plate in related art, a blank plate serves as a shelf to house a printed circuit board on which electronic circuits are mounted. When the printed circuit board is inserted, the blank plate opens and serves as a guide rail supporting the insertion of the printed circuit board (Japanese Laid-open Patent Publication No. 11-340655). [0007] A conventional general blank plate is a monolithic plate formed of iron or the like, and is selectively attached according to the size of open space as occasion demands. Because of this, to mount a new electronic device to the open space, space used to mount the electronic device is checked in advance, a mounting place is determined, and a blank plate attached to the place is removed. Subsequently, casing mounting rails for mounting the electronic device are laid, and the electronic device is mounted on the casing mounting rails. The process for mounting the electronic device to the open space of the rack is thus complicated and time consuming. [0008] The conventional technology that functions as both the guide rail and the blank plate reduces the trouble with removing a blank plate and the trouble with laying rails. However, in an electronic device such as a server, its casing has a thickness. Given this situation, in this conventional technology, when a plurality of blank plates are arranged, an electronic device comes into contact with a protrusion for mounting the electronic device, making it hard to mount the electronic device. SUMMARY [0009] According to an aspect of an embodiment, a casing mounting rail includes: a coupling member coupled to a support column of a rack; a plate-shaped member rotatably engaged with the coupling member with one longitudinal end as an axis; a mounting member including a first flat plate and a second flat plate orthogonal to the first flat plate, with a transverse end of the first flat plate rotatably engaged with one plate face of the plate-shaped member with a longitudinal direction of the plate-shaped member as an axis and with a plate face of the first flat plate in intimate contact with the one plate face, the second flat plate protruding from one transverse end of the plate-shaped member; and a fixing mechanism that fixes the mounting member with the plate face of the first flat plate in intimate contact with the one plate face. [0010] The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. [0011] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. BRIEF DESCRIPTION OF DRAWINGS [0012] FIG. 1 is a perspective view illustrating casing mounting rails according to a first embodiment when installed in a rack; [0013] FIG. 2 is a drawing illustrating the rotation of the casing mounting rails according to the first embodiment with respect to a support; [0014] FIG. 3A is a perspective view illustrating the casing mounting rail according to the first embodiment when installed in the rack, viewed in the direction of the arrow P; [0015] FIG. 3B is a perspective view illustrating the casing mounting rail according to the first embodiment when installed in the rack, viewed in the direction of the arrow Q; [0016] FIG. 4A is a drawing illustrating the casing mounting rails according to the first embodiment viewed in the direction of the arrow P; [0017] FIG. 4B is a drawing illustrating the casing mounting rails according to the first embodiment viewed in the direction of the arrow Q; [0018] FIG. 5 is an exploded view illustrating the casing mounting rail according to the first embodiment; [0019] FIG. 6 is a drawing illustrating the casing mounting rail according to the first embodiment viewed in the direction of the arrow Q; [0020] FIG. 7 is an enlarged view illustrating the area A in FIG. 6 ; [0021] FIG. 8 is the B-B sectional view of FIG. 6 ; [0022] FIG. 9 is a sectional view illustrating an engaging shaft; [0023] FIG. 10 is a sectional view illustrating an engaging hole of engaging parts 111 A to 111 C for passing the engaging shaft through; [0024] FIG. 11A is a drawing illustrating a state in which the engaging shaft is lifted; [0025] FIG. 11B is a drawing illustrating a state in which the engaging shaft is fit in a bearing; [0026] FIG. 12 is a plan view illustrating an L-shaped member in a movable state; [0027] FIG. 13 is a plan view illustrating the L-shaped member in a fixed state; [0028] FIG. 14 is a drawing illustrating a state in which a casing is mounted; [0029] FIG. 15A is a perspective view illustrating a state in which the casing mounting rail is rotating; [0030] FIG. 15B is a perspective view illustrating a state in which the rotation of the casing mounting rail is completed; [0031] FIG. 16 is an enlarged view illustrating a fitting part between the casing mounting rail and the rack; [0032] FIG. 17A is a perspective view illustrating a state in which a casing is mounted; [0033] FIG. 17B is a drawing illustrating a state of the casing mounting rails when the casing is mounted; [0034] FIG. 18A is a perspective view illustrating a state in which a shallow casing is mounted; [0035] FIG. 18B is a drawing illustrating a state of casing mounting rails when the shallow casing is mounted; [0036] FIG. 19A is a perspective view illustrating a state in which a deep casing is mounted; and [0037] FIG. 19B is a drawing illustrating a state of casing mounting rails when the deep casing is mounted. DESCRIPTION OF EMBODIMENTS [0038] Preferred embodiments of the present invention will be explained with reference to accompanying drawings. [0039] The following embodiments do not limit the casing mounting rail, the blank plate, and the rack mount system disclosed by the present application. Because the blank plate serves also as the casing mounting rail, the blank plate will be described as the casing mounting rail. [a] First Embodiment [0040] FIG. 1 is a perspective view illustrating casing mounting rails according to a first embodiment when installed in a rack. [0041] Supports 2 A to 2 F are supports of the rack according to the present embodiment. The supports 2 A to 2 F extend in the vertical direction with respect to the ground with the rack installed. In the following, the ground side face of the rack when the rack is installed, which is the lower face in FIG. 1 , is referred to as “the bottom face of the rack.” The face of the rack opposite the ground, which is the upper face in FIG. 1 , is referred to as “the upper face of the rack.” In the following description, a direction directing from the support 2 B toward the support 2 A is referred to as the “left,” and a direction directing from the support 2 A toward the support 2 B is referred to as the “right.” [0042] The support 2 A and the support 2 B form a front face of the rack, that is, an outer face of the rack on a side through which an electronic device such as a server is put in and out. In the following, a plane formed by the support 2 A and the support 2 B is referred to as “the front face of the rack.” The support 2 E and the support 2 F form a back face of the rack, that is, an outer face of the rack facing the face through which an electronic device such as a server is put in and out. In the following, a surface formed by the support 2 E and the support 2 F is referred to as “the back face of the rack.” The support 2 C is provided in between the support 2 A and the support 2 E. The support 2 D is provided in between the support 2 B and the support 2 F. The distance between the support 2 A and the support 2 C and the distance between the support 2 B and the support 2 D have the same length as the longitudinal length of a casing mounting rail 1 L and a casing mounting rail 1 R, respectively, as will be described below. [0043] The casing mounting rail 1 L and casing mounting rails 11 L to 15 L are attached to the support 2 A. The casing mounting rail 1 R and casing mounting rails 11 R to 15 R are attached to the support 2 B. The casing mounting rails 1 L and 11 L to 15 L have the same structure. The casing mounting rails 1 R and 11 R to 15 R have the same structure. The casing mounting rails 1 L and 1 R, 11 L and 11 R, 12 L and 12 R, 13 L and 13 R, 14 L and 14 R, and 15 L and 15 R each form a pair. When a pair of casing mounting rails is described in the following, the casing mounting rail 1 L and the casing mounting rail 1 R will be described as an example. Each pair of casing mounting rails has nearly a bilateral symmetric structure. In view of this, when the structure of a casing mounting rail is described, the casing mounting rail 1 L will be described as an example. In other words, the casing mounting rails 11 L to 15 L have the same structure as that of the casing mounting rail 1 L described below. The casing mounting rails 1 R and 11 R to 15 R have nearly the same structure as a bilateral symmetric structure of the casing mounting rail 1 L. [0044] As illustrated in FIG. 1 , a direction indicated by the arrow P directing from the front face of the rack to the back face of the rack is referred to as the P direction, and in contrast, a direction indicated by the arrow Q directing from the back face of the rack to the front face of the rack is referred to as the Q direction. [0045] The following describes the rotational motion of the casing mounting rails with respect to the supports of the rack with reference to FIG. 2 . FIG. 2 is a drawing illustrating the rotation of the casing mounting rails according to the first embodiment with respect to the supports. [0046] As will be described below, the casing mounting rails 1 L and 11 L to 15 L are attached to the support 2 A rotatably in a plane having the longitudinal direction of the support 2 A as a normal line. Similarly, the casing mounting rails 1 R and 11 R to 15 R are attached to the support 2 B rotatably in a plane having the longitudinal direction of the support 2 A as a normal line. FIG. 2 illustrates a shift in the stationary positions of the casing mounting rails during rotation starting from the positions of the casing mounting rails 15 L and 15 R in parallel to the front face of the rack to the positions of the casing mounting rails 1 L and 1 R in parallel to the side faces of the rack. The casing mounting rails play a role of blank plates in the state of the casing mounting rails 15 L and 15 R. The casing mounting rails can mount the casing of an electronic device in the state of the casing mounting rails 1 L and 1 R. [0047] FIG. 3A is a perspective view illustrating the casing mounting rail according to the first embodiment when installed in the rack viewed in the direction of the arrow P. FIG. 3B is a perspective view illustrating the casing mounting rail according to the first embodiment when installed in the rack viewed in the direction of the arrow Q. FIG. 4A is a drawing illustrating the casing mounting rails according to the first embodiment viewed in the direction of the arrow P. FIG. 4B is a drawing illustrating the casing mounting rails according to the first embodiment viewed in the direction of the arrow Q. [0048] In FIG. 3A , to make the state of the casing mounting rail easy to understand, the casing mounting rail 1 L and the casing mounting rail 1 R in FIG. 1 are illustrated in an enlarged manner. In FIG. 3B , for understanding of the state of the casing mounting rail when viewed from the Q direction, the casing mounting rail 1 L and the casing mounting rail 1 R in FIG. 1 are illustrated in an enlarged manner. In FIG. 4A , although the casing mounting rail 1 L and the casing mounting rail 1 R are actually hidden behind the supports 2 A and 2 B, the supports are illustrated in a perspective manner for the convenience of description. [0049] The casing mounting rail 1 L and the casing mounting rail 1 R have the same length. As illustrated in FIG. 3A , FIG. 3B , FIG. 4A , and FIG. 4B , when the casing mounting rails 1 L and 1 R are positioned on the plane formed by the support 2 A and the support 2 B, the sum of the longitudinal lengths of the casing mounting rails 1 L and 1 R corresponds to the distance between the support 2 A and the support 2 B. In other words, the length of the casing mounting rails 1 L and 1 R corresponds to half the distance between the support 2 A and the support 2 B. [0050] As illustrated in FIG. 4A , the casing mounting rail 1 L is fixed to the support 2 A with screws 3 A and 3 B. The casing mounting rail 1 R is fixed to the support 2 B with screws 3 C and 3 D. The fixation between the casing mounting rail 1 L and the support 2 A will be described below in detail. [0051] In the following description, a side of the casing mounting rail 1 L illustrated in FIG. 4A , that is, a side of the casing mounting rail 1 L viewed from the P direction in FIG. 3A is referred to as the “front side.” A side of the casing mounting rail 1 L illustrated in FIG. 4B , that is, a side of the casing mounting rail 1 L viewed from the Q direction in FIG. 3B is referred to as the “back side.” [0052] The following describes the structure of the casing mounting rail 1 L in detail with reference to FIG. 5 . FIG. 5 is an exploded view of the casing mounting rail according to the first embodiment. [0053] As illustrated in FIG. 5 , the casing mounting rail 1 L includes a plate-shaped member 101 , an L-shaped member 102 , an engaging shaft 103 , a coupling member 104 , leaf springs 105 A to 105 C, screws 106 A and 106 B, a coil spring 107 , and an engaging shaft 108 . [0054] The plate-shaped member 101 includes a plate member 110 , engaging parts 111 A to 111 C, engaging parts 114 A to 114 C, a rubber sheet 115 , a magnet 118 , a protrusion 117 , and screws 119 A and 119 B. [0055] A recess 113 is formed on the transverse end of the plate member 110 on the upper face side of the rack. A recess 112 is formed on the transverse end of the plate member 110 on the bottom face side of the rack. The engaging parts 114 A to 114 C are formed on the longitudinal end of the plate member 110 on the coupling member 104 side. The engaging parts 111 A to 111 C are formed on the back side of the plate member 110 . A bending part 116 bending in an L shape toward the back side is formed on the longitudinal end of the plate member 110 opposite the coupling member 104 . The protrusion 117 extends from the end of the bending part 116 opposite the plate member 110 in a direction departing from the coupling member 104 . [0056] The magnet 118 is arranged on the side of the bending part 116 opposite the coupling member 104 . The magnet 118 is fixed to the bending part 116 with the screws 119 A and 119 B. In the present embodiment, the magnet 118 and the screws 119 A and 119 B are not arranged on the counter casing mounting rail, such as the casing mounting rail 1 R corresponding to the casing mounting rail 1 L. In place of the magnet 118 , a metal attracted to a magnet is arranged on the counter casing mounting rail. This causes, for example, the casing mounting rail 1 L and the casing mounting rail 1 R to be attracted to each other to stay parallel to the front face of the rack through magnetic force. Consequently, the casing mounting rail according to the present embodiment does not open even when receiving wind or the like, serving as a blank plate satisfactorily. In the present embodiment, the magnet is arranged on one part and the metal attracted to the magnet is arranged on the other part, to which another configuration may be applied. For example, magnets having polarities that are attracted to each other may be arranged. Another locking mechanism such as a bolt may be provided, so long as the casing mounting rails in pairs can be fixed to each other. [0057] The rubber sheet 115 , which is plate-shaped and has a length corresponding to the longitudinal length of the recess 113 , is arranged on the recess 113 of the plate member 110 . This rubber sheet 115 becomes deformed to allow the rotational motion of the L-shaped member 102 , as will be described below. The rubber sheet 115 thus arranged leaves no gap on the front face of the rack even when the L-shaped member 102 is in a fixed state, thereby maintaining the effect of cooling electronic devices. [0058] The coupling member 104 includes an L-shaped plate member 140 and engaging parts 142 A and 142 B. [0059] The engaging parts 142 A and 142 B are arranged on one transverse end of the L-shaped plate member 140 . [0060] A hole 141 for fixation to the support 2 A is formed on the surface of the L-shaped plate member 140 opposite the surface having the engaging parts 142 A and 142 B, that is, on the surface parallel to the plate member 110 in FIG. 5 . Although only one hole 141 is visible in FIG. 5 , actually three holes are formed. The holes 141 and holes of the support 2 A are aligned to each other and are fixed with the screws 3 A and 3 B illustrated in FIG. 4A , thereby fixing the L-shaped plate member 140 and the support 2 A to each other. In the following, the surface of the L-shaped plate member 140 parallel to the plate member 110 in FIG. 5 will be referred to as the “coupling surface.” [0061] The plate-shaped member 101 and the coupling member 104 are engaged with each other so that the engaging part 142 A is interposed between the engaging parts 114 A and 114 B and the engaging part 142 B is interposed between the engaging parts 114 B and 114 C. The engaging part 142 B is formed with a groove nearly at its center, and the coil spring 107 is fit in the groove. The coil spring 107 is arranged so as to hold the plate member 110 and the L-shaped plate member 140 therein. The engaging shaft 108 is disposed so as to pass through the engaging parts 114 A to 114 C, the engaging parts 142 A and 142 B, and the coil spring 107 . This causes the plate-shaped member 101 and the coupling member 104 to pivotally move about the engaging shaft 108 . In other words, when the coupling member 104 is fixed to the support 2 A, the plate-shaped member 101 pivotally moves in a plane with the longitudinal direction of the support 2 A as a normal line. When the plate-shaped member 101 is parallel to the coupling surface of the coupling member 104 as in the state of FIG. 5 , the longitudinal direction of the plate member 110 extends in a direction connecting between the support 2 A and the support 2 B (see FIG. 1 ). When the plate-shaped member 101 in the state of FIG. 5 rotates in a direction departing from the coupling surface of the coupling member 104 , the longitudinal direction of the plate member 110 moves from the direction connecting between the support 2 A and the support 2 B to a direction connecting between the support 2 A and the support 2 C (see FIG. 1 ). When the plate-shaped member 101 moves in the direction departing from the coupling surface of the coupling member 104 from the state of FIG. 5 , a force acts on the plate member 110 and the L-shaped plate member 140 through the coil spring 107 so as to make the plate member 110 and the L-shaped plate member 140 close to each other. In other words, a force acts on the plate member 110 so that its longitudinal direction is positioned on the plane formed by the support 2 A and the support 2 B (see FIG. 1 ). This causes, when no casing is mounted, the plate-shaped member 101 to automatically move to the position of the front face of the rack. [0062] The L-shaped member 102 includes an L-shaped plate member 120 and engaging parts 121 A and 121 B. [0063] The L-shaped plate member 120 is a plate-shaped member having an L shape formed by a support plate 123 and a mounting plate 124 . The support plate 123 is a part of the L-shaped plate member 120 that is parallel to the plate member 110 in FIG. 5 . The mounting plate 124 is a part of the L-shaped plate member 120 that is perpendicular to the plate member 110 in FIG. 5 . [0064] The engaging parts 121 A and 121 B are arranged on a transverse end of the support plate 123 . Recesses 122 A to 122 C are formed on the transverse end of the support plate 123 so as to interpose the engaging parts 121 A and 121 B therebetween. [0065] The mounting plate 124 is formed in a trapezoidal shape of which the width in the normal line direction of the support plate 123 decreases from some midpoint in the longitudinal direction toward the ends. This is in order to facilitate mounting when an electronic device such as a server is mounted. The mounting plate 124 is not necessarily a trapezoid and may be a rectangle. [0066] The plate-shaped member 101 and the L-shaped member 102 are engaged with each other so that the engaging part 121 A is interposed between the engaging parts 111 A and 111 B and the engaging part 121 B is interposed between the engaging parts 111 B and 111 C. The engaging parts 111 A to 111 C have engaging holes. The engaging shaft 103 is disposed so as to pass through the engaging holes of the engaging parts 111 A to 111 C and the engaging parts 121 A and 121 B. This causes the plate-shaped member 101 and the L-shaped member 102 to pivotally move about the engaging shaft 103 . In other words, the L-shaped member 102 pivotally moves in a plane perpendicular to the longitudinal direction of the plate member 110 . The engaging shaft 103 is fixed to the engaging parts 121 A and 121 B with a screw 106 A that reaches the engaging hole through a through hole formed in the engaging part 121 A and a screw 106 B that reaches the engaging hole through a through hole formed in the engaging part 121 B. This causes the engaging shaft 103 to rotate together with the L-shaped member 102 . [0067] The recess 122 A is positioned at a place facing an opening 1101 A of the engaging part 111 A on the plate-shaped member 101 . The recess 122 B is positioned at a place facing an opening 1101 B of the engaging part 111 B on the plate-shaped member 101 . The recess 122 C is positioned at a place facing an opening 1101 C of the engaging part 111 C on the plate-shaped member 101 . [0068] The leaf springs 105 A to 105 C are arranged in the openings 1101 A to 1101 C, respectively. The leaf springs 105 A to 105 C are in contact with the engaging shaft 103 passing through the engaging parts 111 A to 111 C. The leaf springs 105 A to 105 C apply a force on the engaging shaft 103 in the transverse direction of the plate member 110 from the recess 112 toward the recess 113 . Described below in detail are the arrangement of the leaf springs 105 A to 105 C and their pressing against the engaging shaft 103 . [0069] The following describes the arrangement of the leaf springs 105 A to 105 C in detail with reference to FIG. 6 to FIG. 8 . The leaf spring 105 A or the leaf spring 105 c is described here as an example, but the same description applies to all the leaf springs 105 A to 105 C. [0070] FIG. 6 is a drawing illustrating the casing mounting rail according to the first embodiment viewed in the direction of the arrow Q. FIG. 7 is an enlarged view of the area A in FIG. 6 . FIG. 8 is the B-B sectional view of FIG. 6 . [0071] Parts with numerals attached in FIG. 6 are the same as the parts with the same numerals attached in FIG. 5 . As illustrated in FIG. 6 , the leaf springs 105 A to 105 C are arranged at the places of the openings 1101 A to 1101 C of the engaging parts 111 A to 111 C, respectively. [0072] More specifically, the leaf spring 105 B is arranged as illustrated in FIG. 7 . Specifically, a base 153 is arranged on the recess 122 B side of the opening 1101 B of the engaging part 111 B. The leaf spring 105 B is placed on the base 153 . Fixing parts 151 A and 151 B are further arranged on the base 153 for fixing the leaf spring 105 B. The leaf spring 105 B presses the engaging shaft 103 toward the engaging shaft 103 from the base 153 . [0073] The following further describes the state of the leaf spring 105 C with reference to FIG. 8 . As described above, the engaging part 111 C is formed on the plate member 110 . The opening 1101 C is formed in the engaging part 111 C at the place where the leaf spring 105 C is positioned. As illustrated in FIG. 8 , the base 153 that extends perpendicularly from the plate member 110 is arranged on the recess 122 C side of the opening 1101 C. The fixing part 151 A is arranged on the base 153 . The leaf spring 105 C placed on the base 153 is fixed by the fixing part 151 A. The leaf spring 105 C presses the engaging shaft 103 toward the engaging shaft 103 from the base 153 . For example, in FIG. 8 , when the L-shaped member 102 (see FIG. 5 ) rotates about the engaging shaft 103 , the support plate 123 and the recess 122 C rotate, and the leaf spring 105 C, the base 153 , the engaging part 111 C, and the like do not rotate. [0074] FIG. 9 is a sectional view illustrating the engaging shaft 103 . FIG. 10 is a sectional view illustrating a through hole of the engaging part 111 A for passing the engaging shaft through. [0075] As illustrated in FIG. 9 , the sectional shape of the engaging shaft 103 includes arcs 131 A and 131 D and tapered parts 131 B and 131 C. The arcs 131 A and 131 D are on the circumference of the same circle. In other words, the engaging shaft 103 is obtained by trimming the sides of a rod-shaped member having the shape of the circumference of a circle including the arcs 131 A and 131 D as a section to form the tapered parts 131 B and 131 C. [0076] As illustrated in FIG. 10 , the sectional shape of the through hole of the engaging part 111 A includes arcs 201 and 204 and tapered parts 202 and 203 . The tapered parts 202 and 203 and the arc 204 form a bearing for the engaging shaft 103 . In the following, the recessed structure formed by the tapered parts 202 and 203 and the arc 204 may be referred to as the “bearing.” The engaging part 111 A is described here as an example, whereas the engaging parts 111 B and 111 C also have the same through hole. In this through hole, a line connecting the center of the arc 201 and the center of the arc 204 aligns with the transverse direction of the plate member 110 (see FIG. 5 ). The arc 201 is arranged on the recess 113 side of the plate member 110 , and the arc 204 is arranged on the recess 112 side of the plate member 110 . [0077] The arcs 201 and 204 and the arcs 131 A and 131 D are arcs as parts of the circumference of a circle having the same radius. The angles of the tapered parts 202 and 203 are equal to the angles of the tapered parts 131 B and 131 C, respectively. The angle of the tapered parts is an angle with respect to a center line with respect to which a section of the engaging shaft 103 in FIG. 9 or a section of the through hole in FIG. 10 is bilaterally symmetric. [0078] FIG. 11A is a drawing illustrating a state in which the engaging shaft is lifted. FIG. 11B is a drawing illustrating a state in which the engaging shaft is fit in the bearing. Both FIG. 11A and FIG. 11B illustrate sections in which the engaging shaft 103 passes through the through hole of the engaging part 111 A illustrated in FIG. 7 . The following describes the fixation of the engaging shaft 103 with reference to FIG. 11A and FIG. 11B . In the description here, for the convenience of description, the direction from the center of the arc 201 toward the center of the arc 204 in FIG. 11A and FIG. 11B is referred to as the downward direction, and the direction from the center of the arc 204 toward the center of the arc 201 is referred to as the upward direction. The upward and downward directions align with the transverse direction of the plate member 110 in FIG. 5 . [0079] The engaging shaft 103 is pushed up from below by the leaf springs 105 A to 105 C (see FIG. 5 ). With no other force acting on the engaging shaft 103 , as illustrated in FIG. 11A , the arc 131 A of the engaging shaft 103 is in contact with the upper arc 201 of the through hole of the engaging part 111 A. In this case, the engaging shaft 103 can rotate freely within the through hole. [0080] In contrast, when a force larger than the pressing forces of the leaf springs 105 A to 105 C (see FIG. 5 ) acts on the engaging shaft 103 downward, the engaging shaft 103 is pressed against the bearing side. This causes the tapered part 131 B to be in contact with the tapered part 202 , the tapered part 131 C to be in contact with the tapered part 203 , and the arc 131 D to be in contact with the arc 204 as illustrated in FIG. 11B . In this case, the rotational motion of the engaging shaft 103 is inhibited by the parts in contact therewith, fixing the engaging shaft 103 not to rotate within the engaging part 111 A. The above describes about the fixation of the engaging shaft 103 with the engaging part 111 A, and similarly for the engaging parts 111 B and 111 C, when the force acts downward, the engaging shaft 103 is fixed also by the engaging parts 111 B and 111 C. [0081] The following describes overall motion relating to the pivoting motion of the L-shaped member 102 with reference to FIG. 12 and FIG. 13 . [0082] FIG. 12 is a plan view illustrating the L-shaped member 102 in a movable state. FIG. 13 is a plan view illustrating the L-shaped member 102 in a fixed state. The description is provided here with the downward direction in FIG. 12 and FIG. 13 referred to as the downward direction and the upward direction in FIG. 12 and FIG. 13 referred to as the upward direction. The downward direction in the drawings is a direction toward the bottom face of the rack, and the upward direction in the drawings is a direction toward the upper face of the rack. [0083] As described above, when no downward force acts on the leaf springs 105 A to 105 C, the leaf springs 105 A to 105 C press the engaging shaft 103 upward. This force is represented by a tension T in FIG. 12 . As described above, when the tension T acts, the engaging shaft 103 is pressed upward in a state as illustrated in FIG. 11A and allowed to rotate freely within the through hole of the engaging part 111 A. In this case, the L-shaped member 102 rotates in a direction departing from the plate member 110 owing to the weight of the mounting plate 124 . As a result, as illustrated in FIG. 12 , the support plate 123 departs from the plate member 110 , tilting the L-shaped member 102 . [0084] In this situation, the mounting plate 124 moves toward the lower plate member 110 side through the rotation. As described above, the recess 113 is formed on the upper side of the plate member 110 , and the rubber sheet 115 is arranged therein. As a result, the mounting plate 124 can move without interfering with the plate member 110 through the deformation of the rubber sheet 115 . This causes the mounting plate 124 to move from the inside of the rack toward the outside thereof, preventing it from being in contact with the casing of a server or the like. [0085] The following describes a case in which a downward force is acting on the leaf springs 105 A to 105 C (see FIG. 5 ). The force acting on the leaf springs 105 A to 105 C (see FIG. 5 ) is represented by a force S in FIG. 13 . This force S is a force acting when the casing of a serve or the like is mounted. As described above, when the force S acts, the engaging shaft 103 moves downward to be fit into the bearing of the engaging part 111 A. This fixes the engaging shaft 103 not to rotate. Because the engaging shaft 103 and the L-shaped member 102 are fixed to each other, when it is difficult for the engaging shaft 103 to rotate, the L-shaped member 102 is also fixed and has difficulty in pivotally moving. [0086] In this case, the L-shaped member 102 is fixed in the state of FIG. 13 . Specifically, the support plate 123 is in contact with the plate member 110 . The mounting plate 123 is positioned in a direction perpendicular to the plate member 110 , that is, in a direction parallel to the bottom face of the rack. In this situation, the mounting plate 124 passes through the recess 112 (see FIG. 5 ) on the lower side of the plate member 110 . In other words, when the casing of a server or the like is mounted on the mounting plate 124 , the L-shaped member 102 is fixed as in the state of FIG. 13 through the weight of the casing and supports the casing. [0087] FIG. 14 is a diagram illustrating a state in which a casing is mounted. In FIG. 14 , the casing mounting rails 1 L, 11 L, and 12 L are in a position parallel to the side face of the rack, that is, the position of the casing mounting rail 1 L in FIG. 2 . In FIG. 14 , a server 300 illustrated by the two-dot chain line is mounted. FIG. 14 illustrates a state in which the casing of the server 300 is mounted on the casing mounting rail 12 L among the casing mounting rails 1 L, 11 L, and 12 L attached to the support 2 A. [0088] Because the weight of the server is acting on the casing mounting rail 12 L, the mounting plate 124 of the casing mounting rail 12 L is fixed in a direction parallel to the bottom face of the rack. In this state, the server 300 is mounted on the mounting plate 124 of the casing mounting rail 12 L. [0089] In contrast, the weight of the server is not acting on the casing mounting rails 1 L and 11 L. As a result, the casing mounting rails 1 L and 11 L can pivotally move. This causes the casing mounting rails 1 L and 11 L to rotate in a direction toward the outside of the rack through the weights of the respective mounting plates 124 . As a result, as illustrated in FIG. 14 , the mounting plates 124 of the casing mounting rails 1 L and 11 L retract to a position off a position being in contact with the server. This causes the server 300 to be smoothly stored in the rack without interfering with the mounting plates 124 of the casing mounting rails 1 L and 11 L. [0090] The following describes the support of the casing mounting rail 1 L by the support 2 C with reference to FIG. 15A , FIG. 15B , and FIG. 16 . FIG. 15A is a perspective view illustrating a state in which the casing mounting rail is rotating. FIG. 15B is a perspective view illustrating a state in which the rotation of the casing mounting rail is completed. FIG. 16 is an enlarged view illustrating a fitting part between the casing mounting rail and the rack. [0091] When the casing mounting rail 1 L becomes parallel to the side face of the rack, in order to mount the casing of an electronic device, not only the side fixed to the support 2 A but also the opposite side are fixed. This fixation of the casing mounting rail 1 L is performed by the support 2 C. [0092] As illustrated in FIG. 15A , the casing mounting rail 1 L has the protrusion 117 . A recess 210 is formed in the support 2 C at a position corresponding to the protrusion 117 when the casing mounting rail 1 L becomes parallel to the side face of the rack. As illustrated in FIG. 15B and FIG. 16 , when the casing mounting rail 1 L becomes parallel to the side face of the rack, the protrusion 117 and the recess 210 are fit to each other. This causes the support 2 C to support the protrusion 117 through the recess 210 when a force acts on the casing mounting rail 1 L toward the bottom face of the rack when, for example, a casing is mounted, thereby supporting the casing mounting rail 1 L. [0093] The following describes a state in which the casing of a server is mounted with reference to FIG. 17A and FIG. 17B . FIG. 17A is a perspective view illustrating a state in which a casing is mounted. FIG. 17B is a drawing illustrating a state of the casing mounting rails when the casing is mounted. FIG. 17A is a drawing illustrating a case when a server 301 is mounted on the rack in the state of FIG. 1 . FIG. 17B illustrates a state when the server 301 is removed in FIG. 17A . [0094] As illustrated in FIG. 17A and FIG. 17B , when the 3 U server 301 is inserted, three pairs of casing mounting rails, that is, the casing mounting rails 1 L, 11 L, 12 L, 1 R, 11 R, and 12 R are pushed inside the rack. The casing mounting rails 1 L, 11 L, and 12 L are fit into the support 2 C. The casing mounting rails 1 R, 11 R, and 12 R are fit into the support 2 D. The casing mounting rails 12 L and 12 R are fixed through the weight of the server 301 and support the casing of the server 301 from the bottom face side of the rack. The casing mounting rails 13 L to 15 L and 13 R to 15 R maintain the function as blank plates even after the server 301 is mounted. [0095] When the server 301 is removed from the state of FIG. 17A , the casing mounting rails 1 L, 11 L, 12 L, 1 R, 11 R, and 12 R rotate toward the front face of the rack through a force applied by the coil spring 107 and stop at the position parallel to the front face of the rack, thus returning to the state of FIG. 1 . [0096] As described above, the casing mounting rail according to the present embodiment has a role of a blank plate when no electronic device is mounted. When the casing mounting rail according to the present embodiment mounts an electronic device, simply inserting the electronic device pushes in an appropriate number of the casing mounting rail, thereby exhibiting the function of mounting the casing. In addition, simply removing the mounted electronic device causes the casing mounting rail according to the present embodiment to automatically return to a position as the blank plate to play the role of the blank plate. This eliminates the need for operators to consider the size of blank plates to be removed when mounting an electronic device, eliminates a process of removing blank plates, and saves time and effort for fixing rails to supports. This allows operators to reduce time and effort in operation. In the fixation of rails, time and effort have been needed for alignment for fixing rails to the support on the front face of the rack and the support on the back face of the rack; such time and effort are also reduced. After removing the mounted electronic device, processes of selecting and installing blank plates according to space have been conventionally needed; such time and effort are also reduced using the casing mounting rail according to the present embodiment. [b] Second Embodiment [0097] The following describes a rack and a casing mounting rail according to a second embodiment. The present embodiment differs from the first embodiment in that casing mounting rails are arranged in a rack so that a deep casing can be mounted. The casing mounting rail according to the present embodiment has the same configuration as that according to the first embodiment. [0098] FIG. 18A is a perspective view illustrating a state in which a shallow casing is mounted. FIG. 18B is a drawing illustrating a state of casing mounting rails when the shallow casing is mounted. FIG. 19A is perspective view illustrating a state in which a deep casing is mounted. FIG. 19B is a drawing illustrating a state of casing mounting rails when the deep casing is mounted. [0099] In the present embodiment, as illustrated in FIG. 18A to FIG. 19B , in addition to the casing mounting rails 1 L, 11 L to 15 L and 1 R, 11 R to 15 R, casing mounting rails 16 L to 21 L and 16 R to 21 R are arranged also in between the front face of the rack and the back face of the rack. [0100] To attach the casing mounting rails 16 L to 21 L and 16 R to 21 R, a support 2 G and a support 2 H are provided in between the support 2 C and the support 2 E and in between the support 2 D and the support 2 F, respectively in the rack. The distance between the support 2 G and the support 2 E and the distance between the support 2 H and the support 2 F correspond to the longitudinal distances of the casing mounting rails 16 L to 21 L and 16 R to 21 R, respectively. [0101] The casing mounting rails 16 L to 21 L and 16 R to 21 R are fit in the support 2 E and the support 2 F, respectively, when they become parallel to the side faces of the rack. [0102] When no electronic device is mounted, the casing mounting rails 16 L to 21 L and 16 R to 21 R are closed at a position of a plane formed by the support 2 G and the support 2 H. [0103] As illustrated in FIG. 18A and FIG. 18B , when the shallow casing is mounted, the casing does not reach the casing mounting rails 16 L to 21 L and 16 R to 21 R. In other words, for the shallow casing, the casing mounting rails 1 L and 11 L to 15 L and 1 R and 11 R to 15 R can support the casing. As a result, the casing mounting rails 16 L to 21 L and 16 R to 21 R are closed at the position of the plane formed by the support 2 G and the support 2 H. [0104] As illustrated in FIG. 19A and FIG. 19B , when the deep casing is mounted, the casing reaches the casing mounting rails 16 L to 21 L and 16 R to 21 R. In other words, for the deep casing, the casing mounting rails 1 L and 11 L to 15 L and 1 R and 11 R to 15 R alone cannot support the casing. As a result, part of the casing mounting rails 16 L to 21 L and 16 R to 21 R coming into contact with the casing are pushed in to play the role of the casing mounting rail. Because a server 302 is 3 U in FIG. 19A and FIG. 19B , the casing mounting rails 16 L to 18 L and 16 R to 18 R are pushed in. The casing mounting rails 12 L, 12 R, 18 L, and 18 R play the role of the casing mounting rail. This supports the deep casing stably. [0105] With the back of the shallow casing obstructed by the casing mounting rails 16 L to 21 L and 16 R to 21 R, the exhaust air of the shallow casing is discharged to the side of rack, and the exhaust air of the deep casing is prevented from returning to the front by the casing mounting rails 16 L to 21 L and 16 R to 21 R. As a result, the cooling effect is maintained even for the shallow casing. [0106] As a modification, the casing mounting rails 16 L to 21 L and 16 R to 21 R may be reticulated, so long as their strength is ensured. Making them reticular causes the exhaust air of the shallow casing to reach the back face of the rack and makes the flow of the exhaust air similar to that of the first embodiment, thus achieving nearly the same cooling effect as the first embodiment. As another modification, the casing mounting rails 16 L to 21 L and 16 R to 21 R may be arranged at positions parallel to the sides of the rack at all times. In this case, the casing mounting rails 16 L to 21 L and 16 R to 21 R do not partition the rack in the middle, thus achieving nearly the same cooling effect as the first embodiment. [0107] As described above, the rack and the casing mounting rail according to the present embodiment holds even a deep casing. Even the deep casing can be mounted simply by pushing it, thus reducing working time for installing electronic devices. [0108] One aspect of the present invention reduces the trouble with mounting an electronic device to a rack. [0109] All examples and conditional language recited herein are intended for pedagogical purposes of aiding the reader in understanding the invention and the concepts contributed by the inventor to further the art, and are not to be construed as limitations to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.

A coupling member is coupled to a support column of a rack. A plate-shaped member is rotatably engaged with a coupling member with one longitudinal end as an axis. An L-shaped member includes a first flat plate and a second flat plate orthogonal to the first flat plate and includes, with a transverse end of the first flat plate rotatably engaged with one plate face of the plate-shaped member with the longitudinal direction of the plate-shaped member as an axis and with a plate face of the first flat plate in intimate contact with the one plate face, a mounting member in which the second flat plate protrudes from one transverse end of the plate-shaped member and a fixing mechanism that fixes the mounting member with the plate face of the first flat plate in intimate contact with the one plate face of the plate-shaped member.

FIELD OF THE INVENTION This invention relates to semiconductor laser assemblies. BACKGROUND OF THE INVENTION Analog semiconductor lasers, Such as InP Distributed Feedback (DFB) lasers, are finding increasing use in cable TV transmission systems. In one design, the laser is mounted on the surface of a silicon substrate, and the light from the laser is focused onto an optical fiber by means of a spherical lens which is mounted in a cavity in the silicon substrate. (See, e.g., U.S. Patent Application of Anigbo, Ser. No. 60/00916, filed Dec. 22, 1995, which is incorporated by reference herein.) One of the problems associated with fabricating such devices is to keep distortion ripple at a minimum. The "distortion ripple" is defined as the variation of the values of the composite second order distortions and the composite triple beat distortions due to reflection feedback as the temperature is changed. Generally, it is desired to keep the distortion ripple at or better than 4 dB over a laser temperature variation of 2 deg C, which is the typical temperature variation of the laser in the package. SUMMARY OF THE INVENTION The invention is a laser assembly which includes a semiconductor laser and a spherical lens bonded on a first portion of its surface to a supporting member and positioned with respect to the laser to receive light emitted therefrom at a second portion of the surface of the lens and transmit said light out of the lens at a third portion. The lens includes means on a fourth portion of its surface which is distinct from the first, second, and third portions for producing optical asymmetry at said fourth portion of the lens surface. BRIEF DESCRIPTION OF THE FIGURES These and other features of the invention are delineated in detail in the following description. In the drawing: FIG. 1 is a cross sectional view of a portion of a laser assembly in accordance with the prior art illustrating a possible cause of distortion ripple; FIG. 2 is a cross sectional view of a portion of a laser assembly in accordance with an embodiment of the invention; and FIGS. 3-4 are graphs of distortion ripple as a function of laser current illustrating advantages of the invention in accordance with the same embodiment. It will be appreciated that, for purposes of illustration, these figures are not necessarily drawn to scale. DETAILED DESCRIPTION FIG. 1 illustrates a portion of an optical assembly, 10, in accordance with the prior art. The assembly includes a substrate, 11, which is typically silicon. A bonding pad, 12, is formed on a major surface of the substrate. The pad is typically Ti/Pt/Au. Mounted on top of the pad, 12, is a semiconductor laser, 13, which in this example is a 1.3 μm InP DFB laser, but could be any semiconductor analog laser. A spherical lens, 14, is mounted in a cavity, 15, etched in the surface of the substrate. The lens is typically made of M g Al 2 O 3 or YAG or glass, and is positioned with respect to the laser, 13, to collimate the light from the facing edge of the laser as indicated schematically by the rays 16-18. (For a more detailed discussion of an optical assembly formed on a silicon substrate, see, for example, U.S. Patent Application of Anigbo, cited above.) The lens is bonded to a layer, 20, of aluminum formed on the surfaces of the cavity, 15, according to known techniques to form a three point mechanical contact, one of which is shown as 19, the other two being formed with the side walls of the cavity, 15, which are not shown in this view. (See, for example, U.S. Pat. No. 5,178,319 issued to Coucoulas, which is incorporated by reference herein.) Applicants have discovered that a source of distortion ripple in such assemblies is scattered light within the lens, 14, as illustrated, for example by the dotted line, 20. Applicants theorize that since the lens is optically symmetrical, the scattered light is multiply reflected within the lens, 14, and gains in intensity due to constructive interference. The scattered light may then exit the lens at a point which interferes with the main beam, 16-18. Alternatively, the scattered light may exit at any point on the lens, 14, but the intensity of such light may be frequency dependent and thereby cause a nonlinearity in the intensity of the main beam at certain optical frequencies. In accordance with a key feature of the invention, the scattered light, 20, is prevented from being multiply reflected by making the lens optically asymmetrical at some portion of the lens, 14, outside any portion, e.g. 19, which is bonded to the substrate, 11. One technique for producing the asymmetry is illustrated in FIG. 2. Here, a top portion of the lens, 14, was coated with a material, 21, which in this example was either a silica-loaded epoxy or black wax. Other materials may be employed, e.g., organic or inorganic adhesives which may be filled or unfilled. The main requirements for the material are that it be not be highly reflective (i.e., has a reflectivity no greater than 60 percent) and that it have an index of refraction greater than the ambient. Preferably, the index of refraction of the material is equal to or greater than that of the lens, 14. Thus, for example non-metallic solders could also be used. The material, 21, was deposited by mechanical transfer, but other techniques could be used. The material had a thickness of approximately 0.01 inches but thicknesses in the range 0.001 to 0.03 inches would be useful. As illustrated in FIG. 2, the presence of the material, 21, causes the scattered light, 20, to either be refracted out of the lens, 14, at the point of first incidence on the lens surface (ray 22), or, if the scattered light happens to be at less than the critical angle, reflected back into the lens (ray 23). In the latter case, however, the angle of reflection may be such that the scattered light will exit the lens, 14, at the next incidence on the lens surface due to the optical asymmetry produced by the material, 21. In either case, the scattered light, 20, does not have a chance to increase in intensity inside the lens, 14. The dramatic improvement in distortion ripple between the prior art structure of FIG. 1 and the embodiment of FIG. 2 is illustrated in FIG. 3, which is a graph of distortion as a function of dc current supplied to the laser, 13. The dotted line curves, 30 and 31, show the second and third order distortion for different frequencies of modulation of the structure of FIG. 1, and the solid line curves, 32 and 33, show the distortion ripple for the same frequencies of modulation of the device of FIG. 2. Reduction of the distortion ripple from more than 15 dB to approximately 2 dB is achieved. (It will be noted that the distortion minimum at approximately 46 mA is not a ripple feature, but a typical null observed in most DFB lasers.) FIG. 4 illustrates distortion ripple improvement for another embodiment of the invention. Here, the prior art device second and third order distortion is represented by curves 40 and 41. Curves 42 and 43 show distortion ripple for an assembly similar to FIG. 2, but with the black wax applied to the bottom of the lens, 14, so that the black wax covered the bottom portion of the lens which was not bonded to the aluminum metallization, 20, i.e., the portion not including site 19 and the two other sites (not shown) where the lens was attached to the sidewalls of the cavity, 15. The black wax was deposited on the bottom surface of the cavity, 15, and heated so that the black wax melted and surface tension drew the black wax under the lens, 14. As shown in FIG. 4, distortion ripple was reduced from approximately 6-15 dB to 1-4 dB. Various additional modifications will become apparent to those skilled in the art. For example, the optical asymmetry of the lens, 14, can be achieved by mechanically altering the spherical lens by cleaving or grinding a flat on a portion of the surface of the lens outside the path of the main beam.

The invention is a laser assembly for reducing distortion ripple. The assembly includes a spherical lens which has a portion of its surface made optically asymmetric to prevent multiple reflections of scattered light within the lens.

BACKGROUND OF THE INVENTION This invention relates generally to clutch mechanisms and more particularly, it relates to an improved clutch having oversized rollers. In prior art clutches of the type utilizing rollers for achieving a clutching connection between a clutching member and a clutched member, the force-transmitting rollers are rolled "up" a ramp surface in channel means of the clutching member so as to create the clutching connection by pinching the force-transmitting rollers into engagement between the clutching member and the clutched member. For the purposes of completeness, reference is being made to my prior U.S. Pat. No. 3,557,631 which reissued as U.S. Pat. Re.No. 28122 and to my two co-pending U.S. applications, Ser. No. 506,538, now U.S. Pat. No. 3,930,416 and Ser. No. 506,594, now U.S. Pat. No. 3,951,005, wherein the clutches of the type having force-transmitting rollers for achieving a clutching connection is described and illustrated with application to a speed reducing mechanism. In such prior art clutches, due to the weight of the driven shaft and the clutched member acting under the force of gravity on the lower force-transmitting rollers, difficulties have been encountered in providing a smooth and uniform movement of all of the force-transmitting rollers when they are urged in operation toward the narrow end of the channel means for engagement with the clutched member. In this particular situation, the upper force-transmitting rollers tend to move more readily into the narrow end of the channel means because of the action of gravity on the clutch members. On account of such gravitational forces and the fact that the upper rollers move more readily up the ramp, the lower rollers move into the narrow end of the channel means with greater difficulty and often not simultaneous with the upper rollers. This results in uneconomical and inefficient transfer of force or torque from the clutching member to the driven shaft. Further, when the force-transmitting rollers are returned to the larger end of the channel means (disengagement of the clutched member) additional difficulties have been encountered in providing an adequate friction free engagement between the clutching member and the clutched member again due to the weight of the clutched member. Another problem exists in that the force-transmitting rollers become misaligned and askew to the axis of rotation of the driven shaft. This again results in an inefficient transfer of force. Additionally, in applications to a speed reducing mechanism (as in previously mentioned patents) having two arms each with a clutch associated therewith, the force-transmitting rollers are aligned serially and parallel to the axis of rotation of the driven shaft. In this case, a disadvantage occurs when the aligned force-transmitting rollers contact and rub against each other thereby making the force-transmitting rollers askew or cock-eyed and preventing a uniform and constant rate of rotation of the driven shaft or efficient transfer of forces between the clutching member and clutched member. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an improved clutch which overcomes each and every one of the various above-mentioned disadvantages. Another object of the present invention is to provide an improved clutch having oversized rollers disposed so as to facilitate a smooth movement of the force-transmitting rollers during engagement of the clutch and to provide a substantially friction free surface between the clutching member and the clutched member during disengagement of the clutch. Still another object of the present invention is to provide an improved clutch with intermediate barrier means disposed between adjacent aligned force-transmitting rollers to prevent misalignment thereof during rotation of the clutched member. In accordance with these aims and objectives, the present invention is concerned with the provision of a clutch comprising a clutching member having a central aperture and channel means disposed therein, a clutched member disposed within the aperture and spaced apart from the clutching member, and clutch means disposed co-axially in the aperture between the clutching member and the clutched member. The clutched means include a plurality of force-transmitting rollers surrounding the clutched member and roller means larger in diameter than the force-transmitting roller being spaced around the clutched member to support the clutching member on the clutched member independently of the force-transmitting rollers for rotation. Additionally, barrier means are provided to prevent the force-transmitting rollers from becoming askewed and unparallel to the axis of rotation of the driven shaft. BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and advantages of the present invention will become more fully apparent from the following detailed description when read in conjunction with the accompanying drawings, wherein: FIG. 1 is a top plan view of a clutch of the present invention showing a practical application thereof in connection with a speed reducing mechanism; FIG. 2 is an elevational view taken along the lines 2--2 FIG. 1, looking in the direction of the arrows; FIG. 3 is a side view of a representative clutching member; FIG. 4 is an enlarged detailed view of the clutch of the present invention; FIG. 5 is a view of an intermediate barrier plate; FIG. 6 is a partly sectionalized view of part of the clutch of the present invention; FIG. 7 is an enlarged and detailed view showing a second embodiment of the clutch; FIG. 8 is a view of an intermediate barrier plate for the second embodiment; and FIG. 9 is a partly sectionalized view of part of the second embodiment of the clutch. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT It is to be distinctly understood at the outset that the present invention shown in association with a speed reducing mechanism is not intended to serve as a limitation upon the scope or teachings thereof, but is merely for the purpose of convenience of illustration of one example of its application. The present invention has numerous applications in other forms of machines since the invention pertains to a mechanism for providing a clutching connection between a clutching member and a clutched member. Referring now in detail to the drawings of the particular illustration, a speed reducing mechanism designated generally by reference numeral 10 is driven by an electric motor 12 having an output shaft 14. As shown in FIG. 1, the rotating power output shaft 14 is provided with a series of eccentrics 16, each being provided with an aperture through which the shaft 14 passes. It should be noted that any number of eccentrics can be provided on the shaft 14, but they must be angularly oriented to the axis of rotation of the shaft equally from each other in order that the assembly functions in an optimal manner, i.e., three eccentrics must be spaced apart by a 120°. The output shaft 14 transfers power to a driven output shaft 18 having its own independent set of bearings 20. However, it is also possible that the output shaft 18 be supported by bearing sets which are an integral part of the apparatus over which it is driving. In FIG. 2, there is shown a preferred embodiment of the novel clutch having oversized rollers of the present invention which will be described in detail hereinafter. The output shaft 18 is adjacent and generally surrounding a sleeve or clutched member 22 removably secured by a key 24. The speed reducing mechanism extends between the output shaft 14 and the driven output shaft 18 via force transfer arms 26. With reference to my previously mentioned applications and patents, and from a consideration of the clutch assembly 28 as shown in FIG. 2, a full and complete understanding of the operation of the clutch assembly will be seen. Very simply, as the eccentrics 16 rotate the arms 26 are moved alternately in a rapid up and down fashion (rocking motion). The end 30 of the arm 26 is provided with an aperture 32 having channel means 34 therein. As the arms 26 are moved upwardly by the eccentrics 16, the force-transmitting rollers 36 of the clutch assembly 28 are urged toward the narrow end of the channel means 34 and thereby pinching the force-transmitting rollers 36 between the bottom wall 38 of clutching member 40 and the outer surface 41 of the clutched member 22. In this pinching position defining clutch engagement, a force is transmitted through the clutched member 22 to the driven output shaft 18. When the force-transmitting rollers 36 are rolled toward the large end of the channel means 34, no locking action is effected between the clutching member 40 and the clutched member 22. In this latter position defining clutch disengagement, no force is transmitted through the clutched member 22 to the output shaft 18. The improvement of the clutch assembly 28 resides in three oversized rollers 42 positioned in rectangular slots 44 as shown in FIGS. 2, 3 and 4. The oversized rollers 42 are positioned in approximately equal spaced relationship 120° apart around the clutched member 22. It is to be understood that this is a preferred embodiment and that any number of oversized rollers may be used. Further, if more than one oversized roller is used, they do not necessarily have to be equally spaced around the clutched member. The rollers 42 maintain continuous engagement with the clutching member 40 and the clutched member 22. The roller 42 facilitates a smooth and uniform movement of the force-transmitting rollers 36 during clutch engagement since the lower force-transmitting rollers such as force-transmitting roller 46 is not effected by the weight of the driven shaft and clutched member acting on them due to gravity to prevent rotation thereof. Further, during clutch disengagement the rollers 42 provide a substantially friction free surface for rotation of the clutching member relative to the clutched member. Thus, the output shaft 18 can be rotated independently in a uniform and constant rate by virtue of the addition of the three oversized rollers 42. Referring now to FIG. 5, in order to provide an economical and efficient transfer of force or torque and to prevent thus the force-transmitting rollers 36 from becoming askewed or misaligned and unparallel to the axis of rotation of the driven output shaft 18, intermediate barrier means such as metal plate halves 48 and 49 (FIGS. 5 and 8) are press-fitted into recesses or grooves 50 on the outer surface 41 of the clutched member 22. It should be noted that the plate halves 48 and 49 can be mounted by any other convenient means. The intermediate barrier means prevent the adjacently disposed force-transmitting rollers such as force-transmitting rollers 54, 56 (FIG. 1) from rubbing or contacting each other so as to make them become askew or unparallel to the axis of rotation of the driven output shaft 18. As best seen in FIG. 6 end barrier means 58 and 59 are mounted on ends 60, 61 respectively, of the clutched member 22 and serve the same function as the intermediate barrier means. The end barrier means 58 and 59 are metal circular plates which are mounted on the ends 60, 61 by mounting means such as screws 63 threaded into tapped-holes 62 in the clutched member 22 via hole or aperture 64 in the circular plates. In FIGS. 7 and 9, there is shown a second embodiment of the clutch assembly 28. It can be seen that in this embodiment the channel means 34, the force-transmitting rollers 36, and the oversized rollers 42 are located on the clutched member 22 rather than on the clutching member 40. The operation is exactly the same as the first embodiment. Further, it is to be understood that intermediate barrier means and end barrier means can be likewise provided. While there has been illustrated and described what is at present to be a preferred embodiment of the present invention, it would be understood by those skilled in the art that various changes and modifications may be made and equivalence may be substituted for elements thereof without departing from the true scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that this invention not be limited to the particular embodiment disclosed as a best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.

A clutch comprising a clutching member having a central aperture and channel means disposed therein, a clutched member disposed within the aperture and spaced apart from the clutching member, and clutch means disposed co-axially in the aperture between the clutching member and the clutched member. The clutch means include a plurality of force-transmitting rollers surrounding the clutched member and roller means larger in diameter than the force-transmitting rollers being spaced around the clutched member to support the clutching member on the clutched member independently of the force-transmitting rollers for rotation.

RELATIONSHIP TO OTHER APPLICATIONS This application claims priority to and the benefit of U.S. provisional patent application No. 61/941,718 titled EFFICIENT ENCODING AND STORAGE AND RETRIEVAL OF GENOMIC DATA filed 19 Feb. 2014. This application in incorporated by reference for all purposes. GOVERNMENT FUNDING This invention was made with government support under The Center for Research in Storage Systems (CRSS) NSF grant number is IIP-0934401. The government has certain rights in the invention. SEQUENCE LISTING STATEMENT No sequence listing statement is provided because the sequence data provided is solely illustrative of the invention and is not part of the invention or any claim. FIELD OF THE INVENTION The invention is directed towards encoding data, specifically genomic data, more specifically to efficient encoding, storage and retrieval of genomic data by removing data duplications. The invention also encompasses a computerized method of reducing genomic data set sizes having duplicated data into a reduced de-duplicated data set, and a DNA sequencing system for producing multiple DNA data segments and then efficiently encoding those data segments into de-duplicated machine and human readable formats. A sequence listing text (.txt) file is submitted herewith under 37 CFR. 1.821(c) and is hereby incorporated by reference in its entirely. The details of the file as required under 37 CFR. 1.52(e)(5) and 37 CFR 1.77(b)(5) are as follows: Name of file is 2_SC2014_456_SeqList_ST25.txt; date of creation is May 8, 2015; size is 4 kilobytes. The content of the sequence listing information recorded in computer readable form is identical to the written sequence listing (if any) and identical to the sequence information provided with the original filed application and with the priority application, and contains no new matter. BACKGROUND OF THE INVENTION Genomic data is commonly stored in the .bam or .sam file format. The .sam format is a human readable text format for storing sequenced data in tab delimited ASCII columns. It is a human readable version of the .bam format which stores the same data in a compressed, indexed, binary form. Both formats represent aligned data for a sample along with both quality (QUAL) scores and metadata (Tags). The results of many small reads are aligned and stored along with their quality data stores. A typical whole genome sequence of a human we require approximately 300 GB of storage. In a large scale computing environment 300 GB .bam files can easily consume available storage and clog networks. Existing practice relies heavily compression using techniques such as lempil ziv and gziv. More recent techniques use standard reference genomes, such as HG19, compiled from a variety of human genomes. Quality scores are calculated in the standard manner by the sequencer, such an Illumina, MySeq etc. Quality scores are discussed in many publications including in the on-line publication from Illumina called “Understanding Illumina quality scores”; also see E. Green 1998 “Base-calling of automated sequencer traces using phred. II. Error probabilities”; Genome Research 8: 186-194. The .sam (and .bam) file formats are well known, standardized, useful, but unfortunately require about 300-400 GB of storage per human sequence even after using compression techniques such as Lempil, Ziv or Gziv. That storage size is simply too large for many purposes, especially if all cancer patient genomic data is to be gathered, stored, and/or transmitted. Since processing cancer genomic data is best practiced in large scale computing environments storing 300 GB .bam files on thousands of cancer patients would easily consume all available storage and clog computer networks. As an example of the required data sizes consider a rather small trial to correlate genetic mutations with a specific cancer, for example breast cancer, in the hopes of identifying an effective therapy. That trial may have 800 breast cancer patients with 3 to 4 sequences each and would require at least 1 PB of storage per patient. Genomic researchers need to reduce such capacity without loss of quality sequence data, without increased processing time associated with decompression, and without the excessive costs and delays currently associated with moving genomic data from one location to another. Complicating the matter are issues in the alignment of the segment snippet sequences which make existing methods of compression and de-duplication (removal of duplicated data) less effective. As another example, if precision oncology becomes a reality “whole genome sequencing,” particularly in clinical treatments of cancer, would rapidly consume all available storage unless an effective way of reducing the required data size is implemented. In 2010, 13 million Americans had cancer. With existing technology, a single whole genome sequence for every person would require 39 exabytes (39,000 petabytes, 39 million terabytes or 39 billion gigabytes). There simply isn't enough storage for that. In view of the foregoing improved data encoding for genomic data would be useful. Beneficially such data encoding would be computer driven to eliminate redundant genomic data (de-duplication). Preferably such encoded data would be compressed and searchable. In addition it should merge re-reads of the same nucleotide into a single nucleotide having an averaged quality score. In practice, the improved data encoding should enable computer processing of the resulting encoded data without loss of information related to multiple nucleotides in sample segments. Ideally, the encoded data would be produced by a computerized DNA sequencing system that would provide encoded data that is so efficiently packed that it would allow individual cancer patients to store their genomic data on a memory stick or other computer readable memory, would enable faster transmissions of data, would require less data storage space, would support standardized data processing, and could enable improved data processing. BRIEF SUMMARY OF THE INVENTION The invention provides a new method for encoding genomic data that reduces storage footprint by two orders of magnitude while preserving acceptable quality data. The invention encompasses a method that eliminates redundant genomic data. Genomic data is commonly stored in the .bam or .sam file formats. These formats often include re-reads of the same base pairs, resulting in redundant genomic data. Furthermore, each read includes associated quality scores and meta-data. The inventors reduced re-reads of the same base pair to a single nucleotide and average quality score. For base pairs where multiple nucleotides are present, we annotate on a separate conflict stream the number of reads for each nucleotide and the corresponding average quality. This encoding allows the user to establish a threshold for good data, and thereby eliminate noisy or bad data. Above this threshold, all data is preserved. One embodiment of the invention allows the sharing of deduplication libraries. This promotes file sharing by passing references to redundant data in the deduplication library rather the data itself. In another embodiment the deduplication library may be organized as a collection of objects, each representing a gene found in the cancer genome atlas (TCGA). The invention dynamically creates a deduplication library without the need of a standards body to decide what should be in the reference. The method of the invention reduces the alignment information and reference differences to a single data stream storing only what is different from the reference. It then annotates conflict information on a separate file when there are multiple possible values on the same location. FIG. 1 illustrates a highly simplified genomic data set obtained by multiple DNA sequencing runs on a sample. Shown are run snippets (sequences) 1-12 which represent the results of the individual sequencing runs. Also shown in FIG. 1 is a ordered reference sequence which forms a “standard” nucleotide sequence that represents the normalized set of nucleotides in the population. As shown, the individual nucleotides of the snippets can be “aligned” with the reference sequence. Also shown in FIG. 1 is stored additional data that represents QUAL scores, which are the quality measurements of each nucleotide on each snippet as well as the quality of the mapping of each snippet (how well the base pair data align with other snippets). In addition FIG. 1 shows meta-data, which are mostly instructional data tags for machine processing such as data integer sizes, how it is specified (such as 32 bit signed integer data), aids in alignment, and user-defined information. The present invention encompasses a computer implemented system that implements reduced size genomic data to produce encoded data that is compressed and contains de-duplicated data. That computer driven system encodes data by eliminating redundant genomic data by processing reads and re-reads of sample segments against a reference to produce a coalescent nucleotide result having an averaged quality score that is properly aligned in a data sequence. In practice the computer driven system produces encoded data supporting annotations in a separate conflict stream when multiple nucleotides are present in the samples. The encoded data enables faster transmissions of data, requires far less data storage space, supports standardized data processing and improves the speed of data processing. The encoded data enables the user to establish a threshold for good data, thus helping eliminate noisy or bad data, while preserving all data above the threshold. In addition, the computer driven system is suitable for incorporating into a DNA sequencing system which produces the encoded data as an output. The present invention includes the following embodiments: A method for compressing genomic data, the method comprising the steps of: (i) providing a computer having a memory in functional communication with a processor; (ii) inputting multiple segments (multiple reads, polynucleotides) of genomic sequences and their quality scores into the computer memory; (iii) providing reference genomic data comprising a sequence of genomic data; (iv) accessing the reference genomic data; (v) aligning the multiple segments with the reference genomic data; (vi) comparing individual nucleotides in the aligned multiple segments using a processor; (vii) creating a de-duplicated sequence of encoded data aligned with the reference genomic data; wherein the encoded data contains the nucleotide label for agreed upon nucleotides at a particular nucleotide location. In additional embodiments the method may further include the step of creating a conflict file for containing information regarding conflicts in the aligned multiple segments. In an additional embodiment the method may further include the step of placing a quality score threshold in memory. In an additional embodiment the method may further include the step of including the step of ignoring a nucleotide in the aligned multiple segments having a quality below the threshold. In an additional embodiment the method may further include the step of selecting a nucleotide from conflicting nucleotides and inserting the selected nucleotide in the encoded data and inserting information regarding the conflicting nucleotides in the conflict file. Another embodiment of the invention is a computer having a processer, a first memory, a second memory and an input port programmed to produce encoded genomic data, by performing the following steps: inputting multiple segments of genomic sequences and their qualities scores into the input port; storing the multiple segments of genomic sequences in the first memory; accessing and storing reference genomic data comprising a sequence of genomic data into the first memory; aligning the multiple segments of genomic sequences with the reference genomic data; locating a pointer at the first position of the reference data; (a) processing the first memory to compare individual nucleotides in the aligned multiple segments at the pointer position; processing the compared individual nucleotides to determine a culminate nucleotide from the individual nucleotides to be stored in an encoded data file at the pointer position; (b) determining if the pointer is at the last position of the reference data; if the pointer is at the last position of the reference data jumping to step (c); stepping the pointer to the next position of the reference data; returning to step (a); (c) storing the encoded data file as encoded genomic data in the second memory. In an additional embodiment the computer-implemented method may further include the step of creating a conflict file in said second memory for containing information regarding conflicts in aligned nucleotides. In an additional embodiment the computer-implemented method may further include the step of storing a quality score threshold in the first memory. In an additional embodiment the computer-implemented method may further include the step of ignoring a nucleotide in an aligned multiple segment that has a quality below the threshold. Another embodiment is a genomic sequencing system, comprising: a genomic sequencer for producing segments of DNA sequences having QUAL scores and meta-data; a computer having a processer, a first memory, a second memory, and an input port; a genomic buss connecting said genomic sequencer to said input port; wherein the computer interacts with the genomic sequencer to perform the following steps: inputting multiple segments of genomic sequences and their qualities scores into the input port over the genomic buss; storing the multiple segments of genomic sequences in the first memory; accessing and storing reference genomic data comprising a sequence of genomic data into the first memory; aligning the multiple segments of genomic sequences with the reference genomic data; locating a pointer at the first position of the reference data; (a) processing the first memory to compare individual nucleotides in the aligned multiple segments at the pointer position; processing the compared individual nucleotides to determine a culminate nucleotide from the individual nucleotides to be stored in an encoded data file at the pointer position; (b) determining if the pointer is at the last position of the reference data; if the pointer is at the last position of the reference data jumping to step (c); stepping the pointer to the next position of the reference data; returning to step (a); (c) storing the encoded data file as encoded genomic data in the second memory. Another embodiment is a non-transitory computer readable media, comprising encoded data representing a DNA sequencing comprised of multiple DNA segments, the computer readable media produced by: inputting multiple segments of genomic sequences and their qualities scores into a computer memory; accessing reference genomic data comprising a sequence of genomic data; aligning the multiple segments with the reference genomic data; comparing individual nucleotides is the aligned multiple segments using a processor; creating a de-duplicated sequence of encoded data aligned with the reference genomic data; and storing the de-duplicated sequence on a computer storage media; wherein the encoded data contains the nucleotide label for agreed upon nucleotides at a particular nucleotide location. BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention will become better understood with reference to the following detailed description and claims when taken in conjunction with the accompanying drawings, in which: FIG. 1 is an illustration of a reference data set and nucleotide data obtained from multiple sequencing runs; FIG. 2 is a flow chart illustrating the steps of processing input data to produce de-duplicated encoded data in accord with the present invention; FIG. 3 is a flow chart illustrating the steps of processing nucleotide conflicts; FIG. 4 illustrates the process of resolving conflicts to produce encoded data; and FIG. 5 shows a computerized DNA sequencing system for producing encoded data. DETAILED DESCRIPTION OF THE INVENTION The presently disclosed subject matter now will be described more fully hereinafter with reference to the accompanying drawings in which one embodiment is shown. However, it should be understood that this invention may take different forms and thus the invention should not be construed as being limited to the specific embodiment set forth herein. All documents and references referred to in this disclosure are hereby incorporated by reference for all purposes. In the figures like numbers refer to like elements throughout. Additionally, the terms “a” and “an” as used herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. The present invention is explained with reference to FIGS. 1 through 5 . FIG. 1 represents exemplary sequences of nucleotide data along with a reference data set; FIG. 4 illustrates the resulting encoded data of the nucleotide sequences of FIG. 1 ; FIGS. 2 and 3 provide flow charts for processing nucleotide data; and FIG. 5 illustrates a computerized DNA sequencing system for implementing the principles of the present invention. The present invention is a polynucleotide (e.g., DNA or RNA) data encoding scheme that eliminates redundant genomic data, simplifies sequence alignment, and provides an auxiliary conflict file that contains information related to the encoded data. As previously provided, prior art genomic data was commonly stored in .bam or .sam file formats. Those formats include information regarding reads and re-reads of the same nucleotides obtained from different sequencing runs, along with associated quality scores and meta-data; reference snippets 1-12, QUAL data, and meta-data shown in FIG. 1 , all of which in the prior art would have to be stored in a .sam or .bam file format. The result is a large amount of redundant genomic data. The principles of the present invention de-duplicate reads and re-reads of the same nucleotide, reduces those reads and re-reads into a single nucleotide, and inserts the resulting single nucleotide and an averaged QUAL score and meta-data into its proper location in an aligned encoded data stream. That encoded data stream can be stored in computer memory. In addition, information regarding de-duplication is stored in a separate conflict file; reference FIG. 4 . Turning back to FIG. 1 , the present invention compares all sequenced nucleotides in all snippet (polynucleotide) segments at a particular nucleotide location relative to reference data. If the sequenced nucleotides are all the same the agreed upon nucleotide is placed in the resulting encoded data stream. This is shown in FIG. 4 where all agreed upon sequenced (e.g., culminate) nucleotides are encoded in their proper order. Specific attention is directed to position 18 wherein the agreed upon sequenced nucleotide A is stored in position A even when the reference data for position 18 is G. It is the sequenced nucleotides that control, not the reference data. Further, alignment information is contained in the encoded data so alignment information is removable, thus reducing the size of the encoded data. In addition, FIG. 1 shows the conflict file as including the information about position 18 that the nucleotide A was read 8 times. However, if the sequenced nucleotides in all of the sequenced segments do not all agree, which is represented in FIG. 1 by nucleotides T and C highlighted in bold, data is encoded as subsequently described below after conflict resolution processing. The multiple possible values of quality nucleotides (see below) at a position are also annotated in the conflict file. Thus the conflict file can be scanned to identify possible differences between the resulting encoded data and the nucleotides found in the various snippet sequencing. Attention is drawn to nucleotide T in FIG. 4 . No annotation of that nucleotide is provided as its assumed QUAL score is too low, again as subsequently explained. The end result is that the encoded data stream contains differences between the nucleotides in the sequencing snippets following conflict resolution. The result is a tremendous reduction in data size while retaining almost all information regarding sequenced nucleotide disagreements in the conflict file. Preferably, the conflict file includes the number of reads for each nucleotide and the corresponding average quality (QUAL) for that nucleotide. The preferred embodiment of the present invention allows a user to establish (or set) a threshold for good data which is then used to eliminate noisy or bad data from the conflict file. It is that threshold value that was used to eliminate information regarding the T nucleotide in position 6 in FIG. 4 from the conflict file. The T nucleotide was simply not good enough to be tracked. FIG. 1 presents a flow chart for a method 100 of processing input genomic data to produce a de-duplicated encoded data stream that is in accord with the present invention. The method 100 starts, step 102 , and proceeds with accepting an input sequenced data set that is to be de-deduplicate encoded, reference data, and the reference noise level threshold, step 104 . The input data is aligned with the reference data, step 106 . In preparation for de-duplication a computational pointer moves to the aligned first data position, step 108 . The nucleotides in the input data segments at the current (initially the first) position of the pointer are then read and a check is made to determine if all reads of the nucleotides at the current pointer position are the same, step 110 . If yes, a decision is made as to whether the input data matches the reference data, step 112 . If yes, a determination is then made as to whether the pointer is at the end of the input data, step 116 . If not, the pointer is moved to the next position, step 126 , and a return is made to step 110 . These steps represent the fastest processing of the input data. All of its reads are the same, those reads match the reference data set, a high quality rating for the nucleotide exists, the reference data set nucleotide can be used in place of the input data nucleotides, and the next encoded data position is ready to be processed. However, if in step 112 the input data nucleotides agree with each other but do not match the reference nucleotide, the input data nucleotide is written into the encoded data stream along with the averaged quality of the input nucleotides (each read would have its own quality rating) and its meta-data, step 114 . This condition is shown in position 18 of FIG. 4 . In addition to the input data nucleotide being input to the encoded data stream, the conflict file is populated with information regarding position 18 . This is also shown in FIG. 4 . Following step 114 a check is made as to whether the pointer is at the end of data, step 116 . If not, the pointer is advanced to its next position, step 126 and a return is made to the start of step 110 . The immediately foregoing processing produces information in the conflict file. Since most input data base pairs should match the reference data the conflict file is relatively smaller. Given any nucleotide disagreements in the input data set a check of the conflict file provides information about those disagreements. Disagreements can be quickly and efficiently found simply by scanning the conflict file. If it is found in step 110 that all reads and re-reads do not show the same nucleotide the process advances to step 119 for process conflict resolution. FIG. 2 shows a method 200 for handling process conflict resolution. The method 200 starts, step 202 and proceeds by removing reads with quality scores below the noise level, step 204 . Step 204 prevents low quality base pair readings from contaminating the resulting encoded data stream. After step 204 another check is made to determine if all remaining nucleotides at the current pointer position show the same nucleotide, step 206 . If yes the nucleotide conflict is considered resolved and an output resolution tag is set. However, if in step 206 the remaining nucleotides do not show the same value the nucleotide reads are grouped by nucleotides and an average quality score is determined, step 212 . Then a conflict tag is set, step 214 . After step 208 or step 214 one tag will be set. That tag is passed to the method 100 to either show that a conflict exists (conflict tag set) or that the nucleotide reads resolve and that no conflict exists. The method 200 ends, step 210 . Following step 210 a return is made to step 120 of the method 100 for a determination of how to proceed. If the output resolution tag is set the conflict is considered resolved and a jump is made to the start of step 112 for processing as described above and the output resolution tag is cleared for the next possible conflict. However, if the conflict tag is set, step 120 determines that the conflict is not resolved and operation passes to step 122 . In step 122 information related to the conflict is added to the conflict stream. The conflict stream subsequently can be examined to determine the specific nucleotide reads that initiated the conflict. Processing is then passed to the input of step 116 for a determination as to whether the pointer for the reads just processed is at the end of the data. The inventive encoding of the present invention enables a genomic data size reduction (by about 167), far faster data transmission rates, and improved data processing speeds. This is at least partially a result of removal of the standard genome reference. The inventive data encoding also enables the creation and sharing of de-duplicated gene libraries by storing the encoded data in a library. This promotes file sharing by passing references to redundant data in the de-duplicated library rather than in the data itself. The encoded data not only supports the organization of de-duplicated library but also the use of nucleotides as objects, with each object of a cancer gene being part of a cancer genome atlas (TCGA). The inventive genomic data encoding also supports efficient, searchable compression of de-duplicated Genomic Data. In practice the present invention enables a tremendous reduction in the required size of stored genomic data by exploiting the rather limited genomic variations among humans (0.1%). The reduction in size reduces the genomic data storage footprint and the bandwidth required to transport genomic data. Instead of the 39 exabytes required in the prior art to store the whole genome sequences for every person mentioned in the background genomic de-duplication shrinks the genome sequences to under 1 PB. Turning now to FIG. 5 , the actual production of encoded data is a task well suited to a computerized environment. Such a computerized environment may be part of a DNA sequencing system 500 . Such a DNA sequencing system 500 may include a terminal 502 that communicates with other elements (discussed subsequently) that are connected to a shared buss 504 . The terminal 502 is connected to the shared buss 504 by a bi-directional local buss 506 . The terminal 502 communicates as required with a computer 508 which is connected to the shared buss 504 by a computer buss 510 . The computer 508 runs the methods 100 and 200 illustrated in FIGS. 2 and 3 . Input data which includes reference data, QUAL data, and meta-data as exemplary illustrated in FIG. 1 , is produced by a DNA sequencer 530 which is connected to the shared buss 504 via a local sequencer buss 532 . That Input data can be stored in input data storage 512 . The input data is applied to the computer 508 as required over the shared buss 504 and along a local input data bus 514 . The computer 508 processes the input data to produce encoded data, exemplary illustrated in FIG. 4 . That encoded data can be transmitted over the computer bus 510 , along the shared buss 504 to encoded data storage 516 via encoded data storage buss 520 . Alternatively, the encoded data can be streamed out over an encoded data stream buss 524 . The terminal 502 initiates running the method 100 , may operate the DNA sequencer 530 , and may control the overall operation and output human readable information. Following software commands the computer 508 runs the methods 100 and 200 using its processor. It is to be understood that while the figures and the above description illustrate the present invention, they are exemplary only. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. Others who are skilled in the applicable arts will recognize numerous modifications and adaptations of the illustrated embodiments that remain within the principles of the present invention. Therefore, the present invention is to be limited only by the appended claims. Publications that may be relevant to the present invention include the following which are hereby incorporated by reference for all purposes: Avani Wildani, Ian Adams, Ethan L. Miller, Single-Snapshot File System Analysis, Proceedings of the 21st IEEE International Symposium on Modeling, Analysis, and Simulation of Computer and Telecommunication Systems (MASCOTS 2013), August 2013. [Prediction and Grouping]. Ian Adams, Mark W. Storer, Avani Wildani, Ethan L. Miller, Brian Madden, Validating Storage System Instrumentation, Proceedings of the 21st IEEE International Symposium on Modeling, Analysis, and Simulation of Computer and Telecommunication Systems (MASCOTS 2013), August 2013. [Archival Storage] [Tracing and Benchmarking]. Aleatha Parker-Wood, Brian Madden, Michael McThrow, Darrell D. E. Long, Ian Adams, Avani Wildani, Examining Extended and Scientific Metadata for Scalable Index Designs, Proceedings of the 6th International Systems and Storage Conference (SYSTOR 2013), June 2013. [Scalable File System Indexing] [Dynamic Non-Hierarchical File Systems]. Yangwook Kang, Yang-suk Kee, Ethan L. Miller, Chanik Park, Enabling Cost-effective Data Processing with Smart SSD, the 29th IEEE Symposium on Massive Storage Systems and Technologies (MSST 13), May 2013. [Storage Class Memories]. Hsu-Wan Kao, Jehan-Francois Paris, Darrell D. E. Long, Thomas Schwarz, A Flexible Simulation Tool for Estimating Data Loss Risks in Storage Arrays, 29th IEEE Symposium on Massive Storage Systems and Technologies, May 2013. [Archival Storage] [Reliable Storage]. Avani Wildani, Ethan L. Miller, Ohad Rodeh, HANDS: A Heuristically Arranged Non-Backup In-line Deduplication System, Proceedings of the 29th IEEE International Conference on Data Engineering (ICDE 2013), April 2013. [Deduplication] [Prediction and Grouping]. Yan Li, Nakul Dhotre, Yasuhiro Ohara, Thomas Kroeger, Ethan L. Miller, Darrell D. E. Long, Horns: Fine-Grained Encryption-Based Security for Large-Scale Storage, Proceedings of the 11th Conference on File and Storage Systems (FAST 2013), February 2013. [Secure File and Storage Systems] [Ultra-Large Scale Storage]. James Plank, Kevin Greenan, Ethan L. Miller, Screaming Fast Galois Field Arithmetic Using Intel SIMD Extensions, Proceedings of the 11th Conference on File and Storage Systems (FAST 2013), February 2013. Thomas Schwarz, Ignacio Corderi, Darrell D. E. Long, Jehan-Francois Paris, Simple, Exact Placement of Data in Containers, Proceedings of the International Conference on Computing, Networking and Communications (ICNC), January 2013. [Scalable File System Indexing] [Dynamic Non-Hierarchical File Systems] Rekha Pitchumani, Andy Hospodor, Ahmed Amer, Yangwook Kang, Ethan L. Miller, Darrell D. E. Long, Emulating a Shingled Write Disk, Proceedings of the 20th IEEE International Symposium on Modeling, Analysis, and Simulation of Computer and Telecommunication Systems (MASCOTS 2012), August 2012. [Shingled Disk]. Ziqian Wan, Alex Nelson, Tao Li, Darrell D. E. Long, Andy Hospodor, Computer Hard Drive Geolocation by HTTP Feature Extraction, Technical Report UCSC-SSRC-12-04, May 2012. Technical Report UCSC-S SRC-12-04 [Digital Forensics]. Thomas Schwarz, Qin Xin, Ethan L. Miller, Darrell D. E. Long, Andy Hospodor, Spencer Ng, Disk Scrubbing in Large Archival Storage Systems, Proceedings of the 12th International Symposium on Modeling, Analysis, and Simulation of Computer and Telecommunication Systems (MASCOTS '04), October 2004, pages 409-418. Won Best Paper award. [Archival Storage] [Reliable Storage] [Ultra-Large Scale Storage]. Andy Hospodor, Ethan L. Miller, Interconnection Architectures for Petabyte-Scale High-Performance Storage Systems, Proceedings of the 21st IEEE/12th NASA Goddard Conference on Mass Storage Systems and Technologies, April 2004, pages 273-281. [Ultra-Large Scale Storage]. Ewing B, Hillier L, Wendl M C, Green P (1998). “Base-calling of automated sequencer traces using phred. I. Accuracy assessment”. Genome Res. 8 (3): 175-185. Ewing, Green (1998). “Base-calling of automated sequencer traces using phred. II. Error probabilities”. Genome Res. 8 (3): 186-194. doi:10.1101/gr.8.3.186. PMID 9521922. Dear S, Staden R (1992). “A standard file format for data from DNA sequencing instruments”. DNA Seq. 3 (2): 107-110. doi:10.3109/10425179209034003. PMID 1457811. Bonfield J K, Staden R (25 Apr. 1995). “The application of numerical estimates of base calling accuracy to DNA sequencing projects”. Nucleic Acids Res. 23 (8): 1406-1410. doi:10.1093/nar/23.8.1406. PMC 306869.PMID 7753633. Churchill G A, Waterman M S (September 1992). “The accuracy of DNA sequences: estimating sequence quality”. Genomics 14 (1): 89-98. doi:10.1016/S0888-7543(05)80288-5. PMID 1358801; Genome Biology 2011, 12:R112. E. Green 1998 “Base-calling of automated sequencer traces using phred. II. Error probabilities”; Genome Research 8: 186-194. The present invention may be defined, but not limited, by the following claims.

A new method for encoding genomic data that reduces storage footprint by two orders of magnitude while preserving acceptable quality data.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal connecting device which ensures ease and efficiency in performing electrical or other connection operations. 2. Description of the Background Art To facilitate understanding of the present invention, conventional type terminal connectors will be described below with reference to FIGS. 9-11. FIG. 9 is a sectional plan view of a part of a conventional terminal connector disclosed in Japanese Unexamined Utility Model Publication No. 50-5160. FIG. 10 is a sectional front view of a part of the terminal connector shown in FIG. 9. It should be noted that FIG. 9 is a sectional view of the terminal connector taken along line 9--9 in FIG. 10, and FIG. 10 is a sectional view of the terminal connector taken along line 10--10 in FIG. 9. In FIGS. 9 and 10, reference numeral 801 designates a case for an apparatus on which the terminal connector is mounted while reference numeral 802 designates a meandering or snake-like spring of which opposite ends are supported by the case 801. Reference numeral 803 designates a terminal screw which is supported by the spring 802 at a central part thereof so as to be displaceable in the vertical direction as shown in FIG. 10. It should be noted that the terminal screw 803 is illustrated as divided, at an intermediate position, between a head portion and a male-threaded portion 803a. Reference numeral 804 designates a wire retainer for holding the object to be connected, reference numeral 805 designates a stationary terminal having a female-threaded hold 805a formed thereon, and reference numeral 806 designates a leaf spring which is received in an annular groove 801a for urging the stationary terminal 805 vertically upward. A process for fastening and connecting a round type crimp terminal to the conventional terminal connector, as shown in FIGS. 9 and 10, is described hereinafter. First, to ensure that the terminal screw 803 is inserted through a hole of the round type crimp terminal, the terminal screw 803 is loosened so that it is disengaged from the stationary terminal 805. With the terminal screw 803 in a disengaged state, a gap is created between the male-threaded portion 803a and the stationary terminal 805, the gap being wider than at least one plate thickness of the stationary terminal 805. Next, the round type crimp terminal is inserted into the terminal connector such that a hole of the round type crimp terminal is aligned with and located at a position between the male-threaded portion 803a of the terminal screw 803 and the female-threaded hole 805a of the stationary terminal 805. Subsequently, when the terminal screw 803 is rotationally displaced vertically downward with the aid of a thread tightening tool (e.g., a screwdriver) so that it is threadably engaged with the female-threaded hold 805a of the stationary terminal 805, the round type crimp terminal is immovably fastened and connected to the stationary terminal 805. FIG. 11 is a sectional front view of a part of another conventional terminal connector as disclosed in Japanese Unexamined Utility Model Publication No. 59-177176. In FIG. 11, reference numeral 1001 designates a case for an apparatus on which the terminal connector is mounted, reference numeral 1002 designates a stationary terminal which is fixedly secured to the case 1001, reference numeral 1003 designates a coil spring, of which the upper end is held on the case 1001 and the lower end is suspended toward a female-threaded hold 1002a of the stationary terminal 1002, and reference numeral 1004 designates a terminal screw. It should be noted that the terminal screw 1004 includes a spring washer 1006 and a washer 1007 each being undetachably interposed between a head portion 1004a and a male-threaded portion 1004b. The lower end of the coil spring 1003 is fitted over an annular recess 1004c formed concentrically about the head portion 1004a of the terminal screw 1004 such that the male-threaded portion 1004b of the terminal screw 1004 is suspended toward the female-threaded hole 1002a of the stationary terminal 1002. A process for connecting a round type crimp terminal to the conventional terminal connector, as shown in FIG. 11, is described hereinafter. As shown in FIG. 11, when the terminal screw 1004 is disengaged from the stationary terminal 1002, the male-threaded portion 1004b of the terminal screw 1004 is suspended in spaced relationship relative to the stationary terminal 1002 by a distance greater than at least one plate thickness of the round type crimp terminal. Next, the round type crimp terminal is inserted into the region located between the male-threaded portion 1004b of the terminal screw 1004 and the stationary terminal 1002 such that a hole of the round type crimp terminal positionally coincides with the female-threaded hole 1002a of the stationary terminal 1002. As the terminal screw 1004 is displaced downwardly against the contracting force of the coil spring 1003, to be threadably fitted into the female-threaded hole 1002a of the stationary terminal 1002, the round type crimp terminal is fastened and connected to the stationary terminal 1002. Where an open end type crimp terminal is to be fastened and connected to the conventional terminal connector, as shown in FIGS. 9 and 10, the terminal screw 803 is only slightly threaded into the female-threaded hold 805a of the stationary terminal 805, the open end type crimp terminal is inserted in the hollow space between the wire retainer 804 and the stationary terminal 805, and the terminal screw 803 is then displaced further in the downward direction so that it is secured to the stationary terminal 805. Where one end of a cable, e.g., a naked wire, is to be connected, the terminal screw 803 is slightly threaded into the female-threaded hole 805a of the stationary terminal 805 in the same manner as described above. Then, while the foregoing threadably engaged state is maintained, the naked wire is inserted into the hollow space between the wire retainer 804 and the stationary terminal 805, and the terminal screw 803 is then displaced further in the downward direction until the naked wire is immovably secured to the stationary terminal 805. When an open end type crimp terminal or a naked wire is to be immovably fastened and connected to the conventional terminal connector, as shown in FIG. 11, it can be fastened and connected in the same manner as described above with respect to the conventional terminal connector shown in FIGS. 9 and 10. With the conventional terminal connector, as shown in FIGS. 9 and 10, the male-threaded portion 803a of the terminal screw 803 is typically difficult to position so as to coincide with the female-threaded hole 805a of the stationary terminal 805 as the terminal screw 803 and spring 802 are displaced downwardly toward the female-threaded hole 805a of the stationary terminal 805. In such a case, the terminal screw 803 must be displaced, by hand, in the horizontal (left or right) direction until the male-threaded part 803a of the terminal screw 803 positionally coincides with the female-threaded hole 805a of the stationary terminal 805. Thus, with the conventional apparatus, it is extremely difficult to achieve the proper alignment for fastening. Furthermore, the conventional terminal connector, as shown in FIG. 11, suffers from the same problems as noted above with respect to the conventional terminal connector shown in FIGS. 9 and 10. SUMMARY OF THE INVENTION The present invention has been made in consideration of the aforementioned problems, and its objective resides in providing a terminal connecting device in which a male-threaded portion of the terminal screw is easily positioned to coincide with the female-threaded hole of a stationary terminal, and moreover, which assures that a fastening operation is simply and efficiently performed. In first through ninth embodiments of the present invention, a terminal connector is provided having a stationary terminal with a female-threaded hole formed thereon, a supporting member including a stationary portion and a side wall, the stationary portion serving to immovably hold the stationary terminal, a terminal screw including a male-threaded portion adapted to be threadably engaged with the female-threaded hole of the stationary terminal, a terminal screw guiding member for guiding displacement of the terminal screw while the terminal screw guiding member is engaged with the terminal screw, the position of the terminal screw guiding member being determined such that the male-threaded portion of the terminal screw positionally coincides with the female-threaded hole of the stationary terminal, and at least one elastic member of which one end is supported by the side wall and the other end is fixedly secured to or engaged with the terminal screw or the terminal screw guiding member, the elastic member serving to hold the terminal screw and the terminal thread guiding member so as to form a gap or a hollow space between the male-threaded portion of the terminal-screw and the female-threaded hole of the stationary terminal. Preferably, the elastic member and terminal screw guiding member are integrally formed. The side wall is preferably provided with an engaging portion and the terminal screw guiding member is preferably provided with an engaged portion so that the terminal screw is held against the resilient force of the elastic member at the position where the male-threaded portion of the terminal screw abuts or is in close proximity with the female-threaded hole of the stationary terminal. When the engagement portion on the side wall is brought into engagement with the engaged portion of the terminal screw guiding member, the terminal screw is held against the resilient force of the elastic member such that the male-threaded portion of the terminal screw comes in contact with the female-threaded hole of the stationary terminal or the former is located in close proximity to the latter. When the terminal connecting device is released from the foregoing engaged state, a gap or a hollow space is formed between the male-threaded portion of the terminal screw and the female-threaded hole of the stationary terminal. In tenth through twenty-first embodiments of the present invention, the terminal connecting device (e.g., for use with a magnetic contactor) includes at least one holder for retaining the terminal screws in proper alignment with the female threaded terminal, the holder being displaceable in the same two positions as described above or, alternatively, in a third, different position. In these embodiments, the elastic member described above is entirely unnecessary as the holder is in sliding/frictional engagement with the body of the terminal connecting device and includes at least one resilient member preferably including a latch mechanism for securing the holder in either of the two positions described above. Finally, the holder may be employed with a series of terminal screws or, alternatively, with each individual terminal screw. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary, sectional, front view of a terminal connecting device in accordance with a first embodiment of the present invention. FIG. 2 is a fragmentary, sectional, plan view of the terminal connecting device in FIG. 1 as seen from above. FIG. 3 is a fragmentary, sectional, side view of the terminal connecting device in FIG. 1 as seen from one side. FIG. 4 is a fragmentary, sectional, front view similar to FIG. 1, particularly illustrating that an engagement portion on a side wall is engaged with an engaged portion on a terminal screw guiding member. FIG. 5. is a fragmentary, perspective view of the terminal connecting device shown in FIG. 1, particularly illustrating the structure of a terminal screw guiding unit for the terminal connecting device. FIG. 6 is a fragmentary, perspective view of a terminal connecting device in accordance with a second embodiment of the present invention, particularly illustrating a terminal screw guiding unit for the terminal connecting device. FIG. 7 is a fragmentary, perspective view of a terminal connecting device in accordance with a third embodiment of the present invention, particularly illustrating the structure of a terminal screw guiding unit for the terminal connecting device. FIG. 8 is a fragmentary, sectional, front view of a terminal connecting device in accordance with a ninth embodiment of the present invention. FIG. 9 is a fragmentary, sectional, plan view of a conventional terminal connector as seen from above. FIG. 10 is a fragmentary, sectional, front view of the same conventional terminal connector shown in FIG. 9. FIG. 11 is a fragmentary, sectional, front view of a second, conventional terminal connector. FIG. 12 is a sectional view (illustrating a first position) taken along the plane A--A of FIG. 13 which shows the top surface of a magnetic contactor and which relates to a tenth preferred embodiment of the present invention. FIG. 13 is a plan view of the magnetic contactor of the tenth preferred embodiment of the present invention. FIG. 14 is a view in the direction of arrow B in FIG. 13. FIG. 15 is a perspective view of a holder of the tenth preferred embodiment of the present invention. FIG. 16 illustrates the holder in a second position in which the terminal screw front end abuts on an internally threaded hole drilled in the terminal shown in FIG. 12. FIG. 17 is a perspective view of a holder of an eleventh preferred embodiment of the present invention. FIG. 18 is a perspective view of a holder of a twelfth preferred embodiment of the present invention. FIG. 19 is a perspective view of a holder of a thirteenth preferred embodiment of the present invention. FIG. 20 is a perspective view of a holder of a fourteenth preferred embodiment of the present invention. FIG. 21 is a sectional view illustrating the top section of a magnetic contactor which relates to a sixteenth preferred embodiment of the present invention. FIG. 22 is a sectional view taken along the planes P--P, Q--Q and R--R of the terminal section shown in FIG. 21. FIGS. 23(a)-23(b) are perspective view of a terminal screw holder and a cover adjacent to the terminal section shown in FIG. 21. FIG. 24 is a perspective view illustrating the fitting of a terminal screw holder which relates to a seventeenth preferred embodiment of the present invention and which performs identical functions to the holder shown in FIG. 23. FIG. 25 is a perspective view illustrating the fitting of the terminal screw holder which relates to an eighteenth preferred embodiment of the present invention and which performs functions identical to the holder shown in FIG. 23. FIGS. 26(a)-26(d) illustrate the three stable positions of a terminal screw holder and relates to a nineteenth preferred embodiment of the present invention. FIGS. 27(a)-27(c) are perspective views of a terminal screw holder and a terminal screw for which there are three stable positions as shown in the nineteenth preferred embodiment of the present invention. FIG. 28 is a sectional view (illustrating a first position) taken along the plane A--A of FIG. 29 which shows the top surface of a magnetic contactor and is a twentieth preferred embodiment of the present invention. FIG. 29 is a plan view of the magnetic contactor which relates to the twentieth preferred embodiment of the present invention. FIG. 30 is a view in the direction of the arrow B in FIG. 29, illustrating different positions of the terminal screw holder. FIG. 31 is a perspective view of a holder retaining a terminal screw for use with the twentieth preferred embodiment of the present invention. FIG. 32 illustrates a state wherein the holder is in a second position in which a terminal screw front end abuts on an internally threaded hole drilled in the terminal shown in FIG. 28. FIG. 33 illustrates a state, wherein a holder fitting portion, as shown in the twentieth preferred embodiment, is pivoted. DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail hereinafter with reference to the accompanying drawings which illustrate preferred embodiments of the present invention. FIG. 1 is a fragmentary sectional front view of a terminal connecting device in accordance with a first embodiment of the present invention. FIG. 2 is a plan view of the terminal connecting device in FIG. 1, as seen from above. FIG. 3 is a side view of the same. It should be noted that FIG. 3 is the side view of the terminal connecting device as seen in the direction designated by arrow 201 in FIG. 2. In FIGS. 1-3, reference numeral 101 designates a case on which the terminal connecting device is mounted, and reference numeral 102 designates a side wall supported on the case 101 to serve as, e.g., a cover. Reference numeral 103 designates a zigzag shaped spring. An upper support portion 103a of the spring 103 is fitted into a recess 102a of the cover 102. A supporting section is constructed for the terminal connecting device by two components, i.e., the case 101 and the cover 102. Reference numeral 104 designates another zigzag shaped spring opposing the spring 103. An upper supporting portion 104a of the spring 104 is fitted into a recess 102b of the cover 102 for supporting the spring 104. It should be noted that both springs 103 and 104 are preferably formed of an elastic member which expands in the vertical or insertion/removal direction of the terminal screw. As shown in FIG. 2, each of the springs 103 and 104 exhibits an arc-shaped contour as seen from above, and both springs 103 and 104 are arranged such that their arched inside surfaces are opposite one another. It should be noted that the elastic section includes both springs 103 and 104. Reference numeral 105 designates a terminal screw guiding member which is supported by the lower end of the spring 103 and the lower end of the spring 104. Reference numeral 106 designates a terminal screw. The terminal screw 106 includes a head portion 106a, a male-threaded portion 106b and a washer 107 undetachably interposed between the two. In addition, a cable presser or wire retainer 109 is threadably fitted onto the male-threaded portion 106b. The terminal screw 106 is immovably secured to the terminal screw guiding member 105 by fitting the outer peripheral part of the washer 107 into an annular groove 105a of the terminal screw guiding member 105. As is apparent from FIG. 1, the washer 107 is fitted into the annular groove 105a from below. It should be noted that FIG. 2 is a plan view of the terminal connecting device and, for purposes of clarity, does not completely show the terminal screw guiding member 105 or a part of the cover 102 for one of three terminal screws 106. Reference numeral 108 designates a stationary terminal which is supported on the case 101. The stationary terminal 108 is formed with a female-threaded hole 108a to which the terminal screw 106 is to be threadably engaged. While the terminal screw 106 is disengaged from the female-threaded hole 108a, there exists a gap of predetermined width between the male-threaded portion 106 of the terminal screw 106 and the female-threaded hole 108a of the stationary terminal 108. As the terminal screw 106 is displaced downwardly against the resilient force derived from both the springs 103 and 104, as seen in FIG. 1, the male-threaded portion 106b of the terminal screw 106 abuts or slightly engages the female-threaded hole 108a in the stationary terminal 108. Thus, the male-threaded portion 106b of the terminal screw 106 can be threadably engaged with the female-threaded hole 108a of the stationary terminal 108. It should be noted that the downward displacement of the terminal screw guiding member 105 is properly guided by a terminal screw holder guide 99 formed in the side wall or cover 102 such that lowermost end of the male-threaded portion 106 of the terminal screw 106 positionally coincides with the uppermost end of the female-threaded hole 108a of the stationary terminal 108. Reference numeral 102c designates an engaging portion which is disposed on the cover 102 in the form of, e.g., an engaging projection. In addition, reference numeral 105b designates an elastic engaged portion which is disposed on the terminal screw guiding member 105 in the form of, e.g., an elastic forked rod. When the engaging projection 102c is brought in engagement with the forked rod 105b, the lowermost end of the male-threaded portion 106b of the terminal screw 106 abuts or is in close proximity to the uppermost end of the female-threaded hole 108a of the stationary terminal 108. On the contrary, when the forked rod 105b is squeezed in the direction designated by the arrows 202 in FIG. 2, to thereby induce elastic deformation of the forked rod 105b, the rod is disengaged from the projection 102c such that the terminal screw 106 is displaced to the first position in which a gap of predetermined width is formed between the lowermost end of the male-threaded portion 106b of the terminal screw 106 and the uppermost end of the female-threaded hole 108a of the stationary terminal 108. In FIG. 3, the forked rod 105b, represented by solid lines in FIG. 3, is shown in a disengaged position. The dotted lines in FIG. 3 represent an engaged position of the forked rod 105b. FIG. 4 is a fragmentary, sectional, front view of the terminal connecting device of the present invention, particularly illustrating the forked rod 105b of the terminal screw guiding member 105 in engagement with the projection 102c of the cover 102. As long as the projection 102c is engaged with the forked rod 105b, since the lowermost end of the male-threaded portion 106b of the terminal screw 106 is located next to or in the vicinity of the uppermost end of the female-threaded hole 108a, a fastening or connection operation is easily performed with an open end type crimp terminal or a naked connection wire having no terminal. By way of contrast, when the projection 102c is disengaged from the forked rod 105b, a fastening or connection operation is easily performed with a round type crimp terminal. FIG. 5 is a perspective view of the terminal connecting device, particularly illustrating the structure of a terminal screw guiding unit 501 including the springs 103, 104 and the terminal screw guiding member 105. Typically, the springs 103, 104 and the terminal screw guiding member 105 are formed, respectively, of a metallic material. However, they may be molded of an electrical insulating material such as a synthetic resin or the like. FIG. 6 is a fragmentary, perspective view of a terminal connecting device in accordance with a second embodiment of the present invention, particularly illustrating the structure of a terminal screw guiding unit 601 including zigzag-shaped springs 103, 104 and a terminal screw guiding member 105 wherein the forked rod 105b on the terminal screw guiding member 105, as shown in FIG. 5, is removed. In this embodiment, other components may be employed which function in the same manner as those described above with respect to the first embodiment of the present invention. For example, the terminal screw guiding member 105 may be retained in place by force applied by one's hand or simply by friction created between walls of the cover. FIG. 7 is a perspective view of a terminal connecting device in accordance with a third embodiment of the present invention wherein a single coil spring 702 is substituted for the springs 103 and 104 for the terminal screw guiding unit 501 shown in FIG. 5. With a terminal screw guiding unit 701, as shown in FIG. 7, the same advantageous effects as those derived from the first embodiment of the present invention are obtainable. In the foregoing embodiments, the springs 103, 104 and the terminal screw guiding member 105 may be separately fabricated and assembled together. Alternatively, they may be integrally molded from a synthetic resin. In that more preferable construction, designated the fourth embodiment of the invention, production costs are reduced significantly. With the terminal connecting device as constructed in each of the first through fourth embodiments of the present invention, the terminal screw 106 is brought into engagement with the terminal screw guiding member 105 by fitting the outer peripheral edge of an engaging member, e.g., the washer 107, into the annular groove 105a of the terminal screw guiding member 105. However, the present invention should not be limited to this construction. For example, according to a fifth embodiment, the terminal screw 106 may be engaged with the terminal screw guiding member 105 with the same advantageous effects as mentioned above by engaging a projection provided on the terminal screw guiding member 105 with an annular groove formed around the outer peripheral edge of the washer 107. For each of the first through fifth embodiments of the present invention, the terminal screw 106 is engaged with the terminal screw guiding member 105 via a washer 107. However, the present invention should not be limited to this construction. For example, according to a sixth embodiment, the terminal screw 106 may be engaged with the terminal screw guiding member 105, with the same advantageous effects as mentioned above, by engaging a projection or groove provided on the wire retainer 109 with a groove or projection provided on the terminal screw guiding member 105. The terminal screw guiding member 105 constructed in accordance with the first through sixth embodiments may according to a seventh embodiment be rotatably engaged with the washer 107 or the wire retainer 109. In that case, when the terminal screw 106 is threadably tightened, the terminal screw guiding member 105 is prevented from receiving a rotational force due to the frictional forces existing between the terminal screw guiding member 105 and the washer 107 or the wire retainer 109. Thus, even where displacement of the terminal screw guiding member 105 is guided by the cover 102 and where the terminal screw guiding member 105 is not free to turn or rotate, the foregoing arrangement will prevent the terminal screw guiding member 105 and associated components from being damaged or broken as a result of forcible contact between the terminal screw guiding member 105 and the cover 102. According to each of the first through seventh embodiments of the present invention, the terminal screw 106 is engaged with the terminal screw guiding member 105 via the washer 107 or the wire retainer 109. According to an eighth embodiment, the terminal screw 106 may also be engaged with the terminal screw guiding member 105, with the same advantageous effects as mentioned above, by engaging a projection or groove on the head portion 106a of the terminal screw 106 with a groove or projection provided on the terminal screw guiding member 105. According to each of the first through eighth embodiments of the present invention, one end of the springs 103 and 104, or one end of the coil spring 702, is held by the cover 102 while the other end(s) are fixedly secured to the terminal screw guiding member 105. However, the present invention should not be limited to this construction. Alternatively, the other ends may be engaged with the terminal screw 106 so as to support both the terminal screw 106 and the terminal screw guiding member 105. FIG. 8 is a fragmentary, sectional, front view of a ninth embodiment of the present invention. In this embodiment, one end of a coil spring 1202 is immovably held on a cover 1201 while the other end is rotatably fitted into an annular recess 1203b formed around a head portion 1203a of a terminal screw 1203, the terminal screw 1203 being suspended from the coil spring 1202 while a washer 1204, fixedly secured to the terminal screw 1203, is engaged with an annular groove formed in a terminal screw guiding member 1205 to thereby hold the terminal screw guiding member 1205. As the terminal screw 1203 is displaced in the downward direction, as shown in FIG. 8, the displacement of the terminal screw 1205 is guided along a cover 1201 so that the lowermost end of a male-threaded portion 1203c of the terminal screw 1203 coincides with the uppermost end of a female-threaded hole 1206a of a stationary terminal 1206. The terminal connecting device constructed in accordance with the ninth embodiment of the present invention, as shown in FIG. 8, exhibits the same advantageous effects as those of the first through eighth embodiments of the present invention. As is apparent from the above description, a terminal screw is engaged with a terminal screw guiding member adapted to be displaced along a side wall, and the terminal screw or the terminal screw guiding member is supported with the aid of a resilient force derived from one or more elastic members of which one end is supported by the side wall so as to form a gap or a hollow space between the terminal screw and the female-threaded hole of a stationary terminal. With the terminal connecting device constructed as described above, as the terminal screw is displaced toward the female-threaded hole of the stationary terminal, the lowermost end of a male-threaded portion of the terminal screw is maintained in proper alignment with the uppermost end of the female-threaded hole of the stationary terminal. This results in remarkable improvements in the ease and efficiency of performing a fastening or connection operation. In addition, when an engagement portion on the side wall is brought into engagement with an engaged portion on the terminal screw guiding member, the terminal screw can be held against the resilient force of the elastic member at the position where the male-threaded portion of the terminal screw abuts or is in close proximity to the female-threaded hole of the stationary terminal. Thus, while the foregoing engaged state is maintained, a fastening or connecting operation can be performed for the stationary terminal by inserting an open end type crimp terminal or a naked wire into the terminal connecting device. With respect to a round type crimp terminal, while the terminal connecting device is released from the foregoing engaged state, to thereby form a gap of predetermined width between the male-threaded portion of the terminal screw and the female-threaded hole of the stationary terminal, a fastening or connecting operation can be performed for the stationary terminal by inserting the round type crimp terminal into the gap or the hollow space as mentioned above. Consequently, a fastening or connecting operation is easily performed for a wide variety of different terminals. Next, a tenth embodiment of the present invention will be described with respect to FIGS. 12-16. FIG. 13 is a plan view of a magnetic contactor which is just one example of an apparatus in which the following embodiments may be applied. FIG. 12 is a sectional view taken along the plane A--A of FIG. 13. FIG. 14 is a view in the direction indicated by arrow B in FIG. 13. FIG. 15 is a perspective view of a holder. FIG. 16 shows the holder in a second position which is a predetermined distance lower than the position shown in FIG. 12. In these drawings, reference numeral 1 indicates a mounting base, 101 a case, and 3 an exciting coil. Reference numeral 4 indicates a fixed core disposed opposite to a movable core 5, with a predetermined gap therebetween. Reference numeral 6 indicates a crossbar made of an insulating material and connected to said movable core 5. A top window 6a thereof retains a movable contactor 8 which is slidable in a vertical direction as is the crossbar 6 as shown in FIG. 12. Reference numeral 7 indicates a contact spring which is a compression coil spring providing for applying contact pressure to the movable contactor 8. 8a indicates movable contacts mounted at ends of the movable contactor 8 and disposed opposite to stationary contacts 108b with a predetermined contact gap in between. Stationary terminals 108 each include the stationary contact 108b joined at one end thereof and an internally threaded hole 108a bored in the opposite end. 102 indicates a cover for preventing arcs generated between the contacts from escaping. Reference numeral 16 indicates a tripping spring disposed for biasing the joint unit of the crossbar 6 and the movable core 5 upward in FIG. 13. The fundamental structure of the magnetic contactor is identical to that of the background art and need not be discussed further herein. A cable presser 109 is assembled pivotally, as in the conventional art, to a terminal screw 106 provided to be threaded into the internally threaded hole 108a of the stationary terminal 108. 53 indicates a holder made of, for example, a thermoplastic resin, having elastic and insulative properties and shaped as shown in FIG. 15. Since the cable presser 109 is gripped by grippers 53a and 53b of the holder 53, the terminal screw 106 is pivotable with respect to the holder 53 and, since the grippers 53a, 53b are formed of an elastic material, the joint unit of the terminal screw 106 and the cable presser 109 is assembled loadably and unloadably in the axial direction of the screw 106 with respect to the holder 53. As shown in FIG. 14, a pair of V-shaped engagement pieces 53c and 53d are formed in the front face of the holder 53. Engagement bosses 53e and 53f are formed at one corner of the V-shaped engagement pieces 53c, 53d, respectively. Ends 53g, 53h of the V-shaped engagement pieces 53c, 53d are joined to a holder body 53z and other ends thereof 53j, 53k are connected to a latch 53l. Reference numerals 54, 55, 56, 57 and 58 in FIG. 14 indicate barriers formed on the case 101 and disposed to ensure electrical isolation for each phase of the 55a, 55b, 57a, 57b are disposed in the insides of the barriers 55, 57 for engagement with the engagement bosses 53e, 53f of the holder 53. The opening and closing operations of the magnetic contactor will not be described herein as they are not the primary objective of the present invention and, in any event, are assumed to be conventional. The wiring procedure of the terminal connecting device in the present embodiment will be described hereinafter. As above, it is assumed that there are three termination types of cable to be fastened or connected to the terminal of the present invention, i.e., a round solderless terminal, a naked wire or the like, and a beveled solderless terminal. First, the wiring of the round solderless terminal will be described. In FIG. 12, which shows the terminal screws 106 and the holders 53 in a first position, a gap of width "G" is provided between the front end of the terminal screw 106 and the stationary terminal 108. Since this gap is set to be considerably larger than the plate thickness "T" of the solderless terminal, the round solderless terminal can pass through the gap and be inserted into a position where it can be easily connected to the terminal screw 106. By threading the terminal screw 106, i.e., pressing a head 106a of the terminal screw 106 with a screwdriver, the cable presser 109 is released from the grippers 53a, 53b, the terminal screw 106 is moved downward as shown in FIG. 12, and the front end of the terminal screw 106 is inserted into the hole of the round solderless terminal and further threaded into the internally threaded hole 108a. The wiring procedure of the wire or the beveled solderless terminal to the terminal connecting device of the present embodiment will now be described, particularly with reference to FIG. 16. In this case, in order to prevent the wire from entering and biting the internally threaded hole 108a of the stationary terminal 108, the holder 53 is lowered to a position where the front end of the terminal screw 106 abuts on the stationary terminal 108. That is, the holder 53 is moved downward from the position shown in FIG. 12, to a second position as shown in FIG. 16. This movement is achieved by holding down the latch 53l of the holder 53 in the direction of the arrow "Y" in FIG. 14 or FIG. 15 and pushing down the holder 53, i.e., the movement of the latch 53l in the direction of the arrow "Y" causes the V-shaped engagement pieces 53c, 53d to pivot on the ends 53g, 53h of the V shapes as indicated by the broken lines and the arrows Z1, Z2, the engagement bosses 53e, 53f of the holder 53 thereby being disengaged from the barrier grooves 55a, 57a, respectively. By pushing the holder 53 down, the engagement pieces 53c, 53d are returned to their original states due to the elasticity of the holder material, which then causes the engagement bosses 53e, 53f of the holder 53 to be engaged with the barrier grooves 55b, 57b, and the holder 53 and the terminal screw 106 to be fastened with the front end of the terminal screw 106 abutting on, or slightly entering the internally threaded hole 108a. By inserting the wire or the beveled solderless terminal under the cable presser 109 in said engagement state, i.e., in the second position, and tightening the terminal screw 106, the wiring is completed. At this point in time, the joint unit of the terminal screw 106 and the cable presser 109 is released from the grippers 53a, 53b of the holder 53 and threaded into the internally threaded hole 108a of the stationary terminal 108 as described previously in the wiring of the round solderless terminal. To return from the second position in FIG. 16 to the upper position (first position) in FIG. 12, the engagement bosses 53e, 53f are simply disengaged from the barrier grooves 55b, 57b by moving the latch 53l in the direction of the arrow "Y" in FIG. 14 or FIG. 15 while simultaneously moving the holder 53 upward. To return from the state wherein the terminal screw 106 is threaded in the stationary terminal 108 to the state wherein it is gripped by the holder 53, e.g., to change the wiring, etc., the terminal screw 106 may simply be removed (unscrewed) which automatically engages the cable presser 109 with the grippers 53a, 53b. (The dimensions have been set to provide automatic engagement). FIG. 17 is a perspective view of a holder of an eleventh embodiment of the present invention. The general arrangement of the present embodiment will not be described herein since it is identical to that of the tenth lo embodiment described above except with respect to the holder 53 shown in FIG. 17. Referring to FIG. 17, 53 indicates a holder for gripping terminal screws (not shown), cable pressers (not shown), etc., as described in the tenth embodiment. The front face of the holder 53 is provided with a laminar engagement piece 53m which is joined to a holder body 53z of the holder 53 at a center 53n thereof. Also, an engagement boss 53p is formed at the bottom and a latch 53l at the top of the engagement piece 53m. Barrier grooves 56a and 56b engaged with the engagement boss 53p are formed in a center barrier 56, as shown in FIG. 17. Wiring procedures are described hereinafter. In FIG. 17, the engagement boss 53p is engaged with the barrier groove 56a in a first position, i.e., a state compatible with the wiring of the round solderless terminal, and the engagement boss 53p is engaged with the barrier groove 56b in a second position, i.e., a state compatible with the wiring of the naked wire or the like and the beveled solderless terminal. To move the holder 53 between the first and second positions described above, the engagement boss 53p is simply disengaged from the groove 56a or 56b by moving the latch 53l in the direction of the arrow "V" shown in FIG. 17 while simultaneously moving the holder 53 upward or downward. That is, the movement of the latch 53l in the direction of the arrow "V" causes the engagement piece 53m to be flexibly pivoted about the center 53n connected to the holder body 53z, and the engagement boss 53p to move in the direction of the arrow "W" in FIG. 17, thereby accomplishing the disengagement. When the latch 53l is then moved in the direction opposite to the arrow "V", the engagement piece 53m is restored to its original shape due to the elasticity of the holder 53 material, thereby engaging the other groove. Other operations, such as screw tightening, are identical to those of the tenth embodiment described above. FIG. 18 is a perspective view of a holder of a twelfth embodiment of the present invention. The general arrangement of the present embodiment will not be described herein since it is identical to that of the tenth and eleventh embodiments described above, except for the construction of the holder shown in FIG. 18. In FIG. 18, reference numeral 53 indicates a holder for gripping terminal screws (not shown), cable pressers (not shown), etc., as in the tenth and eleventh embodiments. In the front face of the holder 53, a pair of cantilever engagement pieces 53q, 53r are provided with cantilever bases 53s, 53t being connected to the holder body. Also, their cantilever ends are provided with engagement bosses 53u, 53v for engagement with the grooves 55a, 55b, 57a, 57b, etc., as shown in FIG. 14, and are further linked by a flexible bar 53w. Wiring procedures are described hereinafter. In FIG. 18, the movement of a center portion of the flexible bar 53w in the direction of the arrow "Y" causes the bar 53w and the engagement pieces 53q, 53r to be transformed as indicated by the broken line, and the engagement bosses 53u and 53v to move in the directions of the arrows Z1 and Z2, respectively. This disengages the engagement pieces 53u, 53v from the barrier grooves 55a, 57a or the grooves 55b, 57b. In this disengaged state, the holder 53 can be moved upward or downward to the first or second positions. The other operations such as screw tightening are identical to those of the previous embodiments. FIG. 19 is a perspective view of a holder of a thirteenth embodiment of the present invention. The arrangement of the present embodiment will not be described in detail herein since it is identical to that of the tenth through twelfth embodiments except for the construction of the holder as shown in FIG. 19. In FIG. 19, 53 indicates a holder gripping terminal screws (not shown), cable pressers (not shown), etc., as in the previous embodiments. In the front face of the holder 53, a pair of nearly triangular engagement pieces 53c, 53d are formed. On first corners of the nearly triangular pieces, engagement bosses 53e, 53f are formed for engagement with the barrier grooves 55a, 57a or 55b, 57b in FIG. 14, and second corners 53g, 53h are joined in a body 53z of the holder 53. Third corners 53j, 53k are connected with a latch 53l. Wiring procedures are described hereinafter. As described previously with respect to the tenth embodiment, the movement of the latch 53l in the direction of the arrow "Y" causes the engagement pieces 53c, 53d to pivot on the corners 53g, 53h in the directions of the arrows Z1, Z2, respectively, thereby disengaging the engagement bosses 53e, 53f from the barrier grooves 55a, 57a or the grooves 55b, 57b. The subsequent operations are identical to those described above. FIG. 20 is a perspective view of a holder of a fourteenth embodiment of the present invention. While the apparatus of the tenth embodiment grips terminal screws and cable pressers for a plurality of poles, the fourteenth embodiment relates to an apparatus which is designed to include a terminal screw and a cable presser for each pole. That is, a holder 53 grips a terminal screw 106 and a cable presser 109 for a single pole, and a pair of V-shaped engagement pieces 53c and 53d are formed in the front face thereof. Engagement bosses 53e and 53f are formed at the crossings of the V shapes of the engagement pieces 53c, 53d. Ends 53g, 53h of the V shapes are connected to a holder body 53z and other ends thereof 53j, 53k are joined to a latch 53l . The holder 53 shown in FIG. 20 is disposed in each pole. The wiring procedures of the fourteenth embodiment are omitted because they are identical to those described above except that the wiring is conducted for each individual pole. In the fifteenth embodiment, the terminal screw 106 retained by the holder 53 via the cable presser 109, as in the tenth to fourteenth embodiments, is retained in a manner as described in the first, fifth, sixth and eighth embodiments. A sixteenth embodiment of the present invention will now be described with reference to FIGS. 21 to 23. FIG. 21 is a sectional view of the top section of a magnetic contactor showing the cross section of the terminal section taken along the plane "Y" of FIG. 22, on the left-hand side, with the cross section thereof taken along the plane "X", on the right-hand side. FIG. 22 is a sectional view of the terminal section in FIG. 21 taken along the planes P--P, Q--Q and R--R from top to bottom, respectively. FIG. 23 is a perspective view of a terminal screw holder and a cover adjacent to the terminal section shown in FIG. 21. In the above mentioned drawings, reference numeral 50 indicates a terminal screw holder which is slidable in the vertical direction along the cover 102, the holder 50 having two stable positions and being formed of thermoplastic or the like for insulative and elastic properties. Reference numeral 50a indicates grippers for gripping a cable presser 109, reference numeral 50b a positioning projection which enters a recess provided by positioning projections 102b of the cover 102, or the fitting portion with the cover 102, for creating the stable position, and 50c a sliding projection which fits into a recess created by a sliding projection 102c of the cover 102, or the fitting portion of the cover 102. When a terminal screw 106 is retained by the terminal screw holder 50 as shown in FIG. 21, the terminal screw 106 is pivotable, and the holder 50 has a hole into which a screwdriver or other tool (not shown) for threading the terminal screw 106 is inserted. The two lower poles of FIG. 22 show the cross sections of the terminal screw holder 50 and the cover 102, wherein the sliding projections 102c and 50c are slidably interconnected or meshed. Also, as shown in FIG. 23, a contact surface 50d of the terminal screw holder 50 abuts a contact surface 102d of the cover 102 to thereby prevent the terminal screw holder 50 from being removed from the cover 102. The terminal screw holder 50 is provided with two stable positions in the sliding direction by the positioning projections 102b of the cover 102 and the positioning projection 50b of the holder 50. In the first position, a gap is provided between the front end of the terminal screw 106 and a stationary terminal 108 having an internally threaded hole 108a. In the second position, the front end of the terminal screw 106 abuts or is in close proximity to the internally threaded hole 108a of the stationary terminal 108. The above described sliding and positioning portions are provided within the deep recesses of the terminal section. In the present embodiment, the sliding projection 102c and the contact surface 102d constitute a holder mounting section. The wiring procedures of the terminal in the embodiment shown in FIGS. 21-23 are described hereinafter. Being identical to those of the prior art, the opening and closing operations of the magnetic contactor will not be described. It is assumed that there are three termination types of cable, as described above, a round solderless terminal, a wire and a beveled solderless terminal. First, the wiring of the round solderless terminal will be described. In FIG. 21, which shows the terminal screws 106 and holders 53 in the first position, a gap "G" is provided between the front end of the terminal screw 106 and the stationary terminal 108. Since this gap is set to be at least larger than the plate thickness "T" of the solderless terminal, the round solderless terminal can pass through the gap and into the proper alignment with the terminal screw 106. The terminal screw holder 50 may then be slid by hand or with a screwdriver to the second position (where the front end of the terminal screw 106 abuts on the stationary terminal 108), the front end of the terminal screw 106 then being inserted into the hole of the round solderless terminal. After that, the terminal screw 106 may be threaded into the internally threaded hole 108a. This completes the wiring procedure. The wiring procedures for the naked wire or beveled solderless terminal to the terminal connecting device of the present embodiment are described hereinafter. In this case, in order to prevent the wire from entering and biting the internally threaded hole 108a of the stationary terminal 108, the terminal screw holder 50 is lowered into a position where the front end of the terminal screw 106 abuts on the stationary terminal 108, i.e., the terminal screw holder 50 is moved downward from the state of FIG. 21, whereby it is set to the second position shown in FIG. 26(a). In particular, by pushing the terminal screw holder 50, the terminal screw 106 connected thereto moves downward with the terminal screw holder 50 along the sliding portion of the cover 102. At this time, the projection 50b goes beyond one of the positioning projections 102b and settles in the second stable position where the front end of the terminal screw 106 abuts on or slightly enters the internally threaded hole 108a. By inserting the wire or the beveled solderless terminal under the cable presser 109 and tightening the terminal screw 106, the wiring procedure is completed. When the product is set to the second position as, for example, before shipment, the naked wires or beveled solderless terminals can be pre-wired. For the wiring of the round solderless terminals, the movement of the terminal screw holder 50 retaining the terminal screw 106 to said first position allows the cable to be wired with little effort in a "hands off" manner. A seventeenth embodiment will now be described using FIGS. 24 and 25. The present embodiment functions identically to the embodiment shown in FIGS. 21-23, but is different in that the sliding portions and positioning portions are provided not on the cover 102 but rather on a case 101 between the poles or on a barrier 101a of the case 101. The numerals 51, 51a, 51b, 51c and 51d correspond to 50, 50a, 50b, 50c and 50d of FIG. 23. Reference numerals 101b, 101c and 101d correspond to reference numerals 102b, 102c and 102d of FIG. 23 provided on the case 101 or the barrier 101a of the case 101. With this construction, identical functions can be accomplished without the cover 102. It should be noted that reference numerals 101b, 101c and 101d refer to both sides of the stationary terminal 108, although they are only shown on one side thereof. The terminal screw 106 retained by the holder 50 via the cable presser 109 in the sixteenth and seventeenth embodiments may also be retained in a manner as described in the first, fifth, sixth and eighth embodiments. A nineteenth embodiment having three stable positions for a terminal screw holder will now be described in accordance with FIGS. 26 and 27. FIGS. 26(a)-26(d) show an operation principle diagram, FIG. 27(a) and (b) are perspective views of a terminal screw holder according to the present embodiment, and FIG. 27(c) is a perspective view of a terminal screw. In these drawings, 60 indicates a terminal screw holder made of thermoplastic or the like having insulative and elastic properties, 60a an annular retaining ledge, 60b a positioning ledge fit into positioning grooves 101e provided in a barrier 10a of a case 101 for establishing the first and second stable positions, 60c a sliding protrusion, 60e a positioning retainer fitted into a positioning groove 101f provided in the barrier 101a of the cover 101 for determining and retaining a third stable position, 106 a terminal screw, 106c an annular retaining groove provided in a head 106a of the terminal screw 106, fitted to the annular retaining ledge 106a formed on the terminal screw holder 60, and retained by the terminal screw holder 60, 106d a guide slit which permits the retaining groove 106c to fit into the retaining ledge 60a when the terminal screw 106 enters the terminal screw holder 60, and 109 a cable presser. In addition, since, when retained by the terminal screw holder 60, the terminal screw 106 is held by the annular retaining groove 106c provided in the head 106a of the terminal screw 106 and the annular retaining ledge 60a provided on the terminal screw holder 60, the terminal screw 106 is pivotable, easily inserted into the terminal screw holder 60, and retained firmly and securely. FIG. 26(a) shows the second position described in FIGS. 21 to 23 where the front end of the terminal screw 106 abuts on or has slightly entered the internally threaded hole 108a, FIG. 26(b) the first position described in FIGS. 21 to 23 where a gap is provided between the front end of the terminal screw 106 and the stationary terminal 10, FIG. 26(c) a state wherein the terminal screw 106 has been tightened, and FIG. 26(d) a state wherein the retaining groove 106c has just fit to the retaining ledge 60a by loosening the terminal screw 106 in the state of FIG. 26(c), or wherein the terminal screw holder 60 has come to the third stable position by tightening the terminal screw 106 several turns from the state of FIG. 26(a). The positioning structure of the first and second positions of the terminal screw holder 60 is virtually identical to that shown in FIGS. 21 to 23. Wiring procedures will be described hereinafter. FIGS. 26(a) and 26(b) will not be described because they have been explained with respect to the first and second positions. When the terminal screw 106 is tightened in the state of FIG. 26(a), the large fitting force of the retaining groove 106c and the retaining ledge 60a causes the positioning ledge 60b to go beyond the positioning groove 101e provided in the barrier 101a of the case 101, and the terminal screw holder 60 to be lowered together with the terminal screw 106. When the terminal screw 106 is tightened several turns, the positioning gripper 60e fits into the positioning groove 101f as shown in FIG. 26(d), and at the same time, the terminal screw holder 60 comes into contact with the barrier 101a of the case 101 and is stopped at the third stable position. When the terminal screw 106 is further tightened, the extremely large thrust force of the screw causes the retaining groove 106c to be disengaged from the retaining ledge 60a, only the terminal screw 106 to move downward, and the screw to be fully tightened as shown in FIG. 26(c). Conversely, when the terminal screw 106 is loosened in the state of FIG. 26(c), the retaining force of the positioning gripper 60e and the positioning groove 101f, which is designed to be greater than the fitting force of the positioning ledge 60b and the positioning groove 101e and also to be larger than the force required for the fitting of the retaining groove 106c and the retaining ledge 60a, causes the terminal screw holder 60 to stay in the third stable position until the retaining groove 106c fits onto the retaining ledge 60a, as shown in FIG. 26(d). When the terminal screw 106 is further loosened, the thrust force of the screw disengages the positioning gripper 60e from the positioning groove 101f as shown in FIG. 26(a). As described above, the installation and removal of the terminal screw 106 to and from the terminal screw holder 60 are rendered reproducible for the tightening and loosening operations of the screw. In addition, the provision of the guide slit 106d allows the terminal screw 106 to enter the terminal screw holder 60 more smoothly. A twentieth embodiment of the present invention will now be described on the basis of FIGS. 28 to 32. FIG. 29 is a plan view of a magnetic contactor, and FIG. 28 is a sectional view taken along the plane A--A of FIG. 29, showing only the top section. FIG. 30 is a view seen in the direction of the arrow "B" in FIG. 29, FIG. 31 is a perspective view of a holder, and FIG. 29 shows a state wherein the holder has been moved to a position (second position), a predetermined distance lower than the position of FIG. 28. In these drawings, a cable presser 109 is assembled pivotally, as in the prior art, to a terminal screw 106 disposed to be threaded into an internally threaded hole 108a of a stationary terminal 108. A ledge 106e for pivotable engagement with a holder 70 is provided on a screw head 106a. The holder 70 is made of a material, such as thermoplastic resin, having elastic and insulative properties, the terminal screw 106 including a recess 70a for retaining the terminal screw 106 pivotally, and the terminal screw 106 and the holder 70 being joined and fixed with the ledge 106e as, for example, by press-fitting, etc. A gap is provided between the terminal screw 106 and the holder 70 so that the terminal screw 106 is secured pivotally. The joined state of the holder 70 and the terminal screw 106 is shown in FIG. 31. Reference numeral 102e indicates a nearly U-shaped holder fitting portion molded integrally with a cover 102 and made of a material, e.g., thermoplastic resin, having elastic and insulation properties. The holder fitting portion has guide grooves 102f, 102g in two opposing surfaces where projections 70b, 70c , provided on the outer periphery of the holder 70, fit slidably. An engagement projection 70d provided under the projection 70b is fastened in a recess 102h or 102i formed in the guide groove 102f of the holder fitting portion 102e. The lower recess 102i (on the right-hand side in FIG. 30) is longer than the upper recess 102h for fastening in the first position (on the left-hand side in FIG. 30) so that the engagement projection 70d of the holder 70 may fit recess 102i while the terminal screw 106 is threaded into the internally threaded hole 108a of the stationary terminal 108 and may move upward (left in FIG. 30) when the front end of the terminal screw 106 abuts on the internally threaded hole 108a of the stationary terminal 108. There is also provided a holder operating portion 70e, which is in parallel with a surface having the guide groove 102f of the holder fitting portion 102e, at right angles with the projection 70b provided on the outer periphery of the holder 70. The top surface of the holder fitting portion 102e includes an insertion hole 102j for inserting a screwdriver or other tool (not shown) which is employed to thread the terminal screw 106. Further, 102k (See FIG. 33) indicates a connected portion of the cover 102 and the holder fitting portion 102e, which is elastic and can be bent such that the holder fitting portion 102e is pivotable about the connected portion 102k. In FIG. 30, 102l indicates an engagement boss provided on the holder fitting portion 102e which fits into and is engaged with a recess 101e in the case 101 and generally fastens the holder fitting portion 102e to the case 101. The procedures of wiring the terminal connecting device of the present embodiment will be described hereinafter. It is assumed that there are three types of cable terminals to be connected to the terminal connecting device, a round solderless terminal, a naked wire or the like and a beveled, solderless terminal. First, the wiring of the round solderless terminal will be described. In FIG. 28, which shows the terminal screws 106 and the holder 70 in a first position, a gap "G" is provided between the front end of the terminal screw 106 and the stationary terminal 108. Since this gap is set to be at least larger than the plate thickness "T" of the round solderless terminal, the round solderless terminal can pass through said gap into alignment with the terminal screw 106, the terminal screw 106 thereafter being threadably engaged with the female threaded hole of the stationary terminal 108. In particular, by pressing the head 106a of the terminal screw 106 with a screwdriver or the like, the engagement projection 70d of the holder 70 escapes from the recess 102h of the holder fitting portion 102e and is moved downward along with the holder 70, the front end of the terminal screw 106 thereby being inserted into the hole 108a of the round solderless terminal and further threaded therein. This completes the wiring procedure. The wiring procedure of the wire or the beveled solderless terminal to the terminal connecting device of the present embodiment will be described hereinafter. In this case, in order to prevent the wire from entering and biting the internally threaded hole 108a of the stationary terminal 108, the holder 70 is lowered to a position where the front end of the terminal screw 106 abuts on the stationary terminal 108. Namely, as shown in FIG. 28, by pushing the terminal screw 106 downward, the holder 70 joined thereto also moves downward. At this time, the engagement projection 70d of the holder 70 escapes from the recess 102h, moves downward within the guide groove 102f, and is fastened in a position where it fits in the upper side (left-hand side) of the recess 102i, i.e., in wherein the front end of the terminal screw 106 is abutting on or has slightly entered the internally threaded hole 108a. By inserting the wire or the beveled solderless terminal under the cable presser 109 and tightening the terminal screw 106 in this state, i.e., in the second position, the wiring procedure is completed. The above described tightening causes the engagement projection 70d of the holder 70 to escape from the recess 102i and move downward. Since the recess 102i is formed so that the terminal screw 106 may escape by the thrust force of the terminal screw rotation after the same is only slightly threaded into the internally threaded portion 108a, as shown in FIG. 30, the terminal screw 106 need not be pushed down and can be tightened smoothly without significant resistance. To return from the position, as shown in FIG. 32 and at the top of FIG. 30, to the upper position, as shown in FIG. 28 and in the middle of FIG. 30, the holder operating portion 70e is moved upward, or left in FIG. 30. This causes the guide groove 102f of the holder fitting portion 102e to widen in the direction of the arrow "C" shown in FIG. 30, and the engagement projection 70d of the holder 70 to escape from the recess 102i and move upward, left in FIG. 30, whereby the holder 70 is returned to the state shown in FIG. 28 and in the middle of FIG. 30, i.e., the first position. When the terminal screw 106 is loosened from a completely tightened position (not shown), the engagement projection 70d of the holder 70 is positioned into the recess 102i of the holder fitting portion 102e by the thrust force of the terminal screw 106 slightly before it is released from the internally threaded hole 108a. Hence, the terminal screw 106 is loosened smoothly and efficiently. As described above, the terminal connecting device of the present embodiment includes the engagement projection 70d of the holder 70 and the recesses 102h, 102i of the holder fitting portion 102, etc., so that holder 70 may be fastened in two positions, the first position where the front end of the terminal screw 106 is located a predetermined distance away from the surface of the stationary terminal 108, and the second position where the front end of the terminal screw 106 abuts on the internally threaded hole 108a bored in the stationary terminal 108. Since the holder 70 can be readily and reliably fastened in these two positions, the holder 70 and the terminal screw 106 can be preset to either of said two positions depending on the termination type of the cable, and further workability is much improved. In displacing the holder operating portion 70e upwardly, the holder operating portion 70e, which is in parallel with the surface having the guide groove 102f of the holder fitting portion 102e, allows the inclination of the holder 70 (in the direction of the arrow "D" shown in FIG. 28) to be reduced if the uplifting force is applied at a point distant from the center of the terminal screw 106, the holder 70 and the terminal screw 106 being lifted smoothly. As described above, the holder operating portion 70e is designed to be in parallel with the surface including the guide groove 102f of the holder fitting portion 102e and at right angles with the projection 70b of the holder 70. When the holder 70 is moved in the vertical direction, therefore, its inclination is reduced and the holder 70 can be lifted smoothly. The wiring procedure of the round solderless terminal 22 to the terminal connecting device of the present embodiment will now be described with reference to FIGS. 30 and 33. Pushing up the holder operating portion 70e, left in FIG. 30, disengages the engagement boss 102l of the holder fitting portion 102e from the recess 101e of the case 101, whereby the holder fitting portion 102e can be bent as shown in FIG. 33 at the joint portion 102k of the cover 102 and the holder fitting portion 102e. After inserting the terminal screw 106 into the hole of the round solderless terminal 22, the entire assembly is returned to the original position. This engages the engagement boss 102l of the holder fitting portion 102e with the recess 101e of the case 101 as shown in FIG. 28. Thereafter, the wiring is completed by performing the threading work as described above. With the holder fitting portion 102e pivoted as shown in FIG. 33, the holder 70 can be fastened by the engagement projection 70d of the holder 70 and the recess 102h or 102i of the holder fitting portion 102e, thereby keeping the holder 70 from falling off the holder fitting portion 102e. Also, since the projections 70b, 70c of the holder 70 fit into and are engaged with the guide grooves 102f, 102g of the holder fitting portion 102e, respectively, the holder 70 does not rotate, is not offset from the holder fitting portion 102e, and is easily returned to the original position of the case 101. As described above, the present invention is designed to allow the holder fitting portion 102e retaining the holder 70 which retains the terminal screw 106 to be bent and pivoted on the joint portion. Therefore, if the installation position of the equipment is high or low, or the wiring is difficult, e.g., double wiring of the round solderless terminal, the front end of the terminal screw 106 can be inserted beforehand into the hole of the round solderless terminal 22, enhancing workability. Also, since the holder can be fastened by the engagement projection 70d of the holder 70 and the recesses 102h, 102i, etc., of the holder fitting portion 102e, the holder 70 does not fall off. Further, the engagement of the projections 70b, 70c of the holder 70 with the guide grooves 102f, 102g of the holder fitting portion 102e prevents the holder 70 from rotating and allows the holder fitting portion 102e to be returned to the original position smoothly, ensuring improved workability. The terminal connecting device, as described above, may be used not only with magnetic contactors but also with any other electrical equipment having a terminal section such as circuit breakers, overload relays and transformers. The present invention, as described above, relates to a terminal connecting device which aligns the threaded portion of a terminal screw with a threaded hole when the terminal screw is moved toward the threaded hole, ensures ease of tightening the terminal screws, and remarkably improves workability. The present invention further relates to a terminal connecting device which retains the terminal screw in a position where the threaded portion of the terminal screw abuts on or is adjacent to the threaded hole. In this state, a beveled, solderless terminal or naked wire can be connected to a stationary terminal without having part of the terminal wire enter the threaded hole. Furthermore, the terminal screw is retained in a position where a gap is produced between the threaded portion of the terminal screw and the threaded hole. By inserting a round solderless terminal into this gap, the round solderless terminal can be connected to the stationary terminal. Thus, almost any type of terminal is easily and reliably accommodated by the present invention. The present invention further relates to a terminal connecting device that allows either of two positions, a first position where a gap is generated between the threaded portion of the terminal screw and the threaded hole, and a second position where the threaded portion of the terminal screw abuts on or is adjacent to the threaded hole, either of the two positions being easily and efficiently selected. Furthermore, the terminal connecting device permits the round solderless terminal to be wired by selecting the first position and to be temporarily secured by selecting the second position after the round solderless terminal has been inserted, thereby significantly improving the wiring workability for a wide variety of terminal types. The present invention further relates to a terminal connecting device which does not require removal of a terminal screw holder when switching between the two positions, i.e., the first and second positions, thereby preventing hazards such as electrical shock. The present invention further relates to a terminal connecting device wherein a holder portion is slidably engaged in such a manner as to prevent problems with respect to wiring and to prevent the removal of the holder during the same. The present invention further relates to a terminal connecting device that is provided with a third position, as the stable position of the terminal screw holder in the sliding direction, where the front end of the terminal screw has been tightened several turns into the internally threaded hole of the stationary terminal, in addition to the first and second positions, the third position allowing the terminal screw to be retained in and released from the terminal screw holder by the thrust force of the terminal screw, the terminal screw being retained and released automatically with reliable reproducibility by simply tightening and loosening the terminal screw, the terminal screw being removed from the terminal screw holder in the fully tightened position so as to prevent, for example, deformation caused by heat generation within the terminal screw, etc. The present invention relates to a terminal connecting device that is designed such that a holder fitting portion is bent and pivoted about a joint portion with the body if, for example, the mounting position of the equipment is unusually low or high, or wiring is difficult Also, the terminal screw can be inserted beforehand into the hole of the round solderless terminal, improving workability. The present invention further relates to a terminal connecting device in which the holder serves as a guide for a screwdriver or the like for tightening the terminal screw. In addition, since the holder is formed of an insulative material, it may also acts as a safety cover which prevents electrical shock when the terminal screw is contacted.

The present invention relates to a terminal connecting device which simplifies and facilitates achieving the proper alignment between a male-threaded portion of a terminal screw and a female-threaded hole of a stationary terminal, and moreover, which assures that a fastening operation is easily performed. The terminal connecting device includes a terminal screw guiding member adapted to be displaced along a side wall, the terminal screw being engaged with the terminal screw guiding member. The terminal screw or the terminal screw guiding member may also be supported by the resilient action of an elastic member of which one end is supported by the side wall. Alternatively, the terminal screws may be housed in a housing which is slidably attached to the side wall and which may be locked in place with the aid of a resilient member and latching apparatus.

The present invention relates to the use of water-in-oil microemulsions (w/o ME) as a means for wood stabilization. It is further believed that the water-in-oil microemulsions described herein enable the bulking of the wood cell wall to an extent effective to minimize susceptibility to shrinking/swelling cycles. SUMMARY OF THE INVENTION This invention describes an emulsion having oil as the continuous phase and having water as the dispersed phase. The emulsion also includes a surfactant which functions as an emulsifier. In one embodiment, the average particle size of the dispersed phase is less than about 100 nanometers. In one embodiment, the w/o ME includes about, 10% to 30% water by weight of total composition; 15% to 45% emulsifier by weight of total composition; and 25% to 75% oil by weight of total composition. The w/o ME may include mineral oil as the oil that is the continuous phase of the microemulsion. The w/o ME may also include a second surfactant. The second surfactant may include decyl alcohol, linseed oil fatty acid, octanoic acid, sorbitan monooleate, or propylene glycol monooleate. The second surfactant may also be a blend of surfactants. The emulsifier (or primary surfactant) may also be a blend of surfactants. Also described herein is a w/o ME that is an emulsion including a continuous oil phase and having an aqueous dispersed phase, and the emulsion further includes a first surfactant that functions as an emulsifier. In this embodiment, the aqueous dispersed phase includes water. In one example, the continuous oil phase is mineral oil. This embodiment may include about 10% to 30% water; 15% to 45% of the first surfactant; and 25% to 75% oil and a one or more additives. In one embodiment, the additive includes a second surfactant. In yet another embodiment of the present invention, a method for the treatment of cellulosic material is described and claimed. In this embodiment, the method includes treating cellulosic material with a w/o ME that includes an emulsion having oil as the continuous phase and having water as the dispersed phase. Further the emulsion includes an emulsifier. The average particle size of the dispersed phase may be less than about 100 nanometers. In yet another embodiment of the method of treating cellulosic material, the cellulosic material is wood. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates the particle diameters of the w/o ME, as determined by laser light scattering. FIG. 2 illustrates treatment of specimens with water alone. FIG. 3 . illustrates the benefit of using an emulsifier as part of a w/o ME, compared with use of an emulsifier directly in an aqueous solution. FIG. 4 illustrates effective cell wall bulking. FIG. 5A is a contour plot illustrating the effect of chain length in relation to equilibrated width increase before water soak. FIG. 5B is a contour plot illustrating the effect of chain length in relation to equilibrated width increase after water soak. FIG. 6 illustrates the effect of alkyl chain lengths of quaternary ammonium chloride emulsifiers on width change. FIG. 7 shows the width change for w/o MEs over a range of acid/amine adduct emulsifier solids content level. FIG. 8 demonstrates amine oxide/acid adduct as an emulsifier/bulking agent in methyl soyate. FIG. 9 illustrates amine oxide/acid adduct emulsifiers in hydrocarbon solvent. FIG. 10 illustrates the use of a curable acrylic oil phase. FIG. 11 illustrates extraction resistance of a blended emulsifier system. DETAILED DESCRIPTION OF THE INVENTION Wood shrinkage and swelling occurs as water leaves and enters the wood cell walls and is driven by fluctuations in relative humidity. Stabilization of wood is accomplished by minimizing this impact of water through the use of bulking agents that occupy accessible cell wall sites to the exclusion of water. The use of water-in-oil microemulsions (w/o MEs) deliver both the active bulking agent to stabilize wood as well as the means to protect the agent from water extraction in a single-step application process. W/o MEs are a system of water, oil and amphiphile which is a single optically isotropic and thermodynamically stable liquid solution. The multi-functionality of w/o MEs can be augmented by the inclusion of other additives, including co-surfactants to enhance stability of the micro-emulsion, free radical quenchers to improve wood photostability, or driers to promote the oxidative crosslinking of selected oil phase. The w/o MEs of this invention have been found to have the unique ability to deliver a bulking agent into wood while inhibiting its subsequent extraction by water. The stabilized wood surface may further permit topcoats having different characteristics that would not be possible in the absence of the w/o ME treatment described herein, because current topcoats must accommodate larger dimensional changes. Through use of the w/o ME described herein, it is believed that subsequent topcoat composition that may be applied to wood surfaces will experience increased durability. In the w/o ME described herein, an aqueous phase is dispersed in a continuous oil phase having low viscosity. The particle size of the aqueous phase ranges from about 5 to about 100 nanometers. The following compositions of Table 1 were created and measured to provide examples of the particle diameters for two w/o MEs. FIG. 1 illustrates the particle sizes of the w/o ME, as determined by laser light scattering. In these particular examples, the average particle size of the dispersed phase was between 6.0 and 15.7 nm. TABLE 1 Weight [grams] Component Sample #1 Sample #2 Vertellus Citroflex 4, Tri-n-butyl citrate 9.60 [RM# 125217], Lot # 88957 Stepan Neobee M-20 [Propylene glycol 7.50 dicaprylate/dicaprate], Lot # 7425926 Lonza Carboquat MW-50, Lot #A8221806 8.40 Koa Specialties Americas LLC, Farmin M2-1095, 6.23 N-Methyl-N,N-Didecylamine, Lot # ABA-41001 J. T. Baker Glacial Acetic Acid, Lot #G06A16 1.20 Water 2.57 Emulsifier Content [% by weight solids] 23.33 42.46 Water Content [% by weight] 23.33 14.69 Average Particle Diameter [nm., by General 6.0 15.7 Model] The w/o ME compositions of this invention include an oil, water, and surfactant (that functions as the primary emulsifier). Oils can exhibit a range in polarity that function to fill wood lumens and inhibit water extraction of the bulking agent. Water plays the role of penetration aid for the bulking agent. In the w/o MEs described herein, water makes up about 10%-30% of the total w/o ME composition, and for example may make up about 15%-25% of the total w/o ME composition. Insufficient water content decreases the amount of bulking agent that can modify the wood cell walls, while excess water decreases the quantity of the oil continuous phase that protects the bulking agent. The aqueous phase may be water alone, or may optionally contain dissolved additives (including but not limited to calcium chloride, glycerin, free radical scavengers, polymerization initiators, or water soluble surfactants). In a similar manner, the oil phase can also be modified. Surfactants (i.e., surfactants that function as the primary emulsifier in the w/o ME described herein) include quaternary alkyl ammonium salts and acid adducts of trialkylamine salts (including but not limited to didecydimethylammonium chloride and didecylmethylammonium acetate), polyamines, and amine oxides that are proposed to function further as the bulking agent to stabilize wood. The w/o ME of this invention are thermodynamically stable due to the extraordinarily low interfacial tension between phases. They are optically transparent. The range of the solids content is between 70-90% solids by weight of total composition. Microfibrils are the primary structural component in wood and they play a significant role in responding to moisture content. Water exists in wood in either a free or a bound state. Bound water is held between microfibrils in the cell wall by hydrogen bonding with the matrix. Free water exists as liquid and vapor in cell cavities. The Fiber Saturation Point (FSP) is the point at which no water is present in the cell lumen, but the cell wall is completely saturated. As the cell wall loses water below the FSP, pores close, the microfibrils draw closer together and shrinkage occurs. Contrarily, as the cell wall gains water and approaches the FSP, pores become larger, the microfibrils are forced apart and swelling occurs. For large pieces of wood, a distribution of moisture states occurs within cells, so not every cell is at the FSP. Problems that can occur in wood as a result of uneven shrinking/swelling include warping, micro-cracking and splitting. It has been discovered that treatment of the wood substrate with w/o ME, has provided a substantial shrinkage control benefit and a robust resistance to water extraction. Successful mitigation of shrinkage/swelling cycles due to relative humidity fluctuations is believed to be a precursor to improved stain and topcoat durability. The described w/o ME are systems consisting of water, oil, and surfactant that are optically transparent and thermodynamically stable. These compositions provided a particularly effective package for establishing and preserving wood dimensional stabilization. The results that were achieved through the use of w/o micro-emulsions included a five percentage point reduction in shrinkage potential in the test specimens further detailed below, while maintaining at least 75% of the initial benefit following an extraction (water soak) cycle was exceeded, even after the completion of three extraction cycles. Of the many technical approaches applied to the problem of wood shrinkage and stabilization, none appear as successful as using w/o ME treatments. It has been discovered that stable w/o ME can be prepared using a variety of oils. The composition includes a continuous oil phase. For example, oils ranged from being low in polarity, such as mineral oil, to relatively high in polarity, such as tri-n-butyl citrate. Oils contained a variety of reactive functional groups such as in ethoxylated trimethylolpropane triacrylate, trimethylolpropane diallyl ether, epoxidized 2-ethylhexylsoyate, tung methyl ester, or linseed oil in order to permit subsequent crosslinking reactions to occur. Additional oils that may be used include butyl acetyl ricinoleate, propylene glycol dicaprylate/dicaprate, caprylic triglyceride, dehydrated castor oil acid, linseed fatty acid, linseed methyl ester. Oils can, alternatively, be blended to balance properties such as polarity, reactivity or viscosity. Oils that can be employed in the w/o ME described herein include, but not limited to, the following categories and specific examples: hydrocarbons, such as aliphatic solvent (Calumet Specialty Products Magiesol 60) and paraffinic oil (Calumet Calpar 80); esters, such as Tri-n-butyl citrate (Vertellus Citroflex 4), Dibenzoate diester (Eastman Chemicals Benzoflex 50), and Propylene glycol dicaprylate/dicaprate (Stepan Neobee M-20); fatty esters such as butyl acetyl ricinoleate (Vertellus Flexricin P6), rapeseed methyl ester (Excalibur Kemester 213), methyl linoleate (PCAS), methyl soyate (ADM), and tung methyl ester (Sunpol 7101); epoxidized fatty esters, such as epoxidized 2-ethylhexylsoyate (Arkema Vikoflex 4050); fatty acids, such as linseed oil fatty acid (Alnor Oil Co. Inc.) and dehydrated castor oil acid (Vertellus 9-11 Acids); triglycerides, such as caprylic triglyceride (Stepan Neobee 895); drying oils, such as linseed oil (ADM Superb 1110, ADM White Refined Linseed Oil) and sucrose ester resin (Proctor & Gamble Sefose 1618U); and other oils such as ethoxylated [3] trimethylolpropane triacrylate (Sartomer SR454), trimethylolpropane diallyl ether (Perstorp TMPDE-90), and DMPA Pamolyn ester (in-house, Pamolyn 200 (Eastman Chemicals) diester of dimethylolpropionic acid). Other acrylates can also be used in the oil phase, including but not limited to, reactive acrylic and methacrylic compounds including lauryl (meth)acrylate, t-butyl (meth)acrylate, isonorbornyl (meth)acrylate. Stable w/o ME were also prepared using various surfactants that function as the primary emulsifier. For example, the alkyl chain lengths for dialkyldimethylammonium chloride were varied, or a benzyl group could replace one of the alkyl groups. Emulsifiers were created by blending acid/base pairs such as dialkylmethylamine or dimethylalkylamine with acetic acid or octanoic acid, respectively. One system based on in-situ reactive blending of N-methyl-N,N-didecylamine with acetic acid produced stable w/o micro-emulsions and was found to be especially effective for mid- to low-polarity oils. The surfactant that functions as the primary emulsifier may be present in an amount of about 15% to about 45% by weight of total composition, and for example, may be present in an amount of about 20% to about 30% by weight of total composition. Other reactive blending pairs of amines and acids were found to be capable of providing stable w/o micro-emulsions. Examples include the substitution of glycolic acid for acetic acid in the system above, as well as the combination of N-octyl-N,N-dimethylamine with octanoic acid. Another reactive blend approach that was very effective in forming stable w/o micro-emulsions consisted of replacing the amine with an amine oxide. Specifically, it was demonstrated that the in-situ reaction product of octyldimethylamine-N-oxide and octanoic acid was effective with methyl soyate and mineral oil as oil phases. These reactive systems were also blended with quaternary amine salts and with each other. Although any conventionally known and used emulsifier can be used in preparation of the w/o ME described herein, examples of emulsifiers that may be used include quaternary ammonium salts such as 50% didecyldimethylammonium chloride (Lonza Bardac 2250), Dialkyl[C10]dimethylammonium chloride (Stepan BTC-1010 80%), Dialkyl (C8/C10) dimethylammonium chloride (Stepan BTC-818 80%), 80% alkylbenzyldimethylammonium chloride (Lonza Barquat MB-80), and 50% didecyldimethylammonium carbonate/bicarbonate (Lonza Carboquat MW-50). Quaternary ammonium salts useful in this invention may have the following structure: Additionally, amine/acid adducts may be used, including: Octyldimethylamine/Octanoic acid (Koa Specialties Americas LLC, Farmin DM-0898/P&G C-898), Methyldidecylamine/Glacial acetic acid (Koa Specialties Americas LLC, Farmin M2-1095/Eastman Chemicals glacial acetic acid), Methyldidecylamine/Glycolic acid (Koa Specialties Americas LLC, Farmin M2-1095/DuPont 70.0% aqueous glycolic acid), Tetradecyldimethylamine/Octanoic acid (Albemarle ADMA 14 Amine/P&G Chemicals C-898), Hexadecyldimethylamine/Octanoic acid (Albemarle ADMA 16 Amine/P&G Chemicals C-898), Dimethyl oleyl amine/Octanoic acid (Akzo Nobel Armeen DMOD/P&G Chemicals C-898), Octyldimethylamine/Linseed Oil Fatty Acid (Koa Specialties Americas LLC Farmin DM0898/Alnor Oil Co. Inc. Linseed Oil Fatty Acid), Hexadecyldimethylamine/Decanoic acid (Albemarle ADMA 16 Amine/P&G Chemicals C-1095), Dimethyl oleyl amine/Hexanoic acid (Akzo Nobel Armeen DMOD/P&G Chemicals C-698S), Decyldimethylamine/Octanoic acid (Albemarle ADMA 10 Amine/P&G Chemicals C-898), Dodecyldimethylamine/Octanoic acid (P&G Chemical AT-1295A/P&G Chemicals C-898), Decyldimethylamine/Decanoic acid (Albemarle ADMA 10 Amine/P&G Chemicals C-1095), Octyldimethylamine/Decanoic acid (Koa Specialties Americas LLC Farmin DM0898/P&G Chemicals C-1095), Dodecyldimethylamine/Decanoic acid (P&G Chemical AT-1295A/P&G Chemicals C-1095), Tetradecyldimethylamine/Decanoic acid (Albemarle ADMA 14 Amine/P&G Chemicals C-1095), Hexadecyldimethylamine/Hexanoic acid (Albemarle ADMA 16 Amine/P&G Chemicals C-698S), Tetradecyldimethylamine/Hexanoic acid (Albemarle ADMA 14 Amine/P&G Chemicals C-698S), Dodecyldimethylamine/Hexanoic acid (P&G Chemical AT-1295A/P&G Chemicals C-698S), Decyldimethylamine/Hexanoic acid (Albemarle ADMA 10 Amine/P&G Chemicals C-698S), Octyldimethylamine/Hexanoic acid (Koa Specialties Americas LLC Farmin DM0898/P&G Chemicals C-698S), Octyldimethylamine/Propionic acid (Koa Specialties Americas LLC Farmin DM0898/DOW Chemicals Propionic acid), Octyldimethylamine/Acetic acid (Koa Specialties Americas LLC Farmin DM0898/Eastman Chemicals Glacial Acetic acid), Octyldimethylamine/Methacrylic acid (Koa Specialties Americas LLC Farmin DM0898/Aldrich Methacrylic acid), and Octyldimethylamine/Acrylic acid (Koa Specialties Americas LLC Farmin DM0898/Aldrich Acrylic acid). Amine/acid adducts useful in this invention may have the following structure: Additionally, polyamine/acid adducts may be used, such as tetraethylenepentamine/Octanoic acid (Huntsman TEPA/P&G Chemicals C-898). Polyamine/acid adducts useful in this invention may have the following structure, where x=2 to 6, and y=1 to 4: Also, amine oxide/acid adducts may be used as an emulsifier, including but not limited to Octyldimethylamine oxide/Octanoic acid (Mason Chemical Macat AO-8 or Colonial Chemical ColaLux C-8/P&G C-898), Octyldimethylamine oxide/Methacrylic acid (Mason Chemical Macat AO-8, Colonial Chemical ColaLux C-8 or Rhodia Mackamine C-8/Aldrich Methacrylic acid), Octyldimethylamine oxide/Linseed Oil Fatty Acid (Mason Chemical Macat AO-8, Colonial Chemical ColaLux C-8 or Rhodia Mackamine C-8/Alnor Oil Co. Inc. Linseed Oil Fatty Acid), Octyldimethylamine oxide/Hexanoic acid (Mason Chemical Macat AO-8, Colonial Chemical ColaLux C-8 or Rhodia Mackamine C-8/P&G Chemicals C-698S), Octyldimethylamine oxide/Propionic acid (Mason Chemical Macat AO-8, Colonial Chemical ColaLux C-8 or Rhodia Mackamine C-8/DOW Chemicals Propionic acid), and maleic acid. Amine oxide/acid adducts useful in this invention may have the following structure: Additionally, polyacid/amine adducts may be used as an emulsifier. One such useful polyacid/amine adduct may have the following structure, where X=hydrogen, carboxylate, or alkylcarboxylate, and Z=0 to 12: In all of the foregoing exemplary structures, R, R′, R″, and R′″, R″″, and R′″″ can independently be hydrogen, saturated hydrocarbon, unsaturated hydrocarbon, cycloaliphatic hydrocarbon, aromatic hydrocarbon, benzylic hydrocarbon. The sum of all R chain lengths <27. The primary surfactant may also consist of a blend of surfactants. The (primary) surfactant of the w/o ME composition has a dual function of first providing emulsification, then subsequently serving as the bulking agent to impart wood dimensional stabilization by displacing water from the wood cell walls, i.e., by diffusing into the wood cell walls and occupying hydrogen bonding sites to the exclusion of water. Several surfactant systems are effective as both emulsifiers and bulking agents, including but not limited to quaternary ammonium salts, fatty amine salts and fatty amine oxide adducts with acids. The water phase is believed to induce swelling sufficient to permit diffusion of the bulking agent into the wood cell walls. The w/o ME described herein includes a surfactant that primarily functions as an emulsifier. However, as further described below, additional co-surfactants may also be employed. It has been determined that the use of co-surfactants is useful to generate stable w/o ME compositions. In general, alcohols; esters, such as sorbitan monooleate (Croda Span-80 NV LQ); fatty acids; and ester/acid can be employed as co-surfactants. Though many conventional co-surfactants can be employed for use in this invention, some of the more effective co-surfactants that were identified include decyl alcohol, linseed oil fatty acid, octanoic acid, sorbitan monooleate, and propylene glycol monooleate (BASF Loxanol EFC-200). These compounds are oil-soluble with little to no water solubility, which appeared to be advantageous for forming w/o ME since the interfacial packing of these co-surfactants with the primary emulsifier would occur on the oil side of the interface. Other molecular structures that were effective include a Gemini-type surfactant (Air Products Envirogem AD01) and the linoleic acid diester of 2,2-dimethylolpropionic acid (DMPA/Pamolyn 200 (Eastman) diester) made internally. These latter molecules contained two hydrocarbon groups branching from a hydrophilic center. It has also been found that reactive acrylic and methacrylic co-surfactants, such as, for example, hydroxyethyl acrylate, can be used. One example of a co-surfactant that can be used includes hydroxyethylmethacrylate (Aldrich). Finally, additives can also be incorporated into w/o micro-emulsions for the purpose of either enhanced performance or functionality. Additives formulated into these systems include defoamers, metallic drier packages, biocides, UV absorbers, photoinitiators, free radical scavengers, aqueous salts, silanol oligomer, additional surfactants, amines, glycerin, diglycerine, dyes, colorants, and antimicrobials. Light stabilizers that may be used in accordance with the present invention include Eversorb AQ-2 (Everlight USA, Inc.), Eversorb SB-1 (Everlight USA, Inc.), Suncare Concentrate (International Specialties Products, Division of Ashland), Tinuvin 292 (BASF), and Tinuvin 384-2 (BASF). Driers that may be employed include 12% Cobalt 2-ethylhexonoate (OMG Americas), Oxycoat 1101 Drier (Borchi), OXY-Coat (Borchi), 18% Zirconium 2-ethylhexonoate (OMG Americas), Additol VXW-6206 Drier (Cytec Industries). Biocides that may be used include 3-Iodo-2-propynyl-n-butylcarbamate (Lonza Omacide IPBC-100). Salts that may be employed include calcium chloride and magnesium heptahydrate. Wetting and air release additives that may be used include Tego Twin 4100 (Evonik Industries). Silicone additives that may be employed include Dynasylan Hydrosil 2926 (Evonik Industries). Other additives that may also be used include methyl ethyl ketoxime (OMG Americas) and tartaric acid (American Tartaric Products (ATP) Inc.). Photoinitiators, include, but are not limited to, methylbenzoylformate (Rahn Genocure MBF). Additives may also be used in accordance with this invention. Functional additives that can be used include amines, such as, for example, Octyldimethylamine (Koa Specialties Americas LLC), surfonic EDA-4/80 (Huntsman) and AEPD VOX-1000 (Angus Chemical Co., division of DOW). Moreover, amine oxide surfactants can also be employed as additives. Such surfactants that may be used include lauryldimethylamine oxide (Mason Chemicals Macat AO-12), ether amine oxide (Air Products Tomamine AO-405), and octyldimethylamine oxide (Mason Chemicals Macat AO-8 or Colonial Chemical ColaLux C-8) Other functional additives include polyalcohols that may be used include diglycerol (Solvay Performance Chemicals) and glycerin technical grade (Perstorp). The w/o ME composition includes oil, and may additionally include any combination of one or more of the co-surfactants and other additives described above. The w/o ME includes 30% to about 60% oil by weight of total composition. Additionally, to the extent that one or more co-surfactants or additives are utilized in the w/o ME, such co-surfactants and additives, along with the oil, make up 30% to about 60% by weight of the total composition. Through treatment of wood with the w/o ME described herein, it has been found that the wood is less susceptible to dimensional instability. The percentage of change in the width of the wood (or other cellulosic material) is indicative of the level of the bulking of the wood cell wall. In turn, the level of bulking is indicative of the shrinking/swelling potential (i.e., dimensional change that can occur during shrinking/swelling cycles). The w/o MEs described herein may be used for the treatment of wood, as well as other cellulosic materials that are susceptible to dimensional instability, as a means of minimizing dimensional changes in the wood and materials over time. Procedure There is flexibility in the procedure applicable to w/o micro-emulsions preparation. One method that was used is discussed as follows. Weigh the following components directly into a glass jar, in sequence provided: (1) oil and oil phase components; followed by, (2) emulsifier(s) and any co-surfactants; followed by, (3) aqueous phase components. Under some circumstances, the addition sequence was modified. For example, co-surfactant could be added as the final step in order to determine the quantity required to form a stable w/o ME rather than conduct a series of experiments to make that determination. Additional, additives may be added to the components described above at any time, with the understanding that it may be convenient to add certain additives to the oil phase (e.g., oil soluble additives) or to the aqueous phase (e.g., water soluble additives) as appropriate. The jar was shaken by hand after each addition to ensure that it was well dispersed. Judgments regarding stability were made visually on the day of mixing, then again after 1 to 5 days, then finally after 9 to 12 days, typically. Optical clarity equated to stability, and that determination was based on the extent to which printed words on a sheet of white paper were read through the jar without distortion. One simple means to determine whether a w/o ME has been created (i.e., one where oil is the continuous phase), consisted of adding the proposed w/o ME, dropwise, into water. If the microemulsion droplets persist in the water, it can be concluded that the continuous phase of the microemulsion is oil and that the dispersed phase of the microemulsion is water. This process can be visually enhanced by adding water soluble dye (for example, food coloring or other dye) to the microemulsion. If the microemulsion droplets disintegrate immediately upon contact with the water, it can be concluded that a w/o ME has not been created. It should be appreciated that many tests and means can be employed to determine whether a w/o ME has been achieved. Generally, in each of the experiments described below, a set of six (6) specimens (northern white birch, length: ˜148-152 mm., width: ˜16.8-17.8 mm., thickness: ˜1.5-1.8 mm.) were preconditioned for at least seven (7) days in an environmental chamber at 25° C. and 50% relative humidity. Three baseline width measurements (using Caliper #H176223) were made on the lower one-third (⅓) of each specimen to provide sufficient data for statistical evaluation. Width measurements were repeated after each subsequent step in the treatment sequence. Treatment typically included a 24-hour soak in the w/o ME, followed by equilibration for 24, 48, and 120 hours, this was followed by a 24-hour water soak and completed with equilibration for 24, 48, 72 and 144 hours. All treatments (soaking and equilibration) occurred in an environmental chamber at 25° C. and 50% relative humidity. Initial soaking with the w/o ME was conducted by placing each set of specimens into separate 4-ounce glass jars containing 100.0 to 110.0 grams of liquid to completely cover, generally, the lower one-half (½) of each sample. Water soaking (extraction) was typically conducted using 100.0 grams of water weighed into separate 4-ounce glass jars for each set of specimens. For both soaking steps, each bottle was placed into a separate 1-quart metal can, which was capped with a large waxed cup to prevent water evaporation. After each soak, the specimens were thoroughly wiped with a paper towel to remove excess liquid prior to width measurements. Three measurements were made on the portion of the treated specimens that was in direct contact with the soak fluids (submerged), typically on the lower one-third (⅓) of each specimen. Results are reported as the percentage change versus the baseline reading and were calculated using the following equation: % change=100*[(Treatment result−Baseline result)/Baseline result] Soak solution components were weighed directly into the 4-ounce glass jar used for soaking at least 16 hours prior to use. Gentle heating (≦140° F.) may be implemented in order to hasten solubilization. FIG. 2 illustrates treatment of specimens with water alone. Here, treatment included a 24-hour soak in the water, followed by equilibration for 24, 48, 72 and 120 hours. The treatment occurred in an environmental chamber at 25° C. and 50% relative humidity. The water soak was conducted by placing the set of six specimens into a 16-ounce Nalgene bottle containing 500.0 grams of water to completely cover the specimens. The bottle was capped and placed into an environmental chamber at 25° C. and 50% relative humidity. After the soak, the specimens were thoroughly wiped with a paper towel to remove excess liquid prior to weight and width measurements. After 120 hours of equilibration, a second water soak was conducted, using the same procedure described. This second soak was followed by equilibration for 48 hours. Example 1 In an effort to get better insight into the extraction of emulsifier/bulking agent during water soak, results for width change following the water soak stage was considered. Results for one experiment are plotted in FIG. 3 . This experiment illustrates the benefit of w/o ME by comparing BTC-818 as emulsifier/bulking agent in w/o ME system versus as use of BTC-818 directly in an aqueous solution at comparable concentrations. Table 2 shows the components and corresponding amounts of components that were utilized in this example. TABLE 2 Weight [grams] Component Set #1 Set #2 Set #3 Vertellus Citroflex 4, Tri-n-butyl citrate 65.10 68.25 [RM# 125217], Lot # 88957 Stepan BTC-818 80%, dialkyl[C8/C10]di- 26.25 24.92 24.94 methylammoniurn chloride, Lot #7485046 Water 13.65 11.83 80.06 Solids Content [% by weight] 82.00 84.00 19.00 Emulsifier Content [% by weight] 20.00 19.00 19.00 Quantity Used [grams] 105.00 105.00 105.00 FIG. 3 , illustrates the percentage of width change over a 144 hour equilibration period. Sets #1 and #2 show that w/o MEs result in more effective cell wall bulking, as measured by larger dimensional increase (i.e., greater percentage of width change in the specimens). Set #3 shows that, after 144 hour equilibration, there is about one percentage point less width increase, despite the same concentration of emulsifier, therefore, implying that there is less effective cell wall bulking. Furthermore, following a water soak, it can be seen that sets #1 and #2 (w/o ME) maintain the width change that they experienced upon equilibration prior to the water soak (i.e., extraction inhibited by w/o ME), whereas set #3 (not a w/o ME, but merely an emulsifier in water) experiences significant decrease in bulking efficiency. Example 2 In this experiment, the compositions shown in Table 3 were created to illustrate that there is little width response difference for w/o MEs over a large range of emulsifier (BTC-818) and solids contents. TABLE 3 Weight [grams] Component Set #1 Set #2 Set #3 Set #4 Set #5 Set #6 Vertellus Citroflex 4, Tri-n-buy citrate [RM# 125217], 57.60 68.97 59.97 52.41 43.15 33.88 Lot # 88957 Stepan BTC-818 80%, dialkyl[C8/C10]dimethlammonium 26.40 26.25 32.81 40.50 47.25 54.00 chloride, Lot #7355904 Water 24.00 9.78 12.22 15.09 17.60 20.12 Solids Content [% by weight] 72.88 85.69 82.11 78.53 74.95 71.37 Emulsifier Content [% by weight] 19.56 20.00 25.00 30.00 35.00 40.00 Quantity Used [grams] 108.00 105.00 105.00 108.00 108.00 108.00 As shown in Table 3, the emulsifier content was increased to test a wide range of emulsifier concentrations to demonstrate cell wall bulking. A percentage of width increase of 3% or more is indicative of effective cell wall bulking. As can be seen in FIG. 4 , the percentage of width increase values exceed 5% both before and after water soak, demonstrating increased the bulking efficiency and retention of the bulking agent by the specimens through use of w/o MEs. Example 3 Example 3, compositions for which are shown in Table 4, below, demonstrates that amine/acid adducts are capable of providing benefit and establishes chain length relationship to width increase. Width increase >3% is suggestive of good performance (effective cell wall bulking), which suggests that combined chain lengths of amine/acid adducts less than about 27 are useful as effective w/o MEs. Width increase >4.0% is suggestive of even better performance and is achieved at the lower combined chain length, at a value of less than about 23. The most effective performance of width increase >5.0% occurs at the combined chain length value less than about 19. TABLE 4 Weight [grams] Component Set #1 Set #2 Set #3 Set #4 Set #5 Set #6 Set #7 Set #8 Set #9 Calumet Specialty Products Magiesol 60, Lot #K0008 37.30 40.80 40.80 43.60 46.40 52.00 44.30 46.40 47.80 P&G Chemicals C-698S, Hexanoic acid, Lot #411025153 11.62 10.50 9.59 8.89 8.19 7.70 P&G Chemicals C-898, Octanoic acid, Lot #KCX20491 13.09 11.97 10.99 P&G Chemicals C-1095, Decanoic acid, Lot #LPD26395 Koa Specialties Americas LLC, Farmin DM0898, 15.68 14.21 N,N-dimethyl-N-octylamine, Lot # AJD-10004 Albemarle ADMA 10 Amine, Decyldimethylamine, 16.80 15.33 Lot #100000092521 P&G Chemicals AT-1295A, Dodecyldimethylamine, 17.71 16.31 Lot #2011-10-28-Sample Albemarle ADMA 14 Amine, Tetradecyldimethylamine, 18.41 Lot #100000129278 Albemarle ADMA 16 Amine, Hexadecyldimethylamine, 19.11 Lot #100000118482 Akzo Nobel Armeen DMOD [dimethyl oleyl amine], 19.60 Lot #SR1265417X BASF Loxanol EFC-200, propylene glycol C18 19.60 16.10 16.10 13.30 10.50 5.60 12.60 10.50 9.10 monoester, Lot #0007862806 Evonik Industries Tego Twin 4100, Lot #ES52115661 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 Water 20.30 20.30 20.30 20.30 20.30 20.30 20.30 20.30 20.30 Water Content [% by weight] 19.33 19.33 19.33 19.33 19.33 19.21 19.33 19.33 19.33 Emulsifier Content [% by weight] 26.00 26.00 26.00 26.00 26.00 25.83 26.00 26.00 26.00 Oil + Co-surfactant + Defoamer [% by weight] 54.67 54.67 54.67 54.67 54.67 54.97 54.67 54.67 54.67 Quantity Used [grams] 105.00 105.00 105.00 105.00 105.00 105.70 105.00 105.00 105.00 Weight [grams] Component Set #10 Set #11 Set #12 Set #13 Set #14 Set #15 Set #16 Set #17 Calumet Specialty Products Magiesol 60, Lot #K0008 49.90 52.00 56.90 46.40 48.50 49.20 51.30 53.10 P&G Chemicals C-698S, Hexanoic acid, Lot #411025153 P&G Chemicals C-898, Octanoic acid, Lot #KCX20491 10.22 9.52 8.96 P&G Chemicals C-1095, Decanoic acid, Lot #LPD26395 14.28 13.16 12.18 11.34 10.64 Koa Specialties Americas LLC, Farmin DM0898, 13.02 N,N-dimethyl-N-octylamine, Lot # AJD-10004 Albemarle ADMA 10 Amine, Decyldimethylamine, 14.14 Lot #100000092521 P&G Chemicals AT-1295A, Dodecyldimethylamine, 15.12 Lot #2011-10-28-Sample Albemarle ADMA 14 Amine, Tetradecyldimethylamine, 17.08 15.96 Lot #100000129278 Albemarle ADMA 16 Amine, Hexadecyldimethylamine, 17.78 16.66 Lot #100000118482 Akzo Nobel Armeen DMOD [dimethyl oleyl amine], 18.34 Lot #SR1265417X BASF Loxanol EFC-200, propylene glycol C18 7.00 4.90 10.50 8.40 7.70 5.60 3.80 monoester, Lot #0007862806 Evonik Industries Tego Twin 4100, Lot #ES52115661 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 Water 20.30 20.30 20.30 20.30 20.30 20.30 20.30 20.30 Water Content [% by weight] 19.33 19.33 19.33 19.33 19.33 19.33 19.33 19.33 Emulsifier Content [% by weight] 26.00 26.00 26.00 26.00 26.00 26.00 26.00 26.00 Oil + Co-surfactant + Defoamer [% by weight] 54.67 54.67 54.67 54.67 54.67 54.67 54.67 54.67 Quantity Used [grams] 105.00 105.00 105.00 105.00 105.00 105.00 105.00 105.00 Table 5 demonstrates equilibration width change before and after water soak, with corresponding chain length values. TABLE 5 Acid Amine Total Acid R—+ Final Equilibrated R— R— Group Amine Width Change [% Group Chain R— Groups vs. preconditioned Chain Lengths Chain specimen] Length [R′—N Lengths [Before [After [R— (—R″) Total Water Water Set # CO 2 H] (—R″′)] [Sum] Soak] Soak]  1 5 10 15 5.72 4.76  2 5 12 17 5.40 5.26  3 5 14 19 5.03 5.09  4 5 16 21 4.55 5.29  5 5 18 23 2.94 3.75  6 5 20 25 3.37 3.18  7 7 10 17 5.77 5.53  8 7 12 19 5.86 5.96  9 7 14 21 4.77 5.45 10 7 16 23 3.71 4.42 11 7 18 25 2.51 3.41 12 7 20 27 2.87 3.37 13 9 10 19 4.85 5.19 14 9 12 21 4.98 5.43 15 9 14 23 3.98 4.59 16 9 16 25 2.49 2.83 17 9 18 27 2.21 2.48 FIG. 5A is a contour plot depicting the results of a response surface model, which illustrates the effect of chain length in relation to equilibrated width increase before water soak. FIG. 5B is a contour plot depicting the results of a response surface model, which illustrates the effect of chain length in relation to equilibrated width increase after water soak. Example 4 Example 4, illustrates the impact of alkyl chain lengths for quaternary ammonium chloride emulsifiers, which is consistent with the results obtained for acid/amine adducts in Example 3. Table 6 provides the compositions that were tested in Example 4. TABLE 6 Weight[grams] Component Set #1 Set #2 Vertellus Citroflex 4, Tri-n-butyl citrate 52.41 [RM# 125217], Lot # 88957 Calumet Specialty Products Magiesol 60, 52.50 Lot #K0008 Stepan BTC-1010 80%, dialkyl[C10]di- 40.50 methylammonium chloride, Lot #7361621 Croda Incroquat DCMC-LQ [68% dicetyl(C16) 38.50 dimethyl ammonium chloride], Lot #0000375983 Water 15.09 14.00 Solids Content [% by weight] 78.53 74.93 Emulsifier Content [% by weight] 30.00 24.93 Quantity Used [grams] 108.00 105.00 FIG. 6 illustrates the effect of alkyl chain lengths of quaternary ammonium chloride emulsifiers on width change. Example 5 Example 5 shows the width change for w/o MEs over a range of acid/amine adduct emulsifier solids content level. The difference in width change among sets is minimal. These results are consistent with the results from Example 2 showing little width change sensitivity as a function of emulsifier concentration and they are also consistent with the results from Example 3, i.e., the sum of the alkyl groups is <27. The components in the treatment systems for each experimental set are described in Table 7 below. TABLE 7 Weight [grams] Component Set #1 Set #2 Set #3 ADM Methyl Soyate, Lot #KCBD11111937 42.00 48.09 52.85 BASF Loxanol EFC-200, propylene glycol 7.00 7.00 8.40 C18 monoester, Lot #0007862806 P&G Chemicals C-898, Octanoic acid, 16.10 14.35 12.60 Lot #KCX20491 Koa Specialties Americas LLC, Farmin DM0898, 17.50 15.61 13.65 N,N-dimethyl-N-octylamine, Lot # AJD-10004 Water 22.40 19.95 17.50 Solids Content [% by weight] 78.67 81.00 83.33 Emulsifier Content [% by weight] 32.00 28.50 25.00 Quantity Used [grams] 105.00 105.00 105.00 The results are shown in FIG. 7 . Example 6 Example 6 demonstrates that an amine oxide/acid adduct is a suitable emulsifier/bulking agent in methyl soyate, where the equilibrated width change remains >5% both before and after water soak. The compositions used in this example are shown below in Table 8. TABLE 8 Weight Component [grams] ADM Methyl Soyate, Lot #KCBD11111937 50.61 P&G Chemicals C-898, Octanoic acid, 13.65 Lot #KCX20491 Mason Chemical Macat AO-8 [41. 0% solids aq. 40.04 Octyldimethylamine oxide], Lot #103130218 Water 0.70 Solids Content [% by weight] 77.50 Emulsifier Content [% by weight] 28.63 Quantity Used [grams] 105.00 The results are reported in FIG. 8 . Example 7 Example 7 further illustrates amine oxide/acid adduct emulsifiers in hydrocarbon solvent and shows that water content of ˜15% by weight in w/o ME compositions are used to achieve an effective width increase of >4.0%. The compositions used in this example are shown below in Table 9. TABLE 9 Weight [grams] Component Set #1 Set #2 Set #3 Calumet Specialty Products Magiesol 61.00 59.75 58.60 60, Lot #K0008 P&G Chemicals C-898, Octanoic acid, 9.75 9.75 9.75 Lot #KCX20491 Rhodia Mackamine C-8 [41.0% solids aq. 28.60 28.60 28.60 Ocydimethylamineoxide], Lot #UP2F29X06 BASF Loxanol EFC-200, propylene glycol 1 9.95 9.75 C18 monoester, Lot #0007862806 Evonik Industries Tego Twin 4100, 0.50 0.50 0.50 Lot #ES52115661 Water 1.45 2.80 Solids Content [% solids] 84.66 83.34 82.11 Emulsifier Content [% solids] 19.52 19.52 19.52 Quantity Used [grams] 110.00 110.00 110.00 The results are reported in FIG. 9 . Example 8 Example 8 illustrates the use of a curable acrylic oil phase. The compositions used in this example are shown below in Table 10. TABLE 10 Weight Component [grams] Sartomer SR454, Ethoxylated [3] trimethyl- 38.50 olpropane triacrylate, Lot # KT2-1925 Rahn Genomer 1121 [isobornyl acrylate], 19.25 Lot # BA0K75870 Stepan BTC-818 80%, dialkyl[C8/C10] 34.16 dimethylammonium chloride, Lot #7485046 Water 13.09 Solids Content [% by weight] 81.03 Emulsifier Content [% by weight] 26.03 Quantity Used [grams] 105.00 The results are reported in FIG. 10 . Example 9 Example 9 illustrates extraction resistance of a blended emulsifier system. The compositions used in this example are shown below in Table 11. TABLE 11 Weight Component [grams] ADM Methyl Soyate, Lot #KCBD11111937 48.30 P&G Chemicals C-898, Octanoic acid, Lot #KCX20491 11.97 Evonik Industries Tego Twin 4100, Lot #ES52115661 0.70 Mason Chemical Macat AO-8 [41.0% solids aq. 34.79 Octyldimethylamine oxide], Lot #103130218 Stepan BTC-818 80%, dialkyl[C8/C 10] 9.24 dimethylammonium chloride, Lot #7485046 Solids Content [% by weight] 78.69 Emulsifier Content [% by weight] 32.02 Quantity Used [grams] 105.00 The results are reported in FIG. 11 .

This invention describes a treatment for wood and other cellulosic materials for minimizing the net dimensional change in the wood and/or cellulosic material between cycles of shrinking and swelling. Cycles of shrinking and swelling compromise the integrity of cellulosic materials, including wood. The water-in-oil composition disclosed herein can be used as a treatment to reduce the magnitude of the dimensional change, thereby mitigating stress and reduce cracking.

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims priority to foreign French patent application No. FR 1000910, filed on Mar. 5, 2010, the disclosure of which is incorporated by reference in its entirety. FIELD OF THE INVENTION [0002] The invention relates to a radiofrequency circuit embedded onboard in a satellite comprising a thermal control system based on an alarm signal and an isolator generating such a signal. It applies notably to the fields of artificial satellites, in particular telecommunications satellites. BACKGROUND [0003] Artificial satellites are frequently used to implement telecommunications systems. They make it possible notably to cover geographical zones for which terrestrial networks have not been deployed, or else to interconnect distant terrestrial networks. An artificial satellite comprises a payload, that is to say a set of equipment allowing it to perform the operations for which it has been designed. For both technical and also cost reasons, the weight of this payload must be minimized. Thus, processing operations that it would be functionally appropriate to do at the satellite level are sometimes implemented at the level of the terrestrial stations of the system by reason of these constraints. [0004] During the deployment of the system, the satellites are placed at a previously chosen orbit, the choice of this orbit being made during the design of the system. Once in orbit, it is difficult to intervene physically on a satellite, notably in the case of a fault. This must of course be taken into account by the designers, and certain circuits exhibit a certain redundancy so as to be able to replace defective resources. [0005] A telecommunication satellite customarily transmits and receives on several distinct channels, a channel corresponding to a band of frequencies. The payload of the satellites can therefore be channeled, that is to say a set of equipment, such as for example amplifiers, are dedicated to the sending or receiving of signals on a given channel. During transmission, the transmitted signals for each channel are shaped by successions of gains associated with each channel and are multiplexed using an output multiplexer, designated in the subsequent description by the acronym OMUX with reference to the expression “Output Multiplexer”. An OMUX multiplexer corresponds to an assemblage of radiofrequency filters. The signal resulting from the multiplexing is thereafter directed toward a broadband transmission antenna. The filters of the OMUX are, for example, bandpass filters which are allocated to the various transmission channels and make it possible to prevent the signal transmitted on a channel from interfering with the signals of the adjacent channels. A portion of the signal generated by the equipment associated with a channel may be reflected for example at the level of the OMUX multiplexer, this portion corresponding to the frequencies of the signal not belonging to the passband of the filter. These reflections may be the consequence of human error resulting for example from erroneous frequency programming by an operator of a ground control station. These reflections may also be the consequence of malfunctions or poor programming of the equipment of the payload carrying out the steering of the high-power signals output by the gain succession of the channels toward the filters of the OMUX, this equipment being called switches in the subsequent description. Faults may also give rise to reflections, notably if the onboard oscillator used for the frequency transposition of the signal to be transmitted is defective. Moreover, if the satellite is used as a repeater, a fault on the ground involving a shift in the frequency of the signal received by the satellite will give rise to a shift at the level of the transmission channel and therefore reflections at the level of the filters of the OMUX. Moreover, poor adaptation of the output of the repeater may also induce signal reflections. [0006] The radiofrequency power resulting from these reflections must be dissipated so as to guarantee good operation in transmission. For this purpose, existing solutions position high-power isolators (customarily designated by the acronym HPI) composed of a circulator and of a power load, in the successions of radiofrequency gains. [0007] The reflections mentioned induce a dissipation of power in thermal form, and the temperature of the circuits such as the OMUXs and the power loads may increase considerably until they are irreparably damaged. [0008] In order to avoid this, existing solutions for thermal detection propose measuring the temperature at the level of the filters of the OMUX multiplexer with the aid of thermistors, said thermistors generating measurement signals processed by an embedded processor aboard the satellite. The main drawback of these solutions is their reaction time which is of the order of several tens of seconds before the components are adjusted so that the temperature falls. SUMMARY OF THE INVENTION [0009] The invention notably alleviates the aforementioned drawbacks. [0010] For this purpose the subject of the invention is a radiofrequency circuit embedded, or configured to be embedded, onboard a satellite, data being transmitted on several channels by radiofrequency signals, a channel corresponding to a frequency band, a succession of gains being able to be associated with a channel so as to generate the radiofrequency signal to be transmitted on the latter, said succession comprising at least one variable-gain amplifier, the radiofrequency signals thus generated being multiplexed by a multiplexer composed of bandpass filters. The successions of gains comprise a power load arranged so as to dissipate the power of signals which is reflected by the filters of the multiplexer, said load comprising means for generating an alarm signal A(t) representative of the power level of the reflected signals, this alarm signal being used to control the gain of the variable-gain amplifier. [0011] According to one aspect of the invention, control modules associated with the successions of gains comprise means for determining control setpoints for the variable-gain amplifier of said successions, said setpoints being deduced from the comparison between a quantity representative of the alarm signal A(t) and a predefined threshold value S. [0012] According to another aspect of the invention, the quantity representative of the alarm signal is its current strength or its voltage. [0013] The setpoint generated by a control module is, for example, such that the variable-gain amplifier of at least one succession of gains is deactivated when the value representative of the alarm signal is greater than or equal to the threshold value S. [0014] The subject of the invention is also a power load composed of a hollow waveguide piece designed as a short circuit, comprising an opening through which an input signal to be attenuated is introduced, said signal being attenuated by an absorbent material included in the waveguide piece. The power load comprises a radiofrequency detector, said detector being positioned at the end opposite from the opening of the waveguide piece, said piece being such that it lets through a portion of power of the input signal at the level of its end closest to the detector, the radiofrequency detector converting this portion of power into an alarm signal A(t). [0015] The radiofrequency detector is, for example, a detector based on diodes or on transistors. [0016] In an embodiment, the portion of power of the incoming signal is transmitted to the radiofrequency detector by coupling. [0017] The alarm signal corresponds, for example, to a voltage or a current strength dependent on the incident power of the portion of power present at the input of the detector. [0018] The advantage of the invention is notably that it can be implemented entirely in the radiofrequency part of the onboard circuits, thereby easing the design of the circuits. Furthermore, the radiofrequency engineer will not have to interact with other professionals when designing circuits implementing the invention, such as for example thermal engineers. [0019] Another advantage is that the weight of the satellite payload may be reduced by several kilos when the proposed solution is implemented. BRIEF DESCRIPTION OF THE DRAWINGS [0020] Other characteristics and advantages of the invention will become apparent with the aid of the description which follows given by way of nonlimiting illustration, offered with regard to the appended drawings among which: [0021] FIG. 1 gives an example of an onboard radiofrequency circuit comprising a thermal detection system; [0022] FIG. 2 gives an example of a power load; [0023] FIG. 3 presents an improved power load comprising a radiofrequency detector; [0024] FIG. 4 gives an example of an onboard radiofrequency circuit comprising a gain system based on an alarm signal; [0025] FIG. 5 gives an example of a control module for a channel amplifier. DETAILED DESCRIPTION [0026] FIG. 1 gives an example of an onboard radiofrequency circuit comprising a thermal detection system. This example makes it possible to transmit signals on two channels. For this purpose, two successions of gains 100 , 101 are used. The first succession of gains 100 comprises, for example, a first gain-controllable amplifier 102 , called a channel amplifier. This amplifier receives a signal to be transmitted on the channel associated therewith as well as control commands originating from an onboard processor, likewise embedded in the satellite. The signal amplified by the first amplifier 102 is amplified again by a second amplifier 104 , the latter being a power amplifier, for example of the traveling wave tube type. This amplifier 104 is designated in the subsequent description by the acronym TWTA deriving from the expression “Traveling Wave Tube Amplifier”. The signal thus amplified is transmitted through a circulator 106 , and then through a switch 110 carrying out the steering between successions of gains toward one of the bandpass filters 114 of an OMUX multiplexer. A cooling system composed of heat pipes 112 , 113 helping to discharge the heat into space by radiation. Taking account of the bulkiness constraints on a satellite, they cannot be dimensioned to dissipate the whole of the power in the case of abnormal operation. So as to enhance the thermal control, a thermistor 116 is placed in the neighborhood of the filter 114 so that the latter generates a signal representative of the temperature of said filter. This signal is thereafter transmitted to an embedded processor onboard the satellite. As a function of signal, the processor determines a command making it possible to reduce the gain of the channel amplifier 102 so as to decrease the thermal dissipation and thus avoid impairments to the components of the system. [0027] The second succession of gains 101 is associated with the second transmission channel. Elements of the same types as those represented in the first succession 100 are used, that is to say a channel amplifier whose gain is digitally controllable 103 , a TWTA amplifier 105 , a circulator 107 , a switch 111 , one of the bandpass filters 115 of the OMUX multiplexer and a measurement thermistor 117 generating a signal directed toward the onboard processor. [0028] The power reflected at the level of the filters of the OMUX multiplexer is directed by the circulators 106 , 107 of the various channels toward a power load 108 , 109 associated with each pathway, said power then being dissipated in the form of heat. [0029] As indicated previously, a drawback of this type of technique is its reaction time, since the thermistors 116 , 117 exhibit thermal inertia characteristics inducing a significant delay in the detection of the variations in measured temperature. This lack of reactivity of the system with respect to temperature variations may result in irreversible damage to the onboard telecommunications equipment. [0030] FIG. 2 gives an example of a power load for a high-power isolator. These power loads are customarily composed of a waveguide piece 200 , for example made from aluminum of rectangular or other shape. This waveguide comprises an absorbent material 201 , for example Silicon Carbide SiC RS-4200 CHP and is open at one of its ends 203 and closed at the other 202 so as to form a short circuit. It then operates as a power load. [0031] Thus, when such an isolator is used to dissipate the power reflected at the level of the OMUX multiplexer, the reflected signal 204 is directed by a circulator toward the power load, such as described previously, enters the waveguide and is dissipated therein. [0032] FIG. 3 presents an improved power load comprising a radiofrequency detector. This power load is composed of a waveguide piece 300 , for example made from aluminum and of rectangular or cylindrical shape. Said waveguide comprises an opening 303 through which the input signal to be attenuated 306 enters. The attenuation is carried out by virtue of the use of an absorbent material 301 . In this embodiment, a radiofrequency detector 302 is excited by a signal passing through a coupling element 308 positioned at the end of the power load, that is to say in at the level of the end opposite from the opening 303 . The waveguide is designed as a short circuit but in such a way as to let through a portion of power at the level of its end 308 in contact with the detector 302 , for example by coupling. The radiofrequency detector is for example a detector based on diodes. This portion of power is converted into an alarm signal A(t) by the detector 302 . This alarm signal corresponds to a voltage or a current strength dependent on the incident power at the input of the detector 302 . This alarm signal can then be used in such a way as to control the radiofrequency components of the succession of gains with which the isolation and alarm device is associated so as to reduce the temperature of the components in the case of an anomaly. [0033] FIG. 4 gives an example of an onboard radiofrequency circuit comprising a thermal control system based on an alarm signal. [0034] The example of the figure comprises two successions of gains 400 , 401 . For each channel, the same elements as those described in the channels of FIG. 1 are represented, that is to say and for each channel, a gain-controllable channel amplifier 404 , 409 , a power amplifier 405 , 410 , a circulator 406 , 411 , a switch 407 , 412 , and an OMUX multiplexer composed of several bandpass filters 408 , 413 . [0035] The circulators direct the reflected signals toward high-power loads comprising a radiofrequency detector 402 , 403 . These isolators generate an alarm signal directed by a conductor line 414 , 415 toward the channel amplifier 404 , 409 . A control module for the amplifier then makes it possible to adjust the gain of said amplifier as a function of the voltage/of the current strength of said signal. The control module is for example integrated into the channel amplifier. In an alternative embodiment, the latter may be implemented outside the amplifier. [0036] FIG. 5 gives an example of a control module for a channel amplifier. The alarm signal A(t) generated by the radiofrequency detector of the previously described power load is directed toward this control module. The latter is introduced into a threshold-based comparator 500 so as to be compared with a threshold signal S. The value of the threshold signal S is a stored constant but may be modified for programming of the control module. The output signal from the comparator 500 is a binary signal C(t) corresponding to a ‘0’ or to a ‘1’. The comparison is such that, for example: [0000] A ( t )< S C ( t )=0 [0000] A ( t )≧ S C ( t )=1 [0037] A breaker circuit 501 makes it possible to activate or to deactivate the taking into account of the signal C(t), this being equivalent to activating or deactivating the protection against thermal escalations. For example, a binary signal P(t) makes it possible to control this activation such that if P(t)=0, the circuit output signal C′(t) is forced to 0, and if P(t)=1, C′(t)=C(t). [0038] The signal C′(t) is available as control module output and makes it possible to indicate what is the state of the control to the onboard computer. [0039] The signal C′(t) is also used as input to a logic OR gate 502 , the second input corresponding to a binary command signal Mon(t), the signal C′(t) being taken into account for the control of the amplifier when, for example, Mon(t)=1. Stated otherwise, the output signal C″(t) from the OR gate 502 is such that C″(t)=C′(t) when Mon(t)=1 and is forced to 0 if Mon(t)=0. [0040] A module for calculating the control setpoint 503 determines a control setpoint as a function of the value of the signal C′(t). This setpoint may be a command making it possible to deactivate the channel amplifier associated with the control module or else an adjustment command for the gain of said amplifier, taking account of the variations of the signal C′(t) over a given time interval. The calculation of the setpoint may be activated or deactivated with the aid of a signal Moff(t). [0041] In the proposed solution, the reaction time making it possible to take account of an abnormal escalation in the temperature is particularly short. Indeed, the reaction time of the detector as well as the time required by the control module to calculate the setpoint are of the order of a few milliseconds. This order of magnitude is to be compared with that associated with the prior art systems, such as for example those based on thermistors, whose reaction time may be as much as several tens of seconds. [0042] In certain embodiments, the radiofrequency multiplexers are designed so as to withstand temperature increases due to the out-of-band signals. With the implementation of a thermal control system based on an alarm signal, the constraints due to these dissipations are less significant and it is then possible to dimension the filters of the multiplexer such that a saving of the order of 80 grams can be achieved per channel, this being equivalent to several kilos for the onboard radiofrequency circuit as a whole.

A radiofrequency circuit embedded onboard a satellite, data being transmitted on several channels by radiofrequency signals, includes a channel corresponding to a frequency band, and a succession of gains being able to be associated with a channel so as to generate the radiofrequency signal to be transmitted on the latter. The succession includes at least one variable-gain amplifier, the radiofrequency signals thus generated being multiplexed by a multiplexer composed of bandpass filters. The successions of gains comprise a power load arranged so as to dissipate the power of signals which is reflected by the filters of the multiplexer, said load including means for generating an alarm signal representative of the power level of the reflected signals, the alarm signal being used to control the gain of the variable-gain amplifier. The subject of the invention is also a power load.

FIELD OF THE INVENTION This invention broadly concerns a method and for adiabatic heat ignition of a wide variety of combustible materials. This invention relates generally to adiabatically induced ignition, inflaming and detonation of deflagration cartridges, gas generating charges and explosive compositions and which provide a safe and effective system for ignition or detonation thereof and which insures the safe handling of apparatus incorporating such materials prior to ignition or detonation and further insures safe handling of incorporating such materials in the event the materials fail to ignite or detonate. More particularly, the present invention relates to downhole perforating guns for perforating casing of well bores at production formation level and the provision of perforating guns having adiabatically induced detonation of an explosive device that initiates a detonating cord and shaped charges for accomplishing casing perforation activities. BACKGROUND OF THE INVENTION For purposes of simplicity this invention is discussed herein particularly as it relates to detonation of explosives in perforating guns for completing wells for production liquid and gaseous materials such as crude oil and natural gas from production formations in the earth. The invention, however, has many other applications within its spirit and scope. In order to provide an explosive system that is quite safe to handle, it is desirable to eliminate the more sensitive and less reliable components of the explosive system. Of the well perforating gun firing systems currently available, those employing electrical detonators may be accidentally discharged by stray currents from faulty power circuitry or grounding, radio frequency energy, electromagnetic transients or lightening strikes, all which are common hazards on drilling rigs. Percussion or stab detonating devices utilize firing pin impact or friction on highly sensitive initiating material; and the firing pin must be prevented from restriking and possibly causing out of zone discharge from accidental jolts and jars in the event that the gun must be removed from the well unfired. The system of this invention utilizes the abundance of hydrostatic energy typically available in deep well conditions to adiabatically stimulate a mass of gas to an intense heat to reliably initiate detonation of a perforating gun, thereby replacing conventional electrical, percussion, or stab blasting caps that are more vulnerable to accidental discharge during well perforating operations. The hydraulic/adiabatic system hereof is inherently safe and reliable as it can not be fired at surface or down to a depth where sufficient hydrostatic potential exists. Unlike percussion or stab detonating means that require a metal to explosive friction or impact, only hot gases contact the initiating material and once the adiabatic heat has dissipated the gun may be retrieved from the well more safely whether it has fired or not. A further and important feature of this invention is that, since the more highly sensitive compounds can be eliminated and the primary high explosive compounds can be detonated directly by means of adiabatically stimulated heat, the handling characteristics of the resulting explosive system is rendered more safe. Further, if the primary high explosive compounds can be eliminated and direct detonation of a secondary high explosive such as RDX can be stimulated adiabatically then the resulting explosive system will be even more safe. Accordingly, it is a feature of this invention to achieve, by adiabatically induced heat, direct detonation of a secondary explosive composition to thus provide an explosive system that is inherently safe. An explosive is a chemical composition that when ignited by heat, friction, impact or shock results in a sudden outburst of hot gas. Explosives may be classified as deflagrating or detonating explosive depending on whether the velocity of decomposition is sub or supersonic. An arbitrary limit dividing deflagration and detonation is 900 meters per second. Deflagrating or low explosives includes propellants, of which black gun powder is an example, which decompose rapidly with a high heat and pressure at subsonic velocity. As they burn no significant shock waves are produced Smokeless gun powder and ammonium perchlorate used in well bullet and core guns are other examples of powders in this category. In detonating high explosives the chemical reaction takes place at supersonic velocity, principally within a thin detonation shock wave zone, traveling through the explosive in the order of 4500 to 7000 meters/second. The detonating explosive category may be subdivided into, primary high explosives which detonate on exposure to relatively weak mechanical shock or flash, and while secondary high explosives are considerably less sensitive they usually require a detonator shock to induce high order detonation Examples of primary high explosives are: lead azide and lead styphnate used in detonators, while examples of the following secondary high explosives: PETN, RDX, HMX, HNS II, and PYX are of interest for well perforating guns employing shaped charges. Whether the explosive decomposition path of an explosive is deflagration or detonation is dependent on the intensity of the initiating stimulation and confinement pressure as well as the nature of the particular explosive as for example black powder can be made to detonate. The less sensitive but powerful secondary high explosives such as RDX used in well shaped charges and detonating cords traditionally require a detonator containing primary and secondary explosive to deliver the strong shock required to initiate them to high order. Detonators used in well applications are of the electric, percussion or stab type according to the method of initiation. The adiabatic heat detonating device of this patent provides a new and safer method of detonating well perforating guns and other explosive or pyrotechnical devices. Among the various compositions that are capable of being inflamed, ignited or detonated by adiabatically induced heat are the ignition compounds of a common electrical and non-electric blasting caps, deflagration compounds such as gun powder including the well known black powder, primary high order detonation compounds such as lead azide and secondary high order detonating compounds such as RDX. The initiating mixes of common detonators, often lower system temperature ratings AND are typically quite sensitive and therefore involve an element of danger when detonating caps using these compounds are employed in conjunction with powerful high explosive devices such as shaped charge perforating guns in deep oil well conditions. Likewise, primary high explosive compositions such as lead azide and lead styphnate are considered quite sensitive as heat or friction causes them to detonate high order, and thus are dangerous to handle, particularly in an oil well environment. The main body of the explosive charges consists of secondary high explosives, such as RDX, HMX, PYX, HNS, etc. which are extremely powerful but relatively insensitive to heat, shock, impact or friction, and can be handled quite safely but ordinarily require a primary high explosive device for detonation thereof. A typical combination of compounds for use as a high explosive initiating device would include a match compound for initial ignition in an electrical detonator or a friction sensitive compound in a non-electric percussion or a stab detonator that will in turn stimulate a primary detonating explosive compound such as lead azide which detonates and develops a shock wave of sufficient strength to achieve detonation of a secondary explosive such as RDX, etc. Deflagration devices are often used as instantaneous power sources for developing a force that is utilized to do work. These devices incorporate deflagration compounds such as potassium perchlorate, strontium nitrate and sodium nitrate which, when ignited, inflame slowly relative to the deflagration of gun powder and develop a gas pressure which can be used as a pneumatic source for accomplishing work. For example, in downhole operations for completion of wells, plugs and packers may be set by power charges. Accordingly, it is a feature of this invention to provide a novel method by which power charges may be safely ignited by adiabatically induced®d heat. It is also a feature of this invention to achieve adiabatic ignition of other combustible liquids or gases, for example, to release energy for doing any suitable work. After wells have been drilled to the earth formation level of one or more production zones, the well bore intersecting these production zones is most often lined with pipe, typically referred to as well casing. The well casing is cemented in place within the well bore to thus establish a substantially integral relationship between the casing and the formation to thus provide a seal between the casing and the formation and to assure that the casing remains properly in place in the well bore for the extended life of the well being produced. After the casing has been installed, it is necessary to perforate the casing to thus establish communication between the well and the formation to be produced. These perforated intervals may be isolated by means of packers which establish a seal between the casing and production tubing that extends within the casing from the level of the production formation to the surface. THE SHAPED CHARGE GUN The shaped charge perforating gun, well known in the petroleum industry for perforating wells, is an outgrowth of secondary world war armor piercing weaponry. A shaped charge gun is comprised of three explosive elements, a blasting cap used to initiate a detonating cord that in turn initiates a number of individual shaped charges. Most often, the explosive elements are enclosed in a pressure tight carrier tube to protect and isolate them from well fluids. Shaped charges and detonating cords utilize one of several relatively low sensitivity but powerful secondary high explosives such ar RDX, HMX, HNS or PYX. In secondary high explosives the chemical reaction takes place in a detonating shock wave traveling through the explosive in the order of 4500 to 7000 meterssecond. The shaped charge itself consists of a quantity of secondary high explosive compressed into a charge case with a metallic lined hollow cavity at the end opposite from the point of initiation The hollow cavity may be parabolic or of more complex shapes but for the deep penetrating charges it is most commonly conical in form with a thin lining of copper or a mixture of compressed metallic powders. When a charge is initiated by the detonating cord at its axis of symmetry, a detonation shock wave propagates through the explosive typically at 6000 meters/second generating pressures of 300,000 atmospheres causing the metallic liner walls to collapse onto itself along the axis, projecting a portion of the liner material forward as a high speed penetrating jet traveling some 7000 meters/second. The high speed jets impinge with pressures in the order of 500,000 atmospheres and thus easily perforate the well casing, cement and deep into the formation. A significant variety of casing perforation devices have been developed over the years. One of the most practical and most acceptable types of casing perforation devices, typically referred to as perforating guns, are casing perforation tools having a plurality of shaped explosive charges which, when detonated, develop explosive jets which penetrate the steel wall of the casing and cement. The explosive jets also penetrate into the formation to thereby establish significant perforation passage surface area in the formation to stimulate production of hydrocarbon fluids such as crude oil, natural gas, distillate, etc. One important type of well completion employing perforating guns is known as tubing-conveyed perforating or "TCP" completion. A primary purpose of a TCP completion is to establish the best possible communication between the reservoir and the wellbore. This operation involves running large diameter, powerful guns on the production or working tubing string to form shaped charge perforations in cases over hundreds or thousands of feet of wellbore on a single t rip in the well. Inclusion of a production packer above the guns in the tubing string allows the desired underbalance pressure condition to be established between the formation and well so that when the charges are fixed simultaneously an immediate flow of production fluid into the wellbore from the perforations is established, thereby assuring a maximum number of clean, debris free perforations . TCP guns are available with shot densities up to 12 shots per foot or more in optimally distributed patterns. The guns maybe loaded with deep penetrating charges for the more consolidated formations or with large entry hole charges for gravel packing unconsolidated formations. Completions are classified as retrievable or permanent depending on whether or not the guns, packer and tubing string is pulled out of the hole or not after the perforating job. Practical considerations that favor TCP completions are, rig time savings where the long heavy gun strings would otherwise require a number of wire line runs or in highly deviated or horizontal wells where the guns must be pushed out into firing position. Various types of TCP perforating gun firing systems have been developed and are in commercial use at the present time all of which allow the well pressure to be underbalanced or drawn below expected formation pressure prior to firing the guns. In the drop-bar method of firing, a detonating weight bar is dropped from surface through the tubing string and production packer to a percussion detonator located in the head of the gun string. As a drop bar can not function in a highly deviated well or in the more complex completion conditions, pressure firing, either by direct application of pressure at surface through the tubing string to the TCP gun or by differential pressure applied at the surface to the tubing-casing annulus and/or bleeding off the tubing head pressure, may be used to fire the guns. Some direct pressure firing heads are equipped with time delay fuzes or hydraulic time delay devices allowing sufficient time to bleed down the tubing pressure to achieve the desired drawdown pressure in front of the zones to be perforated before firing the guns. Firing systems requiring a combination of actuating means such as drop bar impact and hydrostatic pressure to actuate firing systems give some measure of protection against costly and disastrous consequences of an accidental discharge out of zone or at surface. The temperature problem with explosives is exacerbated in TCP operations which require the guns be left in the well for extended periods of time before firing. Exposing the explosives to elevated temperatures for long periods has deteriorating effects often rendering them more sensitive and more dangerous to handle. It is well known that perforating guns having percussion or stab detonators can detonate accidentally while located at the surface, while being run into the hole and while being retrieved from the hole under circumstances where the perforating gun may have failed to fire at the selected production zone. Although many different types of safety characteristics have been incorporated within commercially available perforating guns, as long as a percussion detonator is present and an apparatus is also present that might impact the percussion detonator, there is a significantly disadvantageous possibility that accidental firing may occur. Obviously, accidental firing of perforating guns can seriously damage the well and constitutes a significant hazard to persons working in the immediate vicinity. It is desirable, therefore, to provide a firing system for perforating guns which does not employ either electrical detonators which are subject to the many sources of radio frequency energy and stray electrical potentials, or, the percussion or stab detonators in mechanical devices that can initiate detonation of an explosive composition in the firing system of a perforating gun. It is also desirable to provide a perforating gun mechanism incorporating shaped charges and where an apparatus for achieving -detonation of the shaped charges is of low cost and simple nature and is reliable in use. SUMMARY OF THE INVENTION According to the general principles of this invention, there is provided a method and mechanism for achieving, by sudden compression of a gas, adiabatically induced heat ignition or detonation of various combustible materials, including materials that inflame when ignited to develop gas pressure for doing work and materials which detonate to accomplish work explosively. These combustible materials include, but are not limited to, ignition compounds, deflagration materials, primary high explosives, secondary high explosives, combustible liquids and gases, etc. Where explosive compositions are utilized, it is a principle feature of this invention to initiate directly by adiabatically induced heat, less sensitive explosive compounds, such as those that typically comprise secondary high explosives. Further, in cases where primary high explosives are employed such as in an explosive chain of explosive compounds, including secondary high explosive compounds and explosive compounds of even less sensitive nature it is within the principles of this invention to achieve directly ignition of the primary explosive composition by means of adiabatically induced heat. Typically, a piston will be driven hydraulically to compress a gas within a cylinder, with the combustible material being exposed to the gas and thus being ignited by the high adiabatically enhanced temperature of the gas. The mass of the piston together with the hydrostatically developed force acting on the piston will ensure that the temperature of the compressed gas will remain at its peak for a sufficient length of time that ignition of the combustible material will be achieved. According to the more specific principles of this invention for perforation of well casing during well completion activities, a perforating gun having shaped charges and detonating cords for detonation thereof is provided with a system and mechanism for adiabatically achieving detonation of a secondary high explosive composition which in turn induces detonation of the detonating cord for detonation of the shaped charges of the gun. In accordance with the preferred embodiment of the invention a secondary high explosive composition for detonation of the detonating cord is in communication with a cylinder having a gas such as air therein. The cylinder is closed by means of a piston which is secured in place by a shear pin or by any other suitable means of releasable retention. One end of the piston is exposed to fluid pressure which is present within the completion tubing string or within the casing at the level of the production zone. Typically this pressurized fluid is drilling or completion fluid or another suitable liquid which by virtue of its significant column a hydrostatic head of significant pressure at the level of the firing mechanism for the perforating gun. Where the piston is restrained by a shear pin or a ball detent latching mechanism, release of the piston may be achieved by means of a detonation bar which is dropped from the surface through the working string and which contacts the exposed end of the piston with sufficient force to shear the pin or is released by application of pressure on the tubing at the surface sufficient to shear the shear pins, the number and strength of which may be varied to actuate at the desired pressure. In the case of ball detent latching mechanisms a retainer sleeve retaining the locking balls in their locking positions can be moved directly by the drop bar or hydraulically to a ball release position. When the piston is released the pressure of the hydrostatic head will suddenly drive the piston downwardly thus compressing the air or other gas in the chamber of the cylinder. The gas is compressed suddenly, thus causing its temperature to very rapidly increase adiabatically to a temperature at which the explosive composition to which the cylinder is exposed will detonate and induce detonation of the detonating cord. The length of the cylinder and the diameter of the pistons are designed with respect to the particular explosive composition to be detonated, such that the pressure and temperature increase of the air will reach or exceed the detonation temperature of the explosive composition. If desired, under circumstances where the pressure established by the hydrostatic head may be insufficient for achieving adiabatic detonation temperature of the gas, a pressure multiplying system may be employed. In this case a large piston is exposed to the hydrostatic head of fluid within the working string or casing. This large piston is then coupled with a smaller piston movably located within a smaller cylinder having air or another gaseous medium therein and being exposed to the explosive composition to be detonated the force of hydrostatic pressure acting on the exposed area of the large piston is transferred to the small piston and thus develops greater gas compressing force than would be developed on the small piston by hydrostatic pressure. Although hydrostatic pressure is an acceptable medium for achieving sudden piston movement for adiabatic compression of the gas, it is not intended that this invention be limited to such. It is within the spirit and scope of this invention to incorporate any suitable means for achieving sufficiently rapid movement of the piston in compression of the gaseous medium to adiabatically raise the temperature of the gas to the ignition or detonation temperature of a combustible material such as an explosive composition, deflagration composition, combustible gas, etc. Thus, the invention is intended for use in a wide variety of circumstances other than for perforation of well casing. It has been determined, that a reasonably low sensitivity but high order detonating medium such as RDX, when used in conjunction with the adiabatic heat device of this invention, initiates a high order detonation in RDX which becomes efficient for stimulating detonation of detonating cord or other such secondary high explosive. In accordance with this invention, spaced segments of RDX are employed with one of the segments being in immediate communication with the detonating cord or with a booster containing only secondary high explosive that is crimped to the detonating cord. The other of the explosive segment is provided with a liner and an energy focusing extremity while its opposite end, sealed with a thin easily ruptured metallic foil moisture barrier, is in communication with the air or other gas within the cylinder. It has been determined that adiabatic compression of the gas will achieve initiation of the first RDX segment and that the energy focusing design of the first RDX segment will stimulate high order detonation of the second RDX segment. It has also been demonstrated through tests that detonation of the RDX segments becomes high order before its propagation reaches the detonating cord. Hence, the detonating cord is subjected to the shock stimulation of a high order detonation. Thus, the detonating cord is subjected to high order detonation by a typically non-initiating explosive composition such as RDX. Although RDX is discussed in this specification, particularly as it relates to a detonating cord initiation system of this invention, it is to born in mind that other non-initiating secondary high explosives may be employed in similar manner to achieve high order detonation of the detonating cord or other secondary high explosive for which detonation is desired. BRIEF DESCRIPTION OF THE DRAWINGS So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be comsidered limiting of its scope, for the invention may admit to other equally effective embodiments FIG. 1A is a sectional view of the upper portion of a casing perforating gun mechanism constructed in accordance with the principles of this invention and showing in broken lines a detonating bar in contact with the upper portion of the piston of the adiabatic system of this invention. FIG. 1B is a sectional view of the lower portion of the casing perforation gun of this invention. FIG. 2A is a fragmentary sectional view of the apparatus of FIG. 1A, illustrating an adiabatically initiated explosive assembly thereof in greater detail. FIG. 2B is a partial sectional view of an alternative embodiment of this invention wherein successive explosive segments of increasing density from top to bottom are present to form an adiabatic heat initiated explosive detonation system. FIG. 3 is a fragmentary sectional view of a modified embodiment of this invention illustrating a ball detent piston restraint and release mechanism that may be utilized instead of the shear pin restraint and release mechanism of FIG. 1A. FIG. 4A is a sectional view of the upper portion of an adiabatic detonating mechanism representing an alternative embodiment of this invention. FIG. 4B is a sectional view illustrating the lower portion of the pressure or force multiplying system of FIG. 4A. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to the drawings and first to FIGS. 1A and 1B, a tubing conveyed perforating gun (TCP gun) incorporating an adiabatic detonating mechanism constructed in accordance with the present invention is illustrated generally at 10. The TCP gun 10 may incorporate a plurality of sub assemblies (subs) including a firing head illustrated generally at 12 which is adapted to achieve detonation of an explosive chain including detonating cord. The TCP gun also includes one or more perforating subs illustrated generally at 14 and incorporating a plurality of spaced shaped charges which are disposed for detonation by the detonating cord which extends to and is coupled with the primer of each of the shaped charges. Referring now particularly to the firing head sub assembly 12, a coupler 16 is provided which defines an externally threaded upper extremity 18 enabling the TCP gun to be received at the lower internally threaded extremity of the well tubing string. The coupler 16 also defines a tapered internal guide surface 20 which serves to guide the lower striking end 22 of a drop bar 24 into an internal passage 26 so that the drop bar, shown in broken lines, will be accurately aligned for its striking and releasing function The passage 26 is typically described as a "no-go" passage which is of a sufficiently small dimension so as to permit only the striking portion of the drop bar to pass through the passage 26 and actuate the firing mechanism of the gun. Virtually all other objects of sufficient weight to actuate the firing mechanism of the gun will be of sufficiently large dimension that, if accidentally dropped into the working tubing string, will be of larger dimension than the no-go passage 26 and therefore will be stopped at the coupler 16. The lower end of the coupler 16 is provided with an externally threaded section 28 which is received by an internally threaded section 30 of an upper housing tube 32 which is also referred to as a debris sub. The upper end of the debris sub defines an internal sealing surface 34 which is engaged by external sealing members 36 which are supported within seal grooves formed within the coupler 16. Upper housing 32 is a "debris sub" for pipe rust, scale or other undesirable material to accumulate leaving the top of firing head 12 to perform its function. The debris sub may be sealed at its upper and lower ends by O-rings at 36 and 50 or left unsealed depending on the completion string design requirements. At times the debris sub 32 may be perforated or slotted. The TCP gun 10 also includes an intermediate coupler 38 having upper and lower externally threaded ends 40 and 42 which respectively receive the lower internally threaded end 44 of the upper housing tube 32 and the internally threaded upper end 46 of a housing tube 48. A safety spacer, not shown which is a section of tubing 10 feet or so in length which positions the perforating gun beneath the rig floor for protection of rig personnel as the firing head detonating mechanism is being connected or disconnected is often included The housing tubes 32 and 48 are sealed with respect to the intermediate coupler by means of respective pairs of seals 50 and 52. Within the gun housing tube 48 is provided a plurality of shaped charges, one of which is shown at 54 which is positioned at one of a plurality of reduced housing sections 56 to permit ease of housing penetration by the explosive jet that is developed when the shaped charge is detonated. Each of the shaped charges is coupled with a length of detonating cord 60. The detonating cord extends through the safety spacer and into the housing tube 48 and also along the length of gun tube housing 62 and other subsequent gun tubes such that detonation of the detonating cord will achieve consequent detonation of all of the shaped charges to thereby induce perforation of the well casing by the explosive jets of the shaped charges. The TCP gun may be of any suitable length designed for achieving perforation of the well casing throughout the length of the casing intersecting the production zone to be produced. As shown in FIG. 1B, other gun intermediate couplers (such as that shown at 61) may be provided which permit additional perforating gun sections 62 to be assembled end to end to thereby establish a TCP gun of desired length. The lower gun housing section 62 is closed by means of a lower end cap 64 having an externally threaded lower extremity 66 and spaced circular seals 68 which are respectively received by the lower internally threaded end 70 and sealing surface 72 of the lower gun housing section 62. The lower end cap 64 also serves as a closure and retainer for the lower detonating cord connector 74 of the lower TCP gun section 62. Since the gun sections are capable of being assembled end-to-end, the detonating cord connector 74 will be substantially identical with respect to the detonating cord connector 76 shown at the lower end of the upper TCP gun section of the lower housing tube 48. It should be born in mind that the TCP gun sections illustrated herein are of conventional nature and comprise a component part of the present invention only to the extent that the same is employed in combination with the adiabatic detonating mechanism set forth in FIG. 1A. It should also be born in mind that the adiabatic detonating mechanism of FIG. 1A is capable of being employed in various other casing perforating gun systems and therefore is not intended to be limited to the particular TCP gun system shown in FIG. 1B. Further, it is envisioned that the adiabatic detonating mechanism of FIG. 1A may be effectively employed for achieving ignition of combustible material in apparatus finding use other than for tubing conveyed perforating guns used in the completion of deep wells for the production of petroleum products. Referring now specifically to the adiabatic detonating mechanism of FIG. 1A, and to the more detailed illustration of FIG. 2A, the intermediate coupler 38 also forms an internally threaded upper end 78 within which is received the externally threaded intermediate portion 80 of a cylinder support 82. The cylinder support is sealed with respect to an internal sealing surface 84 of the intermediate coupler by means of a circular sealing element 86 supported within an appropriate seal groove of the cylinder support. A tubular cylinder 88 is positioned in concentric relation within the upper housing tube 32 by means of the cylinder support 82. The lower end of the cylinder 88 defines an externally threaded section 90 which is received by internal threads 92 of the cylinder support. The cylinder support is sealed with respect to the cylinder support by means of one or more circular seals 94 having sealing engagement with a sealing surface defined by the lower end of the tubular cylinder 88. As shown in FIG. 2A the cylinder support 82 by means of the external threads 83 at its lower end may also function as a connector for the upper end of the explosive chain of the adiabatic detonating mechanism of this invention. As shown at the lower portion of FIG. 1A an explosive barrel 96 having an explosive assembly therein is shown to be connected to the lower end of the cylinder support by means of a-threaded not connector 98 and is also shown to be exposed to an internal gas chamber 100 of the cylinder by means of a firing port 102 which is a short bore also defined by the cylinder support. By threaded attachment of the explosive barrel to the lower end of the cylinder support 82 the cylinder support is not affected by detonation of the explosive 106 and 108 and is reusable. Only the explosive barrel 96 will be replaced because of the high order detonation within its explosive chamber which can deform it and which will rupture the wall 124. The detailed structure of the explosive barrel 96 and its arrangement of explosive detonating composition is illustrated in detail in FIG. 2A. As shown, the explosive barrel defines a blind bore 104 within which is seated a section 106 of a secondary high explosive composition such as RDX, HMX, HNS and PYX, which serves a component part of the detonator system for achieving detonation of detonating cord which in turn detonates the shaped charges with which the perforating gun is provided. The use of a secondary high explosive composition as the detonator of the explosive barrel provides an optimum safety feature for the adiabatic detonating mechanism of this invention. The direct adiabatic initiation of a secondary high explosive composition is less sensitive and therefore a more safe explosive as compared with the highly sensitive and more dangerous primary high explosives (such as lead azide) which are ordinarily employed in percussion caps for detonation of detonating cord in casing perforating guns. Also located within the explosive barrel 96, and preferably in spaced relation with the section 106 of secondary high explosive composition, is a section 108 of secondary high explosive composition which may, if desired, be composed of the same secondary high explosive as the explosive segment 106. The blind bore 104 is enlarged at its upper portion and defines an internal stop shoulder against which is seated the lower end of an internally directed liner 114 which provides support for the upper explosive segment 108 and concentrates explosive energy of the explosive 108 against the lower explosive segment 106. Element 107 is a metallic bore moisture barrier for the explosive materials of the explosive barrel 96. The upper explosive segment 108 further defines an upper surface area 116 having a depression 118 formed therein to increase the surface area which is exposed to the internal chamber 100 of the tubular cylinder 88 after the metallic face 107 has ruptured. The upper explosive segment 108 is detonated adiabatically by sudden increase in the temperature of the gas within the chamber 100 and the firing port 102 in the manner described hereinbelow and concentrates energy to accelerate high order detonation of the explosive segment 106. It has been determined through tests, though the explosive segment 106 is composed of a secondary high explosive composition such as RDX and a low order explosion would ordinarily be expected, nevertheless, a high order explosion is induced in the secondary high explosive composition by virtue of the arrangement of the explosive segments 106 and 108 within the explosive barrel 96. These tests, which were conducted with only RDX, a relatively insensitive but powerful secondary explosive commonly used in oil well charges, achieved a high order detonation in a secondary high explosive composition. The direct initiation of secondary high explosives is an important advantage of the adiabatic detonating device. Since highly sensitive and more dangerous primary high explosive compositions are not required for detonating cord detonation within the spirit and scope of this invention the resulting adiabatically initiated firing head is imminently more safe to use as compared with conventional percussion type firing heads. In the preferred embodiment of FIG. 2A the upper end of a booster charge 120 (identical to those between other gun subs) will achieve detonation of the detonating cord. Blind bore 104 is terminated by a thin partition 124 which is readily ruptured upon detonation of the explosive segment 106. If desired, the detonating cord detonating mechanism may incorporate a booster barrel such as shown at 126 which defines a receptacle 128 within which is received the lower end of the explosive barrel 96. booster barrel 126 defines a booster chamber 130 within which is positioned booster charge 120. The lower end of the booster charge device forms a tubular connector 121 within which the detonating cord 60 is positioned and secured by crimping the connector tube. Although, for simplicity a safety spacer is not illustrated, for purposes of safety a length of tube would be coupled to the lower threaded end of coupler 38 and would be provided with a gun intercarrier head at its lower end which in turn would provide for connection with the upper end of gun housing section 48. The detonating cord 60 would then extend from the adiabatic firing head, through the safety spacer and gun intercarrier head to the first gun section in the perforating string. It is not intended to limit the present invention to the specific explosive barrel and secondary explosive charge construction shown in FIG. 2A. For example, the upper explosive segment 108 may simply be of cylindrical form not requiring a focusing liner such as shown at 114. Additionally, for purposes of handling and ease of installation, the explosive segments 106 and 108 are preferably lined but may be lined or unlined as desired. Or, if required, the focusing configuration of the upper explosive segment may be formed in the explosive composition without the necessity of providing a liner as shown. The desired shape of the lower end of the upper explosive segment may be formed by the explosive composition itself. With reference to FIG. 2B, an alternative embodiment of this invention is illustrated by the partial sectional view wherein the cylinder support 82 is provided with an externally threaded lower end 83 which receives a connecting nut 98 to retain an explosive barrel 96A in sealed assembly therewith. O-ring sealing element 97 forms a seal with the lower end of the cylinder support. The upper portion of the explosive barrel 96A forms a blind bore defining a receptacle 104A for an explosive composition. The lower portion of the explosive barrel 96A forms a blind bore defining a receptacle 104A for an explosive composition. The lower portion of the explosive barrel 96A defines a downwardly directed blind bore 121 which is separated from the upper bore 104A by a thin partition 124A that easily transmits detonation but forms a pressure barrier between the adiabatic firing device and the rest of the gun system. The blind bore 121 is open at its lower end to receive commercial booster shell 123 containing secondary high explosive crimped to an appropriate detonating cord 60. A booster retaining nut 125 threaded to the lower end of the explosive barrel 96A holds the closed end of the booster against the thin partition 124A and suspends the detonating cord 60. The alternate configuration of FIG. 2B also shows the explosive barrel with segments 105 and 106 formed of secondary high explosive but without a metallic liner 114 as in FIG. 2A. In this configuration the blind bore 104A contains explosive segments which are formed by compressing secondary high explosive powder in several separate steps with the most densely compacted portion at the lower end at the thin partition 124A and becoming progressively less compacted, toward the upper end and therefore more easily initiated where the portion of least compaction becomes exposed to the adiabatically heated gas. This technique of varying the explosive compaction is well known in the explosives industry for enhancing the deflagration to detonation transition (DDT) and is well suited to the adiabatic ignition method of this invention As mentioned above, it is a primary feature of this invention to provide a method and mechanism for adiabatically inducing detonation of an explosive composition to thus provide apparatus having characteristics of much greater safety from the standpoint of handling, running into the hole, firing and retrieval in the event the apparatus fails to fire. As also mentioned above, conventional firing mechanisms typically incorporate percussion mechanisms for achieving detonation of the explosives. These detonating mechanisms typically incorporate very sensitive and primary high explosive material such as lead azide. Such conventional devices can detonate while being handled and can also become detonated as they are run into the hole or being retrieved from the hole. In the event that a percussion detonator fails to fire, the gun assembly must be pulled from the well during which jarring or dropping the pipe may cause the released firing pin to restrike, possibly detonating the gun. Although very strict precautions are always taken to insure against malfunction, the presence of percussion caps and apparatus for striking the same significantly increases the possibility that the perforating gun can malfunction which is detrimental to workers and equipment. According to the principles of this invention an adiabatic detonating mechanism is employed which is of simple construction and which is imminently safe during handling, during transportation and at the rig site and while being run into the hole or being retrieved from the hole. Should the apparatus fail to fire, it quickly returns to its safe condition when the adiabatically induced heat dissipates to a level below the detonation temperature of the explosive compound, such that inadvertent firing, since there need be no percussion or piercement of the initiating means, is almost impossible. As shown at the upper portion of FIG. 1A, the tubular cylinder 88 is shown to form an internal cylindrical surface 132 which receives a firing piston 134 therein which is sealed with respect to the cylindrical surface 132 by means of one or more circular piston seals 136 that are received appropriately within seal grooves or in the piston. The piston 134 is provided with a downwardly projecting rod 135, preferably a polished rod which is receivable in close fitting relation within the firing port 102 as the piston approaches the downward extent of its pressure induced travel. The rod 135 is provided with a stop shoulder 137 which contacts the upwardly facing surface 119 to limit downward travel of the piston. At the lowermost position of the rod 135 the end surface of the rod will ordinarily have a few thousandths of an inch clearance with the upper surface of the explosive such that the rod never contacts the explosive. If desired, however, the apparatus may be designed to cause the rod to contact and compress the explosive to any extent that may induce the desired explosive characteristics. The rod will function as a piston and will achieve enhanced compression of gas trapped within the bore 102 thereby enhancing the adiabatic heat to which the explosive 108 is subjected. The tubular cylinder defines an externally threaded upper end portion 138 which provides for a threaded connection thereto of a piston retainer cap 140. The firing piston 134 and the piston retainer cap 140 define registering transverse bores which receive one or more shear pins 142 to secure the piston against movement within the cylinder until such time as the shear pin is sheared. The piston 134 also defines a striker portion 144 which projects upwardly above the level of the piston retainer cap 140. The striker portion is intended to be struck by the lower striking end 22 of the detonation bar 24. When the detonation bar is dropped through the production or working tubing string, it is guided by surface 20 through the no-go passage 26 and into contact with the striker portion 144 of the piston. The piston retainer cap 140 is also provided with a positioning device 147 which insures proper positioning of the piston retainer cap and the striker portion of the piston in centralized relation within the upper housing tube 132 so that the lower end 22 of the detonation bar will contact the striker portion of the piston. When the shear pin 142 is sheared, the piston 134 is released and is capable of being driven downwardly by fluid pressure that is present within the upper housing tube 32. Although this fluid pressure may be provided by any one of a number of suitable sources, a most convenient source of fluid pressure is the pressure that is developed by the hydrostatic head of fluid such as drilling or completion fluid that is present in the tubing above or below a packer or present in the annulus between the casing and tubing when the perforating gun is positioned for firing at the proper formation level within the well. In most wells the column of completion fluid above the gun provides an abundance of hydrostatic pressure that is available to provide a proper hydrostatic pressure for operation of the adiabatic firing mechanism of this invention. A hydrostatic pressure acting upon the surface area prescribed by the seal 136 of the firing piston 134 will develop a pressure induced force acting upon the piston and urging the piston downwardly toward the explosive composition located below the internal gas chamber 100. This downwardly directed force is restrained by the shear pin 142 or by any other suitable means for preventing piston movement until piston movement is desired. The gas chamber 100 of the cylinder 88 may include any gaseous composition. It has been found, however, that air at atmospheric pressure will function quite readily for adiabatic heat detonation of the explosives. To insure that the piston 134 is driven downwardly at its greatest possible velocity in response to the pressure induced force applied thereto, the piston retainer cap 140 defines large fluid inlet ports 146 and 148 which, apart from the passage 150 of the retainer cap through which the striker portion of the piston extends, will permit substantially unrestricted inlet of the hydrostatic pressure fluid medium into the gas chamber 100 above the piston. Thus, the piston will be driven downwardly at high velocity, causing substantially instantaneous compression of the gas within the chamber 100. This instantaneous increase in gas pressure adiabatically induces an instantaneous temperature elevation of the gas to a temperature exceeding the detonation temperature of the upper explosive segment 108. When this occurs the explosive segment 108 will ignite, developing a detonation of at least intermediate order which will then be applied via the focusing aspects defined by the lower inverted liner configuration of the explosive segment 108. The focused explosive energy of segment 108 will be directed against the upper end of the explosive segment 106 which, though it is composed of a secondary high explosive compound, will achieve high order detonation. The high order detonation of explosive segment 106 will induce detonation of the detonating cord 60 or the booster for the detonating cord as the case may be. Under circumstances where the upper explosive segment 108, the explosive segment 106 or the detonating cord fails to detonate and the TCP gun fails to fire, the adiabatic detonating mechanism will very quickly return to its normal, safe condition as the adiabatically induced heat of the gas is quickly dissipated into the surrounding metal surfaces of the tubular cylinder and cylinder support and other components of the well. At the formation level the piston 134 will remain in its gas compressing position determined from the stop surface 119 provided by the cylinder support 82 at the lower end of the cylinder 88. Also, at this position of piston 134 the lower end of the compression rod will be spaced a few thousandths of an inch above the upper face of the explosive barrel 96. Thereafter, the piston can not again compress the gas and achieve adiabatic elevation of its temperature and therefore the upper explosive segment 108 can not thereafter be adiabatically detonated. Since the adiabatic detonating mechanism of this invention will very quickly return to its safe condition upon failure to fire, the working string may be quickly and safely removed from the casing and a replacement TCP gun with an adiabatic detonating mechanism may be substituted for it and quickly run into the hole for another gun firing sequence. As the adiabatic detonating mechanism is withdrawn from the well bore, the hydrostatic pressure that will occur continuous y as the tool is moved upwardly through the liquid column in the well will allow the compressed gas within the chamber 100 to expand, thus moving the piston upwardly within the cylinder 88. As the tool reaches the surface, the gas within the chamber 100 will have expanded almost completely and its pressure will have dissipated substantially to atmospheric level. Thus, the piston 134 becomes pressure balanced during its release and detonation sequence and this pressure balanced condition is sustained thereafter even though the hydrostatic pressure to which the apparatus is subjected at the firing level dissipates as the TCP gun is removed from the well. Thus, after firing, it is not possible for the piston to again function to achieve adiabatic elevation of the temperature of the gas to the detonation temperature of the explosive composition. Although the firing piston 134 may be efficiently restrained by a shear pin such as shown in 142, such is not intended to limit the spirit and scope of this invention As shown in FIG. 3, a piston restraint and controlled release mechanism of the ball detent may be provided. In this case the upper end of a tubular cylinder 152 defines ball detent openings 154 which receive locking balls 156 which are receivable within a locking detent groove or slot 158 of the firing piston 160. Thus locking the piston against movement within the cylinder 152. An external ball retainer sleeve 162 surrounds the cylinder 152 and positions a locking shoulder surface 164 thereof for restraining movement of the locking balls. The sleeve 162 also defines an internally relieved area 166 which permits lateral movement of the balls 156 when the sleeve has been moved downwardly sufficiently to bring the relieved area 166 into registry with the locking ball openings 154. Downward movement of the locking sleeve 162 may be induced by means of the force applied by a detonating bar such as that shown at 24 in FIG. 1A. Alternatively, downward movement of the locking sleeve 162 may be induced hydraulically, if desired, such as by increasing the hydrostatic head of the liquid within the working string or by controlling and using differential pressure between the tubing, casing annulus above a packer and the internal tubing or "rat hole" pressure, thus causing the sleeve which will be sealed by O-rings to other structural components of the firing head to be moved downwardly as a piston. This invention, therefore, is intended to encompass any suitable structure that is capable of retaining the piston against a downwardly directed force induced by any suitable means and then releasing the piston under controlled manner for sudden gas compressing downward movement Under circumstances where the hydrostatic pressure of the liquid within the working string may not be sufficient for application of sufficient force to the piston to achieve adiabatic compression of the gas to the ignition temperature of the explosive medium. It will be desirable to provide for multiplication of the force that is developed by the hydrostatic pressure which is present. In such case, an alternative embodiment of the present invention may conveniently take the form as shown generally at 170 in FIGS. 4A and 4B. In this case an elongated tubular member 172 is provided which is internally threaded at its lower end 174 and is supported by a cylinder support member 176 in much the same manner as shown in FIGS. 1A and 1B. As piston member 178 is positioned for movement within the cylinder 172 and is sealed with respect to the cylinder by means of a circular sealing element 180. A piston retainer cap 182 is coupled to the upper end of the cylinder 172 by means of a threaded connection 184. The piston retainer cap defines a vertical passage 186 through which the upper striker portion 188 of the piston extends so that it may be struck and driven downwardly by means of a detonation bar such as that shown at 24 in FIG. 1A. The piston 178 is restrained in its uppermost position as shown in FIG. 4A by means of a shear pin 190 which extends through registering transverse bores formed in the piston and in the piston retainer cap. The detonating bar will drive the piston 178 downwardly, causing the pin 190 to shear and thus releasing the piston for downward movement under the influence of hydrostatic pressure acting upon the surface area defined by the piston seal 180. For piston force multiplication the piston 178 is provided with a downwardly extending piston shaft 192 having a second piston 194 of smaller dimension as compared with piston 178, located at the lower end of the piston rod. The piston 194 is sealed with respect to a second tubular piston cylinder 196 by means of a circular sealing element 198. The piston chamber 200 defined by the upper cylinder 172 is in communication with the annulus 202 which is formed between the inner and outer cylinders 172 and 196. Thus a significant volume of gas within chamber 200 is available for compression by the large uppermost piston 178. As the upper piston moves downwardly, its piston shaft 192 forces the lower piston 194 downwardly within the inner cylinder 196. The gas present within the smaller piston chambers 204 and 206 defined by the smaller inner cylinder 196 will be acted upon by the force applied by hydrostatic pressure through the large piston 178 thus causing the smaller piston 194 to increase the pressure of the gas significantly above the pressure of the gas within the larger chamber 200 below the piston 178. The lower piston chamber 204 is in communication with the upper explosive segment of the explosive chain via port 206 similar to the manner shown at 102 in FIG. 2A. The net result is that a hydrostatic pressure of smaller force potential may be multiplied to thus develop a force acting upon the piston 194 to achieve sudden pressure increase of the gas within chamber 204 and later 206 to elevate its temperature adiabatically to the detonation temperature of the explosive composition. The lower piston 194 is provided with a downwardly projecting polished rod 195 which is received in close fitting relation within the bore 206 as the piston approaches the downward limit of its travel. Though no mechanical seal is developed between the polished rod and the wells of the receptacle 206 the close fit of the rod and receptacle functions in piston-like manner to achieve even greater compression of the gas and thus even higher adiabatic heat. In view of the forgoing, it is seen that the present invention is well adapted to attain all of the features hereinabove set forth together with other objects and features which are inherent in the apparatus itself. While the foregoing is directed to the preferred embodiment it is recognized that the apparatus may take on various other embodiments within the spirit and scope of the invention the scope hereof is determined by the claims which follow.

A method and apparatus for achieving adiabatic heat ignition of combustible material, particularly explosive compositions which involves entrapping a quantity of gas in a chamber which is in communication with the combustible material and suddenly compressing the gas to the extent that the temperature thereof is increased adiabatically to the ignition temperature of the combustible material. The apparatus is particularly adaptable for use as an adiabatic ignition device for detonating cord and shaped charges of perforating guns for completion of wells. A quantity of high explosive within an explosive barrel is in detonating proximity with the detonating cord. A cylinder forms an air chamber which is in communication with the explosive composition and is provided with a piston for compression of the gas. One or more shear pins or other locking devices are provided to secure the piston in immovable relation with the cylinder. A force is caused to act on the piston which force is typically induced by fluid pressure within the well which acts on the piston and which may also be induced. As this force reaches a predetermined magnitude, or by means of a weight bar dropped or lowered on wireline from the surface, the piston will be released and the force will drive the piston into the cylinder, compressing the gas sufficiently to raise the temperature of the gas adiabatically to the ignition temperature of the explosive composition.

CROSS-REFERENCE TO RELATED APPLICATION This application is a division of application Ser. No. 09/058,477 filed on Apr. 10, 1998, now U.S. Pat. No. 6,079,490. BACKGROUND OF THE INVENTION 1. Field of the Invention The subject invention generally pertains to equipment used for repairing wells that have already been drilled, and more specifically pertains to mobile repair units that frequently travel from one site to another. 2. Description of Related Art After an oil rig drills a well and install the well casing, the rig is dismantled and removed from the site. From that point on, a mobile repair unit is typically used to service the well. Servicing includes installing and removing inner tubing strings, sucker rods, and pumps. The variety of work requires a myriad of tools. When the tooling is not closely associated with the mobile repair unit, the right equipment may not be available when needed. Moreover, the work is carried out by a company that typically owns and operates several mobile repair units. The units are often operating at the same time at various remote sites. Some sites may be separated by hundreds of miles. This makes it difficult to stay abreast of the status at each of the sites. Typically, a supervisor will travel from site to site. However, this is inefficient and often critical steps of an operation get carried out unsupervised. At times, accidents occur in the absence of an unbiased witness. SUMMARY OF THE INVENTION To avoid the problems of today's mobile repair units, a first object of the invention is to closely associate hydraulic and pneumatic systems with a mobile repair unit by having them share a common power supply and monitoring system. A second object of the invention is to provide a remotely accessible mobile repair unit with the necessary equipment to make it universally adaptable to do a variety of work such as removing and installing an inner tubing string, sucker rods, and pumps. A third object is to provide a mobile repair unit that senses and transmits, to a remote home base, data that identifies the extent to which an inner tubing string was stretched prior to flooding the well bore with fluid. A fourth object is to identify from a remote location key events, such as the time of transition of installing steel sucker rods to installing fiberglass ones. A fifth object is to restrict local operator access to a system that monitors the operation of a mobile repair unit so an unbiased and unaltered record can be recorded and maintained of the complete system and activity of the mobile repair unit. A sixth object is to convey to a remote location a record that helps explain events that led to an accident at the work site. When the information is conveyed to remote site, it is not likely to be destroyed by the accident itself, such as a fire. A seventh object is to remotely identify an imbalance of a mobile repair unit caused by wind or leaning inner tubing segments against its derrick. An eighth object is to remotely distinguish between the raising and lowering of an inner tubing string to help establish the cause of an accident. An added benefit is to be able to place the proper predetermined tension on a packer or tubing anchor being set. A ninth object is to enable one to remotely identify when a mobile repair unit is operating for the purpose of determining the amounts to be invoiced for the work performed. A tenth object is to provide a method of alerting a home base of a hazardous level of hydrogen sulfide gas present at a remote work site. These and other objects of the invention are provided by a self-contained mobile repair unit having a universal set of hydraulic and pneumatic tooling for servicing well equipment such as an inner pipe string, a sucker rod and a pump. The repair unit and tooling share a common engine. An extendible derrick supporting a hoist is pivotally coupled to the frame of the repair unit. A monitor senses the load on the derrick and conveys that information to a remote home base where the time of critical events is identified. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a mobile repair unit with its derrick extended. FIG. 2 is a schematic view of a pneumatic slip in a locked position. FIG. 3 is a schematic view of a pneumatic slip in an open position. FIG. 4 is a schematic illustration of a set of hydraulic tongs. FIG. 5 is a side view of a mobile repair unit with its derrick retracted. FIG. 6 is an electrical schematic of a monitor circuit. FIG. 7 is an end view of an imbalanced derrick. FIG. 8 shows digital data associated with a time stamp. FIG. 9 illustrates the raising and lowering of an inner tubing string. FIG. 10 shows an inner tubing being lowered. FIG. 11 shows an inner tubing stopped at a predetermined depth. FIG. 12 shows an inner tubing being locked in a conventional manner to another casing. FIG. 13 shows an inner tubing being stretched. FIG. 14 shows pre-stretched inner tubing locked within an outer casing. FIG. 15 shows a first steel sucker rod (with a pump) being lowered into an inner tubing string. FIG. 16 shows a second steel sucker rod being lowered into an inner tubing string. FIG. 17 shows a first fiberglass sucker rod being lowered into an inner tubing string. FIG. 18 shows a second fiberglass sucker rod being lowered into an inner tubing string. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a retractable, self-contained mobile repair unit 20 is shown to include a truck frame 22 supported on wheels 24 , an engine 26 , a hydraulic pump 28 , an air compressor 30 , a first transmission 32 , a second transmission 34 , a variable speed hoist 36 , a block 38 , an extendible derrick 40 , a first hydraulic cylinder 42 , a second hydraulic cylinder 44 , a first transducer 46 , a monitor 48 , and retractable feet 50 . Engine 32 selectively couples to wheels 24 and hoist 36 by way of transmissions 34 and 32 , respectively. Engine 26 also drives hydraulic pump 28 via line 29 and air compressor 30 via line 31 . Compressor 30 powers a pneumatic slip 84 (FIGS. 2 and 3 ), and pump 28 powers a set of hydraulic tongs 52 (FIG. 4 ). Pump 28 also powers cylinders 42 and 44 which respectively extend and pivot derrick 40 to selectively place derrick 40 in a working position (FIG. 1) and in a lowered position (FIG. 5 ). In the working position, derrick 40 is pointed upward, but its longitudinal centerline 54 is angularly offset from vertical as indicated by angle 56 . The angular offset provides block 38 access to a well bore 58 without interference with derrick pivot point 60 . With angular offset 56 , the derrick framework does not interfere with the typically rapid installation and removal of numerous inner pipe segments (known as an inner pipe string 62 ) and sucker rods 64 (FIG. 16 ). Individual pipe segments of string 62 and sucker rod 64 are screwed to themselves using hydraulic tongs 66 which are schematically illustrated in FIG. 4 . The term “hydraulic tongs” used herein and below refer to any hydraulic tool that can screw together two pipes or sucker rods. An example would include those provided by B. J. Hughes company of Houston, Tex. In operation, pump 28 drives a hydraulic motor 68 forward and reverse by way of valve 70 . Conceptually, motor 68 drives pinions 72 which turn wrench element 74 relative to clamp 76 . Element 74 and clamp 76 engage flats 81 on mating couplings 78 of a sucker rod or inner pipe string of one conceived embodiment of the invention. However, it is well within the scope of the invention to have rotational jaws or grippers that clamp on to a round pipe (i.e., no flats) similar in concept to a conventional pipe wrench, but with hydraulic clamping. The rotational direction of motor 68 determines assembly or disassembly of couplings 78 . Transducer 80 is used to provide a 0-5 VDC signal 82 that in one embodiment of the invention indicates the applied torque to couplings 18 . Referring to FIGS. 2 and 3, when installing inner pipe string 62 , pneumatic slip 84 is used to hold pipe string 62 while the next segment 62 ′ is screwed on using tongs 66 . Compressor 30 provides pressurized air through valve 86 to rapidly clamp and release slip 84 (FIGS. 2 and 3, respectively). A tank 88 helps maintain a constant air pressure. Pressure switch 90 provides monitor 48 with a signal that indirectly indicates that repair unit 20 is in operation. Referring back to FIG. 1, weight applied to block 38 is sensed by way of a hydraulic pad 92 that supports the weight of derrick 40 . Hydraulic pad 92 is basically a piston within a cylinder (alternatively a diaphragm) such as those provided M. D. Totco company of Cedar Park, Tex. Hydraulic pressure in pad 92 increases with increasing weight on block 38 . In FIG. 6, first transducer 46 converts the hydraulic pressure to a 0-5 VDC signal 94 that is conveyed to monitor 48 . Monitor 48 converts signal 94 to a digital value, stores it in a memory 96 , associates it with a real time stamp, and eventually communicates the data to a remote home base 100 by way of a modem 98 . In the embodiment of FIG. 7, two pads 92 associated with two transducers 46 and 102 are used. An integrator 104 separates pads 92 hydraulically. The rod side of pistons 106 and 108 each have a pressure exposed area that is half the full face area of piston 108 . Thus chamber 110 develops a pressure that is an average of the pressures in pads 92 . One type of integrator 104 is provided by M. D. Totco company of Cedar Park, Tex. In one embodiment of the invention, just one transducer 46 is used and it is connected to port 112 . In another embodiment of the invention, two transducers 46 and 102 are used, with transducer 102 on the right side of unit 20 coupled to port 114 and transducer 46 on the left side coupled to port 116 . Such an arrangement allows one to identify an imbalance between the two pads 92 . Returning to FIG. 6, transducers 46 and 102 are shown coupled monitor 48 . Transducer 46 indicates the pressure on left pad 92 and transducer 102 indicates the pressure on the right pad 92 . A generator 118 driver by engine 26 provides an output voltage proportional to the engine speed. This output voltage is applied across a dual-resistor voltage divider to provide a 0-5 VDC signal at point 120 and then passes through an amplifier 122 . Generator 118 represents just one of many various tachometers that provide a feedback signal proportional to the engine speed. Another example of a tachometer would be to have engine 26 drive an alternator and measure its frequency. Transducer 80 provides a signal proportional to the pressure of hydraulic pump 28 , and thus proportional to the torque of tongs 66 . A telephone accessible circuit 124 , referred to as a “POCKET LOGGER” by Pace Scientific, Inc. of Charlotte, N. C., includes four input channels 126 , 128 , 130 and 132 ; a memory 96 and a clock 134 . Circuit 124 periodically samples inputs 126 , 128 , 130 and 132 at a user selectable sampling rate; digitizes the readings; stores the digitized values; and stores the time of day that the inputs were sampled. It should be appreciated by those skilled in the art that with the appropriate circuit, any number of inputs can be sampled. Page Scientific provides circuits that employ multiplexing to provide twelve input channels. An operator at a home base 100 remote from the work site at which repair unit 20 is operating accesses the data stored in circuit 124 by way of a PC-based mode 98 and a cellular phone 136 . Phone 136 reads the data stored in circuit 124 via lines 138 (RJ11 telephone industry standard)and transmits the data to modem 98 by way of antennas 140 and 142 . In one embodiment of the invention, phone 136 includes a CELLULAR CONNECTION™ provided by Motorola Incorporated of Schaumburg, Ill. (a model S1936C for Series II cellular transceivers and a model S1688E for older cellular transceivers). Some details worth noting about monitor 48 is that its access by way of a modem makes monitor 48 relatively inaccessible to the crew at the job site itself. Amplifiers 122 , 144 , 146 and 148 condition their input signals to provide corresponding inputs 126 , 128 , 130 and 132 having an appropriate power and amplitude range. Sufficient power is needed for RC circuits 150 which briefly (e.g., 2-10 seconds) sustain the amplitude of inputs 126 , 128 , 130 and 132 even after the outputs from transducers 46 , 102 and 80 and the output of generator 118 drop off. This ensures the capturing of brief spikes without having to sample and store an excessive amount of data. A DC power supply 152 provides a clean and precise excitation voltage to transducers 46 , 102 and 80 ; and also supplies circuit 124 with an appropriate voltage by way of voltage divider 154 . Pressure switch 90 enables power supply 152 by way of relay 156 whose contacts 158 close by coil 160 being energized by battery 162 . FIG. 8 shows an example of the data extracted from circuit 124 and remotely displayed at PC 164 . The values plotted at a point in time indicated by numeral 166 represent repair unit 20 at rest with engine 26 idling as shown in FIG. 1 . Numeral 168 showing weight on block 38 and high engine speed indicates the raising of an inner pipe string 62 as represented by arrow 170 of FIG. 9 . Numeral 172 showing weight on block 38 and low engine speed indicates the lowering of inner pipe string 62 as represented by arrow 174 of FIG. 9 . Points 176 , 178 , 180 , 182 and 184 correspond to the conditions illustrated in FIGS. 10, 11 , 12 , 13 and 14 , respectively. In FIG. 10, an inner pipe string 62 is being lowered into an outer casing 186 . In FIG. 11, tubing string is stopped at a predetermined depth. In FIG. 12 pipe string 62 is rotated in a conventional manner to lock its lower end 188 to outer casing 186 (note slight torque at point 190 ). In FIG. 13 an upper end 192 of string 62 is raised until the pressure parameter at right and left pads 92 reach the predetermined limit indicated by numeral 194 . In FIG. 14 wedge 196 locks upper end 192 to casing 186 , and block 38 is disconnected from pipe string 62 . Points 198 , 200 , 202 and 204 correspond to the conditions illustrated in FIGS. 15, 16 , 17 and 18 , respectively, which depict the lowering of a string of sucker rods having a pump 77 at its lower end. Intermediate points 199 , 201 and 203 indicate tongs 66 screwing onto the first steel sucker rod 64 a second steel sucker rods 206 , a fiberglass sucker rod 208 , and a second fiberglass sucker rod 210 , respectively. Note the difference in torque and the incremental weight difference at pads 92 when changing over from steel rods to fiberglass ones. Points 212 correspond to the windy conditions illustrated by arrow 214 of FIG. 7 . The absence of data points beyond 12:00 indicates that the windy conditions prevented the crew from continuing, or it was Friday afternoon. Referring back to FIG. 4, it should be noted that transducer 80 represents any one of a variety of devices that produce an electrical signal in response to a change in a sensed condition. In one embodiment of the invention, transducer 80 is actually a hydrogen sulfide gas detector with signal 82 serving as a gas detection signal that varies with a varying concentration of hydrogen sulfide gas 250 . An example of a hydrogen sulfide gas detect or is a CONTROLLER 8000 provided by Industrial Scientific Corporation of Oakdale, Pa. Although the invention is described with respect to a preferred embodiment, modifications thereto will be apparent to those skilled in the art. Therefore, the scope of the invention is to be determined by reference to the claims which follow.

A self-contained mobile repair unit for repairing wells includes the hydraulic and pneumatic tooling required to do a variety of jobs including the installation and removal of an inner pipe string, sucker rods and a pump. The repair unit, hydraulic tooling and pneumatic tooling share a common engine and a common process monitor. Access to data gathered by the monitor is restricted at the job site itself. Instead, the data is transmitted to a remote home base for the purpose of monitoring operations form a central location.

This application is a division of prior application Ser. No. 08/879,125, filed Jun. 19, 1997. FIELD OF THE INVENTION The present invention relates to a device and method for enhanced image and signal processing for Intravascular Ultrasound ("IVUS"), and more specifically, to a device and method for processing IVUS image and signal information which will enhance the quality and utility of IVUS images. BACKGROUND INFORMATION IVUS images are derived from a beam of ultrasonic energy projected by apparatus such as a transducer or transducer array located around, along or at the tip of a catheter inserted within a blood vessel. An ultrasound beam from the apparatus is continuously rotated within the blood vessel forming a 360° internal cross sectional image, i.e., the image is formed in a transverse (X-Y) plane. Depending on the specific apparatus configuration, the image may be derived either from the same transverse plane of the apparatus or from a transverse plane found slightly forward (i.e., distal) of the transverse plane of the apparatus. If the catheter is moved inside and along the blood vessel (i.e., along the Z-axis), images of various segments (series of consecutive cross sections) of the vessel may be formed and displayed. IVUS may be used in all types of blood vessels, including but not limited to arteries, veins and other peripheral vessels, and in all parts of a body. The ultrasonic signal that is received (detected) is originally an analog signal. This signal is processed using analog and digital methods so as to eventually form a set of vectors comprising digitized data. Each vector represents the ultrasonic response of a different angular sector of the vessel, i.e., a section of the blood vessel. The number of data elements in each vector (axial sampling resolution) and the number of vectors used to scan a complete cross section (lateral sampling resolution) of the vessel may vary depending on the type of system used. The digitized vectors may initially be placed into a two-dimensional array or matrix having Polar coordinates, i.e., A(r, θ). In this Polar matrix, for example, the X axis corresponds to the r coordinate and the Y axis corresponds to the θ coordinate. Each value of the matrix is a value (ranging from 0-255 if the system is 8 bit) representing the strength of the ultrasonic response at that location. This Polar matrix is not usually transferred to a display because the resultant image will not be easily interpreted by a physician. The information stored in the Polar matrix A(r, θ) usually undergoes several processing stages and is interpolated into Cartesian coordinates, e.g., X and Y coordinates (A(X, Y)) that are more easily interpreted by a physician. Thus, the X and Y axis of matrix A(X, Y) will correspond to the Cartesian representation of the vessel's cross-section. The information in the Cartesian matrix possibly undergoes further processing and is eventually displayed for analysis by a physician. Images are acquired and displayed in a variable rate, depending on the system. Some systems can acquire and display images in video-display rate, e.g., up to about 30 images per second. IVUS examination of a segment of a bodily lumen, i.e., vessel is generally performed by situating the catheter distal (i.e., downstream) to the segment to be reviewed and then the catheter is pulled back (pullback) slowly along the bodily lumen (Z-axis) so that successive images that form the segment are continuously displayed. In many cases the catheter is connected to a mechanical pulling device which pulls the catheter at a constant speed (i.e., a typical speed is approximately 0.5-1 mm/sec.). In IVUS imaging systems today the technique described above for displaying an image of a cross section of a bodily lumen, e.g., blood vessel, is generally used. These systems are deficient, however, because they do not include any form of stabilization of the images to compensate for movements of the catheter and/or bodily lumen, e.g., blood vessel. It is well known that during IVUS imaging of a bodily lumen, there is always motion exhibited by the catheter and/or the bodily lumen. This motion might be exhibited in the transverse (X-Y) plane, along the vessel axis (Z axis) or a combination of those movements. The imaging catheter can also be tilted in relation to the vessel so that the imaging plane is not perpendicular to the Z axis (This movement shall be termed as angulation). These movements are caused by, among other things, beating of the heart, blood and/or other fluid flow through the lumen, vasomotion, forces applied by the physician, and other forces caused by the physiology of the patient. In IVUS systems today, when the imaging catheter is stationary or when performing slow manual or mechanical pullback, relative movement between the catheter and the lumen is the primary factor for the change in appearance between successive images, i.e., as seen on the display and/or on film or video. This change in appearance occurs because the rate of change of an image due to movements is much greater than the rate of change in the real morphology due to pullback. Stabilization occurs when the images include compensation for the relative movement between the catheter and the lumen in successive images. Because none of the IVUS systems used today perform stabilization, there is no compensation for or correction of relative movements between the catheter and the lumen. As a result, morphological features are constantly moving or rotating, i.e., on the display and/or film or video. This makes it difficult for the physician to accurately interpret morphology in an IVUS dynamic display. Furthermore, when non-stabilized IVUS images are fed as an input to a processing algorithm such as 3D reconstruction or different types of filter that process a set of successive images, this can lead to degraded performance and misdiagnosis or inaccurate determinations. Current IVUS imaging apparatus or catheters may have occasional malfunctions of an electronic or mechanical origin. This can cause displayed images to exhibit both recognized or unrecognized artifacts and obscure the real morphology. Currently there is no automatic methods to determine whether images posses these types of artifacts which hamper the analysis of the images of the vessel or bodily lumen. The behavior of cardiovascular function is generally periodic. The detection of this periodicity and the ability to establish correlation between an image and the temporal phase in the cardiac cycle to which it belongs is referred to as cardiac gating. Currently, cardiac gating is performed by using an external signal, usually an ECG (Electro-Cardiogram). However, ECG gating requires both the acquisition of the ECG signal and its interleaving (or synchronization) with the IVUS image. This requires additional hardware/software. Morphological features in IVUS images of blood vessels can be broken into three general categories: the lumen, i.e., the area through which the blood or other bodily fluid flows; the vessel layers; and the exterior, i.e., the tissue or morphology outside of the vessel. Blood in most IVUS films (images) is characterized by a rapidly changing speckular pattern. The exterior of the vessel also alternates with high temporal frequency. Currently, the temporal behavior of pixels and their textural attributes are not monitored automatically. Vasomotion in the context of bodily lumens, e.g., blood vessel, is defined as the change in the caliber of the lumen, e.g., vessel. This change can be brought about by natural circumstances or under induced conditions. Vasomotion can have a dynamic component, i.e., dynamic change of the lumen's dimensions, e.g., vessel's caliber (contraction and dilation) during the cardiovascular cycle, and a baseline static component, i.e., a change in the baseline caliber of the lumen, e.g., vessel. Vasomotion can be expressed as quantitative physiological parameters indicating the ability of the lumen, e.g., vessel to change its caliber under certain conditions. These types of parameters have current and possibly future medical and diagnostic importance in providing information regarding the state of the lumen, e.g., vessel and the effect of the therapy performed. IVUS can be used to monitor vasomotion because it provides an image of the lumen's baseline caliber and its dynamic changes. Additionally, IVUS can be used to monitor whether the vasomotion is global (uniform), i.e., where the entire cross-section of the lumen contracts/dilates in the same magnitude and direction. IVUS can also be used to determine whether the vasomotion is non-uniform which leads to local changes in the caliber of the lumen, i.e., different parts of the lumen cross-section behave differently. Currently, all types of vasomotion monitoring by IVUS are performed manually. This is tedious, time consuming, and prevents monitoring of the vasomotion in real time. Interpretation of IVUS images is achieved through analysis of the composition of the static images and monitoring their temporal behavior. Most IVUS images can be divided into three basic parts. The most inner section is the flow passage of the lumen, i.e., the cavity through which matter, i.e., blood, flows. Around the flow passage is the actual vessel, which may include blood vessels and any other bodily vessels, which is composed of multiple layers of tissue (and plaque, if diseased). Outside the vessel other tissue which may belong to the surrounding morphology, for example, the heart in a coronary vessel image. When the IVUS film is viewed dynamically, i.e., in film format, the pixels corresponding to matter flowing through the vessel and to the morphology exterior to the vessel exhibit a different temporal behavior than the vessel itself. For example, in most IVUS films, blood flowing through the vessel is characterized by a frequently alternating speckular pattern. The morphology exterior to the vessel also exhibits frequent alternation. Currently the temporal behavior of pixels in dynamic IVUS images is not monitored automatically. In current IVUS displays, if designed into the system, high frequency temporal changes are suppressed by means such as averaging over a number of images. However, this sometimes fails to suppress the appearance of features with high amplitudes, i.e., bright gray values, and it also has a blurring effect. The size of the flow passage of the lumen is a very important diagnostic parameter. When required for diagnosis, it is manually determined by, for example, a physician. This is accomplished by drawing the contour of the flow passage borders superimposed on a static image, e.g., frozen on video or on a machine display. This method of manual extraction is time consuming, inaccurate and subject to bias. Currently, there is commercial image processing software for the automatic extraction of the flow passage. However, these are based on the gray value composition of static images and do not take into account the different temporal behavior exhibited by the material, e.g., blood flowing through the passage as opposed to the vessel layers. During treatment of vessels, it is common practice to repeat IVUS pullback examinations in the same vessel segments. For example, a typical situation is first to review the segment in question, evaluate the disease (if any), remove the IVUS catheter, consider therapy options, perform therapy, e.g., PTCA-"balloon" or stenting, and then immediately thereafter reexamine the treated segment using IVUS in order to assess the results of the therapy. To properly evaluate the results and fully appreciate the effect of the therapy performed, it is desirable that the images of the pre-treated and post-treated segments, which reflect cross sections of the vessel lying at the same locations along the vessel's Z-axis (i.e., corresponding segments), be compared. To accomplish this comparison it must be determined which locations in the films of the pre-treatment IVUS images and post-treatment IVUS images correspond to one another. This procedure, called matching (registration) allows an accurate comparison of pre- and post-treatment IVUS images. Currently, matching is usually performed by viewing the IVUS pullback films of pre- and post-treatment segments, one after the other or side by side by using identifiable anatomical landmarks to locate the sequences that correspond visually to one another. This method is extremely imprecise and difficult to achieve considering that the images are unstable and often rotate and/or move around on the display due to the absence of stabilization and because many of the anatomical landmarks found in the IVUS pullback film of the pre-treatment segment may be disturbed or changed as a result of the therapy performed on the vessel. Furthermore, the orientation and appearance of the vessel is likely to change as a result of a different orientations and relative positions of the IVUS catheter in relation to the vessel due to its removal and reinsertion after therapy is completed. The matching that is performed is manual and relies primarily on manual visual identification which can be extremely time consuming and inaccurate. SUMMARY OF THE INVENTION The present invention solves the problems associated with IVUS imaging systems currently on the market and with the prior art by providing physicians with accurate IVUS images and image sequences of the morphology being assessed, thereby enabling more accurate diagnosis and evaluation. The present invention processes IVUS image and signal information to remove distortions and inaccuracies caused by various types of motion in both the catheter and the bodily lumen. This results in both enhanced quality and utility of the IVUS images. An advantage provided by the present invention is that individual IVUS images are stabilized with respect to prior image(s), thereby removing negative effects on any later processing of multiple images. If the movements in each image are of the transverse type, then it is possible for the motion to be completely compensated for in each acquired image. The present invention also allows volume reconstruction algorithms to accurately reproduce the morphology since movement of the bodily lumen is stabilized. The present invention is applicable to and useful in any type of system where there is a need to stabilize images (IVUS or other) because a probe (e.g., ultrasonic or other) moving through a lumen experiences relative motion (i.e., of the probe and/or of the lumen). The present invention provides for detection of an ultrasonic signal emitted by ultrasonic apparatus in a bodily lumen, conversion of the received analog signal into Polar coordinates (A(r, θ)), stabilization in the Polar field, converting the stabilized Polar coordinates into Cartesian coordinates (A(X, Y)), stabilization in the Cartesian field and then transferring the stabilized image as Cartesian coordinates to a display. Stabilized images, either in Polar or Cartesian coordinates, may be further processed prior to display or they might not be displayed. Conversion into Cartesian coordinates and/or stabilization in the Cartesian field may be done at any point either before or after stabilization in the Polar field. Additionally, either of Polar or Cartesian stabilization may be omitted, depending on the detected shift in the image and/or other factors. Furthermore, additional forms of stabilization may be included or omitted depending on the detected shift and/or other factors. For example, stabilization of rigid motion may be introduced to compensate for rotational motion (angular) or global vasomotion (expansion or contraction in the r direction) in the Polar field and/or for Cartesian displacement (X and/or Y direction) in the Cartesian field. Transverse rigid motion between the representations of successive images is called a "shift," i.e., a uniform motion of all morphological features in the plane of the image. To stabilize IVUS images, the first step that is performed is "shift evaluation and detection." This is where the shift (if any) between each pair of successive images is evaluated and detected. The system may utilize a processor to perform an operation on a pair of successive IVUS images to determine whether there has been a shift between such images. The processor may utilize a single algorithm or may select from a number of algorithms to be used in making this determination. The system utilizes the algorithm(s) to simulate a shift in an image and then compares this shifted image to its predecessor image. The comparisons between images are known as closeness operations which may also be known in the prior art as matching. The system performs a single closeness operation for each shift. The results of the series of closeness operations is evaluated to determine the location (direction and magnitude) of the shifted image that bears the closest resemblance to the predecessor unshifted image. An image can of course be compared in the same manner to its successor image. After the actual shift is determined, the current image becomes the predecessor image, the next image becomes the current image and the above operation is repeated. Using shift evaluation and detection, the system determines the type of transverse shift, e.g., rotational, expansion, contraction, displacement (Cartesian), etc., along with the direction and magnitude of the shift. The next step is "shift implementation." This is where the system performs an operation or a series of operations on successive IVUS images to stabilize each of the images with respect to its adjacent predecessor image. This stabilization utilizes one or multiple "reverse shifts" which are aimed at canceling the detected shift. The system may include an algorithm or may select from a number of algorithms to be used to implement each "reverse shift." The logic which decides upon what reverse shift will actually be implemented on an image, prior to its feeding to further processing or display, is referred to as "shift logic". Once the IVUS images are stabilized for the desired types of detected motion, the system may then transfer the Cartesian (or Polar) image information for further processing and finally for display where the results of stabilization may be viewed, for example, by a physician. Alternatively, stabilization can be invisible to the user in the sense that stabilization can be used prior to some other processing steps, after which, resulted images are projected to the display in their original non-stabilized posture or orientation. It is possible that the transverse motion between images will not be rigid but rather of a local nature, i.e., different portions of the image will exhibit motion in different directions and magnitudes. In that case the stabilization methods described above or other types of methods can be implemented on a local basis to compensate for such motion. The present invention provides for detection of the cardiac periodicity by using the information derived only from IVUS images without the need for an external signal such as the ECG. This process involves closeness operations which are also partly used in the stabilization process. One important function of detecting periodicity (i.e., cardiac gating), when the catheter is stationary or when performing controlled IVUS pullback, is that it allows the selection of images belonging to the same phase in successive cardiac cycles. Selecting images based on the cardiac gating will allow stabilization of all types of periodic motion (including transverse, Z-axis and angulations) in the sense that images are selected from the same phase in successive heart-beats. These IVUS images, for example, can be displayed and any gaps created between them may be compensated for by filling in and displaying interpolated images. The IVUS images selected by this operation can also be sent onward for further processing. The closeness operations used for periodicity detection can also be utilized for monitoring image quality and indicate artifacts associated with malfunction of the imaging and processing apparatus. Operations used for shift evaluation can automatically indicate vasomotion. This can serve the stabilization process as vasomotion causes successive images to differ because of change in the vessel's caliber. If images are stabilized for vasomotion, then this change is compensated for. Alternatively, the information regarding the change in caliber may be displayed since it might have physiological significance. Monitoring of vasomotion is accomplished by applying closeness operations to successive images using their Polar representations, i.e., A(r, θ). These operations can be applied between whole images or between corresponding individual Polar vectors (from successive images), depending on the type of information desired. Since global vasomotion is expressed as a uniform change in the lumen's caliber it can be assessed by a closeness operation which takes into account the whole Polar image. In general, any operation suitable for global stabilization in the Polar representation can be used to assess global vasomotion. Under certain conditions during IVUS imaging there may be non-uniform vasomotion, i.e., movement only in certain sections of the IVUS image corresponding to specific locations in the bodily lumen. This may occur, for example, where an artery has a buildup of plaque in a certain location, thereby allowing expansion or contraction of the artery only in areas free of the plaque buildup. When such movement is detected the system is able to divide the ultrasound signals representing cross sections of the bodily lumen into multiple segments which are then each processed individually with respect to a corresponding segment in the adjacent image using certain algorithm(s). The resulting IVUS images may then be displayed. This form of stabilization may be used individually or in conjunction with the previously discussed stabilization techniques. Alternatively, the information regarding the local change in vessel caliber can be displayed since it might have physiological significance. The temporal behavior of pixels and their textural attributes could serve for: enhancement of display; and automatic segmentation (lumen extraction). If monitored in a stabilized image environment then the performance of the display enhancement and segmentation processes may be improved. According to the present invention, the temporal behavior of IVUS images may be automatically monitored. The information extracted by such monitoring can be used to improve the accuracy of IVUS image interpretation. By filtering and suppressing the fast changing features such as the matter, e.g., blood flowing through the vessel and the morphology exterior to the vessel as a result of their temporal behavior, human perception of the vessel on both static images and dynamic images, e.g., images played in cine form, may be enhanced. Automatic segmentation, i.e., identification of the vessel and the matter, e.g., blood flowing through the vessel may be performed by using an algorithm which automatically identifies the matter, e.g., blood based on the temporal behavior of textural attributes formed by its comprising pixels. The temporal behavior that is extracted from the images can be used for several purposes. For example, temporal filtering may be performed for image enhancement, and detection of the changes in pixel texture may be used for automatic identification of the lumen and its circumference. In all IVUS images, the catheter itself (and imaging apparatus) is best to be eliminated from the image prior to performing stabilization or for monitoring. Failure to eliminate the catheter might impair stabilization techniques and monitoring. Elimination of the catheter may be performed automatically since its dimensions are known. The present invention also provides for automatic identification (i.e., matching or registration) of corresponding frames of two different IVUS pullback films of the same segment of a vessel, e.g., pre-treatment and post-treatment. To compare a first IVUS pullback film, i.e., a first IVUS imaging sequence, with a second IVUS pullback film, i.e., a second IVUS imaging sequence, of the same segment of a bodily lumen, for example, captured on video, film or in digitized form, the imaging sequences must be synchronized. Matching, which will achieve this synchronization, involves performing closeness operations between groups of consecutive images belonging to the two sets of IVUS imaging sequences. Out of one imaging sequence a group of consecutive images, termed the reference group, is selected. This group should be selected from a portion of the vessel displayed in both imaging sequences and it should be a portion on which therapy will not be performed since the morphology of the vessel is likely to change due to therapy. Another condition for this matching process is that the two imaging sequences are acquired at a known, constant and preferably the same pullback rate. Closeness operations are performed between the images of the reference group and the images from the second group which has the same number of successive images extracted from the second imaging sequence. This second group of images is then shifted by a single frame with respect to the reference group and the closeness operations are repeated. This may be repeated for a predetermined number of times and the closeness results of each frame shift are compared to determine maximal closeness. Maximal closeness will determine the frame displacement between the images of the two imaging sequences. This displacement can be reversed in the first or second film so that corresponding images may be automatically identified and/or viewed simultaneously. Thus, corresponding images may be viewed, for example, to determine the effectiveness of any therapy performed or a change in the morphology over time. Additionally, the various types of stabilization discussed above may be implemented within or between the images in the two sequences, either before, during or after this matching operation. Thus, the two films can be displayed not only in a synchronized fashion, but also in the same orientation and posture with respect to one another. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1(a) and (b) show a two-dimensional array or matrix of an image arranged in digitized vectors in Polar and Cartesian coordinates, respectively. FIG. 2 illustrates the results of a shift evaluation between two successive images in Cartesian coordinates. FIG. 3 shows images illustrating the occurrence of drift phenomena in Polar and Cartesian coordinates. FIG. 4 illustrates the effect of performing stabilization operations (rotational and Cartesian shifts) on an image. FIG. 5 illustrates global contraction or dilation of a bodily lumen expressed in the Polar representation of the image and in the Cartesian representation of the image. FIG. 6 shows an image divided into four sections for processing according to the present invention. FIG. 7 shows a vessel, in both Cartesian and Polar coordinates, in which local vasomotion has been detected. FIG. 8 illustrates the results of local vasomotion monitoring in a real coronary vessel in graphical form. FIG. 9 shows an ECG and cross-correlation coefficient plotted graphically in synchronous fashion. FIG. 10 shows a table of a group of cross-correlation coefficient values (middle row) belonging to successive images (numbers 1 through 10 shown in the top row) and the results of internal cross-correlations (bottom row). FIG. 11 shows a plot of a cross-correlation coefficient indicating an artifact in IVUS images. FIG. 12 shows an IVUS images divided into three basic parts: the lumen through which fluid flows; the actual vessel; and the surrounding tissue. FIG. 13 illustrates the results of temporal filtering. FIG. 14 shows an image of the results of the algorithm for automatic extraction of the lumen. FIG. 15 illustrates the time sequence of a first film (left column), reference segment from the second film (middle column) and the images from the first film which correspond (or match) the images of the reference segment (right column). DETAILED DESCRIPTION In intravascular ultrasound (IVUS) imaging systems the ultrasonic signals are emitted and received by the ultrasonic apparatus, for example, a transducer or transducer array, processed and eventually arranged as vectors comprising digitized data. Each vector represents the ultrasonic response of a different angular sector of the bodily lumen. The number of data elements in each vector (axial sampling resolution) and the number of vectors used to scan the complete cross-section (lateral sampling resolution) of the bodily lumen depends on the specific IVUS system used. The digitized vectors are initially packed into a two-dimensional array or matrix which is illustrated in FIG. 1(a). Generally, this matrix has what are known as Polar coordinates, i.e., coordinates A(r, θ). The X-axis of the matrix shown in FIG. 1(a) corresponds to the r coordinate while the Y-axis of the matrix corresponds to the θ coordinate. Each value of the matrix is generally a gray value, for example, ranging from 0-255 if it is 8 bit, representing the strength of the ultrasonic signal at that corresponding location in the bodily lumen. This Polar matrix may then be converted into a Cartesian matrix as shown in FIG. 1(b) having an X-axis and Y-axis which correspond to the Cartesian representation of the vessel's cross-section. This image may then be further processed and transferred to a display. The initial array and the display may each utilize either Polar or Cartesian coordinates. The values for the matrix may be other than gray values, for example, they may be color values or other values and may be less than or more than 8 bits. During an IVUS imaging pullback procedure the bodily lumen, hereinafter referred to as a vessel, and/or the imaging catheter may experience several modes of relative motion. These types of motion include: (1) Rotation in the plane of the image, i.e., a shift in the θ-coordinate of the Polar image; (2) Cartesian displacement, i.e., a shift in the X and/or Y coordinate in the Cartesian image; (3) Global vasomotion, characterized by a radial contraction and expansion of the entire vessel, i.e., a uniform shift in the r-coordinate of the Polar image; (4) Local vasomotion, characterized by a radial contraction and expansion of different parts of the vessel with different magnitudes and directions, i.e., local shifts in the r-coordinate of the Polar image; (5) Local motion, characterized by different tissue motion which vary depending on the exact location within the image; and (6) Through plane motion, i.e., movements which are perpendicular or near perpendicular (angulation) to the plane of the image. Stabilization of successive raw images is applicable to the first 5 types of motion described above because motion is confined to the transverse plane. These types of motion can be compensated for, and stabilization achieved, by transforming each current image so that its resemblance to its predecessor image is maximized. The first 3 types of motion can be stabilized using closeness operations which compare whole or large parts of the images one to another. This is because the motion is global or rigid in its nature. The 4th and 5th types of motion are stabilized by applying closeness operations on a localized basis because different parts of the image exhibit different motion. The 6th type of motion can be only partly stabilized by applying closeness operations on a localized basis. This is because the motion is not confined to the transverse plane. This type of motion can be stabilized using cardiovascular periodicity detection. The next sections shall describe methods for global stabilization, followed by a description of methods for local stabilization. Stabilization using cardiovascular periodicity detection shall be described in the sections discussing periodicity detection. To achieve global stabilization, shift evaluation is performed using some type of closeness operation. The closeness operation measures the similarity between two images. Shift evaluation is accomplished by transforming a first image and measuring its closeness, i.e., similarity, to its predecessor second image. The transformation may be accomplished, for example, by shifting the entire first image along an axis or a combination of axes (X and/or Y in Cartesian coordinates or r and/or θ in Polar coordinates) by a single pixel (or more). Once the transformation, i.e., shift is completed the transformed first image is compared to the predecessor second image using a predefined function. This transformation is repeated, each time by shifting the first image an additional pixel (or more) along the same and/or other axis and comparing the transformed first image to the predecessor second image using a predefined function. After all of the shifts are evaluated, the location of the global extremum of the comparisons using the predefined function will indicate the direction and magnitude of the movement between the first image and its predecessor second image. For example, FIG. 2 illustrates the results of a shift evaluation between two successive images in Cartesian coordinates. Image A is a predecessor image showing a pattern, e.g., a cross-section of a vessel, whose center is situated in the bottom right quadrant of the matrix. Image B is a current image showing the same pattern but moved in an upward and left direction and situated in the upper left quadrant of the matrix. The magnitude and direction of the movement of the vessel's center is indicated by the arrow. The bottom matrix is the C(shiftX, shiftY) matrix which is the resulting matrix after performing shift evaluations using some type of closeness operation. There are many different algorithms or mathematical functions that can be used to perform the closeness operations. One of these is cross-correlation, possibly using Fourier transform. This is where the current and predecessor images each consisting of, for example, 256×256 pixels, are each Fourier transformed using the FFT algorithm. The conjugate of the FFT of the current image is multiplied with the FFT of the predecessor image. The result is inversely Fourier transformed using the IFFT algorithm. The formula for cross-correlation using Fourier transform can be shown as follows: C=real(ifft2((fft2(A))*conj(fft2(B)))) where: A=predecessor image matrix (e.g., 256×256); B=current image matrix (e.g., 256×256); fft2=two dimensional FFT; ifft2=two dimensional inverse FFT; conj=conjugate; real=the real part of the complex expression; *=multiplication of element by element; and C=cross-correlation matrix. Evaluating closeness using cross-correlation implemented by Fourier transform is actually an approximation. This is because the mathematical formula for the Fourier transform relates to infinite or periodic functions or matrices, while in real life the matrices (or images) are of a finite size and not necessarily periodic. When implementing cross-correlation using FFT, the method assumes periodicity in both axes. As a result, this formula is a good approximation and it reflects the actual situation in the θ-axis of the Polar representation of the image, however, it does not reflect the actual situation in the r-axis of the Polar representation or of the X- or Y-axis of the Cartesian representation of the image. There are a number of advantages to cross-correlation utilizing FFT. First, all values of the cross-correlation matrix C(shiftX, shiftY) are calculated by this basic operation. Furthermore, there is dedicated hardware for the efficient implementation of the FFT operation, i.e. Fourier transform chips or DSP boards. Another algorithm that can be used to perform closeness operations is direct cross-correlation, either normalized or not. This is achieved by multiplying each pixel in the current shifted image by its corresponding pixel in the predecessor image and summing up all of the results and normalizing in the case of normalized cross-correlation. Each shift results in a sum and the actual shift will be indicated by the largest sum out of the evaluated shifts. The formula for cross-correlation can be shown by the following formula: ##EQU1## The formula for normalized cross correlation is ##EQU2## Using this direct method of cross-correlation, C(shiftX, shiftY) can be evaluated for all possible values of shiftX and shiftY. For example, if the original matrices, A and B, have 256×256 pixels each, then shiftX and shiftY values, each ranging from -127 to +128 would have to be evaluated, making a total of 256×256=65,536 shift evaluations in order for C(shiftX, shiftY) to be calculated for all possible values of shiftX and shiftY. Upon completion of these evaluations the global maximum of the matrix is determined. Direct cross-correlation can be implemented more efficiently by lowering the number of required arithmetic operations. In order to detect the actual shift between images, evaluation of every possible shiftX and shiftY is not necessary. It is sufficient to find the location of the largest C(shiftX, shiftY) of all possible shiftX and shiftY. A third algorithm that can be used to perform closeness operations is the sum of absolute differences (SAD). This is achieved by subtracting each pixel in one image from its corresponding pixel in the other image, taking their absolute values and summing up all of the results. Each shift will result in a sum and the actual shift will be indicated by the lowest sum. The formula for sum of absolute differences (SAD) can be shown as follows: SAD=absolute(A-B) This formula can also be shown as follows: ##EQU3## While the accuracy of each of these algorithms/formulas may vary slightly depending on the specific type of motion encountered and system settings, it is to be understood that no single formula can, a-priori be classified as providing the best or most accurate results. Additionally, there are numerous variations on the formulas described above and other algorithms/formulas that may be utilized for performing shift evaluation and which may be substituted for the algorithms/formulas described above. These algorithms/formulas also include those operations known in the prior art for use as matching operations Referring again to FIG. 2, if the closeness operation performed is cross-correlation, then C(shiftX, shiftY) is called the cross-correlation matrix and its global maximum (indicated by the black dot in the upper left quadrant) will be located at a distance and direction from the center of the matrix (arrow in matrix C) which is the same as that of the center of the vessel in Image B relative to the center of the vessel in image A (arrow in Image B). If the closeness operation performed is SAD, then the black dot would indicate the global minimum which will be located at a distance and direction from the center of the matrix (arrow in matrix C) which is the same as that of the center of the vessel in Image B relative to the center of the vessel in Image A (arrow in Image B). Rotational motion is expressed as a shift along the current Polar image in the θ-coordinate relative to its predecessor. The rotational shift in a current image is detected by maximizing the closeness between the current Polar image and its predecessor. Maximum closeness will be obtained when the current image is reversibly shifted by the exact magnitude of the actual shift. In for example, a 256×256 pixel image, the value of the difference (in pixels) between 128 and the θ-coordinate of the maximum in the cross-correlation image (minimum in the SAD image), will indicate the direction (positive or negative) and the magnitude of the rotation. Global vasomotion is characterized by expansion and contraction of the entire cross section of the vessel. In the Polar image this type of motion is expressed as movement inwards and outwards of the vessel along the r-axis. Vasomotion can be compensated by performing the opposite vasomotion action on a current Polar image in relation to its predecessor Polar image using one of the formulas discussed above or some other formula. In contrast to angular stabilization, vasomotion stabilization does not change the orientation of the image but actually transforms the image by stretching or compressing it. Cartesian displacement is expressed as a shift in the X-axis and/or Y-axis in the Cartesian image relative to its predecessor. This type of motion is eliminated by shifting the Cartesian image in an opposite direction to the actual shift. Thus, Cartesian displacement, in the Cartesian representation, can be achieved by essentially the same arithmetic operations used for rotational and vasomotion stabilization in the Polar representation. The number of shift evaluations necessary to locate the global extremum (maximum or minimum, depending on the closeness function) of C(shiftX, shiftY) may be reduced using various computational techniques. One technique, for example, takes advantage of the fact that motion between successive IVUS images is, in general, relatively low in relation to the full dimensions of the Polar and/or Cartesian matrices. This means that C(shiftX, shiftY) can be evaluated only in a relatively small portion around the center of the matrix, i.e., around shiftX=0, shiftY=0. The extremum of that portion is assured to be the global extremum of matrix C(shiftX, shiftY) including for larger values of shiftX and shiftY. The size of the minimal portion which will assure that the extremum detected within it is indeed a global extremum varies depending on the system settings. The number of necessary evaluation operations may be further reduced by relying on the smoothness and monotonous property expected from the C matrix (especially in the neighborhood of the global extremum). Therefore, if the value in the C(shiftX, shiftY) matrix at a certain location is a local extremum (e.g., in a 5×5 pixel neighborhood), then it is probably the global extremum of all of matrix C(shiftX, shiftY). Implementing this reduction of the number of necessary evaluations can be accomplished by first searching from the center of the matrix (shiftX=0, shiftY=0) and checking a small neighborhood, e.g., 5×5 pixels around the center. If the local extremum is found inside this neighborhood then it is probably the global extremum of the whole matrix C(shiftX, shiftY) and the search may be terminated. If, however, the local extremum is found on the edges of this neighborhood, e.g., shiftX=-2, shiftX=2, shiftY=-2 or shiftY=2, then the search is repeated around this pixel until a C(shiftX, shiftY) value is found that is bigger (smaller) than all of its close neighbors. Because in a large number of images there is no inter-image motion, the number of evaluations needed to locate the global extremum in those cases, will be approximately 5×5=25, instead of the original 65,536 evaluations. The number of necessary evaluation operations may also be reduced by sampling the images. For example, if 256×256 sized images are sampled for every second pixel then they are reduced to 128×128 sized matrixes. In this case, direct cross-correlation or SAD, between such matrixes involve 128×128 operations instead of 256×256 operations, each time the images are shifted one in relation to the other. Sampling, as a reduction method for shift evaluation operations can be interleaved with other above described methods for reduction. Referring again to FIG. 2, as a result of the closeness operation, the indicated shiftX will have a positive value and shiftY a negative value. In order to stabilize Image B, i.e., compensate for the shifts in the X and Y directions, shift logic will reverse the shifts, i.e., change their sign but not their magnitude, and implement these shifts on the matrix corresponding to Image B. This will artificially reverse the shift in Image B and cause Image B to be unshifted with respect to Image A. The actual values used in the closeness calculations need not necessarily be the original values of the matrix as supplied by the imaging system. For example, improved results may be achieved when the original values are raised to the power of 2, 3 or 4 or processed by some other method. The imaging catheter and the enclosing sheath appear as constant artifacts in all IVUS images. This feature obscures closeness operations performed between images since it is not part of the morphology of the vessel. It is, therefore, necessary to eliminate the catheter and associated objects from each image prior to performing closeness operations, i.e., its pixels are assigned a value of zero. The elimination of these objects from the image may be performed automatically since the catheter's dimensions are known. Shift evaluation and implementation may be modular. Thus, shift evaluation and implementation may be limited to either Polar coordinates or Cartesian coordinates individually, or shift evaluation and implementation may be implemented sequentially for Polar and Cartesian coordinates. Presently, because imaging in IVUS systems is generally organized by first utilizing Polar coordinates and then converting into Cartesian coordinates, it is most convenient to perform shift evaluation and implementation in the same sequence. However, the sequence may be modified or changed without any negative effects or results. The shift evaluation process can be performed along one or two axis. In general, two dimensional shift evaluation is preferred even when motion is directed along one axis. Shift implementation may be limited to both axis, one axis or neither axis. There is not a necessary identity between the area in the image used for shift evaluation and between the area on which shift implementation is performed. For example, shift evaluation may be performed using a relatively small area in the image while shift implementation will shift the whole image according to the shift indicated by this area. A trivial shift logic is one in which the shift implemented on each image (thereby forming a stabilized image) has a magnitude equal, and in opposite direction, to the evaluated shift. However, such logic can result in a process defined as Drift. Drift is a process in which implemented shifts accumulate and produce a growing shift whose dimensions are significant in relation to the entire image or display. Drift may be a result of inaccurate shift evaluation or non-transverse inter-image motion at some part of the cardiovascular cycle. When Cartesian stabilization is implemented, drift can cause, for example, the shifting of a relatively large part of the image out of the display. When rotational stabilization is implemented, drift can cause the increasing rotation of the image in a certain direction. FIG. 3 is an image illustrating the occurrence of drift in Polar and Cartesian coordinates. The left image is the original display of the image while the right image is the same image after Polar and Cartesian stabilization has been performed. Note how the right image is rotated counter-clockwise in a large angle and shifted downward in relation to the left image. In this case, rotational and Cartesian shift implementation do not compensate for actual shifts in the image, but rather arise from inaccurate shift evaluation. The shift logic must be able to deal with this drift so that there will be a minimal implementation of mistaken evaluated shifts. One method for preventing, or at least limiting drift is by setting a limit to the magnitude of allowable shifts. This will minimize the drift but at the cost of not compensating for some actual shift. Additional methods can be used to prevent or minimize shift. These may possibly be interleaved with cardio-vascular periodicity detection methods discussed later. The images shown in FIG. 4 illustrate the effect of performing stabilization operations (rotational and Cartesian shifts) on an image. The left image is an IVUS image from a coronary artery as it would look on a large portion of a regular display (with catheter deleted) while the right image shows how the left image would be displayed after stabilization operations are implemented. Taking a close look at the left and right images in FIG. 4, certain differences can be observed. First, the right image is slightly rotated in a clockwise direction (i.e., by a few degrees) in relation to the left image. This is the result of rotational stabilization. Next, the right image is translated in a general left direction in relation to the left image. This can be detected by noting the distance of the lumen (cavity) from the edges of the picture in each image. This is a result of Cartesian shift stabilization operations. The advantages of stabilization of the displayed image cannot be appreciated by viewing single images as shown in FIG. 4. However, viewing a film of such images would readily illustrate the advantages. In a display which does not include stabilization, the location of the catheter would always be situated in the center of the display and the morphological features would move around and rotate on the display. In contrast, in a stabilized display, the location of the catheter would move around while the morphological features would remain basically stationary. Stabilization does not necessarily have to be exhibited on an actual display. It can be invisible to the user in the sense that stabilization will enhance subsequent processing steps, but the actual display will exhibit the resultant processed images in their original (non-stabilized) posture and orientation. FIG. 5 illustrates global contraction or dilation of a vessel, expressed in the Polar representation of the image as a movement of the features along the r-coordinates, i.e., movement along the Polar vectors. FIG. 5 also shows the same global contraction or dilation expressed in the Cartesian representation of the image. FIG. 5(a) shows the baseline appearance of the cross section of a vessel in both the Polar and Cartesian representations. FIG. 5(b) shows a relative to baseline contraction of the vessel. FIG. 5(c) shows a relative to baseline uniform dilation of the vessel. Since global vasomotion is expressed as a uniform change in the vessel's caliber, any operation suitable for stabilization in the Polar representation can be used to assess global vasomotion, e.g., it can be assessed by a closeness operation utilizing the entire Polar image. After two dimensional shift evaluation is performed, as discussed above, the location of the maximum in matrix C(shiftX, shiftY) on the θ-axis is utilized for rotational stabilization. This leaves the location of the extremum on the r-axis, which can be used as an indication of global vasomotion. Thus, global vasomotion monitoring is a by-product of two dimensional shift evaluation in the Polar image. Each pair of successive images produce a value indicative of the vasomotion. Both the magnitude and the sign of the resulting shift between images characterize the change in the vessel, i.e., vasomotion. Negative shifts indicate dilation, and positive shifts indicate contraction. The magnitude of the value indicates the magnitude of the vasomotion change. Under certain circumstances motion or vasomotion may not be uniform/rigid although confined to the plane of the image, i.e., transverse. To determine the type of motion or vasomotion, the image may be divided into sections and global stabilization evaluation performed on each of these sections. By examining the indicated shifts of these sections relative to the corresponding sections in the predecessor image, a determination can be made as to the type of motion. For example, as shown in FIG. 6, the image in FIG. 6(a) can be divided into four sections as shown in FIG. 6(b). Shift evaluation can be performed separately on each of the four sections. Comparison between the results of the shift evaluation for each of the four sections can possibly identify the type of actual motion. Thus, the type of stabilization applied can be varied depending on the type of motion detected. Stabilization for local motion is achieved by performing closeness operations on a localized basis. Small portions of the predecessor image A ("template" regions) and small portions of the current image B ("search" regions) participate in the local stabilization process. Sometimes, it is best to perform local stabilization after global stabilization has been performed. During local stabilization, template regions in the predecessor image (A) are shifted within search regions and compared, using closeness operations to template sized regions in the current image (B). Each pixel, in the (newly) formed stabilized image (B') will be assigned a new value based on the results of the search and closeness evaluation performed. Local stabilization is illustrated by the following example in which the template region is a 1×1 pixel region, i.e., a single pixel, the search region is a 3×3 pixel region and the closeness operation is SAD. In the following diagram, the pixel valued 3 in A and the pixel valued 9 in B are corresponding pixels. The 3×3 pixel neighborhood of the pixel valued 9 is also illustrated. ______________________________________Pixel in A ("template" region) Pixels in B (3 × 3 "search" region) B'______________________________________3 1 10 10 1 7 9 50 11 7 60______________________________________ In this example, according to the conditions described above the `template` pixel valued 3 is compared using SAD to all pixels found in the 3×3 search region around the pixel valued 9. The pixel valued 1 at the top left corner of the search region will achieve the minimal SAD value (|1-3|=2) out of all the possibilities in the search region. As a result, in the newly formed stabilized image (B'), the pixel corresponding in location to pixels valued 3 and 9 will be assigned the value of 1. In general, the dimensions of the template and search region can be varied along with the closeness operations used. The actual value which is assigned to the pixel of the newly formed stabilized image (B') need not necessarily be an actual pixel value from the current image B (as illustrated in the example) but some function of pixel values. It is important to note that as a result of local stabilization, as opposed to the global/rigid methods, the "composition" of the image, i.e., the internal relationship between pixels, and their distribution in the stabilized image, changes in relation to the original image. Local stabilization can be implemented on both the Polar and Cartesian representations of the image. FIG. 7 shows a vessel, in both Cartesian and Polar coordinates, in which local vasomotion has been detected. When local vasomotion is detected, it is an indication that some parts of the cross-section of the vessel are behaving differently than other parts of the cross-section. FIG. 7(a) shows a baseline figure of the vessel prior to local vasomotion. FIG. 7(b) shows an example of local vasomotion. As indicated in both the Cartesian and Polar representations, four distinct parts of the vessel behave differently: two segments of the vessel do not change caliber, or do not move relative to their corresponding segments in the predecessor image; one segment contracts, or moves up; and one segment dilates, or moves down. As can be observed, global vasomotion evaluation methods are not appropriate for evaluating local vasomotion because the vessel does not behave in a uniform manner. If global vasomotion evaluation was to be applied, for example, on the example shown in FIG. 7, it might detect overall zero vasomotion, i.e. the contraction and dilation would cancel each other. Therefore, local vasomotion evaluation methods must be utilized. This may be achieved by separately evaluating vasomotion in each Polar vector, i.e., in each θ (or Y) vector. Closeness operations are applied using one dimensional shifts in corresponding Polar vectors. For example, if closeness is utilized with cross-correlation, then the following operation illustrates how this is accomplished using one dimensional shifts. ##EQU4## As can be seen, shifting is performed along one axis (X or r-axis) for each and every Polar vector (θ or Y vector). The values assigned in each vector for shift evaluation may not be the actual values of the images but, for example, each pixel in the vector can be assigned the average of its lateral neighbors, i.e., A(X, Y) will be assigned, for example, the average of A(X, Y-1), A(X, Y) and A(X, Y+1). The same goes for B(shiftX, Y). This can make the cross-correlation process more robust to noise. A two dimensional matrix (C(shiftX, Y)) is formed. Each column in the matrix stores the results of closeness/similarity operations performed between corresponding Polar vectors from the current image and the predecessor image. This operation could also have been implemented using FFT. After formation of the matrix, the location of the extremum (maximum in the cross-correlation operation) in each column is detected. This extremum location indicates the match between the current Polar vector and its predecessor. Thus, the vasomotion in each vector can be characterized, i.e., the radial movement in each specific angular sector of the vessel. This information can be used to display the local vasomotion, it can be added up from some or all Polar vectors and averaged to determine an average value for the vasomotion, or it can be used for other purposes. Therefore, by evaluating local vasomotion, both local and global vasomotion can be evaluated. To be effectively used and/or expressed as quantitative physiological parameters, the magnitude of vasomotion must relate in some fashion to the vessel's actual caliber. Thus, measurements of vasomotion monitoring should generally be used in conjunction with automatic or manual measurements of the vessel's caliber Besides for true vasomotion, Cartesian displacement may also be detected as vasomotion. This is because Cartesian displacement, when expressed in Polar coordinates, results in shifts along both the r and θ axes. To distinguish true vasomotion from Cartesian displacement, shift evaluation in the Cartesian image must indicate no, or little motion. If Cartesian displacement is detected, then it must first be stabilized. Thereafter, the Cartesian coordinates may be converted back into Polar coordinates for vasomotion evaluation. This will allow greater success and provide more accurate results when determining actual vasomotion. The graphs in FIG. 8 illustrate the results of local vasomotion monitoring in a human coronary vessel in vivo. Local vasomotion monitoring was performed twice in approximately the same segment of the vessel, and consisted of 190 successive images as shown (X-axis) in FIGS. 8(a) and 8(b). The difference between the two graphs is that the vasomotion evaluation shown in FIG. 8(a) was performed prior to treatment of the artery, i.e., pre-intervention, while the vasomotion evaluation shown in FIG. 8(b) was performed after treatment of the artery, i.e., post-intervention. In every image, vasomotion was assessed locally in every Polar vector and then all detected individual shifts were added and averaged to produce a single global vasomotion indication (Y-axis) for each image, i.e., an indication for vasomotion activity. The units on the Y-axis do not have a direct physiological meaning because the actual caliber of the vessel was not calculated, but the relationship between the values in FIGS. 8(a) and 8(b) have a meaning because they were extracted from the same vessel. Thus, important information may be derived from these figures. Note how the vasomotion increased after treatment (maximal vasomotion from approximately 40 to approximately 150). Therefore, even though vasomotion was not fully quantified, a change in physiology (probably linked to the treatment) has been demonstrated. Cardiovascular periodicity may be monitored solely based on information stored in IVUS images, thereby eliminating the need for an ECG or any other external signal. This means that a link can be established between every image and its respective temporal phase in the cardiovascular cycle without need for an external signal. Once this linkage is established, then monitoring can substitute the ECG signal in a large number of utilities which require cardiac gating. This monitoring may be accomplished using closeness operations between successive images. Moreover, the same closeness operations can produce information regarding the quality of IVUS images and their behavior. The cardiac cycle manifests itself in the cyclic behavior of certain parameters that are extracted by IVUS images. If the behavior of these parameters are monitored, then the periodicity of the cardiac cycle can be determined. Knowing the frame acquisition rate will also allow the determination of the cardiovascular cycle as a temporal quantity. The closeness between successive IVUS images is a parameter which clearly behaves in a periodic pattern. This is a result of the periodicity of most types of inter-image motion that are present. A closeness function may be formed in which each value results from a closeness operation between a pair of successive images. For example, a set of ten images will produce nine successive closeness values. The closeness function can be derived from a cross-correlation type operation, SAD operation or any other type of operation that produces a closeness type of function. Normalized cross-correlation produces very good results when used for monitoring periodicity. The following formula shows the formula for the cross-correlation coefficient (as a function of the Nth image) for calculating the closeness function: ##EQU5## The correlation coefficient is a byproduct of the stabilization process, because the central value (shiftX=0, shiftY=0) of the normalized cross-correlation matrix (C(shiftX, shiftY)) is always computed. This holds true for all types of closeness functions used for stabilization. The central value of the closeness matrix (C(shiftX=0, shiftY=0)), either cross-correlation or another type of operation used for stabilization, can always be used for producing a closeness function. The closeness function can also be computed from images which are shifted one in relation to another, i.e., the value used to form the function is C(shiftX, shiftY) where shiftX and shiftY are not equal to zero. The Closeness function need not necessarily be formed from whole images but can also be calculated from parts of images, either corresponding or shifted in relation to one another. FIG. 9 shows an ECG and cross-correlation coefficient plotted graphically in synchronous fashion. Both curves are related to the same set of images. FIG. 9(a) shows a graph of the ECG signal and FIG. 9(b) shows a graph of the cross-correlation coefficient derived from successive IVUS images. The horizontal axis displays the image number (a total of 190 successive images). As can be observed, the cross-correlation coefficient function in FIG. 9(b) shows a periodic pattern, and its periodicity is the same as that displayed by the ECG signal in FIG. 9(a) (both show approximately six heart beats). Monitoring the periodicity of the closeness function may be complicated because the closeness function does not have a typical shape, it may vary in time, it depends on the type of closeness function used, and it may vary from vessel segment to vessel segment and from subject to subject. To monitor the periodicity of the closeness function continuously and automatically a variety of methods may be employed. One method, for example, is a threshold type method. This method monitors for a value of the closeness function over a certain value known as a threshold. Once this value is detected, the method monitors for when the threshold is again crossed. The period is determined as the difference in time between the crossings of the threshold. An example of this method is shown in FIG. 10 as a table. The table shows a group of cross-correlation coefficient values (middle row) belonging to successive images (numbers 1 through 10 shown in the top row). If the threshold, for example, is set to the value of 0.885, then this threshold is first crossed in the passage from image #2 to image #3. The threshold is crossed a second time in the passage from image #6 to image #7. Thus, the time period of the periodicity is the time taken to acquire 7-3=4 images. Another method that can be used to extract the cardiac periodicity from the closeness curve is internal cross-correlation. This method utilizes a segment of the closeness function, i.e., a group of successive values. For example, in the table shown in FIG. 10, the segment may be comprised of the first four successive images, i.e., images #1 through #4. Once a segment is chosen, it is cross-correlated with itself, producing a cross-correlation value of 1. Next, this segment is cross-correlated with a segment of the same size extracted from the closeness function, but shifted one image forward. This is repeated, with the segment shifted two images forward, and so on. In the example shown in FIG. 10, the segment {0.8, 0.83, 0.89, 0.85} would be cross-correlated with a segment shifted by one image {0.83, 0.89, 0.85, 0.82}, then the segment {0.8, 0.83, 0.89, 0.85} would be cross-correlated with a segment shifted by two images {0.89, 0.85, 0.82, 0.87}, and so on. The bottom row of the table in FIG. 10 shows the results of these internal cross-correlations. The first value of 1 is a result of the cross-correlation of the segment with itself. These cross-correlation values are examined to determine the location of the local maxima. In this example, they are located in image #1 and image #5 (their values are displayed in bold). The resulting periodicity is the difference between the location of the local maxima and the location from which the search was initiated (i.e., image #1). In this example, the periodicity is the time that elapsed from the acquisition of image #1 to image #5, which is 5-1=4 images. Once a period has been detected, the search begins anew using a segment surrounding the local maximum, e.g., image #5. In this example, for example, the new segment could be the group of closeness values belonging to images #4 through #7. Due to the nature of the type of calculation involved, the internal cross-correlation operation at a certain point in time requires the closeness values of images acquired at a future time. Thus, unlike the threshold method, the closeness method requires the storage of images (in memory) and the periodicity detection is done retrospectively. The cardiac periodicity can also be monitored by transforming the closeness curve into the temporal frequency domain by the Fourier transform. In the frequency domain the periodicity should be expressed as a peak corresponding to the periodicity. This peak can be detected using spectral analysis. The closeness function can provide additional important information about IVUS images which cannot be extracted from external signals, such as ECG, that are not derived from the actual images. The behavior of this function can indicate certain states in the IVUS images or image parts used to form the closeness function. Important features in the closeness function which are indicative of the state of the IVUS images are the presence of periodicity and the "roughness" of the closeness function. Normal IVUS images should exhibit a relatively smooth and periodic closeness function as displayed, for example, in FIG. 9(b). However, if "roughness" and/or periodicity are not present then this could indicate some problem in the formation of IVUS images, i.e., the presence of an artifact in the image formation caused by, for example, either a mechanical or electronic malfunction. The following figure helps to illustrate this. FIG. 11 shows a graph of the cross-correlation coefficient derived from successive IVUS images. This graph is analogues, in its formation, to the cross-correlation plot in FIG. 9(b), but in this example it is formed by a different imaging catheter used in a different subject. In this example, it is clear that the closeness function does not exhibit clear periodicity nor does it have a smooth appearance but rather a rough or spiky appearance. In this case the behavior of the closeness graph was caused by the non-uniformity of the rotation of the IVUS transducer responsible for emitting/collecting the ultrasonic signals displayed in the image. This type of artifact sometimes appears in IVUS catheter-transducer assemblies in which there are moving mechanical parts. The closeness function, when considered to reflect normal imaging conditions, can serve for a further purpose. This is linked with the location of the maxima in each cycle of the closeness function. Locating these maxima may be important for image processing algorithms which process several successive images together. Images found near maxima images tend to have high closeness and little inter-image motion, one in relation to the other. Additionally, if images belonging to the same phase of successive cardiac cycles are required to be selected, it is usually best to select them using the maxima (of the closeness function) in each cycle. In one display method, for example, these images are projected onto the display and the gaps are filled in by interpolated images. By this display method all types of periodic motion can be stabilized. The shift logic stage in the stabilization process can also make use of cardiovascular periodicity monitoring. If drift is to be avoided, the accumulated shift after each (single) cardiac cycle should be small or zero, i.e., the sum of all shifts over a period of a cycle should result in zero or near zero. This means that the drift phenomena can be limited by utilizing shift logic which is coupled to the periodicity monitoring. Referring now to FIG. 12, most IVUS images can be divided into three basic parts. The central area (around the catheter), labeled as Lumen in FIG. 12, is the actual lumen or interior passageway (cavity) through which fluid, e.g., blood flows. Around the lumen, is the actual vessel, labeled Vessel in FIG. 12, composed of several layers of tissue and plaque (if diseased). Surrounding the vessel is other tissue, labeled Exterior in FIG. 12, i.e., muscle or organ tissue, for example, the heart in the coronary vessel image. When IVUS images are viewed dynamically (i.e., in film format), the display of the interior, where the blood flows, and of the exterior surrounding the vessel, usually shows a different temporal behavior than the vessel itself. Automatically monitoring the temporal behavior of pixels in the dynamic IVUS image would allow use of the information extracted by the process to aid in interpretation of IVUS images. This information can be used to enhance IVUS displays by filtering and suppressing the appearance of fast changing features, such as fluid, e.g., blood, and the surrounding tissue, on account of their temporal behavior. This information can also be used for automatic segmentation, to determine the size of the lumen automatically by identifying the fluid, e.g., blood, and the surrounding tissue based on the temporal behavior of textural attributes formed by their composing pixels. To accomplish automatic monitoring of temporal behavior there must be an evaluation of the relationship between attributes formed by corresponding pixels belonging to successive images. Extraction of temporal behavior bears resemblance to the methods used for closeness operations on a localized basis, as described previously. High temporal changes are characterized by relatively large relative gray value changes of corresponding pixels, when passing from one image to the next. These fast temporal changes may be suppressed in the display by expressing these changes through the formation of a mask which multiplies the original image. This mask reflects temporal changes in pixel values. A problem that arises in this evaluation is determining whether gray value changes in corresponding pixel values are due to either flow or change in matter, or movements of the vessel/catheter. By performing this evaluation on stabilized images overcomes or at least minimizes this problem. The following definitions apply: B=current (stabilized or non-stabilized) image; A=predecessor (stabilized or non-stabilized) image; C=successor (stabilized or non-stabilized) image; abs=absolute value. The matrices used can be either in Cartesian or Polar form. The following operation, resulting in a matrix D1, shall be defined as follows: D1 is a matrix, in which each pixel with coordinates X, Y is the sum of the absolute differences of its small surrounding neighborhood, e.g., 9 elements (X-2:X+2, Y-2:Y+2--a 3×3 square), extracted from images A and B, respectively. For example, the following illustration shows corresponding pixels (in bold) and their close neighborhood in matrices A and B. ______________________________________A B D1______________________________________1 4 51 3 6 8 1906 7 15 3 4 703 5 83 2 1 6______________________________________ The pixel in matrix D1, with the location corresponding to the pixels with value 4 (in B) and 7 (in A) will be assigned the following value: abs(1-3)+abs (4-6)+abs(51-8)+abs(6-3)+abs(7-4)+abs(15-70)+abs(3-2)+abs(5-1)+abs(83-6)=190 D2 is defined similarly but for matrices B and C. D1 and D2 are, in effect, difference matrices which are averaged by using the 3×3 neighborhood in order to diminish local fluctuations or noise. Large gray value changes between images A and B or between B and C will be expressed as relatively high values in matrices D1 and D2 respectively. A new matrix, Dmax is next formed, in which every pixel is the maximum of the corresponding pixels in matrices D1 and D2: Dmax=max(D1,D2) where: max(D1, D2)=each pixel in Dmax holds the highest of the two corresponding pixels in D1 and D2. Thus, the single matrix Dmax particularly enhances large pixel changes between matrices A, B and C. A mask matrix (MD), is then formed from Dmax by normalization, i.e., each pixel in Dmax is divided by the maximal value of Dmax. Therefore, the pixel values of the mask MD range from zero to one. The role of the mask is to multiply the current image B in the following manner, forming a new matrix or image defined as BOUT: BOUT=(1-MD.sup.n)*B where: B=original current image; BOUT=the new image; n =each pixel in the matrix MD is raised to the power of n. n is generally a number with a value, for example, of 2-10; 1-MD n =a matrix in which each pixel's value is one minus the value of the corresponding pixel in MD. By performing the subtraction 1-MD n , small values of MD which reflect slow changing features become high values in 1-MD n . Moreover, the chance that only slow changing features will have high values is increased because of the prior enhancement of high MD values (by forming MD as a maximum between matrices D1 and D2). The multiplication of the mask (1-MD n ) by the current image B, forms a new image BOUT in which the appearance of slow changing pixels are enhanced while fast changing pixels' values are decreased. The number n determines how strong the suppression of fast changing features will look on the display. FIG. 13 illustrates the results of temporal filtering. The left image is an original IVUS image (i.e., matrix B) from a coronary vessel, as it would look on the current display. The right image has undergone the processing steps described above, i.e., temporal filtering (matrix BOUT). Note that in the right image, blood and the surrounding tissue is filtered (suppressed) and lumen and vessel borders are much easier to identify. Automatic segmentation differentiates fluid, e.g., blood and exterior, from the vessel wall based on the differences between the temporal behavior of a textural quality. As in the case of temporal filtering, this method is derived from the relationship between corresponding pixels from a number of successive images. If pixel values change because of inter-image motion, then performance of the algorithm will be degraded. Performing stabilization prior to automatic segmentation will overcome, or at least minimize this problem. As in the case of temporal filtering, the following definitions shall apply: B=current (stabilized or non-stabilized) image; A=predecessor (stabilized or non-stabilized) image; C=successor (stabilized or non-stabilized) image. The matrices can be either in Cartesian or Polar form. The textural quality can be defined as follows: Suppose the four nearest neighbors of a pixel with value "a" are "b," "c," "d" and "e," then the classification of "a" will depend on its relations with "b," "c," "d" and "e." This can be shown with the following illustration: ##EQU6## The following categories can now be formed: In the vertical direction: if a>b and a>e then "a" is classified as belonging to the category I; if a>b and a<e then "a" is classified as belonging to the category II; if a<b and a<e then "a" is classified as belonging to the category III; if a<b and a>e then "a" is classified as belonging to the category IV; if a=b or a=e then "a" is classified as belonging to the category V. In the horizontal direction: if a>c and a>d then "a" is classified as belonging to the category I; if a>c and a<d then "a" is classified as belonging to the category II; if a<c and a<d then "a" is classified as belonging to the category III; if a<c and a>d then "a" is classified as belonging to the category IV; if a=c or a=d then "a" is classified as belonging to the category V. The vertical and horizontal categories are next combined to form a new category. As a result, pixel "a" can now belong to 5×5=25 possible categories. This means that the textural quality of "a" is characterized by its belonging to one of those (25) categories. For example, in the following neighborhood: ##EQU7## Pixel "a"=10 is classified as belonging to the category which includes category I vertical (because 10>7 and 10>3) and category V horizontal (because 10=10). However, if pixel "a" would have been situated in the following neighborhood: ##EQU8## it would have been classified as belonging to a different category because its horizontal category is now category III (10<11 and 10<14). By determining the relationship of each pixel to its close neighborhood a textural quality has been formed which classifies each pixel into 25 possible categories. The number of categories may vary (increased or decreased), i.e., for example, by changing the categorizing conditions, as may the number of close neighbors used, for example, instead of four, eight close neighbors may be used. The basic concept by which the textural changes are used to differentiate fluid, e.g., blood, from the vessel is by monitoring the change in categories of corresponding pixels in successive images. To accomplish this the category in each and every pixel in matrices A, B and C are determined. Next, corresponding pixels are each tested to see if this category has changed. If it has, the pixel is suspected of being a fluid, e.g., blood, or surrounding tissue pixel. If it has not changed, then the pixel is suspected of being a vessel pixel. The following example shows three corresponding pixels (with values 8, 12 and 14) and their neighborhoods in successive matrices A, B and C. ______________________________________A B C______________________________________ 5 9 19 8 11 19 12 13 21 14 1723 100 20______________________________________ In this example, the category of the pixel valued 12 (in B) is the same as in A and C, so it will be classified as a pixel with a higher chance of being a vessel wall pixel. If, however, the situation was as shown below (20 in C changes to 13): ______________________________________A B C______________________________________ 5 9 19 8 11 19 12 13 21 14 1723 100 13______________________________________ then pixels 8 in A and 12 in B have the same categories, but 14 in C has a different category as in the prior example. As a result, pixel 12 in B will be classified as a pixel with a higher chance of being a fluid (lumen), i.e., blood, or exterior tissue pixel. The classification method described so far monitors the change in the texture or pattern associated with the small neighborhood around each pixel. Once this change is determined as described above, each pixel can be assigned a binary value. For example, a value of 0, if it is suspected to be a vessel pixel, or a value of 1, if it is suspected to be a blood pixel or a pixel belonging to the vessel's exterior. The binary image, serves as an input for the process of identification of the lumen and the original pixel values cease to play a role in the segmentation process. Identification of the lumen using the binary image is based on two assumptions which are generally valid in IVUS images processed in the manner described above. The first, is that the areas in the image which contain blood or are found on the exterior of the vessel are characterized by a high density of pixels with a binary value of 1 (or a low density of pixels with a value of zero). The term density is needed because there are always pixels which are misclassified. The second assumption, is that from a morphological point of view, connected areas of high density of pixels with the value of 1 (lumen) should be found around the catheter and surrounded by connected areas of low density of pixels with the value of 1 (vessel) which are in turn, surrounded again by connected areas of high density of pixels with the value of 1 (vessel's exterior). The reason for this assumption is the typical morphological arrangement expected from a blood vessel. These two assumptions form the basis of the subsequent processing algorithm which extracts the actual area associated with the lumen out of the binary image. This algorithm can utilize known image processing techniques, such as thresholding the density feature in localized regions (to distinguish blood/exterior from vessel ) and morphological operators such as dilation or linking to inter-connect and form a connected region which should represent the actual lumen found within the vessel wall limits. FIG. 14 shows an image of the results of the algorithm for automatic extraction of the lumen. The image is an original IVUS image (for example, as described above as image B) and the lumen borders are superimposed (by the algorithm) as a bright line. The algorithm for the extraction of the lumen borders was based on the monitoring of the change in the textural quality described above, using three successive images. The examples described above of temporal filtering and automatic segmentation include the use of two additional images (for example, as described above as images A and C) in addition to the current image (for example, as described above as image B). However, both of these methods could be modified to utilize less (i.e., only one additional image) or more additional images. The performance of the two methods described above will be greatly enhanced if combined with cardiovascular periodicity monitoring. This applies, in particular, to successive images in which cardiovascular periodicity monitoring produces high inter-image closeness values. Those images usually have no inter-image motion. Thus, most reliable results can be expected when successive images with maximal inter-image closeness are fed as inputs to either temporal filtering or automatic segmentation. During treatment of vessels using catheterization, it is a common practice to repeat IVUS pullback examinations in the same vessel segment. For example, a typical situation is first to review the segment in question, evaluate the disease (if any), remove the IVUS catheter, consider therapy options, perform therapy and then immediately after (during the same session) examine the treated segment again using IVUS in order to assess the results of therapy. To properly assess the results of such therapy, corresponding segments of the pre-treatment and post-treatment segments which lie on the same locations along the length of the vessel, i.e., corresponding segments, should be compared. The following method provides for matching, i.e., automatic identification (registration) of corresponding segments. To accomplish matching of corresponding segments, closeness/similarity operations are applied between images belonging to a first group of successive images, i.e., a reference segment, of a first pullback film and images belonging to a second group of successive images of a second pullback film. Matching of the reference segment in the first film to its corresponding segment in the second film is obtained when some criteria function is maximized. From either one of the two films a reference segment is chosen. The reference segment may be a group of successive images representing, for example, a few seconds of film of an IVUS image. It is important to select the reference segment from a location in a vessel which is present in the two films and has undergone no change as a result of any procedure, i.e., the reference segment is proximal or distal to the treated segment. As an example, the table in FIG. 15 will help clarify the method for matching of corresponding segments. The left column shows the time sequence of the first film, in this case the film consists of twenty successive images. The middle column, shows the reference segment which is selected from the second film and consists of 10 successive images. The right column lists the 10 successive images from the first film (#5-#14) which actually correspond to (or match) the images of the reference segment from the second film (#1-#10). The purpose of the matching process is to actually reveal this correspondence. Once a reference segment is chosen, it is shifted along the other film, one image (or more) each time, and a set of stabilization and closeness operations are performed between the corresponding images in each segment. The direction of the shift depends on the relative location of the reference segment in the time sequence of the two films. However, in general, if this is not known, the shift can be performed in both directions. In the example of FIG. 15: r=reference segment; and f=first film, the first set of operations will take place between the images comprising the following pairs: r#1-f#1, r#2-f#2, r#3-f#3, . . . , r#10-f#10. The second set of operations will take place between the images comprising the following pairs: r#1-f#2, r#2-f#3, r#3-f#4, . . . , r#10-f#11. The third set of operations will take place between the images comprising the following pairs: r#1-f#3, r#2-f#4, r#3-f#5, . . . , f#10-f#12, and so on, etc. As can be observed in this example, the shifting is performed, by a single image each time and in one direction only. For example, the following operations between the images in each pair may be performed. First, an image from the reference segment is stabilized for rotational and Cartesian motion, in relation to its counterpart in the first film. Then closeness operations are performed between the images in each pair. This operation can be, for example, normalized cross-correlation (discussed above in relation to periodicity detection). Each such operation produces a closeness value, for example, a cross-correlation coefficient when normalized cross-correlation is used. A set of such operations will produce a number of cross-correlation values. In the example shown in the table of FIG. 15, each time the reference segment is shifted, ten new cross-correlation coefficients will be produced. The closeness values produced by a set of operations can then be mapped into some type of closeness function, for example, an average function. Using the above example, the cross-correlation coefficients are summed up and then divided by the number of pairs, i.e., ten. Each set of operations results therefore, in a single value, i.e., an average closeness, which should represent the degree of closeness between the reference segment and its temporary counterpart in the first film. Thus, the result of the first set of operations will be a single value, the result of the second set of operations will be another value, etc. We can expect that the maximal average closeness will occur as a result of the operations performed between segments which are very alike, i.e., corresponding or matching segments. In the above example of FIG. 15, these segments should be matched during the fifth set of operations which take place between the images comprising the following pairs: r#1-f#5, r#2-f#6, r#3-f#7, . . . , r#10-f14. The maximal average closeness should, therefore, indicate corresponding segments because each pair of images are, in fact, corresponding images, i.e., they show the same morphology. The criteria might not, however, follow this algorithm. It may, for example, take into account the form of the closeness function, derived from many shifted segment positions instead of using only one of its values which turns out to be the maximum. Once corresponding segments are identified, the complete first and second films may be synchronized one in relation to the other. This will be a result of an appropriate frame shift, revealed by the matching process, implemented in one film in relation to the other. Thus, when watching the two films side by side, the pre-treated segment will appear concurrently with the post-treated section. Besides for synchronizing the corresponding segments, the above operation also stabilizes the corresponding segments one in relation to the other. This further enhances the ability to understand the changes in morphology. Thus, even though when the catheter is reinserted in the vessel its position and orientation are likely to have changed, nevertheless, the images in the pre-treatment and post-treatment films will be stabilized in relation to each other. The number of images used for the reference segment may vary. The more images used in the matching process, the more robust and less prone to local errors it will be. However, the tradeoff is more computational time required for the calculations for each matching process as the number of pairs increases. It is important in acquiring the pullback films that the pullback rate remains stable and is known. It is preferred that the pullback rate be identical in the two acquisitions. Many different variations of the present invention are possible. The various features described above may be incorporated individually and independently of one another. These features may also be combined in various groupings.

A device and method for intravascular ultrasound imaging. A catheter including ultrasonic apparatus is introduced into and may be moved through a bodily lumen. The apparatus transmits ultrasonic signals and detects reflected ultrasound signals which contain information relating to the bodily lumen. A processor coupled to the catheter is programmed to derive a first image or series of images and a second image or series of images from the detected ultrasound signals. The processor is also programmed to compare the second image or series of images to the first image or series of images respectively. The processor may be programmed to stabilize the second image in relation to the first image and to limit drift. The processor may also be programmed to monitor the first and second images for cardiovascular periodicity, image quality, temporal change and vasomotion. It can also match the first series of images and the second series of images.

TECHNICAL FIELD [0001] The invention relates generally to devices that are used to project a sequence of balls at a controlled rate and more particularly to such devices that are easily converted from use with one given-sized ball to a significantly different-sized ball. DESCRIPTION OF THE RELATED ART [0002] There are a number of available devices which are used to improve the playing skills of participants of a particular sport. Ball tossing devices are commonly used in such sports as tennis, baseball and softball to develop hitting and catching skills. Ball tossing devices may also be useful for sports in which the ball is significantly larger (e.g., soccer) and/or has a shape other than a sphere (e.g., American football). [0003] U.S. Pat. No. 4,669,444 to Whitfield et al. describes a ball tossing apparatus which varies the direction of successive tosses. The apparatus includes a cam mechanism which extends to the exterior of a housing. Rotation of a cam shaft changes the tilt angle of the housing and the direction of the next toss. The apparatus may be used in a hitting practice or a fielding practice in such sports as baseball and softball, but different sports require different embodiments of the apparatus. [0004] A ball pitching device is described in U.S. Pat. No. 5,562,282 to Stevenson. The device is particularly adapted for use in softball, since it simulates the mechanics of an underhand fast pitch. A pitching arm is pivoted to a ball-engaging position, where it receives a ball from a supply chamber. The pitching arm is caused to pivot forwardly to project the ball. The pitching arm then returns to its ball-engaging position to receive a next ball. [0005] While the known devices operate well for their intended purposes, the devices are not easily adapted for use in different sports. Thus, a supplier may need to provide a different device for sports in which balls have different sizes. Even within the same sport, the regulation ball may vary. For example, most governing bodies of organized softball dictate a 12-inch (30.48 cm) regulation softball, but allow an 11-inch (27.94 cm) softball for younger players, such as those in ten-and-under age leagues. For some ball tossing devices, this difference in ball size makes the difference between whether a particular machine may be used or is unsuitable. [0006] Not all devices are restricted to use with a single ball. U.S. Pat. No. 5,066,010 to Pingston describes a ball dispensing machine that may be used for different-sized balls. The machine includes a carrier from which a ball is dropped, so that a player can attempt to hit the ball before it reaches the ground. The carrier has a relatively large U-shape, but guide bars may be inserted into the carrier to reduce the dimensions. As a result of the insertable guide bars, the machine is adaptable to be used in sports having different-sized balls. However, there are sports skills that are best practiced by utilizing a means for projecting the ball, rather than dropping it. Thus, the Pingston machine is versatile with respect to the selection of the ball, but its versatility is somewhat limited with respect to the range of skills that can be developed. [0007] What is needed is a ball projecting apparatus which may be used to practice skills in a variety of different sports. SUMMARY OF THE INVENTION [0008] A ball projecting apparatus in accordance with the invention includes a singulator that has a fork-and-actuator mechanism that is adjustable to allow the apparatus to be used for a variety of sports. The positions of fork prongs relative to each other and to a ball-supply path determine the dimensions of the balls for which the singulator is currently suited. In the preferred embodiment, the apparatus includes a set of forks, so that the fork can be changed in order to convert the singulator from use in one sport to use in another. However, the adjustment may be made on a single fork, if the fork is designed to enable adjustments. [0009] The fork of the singulator may also be referred to as a rocker, since it is pivoted between either a first position in which a foremost ball along the ball-supply path is impeded from advancing or a second position in which the foremost ball is released, but the next ball is impeded. Typically, the ball-supply path is a gravity-feed ball path. When the fork is in the first position, a forward prong of the fork contacts the downstream surface of the foremost ball. However, by rocking the fork to the second position, the forward prong rises above the level of the foremost ball, while the rearward prong is lowered to prevent the next ball from advancing with the foremost ball. [0010] The fork prongs extend in a direction that is generally perpendicular to the ball path. In the preferred embodiment, each fork includes a metallic plate from which the fork prongs are cantilevered. In this embodiment, the fork that is presently mounted within the apparatus can be easily removed and replaced with another fork that is designed for a different-sized ball. However, other embodiments are contemplated. For example, each fork may have a pair of plates that are connected at opposite ends of the fork prongs. [0011] In addition to changing the distance between the two fork prongs, a conversion from one sport to another sport may require an adjustment of the space between each prong and the ramp that forms the ball-supply path. This adjustment may be accomplished by varying the length of an actuator arm which controls the rocking of the fork. [0012] The apparatus also includes a projection mechanism for releasing the ball that is within a firing chamber of the apparatus. Preferably, the projection mechanism is also sport-neutral (i.e., does not restrict the apparatus to use for balls of a particular sport). A ball may be projected by first relaxing a belt and then tensioning the belt to propel a ball that is resting on the belt. Since the relaxed belt will conform to the shape of the ball, the dimensions of the ball are not critical to proper operation. Thus, the invention is easily adapted for use in sports that include volleyball, basketball, lacrosse, etc. In fact, if the ball feeding mechanism is properly constructed, the invention may be used in sports having non-spherical balls (e.g., American football) or in hockey if the hockey pucks are fed into the apparatus so that they roll along their circumferential edges as they progress along the supply path. BRIEF DESCRIPTION OF THE DRAWINGS [0013] [0013]FIG. 1 is a side view of a ball projecting apparatus having an adjustable fork-and-actuator mechanism in accordance with one embodiment of the invention. [0014] [0014]FIG. 2 is a top view of the apparatus of FIG. 1, with selected components being shown for greater clarity. [0015] [0015]FIG. 3 is a side view of the apparatus of FIG. 1, but with the adjustable fork-and-actuator mechanism in a ball-release position. [0016] [0016]FIG. 4 is a side view of the fork-and-actuator mechanism of FIG. 1. [0017] [0017]FIG. 5 is a perspective view of the fork of the mechanism of FIG. 4. [0018] [0018]FIG. 6 is a rear view of the fork of FIG. 5. [0019] [0019]FIG. 7 shows a two-piece set of alternative forks for use in the apparatus of FIG. 1. DETAILED DESCRIPTION [0020] With reference to FIG. 1, a sport-convertible apparatus 10 is shown as including a housing 12 in which balls 14 , 16 , 18 , 20 and 22 are gravity-fed along a ball-supply path to a firing chamber 24 . As will be described in detail below, the apparatus includes a singulator that can be adjusted from one that handles a given-sized ball to one that handles a different-sized ball. Many of the features that are unrelated to the adjustable singulator are described in U.S. Pat. No. 4,669,444 to Whitfield et al., which is hereby incorporated by reference. [0021] The apparatus 10 includes a pair of adjustable legs 26 and 28 from which an internally threaded lower portion telescopes by manually rotating the attached feet 30 and 32 . The rearward leg 28 is longer, so that the balls 16 - 22 along the supply path formed by a ramp 34 abut each other while being pulled by gravity toward the singulator position of the foremost ball 16 and then from the singulator position to the firing chamber 24 , as indicated by ball 14 . The use of the legs 26 and 28 is not critical to the invention, since other means for achieving the desired slant of the apparatus 10 may be substituted. [0022] Referring now to FIGS. 1 and 2, the apparatus includes a cylindrical sleeve 36 that provides the opening through which the balls 14 - 22 are introduced. A hopper (not shown) or similar device may be connected to the sleeve to provide a continuous supply of balls to the apparatus. There is also an opening through the housing 12 to the firing chamber 24 , so that the ball 14 may be projected through the opening. Four cylindrical ball guides 38 , 40 , 42 and 44 seat the ball 14 within the firing chamber and guide the ball when fired. [0023] A single motor assembly 46 is used to drive all of the functions of the apparatus 10 . A fan 48 is used to provide cooling. Preferably, the motor assembly includes an electric motor, but other types of motors may be substituted. While not shown in FIGS. 1 and 2, the motor assembly drives rotation of a continuous chain, such as the bicycle-type chain described in the above-referenced patent to Whitfield et al. The chain includes one or more actuating members 50 that determine the timing of the repeating operations, as will be explained more fully below. [0024] A number of non-critical features are illustrated in FIGS. 1 and 2. For example, the shield for protecting the moving parts is included in the drawings. The shield has a pair of end plates 52 and 54 and has upwardly projecting elongated members 56 and 58 . A beneficial, but optional, feature provides adjustable tensioning of a projection belt 60 . It is the projection belt that is manipulated to fire the ball 14 from the firing chamber 24 . The tension on the belt determines the force that will be applied to the ball. One end of the belt 60 is secured to a rod 62 that extends between a pair of posts 64 and 66 . For example, a loop may be formed at the end of the belt and the rod may pass through the loop. The opposite end of the belt is similarly connected to a rod 67 , which passes through a spring-loaded member 68 that is allowed to travel within a slot 70 . As shown in FIG. 1, a coil spring 72 biases the spring-loaded member 68 rearwardly, so that the projection belt 60 is pulled into a taut condition. The tension provided by the coil spring is adjustable by rotating an external knob 74 at the rearward end of the apparatus 10 . Counterclockwise rotation of the knob 74 may increase the tension on the belt 60 , while clockwise rotation decreases the tension. [0025] Some of the mechanical features for implementing the belt-tensioning adjustment are shown in FIGS. 1 and 2, but other arrangements may be substituted. An end of the coil spring 72 is connected to a rotatable shaft 76 that is manipulated by the external knob 74 . A brace has upper and lower horizontal portions 78 and 80 at opposite ends of a vertical portion 82 . The upper horizontal portion 80 is secured to a tube end plate 84 through which the tension shaft 76 passes. [0026] A critical feature of the apparatus 10 is the adjustability of a fork-and-actuator mechanism. Referring to the top view of FIG. 2, this mechanism includes a forward prong 86 and a rearward prong 88 . The prongs are cantilevered from a fork plate 90 . While the cantilevered arrangement provides an advantage with regard to replacing the fork assembly in order to accommodate a different-sized ball, there may be embodiments in which it is preferable to have fork plates at both ends of the prongs 86 and 88 . The spacing between the two prongs plays an important role in determining the size of the ball for which the apparatus is best suited. Moreover, the positions of the prongs relative to the ramp 34 that defines the ball-supply path plays an important role in reliably separating the foremost ball for advancement into the firing chamber 24 . The spacing between the two prongs should be generally equal to the diameter of the balls. The distance between the prongs and the ramp should be such that when the fork plate 90 is rocked about a pivot axis, the prongs individually alternate between being spaced from the ramp by a distance less than the diameter of the balls and being spaced from the ramp by a distance greater than the diameter of the balls. [0027] The manipulation of the fork prongs 86 and 88 will be described in greater detail with reference to FIGS. 3 and 4. However, the structure of the fork itself can be best seen in FIGS. 5 and 6. The fork plate 90 includes internally threaded bores into which the threaded ends 92 and 94 of the prongs 86 and 88 are attached. The prongs should be sufficiently long to ensure that a ball cannot pass to the outside of the prongs while progressing along the ball-supply path of the apparatus. [0028] A lever clamp 96 fits within a cutaway region of the fork plate 90 and is held in position by a pair of fasteners 98 . The lever clamp secures a fork shaft (not shown) in position when the fork assembly is mounted for rocking motion within the apparatus. With the lever clamp in place, an opening 100 has a shape that corresponds to the end of the fork shaft. [0029] [0029]FIGS. 1 and 4 show the fork in a first position, while FIG. 3 shows the fork in a second position. As best seen in FIG. 1, the first position is one in which the forward portion of the fork plate 90 is lowered, so that the forward prong 86 blocks the path of the foremost ball 16 . Thus, the foremost ball is impeded from further travel along the ball-supply path to the firing chamber 24 . On the other hand, in the second position shown in FIG. 3, the forward prong 86 is raised above the level of the foremost ball, allowing the ball 16 to roll toward the firing chamber 24 . In the figure, the ball 16 is shown in a position just prior to dropping into the firing chamber. While the forward portion of the fork 90 is raised, the rearward portion of the fork is lowered, so that the rearward prong blocks the path of the next ball 18 . [0030] In a simplified explanation of the singulation operation, the timing of the release of balls to the firing chamber 24 is determined merely by rocking the fork plate 90 . When the fork plate is angled downwardly from its rearward portion to its forward portion, all of the balls waiting to enter the firing chamber 24 are impeded from progress past the forward prong 86 . On the other hand, when the fork plate is rocked in a counterclockwise direction eighteen to twenty degrees, the forward prong is rotated out of its blocking position, but the rearward prong 88 moves into a blocking position with respect to the next ball 18 . Once the foremost ball has moved past the area of the fork, the fork plate 90 may be again rocked in a clockwise direction to allow the next ball 18 to roll into the foremost position against the forward prong 86 . [0031] In the embodiment of FIGS. 1 - 4 , one possible assembly for providing the fork rocking is illustrated. Referring primarily to FIG. 4, a connecting rod 104 has opposite ends that are attached by hind joints 106 and 108 to a lower lever 112 and an upper lever 110 . The tensioning of the connecting rod is adjusted by securing the lower hind joint 106 to any one of a series of holes 113 . Alternatively, the series of holes may be formed within the upper lever 110 . While the side view may cause it to appear otherwise, only a portion of the fork plate 90 is shown in the side views of FIGS. 1, 3 and 4 , since the upper lever 110 visually blocks all but the forward portion of the fork plate 90 . Referring briefly to FIG. 2, the upper lever 110 is coupled to the fork plate 90 by the fork shaft 102 that was described above. The fork shaft is rotatable, so that rotation of the upper lever 110 causes rotation of the fork plate 90 , and therefore angular displacement of the forward and rearward prongs 86 and 88 . [0032] Returning to FIG. 4, the lower lever 112 rotates about a pivot point that is defined by a pawl shaft 114 . FIG. 4 shows the adjustable fork-and-actuator mechanism 116 in its rest position. This rest position is dictated by a spring member 118 and a stop 120 at opposite sides of the lower lever 112 . The spring member pulls an arm of the lower lever 112 to bias the lever for clockwise rotation. However, the stop 120 limits the extent to which the lever can rotate. Referring briefly to the side views of FIGS. 1 and 3, the spring member 118 is secured to the base 122 of the housing 12 by a cotter pin 124 . The stop 120 is fixed in position and is preferably an elastomeric member. [0033] Again referring briefly to the top view of FIG. 2, the pawl shaft 114 is rotatably held in position at one end by a pawl bearing plate 126 and at the opposite end by a bearing plate 128 that supports the fork shaft 102 in addition to the pawl shaft 114 . A pawl 130 is clamped to the pawl shaft. Thus, force applied to the pawl will cause the fork-and-actuator mechanism 116 of FIG. 4 to be moved out of the rest position illustrated in FIG. 4. The source of this applied force is a dog 132 that is connected to the motor-driven continuous chain described above. In the rest positions of FIGS. 1 and 4, the dog 132 is out of contact with the pawl 130 . However, in FIG. 3, the rotation of the continuous chain has caused the dog 132 to contact the pawl 130 . The continued motion of the dog 132 displaces the pawl to rotate about the shaft 114 on which it is mounted. The rotation of the shaft is transferred to the lower lever 112 , overcoming the bias of the spring member 118 . As a result of the counterclockwise rotation of the lower lever, the connector rod 104 pulls the upper lever 110 downwardly. The counterclockwise rotation of the upper lever 110 is translated to the fork plate 90 via the fork shaft 102 . Consequently, the forward prong of the fork is moved upwardly to allow the foremost ball 16 to progress to the firing chamber 24 . Eventually, the dog 132 releases the contact with the pawl and the fork-and-actuator mechanism 116 returns to the rest position of FIG. 4. The singulation process repeats when a second dog 134 comes into contact with the pawl 130 . The timing of the singulation process is a factor of the spacing between dogs and the drive speed of the chain. [0034] The dogs 132 and 134 also determine the timing of the firing sequence for projecting the ball 14 from the firing chamber 24 of FIG. 1. The ball rests on the projection belt 60 that is held in a taut condition by the coil spring 72 that is connected to the spring-loaded bearing member 68 . However, as the dog 132 moves forwardly from the position of FIG. 1, it will force the bearing member 68 forwardly within the slot 70 . As a consequence, the belt will relax and the ball 14 will be allowed to lower further into the firing chamber 24 . Then, as the dog rotates downwardly toward the pawl 130 , the spring-loaded bearing member 68 is released. The projection belt 60 is again returned to the taut condition by the bias of the coil spring 72 , propelling the ball from the firing chamber 24 . As described in the above-cited patent to Whitfield et al., the tension adjustment achieved by means of the external knob 74 varies the flight-determining factors of the projected ball. [0035] Piecing the various operations together, the dog 132 interacts with the spring-loaded bearing member 68 to relax the projection belt 60 , but then releases the bearing member to fire the ball 14 as the coil spring 72 pulls the projection belt back to a taut condition. The firing chamber is then again ready to accept a ball. The foremost ball 16 of FIG. 1 is released when the forward fork prong 86 is raised by rocking of the fork plate 90 . The elevation of the forward prong 86 is triggered by interaction between the dog 132 and the pawl 130 . Simultaneous with the elevation of the forward prong 86 , the rearward prong 88 is lowered to impede travel of the next ball 18 . This condition is shown in FIG. 3. The dog 132 contacts the pawl 130 , which is mounted to the pawl shaft 114 . Counterclockwise rotation of the pawl shaft pulls the connector rod 104 downwardly to rotate the upper lever 110 that is mounted at the end of the fork shaft 102 opposite to the fork plate 90 . That is, the counterclockwise rotation of the lower lever 112 is accompanied by counterclockwise rotation of both the upper lever 110 and the fork assembly. When the dog releases the pawl, the spring member 118 returns the levers and the fork assembly to the rest position of FIGS. 1 and 4, so that only one ball is allowed to progress to the firing chamber. [0036] The balls 14 - 22 of FIG. 1 may be softballs having regulation 12-inch circumferences. In order to change the apparatus 10 for use with a different-sized ball, the fork assembly may be changed and the length of the connector rod 104 may be adjusted. In the preferred embodiment, the apparatus includes a set of alternative fork assemblies. Referring to FIG. 7, a two-piece set of fork assemblies 136 and 138 is shown. The fork assembly 136 may be the original assembly for use with the 12-inch softballs, while the smaller fork assembly 138 may be dimensioned for use with regulation hard balls or with tennis balls. In the same manner as the original fork assembly, the smaller fork assembly 138 includes a fork plate 140 and a pair of cantilevered prongs 142 and 144 . Regarding the adjustment to the length of the connector rod of FIG. 1, the shortening of the connector rod will vary the distance of angular displacement. [0037] The invention is best suited for periodically projecting a spherical ball, such as a tennis ball, baseball or softball. However, because the projecting belt 60 conforms to the dimensions of the ball, the invention may be used to toss American footballs, if the ball-supply path is configured to maintain the necessary rolling orientation of the footballs past the appropriate fork assembly. Moreover, the ball singulation process may be used in other applications.

The invention relates to a ball projecting apparatus having a ball singulator with a fork-and-actuator mechanism that is adjustable to allow the apparatus to be used for a variety of different sports. A fork assembly is adjustable or replaceable to convert the apparatus from use with balls of one sport to use with balls of a different sport. Each fork may be referred to as a “rocker,” since it is pivoted from a first position in which a foremost ball is impeded from advancing to a second position in which the foremost ball is released, but the next ball is impeded. The rocking motion alternates which of two prongs is within the ball-supply path. When the forward prong is in the ball-supply path, all balls are prevented from advancing. Alternatively, when the rearward prong is in the ball-supply path, the foremost ball is allowed to advance.

This is a national stage application under 35USC 371 of international application Pct/EP93/02306 filed Aug. 26, 1993. FIELD OF THE INVENTION The invention relates to new addition compounds of diamines with fullerenes C 60 and/or C 70 and also a process for their preparation and their use. BACKGROUND OF THE INVENTION Since the discovery of fullerenes, a third modification of carbon, and particularly since their preparation has been possible, work has been carried out worldwide with an increasing tendency toward their chemical modification. This is particularly true of the most stable fullerene molecule C 60 which is also the one most readily obtainable in workable amounts (L. F. Lindoy, Nature, Vol. 357, 443 (1992); R. M. Baum, Chemical a. Engineering News 1991, Vol. 69, No. 50, p. 17). Besides a series of different chemical reactions on the fullerene C 60 , the addition of amines to the C 60 molecule has also already been reported [F. Wudl et al. in "Fullerenes: Synthesis, Properties and Chemistry of Large Carbon Clusters, Edit. G. S. Hammond and V. J. Kuck, ACS Symposium-Series, 481; Washington, D.C., 1992, p. 161; R. Seshadri, A. Govindaraj, R. Nagarajan, T. Pradeep and C. N. R. Rao, Tetrahedron Letters 33, No. 15, 2069 (1992)]. C 60 is a polyfunctional molecule. A significant disadvantage in the reported reactions is the formation of complex mixtures, which cannot be separated by conventional methods, in the reaction of the polyfunctional C 60 with amines. In almost every case, the reactions carried out in the manner reported hitherto give a myriad of different reaction products from which pure individual substances can only be isolated with unjustifiably great effort, if at all [A. Hirsch, Angew. Chem. 104 (1992), 808]. At present there are no known chemical reactions of nucleophiles with fullerenes which, when carried out in a conventional industrial manner, lead directly to uniform compounds or even to monoadducts or for which the subsequent application of conventional separation techniques, such as recrystallization or column chromatography, enables uniform compounds, in particular monoadducts, to be obtained from the mixtures formed. In "Tetrahedron Letters 33, page 2069 (1992)" mention is indeed made, inter alia, of obtaining a virtually pure 1:1 adduct of n-butylamine with C 60 , but apart from information about IR and UV absorption bands, no material data are reported and no information is given on the elemental composition based on analytical results and on the isolation of such a fullerene derivative. SUMMARY OF THE INVENTION It has now surprisingly been found that the action of diamines, preferably disecondary diamines, on fullerene, forms addition compounds of the diamine with fullerene, among which the monoaddition compound and diaddition compounds represent the main products, which can very easily, using conventional separation methods, be separated and separated from multiple-addition compounds and thus be isolated in pure form. The invention accordingly provides addition compounds obtainable by reaction of diamines of the formula I, ##STR2## where R 1 is (C 2 -C 4 )-alkylene or 1,2- or 1,3-cyclo-(C 3 -C 7 )-alkylene and R 2 and R 3 are, independently of one another, hydrogen or (C 1 -C 3 )-alkyl or R 2 and R 3 together are (C 2 -C 4 )-alkylene, with fullerene C 60 and/or C 70 . BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a graphical representation of an IR spectrum of a monoaddition compound according to one embodiment of the invention. FIG. 2 illustrates a graphical representation of a Raman spectrum of a monoaddition compound according to one embodiment of the invention. FIG. 3 is a graphical representation of a UV spectrum of a monoaddition compound according to one embodiment of the invention. FIG. 4 is a graphical representation of an IR spectrum of an addition compound according to one embodiment of the invention. FIG. 5 is a graphical representation of a UV spectrum of an addition compound according to one embodiment of the invention. FIG. 6 is a graphical representation of an IR spectrum of a hydrochloride of a monoaddition compound according to one embodiment of the invention. FIG. 7 is a graphical representation of a UV spectrum of an addition compound according to one embodiment of the invention. FIG. 8 is a graphical representation of an IR spectrum of an addition compound according to one embodiment of the invention. FIG. 9 is a graphical representation of an IR spectrum of a diaddition compound according to one embodiment of the invention. FIG. 10 is a graphical representation of an IR spectrum of a diaddition compound according to one embodiment of the invention. FIG. 11 is a graphical representation of an IR spectrum of a diaddition compound according to one embodiment of the invention. FIG. 12 is a graphical representation of an IR spectrum of a monoaddition compound according to one embodiment of the invention. FIG. 13 is a graphical representation of an IR spectrum of a diaddition compound according to one embodiment of the invention. FIG. 14 is a graphical representation of an IR spectrum of a monoaddition compound according to one embodiment of the invention. FIG. 15 is a graphical representation of an IR spectrum of a diaddition compound according to one embodiment of the invention. FIG. 16 is a graphical representation of an IR spectrum of a diaddition compound according to one embodiment of the invention. FIG. 17 is a graphical representation of an IR spectrum of a diaddition compound according to one embodiment of the invention. FIG. 18 is a graphical representation of an IR spectrum of a diaddition compound according to one embodiment of the invention. FIG. 19 is a graphical representation of an IR spectrum of a diaddition compound according to one embodiment of the invention. FIG. 20 is a graphical representation of an IR spectrum of a diaddition compound according to one embodiment of the invention. FIG. 21 is a graphical representation of an IR spectrum of a diaddition compound according to one embodiment of the invention. FIG. 22 is a graphical representation of an IR spectrum of a monoaddition compound according to one embodiment of the invention. FIG. 23 is a graphical representation of an IR spectrum of a monoaddition compound according to one embodiment of the invention. FIG. 24 is a graphical representation of an IR spectrum of a monoaddition compound according to one embodiment of the invention. FIG. 25 is a graphical representation of an IR spectrum of a monoaddition compound according to one embodiment of the invention. FIG. 26 is a graphical representation of an IR spectrum of a monoaddition compound according to one embodiment of the invention. FIG. 27 is a graphical representation of an IR spectrum of a monoaddition compound according to one embodiment of the invention. FIG. 28 is a graphical representation of an IR spectrum of a diaddition compound according to one embodiment of the invention. FIG. 29 is a graphical representation of an IR spectrum of a monoaddition compound according to one embodiment of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the monoaddition compound of the invention, in which R 1 , R 2 and R 3 are as defined for formula I, is given by formula II. The diamine of the formula I is bonded via its two nitrogen atoms to adjacent carbon atoms of a bond lying between two six-membered rings of the soccer-ball-like fullerene skeleton, i.e. on the fullerene surface. This bond between two six-membered rings of the C 60 or C 70 will hereinafter be referred to as a "6--6 bond". The structure of the C 60 monoadducts of the invention of formula II, in which R 1 , R 2 and R 3 are as defined for the formula I, is the structure having the greatest possible symmetry. The 1 H-NMR, 13 C-NMR and mass spectra indicate that the two hydrogen atoms formally introduced from the diamine of the formula I during the course of addition have been eliminated by dehydrogenation. Signals of hydrogen-bearing C 60 atoms occur neither in the 1 H-NMR nor in the 13 C-NMR spectra. The structure of the diaddition compounds, which are formed as regioisomers, is analogous to that of the monoadducts. As a result of the polyfunctionality of C 60 and C 70 , a number of regioisomeric diaddition compounds are possible. The mass spectra and the 1 H-NMR and 13 C-NMR spectra of the diadducts demonstrate that these too are completely dehydrogenated fullerene derivatives, i.e. both hydrogen atoms introduced per diamine of the formula I have been eliminated. This means that there are no hydrogen atoms present which are bonded to the fullerene skeleton. By way of example, a structure of a diaddition compound arbitrarily selected from among the regioisomeric structures is shown in formula III, in which R 1 , R 2 and R 3 are as defined for formula I. The structure of the diaddition compound of the formula III is, as regards the relative spacing of the diamine units, selected arbitrarily. For diaddition compounds, a number of other relative structures is possible. The relative spacing of the two diamine units is not subject matter of the structural observations presented in this description and is not fixed in the direaction or diaddition products to be obtained according to the invention and has not been determined in the direaction products described in the preparative examples. The same applies to the structures of higher addition compounds, i.e. for those in which more than two diamine units are bonded per C 60 or C 70 . ##STR3## The reaction of the invention is advantageously carried out using pure fullerene C 60 or C 70 or using fullerenes which contain at least 95% of C 60 or C 70 . The reaction of the invention is preferably carried out using C 60 having a purity of >95% or pure C 60 . The reaction of the invention is preferably carried out using diamines of the formula I, in which R 1 is --(CH 2 ) 2 --, ##STR4## R 2 and R 3 are, independently of one another, hydrogen, CH 3 or C 2 H 5 or R 2 and R 3 together are --(CH 2 ) 2 -- or --(CH 2 ) 3 --. Diamines which are particularly preferred for the reaction of the invention are N,N'-dimethylethylenediamine, N-methyl-N'-ethylethylenediamine, N,N'-diethylethylenediamine, N,N'-dimethyltrimethylenediamine, piperazine, homopiperazine, N-methylethylenediamine and N-ethylethylenediamine. The reaction of the invention between the diamine of the formula I and C 60 and/or C 70 is preferably carried out in solution, i.e. the fullerene to be reacted is preferably subjected to the addition reaction in dissolved form. Solvents which can be used here are all those in which fullerene C 60 and/or C 70 is appreciably soluble. Solvents which are advantageously used are aromatic hydrocarbons, aromatic halogen compounds or aromatic ethers, such as, for example, benzene, toluene, xylenes, mesitylene, (C 2 -C 4 )-alkylbenzenes, tetralin, naphthalene, 1- and/or 2-methylnaphthalene, dimethylnaphthalenes, (C 2 -C 6 )-alkylnaphthalenes, fluoro-, chloro-, dichloro-, trichloro and/or bromobenzene, anisole, phenetole, nerolin, ethoxynaphthalene, 1-chloronaphthalene and/or diphenyl ether and/or carbon disulfide. Preference is given to those aromatic hydrocarbons and/or halogen compounds which can be conveniently distilled off from the reaction mixture at atmospheric pressure or under reduced pressure at temperatures of up to 150° C., and also anisole. The aromatic solvents can have further solvents mixed into them, advantageously in such an amount that fullerene C 60 and/or C 70 still remains appreciably soluble. Examples of such solvents which can be mixed in are aliphatic and/or cycloaliphatic hydrocarbons which are liquid at room temperature and boil at below 150° C., mono-, di-, tri- and/or tetrachloroalkanes and/or analogously chlorinated alkenes. In the reaction of the invention, tertiary amines such as, for example, 1,4-diazabicyclo[2.2.2] octane, can be added as basic additives, namely in molar proportions of from 0.05 to 8.0 based on C 60 and/or C 70 . These basic additives are advantageous when only a small molar excess, if any, of the diamine of the formula I relative to C 60 and/or C 70 is used. These possible basic additives control the reaction rate to give a favorable selectivity for formation of monoaddition products. In the addition according to the invention of the diamine of the formula I to fullerene C 60 and/or C 70 , the molar ratio used between the diamine and the respective fullerene influences the composition of the fullerene diamine addition products, namely an increase in the diamine concentration in relation to the amount of fullerene used increases the proportion of multiple-addition products. Within a wide range of molar ratios of diamine to fullerene, for example from about 0.5 to about 20.0 or above, monoaddition product and diaddition products are formed as main products. The ratio in which the monoaddition, the diaddition and multiple-addition or reaction products are formed also depends strongly on the structure of the diamine of the formula I which is used. Thus, in the reaction of piperazine and homopiperazine within the abovementioned range (0.5 to about 20.0) of the molar ratio of diamine to fullerene, the monoreaction product is formed very predominantly. In the case of N,N'-dimethylethylenediamine, in contrast, the predominant main products formed under these conditions are the monoreaction product and direaction product in comparable amounts. For ethylenediamine and N,N'-diethylethylenediamine, the multiple-reaction products predominate relative to molar monoreaction and direaction product(s) in the reaction of the invention under comparable reaction conditions. The reaction of the invention of a diamine of the formula I with fullerene C 60 and/or C 70 can be carried out within a very wide temperature range. Thus, the reaction can be carried out, for example, between -30° C., preferably 0° C., and +300° C., preferably +160° C. The reaction can however also take place at higher or lower temperatures. Likewise, the reaction of the invention can be carried out within a very wide concentration range, based on the concentration of C 60 and/or C 70 and the concentration of the diamine of the formula I in the respective solvent or solvent mixture. This concentration range extends from about 10 -3 millimolar to the saturation concentration of the C 60 or C 70 in the solvent or solvent mixture used in each case. The reaction can, however, also be carried out at a fullerene concentration of <10 -3 millimolar or even in the presence of undissolved fullerene C 60 and/or C 70 . The reaction of the invention is preferably carried out between a diamine I and C 60 and/or C 70 at a concentration of from 0.2, in particular 0.6, to 5.5, in particular 3.5, millimole of C 60 or C 70 or (C 60 +C 70 ) per liter. The concentration of the diamine of the formula I in the reaction medium is determined by the molar ratio. In the reaction of the invention, the reaction times can vary within a very wide range. First, there is the relationship, generally known in chemistry, between reaction time and reaction temperature, whereby increasing reaction temperature reduces the reaction time necessary. However, the reaction time necessary also depends on the concentration of the reactants, the diamine and C 60 and/or C 70 , in the reaction medium and also on their mutual molar ratio. In general, times required for the reaction decrease with increasing concentrations of the reactants in the reaction medium and with increasing molar ratio between the diamine and C 60 and/or C 70 . Since this molar ratio in turn influences the product spectrum obtained for the addition products of the invention, the intended course of the reaction, i.e. the product spectrum obtained, can be controlled via this molar ratio and the reaction time. The greater the molar ratio of diamine of the formula I to C 60 and/or C 70 and the greater the concentration of the diamine in the reaction solution, the shorter the reaction times required become and the more multiple adducts of the respective diamine of the formula I used with C 60 and/or C 70 are formed in comparison with the monoadduct and diadducts which are usually obtained in the highest proportion. The other way around, a small molar ratio of diamine to C 60 or C 70 , for example from 0.5 to 2.5, and a low concentration of the reactants in the reaction solution, for example <2 millimolar, greatly increases the reaction time required and the proportion of the usually predominant monoadduct. In this way, the monoadduct can, under particular conditions, become essentially the only reaction product formed. A preferred embodiment of the reaction of the invention therefore comprises adding to a 0.2-5.0 millimolar solution of C 60 and/or C 70 in an aromatic hydrocarbon, fluorinated hydrocarbon or chlorinated hydrocarbon which is liquid at room temperature or anisole or a mixture of such aromatic solvents which is liquid at room temperature, 0.5-10 times, preferably 0.5-5 times, the molar amount of a diamine of the formula I and leaving this mixture for from 0.3 to 30 days, preferably 2-14 days, at a temperature between 0° C., preferably 20° C., and 160° C., preferably 110° C. The known relationship of increasing reaction temperature being able to shorten the reaction times is applicable here. Particularly preferred solvents are benzene, toluene, xylene, chlorobenzene, 1,2- and/or 1,3-dichlorobenzene and/or anisole. Of course, it is possible for the molarity of the reaction solution and also the ratio of diamine of the formula I to C 60 and/or C 70 and the reaction time for the reaction according to the invention to be below or above the abovementioned limits, depending on how completely the valuable fullerene is to be utilized in the reaction and on which distribution of the addition products is desired. The addition products of the diamine of the formula I with fullerene C 60 and/or C 70 , which are formed according to the invention, are satisfactorily characterized by their chemical properties, chemical composition and their spectroscopic data. Among the chemical properties, the behavior on chromatography, such as conventional thin-layer and column chromatography and also HPLC, serves to characterize the new compounds formed. The number of base equivalents per defined new adduct also characterize, in combination with the chemical composition, the new compounds of the invention. The chemical composition of the new fullerene derivatives of the invention is obtained from elemental analyses. For uniform adducts of the invention of a diamine of the formula I with C 60 and/or C 70 , these analyses show whether a monoadduct or a multiple adduct, for example a di-, tri-, tetra-, penta- or hexaadduct or a higher adduct is present. Furthermore, the spectroscopic data of the new compounds of the invention are particularly useful in their unambiguous characterization. These include the absorption spectra in the UV, visible and IR regions. The uniform addition compounds of the invention show characteristic IR spectra having a sharp bend structure. Likewise, the compounds of the invention each have characteristic UV absorptions, i.e. they differ in the position of their maxima. The mass spectra, recorded using the FABMS (fast atom bombardment) technique likewise characterize the respective compounds and confirm the molecular weights, insofar as the molecular peak is present or can be inferred. The NMR spectra too, measured both on solids and solutions, are also used for the characterization and structure assignment of the compounds of the invention. Thus, for example, the IR spectrum of a monoaddition or a diaddition compound of a diamine I of the invention, in which R 1 and also R 2 and R 3 are as defined above except for hydrogen, with C 60 shows no N-H bands. This characteristic demonstrates that both nitrogen atoms of the diamine of the formula I are bonded to carbon atoms of the fullerene. The new fullerene addition compounds formed according to the invention can be present in the reaction mixture in dissolved and/or undissolved form, depending on the solvent or solvent mixture used and on the temperature. In the preferred embodiments of the reaction of the invention, which are carried out at a total concentration of the two reaction participants (starting materials), i.e. fullerene C 60 and/or C 70 and the diamine of the formula I, of <25 mmolar in benzene, toluene, xylene, tetralin, ethylbenzene, 1,2-dichlorobenzene and/or anisole, with or without addition of naphthalene, the new monoaddition and diaddition compounds formed are generally present, at a temperature between 0° C. and 110° C., in dissolved or substantially dissolved form. For the purposes of isolation and purification, the new addition compounds formed, primarily the monoaddition compounds, can be partially precipitated as crystalline materials by evaporation of the reaction solution and as such can be isolated in a customary manner, e.g. by filtration. A preferred embodiment for isolating and purifying the addition compounds of the invention comprises separating the reaction mixture, either directly or after prior filtration, by column chromatography, preferably on silica gel, into any unreacted fullerene C 60 and/or C 70 and the addition compounds formed. The column chromatography is advantageously carried out on silica gel using toluene and dichloromethane and dichloromethane/methanol mixtures as eluant. In this procedure, fullerene C 60 and/or C 70 , is still present, if eluted first. This is followed, sharply delineated, by the respective monoaddition product and then, clearly spaced since they are more polar, any diaddition and multiple-addition compounds formed. It is also, on the other hand, possible to carry out such chromatographic separations using reversed phase (RP) silica gel or Al 2 O 3 or other adsorbents as stationary phase. After evaporation of the eluant, the addition compounds of the invention are obtained as solid, frequently crystalline materials. The latter is particularly the case for the monoaddition and diaddition compounds. Among these, the monoaddition product formed by action of piperazine (R 1 and also R 2 and R 3 together each --(CH 2 ) 2 --) on C 60 has a particularly high tendency to crystallize. This separation and purification of new fullerene derivatives into mono-, di- and multiple-addition compounds, which can be achieved by simple column chromatography, is exceptionally surprising. It is precisely the formation of complex mixtures from which it is virtually impossible to isolate individual compounds which is a very burdensome or disadvantageous characteristic of the fullerene chemistry known hitherto [A. Hirsch, A. Soi and H. R. Karfunkel, Angew. Chem. 104 (1992), 808]. The above-cited publication by A. Hirsch shows what great effort is necessary to be able to prepare and isolate a monoreaction product of fullerene C 60 in a suitable manner by means of a combination of analytical and preparative high-pressure liquid chromatography (HPLC). It is (also) a feature of this invention that it provides a simple formation route to monoaddition compounds of C 60 and/or C 70 , in particular of C 60 , and that the reaction products, in particular the mono- and direaction products, can be isolated in pure form in such a simple and inexpensive way by conventional column chromatography, i.e. without use of high-pressure liquid chromatography which requires complicated apparatus and is suitable only for the preparation of small amounts. The addition compounds of the invention which are obtained by column chromatography or by other workup methods can, if necessary, be further purified by recrystallization. Although, for the purposes of the present invention, the use of HPLC technology is surprisingly not necessary for the separation, isolation and purification of the compounds of the invention, the HPIC technique is suitable for characterizing the addition compounds obtained according to the invention. Retention time together with the stationary phase used and the liquid phase, the flow rate and also the usual column parameters serve as reliable material parameters for the characterization of pure substances of the invention or even mixtures. A further advantage of the workup of the reaction mixture by column chromatography, which is possible according to the invention, is that any unreacted C 60 and/or C 70 is simply and cleanly separated off and can thus be recovered for reuse. In view of the high price of fullerene C 60 and/or C 70 , this is of considerable importance. The addition compounds of diamines of the formula I, in which R 1 , R 2 and R 3 are as defined above, with C 60 and/or C 70 which are obtainable according to the present invention are basic compounds and form acid-addition salts with protic acids, reacting with at least 1 equivalent of acid per unit of diamine added to fullerene C 60 and/or C 70 . This means that, for example, a monoaddition compound can bind at least 1 equivalent of acid, and a diaddition compound can bind at least 2 equivalents of acid, to form acid-addition salts. With hydrochloric acid, for example, a hydrochloride is formed from the monoaddition compound of piperazine with C 60 . These acid-addition salts of the fullerene derivatives obtainable according to the invention are likewise subject matter of this invention. The acid-addition salts are considerably less soluble in nonpolar solvents than the corresponding bases. Thus, for example, addition of etherical hydrochloric acid to a solution of the monoaddition product formed from piperazine and C 60 in anisole results in virtually quantitative precipitation of the corresponding hydrochloride. For the preparation of acid-addition salts of the fullerene derivatives of the invention, all intermediate-strength and strong acids are suitable in principle. The disecondary diamines of the formula I required as starting materials are known or can be prepared by known methods. Fullerenes C 60 and C 70 are likewise prepared by known methods [W. Kratschmer, L. D. Lamb, K. Fostiropoulos, D. R. Huffman, Nature 1990, 347, 354; W. Kratschmer, K. Fostiropoulos, D. R. Huffman, Chem. Phys. Lett. 1990, 170, 167; H. Ajie, M. M. Alvarez, S. J. Anz, R. D. Beck, F. Diederich; K. Fostiropoulos, D. R. Huffman, W. Kratschmer, Y. Rubin, K. E. Schriver, D. Sensharma, R. L. Wetten, J. Phys. Chem. 1990, 94, 8630]. The fullerene derivatives of the invention are suitable for use as complex ligands. This property can be used for modifying catalysts. In addition, the compounds of the invention can be used for the inhibition of enzymes, for example for the inhibition of HIV (human immunodeficiency virus)-enzymes such as HIV-1 protease, and thus represent biological active compounds which can, for example, be used as antiviral agents. Furthermore, the addition compounds are electrically conductive in the solid state. Thus, for example, conductive casings of this material can be applied from solution. The monoaddition compound obtained by action of piperazine on C 60 shows intrinsic conductivity. The following examples illustrate the invention, without restricting it to the conditions specified by way of example. Unless otherwise mentioned in the following examples, column chromatography was carried out on Kieselgel S, particle size from 0.063 to 0.2 mm, from Riedel-de Haen AG, Seelze and thin-layer chromatography on Kieselgel 60 F 254 (layer thickness 0.25 mm) from Riedel-de Haen AG, Seelze. High-pressure liquid chromatography (HPLC) was carried out using a Hewlett-Packard apparatus "HP 1090 Series II Liquid Chromatograph" having a "Hewlett Packard HP 1040 A Diode-Array Detector" at 256 nm (band width 4 nm). Furthermore, the solvent mixtures used in the column chromatography which are not specified in more detail are CH 2 Cl 2 /CH 3 OH mixtures. EXAMPLE 1 Under a blanket of nitrogen, a solution of 1100 mg C 60/70 (97.25:2.75) in 592 ml of toluene was admixed at room temperature (RT) with a solution of 1035 mg of piperazine in 183 ml of toluene and the mixture was stirred for 45 hours at 50° C. and 96 hours at room temperature. The reaction mixture was then filtered through a filter aid and the filtrate was applied to or filtered through a Kieselgel S (0.063 to 0.2 mm) CH 2 Cl 2 column (H:38; φ3.6 cm). After the filtered reaction solution had been drawn in, elution was continued using CH 2 Cl 2 . The first 1200 ml of eluate contained (after evaporation in vacuo, digestion of the residue in 40 ml of ether, filtration with suction and drying) 192 mg (=17.5% of material used) of fullerene C 60>70 . Elution was subsequently continued using CH 2 Cl 2 /CH 3 OH (100:0.8). After 2500 ml of substance-free eluate, 1530 ml of eluate containing a brown-black moving zone were selected. After evaporating the solvent of this fraction, digestion of the crystalline residue (560 mg) in 40 ml of ether and filtration by suction, there were obtained after drying (4 hours, 50° C., 2 millibar) 507 mg of crystalline product which is essentially pure (>97.5%) monoaddition compound of piperazine with C 60 . The yield of this compound is, based on fullerene reacted, 50% of theory. Molecular formula: C 64 H 8 N 2 (MW 804.78) calc. C 95.52H 1.00N 3.48% found C 95.0H 1.4N 3.2% found C 95.0H 0.8N 3.4% The IR spectrum (recorded using an IR microscope. Powder on KBr) of this monoaddition compound formed from piperazine and C 60 is shown in FIG. 1 below. The Raman spectrum of this monoaddition product is shown in FIG. 2. The mass spectrum (FAB) gives a molecular mass M=804 Dalton, indicated by two intense peaks, MH.sup.⊕ at m/e 805 and M.sup.⊖ at m/e 804. Thin-layer chromatography (TLC) on Kieselgel 60/F 254, layer thickness 0.25 mm, from Riedel-de Haen, eluant: CH 2 Cl 2 /C 2 H 5 OH=10:1 (v/v): R F : 0.58 to 0.63 (the mono-addition product runs significantly behind C 60 and significantly in front of all other fullerene derivatives also formed). High-pressure liquid chromatography (HPLC): on LiChrospher® 100 RP-18 (5 μm), length 250×φ4 mm, eluant CH 2 Cl 2 /i-C 3 H 7 OH: 60:40+0.1% (C 2 H 5 ) 2 NH, flow 0.8 ml/min.; retention time: 3.85 min. (% by area 98.6). The UV spectrum of this monoaddition compound is shown in FIG. 3. This monoaddition product of piperazine with C 60 (≡ described as addition compound No. 1) can be recrystallized from solvents and further purified in this way. It crystallizes in thin, long, dark-colored, strongly reflecting needles. Suitable solvents for this purpose are chlorobenzene, dichlorobenzene and/or anisole. The new compound (No. 1) is sparingly soluble or essentially insoluble in benzene, toluene, CHCl 3 , CH 2 Cl 2 and CH 3 OH, and soluble in CS 2 . After the main product described above (≡ addition compound No. 1) had been eluted from the column, elution was continued using CH 2 Cl 2 /CH 3 OH (100:2) and (100:4). After 600 ml of substance-free eluate, elution with 1000 ml (100:4) gave 33 mg of a second new addition compound of piperazine with C 60 (≡ addition compound No. 2) which was obtained in crystalline form from CH 2 Cl 2 solution. Filtration with suction and drying (50° C., 3 mbar) of the crystalline product gave 10 mg of addition compound No. 2 in pure, crystalline form. This addition compound No. 2 proved to be a diaddition compound. Molecular formula: C 68 H 16 N 4 (MW 888.91) calc. C 91.88H 1.81N 6.30% found C 90.1H 1.7N 6.0% The IR spectrum (recorded using an IR microscope, powder on KBr) is shown in FIG. 4. TLC (CH 2 Cl 2 /C 2 H 5 OH 10:1) R F : 0.42 to 0.48 HPLC: column, eluant as for addition compound No. 1, flow 0.8 ml/min. Retention time: 3.09 or 3.12 min. (% by area 98.4). The UV spectrum of this addition compound No. 2 is shown in FIG. 5. The mass spectrum gives a molecular mass M=888 Dalton, indicated by an intense M.sup.⊖ peak at m/e 888. After the addition compound No. 2 had been eluted from the column, elution with CH 2 Cl 2 /CH 3 OH 100:4 (500 ml) gave 27 mg of product which proved to be a mixture of the diaddition compounds No. 2, No. 3, No. 3a and No. 4. Subsequent elution using 1200 ml (100:5) and 500 ml (100:6) gave 60 mg of a mixture of the diaddition compounds No. 3, No. 3a and No. 4. Crystallization of this mixture from CH 2 Cl 2 gave 15 mg of an otherwise pure mixture of the diaddition compounds No. 3, No. 3a and No. 4 (approximately equal amounts) in crystalline form. After the addition compounds No. 3, No. 3a and No. 4 had been eluted from the column, elution using CH 2 Cl 2 /CH 3 OH 100:7 (1000 ml) and 100:10 (1000 ml) gave 90 mg (evaporation residue) of the addition compound No. 5. This gave, from CH 2 Cl 2 , 43 mg of pure addition compound No. 5 in crystalline form (dried: 5 hours at 50° C., 3 to 4 mbar). This compound No. 5 is likewise a diaddition compound. Molecular formula: C 68 H 16 N 4 (MW 888.91) calc. C 91.88H 1.81N 6.30% found C 85.7; 85.4H 2.1; 2.0N 5.9; 6.2% The mass spectrum gives a molecular mass M=888 Dalton, indicated by an intense MH.sup.⊕ peak at m/e 889. The IR spectrum of the pure diaddition compound No. 5 is shown in FIG. 8, the UV spectrum in FIG. 7. TLC (CH 2 Cl 2 /C 2 H 5 OH 10:1) R F : 0.06 to 0.14 HPLC (conditions as for No. 1 and No. 2), Retention time: 3.05 or 3.20 min. (% by area 93.5). After elution of the diaddition compound No. 5, further polar substances can be eluted in small amounts using polar eluants, for example CH 2 Cl 2 /CH 3 OH 5:1 to 1:1. EXAMPLE 2 Under a blanket of nitrogen, a solution of 184 mg of C 60/70 (96.7:3.3) in 200 ml of benzene was admixed at room temperature with a solution of 68.5 mg (0.795 mmol) of piperazine in 25 ml of benzene and the mixture was allowed to stand for 95 hours at from 25≅ to 27° C. It was subsequently stirred for a total of 41 hours at from 51° to 52° C. and was, in between, allowed to stand for a total of 125 hours at room temperature. The reaction solution was then filtered through a filter aid and applied to a Kieselgel S--CH 2 Cl 2 column (H:30, φ2.9 cm). The column chromatography was carried out, in principle, in the same way as described in Example 1. The total amount of eluate was 4200 ml. This chromatography gave, in the same manner as described in Example 1: unreacted fullerene C 60/70 (about 97:3):89 mg (=48.4% of the amount used); addition compound No. 1 (monoaddition compound of piperazine with C 60 ): 72 mg (=67.4% yield based on reacted fullerene). A total of only 3 mg (unseparated) of further addition compounds running after this main reaction product during the column chromatography were obtained. EXAMPLE 3 Under a blanket of N 2 , a solution of 467 mg of C 60/70 (97.2:2.8) in 200 ml of toluene was admixed at room temperature with a solution of 34.5 mg (0.40 mmol) of piperazine in 40 ml of toluene and the mixture was allowed to stand for 11 days at from 26° C. to 32° C. The turbid reaction solution was filtered through Clarcel and applied to a Kieselgel S--CH 2 Cl 2 column (H 24, φ2.4 cm). The column chromatography was carried out, in principle, in the same way as described in Example 1; the following overview shows the breakdown of the fractions and their content of eluted product. ______________________________________ ContentFrac- Vol. (residue)tion Eluant ml in mg______________________________________1 CH.sub.2 Cl.sub.2 150 -- Initial frac- tion, discarded2 Toluene 300 363 Fullerene C.sub.60>70 CH.sub.2 Cl.sub.23 CH.sub.2 Cl.sub.2 /CH.sub.3 OH, 1000 -- Intermediate 100:0.8 fraction4 CH.sub.2 Cl.sub.2 /CH.sub.3 OH, -1000 143 Addition com- 100:0.8 pound No. 15 CH.sub.2 Cl.sub.2 /CH.sub.3 OH, -1000 26 A mixture of the 5:1 diaddition com- pounds No. 2, 3, 3a, 4 and 5______________________________________ The residue of the fraction 2 (363 mg) was suspended in 30 ml of ether, allowed to stand for 30 min. at room temperature and then filtered with suction, washed with ether and dried for 4 hours at 55° C., 3 to 4 mbar. This gave 336 mg (=72% of material used) of fullerene C 60/70 . The residue of the fraction 4 (143 mg) was treated likewise with ether, filtered with suction and dried: this gave 130 mg (=88.6% yield based on reacted fullerene) of the monoaddition compound of piperazine with C 60 (≡ addition compound No. 1) in microcrystalline form. EXAMPLE 4 to 10 The Examples 4 to 10 which are shown below in tabular form were carried out, in principle, in the same way as the Examples 1, 2 and 3 which have been described in detail. This applies particularly to the column chromatography procedure. In Example 6, the solvent used was a mixture of toluene and tetrahydrofuran (THF) and in Example 10 the solvent was a mixture of toluene and tetrachloroethylene. The diaddition compounds (No. 2, 3, 3a, 4 and 5), eluted after the monoaddition compound (of piperazine with C 60 ) (No. 1) in the respective column chromatography were in each case collected together, i.e. not separated into the individual diaddition compounds 2, 3, 3a, 4 and/or 5. __________________________________________________________________________Fullerene Reaction Recovered fullereneC.sub.60/70 time in days; % of AdditionEx. (. . ./. . .) Piperazine at temp. material compound Yield*.sup.)No. mg mg (mmol) Solvent (ml) [°C.] mg used No. mg [%]__________________________________________________________________________4 467 157 (1.82) Toluene (334) 2.0; 28-31 225 48.2 1 242 89.3 (97.2/2.8) 1.2; 69-78 2-5 55 241 18 (0.21) Toluene (151) 19.3; 27-36° 206 85.4 1 28 71.0 (97.2/2.8) 2-5 306 186 33 (0.38) Toluene (105) 2.6; 50-52 97 52.2 1 52 52.4 (97.2/2.8) THF (34) 8.2; 26-32 2-5 227 429 487 (5.65) Toluene (425) 11.0; 27-32 84 19.6 1 190 49.2 (96.8/3.2) 2-5 80 (#) 1108 287 173 (2.00) Toluene (186) 1.8; 90 113 39.4 1 128 65.9 (97.2/2.8) 5.0; 25-29 2-5 289 225 134 (1.56) Anisole (133) 2.5; 50-52 23 10.2 1 89 39.3 (97.2/2.8) 8.3; 22-28 2 22 3 + 4 28 5 2010 168 82 (0.95) Toluene (220) 2.8; 76-78 90 53.6 1 41 47.0 (97.2/2.8) Cl.sub.2 C═CCl.sub.2 (16) 8.7; 26-32 2-5 18__________________________________________________________________________ *.sup.) Yield is based on reacted fullerene C.sub.60/70 (˜97:3) (#)Reaction products which are more polar than the diaddition compounds No. 2-5 are eluted from the column far behind No. 5. EXAMPLE 11 Under a blanket of N 2 , 85 mg of fullerene C 60/70 (97.2/2.8) were dissolved at 83° C. in 100 g of naphthalene. To this solution was added, at from 82° to 83° C., a solution of 21.5 mg (0.25 mmol) of piperazine in 3.1 ml of toluene and the mixture was stirred for 61.5 hours (with interruptions each night) at from 86° to 87° C. and for 151 hours at room temperature (from 24° to 29° C.). The reaction mixture was then diluted with 180 ml of toluene, cooled to room temperature and applied to a Kieselgel S/CH 2 Cl 2 column (H:29; φ3.4 cm). Elution was carried out initially using CH 2 Cl 2 (cf. tabular summary below) and then using CH 2 Cl 2 /CH 3 OH mixtures. ______________________________________ Content Vol. (residue)Fraction Eluant ml in g______________________________________1 CH.sub.2 Cl.sub.2 ; (toluene) 300 -- Initial frac- tion, discarded2 CH.sub.2 Cl.sub.2 ; (toluene) 700 82.70 Naphthalene + Fullerene C.sub.60>703 CH.sub.2 Cl.sub.2 500 -- Intermediate fraction4 CH.sub.2 Cl.sub.2 /CH.sub.3 OH 500 -- Intermediate 100:0.6 fraction5 CH.sub.2 Cl.sub.2 /CH.sub.3 OH 500 -- Intermediate 100:0.8 fraction6 CH.sub.2 Cl.sub.2 /CH.sub.3 OH 800 0.033 Addition com- 100:0.8 pound No. 17 CH.sub.2 Cl.sub.2 /CH.sub.3 OH 500 0.010 Mixture of the 10:1 diaddition com- pounds No. 2, 3, 3a, 4 and 58 CH.sub.2 Cl.sub.2 /CH.sub.3 OH 500 0.006 Mixture of the 10:1.5 diaddition com- pounds no. 2, 3, 3a, 4 and 5______________________________________ The naphthalene was distilled from the residue of fraction 2 in a bulb tube (0.05 mbar, 80° bath temperature). 114 mg of residue remained. This was suspended for 30 minutes in 25 ml of ether and filtered off with suction after standing for 30 minutes, washed with ether and dried for 4 hours at 52° C. and from 3 to 4 mbar. This gave back 48 mg (=56.5% of material used) of fullerene C 60>70 . The residue from fraction 6 (33 mg) was suspended in 20 ml of ether, filtered off with suction after standing for 1 hour, washed with ether and dried (4 hours, 52°, 3 to 4 mbar). This gave 28 mg (=67.6% yield based on reacted fullerene) of pure monoaddition compound (addition compound No. 1). The residue of the fractions 7+8 (16 mg) comprised the diaddition compounds No. 2, 3, 3a, 4 and 5. EXAMPLE 12 Hydrochloride of the monoaddition compound of piperazine with C 60 : 81 mg (0.1 mmol) of the monoaddition compound (addition compound No. 1) of piperazine with C 60 were dissolved at 110° C. in 30 ml of anisole. This solution was cooled without stirring to 50° C. At this temperature, 0.36 ml of a 0.61 molar solution of HCl in ether were added with stirring (below the liquid surface). Solid was immediately formed as a light brown precipitate. The mixture was stirred for a further 30 min., with the temperature falling from 50° C. in the direction of room temperature, the solid was then filtered off with suction, washed with 5 ml of anisole and with plenty of ether and was dried for 4 hours at 65° C. and from 3 to 5 mbar. This gave 80 mg of brown, crystalline solid which is a hydrochloride of the monoaddition compound of piperazine with C 60 . Elemental analysis: found C 89.2H 2.0 Cl4.6; 4.8N 3.1% for C 64 H 9 CIN 2 (MW 841.25) calc. C 91.38H 1.08 Cl 4.21N 3.33% for C 71 H 17 CIN 2 O*) (MW 949.39) calc. C 89.82H 1.80 Cl 3.73N 2.95% *)=hydrochloride containing 1×anisole as solvent of crystallization. The IR spectrum of the hydrochloride obtained is shown in FIG. 6. EXAMPLE 13 Isolation of diaddition compounds of piperazine with C 60 by chromatography: 869 mg of a mixture of the diaddition compounds No. 2, No. 3, No. 3a and No. 4 formed from piperazine and C 60 were dissolved in 350 ml of CH 2 Cl 2 and applied to a Kieselgel S/CH 2 Cl 2 column (H:65; φ4 cm). Elution was carried out using, in succession, CH 2 Cl 2 and CH 2 Cl 2 /CH 3 OH (100:1) (each 1000 ml) and (100:2; 2000 ml). After 4 liters of substance-free eluate, elution was continued using CH 2 Cl 2 /CH 3 OH mixtures (100:2.2; 100:2.4; 100:2.6 and 100:2.8) (6×1000 ml). This eluate contained a total of 125 mg of a mixture of the compounds No. 2 and No. 4. Further elution using 2 l (100: 2.8) gave 110 mg of a virtually pure compound No. 4 as evaporation residue. This was dissolved in hot toluene, the solution was filtered and again evaporated in vacuo. The residue was digested with ether and the crystalline material was filtered off with suction. After drying (4 hours at 50° C., 3-5 mbar), 65 mg of TLC-pure diaddition compound No. 4 were obtained. Molecular formula: C 68 H 16 N 4 (MW 888.91) calc. C 91.88H 1.81N 6.30% found C 89.8H 2.3N 6.2% The mass spectrum gives a molecular mass M=888 Dalton, indicated by an intense MH.sup.⊕ peak at m/e 889. The IR spectrum (recorded using an IR microscope, powder on KBr) of this diaddition compound (No. 4) formed from piperazine and C 60 is shown in FIG. 11. Thin-layer chromatography (TLC) (CH 2 Cl 2 /C 2 H 5 OH 10:1) R F 0.22-0.25. After elution of pure compound No. 4, elution was continued using CH 2 Cl 2 /CH 3 OH (100:3). 1000 ml of eluate gave 110 mg of a mixture of the direaction products No. 3 and No. 4. 1500 ml of further eluate gave 173 mg of enriched compound No. 3 containing a small amount of compound No. 4 as residue. After digestion with ether and filtration with suction and drying of the crystalline material, 128 mg of enriched compound No. 3 were obtained. This substance was dissolved in a mixture of 30 ml of toluene, 20 ml of CH 2 Cl 2 and 20 ml of CH 3 OH. The CH 2 Cl 2 and CH 3 OH were then largely drawn off in vacuo. Crystallization occurred from the remaining solution. The crystalline product was filtered off with suction, washed with toluene and ether and dried for 4 hours at 50° C., 5 mbar. This gave 55 mg of almost pure, according to TLC, diaddition compound No. 3. Molecular formula: C 68 H 16 N 4 (MW 888.91) calc. C 91.88H 1.81N 6.30% found C 90.2H 2.0N 6.1% The mass spectrum gives a molecular mass M=888 Dalton, indicated by an intense MH.sup.⊕ peak at m/e 889 and a M.sup.⊖ peak at m/e 888. The IR spectrum (recorded as for No. 4) of this diaddition compound (No. 3) formed from piperazine and C 60 is shown in FIG. 9. Thin-layer chromatography (TLC) (CH 2 Cl 2 /C 2 H 5 OH 10:1) R F 0.26-0.30. After elution of enriched compound No. 3, elution was continued using CH 2 Cl 2 /CH 3 OH (100:4; 100:5 and 100:6) (each 1000 ml). These fractions contained 275 mg of a mixture (about 1:1) of the diaddition compounds No. 3 and No. 3a. These 275 mg of mixture were partially separated into the pure diaddition compounds No. 3 and No. 3a in a further column chromatography step (cf. Example 14 below) . EXAMPLE 14 275 mg of an approximately 1:1 mixture of the diaddition compounds No. 3 and No. 3a formed from piperazine and C 60 (obtained as a last fraction in the chromatography described in Example 13) were dissolved in 280 ml of toluene and applied to a Kieselgel S/toluene column (H:42; φ3 cm). Elution was carried out using, in succession, toluene/methanol mixtures (100:0.5; 100:0.75; 100:1; 100:1.1) (each 500 ml). These 2 l of eluate contained 6 mg of virtually new, according to TLC, diaddition compound No. 3 (data cf. Example 13). Elution was then continued using toluene/methanol 100:1.2; 100:1.4 and 100:1.6 (each 1000 ml). These fractions contained 187 mg of a mixture of the compounds No. 3 and No. 3a. Elution was then continued in a similar way using 100:1.8 and 100:2 (each 1000 ml). This last fraction gave 25 mg of almost pure diaddition compound No. 3a. Molecular formula: C 68 H 16 N 4 (MW 888.91) calc. C 91.88H 1.81N 6.30% found C 90.1H 2.0N 6.1% The mass spectrum gives a molecular mass M=888 Dalton, indicated by an intense M.sup.⊖ peak at m/e 888 and MH.sup.⊕ peak at m/e 889. The IR spectrum (powder on KBr) of this addition compound No. 3a is shown in FIG. 10. Thin-layer chromatography (TLC) (CH 2 Cl 2 /C 2 H 5 OH 10:1) R F 0.20-0.25. EXAMPLE 15 Under a blanket of nitrogen, a solution of 360 mg of C 60/70 (96.8:3.2) in 210 ml of toluene was admixed at RT with a solution of 396 mg of homopiperazine in 50 ml of toluene and was stirred for 3.1 days at 60° C. and for 10 days at RT. After filtration, the solution was applied to a Kieselgel S(0.063 to 0.2 mm)--CH 2 Cl 2 column (H: 43; φ2.9 cm) and filtered through it. After withdrawal of the filtered reaction solution, elution was continued using CH 2 Cl 2 . The first 1000 ml of eluate contained (after evaporation in vacuo, digestion of the residue in 20 ml of ether, filtration with suction and drying) 10 mg (≡2.8% of material used) of fullerene C 60>70 . Subsequently, elution was continued using CH 2 Cl 2 /CH 3 OH (100:0.2 to 0.4). After 500 ml of substance-free eluate, 1000 ml of eluate containing a brown-black moving zone were selected. After evaporation of the solvent of this fraction, digestion of the crystalline residue (194 mg) in 40 ml of ether and filtration with suction, there were obtained, after drying (4 hours, 50° C., 2 millibar), 160 mg of a crystalline product which is the pure monoaddition compound No. 7 of homopiperazine with C 60 . The yield of this compound is, based on reacted fullerene, 40% of theory. Molecular formula: C 65 H 10 N 2 (MW 818.81) calc. C 95.35H 1.23N 3.42% found C 94.7H 1.1N 3.4% The IR spectrum (recorded using an IR microscope. Powder on KBr) of this monoaddition compound No. 7 formed from homopiperazine and C 60 is shown in FIG. 12. The mass spectrum (FAB) shows a molecular mass M=818 (intense MH.sup.⊕ peak at m/e 819). Thin-layer chromatography (TLC) on Kieselgel 60/F 254, layer thickness 0.25 mm, from Riedel-de Haen, eluant: CH 2 Cl 2 /C 2 H 5 OH=10:1 (v/v): R F : 0.61 to 0.64 (the monoaddition product runs closely behind C 60 and significantly in front of all other fullerene derivatives formed). High-pressure liquid chromatography (HPLC): on Shandon Hypersil (5 μm), length 250×φ4 mm, eluant CH 2 Cl 2 /C 2 H 5 OH; gradient flow 1.5 ml and 2.0 ml/min.; retention time: 5.66 min. (% by area >98.5). This monoaddition product of homopiperazine with C 60 (≡ referred to as addition compound No. 7) can be recrystallized from solvents and further purified in this way. Suitable solvents for this purpose are chlorobenzene, dichlorobenzene and/or anisole. The new compound (No. 7) is sparingly soluble in benzene, toluene, CHCl 3 , CH 2 Cl 2 and CH 3 OH, but readily soluble in CS 2 . After the above-described main product (≡ addition compound No. 7) had been eluted from the column, elution was continued using CH 2 Cl 2 /CH 3 OH (100:1). After 500 ml of substance-free eluate, elution using 1000 ml (100:1.5) gave 15 mg of a further addition compound of homopiperazine with C 60 (≡ addition compound No. 8) which was obtained in crystalline form after digestion with ether. After filtration with suction and drying (50° C., 3 mbar) of the crystalline product, 13 mg of addition compound No. 8 were obtained. TLC (CH 2 Cl 2 /C 2 H 5 OH 10:1) R F : 0.52 to 0.56 HPLC: column, eluant and flow as for addition compound No. 7, retention time in min. (% by area): 5.81 (64.1%); 6.09 (15.3%) and 6.25 (20.6%). HPLC thus shows that the 0addition compound No. 8 consists of 3 components. These are 3 regioisomeric diaddition compounds of homopiperazine with C 60 . This is shown by the mass spectrum which indicates a molecular mass M=916 Dalton by means of an intense MH.sup.⊕ peak at m/e 917. After the diaddition compound No. 8, consisting of 3 isomers, had been eluted from the column, elution using 500 ml each of CH 2 Cl 2 /CH 3 OH (100:2) and (100:2.2) gave 9 mg of a mixture of diaddition compounds. Subsequent elution using 500 ml (100:2.5) gave, as a sharp dark zone, 30 mg of addition compound from which 25 mg of addition compound No. 9 were obtained in crystalline form by crystallization from ether, after filtration with suction and drying. HPLC: column, eluant and flow as for addition compound No. 7, retention time in min. (% by area): 6.58 (14.0%); 6.78 (11.2%) and 6.97 (68.5%); 6.3% by area correspond to the 3 isomers of the compound No. 8. Thus, this product No. 9 also consists of 3 isomers besides this proportion (6.3%) of the compound No. 8. The fact that compound No. 9 is a diaddition product consisting of 6 regioisomers is evidenced by the following C, H, N analysis. Molecular formula: C 70 H 20 N 4 (MW 916.96) calc. C 91.69H 2.20N 6.11% found C 91.1H 2.1N 6.0% The mass spectrum (FAB) shows a molecular mass M=916 (intense M.sup.⊖ peak at m/e 916 and MH.sup.⊕ peak at m/e 917); TLC (CH 2 Cl 2 /C 2 H 5 OH 10:1) R F : 0.45 to 0.47. After elution of the diaddition compound No. 9 consisting of 3 isomers and a residual proportion (6.3%) of the compound No. 8, elution using CH 2 Cl 2 /CH 3 OH 100:2.7 (500 ml) gave 26 mg (evaporation residue) of the addition compound No. 10. According to HPLC (conditions as for compound No. 7), this substance is also a diaddition product consisting of 3 regioisomers in proportions of 27.5:17.7:54.8% by area. The mass spectrum (FAB) shows a molecular mass M=916 (intense M.sup.⊖ peak at m/e 916 and MH.sup.⊕ peak at m/e 917); TLC (CH 2 Cl 2 /C 2 H 5 OH 10:1) R F : 0.38-0.40. After elution of the diaddition compound No. 10, elution wag continued using CH 2 Cl 2 /CH 3 OH (20:1) and (10:1) (each 500 ml). This gave 31 mg of a substance as evaporation residue from which were obtained, after digestion with ether, filtration with suction and drying (50° C., 3 mbar), 20 mg of diaddition compound No. 11 which was uniform according to TLC (CH 2 Cl 2 /C 2 H 5 OH 10:1). According to HPLC (conditions as for compound No. 7) this substance consists of 27.5% (by area) of two regioisomeric diadducts, which are also present in the diaddition compound No. 10, and 72.5% (by area) of the diaddition compound No. 11. The C,H,N analysis and the mass spectrum show that these are diadducts. Elemental analysis: found C 89.5H 2.5N 6.3%. The IR spectrum of this diaddition compound No. 11 is shown in FIG. 13. The mass spectrum (FAB) shows a molecular mass M=916 (intense M.sup.⊖ peak at m/e 916 and MH.sup.⊕ peak at m/e 917); TLC (CH 2 Cl 2 /C 2 H 5 OH 10:1) R F : 0.28 to 0.30. EXAMPLE 16 Under a blanket of nitrogen, a solution of 2907 mg of C 60/70 (97.25: 2.75) in 1200 ml of toluene was admixed at room temperature with a solution of 5.0 g of N,N'-dimethylethylenediamine in 300 ml of toluene and the mixture was stirred for 19.7 days at 85° C. and 14.1 days at room temperature. The reaction mixture was then filtered through a filter aid and the filtrate was applied to or filtered through a Kieselgel S(0.063 to 0.2 mm)-toluene column (H: 64; φ3.4 cm). After the filtered reaction solution had been drawn in, elution was continued using 500 ml of toluene and 500 ml of CH 2 Cl 2 . The first 2500 ml of eluate contained (after evaporation in vacuo, digestion of the residue in 40 ml of ether, filtration with suction and drying) 115 mg (≡4% of material used) of fullerene C 60>70 . Subsequently, elution was continued using CH 2 Cl 2 and CH 2 Cl 2 /CH 3 OH (100:0.5). After 1000 ml of substance-free eluate, 2500 ml of eluate (100:0.5) containing a brown-black moving zone were selected. After evaporation of the solvent from this fraction, digestion of the crystalline residue (490 mg) in 40 ml of ether and filtration with suction, there were obtained, after drying (4 hours, 50° C., 2 millibar), 462 mg of a crystalline product which is essentially pure monoaddition compound of N,N'-dimethylethylenediamine with C 60 . The yield of this compound No. 12 is, based on reacted fullerene, 14.8% of theory. Molecular formula: C 64 H 10 N 2 (MW 806.80) calc. C 95.28H 1.25N 3.47% found C 94.2H 1.1N 3.4% The IR spectrum (recorded using an IR microscope. Powder on KBr) of this monoaddition compound No. 12 formed from N,N'-dimethylethylenediamine and C 60 is shown in FIG. 14. The mass spectrum (FAB) shows a strong MH.sup.⊕ peak at m/e 807, which gives a molecular mass M=806. Thin-layer chromatography (TLC) on Kieselgel 60/F 254, layer thickness 0.25 mm, from Riedel-de Haen, eluant: CH 2 Cl 2 /C 2 H 5 OH=10:1 (v/v): R F : 0.53 to 0.58 (the monoaddition product runs closely behind C 60 and in front of the diaddition products. This monoaddition product of N,N'-dimethylethylenediamine with C 60 (≡ referred to monoaddition compound No. 12) can be recrystallized from solvents and be further purified in this way. Suitable solvents for this purpose are dichlorobenzene, chlorobenzene and/or anisole and CS 2 . The new compound (No. 12) is sparingly soluble or essentially insoluble in benzene, toluene, CHCl 3 , CH 2 Cl 2 and CH 3 OH, but readily soluble in CS 2 . After the above-described main product (≡ addition compound No. 12) had been eluted from the column, elution was continued using CH 2 Cl 2 /CH 3 OH (100:1 and 100:1.5) (each 1500 ml). After 300 ml of substance-free eluate, elution using 1200 ml (100:1) and 1500 ml (100:1.5) gave 1030 mg of a second addition compound. After digestion with ether, filtration with suction and drying (50° C., 3 mbar) this gave 957 mg of diaddition compound (referred to as addition compound No. 13G) in crystalline form (≡27.7% yield based on reacted fullerene). This addition compound No. 13G proved to be, according to TLC (eluant: CH 2 Cl 2 /C 2 H 5 OH=100:1.5), a mixture of 5 regioisomeric diaddition compounds. The presence of diadducts is shown by the elemental analysis and by the mass spectrum. The mass spectrum (FAB) shows a molecular mass M=892 by an intense MH.sup.⊕ peak at m/e 893. Molecular formula (for diadducts 13G): C 68 H 20 N 4 (MW 892.94) calc. C 91.47H 2.26N 6.27% found C 91.5H 2.2N 5.7% The separation of this mixture into 5 pure diaddition compounds is described in Example 17. After the diaddition compound No. 13G, consisting of 5 isomers, had been eluted from the column, elution was continued using 1 l (100:2) and a substance-free fraction was obtained. Further elution using CH 2 Cl 2 /CH 3 OH 100:3 and 100:4 (each 2 l) gave 1143 mg of redish brown-black eluate residue. This gave, after digestion with ether, filtration with suction and drying, 919 mg of a crystalline substance (≡26.6% yield based on reacted fullerene) which, according to TLC (CH 2 Cl 2 /C 2 H 5 OH 100:1.5), consisted of 3 regioisomeric diadducts. These are referred to as diaddition compounds No. 14, 15 and 16. The presence of diadducts is shown by the elemental analysis and by the mass spectrum. The mass spectrum (FAB) shows a molecular mass M=892 by an intense MH.sup.⊕ peak at m/e 893. Molecular formula (for diadduct): C 68 H 20 N 4 (MW 892.94) calc. C 91.47H 2.26N 6.27% found C 90.6H 2.6N 5.8% The chromatographic separation of this mixture into the pure diaddition compounds 14, 15 and 16 is described in Example 18. EXAMPLE 17 Isolation in pure form of the 5 regioisomeric diadducts formed from N,N'-dimethylethylenediamine and C 60 , described as a mixture in Example 16: 955 mg of the addition compound No. 13G obtained as described in Example 16 were dissolved at 80° C. in 400 ml of toluene and the solution was applied while warm to a Kieselgel 60 (grain size 0.04-0.064 mm)/toluene column (H =65; φ3.4 cm). The elution was carried out under 0.2 bar gauge pressure of N 2 . After elution using 2 l of toluene, during which a substance-free eluate ran out, elution using CH 2 Cl 2 ; CH 2 Cl 2 /CH 3 OH (100:0.1), (100:0.2), (100:0.3) and (100:0.35) (each 1.5 l) gave 72 mg of eluate residue which, after digestion with ether, filtration with suction and drying, gave 68 mg of pure diadduct No. 13A. The IR spectrum (KBr) of this diaddition compound No. 13A is shown in FIG. 15. Continuing elution using (100:0.4) and (100:0.45) (2 and 3 l respectively) gave 123 mg of eluate residue which, processed as above, gave 114 mg of pure diaddition compound No. 13B. The IR spectrum (KBr) of this compound No. 13B is shown in FIG. 16. Further elution using 1 l (100:0.45), 4 l (100:0.5) and 1 l (100:0.55) gave, after evaporation of the solvents, 328 mg of eluate residue. From this were obtained, after the above-described procedure, 317 mg of pure crystalline diaddition compound No. 13. The IR spectrum (KBr) of this compound No. 13 is shown in FIG. 17. Further elution using 2 l each of CH 2 Cl 2 /CH 3 OH (100:1) and (100:2) gave 112 mg of eluate residue which, processed as above, gave 110 mg of pure crystalline diaddition compound No. 13C. The IR spectrum (KBr) thereof is shown in FIG. 18. Further elution using 2 l each of (100:3) and (100:5) produced 225 mg of eluate residue which, after processing as described above, gave 201 mg of pure, dark red-brown, crystalline diaddition compound No. 14. The IR spectrum (KBr) thereof is shown in FIG. 19. TLC (Kieselgel 60/F254, layer thickness 0.25 mm; eluant: CH 2 Cl 2 /C 2 H 5 OH=100:1.5): the diaddition compounds No. 13A to No. 13C have the following R F values: ______________________________________No. 13A 13B 13 13C______________________________________R.sub.F : 0.17-0.20 0.11-0.14 0.07-0.10 0.05-0.07______________________________________ EXAMPLE 18 Isolation in pure form of the 3 regioisomeric diaddition products No. 14, No. 15 and No. 16 formed from N,N'dimethylethylenediamine and C 60 described as a mixture in Example 16: 919 mg of the diaddition compounds No. 14, 15 and 16 obtained as a mixture as described in Example 16 were dissolved at 80° C. in 500 ml of toluene, and the solution was applied while warm to a Kieselgel 60 (grain size 0.04-0.064 mm)/toluene column (H=45; φ3.2 cm). The elution was carried out under 0.2 bar gauge pressure of N 2 . After elution using 200 ml of toluene and 1 l each of CH 2 Cl 2 /CH 3 OH (100:0.5) and (100:1), during which substance-free eluate ran out, elution using 2 l (100:1) gave 130 mg of eluate residue which, after digestion with ether, filtration with suction and drying (4 hours, 3-5 mbar) gave 121 mg of TLC-pure diaddition compound No. 14. Continued elution using 1 l (100:1) produced, after evaporation, 98 mg of eluate residue which, after processing as described above, gave 83 mg of TLC-pure diaddition compound No. 15. The IR spectrum (KBr) of this diaddition compound No. 15 is shown in FIG. 20. Further elution using 1 l of CH 2 Cl 2 /CH 3 OH (100:1.5), 1 l (100:1.75) and 1 l (100:2) gave, after evaporation, 300 mg of eluate residue which, after processing as described above, gave 279 mg of product which consisted of the diadducts No. 15 and No. 16. Further elution using 1 l of (100:3) produces 210 mg of eluate residue which, after processing as described above, gave 180 mg of TLC-pure diaddition compound No. 16. The IR spectrum (KBr) thereof is shown in FIG. 21. TLC (Kieselgel 60/F254, layer thickness 0.25 mm; eluant: CH 2 Cl 2 /C 2 H 5 OH=100:4): the diaddition compounds No. 14-No. 16 have the following R F values: ______________________________________No. 14 15 16______________________________________R.sub.F : 0.11-0.12 0.09-0.11 0.04-0.06______________________________________ EXAMPLE 19 Using a similar procedure to Example 16, a solution of 727 mg of C 60/70 (97.25:2.75) in 300 ml of toluene was admixed with a solution of 1.16 g of N,N'-diethylethylenediamine in 50 ml of toluene and the mixture was stirred for 6 days at 85° C. and for 8 days at RT. The reaction mixture was then filtered. The washed and dried (5 hours at 50° C., 6 mbar) filter residue weighed 1.06 g and is a complex mixture of higher adducts (>2) of N,N'-diethylethylenediamine and C 60/70 . The filtrate was applied to a Kieselgel S/toluene column (H=42; φ1.9 cm). The chromatography was carried out using a similar procedure to that described in Examples 1 and 16. After elution using 100 ml of toluene, during which 44 mg (=6% of material used) of unreacted C 60/70 were recovered, elution using 80 ml of toluene gave (after evaporation of the toluene) 51 mg of eluate residue. After digestion with ether, filtration with suction and drying (4 hours at 50° C., 6 mbar) this gave 27 mg (≡3.4% yield, based on reacted fullerene) of TLC-pure, crystalline monoadduct of N,N'-diethylethylenediamine with C 60 . This substance is referred to as addition compound No. 17. Molecular formula: C 66 H 14 N 2 (MW 834.85) calc. C 94.95H 1.69N 3.36% found C 95.6H 1.9N 3.3% The IR spectrum (KBr) of this compound No. 17 is shown in FIG. 22. The mass spectrum (FAB) shows a strong MH.sup.⊕ and strong M.sup.⊖ peak at m/e 835 and m/e 834 respectively. TLC (eluant: CH 2 Cl 2 /C 2 H 5 OH 10:1): R F =0.68-0.70 TLC (eluant: toluene): R F =0.30-0.32 EXAMPLE 20 Using a similar procedure to Example 16, a solution of 1211 mg of C 60/70 (97.25:2.75) in 500 ml of toluene was admixed with a solution of 2.06 g of N,N'-dimethyltrimethylenediamine in 80 ml of toluene and the mixture was stirred for 4.7 days at 80°-82° C. and for 12.2 days at RT. The reaction mixture was then filtered. The washed and dried filter residue weighed 126 mg and is presumably a complex mixture of higher (>2) adducts of N,N'-dimethyl-1,3-propylenediamine with C 60/70 . The filtrate was applied to a Kieselgel S/toluene column (H=90; φ2.9 cm). The chromatography was carried out using a similar procedure to that described in Examples 1, 16 and 19. After elution using 600 ml of toluene, during which 403 mg (=33.3% of material used) of unreacted C 60/70 were recovered, further elution using 2.6 l of toluene and 1 l of CH 2 Cl 2 gave, after evaporation of the solvents, 260 mg of eluate residue. After digestion with ether, filtration with suction and drying (4 hours at 50° C., 4-6 mbar), this gave 189 mg(≡20.5% yield, based on reacted fullerene) of TLC-pure, crystalline monoadduct of N,N'-dimethyl-l-1,3-propylenediamine with C 60 . This substance is referred to as addition compound No. 18. Molecular formula: C 65 H 12 N 2 (MW 820.83) calc. C 95.11H 1.47N 3.41% found C 94.8H 1.5N 3.4% The IR spectrum (KBr) of this compound No. 18 is shown in FIG. 23. The mass spectrum (FAB) shows a strong MH.sup.⊕ and a strong M.sup.⊖ peak at m/e 821 and m/e 820 respectively. TLC (eluant: CH 2 Cl 2 /C 2 H 5 OH 10:1): R F =0.68-0.70. EXAMPLE 21 Using a procedure similar to Example 16, a solution of 2180 mg of C 60/70 (97.25:2.75) in 900 ml of toluene was admixed with a solution of 2225 mg of N-methylethylenediamine in 150 ml of toluene and the mixture was stirred for 3.1 days at 70°-73° C. and 2.6 days at RT. The reaction solution was then filtered and applied to a Kieselgel 60 (grain size 0.04-0.063 mm) toluene column (H=46 cm, φ4.8 cm). The chromatography was carried out under 0.2 bar gauge pressure of N 2 in a similar manner to Examples 1, 16 and 19. After elution using 1 l of toluene and 0.5 l of CH 2 Cl 2 , during which 137 mg (=6.3% of material used) of unreacted C 60/70 were recovered, further elution using 2 l each of CH 2 Cl 2 /CH 3 OH (100: 0.25) (100:0.5) and (100:0.75) gave an eluate residue of 13 mg which, after digestion in ether, filtration with suction and drying, gave 10 mg of a brown substance. Continued elution using 3 l (100:1), 1 l (100:1.5) and 2 l (100:2) produced, after evaporation of the solvents, 807 mg of eluate residue which, after digestion with 15 ml of ether, filtration with suction and drying (4 hours at 50° C., 3-6 mbar), gave 794 mg (=35.3% yield based on conversion) of crystalline, TLC-pure monoadduct of N-methyldiamine with C 60 (formula II: R 1 ═--(CH 2 ) 2 --, R 2 ═CH 3 , R 3 ═H). This monoadduct is referred to as addition compound No. 19. Molecular formula: C 63 H 8 N 2 (MW 792.77) calc. C 95.54H 1.02N 3.53% found C 94.6H 1.0N 3.5% The IR spectrum (KBr) of this compound No. 19 is shown in FIG. 24. The mass spectrum (FAB) shows a strong MH.sup.⊕ and M.sup.⊖ peak m/e 793 and m/e 792 respectively. TLC (eluant: CH 2 Cl 2 /C 2 H 5 OH 100:3): R F =0.21-0.22. EXAMPLE 22 Using a procedure similar to Example 16, a solution of 2720 mg of C 60/70 (97.75:2.25) in 1350 ml of toluene was admixed with a solution of 2224 mg of N-methylethylenediamine in 100 ml of toluene and the mixture was stirred for 2.5 days at 65° C. and 3.5 days at room temperature. The reaction solution was then filtered and applied to a Kieselgel 60 (grain size 0.043-0.060 mm)-toluene column (H=52 cm, φ3.6 cm). The chromatography was carried out under 0.25 bar gauge pressure of N 2 in a similar manner to Examples 1, 16 and 19. After elution using 1.2 l of toluene, during which 102 mg (=3.8% of material used) of unreacted C 60/70 were recovered, further elution using 1 l of toluene and 2 l of toluene/CH 3 OH (100:1) gave 47 mg of a substance which was not characterized in more detail. Continued elution using 2 l each of toluene/CH 3 OH (100:1) and (100:1.5) produced, after evaporation of the solvents, 2400 mg of eluate residue which, after digestion with ether, filtration with suction and drying (4 hours at 50° C., 3-6 mbar), gave 2075 mg (72% yield based on conversion) of crystalline, TLC-pure monoadduct of N-methylethylenediamine with C 60 (addition compound No. 19, cf. Example 21). EXAMPLE 23 Using a procedure similar to Example 16, a solution of 2290 mg of C 60/70 (97.75:2.25) in 1000 ml of toluene was admixed with a solution of 2556 mg of a 98%-pure N-ethylethylenediamine in 80 ml of toluene and the mixture was stirred for 3.15 days at 68° C. and 4.65 days at room temperature. The reaction solution was then filtered and applied to a Kieselgel 60 (grain size 0.043-0.060 mm)-toluene column (H=52 cm, φ3.6 cm). The chromatography was carried out under 0.35 bar gauge pressure of N 2 in a similar manner to Examples 1, 16 and 19. After elution using 2.1 l of toluene, during which 260 mg (=11.4% of material used) of unreacted C 60/70 were recovered, further elution using 2 l each of toluene/CH 3 OH (100: 1), (100:1.25) and (100:1.50) gave, after evaporation of the solvents, 1400 mg of eluate residue. After digestion with ether, filtration with suction and drying (4 hours at 50° C., 3-6 mbar), this gave 1309 mg (57.6% yield based on conversion) of crystalline, TLC-pure monoadduct of N-ethylethylenediamine with C 60 ( formula II: R 1 =--(CH 2 ) 2 --, R 2 =C 2 H 5 , R 3 =H). This monoadduct is referred to as addition compound No. 20. Molecular formula: C 64 H 10 N 2 (MW 806.80) calc. C 95.28H 1.25N 3.47% found C 92.6H 1.3N 3.4% The IR spectrum (KBr) of this compound No. 20 is shown in FIG. 25. The mass spectrum (FAB) shows a strong MH.sup.⊕ and M.sup.⊖ peak at m/e 807 and m/e 806 respectively. TLC (eluant: CH 2 Cl 2 /C 2 H 5 OH 100:4): R F =0.46-0.48. EXAMPLE 24 Using a procedure similar to Example 16, a solution of 648 mg of C 60/70 (97.75:2.25) in 275 ml of toluene was admixed with a solution of 986 mg of cis-1,2-diaminocyclohexane in 10 ml of toluene and the mixture was stirred for 2.9 days at 68°-70° C. and for 4.9 days at room temperature. The reaction solution was then filtered and applied to a Kieselgel 60 (grain size 0.043-0.06 mm)-toluene acid (H=40 cm, φ2.5 cm). The chromatography was carried out under 0.3 bar gauge pressure of N 2 in a similar manner to Examples 1, 16 and 19. After elution using 0.55 l of toluene, during which 71 mg (=11% of material used) of unreacted C 60/70 were recovered, further elution using 2 l of toluene gave, after evaporation of the solvent, an eluate residue of 150 mg which, after digestion in ether, filtration with suction and drying, gave 140 mg (=21% yield based on conversion) of crystalline, TLC-pure monoadduct of cis-1,2-diaminocyclohexane with C 60 (formula II: R 1 = ##STR5## R 2 , R 3 =H). This monoadduct is referred to as addition compound No. 21. Molecular formula: C 66 H 12 N 2 (MW 832.84) calc. C 95.18H 1.45N 3.36% found C 94.5H 1.5N 3.3% The IR spectrum (KBr) of this compound No. 21 is shown in FIG. 26. The mass spectrum (FAB) shows a strong M.sup.⊖ peak at m/e 832. TLC (eluant: CH 2 Cl 2 /C 2 H 5 OH 100:4): R F =0.68-0.70. EXAMPLE 25 Using a procedure similar to Example 16, a solution of 303 mg of C 60/70 (97.25:2.75) in 125 ml of toluene was admixed with a solution of 360 mg of ethylenediamine in 15 ml of toluene and the mixture was stirred for 7 days at 80° C. and for 21 days at RT. The reaction mixture was then filtered. The washed and dried filter residue weighed 348 mg and is presumably a complex mixture of higher adducts of ethylene diamine with C 60/70 . The filtrate was applied to a Kieselgel S/toluene column (H=30, φ2.9 cm). The chromatography was carried out in a similar manner to that described in Examples 1, 16 and 19. After elution using 250 ml of toluene and 200 ml of CH 2 Cl 2 , during which 36 mg (=11.9% of material used) of unreacted C 60/70 were recovered, further elution using 250 ml of CH 2 Cl 2 /CH 3 OH (100:0.5), 1 l (100:1), 300 ml (100:1.5) and 300 ml (100:2) gave, after evaporation of the solvents, 43 mg of eluate residue. After digestion with ether, filtration with suction and drying (4 hours at 50° C., 3-6 mbar), this gave 39 mg (≡13.5% yield, based on reacted fullerene) of a crystalline substance which, according to TLC, contains a small amount (<10%) of a byproduct. The elemental analysis and the mass spectrum show the strongly enriched main component to be a monoadduct of ethylenediamine with C 60 . This substance is referred to as addition compound No. 22 (formula II: R 1 =--(CH 2 ) 2 --, R 2 , R 3 =H) Molecular formula: C 62 H 6 N 2 (MW 778.75) calc. C 95.63H 0.78N 3.60% found C 89.8H 0.8N 3.6% The IR spectrum (KBr) of this compound No. 22 is shown in FIG. 27. The mass spectrum (FAB) shows a strong MH.sup.⊕ and strong M.sup.⊖ peak at m/e 779 and m/e 778 respectively. TLC (eluant: CH 2 Cl 2 /C 2 H 5 OH 10:1): R F =0.43-0.45 (R F of the byproduct present: 0.49-0.52). EXAMPLE 26 Isolation of diaddition compounds of N-methylethylenediamine with C 60 by chromatography: 1 g of the substance which had been obtained after elution of the main part of the monoaddition compound No. 19 in the chromatography of a reaction mixture obtained as described in Examples 21 and 22, and which consisted of unseparated monoaddition compound No. 19 and diadducts of N-methylethyldiamine with C 60 , was further separated by chromatography as follows. The substance to be separated (1 g) was dissolved in 100 ml of CS 2 and applied to a Kieselgel 60 (grain size: 0.040-0.063 mm)--CH 2 Cl 2 column (H=30 cm, φ3.4 cm). The chromatography was carried out under 0.3 bar gauge pressure of N 2 in a similar manner to Examples 1, 16 and 19. After elution using 3 l of CH 2 Cl 2 and 2 l each of CH 2 Cl 2 /CH 3 OH (100:0.1) and (100:0.2), during which substance-free eluates were obtained, further elution with 2 l each of CH 2 Cl 2 /CH 3 OH (100:0.2) and (100:0.3) and 1 l (100:0.3) gave, after evaporation of the solvents, 659 mg of eluate residue. This gave, after digestion with ether, filtration with suction and drying, 586 mg of TLC-pure monoaddition compound (addition compound No. 19; formula II: R 1 ═--(CH 2 ) 2 --, R 2 ═CH 3 , R 3 ═H). Elution was continued using CH 2 Cl 2 /CH 3 OH (100:3). The next fraction (0.5 l of eluate) left, after evaporation, 208 mg of residue which, treated as described above, gave, after drying, 195 mg of diaddition compound of N-methylethylenediamine with C 60 as described by formula III: R 1 ═--(CH 2 ) 2 --, R 2 ═C 3 , R 3 ═H). According to TLC (eluant: toluene/CH 3 OH 100:1), this substance consists of five regioisomeric diaddition compounds. This substance is referred to as diaddition compound No. 23G. Molecular formula: C 66 H 16 N 4 (MW 864.89) calc. C 91.66H 1.86N 6.48% found C 89.2H 2.4N 6.2% The mass spectrum (FAB) of this substance shows a strong MH.sup.⊕ and strong M.sup.⊖ peak at m/e 865 and m/e 864 respectively. The next fraction (0.5 l of eluate) gave, after evaporation and similar treatment of the eluate residue as for previous fractions, 19 mg of diadduct after drying (according to TLC this has a somewhat different composition with regard to the regioisomers than does the previously eluted diadduct fraction). The following fraction (1 l of eluate) left, after similar treatment to that described above, 33 mg of a mixture of regioisomeric diadducts in which the more polar regioisomers are, according to TLC, present in greater amounts than in the previous fractions. On further elution using 1 l of CH 2 Cl 2 /CH 3 OH (20:1), a dark zone was eluted and after evaporation, digestion of the eluate residue with ether, filtration with suction and drying there were obtained 28 mg of a diadduct which, according to TLC, contained one component (regioisomer) in greatly enriched form. Molecular formula: C 66 H 16 N 4 (MW 864.89) calc. C 91.66H 1.86N 6.48% found C 89.5H 2.5N 6.3% The mass spectrum (FAB) of this substance shows a strong MH.sup.⊕ peak at m/e 864. TLC (eluant: CH 2 Cl 2 /C 2 H 5 OH 10:1): R F =0.30-0.36. This substance is referred to as diaddition compound No. 23K. The IR spectrum (KBr) of this compound No. 23K is shown in FIG. 28. EXAMPLE 27 Using a procedure similar to Example 16, a solution of 545 mg of C 70/60 (96.7:3.3) in 500 ml of toluene was admixed with a solution of 447 mg of N-methylethylenediamine in 20 ml of toluene and the mixture was stirred for 4.3 days at 79°-80° C. and for 2.7 days at room temperature. The reaction mixture was then filtered and applied to a Kieselgel 60 (grain size 0.04-0.063 mm)-toluene column (H=75 cm, φ2.5 cm). The chromatography was carried out at 0.35 bar gauge pressure of N 2 in a similar manner to Examples 1, 16 and 19. After elution using 0.7 l of toluene, during which 155 mg (=28.4% of material used) of unreacted C 70 were recovered, further elution using 1 l of toluene/CH 3 OH (100: 0.5); 1.3 l (100:0.75); 0.3 l (100:1) and 1 l (100:1.5) gave, after evaporation of the solvents, an eluate residue of 255 mg which, after digestion with 15 ml of ether, filtration with suction and drying (4 hours at 50° C., 3-6 mbar), gave 230 mg (=56.5% yield based on fullerene conversion) of crystalline, TLC-pure monoadduct of N-methylethylenediamine with C 70 . This monoadduct is referred to as addition compound No. 24. Molecular formula: C 73 H 8 N 2 (MW 912.88) calc. C 96.05H 0.88N 3.07% found C 93.8H 1.3N 3.0% The IR spectrum (KBr) of this compound No. 24 is shown in FIG. 29. The mass spectrum (FAB) shows a strong MH.sup.⊕ and strong M.sup.⊖ peak at m/e 913 and m/e 912 respectively. TLC (eluant: CH 2 Cl 2 /C 2 H 5 OH 10:1): R F =0.56-0.66. EXAMPLE 28 Using a procedure similar to Example 16, a solution of 234 mg of C 60/70 (97.75:2.25) in 126 ml of toluene was admixed with a solution of 27.3 mg (0.317 mmol) of piperazine and 67.3 mg (0.6 mmol) of 1,4-diazabidyclo [2.2.2]octane in 125 ml of toluene and the mixture was stirred for 16.7 days at room temperature. The reaction solution was then applied to a Kieselgel S (grain size 0.063-0.20 mm)--CH 2 Cl 2 column (H=21 cm, φ2.9 cm). After elution using 1 l of CH 2 Cl 2 , during which 158 mg (=67.5% of material used) of unreacted C 60/70 were recovered, further elution using 0.5 l each of CH 2 Cl 2 /CH 3 OH (100:0.5), (100:1), and (100:2) gave, after evaporation of the solvents, 82 mg of eluate residue. After digestion with ether, filtration with suction and drying (4 hours, 50° C., 4-7 mbar), this gave 60 mg (70.4% yield based on C 60/70 conversion) of crystalline, TLC-pure addition compound No. 1 (formula II: R 1 and R 2 --R 3 =--(CH 2 ) 2 --). After elution of this addition compound No. 1, more polar eluants gave virtually only traces of higher addition products (<2 mg).

The invention relates to an addition compound which is obtainable by reaction of a diamine of the formula I, ##STR1## where R 1 is (C 2 -C 4 )-alkylene or 1,2- or 1,3-cyclo-(C 3 -C 7 )-alkylene and R 2 and R 3 , which are identical or different, are (C 1 -C 3 )-alkyl or hydrogen or R 2 and R 3 together are (C 2 -C 4 )-alkylene, with fullerenes C 60 and/or C 70 . The fullerene derivatives are useful as electrically conducting materials.

BACKGROUND [0001] This disclosure relates generally to deaerating a fluid and, more particularly, to deaerating the fluid without requiring a separate assembly dedicated to deaerating. [0002] Fluid, such as oil, that has been used to cool and lubricate moving components is often recirculated. Fluid mixed with substantial amounts of air is less suitable for cooling and lubricating. Because the fluid mixes with air during use, the fluid is deareated prior to reuse. [0003] Gearboxes include many rotating components that are cooled and lubricated with a fluid. After circulating through the gearbox, the fluid moves through a cylindrical deaerating structure to remove air. The fluid then flows from the deaerating structure to a holding reservoir where it is stored until being moved back into the gearbox. SUMMARY [0004] An example method of deaerating a mixture of fluid and air includes communicating a two-phase mixture of fluid and air directly against a wall of a reservoir to separate the air from the fluid. The method recirculates the fluid held within the reservoir after the separating. [0005] A method of deaerating a mixture of aircraft lubricating fluid and air includes communicating the mixture into an open area of a reservoir. The method includes collecting the aircraft lubricating fluid in a lower portion of the reservoir and collecting the separated air in an upper portion of the reservoir that is different from the first portion. The method uses the aircraft lubricating fluid from the first portion to lubricate an aircraft component. [0006] An example component lubrication assembly includes a reservoir providing a retention volume. An open, first area of the volume receives a mixture of a fluid that is not deaerated. A second area of the volume receives and holds the fluid that has been deaereated. DESCRIPTION OF THE FIGURES [0007] The various features and advantages of the disclosed examples will become apparent to those skilled in the art from the detailed description. The figures that accompany the detailed description can be briefly described as follows: [0008] FIG. 1 is a perspective view of an example rotary wing aircraft. [0009] FIG. 2 is a perspective view of an example drive system for the FIG. 1 rotary wing aircraft. [0010] FIG. 3 is a perspective view of a secondary gearbox within the FIG. 2 drive system. [0011] FIG. 4 is a section view in perspective at line 4 - 4 in FIG. 3 . [0012] FIG. 5 is a true section view of the FIG. 4 section view. [0013] FIG. 6 is a perspective view representing a reservoir volume within the FIG. 3 secondary gearbox. [0014] FIG. 7 is a section view at line 4 - 4 in FIG. 3 in an opposite direction from FIG. 5 . [0015] FIG. 8 is a section view at line 8 - 8 in FIG. 3 . [0016] FIG. 9 is a perspective view of a nozzle of the FIG. 3 secondary gearbox. [0017] FIG. 10 is a perspective view of a portion of the FIG. 3 secondary gearbox opposite the direction of view in FIG. 3 . [0018] FIG. 11 is a section view at line 11 - 11 in FIG. 10 . DETAILED DESCRIPTION [0019] Referring to FIGS. 1 and 2 , an example high-speed vertical takeoff and landing rotary-wing aircraft 10 has a counter-rotating, coaxial primary rotor system 12 and a secondary rotor system 14 . The aircraft 10 includes an airframe 16 that supports a drive system 18 used to drive the primary rotor system 12 and the secondary rotor system 14 . The primary rotor system 12 rotates about an axis of rotation A. The secondary rotor system 14 rotates about an axis of rotation T. [0020] The primary rotor system 12 includes an upper rotor assembly 22 A and a lower rotor assembly 22 B. Each rotor assembly 22 A and 22 B includes a plurality of primary rotor blades 24 mounted to a respective upper rotor hub 26 A or lower rotor hub 26 B. The primary rotor blades 24 rotate with the respective hub 26 A or 26 B about the axis A. Any number of blades may be used within the primary rotor system 12 . [0021] The primary rotor system 12 is driven through a main gearbox 30 by a multi-engine power plant system having an engine package ENG 1 and an engine package ENG 2 . [0022] The multi-engine power plant system also provides a rotational input into the secondary rotor system 14 . In this example, the secondary rotor system 14 includes a propeller pusher system 34 that provides translational thrust in a direction that is generally parallel to a longitudinal axis L of the aircraft 10 . The secondary rotor system 14 provides thrust for high-speed flight of the aircraft 10 , in this example. [0023] To rotate the propeller pusher system 34 , a secondary gearbox 38 steps down a rotational input from a main shaft 42 to rotate a secondary drive shaft 44 at a lower speed. The multi-engine power plant system drives the main shaft 42 . [0024] In this example, the secondary rotor system 14 is mounted to the rear of the airframe 16 with the rotational axis T oriented substantially horizontal and parallel to the axis L. Other configurations of the secondary rotor system 14 , such as a propeller system mounted to each side of the airframe 16 may alternatively be used. [0025] The following examples are disclosed with reference to the secondary gearbox 38 of the aircraft 10 . Although a particular aircraft and environment is illustrated and described, other configurations, machines, or both may incorporate rotatable components suitable for use with the examples disclosed herein. For example, other moving components, and other gearboxes, may benefit from the following examples. Other types of aircraft, and other types of machines may also benefit. [0026] Referring now to FIGS. 3-11 with continuing reference to FIGS. 1 and 2 , the secondary gearbox 38 includes a secondary driveshaft housing 48 and a gear housing 50 . Fluid, such as a lubricating oil, circulates through the gear housing 50 to cool and lubricate the gears and bearings (not shown) within the gear housing 50 . As known, the fluid becomes mixed with air when cooling and lubricating the gears and bearings. It is further blended and mixed during the fluid recovery process, where the scavenge pumps pull the oil and air in varying proportions from the bottom of the gear cavity. [0027] Fluid that exits the gear housing 50 is collected and recirculated. However, the reused fluid re-entering the gear housing 50 is typically reasonably void of air content. Fluid mixed with significant amounts of air is less suitable for cooling and lubricating the gears and bearings as is known. Circulation systems employing other details such as control circuits and valves are more sensitive to air content due to the compressibility of that media. [0028] To remove air from the mixed fluid, the fluid is deaerated prior to circulation back to the gear housing 50 . A person having skill in this art and the benefit of this disclosure would understand how much air would need to be separated from the fluid to make the fluid suitable for lubricating and cooling gears within the gear housing 50 . [0029] In this example, a nozzle 58 introduces the mixture of fluid and air to the reservoir 54 . The mixture is collected using a scavenge pump within the gear housing 50 and is communicated directly from the gear housing 50 to the reservoir 54 . The manner in which the mixture is introduced to the reservoir 54 encourages air to separate from the fluid. [0030] The example reservoir 54 includes an outer curved wall 62 and an inner curved wall 64 . The outer wall 62 is “outer” relative to the inner wall 64 with reference to axis T. Radially extending walls 66 and 68 connect the outer wall 62 to the inner wall 64 . Axially facing end walls 70 and 72 complete the reservoir 54 . [0031] As can be appreciated from the Figures, the outer wall 62 and the inner wall 64 are curved such that a volume established by the reservoir 54 extends circumferentially around a portion of the axis T. Notably, the volume is continuous and uninterrupted. That is, other than the walls, inlet structures, and outlet structures, there are no additional structures or features extending into, or disposed within, the volume of the reservoir. The reservoir 54 is integrated within the secondary driveshaft housing 48 . [0032] In this example, the radial wall 68 is located at a vertical bottom of the reservoir 54 and the radial wall 66 is located near a vertical top of the reservoir 54 . Relative vertical positions, in this example, refer to the aircraft 10 being on the ground or in straight (or level) flight. Since the aircraft 10 maintains a relatively consistent attitude during flight, the relative vertical positions of the end wall 68 and 66 are maintained during flight. Where flight angles might vary from that vertical orientation, the nature of the coordinated maneuvers generates a G-vector on the fluids that emulates the relative orientation for the fluid volumes. [0033] Fluid pools at the vertical bottom of the reservoir 54 due to gravity. The wall 68 is thus typically submersed by fluid. The radial wall 66 is, in this example, located vertically above the normal maximum level of fluid held within the reservoir 54 . Accordingly, during normal operation, the wall 66 is in an open area of the reservoir 54 . (The open area is an area without pooled fluid.) Notably, the vertical form of the reservoir 54 improves separation and stratification of varying densities of flow mixture, such as fine air entrainment that can lead to foaming. [0034] The example radial wall 66 is curved and has a general C-shape. The radial wall 66 is curved relative to an axis C that is parallel to the axis T. [0035] The nozzle plug 58 , which is aluminum in this example, includes a conduit portion 74 that creates a nozzle jet which directs the mixture from the nozzle 58 in the direction D toward the radial wall 66 . The mixture is introduced into an open area of the reservoir 54 . [0036] The nozzle 58 receives the mixture from the gear housing 50 via a flow conduit 76 . In this example, the nozzle 58 is located on an opposite axial end of the secondary driveshaft housing 48 from the gear housing 50 , thus the conduit 76 extends axially across the entire length of the reservoir section of the secondary driveshaft housing 48 . [0037] In this example, the mixture of oil and air from the gear housing 50 is introduced to the reservoir 54 at a relatively high flow rate so that the mixture exits from the nozzle 58 at a suitable velocity and impinges onto the radial wall 66 . The curvature of the radial wall 66 is paired with the flow velocities to ensure suitable centrifugal forces and adequate separation. Notably, the direction D has a vector component D A that is parallel to the axis C, and a vector component D T that is tangential to the partial cylinder about axis C ( FIG. 9 ). [0038] The mixture flows along path P after impinging upon the end wall 66 . The mixture moves tangentially and axially relative to the axis C as the mixture is centrifuged by the contour of the wall. [0039] Primary separation of the air from the fluid is encouraged by the curved contour and the contact with the curved radial wall 66 . This half-curl centrifuge causes the denser fluid to be flung outward onto the outer wall and coalesced, which displaces the less dense air and prompting it to move inward toward the rotational center of the curved flow. The principally separated and coalesced fluid flows downward within the reservoir 54 along the sloped portion of the wall 66 , against the inner wall 64 , and into the fluid collected at the vertical bottom of the reservoir 54 . The principally separated fluid flows as a widening sheet against the end wall 66 and the inner wall 64 . The progressively widening of the sheet flow permits the flow to get thinner, and further encourages the separation of the finer air bubbles within the principally separated fluid. The increased contact area of the flow reduces its velocity, providing for more peaceful entry into the collected fluid volume. The separated air rises and collects within the open area. [0040] In this example, the sheet flow improves separation of the fluid and the air. The sheet flow is relatively thin, which shortens the travel path for the air to separate from the fluid. The relatively thin sheet means even smaller bubbles are released compared to thicker layers of flow. Further, the sheet flow, in this example, is spread across a relatively wide surface area, which provides more of a boundary layer against the walls, yields reduced velocity of flow, and eases entry into solid oil volume. Because the entry is eased, there is less agitation related to entry into the separated and collected fluid. Thus, less air is re-introduced. [0041] Typical prior art deaerators sustain flow velocity thru to discharge, leaving a very active spray and potential for churn, which can introduce air back into the fluid. [0042] During operation of the secondary gearbox 38 , air collected in the open area of the reservoir 54 vents back to the gear housing 50 through an air conduit 78 . [0043] During operation of the secondary gearbox, fluid is pumped from a vertical bottom of the reservoir and reintroduced into the gear housing 50 . The reintroduced fluid is used for cooling, lubrication, or both. [0044] A fluid pump may be used to communicate fluid from the reservoir 54 to the gear housing 50 . Positioning the reservoir fluid outlet 82 (pump inlet) near the vertical bottom of the reservoir 54 further improves separation of the air bubbles from the fluid, and helps lessen the chance that air becomes part of the cooling flow and is reintroduced to the gear housing 50 through the fluid outlet 82 . [0045] Features of the disclosed examples include introducing a mixture of air and fluid into an open area of a reservoir in a way that encourages the separation of air from the fluid. Notably, no separate deaerating structure is required to encourage such separation. Also, no such separate deaerating structure is positioned within the reservoir. Further, secondary aeration of separated fluid is minimized by easing flow entry into the collected fluid volume. [0046] The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. Thus, the scope of legal protection given to this disclosure can only be determined by studying the following claims.

An example method of deaerating a mixture of fluid and air includes communicating a mixture of fluid and air directly against a wall of a reservoir to separate the fluid from the air. The method reuses the fluid held within the reservoir after the separating.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to hand trowels and more particularly to a hand trowel having a novel design to create a base depth during the installation of marble, granite and onyx flooring. 2. Description of the Prior Art Marble, granite and onyx flooring tiles are typically laid on a substrate in side-by-side relation, leaving uniform spaces between tiles for grout lines. The flooring pieces are affixed to the substrate with an adhesive material commonly referred to as “thinset,” which is spread onto the substrate or sub floor. Then a layer of mortar mix is dispersed in a certain thickness to allow leveling of the floor. The mortar mix is prepared to a consistency that is workable but capable of standing in shape, supporting the different marble size and thickness throughout. In order to install a run of marble, granite or onyx flooring, the mud bed, or mortar mix, is dispersed over the adhesive that was previously spread onto the sub floor, in a layer having variable thickness for leveling or pitching the floor. When the flooring material is pressed onto the layer of mortar bed material, the material evenly supports the flooring material, which has also been spread with the adhesive, forming a strong bond with the sub floor to allow the mud to disperse. This allows the excess mortar mix to spread without compromising the flooring material. Additionally, the raised level of mortar allows the installer to place a flooring piece in contact with the mortar bed and then mallet the flooring piece down to the degree necessary to achieve a level installation relative to the other previously installed flooring pieces, or pitched to the correct degree for patio or shower flooring. Various techniques are used to spread the surface of the mortar prior to pressing the flooring pieces into place. The conventional technique for preparing the surface of the mortar bed is performed by hoeing the mortar toward the installer with a conventional margin trowel, so as to form air pockets resembling an egg carton within the thickness, of the mortar mix. This technique also enables the raising and lowering of the height of the layer of adhesive, and allows the flooring material to be installed in contact with the mud bed and tapped into place with the mallet. This technique is frequently used during the installation of marble, granite and onyx flooring and is typically performed with a conventional margin trowel. The mortar spreads by exploding into the air pockets, filling the space as the flooring is pounded down with a mallet. This technique is frequently used during the installation of marble, granite and onyx flooring, and is typically performed with the use of a conventional prior art margin trowel, as shown in FIG. 1 . Conventionally, the trowel has a handle and a rectangular blade, which is typically 2 inches wide and 5+ inches in length. The installer uses the margin trowel to work the mortar bed in order to form air pockets. Each draw stroke of the trowel pulls a single furrow in the layer of the mortar bed to form egg carton shaped pockets. There is a need for a new type of trowel that can hoe multiple furrows with each stroke, to increase the efficiency of the process for creating an ideal height/depth of mortar during the installation of marble flooring. SUMMARY OF THE INVENTION The present invention is directed to an improved trowel designed for increasing the efficiency of hand working a mortar mix thickness, to produce air pockets in an egg carton style layer of mortar conforming to a certain height of the sub floor. The trowel includes a handle and an elongated slotted blade, securely joined together by a shank with a wooden or rubber handle. The blade has a gradually narrowing shape defined by edges extending to a distal end. The distal end is provided with a plurality of tips, which are spaced apart and separated by V-shaped notches. The tips are intended for raking through the mortar mix, toward the installer, to prepare the surface in multiple furrows instead of a single furrow. Preferably, the blade is constructed having two, three or four tips. The tips may be defined by a pair of edges converging at a point, wherein the edges converge at an acute angle. Alternatively, the tips may be defined by a pair of edges terminating at a flat, in which case the flat preferably has a length in the range of about 0.5 inches (1.27 cm) to 1.0 inch. (2.54 cm), and preferably about 0.875 inches (2.2 cm). Furthermore, combinations of tips of varying shapes and widths may be combined in the same trowel, depending on the consistency of the mortar mix to be worked. In addition, the V-shaped notches may be provided in varying sizes to accommodate the characteristics of differing adhesive materials or the installer's preferences. The V-shaped notches preferably vary from a depth of approximately 1.5 to 7.0 inches (3.8 to 17.75 cm) or a depth of from approximately 2% to 90% of the length of the blade. It is an object of the present invention to provide an improved trowel that increases the efficiency of each stroke, when the trowel is manually worked in a layer of adhesive, so as to increase the production of air pockets with each stroke of the trowel. It is a further object of the invention to provide an improved trowel that increases the efficiency of each stroke, when the trowel is manually worked in a layer of mortar mix, by presenting a plurality of tips having varied shapes specifically suited to the consistency of the mortar bed. It is a further object of the present invention to provide an improved trowel that increases the efficiency of each stroke, when the trowel is manually worked in a layer of adhesive, by providing V-shaped notches of varying depths specifically suited to the consistency of the mortar bed. These and other objects, features and advantages of the present invention will become more readily apparent from the attached drawings and the detailed description of the preferred embodiments, which follow. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be further understood, by way of example, with reference to the accompanying drawings, in which: FIG. 1 is a plan view of a representative conventional trowel of the prior art. FIG. 2 is a plan view of a trowel of the present invention having three pointed tips and V-shaped notches having a depth of approximately fifty percent of the blade length. FIG. 3 is a plan view of a trowel of the present invention having two pointed tips and V-shaped notches having a depth of approximately fifty percent of the blade length. FIG. 4 is a plan view of a trowel of the present invention having one pointed tip, two flat tips and V-shaped notches having a depth of approximately thirty percent of the blade length. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Shown throughout the drawings, the present invention is generally directed to an improved trowel for improving the efficiency of the process of manually working mortar mix in preparation for the installation of marble, granite and onyx flooring. The trowel of the present invention, as shown in various embodiments in FIGS. 2-4 , is particularly suited for the work of preparing the surface of a layer of mortar to produce air pockets in the mortar mix material. The trowel of the present invention includes a handle 15 and a blade 20 a - 20 c , joined by a shank 25 . It is preferred that the handle 15 be formed of rigid material and have a generally cylindrical shape suitable for grasping, as shown in FIGS. 2-4 . Wood is the preferred material for the handle 15 , but other materials, such as metal surrounded by high strength rubber, may be used. The shank 25 is preferably formed of metal and has a tang (not shown) extending into a bore provided in the handle 15 . The tang is securely fixed in the bore, preferably by being wedged into position and glued. It is preferred that the shank 25 have an end opposite the tang, which is securely fixed to the blade 20 a - 20 c by fastening means, such as by welding or screwing, such that the fastening means lie flush with the blade 20 a - 20 c on the surface opposite the shank 25 . It is preferred that the shank 25 be provided with a curved portion between the handle 15 and the blade 20 a - 20 c to displace the handle 15 from the plane of the blade 20 a - 20 c , so that a user may conveniently introduce the blade 20 a - 20 c to a layer of mortar without contacting the mortar with the handle 15 . The blade 20 a - 20 c is preferably of elongated shape, formed of metal selected to have resilient flexibility with some stiffness and a thickness of approximately 1/64 inch (0.04 cm). Metal used for a conventional trowel, of the prior art, as shown in FIG. 1 , is suitable for the trowel of the present invention. It will be appreciated by those skilled in the art that a trowel blade having a thickness of approximately 1/64 inch provides an appropriate spacer for gauging the correct spacing for marble flooring tiles. The blade 20 a - 20 c has a gradually narrowing shape, defined by edges 30 , as shown in FIGS. 2-4 , extending to a distal end. The distal end is provided with a plurality of tips 35 a - b adapted for working a layer of mortar mix material. The tips 35 a - b are spaced apart and separated by V-shaped notches 40 . The present invention contemplates a number of versions having different designs of blades 20 a - 20 c . A version of the invention is depicted in FIG. 2 having a blade 20 a with three tips 35 a , each narrowing, at an acute angle, to a point. A version of the invention is depicted in FIG. 3 having a blade 20 b with two tips 35 a , each narrowing, at an acute angle, to a point. A version of the invention is depicted in FIG. 4 having a blade 20 c with three tips 35 a - b , two of which tips 35 b narrow to a flat, and a central tip 35 a , which narrows to a point. In use, a flooring installer must apply a layer of thinset adhesive to a substrate, followed by a mortar mix, followed by thinset adhesive spread onto flooring material, such as marble, granite or onyx, to be laid in side-by-side relation. The flooring pieces must be aligned in a uniform pattern, leveled relative to each other, and spaced apart evenly to provide uniform grout lines. After laying the flooring pieces, the adhesive is allowed to cure, leaving the flooring pieces firmly affixed to the substrate. When laying marble pieces, it is conventional practice to space the flooring pieces 1/64 inch (0.04 cm) apart. It is also conventional to increase or decrease the height of the layer of mortar mix by disrupting the surface of the mortar bed to form air pockets. The installer works the mortar material in a continuous hoeing motion known to those skilled in the art. With the hoeing motion, each of the plurality of tips 35 a - b , of the trowel of the present invention, rakes a furrow in the mortar mix material, turning the mix to trap air and form the desired light air pockets. The installer may manipulate the trowel to control the movement of mortar mix along the edges 30 and along the V-shaped notches 40 , to simultaneously plow multiple furrows and produce egg carton like pockets in the layer of mortar mix. Mortar mix materials vary in their workability and it is contemplated that the present invention may be provided in different versions to best accommodate varying consistencies of mortar mix. The V-shaped notches 40 preferably have a depth ranging from approximately 1.5 to 7.0 inches (3.8 to 17.75 cm). With regard to the length of the blade 20 a - 20 c , it is preferred that the V-shaped notches extend approximately in the range of 2% to 90% of the length of the blade 20 a - 20 c . Generally, increasing the number of tips 35 a - b increases the efficiency of the trowel by allowing a corresponding number of furrows to be hoed by each of the tips 35 a - b . However, for a given consistency of mortar mix material, a sufficient depth of V-shaped notches 40 is required to successfully turn the mortar mix and produce the air pockets. The number of tips 35 a - b is limited by the overall width of the blade 20 a - c . A blade 20 a having three tips 35 a is shown in FIG. 2 , and a blade 20 b having two tips 35 a is shown in FIG. 3 . For a less viscous mortar mix material, the trowel may have V-shaped notches 40 of less depth, as shown in FIG. 4 , which depicts a trowel with a shorter blade 20 c and three tips 35 a - b. Furthermore, varying consistencies of mortar mix material may be worked with trowels having tips 35 a - b of different shape. FIGS. 2 and 3 depict tips 35 a that narrow to a point. FIG. 4 depicts three tips 35 a - b , two of which tips 35 b narrow to a flat, and one of which tips 35 a narrows to a point. Other combinations of number and type of tips 35 a - b and depth of V-shaped notches 40 not specifically shown in the drawings are also considered to be within the scope of the invention. While the preferred embodiments of the invention have been described above, it will be recognized and understood that various modifications can be made in the invention and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention.

An improved trowel for facilitating the production of air pockets in a layer of mortar mix applied to a substrate for receiving marble-flooring pieces thereon. The trowel comprises a handle and an elongated blade joined together by a shank. The shape of the blade gradually narrows to a distal end that includes a plurality of tips separated by one or more V-shaped notch or notches. In various versions of the invention, the number of tips may vary and the tips may be flat or pointed. The V-shaped notch or notches may vary in depth.

This is a continuation of application Ser. No. 119,443, filed Nov. 12, 1987, now abandoned, which was a division of application Ser. No. 394,395, filed July 1, 1982, now U.S. Pat. No. 4,757,479. BACKGROUND OF THE INVENTION 1. Field of Invention The present invention relates to cement bond logging and more particularly to methods and apparatus for measuring the attenuation rate of sonic energy traversing casing cemented in a borehole. 2. The Prior Art In a well completion, a string of casing or pipe is set in a borehole and cement is forced into the annulus between the casing and the borehole primarily to separate oil and gas producing formations from each other and from water bearing strata. Obviously, if the cementing fails to provide a separation of one zone from another, then fluids under pressure from one zone may be able to migrate and contaminate an otherwise productive nearby zone. Migration of water, in particular, produces undesirable water cutting of a producing zone and possibly can make a well non-commercial. It is a problem to obtain an accurate picture of conditions behind a casing because of the difficulty of propagating signals through the casing wall. Various prior proposals to determine the separation effectiveness, (i.e., the blocking or sealing characteristics) of the cement behind the casing have not been entirely successful in clearly determining the effective presence of cement in the annulus between the casing and the formation. Further, it has not been possible to measure reliably the quality of the cement bond between the casing and the cement. The mere presence or absence of cement in the annulus between the casing and formation is valuable information, however, this does not provide a complete picture of the cement conditions. While cement may be present in the annulus, channels or inadequate sealing may still permit fluid communication between adjacent formations. Use of the term "bond" in connection with the relationship of cement to the casing or the formation is somewhat vague, since adherence along the entire boundary between the casing and the cement or between the cement and formation is not necessary to prevent fluid communication between adjacent porous zones. All that is necessary of a bond is that the relationship prevents the migration of fluids. Hereafter, reference to bond will means that separation of zones by cement is adequate to prevent fluid migration between the zones. Several prior developments for obtaining a measure of the quality of a cement bond relative to the casing have been disclosed in U.S. Pat. Nos. 3,291,274, 3,291,248 and 3,292,246. These systems generally utilize acoustic principles where an acoustic signal is transmitted between a transmitter and a receiver. The amplitude of the early arrival signal (this early arrival usually is the casing signal since the acoustic energy under average conditions generally travels faster in the casing than in the surrounding cement or formation) at the receiver is measured as a determination of the quality of the bond of cement to the casing. If a good bond existed, the casing signal would be expected to be attenuated because of the energy dissipated from the casing to the cement and surrounding formations, whereas if no bond or a poor bond existed the casing signal would be relatively unattenuated. A more refined technique for determining the quality of cement in the annulus between the casing and the formations is disclosed in U.S. Pat. No. 3,401,773 entitled, "Method and Apparatus for Cement Logging of Cased Boreholes" by Judson D. Synnott, III and assigned to the assignee of the present invention. In this technique the amplitude of a reverberated early (casing) signal arrival is recorded and additionally, the total energy of a selected later portion of the sonic signal is obtained by integration to provide a second indication of the quality of the cement bond. Even in the absence of a weak casing arrival, the additional step of observing the total energy obtained by integrating a later portion of the signal in this manner can confirm the presence of cement in the casing-annulus-formation system. Details of related methods may also be had by reference to U.S. Pat. No. 3,401,772 entitled, "Methods for Logging Cased Boreholes" by Frank P. Kokesh, which is assigned to the assignee of the present invention. While the foregoing methods and apparatus provide very useful information, it is desirable to more precisely determine the quality of the cement bond. It has been established that the energy content of the acoustic logging signals arriving at the receiver depends on other factors than the quality of the cement bond to the casing or the integrity of the cement column (sometimes called cement quality). The following factors were found to have substantial effect on signal arrivals, receiver sensitivity; the formation hardness; eccentering of the acoustic logging tool; the high temperature environment and the temperature variations in the well bore; type of casing; and the diameter of the borehole and casing as well as their shape or geometry. It will be appreciated, therefore, that it is highly desirable to provide methods and apparatus for determining the quality of the cement bond in a cased borehole, which methods and apparatus reduce the detrimental effects of the aforementioned factors. SUMMARY OF THE INVENTION In accordance with the principles of the present invention, the reception of an acoustic signal, generated at a location along the cased borehole is effected at a pair of spaced apart locations by acoustic receivers, spaced at respective fixed distances from the point of signal generation. The receivers intercept the acoustic signal energy transmitted along the casing and produce corresponding electrical signals each consisting of a plurality of alterations. The signals are passed through gates operative to select signal portions which follow the portion of the signals representative of direct compressional wave transmission along the casing. The selected signal portions from each receiver are then further processed and a product representative of a ratio of the respective processed signal portions is provided. This ratio product, in accordance with the invention, provides for a measurement indicative of the presence or absence of cement behind the casing in the region between the receivers, independently of factors such as the diameter, shape and geometry of the casing and borehole. Further, in accordance with principles of the invention, in order that the signal arrivals be reliable representations of the acoustic energy travel through the media forming the casing-cement-formation system means are provided to effect the exclusion of the adverse representations of the acoustic energy travel between the sonde and the casing. Thus, in a borehole where a sonde as suggested by the prior art and having a single transmitter and receiver is used, it is necessary to correct the measured acoustic signal by some incremental value representing the effect of travel of acoustic energy between the sonde and the adjacent media. However, this incremental value is itself sometimes subject to error due to irregular spacing of the instrument from the media, resulting from the tilt of the sonde relative to the axis of the well bore. The logging system in accordance with the present invention, includes a sonde comprising two transmitters spaced respectively above and below the receivers. The transmitters are operated to obtain independent signals representing acoustic energy travel through the casing-cement-formation system. Thus two measurements are provided for each receiver, which measurements when combined, in accordance with the present invention, provide an output substantially free of the effects of the adverse representations of acoustic energy travel between the sonde and the casing. Advantageously, the result obtained from combining the signal outputs of the receivers, in accordance with the present invention, is also independent of receiver sensitivity. This independence represents a major advance over the prior art systems since it eliminates the need for constant correction or calibration of the receiver outputs for changes in receiver sensitivity which changes are due mostly to temperature effects. While the prior art does include examples of sonic logging systems comprising a sonde having a pair of spaced apart receivers included between an upper and a lower receiver, it will be appreciated that these systems were configured for operation in open (i.e., uncased) well bores for detecting formation parameters. These tools have little relevance to the field of cement bond logging due to the very nature of the signal being there measured, i.e., acoustic travel time. The distances between the receivers and transmitters on a sonde are selected to maximize the travel time of acoustic waves through the formation media under investigation relative to the travel time of the acoustic waves between the sonde and the formations. This leads to the selection of relatively large spacings between the receivers and the transmitters. In contrast, for cement bond logging purposes, in accordance with principles of the present invention, the spacings between the transmitters and receivers are selected to enhance not the travel time through the formations but the correlation between the combined output of the receivers and the quality of the cement bond. It will be appreciated that to provide receiver transmitter spacings of the order of those provided in tools configured for open hole logging purposes while appearing to be quite acceptable is actually detrimental to the operation of the system in cased holes since by the very nature of the measurement, the noise content of the signal in cased holes will increase proportionately with the distance between the receiver and the transmitter. Therefore, the choice of transmitter to receiver spacings is crucial to the realization of the advantages of the present invention. Yet in further accordance with principles of the present invention, a system is provided for effecting cement bond logging in "hard" formations. Hard formations are characterized by an acoustic travel time which approaches that of the casing or in some cases is less. Therefore, with the conventional transmitter to receiver spacings provided, the acoustic signal transmitted through the casing arrives at a receiver substantially with or before the acoustic signal transmitted through the hard formation and therefore leads to erroneous conclusions relative to the quality of the cement bond. It is therefore proposed, in accordance with principles of the present invention, a transmitter to receiver spacing which would allow for sufficient separation between the casing arrivals and the formation arrivals when logging in hard formations. This is accomplished by selecting a transmitter to receiver spacing where the acoustic travel time, of a generated wave, through the casing and cement to the formation is a significant portion of the travel time of the acoustic wave through the formation. In this manner the delay afforded by the passage of the waves through the casing and cement to the formation and the return passage to the borehole is sufficient to allow at the receiver the separation of the casing arrivals from the formation arrivals and therefore allow for a determination of the quality of the cement bond between the casing and the hard formation. In accordance with the objects of the present invention, methods and apparatus for logging cased boreholes to obtain an evaluation recording of cement conditions are provided. This is made possible by the use of novel logging apparatus and methods including the use of a plurality of spaced apart receivers supported on a sonde between an upper and a lower transmitter. The signals received by two of the receivers are combined in a novel way to reduce adverse effects due to borehole conditions and receiver sensitivity. The transmitter to receiver spacings are selected to enhance the correlation between the quality of the cement bond and the combination of the receiver outputs. A third receiver is supported on the sonde for effecting a measurement of the cement bond in hard formations. It is a further object of the present invention to modify the amplitude of energy detected at each receiver to compensate for fluctuations in transmitter output. The novel features of the present invention are set forth with particularity in the appended claims. The operation together with further objects and advantages of the invention may be best understood by way of illustration and examples of certain embodiments when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTIONS OF THE DRAWINGS FIG. 1 illustrates an embodiment of a logging system using the principles of the present invention in block form; FIG. 2 is an enlarged view of a portion of FIG. 1 indicating acoustic wave paths through the drilling fluid and the casing; FIG. 3 illustrates the form of acoustic signal travelling through a cemented casing under different cement bond conditions; FIG. 4 illustrates modification of a downhole sonde providing for minimum eccentering under substantial well deviation conditions; and FIG. 5 illustrates a typical cement bond attenuation rate log produced in accordance with the present invention as well as other types of logs produced with the system of FIG. 1. DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 there is illustrated a logging system for carrying out the invention and including an elongated logging tool 10 provided with centralizers 11 for maintaining the tool centered as effectively as possible in a borehole 12. The borehole 12 is shown filled with fluid 13. The tool 10 is suspended in the well bore by means of cable 15 extending from the upper end of the tool to the surface of the earth. The cable 15, typically a mono-cable, is spooled on a winch, not shown, but as well known in the art the operation serves to raise and lower the tool 10 through the well bore 12. Indications of the depth at which the tool is suspended in the bore hole can be provided by means (not shown) for measuring the length of the cable. This information is utilized to provide one of the functions in the typical well log. The tool 10 itself is divided into several sections. The lower section between the centralizers 11 includes a plurality of acoustic transducers including transmitters T1 and T2 as well as three acoustic receivers R1, R2 and R3. Above the acoustic transducers is a sonic cartridge containing the required electronics for processing data from the acoustic transducers as well as data from a collar detector 21 and a natural gamma ray detector 22. The upper part of the logging tool includes a telemetry modem 23 utilized to transmit information uphole as well as to act as a receiver of control information for the downhole equipment. Operation of the logging system is under control of a properly programmed digital computer 30 located at the surface. The program or instructions for the computer are initially stored on tape transport 31 and upon command from terminal 32, are loaded into the computer 30. The terminal 32 includes a printer which provides a monitor for instructions from the terminal to the computer and also enables an operator to interrogate the computer. When the system is ready for operation the computer 30 will send a command to the downhole equipment via bus 33, telemetry modem 34 and cable 15. The telemetry modem 23, in the downhole tool 10, applies the control data or command to a timing and control 35 which establishes conditions for the specific task to be performed in the sequence of operations. For example, the timing and control 35 under the computer instructions will establish whether transmitter T1 will be fired by way of transmitter energizer 36 and conductor 37 or whether transmitter T2 is to be fired via the transmitter energizer 36 and conductor 38. The timing and control 35 also establish which of the receiver outputs will be selected and amplified by way of receiver select and amplification means 40. Having now established the downhole task to be performed a handshake or sync signal is transmitted from the computer by way of telemetry modem 23 and conductor 41 to the timing control 35 to begin a cycle of the sequence of operations which includes measuring the peak or amplitude of the first halfcycle of the casing signal appearing at the receivers. While the information concerning the amplitude of the received signals travelling by way of casing can be utilized in the generation of conventional cement bond logs, the amplitude information is processed by the computer in accordance with the present invention to generate an attenuation rate log which more accurately represents the condition or degree of bonding of cement to the casing. In a conventional cement bond log where the amplitude of the received signal is plotted as a function of depth there are a number of conditions or factors that affect the signal and tend to introduce errors in the resultant log. These conditions include receiver sensitivity, transmitter output, borehole temperature variations, drilling fluid condition, formation hardness or velocity and eccentering of the logging tool. The effects of these various parameters or conditions can be largely reduced or eliminated by the transmitter and receiver arrangement and physical relationship shown in FIGS. 1 and 2 operating in conjunction with the method and apparatus of the present invention. For convenience the attenuation due to the drilling fluid may be lumped into a single attenuation factor M which may be assumed to be effective over a lateral portion of the acoustic energy wave path between the casing and the respective transmitters and receivers. In FIG. 2 the lump attenuation factor between the transmitters T1 and T2 and the casing have been designated as M1 and M4 whereas the attenuation factor between the receivers R1 and R2 and the casing have been designated as M2 and M3. The factors M1, M2, M3 and M4 can be eliminated by taking a ratio of the acoustic signal amplitudes received at each receiver from one of the transmitters and multiplying this ratio by a similar ratio obtained from a comparison of acoustic signal amplitudes at these receivers from the other transmitter. The various sonic signal amplitudes corresponding to each transmitter-receiver pair are designated T1 R1, T1 R2, T2 R1, T2 R2. The attenuation through the longitudinal zone between the transmitter T1 and the receiver R1 is designated C1 and the transmission over the longitudinal zone between the transmitter T2 and the receiver R2 is designated C2. C3 is the desired attenuation function between the longitudinal zone defined between the receivers R1 and R2. It can be shown by relative simple mathematical manipulation that the undesired transfer or attenuation functions M1, M2, M3 and M4 can be eliminated together with the attenuation functions C1 C2 leaving only the desired attenuation function C3 by taking the product ratio of the amplitudes of signals from the various receivers. When investigation the media forming a cased well bore, it is important that the logging tool be substantially centered in the borehole. The reason for this concerns the length of the path which acoustic energy must travel between the acoustic transmitter and receiver and the maximum amplitude of the first arrival of the casing signal. The time for acoustic energy to travel through casing to the receiver is known thus enabling a gate to be opened at the appropriate time to measure the peak amplitude of the first energy (the casing signal) arrival at the receiver. The time and amplitude is determined for the case of a centered logging tool. If the logging tool is eccentric in the borehole, the energy emitted from one side of the tool will have a shorter path to and from the casing thus causing the casing arrival at the receiver to be sooner than expected. Thus the above-mentioned gate will not be time centered and the measured casing arrival amplitude will be lower, causing errors in the cement bond log. However, with the configuration of and operation of transducers shown in FIG. 2 the problem introduced by eccentering is minimized in as much as the same portion of the casing signal from all receivers will be measured. The determination of attenuation rate in accordance with the present invention, is explained by reference to FIG. 2 where the two transmitters T1 and T2 are located symmetrically with respect to the two receivers R1 and R2. At a distance d1 from the upper transmitter T1 the amplitude of the casing-borne sonic wave initiated by transmitter T1 will be attenuated and can be expressed as: ##EQU1## where A 11 is the output of the receiver R 1 in millivolts, P 1 is the pressure amplitude for d1=0, S 1 is the receiver sensitivity in millivolts per bar and a is the attenuation rate of the sonic signal in decibels per foot. This relationship was established by Pardue, et. al., in an article entitled "Cement Bond Log--A Study of Cement and Casing Variables," appearing in the Journal of Petroleum Technology, May, 1963, at page 545. The output of receiver R2 can be written as: ##EQU2## Similarly, when firing the lower transmitter T 2 , the output of the receivers R 1 and R 2 can be written as: ##EQU3## Utilizing equations (1) to (4) the following ratio is formed: ##EQU4## The foregoing relationship shown in equation (5) is called the BHC ratio. From the BHC-ratio (5) the attenuation rate a can be obtained by performing: ##EQU5## where a is expressed in decibels per foot. It is to be observed that the measured attenuation is independent of receiver sensitivity, transmitter output power and fluid attenuation for any given sequence of operation. The BHC attenuation measurement as established by the present invention has a number of advantages over the standard cement bond log measurement and can be summarized as follows. As seen from FIG. 2 the sonic signals reaching R1 or R2 have travelled the same path through the casing fluid and its effect is thus eliminated while performing the ratio of amplitudes. The fluid attenuation effect can be important in heavy or gas cut muds. The transducer output will ordinarily decrease with increase in temperature and the receiver sensitivity may also decrease with age. These effects are effectively cancelled by utilizing the ratio technique. As mentioned earlier the BHC attenuation or ratio technique is independent of the absolute value of signal level. The measuring range of up to twenty db per foot is only limited by the value of the signal-to-noise ratio. In addition eccentering of up to 0.3 inches can be tolerated without having a significant effect upon the accuracy of the measurement. We have found that the spacing, the physical distance between the transmitters and the receivers is critical in order to obtain an accurate and reliable cement bond log. If the spacing is too long the signal noise ratio suffers to the point where the casing signal is buried in noise and cannot be detected. Even if the spacing is adjusted to enable the detection of the casing signal there are situations where the detected signal does not represent the casing signal. This occurs in situations where the velocity of the surrounding formations is higher than the velocity of sound through casing and where the transmitter to receiver spacing is large the formation signal will appear at the receiver prior to the arrival of the casing signal giving rise to an erroneous measurement. On the other hand if the receiver to transmitter spacings are too close the errors introduced by eccentering introduce errors. Accordingly the spacing between the transmitters and the receivers should be such as to provide for a measurable signal-noise-ratio, the arrival of the cement bond signal prior to the arrival of a formation signal and to tolerate eccentering of as much as 0.3 inches. The foregoing is accomplished by establishing a distance of approximately 2.4 feet from the transmitter T1 to the receiver R1 and similarly a distance of 2.4 feet from the transmitter T2 to the receiver R2. The receiver R2 should be approximately 3.4 feet from the transmitter T1 and the receiver R1 should be approximately 3.4 feet from the transmitter T2. The receiver R3 utilized principally in production of a variable density log, is in one embodiment, spaced 5 feet from the transmitter T2. Referring to FIG. 1 there will now be described the system for acquiring the casing signal data for use in the relationship defined by expression (6). Upon instructions from computer 30 to timing and control 35 a handshake or sync signal follows. The timing and control 35 now sends a firing command to the transmitter energizer 36 by way of conductor 42 for the generation by transmitter T1 of acoustic energy which travels outwardly through the drilling fluid and is refracted along the casing and back through the drilling fluid to receiver R1. The output of receiver R1 is applied by way of conductor 43 to the receiver select and amplification means 40 whose output, an analog signal, is transmitted uphole by way of conductor 44 telemetry modem 23 cable 15 telemetry modem 34 to the monitor oscilloscope 50. The analog output from the receiver select and amplification means 40 is also applied to the amplitude and transit time detection means 51 where the peak amplitude of the casing signal is detected and the transit time of the signal determined. A typical waveform for casing signals arriving at receivers under different cement bond conditions is illustrated in FIG. 3. It will be observed that where the casing is unbonded the halfcycles of the waveform comprising peaks E1, E2 and E3 are significantly greater than the amplitude of the corresponding peaks under conditions where the casing is well bonded to the cement. The halfcycle whose peak is to be detected is optional with the operator who, having knowledge of the transit time of acoustic energy through casing as well as the distance between the transmitter and the selected receiver, can establish by way of the computer an effective gate onset which is implemented by way of the timing and control 35 which conditions the amplitude and transit time detection means 51 to measure the peak amplitude of a selected halfcycle of the casing signal. Typically, the amplitude of peak E1 is detected. Transit time detection or measurement is effected also by way of a control pulse from the timing and control means 35 applied by way of conductor 54 to the amplitude and transit time detection means 51 which control pulse signifies the time at which the transmitter T1 has been fired. Utilizing conventional timing circuits in the means 51 a digital signal is produced representative of the value of the transit time for acoustic energy to travel from the transmitter T1 to the receiver R1. This digital signal is applied directly by way of conductor 55 to the telemetry modem 23 for transmission to the surface. The analog signal representative of the peak amplitude of the detected casing signal is applied by way of conductor 56 to the multiplex and A/D converter 60 whose digital output is also applied to telemetry modem 23 for transmission to the surface. The transit time signal is processed by the computer 30 converted to an analog signal and is available, at the option of the operator, to be recorded by the analog recorder 62 as a function of depth; the depth function as previously described being generated by conventional means also being processed by the computer and utilized to displace the data with respect to the recording medium. The digital representation of the detected amplitude of the casing signal is momentarily stored by the computer 30 to be utilized in conjunction with other data to generate a signal representative of attenuation rate in accordance with the present invention. The system having performed the first cycle in the sequence the computer 30 now sends additional instructions to the timing and control means in the manner above described once again to fire transmitter T1 and effectively now to connect the output of receiver R2 to the receiver select and amplification means 30. Again there is detected the amplitude of a casing signal arriving at receiver R2 and the transit time of that signal between the transmitter T1 and the receiver R2. The transit time may be recorded at the analog recorder 62 as a function of depth and again the digital value of the amplitude of the received casing signal is stored in the computer 30. In the next cycle of the sequence, instructions are transmitted from the computer 30 to the timing and control means 35 to establish conditions for the firing of the transmitter T2 and for the connection of the receiver R2. Upon the handshake by way of conductor 41, the transmitter T2 fires and acoustic energy travelling by way of the casing is detected at the receiver R2 where the peak amplitude E1 of the first halfcycle is detected by the amplitude detector 51 and applied by way of conductor 56 where it is converted to a digital signal in the multiplex and A/D converter 60 and transmitted uphole for storage in the computer 30. The transit time of the energy between the transmitter T2 and the receiver R2 is also measured or detected in the manner aforesaid and transmitted uphole. Upon further instructions from the computer 30 and following the handshake signal the transmitter T2 again fires and the energy received at the receiver R1 by way of the casing is applied by way of conductor 43 to the receiver select and amplification 40 where again the analog representation of the signal is transmitted over conductor 44 by way of telemetry modem 23 to the uphole monitor oscilloscope 50. In the manner above described the amplitude of the first halfcycle of the energy arriving by way of the casing is detected and applied to the multiplex and A/D converter for transmission to the computer 30 and the transit time is detected and the digital representation from the amplitude and transit time detection means 51 is applied to the telemetry modem 23 by way of conductor 55 for transmission uphole to the computer 30 for recording, if desired, on the analog recorder 62. Now in the final stage of the sequence as it relates to the generation of acoustic energy and detection after travel by way of the casing the transmitter T2 is again fired and the output of receiver R3 is applied by way of conductor 65 and receiver select and amplification means 40 to the telemetry modem 23 by way of conductor 44. The signal or wave train from the receiver R3 is utilized for the production of a variable density log in a manner well known in the art. Thus where the recorder 62 is comprised of an oscilloscope and photographic film, such a log is produced by sweeping an electron beam across the face of the oscilloscope and modulating the beam intensity with the received acoustic energy waveform while moving the film, as a function of depth of the logging tool, past the face of the oscilloscope. A typical variable density log is illustrated in FIG. 4 of U.S. Pat. No. 3,696,884. This now completes the sequence of operations which are comprised in the acoustical detection of five cycles, namely T1 to R1, T1 to R2, T2 to R2, T2 to R1, and T2 to R3. Each cycle requires control information to be transmitted from the computer 30 to the downhole equipment followed by a handshake. The handshake is the sync signal that informs the downhole equipment to execute the instructions. Following the acquisition of casing signal amplitude for each seqsuence, computer 30 produces an attenuation rate signal a in accordance with the relationship defined by expression (6) and this signal is recorded as a function of depth of the logging tool by recorder 62. The downhole tool also includes the collar detector 21 and the natural gamma ray detector 22. The outputs of these detectors are shown being applied by way of conductor 70 to the multiplex and A/D converter 60 which is under control of the timing and control means 35. The digital representations of these signals which fire the five cycles of the acoustic mode of operation are applied uphole by way of the telemetry modem 23 cable 15 to the computer where they are processed and recorded as a function of depth by the analog recorder 62. The parameters of natural gamma ray and collar detector are useful in correlating the resulting cement bond log with other logs previously taken in open hole. In the system of FIG. 1, the transmitters T1 and T2 are fired four times in each sequence of casing signal amplitude measurement. It is possible that between successive firing of the transmitter T1 or successive firing of the transmitter T2 the output of either transmitter may change. In that event an error would be introduced to the ratio determination. Such error, due to sudden variation in transmitter output can be avoided by way of a method in which signals from receivers R1 and R2 are produced for each firing of transmitter T1. Likewise signals from receivers R2 and R1 would be produced for each firing of the transmitter T2. The system of FIG. 1 would be modified to include a second amplitude and transit time detection means like that means 51. In such event the receiver select 40 would connect receiver R1 to one of the detection means and connect receiver R2 to the other of the detection means. Therefore, each transmitter firing results in the production of two receiver signals utilized in a ratio relationship and accordingly the operation avoids the introduction of error due to any types of changes in transmitter output. It will be recalled that the system of FIG. 1 provides for the determination of acoustic transit time between transmitters and receivers and the recording of same. This information is useful where hard formations may be encountered. In formations where the travel time is less than 57 microseconds per foot the 3.4 foot amplitude measurement is no longer valid. Indeed neither is a measurement taken with a transmitter to receiver spacing of 3 feet. Under such conditions the formation signal travelling behind the cement sheath precedes and superimposes itself on the casing-borne signal. It is now impossible to measure the attenuation rate due to the casing-cement bond with the transducer spacings described. Shorter transducer spacing would seem dictated when measuring attenuation rate in the environment of a hard or fast formation. However, shorter spacing introduces error due to eccentering. The shorter the T to R spacing the more pronounced is the eccentering effect. Since under such fast formation conditions, attenuation rate measurement is impractical, rather than stop the gathering of data, advantage is taken of the physical position of the receiver R3 to continue to obtain some measure of cement bond conditions. The receiver R3 has been placed 5 feet from transmitter T2 for the purpose of obtaining a standard variable density log. This places receiver R3 approximately 0.8 feet from transmitter T1. We have determined that at this spacing, the first arriving signal will be the casing signal even where the formation traveltime is as low as 57 microseconds per foot. The operator, in the course of the logging operation, will observe the value of transit time between a selected pair of transmitter and receiver. When the observed transit time falls below the transit time of acoustic energy in casing the computer 30 will be instructed via terminal 32 to change the sequence of downhole operations. The system operation will be modified to produce a conventional cement bond log where the peak of the first halfcycle of signal from receiver R3 in response to acoustic energy from transmitter T1 will be detected by the amplitude detection means 51 and recorded by recorder 62. When the foregoing operations are being conducted to produce the conventional cement bond log transmitter output variation poses a problem. In accordance with another aspect of the present invention errors introduced by variations in transmitter output are circumvented. More particularly the output of the receivers is modified as a function of transmitter output. The downhole system includes a transmitter energy detector which provides a measure of the energy being generated by the transmitters T1 and T2 each time they are fired. The measurement is of the voltage being applied to the transmitters by the transmitter energizer 36. For example, a typical voltage applied to each transmitter is approximately 1500 volts. Should the voltage output of the energizer vary and drop to as low as 750 volts between successive firings of the transmitter T1 the detected peak amplitude of the received signal will also drop resulting in an error. A measure of transmitter voltage (TV) is produced in the transmitter energizer 36 and applied by way of conductor 75 to the multiplex and A/D converter 60. The digital value of the measured transmitter voltage is utilized by computer 30 in accordance with the following expression: ##EQU6## where: A'13 is the amplitude of the signal to be recorded or otherwise used, A13 is the measured signal amplitude, and G is the gain of the amplification means 40. The above described modification of the receiver signal as a function of transmitter voltage gives rise to more accurate conventional type cement bond logs and may be utilized in systems other than illustrated in FIG. 1. It is also valuable in the ratio method where the possibility exists of fluctuations in transmitter voltage between sucessive firing of a given transmitter. Accordingly the system of FIG. 1 is arranged to be operated in such manner as to sense the value of the transmitter voltage for each firing of the transmitters T1 and T2 and each received signal is modified by a factor comprised of the ratio of the predetermined transmitter voltage to the measured transmitter voltage. In the discussion above reference was made to eccentering and problems introduced when eccentering became significantly high. The present system can produce an accurate attenuation rate log where the eccentering is as great as 0.3 inches. Maintaining this limit becomes a problem in deviated wells where the deviation is in excess of 20 degrees. In those instances the weight of the logging tool is increasingly applied against the centralizers causing the tool to move away from a centered position to a position closer to the casing. The eccentering problem is materially reduced by utilizing the logging tool of FIG. 4. This arrangement makes it possible to maintain the tool to within 0.3 inches of the casing axis where the well deviation is as great as 90 degrees. The lower portion 80 of the tool houses the transmitters T1 and T2 and the receivers R1, R2 and R3. The lower portion 80 is maintained centrally of the casing by means of in-line centralizers 81 and 82 each respectively having wheels 84 and 83 to ease the passage of the tool along the casing. The lower portion 80 is, in and of itself, light enough to avoid significantly compressing the centralizers 81 and 82 even when the portion is in a horizontal position, i.e., a well deviation of 90 degrees. The light weight is maintained by effectively mechanically decoupling the lower portion 80 from the remainder of the logging tool. The decoupling is provided by two flex joints 91 and 92 located between cartridge 90 and the lower portion 80. The articulation provided by the flex joints renders the lower portion free from lateral excursions of the cartridge 90 and other upper portions of the logging tool due to forces including gravity. The cement bond tool is a 23/4 inch size logging tool rated at 350° F. and 21,000 p.s.i. That portion of the tool housing the transducers is light, about 100 pounds, and made rigid. The optimum transmitter to receiver separation was set at 2.4 feet and 3.4 feet for the near and far receivers, respectively. A separate receiver was set at 5 feet from the lower transmitter to provide data for a variable density log. This same receiver spaced 0.8 feet from the upper transmitter provides data for a conventional cement bond log when logging through fast formations. The computer 30 used in one embodiment is a PDP 1134. Referring now to FIG. 5 there are shown examples of the BHC attenuation log, produced in accordance with the present invention, as well as a natural gamma log, a collar locator log and a transit time log. The transit time log is fairly constant in value indicating that the detected signals are casing-borne. Not unexpected in the transit time log are abrupt changes which are due to malfunction and known in the art as cycle skipping. The attenuation rate log shows at a depth of 1296 feet a very low attenuation rate indicative of a poor cement bond. Any measure above 10 db/ft would indicate a good cement bond. Values less than 10 db/ft may be acceptable, and certainly low values of attenuation rate should raise a question concerning the competency of the cement bond. While there have been described what are at present considered to be preferred embodiments of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the invention concepts involved and it is the intention of the appended claims to cover all such changes and modifications falling within the true spirit and scope of the present invention.

In accordance with principles of the present invention methods and apparatus are provided for evaluating the quality of the cement bond in cased boreholes. Acoustic energy is used to excite the borehole-casing-annulus-formation system and the quality of the cement bond is determined by examining the ratios of the signals received by two longitudinally spaced apart receivers supported on a sonde. The acoustic energy is generated by two transmitters symmetrically disposed above and below the receivers along the sonde. The spacings between the receivers themselves and between the receivers and the transmitters are selected so as to enhance the correlation between the ratios of the received signals and the quality of the cement bond log. An additional receiver, supported on the sonde at a small distance from one of the transmitters, is employed to determine the quality of the cement bond in hard formations.

REFERENCES CITED U.S. PATENT DOCUMENTS [0001] [0000] 6,944,260 B2 September 2005 Hsieh et al. 2011/0150308 A1 June 2011 Thibault et. al. FOREIGN PATENT DOCUMENTS [0002] [0000] EP2367153 A1 September 2011 Hsieh OTHER PUBLICATIONS [0000] [1] G. N. Ramachandran, A. V. Lakshminarayanan, Three - dimensional reconstruction from radiographs and electron micrographs: II. Application of convolutions instead of Fourier transforms, Proc. Nat. Acad. Sci. of USA, vol. 68, pp. 2236-2240, 1971. [2] R. M. Lewitt, Reconstruction algorithms: transform methods, Proceeding of the IEEE, vol. 71, no. 3, pp. 390-408, 1983. [3] S. Kaczmarz, Angeneaherte Aufloesung von Systemen Linearer Gleichungen, Bull. Acad. Polon. Sci. Lett. A., vol. 35, pp. 355-357, 1937. [4] Y. Censor, Finite series - expansion reconstruction methods, Proceeding of the IEEE, vol. 71, no. 3, pp. 409-419, 1983. [5] K. Sauer, C. Bouman, A local update strategy for iterative reconstruction from projections, IEEE Transactions on Signal Processing, vol. 41, No. 3, pp. 534-548, 1993. [6] C. A. Bouman, K. Sauer, A unified approach to statistical tomography using coordinate descent optimization, IEEE Transactions on Image Processing, vol. 5, No. 3, pp. 480-492, 1996. [7] J.-B Thibault, K. D. Sauer, C. A. Bouman, J. Hsieh, A three - dimensional statistical approach to improved image quality for multislice helical CT, Medical Physics, vol. 34, No. 11, pp. 4526-4544, 2007. [8] R. Cierniak, A novel approach to image reconstruction from projections using Hopfield - type neural network, Lecture Notes in Artificial Intelligence 4029, pp. 890-898, Springer Verlag, 2006. [9] R. Cierniak, A new approach to image reconstruction from projections problem using a recurrent neural network, International Journal of Applied Mathematics and Computer Science, vol. 183, No. 2, pp. 147-157, 2008. [10] R. Cierniak, A new approach to tomographic image reconstruction using a Hopfield - type neural network, International Journal Artificial Intelligence in Medicine, vol. 43, No. 2, pp. 113-125, 2008. [0013] [11] R. Cierniak, New neural network algorithm for image reconstruction from fan - beam projections, Neurocomputing, vol. 72, pp. 3238-3244, 2009. [12] R. Cierniak, A three - dimensional neural network based approach to the image reconstruction from projections problem, Lecture Notes in Artificial Intelligence 6113, S. 505-514, Springer Verlag, 2010. [13] R. Cierniak, X - Ray Computed Tomography in Biomedical Engineering, Springer, London, 2011. TECHNICAL FIELD [0016] This invention relates to three dimensional imaging, and particularly to the high resolution and low dosage three dimensional tomographic imaging. BACKGROUND OF THE INVENTION [0017] Analytical methods are one of the most important approaches to the image reconstruction from projections problem (see e.g. [1] G. N. Ramachandran, A. V. Lakshminarayanan, Three - dimensional reconstruction from radiographs and electron micrographs: II. Application of convolutions instead of Fourier transforms, Proc. Nat. Acad. Sci. of USA, vol. 68, pp. 2236-2240, 1971, [2] R. M. Lewitt, Reconstruction algorithms: transform methods, Proceeding of the IEEE, vol. 71, no. 3, pp. 390-408, 1983.). Another major category of reconstruction method is the algebraic reconstruction technique (ART) (see e.g. [3] S. Kaczmarz, Angeneaherte Aufloesung von Systemen Linearer Gleichungen, Bull. Acad. Polon. Sci. Lett. A., vol. 35, pp. 355-357, 1937, [4] Y. Censor, Finite series - expansion reconstruction methods, Proceeding of the IEEE, vol. 71, no. 3, pp. 409-419, 1983). All of the recent practically applicable reconstruction algorithms can be classified as belonging to one of these two methodologies of image reconstruction. [0018] In conventional tomography, analytical algorithms, especially those based on convolution and back-projection strategies of image processing, are the most popular. Algebraic algorithms are much less popular because algebraic reconstruction problems are formulated using matrices with very large dimensionality. Thus algebraic reconstruction algorithms are much more complex than analytical methods. [0019] Recently, there have been some new concepts regarding reconstruction algorithms. Among these new ideas, the statistical approach to image reconstruction is preferred (see e.g. [5] K. Sauer, C. Bouman, A local update strategy for iterative reconstruction from projections, IEEE Transactions on Signal Processing, vol. 41, No. 3, pp. 534-548, 1993, [6] C. A. Bouman, K. Sauer, A unified approach to statistical tomography using coordinate descent optimization, IEEE Transactions on Image Processing, vol. 5, No. 3, pp. 480-492, 1996.). This concept has been adapted for three-dimensional multi-slice helical computed tomography (see e.g. [7] J.-B Thibault, K. D. Sauer, C. A. Bouman, J. Hsieh, A three - dimensional statistical approach to improved image quality for multi - slice helical CT, Medical Physics, vol. 34, No. 11, pp. 4526-4544, 2007.) as the iterative coordinate descent (ICD) approach. In the ICD algorithm, the reconstruction process is performed using the maximum a posteriori probability (MAP) approach formulated principal as an algebraic reconstruction problem. This methodology is presented in the literature as being more robust and flexible than analytical inversion methods because it allows for accurate modeling of the statistics of projection data. [0020] The present applicant furnishes a new statistical approach to the image reconstruction problem, which is consistent with the analytical methodology of image processing during the reconstruction process. The preliminary conception of this kind of image reconstruction from projections strategy is represented in the literature only in the original works published by the present applicant for parallel scanner geometry (see e.g. [8] R. Cierniak, A novel approach to image reconstruction from projections using Hopfield-type neural network, Lecture Notes in Artificial Intelligence 4029, pp. 890-898, Springer Verlag, 2006., [9] R. Cierniak, A new approach to image reconstruction from projections problem using a recurrent neural network, International Journal of Applied Mathematics and Computer Science, vol. 183, No. 2, pp. 147-157, 2008., or [10] R. Cierniak, A new approach to tomographic image reconstruction using a Hopfield - type neural network, International Journal Artificial Intelligence in Medicine, vol. 43, No. 2, pp. 113-125, 2008.), for fan-beam geometry (see e.g. [11] R. Cierniak, New neural network algorithm for image reconstruction from fan-beam projections, Neurocomputing, vol. 72, pp. 3238-3244, 2009) and for spiral cone-beam tomography (see e.g. [12] R. Cierniak, A three - dimensional neural network based approach to the image reconstruction from projections problem, Lecture Notes in Artificial Intelligence 6113, S. 505-514, Springer Verlag, 2010.). In all these algorithms the reconstruction problem for any geometry of scanner is reformulated to the parallel-beam reconstruction problem using a re-binning operation. Thanks to the analytical origins of the reconstruction method proposed in the above documents, most of the above-mentioned difficulties connected with using ART methodology can be avoided. BRIEF DESCRIPTION OF THE INVENTION [0021] Although the proposed reconstruction method has to establish certain coefficients, this can be performed in a much easier way than in comparable methods. Additionally, it need only be done in one plane in 2D space, thus simplifying the problem. In this way, the reconstruction process can be performed for every cross-section image separately, allowing the collection of the whole 3D volume image from a set of previously reconstructed 2D images. Moreover, the optimization criterion used in this approach depends on an imposed loss function. And, what is most important, a modification of this function has been proposed so as to limit the analytical statistical model to the maximum likelihood (ML) scheme, thus preventing any instabilities in the reconstruction process. But firstly, it was necessary to formulate a reconstruction problem suitable for the analytical methodology of reconstructed image processing. The problem as formulated by the applicant of this application can be defined as an approximate discrete 2D reconstruction problem (see e.g. [11] R. Cierniak, New neural network algorithm for image reconstruction from fan - beam projections, Neurocomputing, vol. 72, pp. 3238-3244, 2009). It takes into consideration a form of the interpolation function used in back-projection. The form of the analytical statistical reconstruction problem proposed by the applicant of this application is very compact. All the geometrical conditions of the projections and the frequency operations performed on the reconstructed image fit into a matrix of coefficients. [0022] A method for reconstructing an image of an examined object of a spiral computed tomographic scan comprises establishing a radiation source, establishing a detector array, calculating coefficients h Δi,Δj , performing a scanning of an examined object by using a spiral computed tomographic imaging system to obtain a projection dataset, and performing of a back-projection operation for a fixed cross-section of an examined object wherein projections are used in the back-projection operation in a direct way. The coefficients g i,j are calculated and an initial image for an iterative reconstruction process is calculated and the iterative reconstruction process is performed. [0023] A 2D FFT is performed of the reconstructed image. The multiplication of the elements of the frequency representation of the reconstructed image by corresponding elements of the matrix H k,l is performed. A 2D IFFT of the resulting matrix is performed. Every pixel of the image obtained as the result of the above operations is performed by a nonlinear function. The 2D FFT of the resulting matrix is performed. A multiplication of elements of a frequency representation of the resulting matrix is performed by corresponding elements of the matrix H k,l . The 2D IFFT of the resulted matrix is performed. A correction of the reconstructed image is performed. A criterion of an iterative process for stopping is performed. [0024] No geometric correction of projections obtained from the spiral computed tomographic scanner is performed. [0025] Coefficients h Δi,Δj used in the iterative reconstruction process are established according to the relation: [0000] h Δ   i , Δ   j = ( Δ s ) 2  Δ h  ∑ θ  Int  (  Δ   i  · Δ s  cos  ( θ · Δ α ) +  Δ   j  · Δ s  sin  ( θ · Δ α ) ) [0000] wherein Δi (Δj) is the difference between the index of a pixel in the reconstructed image in the x direction (y direction); Δ s is a distance between pixels in a reconstructed image; Int is an interpolation function used in the back-projection operation; Δ α is an angular raster between angles of projections; θ=1, . . . , Θ max is an index of the angles, where Δ α Θ max =2π. [0026] The method in accordance with claim 1 wherein coefficients g i,j used in the iterative reconstruction process are established according to the relation [0000] g i , j = ∑ θ  ∑ η  ∑ k  w ij , β 2  v ij , k 2   p h  ( β η , α θ h , z . k ) , [0000] wherein p h (β η , α θ h , ż k ) are projections used in the back-projection operation for a specific pixel of the reconstructed image (this pixel is indicated by the pair (i, j)); w ij,η and v ij,k are calculated weights assigned to the projections used in the back-projection operation for a specific pixel (i, j) in the reconstructed image. [0027] A plane is oriented, an image is placed in the plane by a coordinate system (x, y), and the topology of the pixels in the reconstructed image is placed according to the following description: [0000] x = …  , - 5  Δ s 2 , - 3  Δ s 2 , - Δ s 2 , Δ s 2 , 3  Δ s 2 , 5  Δ s 2 , …  , [0000] for the x direction, and [0000] y = …  , - 5  Δ s 2 , - 3  Δ s 2 , - Δ s 2 , Δ s 2 , 3  Δ s 2 , 5  Δ s 2 , …  [0000] for the y direction, wherein Δ s is a raster of pixels in the reconstructed image, for both x and y directions. 1. The method in accordance with claim 1 wherein the placement of the x-ray detectors in every column of the detector array is specified by the following description: [0000] β η =(η− H s −0.5)·Δ β [0000] where Δ β is the angular distance between the radiation detectors in columns of the detector array; H s is a positive integer value denoting number of detectors in columns; η is an index of detectors in columns. The transformation by a nonlinear function can be performed using the following relation [0000] b i , j t = g i , j · tanh   ( a i , j t - μ ~ i , j λ ) [0000] wherein a i,j t is a pixel from the transformed image; g i,j is a coefficient established for a given pixel (i, j); {tilde over (μ)} i,j is a value of the pixel from the image obtained after back-projection operation; λ is a constant slope coefficient. BRIEF DESCRIPTION OF THE DRAWINGS [0028] FIG. 1 shows a general view of a tomographic device; [0029] FIG. 2 . shows the geometry of the scanner in the gantry; [0030] FIG. 3 illustrates the movement of the projection system relative to the patient in the spiral scanner with the cone beam; [0031] FIG. 4 depicts a projection system of a cone-beam scanner in a three-dimensional perspective view; [0032] FIG. 5 shows the geometry of a cone-beam projection system in a plane perpendicular to the axis of rotation; [0033] FIG. 6 shows the location of a test object in a plane along the axis of rotation of the projection system; [0034] FIG. 7 depicts the topology of the detectors on a cylindrically-shaped screen (at the projection angle α h =π/2); [0035] FIG. 8 depicts a schematic block diagram of a method used to practice the present invention with connection to a computed tomography apparatus; [0036] FIG. 9 illustrates schematically a proposed topology of the pixels in the reconstructed image; [0037] FIG. 10 depicts a schematic block diagram of an iterative reconstruction process; [0038] FIG. 11 is a prior art reconstructed image of a mathematical phantom using a Feldkamp-type reconstruction algorithm; [0039] FIG. 12 is a reconstructed image of the mathematical phantom using the reconstruction method which embodies the presented invention. DETAILED DESCRIPTION OF THE INVENTION [0040] FIG. 1 shows a general scheme of the spiral tomography apparatus, which consists of three main parts: gantry 1 , table 2 (on which an examined patient 3 is placed), and a computer (which is used to control the whole device and to perform the reconstruction procedure). The here described image reconstruction method is carried out using projections based on measurements performed by a measuring system installed in the gantry 1 . Every measurement is obtained thanks to the measuring circuit (see FIG. 2 ): x-ray tube 5 and detector placed on the screen in the detector array 6 . The examined cross-section of the patient 7 is placed inside the gantry. The reconstruction method of the present invention is dedicated for the x-ray apparatus with a spiral movement trace of the measurement system (called also a scanner) and with a cone shaped beam of x-rays. This type of scanner is well-known in tomography technology, and is used commonly in practice (see for example US Pat. U.S. Pat. No. 6,944,260, US Patent Application Publication 2011/0150308 and European Patent EP2367153). FIG. 3 depicts the movement of the parts of the measurement system relative to the patient. FIG. 4 depicts the general view of the geometry of a spiral cone-beam scanner used in the present invention. This drawing shows the projection system of a cone-beam scanner oriented by x-y-z coordinates in a three-dimensional perspective view. This construction of scanners combines the movement of the x-ray tube 5 around the patient with a simultaneous displacement of the table 2 with a patient. In consequence, the measurement system moves in a spiral around the patient. The x-ray beam takes the form of a cone and reaches a detector array 6 . During a scan, this assembly rotates around the z-axis, which is the principal axis of the system. This construction permits three-dimensional projection techniques to be mastered and so paved the way for the development of reconstruction techniques operating in three dimensions. FIG. 5 depicts the geometry of the cone-beam scanner in a plane perpendicular to the axis of rotation z; FIG. 6 shows the location of the examined body in the plane along the axis of rotation of the measurement system. Every measurement registers x-ray intensity by a detector placed on the screen at a specific position of the rotated measurement system. These direct measurements are transformed by a nonlinear function into variables called projections, as follows: [0000] p = ln   I 0 I , ( 1 ) [0000] wherein: I is a measured x-ray intensity; I 0 is an x-ray intensity emitted by the tube. [0041] Not all possible measurements are performed. The parameters of the carried out projections obtained through the scanner can be defined as it is presented below. [0042] At a given moment, assuming that the tube rotating around the examined object starts at a projection angle α h =0, the vertical plane of symmetry of the projection system moves along the z-axis and its current location along this axis (see FIG. 6 ) is defined by the relationship: [0000] z 0 = λ   α h 2  π , ( 2 ) [0000] where: λ is the relative travel of the spiral described by the tube around the test object, measured in [0000] [ m rad ] . [0043] Each x-ray ray emitted at a particular angle of rotation α h and reaching any of the detectors 7 placed in the detector array 6 can be identified by measurement parameters (β η , α θ h , ż k ), wherein: β η is the angle between a particular ray in the beam and the axis of symmetry of the moving measurement system (η 0 is a number of detectors in a particular column of the detector array 6 (see FIG. 5 )); α θ h is the angle at which the projection is made (using all detectors the measurements are performed), i.e. the angle between the axis of symmetry of the rotated scanner and the y-axis; [0046] ż k is the z-coordinate position relative to the current position of the moving measurement system (k is a detector number in a particular row of the detector array 6 (see FIG. 6 )). [0047] The acquisition of the projection values p h (β η , α θ h , ż k ) only takes place at specific angles of rotation α h : [0000] α θ h =θ·Δ α h [0000] wherein: Δ α h =2π/Θ 2π is the angle through which the scanner is rotated a following each projection; Θ 2π is the number of projections made during one full rotation of the scanner; θ=0, . . . , θ−1 is the global projection index; Θ=number_of_rotations·Θ 2π is the total number of projections. [0048] The position of a detector in the array placed on the cylindrically shaped screen is determined by the pair (η, k), where η=0, . . . , H−1 is index of the detector in every column (it is called a channel) and k=0, . . . , K−1 is the index of the column (it is called a row). H and K denote the total number of detectors in the channels and the total number of rows, respectively. [0049] The useful rays are striking the detectors in the individual rows. These detectors are distributed evenly. Thus, we can write: [0000] β η =(η− H s −0.5) Δ β ,   (4) [0000] wherein: Δ β is the angular distance between the radiation detectors on the cylindrical screen; H s is a positive integer value (it is convenient to assume, if H is an even value, that H s =H/2). The shift by an angle 0.5·Δ β is claimed in this application. [0050] We can write, too: [0000] γ k =( k−K s )·{dot over (Δ)} z ,   (5) [0000] wherein: we assume that detectors are equidistantly placed in every channel and {dot over (Δ)} z is the distance between detectors in channels related to the z-axis; K s is a positive value (it is convenient to assume, if K is an odd value, that K s =(K−1)/2). [0051] Above assumptions make it easy to locate the detectors in the array on the surface of the partial cylinder, as shown in FIG. 7 . [0052] Before the reconstruction method is applied, the center of reconstructed cross-section is chosen by an operator, and will be assigned as z p . X-ray tube 5 reaches this point when it is at an angle (if the tube rotating around the examined object starts at a projection angle α h =0): [0000] α p h = z p  2  π λ . ( 6 ) [0053] Next, all projections p h (β η , α θ h , ż k ) necessary for a reconstruction method are obtained using measurements of x-ray intensity performed by the helical cone-beam scanner. It is needed for a reconstruction of the cross-section with a center located at the position z p to collect all projections from a range α p h −π≦α θ h ≦α p h +π and some projections outside this range next to the values α h =α p h −π and α h =α p h +π (because of a requirement of an interpolation operation in the further steps of the reconstruction procedure). [0054] Having all necessary projection values p h (β η , α θ h , ż k ), the reconstruction algorithm 8 can be started, as specified in the following steps. Step 1. [0055] Before the main reconstruction procedure is started, the h Δi,Δj coefficient matrix is established (see FIG. 8 ). All calculations in this step of the presented reconstruction procedure can be pre-calculated, i.e. the calculation can be carried out before the scanner performs all necessary measurements. We make a simplification in that the coefficients h Δi,Δj are the same for all pixels of the reconstructed image, and they can be calculated in a numerical way, as follows: [0000] h Δ   i , Δ   j = ( Δ s ) 2  Δ α  ∑ θ   Int   (  Δ   i  · Δ s  cos   ( θ · Δ α ) +  Δ   j  · Δ s  sin  ( θ · Δ α ) ) , ( 7 ) [0000] where: Δi (Δj) is the difference between the index of pixels in the x direction (y direction); Δ s is a distance between pixels in a reconstructed image; Δ α is a raster of angles (Δ α is many times less than Δ α h , for instance 1000 times); [0000] θ = 0 , 1 , …  , 2  π Δ α - 1 ; [0000] Int is an interpolation function. [0056] In general, the interpolation function Int can be any interpolation function. In this application, it is the ordinary linear interpolation function, which is expressed in the following way [0000] Int   ( Δ ) = { 1 Δ s  ( 1 -  Δ  Δ s ) for  Δ  ≤ Δ s 0 for  Δ  > Δ s . ( 8 ) [0057] The invention presented here relates also to the technical problem of how to avoid the consequences of the central pixel in the reconstructed image being preferred over other pixels during the calculation of coefficients hΔi,Δj performed in Step 1. Because a relation (7) prefers the central point of the (x,y) coordinate system, the pixel lying at this point is also preferred over other pixels. This is because it is only at the point lying at the origin of the coordinate system that the interpolation function gets the value 1 at every angle θ·Δ α . In this application, to avoid the consequences of this preference for the central pixel in the reconstructed image during the calculation of coefficients h Δi,Δj the topology of the pixels in a reconstructed image presented in FIG. 9 is proposed, to avoid the situation when any pixel is placed in a central point of a reconstructed image. These pixels are placed in this image according to the following description: [0000] x =  …  , - 5  Δ s 2 , - 3  Δ s 2 , - Δ s 2 , Δ s 2 , 3  Δ s 2 , 5  Δ s 2 , … =  - I 2 - 0.5 , …  , - 0.5 , 0.5 , …  , I 2 - 0.5 , ( 9 ) [0000] for the x direction, and [0000] y =  …  , - 5  Δ s 2 , - 3  Δ s 2 , - Δ s 2 , Δ s 2 , 3  Δ 3 2 , 5  Δ s 2 , … =  - I 2 - 0.5 , …  , - 0.5 , 0.5 , …  , I 2 - 0.5 ( 10 ) [0000] for the y direction, if a reconstructed image has dimensions I×I (I is chosen to be equal to a positive integer power of 2). [0058] Output for this step is a matrix of the coefficients h Δi,Δj . If a reconstructed image has dimensions I×I then this matrix has dimensions 2I×2I . Step 2. [0059] In this step the matrix of the coefficients h Δi,Δj is transformed into a frequency domain using a 2D FFT transform (see FIG. 8 ). All calculations in this step of the presented reconstruction procedure can be pre-calculated, i.e. it can be carried out before the scanner performs all necessary measurements. [0060] Output for this step is a matrix of the coefficients H k,l with dimensions 2I×2I. Step 3. [0061] The essential part of the invented reconstruction algorithm begins with performing the back projection operation. This operation is described by the following relation: [0000] μ ~ i , j = Δ α h  ∑ θ   p _ h  ( β ij , α θ h , z . ijp ) , ( 11 ) [0000] wherein: {tilde over (μ)} i,j is the image of a cross-section obtained after the back-projection operation at position z p ; α θ h is an angle at which a given projection is carried out; h i [0000] α p h - π Δ α h ≤ θ ≤ α p h + π Δ α h [0000] is the index of the projections used; p h (β ij , α θ h , z ijp ) are the interpolated values of the projections at an angle α θ h for voxel described by coordinates (i, j, z p ); i =1,2, . . . , I; j=1,2, . . . , I. [0062] Projections p h (β ij , α θ h , ż ijp ) are interpolated for all pixels (i, j) in reconstructed image at every angle α θ h using the following interpolation formula: [0000] p _ h  ( β ij , α θ h , z p ) = Δ β  Δ . z  ∑ η   ∑ k   p h  ( β η , α θ h , z . k ) · w ij , η  v uj , k  ( z . ijp - z . k ) , ( 12 ) [0000] wherein weights are established in the following way: [0000] w ij , η = Int  ( β ij - β η )   and ( 13 ) v ij , k = Int  ( z . ijp - z . k )   wherein ( 14 ) β ij = arc   tan  i · Δ s · cos   α θ h + j · Δ s · sin   α θ h R f + i · Δ s · sin   α θ h - j · Δ s · cos   α θ h ( 15 ) [0000] is a projection of a voxel (i, j, z p ) on the screen at a given angle α θ h for coordinate β, and [0000] z . ijp = R f · ( z 0 - z p ) R f + i · Δ s · sin   α θ h - j · Δ s · cos   α θ h , ( 16 ) [0000] is a projection of voxel (i, j, z p ) on screen at a given angle α θ h for coordinate ż, and (η, k) are the indices of the detectors on the screen; p h (β η , α θ h , ż k ) are projections obtained in the scanner. The interpolation function Int must be the same as was used in Step 1, in this application it is the ordinary linear interpolation function, which is expressed in the following way [0000] Int  ( Δ   β ) = { 1 Δ β  ( 1 -  Δ   β  Δ β ) for    Δ   β  ≤ Δ β 0 for    Δ   β  > Δ β ,   and ( 17 ) Int  ( Δ   z . ) = { 1 Δ . z  ( 1 -  Δ   z .  Δ z ) for    Δ   z .  ≤ Δ . z 0 for    Δ   z .  > Δ . z ( 18 ) [0000] for β and ż dimensions, respectively. [0063] Output for this step is an image {tilde over (μ)} i,j ; i=1,2, . . . , I ; j=1,2, . . . , I, i.e. an image obtained after the back-projection operation at position z p . Step 4. [0064] After the back-projection operation, the calculation of the weight coefficients g i,i for all pixels in the reconstructed image is performed. This step is carried out according to the following equation: [0000] g i , j = ∑ θ  ∑ η  ∑ k  w ij , η 2  v ij , k 2   p h  ( β η , α θ h , z . k ) , ( 19 ) [0000] wherein weights w ij,η and v ij,k are established according to the relations (13) and (14), respectively. [0065] Output for this step is a matrix of weights g i,j ; i =1,2, . . . , I; j=1,2, . . . I. Step 5. [0066] In this step, an initial image for the iterative reconstruction procedure is determined. It can be any image μ i,j 0 but for the accelerating of the reconstruction process it is determined using a standard reconstruction method based on projections p h (β η, α θ h , ż k ) for instance a well-known Feldkamp-type method constructed for a spiral cone beam scanner, for example presented in [13] R. Cierniak, X - Ray Computed Tomography in Biomedical Engineering, Springer, London, 2011. [0067] Output for this step is an initial reconstructed image μ i,j 0 ; i=1,2, . . . , I; j=1,2, . . . , I. Step 6. [0068] The reconstructed image μ i,j t can be processed using parameters g i,j and H i,j by the iterative reconstruction process being a sub-procedure of the reconstruction algorithm. As an initial for this sub-procedure image μ i,j 0 is used an image obtained in Step 5. [0069] Output for this step is a reconstructed image μ i,j t — stop ; i=1,2, . . . , I; j=1,2, . . . , I. [0070] An image obtained in such a way is designated to present the image on screen for diagnostic interpretation using a different method of presentation developed for computed tomography. [0071] The iterative reconstruction procedure performed in Step 6 consists of several sub-operations as presented in FIG. 10 , as follows. Step 6.1. [0072] At the beginning of every iteration of this sub-procedure, the 2D FFT of the reconstructed image μ i,j t is performed. Of course, at the first iteration, the image μ i,j 0 is transformed. [0073] If the reconstructed image has dimensions I×I then this frequency representation of this image M k,l t has dimensions 2I×2I. Step 6.2. [0074] In this step, multiplication of every element of a matrix M k,l t by a corresponding element of the matrix H k,l (obtained in Step 2) is carried out. This operation represents a convolution operation transformed to the frequency domain. This way, the number of necessary calculations is drastically reduced. [0075] In the way of 4I 2 multiplications, the matrix A k,l t is obtained with dimensions 2I×2I. Step 6.3. [0076] In this step, the inverse 2D FFT of the matrix A k,l t is performed. [0077] If the matrix A k,l t has dimensions 2I×2I then the spatial representation of this matrix a i,j t has dimensions I×I . Step 6.4. [0078] In this step, all values a i,j t are transformed by a nonlinear function, in the following way: [0000] b i , j t = g i , j · tanh ( a i , j t - μ ~ i , j λ ) , ( 20 ) [0000] wherein λ is a constant slope coefficient, and strongly depends on the reconstructed image dimensions; coefficients g i,j are obtained in Step 4. [0079] A result of this operation is a matrix b i,j with dimensions I×I. Step 6.5. [0080] The 2D FFT of the matrix b i,j t is performed. [0081] If the reconstructed image has dimensions I×I then this frequency representation of this matrix B k,j t has dimensions 2I×2I. Step 6.6. [0082] In this step, multiplication of every element of the matrix B k,l t by a corresponding element of the matrix H k,l (obtained in Step 2) is carried out. This operation represents a convolution operation transformed to the frequency domain. This way, the number of necessary calculations is drastically reduced. [0083] In the way of 4I 2 multiplications, the matrix C k,l t is obtained with dimensions 2I×2I. Step 6.7. [0084] In this step, the inverse 2D FFT of the matrix C k,l t is performed, and the matrix C i,j t in a spatial domain is obtained. [0085] If the matrix C k,l t has dimensions 2I×2I then the spatial representation of this matrix c i,j t has dimensions I×I. Step 6.8. [0086] The correction operation is performed in this step, according to [0000] μ i,j t+1 =μ i,j t −ρ·c i,j t ,   (21) [0000] where ρ is a constant coefficient. Step 6.9. [0087] In this step, it is decided whether the iterative process is continued or not. This decision can be made based on a subjective evaluation of the reconstructed image quality at this stage of the reconstruction process (quality of reconstructed image is satisfying). Alternatively, this reconstruction process can be stopped after an in advance established number of iterations. [0088] If the reconstruction process is continued then an image μ i,j t+1 is an input matrix (representing the reconstructed image) for the next iteration of the iterative reconstruction process 8 , i.e. μ i,j t =μ i,j t+1 , or if it is not continued then image μ i,j t+1 is considered to be a final reconstructed image, i.e. μ i,j t — stop =μ i,j t+1 . [0089] Using the image reconstruction method and apparatus to practice the presented invention, image artifacts and distortions are significantly reduced, as shown by the contrast between FIG. 11 and FIG. 12 . In consequence, it allows to improve the resolution of the reconstructed images and/or to decrease the X-ray intensity at maintenance of quality of the obtained CT images, because this intensity is strongly related to the resolution of the obtained images. Furthermore, in contrast with the ICD approach, where the computational complexity of every iteration of the reconstruction procedure is approximately proportional to I 4 ×number of reconstructed images×number of used projection measurements, the application method is very attractive (feasible and giving high quality images) from the perspective of a 3D implementation, with a computational complexity of approximately 2I 2 log 2 I for one iteration of the iterative reconstruction process.

This invention relates to a high resolution and low dosage tomographic imaging in three dimensions, and more particularly, to a fully analytical fast iterative statistical algorithm for image reconstruction from projections obtained in a spiral cone-beam x-ray scanner is described. The presented method allows to improve the resolution of the reconstructed images and/or to decrease the x-ray intensity while maintaining the quality of the obtained CT images, because the signals obtained are adapted to the specific statistics for this imaging technique. The location of pixels in a reconstructed image and the location of detectors in a detector array in this new approach are described. The topology of pixels and detectors presented here avoids an inconsistency in the distribution of the coefficients assigned to the pixels in the image, which appears in the formulation of the analytical iterative statistical reconstruction problem.

FIELD OF THE INVENTION [0001] The present invention relates to a pharmaceutical formulation comprising a pharmaceutically active agent; water; a polyethylene glycol or a poloxamer; and a polyethylene glycol mono- or di-ether. Preferably the pharmaceutically active agent is an anti-fungal or anti-mycotic agent. Preferably the pharmaceutically active agent is lipophilic and/or keratinophilic. The present invention also relates to the use of the formulation in treating diseases, disorders or pathological conditions of the nail or skin, such as onychomycosis, dermatomycosis and other mycoses. The present invention also relates to a method of administering a pharmaceutically active agent to a subject by applying the formulation comprising the pharmaceutically active agent to a nail or skin of the subject. The present invention further relates to a method of preparing the formulation. BACKGROUND OF THE INVENTION [0002] Although diseases and disorders of the skin can often be treated effectively by topical administration of pharmaceutically active agents, successful treatment of diseases and disorders of the nails has remained elusive. It has proven difficult to deliver pharmaceutically active agents effectively into and beneath the nails where the cause of most pathological conditions of the nails originates. [0003] In particular fungal infections of the nails remain ineffectively treated. Fungal infections in, under and around fingernails and toenails are generally referred to as onychomycosis. Onychomycosis is most frequently caused by dermatophytes such as Trichophyton rubrum, Trichophyton mentagrophytes and Epidermophyton floccosum, but can also be caused by other types of fungi including moulds, yeasts and the like. Onychomycosis that is not caused by dermatophytes is normally caused by Candida species. Mixed infections can also occur. [0004] Onychomycosis causes thickening, roughness, splitting and discolouration of the nail and can even result in its loss or destruction. In addition, it can be the cause of pain, inadequate blood supply, problems with walking, and other undesirable phenomena. [0005] In the past, onychomycosis was treated inter alia by removing the affected part of the nail or the whole nail. However, this type of treatment can lead to permanent damage to the nail. Also, the newly growing nail can grow in a misshapen form. Moreover, there is no guarantee that the onychomycosis can be completely cured by removing the nail. [0006] Instead of removing the nail, onychomycosis can also be treated by the use of various anti-mycotic agents. The anti-mycotic agents can be administered orally, for example. In this form of treatment, however, stress is put on the body as a whole and only a small amount of the anti-mycotically active substance reaches the nail via the nail matrix. Oral treatment has the further disadvantage that such treatment requires a treatment time of at least 12 weeks for toenails and about 6 to 8 weeks for fingernails. Such long treatment times make the treatment expensive and reduce patient compliance. Furthermore, oral treatment increases the risk of side-effects, such as, for example, irritation of the gastro-intestinal tract, nausea, undesirable interactions with other medicaments, active ingredient induced skin rashes etc. The oral treatment of onychomycosis is further rendered difficult by variable rates of absorption and metabolism. [0007] Another method of treating onychomycosis comprises the topical application of a pharmaceutical formulation containing an anti-mycotic active ingredient. For example, it is known to treat onychomycosis with nail lacquer formulations that contain an anti-mycotic active ingredient. However, such anti-fungal nail lacquers lack the necessary penetrating power to reach the fungal infection, because the nail is a difficult barrier for the anti-fungal compounds to penetrate. [0008] Accordingly, there remains a need for the effective treatment of diseases, disorders and pathological conditions of the nail such as onychomycosis. It would be advantageous to have a topical formulation that is capable of penetrating the nail barrier and capable of effectively treating nail fungal diseases, thus avoiding oral administration of anti-fungal agents and the necessity of removing the nail. To be effective, a topical treatment for onychomycosis should exhibit a powerful potency for pathogens and must be able to permeate through the nail barrier. SUMMARY OF THE INVENTION [0009] Accordingly, a first aspect of the present invention provides a formulation comprising: [0010] (a) a pharmaceutically active agent; [0011] (b) water; [0012] (c) a polyethylene glycol (PEG) or a poloxamer; and [0013] (d) a polyethylene glycol mono- or di-ether. [0014] A polyethylene glycol (PEG) has the general formula HO—(CH 2 CH 2 O) n —H. Preferably n=4-2000, preferably n=6-750, preferably n=150-500. In a preferred embodiment, the polyethylene glycol has a mean molecular weight of at least 400, preferably at least 500, preferably at least 700, preferably at least 1000, preferably at least 1500, preferably at least 4500, preferably at least 5000, preferably at least 6000, and more preferably at least 8000. Preferably the mean molecular weight of the polyethylene glycol is no more than 100000, preferably no more than 30000, and more preferably no more than 20000. Any of these preferred lower molecular weight limits can be combined with any of these preferred upper molecular weight limits to give preferred molecular weight ranges. Preferably the mean molecular weight of the polyethylene glycol is in the range of 200-100000, preferably in the range of 300-30000. In a preferred embodiment, the polyethylene glycol is PEG 8000-20000, i.e. a polyethylene glycol having a mean molecular weight between 8000 and 20000. In an alternate preferred embodiment, the mean molecular weight of the polyethylene glycol is in the range of 200-600, preferably in the range of 300-500, and more preferably the mean molecular weight of the polyethylene glycol is about 400. In a preferred embodiment, the formulation comprises the polyethylene glycol in an amount of 5-50%, preferably in an amount of 10-40%, preferably in an amount of 15-35%. [0015] For the purposes of the present invention, unless stated otherwise all amount percentages refer to the percentage by weight. [0016] A poloxamer is a polyethylene glycol-polypropylene glycol block copolymer with the general formula HO—(CH 2 CH 2 O) a —(CH(CH 3 )CH 2 O) b —(CH 2 CH 2 O) c —H. Preferably a=4-200. Preferably b=15-350. Preferably c=4-200. Preferably the polyoxyethylene content of the poloxamer is 10-80% of the total polymer weight. [0017] In a preferred embodiment, the poloxamer has a mean molecular weight of at least 1000, preferably at least 2000, preferably at least 4500, preferably at least 5000, preferably at least 6000, and more preferably at least 8000. Preferably the mean molecular weight of the poloxamer is no more than 100000, preferably no more than 30000, and more preferably no more than 15000. Any of these preferred lower molecular weight limits can be combined with any of these preferred upper molecular weight limits to give preferred molecular weight ranges. Preferably the mean molecular weight of the poloxamer is in the range of 1000-16000, preferably in the range of 2000-15000. In a preferred embodiment, the formulation comprises the poloxamer in an amount of at least 1%, preferably at least 2%, preferably at least 5%. Preferably the formulation comprises the poloxamer in an amount of 5-50%, preferably in an amount of 10-40%, preferably in an amount of 15-35%. [0018] The formulation of the present invention may comprise a polyethylene glycol or a poloxamer. Preferably the formulation comprises a polyethylene glycol. In one embodiment, the formulation does not comprise a poloxamer. [0019] A polyethylene glycol mono- or di-ether has the general formula RO—(CH 2 CH 2 O) m —R. Preferably m=2-250, preferably m=4-175, preferably m=6-125. Preferably each R is independently selected from hydrogen or an optionally substituted alkyl, alkenyl, alkynyl, aryl, arylalkyl, arylalkenyl, arylalkynyl, alkylaryl, alkenylaryl or alkynylaryl group; more preferably each R is independently selected from hydrogen or an optionally substituted alkyl, aryl, arylalkyl or alkylaryl group; more preferably each R is independently selected from hydrogen or an optionally substituted alkyl group; more preferably each R is independently selected from hydrogen or a methyl or ethyl group; all provided that at least one R is not hydrogen. In a preferred embodiment, one R is hydrogen. Preferably R is not substituted. Preferably R comprises no heteroatoms in its carbon skeleton. Preferably R contains from 1 to 20 carbon atoms, preferably from 1 to 15 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, more preferably from 1 to 4 carbon atoms. Preferably the polyethylene glycol mono- or di-ether contains a single —(CH 2 CH 2 O) m — group, i.e. no R comprises a —(CH 2 CH 2 O) m — group. Preferably the mean molecular weight of the polyethylene glycol mono- or di-ether is in the range of 120-10000, preferably in the range of 200-8000, preferably in the range of 300-5000. In a preferred embodiment, the formulation comprises the polyethylene glycol mono- or di-ether in an amount of 0.1-30%, preferably in an amount of 2-15%, preferably in an amount of 3-10%, more preferably in an amount of about 5%. In an alternative preferred embodiment, the formulation comprises the polyethylene glycol mono- or di-ether in an amount of 4-30%, preferably in an amount of 4-20%, more preferably in an amount of about 5%. [0020] Preferably the formulation comprises a polyethylene glycol mono-ether. [0021] In one embodiment, the formulation comprises a polyethylene glycol di-ether, preferably wherein each R independently contains from 1 to 20 carbon atoms, preferably from 1 to 15 carbon atoms, preferably from 1 to 10 carbon atoms, preferably from 1 to 5 carbon atoms, more preferably from 1 to 4 carbon atoms. [0022] In a preferred embodiment, the polyethylene glycol mono- or di-ether is a polyethylene glycol mono- or di-methyl or ethyl ether, more preferably the polyethylene glycol mono- or di-ether is polyethylene glycol monomethyl ether (MPEG). Preferably the polyethylene glycol monomethyl ether is MPEG 350-10000, i.e. a polyethylene glycol monomethyl ether having a mean molecular weight between 350 and 10000. More preferably, the polyethylene glycol monomethyl ether is MPEG 350-5000, i.e. a polyethylene glycol monomethyl ether having a mean molecular weight between 350 and 5000. Preferably, the polyethylene glycol monomethyl ether is MPEG 2000, i.e. a polyethylene glycol monomethyl ether having a mean molecular weight of about 2000. In a preferred embodiment, the formulation comprises polyethylene glycol monomethyl ether in an amount of 2-15%, preferably in an amount of 3-10%. [0023] Preferably the polyethylene glycol (PEG) or poloxamer on the one hand and the polyethylene glycol mono- or di-ether on the other hand are used in a ratio of at least 1:1, preferably at least 2:1, more preferably at least 3:1. Preferably the polyethylene glycol (PEG) or poloxamer on the one hand and the polyethylene glycol mono- or di-ether on the other hand are used in a ratio of no more than 10:1, preferably no more than 8:1, more preferably no more than 6:1. Any of these preferred lower ratios can be combined with any of these preferred upper ratios to give preferred ratio ranges. Preferably the polyethylene glycol (PEG) or poloxamer on the one hand and the polyethylene glycol mono- or di-ether on the other hand are used in a ratio of from 10:1 to 1:1, preferably in a ratio of about 4:1. [0024] For the purposes of the present invention, an ‘alkyl’ group is defined as a monovalent saturated hydrocarbon, which may be straight-chained or branched, or be or include cyclic groups. An alkyl group may optionally include one or more heteroatoms N, O or S in its carbon skeleton. Examples of alkyl groups are methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl and n-pentyl groups. Preferably an alkyl group is straight-chained or branched and does not include any heteroatoms in its carbon skeleton. Preferably an alkyl group is a C 1 -C 12 alkyl group, which is defined as an alkyl group containing from 1 to 12 carbon atoms. More preferably an alkyl group is a C 1 -C 6 alkyl group, which is defined as an alkyl group containing from 1 to 6 carbon atoms. An ‘alkylene’ group is similarly defined as a divalent alkyl group. [0025] An ‘alkenyl’ group is defined as a monovalent hydrocarbon, which comprises at least one carbon-carbon double bond, which may be straight-chained or branched, or be or include cyclic groups. An alkenyl group may optionally include one or more heteroatoms N, O or S in its carbon skeleton. Examples of alkenyl groups are vinyl, allyl, but-1-enyl and but-2-enyl groups. Preferably an alkenyl group is straight-chained or branched and does not include any heteroatoms in its carbon skeleton. Preferably an alkenyl group is a C 2 -C 12 alkenyl group, which is defined as an alkenyl group containing from 2 to 12 carbon atoms. More preferably an alkenyl group is a C 2 -C 6 alkenyl group, which is defined as an alkenyl group containing from 2 to 6 carbon atoms. An ‘alkenylene’ group is similarly defined as a divalent alkenyl group. [0026] An ‘alkynyl’ group is defined as a monovalent hydrocarbon, which comprises at least one carbon-carbon triple bond, which may be straight-chained or branched, or be or include cyclic groups. An alkynyl group may optionally include one or more heteroatoms N, O or S in its carbon skeleton. Examples of alkynyl groups are ethynyl, propargyl, but-1-ynyl and but-2-ynyl groups. Preferably an alkynyl group is straight-chained or branched and does not include any heteroatoms in its carbon skeleton. Preferably an alkynyl group is a C 2 -C 12 alkynyl group, which is defined as an alkynyl group containing from 2 to 12 carbon atoms. More preferably an alkynyl group is a C 2 -C 6 alkynyl group, which is defined as an alkynyl group containing from 2 to 6 carbon atoms. An ‘alkynylene’ group is similarly defined as a divalent alkynyl group. [0027] An ‘aryl’ group is defined as a monovalent aromatic hydrocarbon. An aryl group may optionally include one or more heteroatoms N, O or S in its carbon skeleton. Examples of aryl groups are phenyl, naphthyl, anthracenyl and phenanthrenyl groups. Preferably an aryl group does not include any heteroatoms in its carbon skeleton. Preferably an aryl group is a C 4 -C 14 aryl group, which is defined as an aryl group containing from 4 to 14 carbon atoms. More preferably an aryl group is a C 6 -C 10 aryl group, which is defined as an aryl group containing from 6 to 10 carbon atoms. An ‘arylene’ group is similarly defined as a divalent aryl group. [0028] For the purposes of the present invention, where a combination of groups is referred to as one moiety, for example, arylalkyl, arylalkenyl, arylalkynyl, alkylaryl, alkenylaryl or alkynylaryl, the last mentioned group contains the atom by which the moiety is attached to the rest of the molecule. A typical example of an arylalkyl group is benzyl. [0029] For the purposes of this invention, an optionally substituted alkyl, alkenyl, alkynyl, aryl, arylalkyl, arylalkenyl, arylalkynyl, alkylaryl, alkenylaryl or alkynylaryl group may be substituted with one or more of —F, —Cl, —Br, —I, —CF 3 , —CCl 3 , —CBr 3 , —CI 3 , —OH, —SH, —NH 2 , —CN, —NO 2 , —COOH, —R α —O—R β , —R α —S—R β , —R α —SO—R β , —R α —SO 2 —R β , —R α —SO 2 —OR β , —R α O—SO 2 —R β , —R α —SO 2 —N(R β ) 2 , —R α —NR β —SO 2 —R β , —R α O—SO 2 —OR β , —R α O—SO 2 —N(R β ) 2 , —R α —NR β —SO 2 —OR β , —R α —NR β —SO 2 —N(R β ) 2 , —R α —N(R β ) 2 , —R α —N(R β ) 3 + , —R α —P(R β ) 2 , —R α —Si(R β ) 3 , —R α —CO—R β , —R α—CO—OR β , —R α O—CO—R β , —R α —CO—N(R β ) 2 , —R α —NR β —CO—R β , — α O—CO—OR β , —R α O—CO—N(R β ) 2 , —R α —NR β —CO—OR β , —R α —NR β —CO—N(R β ) 2 , —R α —CS—R β , —R α —CS—OR β , —R α O—CS—R β , —R α —CS—N(R β ) 2 , —R α —NR β —CS—R β , —R α O—CS—OR β , —R α O—CS—N(R β ) 2 , —R α —NR β —CS—OR β , —R α —NR β —CS—N(R β ) 2 , —R β a bridging substituent such as —O—, —S—, —NR β — or —R α —, or a π-bonded substituent such as ═O, —S or ═NR β . In this context, —R α — is independently a chemical bond, a C 1 -C 10 alkylene, C 1 -C 10 alkenylene or C 1 -C 10 alkynylene group. —R β is independently hydrogen, unsubstituted C 1 -C 6 alkyl or unsubstituted C 6 -C 10 aryl. Optional substituent(s) are taken into account when calculating the total number of carbon atoms in the parent group substituted with the optional substituent(s). Preferably an optionally substituted alkyl, alkenyl, alkynyl, aryl, arylalkyl, arylalkenyl, arylalkynyl, alkylaryl, alkenylaryl or alkynylaryl group is not substituted with a bridging substituent. Preferably an optionally substituted alkyl, alkenyl, alkynyl, aryl, arylalkyl, arylalkenyl, arylalkynyl, alkylaryl, alkenylaryl or alkynylaryl group is not substituted with a π-bonded substituent. Preferably a substituted group comprises 1, 2 or 3 substituents, more preferably 1 or 2 substituents, and even more preferably 1 substituent. [0030] Any optional substituent may be protected. Suitable protecting groups for protecting optional substituents are known in the art, for example from ‘Protective Groups in Organic Synthesis’ by T. W. Greene and P. G. M. Wuts (Wiley-Interscience, 4 th edition, 2006). [0031] In a preferred embodiment, the formulation comprises: [0032] (a) a pharmaceutically active agent; [0033] (b) water; [0034] (c) polyethylene glycol (PEG); and [0035] (d) polyethylene glycol monomethyl ether (MPEG). [0036] In another preferred embodiment, the formulation comprises: [0037] (a) 0.1-30% pharmaceutically active agent; [0038] (b) 5-50% water; [0039] (c) 5-50% polyethylene glycol; and [0040] (d) 2-15% polyethylene glycol monomethyl ether; [0041] and also optionally: [0042] (e) 0-70% alcohol; [0043] (f) 0-5% acid or base for pH adjustment; [0044] (g) 0-10% penetration enhancer; and [0045] (h) 0-6% plasticizer. [0046] In another preferred embodiment, the formulation comprises: [0047] (a) 0.1-30% pharmaceutically active agent; [0048] (b) 5-50% water; [0049] (c) 5-50% polyethylene glycol; and [0050] (d) 2-15% polyethylene glycol monomethyl ether; [0051] and also optionally: [0052] (e) 0-70% alcohol; [0053] (f) 0-5% acid or base for pH adjustment; [0054] (g) 0-1% isopropyl myristate; [0055] (h) 0-4% transcutol; and [0056] (i) 0-5% propylene glycol. [0057] In a preferred embodiment, the pharmaceutically active agent is an anti-fungal or anti-mycotic agent. The terms ‘anti-fungal’ and ‘anti-mycotic’ are used interchangeable herein. Preferably the pharmaceutically active agent is lipophilic and/or keratinophilic. [0058] In another preferred embodiment, the anti-fungal or anti-mycotic agent is an azole, imidazole, triazole, thiazole, thiadiazole, guanidine, pyrimidine, imine, morpholine, 2-pyridone, 2-pyrimidone, allylamine, benzylamine, polyene, echinocandin, benzofuran, benzoxaborole, pyridine, or thiocarbamate. If the anti-fungal or anti-mycotic agent is an imidazole, then it is preferably bifonazole, clotrimazole, econazole, fenticonazole, isoconazole, ketoconazole, miconazole, oxiconazole, tioconazole, sertaconazole, sulconazole, or a pharmaceutically acceptable salt thereof. If the anti-fungal or anti-mycotic agent is a triazole, then it is preferably fluconazole, itraconazole, posaconazole, ravuconazole, terconazole, voriconazole, or a pharmaceutically acceptable salt thereof. If the anti-fungal or anti-mycotic agent is a thiazole, then it is preferably a 2-amino-thiazole, preferably abafungin or a pharmaceutically acceptable salt thereof. If the anti-fungal or anti-mycotic agent is a guanidine, then it is preferably an arylguanidine, preferably abafungin or a pharmaceutically acceptable salt thereof. If the anti-fungal or anti-mycotic agent is a pyrimidine, then it is preferably a 2-pyrimidinimine, preferably abafungin or a pharmaceutically acceptable salt thereof. If the anti-fungal or anti-mycotic agent is an imine, then it is preferably a 2-pyrimidinimine, preferably abafungin or a pharmaceutically acceptable salt thereof. If the anti-fungal or anti-mycotic agent is a morpholine, then it is preferably amorolfine or a pharmaceutically acceptable salt thereof. If the anti-fungal or anti-mycotic agent is a 2-pyridone, then it is preferably ciclopirox or a pharmaceutically acceptable salt thereof. If the anti-fungal or anti-mycotic agent is a 2-pyrimidone, then it is preferably flucytosine or a pharmaceutically acceptable salt thereof. If the anti-fungal or anti-mycotic agent is an allylamine, then it is preferably terbinafine, naftifine, or a pharmaceutically acceptable salt thereof. If the anti-fungal or anti-mycotic agent is a benzylamine, then it is preferably butenafine or a pharmaceutically acceptable salt thereof. If the anti-fungal or anti-mycotic agent is a polyene, then it is preferably amphotericin B, nystatin, pimaricin (also called natamycin), or a pharmaceutically acceptable salt thereof. If the anti-fungal or anti-mycotic agent is an echinocandin, then it is preferably caspofungin, micafungin, anidulafungin, or a pharmaceutically acceptable salt thereof. Preferably the anti-fungal or anti-mycotic agent is abafungin or a pharmaceutically acceptable salt thereof, preferably abafungin. [0059] For the purposes of the present invention, if a compound is said to be an azole, imidazole, triazole, thiazole, 2-amino-thiazole, thiadiazole, guanidine, arylguanidine, pyrimidine, imine, 2-pyrimidinimine, morpholine, 2-pyridone, 2-pyrimidone, allylamine, benzylamine, polyene, echinocandin, benzofuran, benzoxaborole, pyridine, thiocarbamate etc, then this means that the compound comprises an azole, imidazole, triazole, thiazole, 2-amino-thiazole, thiadiazole, guanidine, arylguanidine, pyrimidine, imine, 2-pyrimidinimine, morpholine, 2-pyridone, 2-pyrimidone, allylamine, benzylamine, polyene, echinocandin, benzofuran, benzoxaborole, pyridine, thiocarbamate etc functional group. [0060] Azoles are generally considered to be five-membered aromatic heterocycles comprising one nitrogen atom and at least one further heteroatom, such as a nitrogen, oxygen or sulphur atom. Therefore imidazoles (five-membered aromatic heterocycles comprising two nitrogen atoms), triazoles (five-membered aromatic heterocycles comprising three nitrogen atoms), thiazoles (five-membered aromatic heterocycles comprising one nitrogen atom and one sulphur atom), and thiadiazoles (five-membered aromatic heterocycles comprising two nitrogen atoms and one sulphur atom) are generally considered to be azoles. [0061] However, when referring to azole anti-fungal agents, generally only imidazole and triazole anti-fungal agents are meant, not thiazole or thiadiazole anti-fungal agents. Without wishing to be bound by theory, this is because currently the anti-fungal activity of imidazole and triazole anti-fungal agents is believed to be due to the inhibition of the ergosterol biosynthesis by inhibiting 14α-demethylase. Thiazole anti-fungal agents, on the other hand, are currently not believed to inhibit 14α-demethylase and their anti-fungal activity is currently believed to be at least partially due to the inhibition of the ergosterol biosynthesis by inhibiting 24-sterolmethyltransferase. [0062] Therefore, for the purposes of the present invention, the term ‘azole’ encompasses all five-membered aromatic heterocycles comprising one nitrogen atom and at least one further heteroatom, and therefore includes imidazoles, triazoles, thiazoles, and thiadiazoles. In a preferred embodiment, the term ‘azole’ only encompasses imidazoles and triazoles. [0063] In one embodiment of the present invention, the anti-fungal or anti-mycotic agent is not a triazole. In another embodiment, the anti-fungal or anti-mycotic agent is not an imidazole. In another embodiment, the anti-fungal or anti-mycotic agent is a thiazole or a thiadiazole. [0064] In a preferred embodiment of the present invention, the anti-fungal or anti-mycotic agent is a compound of the general formula (I): [0000] [0000] wherein R 1 is hydrogen or alkyl; and R 2 is a group of the formula: [0000] [0000] wherein R 3 , R 4 , R 5 and R 6 are independently hydrogen, halogen, nitro, alkyl, alkoxy, alkoxy-carbonyl, dialkylamino, alkylthio, alkylsulphinyl, alkylsulphonyl, haloalkyl, haloalkoxy, haloalkylthio, haloalkylsulphinyl, or haloalkylsulphonyl; X is oxygen, sulphur, sulphinyl, or sulphonyl; and Ar is an optionally substituted aryl group; or a pharmaceutically acceptable salt thereof. [0070] The compounds of formula (I) are in equilibrium with their tautomers of formulae (Ia) and (Ib): [0000] [0071] Preferably R 1 is hydrogen or C 1-3 alkyl, preferably hydrogen. Preferably R 3 , R 4 , R 5 and R 6 are independently hydrogen or C 1-3 alkyl, preferably hydrogen. Preferably X is oxygen. Preferably Ar is a phenyl group optionally substituted with one, two or three C 1-3 alkyl or C 1-3 alkoxy groups. Preferably R 2 is: [0000] [0072] The compounds of formula (I) can be classified as being 2-amino-thiazoles, or arylguanidines, or 2-pyrimidinimines. [0073] A preferred compound of the general formula (I) is abafungin of the formula (II): [0000] [0000] which is in equilibrium with its tautomers of formulae (IIa) and (IIb): [0000] [0074] In another preferred embodiment, the anti-fungal or anti-mycotic agent is abafungin, ciclopirox olamine, terbinafine hydrochloride, or amorolfine. Preferably the anti-fungal or anti-mycotic agent is abafungin or a pharmaceutically acceptable salt thereof, preferably abafungin. If the anti-fungal or anti-mycotic agent is abafungin, the formulation preferably further comprises an acid such as formic acid for pH adjustment. Preferably the formulation has a pH in the range of about 5-8, preferably about 5-7, preferably about 5-6, preferably about 5.5, which simulates the conditions of human skin and nails. In an alternate embodiment, the formulation has a pH in the range of about 1-7, preferably about 2-6, preferably about 3-6, preferably about 3-5, more preferably about 4-5. [0075] In a preferred embodiment, the formulation comprises the pharmaceutically active agent in an amount of 0.1-30%, preferably in an amount of 0.5-20%, preferably in an amount of 1-15%. Preferably the formulation comprises the pharmaceutically active agent in an amount of at least 2.5%, preferably at least 4%, preferably at least 5%, more preferably in an amount of about 10%. [0076] In a preferred embodiment, the pharmaceutically active agent is substantially dissolved in the formulation, i.e. at least 75% of the pharmaceutically active agent present in the formulation is in solution in the formulation. Preferably at least 90%, preferably at least 95%, preferably at least 98%, preferably at least 99%, more preferably at least 99.9% of the pharmaceutically active agent present in the formulation is in solution in the formulation. [0077] In a preferred embodiment, the formulation comprises water in an amount of 5-50%, preferably in an amount of 10-50%, preferably in an amount of 17-25% or 20-40%. More preferably the formulation comprises water in an amount of about 20%. [0078] In a preferred embodiment, the formulation further comprises an alcohol, such as 2-propanol, ethanol, benzyl alcohol, or 2-phenoxyethanol. The formulation may comprise up to 70% alcohol. If the formulation comprises an alcohol, it is preferably present in an amount of 10-70%, preferably in an amount of 20-60%, preferably in an amount of 30-50%. [0079] In some embodiments, the formulation further comprises an acid or a base for pH adjustment. Suitable acids include organic fatty acids which may be saturated or unsaturated (such as citric acid, myristic acid and formic acid) and inorganic acids (such as hydrochloric acid and sulphuric acid). A preferred acid is formic acid. Suitable bases include sodium hydroxide. The formulation may comprise up to 5% acid or base. Preferably the formulation has a pH in the range of about 5-8, preferably about 5-7, preferably about 5-6, preferably about 5.5, which simulates the conditions of human skin and nails. In an alternate embodiment, the formulation has a pH in the range of about 1-7, preferably about 2-6, preferably about 3-6, preferably about 3-5, more preferably about 4-5. [0080] In a preferred embodiment, the formulation further comprises a penetration enhancer and/or a plasticizer. Preferred penetration enhancers and/or plasticizers include, but are not limited to isopropyl myristate, transcutol, propylene glycol, isopropyl palmitate, terpenoides, decyl oleate, oleic acid, sulphoxides, keratinolytics (such as urea), azones, terpenes, essential oils, surfactants (such as Tween 20, Tween 80, Span, Labrasol, Isoceteth-20), alcohols, polyols, fatty acids, glycols, and pyrrolidones. The formulation may comprise up to 10% penetration enhancer preferably up to 6%. The formulation may comprise up to 6% plasticizer, preferably up to 5%. [0081] In a preferred embodiment, the formulation comprises isopropyl myristate. The formulation may comprise up to 1% isopropyl myristate. If the formulation comprises isopropyl myristate, it is preferably present in an amount of 0.1-1%, preferably 0.5-1%. [0082] In a preferred embodiment, the formulation comprises a penetration enhancer such as transcutol. The formulation may comprise up to 4% transcutol. If the formulation comprises transcutol, it is preferably present in an amount of 0.5-4%, preferably in an amount of 1-4%, preferably in an amount of 2-4%. [0083] In a preferred embodiment, the formulation comprises propylene glycol. The formulation may comprise up to 5% propylene glycol. If the formulation comprises propylene glycol, it is preferably present in an amount of 0.5-5%, preferably in an amount of 0.5-4%, preferably in an amount of 0.5-3%. [0084] In a preferred embodiment, the formulation has a viscosity of at least 1100 mPas, preferably at least 1200 mPas, preferably at least 1300 mPas, preferably at least 1500 mPas, preferably at least 2000 mPas, preferably at least 5000 mPas, preferably at least 10000 mPas. In an alternate preferred embodiment, the formulation has a viscosity of between 2 and 1000 mPas, preferably between 5 and 900 mPas, preferably between 10 and 750 mPas, preferably between 30 and 500 mPas. [0085] In a particularly preferred embodiment the formulation has a viscosity of between 100 and 500 mPas, preferably between 200 and 300 mPas, more preferably about 250 mPas. Preferably such a formulation is suitable for application to the nail, preferably as a gel. [0086] In another particularly preferred embodiment the formulation has a viscosity of between 30 and 100 mPas, preferably between 40 and 80 mPas, more preferably about 60 mPas. Preferably such a formulation is suitable for application to the skin, preferably as a spray. [0087] In a preferred embodiment, the formulation is not a solid. Preferably the formulation is a spray, cream, ointment, gel or paste. More preferably the formulation is a hydrophilic water-based gel. [0088] The formulation of the present invention can be used for the treatment of a disease, disorder or pathological condition of the nail or skin. For example, the formulation of the present invention can be used for the treatment of onychomycoses, dermatomycoses, oral, vaginal or anal mycoses, skin diseases such as acne, topical bacterial infections such as Staphylococcus aureus, or topical viral infections such as herpes. The formulation of the present invention can also be used to aid wound healing. [0089] Accordingly, it is preferred that the formulation of the present invention is suitable for topical application, preferably to the nail or skin. [0090] Alternatively the formulation of the present invention can be used for the treatment of a disease, disorder or pathological condition of the hooves, horn, claws or skin of a subject, preferably a non-human mammal such as a cow, pig, sheep, dog or cat. Preferably the disease, disorder or pathological condition is a fungal infection. [0091] A second aspect of the present invention provides a method of administering a pharmaceutically active agent to a subject, comprising applying a formulation according to the first aspect of the present invention to a nail of the subject. Preferably the pharmaceutically active agent is lipophilic and/or keratinophilic. [0092] Lipophilic and/or keratinophilic pharmaceutically active agents are often capable of penetrating skin. Hydrophilic pharmaceutically active agents are often capable of penetrating nails. The method of the second aspect of the present invention uses a hydrophilic formulation to make it possible for lipophilic and/or keratinophilic pharmaceutically active agents to penetrate nails. [0093] Preferably the subject is a human or non-human mammal, preferably a human. Preferably the pharmaceutically active agent penetrates into the subject's nail and nail matrix by penetrating through the nail and through the skin surrounding the nail. [0094] A third aspect of the present invention provides a method of treating onychomycosis, the method comprising applying a formulation according to the first aspect of the present invention to the nail of a subject suffering from onychomycosis. [0095] The third aspect of the present invention also provides a method of treating dermatomycosis, the method comprising applying a formulation according to the first aspect of the present invention to the skin of a subject suffering from dermatomycosis. [0096] The third aspect of the present invention further provides a method of treating an oral, vaginal or anal mycosis, the method comprising applying a formulation according to the first aspect of the present invention to the skin or mucosa of a subject suffering from the oral, vaginal or anal mycosis. [0097] The third aspect of the present invention further provides a method of treating a skin disease (such as acne), the method comprising applying a formulation according to the first aspect of the present invention to the skin of a subject suffering from the skin disease. [0098] The third aspect of the present invention further provides a method of treating a topical bacterial infection (such as Staphylococcus aureus) or a topical viral infection (such as herpes), the method comprising applying a formulation according to the first aspect of the present invention to the skin or mucosa of a subject suffering from the topical infection. [0099] The third aspect of the present invention further provides a method of aiding wound healing, the method comprising applying a formulation according to the first aspect of the present invention to the wound of a subject. [0100] In any method of the third aspect of the present invention, the subject may be a human or non-human mammal. Preferably the subject is a human. [0101] A fourth aspect of the present invention provides a method of preparing a formulation according to the first aspect of the present invention, the method comprising the steps of: (a) dissolving the pharmaceutically active agent and, if present, the acid or base in water; (b) adding the polyethylene glycol or poloxamer, the polyethylene glycol mono- or di-ether and, if present, the alcohol, the penetration enhancer and the plasticizer to the solution; and (c) stirring the mixture until a hydrophilic gel is obtained. [0105] In a preferred embodiment, the pharmaceutically active agent can be protonated and an acid is used in step (a), which protonates the pharmaceutically active agent. A preferred pharmaceutically active agent, which can be protonated, is abafungin or a pharmaceutically acceptable salt thereof. In an alternative embodiment, the pharmaceutically active agent can be deprotonated and a base is used in step (a), which deprotonates the pharmaceutically active agent. [0106] For the avoidance of doubt, insofar as is practicable any embodiment of a given aspect of the present invention may occur in combination with any other embodiment of the same aspect of the present invention. In addition, insofar as is practicable it is to be understood that any preferred or optional embodiment of any aspect of the present invention should also be considered as a preferred or optional embodiment of any other aspect of the present invention. [0107] In addition, it is also to be understood that any lower limit specified in connection with a variable of the preset invention may be combined with any upper limit specified in connection with the same variable so as to form a range that is also encompassed by the present invention. BRIEF DESCRIPTION OF THE DRAWINGS [0108] FIG. 1 shows three horse hoof horn membranes (labelled 1, 2 and 3) 24 hours after the application of three formulations comprising abafungin. [0109] FIG. 2 is a graph showing the amount of abafungin which has penetrated into horse hoof horn membranes 24 hours after the application of three formulations comprising abafungin. [0110] FIG. 3 shows the toenail of a volunteer suffering from onychomycosis after topical application of a formulation of the present invention comprising abafungin. [0111] FIG. 4 shows the toenails of another volunteer suffering from onychomycosis before treatment and after oral itraconazole administration and concurrent topical application of a formulation of the present invention comprising abafungin. In [0112] FIG. 4 , ‘(1)’ refers to the oral itraconazole administration, and ‘Abagel 10%’ refers to the topical application of the abafungin formulation. [0113] FIG. 5 is a graph showing the amount of abafungin, ciclopirox or ciclopirox olamine which has penetrated into horse hoof horn membranes 24 hours after the application of five formulations comprising abafungin, ciclopirox or ciclopirox olamine. [0114] FIG. 6 is a graph showing the amount of abafungin or hydrocortisone which has penetrated into porcine ear skin 24 hours after the application of four formulations comprising abafungin or hydrocortisone. [0115] FIG. 7 is a graph showing the percentage deviation of TEWL (transepidermal water loss) measurements one hour after treatment with Batrafen®, Loceryl® or a formulation according to the present invention to the measurements before the treatment. [0116] FIG. 8 shows a schematic diagram of a fungal inhibition zone. [0117] FIG. 9 are photographs of Sabouraud plates inoculated with T. rubrum 34 and treated with bovine hoof horn membrane treated with four formulations comprising abafungin. DETAILED DESCRIPTION OF THE INVENTION [0118] A preferred formulation of the present invention is a water-based, hydrophilic, non-irritating gel formulation suitable for the treatment of onychomycosis, dermatomycosis and other mycoses (see examples 5 and 10). The formulation comprises a polyethylene glycol mono- or di-ether (preferably polyethylene glycol monomethyl ether (MPEG)) and a polyethylene glycol or a poloxamer (preferably polyethylene glycol (PEG)) as adhesives and film formers, which ensure that the formulation is capable of releasing pharmaceutically active agents slowly. [0119] Polyethylene glycols and poloxamers, in particular PEG, are known permeation enhancers and known for the sustained release of pharmaceutically active agents. Polyethylene glycol ethers, in particular MPEG, are solubilisers and film builders. Without wishing to be bound by theory, it is thought that together they act as adhesives and film formers and ensure that the formulation of the present invention forms a breathable film incorporating a pharmaceutically active agent. The water naturally present in the nail or skin dissolves the pharmaceutically active agent out of the PEG or poloxamer/PEG-ether depot, which releases the pharmaceutically active agent slowly. The presence of the polyethylene glycol ether is thought to lead to higher interactions of all substances concerned, for example, the ether group is thought to lead to greater adhesion of the formulation to the organic nail or skin material. The ether group is also thought to be responsible for the observed high solubility of lipophilic and/or keratinophilic pharmaceutically active agents in the formulation. [0120] Known water-based formulations use swelling gel builders (e.g. hydroxymethyl cellulose) and/or water-soluble acrylic acid copolymers. These gel builders can be used in a concentration of only up to 1.5% in water, since otherwise the viscosity of the formulation becomes too high. However, such small amounts of gel builders are not enough to provide an effective depot for a pharmaceutically active agent. [0121] The hydrophilic gel formulations according to the present invention, on the other hand, act as a depot for the pharmaceutically active agent. The water naturally present in the nail or skin dissolves the pharmaceutically active agent out of the PEG or poloxamer/PEG-ether depot, which releases the pharmaceutically active agent slowly, providing for a modified release such as delayed, extended, sustained or controlled release. [0122] Pharmaceutically active agents suitable for use in the formulation of the present invention include lipophilic and/or keratinophilic substances, e.g. anti-mycotics, which can be applied to the nail, skin and mucosa for the treatment of onychomycosis, dermatomycosis and other mycoses, such as oral, vaginal and rectal mycoses. Suitable anti-mycotics include, but are not limited to azoles (such as imidazoles and triazoles), imidazoles (such as bifonazole, clotrimazole, econazole, fenticonazole, isoconazole, ketoconazole, miconazole, oxiconazole, tioconazole, sertaconazole, and sulconazole), triazoles (such as fluconazole, itraconazole, posaconazole, ravuconazole, terconazole, and voriconazole), thiazoles (such as 2-amino-thiazoles such as abafungin), thiadiazoles, guanidines (such as arylguanidines such as abafungin), pyrimidines (such as pyrimidinimines such as abafungin), imines (such as pyrimidinimines such as abafungin), morpholines (such as amorolfine), 2-pyridones (such as ciclopirox), 2-pyrimidones (such as flucytosine), allylamines (such as terbinafine and naftifine), benzylamines (such as butenafine), polyenes (such as amphotericin B, nystatin, and pimaricin (also called natamycin)), echinocandins (such as caspofungin, micafungin, and anidulafungin), benzofurans, benzoxaboroles, pyridines, thiocarbamates, and others. [0123] In a preferred embodiment of the present invention, the formulation comprises abafungin, ciclopirox olamine, terbinafine hydrochloride, or amorolfine; more preferably abafungin. A formulation comprising abafungin also preferably comprises an acid for adjusting the pH of the formulation, such that the abafungin in the formulation is protonated into the active molecule, the guanidinium ion. [0124] Lipophilic and/or keratinophilic pharmaceutically active agents, such as abafungin, ciclopirox olamine and terbinafine hydrochloride, are surprisingly stable and soluble in the formulation of the present invention. For example, abafungin is lipophilic and poorly soluble in many excipients (see example 1). It is therefore very difficult to solubilise a pharmaceutically active agent such as abafungin in a pharmaceutical formulation in an amount sufficient for an acceptable permeation rate (see examples 2, 3, 4, 6 and 7). The PEG or poloxamer/PEG-ether mixture of the formulation of the present invention makes it possible for a lipophilic and/or keratinophilic pharmaceutically active agent such as abafungin to be solubilised adequately and the PEG or poloxamer/PEG-ether mixture is thought to prevent the lipophilic and/or keratinophilic pharmaceutically active agent from crystallising out of the formulation. For example, a concentration of up to 30% abafungin can be achieved in the formulation of the present invention (see example 8). [0125] Pharmaceutically active agents, such as abafungin, also showed surprisingly much higher permeation rates into and across the nail and into the skin from the formulation of the present invention compared to conventional lacquer formulations and compared to hydrophilic nail gels without a polyethylene glycol ether (see examples 2, 3, 4, 6 and 7). [0126] Human nails behave like hydrophilic membranes and have a high transungual diffusion of water (1.8 to 3.1 mg/cm 2 ) (K. A. Walters et al., Journal of Pharmacy and Pharmacology, 1985, vol. 37, pages 771-775; D. Mertin et al., Journal of Pharmacy and Pharmacology, 1997, vol. 49, pages 30-34; Y. Kobayashi et al., European Journal of Pharmaceutical Sciences, 2004, vol. 21, pages 471-477). The permeability of the nail to water is some 1000-fold greater than that of the stratum corneum (D. Spruit, Journal of Investigative Dermatology, 1971, vol. 56, pages 359-361; K. A. Walters et al., Journal of Investigative Dermatology, 1981, vol. 36, pages 101-103). [0127] For a healthy nail, a high transungual diffusion of free nail water is of great importance. The formulations according to the present invention are hydrophilic water-based gels, which allow water to pass into and out of the nail after application of the formulations to the nail. This is in contrast to conventional lacquers, which reduce the transungual diffusion of water significantly (de Berker & Baran, Int. J. Cosmetic Science, 2007, vol. 29, pages 241-275; Spruit, Am. Cosmet. Perfum., 1972, vol. 87, pages 57-58). This was also confirmed by example 9 below. [0128] It is currently believed that because water is able to permeate freely across the nail and into the formulation according to the present invention, the pharmaceutically active agent contained in the formulation will be dissolved over time out of the gel formulation into the nail. Conventional lacquers, using water insoluble polymers as film builders, cover the nail and inhibit the free permeation of nail water, and thus the dissolution of a pharmaceutically active agent out of the hydrophobic lacquer film is much lower compared to a hydrophilic gel formulation according to the present invention. [0129] Conventional anti-mycotic nail lacquers, such as Penlac® (also called Batrafen®) (ciclopirox) from Aventis and Loceryl® (amorolfine) from Galderma, use alcohols as solvents and water insoluble polymers. Therefore the lacquer films formed from such conventional lacquers are water insoluble and the water which is naturally present in nails cannot dissolve the anti-mycotic agents out of the water insoluble polymer matrices. This results in a slow penetration rate of the anti-mycotic agents from the conventional lacquers into the nail. The formulations of the present invention on the other hand are hydrophilic and the pharmaceutically active agents move easily from the hydrophilic formulations into the nail water. [0130] Moreover, conventional nail lacquers irritate and damage the skin and therefore cannot be used on skin. The formulation of the present invention on the other hand allows pharmaceutically active agents to penetrate through the skin surrounding the nail into the nail bed and nail matrix. [0131] The formulation of the present invention can deliver an anti-fungal or anti-mycotic agent to the nail plate (the stratum corneum unguis) and to the nail bed (the modified area of the epidermis beneath the nail, over which the nail plate slides as it grows) through the nail plate and around the nail periphery. Desirably the anti-fungal or anti-mycotic agent is also concurrently delivered to the nail matrix, the cuticle and the hyponychium (the thickened epidermis underneath the free distal end of a nail). [0132] The hydrophilic nature of the formulation of the present invention simulates the conditions and characteristics of a human nail, especially the hydrophilic membranes of the nail. Polyethylene glycols and poloxamers have an occlusive effect which enhances the level of hydration of the nail. Moreover, unlike conventional nail lacquers, the PEG or poloxamer/PEG-ether mixture of the formulation of the present invention is skin compatible and breathable. Preferably the formulation has a pH of about 5.5, which simulates the conditions of human skin. When applied to the nail of a patient, the formulation of the present invention is thought to allow a pharmaceutically active agent to penetrate into the patient's nail and nail bed including the nail matrix in two ways, namely through the nail itself and through the skin surrounding the nail. Therefore another advantage of the formulations of the present invention is the two-way transport of the pharmaceutically active agent into and across the hydrophilic nail: transungual and transdermal. The onychomycosis will be treated by an application of the formulations of the present invention not only on the nail, but also on the surrounding skin area. [0133] Another advantage of the formulation of the present invention is that compared to other hydrophilic gels (e.g. on the basis of hydroxymethyl cellulose or PEG), the PEG or poloxamer/PEG-ether mixture showed surprisingly excellent drying times that are comparable or even better than those of conventional lacquers (e.g. based on polyvinylacetate, (meth)acrylic acid alkyl ester copolymers, or methylvinyl ether maleic acid monoalkyl ester copolymers). [0134] Moreover, unlike conventional nail lacquers, the formulation of the present invention can be washed off. This results in better patient compliance, because it avoids the need for time consuming removal of conventional nail lacquers by filing or the use of solvent based formulations. Standard nail lacquers have to be removed at least weekly with alcoholic wipes and by using a nail file. Especially for older patients, this therapy plan is difficult to adopt. Moreover, the use of a nail file can induce severe injuries of the skin surrounding the nail, which can result in systemic uptake of fungi. The formulations of the present invention will ease the therapy plan for patients, because the formulations can be removed easily by washing. Therefore the formulations of the present invention increase patient compliance. Examples Example 1 Abafungin Solubility [0135] To order to study the solubility of abafungin, abafungin was dissolved in a number of excipients. The results of the solubility studies are summarised in Table 1. [0000] TABLE 1 Excipient group Excipient Soluble Not soluble cosmetic oils isopropyl palmitate ✓ isopropyl myristate ✓ cetearyl ethylhexanoate ✓ decyl oleate ✓ medium chain triglyceride ✓ transcutol ✓ (3%) water water ✓ monohydric ethanol ✓ alcohols ethanol 70% ✓ isopropanol ✓ polyhydric alcohols propylene glycol ✓ glycerine ✓ polyethylene glycols PEG 20000 ✓ PEG 12000 ✓ PEG 6000 ✓ PEG 4500 ✓ PEG 1500 ✓ PEG 400 ✓ polyethylene glycol MPEG 2000 ✓ monomethyl ethers MPEG 550 ✓ [0136] Abafungin is insoluble in most excipients, even in each of water, polyethylene glycol and polyethylene glycol monomethyl ether. However, surprisingly, it was found that abafungin is soluble in a mixture of water, polyethylene glycol, polyethylene glycol monomethyl ether and an acid such as formic acid. Example 2 Proximal Flux and Affinity of Three Abafungin Formulations into Horse Hoof Horn Membranes [0137] In order to study the ability of abafungin to penetrate into nails, three abafungin formulations were prepared, comprising the ingredients set out in Table 2. Formulations 1 and 2 were hydrophilic gels, and formulation 3 was a lacquer. Formulation 2 is according to the present invention, and formulations 1 and 3 are comparative formulations. [0000] TABLE 2 Formulation 1 Formulation 2 Formulation 3 amounts (%) amounts (%) amounts (%) Abafungin 10 10 10 2-Propanol 37 37 — PEG 20000 18.4 18.4 — PEG 8000 3 3 — MPEG 2000 — 5 — Water 24 20 — Formic acid 1.6 1.6 — Isopropyl myristate 0.5 0.5 — Transcutol 3.5 3.5 — Propylene glycol 1 1 — Hydroxyethyl cellulose 1 — — Gantrez ES 425 — — 30 Ethyl acetate — — 17.2 Butyl acetate — — 5.7 Triacetin — — 1.2 Miglyol 812N — — ad. 100 ml [0138] The formulations were applied to horse hoof horn membranes of about 600-700 μm thickness for 24 hours to ascertain the amount of abafungin penetration. The horse hoof horn membranes are shown in FIG. 1 and the results are summarised in Table 3. [0000] TABLE 3 μg/g abafungin in horse hoof horn membranes (+/−S.D., n = 3, after 24 h) [mm] Formulation 1 Formulation 2 Formulation 3 0-6 2332.47 +/− 654.56 2546.14 +/− 856.13 2532.59 +/− 757.66  6-12 1980.54 +/− 612.45 2617.71 +/− 944.71 2157.89 +/− 916.72 12-18  274.23 +/− 139.26 2618.28 +/− 903.49  488.44 +/− 388.52 18-30  53.87 +/− 47.68 1559.44 +/− 461.42 105.57 +/− 97.29 Total 4641.11 9341.57 5284.49 [0139] When applied in the formulation according to the present invention (formulation 2), abafungin penetrated the horse hoof horn membranes much better, namely more in total (9341.57 μg/g compared to 4641.11 μg/g and 5284.49 μg/g) and further in distance (higher proportion in the 18-30 mm penetration distance), than when applied in the comparative formulations (formulations 1 and 3). Example 3 Ex vivo Penetration Studies of Three Abafungin Formulations into Horse Hoof Horn Membranes [0140] In order to simulate human in vivo conditions, ex vivo penetration studies on horse hoof horn membranes were performed. Animal hoof is made of essentially the same material as human nails. Horse hoof was sawn into horn membranes having an area of about 2 cm 2 and a thickness of 600-700 μm which conforms to human nails. Human finger nails are about 500 μm thick and human toenails about 800 μm. [0141] 1 ml of each of formulations 1, 2 and 3 of example 2 was applied to a horse hoof horn membrane. The horse hoof horn membranes were placed in Franz diffusion cells (area 1.76 cm 2 ) and the cells were filled with a tempered blood simulating buffer (phosphate buffered saline). The buffer was stirred at 300 rpm. After 24 hours, the horse hoof horn membranes were removed from the Franz diffusion cells and residues of the formulations were removed. The effective penetration area of 1.76 cm 2 was cut into small pieces and abafungin was extracted using a mixture of 80% acetonitrile, 19.6% water and 0.4% perchloric acid. The samples were extracted for 30 minutes using an ultrasonic water bath at 60° C. The supernatant was analysed using HPLC. [0142] The results are presented in FIG. 2 . When applied in the formulation according to the present invention (formulation 2), more abafungin penetrated the horse hoof horn membranes than when applied in the comparative formulations (formulations 1 and 3). Example 4 Penetration of Abafungin into Stratum Corneum and Epidermis/Dermis [0143] In order to study the ability of abafungin to penetrate into skin, penetration studies with the abafungin formulation 2 of example 2 were performed. Penetration tests with unstripped porcine ear skin (thickness 2 mm) were performed using Franz diffusion cells (buffer conditions: thermo jacket 36° C., 300 rpm, BPS buffer). 1 ml of formulation 2 of example 2 was applied onto the skin. After 24 hours incubation, the stratum corneum was removed and abafungin was extracted from both the stratum corneum and the epidermis/dermis, with 1 ml of a mixture of 80% acetonitrile, 19.6% water and 0.4% perchloric acid at 60° C. for 1.5 hours. The supernatant was analysed using HPLC. It was found that fungicidal concentrations (16-30 μg/ml) of abafungin had been achieved in both the stratum corneum and the epidermis/dermis (Franz diffusion cells, n=3). The abafungin concentration in the epidermis/dermis was found to be 32.19±1.19 μg/g, and in the stratum corneum 4617.50±731.86 μg/g. Example 5 Abafungin for the Treatment of Onychomycosis [0144] A hydrophilic gel formulation according to the present invention was prepared, comprising the ingredients set out in Table 4. The formulation was the same as formulation 2 in example 2. [0000] TABLE 4 Ingredient Amount (%) 2-Propanol 37.0 Abafungin 10.0 Water 20.0 Formic acid 1.6 PEG 20000 18.4 PEG 8000 3.0 MPEG 2000 5.0 Isopropyl myristate 0.5 Transcutol 3.5 Propylene glycol 1.0 Total 100 [0145] The gel formulation was prepared by dissolving abafungin and formic acid in water. Then the remaining ingredients (namely 2-propanol, PEG 20000, PEG 8000, MPEG 2000, isopropyl myristate, transcutol, and propylene glycol) were added to this solution and the mixture was stirred until a gel formulation was formed. [0146] The gel formulation was applied once daily to the left toenail of a male volunteer (aged 32) suffering from onychomycosis. The results are shown in FIG. 3 , which shows the toenail (a) after one month, (b) after two months, and (c) after three months of once daily application of the formulation. There is a marked improvement in the toenail's condition. [0147] A second male volunteer (aged 55), also suffering from onychomycosis, was treated orally with 100 mg itraconazole (Itracol®) twice daily for one week followed by three weeks intermission. After one month of itraconazole administration, the volunteer additionally applied the gel formulation once daily to his toenails. The results are shown in FIG. 4 , which shows the toenails (a) before treatment, (b) after one month of itraconazole administration, (c) after two months of itraconazole administration and one month application of the abafungin formulation, (d) after three months of itraconazole administration and two months application of the abafungin formulation, and (e) after four months of itraconazole administration and three months application of the abafungin formulation. There is a marked improvement in the toenails' condition. Example 6 Ex vivo Penetration Studies of Five Formulations Comprising Abafungin, Ciclopirox or Ciclopirox Olamine into Horse Hoof Horn Membranes [0148] In order to simulate human in vivo conditions, ex vivo penetration studies on horse hoof horn membranes were performed. Animal hoof is made of essentially the same material as human nails. Horse hoof was sawn into horn membranes having an area of about 2 cm 2 and a thickness of 600-700 μm which conforms to human nails. Human finger nails are about 500 μm thick and human toenails about 800 μm. [0149] Formulations 1-3 and 5 were prepared and formulation 4 was purchased, comprising the ingredients set out in Table 5. Formulations 1, 2 and 5 were hydrophilic gels, and formulations 3 and 4 were lacquers. Formulations 2 and 5 are according to the present invention, and formulations 1, 3 and 4 are comparative formulations. [0000] TABLE 5 Formulation 1 Formulation 2 Formulation 3 Formulation 4* Formulation 5 amounts (%) amounts (%) amounts (%) amounts (%) amounts (%) Abafungin 10 10 10 — — Ciclopirox — — — 8 — Ciclopirox olamine — — — — 8 2-Propanol 37 37 — yes 37 PEG 20000 18.4 18.4 — — 18.4 PEG 8000 3 3 — — 3 MPEG 2000 — 5 — — 5 Water 24 20 — — 22 Formic add 1.6 1.6 — — 1.6 Isopropyl myristate 0.5 0.5 — — 0.5 Transcutol 3.5 3.5 — — 3.5 Propylene glycol 1 1 — — 1 Hydroxyethyl cellulose 1 — — — — Gantrez ES 425 — — 30 — — Ethyl acetate — — 17.2 yes — Butyl acetate — — 5.7 — — Triacetin — — 1.2 — — Miglyol 812N — — ad. 100 ml — — Poly(butylhydrogen- — — — yes — maleate, methoxy- ethylene) (1:1) *commercially available Batrafen ® (also called Penlac ®), therefore amounts of excipients unknown [0150] 250 μl of each of formulations 1-5 was applied to a horse hoof horn membrane. The horse hoof horn membranes were placed in Franz diffusion cells (area 1.76 cm 2 ) and the cells were filled with a tempered blood simulating buffer (phosphate buffered saline). The buffer was stirred at 300 rpm. After 24 hours, the horse hoof horn membranes were removed from the Franz diffusion cells and the residues of the formulations were removed. The effective penetration area of 1.76 cm 2 was cut into small pieces and the API (abafungin, ciclopirox, or ciclopirox olamine) was extracted using an appropriate solvent. The samples were extracted for 30 minutes using an ultrasonic bath at 60° C. The supernatant was analysed using HPLC. [0000] TABLE 6 [mg/g nail] +/− [mg/cm 2 nail] +/− number of Formulation API S.D. S.D. cells 1 10% abafungin 0.71000 +/− 0.05000 0.05244 +/− 0.01468 3 2 10% abafungin 1.96571 +/− 0.50360 0.14432 +/− 0.04222 7 3 10% abafungin 0.47377 +/− 0.20475 0.03377 +/− 0.01374 7 4  8% ciclopirox 1.20527 +/− 0.35257 0.06639 +/− 0.01802 7 5  8% ciclopirox 2.39251 +/− 0.07734 0.18347 +/− 0.00642 3 olamine [0151] The results are presented in Table 6 and FIG. 5 . When applied in the formulations according to the present invention (formulations 2 and 5), more abafungin and ciclopirox olamine penetrated the horse hoof horn membranes than when applied in the comparative formulations (formulations 1, 3 and 4). [0152] The in vitro trials with ciclopirox in a formulation according to the present invention (formulation 5) demonstrate higher penetration rates into the nail in comparison to the marketed ciclopirox lacquer used in Batrafen® (formulation 4). Example 7 Ex vivo Penetration Studies of Four Formulations Comprising Abafungin or Hydrocortisone into Porcine Ear Skin [0153] In order to simulate human in vivo conditions, ex vivo penetration studies on porcine ear skin were performed. Porcine ear skin is made of essentially the same material as human skin. Porcine ear skin was removed carefully from the chondral tissue and cut into pieces having an area of about 2 cm 2 and a thickness of about 2000 μm which conforms to human skin. [0154] Formulations a, b and d were prepared and formulation c was purchased, comprising the ingredients set out in Table 7. Formulations a and d were hydrophilic gels according to the present invention, and formulations b and c were comparative cream formulations. [0000] TABLE 7 Formu- Formu- Formulation Formulation lation c* lation d a b amounts amounts amounts (%) amounts (%) (%) (%) Abafungin 1 1 — — Hydrocortisone — — 1 1 2-Propanol 29 — — 29 PEG 400 8 — — 8 PEG 8000 21.4 — — 21.4 MPEG 2000 5 — — 5 Water 24 yes yes 24 Formic acid 0.6 — — 0.6 Isopropyl myristate 0.5 — yes 0.5 Transcutol 3.5 — — 3.5 Propylene glycol 7 — — 7 2-Octyldodecanol — yes — — Cetostearyl alcohol — yes — — Cetyl palmitate — yes — — Polysorbate 60 — yes — — Sorbitan monostearate — yes — — Stearic acid — yes — — Benzyl alcohol — yes — — Urea — — yes — White vaseline — — yes — Maize starch — — yes — Sorbitan laurate — — yes — Sorbitol solution — — yes — Poly(oxyethylene)-25 — — yes — hydrogenated castor oil *commercially available Hydrodexan Crème ®, therefore amounts of excipients unknown [0155] 250 μl of each of formulations a-d was applied to a porcine ear skin piece. The porcine ear skin pieces were placed in Franz diffusion cells (area 1.76 cm 2 ) and the cells were filled with a tempered blood simulating buffer (phosphate buffered saline). The buffer was stirred at 300 rpm. After 24 hours, the skin pieces were removed from the Franz diffusion cells and the residues of the formulations were removed. The effective penetration area of 1.76 cm 2 was cut into small pieces and the API (abafungin or hydrocortisone) was extracted using an appropriate solvent. The samples were extracted for 30 minutes using an ultrasonic bath at 60° C. The supernatant was analysed using HPLC. [0000] TABLE 8 [mg/g skin] +/− [mg/cm 2 skin] +/− number of Formulation API S.D. S.D. cells a 1% abafungin 0.04751 +/− 0.01262 0.01110 +/− 0.00368 6 b 1% abafungin 0.00535 +/− 0.00165 0.00096 +/− 0.00036 6 c 1% hydrocortisone 0.01500 +/− 0.00190 0.00183 +/− 0.00042 5 d 1% hydrocortisone 0.10960 +/− 0.00328 0.00185 +/− 0.00085 5 [0156] The results are presented in Table 8 and FIG. 6 . When applied in the formulations according to the present invention (formulations a and d), more abafungin and hydrocortisone penetrated into porcine ear skin than when applied in the comparative formulations (formulations b and c). [0157] The hydrocortisone formulation according to the present invention (formulation d) enhances the penetration rate of the cortico steroid hydrocortisone in comparison to the marketed formulation Hydrodexan Creme® (formulation c). Example 8 Solubility and Stability Studies with Abafungin, Hydrocortisone and Ciclopirox Olamine [0158] The solubility and stability of abafungin, hydrocortisone and ciclopirox olamine were tested in a formulation according to the present invention, in a standard ethanol gel (Ethanolhaltiges Erythromycin Gel, NRF 11.84, ABDA, Govi Verlag Pharmazeutischer Verlag GmbH, Eschborn), in pure water and in pure ethanol. The maximum solubilities of the three APIs without crystallisation in the different formulations are summarised in Table 9. [0000] TABLE 9 Ciclopirox Abafungin Hydrocortisone Olamine Formulation according to    ~30%* 2  ~2.7%  ~11.0% the present invention* 1 Formulation according  ~102.6% ~103.7% ~104.4% to the present ([c] 10%)* 4 ([c] 1%)* 4 ([c] 8%)* 4 invention* 3 after 3 months at 24° C. (HPLC recovery) Ethanol gel (NRF 11.84)    0.2%  ~1.2% ~soluble* 5 Pure water <0.00002% ~0.028%  ~1-3%* 5 Pure ethanol   <0.24%  ~1.5% ~soluble* 5 * 1 formulation comprising the same excipients in the same ratios as formulation 2 of example 2/6, with abafungin, hydrocortisone or ciclopirox olamine being added gradually * 2 dependent on pH * 3 same as formulation 2 of example 2/6, formulation d of example 7, and formulation 5 of example 6 respectively * 4 initial API concentration * 5 not measured, data according to Neues Rezeptur-Formularium ABDA, Bundesvereinigung Deutscher Apothekerverbände, Pharmazeutisches Laboratorium, Govi Verlag Pharmazeutischer Verlag GmbH, Eschborn [0159] It was found that the formulation according to the present invention prevents crystallisation and increases the solubility and stability of the three APIs (abafungin, hydrocortisone and ciclopirox olamine) in comparison to the standard ethanol gel, pure water and pure ethanol. Example 9 TEWL (Transepidermal Water Loss) Studies [0160] The influence of the application of standard nail lacquers (Batrafen® and Loceryl®) and of a formulation according to the present invention on TEWL (transepidermal water loss) was studied. [0161] The thumbnails of three volunteers were treated with three different formulations, namely a formulation according to the present invention (formulation 2 of example 2) and commercially available lacquer formulations Batrafen® and Loceryl®. The TEWL of the thumbnail was measured before and one hour after treatment of the three volunteers. The results are presented in FIG. 7 , which shows the percentage deviation of the measurements one hour after treatment to the measurements before the treatment. [0162] Both, the Batrafen® and Loceryl® lacquers resulted in a significant reduction of water loss and humidity above the nail. Only with the formulation according to the present invention, the free nail water can still permeate freely across the nail plate, moisten the nail plate and dissolve the pharmaceutically active agent out of the hydrophilic gel formulation into the nail. Example 10 Fungal Inhibition Assays [0163] The objective of this study was to determine the ability of abafungin, formulated according to the present invention, to permeate through bovine hoof horn membrane (a model of human nail) and inhibit the growth of Trichophyton rubrum 34. T. rubrum is the most prevalent pathogen responsible for onychomycosis of the toenail (W. K. Foster, M. A. Ghannoum and B. E. Elewski, J. Am. Acad. Dermatol., 2004, vol. 50, pages 748-752). One formulation according to the present invention (A) was tested alongside three alternative abafungin formulations not according to the present invention (B-D) for comparative purposes. [0164] Bovine hoof horn membranes were hydrated in sterile distilled water in petri dishes for 2 hours. Subsequently, the bovine hoof horn membranes were removed from the petri dishes and dried on a filter paper. [0165] To prepare an inoculum of T. rubrum 34, 1-2 ml of sterile saline was added to the surface of the corresponding colony in agar gel in petri dishes and the surface was agitated with a swab. The suspension was then transferred to a Universal tube and its turbidity was adjusted (using sterile saline or suspension) to a McFarland Standard 2. The surfaces of fresh Sabouraud agar plates were swabbed using the inoculum. [0166] Drug formulations A-D were applied onto the bovine hoof horn membranes. A blank, untreated bovine hoof horn membrane was used as a control. Once the treatments had dried, the bovine hoof horn membranes were placed with the treated surface uppermost in the middle of an inoculated Sabouraud plate and the plates were incubated at 27° C. for 5 days. Three repetitions of each test condition were performed. [0167] Following incubation for 5 days, an inhibition zone was observed (see FIG. 8 ), as the drug permeated into the bovine hoof horn membrane and through the latter into the agar gel. Photographs were taken of the agar plates (see FIG. 9 ) and the diameter of the inhibition zone was calculated as per the following equation: [0000] Diameter  ( dia )   of   inhibition   zone   ( mm ) = dia   of   inhibition   zone   on   photograph × real   dia   of   petri   dish dia   of   petri   dish   on   photograph [0168] The results are presented in Table 10, which summarises the diameter of the inhibition zones of T. rubrum 34 following incubation of the bovine hoof horn membranes treated with formulations A-D. The results of the three repetitions of each test condition are provided. [0000] TABLE 10 Diameter of inhibition zone (mm) Abafungin Ave ± Formulation concentration 1 2 3 S.D. — Blank bovine hoof horn membrane — 0  0 0 0 (photograph not shown) A Formulation according to the present 10% 88  88 88  88 ± 0   invention** B Lacquer, not according to the present 10.7%   31* 39 27* — invention C Gel 1, not according to the present 10% 51  57 62  57 ± 5.5 invention D Gel 2, not according to the present 5.1%  40* 28 33* — invention *agar gel within inhibition zone did not become completely clear, but the density of fungi within inhibition zone was less than outside of inhibition zone **same as formulation 2 of example 2 [0169] The application of the abafungin formulation according to the present invention (A) resulted in complete clearance of the plate. This was not achieved by application of any of the three alternative abafungin formulations not according to the present invention (B-D).

The present invention relates to a pharmaceutical formulation comprising a pharmaceutically activeagent; water; a polyethylene glycol or a poloxamer; and a polyethylene glycol mono- or di-ether. Preferably the pharmaceutically active agent is an anti-fungal or anti-mycotic agent. Preferably the pharmaceutically active agent is lipophilic and/or keratinophilic. The present invention also relates to the use of the formulation in treating diseases, disorders or pathological conditions of the nail or skin, such as onychomycosis, dermatomycosis and other mycoses. The present invention also relates to a method of administering a pharmaceutically active agent to a subject by applying the formulation comprising the pharmaceutically active agent to a nail or skin of the subject. The present invention further relates to a method of preparing the formulation.

BACKGROUND OF THE INVENTION The present invention relates to apparatus for automatically generating arpeggios from played chords on an electronic musical instrument and, more particularly, to apparatus for automatically providing a wide variety of musically sophisticated tonal sequences under microprocessor control while requiring only a minimum amount of sophistication and dexterity on the part of the person playing the instrument. Electronic musical instruments which automatically generate arpeggios are known in the art. Such systems, as those disclosed in U.S. Pat. Nos. 3,718,748, 3,822,407, 3,842,182, and 4,137,809, all in the name of Bunger; U.S. Pat. No. 3,725,562-Munch, et al.; and U.S. Pat. No. 3,842,184-Kniepkamp, et al., provide a fully automatic arpeggio initiated by the playing of one or more keys and terminated by the release of the keys. These arpeggio systems provide up, down, and up/down tonal sequences. However, an arpeggio played by a skilled musician may include a variety of fanciful, tonal sequences in addition to the up, down, and up/down sequences, none of which are provided by these prior art automatic systems. The next generation of arpeggio systems, as disclosed in U.S. Pat. Nos. 4,154,131 and 4,156,379, both in the name of Studer, et al., provided a variety of tonal sequences in addition to the up, down, and up-down arpeggios. However, the artistic use of these new variations requires a greater musical sophistication and performance capability on the part of the musical performer than that of a musical amateur. In contrast, a musical beginner can play musical instruments, including electronic organs, incorporating the present invention to provide a wide variety of musically sophisticated tonal sequences. BRIEF DESCRIPTION OF THE INVENTION The present invention comprises an improved system and method for the generation of arpeggios from selected chords on an electronic musical instrument, such as an electric organ having an array of playing keys corresponding to a plurality of octaves. The improved arpeggio-generating system enables the user to preselect one or more voice-related rhythmic patterns and arpeggio variations of these tones before playing a chord on the organ's keyboard. Priority of the voice-related patterns and their arpeggio variations depends upon the order in which the particular patterns and variations are selected. Thereafter, by playing a particular chord, the played notes and their corresponding notes in higher octaves are selected to form an array (up to a maximum of twenty-six notes in the array) which is stored in a microprocessor's random access memory. An arpeggio is formed from this array. The selected notes in the random access memory may include up to five octaves of five different notes plus a sixth octave comprising a low C. Normally less than five different notes are played. The notes in octaves below each played note are not stored. The exact position of each played note of the chord with respect to the note C is also stored. In addition, data representing the lowest and highest notes played, the preselected rhythm rate, the selected voice variation, and the desired up or down movement in pitch of the arpeggio are stored in the random access memory. The microprocessor then searches the array of selected notes for the beginning note of a note group or the note within a selected note group, depending upon the preselected voice-related rhythmic pattern. When a note is detected, data is transferred to another memory area representing the desired condition of the latches which control which notes will be sounded. Thereafter, this data is converted to audible tones and the next available note for the preselected pattern variation is searched for and sounded. The system of the present invention can reverse the order of search whenever the highest or lowest notes are reached or exceeded, stop the search, and produce a five note trill. Further, the present invention can skip one or more active notes during a search and immediately search for another note to be played simultaneously in a chord, or change the direction of search, as the situation dictates. The principal object of the present invention is to provide an improved arpeggio-generating system for performing sophisticated tonal sequences. It is a further object of the present invention to provide a system by which amateur musicians may generate sophisticated musical sequences. These and other objects and advantages of the present invention are presented, by way of illustration and not limitation, by the following detailed description of a preferred embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified circuit diagram of the arpeggio-generating system of the present invention. FIG. 2 is a simplified flow chart of the arpeggio-generating system illustrating the preferred embodiment of the present invention. FIGS. 3a and 3b taken together constitute a flow chart detailing block 70 of FIG. 2. FIG. 4 is a flow chart illustrating an algorithm for octave priming. FIG. 5 is a musical example of a three note banjo arpeggio resulting from a three note chord being played. FIG. 6 is a musical example of a three note guitar arpeggio resulting from a three note chord being played. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, a microprocessor 10 is connected via communications bus 12 to another microprocessor (not shown) which reads the tabs and key switches of an organ 14. The microprocessor 10 in turn is connected to eight 8-bit addressable latches 16 and to a line decoder 18. The latches 16 generate ten millisecond pulses at the start of each tone to charge a condenser (not shown) in a gate circuit and initiate a percussive tone. The condensers (not shown) normally discharge slowly to give long sustaining tones. Additional latches (not shown) permit individual damping for each tone. When an arpeggio is not desired and normal organ tones are to be played, the ten millisecond pulse is produced by a latch (not shown) corresponding to each newly depressed key. When the key is released a damp latch (not shown) is energized, giving a piano-like operation to the organ. The microprocessor 10 receives communications from the organ 14 as to which notes are played, which variation and voice buttons and rhythm tabs are pressed, and the state of certain counters and rate pulses. In particular, one or more voice-related rhythmic patterns or variations are preselected by the user. The variations comprising VAR 2, 3, 4 determine the rate and the synchronization means by which the arpeggio is to be produced. Other tabs such as the preferred rhythm rate are also preselected. The user initiates a desired arpeggio simply by playing one note or a chord. The notes comprising the played chord are chosen from the various octaves on the lower accompaniment manual, i.e., keyboard (not shown), of the organ 14. The keyboard has six octaves, i.e., five full octaves and a sixth (lowest) C note. The highest C note on the keyboard is in the fifth full octave, octave 5, while the lowest C note at the left end of the keyboard is in an octave all by itself, octave 0. The microprocessor 10 receives the notes played from the organ 14 via communications bus 12 and stores these notes and their corresponding notes in higher octaves in a memory block defined by registers R20 through R24 (see TABLE 1 at the end of the specification) in the random access memory of microprocessor 10. A portion of the random access memory of microprocessor 10, including registers R20-24 as well as other registers, is depicted by TABLE 1, which is discussed in more detail below. Each register in the memory block R20-24 contains eight bits, as indicated by bits 0-7 (reading from right to left). However, only the six right-most bits, bits 0-5, are needed in the preferred embodiment. Binary zeroes are stored in the two left-most bits. The six right-most bits represent the six octaves of the lower keyboard (i.e., octave 0 through octave 5, from right to left). Accordingly, registers R20-24 can store up to a maximum of 26 notes--five notes in each of the five full octaves plus the low C note in octave 0 (the sixth octave). In the preferred embodiment, the lowest note played first is the first note stored in memory block R20-24. Thereafter, the next lowest note played is stored, etc. A C♯ note is considered the lowest note within the octave and will always be the first note stored if it is played on the keyboard. A C note is the highest note within the octave and is always considered note n if it is played where n notes are played in all. Accordingly, all C♯ notes are listed first, if a C♯ is played. Then, all D notes are listed, if a D is played. Thereafter, all D♯ notes are listed, if a D♯ is played, etc. Finally, all C notes are listed, if a C is played. The two following examples illustrate how notes are stored in memory block R20-24 of Table 1. ______________________________________Example 1, Play Example 2, PlayC2, E3, G3, C3 C2, E3, G3, A3, B3, D4______________________________________R20 00111000(E) 00110000(D) Note 1R21 00111000(G) 00111000(E) Note 2R22 00111100(C) 00111000(G) Note 3R23 00000000 00111000(A) Note 4R24 00000000 00111000(B) Note 5______________________________________ In example 1 (a simple major triad) , E3 (E note, octave 3) is stored in register R20, TABLE 1, by placing a binary one in bit 3. For purposes of performing the arpeggio, notes in higher octaves of the same nomenclature as the note played on the lower keyboard are also entered in the same register. For example, The E notes in octaves 4 and 5 are also stored in register R20 by entering a binary one in bits 4 and 5. Next, G3 (G note, octave 3) and G notes in octaves 4 and 5 are stored in register R21 in the same manner. Thereafter, C2 (note C, octave 2) and the corresponding C notes in octaves 3, 4, and 5 are stored in memory block R20-24 by entering a binary one in bits 2-5 of register R22. Although Example 1 shows four notes played, only the lowest notes E3, G3, and C2 are entered in separate registers in memory block R20-R24. Notes C2 and C3 are considered the same note for storing purposes because if C2 is played, C3 will automatically be stored too. The presence of C3 is stored in bit 3 of register R22--as represented by a binary one. In addition, the C notes are always stored last in memory block R20-R24, even if a C note was the lowest note played, because the C note is the highest note in each octave as defined above. When progressing upward in frequency, the microprocessor 10 scans each column of bits (i.e., 0-5) in memory block R20-24 from right to left. Thus, in Example 1, note C2 is the first note encountered by microprocessor 10 when a search is initiated. In Example 2 (a complex and dissonant chord) , the notes are stored in memory block R20-24 in a similar manner. First, D4 (D note, octave 4) and the D note in octave 5 are stored in register R20, Table 1, by entering a binary one in bits 4 and 5. Next E3 (E note, octave 3) and its corresponding notes in octaves 4 and 5 are stored in register R21 by entering a binary one in bits 3, 4 and 5. Similarly, G3, A3, and B3 (and their corresponding notes in octaves 4 and 5) are stored in registers R22, R23, and R24, respectively. In Example 2, C2 (C note, octave 2) is not stored in the memory block R20-24 because a maximum of five played notes may be entered and the C note is not among the five lowest notes in an octave. It should be understood that a chord must be quite dissonant (as in this example) in the preferred embodiment to omit a played note. The selection of notes as a result of a desired chord being played is called octave priming and, except for the five note limitation, is performed by electronic circuits in previous organs. Octave priming is performed in the present invention by the execution of an algorithm in microprocessor 10 (see FIG. 4 and main program block 60 in FIG. 2). For Example 1 above, the value stored in register R22 is obtained by starting with byte 11110011 where a logic 0 (negative logic) indicates that C2 and C3 are being played. A mask set to a binary 1 (00000001) at block 61 is "anded"to byte 11110011. Thereafter, comparator 67 determines whether the resulting byte is equal to 00000000. If not, the binary 1 in the mask is shifted to the left at block 65 and block 63 is repeated. When the shifted mask becomes 00000100 at block 65, then "anding" the mask at block 63 results in a byte equal to 00000000. Subsequently, comparator 67 detects the zeros and microprocessor 10 executes block 69. There, the mask is complemented for a resultant 11111011 and incremented to 11111100. Then bits 6 and 7 of register R22 are set to 0 and the resultant number in register R22 (00111100) indicates that C5, C4, C3, C2 are available for the arpeggio because C2 was the lowest played C. The microprocessor 10 receives data from the organ 14 via the communications bus 12 following an external interrupt signal received at input terminal 10i every 5.2 milliseconds. This data informs the microprocessor 10 which notes are played and which tabs and voice buttons are actuated. Receipt of such data is represented by block 19 in FIG. 2. The data received may not only represent actual keys played but also chord notes depending on a single key being played. A tab marked "one-finger" may be used to actuate this mode. Besides this data stored in registers R20-24, the arpeggio-generating system detects and records the exact position of the notes played with respect to the note C generally. The exact positions of the notes are stored in registers R10-14 on a descending basis as represented by a descending scale number ("DSN") value, i.e., the number of notes that the particular note is below C. Referring to Example 1, the DSN values for E3, G3, and C2 are 8, 5, 0, respectively. These values (8, 5, 0) are stored in the DSN memory area, as represented by registers TABLE 1, in the following manner. Of the notes played, the E3 note is the note farthest away from C. In fact, an E note is eight notes below a C on the musical scale. Therefore, a binary number 8 (1000) is entered in register R10. Similarly, a binary 5 (0101) and a binary 0 (0000) are entered in registers R11 and R12, respectively, indicating that the G2 note is five notes below note C o the musical scale and that C2 is zero notes below C. DSN values for Example 2 are determined similarly with values of 10 (1010), 8 (1000), 5 (0101), 3 (0011), and 1 (0001) corresponding to D, E, G, A, and B, respectively. As illustrated by block 60 in FIG. 2, microprocessor 10 also determines which voice button (not shown) has priority. More than on voice button (not shown) may be depressed to produce a combination of tone colors. However, the priority for the voice patterns is determined by whichever voice button is depressed first. The priority indicates which voice pattern is dominant. Register R8, bits 0-3, as represented by VPR (see TABLE 1) identifies voice has priority. In this preferred embodiment, a binary one (001) in register R8 represents a muted guitar voice (VPR=1); a binary two (010) represents a piano voice (VPR=2); a binary three (011) represents a banjo voice (VPR=3); a binary four (100) represents a guitar voice (VPR=4); a binary five (101) represents a harpsichord voice (VPR=5); a binary six (110) represents rinky tink voice (VPR=6); a binary seven (111) represents a fantom piano voice (VPR=7); a binary eight (1000) represents a fantom harp voice (VPR=8); and a binary zero (000) represents no voice. During the time microprocessor 10 receives information from organ 14, as illustrated in block 19 (FIG. 2), the progress of a rhythm preselected by the user is entered in a rhythm counter RX as represented by register R1 in TABLE 1. For every one-forty-eighth of a measure, rhythm counter RX increases by 1, except when bits 0 and 1 of register R1 contain a binary two (10), in which case the rhythm counter RX increases by 2. Accordingly, rhythm counter RX progresses as follows: 0, 1, 2, 4, 5, 6, 8, 9, 10, 12, 13, 14, 16, 17, 18, 20, 21, 22, etc. This progression indicates that bits 2 and 3 count one-sixteenth notes within a quarter note, bits 4 and 5 count quarter notes within a measure, and bits 6 and 7 count measures up to four. The rate at which the one-forty-eighth notes are produced is determined by a tempo potentiometer (not shown) connected to another microprocessor (not shown) as described in the U.S. patent application entitled "Tempo Measurement, Display, and Control System for an Electronic Musical Instrument", U.S. Ser. No. 273,788, filed June 15, 1981. The microprocessor 10 also receives data for a one bit flag FP representing an external rate which is determined by an external rate potentiometer (not shown). This external rate is used only when the variations 4 button is pushed. When the variations 2 or variations 3 button is pushed the arpeggios are in synchonism with the rhythm-counter, but as explained below the arpeggio rate is twice as fast in variations 3 as in variations 2, and the rate is altered for certain rhythms. With no variation button pushed, the latches in FIG. 1 are used to produce accompaniment sequences of chords which are different for each rhythm (as described in the U.S. patent application entitled "Memory Condensation System for Rhythms and Sequences in an Electronic Musical Instrument", U.S. Ser. No. 275,032, filed June 18, 1981). However if a "fantom touch strip" is touched, and the "fantom harp or fantom piano" button is pushed, then even without pressing the variations buttons the arpeggios listed for VPR equals 7 or 8 are obtained. These occur at fixed rates as described below. A two bit countdown flag, CDC, is stored in bits 0 and 1 of register R2, TABLE 1. Flag CDC is decremented by one from an initial binary three (11) after communications are completed between the microprocessor 10 and organ 14. When Flag CDC is decremented to 1, the latches 16 are set to zero by block 52 to end their ten millisecond pulses (which started when CDC was 3), thereby indicating the sounding of the corresponding tones. Flag CDC also triggers the damping latches (not shown). Referring to FIG. 2, the decrementing of flag CDC is shown by block 20. Thereafter, microprocessor 10 determines at comparator 22 whether variations button 2, 3, or 4 is pushed, or the fantom touch strip is touched and the fantom piano or voice harp is pushed. If no tonal arpeggio or pattern has been selected by the variation or fantom buttons, the microprocessor 10 bypasses the arpeggio variation routine 70 and searches for the value stored in flag CDC at comparator 50. If CDC equals the latches are turned off in blocks 56, 58 and 60 to end any ten millisecond pulses. If, however, an arpeggio is selected, the microprocessor 10 determines whether a note is being played at comparator 24. If no note is being played, the starting note of the chord ("STRT") as represented by register R16, bits 0-2 (TABLE 1), is set to 0 at block 26. This represents note 0, octave 0 which is below any real note and assures that the arpeggio will start at the beginning. Also, a timer, V2S, is set to a binary five (101) at block 26 to delay the start of the arpeggio for twenty-six milliseconds after a note is played (the arpeggio begins one millisecond after the timer V2S has counted down to 0). This delay is implemented so that when a chord is played, the first note of the arpeggio will be properly selected even if the lowest note (which is usually the first note sounded) is played few milliseconds after the other notes in the chord. When timer V2S has been decremented from five to zero, the first note is sounded by going into the arpeggio routine, which is illustrated by block 70, regardless of the state of the rhythm counter RX or the external rate flag FP. Subsequent notes of the chord are controlled by rhythm counter RX or flag FP. Nevertheless, the first time interval is approximately correct because another microprocessor (not shown) synchronizes rhythm counter RX and flag FP with the playing of the first note. Thereafter, the microprocessor 10 examines the value stored in flag CDC at comparator 50. If a note is detected as being played at comparator 24, then comparator 28 determines whether timer V2S has counted down to 0. If timer V2S does not equal 0, then block 30 decrements timer V2S by 1, and comparator 32 determines whether timer V2S is now equal to 0. If timer V2S still does not equal 0, then comparator 50 examines the value of flag CDC. If timer V2S does equal 0 at comparator 32, then the first note is sounded by execution of the arpeggio routine 70, as discussed below. Referring to comparator 28, if timer V2S equals 0, then variations comparator 34 determines which arpeggio variation has been selected by depression of the variations button (not shown). If variations 4 is selected, comparator 36 checks the value of flag FP. If flag FP is equal to 1, then the arpeggio routine 70 is executed. If flag FP is equal to 0, then comparator 50 examines the value of flag CDC, as discussed below. The synchronism of the arpeggio notes generated with the rhythm counter RX is more complicated for variations 2 (slow) and variations 3 (fast). In variations 2, notes at an eighth note rate are desired for most rhythms. But for the ballad, rock, shuffle and country rhythms, a twelfth note rate is desired. Further, for the six-eight march, a sixth note rate is desired. Variations 3 produces arpeggio notes at twice these rates. The aforementioned rhythm rates are produced from an array of twelve bytes of data shown in TABLE 3 at the end of this specification. A mask is produced in register R7 where one of the bits is set to 0 or 1 depending upon whether variation 2 or 3 is selected and whether a special rhythm is selected. In either case, one of the vertical columns shown in TABLE 3 is implemented. Further, a binary one occurs in TABLE 3 at regular intervals throughout the incrementing of rhythm counter RX. Each vertical step represents a one-forty-eighth note. Accordingly, the proper timing in each column is obtained. For example, bit 7 is used for most rhythms in variation 3 where a binary one occurs every three one-forty-eighth notes to produce one-sixteenth notes. The last four bits for rhythm counter RX (bits 0-3) are sufficient to control all cases except when one-sixth notes are required by the six-eight march. Then, two columns have to be implemented, one for bit 4 of rhythm counter RX equalling 0 and the other for bit 4 of rhythm counter RX equalling 1. By using these columns alternately, the sixth notes repeat every eight one-forty-eighth notes. The memory block at VA2P as represented by TABLE 3 actually contains sixteen bytes. However, as previously explained, the rhythm counter RX always skips the locations for right RX equal 3, 7, 11, 15. Referring to variations comparator 34, if variation 2 has been selected, then a binary one is stored in register R7, bit 6 (TABLE 1), by block 35. If variations 3 has been selected, then a binary one is stored in register R7, bit 7, by block 37. Subsequently, block 38 examines whether the value stored in rhythm counter RX has changed. If RX has not changed, microprocessor 10 executes the logic initiated by comparator 50. If RX has changed, then rhythm comparator 40 determines which rhythm has been selected. If the ballad, rock, shuffle, or country rhythm has been selected, block 42 shifts the contents in register R7 to the right two bits before the microprocessor 10 proceeds to block 46. If the six-eight march is selected, the contents of register R6 are shifted in block 44 to the right four bits if RX, bit 4, is equal to 0 and to the right six bits if RX, bit 4, is equal to 1. The purpose of shifting the contents of register R7 to the right is to select the different pairs of columns in TABLE 3. Then, the microprocessor 10 proceeds to block 46. If any other rhythm is detected at rhythm comparator 40, microprocessor 10 proceeds directly to block 46. There, one of the twelve memory bytes in TABLE 3 is selected according to the value of the last four bits RX (bits 0-3). Subsequently, the selected memory byte from TABLE 3 is "anded" to the contents of register R7 at block 48. If the result is 0, the microprocessor 10 advances to comparator 50. If the result is not 0, the arpeggio routine 70 is executed before the microprocessor 10 advances to comparator 50. The arpeggio routine 70 places a note from the arpeggio sequence, or several notes if a chord is desired, into random access memory registers R64-75 (see TABLE 1). Referring to comparator 50 in FIG. 2, flag CDC is initially preset to a binary 3 (11) during most executions of routine 70. As a result, the latch-setting routines 54, 56 and 58 start the trigger pulses on the outputs of the latches 16 which are connected to the percussive gates (not shown) using all the data in memory block represented by registers R64-75. Ten milliseconds later when CDC becomes l, all the data in registers R64-75 is set by block 52 to a "logic 0" (actually 1's because negative logic is used), and the latches 16 are reset by routines 54, 56 and 58 so that all the trigger pulses last ten milliseconds on the latches to operate the gate circuits (not shown) and sound the arpeggio notes. It should be noted that bits 5-7 in registers R64-75 are fixed bits (except register R64, bit 5) which address the latches. These bits are refreshed when the contents of flag CDC becomes 1 by starting with 01111111 and decrementing by 00100000 as each byte of data is stored in the memory block R64-75. As a result, the desired logic 0 is given for all notes, and the desired fixed bits are stored. Referring to FIG. 1, a strobe pulse from output terminal 10j is received by decoder 18 at input terminal 18h every time microprocessor 10 generates an output at terminals 10k, 10l and 10m. The strobe pulse is directed to one of several strobe output terminals 18a-d of decoder 18 according to the bits at lOk, 10l and 10m. Output terminals 18a and 18b are connected to the eight latch packages 16 for generating the beginning and the end of a 10 millisecond pulse which initiates the percussive tone for each selected note of the arpeggio. Output terminals 18c and 18d are connected to a similar set of latches (not shown) for damping purposes. The eight output terminals 16f-m of each latch 16 are connected to percussive gates (not shown) and remain in a high or low state until a negative strobe pulse is received at the enable input terminal 16e. Thereafter, the data on the input terminal 16d is transferred to one of eight output terminals 16f-m according to a previously set address stored at address terminals 16a-c. As represented by blocks 54 and 56 (FIG. 2), output terminal 18a sets the three left-most latch packages 16 (FIG. 1). The data in R64-R67 (TABLE 1) is transferred to the C, B, A♯, and A output terminals of the latch packages 16. However, in each case, data pertaining to octaves 5, 3 and 1 is outputted first. Then the data is shifted to the right and data pertaining to octaves 4, 2, and 0 is outputted. The five right-most latch outputs can be set simultaneously by applying an appropriate strobe pulse from line decoder 18 simultaneously to the enable input terminal 16e of the five right-most latch packages 16. The logic illustrated by block 58 first outputs the data in register R68 to port 0, bits 0-7. Since the microprocessor 10 inverts all the data at its output terminals, the binary 1 in bits 7, 6 and 5 of register R68 change to a binary 0 when outputted to address terminals 16a-c of the five right-most latch packages. Accordingly, output terminal 16f is actuated in these latch packages. Subsequently, output terminals 10k-m are set to a binary one (001), thereby transmitting the strobe pulse to output terminal 18b and transferring all the data to all the G♯ output terminals in the five right-most latches 16. This data is an inverted version of the contents of register R68, bits 0-4. Accordingly, it is positive logic. As a result, ten millisecond positive pulses are started on selected output terminals 16f representing the G♯ note. Then, the data in register R69 is transferred to port 0, and output terminals 10k-m are again set to actuate output terminal 18b. This time, the address terminals 16a-c receive the complement of 110, i.e., 001. Accordingly, all the desired G notes are selected. By repeating this procedure six more times with the appropriate addresses applied to address terminals 16a-c, the F♯, F, E, D♯, D and C♯ notes are set. Although not shown in FIG. 2, the three latch setting blocks 54, 56, and 58 trigger signals from output terminals 18c-d for damping. The latches controlled by these registers are set to 1 if no damping is required and it is intended that the tones have a long decay. The latches are set to 0 if damping is required so that the tones decay quickly. This is similar to releasing played keys on a piano and not using the sustaining pedal. FIGS. 3a and 3b together disclose the overall flow diagram for the arpeggios routine 70. This routine 70 accesses data from the R20-24 storage area as illustrated by Table 1, transfers that data to the R64-75 storage area, and sets flag CDC to equal a binary three (11). As a result the corresponding latches are set, except if VPR equals 0 (no voices) or if STRT or the next note within a group (CRNT) equals 10000110 (note 6, octave 5), which is a flag to produce silence at the end of a fantom touch piano or harp sequence. If no notes are played, i.e., register R20 contains a 0, then arpeggio routine 70 is bypassed as shown in FIG. 2. Upon entering the arpeggio routine 70 (see FIGS. 3a and 3b), the following flags in register R3 are preset to zero by block 72: the next note extreme ("NNE") flag; search for another note ("CHD") flag, and the number of skipped notes ("SKIP") flag. The NNE flag is stored in register R3, bit 5. The CHD flag is stored in register R3, bit 2. If CHD were equal to 1 for a particular note, then another note would be searched for and stored in memory area R64-75. The SKIP flag is a two bit number which indicates how many notes are to be skipped when searching for the next note to be outputted. In the preferred embodiment, the SKIP flag skips up to three notes between any adjacent chord notes and is stored in bits 0 and 1 of register R3 in TABLE 1. At the end of a group of notes there can be considerably more gap because SKIP for the STRT note of a new group refers to the number of notes skipped when relating it to the STRT note of the previous group and not the last CRNT note of the previous group. Block 72 determines the lowest note (BOT) and the highest available note (TOP) played by examining the memory area R20-R24. In the preferred embodiment, BOT is stored in register R17. Bits 0-2 of BOT (see TABLE 1) give the note number which is 1 to 5 according to its position in memory R10-14 or R20-24 where the notes are listed in order of their frequency with DSN decreasing in value. As mentioned previously, note C♯ is considered the lowest note and is note 1 of the chord if it has been played. Note C is the highest note and is note n of the chord if it is being played and if n notes in all are being played. The octave number of BOT is indicated by entering a 1 in only one of the bits 3 through 7 of register R17. However, the lowest C (octave 0) would have a binary 0 entered in all bits 3-7. The advantage of this format is that the position of one note compared to another note (i.e., whether the first note is lower than, equal to, or higher than the second note) can be determined by comparing the corresponding binary numbers. Data corresponding to the notes representing STRT, CRNT and TOP is similarly stored in registers R16, R19, and R18, respectively. However, it is understood that other formats may be utilized with the present invention. It should be understood that STRT and CRNT sometimes refer to nonexistent notes 0 or 6 as a temporary expedient. With reference to FIG. 3a, once the binary data has been stored in the aforementioned registers R3 and R16-19, comparator 74 determines whether the touch strip (not shown) is being contacted (i.e., whether the touch strip mode is being selected) by the user. The touch strip provides two additional arpeggio patterns for piano and harp voices. If the user is not contacting the touch strip, then the value of VPR in register R8 is determined at comparator 78. If the user touches the touch strip, then comparator 76 determines if the fantom piano button (not shown) has been pressed (as represented by a binary one being detected). If the fantom piano button has been pressed, block 80 sets VPR in register R8 equal to a binary seven and timer V2S equal to a binary twenty before block 90 is executed. If the fantom piano button has not been pressed, then comparator 82 determines if the fantom harp button has been pressed. If pressed, then block 84 sets VPR in register R8 equal to a binary eight and timer V2S equal to a binary fourteen before block 90 is executed. If the fantom harp button is not pressed at comparator 82, then the value of VPR is checked at comparator 78. It should be noted that by setting timer V2S, the rates for fantom harp and fantom piano are fixed since the next note of the arpeggio being generated will not be produced until timer V2S (which is decremented every 5.2 ms) decrements to 0 (see blocks 30, 32 in FIG. 2). Also, there is no synchronization of the arpeggio notes to the rhythm rate or external rate. If VPR equals 0 at comparator 78, indicating that no voice button is depressed, then the rest of the arpeggio routine 70 is bypassed except that STRT in register R16 is set to 0 at block 188 (FIG. 3b) so that any future arpeggio pattern will start at the beginning of the played chord. If VPR does not equal 0 at comparator 78 or if either comparator 76 or 82 indicates that the fantom piano button (not shown) or the fantom harp button (not shown) is depressed (binary one), then the execution of block 90 performs the following logical steps. A flag N4, located at register R6, bit 5, is set to 1 if the played chord includes 4 or 5 notes. Otherwise, N4 is set to 0. The same note played in two or more octaves constitutes only one note for this test. Also, if STRT equals 0, then block 90 sets CRNT equal to 0, up-down STRT (UDS) flag equal to 1, up-down CRNT (UDC) flag equal to 1, and the count of notes within each arpeggio group (PCNT) equal to 15 so the sequence will be ready to start upward. The UDS and UDC flags indicate whether the search for a STRT or a CRNT note moves up or down in pitch from the previous STRT or CRNT note (hereinafter, UD includes both UDS and UDC). A binary 1 in the UD flags indicates that the search is to move up in frequency, and a binary zero in the UD flags indicates that the search is to move down in frequency. Thereafter, comparator 92 examines the CRNT note to determine if it is equal to or greater than the TOP note. Also, comparator 92 determines whether the selected UD flag is equal to 1. If the CRNT note is greater than or equal to the TOP note and the selected UD flag is equal to 1, some ending conditions are tested for at blocks 96 and 100, as discussed below. If the CRNT note is lower than the TOP note or if the selected UD flag is not equal to 1, then block 94 increments PCNT unless certain conditions are present. If the maximum size of the group of notes is sixteen, then PCNT is always set to zero if its previous value was 15. For groups of four notes such as used for the piano, guitar or harpsichord voices (i.e., when VPR equals 2, 4 or 5), PCNT is set to 0 if the previous value was 3. For groups of two notes such as used for the muted guitar or fantom piano (i.e., when VPR equals 1 or 7), PCNT is set to 0 if the previous value was 1. This is accomplished automatically by setting bits 3 and 2 of PCNT to 0 for VPR equals 2, 4, or 5 and by also setting bit 1 of PCNT to 0 for VPR equals 1 or 7, as illustrated in block 94, FIG. 3a. The four bits comprising the CHD, SKIP, and UDC flags are stored in memory for each note of a chord for all voices for which these effects are desired. The 42 bytes shown in TABLE 2 is all the data needed for VPR equals 3, 4, 5, 6, and 7. Separate data is illustrated in TABLE 2 for the case of less than four notes within an octave and for the case of four or five notes. TABLE 2 illustrates the data used to obtain the desired response to the three note chords shown in FIGS. 5 and The only difference between the three and four note cases are the values for SKIP. The values for the UDC flag in TABLE 2 are used to override the effect of any previous initialization due to STRT being equal to 0 in block 90 (FIG. 3a) or any previous effect of blocks 174, 158, 162, 116, and 120. The UD flags (if VPR equals 1, 2 or 8) are controlled by blocks 174, 158, 162, 116, and 120. Block 94 (FIG. 3a) shows how the data is extracted from TABLE 2. If VPR is equal to 3, 4, 5, 6 or 7, data counter DC is set to V2 +0, V2 +16, V2 +20, V2 +24, or V2 +40, respectively. Next, PCNT is added to data counter DC and the appropriate UDC, CHD, and SKIP values are selected. The left or right half of the memory byte selected by DC is used depending on whether N4 equals 0 or 1 (see TABLE 1). If VPR is equal to 1, 2 or 8, SKIP and CHD are set to 0. Whenever a note is found by block 142, block 150 determines whether SKIP is 0. If SKIP is 0, the note is out-putted by branching to block 176. Otherwise, SKIP is decremented by block 156 and another note is searched for by returning to comparator 124 and checking the appropriate UD flag. The selected UD flag is not changed so the search continues in the same direction. Therefore, a number of notes will be skipped according to the original value of SKIP, unless TOP or BOT is encountered, in which case that note will be sounded and the UD flag will be changed. The CHD flag is tested by comparator 178 after block 182 stores note in the R64-75 storage area and block 180 sets CDC equal to 3. If the CHD flag is equal to 1, as determined by block 178, the routine branches to block 92. PCNT is incremented and a new CHD flag is obtained in block 94. Accordingly, n notes could be included in a chord by having n-1 chord flags in succession in TABLE 2. A new value of SKIP is also obtained so the chord can be opened up in any desired manner as long as not more than three available notes are skipped between any adjacent chord notes. In one special case, TABLE 2 is not consulted for a chord. If VPR is equal to 7 (fantom piano variation) and if the second note of a two note group (i.e., the top note of a chord) has reached TOP, then the CHD flag is set to 1 by block 60 so that a transfer back to block 92 is enabled via blocks 158, 176, 182, 180 and 178. Since CRNT is equal to TOP and UDC is equal to 1 in this special case, block 92 (FIG. 3a) executes comparator 96. When VPR is equal to 7 at comparator 96, comparator 100 determines whether STRT is greater than or equal to TOP. If it is, then STRT and CRNT are set for note 6, octave 5 before microprocessor 10 proceeds to comparator 50 (FIG. 2). If STRT is less than TOP, the program branches back to comparator 124 with STRT being selected. Since the UDS flag is equal to 1 at comparator 124, STRT is incremented by block 126 to the next available note. CHD remains at 1 since it is not reset by block 94 so that all the available notes in between are filled, including the TOP note for the second time. Finally, STRT is greater than TOP, and comparator 100 branches to comparator 50 (FIG. 2) to terminate the sequence without any note being sounded until the following conditions occur STRT is set to zero again by block 26 in FIG. 2 if the notes are released or by block 188 in FIG. 3b if VPR becomes 0 by the touch strip (not shown) being released. A search is usually made for the next available note to be sounded among the octave primed notes listed in memory storage R20-24, Table 1. The search begins with the previous STRT note where PCNT is 0 indicating that the note to be searched for is the first note in an arpeggio group, or with the previous CRNT note where PCNT is not 0. Initially CRNT and STRT are preset to 0 (note 0, octave 0) by blocks 26 and 90. PCNT is set to 15 by block 90 and is immediately incremented to 0 at block 94. In addition, the UDS and UDC flags are set to 1 indicating the search is upward regardless of whether the search starts with the STRT or CRNT note. The value of PCNT is then examined at comparator 102. When PCNT equals 0, register R16 (containing STRT) is selected at block 106. Accordingly, the arpeggio begins with the STRT note, and not the CRNT note. Next, comparator 108 examines the value of VPR. If VPR equals 2 (piano voice), microprocessor 10 moves to comparator 124. If VPR had equalled 3, 4, 6 or 8 at comparator 108, a number of steps would have been taken prior to microprocessor 10 executing comparator 124. If VPR equals 4, block 110 determines whether STRT is greater than or equal to the octave above BOT before proceeding to comparator 124. If so, then the UD flags are set to 0 and STRT is set equal to the octave above BOT. If VPR equals 3 at comparator 108, then comparator 112 determines whether STRT equals 0 or 8. If STRT equals 0 or 8, then STRT and SKIP are set equal to 0 by block 120. In addition, the UD flags are set equal to 1. Then, microprocessor 10 proceeds to comparator 124. If VPR equals 6, block 116 sets PCNT and the UD flags to 0. In addition, STRT is set for note 6, octave 5 before the execution of comparator 124. If VPR equals 8, comparator 114 determines whether STRT had been set to 0. If so, then block 116 is executed as previously described. If not, then micro-processor 10 proceeds to comparator 124. As mentioned previously, the UD flags were initialized to 1 at block 90, which is detected by comparator 124. Next, the note number in STRT is incremented to one by block 126 before microprocessor 10 proceeds to block 136 in FIG. 3B. Referring to block 102, later when PCNT is not equal to 0, register R19 (containing CRNT) is selected at block 104. Accordingly, the arpeggio continues with the CRNT note and not the STRT note. Next, comparator 118 examines the value of VPR. If VPR equals 2 (piano voice), microprocessor 10 executes comparator 124. If VPR had been equal to 1 (muted guitar), then microprocessor 10 would have proceeded to block 122 to determine whether STRT was greater than or equal to two octaves above the BOT note. In addition, the UD flags would be set equal to 0 and CRNT would be selected again. Thereafter, microprocessor 10 would proceed to block 176, as discussed below. When comparator 124 finds that in the UDS flag is set to 1, block 126 is executed. STRT was initially set to 0 (note 0, octave 0, a non-existent note lower than the lowest possible note on the lower keyboard) by block 26 (see FIG. 2). Therefore, when STRT is incremented by block 126 to 1 (note 1, octave 0), it will be a real note if low C is being played. Next, block 136 is executed. If a 1 is stored in STRT, note number 6 or 7 is not found at block 136. Consequently, micro-processor 10 branches to accumulator 134. In the cases where a 6 or 7 is detected by block 136, comparator 140 detects whether the note is in octave 5. If not, then in block 154 STRT is set to note number 1 in the next higher octave before microprocessor 10 branches to accumulator 134. If the note is in octave 5, then microprocessor 10 proceeds to block 176, as discussed below. At accumulator 134, TOP is substracted from STRT. The result is a negative number in this case, thereby causing microprocessor 10 to determine in block 142 whether a note found is in storage area R20-24. If the result had been positive, then microprocessor 10 would have executed block 174, as discussed below. When the result is zero, the TOP note has been reached, as discussed below. In the present example, block 142 determines that the note number is 1 and examines register R20. Block 142 tests for a 1 in bit 0 (octave number 0) and finds a 1 there for the C0 note (assuming the low-C note is played). As a result, the search is complete and microprocessor 10 proceeds to comparator 150. If no note had been found, then microprocessor 10 would have returned to comparator 124 (FIG. 3a). In the present example (i.e., the start of a piano arpeggio), comparator 150 determines the value of SKIP to be 0, and the microprocessor 10 branches to block 176 where CRNT is set equal to STRT. This is the only operation performed at block 176 for th piano voice case where VPR equals 2. If VPR was equal to 3 and if STRT was greater than BOT, block 176 would set STRT equal to 8. Thereafter, block 176 would insert C0 (low C) into register R64. The storage of notes in the register R64-R75 area, including the special low C case, is discussed below. In most cases at block 142, no note is found in the memory storage area R20-24. Accordingly, the microprocessor 10 returns to block 124 and identifies that UDS is equal to 1. Accordingly, the previously discussed steps illustrated in block 124 are repeated, thereby incrementing the note number and searching the storage area R20-24 for that note. Upon repeating these steps, there still may be no note found in storage area R20-24. If no note is found, the steps are repeated again. When the note number for STRT is incremented to 6 at block 126 (FIG. 3a), comparator 136 proceeds to comparator 140 to determine whether the octave number has reached 5. In cases where the octave is not 5, block 154 changes the note number back to 1 and increments the octave number before microprocessor 10 moves to block 134 and continues the search for the next note in the arpeggio group. For example, if the notes G3, C3, and E4 are played, the search for the first note would continue until STRT has been incremented to 00100010 (octave 3, note 2) by block 126. In this case, the G notes are represented in register R21 by 00111000. Bits 0-2 in STRT are equal to 010 causing the block 142 to find register R21 for note 2. Then STRT is temporarily shifted right 2 bits with bit 0 being set to 0 to get 00001000. Thereafter, R21 is "ANDED" to this modified STRT. The non-zero result shows the presence of G3 in register R21 and the search would stop with G3 being sounded as described below. With STRT equal to 00100010 (i.e., note 2 in octave 3 is G3) and that note having been found in block 142, the program is directed by SKIP comparator 150 to block 176, which sets CRNT equal STRT (assuming STRT was selected). It is necessary to have G3 in both CRNT and STRT because during the search for the next note after G3 that next note will be put in CRNT and sounded. However, the STRT register continues to contain the note G3. When it is time for a new chord group to be sounded, PCNT will again be 0, and STRT will be selected (as opposed to CRNT) and incremented to the next note so that the first note of the new chord group will be sounded. Therefore, the note sounded in block 182 is always the one in CRNT. For a note to sound, the corresponding DSN value must be found in the R10-R14 area (specifically Rll for note number 2). This is accomplished by using the note number in CRNT as a pointer to one of the registers R10-R14. Since DSN is the number of notes below C, the proper location in the memory block registers R64-75 is found by setting the DC data counter to R64 plus DSN at block 182. The note is inserted into this memory location by shifting CRNT to the right three bits, complementing, and "anding" to the memory byte pointed to by DC. The shifting causes the octaves of CRNT to correspond to the octaves in the R64-75 memory area. Complementing causes a zero to occur in the proper octave. Therefore, the proper bit in the R64-75 memory area is set to 0 according to the desired note. For example, if the CRNT note represents G3, i.e. 00100010 (note 2, octave 3), the register Rll (for note number 2) will have a DSN value equal to 5. Therefore, the memory byte to be affected will be R64+5 which equals R69. CRNT shifted to the right three bits and complemented is 11111011 and "anding" to R69 causes the G3 bit to be set to 0 (logic 1) which will be sounded in block 58, FIG. 2. Low C is a special case. If bits 3-7 of CRNT are 0 (which means octave 0), 11011111 is "anded" to memory instead, thereby setting bit 5 of register R64 to 0. Referring to block 124 in FIG. 3a, when the UDC or UDS flag is 0, a downward search for the next note to be sounded is implemented. Accordingly, block 128 decrements STRT when PCNT is 0 at block 102 or otherwise decrements CRNT. If note number 0 is found at comparator 130 and if octave number 0 is found at comparator 138, then the overflow routine in block 174 is executed, as discussed below. STRT is never decremented below 0 by execution of block 128 (FIG. 3a) because whenever STRT is set to 0 for initialization, the UDS and UDC flags are set to 1. Accordingly, comparator 102 causes the note number to be incremented in block 126, rather than decremented. In the other cases, the note number for STRT or CRNT will not be 0 when the 0 in the UDS or UDC flags trigger block 128 in FIG. 3a. Assuming that STRT has been selected, its note number is decremented by block 128. Thereafter, comparator 130 determines whether the note number for STRT is 0. If the note number is 0, then comparator 138 determines whether the octave number is 0. If so, then the overflow routine in block 174 is executed in order to set UD flags back to one. If the octave number is not 0 at block 138, then the octave number is decremented and the note number is set to 5 at block 144. Thereafter (and also in the case where the note number is not 0 at block 130), comparator 146 examines the value of VPR. Unless VPR is equal to 8, block 132 is exeouted next. In the case where VPR is 8 (fantom harp), comparator 148 detects whether STRT is active and, if so, executes block 132. When CRNT is active instead, block 164 determines whether CRNT is two octaves below STRT. If not, block 132 is executed. If CRNT is two octaves below STRT, PCNT is set to 0 and STRT is selected at block 172. Then, microprocessor 10 returns to comparator 124. Execution of block 132 determines whether the BOT note has been reached by subtracting BOT from STRT (or CRNT depending on which register has been selected). When BOT has been reached, i.e., STRT minus BOT is equal to zero, comparator 152 is executed. If BOT has not been reached, block 142 is executed. Also, if accumulator 132 registers a negative number, the overflow routine at block 174 is executed. If VPR is equal to 2 (piano voice) and the UD's are zero, then each group of four notes is a downward progression with each group of four starting at the next lower available note than the start of the previous group. When the fourth note of a group of four reaches the lower limit, the pattern continues as if nothing had happened until four notes later when CRNT goes one note lower than BOT and the negative output from block 132 (or the positive output from block 134 when testing for TOP in an upward progression) is applied to the overflow routine performed at block 174. When the notes being played are suddenly changed, thereby changing TOP or BOT, CRNT or STRT may suddenly be outside the note range defined by BOT and TOP. Whenever this occurs, the overflow routine in block 174 is executed. For example, if D2, G2, and B2 are played and the upward progression has already reached G5, the next note would normally be equal to TOP (B5). If B2 is released before B5 is sounded, then TOP becomes note 2, octave 5 (G5). CRNT will increment to note 3, octave 5, and block 134 will branch to the block 174 overflow routine. Block 174 changes the UD flags but also changes STRT (or CRNT) to TOP if the UDS (or UDC) flag is 1 or to BOT if the UDS (or UDC) flag is 0. The search then continues down from TOP or up from BOT. Typically, execution of block 174 causes the TOP or BOT note to sound by branching to block 176 via block 170. For the piano voice variation, the BOT or TOP note has sounded before entering block 174. In order to avoid repetition, the next-to-last note of the arpeggio group is sounded to produce a more desirable musical effect by branching back to comparator 124 (FIG. 3a) via blocks 168 and 166 (FIG. 3b) with the UD flags reversed, thereby assuring that the previous note will be found. The NNE flag is set to 1 at block 166. This causes TOP or BOT to be sounded again after the next-to-last note has sounded. Sometimes the next note extreme cannot be found because TOP and BOT are the same note. This situation occurs in the upward movement of an arpeggio when the only note played is in octave 5 on the lower keyboard. In that case, comparator 140 proceeds to overflow block 174. The UD flags are changed, and the NNE flag is determined to be l by block 170. As a result, an endless loop is avoided, and the microprocessor 10 branches to block 178 via blocks 176, 182, which causes the one note to be repeated. Where the NNE flag has been set and the next-to-last note has been repeated by execution of block 182 (FIG. 3b), CDC is set equal to three (11) by block 180, and block 178 determines that the CHD flag has a 0 stored therein. Accordingly, the NNE flag is determined to be 1 by comparator 184. Depending on the state of the UDS flag, as detected by comparator 186, STRT is either set at a value above TOP (when UDS is equal to 0) by block 190 or below BOT (when UDS is equal to 1) by block 188. Also, PCNT is set to 15 and the two UD flags are set to 0 by block 190 if the previous four note group ended prematurely because of a last minute change in TOP. Otherwise, if the UDS flag is equal to 1, PCNT is set in the initializing procedure at block 90 (FIG. 3a). The NNE flag is reset at block 72 when it is time to sound the next note, but the conditions are already set up for a TOP or BOT note by block 188 or 190 in FIG. 3b. The TOP note represents an upward movement despite the fact that the U/D flags are set up for a subsequent downward movement. Similarly, the BOT note represents a downward movement even though the U/D flags are already set up for a subsequent upward movement. Accordingly, there is always a five note trill at the top and bottom of the piano note pattern. For voice variations other than the piano, additional arpeggio patterns are obtained by implementing the CHD and SKIP flags, and by utilizing the UDC flag to control the search. When the CHD flag equals 1 at block 178 (FIG. 3b), another note will be searched for and put into the R64-75 storage area (see TABLE 1). If CHD equals 1 for the second note, a third note will be searched for, etc. The two or more notes will be outputted practically simultaneously by the latch-setting routine as illustrated in FIG. 2 by blocks 54, 56 and 58, as previously described. The fantom piano and harp sequences (VPR equals 7 and 8, respectively) are the only sequences which have definite ends to them. Definite ends are provided by setting STRT and CRNT equal to 10000110 (note 6, octave 5) at block 98. This value is higher than any value that TOP might have or change to if legato notes are played after the end. Therefore, comparator 100 continues to branch to block 98. The decay of the last notes and subsequent silence continues until no keys are played (see block 26, FIG. 2) or other times that STRT is set to 0 for reinitialization of the sequence. The following are deviations of the arpeggio system described above. When VPR equals 1 (muted guitar), CRNT is selected every other time because PCNT alternates between 0 and 1. When CRNT is selected, the incrementing procedure is bypassed and a repeated note occurs because CRNT has been set equal to STRT in the previous block 176 routine. When a note two octaves above BOT is being repeated, the UD's are set to 0. This limits the upward progression to two octaves. The CHANGE UD blocks 162 and 174 reverse the direction in the other cases. When VPR equals 3 (banjo), SKIP equals 1 or 2 for the very first note as shown on TABLE 2 at V2 where PCNT equals 0 and STRT is selected. These values are selected so that after twelve beats (sixteen notes counting a chord as two notes) STRT is incremented to the correct value (see FIG. 5). STRT starts at G2 but at the beginning of the fourth group of four notes advances to E3 by skipping one note, C2. At that time, STRT still equals BOT. But then, block 176 creates a special STRT flag equal to 8 (a nonexistent note number 0, octave 1). This flag lasts for twenty-four beats, whereupon it starts over. At that time, PCNT is set to 0 again, VPR is equal to 3, and STRT is equal to 8. Block 120 sets the STRT and SKIP flags to 0, thereby causing comparator 124 to branch to block 126 where STRT is incremented until BOT is reached. Also the UD flags are set to 1 at block 120. If VPR equals 4 (guitar), each four note group of the arpeggio sequence starts 1 note higher than the previous one until a group that is an octave higher has been selected and sounded (see FIG. 6). Then, the VPR equal 4 output of block 108 causes the UD flags to be set to 0 at block 110, causing each group to start one note lower than the previous group. If BOT suddenly decreases by playing a low note, STRT is immediately adjusted to be not more than 1 octave above BOT. When STRT reaches BOT again, one of the CHANGE UD routines causes STRT to progress upwards again. These CHANGE UD routines also handle the UD progression of the VPR equal to 5 harpsichord sequence. For VPR equal to 6 or 8 (rinky tink or fantom harp, respectively), the patterns start at TOP by setting STRT for note 6, octave 5 which is a nonexistent note above TOP. In addition the UD flags are set to 0. This occurs for VPR equal to 8 in response to the initialization of STRT flag equal to 0 and at the start of each 16-note group for VPR equal to 6. The arpeggio sequence sounded for VPR equal to 8 goes down according to a first sequence and up according to another sequence when block 158 sets UDC and UDS to 1. Although the invention has been described in terms of a preferred embodiment, it will be obvious to those skilled in the art that many alterations and modifications may be made without departing from the invention. Accordingly, it is intended that all such alterations and modifications be included within the spirit and scope of the invention as defined by the appended claims. TABLE 1__________________________________________________________________________REGISTER BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0__________________________________________________________________________R3 NNE CHD SKIPR6 UDS UDC N4 PCNTR8 VPRR16 OCT 5 OCT 4 OCT 3 OCT 2 OCT 1 NOTE ♯ STRTR17 OCT 5 OCT 4 OCT 3 OCT 2 OCT 1 NOTE ♯ BOTR18 OCT 5 OCT 4 OCT 3 OCT 2 OCT 1 NOTE ♯ TOPR19 OCT 5 OCT 4 OCT 3 OCT 2 OCT 1 NOTE ♯ CRNTR10 DSN FOR NOTE #1 DSNR11 DSN FOR NOTE ♯2 DECREASESR12 DSN FOR NOTE ♯3 ↓R13 DSN FOR NOTE ♯4 ↓R14 DSN FOR NOTE ♯5 ↓R20 OCT 5 OCT 4 OCT 3 OCT 2 OCT 1 OCT .0. NOTE ♯1R21 OCT 5 OCT 4 OCT 3 OCT 2 OCT 1 OCT .0. NOTE ♯2R22 OCT 5 OCT 4 OCT 3 OCT 2 OCT 1 OCT .0. NOTE ♯3R23 OCT 5 OCT 4 OCT 3 OCT 2 OCT 1 OCT .0. NOTE ♯4R24 OCT 5 OCT 4 OCT 3 OCT 2 OCT 1 OCT .0. NOTE ♯5R64 0 1 C.0. C5 C4 C3 C2 C1 DSN = 0R65 0 1 0 B5 B4 B3 B2 B1 DSN = 1R66 0 0 1 A♯5 A♯4 A♯3 A♯2 A♯1 DSN = 2R67 0 0 0 A5 A4 A3 A2 A1 DSN = 3R68 1 1 1 G♯5 G♯4 G♯3 G♯2 G♯1 DSN = 4R69 1 1 0 G5 G4 G3 G2 G1 DSN = 5R70 1 0 1 F♯5 F♯4 F♯3 F♯2 F♯1 DSN = 6R71 1 0 0 F5 F4 F3 F2 F1 DSN = 7R72 0 1 1 E5 E4 E3 E2 E1 DSN = 8R73 0 1 0 D♯5 D♯4 D♯3 D♯2 D♯1 DSN = 9R74 0 0 1 D5 D4 D3 D2 D1 DSN = 10R75 0 0 0 C♯5 C♯4 C♯3 C♯2 C♯1 DSN = 11R1 MEASURE ♯ QUARTER NOTE ♯ 1/16 NOTE ♯ 1/48 NOTE ♯ RXR2 CDCR 7__________________________________________________________________________ NOTE: R64-75 use negative logic TABLE 2__________________________________________________________________________N4 = 0, NCNT < 4 N4 = 1, NCNT = 4 or 5DC UDC CHD SKIP UDC CHD SKIP VPR__________________________________________________________________________V2 + 0X 1 01 X 1 10 3 (BANJO)+ 1 1 0 01 1 0 10+ 2 0 0 00 0 0 00+ 3 0 0 00 0 0 00+ 4 1 1 01 1 1 01+ 5 1 0 00 1 0 00+ 6 0 0 00 0 0 00+ 7 0 0 00 0 0 00+ 8 0 1 00 0 1 01+ 9 1 0 01 1 0 10+ 10 0 0 00 0 0 00+ 11 0 0 00 0 0 00+ 12 1 1 01 1 1 01+ 13 1 0 00 1 0 00+ 14 0 0 00 0 0 00+ 15 0 0 00 0 0 00V2 + 16X 0 00 X 0 00 4 (GUITAR)+ 17 1 0 01 1 0 10+ 18 0 0 00 0 0 00+ 19 0 0 00 0 0 01V2 + 20X 0 00 X 0 00 5 (HARPSICHORD)+ 21 1 0 01 1 0 10+ 22 0 0 00 0 0 00+ 23 1 0 00 1 0 00V2 + 24X 0 00 X 0 00 6 (RINKYTINK)+ 25 0 0 00 0 0 00+ 26 0 0 00 0 0 00+ 27 0 0 00 0 0 00+ 28 1 0 01 1 0 01+ 29 0 0 00 0 0 00+ 30 0 0 00 0 0 00+ 31 1 0 00 1 0 00+ 32 0 0 00 0 0 00+ 33 1 0 00 1 0 00+ 34 1 0 00 1 0 00+ 35 1 0 00 1 0 00+ 360 0 01 0 0 01+ 37 1 0 00 1 0 00+ 38 1 0 00 1 0 00+ 39 0 0 00 0 0 00V2 + 40X 1 00 X 1 00 7 (FANTOM PIANO)+ 41 1 0 01 1 0 10__________________________________________________________________________ TABLE 3__________________________________________________________________________ RHYTHM Ballad Rock Country 6/8 March 6/8 March Other Rhythms Shuffle RX B4 = 0 RX B4 = 1 VARIATIONS 3 2 3 2 3 2 3 2 BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0__________________________________________________________________________RIGHT RX = 0 1 1 1 1 1 1 1 0 1 0 0 0 0 0 0 0 0 2 0 0 1 0 0 0 0 0 4 1 0 0 0 0 0 0 0 5 0 0 1 1 1 0 1 1 6 0 0 0 0 0 0 0 0 8 1 1 1 0 0 0 0 0 9 0 0 0 0 0 0 0 0 10 0 0 1 1 1 1 1 0 12 1 0 0 0 0 0 0 0 13 0 0 1 0 0 0 0 0 14 0 0 0 0 0 0 0 0__________________________________________________________________________

In an electronic musical instrument, an apparatus and method are described for automatically generating arpeggios from selected chords while requiring only a minimum amount of performance sophistication and dexterity. In the preferred embodiment, a plurality of voice priority switches are included, each of which corresponds to a voice-related rhythmic pattern or an arpeggio variation of tones played. The desired variation of the voice-related rhythmic pattern of tones is implemented as selected notes are played. The played notes and corresponding notes in higher octaves are stored in a random access memory and subsequently accessed by a microprocessor which searches up or down in frequency to find the available notes in the random access memory. Subsequently, the microprocessor converts chosen notes to audible tones. The system of the subject invention, under certain predetermined conditions, reverses the order of search whenever the highest or lowest notes are reached or exceeded, stops the search, and produces a five-note trill. Further, the system of the subject invention, under certain predetermined conditions, skips one or more active notes during a search and immediately searches for another note in the chord or changes the direction of search in the middle of the chord or sequence.

BACKGROUND [0001] The nuclear magnetic resonance (NMR) response of gas in gas shale nanopores is different from that of bulk gas, where relaxation is dominated by spin rotation and diffusion is unrestricted. Gas shales are characterized by very low porosity and ultra low permeabilities. Their porosity is dominated by nanometer-scale pores in the organic kerogen that restricts diffusion motion, in addition to having very high surface-to-volume ratios that enhance surface relaxation. At high pressure, the gas exists as an adsorbed phase on the pore surface and as free gas phase in the pore interior. Thus, relaxation and diffusion properties of gas in gas shales are affected by the combined effects of adsorption, enhanced surface relaxation, restricted diffusion and molecular exchange between the adsorbed and free phases. SUMMARY [0002] Embodiments herein relate to an apparatus and methods for characterizing hydrocarbons in a subterranean formation including sending and measuring NMR signals; analyzing the signals to form a distribution; and estimating a property of a formation from the distribution, wherein the sending comprises pulse sequences configured for a formation pore size, and wherein the computing comprises porosity. Embodiments herein relate to an apparatus and methods for characterizing hydrocarbons in a subterranean formation including sending and measuring NMR signals; analyzing the signals to form a distribution; and estimating a property of a formation from the distribution, wherein the formation comprises a distribution of pore sizes of about 10 nm or more, and wherein the computing comprises natural gas composition. [0003] Some embodiments may have relaxation times that are about 0.1 msec to about 10,000 msec and/or the relaxation times are of the same order of magnitude of the inter-echo time. In some embodiments, the formation comprises a core, cuttings, material in communication with a wellbore, or a combination thereof. In some embodiments, the formation comprises shale, coal, kerogen, or a combination thereof. In some embodiments, the formation comprises a distribution of pore sizes of about 10 nm or more. [0004] Some embodiments may form an hydrogen index which may include observing controlled temperature and pressure samples. The samples may include core, cuttings, or a combination thereof. [0005] In some embodiments, the methods may include analzying a mud log, performing a fluid analysis in a wellbore, using fluid collected from a wellbore, performing resistivity measurements and/or performing dielectric measurements. FIGURES [0006] FIGS. 1A-1B show a composite view of a SEM picture (Ambrose et al., 2010) on the left depicts the kerogen patches in the matrix which host the dominant porosity and on the right is a conceptualized picture of the free and adsorbed gas in the kerogen pores. [0007] FIG. 2 Schematic 2D-NMR plot for gas inside gas shales shows reduced diffusion coefficients and relaxation times as a result of adsorption, surface relaxation and restricted diffusion in the small pore sizes. [0008] FIGS. 3A-3B show T 2 distributions of bulk methane (left panel) and T 2 peak amplitudes versus pressure (right panel). Both the T 2 peak amplitude and intensity of the T 2 distributions increase with pressure. [0009] FIGS. 4A-4B show Bulk methane gas T 1 -T 2 plot (left panel) and D-T 2 plot (right panel). The left panel clearly shows the signal falling on the diagonal line as T 1 =T 2 for the bulk, motionally averaged gas. The right panel shows the bulk gas diffusion coefficients at 5 kpsi and 30° C. to be clearly an order of magnitude larger than the values for bulk water. [0010] FIGS. 5A-5B show Brine-saturated T2 distributions for all four gas shale plugs studied. The distributions are peaked around 1 ms indicating the strong surface relaxation of the fluid in the nanoscale pores. [0011] FIGS. 6A-6D show Brine (irreducible state) and methane-saturated T 2 distributions for all the four gas shale plugs. Brine (irreducible state) and methane saturated states have T 2 distributions peaked about 1 ms and 10 ms and with overlap between the distributions. The methane saturated samples with brine (irreducible state), also clearly shows that the signals are not well separated in the T 2 dimension. [0012] FIGS. 7A-7D show D-T 2 plots for the methane gas inside the gas shale samples. The restricted diffusion formalism (Lukasz et al., 2008) has been applied for both the gas and water for the four different surface relaxivity values of 1 um/sec, 10 um/sec, 50 um/sec and 100 um/sec. The data to the left of the vertical line is the relevant contribution from the fluids in the gas shale. [0013] FIGS. 8A-8D show T 1 -T 2 map of the Brine (irreducible state) and methane-saturated state for one of the gas shale plugs are shown. The T 1 -T 2 experiments enable the application of cutoffs in both the relaxation dimensions for the separation of the fluids. [0014] FIGS. 9A-9D show D-T 2 map of brine and gas saturated in 4 nm Vycor glass beads. The brine and gas contributions are well separated in the diffusion dimension even though they overlap in the relaxation dimension, exhibiting the potential of 2-D NMR D-T 2 experiments for such applications. A SEM picture of the Vycor porous glass (Mattea et al., 2004), is shown on the right panel. [0015] FIGS. 10A-10B show correlations between the T 2 distributions in the different gas shales with their clay, carbonate and total organic content and their surface to volume ratios. DESCRIPTION [0016] At the outset, it should be noted that in the development of any such actual embodiment, numerous implementation—specific decisions must be made to achieve the developer's specific goals, such as compliance with system related and business related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. In addition, the composition used/disclosed herein can also comprise some components other than those cited. In the summary of the invention and this detailed description, each numerical value should be read once as modified by the term “about” (unless already expressly so modified), and then read again as not so modified unless otherwise indicated in context. Also, in the summary of the invention and this detailed description, it should be understood that a concentration range listed or described as being useful, suitable, or the like, is intended that any and every concentration within the range, including the end points, is to be considered as having been stated. For example, “a range of from 1 to 10” is to be read as indicating each and every possible number along the continuum between about 1 and about 10. Thus, even if specific data points within the range, or even no data points within the range, are explicitly identified or refer to only a few specific, it is to be understood that inventors appreciate and understand that any and all data points within the range are to be considered to have been specified, and that inventors possessed knowledge of the entire range and all points within the range. [0017] The statements made herein merely provide information related to the present disclosure and may not constitute prior art, and may describe some embodiments illustrating the invention. [0018] We provide understanding of the measurement effects of gas shale through lab experiments and devise techniques to quantitatively log these unconventional plays in this application. We also determine the average hydrogen index of the gas in the gas shale pores under certain lab conditions and discuss how they can be used in downhole logs with NMR and other techniques for evaluating the hydrocarbon response. Thus in this invention we propose optimal ways of logging gas shales with T 2 , T 1 , T 1 -T 2 , DT 1 and DT 2 logs, interpretation techniques based on the hydrogen index and propose how they can be complimented with other logs like resistivity, dielectric, density and neutron, etc., for downhole fluid determination. [0019] We studied the NMR responses of water and methane in core plugs taken from a gas-shale formations and established methodologies for dealing with the formations. NMR T 2 , T 1 and diffusion data were acquired at pressure up to 5 kpsi on core plugs in their methane saturated, water saturated, centrifuged, then re-saturated with methane states, to study separately the effects of bound water and gas in nanopores. Hydrogen index of the gas is estimated from a few different methods including comparison of 100% water-saturated and 100% methane-saturated NMR porosities and comparison of gas filled NMR response with porosities obtained from conventional methods. The goals were to find better ways of obtaining NMR information downhole and their petrophysical applications and to also determine and use the hydrogen index for lab and downhole petrophysics. [0020] A methodology is used for optimal logging methods and interpretation in unconventional plays like gas shale for the gas, water and oil response. Application of NMR logging like T 1 , T 2 , T 1 -T 2 , DT 2 , DT 1 with optimized parameters are proposed for better logging of these reservoirs. A methodology for the acquisition of an average value for the hydrogen index of the gas in the gas shale under certain conditions has been proposed and its application in various downhole logs is discussed. Application of other techniques like dielectric, resistivity, density and neutron are used to compliment NMR for the determination of fluid volumes downhole is also discussed. [0021] Some embodiments may benefit from NMR tools including CMR, MRX, Magnetic Resonance Scanner, and/or ProVision commercially available from Schlumberger Technology Corporation of Sugar Land, Tex. Some embodiments may benefit from additional tools including AIT, RT Scanner, and/or the dielectric scanner commercially available from the Schlumberger Technology Corporation of Sugar Land, Tex. [0022] 1. NMR Relaxation Properties of Gas Molecules in Gas Shale [0023] The dominant mechanism of NMR relaxation in bulk methane is spin rotation. The basis of this mechanism is that when a molecule rotates, the motion of the electron cloud in the molecule generates a magnetic field at the position of the nuclei. The molecular rotations produce a time-dependent field at the nucleus, which is a small perturbation to the applied field, causing the relaxation of the nucleus (Abragam., 1961). In cases where the pressure of the bulk gas is increased, increased collisions between gas molecules occur and molecular rotations are disturbed. This reduces efficiency of the spin rotation mechanism and resulting in longer relaxation times. [0024] When the gas is confined in the nanopores of gas shales, the dominant mechanism of relaxation is no longer spin rotation but surface relaxation. The strong dipolar interaction of the gas molecules with paramagnetic impurities and protons of the kerogen, enhanced by the high surface-to-volume ratios, strongly influences the relaxation mechanism. As surface relaxation is a much stronger relaxation mechanism than spin rotation, this results in large reductions of the relaxation times from their bulk values. Another important phenomenon to be considered for gas at high pressure is that of adsorption on the pore surface. The behavior of methane adsorption on the surface of gas shale pores can be approximated by Langmuir isotherm behavior. This mechanism results in about a monolayer of methane being formed on the surface of the pores. Adsorbed gas has much shorter relaxation times than free gas due to the strong interaction with the pore surface. As FIGS. 1A-1B illustrate, the surface of the pore may have a higher density or concentration of gas as the gas interacts with the pore surface. Because the pore surface may be wet with hydrocarbon and/or have a higher pore surface area to pore volume than other formation types, some formation types that may benefit from processes described herein include shale, shale gas, coal, kerogen, or any hydrocarbon wet formation. [0025] The gas molecules in the kerogen nanopores are adsorbed or free at any given instant of time as shown in FIGS. 1A-1B . However, the two populations are in fast exchange with each other. Thus, the resulting relaxation can be expressed as [0000] 1 T i , eff = 1 - ɛ T i , free + ɛ T i , adsorbed , ( 1 ) [0026] where ∈ is the fraction of molecules in the adsorbed phase and 1−∈ the fraction of non-adsorbed molecules in the pore interior and i is 1 or 2 depending on weather we consider T 1 or T 2 . The net relaxation times inside the pores are dominated by surface relaxations and can also be expressed as [0000] 1 T i = 1 T i , bulk + ρ i  S V , ( 2 ) [0027] where i is 1 or 2 depending on weather we deal with T 1 or T 2 and ρ i the surface relaxivity and S/V the surface-to-volume ratio. In this case we have ignored the effect of any applied or internal gradients. The effect of applied and internal gradients, if present, would not have any impact on the longitudinal spin-lattice relaxation time T 1 but will affect T 2 . Thus the relation for T 2 in the presence of gradients, either internal or externally applied, is given by [0000] 1 T 2 , pore = 1 T 2 , bulk + ρ 2  S V + ( γ   G   T E ) 2  D 12 , ( 3 ) [0028] where the last term takes the effect of diffusion dephasing on T 2 into account. [0029] 2. NMR Diffusion Properties of Gas Molecules in Gas Shale. [0030] The diffusion dynamics for gas in gas shale is different from the bulk gas behavior. This is because the gas in gas shale exists in two phases, absorbed on the pore surface and the other as free gas in the pore interiors. The net diffusion coefficients are a sum of the contributions in both these phases and are modulated by their exchange. The free gas in the pores can exhibit the short or long time limit diffusion behavior depending upon the NMR diffusion encoding times used. The free gas diffusion can also be dominated by Knudsen or bulk diffusion characteristics depending upon weather the mean free path is larger or smaller than the pore diameters. The diffusion dynamics of the adsorbed gas might be mainly through the mechanism of thermal hopping on the surface. [0031] The diffusion coefficient of bulk gas is about 6×10 −8 m 2 /s at 30° C. and 5 kpsi, which is an order of magnitude greater than that of bulk water. The high diffusion coefficients of bulk gas can be exploited to separate gas from other fluids with lower diffusivity such as oil and water in 2D-NMR experiments. For the free gas phase, the mean squared displacement of the diffusing molecules acquire time dependence and the quantity defined by the Einstein relation above is referred to as the time-dependent diffusion coefficient. For short times, i.e., when the diffusion length scale is much smaller than the pore size scale, the diffusion coefficient is reduced from its bulk value D 0 by an amount proportional to the total surface-to-volume ratio S/V of the pore space (Mitra et al., 1993). [0000] D  ( t ) = D 0  [ 1 - 4 9  π  D 0  t  S V ] . ( 4 ) [0032] However, this regime is generally not encountered for gas diffusion in the kerogen pores of gas shales because the pore scales are very small in comparison to the root-mean-square displacements during diffusion encoding time. In the case of a connected pore system, the long time limit diffusion coefficient approaches the tortuosity limit given by [0000] D  ( t -> ∞ ) ≈ D 0 τ , ( 5 ) [0033] where τ is called the tortuosity of the medium and is related to the formation factor F and the porosity φ by [0000] r=Fφ   (6) [0034] In gas shale, the diffusion is in the tortuosity limit as the heterogeneity length scales are short compared to the root mean square displacements during NMR encoding time. We next consider the limiting cases of Fickian (bulk) and Knudsen diffusion regimes. The case of Fickian diffusion occurs when the molecule-molecule collisions are dominant due to the mean free path being smaller than the pore dimensions (λ<<d). On the other hand, Knudsen diffusion, occurs when the molecule-surface collisions are dominant due to the mean free path being larger than the pore dimension (λ>>d). In the tortuosity limit the two regimes are given by [0000] D k = D 0   k τ k , and   D b = D 0   b τ b , ( 7 ) [0035] where the subscript k denotes “Knudsen” and the subscript b denotes “Fickian or bulk”. Depending on the pore sizes in gas shales and the mean free path of the gas molecules, we could be in one of the above two regimes or in the transition regime between the two. Pore filling resulting from adsorption on the pore surfaces would decrease the effective diameter d and the Knudsen diffusion coefficient. [0036] The adsorbed gas phase on the pore walls can also have its own diffusion dynamics. The surface diffusion mechanism is known to play an important role in mass transport through porous media and is associated with thermally activated hopping. The net diffusion coefficient is a function of the exchange time and bulk and surface diffusion mechanisms. The net diffusion coefficient can be written as the sum of the diffusion in each phase weighted appropriately [0000] D eff =(1−∈) D gas +∈D ad   (8) [0000] where 1−∈ and ∈ are the respective fractions in the gas and adsorbed phases respectively, and D gas and D ad are the corresponding diffusion coefficients. [0037] 1. Experimental Setup and Methodology [0038] The NMR laboratory experiments were done on a 2.2 MHz Oxford Instrument's Maran-2 spectrometer. The spectrometer was also equipped with gradient coils enabling application of strong magnetic field gradients of up to 50 Gauss/cm axially along the bore. The pressure cell for holding the sample is designed such that that it can fit inside the magnet bore. The maximum pressure applied in our experiments was 5 kpsi. At the beginning of the experiment, a vacuum pump is attached to de-gas the entire setup. Oxygen, which is paramagnetic and thus could act as a strong relaxation agent even in small quantities, resulting in measurable reduction of the relaxation times of the methane gas, needs to be completely removed. Thus, care is taken to make sure that there is no oxygen present in the system when methane gas is measured. Once evacuated, 99.99% ultra pure methane is let into the system. This cycle of evacuation and injection of methane is repeated four times so that no trace of oxygen remains in the system. At the end of this process, the setup is filled with methane gas again and a hydraulic pump is used to compress the gas in the accumulator and the NMR cell. This results in high pressure gas in the NMR cell which can then be inserted into the magnet bore of the Maran spectrometer. The spectrometer also has temperature control capability with a range from 30° C. to 120° C. Heating is achieved by passing dry air through a heater from under the magnet and then passing the heated air onto the sample. A thermocouple is present close to the magnet bore to monitor the temperature of the sample. [0039] The experiments on gas shale were performed on four core gas shale samples. The samples of a foot in length were cut out from four different depths and Hassler size plugs (1.69 in.×0.69 in.) were drilled out of these cores. The samples were then preserved in sealed containers until they were used in the experiments. The gas shale plugs were inserted in a tight fitting PEEK container and placed in the NMR cell. Though the sample fits snugly in the PEEK container there was a small amount of gas trapped in the annulus between the sample and the holder, which is referred to as the dead volume henceforth. [0040] Spin-spin relaxation times or T 2 are measured using a Carr-Purcell-Meibolm-gill (CPMG) sequence. Both 2D-NMR experiments such as T 1 -T 2 and D-T 2 were also carried out on bulk gas and water/gas confined in the plugs. The pulse sequence used for T 1 -T 2 experiments consists of an inversion recovery period to encode for T 1 followed by the CPMG echo train to measure T 2 . For the D-T 2 experiments, pulse field gradients (PFG) were used for diffusion encoding. This is because the MARAN spectrometer has a homogenous magnetic field as opposed to the steady gradients found in downhole NMR tools. PFG-NMR technique involves the application of pulsed gradients (as opposed to the steady gradients) to non-invasively measure the ensemble average molecular mean square displacement of the spin bearing molecules of interest and has been extensively used to study diffusion of molecules in porous media. The applied gradients and the encoding times can be effectively adjusted to replicate the results that would be obtained using steady gradient diffusion logging on NMR downhole tools. The pulse gradients were varied from 0-50 G/cm in the axial direction. The sequence used here consists of two RF pulses, first the 90 and then the 180 each followed by a gradient pulse of 2.5 ms duration to encode diffusion. This sequence is then followed by the CPMG echo train of 5000 echoes to measure T 2 . The T 1 -T 2 experiments were carried out by applying an inversion recovery pulse sequence followed by the CPMG train. All data were processed using Inverse Laplace Transform to obtain 1D and 2D plots. Some embodiments may benefit from a pulse sequence selected for fast relation times such as the methods described in “Improved Precision Magnetic Resonance Acquisition: Application to Shale Evaluation” by Peter Hook, David Fairhurst, Erik Rylander, Rob Badry, Nate Bachman, Steve Crary, Kirck Chatawanich, and Tim Taylor, presented at the SPE Annual Technical Conference and Exhibition held in Denver, Colo. on Oct. 30-Nov. 2, 2011 by the Society of Petroleum Engineers available with the journal number SPE 146883, which is incorporated by reference herein. [0041] 2. Experimental Results [0042] 1. NMR Measurements of Bulk Gas [0043] We used pure methane gas for the experiments, which is a reasonable approximation for natural gas, since methane is a major component of natural gas. In our experiments, which are conducted at pressures from 1 kpsi to 5 kpsi and at a temperature of 30° C., methane exists as a supercritical fluid. The bulk methane gas at the pressure and the temperature conditions specified, is therefore not an ideal gas. [0044] Its physical properties, including the variation of relaxation times with pressure and temperature, have already been well characterized experimentally (Gerritsma et al., 1971). [0045] The measured T 2 distributions are shown in FIG. 3A . In FIG. 3B , the absolute values of T 2 corresponding to the maximum of the distributions are plotted as a function of pressure. The bulk methane gas T 1 values are equal to that of T 2 due to motional averaging and the peak is on the diagonal line as expected, in the T 1 -T 2 plot shown in FIG. 4A . The D-T 2 map is shown in FIG. 4B . The diffusion coefficient of bulk methane gas at 5 kpsi and 30° C. is 6×10 −8 m 2 /s, which is more than an order of magnitude greater than that of bulk water at the same temperature. [0046] 2. NMR T 2 Measurements of Gas Filled Shale Plugs [0047] We next investigated the relaxation dynamics of methane inside the gas shale samples. Hassler size plugs (1.69 in.×0.69 in.) were drilled out of these cores for the measurements. The samples were then heated to 60° C. under vacuum overnight to remove any trace moisture in them. Methane gas at 5 kpsi was injected into the samples and the T 2 relaxation times of the completely gas saturated samples were measured. The results of the methane relaxation times for all the four plugs are shown in FIGS. 6A-6D . Because of the very low permeability, T 2 measurements were carried out periodically until there was no change in the T 2 spectrum, indicating attaining equilibrium state. The samples were then evacuated and taken out for pressure saturation with brine. Saturation of the plugs with brine at 250 ppk to avoid clay swelling was carried out over a 24 h period at 1.2 kpsi. T 2 distributions of the brine saturated samples are shown in FIGS. 5A-5D . [0048] The samples were centrifuged at 340 psi (irreducible state) and the T 2 distributions measured are shown in FIGS. 6A-6D . Next, methane gas was injected into the plugs (which are at irreducible state), and the gas pressure maintained at a value of 5 kpsi. The T 2 experiments were done at 30° C. with long wait times of 30 s, inter-echo times of 0.4 ms and 15000 echoes. The results are shown in FIGS. 6A-6D . The relevant part of the distribution is from 0.1 ms to 100 ms and is the important fraction for job planning and anything larger than 100 ms is from the larger length scales and the annulus dead volume between the sample and the peek sample holder. The gas T 2 distribution is peaked around 10 ms and the bound water is peaked about 1 ms. [0049] 3. D-T 2 of Gas in Gas Shale Plugs [0050] 2D NMR D-T 2 results of the gas shale samples are shown in FIGS. 7A-7D . The reduction in diffusion coefficients is caused by restricted diffusion and surface adsorption. The restricted diffusion lines for gas (dash) and water (dash) without taking adsorption into account (Zielinski et al., 2008), has been plotted for different surface relaxivities. The experiments were carried out with wait times of one second, which is sufficient to completely polarize the methane inside the gas shale plugs (the species of interest) but not the free gas in the dead volume. [0051] 4. T 1 -T 2 of Gas in Gas Shale Plugs [0052] 2D-NMR T 1 -T 2 experiments of the gas in gas shale and of the BFV for Sample#1 is shown in FIGS. 8A-8B . The 2D NMR experiments enable the application of cutoffs in both the relaxation dimensions (T 1 and T 2 ) and thus lead to better separation of the fluids. [0053] 5. NMR Measurements on Vycor [0054] To understand the effects of adsorption and surface relaxation in the organic kerogen pores, experiments were also carried out on methane gas confined in Vycor porous glass, for the purpose of comparison. The Vycor porous glass is made up of pure silicon oxide and has a known pore size of 4 nm which is comparable to the smallest pore sizes encountered in gas shales. The pulse sequence parameters such as wait times and inter-echo times were kept the same as in the case of the gas shale samples. It is interesting to note that relaxation time of the gas molecules restricted inside the pores of the Vycor glass sample are peaked at around 100 ms, which is 10 times longer than in the case of methane in the gas shale samples. The relaxation distribution for the fluids in the Vycor porous glass is narrow, reflecting the homogeneous 4 nm pore size of the sample. Note that the gas and water T 2 distributions overlap and thus cannot be separated in the relaxation dimension. Though both water and gas have lower diffusion coefficients compared to their respective bulk values due to restricted diffusion, they are well separable in the diffusion dimension. Hydrogen Index Measurement [0055] The nuclear magnetic resonance (NMR) lab and logging tools measure signal amplitude which is proportional to the density of hydrogen nuclei of the sample. In order to obtain sample quantities (e.g., volumes and eventually porosities) the hydrogen index has to be known. Different fluids have different Hydrogen indices and they also vary as a function of temperature and pressure. The Hydrogen index of formation water and different crude oils have been tabulated for different conditions. Natural gas in bulk like state tends to have a significantly lower hydrogen index whose dependence on pressure and temperature is known in prior art. But for natural gas in unconventional plays like gas shales and coal bed methane or other tight gas plays it is challenging to obtain the hydrogen index at specific pressures and temperatures existing downhole. [0056] If the quantity of fluids in the rock is known then the porosity (fluid volume/rock volume) can be determined. Traditionally the NMR tools have been calibrated to 100% porosity with water at the surface, whose hydrogen index is assigned a value of one. NMR porosity logs can therefore be obtained downhole, by comparing the measured T 2 response for each fluid with the calibrated 100% porosity. [0057] Here we consider only the case where the reservoir fluids are the irreducible water and gas. In the case of some oil (base or invaded) being present the same analysis can be extended. The NMR determined porosity in this case is given by [0000] φ MR =HI w V w (1− e −p/T 1w )+HI g V g (1− e −p/T 1g )  (9) [0000] where HI w and HI g are the hydrogen index of the water and gas phase, V w and V g are the respective volumes, p the wait time, T 1 the spin lattice relaxation time and 1−e −P/T1 takes care of the insufficient polarization times. Eqn (1) can be rewritten as [0000] φ MR =(1− S g )φ(1− e −p/T 1w )+HI g S g φ(1− e −p/T 1g )  (10) [0058] where S g is the gas saturation and φ is the actual porosity, i.e., the volumetric fraction of the rock that is pore space. In the case of complete polarization of the spins the NMR measured porosity is given by [0000] φ MR =HI w (1− S g )φ+HI g S g φ. [0059] The above equation can also be written as φ MR =φ MR(water) +φ MR(gas) . In the above equation both the water saturation (S w =1−S g ) and the hydrogen index are unknown. If the gas and water contributions can be separated in the T 2 or T 1 dimension then the water saturation can be determined. But it has been shown that there can be significant overlap making this separation difficult in many cases. To overcome this problem and determine the water saturation many different logging techniques can be used in combination, as will be discussed below. If the water saturation can thus eventually be determined then the apparent NMR gas filled porosity can be expressed as [0000] φ MR(gas) =HI g S g φ.  (12) [0060] Therefore, knowledge of the gas phase hydrogen index (obtained from knowledge formation temperature and pressure, and the known equation of state of natural gas) and the actual porosity (generally obtained from other well logs) connects apparent NMR gas-filled porosity with gas saturation. [0061] Hydrogen index is therefore a very important petrophysical parameter measurement as it is necessary for obtaining gas volumes. In the case of bulk natural gas (e.g., as found in conventional reservoirs) the Hydrogen index is easy to calculate if the pressure and temperature and gas composition are known. But for gas in shales or other tight rocks where the gas exists in free and adsorbed form determining the hydrogen index is more challenging. This is because the Hydrogen index of the adsorbed gas would be higher than the gas in the pore interiors and its dependence on pressure and temperature is difficult to accurately quantify. The free and adsorbed gas phases are also in exchange with each other. Therefore given the challenge and importance of determining the hydrogen index we discuss a few methods of determining the gas hydrogen index. 1. The HI can be determined in the lab under the same conditions as found downhole and then applied for log interpretation or for lab experiments. One methodology is the calculation of the hydrogen index from the T 2 distributions of the completely water-saturated and gas-saturated samples, under the conditions that the same pore spaces are occupied by either phase during their respective measurements. As the hydrogen index of water is known simply comparing the gas and water NMR T2 distributions, the HI of gas can be determined. For obtaining the hydrogen index at specific downhole conditions, the gas phase NMR experiments have to be carried out at those same conditions. Instead of water, other solvents (e.g., toluene) which are better in saturating the gas shales can also be used. [0063] The results of one such experiment are summarized in Table 1. Note that the calculated HI is the weighted average across all pores in the sample. The calculated HI are substantially higher than that of bulk methane at 5 kpsi and 30° C. (HI˜0.42) in this case. The average HI of the 4 samples in this particular example is 0.735, and is higher than the HI of bulk methane at the same pressure and temperature. [0000] TABLE 1 The HI results of the 4 gas shale core samples. Gas Shale Sample Hydrogen index (HI) Sample #1 0.71 Sample #2 0.86 Sample #3 0.73 Sample #4 0.64 2. The hydrogen index can be calculated by comparing gas filled NMR signal (at conditions similar to those downhole) of dried cores or cuttings with porosity. As the samples are dry the only fluid is the injected gas which completely saturates the sample and thus the hydrogen index is determined as shown in eqn 12. The methods of conventional determination of porosity include but are not limited to commercially available laboratory techniques/instruments like GeoPyc and AccuPyc. 3. The hydrogen index is even more accurately calculated by carrying out the experiment detailed above for samples in their irreducible state. These experiments can be carried out on both cores and cuttings. The irreducible state can obtained by either using well preserved cores or by creating them in the lab by saturation and centrifuging. The total porosity is the sum of the gas filled and water filled porosities. The water filled porosity can be calculated first by NMR experiments of the preserved samples or in the samples where the irreducible state is created. The gas filled remaining porosity of these samples in the irreducible state is then measured by other techniques (e.g., using pycnometer). This gas filled porosity is then compared to the NMR gas filled T 2 distribution (after the water contributions are subtracted) and the hydrogen index is determined. 4. The above mentioned experiments for the determination of the hydrogen index can also be carried out on drill cuttings. Just as in core samples the drill cutting samples can be measured for the NMR response of the irreducible state. The gas can then be pushed in at conditions similar to downhole and the gas phase NMR experiments carried out on them either in laboratory or at the wellsite. The NMR of the irreducible water and gas phase can be compared to independently obtained porosity and thus the HI determined. 5. Methods like dielectric are capable of measuring the water saturations and volumes. When combined with traditional porosity measurements and gas phase NMR they can help provide the hydrogen index. 6. Creation of a HI versus pressure chart: the hydrogen index measured in the lab has to be under the same conditions (temperature, pressure, etc.) as downhole. The experiments have to also be carried out for samples from each depth as due to the pore size distributions, geometries and type the free and adsorbed gas fractions might differ and so will the hydrogen index and its dependence on pressure and temperature. But in cases where there is no drastic change in the pore seizes and type the hydrogen index can be determined for one sample for various temperatures and pressures and this chart could be used for the entire well. [0069] Some embodiments may benefit from the following procedure. The laboratory methods show higher hydrogen index (due to higher density) than the known low HI for the gas in bulk state at the same conditions. For example, in our lab experiments on 4 different gas shale plugs the Hydrogen index measured for the gas in the kerogen are 0.71, 0.86, 0.73 and 0.64 at 5000 psi and 30° C. Thus determination and application of the hydrogen index for NMR and other petrophysical measurements can be carried out. The methods and applications include the following. 1. Gas phase NMR and comparison with water or solvent saturated NMR. 2. Gas phase NMR of dry core and cuttings and its comparison with porosity. 3. Gas phase NMR and porosity determined on samples in irreducible water saturations. 4. Carrying out all the above mentioned experiments on drill cuttings. 5. Determine water saturations from other techniques like dielectric and then along with total porosity obtaining the HI from the NMR data. 6. Creation of a HI chart. [0076] Methods to separate the water and gas contributions: a. NMR (1D or 2D methods like DT2, T1T2 or from T1 and T2) can be used. b. Spectral deconvolution can be sued to aid the process. c. dielectric, d. resistivity e. Cutting and core analysis are additional techniques for such applications. f. Either in combination or by themselves. Obtaining the Natural Gas Composition: [0083] As proton NMR responds to only the hydrogen atoms in the gas, we need the accurate gas composition for the proper application and interpretation of the laboratory and downhole NMR measurements. Dry natural gas is mostly methane, but for wet gas the correct gas compositional analysis is important. A few ways of determining the compositional information include: 1. Mud Logging: While a well is being drilled, the drilling mud is monitored continuously for gases released. Gases are measured quantitatively by gas chromatography or other means, and associated with a particular depth interval by standard means. One example is Fluid Logging and Analysis in Real Time (FLAIR) offered by GeoServices which is owned by and commercially available from Schlumberger Technology Corporation of Sugar Land, Tex. FLAIR provides a quantitative analysis of C 1 -C 5 and qualitative information on the C 6 -C 8 components and light aromatics. As only lower carbon numbers are important for obtaining of gas composition, this is ideal for such analysis. a. DFA (Downhole Fluid Analysis): DFA is used for characterizing the distribution of reservoir-fluid properties downhole. The DFA technique is based largely on optical spectroscopy and provides hydrocarbon composition in five groups: methane (C 1 ), ethane (C 2 ), propane to pentane (C 3 -C 5 ), hexane and heavier hydrocarbons (C 6+ ), and carbon dioxide (CO 2 ). b. Standard fluid analysis: Laboratory fluid analysis of the released gas or from production data or information/analysis in offset wells. [0087] Some embodiments may benefit from the following methods for obtaining the natural gas composition. As proton NMR responds to only the hydrogen atoms in the gas we need the accurate gas composition for the lab experiments explained above. Dry natural gas is mostly methane, but for wet gas the correct gas compositional analysis is important. A few ways of determining the compositional information include: a. Mud logging. b. DFA. c. Standard fluid analysis. d. Production data or from offset wells. Applications of the Hydrogen Index: [0092] The multi fluid, multi mineral inversion models like the Schlumberger standard ELAN models are based on density of the formation fluids and the matrix. ELAN is a non-deterministic petrophysical analysis package available from Schlumberger Technology Corporation of Sugar Land, Tex. The density of the gas phase is thus an important parameter for interpreting various downhole logs. Once the hydrogen index of the gas phase is obtained it can be converted into a gas phase density and can be used for the various other petrophysical measurement interpretation. Some embodiments may benefit from applications of the hydrogen index such as petrophysical applications which include but are not limited to [0093] a. Density logging: The hydrogen index determined form the lab experiments can be converted into a density and used for density log interpretation. [0094] b. Neutron logging: The hydrogen index determined from the above mentioned NMR lab experiments can be directly used for neutron log interpretation. [0095] Some examples other than NMR include: [0096] Neutron Logs: [0097] Neutron tools are sensitive to the formation hydrogen index as they respond strongly to neutron scatterers. Protons are good neutron scatterers, so in general the neutron tools are sensitive to the protons—i.e., the hydrogen index. Therefore determining the hydrogen index from the above mentioned NMR experiments we can directly apply them to the neutron logs for their petrophysical evaluation. [0098] Density Measurements: [0099] The density log responds to the electron density of the formations. The electron density depends on the bulk density of the formation which depends on the density of the rock matrix material, the density of the formation fluids and porosity. Thus the actual density of the gas in the unconventional reservoirs at downhole conditions in an important input. Normally this is known for bulk gas if the temperature and pressure and gas compositions are known. But for unconventional plays they can be obtained from the hydrogen index, which is in turn determined using the NMR based measurements detailed above. [0100] Correlation of NMR Relaxation Distributions with Material Properties: [0101] The absolute value of the gas relaxation times can be correlated to the lithology (Organic kerogen or carbonate content, etc.) in laboratory experiments or from logs as shown in FIGS. 10A-10B . Therefore this correlation can be used to determine the lithology from NMR relaxation logs or core data or vice versa. The T 2 distributions can also be sued to obtain the surface to volume ratios and thus the pore size distributions once the surface relaxivity of the shales are determined. The volume of gas determined from the NMR gas logs can be correlated to the TOC and thus can be used to provide an NMR derived TOC log. [0102] Overlapping Gas and Water Signals [0103] NMR logs downhole might have overlapping water and gas signals. If the water contribution is separated then the gas volumes can be calculated using the gas hydrogen index. To separate the water contribution a number of techniques can be used. Some of them include 1. NMR Measurements: [0104] If the gas and water contributions can be separated in the T 2 dimension then the gas saturation factor (S g =1−S w ) can be calculated. But in magnetic resonance T 2 logs, water and gas signals from gas shale will often overlap and thus φ MR(water) cannot be easily determined. This has been shown to be true even though the irreducible water magnetic relaxation time peaks at 1 ms and gas magnetic relaxation time peaks at 10 ms. Even if the water and gas signals are resolvable in laboratory T 2 measurements, this can be a challenge downhole because of the low signal-to-noise ratio due to low porosity of gas shale reservoirs (Kausik et al., 2011). Other NMR measurements like D-T 2 and T 1 -T 2 experiments maybe used for the separation of the water and gas contributions. [0105] NMR D-T 2 measurements can be applied for the better resolution of the water and gas signals, especially in situations where there is significant overlap in the relaxation dimension. As an example, D-T 2 experiments on Vycor porous glass (4 nm narrow pore size distribution) is shown. Note that the gas and water T 2 distributions overlap and thus cannot be separated in the relaxation dimension. Though both water and gas have lower diffusion coefficients compared to their respective bulk values due to restricted diffusion, they are well separable in the diffusion dimension (Kausik et al., 2011). The oil if present would also be clearly be differentiated from the other contributions by falling on the alkane line. [0106] NMR T 1 -T 2 correlation experiments can also be carried out for the separation of the irreducible water and confined gas components. This is based on the premise that the T 1 /T 2 ratio of the irreducible water is different from that of the confined gas and thus cutoffs in both the dimensions would help in their better separation. [0107] Spectral deconvolution: Spectral deconvolution techniques can be applied to separate the gas and water contributions from the various T 2 , D t -T 2 and T 1 -T 2 experiments. 2. Resistivity Measurements: [0108] In clean sands, applying resistivity measurements is fairly straightforward, but source rocks are challenging. A number of models exist for determining the water saturations especially in shaly sand. These can be broadly separated to those approaches based on V-Shale (resistivity models) or Cation exchange (conductivity models). Some of these models (e.g., Simandoux model and Modified Simandoux model) have been applied successfully for the determination of water volumes in gas shale and other unconventional reservoirs. 3. Dielectric Measurements: [0109] Dielectric logs are another method to obtain the water volumes. The dielectric constant method has been tested in oil shales. It has been found to give reliable results for water saturation in the presence of clays, various other minerals, and kerogen [Seleznev et al., 2011]. Inorganic minerals, kerogen, and gas all have low permittivity, see and thus they all appear to be part of the “matrix” (grain space), in contrast to water, which has a very high permittivity. [0110] Gas response can then be determined using [0000] φ MR(gas) =φ MR −φ diel (water)  (18) [0000] where φ MR is a total magnetic resonance porosity (e.g., TCMR) and φ diel (water) is the water-filled porosity as determined by a dielectric logging tool. Some of the challenges with the dielectric response include those of OBM (Oil Based Mud) and the presence of clays. Just as in the case of resistivity, existing and newly developed models can be applied to interpret the dielectric data for water saturation in gas shale. 4. Cuttings Analysis: [0111] During drilling process, rock debris is carried up from the bottom of the well to the surface by the recirculation of the drilling fluid. Such debris also called cuttings are inspected at the well site by geologists and petrophysicists to determine drilling process and estimate rock properties like composition and microstructure as a function of drilling depth. Drill cuttings are inspected at the well site by geologists and petrophysicists to determine drilling process and estimate rock properties like composition and microstructure as a function of drilling depth. NMR experiments to determine the residual water, NMR gas phase experiments for determining gas relaxation and diffusion properties can be carried out on these samples to provide depth dependent information. Analysis (using NMR or other techniques like density, resistivity, dielectric, etc.) of the drill cuttings can be carried out after letting the gas out to determine the water volumes. Additional cuttings analysis techniques are provided by U.S. patent application Ser. No. 13/447,109, entitled, “Reservoir And Completion Quality Assessment In Unconventional (Shale Gas) Wells Without Logs Or Core,” filed on Apr. 13, 2012, which is incorporated by reference herein. 5. Core Analysis: [0112] Cores drilled from the formation can be preserved and examined in the lab for the estimation of the irreducible water content. If the gas could escape leaving the water behind then the NMR response of the core can be used to determine the water volume. But maintaining the core with the downhole water saturations can be challenging. Thus an alternative is to saturate the core with brine (same as the formation salinity) and then centrifuge it to the pressures to result in irreducible water saturations as expected downhole. Measuring the NMR such samples helps in the estimation of the water filled porosity. This methodology works well for unconventional plays like gas shale where the water is mainly present at irreducible state. NMR Logging in Gas Shales [0113] The relaxation times (T 2 and T 1 ) of the gas in the (nano-micrometer) pores of the gas shale have been found to be short compared to those in conventional reservoirs. Therefore the presence of gas in gas shale can be identified in the NMR logs when acquired with appropriate pulse sequences. The relaxation (T 2 and T 1 ) window can be determined through laboratory measurements on cores specific to the reservoir at in situ conditions. Alternatively, the relaxation (T 2 and T 1 ) window can be determined from the NMR response of the gas bearing zone in the NMR logs of the reservoir. For example in our lab experiments on gas shale plugs the T 2 's are peaked about 8-15 ms and T 1 's at about 20-40 ms respectively at 5000 psi and 30° C. [0114] The relaxation times (T 2 and T 1 ) of the bound water in the gas shales have been identified to be very short and thus the bound fluid volume can be identified in the NMR logs when acquired with appropriate pulse sequences. The relaxation (T 2 and T 1 ) times for the BFV can be determined through laboratory measurements on cores/cuttings specific to the reservoir at insitu conditions and/or can be determined from the NMR response of the BFV in the NMR logs of the reservoir. For example in our lab experiments on gas shale plugs the BFV T 2 's are peaked about 0.5-2.5 ms. [0115] The diffusion coefficients of the gas in gas shale plays are reduced from those in formations where the gas is in bulk state. The diffusion coefficients of the gas in gas shale can be determined through laboratory measurements on cores/cuttings specific to the reservoir at insitu conditions and/or can be determined from the NMR response of the gas in the NMR logs of the reservoir. For example in our lab experiments on gas shale plugs, the reduction is by about a factor of 5 at 5000 psi and 30° C. [0116] The diffusion coefficients of the BFV in gas shale plays are reduced from that in formations where the water/brine exists in bulk state. The diffusion coefficients of the BFV in gas shale can be determined through laboratory measurements on cores specific to the reservoir at in situ conditions and/or can be determined from the NMR response of the BFV in the NMR logs of the reservoir. [0117] Relaxation— [0118] Conventional NMR fluid typing modes focus on gas in the free fluid region with long T 1 and T 2 relaxation times. In gas shales, we have shown that T 2 has the values of few tens of milliseconds. Therefore, the NMR acquisition parameters in gas shales should focus on the shorter relaxation times. Even though it has been shown that the gas HI in gas shales is more favorable than the gas HI in conventional reservoirs, pulse sequences have to address the low SNR, inherent to low porosity. A SNR greater than 20 is recommended for NMR logging in gas shales. One way to achieve this goal is to stack repeated data obtained from pulse sequences with just long enough WT to polarize up to T 2 ˜100 ms, and with high sensitivity to low T 2 region (0.1 ms-50 ms) by using short bursts and the smallest possible inter-echo time. Therefore NMR pulse sequences with short recycle delays to cover the short relaxation times can be carried out enabling the application of more scans for the same time as conventional logging to overcome the signal to noise ratio issue encountered in these low porosity plays. [0119] Diffusion— [0120] The reduction in the diffusion coefficients caused by restricted diffusion in small pores and adsorption on the pore surface has been quantified by our laboratory experiments. This information can be used to determine the appropriate diffusion encoding times for the downhole NMR tools in for gas shale plays. Typically experiments can be carried out with gas phase at downhole pressure and temperature to determine the NMR logging parameters for each well or depth. This is especially important as the T 2 's are short in these plays and thus application of most conventional diffusion encoding times would result in the loss of signal. Method Considerations [0121] The relaxation properties that have been discovered enable the formulation of new 1D-T 1 or T 2 pulse sequences targeting the gas and water response in gas shale. For example, from our experiments on gas shale plugs we propose for that reservoir new pulse sequences consisting of more number of scans (˜50) covering the 0-50 ms with shorter wait times of around 250 ms to focus on the gas in kerogen and BFV contributions. These help provide higher accuracy and optimum SNR (>20) for better resolution at the shorter relaxation times. The relaxation and diffusion properties of fluids in gas shale that have been discovered enable the application of new 2D T 1 -T 2 or DT 2 or DT 1 or other multi dimensional NMR pulse sequences targeting the gas and water response in gas shale. For example, these new pulse sequences would consist of more number of scans at short wait times for improved measurement of the fast relaxing components as explained earlier. In combination, the right diffusion encoding times can be chosen to better cover the gas diffusion (e.g., in core samples: 1·10 −7 to 1·10 −9 m 2 /s@ 5000 psi and 30° C.) and water diffusion coefficients. Special diffusion encoding times based D-T 2 pulse sequences are necessary to enable optimized logging to efficiently measure the short T 2 contributions as the diffusion properties can be used to tune the parameters for diffusion encoded pulse sequences downhole. For example, as the gas T 2 is peaked at 10 ms for some of the gas shales studied the encoding times would be far shorter to avoid loss of these signals due to relaxation. [0122] The study of the relaxation and diffusion properties of the gas in gas shale using specialized pulse sequences enable the separation of the gas in the kerogen from the gas in the large pores/fractures of the matrix. [0123] The special laboratory relaxation and diffusion experiments devised for gas shales enable the application of field based cut-offs in both the dimensions in the DT 2 or T 1 T 2 or DT 1 or other multidimensional NMR logs. The cutoffs can be determined through laboratory measurements on cores or cuttings specific to the reservoir at insitu conditions and/or can be determined from the NMR response of the logs of the reservoir. For example, from our lab experiments on gas shale the T 2 and T 1 cutoffs for the gas in kerogen are about 50 ms and 100 ms respectively at 5000 psi and 30° C. 1. We can interpret the lithology type, size of the pores and adsorbed gas based on the relaxation time of the gas relative to the response of bound water. For example the absolute value of the T 2 of the confined gas is about 100 ms for silica glass with 4 nm pores, about 8-15 ms for gas in gas shale samples. With increased adsorption and increase of small kerogen pores, the relaxation times are reduced. 2. The absolute value of the gas relaxation times can be correlated to the lithology (Organic kerogen or carbonate content, etc.) in laboratory experiments or from logs. Therefore this correlation can be used to determine the lithology from NMR relaxation logs or core data or vice versa. 3. The quantity of gas determined from the NMR gas logs can be correlated to the TOC and thus can be used to provide an NMR derived TOC log.

Apparatus and methods for characterizing hydrocarbons in a subterranean formation including sending and measuring NMR signals; analyzing the signals to form a distribution; and estimating a property of a formation from the distribution, wherein the sending comprises pulse sequences configured for a formation pore size, and wherein the computing comprises porosity. Apparatus and methods for characterizing hydrocarbons in a subterranean formation including sending and measuring NMR signals; analyzing the signals to form a distribution; and estimating a property of a formation from the distribution, wherein the formation comprises a distribution of pore sizes of about 10 nm or more, and wherein the computing comprises natural gas composition.

CROSS REFERENCE TO RELATED APPLICATIONS The present application is a continuation application under 35 U.S.C. §120 of U.S. patent application Ser. No. 13/795,963, filed on Mar. 12, 2013, entitled SURGICAL STAPLING DEVICE WITH A CURVED CUTTING MEMBER, now U.S. Patent Application Publication No. 2013/0186934, which is a continuation application under 35 U.S.C. §120 of U.S. patent application Ser. No. 11/652,169, filed on Jan. 11, 2007, entitled SURGICAL STAPLING DEVICE WITH A CURVED CUTTING MEMBER, now U.S. Patent Application Publication No. 2008/0169332, the entire disclosures of which are hereby incorporated by reference herein. The subject application is also related to six co-pending and commonly-owned applications filed on Jan. 11, 2007, the disclosure of each is hereby incorporated by reference in their entirety, these six applications being respectively entitled: (1) U.S. patent application Ser. No. 11/652,166, entitled SURGICAL STAPLING DEVICE HAVING SUPPORTS FOR A FLEXIBLE DRIVE MECHANISM, now U.S. Patent Application Publication No. 2008/0169331; (2) U.S. patent application Ser. No. 11/652,165, entitled SURGICAL STAPLING DEVICE WITH A CURVED END EFFECTOR, now U.S. Patent Application Publication No. 2008/0169330; (3) U.S. patent application Ser. No. 11/652,188, entitled APPARATUS FOR CLOSING A CURVED ANVIL OF A SURGICAL STAPLING DEVICE, now U.S. Pat. No. 7,434,717; (4) U.S. patent application Ser. No. 11/652,164, entitled CURVED END EFFECTOR FOR A SURGICAL STAPLING DEVICE, now U.S. Patent Application Publication No. 2008/0169329; (5) U.S. patent application Ser. No. 11/652,423, entitled BUTTRESS MATERIAL FOR USE WITH A SURGICAL STAPLER, now U.S. Patent Application Publication No. 2008/0169328; and (6) U.S. patent application Ser. No. 11/652,170, entitled SURGICAL STAPLER END EFFECTOR WITH TAPERED DISTAL END, now U.S. Patent Application Publication No. 2008/0169333. BACKGROUND 1. Field of the Invention The present invention generally relates to surgical staplers, and, more particularly, to surgical staplers having a curved end-effector and to surgical techniques for using the same. 2. Description of the Related Art As known in the art, surgical staplers are often used to deploy staples into soft tissue to reduce or eliminate bleeding from the soft tissue, especially as the tissue is being transected, for example. Surgical staplers, such as an endocutter, for example, often comprise an end-effector which is configured to secure the soft tissue between first and second jaw members. The first jaw member often includes a staple cartridge which is configured to removably store staples therein and the second jaw member often includes an anvil. In use, the staples are typically deployed from the staple cartridge by a driver which traverses a channel in the staple cartridge. The driver causes the staples to be deformed against the anvil and secure layers of the soft tissue together. Often, as known in the art, the staples are deployed in several staple lines, or rows, in order to more reliably secure the layers of tissue together. The end-effector may also include a cutting member, such as a knife, for example, which is advanced between two rows of the staples to resect the soft tissue after the layers of the soft tissue have been stapled together. The end-effectors of previous endocutters are often configured to deploy staples in straight lines. During many surgical techniques, such as the resection of stomach tissue, for example, such a linear deployment is often preferred. During these techniques, the end-effector is typically inserted through a cannula to access the surgical site and, as a result, it is often desirable for the end-effector to have a linear configuration that can be aligned with an axis of the cannula before the end-effector is inserted therethrough. However, in some circumstances, end-effectors having such a linear configuration are somewhat difficult to use. More particularly, for example, when the end-effector must be placed adjacent to or against a cavity wall, such as the thoracic cavity wall, for example, it is often difficult for the surgeon to position a jaw of the end effector behind delicate or fragile tissue which is proximal to and/or attached to the cavity wall. Furthermore, even if the surgeon is successful in positioning a jaw behind the tissue, owing to the linear configuration of the end-effector, the surgeon may not be able to see the distal end of the end-effector. In some circumstances, endocutters having a curved end-effector have been used for accessing, stapling and transecting tissue. These end-effectors typically include curved anvils and staple cartridges which co-operate to deploy the staples in curved rows. To deploy the staples in this manner, the staple driver and the cutting member can be moved through a curved path by a flexible drive member. However, owing to the amount of force that is typically transmitted through the flexible drive member, the drive member may buckle or otherwise deform in an unsuitable manner. Furthermore, previous curved end-effectors are configured such that the distal ends of the jaw members are the last portions of the jaw members to contact the soft tissue. As a result, tissue may escape from between the jaw members before the jaw members are completely closed. What is needed is an improvement over the foregoing. SUMMARY In various embodiments, an end effector for use with a surgical instrument is disclosed comprising a linear portion, a first jaw, and a second jaw moveable relative to the first jaw, wherein one of the first jaw and the second jaw comprises a plurality of staple cavities arranged in a plurality of curved staple cavity rows, and wherein the curved staple cavity rows curve in a first direction. The end effector further comprises a curved path extending between two curved staple cavity rows of the plurality of curved staple cavity rows, wherein the curved path curves in the first direction, and a drive assembly extending along at least a portion of the linear portion, wherein the drive assembly comprises a cutting element structured to travel along the curved path, wherein the cutting element comprises a distal pre-biased cutting edge structured to lead the cutting element in the first direction. In various embodiments, an end effector for use with a surgical instrument is disclosed comprising a linear portion, a first jaw, and a second jaw moveable relative to the first jaw, wherein one of the first jaw and the second jaw comprises a plurality of staple cavities arranged in a plurality of curved staple cavity rows, and wherein the curved staple cavity rows curve in a first direction. The end effector further comprises a curved slot extending between two curved staple cavity rows of the plurality of curved staple cavity rows, wherein the curved slot curves in the first direction, and a drive assembly extending along at least a portion of the linear portion, wherein the drive assembly comprises a cutting element structured to travel along the curved slot, wherein the cutting element comprises a distal pre-biased cutting edge structured to guide the cutting element toward the first direction. In various embodiments, an end effector for use with a surgical instrument is disclosed comprising a linear portion, a first jaw, a second jaw moveable relative to the first jaw, wherein one of the first jaw and the second jaw comprises a plurality of staple cavities arranged in a plurality of curved staple cavity rows, and wherein the curved staple cavity rows curve in a first direction. The end effector further comprises a curved path extending between two curved staple cavity rows of the plurality of curved staple cavity rows, wherein the curved path curves in the first direction, and a flexible drive assembly extending along at least a portion of the linear portion, wherein the flexible drive assembly comprises a cutting element structured to travel along the curved path, wherein the cutting element comprises distal means for leading the cutting element in a predisposed direction, and wherein the predisposed direction corresponds to the first direction. BRIEF DESCRIPTION OF THE FIGURES The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: FIG. 1 is a schematic of an endocutter being used to transect and staple tissue; FIG. 2 is a partial cut-away view of the endocutter of FIG. 1 ; FIG. 3 is a partial cross-sectional view of the endocutter of FIG. 2 taken along line 3 - 3 in FIG. 2 ; FIG. 4 is a perspective cut-away view of the endocutter of FIG. 2 ; FIG. 5 is a bottom view of the anvil of the endocutter of FIG. 2 ; FIG. 6 is a schematic view of staples being deployed from the staple cartridge of the endocutter of FIG. 2 by a staple driver; FIG. 7 is a schematic view of staples being deployed from the staple cartridge of FIG. 2 where the staple driver has been advanced within the staple cartridge with respect to its position in FIG. 6 ; FIG. 8 is a perspective view of the cutting member and drive bar of the endocutter of FIG. 2 ; FIG. 9 is a schematic of an opened thoracic cavity; FIG. 10 is a schematic of an endocutter having a curved end-effector in accordance with an embodiment of the present invention being positioned against the side wall of a thoracic cavity; FIG. 11 is a perspective view of the endocutter of FIG. 10 illustrated in a closed configuration and positioned about a pulmonary artery; FIG. 12 is a perspective view of the end-effector of the endocutter of FIG. 11 ; FIG. 13 is a top view of the staple cartridge of the end-effector of FIG. 12 ; FIG. 14 is a bottom view of the jaw configured to support the staple cartridge of FIG. 13 ; FIG. 15 is a perspective view of the cutting member and staple driver of the endocutter of FIG. 2 ; FIG. 16 is a top view of the cutting member and staple driver of FIG. 15 ; FIG. 17 is a top view of a cutting member and staple driver in accordance with an embodiment of the present invention; FIG. 18 is a perspective view of an endocutter having a curved end-effector in accordance with an alternative embodiment of the present invention; FIG. 19 is a top view of the staple cartridge of the end-effector of FIG. 18 ; FIG. 20 is a perspective view of an endocutter having a curved end-effector in accordance with an alternative embodiment of the present invention; FIG. 21 is a top view of the staple cartridge of the end-effector of FIG. 20 ; FIG. 22 is a perspective view of an endocutter having a curved end-effector in accordance with an alternative embodiment of the present invention; FIG. 23 is a top view of the staple cartridge of the end-effector of FIG. 22 ; FIG. 24 is a cross-sectional view of the end-effector of FIG. 12 taken along line 24 - 24 in FIG. 12 ; FIG. 25 is a cross-sectional view of the end-effector of FIG. 12 after the drive bar has been advanced into the end-effector; FIG. 26 is a schematic of the cutting member and drive bar of the endocutter of FIGS. 24 and 25 ; FIG. 27 is a perspective view of an endocutter having a curved end-effector configured to close in an asymmetric manner in accordance with an embodiment of the present invention; FIG. 28 is a cross-sectional view of the hinge connection between the jaws of the curved end-effector of FIG. 27 wherein the jaws are in an open configuration; FIG. 29 is a cross-sectional view of the hinge connection of FIG. 28 wherein the jaws are in a partially closed configuration; FIG. 30 is an end view of the curved end-effector of FIG. 27 illustrated in a partially closed configuration; FIG. 31 is a cross-sectional view of the hinge connection of FIG. 28 wherein the end-effector is in a closed configuration; FIG. 32 is an end view of the curved end-effector of FIG. 27 illustrated in a closed configuration; FIG. 33 is a detail view of a first slot of the hinge connection of FIG. 28 that is configured to receive a first projection extending from the anvil and is also configured to define a first path for relative movement therebetween; FIG. 34 is a detail view of a second slot of the hinge connection of FIG. 28 that is configured to receive a second projection extending from the anvil and is also configured to define a path for relative movement therebetween that is different than the first path; FIG. 35 is a perspective view of an endocutter having a curved end-effector in accordance with an alternative embodiment of the present invention; FIG. 36 is a side view of the endocutter of FIG. 35 ; FIG. 37 is a schematic of the endocutter of FIG. 35 being used to transect a pulmonary artery; FIG. 38 is a perspective view of an endocutter having a curved end-effector in accordance with an alternative embodiment of the present invention; FIG. 39 is a perspective view of the staple cartridge of the end-effector of FIG. 38 ; FIG. 40 is a side view of the end-effector of the endocutter of FIG. 39 ; FIG. 41 is a partial cross-sectional view of the end-effector of the endocutter of FIG. 38 ; FIG. 42 is a perspective view of the staple driver, cutting member and drive bar of FIG. 41 ; FIG. 43 is a perspective view of the cutting member and drive bar of FIG. 41 ; FIG. 44 is a perspective view of an endocutter having a curved staple cartridge and a curved anvil configured to retain buttress material thereon in accordance with an embodiment of the present invention; FIG. 45 is a top view of the staple cartridge of FIG. 44 illustrating a piece of buttress material positioned thereon; FIG. 46 is a bottom view of the anvil of FIG. 44 illustrating two pieces of buttress material positioned thereon; FIG. 47 is a cross-sectional view of the end-effector of the endocutter of FIG. 44 taken along line 47 - 47 in FIG. 44 ; FIG. 48 is a perspective view of an endocutter in accordance with an embodiment of the present invention; FIG. 49 is a cross-sectional view of the end effector of FIG. 48 taken along line 49 - 49 in FIG. 48 ; and FIG. 50 is an enlarged cross-sectional view of the distal end of the end effector of FIG. 49 . Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate preferred embodiments of the invention, in various forms, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. DETAILED DESCRIPTION As known in the art, it is often necessary to resect tissue from a patient after the tissue has become necrotic or cancerous, for example. Frequently, blood vessels within the tissue are transected as the tissue is being cut. As a result, blood may flow from the blood vessels and complicate the surgery or endanger the patient. Often, a surgical stapler is used to secure and compress several layers of tissue together in order to substantially close the blood vessels. For example, referring to FIG. 1 , a surgical stapler, such as an endocutter, can include devices which staple and then cut the tissue. As a result, the blood vessels can be substantially closed by the staples before the tissue is cut, thereby reducing bleeding therefrom. Referring to FIGS. 1 and 2 , endocutters, such as endocutter 100 , for example, typically include an end-effector 102 , a handle portion 104 ( FIG. 2 ), and a shaft 106 extending therebetween. End-effector 102 includes first jaw 108 and second jaw 110 which can be configured in one of an open or a closed configuration. In their open configuration, jaws 108 and 110 can be configured to receive soft tissue therebetween, for example, allowing jaws 108 and 110 to be placed on opposite sides thereof. To close the jaws and secure the tissue therebetween, at least one of the jaws is moved against the tissue such that it holds the tissue against the opposing jaw. In the illustrated embodiment, jaw 108 is moved relative to jaw 110 . Once closed, as known in the art, an anti-firing mechanism can be released allowing cutting member 120 to be advanced toward the tissue. Thereafter, as described in greater detail below, staples 132 can be deployed from staple cartridge 112 in jaw 110 to secure the layers of tissue together. Such mechanisms are described in greater detail in U.S. Pat. No. 7,000,818, the disclosure of which is hereby incorporated by reference herein. Referring to FIGS. 3-4 and 6-8 , cutting member 120 includes body 122 and cutting surface 124 . Cutting member 120 is operably engaged with firing trigger 128 of handle portion 104 via drive bar 126 wherein the actuation of firing trigger 128 advances drive bar 126 and cutting member 120 toward the distal ends of jaws 108 and 110 . In various embodiments, firing trigger 128 can activate a firing drive system which may be manually, electrically, or pneumatically driven. Cutting member body 122 further includes distal portion 123 which is configured to engage a staple driver 130 commonly supported within staple cartridge 112 and advance staple driver 130 therein. As staple driver 130 is advanced, staples 132 are lifted by driver 130 toward anvil 134 . Referring to FIG. 5 , anvil 134 includes pockets 136 which are configured to deform the legs of staples 132 and capture the layers of tissue therein in a known manner. In the present embodiment, as staple driver 130 is advanced, cutting member 120 is also advanced to resect the tissue after it has been stapled. In other embodiments, cutting member 120 can be configured to resect the tissue during or before the tissue has been stapled. Referring to FIGS. 1-7 , the end-effector of many typical endocutters is linear, i.e., it is configured to deploy staples in straight lines. In these endocutters, drive bar 126 is configured to move cutting member 120 in a straight line and, accordingly, drive bar 126 is rigid such that it does not substantially deflect when the force to deploy the staples and transect the tissue is transmitted therethrough. In addition to the above, a variety of other drive arrangements are known for deploying staples in straight lines while resecting the tissue located between opposite lines of staples. However, it is often difficult to position such linear end-effectors in a surgical site. During at least one surgical technique, referring to FIGS. 9 and 10 , an endocutter is used to transect and staple a pulmonary artery (PA) during a partial or total pneumonectomy. During this technique, the end-effector is typically placed against the wall of the thoracic cavity (TCW) such that jaw 110 , and staple cartridge 112 , are positioned behind the pulmonary artery. However, as the wall of the thoracic cavity is typically curved, it is often difficult to position linear jaw 110 behind the pulmonary artery. Furthermore, even if the surgeon is successful in positioning a jaw behind the pulmonary artery, the surgeon, owing to the linear configuration of the end-effector, cannot readily see the end of the jaw as it is typically hidden behind the pulmonary artery. As a result, it is difficult for the surgeon to readily determine whether the end of the jaw extends beyond the pulmonary artery, i.e., whether the pulmonary artery is entirely captured between the jaws of the end-effector. In various embodiments of the present invention, referring to FIG. 10 , the end-effector of the endocutter is curved. A curved end-effector allows a surgeon to more easily position the end-effector against the curved wall of the thoracic cavity, for example. In at least one embodiment, the curvature of the end-effector can be configured to substantially match the contour of a typical thoracic cavity wall. In these embodiments, the curvature of several thoracic cavity walls can be measured and statistically analyzed to determine the optimum profile of the curved end-effector. This profile can include several arcuate portions and, in addition, several linear portions. In other embodiments, referring to endocutter 200 of FIGS. 10-14 , the curvature of the thoracic cavity wall can be approximated by a single radius of curvature. Such embodiments can be simpler and less expensive to manufacture. In at least one embodiment, this radius of curvature is 1.2″. In other various embodiments, the curvature of the end-effector can be configured to match the profile of the lower rectum, pelvis, or lower abdomen. In order to transect the pulmonary artery PA, as mentioned above, a surgeon typically positions one of jaws 208 and 210 behind the pulmonary artery PA against the thoracic cavity wall TCW. Once positioned, referring to FIGS. 10 and 11 , closure trigger 117 is actuated to pivot jaw 208 with respect to jaw 210 such that anvil 234 contacts the pulmonary artery and compresses the pulmonary artery between anvil 234 and staple cartridge 212 . Unlike previous linear end-effectors, the curved profile of end-effector 202 assists the surgeon in locating the distal end of the end-effector with respect to the pulmonary artery. More particularly, referring to FIGS. 13 and 14 , end 240 of jaw 210 can extend to one side of a centerline, or axis 242 , defined by the distal end of shaft 106 . As a result of this offset, the surgeon may be able to more readily see distal end 240 and evaluate whether the pulmonary artery is completely captured within the end-effector, for example. Once the jaws of the endocutter have been closed, the cutting member of the endocutter can be advanced toward the tissue, as described above. In previous endocutters, referring to FIGS. 4, 15 and 16 , cutting member 120 is configured to travel within linear slots defined by staple cartridge 112 , staple cartridge channel 138 , and anvil 134 . Similarly, staple driver 130 is configured to travel within at least one linear slot defined by staple cartridge 112 . As a result of these linear slots, cutting member 120 and staple driver 130 are moved in a straight line between the proximal and distal ends of the end-effector. For example, referring to FIG. 4 , cutting member 120 includes first projections 146 extending from body 122 which are sized and configured to fit within slot 148 of anvil 134 . Cutting member 120 further includes second projections 150 extending from body 122 which are sized and configured to retain cutting member body 122 within slot 164 of staple cartridge 112 and slot 152 of jaw 110 . Accordingly, as cutting member 120 is advanced from the proximal end of the end-effector to the distal end, linear slots 148 , 152 and 164 define a linear path for cutting member 120 . In various embodiments of the present invention, referring to FIGS. 13 and 14 , staple cartridge 212 , staple cartridge channel 238 and anvil 234 can include curved slots for controlling the movement of cutting member 120 and staple driver 130 along a curved path. These curved slots can include several arcuate portions and several linear portions. In various embodiments, the curved slots can be defined by one radius of curvature. In the embodiment illustrated in FIGS. 13 and 14 , staple cartridge 212 and staple cartridge channel 238 can include curved slots 264 and 252 , respectively. Similar to the above, curved slots 264 and 252 can be configured to receive a portion of cutting member 120 and guide cutting member 120 along a path defined by slots 264 and 252 . However, owing to the substantially linear configuration of cutting member 120 , cutting member 120 may, in some circumstances, become misaligned or stuck within curved slots 264 and 252 , or a corresponding curved slot in anvil 234 . To ameliorate the above-described problem, at least a portion of the cutting member and staple driver can be curved. In at least one embodiment, the cutting member and staple driver can be configured to substantially match the curvature of the path defined by curved slots 264 and 252 , i.e., path 258 . More particularly, referring to FIGS. 13 and 17 , cutting member body 222 can include a center portion which is configured to match the radius of curvature of path 258 , and a curved inner portion 260 and a curved outer portion 262 which are configured to co-operate with the sidewalls of curved slots 264 and 252 . For example, curved cartridge channel slot 252 can include inner surface 254 and outer surface 256 and curved staple cartridge slot 264 can include inner surface 266 and outer surface 268 where, in the present embodiment, inner surfaces 254 and 266 are substantially defined by radius of curvature D, which is smaller than the radius of curvature of path 258 , and outer surfaces 256 and 268 are substantially defined by radius of curvature C, which is larger than the radius of curvature of path 258 . As illustrated in FIG. 17 , inner portion 260 of cutting member 220 can be configured to closely parallel the profile of inner surfaces 254 and 266 , and outer portion 262 of cutting member 220 can be configured to closely parallel the profile of outer surfaces 256 and 268 . Furthermore, although not illustrated, anvil 234 can include a curved slot which, similar to slots 264 and 252 , co-operates with curved cutting member 220 to guide cutting member along path 258 . As a result of the above, the likelihood of cutting member 220 becoming misaligned or stuck within curved path 252 can be reduced. Alternatively, although not illustrated, the cutting member can include slots which are configured to co-operate with features on the anvil and/or staple cartridge and guide the cutting member along a curved path. More particularly, the anvil and/or staple cartridge can each include an elongate, arcuate projection, or a plurality of projections, which define a curved, or curvilinear, path for the cutting member. The slots of the cutting member can be configured to receive the projections and guide the cutting member along the curved path. In one embodiment, one of the anvil and staple cartridge can include such a projection, or a plurality of projections, and the other of the anvil and staple cartridge can include a slot configured to receive a portion of the cutting member, as described above. Similar to the above, at least a portion of staple driver 230 can be configured to substantially match the curvature of path 258 . More particularly, referring to FIG. 17 , staple driver 230 can include a center arcuate portion 270 which is configured to match the radius of curvature of path 258 , and an inner arcuate portion 272 and an outer arcuate portion 274 which are configured to co-operate with the sidewalls of slots, or channels, within staple cartridge 212 . Similar to staple driver 130 , staple driver 230 can include ramps which are configured to lift, or deploy, staples 132 against anvil 234 positioned opposite staple cartridge 212 . However, in the present embodiment, ramps 276 of staple driver 230 can be curved to deploy staples 132 along a curved staple line. More particularly, for example, the ramps can be defined by a radius of curvature which substantially matches the radius of curvature of a staple line. For example, ramp 278 is defined by a radius of curvature which substantially matches the radius of curvature of staple line 280 , i.e., radius of curvature A. Although the path of the cutting member has been described above as being defined by a single radius of curvature, the invention is not so limited. In various embodiments, referring to FIGS. 13 and 14 , end-effector 202 of endocutter 200 can include curved portion 263 and, in addition, linear portion 261 which is substantially collinear with an axis defined by the distal portion of shaft 116 , i.e., axis 242 . In at least one embodiment, curved portion 263 can further include first portion 265 and second portion 267 . Referring to FIG. 13 , first portion 265 can include a proximal end connected to linear portion 261 positioned along axis 242 and a distal end spaced from axis 242 wherein second portion 267 can include a proximal end connected to the distal end of first portion 265 and extend toward axis 242 . Stated another way, first portion 265 can define an arcuate portion which extends away from axis 242 and second portion 267 can define an arcuate portion which extends toward axis 242 . As described above, an end-effector having such a profile may facilitate the positioning of the end-effector against the wall of the thoracic cavity, for example. Referring to FIGS. 18-21 , the end-effector of other various embodiments of the present invention can include other advantageous profiles. For example, referring to FIGS. 18 and 19 , end-effector 302 can include linear portion 361 and curved portion 363 wherein the distal end of slot 364 can be positioned along axis 242 . As a result, although the cutting member progresses along an arcuate path offset with respect to axis 242 , the cutting member will stop at a point along axis 242 . Thus, as long as the surgeon is able to discern the orientation of axis 242 , the surgeon will know that the cutting member will not progress beyond axis 242 and can thereby gauge the point at which the tissue will no longer be transected. In another embodiment, referring to FIGS. 20 and 21 , end-effector 402 can include linear portion 461 and curved portion 463 wherein distal tip 440 of the end-effector lies along axis 242 although at least a portion of the end-effector is offset with respect to axis 242 . In this embodiment, as long as the surgeon is able to discern the orientation of axis 242 , the surgeon can gauge the location of the distal end of the end-effector when moving or dissecting tissue. In other various embodiments, referring to FIGS. 22 and 23 , the end-effector can define an arcuate path for the cutting member that is defined by an angle that is greater than or equal to 90 degrees. More particularly, for example, path 558 can include linear portion 561 and curved portion 563 wherein curved portion 563 is defined by a radius of curvature that spans an arc corresponding to an approximately 110 degree angle. As a result of the significant curvature of curved portion 563 , a surgeon can position a pulmonary artery, for example, entirely within curved portion 563 . In various embodiments, referring to FIG. 26 , staples 132 may only be positioned within cavities in curved portion 563 , and not linear portion 561 . In these embodiments, the staple lines can be comprised of continuous, curved rows without abrupt changes in direction within the staple line. As known in the art, abrupt changes in a staple line may provide a leak path for blood to flow therethrough. As a result of the above embodiments, the likelihood of such a leak path is reduced. As described above, the anvil and staple cartridge can include curved slots for receiving and guiding the cutting member. In many embodiments, the anvil and the staple cartridge can be configured such that their features parallel the curved slots therein. For example, referring to FIGS. 13 and 14 , curved portion 263 of staple cartridge 212 can include an inner radius of curvature and an outer radius of curvature which parallel the radius of curvature of curved slot 264 . More particularly, referring to FIG. 13 , the inner surface of staple cartridge 212 can be defined by radius of curvature E and the outer surface of staple cartridge 212 can be defined by radius of curvature B, wherein curvatures B and E share a substantially common radial point with radius of curvatures C and D which, as described above, substantially define the inner and outer surfaces of slot 264 . However, in various embodiments, although not illustrated, the inner and outer surfaces of the anvil and/or staple cartridge, or any other features thereof, may be non-parallel to the curved slot. In these embodiments, the anvil and staple cartridge, and the jaws surrounding them, may be configured to achieve any suitable configuration or purpose. In previous endocutters, as described above and referring to FIGS. 4 and 8 , linear drive bar 126 is configured to advance cutting member 120 along a linear path and, as a result, drive bar 126 is constructed such that is rigid and does not substantially deflect. After cutting member 120 has been advanced into slots 148 , 164 and 152 of anvil 134 , staple cartridge 112 , and staple cartridge channel 138 , respectively, at least a portion of drive bar 126 can enter into slots 148 , 164 and 152 . However, although cutting member 120 is guided and supported within slots 148 , 164 , and 152 , drive bar 126 , in these previous devices, is unsupported within slots 148 , 164 , and 152 . As a result, drive bar 126 may deflect or buckle in an uncontrollable and undesirable manner when load is transmitted therethrough. In various embodiments of the present invention, a flexible drive bar can be used to advance the cutting member within the end-effector. More particularly, in order for the drive bar to be advanced into and translate within the curved slots of the end-effector, the drive bar can deflect to closely parallel the curvature of the curved slots of the end-effector. In various embodiments, unlike previous endocutters, the slots within the anvil and staple cartridge can be configured to support the flexible driver bar. More particularly, referring generally to FIGS. 24-26 , after cutting member 120 has been at least partially advanced within slots 248 , 264 , and 252 , referring to FIG. 25 , at least a portion of drive bar 226 can enter slots 248 , 264 , and 252 . Slot 248 can include support surfaces 249 which are configured to abut, or be positioned closely adjacent to, side surfaces 227 of drive bar 226 . Similarly, surfaces 254 and 256 of slot 252 and surfaces 266 and 268 of slot 264 can also support the drive bar. While these features are particularly advantageous when used with curved end-effectors, they can also be used in linear end-effectors. In these embodiments, even though the slots may be linear, the slots can support the driver, whether rigid or flexible, and prevent it from buckling in the event that it is overloaded, for example. Although flexible drive bar 226 can be used to advance linear cutting member 120 and linear staple driver 130 within a curved end-effector, as described above, flexible drive bar 226 can also be used to advance curved cutting members and staple drivers, such as cutting member 220 and staple driver 230 , for example, within a curved end-effector. Furthermore, although not illustrated, one of the anvil and staple cartridge can include a slot configured to receive and guide the cutting member and the other of the anvil and staple cartridge can include a slot configured to receive and support the drive bar. In these embodiments, the slot which is configured to receive the cutting member can have a different geometry than the slot which is configured to receive the drive bar. Accordingly, the cutting member and the drive bar can have different thicknesses, for example. In various embodiments, the support surfaces of slots 248 , 264 and 252 may be continuous, i.e., they may be configured to contact drive bar 226 continuously along the length thereof, or, alternatively, slots 248 , 264 and 252 may be configured to contact drive bar 226 at various, spaced-apart locations. In these embodiments, projections may extend from the slot walls to define the path of the cutting member and the drive bar. In various embodiments, drive bar 226 may be comprised of a flexible, unitary material such as plastic, for example. Alternatively, referring to FIGS. 25 and 26 , drive bar 226 may be comprised of a laminated material, i.e., a material comprised of two or more materials bonded together. In these embodiments, two or more strips of material may be glued together where the strips have the same cross-sectional geometry, or, alternatively, different cross-sectional geometries. Furthermore, the strips may be comprised of the same material or different materials. The cross-sectional geometries and materials of the above-described embodiments may be selected such that the drive bar is more flexible when deflected in one direction and less flexible when deflected in a different direction. As described above, the curvature of an end-effector can be selected such that it facilitates the placement of the end-effector in a particular surgical site. In various embodiments, referring to FIGS. 35-37 and 38-40 , the end-effector can be curved in a downward or upward direction, i.e., it can be curved in a plane that is substantially parallel to planes defined by the staple lines. More particularly, referring to FIGS. 38 and 39 , staple cavities 803 , which are configured to store staples 132 therein, are positioned along staple lines 805 and 807 , for example, such that staples 132 , when they are deployed from staple cartridge 812 , are deployed in substantially parallel planes which are at least partially defined by staple lines 805 and 807 . For each parallel plane described above, as a result of these upward and/or downward curvatures, staples 132 can be deployed along axes which are co-planar, but not parallel. More particularly, referring to FIG. 39 , a first staple 132 (not illustrated in FIG. 39 ) can be deployed from its staple cavity 803 along axis 853 and a second staple 132 can be deployed from its staple cavity 803 along axis 855 . While axis 853 and axis 855 can be co-planar, as illustrated in FIG. 39 , axis 853 and axis 855 are not parallel. In some embodiments, the axes defined by staple cavities 803 can converge, as illustrated in FIGS. 38 and 39 , or diverge, as illustrated in FIGS. 35-37 . In various embodiments, the staple deployment axes can define an angle therebetween which is greater than or equal to 30 degrees. In other various embodiments, the axes can be substantially perpendicular and, in further embodiments, the axes can define an angle that is greater than ninety degrees. As described above, an endocutter in accordance with an embodiment of the present invention can include a cutting member which is advanced through and guided by curved slots in the staple cartridge and/or anvil. For example, referring to FIGS. 38-43 , staple cartridge 812 can include slot 864 which is configured to receive and guide cutting member 120 . Similar to the above, endocutter 800 can further include a drive bar for advancing cutting member 120 within slot 864 of staple cartridge 812 , however, owing to the direction and degree of the curvature of staple cartridge 812 , some drive bars may be largely unsuitable for use with endocutter 700 or 800 , for example. More particularly, the illustrated drive bars 126 and 226 in FIGS. 4 and 24 , respectively, owing to their cross-sectional geometries, may not be particularly well-suited to flex in a substantially downward or substantially upward direction as required by endocutters 700 and 800 , respectively. Referring to FIG. 26 , for example, the illustrated cross-section of drive bar 226 is substantially rectangular and is defined by height 257 and width 259 . As illustrated in FIG. 26 , height 257 is substantially greater than width 259 and, as a result, the cross-section of the illustrated drive bar 226 has a moment of inertia with respect to height 257 that is substantially greater than the moment of inertia with respect to width 259 . Accordingly, the illustrated drive bar 226 is substantially less flexible with respect to height 257 than width 259 and may not be able to sufficiently bend in the substantially downward and upward directions described above. It is important to note that drive bars 126 and 226 are not limited to the configurations described above. On the contrary, drive bars 126 and 226 can have cross-sections in which the width is greater than the height. Any reference in this paragraph to drive bars 126 and 226 are references to the particular drive bars 126 and 226 that happen to be illustrated in FIGS. 4 and 24 , respectively. Referring to FIGS. 41-43 , endocutter 800 can include drive bar 826 which, similar to drive bar 226 , is configured to advance cutting member 120 , or a curved cutting member, through curved slots in an end-effector. In various embodiments, drive bar 826 can include a cross-sectional geometry having a width 859 that is greater than its height 857 . In these embodiments, the moment of inertia of the cross-section with respect to height 857 is less than the moment of inertia with respect to width 859 . As a result, drive bar 826 can be more flexible with respect to height 857 , i.e., in the upward and downward directions, than with respect to width 859 . In at least one embodiment, width 859 can be approximately 0.12″ and height 857 can be approximately 0.05″. Although drive bar 826 is illustrated as having a rectangular cross-section, the invention is not so limited. On the contrary, the cross-section of drive bar 826 can include various embodiments in which the width of the drive bar cross-section is greater than its height. In at least one embodiment, drive bar 826 can include a cross-section defined by a width and a height wherein the width is greater than the height, and wherein the width defines an axis that is not parallel to an axis defined by cutting edge 124 of cutting member 120 . In various embodiments, as known in the art, cutting edge 124 can include a knife edge or a wire configured to conduct current therethrough. Furthermore, in various embodiments, the drive bar can be asymmetric with respect to centerline 224 of the distal end of shaft 116 , for example. In these embodiments, as a result, drive bar 826 can be predisposed to bending in a pre-determined direction. Similar to drive bar 226 , drive bar 826 can be comprised of one material or, alternatively, several layers of material bonded together. As above, the flexibility of drive bar 826 can be pre-determined by the types of materials used and the arrangement of the layers within the drive bar. Referring to FIG. 41 , cutting member body 822 can include slot 869 which is configured to receive the distal end of drive bar 826 . In the present embodiment, slot 869 is configured to receive drive bar 826 in a press-fit relationship, however, other means, such as adhesive or fasteners, can be used to secure drive bar 826 to cutting member 820 . Similar to the above, staple cartridge 812 can include a slot configured to receive and support drive bar 826 when it enters into staple cartridge 812 . In various embodiments, although not illustrated, anvil 834 could be configured to receive and support drive bar 826 . As described above, the jaws of an endocutter can be placed on opposite sides of several layers of tissue, for example, and then closed onto the tissue. In the illustrated embodiments, referring to FIG. 4 , jaw 108 can be pivoted between opened and closed positions with respect to jaw 110 via the interaction of inner portion 114 and outer sleeve 116 of shaft 106 in a known manner. Although not illustrated, jaw 108 is connected to jaw 110 via a pivot connection such that when inner portion 114 moves jaw 108 relative to outer sleeve 116 , jaw 108 is pivoted toward jaw 110 . Throughout the movement of jaw 108 , the proximal portion of jaw 108 , i.e., proximal portion 111 , is positioned closer to jaw 110 than its distal portion, i.e., distal portion 113 , until jaw 108 is brought into its final position opposite staple cartridge 112 . In this final, closed position, distal portion 113 and proximal portion 111 can be substantially equidistant from staple cartridge 112 . However, as a result of distal portion 113 being the last portion of jaw 108 to reach its final position, a portion of the tissue, or an artery, for example, can escape from between jaws 108 and 110 before distal portion 113 is moved into its final position. Accordingly, the surgeon may have to reopen the jaws and reposition the end-effector in an attempt to properly capture the tissue, or artery, therebetween. As detailed below, an end-effector in accordance with an embodiment of the present invention can be configured to capture the tissue, or an artery, between the distal and proximal portions of the end-effector before the jaws are moved into their final position. In at least one embodiment, referring to FIGS. 27-34 , jaw 608 can be pivotally connected to jaw 610 via pivot connection 609 . Pivot connection 609 can include first trunnion 615 and second trunnion 617 extending from jaw 608 , and, in addition, first slot 619 and second slot 621 in jaw 610 . Trunnions 615 and 617 can be sized and configured to fit within slots 619 and 621 , respectively, such that pivot connection 609 allows for relative rotational and translation movement between jaw 608 and jaw 610 . In other alternative embodiments, jaw 608 may include slots 619 and 621 and jaw 610 may include trunnions 615 and 617 , or any other combination thereof. Referring to FIGS. 28, 29 and 31 which schematically illustrate slot 619 in solid and slot 621 in dashes, trunnions 615 and 617 are configured to travel within slots 619 and 621 , respectively, and define the relative movement between jaws 608 and 610 . In the present embodiment, slots 619 and 621 define two different arcuate paths for trunnions 615 and 617 . More particularly, referring to FIGS. 33 and 34 , slot 619 includes first portion 623 , second portion 625 , and intermediate portion 627 extending therebetween wherein slot 621 also includes first portion 623 and second portion 625 , however, slot 621 includes an intermediate portion, i.e., portion 629 , which is different than intermediate portion 627 . Referring to FIG. 27 , as a result of slots 619 and 621 having different intermediate portions, slots 619 and 621 can cause jaw 608 to tilt, or otherwise move in a non-symmetrical manner, with respect to jaw 610 as it is opened and closed. Advantageously, referring to FIGS. 30 and 32 , such an asymmetric motion, or tilting, can allow distal portion 613 of jaw 608 to be placed in close proximity to staple cartridge 612 before the intermediate portion of jaw 608 , i.e., portion 631 , is moved into its final position illustrated in FIG. 32 . As a result, referring to FIG. 30 , an end-effector in accordance with the above can be used to capture tissue, or an artery, between proximal end 611 and distal end 613 before intermediate portion 631 is moved into its final, or closed, position. As a result, the possibility of a portion of the tissue, or artery, escaping from between jaws 608 and 610 is reduced. In addition to the above, the distal ends of jaws 608 and 610 can be brought into close opposition to each other in order to grip delicate tissue, for example, without having to completely close the end-effector. As outlined above, slots 619 and 621 can define different paths for trunnions 615 and 617 , respectively, when jaw 608 is moved between an open and a closed position. When jaw 608 is in its open position, referring to FIG. 28 , trunnions 615 and 617 are positioned within first portions 623 of slots 619 and 621 . In this position, axis 633 , which is defined by trunnions 615 and 617 , is substantially collinear with axis 635 defined between first portions 623 of slots 619 and 621 . Thereafter, jaw 608 can be moved distally such that trunnions 615 and 617 move upward through slots 619 and 621 . Owing to the asymmetric configurations of slots 619 and 621 , referring to FIG. 27 which illustrates jaw 108 in a partially closed position, trunnion 615 is elevated to a relatively higher position with respect to trunnion 617 , as evidenced by the tilting of axis 633 . In this position, an inner edge of jaw 608 , i.e., edge 639 , can be in closer proximity to staple cartridge 612 than an outer edge of jaw 608 , i.e., edge 641 . Advantageously, as a result, inner edge 639 can be brought into contact against the tissue, or an artery, for example, allowing the surgeon to evaluate the position of the end-effector with respect to the tissue, or artery, without having to bring the entire anvil 634 of jaw 608 against the tissue. This feature may be particularly advantageous when the end-effector is positioned around a pulmonary artery as pulmonary arteries are especially susceptible to rupture. After the tissue, or artery, has been captured between the proximal and distal ends of the end-effector, referring to FIGS. 31 and 32 , jaw 608 can be moved into its final, or closed, position with respect to staple cartridge 612 . In this position, axis 633 , which is defined by trunnions 615 and 617 , can be substantially collinear with axis 637 defined between second portions 625 of slots 619 and 621 . Furthermore, in this final position, intermediate portion 631 , distal portion 613 and proximal portion 611 can be equidistant from staple cartridge 612 . Similarly, outer edge 641 and inner edge 639 can also be positioned equidistant with respect to staple cartridge 612 . In this final position, tissue, or an artery, for example, can be securely retained between jaws 608 and 610 . Although the above-described embodiments include a curved end-effector, the invention is not so limited. On the contrary, the above features can be utilized with a linear end-effector, for example, to achieve the advantages described above. In various embodiments, slots 619 and 621 can define paths having different centerlines wherein each centerline can be defined as the line equidistant from the top and bottom surfaces of each slot. For example, referring to FIGS. 33 and 34 , slot 619 can include bottom surface 642 and top surface 643 which define a centerline therebetween that is different than the centerline defined by bottom surface 645 and top surface 647 of slot 621 . In these embodiments, slots 619 and 621 can be configured to closely retain trunnions 615 and 617 between these top and bottom surfaces such that axis 633 of trunnions 615 and 617 substantially travels along the centerlines of slots 619 and 621 . In various embodiments, jaws 608 and 610 can be configured such that trunnions 615 and 617 contact bottom surfaces 642 and 645 of slots 619 and 621 . In these embodiments, jaw 608 can be biased by a spring, for example, such that trunnions 615 and 617 are positioned against bottom surfaces 642 and 645 throughout the movement of jaw 608 . Owing to different profiles for bottom surfaces 642 and 645 , the advantages described above can be achieved. As described above, once the jaws of the end-effector are closed onto the layers of tissue, for example, staples can be deployed into the tissue. However, oftentimes, the layers of tissue are very thin and the staples may not properly capture the tissue therein. To ameliorate this problem, as known in the art, buttress material can be placed on one or both sides of the tissue to support the tissue as it is being stapled. In such embodiments, the purchase of the staples is improved and the clamping force of the staples may be spread more evenly across the buttress material. In various embodiments, the buttress material can be comprised of a bioabsorbable material such that it can dissolve away during the healing process. Previously, however, the buttress material has been provided in linear strips which are configured to accommodate linear staple lines and end-effectors. Such linear strips may be unsuitable for use with endocutters having a curved end-effector configured to deploy staples in curved staple lines. In accordance with an embodiment of the present invention, referring to FIGS. 44-47 , curved staple cartridge 912 can be configured to receive a curved piece, or pieces, of buttress material thereon, such as buttress material 971 . Curved buttress material 971 can include inner edge 973 which can be configured to substantially parallel the inner radius of curvature of jaw 910 , and, in addition, outer edge 975 which can be configured to substantially parallel the outer radius of curvature of jaw 910 . In some embodiments, referring to FIG. 47 , staple cartridge 912 can include lip 977 extending therefrom which is configured to retain buttress material 971 on staple cartridge 912 . More particularly, lip 977 , as illustrated, can be configured to limit lateral movement of buttress material 971 with respect to staple cartridge 912 and, although not illustrated, lip 977 can also be configured to extend distal to and/or proximal to the ends of the buttress material to limit relative axial movement between buttress material 977 and staple cartridge 912 . Similar to the above, curved anvil 934 can be configured to receive a piece, or pieces, of curved buttress material thereon, such as buttress material 979 and 981 , for example. Referring to FIG. 47 , anvil 934 can include several lips 982 which are configured to limit relative movement between buttress material 979 and 981 and anvil 934 . In various embodiments, an adhesive, such as cyanoacrilate, for example, can be applied to the buttress material, anvil and/or staple cartridge to further limit the movement of the buttress material or otherwise prevent the mobilization thereof. As a result of the above, a surgeon may be able to position the end-effector into a surgical site without the buttress material falling off or moving relative to the staple cartridge and/or anvil. Once positioned, cutting member 120 can be advanced to cut buttress material 971 . More specifically, referring to FIG. 47 , cutting edge 124 can be aligned with buttress material 971 such that it cuts the buttress material as cutting member 920 is advanced through staple cartridge 912 . However, in some circumstances, the cutting member may at least partially dislodge the buttress material relative to the staple cartridge. This relative movement may especially occur when the buttress material is thick, or, the cutting member must cut more than one piece of buttress material at a time. To ameliorate this problem, the buttress material may include a series of perforations, for example, positioned along the path in which the cutting member will cut the buttress material. In these embodiments, these perforations may be formed along a radius of curvature which is parallel to and positioned intermediate two curved staple rows. In other various embodiments, the buttress material may include other features which disrupt the cross-sectional thickness of the buttress material to facilitate the cutting of the buttress material. As a result of the above, less force may be required to cut the buttress material and, accordingly, it is less likely the buttress material may slide, for example, when it is cut. FIGS. 48-50 illustrate another surgical instrument of the present invention. As can be seen in these Figures, the surgical instrument 1000 includes an end-effector 1002 that has a first jaw 1008 and a second jaw 1010 . The second jaw 1010 may comprise a channel 1038 that is configured to operably support a staple cartridge 1012 therein. Staple cartridge 1012 may be removably supported in the channel 1038 or, in various embodiments, staple cartridge 1012 may form an integral part of the second jaw 1010 . The surgical instrument 1000 further includes a movable anvil 1034 that may be movably coupled to the lower jaw 1010 in the various manners described above or in other manners that are known in the art. In the embodiment depicted in FIGS. 48-50 , the end effector 1002 has a distal end generally designated as 1040 . As can further be seen in those Figures, the staple cartridge 1012 has a blunt first tip portion 1088 thereon. The first tip portion 1088 may be integrally formed (molded, machined, etc.) on the distal end 1013 of the staple cartridge 1012 or it may comprise a separate piece that may be formed with a cavity 1089 ( FIG. 50 ) configured to receive a nose 1083 of a conventional staple cartridge 1012 . The first tip portion 1088 can include snap features 1090 ( FIG. 50 ) or other suitable retainer portions formed therein to retainingly mate with complementary retention grooves 1084 formed in the nose 1083 . In addition, or in the alternative, the first tip portion 1088 may be affixed to the cartridge 1012 by adhesive such as, for example, cyanoacrylates, light-curable acrylics, polyurethanes, silicones, epoxies, and ultra-violet curable adhesives such as Henkel Loctite ®. In other embodiments, a combination of snap features and grooves may be provided in both the staple cartridge 1012 and the first tip portion 1088 . Still other forms of fasteners and fastener arrangements may be used to affix the first tip portion 1088 to the staple cartridge 1012 . In other embodiments, the first tip portion 1088 may be affixed to the channel 1038 . As can be seen in FIG. 50 , the first tip portion 1088 has a first upwardly extending curved outer surface. Similarly, in this embodiment, the anvil 1034 may be equipped with a second tip portion 1092 . The second tip portion 1092 may be integrally formed (molded, machined, etc.) on the distal end 1085 of the anvil 1034 or it may comprise a separate piece that may be formed with a cavity 1093 configured to receive an end portion of a conventional anvil 1034 with snap features 1094 or other suitable retainer portions formed therein to retainingly mate with complementary retention grooves 1086 formed in distal end 1085 . In addition, or in the alternative, the second tip portion 1092 may be affixed to the anvil 1034 by adhesive such as, for example, cyanoacrylates, light-curable acrylics, polyurethanes, silicones, epoxies, and ultra-violet curable adhesives such as Henkel Loctite ®. In other embodiments, a combination of snap features and grooves may be provided in both distal end 1085 and the second tip portion 1092 . Still other forms of fasteners may be used to affix the second tip portion 1092 to the anvil 1034 . As can be seen in FIG. 50 , the second tip portion 1092 has a downwardly extending substantially curved outer surface. In various embodiments, the first tip portion 1088 and the second tip portion 1092 may be fabricated from a variety of different materials that may be identical to or different from the materials from which the staple cartridge 1012 and anvil 1034 are manufactured. For example, the first tip portion 1088 and the second tip portion 1092 may be manufactured from soft plastic, rubber, etc. The first tip portion 1088 and the second tip portion 1092 may be fabricated from the same or different materials. In various embodiments, the first tip portion 1088 and the second tip portion 1092 are shaped such that their respective outer surfaces 1088 ′, 1092 ′ cooperate to substantially form a substantially blunt end effector nose generally designated as 1096 that, in one exemplary embodiment, has a paraboloid surface 1098 when the anvil 1034 is in the closed position as shown in FIG. 50 . As used herein, the term “paraboloid surface” means a surface having parabolic sections parallel to a single coordinate axis and elliptic sections perpendicular to that axis. Those of ordinary skill in the art will appreciate that when employing various embodiments of the instrument 1000 , as long as the surgeon can see one or the other of the first tip portion or second tip portion, the surgeon will know where the other tip portion is, even if it is behind tissue or other structures. In addition, the unique and novel tip configurations permit the surgeon to pass the anvil and/or channel around tissue without great risk of incidental trauma to adjacent tissues. Furthermore, when in the closed orientation as depicted in FIGS. 49 and 50 , these embodiments are particularly well suited for use as a dissector for separating and manipulating tissues. The first tip portion and the second tip portion have been described and depicted in the Figures as being used in connection with a curved end effector. Those of ordinary skill in the art will readily appreciate, however, that the first and second tip portions may be used in connection with a variety of different end effector configurations such as linear endocutters and other types of end effectors without departing from the spirit and scope of the present invention. Thus, the first and second tip portions described above should not be limited solely to use in connection with curved endocutters/staplers. As was described above, the first tip portion may be constructed for attachment to the distal end of a conventional staple cartridge or it may be integrally formed on the end of the staple cartridge. In still other embodiments, the first tip portion may be constructed for attachment to a distal end of the channel or it may be integrally formed on the distal end of the channel. Similarly, the second tip portion may be constructed for attachment to a conventional endocutter anvil or it may be integrally formed on the distal end of the anvil. In those applications wherein the first tip portion and/or second tip portion are fabricated separately from the cartridge and anvil, respectively, the tip portions may be supplied as a kit for retrofitting onto the cartridge and anvil by the end user. For example, in such arrangements, the tip portions may be presterilized and packaged and be configured to snap onto or otherwise attach to the staple cartridge and anvil or channel and anvil, whichever the case may be. The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, the device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps of disassembly of the device, followed by cleaning or replacement of particular pieces, and subsequent reassembly. In particular, the device can be disassembled, and any number of the particular pieces or parts of the device can be selectively replaced or removed in any combination. Upon cleaning and/or replacement of particular parts, the device can be reassembled for subsequent use either at a reconditioning facility, or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application. Preferably, the invention described herein will be processed before surgery. First, a new or used instrument is obtained and if necessary cleaned. The instrument can then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument are then placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, or high-energy electrons. The radiation kills bacteria on the instrument and in the container. The sterilized instrument can then be stored in the sterile container. The sealed container keeps the instrument sterile until it is opened in the medical facility. While this invention has been described as having exemplary designs, the present invention may be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.

In various embodiments, an end effector for use with a surgical instrument is disclosed comprising a linear portion, a first jaw, and a second jaw moveable relative to the first jaw, wherein one of the first jaw and the second jaw comprises a plurality of staple cavities arranged in a plurality of curved staple cavity rows, and wherein the curved staple cavity rows curve in a first direction. The end effector further comprises a curved path extending between two curved staple cavity rows of the plurality of curved staple cavity rows, wherein the curved path curves in the first direction, and a drive assembly extending along at least a portion of the linear portion, wherein the drive assembly comprises a cutting element structured to travel along the curved path, wherein the cutting element comprises a distal pre-biased cutting edge structured to lead the cutting element in the first direction.

FIELD OF INVENTION This invention relates to a process to extract residue from hydrogenated nitrile rubber (HNBR). BACKGROUND OF THE INVENTION Processes are known to remove residue from rubber. Most typically, the rubber is dissolved in a suitable solvent and a physical or chemical process is then used to separate the rubber from the undesirable residue. This type of process is cumbersome, particularly if toxicological concerns exist regarding the solvent, because it requires the handling of a large volume of viscous rubber solution. Thus, a need exists for a process to remove residue from solid rubber without dissolving the rubber. It is an object of the present invention to provide a process to extract residue from hydrogenated nitrile rubber without substantially dissolving the rubber. SUMMARY OF THE INVENTION Although the process technology as generally described herein may be suitable for the extraction of a wide variety of residues (for example, residual solvent, residual monomer, residual catalyst) from a wide variety of rubbers (such as butyl rubber and its halogenated derivatives, acrylonitrile-butadiene rubber, ethylene-propylene copolymers and terpolymers, and polybutadiene), the present invention relates solely to a process to extract residue from hydrogenated nitrile rubber. Thus, in accordance with the present invention, there is provided: a process to extract residue from hydrogenated nitrile rubber, consisting of: (i) adding residue-containing hydrogenated nitrile rubber to a mixing/kneading zone which comprises a housing with at least one mixing shaft therein, said mixing shaft having mixing elements attached thereto and being rotatably mounted within said housing; (ii) adding from 20 to 500 parts by weight, per 100 parts by weight of said rubber, of an extractant liquid to said mixing/kneading zone; (iii) subjecting said hydrogenated nitrile rubber and said extractant liquid to a period of continuous mixing/kneading within said mixing/kneading zone, at a temperature below the boiling point of said extractant liquid; (iv) repeatedly mechanically cleaning the mixing/kneading zone; (v) discharging said hydrogenated nitrile rubber and said extractant liquid from said mixing/kneading zone; and (vi) separating said liquid from said rubber; characterized in that said process is completed without the addition of a solvent for said hydrogenated nitrile rubber. The extractant liquid is essential to the present process. Whilst it is not intended that the invention should be limited by any particular theory, it is believed that the extractant becomes dispersed throughout the without substantially dissolving the rubber) during the mixing/kneading process. The extractant liquid extracts residue from the hydrogenated nitrile rubber during the mixing and kneading step. The extractant liquid, containing residue, is then separated from the hydrogenated nitrile rubber. It will be clear from the above description that the extractant liquid must be miscible with at least part of the residue contained in the hydrogenated nitrile rubber. However, the extractant must not be a good solvent for the rubber. Suitable examples of the extractant liquid include lower alcohols (such as methanol and ethanol), acetonitrile, and perchloroethylene. More than one extractant may be employed. The term hydrogenated nitrile rubber as used herein refers to the product which is obtained by hydrogenating an unsaturated polymer of a C 3-5 , α,β unsaturated nitrile and a C 4-6 conjugated diene (for example, acrylonitrile-butadiene rubber). Hydrogenated nitrile rubbers are sold under the trade name ZETPOL by Nippon Zeon. A process to prepare hydrogenated nitrile rubber is described in U.K. Pat. No. 1,558,491, the disclosure of which is incorporated herein by reference. It will be clear to persons skilled in the art that hydrogenated nitrile rubber may contain residue remaining from the hydrogenation process, such as residual catalyst, residual co-catalyst, residual solvent and/or residue which may have been contained within the nitrile rubber prior to hydrogenation. Thus, although the present invention relates to a "solvent-free" process (meaning that no solvent for the rubber is added during the process), it must be recognized that a minor amount of solvent may be contained within the rubber as a residue. Residue is removed from hydrogenated nitrile rubber in the present process with the assistance of an extractant liquid. The amount of extractant employed is from 20 to 500 parts by weight per 100 parts by weight rubber, preferably from 30 to 200 parts by weight. It is particularly preferred to further include in the extractant fluid a chelating agent, such as thiourea or alkyl bromide. Preferred embodiments of the invention will now be described in detail, with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic representation of an apparatus and process flow sheet for removing residue from hydrogenated nitrile rubber. FIG. 2 is a detailed diagrammatic view partly in section of a mixing/kneading zone of the apparatus of FIG. 1, taken along the line 2--2 of FIG. 1 so as to show the lower part in plan; FIG. 3 is a perspective view of the mixing/kneading zone of FIG. 2; FIGS. 4a and 4b are cross-sectional views of the apparatus along the lines 4a--4a and 4b--4b respectively of FIG. 2; FIG. 5 is a cross-sectional view along line 5--5 of FIG. 2. DESCRIPTION OF THE PREFERRED EMBODIMENTS The mixing/kneading zone into which the hydrogenated nitrile rubber and extractant liquid are introduced is suitably an apparatus equipped with mixing/kneading elements to which the rubber/liquid mixture is brought into continuously moving contact. The function of the mixing/kneading elements is to ensure continuous intimate mixing of the mixture in the zone, and to ensure that the mixture is in continuously moving contact with the mixing surfaces. It is believed that the mixing generates new rubber surfaces which assist with mass transfer of residue from the rubber to the extractant liquid. There is preferably no dead-space within the mixing/kneading zone. Preferably, the apparatus constituting the mixing/kneading zone is in the form of a stationary drum, equipped with rotary mixing/kneading elements arranged to wipe continuously against the interior of the boundary walls as they rotate and perform their mixing/kneading function. The boundary walls and/or the mixing/kneading elements may be heated. In this way the rotary mixing/kneading elements serve to clean the mixing zone walls as they mix and knead. These mixing/kneading elements can be paddles, arms, bars, discs, disc segments, pins or combination thereof. These elements are preferably mounted on at least one rotatable shaft within the housing. The use of two shafts is particularly preferred and such shafts may be either co-rotating or counter-rotating during operation and the mixing/kneading elements on the shafts may intermesh or be non-intermeshing during operation. The shaft or shafts may also reciprocate as well as rotate. Also in the preferred embodiment, a further set of rotary elements is provided, to move relative to the rotary mixing/kneading elements, and arranged to wipe against the mixing/kneading elements as they rotate and thereby clean the surfaces of the mixing/kneading elements, and the rotary shaft on which they are mounted, as the mixing and kneading proceeds. Such an apparatus is available on the commercial market, for example that known as the AP CONTI, available from List A.G., of Pratteln, Switzerland. Preferably, the mixing/kneading zone is divided into sub-zones. This can be effected using weirs or baffles mounted on the housing or by using discs on the shaft or shafts. Also preferred is to have liquid removal means in at least one of the sub-zones. This liquid removal means is located in the lower half of the housing and is preferably provided with means to keep the liquid removal means clear of rubber. In practice, the mixing/kneading zone is maintained from about one quarter to about three quarters full of mixture to allow sufficient mixing/kneading space within the mixing/kneading zone for efficient residue removal. This zone can be operated at any suitable pressure, i.e. atmospheric, below atmospheric or above atmospheric, within the tolerance limits of the chosen apparatus. The temperature is maintained below the boiling point of the extractant liquid. In one preferred embodiment of the present invention, the rubber discharged from the mixing/kneading zone is supplied to a devolatilizing extruder thereby yielding rubber containing essentially no extractant liquid and which is suitable, after cooling, for packaging. The operation of the residue removal process will now be described with reference to FIG. 1. Hydrogenated nitrile rubber is introduced in a continuous manner, into the mixing/kneading apparatus 30 through the inlet 40, near the forward end 33. In one embodiment of the invention, extractant liquid is added co-currently through inlet port 46. The rubber/extractant mixture is mixed and kneaded in the apparatus 30. The temperature of the mixing/kneading zone is slightly below the boiling point of the extractant liquid. When the rubber and extractant enter the apparatus 30, they contact the moving internal surfaces of the mixing zone (such as mixing shaft 80 and cleaning shaft 82, illustrated in FIG. 2). The moving internal surfaces of the apparatus 30 mix and knead the mixture, which is transported towards the downstream end 34. The extractant liquid is removed at drain 101, and the rubber is discharged through the extruder 62. This extruder 62 is provided with a jacket 64 through which heat transfer medium can flow. The extractant liquid contains residue which has been removed from the rubber. In this preferred embodiment, the rubber which is discharged from the extruder 62 is ready for final finishing (which may include devolatilization, drying and packaging). In the continuous process described above, the hydrogenated nitrile rubber (HNBR) is continuously added at 40, and is withdrawn from the extruder 62 at a similar rate. It will be apparent that the process may be operated with the extractant liquid being added counter-currently (rather than co-currently, as described above). It will also be apparent that the process could be completed batch-wise, using a mixing/kneading apparatus which is designed for batch use. The mixing/kneading apparatus 30 will now be described in more detail with reference to FIGS. 1 to 5. The apparatus has an internal mixing/kneading zone and is shown in FIG. 2 as consisting of three interconnected, commercially-available AP CONTI modules 66 similar to the apparatus described in U.S. Pat. No. 3,689,035. All the modules are not identical: they may be equipped with vent ports, drain openings and the like. However, all the modules are of otherwise similar configuration. From three to ten of such modules 66 can be interconnected to form the mixing/kneading apparatus. These modules 66 each have a housing 67 with a "Figure 8"-shaped cross-section (FIG. 4a). One portion of the cross-section (FIG. 3) is the main housing portion 68 and the other portion is the auxiliary housing portion 70. The housing 67 as a whole is provided (FIG. 2) with an outer jacket 72, for heating and cooling purposes. The jacket is suitably designed for handling pressurized fluids up to about 12 atmospheres at temperatures up to about 350° C. The modules are interconnected via spacer plates 74, 76 shown on FIGS. 4a and 4b, which are of two different types. Spacer plate 74 is simply a metal gasket, of the same size and periphery as the ends of the modules it interconnects. It allows for free flow and communication of materials contained in the mixer, between one module and the next. Spacer plate 76 is a metal gasket equipped with a weir plate extending part way up from the bottom periphery and having a straight horizontal upper edge, with appropriate indentation to accommodate the shafts of the mixing/kneading apparatus, so as to provide a weir between adjacent modules, whereby hold-up and thus residence time of material in a given module can be controlled. The height of the upper edge of the spacer plate 76 may be adjusted for this purpose. The upstream end 33 and the downstream end 34 (FIG. 1) of the apparatus are each provided with "Figure 8"-shaped flanged covers 75 and 75' (FIG. 2). At the upstream end 33 of the apparatus, there is provided a transmission 77 and a drive motor 78 capable of providing variable speed rotation to each shaft. Each module has two hollow shafts 80, 82 rotatably mounted therein, the first mixing shaft 80 being located in the main housing portion 68 and the other, cleaning shaft 82 being parallel to the mixing shaft 80 and located in the auxiliary housing portion 70. At the inlet end of the apparatus, packing rings 86 are located between the shafts 80, 82 and the flanged cover 75. At the outlet end of the apparatus, shafts 80 and 82 are supported and rotate on bearings 87. As best shown in FIG. 3, mounted on the mixing shaft 80 are axially spaced, radially extending, disk-shaped hollow segments 88 arranged in four circumferentially spaced sets, each set extending helically down the shaft 80, only two of which are shown in FIG. 3 for clarity purposes. Each set of segments 88 is connected together along the leading periphery by kneading bars 90 which extend along a helical line from one end of the shaft 80 to the other. These kneading bars contact the inner surface of the main housing portion 68. The cleaning shaft 82 has one set of helically arranged, radially extending arms 92 with adjacent pairs of these arms 92 being interconnected by cleaning bars 94 to provide a hurdle-type arrangement. These cleaning bars 94 contact the inner surface of the auxiliary housing portion 70. The helical angle of the arms 92 is greater than that of the mixing shaft kneading bars 90 and is chosen so that the arms 92 of the cleaning shaft 82 mesh with and clean the sides of the disk-shaped hollow segments 88 of the mixing shaft 80 upon rotation of the two shafts 80, 82. Also, the height of the upper surfaces of the cleaning bars 94 is arranged so that they can wipe the undersurface of kneading bars 90 and the surface shaft 80. End wall wipers 97 are optionally provided (FIG. 2) at each end of the mixing shaft 80 to wipe the inside surfaces of the flanged covers 75 and 75'. Spacer plate 76 as shown in FIG. 4b may be wiped with additional wipers which may be provided on the shafts for that purpose. Suitably, the motor and transmission can drive the mixing shaft at 3-20 rpm and the cleaning shaft at 12-80 rpm. The speed ratio of the mixing shaft to the cleaning shaft is preferably essentially constant at from 1:2 to 1:6, most preferably at about 1:4. At the downstream end 34 of the apparatus 30, the flanged cover 75', as can be best seen in FIG. 5, is provided with a vertical slot 98 extending from apex 99 to apex 100 of the "Figure-8"-shaped cross-section of the housing and with circular apertures for bearings 87 to support shafts 80 and 82. This slot 98 provides communication to the downwardly extending discharge extruder 62. Also provided toward the downstream end 34 of the apparatus 30 is a drain opening 101 indicated in FIGS. 1, 2 and 4a. This drain opening is suitably covered by a screen to retain rubber. This screen is most suitably made up of tri-rod or iso-rod screen bars, a wire mesh, or a plate with plurality of small holes therein. The discharge extruder 62 is provided with a variable speed drive (not shown) so that suitably the screw of the extruder can be driven at speeds from 10-200 rpm. It will be noted that the apparatus 30 of the preferred embodiment described above is an apparatus provided with vents, drains, etc. Material is moved downstream therein, not by the rotation and disposition of the mixing elements, but is gently pushed by the kneading bars 90 and 94, with positive discharge, out of exit slot 98 into extruder 62. The apparatus 30 is in no sense an extruder, because the mixing/kneading elements are not capable of compressing the rubber for the apparatus to act as an extruder. The process will be further described with respect to the following, non-limiting examples which were carried out using either a continuous process or a batch process. EXAMPLE 1 A hydrogenated nitrile rubber was prepared with a rhodium-based catalyst and a triphenyl phosphine based co-catalyst. Analysis of this rubber showed it to contain 116 ppm Rh and 1.46 weight percent triphenyl phosphine. The rubber was introduced into an A. P. Conti machine operated in a continuous manner. The machine was operated at atmospheric pressure, after heating it to about 60° C. and setting the main rotor speed set at 6.5 rpm and the cleaning rotor speed set at 26 rpm. The rubber feed rate was about 25 Kg per hour. Methanol, added counter-currently at a rate of 30 liters per hour, was used as the extractant fluid. Rubber was collected from the discharge end and subjected to analysis. The rhodium content was determined to be reduced to 86 ppm and the triphenyl phosphine concentration was found to be 1.18 weight percent. A sample of the extractant fluid was also analyzed, and found to contain 15 ppm Rh and 0.04 weight percent triphenyl phosphine. EXAMPLE 2 Rubber which was treated in the manner described in Example 1 was re-introduced into the same A. P. Conti machine, operating under the same temperature and speeds of rotation. Thus, once-extracted rubber was added to the machine in a continuous process, at a rate of about 32 Kg per hour. The extractant fluid used in this example was thiourea-in-methanol (0.1 weight/volume percent), and was added at a rate of 30 liters/hour. Three samples of hydrogenated nitrile rubber were analyzed and found to contain 66, 71 and 69 ppm of Rh, respectively, indicating a further reduction in the amount of Rh contained in the rubber. EXAMPLE 3 This example illustrates a batch extraction process. 2.4 Kg of hydrogenated nitrile rubber containing 1.2% weight percent residual solvent (chlorobenzene) was added to a batch kneading/mixing machine, manufactured by List. 2.4 Kg of methanol were also added to the machine. The machine was operated at about 60° C. and atmospheric pressure, well below boiling conditions for methanol. After 60 minutes, 1.6 Kg of the extractant fluid was drained. A sample of the rubber was analyzed and found to contain about 0.8 weight percent chlorobenzene. 1.6 Kg of fresh methanol was then added to the machine, and the process was repeated at about 60° C. for a further 60 minutes. The extractant fluid was then drained. A sample of the rubber was analyzed and found to contain 0.4 weight percent chlorobenzene.

The present invention relates to a process to remove residue from partially hydrogenated nitrile rubber. The process is undertaken by mixing and kneading the rubber in the presence of an extractant fluid. The extractant fluid is a solvent for the residue but is not a solvent for the rubber. At the conclusion of the process, the rubber is separated from the residue-containing extractant fluid.

This invention relates to a photosensor using a solid state CCD (Charge Coupled Device) chip, the chip design of the CCD, and further to an application of the photosensor to a spectrophotometer. BACKGROUND A photosensor using a CCD has a great advantage in that only one amplifier is needed for the output signal because it has a simple one output terminal. But its rather narrow dynamic range has limited the application. For example, a common spectrophotometer requires a very wide dynamic range which the conventional normal CCD photosensor cannot cover. Japanese laid-open patent publication No. S62-76765 discloses one solution to the problem: the floating diffusion of the output section of a CCD device is given a knee-shape characteristic to prevent saturation or overflow. This widens the dynamic range, but the output from this device does not have a linear relationship with the strength of the sensed light, and needs a linearlization circuit. Further it is difficult to obtain a stable knee-characteristic due to manufacturing deviations. Japanese laid-open patent publication No. S63-63928 proposes another solution: the charge-generating time (integration time) is switched from one to the other. This device also requires an additional device control, and it cannot respond to a momentary change in the light strength. SUMMARY OF THE INVENTION The CCD photosensor used in the spectrophoto-measurement requires not only the wide dynamic range but also high accuracy, reliability and stability of the output in relation to the input light amount. This is the point that greatly differs from normal CCD photosensors used in imaging devices (or those used in video cameras). When an accurate spectrophoto-measurement is to be performed, other cares (than improving the CCD photosensor) should be taken. That is, the incident light should be strictly decomposed into monochrome lights each having a narrow band of wavelength and should not include other components. The objects of the present invention is therefore: To provide a CCD photosensor that ensures an accurate, reliable and stable spectrophoto-measurement while giving a wide dynamic range of the measurement. Some measures of the present invention address this object by increasing the charge amount handled in every part of the CCD photosensor. To provide an optical configuration to serve enhancing the accuracy of the spectrophoto-measurement. To provide various signal processing methods for correcting the raw outputs of the CCD photosensor including some error by the transfer inefficiency. To achieve these various objects, the CCD photosensor and the spectrophotometer according to the present invention adopts the following measures. a. A plurality of bandpass filters are used in combination with a spectrofilter to eliminate the influence of undesirable sidebands inevitably accompanying the object monochrome light when passing through the spectrofilter (cf. FIG. 4). This optical configuration enhances the accuracy and reliability of the spectrophoto-measurement. b. A high-sensitivity photosensor and a low-sensitivity photosensor are used to simultaneously sense an incident light (cf. FIGS. 9 and 10). The output of the high-sensitivity photosensor is adopted as the output of the integrated photosensor unless it is saturated. In any case, the output from either sensor is normalized to make the final output proportional to the incident light (cf. FIG. 28). This integrated photosensor widens the dynamic range. c. A common transfer register array is placed between the two photosensor arrays (an array of high-sensitivity photosensors and an array of low-sensitivity photosensor arrays) in a CCD photosensor. Output signals of the both high- and low-sensitivity photosensors are sequentially obtained through one output terminal (FIGS. 18, 19 and 22). This simplifies the output amplifier and other peripheral circuits when the two (high- and low-sensitivity) photosensor arrays are simultaneously used. d. The photodiode is completely buried in the substrate, which fixes the potential of the photodiode. The charge storage is also buried in the substrate and placed directly adjacent to the photodiode (FIGS. 16, 17 and 23). This structure enables omitting a barrier gate between them which formed a charge sink causing a rather great dark output. e. The overflow gate of the CCD photosensor is controlled by a pulse signal so that the applied bias is set low (the potential of the overflow gate is high) when the photoelectric converting process is being carried out (and the charges are produced) at the photodiodes, while the bias is set high (the potential is low) when the photoelectric process ends to drain the excessive charges on the photodiodes that has not been transferred to the storage (cf. FIG. 14). This reduces the amount of residue charges causing the "lag", and enables an increase in the amount of charges produced in a photodiode and thus reduces the influence of shot noises on the output signal. f. The charge storage of the CCD photosensor is applied with a pulse voltage that lowers the potential at the storage when the charges are being stored, while raises the potential when the charges are transferred to the transfer register (cf. FIGS. 14 and 15). This reduces the amount of residue charges, whereby the "lag" of the output is eliminated. g. The charge storage is divided into two parts and potential differences are given to those parts to increase the total charge capacity while maintaining the charge readout time short (cf. FIGS. 11 and 12). This increases the handling charge amount at the storage. h. A MOS capacitor is provided to the floating diffusion of the output circuit of the CCD photosensor chip to increase the charge handling amount at the output section (cf. FIG. 21). i. The overflow drain is placed between neighboring photodiodes to reduce the "crosstalk" (charge leakage) between them. The overflow drain is formed by the N + diffusion process after the polysilicon patterns are formed on the CCD chip, avoiding interference with the overflow gate (cf. FIGS. 11 and 13). j. The influence of the transfer inefficiency is eliminated from the output signal by a correction calculation and the simplified measurement of the transfer inefficiency (cf. FIG. 32). k. The transfer inefficiency is compensated for by a hardware configuration of the photodiodes and transfer registers, and an appropriate transfer driving method. BRIEF EXPLANATION OF THE ATTACHED DRAWINGS FIG. 1 schematically shows the structure of a spectrophotometer embodying the present invention. FIG. 2(a) and 2(b) are a diagram and a graph explaining the decomposition of the incident light and the sensing of the decomposed monochrome light. FIG. 3 is a graph showing the unnecessary passing bands accompanying the principal light passing at a position of the spectrofilter of the spectrophotometer. FIG. 4(a) is a plan view of the CCD, spectrofilter and bandpass filter of the embodiment, and FIGS. 4(b) and 4(c) are cross-sectional views respectively taken along lines IV-B--IV-B and IV-C--IV-C of FIG. 4(a). FIGS. 5(a), 5(b), 5(c), 5(d), 5(e) and 5(f) are graphs for explaining how the bandpass filter works in the embodiment. FIGS. 6(a) and 6(b) are graphs showing the continuity of the two CCD arrays of the embodiment. FIG. 7 is a spectrum diagram according to the spectrophotometer of the embodiment. FIG. 8 is a block diagram showing the electrical connection of the embodiment. FIG. 9 is a plan view of a CCD photosensor array and the output section according to the embodiment. FIGS. 10(a) and 10(b) are graphs for explaining how the dynamic range of the present embodiment is expanded. FIG. 11 shows the layer structure of the CCD chip of the embodiment. FIG. 12(a) is a cross-sectional view taken along line XII--XII of FIG. 11, and FIG. 12(b) is a potential diagram of the cross-section. FIG. 13(a) is a cross-sectional view taken along line XIII--XIII of FIG. 11, and FIG. 13(b) is a potential diagram of the cross-section. FIGS. 14(a-1), 14(a-2), 14(a-3), 14(a-4), 14(a-5), 14(a-6), 14(b-1), 14(b-2), 14(b-3), 14(b-4), 14(b-5) and 14(b-6) are potential diagrams showing how the charges are transferred to the transfer register. FIG. 15 is a timing chart corresponding to the process of FIG. 14. FIG. 16 is a cross-sectional view of a CCD of the embodiment having a two-part storage. FIGS. 17(a) and 17(b) are cross-sectional views and their potential diagrams of two typical examples of layer structure of a photodiode. FIG. 18 shows the layer structure of the transfer registers of the CCD chip of the embodiment. FIG. 19 is another example of the layer structure of the transfer registers. FIG. 20 is a timing chart of the transfer-driving pulses corresponding to the example of FIG. 19. FIG. 21 is a plan view of the output section of the CCD of the embodiment. FIG. 22 shows a layer structure of the transfer registers of the CCD as another embodiment of the present invention. FIG. 23 shows a layer structure of the photosensing section of the CCD of the embodiment. FIGS. 24(a) and 24(b) are a cross-sectional view taken along the line XXIV--XXIV of FIG. 23 and its potential diagram. FIGS. 25(a) and 25(b) are a cross-sectional view taken along the bending line XXV--XXV of FIG. 23 and its potential diagram. FIG. 26 is a flowchart of the spectrophoto-measurement according to the embodiment. FIG. 27 is a flowchart of a subroutine for selecting either one of the two CCD arrays of the CCD chip of the embodiment. FIG. 28 is a flowchart of a subroutine for selecting one of two outputs from the high-sensitivity and low-sensitivity photosensors. FIG. 29 is a circuit diagram of a temperature sensor of the CCD chip of the embodiment. FIGS. 30 and 31 are a timing chart and potential diagrams showing how two packets are added by the hardware. FIG. 32 is a matrix equation between the outputs and the original charge amounts. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention is a spectrophotometer, in which incident light is decomposed into many monochrome lights using a spectrofilter, and each monochrome light is sensed by a photodiode in a CCD line sensor including an array of photodiodes. This spectrophotometer can be used in analyzing light reflected from an object surface. The description of the embodiment is conducted as: I Principle and structure of a spectrophotometer II Structure of a CCD line sensor used in the spectrophotometer of the present embodiment (1) CCD and peripheral components (2) Structure of a photoelectric cell of the CCD line sensor and its operation First example Second example (3) Structure of the common transfer registers and their operation First example Second example Third example (4) Structure of the output terminal of the transfer registers III Operation of the CCD line sensor and the signal processing (1) Correction of the output for the transfer inefficiency First example Second example Third example (2) Spectrophoto-measurement Selection of the effective pixel Compensation for the dark output Correction for the sensitivity deviations I Principle and structure of a spectrophotometer The spectrophotometer embodying the present invention is constructed, as shown in FIG. 1, mainly of a bandpass filter 6, spectrofilter 1 such as an interference filter and a CCD line sensor 2. At one point, the spectrofilter 1 passes a monochrome light having a certain wavelength ("principal wavelength"), and the principal wavelength varies continuously along the X-axis while fixed along the Y-axis. One example of such spectrofilter 1 is made as follows: Glass/(HL).sup.2 2H(LH).sup.5 /Air, where H represents a dielectric layer with high refractive index, and L represents a dielectric layer with low refractive index. By determining the thickness d of each layer considering the following formula, such spectrofilter 1 can be obtained. n·d/λ=1/4, where n is the refractive index of the layer, and λ is the principal wavelength. The strength of lights of various wavelengths passing a certain point (X o ,Y o ) of the spectrofilter 1 is shown in FIG. 3. Besides the principal light having wavelength of λ o , unnecessary lights with wavelength shorter than λ o -λ s and longer than λ o +λ L passes the spectrofilter 1. When TiO 2 is used in the dielectric layer with high refractive index and SiO 2 is used in the dielectric layer with low refractive index, λ S and λ L is about 0.15 times λ o . In using the spectrofilter 1 in the 400-700 nm wavelength region, λ S and λ L are about 75 nm at the principal wavelength λ o of 500 nm, which means that light with wavelength shorter than 425 nm and longer than 575 nm passes besides the principal wavelength λ o =500 nm. It is for this reason that the bandpass filter 6 is placed over the spectrofilter 1, as shown in FIG. 1. Under the spectrofilter 1 is placed a CCD line sensor 2 having a plurality of unit photocells (pixels). As shown in FIGS. 2(a) and 2(b), the incident light 3 coming down in the Z-direction first passes through the bandpass filter 6 to be cut off the unnecessary sidebands, then through the spectrofilter 1 to be decomposed into monochrome lights, as with λ 1 and λ 2 , and finally enters the CCD line sensor 2 to be converted into electric signals 5a and 5b representing the intensity of the respective monochrome lights. II Structure of a CCD line sensor used in the spectrophotometer of the present embodiment (1) CCD and peripheral components Geography of photocells (pixels) of the CCD line sensor 2, the spectrofilter 1 and the bandpass filter 6, as well as the spectroscopy by the arrangement, is explained with reference to FIGS. 4 through 7. As shown in FIG. 4(a), the CCD line sensor 2 of this embodiment is composed of two arrays CCD-A and CCD-B of pixels, and the bandpass filter 6 is composed of four segments 3-a, 3-b, 3-c and 3-d. A set of two segments (3-a, 3-c) or (3-b, 3-d) covers an array CCD-A or CCD-B, and the member segments of each set differ in the passing band. The spectroscopy is explained referring to the bottom left segment 3-a of the bandpass filter 6. The transmission characteristic of the spectrofilter 1 at the pixel 2-a is shown in FIG. 5(a), and that at the pixel 2-e is shown in FIG. 5(c). The transmission characteristic of the bandpass filter segment 3-a is shown in FIG. 5(e), in which the shortside cutoff wavelength λ CS and the longside cutoff wavelength λ CL are set to satisfy the inequality λ.sub.Se <λ.sub.CS <λ.sub.a, and λ.sub.e <λ.sub.CL <λ.sub.La, where λ Se is the longest wavelength of the shortside unnecessary transmission band of spectrofilter 1 at pixel 2-e, λ La is the shortest wavelength of the longside unnecessary transmission band at pixel 2-a, λ a is the principal transmission wavelength at pixel 2-a, and λ e is that at pixel 2-e. Therefore, the overall transmission characteristic inclusive of the bandpass filter 6 and the spectrofilter 1 are as shown in FIGS. 5(b) and 5(d) respectively at pixels 2-a and 2-e, and the final spectrogram at the pixels 2-a through 2-e are as shown in FIG. 5(f) where the principal wavelengths sensed by the pixels 2-a through 2-e change at a constant pitch. The continuity between the group of pixels 2-a through 2-e in the line A (CCD-A) and the group of pixels 2-f through 2-k in the line B (CCD-B) is now explained. The spectrograms of the two groups are shown in FIGS. 6(a) and 6(b) respectively. In each group, the principal wavelengths of the pixels differ at a constant wavelength-pitch because the pixels are placed at a constant site-pitch. Though the pixels in the line B is separated from those in the line A in the Y direction, the pixel 2-e and the pixel 2-f are arranged to place at the same X-coordinate. The pixel group (2-f through 2-k) and the pixel group (2-l through 2-q), and the latter and the group (2-r through 2-w) have the same relations. By so arranging the two line pixels 2-a through 2-w, the spectrofilter 1 and the bandpass filter segments 3-a through 3-d, the incident light is decomposed into monochrome lights with wavelengths separated equally in the range 400-700 nm, whereby an accurate spectrophotometry can be achieved. The same incident light is simultaneously sensed by two pixels in different lines in the above structure in order to always obtain the continuous output as shown in FIG. 7 when one of the pixel does not produce a normal output due to a manufacturing failure of the bandpass filter 6 or so and the above inequality of the cutoff wavelengths does not stands. (2) Structure of the photoelectric cell of the CCD line sensor and its operation As described above, the CCD line sensor chip 7 includes the two linear pixel arrays CCD-A (8-a) and CCD-B (8-b). The chip 7 further includes a temperature sensor 8-c for compensating for the thermal drift of the photosensing outputs. Temperature sensor: An example of the temperature sensor 8-c is shown in FIG. 29. This example uses a depletion-type MOS-FET 80, which adopts the same buried structure as the CCD photosensor (described later) with N - layer on the P-substrate. The gate and the source of the FET 80 both connects to the ground, whereby this FET 80 works as a constant-current source whose current changes according to the chip temperature. Suppose the carrier concentration in the N - layer is 1×10 16 cm -3 , and its depth is 1.0 μm, the current I (T) at temperature T is I (T)=I (T.sub.o)·{1+α.sub.1 ·(T.sub.1 -T.sub.o)}, where T o is a reference temperature. In the above case, the thermal coefficient α 1 is about 5600 ppm. The drain of the FET 80 connects to the source voltage B (12 V) via a resistance 81 of 20 kΩ, which is prepared outside of the chip 7, having thermal coefficient of ±150 ppm. The temperature-dependent voltage at the junction of the drain and the resistance 81 is detected at the output terminal 83 through a buffer amplifier 82 for impedance matching. If the current through the FET 80 is set at 50 μA, the working point of the output is 11 V, and the output deviation due to temperature change is ΔV.sub.TMP /(T-T.sub.o)=5.5 mV/deg, which makes a high sensitivity temperature sensor. Signal processors: Returning to FIG. 8, the outputs from the pixel arrays 8-a and 8-b and the temperature sensor 8-c (OSA, OSB and TMP respectively) are transmitted through the multiplexer 9 to an analog signal processor 10 as a signal OS. The analog signal processor 10 shapes and amplifies the output signal OS of the CCD line sensor 7 to make a signal V OS to pass to an A/D converter 11. The signal V OS is digitized in the A/D converter 11 and is sent to a microcomputer 12 with an A/D-end code EOC. Controllers: A clock pulse generator 14 generates clock pulse signal CP using a crystal oscillator to give it to a pulse generator logic circuit 15. Using the clock pulse signal CP and CCD control signals HRS and LRS from the microcomputer 12, the pulse generator logic circuit 15 generates various CCD driving pulse signals, such as φ OFG , φ 1 , φ 2 , φ 3 , φ 4 , φ RS , φ LSH , φ LST , φ HSH and φ HST , and sends them to an interface circuit 16. The pulse generator logic circuit 15 further makes and sends signal-processing-timing pulse signals φ S/H and φ ARS to the analog signal processor 10, and an A/D-starting pulse signal φ ADS to the A/D converter 11. The interface circuit 16 changes the amplitude of the received pulse signals to adapt to the CCD level, and includes itself a DC-bias generator to be used for the CCD sensor 7. The spectrophotometer of the present embodiment uses a strobe light as the light source, so a strobe driving circuit 13 is prepared under the control of the microcomputer 12 by a strobe trigger signal STT. CCD line sensor: Since the pixel arrays CCD-A and CCD-A have the same structure, the following description is made for one of them CCD-A 8-a (which will be simply referred to as CCD). The structure of the CCD is as shown in FIG. 9, in which the X and Y directions are the same as those in FIG. 1 (i.e., the principal wavelength of light passing through the spectrofilter 1 changes in the X direction but fixed in the Y direction). A significant structure of the CCD of the present embodiment is that it has two kinds of photosensor rows: one 30 having high sensitivity and the other 31 having low sensitivity. The high-sensitivity photosensor rows 30 and the low-sensitivity photosensor rows 31 are placed parallel along the X direction with a common transfer register 23 between them. Outside (top and bottom in FIG. 9) of the two photosensor rows 30 and 31 are placed overflow drain 17 and 24 to drain charges overflowing from the photodiodes 19 and 26 of the photosensors 30 and 31. The drainage of each overflow drain 17 or 24 is controlled by an overflow gate 18 or 25. Electrical charges generated at the photodiodes 19 and 26 are transferred via barrier gates 20 and 27 to storages 21-a, 21-b, 28-a and 28-b, and are temporarily stored there. Then the charges are transferred to the common transfer registers 23 via transfer gates 22 and 29, and the linearly arranged transfer registers 23 transfer the charges from one to the neighbor until the output of this CCD. As described before, light passing through a certain X-directional position X o of the spectrofilter 1 enters simultaneously into a high-sensitivity photodiode 19 and into a low-sensitivity photodiode 26. In this embodiment, one 19 of the photodiodes has a larger surface area than the other photodiode 26 so that the larger photodiode 19 has the higher sensitivity. In this embodiment, since the transfer registers 23 are commonly used for the high-sensitivity photosensors 30 and low-sensitivity photosensors 31, the number of the transfer registers 23 is the sum of the number of photodiodes 19 and 26 of the both photosensors 30 and 31, and the site-pitch of the transfer register array 23 is half that of the photodiode array 19 or 26. The charges generated in the high-sensitivity photodiodes 19 (A1, A2, . . . ) and temporarily stored in the respective storages 21-a and 21-b are transferred to the transfer registers at odd numbers (C1, C2, . . . ) by applying a bias voltage on the transfer gate 22, and the charges generated in the low-sensitivity photodiodes 26 (B1, B2, . . . ) and temporarily stored in the respective storages 28-a and 28-b are transferred to the transfer registers at even numbers (C1', C2', . . . ) by applying bias on the transfer gate 29. Thus charges of all photodiodes 19 and 26 (A1, A2, . . . , B1, B2, . . . ) are transferred to the transfer registers 23, and then transferred in the transfer registers 23 (C1→C1' →C2→C2'→ . . . ) until the output terminal. The number of charges at the output terminal is converted into a voltage by a capacitor 33, and then it is sent out from the output terminal as the output signal OS (OSA or OSB) via the impedance-matching buffer 35. The output circuit further includes a diode 32 and an FET 34 for discharging the remaining charges before the new (next) charges come in. The above structure of the present embodiment gives a very broad dynamic range to CCD sensors, which is especially suitable for use in spectrophotometer. The reason of the expansion of the dynamic range is explained now. FIG. 10(a) is a graph of output voltage of a conventional CCD sensor against input light amount. In the region I where the coming light amount is less than L o , the output is constant (dark output V dark ) irrespective of the input light amount whereby the sensor is not effective in this region I. In the region III where the input light amount is greater than L 1 , the pixel photosensor is saturated by the generated charges and the output is constant at V sat whereby also the sensor is not effective. After all, the conventional sensor is effective only in the middle region II (whose width is the dynamic range). The dynamic range is approximately 2-3 orders (about 1:100 to 1:1000), which is insufficient to be used in spectrophotometers. In the present embodiment, the CCD sensor includes two kinds of photosensors having different sensitivities as shown in FIG. 10(b). The curve 36a of FIG. 10(b) is the output of the high-sensitivity photosensor and the curve 36b is the output of the low-sensitivity photosensor. In this case: in the region I where the input light amount is less than L ao , both high-sensitivity and low-sensitivity photosensors output the dark voltage V dark and the sensor is not effective; in the region II-a where the input is between La0 to Lb0, the high-sensitivity photosensor produces an output corresponding to the input while the low-sensitivity photosensor outputs the constant V dark ; in the region II-b where the input is between Lb0 to La1, both high-sensitivity and low-sensitivity photosensors produce outputs corresponding to the input; in the region II-c where the input is between La1 to Lb1, the high-sensitivity photosensor outputs the constant V sat while the low-sensitivity photosensor outputs according to the input; and in the region III where the input is greater than Lb1, both outputs are V sat . Thus in this embodiment, the sensor is effective in the regions II-a, II-b and II-c, which is broader than the conventional effective region II. The expanded dynamic range allows its use in spectrophotometers. The effective regions of the high-sensitivity and low-sensitivity photosensors are overlapped in the region II-b because the output can be always obtained even when the limit values La0, La1, Lb0 and Lb1 deviate in the manufacture. Here the detailed structure of the photosensors of the present embodiment is described with reference to FIGS. 11 to 13. Since the high-sensitivity and low-sensitivity photosensors 30 and 31 in FIG. 9 have the same structure except the size, the description is made for the high-sensitivity photosensor 30. As shown in the plan view of FIG. 11, sectional view of FIG. 12(a) along the line XII--XII of FIG. 11, and the potential diagram FIG. 12(b) corresponding to the sectional view of FIG. 12(a), the photodiode PD in this embodiment is a buried type with an N - layer 39 and a P + layer 40 on a P-type substrate 42. Since the N - layer 39 is sandwiched between the P-substrate 42 and the P + layer 40, it becomes a complete depletion layer and its potential is fixed at φ PD . The N + layer 37 makes the overflow drain OFD which drains excessive charges overflowing from the photodiode PD when applied a positive voltage V OFD . The electrode 38 makes the overflow gate OFG, which has a MOS structure with the first polysilicon layer on a P-substrate 42 via SiO 2 layer of 100 nm thickness. A pulse signal is applied on the OFG terminal: when the pulse is at H-level, the potential in the substrate 42 under the OFG electrode 38 is φ OFG .sup.(H) that bears the relation φ OFD <φ OFG .sup.(H) <φ PD ; and when the pulse is at L-level, the potential is φ OFG .sup.(L) that bears the relation φ SUB >φ OFG .sup.(L) >φ PD (φ SUB is the potential of the substrate 42, which is zero). By switching the voltage on the overflow gate electrode 38 ON and OFF, the charge flow between the photodiode PD and the overflow drain OFD 37 can be controlled. The electrode 41 is the barrier gate BG which is made of the first polysilicon layer on the substrate 42 via the 100 nm-thick SiO 2 layer. By applying an appropriate voltage to this BG electrode 41 to make the potential φ BG under the electrode 41 as φ BG <φ PD , the charges in the photodiode PD moves to the storages HST1 and HST2. Electrodes 43 and 44 make two storages HST1 and HST2 respectively each having the MOS structure. The first storage HST1 43 is formed by the first polysilicon layer and the second storage HST2 44 is formed by the second polysilicon layer on the substrate 42 via the 100 nm-thick SiO 2 insulator. Each electrode 43 or 44 is applied a pulse signal and the potentials under the electrodes 43 and 44 when the pulse is in H-level are φ HST1 .sup.(H) and φ HST2 .sup.(H) respectively. Here the voltages applied to the two electrodes 43 and 44 are given a difference of about 1 V to make φ HST1 .sup.(H) <φ HST2 .sup.(H). When the pulse signal is in L-level, the potentials are φ HST1 .sup.(L) and φ HST2 .sup.(L) respectively, and the applied voltages are determined so that always φ PD >φ HST1 .sup.(L) >φ HST2 .sup.(L). The electrode 45 makes the transfer gate HSH with the second polysilicon electrode on the P-substrate 42 via the 100 nm-thick SiO 2 . This HSH electrode 45 also receives a pulse signal, where the potential φ HSH under the electrode 45 is zero when the pulse is at L-level and is φ HSH .sup.(H) at H-level. Here the H-level is set so that φ HSH .sup.(H) <φ HST2 .sup.(L). The electrode 46 of the first polysilicon and the N - layer 47 (with the 100 nm-thick SiO 2 insulator therebetween) make the transfer register having the two-layer polysilicon, four-phase driven structure. In this embodiment, the N - layer 47 exists under a portion (right-hand side in FIG. 12(a)) of the electrode 46, which makes the buried channel transfer register. The other portion of the electrode 46 between the transfer gate HSH 45 and the N - layer 47 makes the surface channel MOS structure. When the pulse signal on the electrode 46 is in L-level, the potential at the surface channel portion is almost zero, and when in H-level, the potential is φ S .sup.(H). At the buried channel portion, the potential is φ B .sup.(L) at L-level and φ B .sup.(H) at H-level. Here the bias voltage on this electrode 46, the doping concentration in the N - layer and its depth are determined so that the potentials φ S .sup.(H) and φ B .sup.(H) of the two portions at H-level become φ B .sup.(H) <φ S .sup.(H) <φ HSH .sup.(L). In FIG. 11, solid lines delimit the first polysilicon layer and broke lines delimit the second polysilicon layer. The XIII--XIII section of the structure is explained referring to FIGS. 13(a) and 13(b). As the N + layer 37 of the overflow drain is formed at the same time as the source-drain of the output FET of the CCD, it is formed after the first polysilicon layer. Since the N + layer 37 should electrically connect to the overflow drain OFD in the XII--XII section (FIG. 12(a)), the overflow gate 38 is partially cut (FIG. 11) to make the connection path. Thus the electrical connection is assured even when the N + layer 37 is formed after forming the first polysilicon layer. The N - layer 39 and the P + layer 40 make a photodiode. Since the upper P + layer 40 completely covers the N - layer 39, the photodiode has the buried structure, and the peripheral excessive portion of the P + layer 40 beyond the N - layer 39 works as the channel stop that prevents formation of the surface channel. The whole chip except the windows at the photodiode portion is covered by a photoprotection layer. As shown by the broken lines in FIG. 13(a), depletion zones 50 and 51 in the P-substrate 42 are formed under the overflow drain 37 and under N - layer 39 of the photodiode. The depth L DOFD of the depletion zone 50 under the overflow drain 37 is greater than that 51 under the photodiode. Therefore, the carriers generated by the photoelectric reaction under the photodiode within the depth L DOFD are trapped by the depletion zone 50 under the overflow drain 37, whereby their leak to the neighbor photodiode is prevented. Carriers generated deeper than the depth L DOFD die out by recoupling before reaching the neighbor photodiode. After all, the "crosstalk" between neighbor photodiodes are minimized in the present CCD, which gives high reliability in quantitative measurement. The integral read-out process is then described referring to FIGS. 14 and 15. Since high-sensitivity and low-sensitivity photosensors are simultaneously used in this embodiment, the CCD should work properly when the high-sensitivity photosensor saturates. So the process is explained separately in the unsaturated case (FIG. 14, (a-1) to (a-6)) and in the saturated case ((b-1) to (b-6)). At time t1 of FIG. 15, the potential state of an unsaturated photosensor is as (a-1) and that of a saturated photosensor is as (b-1) of FIG. 14. Before this time t1, charges generates by the strobe light irradiation in the high-sensitivity and low-sensitivity photodiodes are stored in respective storage HST. The excessively generated charges beyond the capacity of the storage HST overflow to the overflow drain OFD through the overflow gate OFG, whose potential is set at φ OFG .sup.(L). Since φ OFG .sup.(L) <φ HSH .sup.(L), as described before, the excessive charges do not flow into the transfer register RG (a-1) and (b-1). At time t2 when H-level voltage is applied on the overflow gate OFG, its potential lowers to φ OFG .sup.(H) (a-2) and (b-2), and the charges in the photodiode PD flows into the overflow drain OFD, while charges remain in the storage HST and in the barrier gate BG. This drainage is executed to reduce the amount of charges that the transfer registers RG should transfer because too large transfer amount requires enlarged transfer channel width. At time t3, the overflow gate voltage is returned to L-level to raise the potential and stop the drainage (a-3, b-3). At time t4 when H-level voltage is applied on the φ 4 electrode of the transfer register and H-level voltage is applied on the transfer gate HSH, the transfer gate potential lowers to φ HSH .sup.(H) and a part of the charges in the storage HST are transferred to the transfer register RG (a-4, b-4). Then at time t5 when L-level voltage is applied on the storage electrodes HST1 and HST2, respective potentials rise to φ HST1 .sup.(L) and φ HST2 .sup.(L). Since φ HST1 .sup.(L) >φ HST2 .sup.(L) >φ HSH .sup.(H), as described before, the remaining charges in the storage HST transfer to the transfer register RG (a-5, b-5). This potential state is kept until the charges in the storage HST completely transfer to the transfer register RG. If this process requires time longer than half of the transfer clock cycle, the clock may be stopped as needed. After the charges transfer to the transfer register RG, the transfer gate voltage is returned to L-level at time t6 (a-6, b-6). After that, transfer clock pulse signals φ 1 through φ 4 are fed to the transfer register electrodes to output the charges. Now the reason is explained why the storage electrode is divided into two separate portions HST1 and HST2. The CCD of the present embodiment is required to have higher stability than ordinary image-sensing CCDs because it is used for the spectrophotometer. The stability of photosensors is greatly affected by shot noises in the photoelectric conversion process, and the amount of the shot noises is given by the square-root of the amount of generated electrons. Therefore, the ratio of the number of shot noises to the number of generated electrons √N/N can be reduced by increasing the number of electrons N. If the ratio √N/N is designed to be less than 0.03%, N should be greater than 1.1×10 7 (or the charge greater than 1.8 pC). Since, in ordinary CCD line sensors, the number N is about 10 6 , the CCD of the present embodiment needs to deal with 10 to 100 times greater amount of electrons. When a surface channel MOS is used as the electron storage as in this embodiment, the capacity depends on the area, dopant concentration and bias voltage (greater area, higher concentration and higher bias voltage yields greater capacity). For the CCD transfer register, however, higher dopant concentration makes the manufacture process difficult because slight deviations in the concentration and depth of the N-well greatly affects the channel potential. As for the bias voltage, it is restricted by the source voltage of the CCD device, and the greater bias voltage leads to a greater dark output from the storage. After all, increase in the area is the realistic solution to the big charge capacity. Since the width of the storage area is limited by the array pitch of the photodiodes, there is no way but to increase the length. But the elongated storage will need longer read-out time: the charge transfer process through the transfer gate to the transfer register depends on the thermal diffusion of the charges. The time t tr is calculated as t.sub.tr =4·L.sub.st.sup.2 /(π.sup.2 ·D), where L st is the length of the storage and D is the diffusion coefficient. This equation shows that the time t tr increases with the square of the length L st . The present embodiment addresses the problem by dividing the storage into two portions each having the half length L st /2 and giving them different potentials. By this structure, the read-out time t tr ' halves, as t.sub.tr '=4·(L.sub.st /2).sup.2 /(π.sup.2 ·D)+4·(L.sub.st /2).sup.2 /(π.sup.2 ·D)=t.sub.tr /2. Then the reason is explained why the voltage applied on the storage is not DC bias voltage but pulse voltage. As described above, greater bias voltage yields greater charge capacity. But, if the potential of the storage is set lower than the potential of transfer gate when the transfer gate is applied H-level voltage, some charges remain in the storage, as shown in FIG. 14(a-4) or 14(b-4). So the potential of the storage should be raised to completely drain the charges to the transfer register. This is why the storage is applied a pulse signal. A variation is shown in FIG. 16 where the two storages are given different potentials too. In this case, after making the first polysilicon layer, boron ions are doped in the P-substrate 42 using the resist layer and the first polysilicon layer as the mask. By this boron doping, the left storage area 43 with higher dopant concentration has lower potential. In this case, a common terminal HST can be used for the two storage electrodes 43 and 44, because the same voltage automatically produces different potentials in those areas. Further, since the doped area 43 has higher concentration, its capacity is large and the read-out time is reduced. Another example of the CCD structure is described. When the photodiode is buried, there are two ways to put the N - layer 39 and the P + layer 40 as shown in (a) and (b) of FIG. 17. In FIG. 17(a), the upper P + layer 40 extends beyond the N - layer 39, while in FIG. 17(b), the P + layer 40 is buried in the N - layer 39. In the former design (a), there emerges a potential fence 90 which causes an incomplete charge transfer from the photodiode to the barrier gate. In this case, the charge transfer from the photodiode to the storage is performed by the thermal diffusion process, the charge transfer takes very long time. In the latter design (b), the part of the N - layer 39 not covered by the P + layer 40 makes a charge sink 91. It also needs long time to evacuate charges by the thermal diffusion from the charge sink 91, but this time is short compared to the take-out time of the former design (a). For that reason, the present embodiment adopts the latter design (b). Yet, when high-speed response is required to the photosensor (e.g., that for a spectrophotometer using stationary light), the evacuation time is undesirable. The following example of the CCD structure addresses the problem. As shown in the plan view of FIG. 23 and the sectional view of FIG. 25 along the line XXV--XXV (which is along the direction of charge transfer to the transfer register), the photodiode PD has the buried structure which is constructed by the N - layer 39 and the P + layer 40 in the P-type substrate 42. The storage HST 72 has the buried channel MOS structure which is constructed by the N - layer 39 on the P-substrate 42 and the first polysilicon electrode on the N - layer 39 via a 100 nm-thick SiO 2 insulator. In this example, a DC bias voltage is applied on the storage electrode HST to fix the potential lower than that of the photodiode PD. The transfer gate HSH 45 has a similar structure to that of the storage HST 72 but the electrode is made of the second polysilicon layer which is insulated from the first polysilicon layer. The HSH electrode 45 is applied a pulse voltage: at its H-level, the potential becomes lower than that of the storage HST 72 to enable the charge flow to the transfer register RG 46. The transfer register RG 46 also has a similar structure as the storage HST 72, and the transfer register array transfers charges with the four-phase pulse voltage. FIG. 24 shows the section along the line XXIV--XXIV (which is along the direction of the charge drainage) of FIG. 23. The overflow drain OFD 37 drains excessive charges produced in the photodiode PD and overflowed from the storage HST 72. The overflow gate OFG 38, whose voltage determines the drainage level, has a similar structure to the storage HST 72 but the electrode is made by the second polysilicon layer. The overflow gate OFG 38 is applied a DC voltage which fixes the overflow gate potential lower than that of the transfer gate HSH at L-level and higher than that of the storage HST. By this potential arrangement, the storage HST stores charges to the overflow gate level, and after reaching the level, they overflow to the overflow drain OFD but not to the transfer register RG. The CS 48 in FIG. 24 is the channel stop. In the above example, no barrier gate BG is used between the photodiode PD and the storage HST (cf. FIGS. 12 and 13) because it is unnecessary to fix the potential of the photodiode PD with the barrier gate BG since the photodiode PD is completely depleted. Further, the storage HST, the transfer gate HSH and the overflow gate OFG are all buried in the substrate (i.e., the buried channel MOS structure) in the above example in order to eliminate charge sink as shown in FIG. 17(b) by making the whole photosensor (including the photodiode) depleted. The storage HST is not applied a pulse voltage in the above example because, as the concentration of the N - layer 39 is about 10 times that of the P-substrate, the buried channel MOS structure can deal with greater amount of charges than the surface channel structure per unit area. Therefore there is no need to divide the storage HST as in the previous example, nor complicated bias control (to set the storage potential lower than the transfer gate potential at H-level in storing the charges) is necessary, which reduces burden of the bias control circuit. (3) Structure of the common transfer registers and their operation Now the structure and operating method of the transfer registers commonly used by the high-sensitivity photosensors and low-sensitivity photosensors are described. FIG. 18 shows the first example in which: numeral 54 is a storage of the high-sensitivity photosensor, 57 is a storage of the low-sensitivity photosensor, 55 is the transfer gate of the high-sensitivity photosensor, 56 is the transfer gate of the low-sensitivity photosensor, 58 is the channel stop and 59 is the transfer channel of the transfer registers. Numerals 60, 61, 62 and 63 designate the four transfer electrodes (the CCD is driven by a four-phase pulse signal) receiving the four transfer pulse signals φ 1 , φ 2 , φ 3 and φ 4 respectively. Among the four electrodes, two 60 and 62 are made by the underlying first polysilicon layer (shown by broken line) and are connected to the respective terminal through the contact holes 64. When the transfer pulse φ 2 is at H-level, the charges in the transfer register (which have been produced in a high-sensitivity photosensor) are transferred to the second-neighbor transfer register under the terminal φ 4 . To the transfer register under the neighbor φ 4 electrode is transferred charges generated in a low-sensitivity photosensor. Thus, charges generated at the high-sensitivity photosensors are transferred to the transfer registers at even ordinal numbers, charges generated at the low-sensitivity photosensors are transferred to the transfer registers at odd ordinal numbers, and the final transfer register gives forth the output of high-sensitivity photosensors and the output of low-sensitivity photosensors alternately. The second example of the transfer register is shown in FIG. 19 (same numerals are used for the same elements of FIG. 18) and the operating timing chart is shown in FIG. 20. When the voltage of the transfer register terminal φ 4 is at H-level, charges in the low-sensitivity photosensors are transferred to the transfer registers at even numbers under φ 4 electrodes. When the voltage of the transfer register terminal φ 2 is at H-level, the charges are transferred to the transfer registers at odd numbers under φ 2 electrodes. At this time, the charges in the high-sensitivity photosensors are transferred to the transfer registers at even numbers under φ 2 electrodes. Thus outputs from the high-sensitivity photosensors are transferred to the transfer registers at even numbers, the outputs from the low-sensitivity photosensors are transferred to the transfer registers at odd numbers, and the final transfer register gives forth the output of high-sensitivity photosensors and the output of low-sensitivity photosensors alternately. Another method of reading out the outputs of the high-sensitivity and low-sensitivity photosensors to the transfer registers is described. In the above example, the both outputs are simultaneously transferred to the transfer registers. But when longer reading-out time is allowed, the following reading out method can be adopted. First the outputs of the high-sensitivity photosensors are transferred to the transfer registers, while the low-sensitivity photosensor outputs are held in the storages, and then after the read-out of the high-sensitivity photosensor outputs is completed, the low-sensitivity photosensor outputs are transferred to the transfer registers. In this case, outputs from the final transfer register come out every two packets, which will be suitable in calculating the transfer inefficiency correction (described later). It should be noted here that outputs from the high-sensitivity photosensors should be read out first because there may be some high-sensitivity photosensor cells that overflow by the dark output during holding. The transfer register structure as shown in FIG. 22 suits such alternate batch reading out method (same numerals are used for the same elements of FIG. 18). When H-level voltage is applied on the φ 2 electrode 61 and H-level voltage is applied on the transfer gate 55, charges in the high-sensitivity photosensors transfer to the transfer registers. Then when H-level voltage is applied on the φ 4 electrode 63 and H-level voltage is applied on the transfer gate 55, charges in the low-sensitivity photosensors transfer to the transfer registers. As seen in FIG. 22, the array pitch of the photosensors and that of the transfer registers are equal so that higher cell density can be obtained. (4) Structure of the output terminal of the transfer registers FIG. 21 shows the output portion of the CCD where the numerals 60, 61, 62 and 63 designate transfer register electrodes, 65 is the output gate, 68 (hatched) is the floating diffusion, and 67 is the reset drain. The reset drain 67 is to reset the voltage of the floating diffusion 68 before new charges come in, and is controlled by the reset gate 66. Numerals 70 and 71 designate source and drain respectively of the output FET. The drain 71 connects to the power source of the CCD, and the source 70 connects to the ground via a resistance or a constant-current source to form a source-follower amplifier. The gate of the FET connects to the floating diffusion 68, and the voltage of the source 70 is the output of the CCD transfer registers. The numeral 69 designates a MOS capacitor made by [channel stop (P + )]/[100 nm-thick SiO 2 insulator]/[polysilicon electrode] structure. Since, in the present embodiment, the amount of transferring charges is increased to minimize the influence of the shot noises, the floating diffusion 68 should have a large capacity to yield a sufficient output voltage (1-2 V). But the floating diffusion 68 is made of a PN junction which can not have sufficient capacity per area. Therefore the MOS capacitor 69 is provided in this embodiment to add to the capacity of the floating diffusion 68. Suppose the concentration in the P-substrate 42 is 1×10 15 , that in the N layer is 1×10 20 and the bias voltage is 14 V, the capacity per area C PN of the PN junction is about 2.4×10 -9 F/cm 2 , while that C MOS of the MOS capacitor 69 is about 3.5×10 -8 F/cm 2 . This means one tenth the area of the floating diffusion 68 is sufficient to obtain the same capacity of the MOS capacitor 69. Further, since the capacity of a PN junction changes as the depth of the depletion layer changes, the output voltage does not linearly correspond to the amount of transferred charges which is undesirable for use in spectrophotometers. This shortcoming is solved in the present embodiment by making the capacity of the MOS capacitor 69 far greater than that of the PN junction (i.e., floating diffusion 68). In this case, the unchangeable capacity of the MOS capacitor 69 is dominant in the total capacity and the output voltage shows linearity to the amount of transferred charges. The channel stop 58 tapers toward the floating diffusion 68 in order to smoothly lead charges to the floating diffusion 68. The array pitch of the transfer register electrodes increases toward the output terminal in order to keep the capacity under every transfer register terminal constant despite the shrinking channel width. III Operation of the CCD line sensor and the signal processing (1) Correction of the output for the transfer inefficiency Here a method to correct the output excluding the transfer inefficiency is explained because analog shift registers as used in this embodiment include some transfer inefficiency in transferring charges. Even if the transfer register is as small as 1×10 -15 , total transfer inefficiency after 100-step transfer becomes 0.1%, which is unacceptable in spectrophoto-measurements. The correction method we used in this embodiment is as follows. When the transfer inefficiency by one-step transfer is ε and the size (amount of charges) of an original charge packet is Q.sup.(o), the amount of charges remaining in the packet after n-time transfer is (1-n·ε)·Q.sup.(o), and the amount of charges that is given to the next packet is n·ε·Q.sup.(o). In precise, there are some amount that is given to the two-next packet, but it is of the order of ε 2 which is negligible when the transfer inefficiency is about 10 -5 . When the initial charge amount at the i-th register (counted from the output end) is Q i .sup.(o), the j-th output is Q j , and the total number of transfer registers is N, the remaining amount in the i-th packet is (1-i·ε)·Q.sub.i.sup.(o), and the amount given to the (i+1)-th packet is i·ε·Q.sub.i.sup.(o). This amount is outputted in addition to the original amount of the (i+1)-th packet. In summary, the output amounts are: Q.sub.1 =(1-1·ε)·Q.sub.1.sup.(o), Q.sub.2 =(1-2·ε)·Q.sub.2.sup.(o) +1·ε·Q.sub.1.sup.(o), Q.sub.3 =(1-3·ε)·Q.sub.3.sup.(o) +2·ε·Q.sub.2.sup.(o), . . . , Q.sub.i =(1-i·ε)·Q.sub.i.sup.(o) +(i-1)·ε·Q.sub.(i-1).sup.(o), . . . , Q.sub.N-1 =(1-(N-1)·ε)·Q.sub.N-1.sup.(o) +(N-2)·ε·Q.sub.N-2.sup.(o), and Q.sub.N =(1-N·ε)·Q.sub.N.sup.(o) +(N-1)·ε·Q.sub.(N-1).sup.(o). These equations are combined as FIG. 32 to make a vector and matrix equation, and is simply expressed as follows by using an output vector Q, a transformation matrix R, and an original charge amount vector Q.sup.(o) : Q=R·Q.sup.(o). Therefore the original charge amount Q.sup.(o) is calculated by Q.sup.(o) =R.sup.-1 ·Q, where R -1 is the inverse matrix of R. The inverse matrix R -1 is calculated by R.sup.-1 =adjR/|R|, where ##EQU1## The one-step transfer inefficiency ε should be measured. Since the transfer inefficiency ε depends on the temperature, it should be measured just before the spectrophoto-measurement. The transfer inefficiency ε can be measured by the known method in which charges are input before the transfer registers, and the input and output amounts are compared. In this embodiment where the transfer registers are arranged at half the pitch of photosensors, the following method can be used. Usually, deviations in the sensitivity among the photosensors are measured using a standard white board before a spectrophoto-measurement. The transfer inefficiency ε can also be measured at this time. When the strobe light flashes, only the low-sensitivity photosensor outputs are read out. As described before, the outputs of the low-sensitivity photosensors come out every two packets. Since there is a transfer loss in the output of the last pixel, the last output is (1-N·ε)·Q N .sup.(o), where Q N .sup.(o) is the original amount of the last pixel. Since the charges are in every two transfer registers, the amount of remainder of the previous packet Q N-1 .sup.(o) is zero and the remainder of the two-previous packet is of ε 2 order which is negligible, the output Q N of the N-th packet is Q.sub.N =(1-N·ε)·Q.sub.N.sup.(o). The remainder (i.e., loss) of the Q N .sup.(o) packet given to the next packet is N·ε·Q N .sup.(o), which is the amount of the (N+1)-th packet. Q.sub.N+1 =N·ε·Q.sub.N.sup.(o) From the last two equations, Q.sub.N+1 /(N·ε)=Q.sub.N /(1-N·ε), (1-N·ε)·Q.sub.N+1 =N·ε·Q.sub.N, or Q.sub.N+1 =N·ε·(Q.sub.N Q.sub.N+1). This gives the transfer inefficiency ε as ε={Q.sub.N+1 /(Q.sub.N +Q.sub.N+1)}/N. The correction of the outputs is thus enabled using this transfer inefficiency ε. When the high-sensitivity photosensor outputs and low-sensitivity photosensor outputs are separately read out as described before, the following correction calculation is used. This method is effective where the array pitch of the transfer registers is half that of the pixel array, and the principle is the same as the above described ε-calculating method: the original packet size at every two packet is zero. The output of a significant packet does not include a remainder of the previous packet, but it leaves a transfer loss to the next packet which was originally vacant. Thus the output Q i of i-th significant packet (whose original size was Q i .sup.(o)) is Q.sub.i =(1-i·ε)·Q.sub.i.sup.(o), and the next output Q 2+1 is Q.sub.i+1 =i·ε·Q.sub.i.sup.(o). By adding these two outputs Q i and Q i+1 , the original charge amount (packet size) Q i .sup.(o) is obtained, as Q.sub.i.sup.(o) =Q.sub.i +Q.sub.i+1. This addition can be calculated in the microcomputer 12. Alternatively, the addition can be performed by the hardware. At time t1 of the timing chart of FIG. 30, there are charges 73 in the charge packet proximate to the output terminal and their remainder (transfer loss) 74 in the following packet, as shown in FIG. 31. At subsequent times t2 and t3, the packets come closer to the output. At time t4, H-level voltage is applied on the reset gate RG and the potential of the floating diffusion FD is reset at the level of the reset drain RD. After the reset gate RG shuts at time t5, the charges in the packet 73 flow into the floating diffusion FD at times t6 and t7 and the potential there lowers by the amount denoted by 75. This state is maintained at times t8 and t9 when the following packet 74 approaches the output, and the remainder charges in the packet 74 adds to the floating diffusion FD at time t11 to lower the potential by the amount denoted by 76. After all, the potential of the floating diffusion FD lowers by the amount denoted by 77 which is the total of the two packets 73 and 74, and this total is read out as an output. Thus, by simply doubling the cycle time of the reset gate pulses as that of the transfer pulses, the transfer inefficiency is compensated for. (2) Spectrophoto-measurement Now the process of the spectrophoto-measurement according to the present embodiment is described referring to the flowcharts of FIGS. 26, 27 and 28. The general flow is shown in FIG. 26 where first residual charges are drained at step #1. Charges in the photosensors and transfer registers of the CCD are drained to initialize because the buried channel of the transfer registers is not vacant after the power to the CCD is turned on. The initialization of the transfer registers is done by applying transfer drive pulses on them. Initial charges due to dark output of the photodiodes in the photosensors are also transferred through the transfer registers to drain. After the initialization, the strobe light is flashed at step #2, and charges corresponding to the filtered and spectrum-decomposed light are generated at the photodiodes. Step #3 is to select either of photodiodes of the CCD-A or CCD-B (FIG. 4(a)) that is effective. This step #3 is detailed by the flowchart of FIG. 27. First in this routine, the loop index I is initialized to 1 at step #101, and it is determined at step #102 which of the i-th pixels in the CCD-A and CCD-B is effective. As described before, the four segments 3-a through 3-d of the bandpass filter 6 are separately arranged on the two CCD arrays CCD-A and CCD-B, and either one of the outputs of the two pixels at the same X position is invalid because it includes components corresponding to the unnecessary transmission band. This selection is executed based on the information previously stored in the E 2 PROM in the microcomputer 12. If the output of a pixel in the CCD-A is determined effective at step #102, the CPU of the microcomputer 12 sends a select signal SELECT-A to the multiplexer 9 to choose the output OSA of the pixel in the CCD-A as the output OS of the CCD at step #103. If the pixel in CCD-B is determined effective, select signal SELECT-B is sent to the multiplexer 9 to choose the output OSB of the pixel in the CCD-B as the output OS of the CCD at step #104. The selected output OS is sent to the A/D converter 11 via the analog signal processor 10 to be A-D converted. At step #105, the A-D converted signal is read by the microcomputer 12. Then it is determined at step #106 whether this data is final (i.e., whether the loop index I equals the effective number of pixels N), and if so the routine ends. If I<N, the index I is incremented by 1 at step #107 and the steps #102-#106 are repeated to read out all outputs from the N pixels. When the high-sensitivity photosensor outputs and low-sensitivity photosensor outputs are separately read out, this process is repeated twice. After reading out outputs of all pixels at step #3 of FIG. 26, outputs are read out while the strobe light does not flash (dark outputs) at step #4 to compensate for the previously read-out data. Then the correction calculations as described above are performed at step #5 to obtain the originally generated charge amount from the outputs affected by the transfer inefficiency ε. This correction calculations are performed for both the normal outputs and the dark outputs, and the corrected normal outputs are subtracted by the corrected dark outputs at step #6 to obtain the data truly corresponding to the input light intensities. Finally at step #7, one of the high-sensitivity photosensor output and the low-sensitivity photosensor output is chosen and is normalized. This step #7 is detailed by the flowchart of FIG. 28. At first of the flow of FIG. 28, the loop index I is initialized to 1 at step #201, and then the high-sensitivity photosensor output V H (I) is compared at step #202 with the saturated output V sat which is previously stored in the E 2 PROM. If V H (I)<V sat , the high-sensitivity photosensor output V H (I) is preferred to the low-sensitivity photosensor output V L (I) of the same pixel, and is normalized by dividing by the sensitivity R H (I) of the high-sensitivity photosensor at step #204 to make the final intensity data D(I) of the I-th pixel. After choosing the final data D(I), the index I is compared with the number N of pixels to check whether all the final data D(I) have been determined. If I<N, then the index I is incremented by 1 at step #205 and the steps #202 through #205 are repeated until I=N. When all the final data D(1) through D(N) are determined, this routine ends. Suppose here that light of the region II-b of FIG. 10(b) enters the i-th pixel, that of region II-c enters in (i+1)-th pixel and that of region II-a enters in (i+2)-th pixel. When I=i in the flow of FIG. 28, low-sensitivity photosensor output V L (i) is also lower than the saturated level V sat (and higher than the dark level V dark ), but the higher output V H (i) is preferred (note that always V H (I)≧V L (I)) because it is less vulnerable to various noises. When I=i+1, since V H (i+1)=V sat , the low-sensitivity photosensor output V L (i+1) is chosen and normalized to make the final data D(i+1) at step #203. Thus the effective measurement data can be obtained for any light amount falling in the regions II-a, II-b and II-c of FIG. 10(b), spectrophotometer having very wide dynamic range can be constructed by using the CCD of the present embodiment. The sensitivities R H (I) and R L (I) of the photosensors that are used to normalize the output data at steps #203 and #204 are obtained as follows. In the memory of the microcomputer 12 are stored sensitivities R H (I).sup.(o) and R L (I).sup.(o) at a reference temperature T o and temperature coefficients k i of the sensitivities. Before the photomeasurement, the CPU of the microcomputer 12 sends a select signal SELECT-T to the multiplexer 9 to select the signal TMP from the temperature sensor 8-c of the chip 7. Using the temperature data T and the stored data, the sensitivities R H (I) and R L (I) are calculated by R.sub.H (I)=R.sub.H (I).sup.(o) +k.sub.i ·(T-T.sub.o), and R.sub.L (I)=R.sub.L (I).sup.(o) +k.sub.i ·(T-T.sub.o). In the above description of the specific embodiment, the CCD line sensor is an N-channel type where electrons are transferred. But it is apparently possible to use P-channel type instead under the present invention. Similarly, the two-polysilicon-layer structure or the four-phase transfer driving is only an example specified for comprehension, and those skilled in the art can employ other structures without departing from the spirit of the present invention. The spectrofilter 1 may be replaced by a grating type. Though the transfer register array is commonly used by the high-sensitivity and low-sensitivity photosensor arrays in the above embodiment, each photosensor array can have its own transfer register array.

A spectrophotometer is composed of a spectrofilter, a plurality of bandpass filters for cutting unnecessary transmission bands, and a CCD photosensor. The photosensor is composed of two sets of photosensors having different sensitivity ranges that overlap at some portion to increase the dynamic range of the device. The handling amount of charges is increased at every portion of the CCD photosensor in order to reduce the influence of the shot noise. Further, various technologies are used to enhance the accuracy and stability of the spectrophoto-measurement.

FIELD OF THE INVENTION The present invention relates to a pallet adapted for independent individual transport of textile yarn bobbins and tubes, particularly pallets of the type having a base plate and an upstanding arbor or pin for insertion into the bobbin or tube when placed on the base plate. BACKGROUND OF THE INVENTION Transport systems for textile yarn bobbins or cops in which pallets of the above type circulate on various segments of transport paths formed by rail-like transport channels for the base plates of the pallets have been known for a relatively long period of time, for example from Japanese Published, Non-Examined Patent Application JP-OS-52-25139. Pallets of this type for cylindrical or conical cross-wound bobbins are also known from German Patent Publication DE 34 16 387 A1, for example. In either case, it is common to prepare the cop or bobbin for subsequent yarn unwinding by locating and placing the leading end of the yarn at an accessible disposition on the cop or bobbin, e.g., by placement within the interior of the cop's tube or on the outer surface thereof. To prepare cops with a yarn end preparation mechanism or machine, it is known from German Patent Publication DE 33 08 171 A1, for example, to remove the cops from their pallets to prepare the arbors and to transport the cops through the preparation device in this form. For this purpose each cop is gripped at the tip of its tube and, thus, the gripping device must conform to the tip of the tube. Moreover, the axial length of the tip of the tube unoccupied by yarn windings must be sufficient to enable gripping of the cop reliably without damaging the yarn windings thereon. In addition, when the leading end of the yarn is not to be positioned within the tube, but as an outer winding thereon, there must be sufficient space remaining beneath the gripping element on the tip of the tube. For relatively large textile bobbins, such as conical or cylindrical cross-wound bobbins that have a correspondingly high weight, it is very difficult to generate a sufficiently strong clamping force on the tip of the tube without causing damage to the tube. German Patent Application P 41 31 527.8 (which is not a prior art publication) discloses a pallet whose arbor and base plate respectively are produced from separate components that can be connected to one another by means of a lockable connection used for the purpose of selectively connecting any one of several different arbors to a uniform base plate construction when cops with varying inside tube diameters are to be prepared during a batch change. Accordingly, the lockable connection is designed such that the pallets whose arbors are to be changed can have the old arbor released by an auxiliary device and provided with a new arbor. SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved pallet that permits advantageous handling of the textile bobbins in different processing stations, particularly in preparation stations for textile bobbins of various sizes, by means of temporary separations of the arbor from the base plate of the pallet. Briefly summarized, this object is attained in accordance with the present invention by means of a pallet having an arbor which is separable from the base plate of the pallet and which is also longer in axial dimension than the textile bobbin it supports so as to protrude sufficiently beyond the tip of the bobbin tube to be grasped by a gripping means in the assembled condition of the pallet. The connection between the base plate and the arbor should be a detachable plug-type connection enabling temporary separation and reassembly of the base plate and arbor. Particularly in preparation devices in which the beginning of the yarn of the textile bobbin is searched for and repositioned at a suitable point from which the yarn end can later be regripped at a winding station, it is necessary for the bobbin to be accessible at every position for searching for the leading end of the yarn. Furthermore, it is advantageous that the bobbin and yarn-searching element be positioned as closely to each other as possible. In this case, the considerable differences in various wound diameters and configurations between various conical and cylindrical cross-wound bobbins, for example, must also be taken into consideration. All of these considerations and objectives can be accommodated by the pallet of the present invention in that the textile bobbin can be removed from the pallet's base plate and in turn from the pallet transport system by a gripping means pulling the arbor with the bobbin from the base plate. The textile bobbin can then be positioned, with the aid of the gripping means, at an arbitrary point and thus also in the optimum position with respect to the yarn-gripping means. In this instance, the textile bobbin tube is not touched at all by the gripping means. Therefore the gripping means also need not be adapted in its configuration, size or otherwise to the textile bobbin tube. There is no requirement of a specific length of the tip of the tube for reliable gripping of the textile bobbin. By the gripping means, the extended arbor of the present pallet can receive the leading end of the yarn beneath the gripping location in a plurality of yarn windings if the yarn end has not been positioned on the tip of the tube or inside the tube. Moreover, it is also possible to further transport the separated base plate on its transport path, and load a new textile bobbin thereon with another arbor, which presents the option of increasing flexibility in the transport system. The invention offers the advantageous possibility of fixedly disposing a pot-like covering body on the base plate that, when used particularly with conical and cylindrical cross-wound bobbins, protects the base plate outwardly and, during yarn unwinding, can simultaneously function as a balloon delimiter. In contrast to a divided collar, disclosed for example from German Patent Disclosure DE 38 433 553 A1, this pot-like covering body has the advantage that it need not be pivoted in the unwinding position for the entrance and exit of the cross-wound bobbins which, given the size of the bobbins, would cause considerable problems with respect to the distribution of the bobbin position. The plug connection between the arbor and the base plate is preferably a resilient snap-type connection engageable and disengageable by applying an axial force to the arbor and base plate, which permits frequent release and re-establishment of the connection on a substantially arbitrary basis. In this case there are no axial forces that must be overcome. Therefore, the connection is highly dependable both for transport of the pallets and also in the processing stations. Because the textile bobbin must also be supported reliably after the arbor has been released from the base plate, appropriate means are provided for securing the bobbin position, preferably in the form of a conical base portion on the arbor for supporting a lower end of the textile bobbin tube. By virtue of its conical shape, the base portion of the arbor serves to center the textile bobbin tube on the arbor. Resilient elements that are radially inwardly elastic prevent the bobbin from twisting on the arbor. However, the biasing forces of these flexible elements should not be so great that the force necessary to remove the bobbin or its tube from the arbor simultaneously separates the arbor from the base plate. Optionally, the arbor could be supported from above to prevent separation from the base plate when the bobbin or tube is pulled off, or alternatively the arbor could be intentionally separated from the base plate for pulling off the tube or bobbin. It is also preferred that the arbor have a groove at its upper end so that the gripping means can grip the arbor in a reliable form-fitting manner, whereby the demands on the clamping capability of the gripping means may be decreased. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of an arbor of a pallet according to the present invention, shown carrying a textile bobbin and separated from the base plate of the pallet by a gripping means of a yarn end preparation device; FIG. 2 is a detailed view of the pallet of the present invention, partially in side elevation and partially in axial cross-section, shown traveling in a transport track with an arbor inserted into the base plate; and FIG. 3 is a side elevation of a separated arbor of the pallet in accordance with the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT In the accompanying drawings, the pallet of the present invention is shown as supporting a textile bobbin in the form of a conical cross-wound bobbin 1 having a body of yarn wound on a textile bobbin tube 2, which is supported on an arbor of the pallet. Those persons skilled in the art will of course recognize, however, that the present pallet is equally susceptible of use with other forms of bobbins. Referring initially to FIG. 2, a preferred embodiment of the pallet of the present invention is shown generally at 3, partially sectioned in order to illustrated the connection of its base plate 4 with its arbor 5. For this purpose, the base plate 4 has a central, axial bore 4" that extends through a platform 4' of the base plate 4, almost to the bottom surface of the base plate 4. The bore 4" in turn has radial bores 16, into which compression springs 18 and balls 17 are inserted. The radial bores 16 are enlarged in the shape of a dome adjacent their ends facing the central longitudinal axis of the pallet 3 to enable receipt of the balls 17. However, the openings of these bores 16 into the bore 4" have a diameter that is, of course, smaller than the diameter of the balls to prevent the balls from falling out. The radial bores 16 with the balls 17 and the compression springs 18 are present in four sets in the illustrated embodiment and are distributed at equal intervals about the circumference of the bore 4". In this embodiment, the balls 17 engage in an annular groove 6 of the arbor 5, by which the arbor is held securely. Further details of the description of this resilient snap-type connection are omitted because snap connections of the described type are generally known. As can further be seen from FIG. 2, the arbor 5 rests with its lower end edge against the lower end of the bore 4" and a chamfer of the shank 10 of the arbor 5 rests on an outwardly tapering region of the bore 4". The arbor 5 further includes a base 7 affixed to the shank 10 above the tapered region, which base 7 rests on a portion of the bottom surface of a pot-shaped covering body 20 secured to the platform surface 4' of the base plate 4. By means of this collective arrangement of components of the arbor 5, the weight of the conical cross-wound bobbin 1 can be reliably received and supported by the pallet 3. At least two vertical internally-threaded bores 4" are formed in the platform 4' of the base plate 4 and fastening screws 19 for the pot-like covering body 20 are engaged threadedly into these bores 4". In this manner, the pot-like covering body 20 is connected securely to the base plate 4. In the illustration of FIG. 1, the conical cross-wound bobbin together with the arbor 5 is shown as lifted out of this pot-like covering body 20, whereby the conical cross-wound bobbin 1 is accessible from all sides for mechanical or manual searching for the leading end of the yarn thereon. A typical transport system for the pallets 3 is also indicated in FIG. 2. This system essentially comprises a conveyor belt 13 that is supported along its pallet-carrying run by a sheet metal support plate 14. The transport path of the pallets 3 is defined laterally by guide profiles 15. A stop element 45, which is displaceable into and out of the transport path by a horizontally disposed fluid cylinder 46, is disposed downstream and can stop each respective pallet 3 by engaging its base plate 4 on the continuously moving conveyor belt 13. In such stopped position, the arbor 5 can be lifted from the base plate 4 onto which the pot-like covering body 20 is screwed. The fluid cylinder 46 for the stop element 45 is connected to a compressed air source (not shown) via a valve 47 which can be operated by a control unit 21 to be able to accurately control the stopping and release of the arriving pallets 3. FIG. 1 illustrates a lifting mechanism 22 which is preferably disposed above the stop position and is equipped with gripping means in the form of claw arms 37 which engage in a groove 9 on the upper end portion 8 of the arbor 5 protruding beyond the upper tip end of the bobbin tube 2. This conforming fit of the gripping means with the arbor 5 permits a reliable gripping of the arbor 5. The lifting mechanism 22 has two fluid cylinders 23,24, to whose pistons respective supports 26,26' are secured. These supports 26,26' are in turn connected to an outside race 27' of a ball bearing assembly 27. The inside race of the ball bearing assembly 27 is formed by a tubular element 28, in which are secured a fluid cylinder 29 supported by a holding device 31 and holding devices for pivot shafts 36 of the claw arms 37. An actuating pin 34 extends through longitudinal holes 35 in cross arms 33 of the gripping means and is affixed to a piston 32 of the fluid cylinder 29. The cross arms 33 are attached, together with claw arms 37, to the pivot shafts 36. The fluid cylinder 29 can be temporarily connected via a valve 30 to a compressed air source (not shown). The valve 30 can also be activated by the control unit 21. The two fluid cylinders 23 and 24 can likewise be temporarily connected to the compressed air source by a common valve 25. An angular aspiration tube 38 is disposed adjacent to the lifting mechanism and has an aspiration slit 39 oriented to the conical cross-wound bobbin when it is stopped and lifted into the position shown in FIG. 1. The aspiration tube 38 is connected to the base of the associated textile machine via a mounting bracket 41. The aspiration tube 38 is connected via a valve 40 to an aspiration air source (also not shown). A friction driving wheel 42 and a drive motor 44 for driving rotation of the wheel 42 are mounted on the aspiration tube 38 by means of a bracket 43. After a pallet 3 with a conical cross-wound bobbin 1 has arrived under the lifting mechanism 22, the base plate 4 is stopped on the conveyor belt 13 by means of actuating the stop element 45. The arrival of the pallet 3 is signalled to the control unit 21 by means of an appropriate sensor (not shown). The control unit 21 first actuates the two fluid cylinders 23,24 via their valve 25, which lowers the tubular element 28 to position the claw arms 37 at the height of the groove 9 of the arbor 5. At the same time, the piston 32 is also extended by means of a compression spring within the cylinder 29, whereby the claw arms 37 are spread open. After the described disposition for the tubular element 28 has been reached, the controller 21 actuates delivery of compressed air into the lower part of the fluid cylinder 29 via the valve 30, by means of which the piston 32 is withdrawn counter to the force of the compression spring, whereby the aforedescribed connection of the piston to the cross arms 33 and, via the shafts 36, with the claw arms 37 causes the claw arms to move toward one another and enter into the groove 9, into which they are pressed by means of the air pressure present in the fluid cylinder 29. After a predetermined period of time, the fluid cylinders 23,24 are again triggered via the valve 25 to lift the tubular element 28 via the support 26 until it reaches the elevated position shown in FIG. 1. After this position has been reached, the motor 44 is activated by the control unit 21, causing the driving wheel 42 to rotate and to drive the conical cross-wound bobbin 1 by frictional engagement with its circumference. The search for the free leading end of the wound yarn is executed during this period of time. For this purpose the valve 40 is opened to connect the aspiration tube 38 to a suction air source. As soon as the end of the yarn passes the aspiration slit 39 during rotation of the conical cross-wound bobbin 1, the end is entrained by the aspiration flow and sucked into the aspiration tube 38. A sensor (not shown) identifies the arrival of the leading end of the yarn and transmits a corresponding signal to the control unit 21. The control unit then immediately stops the motor 44 so that no additional length of yarn is sucked into the aspiration tube 38. In this case, the yarn is diverted at the upper end of the aspiration slit 39. Advantageously, the end of the yarn is then shortened to a predetermined length by means of a separating, cutting or other suitable device (not shown) in the aspiration tube 38. Thereafter, the motor 44 is triggered again by the control unit 21 to drive the driving wheel 42 in the opposite direction from that previously carried out. After approximately a half-rotation of the conical cross-wound bobbin 1, the yarn 1', shown in dashed lines in FIG. 1, then extends from the outer edge of the conical cross-wound bobbin to the upper edge 39' of the aspiration slit 39 in the form of a chord relative to the bobbin diameter. As the conical cross-wound bobbin 1 is rotated further, the chord travels toward the exposed upper end portion 8 of the arbor 5 protruding out of the bobbin tube 2 and is wound on in several windings 1" as the conical cross-wound bobbin 1 rotates further, as can be seen in FIG. 1. After a predetermined number of rotations of the conical cross-wound bobbin 1, the motor 44 is stopped by the control unit 21 to complete the positioning of the yarn windings on the arbor 5, at which point the shortened yarn end has exited the aspiration tube 38. The end of the aspiration slit 39 is shown as a variant in a position 39" in FIG. 1, which achieves a clearly shortened distance from the exposed portion 8 of the arbor 5 protruding from the tube 2. In this manner, the length of the yarn end, which is released after being wound onto the arbor portion 8, is kept considerably shorter. Yarn guiding means (not shown) that accomplish an exact positioning of the yarn end windings on the arbor 5 are also conceivable. For example, a lever may be attached to the outer ball bearing race 27' to extend to the protruding portion 8 of the arbor 5. It is also conceivable to place the yarn windings of the leading end of the yarn onto the tip 2' of the bobbin tube 2 itself when the tube tip 2' protrudes sufficiently beyond the yarn windings of the cross-wound bobbin 1. After such yarn end preparation of the conical cross-wound bobbin 1 has been completed, the two fluid cylinders 23,24 are deventilated via the valve 25, so that the tubular element 28 lowers again due to the textile bobbin's own weight. The weight of the cross-wound bobbin 1 is also normally sufficient to overcome the resistance of the compression springs 18 so as to re-establish the snap connection of the arbor 5 to the base plate 4. However, to ensure that the snap connection locks completely, the option exists of connecting the fluid cylinders 23,24 to the compression air source by their other end via another valve (not shown) to increase the lowering force, at least during the end of the lowering phase, to insure a reliable locking engagement of the snap connection. After the tubular element 28 has reached its end position, the valve 30 is triggered via the control unit 21 to vent the fluid cylinder 29 so that the piston 32 is extended. Thus, the claw arms 36 reopen and release the arbor 5. Subsequently, the valve 47 can be triggered to retract the stop element 45 into the fluid cylinder 46 and release the pallet 3 for further transport by means of the conveyor belt 13. FIG. 3 illustrates the entirety of the arbor 5 separated from the base plate 4 and without any supported bobbin thereabout. In addition to the conical base 7, on which the tube 2 is supported by its tube foot 2' and simultaneously centered, spring wires 11 extend lengthwise along the shank 10 of the arbor 5 to act as radially inwardly flexible, elastic elements to provide additional guidance for the tube 2 of the conical cross-wound bobbin 1. Check nuts 12 threadedly screwed onto the shank 10 of the arbor 5 serve to adjust the flexing of the spring wires 11 which can thus be bowed outwardly to varying degrees to be adaptable to varying tube inside diameters. If the conical cross-wound bobbin 1 is prepared in the described manner for subsequent yarn unwinding, it is possible to re-expose the leading end of the yarn within the winding station in which the conical cross-wound bobbin 1 is subsequently to be unwound, and to deliver the yarn end to an appropriate gripping element of a yarn-connecting device, e.g., a splicer, even if the arbor 5 remains on the base plate 4 and the conical cross-wound bobbin 1 is enclosed by the pot-like cover 20. This is possible when a compressed air nozzle arrangement mounted to a repositionable support is disposed with respect to a bobbin supplied to the unwinding station in the region of the windings of the leading end of the yarn. If this nozzle arrangement encloses the protruding portion 8 of the arbor 5, it is also unnecessary, in contrast with known devices, to dispose a nozzle beneath the unwinding station to blow out a yarn end positioned in the tube through a hollow arbor and the tube itself. The lifting mechanism 22 can additionally be connected to a displacement or pivoting device (not shown) that operates to position the textile bobbin in contact with the driving roller 42 so that the same spacing is always maintained between the upper yarn winding surface of the bobbin and the aspiration slit 39, regardless of the amount of yarn on the bobbin. To simultaneously take into consideration possible differences in the conical shape of conical cross-wound bobbins 1 as a result of differing amounts of yarn on the bobbins, it is also possible to provide a second drive roller 42', shown in dashed lines in FIG. 1, on the same drive shaft as the drive roller 42. This arrangement ensures that the yarn winding surface of the bobbin is always disposed parallel to the aspiration slit 39. A slight tilting of the conical cross-wound bobbin 1 itself can be compensated by a pivotability of the aspiration nozzle 38, for example. Unlike the illustrated representation, it is therefore also possible in principle to pivot the arbor 5 or the lifting mechanism 22 out of the longitudinal axis of the pallet 3 for yarn end preparation operations when the aspiration tube 38 is correspondingly offset to the side. The pivoting of the arbor 5 would then always be executed to a sufficient degree to bring the bobbin surface into contact with the drive roller 42 or the two drive rollers 42 and 42'. It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.

The handling of textile bobbins and textile bobbin tubes, particularly in yarn end preparation of textile bobbins, is improved by the pallet of the present invention which has an arbor of longer axial length than the textile bobbin tube it supports so as to protrude sufficiently from the textile bobbin tube that the arbor can be gripped while the textile bobbin remains supported on the pallet. A releasable connection between the base plate and arbor of the pallet in the preferred form of a functionally detachable plug-type snap connection allows for a temporary separation of these components. A pot-like covering body for the textile bobbin is connected to the base plate, particularly for conical or cylindrical cross-wound bobbins.

RELATED APPLICATION INFORMATION [0001] The present application is a continuation application of U.S. patent application Ser. No. 12/252,324 filed Oct. 15, 2008, which claims priority under 35 U.S.C. Section 119(e) to U.S. Provisional Patent Application No. 60/999,182 filed Oct. 16, 2007, the disclosures of which are incorporated herein by reference in their entirety. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates in general to radio communication systems and components. More particularly the invention is directed to antenna elements and antenna arrays for radio communication systems. [0004] 2. Description of the Prior Art and Related Background Information [0005] Modern wireless antenna implementations generally include a plurality of radiating elements that may be arranged to provide a desired radiated (and received) signal beam width and azimuth scan angle. For a common three sector cellular coverage implementation each antenna will have a 65 degree (deg) azimuthal coverage area. It is desirable to achieve a near uniform beam pattern that exhibits a minimum variation over the desired azimuthal degrees of coverage. In modern applications, it is also necessary to provide a consistent beam width over a wide frequency bandwidth. [0006] In addition in modern cellular applications a number of antenna elements may be configured in an array to provide beam control by phase control of the beam, for example to provide beam tilt or beam steering. Providing an antenna array with a number of antenna elements in a typical cellular installation can create problems related to antenna weight and size. Also, cost is very important in such applications. Accordingly, providing the desired antenna performance is made more difficult by the need to maintain low cost, weight and size. [0007] Consequently, there is a need to provide an improved antenna structure with desired beam uniformity over a desired coverage area. Furthermore, it is desirable to provide such an antenna in a relatively compact and low cost construction suitable for use in antenna arrays. SUMMARY OF THE INVENTION [0008] In a first aspect the present invention provides an antenna array comprising first, second and third generally planar reflectors each having one or more radiators coupled thereto, the second reflector configured adjacent to and between the first and third reflectors. The first and third reflectors are configured with their planar surfaces oriented at opposite angles between about 20 to 30 degrees relative to that of the second reflector. The antenna array includes beam forming means coupled to the radiators for providing a dual beam radiation pattern from the radiators. [0009] In a preferred embodiment of the antenna array the dual beam radiation pattern comprises an approximately 33 degree half power beam width for each of the dual beams forming a total beam pattern of approximately 65 degrees at half power beam width. The beam forming means preferably comprises means for combining signals provided to the radiators and means for providing an unequal splitting of the signals provided to the radiators. The means for providing an unequal splitting preferably employs an unequal amplitude weight function. The beam split loss is less than about 0.25 dB. The beam forming means preferably comprises a microstrip transmission line pattern and the transmission line pattern and line width implement the unequal amplitude weight function. The means for providing an unequal splitting preferably comprises first and second 180 degree splitters. The means for combining signals preferably comprises first and second 0 degree combiners. The beam forming means preferably further comprises means for coupling the first and second 180 degree splitters and the first and second 0 degree combiners with a non-overlapping transmission line pattern. [0010] In another aspect the present invention provides an antenna array comprising a reflector structure having a center panel and first and second outer panels with respective generally planar panel surfaces oriented in different directions. One or more first radiators are coupled to the first outer panel, one or more second radiators are coupled to the second outer panel, and one or more third radiators are coupled to the center panel. The antenna array further comprises first, second and third radiator coupling ports, first and second RF signal input coupling ports, and a three to two beam forming network coupled between the first, second and third radiator coupling ports and the first and second RF signal input coupling ports. The beam forming network comprises a first 0 degree combiner, a second 0 degree combiner, a first 180 degree splitter, a second 180 degree splitter, and a non-overlapping transmission line pattern coupling the splitters and couplers to the first and second RF signal input coupling ports and the first, second and third radiator coupling ports. [0011] In a preferred embodiment of the antenna array each of the first, second and third radiators comprise plural radiators, respectively configured on the first and second outer panels and center panel in first, second and third columns, respectively. The first, second and third plural radiators may be arranged in groups of six radiators wherein each group is coupled to a beam forming network. The transmission line, splitters and couplers together comprise a microstrip line pattern having plural segments of varying width and length to implement a phase and amplitude control to create a dual beam radiation pattern from the first, second and third radiators. The first 0 degree combiner and second 0 degree combiner are preferably coupled directly to the first and second RF input signal coupling ports, the first 180 degree splitter and second 180 degree splitter are preferably coupled directly to the first and second radiator coupling ports and the first 180 degree splitter and second 180 degree splitter are preferably coupled to the third radiator coupling port by a split transmission line. The first 180 degree splitter and second 180 degree splitter are preferably both coupled directly to the first and second 0 degree combiners. The first and second 0 degree combiners are preferably configured symmetrically on opposite sides of the first and second 180 degree splitters. The split transmission line and third radiator coupling port are preferably configured between the first and second 0 degree combiners and the first and second 180 degree splitters. The first and second outer panels are preferably oriented at angle of about 20 to 30 degrees relative to the center panel. [0012] In another aspect the present invention provides a method of providing a dual signal beam radiation pattern in a wireless antenna array. The method comprises providing a left and right beam signal to a beam forming network and providing first, second and third signals from the beam forming network to at least three radiators respectively configured on three separate non-planar reflector panels, the signals having an amplitude and phase adjusted by the beam forming network to provide a dual beam radiation pattern. [0013] In a preferred embodiment of the method of providing a dual signal beam radiation pattern the three separate non-planar reflector panels comprise left and right panels oriented at an angle of 20 to 30 degrees relative to a center panel and the dual beam radiation pattern comprises two symmetric approximately 33 degree beams at half power beam width, the dual beams together covering an azimuth angle of about 65 degrees. [0014] Further features and advantages are set out in the following detailed description of the invention. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIGS. 1A and 1B are front and sectional views respectively of an antenna array in accordance with a preferred embodiment of the invention. [0016] FIG. 2 is a graph showing the simulated dual beam patterns provided by the antenna array at an RF frequency of 2200 MHz. [0017] FIG. 3 is a graph showing the simulated dual beam patterns provided by the antenna array at 1700 MHz. [0018] FIG. 4 is a schematic drawing of a beam forming network, showing amplitude and phase taper, for generating a dual beam pattern from the three column antenna array of FIG. 1 . [0019] FIG. 5 is a schematic drawing of a preferred embodiment of the beam forming network, showing amplitude and phase taper, for generating a dual beam pattern from the three column antenna array of FIG. 1 . [0020] FIG. 6 is a schematic drawing of a microstrip implementation of the beam forming network of FIG. 5 . [0021] FIG. 7 is a graph showing the simulated isolation between the antenna ports of the beam forming network of FIGS. 5 and 6 . DETAILED DESCRIPTION OF THE INVENTION [0022] FIGS. 1A and 1B show the structure of a preferred implementation of a dual beam sector antenna array 100 in accordance with the invention. As shown in FIG. 1A , radiators 112 , 122 and 132 are mounted on three separate planar reflector panels 110 , 120 , 130 to form a non-planar three-column antenna array. For example the radiators 112 , 122 and 132 may be aperture slot coupled patch antenna elements as generally shown. Other radiators may also be employed such as planar dipole, etc. as well known in the art. The relative slope of the two edge columns, a, with respect to the center column, shown in FIG. 1B , is important in achieving the required pattern shapes and minimum cross-over and beam-split losses. Typically, a preferred range for this angle is between 20 deg to 30 deg with respect to the center column panel 120 . A beam forming network described below creates dual beam radiation patterns from the three column radiator structure. The dual beam patterns can be maintained over a relatively broad frequency bandwidth. [0023] To provide desired elevation beam control a plurality of vertically arranged antenna element groups 140 may be provided as shown. In the illustrated embodiment five groups 140 are shown but more or fewer may be provided depending on the application. As shown in the illustrated embodiment each group 140 includes left, center and right sub groups 142 , 144 and 146 of antenna elements configured on respective panels 110 , 120 and 130 . This grouping corresponds to a separate beam forming network for each group of six radiators which may be respectively phase controlled to provide beam tilt capability. Different groupings are possible, however, including as few as three radiators per group or greater than six. Further details on such beam tilt control as well as details on suitable radiator and network coupling are provided in U.S. patent application Ser. No. 12/175,725 filed Jul. 17, 2008, the disclosure of which is incorporated herein by reference in its entirety. Remotely controllable down tilt based on remotely controllable signal phase shifting is also described in U.S. Pat. No. 5,949,303 incorporated herein by reference in its entirety. [0024] FIG. 2 and FIG. 3 show the simulated dual beam patterns at 2200 MHz and 1700 MHz. Both co-polarized (COPOL) and cross polarized (CXPOL) beam patterns are shown. In this case, the angle (α) is set at 20 deg. The half-power beamwidth (HPBW) of each individual beam is approximately 33 deg, which provides combined azimuth coverage of 65 degrees. The cross-over pattern loss at AZ=0 deg is approximately 3.9 dB. [0025] FIG. 4 is a schematic drawing of a 3-to-2 Beam-Forming Network (BFN) 400 of the three-column antenna array in accordance with the present invention. One such network is preferably provided for each group of radiators 140 in the array of FIG. 1 . FIG. 4 shows amplitudes and phases of the array at the input of the 3-to-2 Beam-Forming Network (BFN). The signal flow is shown flowing from the radiators but since the antenna will operate in both receive and transmit modes the opposite signal flow is equally implied. As shown the BFN 400 employs two splitters 410 and 420 . Implementation of a 3-to-2 BFN using a traditional method, such as the Butler matrix, will require a series of parallel structures of hybrids and combiners. This leads to additional losses due to signal splits between the two beams and path losses in the series hybrids. The BFN 400 shown in contrast can reduce such undesirable beam losses as described in more detail below. [0026] FIG. 5 shows a derived signal flow diagram of the 3-to-2 BFN in accordance with a preferred implementation 500 which reduces the number of signal path crossings which has advantages for a low cost and light weight microstrip implementation. The implementation 500 employs two 0 deg combiners 510 , 520 and two 180 deg splitters 530 , 540 . The split coupling to port 504 also may be considered a 0 deg combiner. Also shown are the coupling ports 502 , 504 and 506 to the antenna radiators and the RF signal input coupling ports 532 , 542 to the external phase shifting network. [0027] FIG. 6 shows the actual implementation of the BFN 500 using microstrip transmission lines. These microstrip transmission lines may be formed on a suitable substrate such as a planar dielectric material with a lower ground plane layer, as known in the art. With proper slope angles (α) for the two edge columns, for example, 20 deg, the 3-to-2 BFN can be formed using two unequally-split 180 deg splitters 510 , 520 and two 0 deg combiners 530 , 540 . Also, the split microstrip line 604 may functionally be considered as a 0 deg combiner in coupling port 504 to the separate splitters 510 , 520 as shown. The width and length of the microstrip line segments is chosen to implement the desired phase and amplitude relations set out in FIG. 5 . The BFN implementation of FIG. 6 has a number of advantages. The use of microstrip lines while avoiding signal line crossovers simplifies construction and reduces cost and weight. Path length between ports is reduced, which also reduces RF losses. For, example strip segments 602 , 632 between port 502 and 532 , and similarly segments 604 , 634 , 604 , 644 and 606 , 642 between respective ports are configured to minimize path length as shown. [0028] FIG. 7 is a graph showing the simulated isolation between the antenna ports of the beam forming network of FIGS. 5 and 6 . As shown in FIG. 7 , this simple implementation of the beam forming network has an inherently high isolation between antenna ports from the port cancellation at the 180 deg splitters. The beam forming structure also minimizes the overall front-end losses. The path loss is minimized from the compact design and minimum cross-over. The design minimizes the signal losses because of the beam split loss by use of unequal amplitude weight function. With the amplitude taper function, the beam split loss is less than 0.25 dB because of the unequal signal split ratio. The beam split loss can be as much as 3 dB if typical equally-split hybrids are used in the beam forming. [0029] The foregoing description is not intended to limit the invention to the form disclosed herein. Accordingly, variants and modifications consistent with the following teachings, and skill and knowledge of the relevant art, are within the scope of the present invention. The embodiments described herein are further intended to explain modes known for practicing the invention disclosed herewith and to enable others skilled in the art to utilize the invention in equivalent, or alternative embodiments and with various modifications considered necessary by the particular application(s) or use(s) of the present invention.

A low loss beam forming method and antenna structure are disclosed. The method and structure may preferably be used in forming two narrow beams within a cellular sector. This method allows an increase in the overall network capacity by using a three-column non-planar array and a compact, low-cost, low-loss 3-to-2 Beam-Forming Network (BFN). This structure produces two symmetrical beams with respect to the azimuth boresight. Radiation patterns of the two beams are designed to cover the entire azimuth coverage angle of a cellular sector with minimum beam-split loss and cross-over losses.

RELATED APPLICATIONS This application claims priority from Provisional U.S. Patent Application 60/957,984 “Integrated Microfluidic Optical Device for Sub-Micro Liter Liquid Sample Microspectroscopy,” by Shen, et al., filed on Aug. 24, 2007, which is incorporated herein by reference for all purposes noting that this application controls to the extent of any differences. TECHNICAL FIELD The field of the invention is excitation and detection of light emitting, or absorption entities in microchannels and the fabrication of devices for this purpose. Embodiments of the invention relate to the field of microchips with microfluidic optical chambers for multiplexed optical spectroscopy. Advantages include ultra small sample volume, high detection speed, and throughput over the conventional optical sample cuvette used in optical spectroscopy, as well as automated fluidic sample flow and temperature control. This may be applied to the spectroscopic detection of many analytical chemistry applications or biochemical assays for disease diagnosis. BACKGROUND Microfluidic devices and systems of such devices employ small capillaries or microchannels attached or integrated with a solid substrate to perform a variety of operations in a number of analytical chemical and biochemical applications on a very small scale. For example, integrated microfluidic devices can first employ electrical fields to effectively separate nucleic acids, proteins or other macromolecules of interest and then use microscale detection systems for characterization and analysis of the separation products. Such microfluidic devices accomplish these operations using remarkably small reaction volumes that can be at least several orders of magnitude smaller than conventional methods. The small size of these systems allows for increased reaction rates that use less reagent volume and that take up far less laboratory or industrial space. Microfluidic systems thus offer the potential for attractive efficiency gains, and consequently, substantial economic advantages. Microfluidic devices are particularly well-suited to conduct analytical methods that employ spectroscopic detection systems. A variety of spectroscopic techniques can be employed in conjunction with microfluidic devices, including infrared (IR), visible light, ultraviolet (UV), X-ray, microwave, electron beam, ion beam, positron emission, nuclear magnetic resonance (NMR), as well as various adsorption, emission, fluorescence, surface plasmon resonance (SPR), polarization, and light scattering spectroscopy, such as Raman spectroscopy. The particular technique employed will depend on the particular application. In research or industrial settings, microfluidic devices are typically employed in biochemical or cell-based assays that use spectroscopic detection systems to quantify labeled or unlabeled molecules of interest. For example, such an assay measures the expression of green fluorescent protein in mammalian cells following treatment by a candidate small molecule or biologic drug of interest. Another example is the use of the quantitative polymer chain reaction technique (PCR) in microfluidics devices for gene amplification and analysis with intercalating fluorescence dye as the spectroscopic indicator. Other examples include, but are not limited to, enzymatic and biochemical reactions in general, chemical reactions, phase transition detections, etc. Microfluidic devices generally employ networks of integrated microscale channels and reservoirs in which materials are transported, mixed, separated and detected, with various detectors and sensors embedded or externally arranged for quantification, as well as actuators and other accessories for manipulations of the fluidic samples. The development of sophisticated material transport systems has permitted the development of systems that are readily automatable and highly reproducible. Such operations are potentially automatable and can be incorporated into high-throughput systems with tremendous advantages for numerous industrial and research applications. Microfluidic devices often use plastics as the substrate. While polymeric materials offer advantages of easy fabrication, low cost and availability, they tend to be fluorescent. For example, when irradiating a sample with excitation light, light scatter may result in a significant background signal, particularly when the excitation pathway and emission pathway are the same. Other materials, such as glass, silicon, and metal may be used as well. BRIEF DESCRIPTION OF RELEVANT ART U.S. Patents of interest include U.S. Pat. No. 4,863,560, “Fabrication of Silicon Structures by Single Side, Multiple Step Etching Process”; U.S. Pat. No. 5,006,202, “Fabrication Method for Silicon Devices Using a Two Step Silicon Etching Process”; and U.S. Pat. No. 5,738,757, “Planar Masking for Multi-Depth Silicon Etching.” Publications of interest include Backlund and Rosengren, “New shapes in (100) Si using KOH and EDP etches,” J. Micromach. Microeng. 1992, 2:75-79; Sekimura and Naruse, Fabrication of 45° optical mirrors on (100) silicon using surfactant-added TMAH solution,” International Conference on Solid State Sensors and Actuators, pp. 550-551, Sendai, Japan, Jun. 7-10, 1999; Strandman, et al., “Fabrication of 45° Mirrors Together with Well-Defined V-grooves Using Wet Anisotropic Etching of Silicon, J. of Microelectromechanical Systems ( MEMS ) and Chang and Hicks, “Mesa structure formation using potassium hydroxide and ethylene diamine based etchants.” IEEE Workshop on Solid State Sensors and Actuators, pp. 102-103, Hilton Head, S. C., June 1988; Resnik et al, “The role of Triton surfactant in anistropic etching of 110 reflective plans on 100 silicon,” J. of Micromech. Microeng. 15, 1174-1183 (2005). SUMMARY OF THE INVENTION Methods and devices are provided for an optical system for emission detection from microchannels in silicon or plastic substrates. The silicon device can be formed by separately etching different microstructures with appropriate masking and different protective coatings and layers, which may be individually removed prior to final etching to provide deep microstructures. The device can accommodate parallel fluid streams, optionally separated with at least substantially perpendicular or slanted side walls, and on each side of the streams is, e.g., a microfabricated optic with reflecting walls for directing a light beam through the streams and then into a waste light dump. For molding with polymeric materials, the silicon device may be replicated twice and used with polymers to obtain a desired result. Microfabrication techniques are provided for molding microfluidic devices employing the optical system for use in fluorescent based operations. The present invention demonstrates an integrated microscale chamber with sub-micro liter volume for standard optical spectroscopy such as absorption spectroscopy, fluorescence spectroscopy, photoluminescence spectroscopy, Raman spectroscopy, circular dichroism, etc. The microscale optical chamber has two integrated 45° or other suitable angle reflectance surfaces allowing the light coupling to external optics. The optical path length of the microscale chamber can be shorter or even longer than that of the conventional optical cuvette used for absorption and fluorescence measurements (usually at 1 cm), but the volume may be smaller than 1 μL. The longer light path can allow for greater sensitivity in absorbance detection. The shorter light path can allow for further miniaturization of the detection module in the chip. The absorption is significant to be detectable by a spectrometer camera but the required volume can be more than 1000 times smaller than that used in conventional spectroscopy. The microscale dimension of the optical chamber can enable integration of multiple individual optical chambers in one chip, so a multiplexed optical spectroscopy of 2, 3, 8, 16, 32, 48, 96, 192, 384, 768, and even 1536 samples can be accomplished using a single device which holds all the samples at once. Accordingly, present embodiments of the invention present high sensitivity biomolecule detection on a chip with simultaneous detection of absorbance/fluorescence spectrums. The fluidic sample flow and reaction temperature in the microscale chamber may be controlled by external electronics, and/or mechanical micro-pumps. Due to the relatively small volume of the microchip and the fluidic sample, the flow rate and heating/cooling rate can be orders of magnitude higher than bulk scale counterparts, which enable many special applications, such as on-chip PCR and fast fluidic exchange. Compared to the prior art, the claimed subject matter involves monolithically fabricated optical detection chambers, which also serve the purpose of the microfluidic chamber. In this way, the optical detection of microfluidic biological and chemical samples can be implemented in the same device without the need for further assembly with other microdevices. In addition, the unique three optical window design claimed herein allows for the detection of multiple optical spectra such as absorption, transmission, fluorescence, scattering and many other spectra. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention are best understood from the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that, according to common practice, the various features of the drawings are not to-scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity. FIG. 1 shows an example system configuration with a microfluidics optical device and detection apparatus in accordance with embodiments of the present invention. FIGS. 2A-2E show cross-sectional views of example semiconductor processing steps for forming a microfluidic optical device in accordance with embodiments of the present invention. FIG. 3 shows an example integrated liquid handling package including the processed semiconductor device in accordance with embodiments of the present invention. FIG. 4A shows an example top view of microfabrication masks for making two-channel devices in accordance with embodiments of the present invention. FIG. 4B shows an example close-up top view of mask structures for making a microfluidic optical device in accordance with embodiments of the present invention. FIG. 5 shows example mask structures for making multiple channel devices in accordance with embodiments of the present invention. FIG. 6 shows an example cross-section of a two-level etched silicon microfluidic channel in accordance with embodiments of the present invention. FIG. 7A shows an example top view of an integrated well plate and silicon microfluidic device structure in accordance with embodiments of the present invention. FIG. 7B shows a cross-section view of the example structure of FIG. 7A . FIG. 8 shows an example processing flow for forming a microfluidic optical device in accordance with embodiments of the present invention. FIG. 9 shows an example flow for packaging a microfluidic optical device in accordance with embodiments of the present invention. FIG. 10 shows an example flow for characterizing a liquid sample in accordance with embodiments of the present invention. FIG. 11 shows an example microchip design with the through-wafer fluidic inlet and outlet pathways outside the optical detection chamber in accordance with embodiments of the present invention. FIG. 12 shows an example surface plasmon resonance (SPR) spectroscopy system using an integrated microfluidic optical device in accordance with embodiments of the present invention. FIG. 13 shows an example dynamic particle optical scattering analysis system using a microfluidic optical device in accordance with embodiments of the present invention. FIG. 14 shows an example molecule circular dichroism (CD) measurement system using a microfluidic optical device in accordance with embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before the methods and devices of embodiments of the present invention are described, it is to be understood that the invention is not limited to any particular embodiment described, as such may, of course, vary. It is also to be understood that the terminology used herein is with the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention which will be limited only by the appended claims. Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limits of that range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in that stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range, and each range where either, neither or both limits are included in the smaller ranges is also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited. The present disclosure is controlling to the extent there is a contradiction between the present disclosure and a publication incorporated by reference. It must be noted that as used herein and in the appended claims, the singular forms “a”, “and”, and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a peptide” includes a plurality of such peptides and reference to “the method” includes reference to one or more methods and equivalents thereof known to those skilled in the art, and so forth. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed. Conventionally, a chemical or biological sample must be in a cuvette for optical spectroscopic analysis. The present invention is based on the discovery that it is possible to shrink such cuvettes down onto chips (e.g., cut from silicon wafers) to create an optical path giving an absorption spectrum and/or a fluorescence spectrum of the sample. The resulting design may be considered an array of “on-chip microcuvettes.” Nanostructures may be fabricated on the surface of the microfluidics channel to provide enhancement of optical signals or substrate to anchor detection probes or to capture target molecules or particulates for detection. Molecular probes, such as antibodies, aptamers, DNA or RNA oligonucleotide and longer probes, peptides, polysaccharides, polymers, small molecules, etc., can be chemically linked to the surfaces of the microfluidic chamber in the chip, which can increase the detection specificity and expand potential applications. The molecular probes may also be tethered to physically fabricated nanostructures to create nanobio hybrid probes in the microfluidic chamber. Embodiments of the technology presented herein have applications in, inter alia, diagnostic tests or molecular diagnostics. For example, molecular diagnostics, and in particular molecular diagnostics that detect biomarkers related to cancer, measure biomarkers including small molecule metabolites or metabolic intermediates, nucleic acids, carbohydrates, proteins, protein fragments, protein complexes or derivatives or combinations thereof. Chemical assays and in particular analytical methods that employ spectroscopic detection systems may be used in the detection and quantification of such biomarkers, and may provide information about the interaction of biomarkers with test molecules such as small molecules, enzymes, carbohydrates, nucleic acid probes, nucleic acid or protein aptamers, peptide nucleic acids, peptides, or polyclonal or monoclonal antibodies. Such assay methods may be employed initially during the identification, characterization, and development of molecular diagnostics, and may also be employed as molecular diagnostic tests used to assay biological samples and thus measure the health status of patients or to provide information that may support medical decisions. Particular embodiments also have applications in, inter alia, molecular therapeutics. For example, identification and characterization of drug targets may involve detection and quantification of such drug targets in biological samples. Chemical assays and analytical methods that employ spectroscopic detection systems may be used to detect and quantify potential drug targets including proteins such as cell surface proteins, extracellular proteins, peptide hormones, transmembrane proteins, receptor proteins, signaling proteins, cytosolic proteins or enzymes, nuclear proteins, DNA-binding proteins, RNA molecules including messenger RNA or micro-RNAs, or DNA. Such assays and methods may also provide information about the interaction of drug targets with drugs such as small molecules, polyclonal or monoclonal antibodies, therapeutic proteins or therapeutic enzymes, antisense nucleic acids, small-interfering RNAs, nucleic acid or protein aptamers, peptide nucleic acids, or other drugs and potential drugs. Such assay methods may be employed initially during the identification, characterization, and development of molecular therapeutics, and may also be employed in tests to identify individual patients' responsiveness to treatment with drugs or potential drugs, and thus provide valuable information that may support medical decisions. The terms “nucleic acid” and “polynucleotide” are used interchangeably herein to refer to deoxyribonucleotides or ribonucleotides, and polymers thereof, in either single- or double-stranded form. The terms generally encompass nucleic acids containing known nucleotide analogs or modified backbone residues or linkages, which are synthetic, naturally occurring, and non-naturally occurring, which have similar binding properties as the reference nucleic acid, and which are metabolized in a manner similar to the reference nucleotides. Examples of such analogs include, without limitation, phosphorothioates, phosphoramidates, methyl phosphonates, chiral-methyl phosphonates, 2-O-methyl ribonucleotides, peptide-nucleic acids (PNAs). The terms “polypeptide,” “peptide” and “protein” are used interchangeably herein to refer to a polymer of amino acid residues. The terms apply to amino acid polymers in which one or more amino acid residue is an artificial chemical mimetic of a corresponding naturally occurring amino acid, as well as to naturally occurring amino acid polymers and non-naturally occurring amino acid polymer. The term “amino acid” refers to naturally occurring and synthetic amino acids, as well as amino acid analogs and amino acid mimetics that function in a manner similar to the naturally occurring amino acids. Naturally occurring amino acids are those encoded by the genetic code, as well as those amino acids that are later modified, e.g., hydroxyproline, γ-carboxyglutamate, and O-phosphoserine. Amino acid analogs refers to compounds that have the same basic chemical structure as a naturally occurring amino acid, e.g., an α carbon that is bound to a hydrogen, a carboxyl group, an amino group, and an R group, e.g., homoserine, norleucine, methionine sulfoxide, methionine methyl sulfonium. Such analogs have modified R groups (e.g., norleucine) or modified peptide backbones, but retain the same basic chemical structure as a naturally occurring amino acid. Amino acid mimetics refers to chemical compounds that have a structure that is different from the general chemical structure of an amino acid, but that functions in a manner similar to a naturally occurring amino acid. Further, silicon wafers are preferable to conventional antibody affinity binding assay substrates that can only detect concentration. Other semiconductor wafers (e.g., GaAs, InP, GaP, GaSb, InSb, InAs, CaF 2 , LaAl2O3, LiGaO2, MgO, SrTiOq, YSZ and ZnO) can also be used in certain embodiments. Suitable semiconductor materials for the wafer include, but are not limited to, elements of Groups II-VI (ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe, MgS, MgSe, MgTe, CaS, CaSe, CaTe, SrS, SrSe, SrTe, BaS, BaSe, BaTe, etc.) and III-V (GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, etc.) and IV (Ge, Si, etc.) groups on the periodic table, and alloys or mixtures thereof. Suitable metals and metal oxides for the surface coating include, but are not limited to, Au, Ag, Co, Ni, Fe 2 O 3 , TiO 2 , and the like. Suitable carbon nanoparticles for surface coating include, e.g., carbon nanospheres, carbon nano-onions, carbon nanotubes, and fullerene. In particular embodiments, enzymatic activity and protein concentration may also be detected. In the context of prostate tumors, for example, whereas prostate-specific antigen (PSA) concentration can now be detected, it may not be clear whether the antigen is active or not, possibly providing a misleading measurement. An aspect of certain embodiments includes generating information regarding not only concentration, but also activity. Further, particular embodiments also include a detection system in lieu of a chip scanner. A system for liquid sample microspectroscopy in certain embodiments may generally include a detection apparatus (e.g., instrumentation portion) coupled to a microfluidics optical device (e.g., a chip or integrated circuit (IC) portion). The detection apparatus can include a light source for sending light through a liquid sample to be characterized, and a spectrograph and/or analysis unit to analyze the light (e.g., fluorescence, absorbance, etc.) affected by molecules of the sample. The microfluidic optical device can be fabricated using semiconductor processing techniques, and may be packaged to protect the semiconductor therein and to accommodate inlet/outlet ports for the liquid sample. “Biological sample” as used herein is a sample of biological tissue or chemical fluid that is suspected of containing an analyte of interest. Samples include, for example, body fluids such as whole blood, serum, plasma, cerebrospinal fluid, urine, lymph fluids, and various external secretions of the respiratory, intestinal and genitourinary tracts such as tears, saliva, semen, milk, and the like; and other biological fluids such as cell culture suspensions, cell extracts, cell culture supernatants. Samples may also include tissue biopsies, e.g., from the lung, liver, brain, eye, tongue, colon, kidney, muscle, heart, breast, skin, pancreas, uterus, cervix, prostate, salivary gland, and the like. A sample may be suspended or dissolved in, e.g., buffers, extractants, solvents, and the like. A sample can be from any naturally occurring organism or a recombinant organism including, e.g., viruses, prokaryotes or eukaryotes, and mammals (e.g., rodents, felines, canines, and primates). The organism may be a nondiseased organism, an organism suspected of being diseased, or a diseased organism. A mammalian subject from whom a sample is taken may have, be suspected of having, or have a disease such as, for example, cancer, autoimmune disease, or cardiovascular disease, pulmonary disease, gastrointestinal disease, muscoskeletal disorders, central nervous system disorders, infectious disease (e.g., viral, fungal, or bacterial infection). The term biological sample also refers to research samples which have been deliberately created for the study of biological processes or discovery or screening of drug candidates. Such examples include, but are not limited to, aqueous samples that have been doped with bacteria, viruses, DNA, polypeptides, natural or recombinant proteins, metal ions, or drug candidates and their mixtures. Referring now to FIG. 1 , an example system configuration with a microfluidics optical device and detection apparatus in accordance with embodiments of the present invention is shown and indicated by the general reference character 100 . Light source 102 can provide a beam that is reflected using mirror 114 , and that can pass via lens 116 for focusing and input to microfluidic optical chamber 118 via an optically transparent opening. Light source 102 can provide an illumination/excitation light beam that may be any suitable form of light, such as white light, laser light (e.g., visible laser, ultraviolet (UV) laser, near infrared laser etc.), light emitting diode (LED), super luminescent diode, polarized light, halogen lamp-generated light, continuous or pulsed Xenon Lamp, Mercury light source, Argon light source, Deuterium light source, Tungsten light source and Deuterium-Tungsten-Halogen mixed light source, etc. Generally, the microfluidic optical chamber can be populated by molecules of a liquid or sample to be characterized, where the liquid is received via the inlet port, and can also be discharged via the outlet port. Incoming light (e.g., focused via lens 116 ) can be reflected in microfluidic optical chamber 118 using reflective coating 106 . For example, reflective coating 106 can be aluminum, gold, silver, chromium, multilayer dielectrics or any suitable reflective metal, or non-reflective material (which can still be used to measure surface plasmon resonance (SPR)), or nano-material (e.g., nano-fibers, nanoparticles, nanocoating, nanopatterns, etc.). Multilayer composite material reflective coating can be made on the side wall as a narrow bandwidth reflector. The semiconductor surface may further include a hydrophilic coating (e.g., a coating of hydrophilic materials or stabilizing groups) to enhance the hydrophilicity of the semiconductor surface, so as to facilitate the entrance of the liquid sample into the microchannel. Suitable hydrophilic materials include, e.g., SiO, SiO 2 , polyethylene glycol, ether, mecapto acid and hydrocarbonic acid, and dihydroxylipoic acid (DHLA). In particular embodiments, the hydrophilic coating is a silica layer (e.g., including SiO 2 ). Typical methods of silanizing semiconductor surfaces can also be used. Suitable stabilizing groups include, e.g., positively or negatively charged groups or groups that facilitate steric repulsion. Other suitable strategies for generating water-soluble semiconductor surface can be employed as well. Once the light is passed through microfluidic optical chamber 118 , absorbance can occur via objective lens 126 , with reflection off mirror 128 , and sending to beam splitter 122 . Also, fluorescence can emanate from microfluidic optical chamber 118 , may be received via optical lens 120 , and passed to beam splitter 122 . From beam splitter 122 , light can be reflected using mirror 124 for receipt in spectrograph 130 . Spectrograph 130 may also include a charge coupled device (CCD) for analysis of the various wavelengths contained in the received light beam. In this fashion, one or more characteristics of the sample found in chamber 118 can be determined based on analysis of received fluorescence and/or absorbance light in spectrograph 130 . Further, and as will be discussed in more detail below, the microscale dimensions of the optical chamber presented herein can allow for integration of multiple individual optical chambers in one chip, such that the multiplexed optical spectroscopy of 2, 96, and even 384 samples, can be accomplished. Generally, certain embodiments can include an instrumentation portion discussed above, as well as an IC portion. The IC portion can include semiconductor material 108 , with via-holes therein to accommodate inlet and outlet ports as shown, and polymer bounding layer 104 covering the semiconductor material 108 . Semiconductor material 108 can include any suitable semiconductor material, such as silicon (Si), germanium, silicon dioxide, gallium arsenide (GaAs), etc. Suitable semiconductor materials for the wafer include, but are not limited to, elements of Groups II-VI (ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe, MgS, MgSe, MgTe, CaS, CaSe, CaTe, SrS, SrSe, SrTe, BaS, BaSe, BaTe, etc.) and III-V (GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, etc.) and IV (Ge, Si, etc.) groups on the periodic table, and alloys or mixtures thereof. Further, transparent window 110 can isolate the IC portion from the instrumentation portion, and material 112 (e.g., silicon dioxide, polydimethylsiloxane (PDMS), coc polymer, or any UV transparent plastics) can be utilized to coat transparent window 110 to define optically transparent openings or through channels for light. In certain embodiments, inlet and outlet ports need not be aligned with the through channels for light, but rather may be placed to accommodate other connections and/or pathways for fluid ingress/egress. In addition, because certain embodiments can include placing the optical apparatus or instrumentation portion on the opposite chip side (e.g., the bottom side) relative to inlet/outlet channels (e.g., the top side), there is substantial leeway as to placing the inlet and outlet channels without interfering with the optical analysis aspects. Further, sizes of the inlet and outlet channels or ports can be varied, and may thus provide a filtering function by allowing for different sample volumes, molecule sizes, etc., depending upon the particular application. In particular embodiments, the shape of microfluidic optical chamber 118 can be other than straight, such as serpentine or spiraled. In addition, fluorescence and scattering spectra can alternatively be collected not strictly from reflective mirrors, but also from the entire channels as all-direction fluorescence and scattering light emissions. Semiconductor fabrication can generally be done using existing semiconductor processing techniques, thus allowing for high-volume production. In this fashion, the IC portion of the microfluidic optical device can be manufactured. FIGS. 2A-2E show example cross-sectional views of semiconductor processing steps for forming a microfluidic optical device in accordance with embodiments of the present invention. First, photolithography can be used to pattern the backside of the semiconductor wafer (see, e.g., FIG. 2A ). Single crystal silicon 202 can be arranged with the ‘100’ silicon surface facing down, as shown. Photoresist 204 can be patterned as shown to allow for subsequent etching of silicon 202 in areas not protected by photoresist 204 . This step can define an extent of an elongated length of optical chamber 118 . FIG. 2B shows a cross-section view after etching the backside using patterned photoresist 204 . For example, wet etching using an alkaline etchant can be used for this process. As shown, the resulting silicon surfaces exposed include the ‘100’ silicon surface, as well as the ‘110’ silicon surface at about a 45° angle. Also in particular embodiments, the reflectivity and reflective spectrum of the etched ‘110’ silicon surface can be modified by depositing a metallic layer including any suitable material and thickness. Further, other surfaces (e.g., the ‘111’ silicon surface) can be also used as the reflective surface, where an associated adjustment can be made to about a 53.7° angle relative to the elongated length. In FIG. 2C , photolithography can be used to pattern in the wafer frontside by utilizing patterned photoresist 206 to define holes or channels for coupling to inlets/outlets. Via-holes can be etched through the silicon above the through channel area, as shown in FIG. 2D . In one embodiment, these via-holes may have a diameter or width of about 100 μm. Of course, any suitable width for these via-holes (e.g., within ranges of from about 80 μm to about 120 μm, or from about 50 μm to about 150 μm) can be utilized in particular embodiments. For example, these via-hole widths may also be configured to form a filtering function, such as by disallowing larger molecules from flowing into the through channel or chamber. Further, the location of the via-holes can be varied, as discussed above. For example, the locations of these via-holes may be beyond the micro channel, as shown below in FIGS. 6 and 11 . In this case, the via-hole opening on the microfluidics channel side may not affect the integrity of the optical chamber, especially the reflective surfaces. FIG. 2E shows an example application of polymer bounding layer 208 over silicon areas 202 to accommodate inlet and outlet channels. In one embodiment, two mirrors oriented at about 45° may also be fabricated at each end of the chamber. The microscale optical chamber is typically between about 0.1 and 5 cm long, between about 20 and 500 μm in width and between about 10 and 250 μm in depth (see e.g., chamber 118 shown in FIG. 1 ). Although any of a range of optical chamber sizes might be especially well suited for each particular application, preferred embodiments include an optical chamber of about 2 cm long, 200 μm in width and 100 μm in depth. The mirror surfaces can be monolithically fabricated together with the microscale optical chamber using a wet silicon etching method. Since the micro channels can be aligned at about 45° with respect to the major flat or elongated length of the ‘100’ silicon wafer, the end surfaces of the micro chambers are ‘110’ silicon surfaces oriented at about 45° with respect to the ‘100’ silicon wafer surface. After wet etching to make the 45° angles exposing ‘100’ silicon surfaces, an aluminum (Al) layer having a thickness of about 100 nm may be deposited on the surface to create the reflective mirrors. Referring now to FIG. 3 , an example integrated liquid handling package including the processed semiconductor device in accordance with embodiments of the present invention is shown. Inlet 302 and/or outlet 304 may be coupled to multiple channels, where these pathways can be routed, and may be arranged in an array format to allow easy loading via robots (e.g., to accommodate standard distances for such loading). Polymer bounding layer 104 can be any suitable layer of soft or hard plastic (e.g., poly(dimethylsiloxane) (“PDMS”)), epoxy, adhesive rubber or a metal, etc. The surface of the silicon device may also be oxidized by plasma enhanced chemical vapor deposition (PECVD) or electron beam evaporation. In addition, liquid handling package 306 can surround left and right edges of the structure, as well as covering the top portion along with sealing material 308 (e.g., epoxy, PDMS, rubber, glass, quartz, etc.). In certain embodiments, mixing of a sample solution can be controlled for optical chamber 118 in order to observe real-time reactions of different chemicals and/or multiple components being pumped into the inlet at the same time. Further, inlet 302 and/or outlet 304 can involve any type of tubing, such as, for example tubing made of polymeric materials. The diameter of the via-holes may range from about 100 μm to about 1 mm. In the detection or instrumentation module, absorbance and/or fluorescence of the supplied light can be analyzed. Typically, the fluorescence light is at higher wavelengths than the excitation light. Particular embodiments can also support photonic or multiphotonic excitation, where the excitation wavelengths are higher than the emission wavelengths, as well as epi-fluorescence applications that may utilize a separate filter. Certain embodiments can also accommodate measurement of scattering light (e.g., X-ray small angle scattering spectroscopy), and may also take measurements using polarized light in circular dichrotomomy (CD) applications involving a measurement of the response degree of angle movement of the sample molecules. The fluorescence lifetimes can also be measured for Fourier transformed infrared (FTIR) applications, as well as Raman scattering, and luminescence. SPR and nuclear magnetic resonance (NMR) spectroscopy can also be accommodated in particular embodiments. For such applications, the illumination window can receive optically pumped hyper polarized light, and such optical pumping, as well as the optical realization, can generally occur in close proximity. NMR may typically utilize a homogeneous field for measurement because this approach usually utilizes a metal coil, where the magnetic field can be reversed, and the optical pumping can be through chamber 118 , where the magnetic field is around chamber 118 . In this fashion, the microfluidic optical chamber can be optically activated. Other electromagnetic sources can also be incorporated for manipulating the material sample in the microfluidic optical chamber. For example, particular embodiments can allow for manipulation of sample physical properties using thermal, electromagnetic, optical, dielectric, inhomogeneality, etc. In particular embodiments, transparent window 110 can generally be relatively thin such that optical loss due to absorption in the window can be minimized (e.g., to under about 10%). Typical window implementations can be in a range of about 1-3 mm thick, whereas particular embodiments can allow for a thickness of from about 200 μm to about 300 μm. On the other hand, the opening width of the window may from 200 μm to 1 mm. Further, a transparent window in certain embodiments can be formed of any suitable material that is transparent to the spectrum of light (e.g., via light source 102 ) used in the system. For example, transparent window 110 can be made of plastic, glass, coc polymer, PDMS and/or any other suitable UV or visible light transparent materials. Thus, transparent window 110 may have a minimized height to reduce optical signal loss in either absorption or auto fluorescence. In another embodiments, there can be as many as three transparent windows 110 distributed near the inlet, outlet and the center portion of the microfluidic chamber. The two windows near the inlet and outlet may serve as an optical pathway for illuminating and transmitting light into and out of the chamber. The window near the center of the chamber serves as the optical pathway for the fluorescence and scattering light emitted from the liquid sample in the microfluidic chamber. The three-window design allows for multiple functionality in the measurement of absorbance, fluorescence, phosphorous, photoluminescence, Rayleigh and Raman scattering light from the same microfluidic chamber device. As shown in FIG. 3 , the top surface of the silicon chip can include etched inlet and outlet reservoirs with guiding micro channels connected to the through holes. The liquid samples can be introduced from the inlet reservoir and guided into the via-hole. The liquid samples can then flow to the other side of the chips into the microscale optical chamber. Also, the liquid sample can be drawn out from microscale optical chamber 118 into outlet 304 by passing through another via-hole. In one embodiment, two through-holes may be made inside micro channels across both surfaces of the silicon chip. Such holes can provide ducts for liquid sample flowing from one surface to another, such that that the liquid handling units can be installed on a side of the silicon chip other than the side where the microscale optical chambers are positioned. Without having the liquid handling units (e.g., reservoirs, connectors, tubings, or pumps) obstructing the microscale optical chamber, optical systems can have substantial exposure to chamber 118 . Also, chamber 118 in certain embodiments may be from about 1 cm to about 2 cm long to provide a relatively long light path. This approach allows for lower concentrations of materials needed for characterization. For example, as to absorption, a longer light path (e.g., about 2 cm) may double sensitivity relative to a typical light path length of about 1 cm. Thus, measurement flexibility can be increased for a given amount of material by using a relatively long light path channel. For fluorescence, the length of the light path can be very short, so that less light is lost in the light path. The reduced light attenuation associated with shorter light path can allow better sensitivity for fluorescence measurement. In addition, any suitable range for the length of chamber 118 can be formed in certain embodiments, such as ranging from about 1 cm to about 10 cm. In certain embodiments the width of chamber 118 in may be from about 10 μm to about 500 μm long and the depth in certain embodiments may be from about 10 μm to about 200 μm to provide a microlitter or sub-microlitter volume. This approach allows for a reduction in volume and reduced consumption of materials needed for characterization. The chamber may hold a volume in the range of about 0.10 μL to 2 μL of fluid. Another aspect of a particular embodiment of the invention involves the relatively strong thermal conducting nature of silicon material 104 , thus allowing the temperature of chamber 118 to be controlled by coupling to a thermal device (heating and/or cooling). For example, a metal block or junction can be used to measure sample material not only at room temperature, but as low as from about 0° C. up to about 300° C., or as otherwise determined by the limits of the sample material itself. Thus, if a protein is active and in order to prevent denaturing at higher temperature, a sample measurement can be performed at about 37° C. In another embodiment, thermostable enzymes (e.g. Taq polymerase, and other thermal stable enzymes isolated or engineered from thermophilic microbes) can allow higher temperature (up to 99° C.) measurements. This type of measurement may not be possible with standard cuvettes without relatively bulky heating/cooling elements being coupled thereto. In particular embodiments, such temperature control and an associated sensing unit can be integrated with the microfluidics optical device. For example, such an integrated temperature control and sensing unit can be a Peltier junction heater or metal line resistance heater. This approach can allow for thermocycling analysis of samples at varying temperatures, such as relatively low temperatures to prevent heat-denaturation of proteins, and higher temperatures for real-time genetic amplification using polymerase chain reactions (PCR). In this fashion, measurement of chemical, biological, and/or physical reactions to temperature can be accommodated in chamber 118 . Any temperature dependent characteristic can be isolated, such as measuring the melting point of chemicals for assessing chemical purity. Further, some applications may also include a camera. PCR can include a cycling temperature (e.g., between about 55° C. and about 95° C.), with observance of fluorescence in the reaction (e.g., about 10 ms per frame to about one second per frame) in order to observe a real-time PCR signal. In addition, any number of different enzymes such as nucleases, proteases, kinase, polymerase, glycosylase, topoisomerase, ligase, and phosphatases can also be measured using microfluidic optical chambers of particular embodiments. Referring now to FIG. 4A , an example top view of microfabrication masks for making two-channel devices in accordance with embodiments of the present invention is shown. In this example, a silicon wafer 402 can be defined with device masking, inlet/outlet reservoir 404 masking, microfluidic optical chamber 406 masking, and via-hole masking layers. As shown in the example close-up top view of the mask structures in FIG. 4 B, via-hole masking layer 408 can be aligned with an edge of microfluidic optical chamber 406 , and within inlet/outlet reservoir 404 masking layer. Referring now to FIG. 5 , example mask structures for making multiple channel devices in accordance with embodiments of the present invention are shown. Here, connections 504 - 0 and 504 - 1 can be made to external tubing portions 502 - 0 and 502 - 1 , respectively. In such embodiments, the number of microchannels on each chip may be variable for different sample numbers that can be measured simultaneously. The channel number on one chip can be 1, 2, 4, 8, 16, 48, 96, 384, 768, 1536, etc. In the particular examples of FIGS. 4 and 5 , photolithography masks for 2-channel and 96-channel chips are shown. Referring now to FIG. 6 , an example cross-section of a two-level etched silicon microfluidic channel in accordance with embodiments of the present invention is shown. In this particular example, microchannel 618 can have two levels in different depths, with the shallower level being connected to a top side of the chip through a via-hole, and the deeper level having the slanted reflective surfaces at both ends. Such a two-level design may be configured to prevent air bubbles trapped near the reflective surfaces. This approach can similarly use a semiconductor material (e.g., silicon) 602 , as well as polymer bounding layer 608 , and transparent windows 610 . Referring now to FIG. 7A , an example top view of an integrated well plate and silicon microfluidic device structure in accordance with embodiments of the present invention is shown. FIG. 7B shows a cross-section view of the example structure of FIG. 7A . Silicon device 704 can be topped by microfluidic network layer (e.g., PDMS) 706 , and well plate 702 . Thus, such a multichannel version can have access holes through to the top of the structure for a microfluidic channel or routing layer. In this fashion, a microfluidics optical chip can be integrated with 96 , 384 , 1536 , etc., micro well plates that may comply with standard micro well plate dimensions. The assembly of the microfluidics optical chip with the micro well plates may then be compatible with standard robotic liquid handling systems. Referring now to FIG. 8 , an example processing flow for forming a microfluidic optical device in accordance with embodiments of the present invention is shown. The flow can begin ( 802 ), and photolithography may be utilized to pattern the backside of a silicon wafer that is oriented along the ‘100’ silicon surface ( 804 ). Wet etching may then be performed on the backside (e.g., using an alkaline etchant) to expose, e.g., the ‘110’ silicon surface at an angle of about 45° for forming a microfluidic optical chamber ( 806 ). The photolithography can also be used to pattern the frontside of the wafer, where etching can then be performed for via-hole formation ( 808 ). Chips separated from the wafer can then be integrated with liquid handling units coupled to the microfluidic optical chamber ( 810 ), completing the flow ( 812 ). Referring now to FIG. 9 , an example flow for packaging a microfluidic optical device in accordance with embodiments of the present invention is shown. The flow can begin ( 902 ), and a silicon microfluidic device may be placed into a metal heat block and base structure ( 904 ). A metal heat transfer plate may then be placed over the silicon microfluidic device ( 906 ). In this fashion, the metal heat transfer plate (e.g., a heat sink) may be connected to the microfluidics optical device such that the device can be rapidly cooled by way of transferring heat away from the chip portion. Further, the packaging material may have relatively high thermal conductivity, and can be in good contact with the silicon-based microfluidics chip. A plastic fluidic connector can then be placed over the metal heat transfer plate ( 908 ). A plastic cover can then be placed over the metal heat assembly block and base to protect ( 910 ) and complete ( 912 ) the assembly. Referring now to FIG. 10 , an example flow for characterizing a liquid sample in accordance with embodiments of the present invention is shown. The flow can begin ( 1002 ), and a light source may pass a beam through a lens to provide excitation light through a first optically transparent opening of a microfluidic optical chamber ( 1004 ). The excitation light can then be reflected off a first surface aligned with the first optically transparent opening such that the reflected excitation light can interact with a sample in the microfluidic optical chamber ( 1006 ). Fluorescence light can be received through a second optically transparent opening, and passed through a first objective lens to a beam splitter ( 1008 ). Absorbance light can also be received after being reflected off a second surface once passed through the sample, where the second surface is aligned with a third optically transparent opening, and where the absorbance light can then be passed through a second objective lens to the beam splitter ( 1010 ). A spectrograph can be used to analyze the fluorescence light and/or the absorbance light from the beam splitter in order to determine a characteristic of the sample ( 1012 ), thus completing the flow ( 1014 ). FIG. 11 shows an example microchip design with the through-wafer fluidic inlet and outlet pathways outside the optical detection chamber in accordance with embodiments of the present invention. In this particular example, microchannel 1118 can have two levels in different depths, with the shallower level being connected to a top side of the chip through a via-hole, and the deeper level having the slanted reflective surfaces at both ends. In such an arrangement, the via-hole opening on the microfluidics channel side may not affect the integrity of the optical chamber (e.g., microchannel 1118 ), and particularly the reflective surfaces (e.g., at 45° angles). This approach can similarly use a semiconductor material (e.g., silicon) 1102 , as well as transparent window 1110 , which can isolate the IC portion from the instrumentation portion, and material 1112 (e.g., SiO 2 , polydimethylsiloxane (PDMS), coc polymer, or any UV transparent plastics) for coating transparent window 1110 to define optically transparent openings or through channels for light. FIG. 12 shows an example surface plasmon resonance (SPR) spectroscopy system using an integrated microfluidic optical device in accordance with embodiments of the present invention. A collimated broad band light beam 1220 (e.g., from light source 1206 ) can be reflected by a triangle or dove prism 1208 , and illuminated through transparent window 1210 (e.g., transparent window 110 ) on the 45° angle reflective surface in microchannel 1218 (e.g., microfluidic optical chamber 118 ). This approach can similarly use a semiconductor material 1202 (e.g., the same or similar to material 108 described above). Because the incident angle is not perpendicular to the microfluidic channel, the light path is not parallel to the channel direction, and there can be a one time reflection on the channel bottom surface 1222 . The channel bottom surface 1222 may be coated with a thin film of gold, and molecular probes may be tethered on the surface. When reagents flow through microchannel 1218 and react with the immobilized molecular probes, the SPR frequency of this gold thin film may shift. The frequency shift can be picked up by the external spectrometer or photo detector 1204 . FIG. 13 shows an example dynamic particle optical scattering analysis system using a microfluidic optical device in accordance with embodiments of the present invention. The scattering light from small particles and biological cells can be measured in microfluidic optical channel 1318 (e.g., 118 ). As the scattering light emits from all directions, it can be detected from the center area of the microchannel via lens 1320 in charge-coupled device (CCD) camera 1306 . Transparent window 1310 (e.g., 110 ) can isolate the IC portion from the instrumentation portion, and material 1312 (e.g., silicon dioxide, polydimethylsiloxane (PDMS), coc polymer, or any UV transparent plastics, and the same or similar to material 112 ) can be utilized to coat transparent window 1310 to define optically transparent openings or through channels for light. For example, this approach can also use a semiconductor material 1302 that is the same or similar to material 108 described above. FIG. 14 shows an example molecule circular dichroism (CD) measurement system using a microfluidic optical device in accordance with embodiments of the present invention. Dichroism spectroscopy can be performed in the microfluidic optical chamber by introducing a circular polarizer (e.g., 1402 ) and analyzer (e.g., 1404 ) in the external optical spectroscopy system. In certain embodiments, a digital light processing (“DLP”) device can be used for fine adjustments of the light incident angle with computerized feedback control. For example, such a DLP can replace mirror 114 in the configuration shown in FIG. 1 . This approach can be utilized to accommodate situations where the etched reflective surfaces (e.g., 106 ) have slight variations in slant angles and surface roughness. In certain embodiments, the volume and depth of the microfluidics optical chambers can be changed by varying an associated etching time. The etch rate for the single crystal silicon may be about 1 μm per minute, so the etch depth can be well-controlled. For example, the chamber volume can range from about 1 nL to about 10 μL. Also in certain embodiments, the surface of via-holes connecting the two sides of the chip can be modified with a self-assembly monolayer of chemical molecules configured to change the hydrophilicity and/or hydrophobicity. After surface modification, the liquid sample can flow more easily through the via-hole to another side of the chip. Various materials can be deposited on the surface using different techniques, such as chemical vapor deposition (CVD), oxidation, electroplating, polymer deposition, etc. Particular embodiments can also involve biomolecules that are tethered to the surface. For example, such biomolecules can include nucleic acids (DNA and RNA), proteins, peptides, sugar/carbon hydrates, metabolites and small chemical compounds. Further, the surface-tethered biomolecules and chemical molecules can be patterned to form a microscale array of biochemical assay. Various biochemical libraries may also be deposited on the surface of the microfluidics optical chamber for combinatorial detection. Functional groups can include reactive groups. Functional groups can also include bifunctional crosslinkers having two reactive groups capable of forming a bond with two or more different functional targets (e.g., peptides, proteins, macromolecules, surface coating/surface, etc.). In some embodiments, the bifunctional crosslinkers are heterobifunctional crosslinkers with two different reactive groups. To allow covalent conjugation of biomolecule to the surface, suitable reactive groups include, e.g., thiol (—SH), carboxylate (COOH), carboxyl (—COOH), carbonyl, amine (NH 2 ), hydroxyl (—OH), aldehyde (—CHO), alcohol (ROH)ketone (R 2 CO), active hydrogen, ester, sulfhydryl (SH), phosphate (—PO 3 ), or photoreactive moieties. Amine reactive groups can include, e.g., isothiocyanates, isocyanates, acyl azides, NHS esters, sulfonyl chlorides, aldehydes and glyoxals, epoxides and oxiranes, carbonates, arylating agents, imidoesters, carbodiimides, and anhydrides. Thiol-reactive groups include, e.g., haloacetyl and alkyl halide derivates, maleimides, aziridines, acryloyl derivatives, arylating agents, and thiol-disulfides exchange reagents. Carboxylate reactive groups include, e.g., diazoalkanes and diazoacetyl compounds, such as carbonyldiimidazoles and carbodiimides. Hydroxyl reactive groups include, e.g., epoxides and oxiranes, carbonyldiimidazole, oxidation with periodate, N,N′-disuccinimidyl carbonate or N-hydroxylsuccimidyl chloroformate, enzymatic oxidation, alkyl halogens, and isocyanates. Aldehyde and ketone reactive groups include, e.g., hydrazine derivatives for schiff base formation or reduction amination. Active hydrogen reactive groups include, e.g., diazonium derivatives for mannich condensation and iodination reactions. Photoreactive groups include, e.g., aryl azides and halogenated aryl azides, benzophenones, diazo compounds, and diazirine derivatives. In one embodiment, a heterobifunctional crosslinker includes two different reactive groups that form a heterocyclic ring that can interact with a substrate peptide. For example, a heterobifunctional crosslinker, such as cysteine, may include an amine reactive group and a thiol-reactive group that can interact with an aldehyde on a derivatized peptide. Additional combinations of reactive groups for heterobifunctional crosslinkers include, e.g., amine- and sulfhydryl reactive groups, carbonyl and sulfhydryl reactive groups, amine and photoreactive groups, sulfhydryl and photoreactive groups, carbonyl and photoreactive groups, carboxylate and photoreactive groups, and arginine and photoreactive groups. Also in particular embodiments, the microfluidic optical chip can be automatically transported and aligned with the spectroscopic imaging system. For example, such transportation and/or alignment may be controlled by a computer using optimization algorithms. Also, special markers can be included on the microfluidic chips, and may be used in automated pattern recognition. Certain embodiments can also provide electrodes integrated into the channels such that a voltage potential can be applied across the microfluidics optical chamber to form a capillary electrophoresis system. For example, DNA and protein separation using electrophoresis and isoelectrical focusing can then be realized, and the optical spectra of the biomolecules can be monitored in real-time. Also in certain embodiments, real-time kinetics, and not merely endpoints of the biochemical reactions in the microfluidic optical chamber 118 , can be measured. Also, the liquid sample can be delivered into microfluidic optical chamber (e.g., 118 ) by relying on gravity or active pumping, such as peristaltic and piezoelectrical pumping. Also in certain embodiments, the content within the microfluidic optical chamber can be gas phase material, rather than liquid. The optical properties of gas can be measured or monitored continuously in real-time. For example, concentration of particulates in the air can be monitored. Definitions By “protein” is meant a sequence of amino acids for which the chain length is sufficient to produce the higher levels of tertiary and/or quaternary structure. This is to distinguish from “peptides” or other small molecular weight drugs that do not have such structure. Typically, a protein will have a molecular weight of about 15-20 kD to about 20 kD. The terms “peptide” and “peptidic compound” are used interchangeably herein to refer to a polymeric form of amino acids of from about 10 to about 50 amino acids (may consist of at least 10 and not more than 50 amino acids), which can comprise coded and non-coded amino acids, chemically or biochemically modified or derivatized amino acids, L- or D-amino acids, peptides having modified peptide backbones, and peptides comprising amino acid analogs. The amino acid may be limited to only amino acids naturally occurring in humans. The peptidic compounds may be polymers of: (a) naturally occurring amino acid residues; (b) non-naturally occurring amino acid residues, e.g., N-substituted glycines, amino acid substitutes, etc.; or (c) both naturally occurring and non-naturally occurring amino acid residues/substitutes. In other words, the subject peptidic compounds may be peptides or peptoids. Peptoid compounds and methods for their preparation are described in WO 91/19735, the disclosure of which is hereby incorporated in its entirety by reference herein. A peptide compound of the invention may comprise or consist of 23 amino acids or from 18 to 28 amino acids or from 20 to 26 amino acids. The active amino acid sequence of the invention comprises or consists of three motifs which may be overlapping, which are: an integrin binding motif sequence, a glycosaminoglycan binding motif sequence, and a calcium-binding motif. The terms “treatment”, “treating” and the like are used herein to refer to both therapeutic treatment and prophylactic or preventative measures. Those in need of treatment include those already with the disorder as well as those in which the disorder is to be prevented. In general, this encompasses obtaining a desired pharmacologic and/or physiologic effect, e.g., stimulation of angiogenesis. The effect may be prophylactic in terms of completely or partially preventing a disease or symptom thereof and/or may be therapeutic in terms of a partial or complete cure for a disease and/or adverse effect attributable to the disease. The terms as used herein cover any treatment of a disease in a mammal, particularly a human, and include: (a) preventing a disease or condition (e.g., preventing the loss of cartilage) from occurring in a subject who may be predisposed to the disease but has not yet been diagnosed as having it; (b) inhibiting the disease, e.g., arresting loss of cartilage; or (c) relieving the disease (e.g., enhancing the development of cartilage). The terms “subject,” “individual,” “patient,” and “host” are used interchangeably herein and refer to any vertebrate, particularly any mammal and most particularly including human subjects, farm animals, and mammalian pets. The subject may be, but is not necessarily under the care of a health care professional such as a doctor. “Mammal” for purposes of treatment refers to any animal classified as a mammal, including humans, domestic and farm animals, and zoo, sports, or pet animals, such as dogs, horses, cats, cows, etc. Preferably, the mammal is human. A “disorder” is any condition that would benefit from treatment with the peptide. This includes chronic and acute disorders or diseases including those pathological conditions which predispose the mammal to the disorder in question. Non-limiting examples of disorders to be treated herein include skeletal loss or weakness and bone defects or breakage. The preceding merely illustrates the principles of the invention. It will be appreciated that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the invention and are included within its spirit and scope. Furthermore, all examples and conditional language recited herein are principally intended to aid the reader in understanding the principles of the invention and the concepts contributed by the inventors to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents and equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure. The scope of the present invention, therefore, is not intended to be limited to the exemplary embodiments shown and described herein. Rather, the scope and spirit of present invention is embodied by the appended claims.

The present disclosure relates to the fields of microchips with microfluidic optical chambers for multiplexed optical spectroscopy. Embodiments of the present invention allow for ultra small sample volume, as well as high detection speed and throughput, as compared to conventional optical sample cuvettes used in optical spectroscopy. Particular embodiments relate specifically to the spectroscopic detection of many biochemical assays for disease diagnosis or other suitable analysis.

CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims benefit of U.S. Provisional Application No. 60/811,463 filed on Jun. 5, 2006. FIELD OF THE INVENTION The invention concerns novel compounds that modulate potassium ion channels. The compounds are useful for the treatment and prevention of diseases and disorders which are affected by regulation of potassium ion channels. One such malady is seizure disorders. BACKGROUND OF THE INVENTION Retigabine (N-[2-amino-4-(4-fluorobenzylamino)phenyl]carbamic acid, ethyl ester] (U.S. Pat. No. 5,384,330) has been found to be an effective treatment of seizure disorders in children. Bialer, M., et al., Epilepsy Research 1999, 34, 1-41. Retigabine has also been found to be useful in treating pain, including neuropathic pain. Blackburn-Munro and Jensen, Eur. J. Pharmacol. 2003, 460, 109-116. “Benign familial neonatal convulsions” have been associated with mutations in the KCNQ2/3 channels. Biervert, C., et al., Science 1998, 27, 403-06; Singh, N. A., et al., Nat. Genet. 1998, 18, 25-29; Charlier, C., et al., Nat. Genet. 1998, 18, 53-55, Rogawski, Trends in Neurosciences 2000, 23, 393-398. Subsequent investigations have established that the major site of action of retigabine is the KCNQ2/3 channel. Wickenden, A. D. et al., Mol. Pharmacol. 2000, 58, 591-600; Main, M. J., et al., Mol. Pharmcol. 2000, 58, 253-62. Retigabine has been shown to increase the conductance of the channels at the resting membrane potential and to bind the activation gate of the KCNQ 2/3 channel. Wuttke, T.V., et al., Mol. Pharmacol. 2005, 67, 1009-1017. The recognition of the site of action of retigabine has prompted a search for other potassium channel modulators among compounds structurally related to retigabine. Several such searches have been reported in the patent literature, most notably the following: WO 2004/058739; WO 2004/80950; WO 2004/82677; WO 2004/96767; WO 2005/087754; and WO 2006/029623. DETAILED DESCRIPTION OF THE INVENTION The invention provides compounds of formula I, where Ar 1 is a 5- to 10-member mono- or bicyclic aromatic group, optionally containing 1-4 heteroatoms selected independently from N, O, and S; R 1 and R 2 are selected, independently, from H, CN, halogen, CH 2 CN, OH, NO 2 , CH 2 F, CHF 2 , CF 3 , CF 2 CF 3 , C 1 -C 6 alkyl, OR 8 , C(═O)R 9 , C(═O)OR 10 , OC(═O)R 11 , SR 12 , NR 13 C(═O)R 14 , C(═O)NR 15 R 16 , CH 2 C(═O)NR 15 R 16 , NR 17 R 18 , SO 2 R 19 , N(R 20 )SO 2 R 21 , SO 2 NR 22 R 23 , C 3 -C 6 cycloalkyl, CH 2 C 3 -C 6 cycloalkyl, C 5 -C 6 cycloalkenyl, C 2 -C 6 alkenyl, or C 2 -C 6 alkynyl; where the —NR 3 R 4 group is situated ortho to the NHC(═X) group and R 3 and R 4 are, independently, H or C 1-6 alkyl, which C 1-6 alkyl group is optionally substituted with 1 or 2 groups selected, independently, from methyl, halogen, methoxy, and hydroxy, or R 3 and R 4 together form a 5- or 6-membered ring, optionally substituted with halogen, methyl, methoxy, or hydroxy and optionally containing one or two double bonds; n=1 or 2; X is O or S; Y is O or S; q=1 or 0; R 5 is C 1 -C 6 alkyl, (CHR 6 ) w C 3 -C 6 cycloalkyl, (CHR 6 ) w CH 2 C 3 -C 6 cycloalkyl, CH 2 (CHR 6 ) w C 3 -C 6 cycloalkyl, (CHR 6 ) w C 5 -C 6 cycloalkenyl, CH 2 (CHR 6 ) w C 5 -C 6 cycloalkenyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, Ar 2 , (CHR 6 ) w Ar 2 , CH 2 (CHR 6 ) w Ar 2 , or (CHR 6 ) w CH 2 Ar 2 , where w=0-3, Ar 2 is a 5- to 10-member mono- or bicyclic aromatic group, optionally containing 1-4 ring heteroatoms selected independently from N, O, and S; R 6 is C 1 -C 3 alkyl; and R 8 -R 23 are, independently, H, C 1 -C 6 alkyl, C 3 -C 6 cycloalkyl, (CHR 6 ) w C 3 -C 6 cycloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, where all alkyl, cycloalkyl, alkenyl, alkynyl, aryl, groups are optionally substituted with one or two substituents selected independently from C 1 -C 3 alkyl, halogen, OH, OMe, CN, CH 2 F, and trifluoromethyl; where, additionally, the alkenyl and alkynyl groups are optionally substituted with phenyl or C 3 -C 6 cycloalkyl; and where all cycloalkyl groups optionally contain one or two ring heteroatoms selected independently from N, O, and S. Such compounds are potassium channel modulators. By “modulators” is meant potassium channel openers or activators at the resting membrane potential, but inhibitors for peak current at the positive voltage range of action potential. In one generic embodiment, the invention provides or contemplates a compound of formula I, where NH—C(═X)—(Y) q —R 5 is NHC(═O)R 5 . In another generic embodiment, the invention provides or contemplates a compound of formula I, where NH—C(═X)—(Y) q —R 5 is NHC(═O)OR 5 . In another generic embodiment, the invention provides or contemplates a compound of formula I, where NH—C(═X)—(Y) q —R 5 is NHC(═S)SR 5 . In another generic embodiment, the invention provides or contemplates a compound of formula I, where NH—C(═X)—(Y) q —R 5 is NHC(═S)R 5 . In another generic embodiment, the invention provides or contemplates a compound of formula I, where NH—C(═X)—(Y) q —R 5 is NHC(═S)OR 5 . In another generic embodiment, the invention provides or contemplates a compound of formula I, where NH—C(═X)—(Y) q —R 5 is NHC(═O)SR 5 . In one subgeneric embodiment, the invention provides compounds of formula IA, where Q=CR 7 or N, where R 7 is H or C 1 -C 6 alkyl. In another subgeneric embodiment, the invention provides or contemplates a compound of formula IB, where L is O, S, or NH, and K is N or CH. In another subgeneric embodiment, the invention provides or contemplates a compound of formula IC-1 or IC-2, where L is O, S, or NH, and K is N or CH. In another subgeneric embodiment, the invention provides or contemplates a compound of formula ID-1 or ID-2, where K and L are, independently, N or CH. In a more specific subgeneric embodiment, the invention provides or contemplates compounds of formula IA, where NH—C(═X)—(Y) q —R 5 is NHC(═O)R 5 or NHC(═O)OR 5 . In another more specific subgeneric embodiment, the invention provides or contemplates compounds of formula IA, where NH—C(═X)—(Y) q —R 5 is NHC(═S)R 5 or NHC(═S)SR 5 . In another more specific subgeneric embodiment, the invention provides or contemplates compounds of formula IA, where NH—C(═X)—(Y) q —R 5 is NHC(═S)OR 5 or NHC(═O)SR 5 . In another more specific subgeneric embodiment, the invention provides or contemplates compounds of formula IB, where NH—C(═X)—(Y) q —R 5 is NHC(═O)R 5 or NHC(═O)OR 5 . In another more specific subgeneric embodiment, the invention provides or contemplates compounds of formula IB, where NH—C(═X)—(Y) q —R 5 is NHC(═S)R 5 or NHC(═S)SR 5 . In another more specific subgeneric embodiment, the invention provides or contemplates compounds of formula IB, where NH—C(═X)—(Y) q —R 5 is NHC(═S)OR 5 or NHC(═O)SR 5 . In another more specific subgeneric embodiment, the invention provides or contemplates compounds of formula IC-1 or IC-2, where NH—C(═X)—(Y) q —R 5 is NHC(═O)R 5 or NHC(═O)OR 5 . In another more specific subgeneric embodiment, the invention provides or contemplates compounds of formula IC-1 or IC-2, where NH—C(═X)—(Y) q —R 5 is NHC(═S)R 5 or NHC(═S)SR 5 . In another more specific subgeneric embodiment, the invention provides or contemplates compounds of formula IC-1 or IC-2, where NH—C(═X)—(Y) q —R 5 is NHC(═S)OR 5 or NHC(═O)SR 5 . In another more specific subgeneric embodiment, the invention provides or contemplates compounds of formula ID-1 or ID-2, where NH—C(═X)—(Y) q —R 5 is NHC(═O)R 5 or NHC(═O)OR 5 . In another more specific subgeneric embodiment, the invention provides or contemplates compounds of formula ID-1 or ID-2, where NH—C(═X)—(Y) q —R 5 is NHC(═S)R 5 or NHC(═S)SR 5 . In another more specific subgeneric embodiment, the invention provides or contemplates compounds of formula ID-1 or ID-2, where NH—C(═X)—(Y) q —R 5 is NHC(═S)OR 5 or NHC(═O)SR 5 . In a more specific subgeneric embodiment, the invention provides compounds of formula IA, where NH—C(═X)—(Y) q —R 5 is NHC(═O)—C 1 -C 6 alkyl, NHC(═O)—OC 1 -C 6 alkyl, NHC(═O)—(CH 2 ) 2 C 5 -C 6 cycloalkyl, or NHC(═O)O)—(CH 2 ) 2 C 5 -C 6 cycloalkyl. In another specific subgeneric embodiment, the invention provides compounds of formula IA according to the structure below In some embodiments, the invention provides a pharmaceutical composition that includes, in addition to a pharmaceutically acceptable carrier, one or more of the following: a compound of formula IA, a salt, ester, or prodrug thereof. In another specific subgeneric embodiment, the invention provides compounds of formula IA according to the structure below In another more specific subgeneric embodiment, the invention provides compounds of formula IA according to the structure below In another more specific subgeneric embodiment, the invention provides compounds of formula IA according to the structure below In another more specific subgeneric embodiment, the invention provides compounds of formula IA according to the structure below In another more specific subgeneric embodiment, the invention provides compounds of formula IA according to the structure below In another more specific subgeneric embodiment, the invention provides compounds of formula IA according to the structure below In another more specific subgeneric embodiment, the invention provides compounds of formula IA according to the structure below In another more specific subgeneric embodiment, the invention provides compounds of formula IA according to the structure below In another more specific subgeneric embodiment, the invention provides compounds of formula IA according to the structure below In another more specific subgeneric embodiment, the invention provides compounds of formula IA according to the structure below In another more specific subgeneric embodiment, the invention provides compounds of formula IA according to the structure below In another more specific subgeneric embodiment, the invention provides compounds of formula IA according to the structure below In additional more specific subgeneric embodiments, the invention provides compounds of formula IA as shown below In another subgeneric embodiment, the invention provides a compound of formula IC-2 as shown below In another subgeneric embodiment, the invention provides a compound as shown below In another subgeneric embodiment, the invention provides a compound of formula IC-2 as shown below In still more specific subgeneric embodiments, the invention provides compounds where Ar 1 is phenyl, as shown below In additional still more specific subgeneric embodiments, the invention provides compounds where Ar 1 is quinolyl, as shown below In additional more specific subgeneric embodiments, the invention provides compounds where Ar 1 is pyridyl, as shown below In additional, more specific subgeneric embodiments, the invention provides compounds as shown below In additional, more specific subgeneric embodiments, the invention provides compounds as shown below In yet additional more specific subgeneric embodiments, the invention provides compounds as shown below In more specific subgeneric embodiments, the invention provides compounds as shown below In additional more specific subgeneric embodiments, the invention provides compounds as shown below In additional subgeneric embodiments, the invention provides compounds as shown below In additional subgeneric embodiments, the invention provides compounds as shown below In additional subgeneric embodiments, the invention provides compounds as shown below In another embodiment, this invention provides or contemplates a compound of formula IB, where Ar 1 is a 2- or 3-thienyl or furanyl or a compound of formula IC-1, where Ar 1 is benzothienyl, which group may be substituted. Subgeneric compounds of that type are shown below. In additional embodiments, the invention provides compounds in which Ar 1 is pyrrole or indole, as shown below In additional subgeneric embodiments, the invention contemplates compounds in which Ar 1 is purine, as shown below In additional subgeneric embodiments, the invention contemplates compounds as shown below In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, n is zero or 1, R 1 is CN, CH 2 CN, or halogen, q is 1, and X and Y are both O. In another more specific embodiment, this invention provides a compound of formula IA, formula IB, formula IC-1, or formula IC-2, where n is zero or 1, R 1 is F, CH 2 F, CHF 2 , CF 3 , or CF 2 CF 3 , q is 1, and X and Y are both O. In another more specific embodiment, this invention provides a compound of formula IA, or formula IB, or formula IC-1 or IC-2, where n is zero or 1, R 1 is NHC 1 -C 6 alkyl or NHC(═O)C 1 -C 6 alkyl, q is 1, and X and Y are both O. In a more specific embodiment, this invention provides a compound of formula IA, or formula IB, or formula IC-1 or IC-2, where n is zero or 1, R 1 is C(═O)—NH—C 1 -C 6 alkyl, SO 2 C 1 -C 6 alkyl, SO 2 NHC 1 -C 6 alkyl, q is 1, and X and Y are both O. In a more specific embodiment, this invention provides a compound of formula IA, or formula IB, or formula IC-1 or IC-2, where n is zero or 1, R 1 is OH, OMe, OEt, SMe, or SEt, q is 1, and X and Y are both O. In another more specific embodiment, this invention provides a compound of formula IA, or formula IB, or formula IC-1 or IC-2, where n is zero or 1, R 1 is vinyl, allyl, methylethynyl, or phenylethynyl. In another more specific embodiment, this invention provides a compound of formula IA, or formula IB, or formula IC-1 or IC-2, where n is zero or 1, R 1 is C(═O)OC 1 -C 6 alkyl or OC(═O)C 1 -C 6 alkyl, q is 1, and X and Y are both O. In a still more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, n is zero or 1, R 1 is C(═O)—NH—C 1 -C 4 alkyl, SO 2 C 1 -C 4 alkyl, SO 2 NHC 1 -C 4 alkyl, q is 1, and X and Y are both O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, n is zero or 1, R 1 is OH, OMe, OEt, SMe, or SEt, q is 1, and X and Y are both O. In another more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, n is zero or 1, and R 1 is vinyl, allyl, methylethynyl, or phenylethynyl. In another more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, n is zero or 1, R 1 is C(═O)OC 1 -C 4 alkyl or OC(═O)C 1 -C 4 alkyl, q is 1, and X and Y are both O. In another more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 1 is C 2 -C 6 alkenyl or C 2 -C 6 alkynyl, n is zero or 1, q is 1, and X and Y are both O. In another more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 1 is C 1 -C 4 alkyl, n is zero or 1, q is 1, and X and Y are both O. In another more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 1 is SC 1 -C 6 alkyl, n is zero or 1, q is 1, and X and Y are both O. In another more specific embodiment, this invention provides a compound of formula I, where Ar 1 is monosubstituted phenyl, X is O, q is 1, and Y is S. In another more specific embodiment, this invention provides a compound of formula I, where Ar 1 is monosubstituted phenyl, X is O, q is 1, and Y is O. In another more specific embodiment, the invention provides a compound of formula I, where Ar 1 is monosubstituted phenyl, X is O, and q is zero. In another more specific embodiment, this invention provides a compound of formula I, where Ar 1 is monosubstituted phenyl, X is S, q is 1, and Y is S. In another more specific embodiment, this invention provides a compound of formula I, where Ar 1 is monosubstituted phenyl, X is S, q is 1, and Y is O. In another more specific embodiment, the invention provides a compound of formula I, where Ar 1 is monosubstituted phenyl, X is S, and q is zero. In a still more specific embodiment, this invention provides a compound of formula I, where Ar 1 is monosubstituted phenyl, R 1 is alkyl, monofluoroalkyl, difluoroalkyl, trifluoroalkyl, F, or Cl; R 3 and R 4 are both H; X is O; and q is zero. In a still more specific embodiment, this invention provides a compound of formula I, where Ar 1 is monosubstituted phenyl, R 1 is alkyl, fluoroalkyl, or halo, R 3 and R 4 are H or methyl, X is O, q is 1, and Y is O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 3 and R 4 are H or methyl, n is zero or 1, R 1 is C 1 -C 6 alkyl, q is 1, and X and Y are both O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 3 and R 4 are H or methyl, n is zero or 1, R 1 is CN, CH 2 CN, or halogen, q is 1, and X and Y are both O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, n is zero or 1, R 1 is CH 2 F, CHF 2 , CF 3 , or CF 2 CF 3 , q is 1, and X and Y are both O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, n is zero or 1, R 1 is OC 1 -C 6 alkyl or C(═O)C 1 -C 6 alkyl, q is 1, and X and Y are both O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, n is zero or 1, R 1 is C(═O)OC 1 -C 6 alkyl or OC(═O)C 1 -C 6 alkyl, q is 1, and X and Y are both O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 1 is C 2 -C 6 alkenyl or C 2 -C 6 alkynyl, n is zero or 1, q is 1, and X and Y are both O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 1 is SC 1 -C 6 alkyl, n is zero or 1, q is 1, and X and Y are both O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 3 and R 4 are H or methyl, n is zero or 1, R 1 is C 1 -C 6 alkyl, q is zero, and X is O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 3 and R 4 are H or methyl, n is zero or 1, R 1 is CN, CH 2 CN, or halogen, q is zero, and X is O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 3 and R 4 are H or methyl, n is zero, R 1 is F, CH 2 F, CHF 2 , CF 3 , or CF 2 CF 3 , q is 1, and X is O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, n is zero or 1, R 1 is OC 1 -C 6 alkyl or C(═O)C 1 -C 6 alkyl, q is 1, and X is O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, n is zero or 1, R 1 is C(═O)OC 1 -C 6 alkyl or OC(═O)C 1 -C 6 alkyl, q is 1, and X is O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 1 is C 2 -C 6 alkenyl or C 2 -C 6 alkynyl, n is zero or 1, q is 1, and X is O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 1 is SC 1 -C 6 alkyl, n is zero or 1, q is 1, and X is O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 3 and R 4 are H or methyl, n is zero or 1, R 1 is C 1 -C 6 alkyl, q is 1, and X is O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 3 and R 4 are H or methyl, n is zero or 1, R 1 is CN, CH 2 CN, or halogen, q is 1, and X is O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 3 and R 4 are H or methyl, n is 1, R 1 is F, CH 2 F, CHF 2 , CF 3 , or CF 2 CF 3 , q is 1, and X is O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, n is zero or 1, R 1 is OC 1 -C 6 alkyl or C(═O)C 1 -C 6 alkyl, q is 1, and X is O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, n is zero or 1, R 1 is C(═O)OC 1 -C 6 alkyl or OC(═O)C 1 -C 6 alkyl, q is 1, and X is O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 1 is C 2 -C 6 alkenyl or C 2 -C 6 alkynyl, n is zero or 1, q is 1, and X is O. In a more specific embodiment, this invention provides a compound of formula I, where Ar 1 is phenyl or pyridyl, R 1 is SC 1 -C 6 alkyl, n is zero or 1, q is 1, and X is O. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is C 1 -C 6 alkyl. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is (CHR 6 ) w C 3 -C 6 cycloalkyl, where w is 1 or 2 and R 6 is H or methyl. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is (CHR 6 ) w CH 2 C 3 -C 6 cycloalkyl, where w is 1 or 2 and R 6 is H or methyl. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is CH 2 (CHR 6 ) w C 3 -C 6 cycloalkyl, where w is 1 or 2 and R 6 is H or methyl. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is (CHR 6 ) w C 5 -C 6 oxacycloalkyl, where w is 1 or 2 and R 6 is H or methyl. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is (CHR 6 ) w C 5 -C 6 azacycloalkyl, where w is 1 or 2 and R 6 is H or methyl. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is (CHR 6 ) w C 5 -C 6 thiacycloalkyl, where w is 1 or 2 and R 6 is H or methyl. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is (CHR 6 ) w CH 2 C 5 -C 6 azacycloalkyl, where w is 1 or 2 and R 6 is H or methyl. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is CH 2 (CHR 6 ) w C 3 -C 6 azacycloalkyl, where w is 1 or 2 and R 6 is H or methyl. In a more specific embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is (CHR 6 ) w Z, where w is 1 or 2, R 6 is H or methyl, and Z is piperidinyl. In another more specific embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is (CHR 6 ) w Z, where w is 1 or 2, 6 is H or methyl, and Z is 1-pyrrolidinyl or 1-piperidinyl. In another more specific embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is (CHR 6 ) w Z, where w is 1 or 2, R 6 is H or methyl, and Z is 2-pyrrolidinyl or 3-pyrrolidinyl. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is (CHR 6 ) w Z, where w is 1 or 2, R 6 is H or methyl, and Z is morpholyl, thiazolidinyl, oxazolidinyl, isothiazolidinyl, or isoxazolidinyl. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is (CHR 6 ) w CH 2 C 3 -C 6 cycloalkyl, where w is 1 or 2 and R 6 is H or methyl. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is CH 2 (CHR 6 ) w C 3 -C 6 cycloalkyl, where w is 1 or 2 and R 6 is H or methyl. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is (CHR 6 ) w C 3 -C 6 cycloalkyl, where w is 1 or 2 and R 6 is H or methyl. In a more specific embodiment, this invention provides or contemplates a compound of formula IA, in which R 5 is (CH 2 ) w —C 5 -C 6 cycloalkyl. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is CH═CH—C 3 -C 6 cycloalkyl, where the carbon-carbon double bond has the E configuration. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is CH═CH—C 3 -C 6 cycloalkyl, where the carbon-carbon double bond has the Z configuration. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is CH 2 —CH═CH—C 3 -C 6 cycloalkyl, where the carbon-carbon double bond has the E configuration. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is CH 2 CH═CH—C 3 -C 6 cycloalkyl, where the carbon-carbon double bond has the Z configuration. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is CH═CH—CH 2 —C 3 -C 6 cycloalkyl, where the carbon-carbon double bond has the E configuration. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is CH═CH—CH 2 —C 3 -C 6 cycloalkyl, where the carbon-carbon double bond has the Z configuration. In another, more specific embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is (CHR 6 ) w C 3 -C 6 cycloalkyl, where the cycloalkyl group is monosubstituted. In another embodiment, this invention provides or contemplates a compound of formula I, in which R 5 is CH═CH—CH 2 —C 3 -C 6 cycloalkyl or CH═CH—C 3 -C 6 cycloalkyl, where the cycloalkyl group is monosubstituted. In another embodiment, this invention provides a compound of formula IA, in which R 3 and R 4 are H or methyl, n is 1 , q is 1, X is O and R 5 is C 5 -C 6 alkyl. Illustrative examples of contemplated compounds of this invention are provided below. These are provided in order to indicate that a broad range of compounds and substitution patterns is contemplated. This group of examples should not be construed as limiting the scope of this invention. Biological Results Several typical compounds of this invention were assayed as potassium channel modulators by measuring rhubidium release. Methods: PC-12 cells were grown at 37° C. and 5% CO 2 in DMEM/F12 Medium supplemented with 10% horse serum, 5% fetal bovine serum, 2 mM glutamine, 100 U/ml penicillin, 100 U/ml streptomycin. They were plated in poly-D-lysine-coated 96-well cell culture microplates at a density of 40,000 cells/well and differentiated with 100 ng/ml NGF-7s for 2-5 days. For the assay, the medium was aspirated and the cells were washed once with 0.2 ml in wash buffer (25 mM HEPES, pH 7.4, 150 mM NaCl, 1 mM MgCl 2 , 0.8 mM NaH 2 PO 4 , 2 mM CaCl 2 ). The cells were then loaded with 0.2 ml Rb + loading buffer (wash buffer plus 5.4 mM RbCl 2 , 5 mM glucose) and incubated at 37° C. for 2 h. Attached cells were quickly washed three times with buffer (same as Rb + loading buffer, but containing 5.4 mM KCl instead of RbCl) to remove extracellular Rb + . Immediately following the wash, 0.2 ml of depolarization buffer (wash buffer plus 15 mM KCl) with or without compounds was added to the cells to activate efflux of potassium ion channels. After incubation for 10 min at room temperature, the supernatant was carefully removed and collected. Cells were lysed by the addition of 0.2 ml of lysis buffer (depolarization buffer plus 0.1% Triton X-100) and the cell lysates were also collected. If collected samples were not immediately analyzed for Rb + contents by atomic absorption spectroscopy (see below), they were stored at 4° C. without any negative effects on subsequent Rb + analysis. The concentration of Rb + in the supernatants (Rb + Sup ) and cell lysates (Rb + Lys ) was quantified using an ICR8000 flame atomic absorption spectrometer (Aurora Biomed Inc., Vancouver, B.C.) under conditions defined by the manufacturer. One 0.05 ml samples were processed automatically from microtiter plates by dilution with an equal volume of Rb + sample analysis buffer and injection into an air-acetylene flame. The amount of Rb + in the sample was measured by absorption at 780 nm using a hollow cathode lamp as light source and a PMT detector. A calibration curve covering the range 0-5 mg/L Rb + in sample analysis buffer was generated with each set of plates. The percent Rb + efflux (F) was defined by F=[Rb + Sup /( Rb + Sup +Rb + Lys )]×100% The effect (E) of a compound was defined by: E=[(F c −F b )/(F s −F b )]×100% where the F c is the efflux in the presence of compound in depolarization buffer, F b is the efflux in basal buffer, and F s is the efflux in depolarization buffer, and F c is the efflux in the presence of compound in depolarization buffer. The effect (E) and compound concentration relationship was plotted to calculate an EC 50 value, a compound's concentration for 50% of maximal Rb + efflux. TABLE 1 ACTIVITIES OF SELECTED COMPOUNDS EC 50 Structure (μM) C C A B B A A legend: A: <0.5 μM; B: 0.5-5 μM; C: >5 μM Synthetic Procedure Section I. The preparation of compound of formula IX is outlined in Scheme 1. Section II. The preparation of compound of formula XIII is outlined in Scheme 2. Section III. The preparation of compound of formula XVIII is outlined in Scheme 3. Section IV. The preparation of compound of formula XXVI is outlined in Scheme 4. Section V. The preparation of compound of formula XXVII is outlined in Scheme 5. Section VI. The preparation of compound of formula XXXV is outlined in Scheme 6. Section VII. The preparation of compound of formula XXXVIII is outlined in Scheme 7. EXAMPLE 1 Scheme 1 Synthesis of N-[6-Amino-1-(4-trifluoromethyl-phenylamino)-indan-5-yl]-3-cyclopentyl-propionamide a. N-(6-Nitro-indan-5-yl)-acetamide A mixture of 5-aminoindane (13.3 g, 0.1 mol) in 150 ml of acetic anhydride was stirred at room temperature for 3 hours. The reaction mixture was cooled to 0° C., and an ice-cooled solution of 90% nitric acid (d1.4) (8.4 g, 0.12 mol) in 15 ml of acetic anhydride (HNO 3 was added dropwise to acetic anhydride with stirring at 0° C.) was added dropwise. After addition, the reaction mixture was stirred at 0° C. for 1 hour and then at room temperature overnight. The reaction mixture was poured into 800 ml of ice-water with strong stirring. The precipitate was filtered and washed thoroughly with water and dried at 40° C. to give a yellow solid (20.9 g, 95%). b. N-(6-Nitro-1-oxo-indan-5-yl)-acetamide A solution of CrO 3 (26.5 g) in a mixture of 15 ml of H 2 O and 235 ml of AcOH was prepared by sonicating the suspension for 45 min. The resulting solution was added dropwise to a cooled solution of N-(6-nitro-indan-5-yl)-acetamide (22 g, 0.1 mol) in Ac 2 0 (2.5 L) while maintaining the temperature between 15-20° C. After the addition was completed, the mixture was stirred at 25° C. overnight, poured into 10 L of water, and stirred for 1 h. The solution was then extracted with two 2-L portions of CH 2 Cl 2 . The organic layers were combined, and concentrated to 500 ml, washed with two 50-ml portions of 10% NaOH followed by water, and then dried (Na 2 SO 4 ). The solvent was removed, leaving a yellow powder (16 g, 75%), which was used for next step without further purification. c. 5-Amino-6-nitro-indan-1-one A suspension of N-(6-nitro-1-oxo-indan-5-yl)-acetamide (10 g, 0.042 mol) in HCl (200 ml, 2 N)) and EtOH (100 ml) was refluxed for 30 min. The reaction was cooled to 15° C. and the resulting precipitate was isolated and recrystallized from dilute ethanol to give 7.9 g (97.5%) of yellow solid. d. N-(6-Nitro-1-oxo-indan-5-yl)-3-cyclopentyl-propionamide Pyridine (0.1 g, 1.3 mmol) was added to a suspension of 5-amino-6-nitro-indan-1-one (0.19 g, 1 mmol) in 15 ml of anhydrous dichloroethane followed by the addition of 3-cyclopentylpropionyl chloride (0.193 mg, 1.2 mmol) at room temperature under argon. The mixture was stirred at room temperature for 24 hours. The solvent was removed under reduced pressure and the residue was purified by column (hexane/EtOAc, 5:1) to give a yellow solid (0.26 g, 83%). 1 H-NMR (DMSO-d 6 ): δ 10.47 (s, 1H, NH, exchangeable with D 2 O), 8.06 (s, 1H), 7.87 (s, 1H), 3.15 (m, 2H), 2.69 (m, 2H), 2.38 (t, 2H, J=7.8 Hz), 1.74 (m, 2H), 1.59-1.46 (m, 7H), 1.08 (m, 2H). MS: 317 (M+1). e. N-[6-Nitro-1-(4-trifluoromethyl-phenylamino)-indan-5-yl]-3-cyclopentyl-propionamide A mixture of N-(6-nitro-1-oxo-indan-5-yl)-3-cyclopentyl-propionamide (0.57 g, 1.8 mmol), 4-trifluoromethylaniline (0.35 g, 2.2 mmol), and decaborane (200 mg) in 20 ml of anhydrous methanol was stirred at room temperature overnight. The solvent was removed in vacuo and the residue was purified by column (hexane/EtOAc, 5:1) to give a pure product (0.65 g, 90%). f. N-[6-Amino-1-(4-trifluoromethyl-phenylamino)-indan-5-yl]-3-cyclopentyl-propionamide To a solution of N-[6-nitro-1-(4-trifluoromethyl-phenylamino)-indan-5-yl]-3-cyclopentyl-propionamide (200 mg) in 20 ml of methanol was added a catalytic amount of Raney Nickel. The resulting mixture was hydrogenated under regular pressure at room temperature for 4 hours. The reaction mixture was filtered through celite and washed with methanol. The filtrate was evaporated to dryness in vacuo and the residue was purified by column (hexane/EtOAc, 3:1) to give a white solid product in a quantitative yield. 1 H-NMR (DMSO-d 6 ): δ 9.01 (s, 1H, NH, exchangeable with D 2 O), 7.36 (d, 2H, J=8.4 Hz), 7.05 (s, 1H), 6.78 (d, 2H, J=8.4 Hz), 6.66 (d, 1H, NH, J=8.4 Hz, exchangeable with D 2 O), 6.31 (s, 1H), 4.88 (q, 1H, J=8.4 Hz), 4.69 (brs, 2H, NH 2 , exchangeable with D 2 O), 2.77 (ddd, 1H, J=15.3, 8.4, 3.6 Hz), 2.67 (m, 1H), 2.42 (m, 1H), 2.29 (t, 2H, J=7.5 Hz), 1.73 (m, 4H), 1.56 (m, 4H), 1.48 (m, 2H), 1.07 (m, 2H). MS: 432 (M+1). The following compounds were prepared by the above procedure (Scheme 1) EXAMPLE 2 N-[6-Amino-1-(4-fluoro-phenylamino)-indan-5-yl]-3-cyclopentyl-propionamide 1 H-NMR (DMSO-d 6 ): δ 9.01 (s, 1H, NH, exchangeable with D 2 O), 7.03 (s, 1H), 6.89 (t, 2H, J=9.0 Hz), 6.65 (dd, 2H, J=4.8, 9.0 Hz), 6.64 (s, 1H), 5.73 (d, 1H, NH, J=8.4 Hz, exchangeable with D 2 O), 4.74 (q, 1H, J=7.2 Hz), 4.66 (brs, 2H, NH 2 , exchangeable with D 2 O), 2.75 (ddd, 1H, J=15.0, 8.4, 3.3 Hz), 2.65 (m, 1H), 2.39 (m, 1H), 2.29 (t, 2H, J=7.5 Hz), 1.74 (m, 4H), 1.56 (m, 4H), 1.48 (m, 2H), 1.07 (m, 2H). MS: 382 (M+1). EXAMPLE 3 N-[6-Amino-1-(4-fluoro-phenylamino)-indan-5-yl]-3,3-dimethyl-butyramide 1 H-NMR (DMSO-d 6 ): δ 9.00 (s, 1H, NH, exchangeable with D 2 O), 7.01 (s, 1H), 6.89 (t, 2H, J=9.0 Hz), 6.65 (dd, 2H, J=4.8, 9.0 Hz), 6.65 (s, 1H), 5.73 (d, 1H, NH, J=8.4 Hz, exchangeable with D 2 O), 4.74 (q, 1H, J=7.2 Hz), 4.66 (brs, 2H, NH 2 , exchangeable with D 2 O), 2.75 (ddd, 1H, J=15.0, 8.4, 3.3 Hz), 2.65 (m, 1H), 2.39 (m, 1H), 2.15 (s, 2H), 1.68 (m, 1H), 1.01 (s, 9H). MS: 356 (M+1). EXAMPLE 4 N-[6-Amino-1-(4-trifluoromethyl-phenylamino)-indan-5-yl]-3,3-dimethyl-butyramide 1 H-NMR (DMSO-d 6 ): δ 9.00 (s, 1H, NH, exchangeable with D 2 O), 7.35 (d, 2H, J=8.7 Hz), 7.03 (s, 1H), 6.77 (d, 2H, J=8.7 Hz), 6.64 (d, 1H, NH, J=8.4 Hz, exchangeable with D 2 O), 6.63 (s, 1H), 4.87 (q, 1H, J=7.5 Hz), 4.67 (brs, 2H, NH 2 , exchangeable with D 2 O), 2.77 (ddd, 1H, J=15.0, 8.4, 3.3 Hz), 2.65 (m, 1H), 2.40 (m, 1H), 2.15 (s, 2H), 1.73 (m, 1H), 1.00 (s, 9H). MS: 406 (M+1). EXAMPLE 5 Scheme 2 Synthesis of ethyl 6-amino-1-(4-fluorophenylamino)-2,3-dihydro-1H-inden-5-ylcarbamate a. Ethyl 6-nitro-1-oxo-2,3-dihydro-1H-inden-5-ylcarbamate A mixture of 5-amino-6-nitro-2,3-dihydro-1H-inden-1-one (1.19 g, 6.2 mmol), of anhydrous ethanol (15 ml) and diethyl pyrocarbonate (1.2 g, 7.4 mmol) was stirred at room temperature for 3 hours. The solvent was removed in vacuo and the crude product was dried under reduced pressure and used for next step without further purification. b. Ethyl 1-(4-fluorophenylamino)-6-nitro-2,3-dihydro-1H-inden-5-ylcarbamate A mixture of ethyl 6-nitro-1-oxo-2,3-dihydro-1H-inden-5-ylcarbamate (0.47 g, 1.8 mmol), 4-fluoroaniline (0.24 g, 2.2 mmol), and decaborane (200 mg) in 20 ml of anhydrous methanol was stirred at room temperature overnight. The solvent was removed in vacuo and the residue was purified by column (hexane/EtOAc, 5:1) to give a pure product (0.51 g, 81%). c. Ethyl 6-amino-1-(4-fluorophenylamino)-2,3-dihydro-1H-inden-5-ylcarbamate To a solution of ethyl 1-(4-fluorophenylamino)-6-nitro-2,3-dihydro-1H-inden-5-ylcarbamate (250 mg) in 20 ml of methanol was added a catalytic amount of Raney Ni, and the resulting mixture was hydrogenated under ambient temperature and pressure for 4 hours. The reaction mixture was filtered through celite and washed with methanol. The filtrate was evaporated to dryness in vacuo and the residue was purified by column (hexane/EtOAc, 3:1) to give a white solid product. MS: 330 (M+1). The following compound was prepared by the above procedure (Scheme 2). EXAMPLE 6 Scheme 2 ethyl 6-amino-1-(4-(trifluoromethyl)phenylamino)-2,3-dihydro-1H-inden-5-ylcarbamate MS: 380 (M+1). EXAMPLE 7 Scheme 3 Synthesis of [4-Amino-1-(4-fluoro-phenylamino)-indan-5-yl]-carbamic acid ethyl ester a. (1-Oxo-indan-5-yl)-carbamic acid ethyl ester 5-Amino-indan-1-one (0.91 g, 6.2 mmol) was dissolved in 15 ml of anhydrous ethanol and diethyl pyrocarbonate (1.2 g, 7.4 mmol) was added dropwise with stirring at room temperature. After addition, the reaction mixture was stirred at room temperature for 3 hours. The solvent was removed in vacuo and the crude product was dried under reduced pressure and used for next step without further purification. b. (4-Nitro-1-oxo-indan-5-yl)-carbamic acid ethyl ester (1-Oxo-indan-5-yl)-carbamic acid ethyl ester (0.94 g, 4.3 mmol) was dissolved in 20 ml of concentrated sulphuric acid and cooled to 0° C. using an ice-bath. Potassium nitrate (477 mg, 4.7 mmol) was added in small portions. After complete addition, the mixture was stirred for 3 hours at 0° C. and then poured onto crushed ice. The yellow precipitate was filtered off, washed thoroughly with water and dried in vacuo to give a yellow solid product (0.85, 75%). c. [4-Nitro-1-(4-fluoro-phenylamino)-indan-5-yl]-carbamic acid ethyl ester A mixture of (4-nitro-1-oxo-indan-5-yl)-carbamic acid ethyl ester (0.47 g, 1.8 mmol), 4-fluoroaniline (0.24 g, 2.2 mmol), and decaborane (200 mg) in 20 ml of anhydrous methanol was stirred at room temperature overnight. The solvent was removed in vacuo and the residue was purified by chromatography using a mixture of hexane/EtOAc (5:1) as eluant to give a pure product (0.54 g, 83%). d. [4-Amino-1-(4-fluoro-phenylamino)-indan-5-yl]-carbamic acid ethyl ester A solution of [4-nitro-1-(4-fluoro-phenylamino)-indan-5-yl]-carbamic acid ethyl ester (200 mg) in 20 ml of methanol was added a catalytic amount of Raney Ni. The resulting mixture was hydrogenated under regular pressure at room temperature for 4 hours. The reaction mixture was filtered through celite and washed with methanol. The filtrate was evaporated to dryness in vacuo and the residue was purified by column (hexane/EtOAc, 3:1) to give a white solid product. 1 H-NMR (DMSO-d 6 ): δ 8.51 (brs, 1H, NH, exchangeable with D 2 O), 6.94 (dd, 2H, J=9.0, 18.6 Hz), 6.88 (d, 1H, J=8.1 Hz), 6.66 (dd, 2H, J=4.2, 9.0 Hz), 6.49 (d, 1H, J=8.1 Hz), 5.70 (brs, 1H, NH, exchangeable with D 2 O), 4.80 (m, 3H, NH 2 and CH)), 4.05 (q, 2H, J=7.2 Hz), 2.74 (ddd, 1H, J=3.6, 8.7, 15.6 Hz), 2.60-2.36 (m, 2H), 1.71 (m, 1H), 1.20 (t, 3H, J=7.2 Hz). MS: 330 (M+1). EXAMPLE 8 Scheme 4 [1-Amino-5-(4-trifluoromethyl-phenylamino)-5,6,7,8-tetrahydro-naphthalen-2-yl]-carbamic acid ethyl ester a. (5-Oxo-5,6,7,8-tetrahydro-naphthalen-2-yl)-carbamic acid ethyl ester A mixture 6-Amino-3,4-dihydro-2H-naphthalen-1-one (1g, 6.2 mmol), anhydrous ethanol (15 ml) and diethyl pyrocarbonate (1.2 g, 7.4 mmol) was stirred at room temperature for 3 hours. The solvent was removed in vacuo and the crude product was dried under reduced pressure and used for next step without further purification. b. (1-Nitro-5-oxo-5,6,7,8-tetrahydro-naphthalen-2-yl)-carbamic acid ethyl ester and (3-Nitro-5-oxo-5,6,7,8-tetrahydro-naphthalen-2-yl)-carbamic acid ethyl ester (5-Oxo-5,6,7,8-tetrahydro-naphthalen-2-yl)-carbamic acid ethyl ester (1 g, 4.3 mmol) was dissolved in 20 ml of concentrated sulphuric acid and cooled to 0° C. using an ice-bath. Potassium nitrate (477 mg, 4.7 mmol) was added in small portions. After complete addition, the mixture was stirred for 3 hours at 0° C. and then poured onto crushed ice. The yellow precipitate was filtered off, washed thoroughly with water and dried in vacuo to give the product as a mixture in a 2:1 ratio (0.84 g, 70%). c. [1-Nitro-5-(4-trifluoromethyl-phenylamino)-5,6,7,8-tetrahydro-naphthalen-2-yl]-carbamic acid ethyl ester and [3-Nitro-5-(4-trifluoromethyl-phenylamino)-5,6,7,8-tetrahydro-naphthalen-2-yl]-carbamic acid ethyl ester A mixture of (1-nitro-5-oxo-5,6,7,8-tetrahydro-naphthalen-2-yl)-carbamic acid ethyl ester and (3-nitro-5-oxo-5,6,7,8-tetrahydro-naphthalen-2-yl)-carbamic acid ethyl ester (0.5 g, 1.8 mmol), 4-trifluoromethylaniline (0.35 g, 2.2 mmol), and decaborane (200 mg) in 20 ml of anhydrous methanol was stirred at room temperature overnight. The solvent was removed in vacuo and the residue was purified by chromatography using a mixture of hexane/EtOAc (5:1) as eluant to give a pure product as a mixture (0.55 g, 85%). d. [1-Amino-5-(4-trifluoromethyl-phenylamino)-5,6,7,8-tetrahydro-naphthalen-2-yl]-carbamic acid ethyl ester and [3-Amino-5-(4-trifluoromethyl-phenylamino)-5,6,7,8-tetrahydro-naphthalen-2-yl]-carbamic acid ethyl ester To a solution of a mixture of [1-nitro-5-(4-trifluoromethyl-phenylamino)-5,6,7,8-tetrahydro-naphthalen-2-yl]-carbamic acid ethyl ester and [3-Nitro-5-(4-trifluoromethyl-phenylamino)-5,6,7,8-tetrahydro-naphthalen-2-yl]-carbamic acid ethyl ester (500 mg) in 20 ml of methanol was added a catalytic amount of Raney Ni. The resulting mixture was hydrogenated under regular pressure at room temperature for 4 hours. The reaction mixture was filtered through celite and washed with methanol. The filtrate was evaporated to dryness in vacuo and the residue was separated by preparative HPLC to give two products as white solids in a quantitative yield. [1-Amino-5-(4-trifluoromethyl-phenylamino)-5,6,7,8-tetrahydro-naphthalen-2-yl]-carbamic acid ethyl ester. 1 H-NMR (DMSO-d 6 ): δ 8.50 (brs, 1H, NH, exchangeable with D 2 O), 7.33 (d, 2H, J=8.4 Hz), 6.95 (d, J=8.1 Hz, 1H, exchangeable with D 2 O), 6.74 (d, 2H, J=8.4 Hz), 6.59 (d, 1H, J=8.1 Hz,), 6.49 (d, 1H, J=8.1 Hz), 4.57 (brs, 2H, NH 2 , exchangeable with D 2 O), 4.53 (q, 1H, J=8.1 Hz), 4.05 (q, 2H, J=7.2 Hz), 2.43-2.25 (m, 3H), 1.83 (m, 1H), 1.75 (m, 2H), 1.20 (t, 3H, J=7.2 Hz). MS: 394 (M+1). [3-Amino-5-(4-trifluoromethyl-phenylamino)-5,6,7,8-tetrahydro-naphthalen-2-yl]carbamic acid ethyl ester. 1 H-NMR (DMSO-d 6 ): δ 8.49 (brs, 1H, NH, exchangeable with D 2 O), 7.33 (d, 2H, J=8.7 Hz), 6.96 (s, 1H), 6.74 (d, 2H, J=8.7 Hz), 6.60 (s, 1H), 6.60 (d, 1H, J=8.1 Hz, exchangeable with D 2 O), 4.67 (brs, 2H, NH 2 , exchangeable with D 2 O), 4.49 (m, 1H), 4.06 (q, 2H, J=7.2 Hz), 2.53 (m, 2H), 1.79 (m, 2H),), 1.68 (m, 2H), 1.20 (t, 3H, J=7.2 Hz). MS: 394 (M+1). The following compound was prepared by the above procedure. EXAMPLE 9 Scheme 4 [1-Amino-5-(4-fluoro-phenylamino)-5,6,7,8-tetrahydro-naphthalen-2-yl]-carbamic acid ethyl ester 1 H-NMR (CDCl 3 ): δ 7.09 (d, 1H, J=8.1 Hz), 6.89 (m, 3H), 6.58 (m, 2H), 6.15 (brs, 1H, NH, exchangeable with D 2 O), 4.49 (m, 1H), 4.22 (q, 1H, J=6.9 Hz), 3.76 (brs, 3H, NH 2 and NH, exchangeable with D 2 O), 2.54 (m, 2H), 1.94 (m, 4H), 1.31 (t, 3H, J=6.9 Hz). MS: 344 (M+1).

This invention provides compounds of formula I where Ar 1 is a 5- to 10-member mono- or bicyclic aromatic group, optionally substituted; where the —NR 3 R 4 group is situated ortho to the NHC(═X) group; n=1 or 2; X═O or S; Y is O or S; and q=1 or 0. The invention also provides pharmaceutical compositions comprising compounds of formula I and/or salts, esters, and prodrugs thereof. These compounds modulate the activation and inactivation of potassium channels. The compounds are useful for the treatment and prevention of diseases and disorders—such as seizure disorders—which are affected by modulation of potassium ion channels.

This application is a Continuation of application Ser. No. 12/660,423, filed on Feb. 26, 2010 now U.S. Pat No. 8,117,286, which is a Continuation of application Ser. No. 11/031,100, filed on Jan. 6, 2005, now U.S. Pat. No. 7,702,752, which is a Continuation of application Ser. No. 10/190,341, filed on Jul. 3, 2002, now U.S. Pat. No. 6,859,833, which application is a Continuation of application Ser. No. 09/655,999, filed on Jun. 6, 2000, now U.S. Pat. No. 6,466,966, which application is a Continuation of application Ser. No. 09/071,674, filed on May 1, 1998, now U.S. Pat. No. 6,189,030, which is a Continuation-In-Part of application Ser. No. 08/999,727, filed on Dec. 23, 1997, now U.S. Pat. No. 5,870,546, which is a Continuation of application Ser. No. 08/604,468, filed on Feb. 21, 1996, now U.S. Pat. No. 5,751,956, which applications are incorporated herein by reference in their entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is generally related to the control of network information server systems supporting World Wide Web based data pages and, in particular, to a server system and process for efficiently redirecting external server hyper-link references for purposes of controlling, moderating, and accounting for such references. 2. Description of the Related Art The recent substantial growth and use of the internationally connected network generally known as the Internet has largely been due to widespread support of the hypertext transfer protocol (HTTP). This protocol permits client systems connected through Internet Service Providers (ISPs) to access independent and geographically scattered server systems also connected to the Internet. Client side browsers, such as Netscape Mozilla® and Navigator® (Netscape Communications Corp.), Microsoft Internet Explorer® and NCSA Mosaic®, provide efficient graphical user interface based client applications that implement the client side portion of the HTTP protocol. Server side application programs, generically referred to as HTTPd servers, implement the server side portion of the HTTP protocol. HTTP server applications are available both commercially, from companies such as Netscape, and as copyrighted freeware available in source code form from NCSA. The distributed system of communication and information transfer made possible by the HTTP protocol is commonly known as the World Wide Web (WWW or W3) or as simply “the Web.” From a client side user interface perspective, a system of uniform resource locators (URLs) is used to direct the operation of a web browser in establishing atomic transactional communication sessions with designated web server computer systems. In general, each URL is of the basic form: http://<server_name>.<sub_domain.top_level-domain>/<path> The server_name is typically “www” and the sub_domain.top_level domain is a standard Internet domain reference. The path is an optional additional URL qualifier. Specification by user selection of a URL on the client side results in a transaction being established in which the client sends the server an HTTP message referencing a default or explicitly named data file constructed in accordance with the hypertext mark up language (HTML). This data file or web page is returned in one or more response phase HTTP messages by the server, generally for display by the client browser. Additional embedded image references may be identified in the returned web page resulting in the client browser initiating subsequent HTML transactions to retrieve typically embedded graphics files. A fully reconstructed web page image is then presented by the browser through the browser's graphical user interface. Due to the completely distributed client/server architecture of the Web, as made possible by the URL system further supported by the existing Internet name resolution services and routing conventions, HTTP servers can be independently established with little difficulty. Consequently, the Web has no centrally or even regionally enforced organization other than loosely by name of the top level domain. Searching for information or other resources provided by individual HTTP servers is therefore problematic almost by definition. Because of the time, cost and complexity of assembling comprehensive, yet efficiently searchable databases of web information and resources, commercial Internet Business Services (IBS) have been established to provide typically fee based or advertising revenue supported search engine services that operate against compilations of the information and resources available via the Web correlated to source URLs. Access to such search engines is usually provided through server local web pages served by the Internet Business Services. The results of a search are served in the form of local web pages with appropriate embedded remote or hyper-linked URLs dynamically constructed by the server of the Internet Business Service. Because of the opportunity presented by the likely repeated client access and retrieval of search engine and search result web pages, providers of other Internet based services have begun to actively place advertisements on these web pages. As is typical in advertising mediums, the frequency of display of an advertisement generally defines the compensation paid to the advertisement publisher. Thus, the number of times that an advertisement is simply transferred to a client browser provides an indication of how effectively the advertisement is being published. A more direct measure of the effectiveness of a particular advertisement on a particular web page is the number of times a client web browser chooses to actively pursue the URL represented by the advertisement. Thus, there is a need to be able to track information obtainable from a client browser when a hyper-linked advertiser's URL is selected. The difficulty in obtaining direct reference information arises from the fact that a web page with an embedded advertisement and corresponding remote URL is served in its entirety to the client browser upon first reference to the web page. The selection of a particular advertiser's URL is then by definition performed through an independent transaction directed to the HTTPd server associated with the advertiser. Since the advertiser publishing HTTPd server is not part of this subsequent transaction, the publishing server is conventionally incapable of tracking client browser hyper-links actually executed to an advertiser's URL or any other URLs embedded in a web page previously served to the client browser. Simple web page access counters are relatively well known and used throughout the Web. These access counters are based on a common gateway interface (CGI) facility supported by modern HTTPd server systems. The CGI facility permits generally small programs, at least typically in terms of function, to be executed by a server in response to a client URL request. That is, the HTML web page definition provides for the embedding of a specific HTML reference that will specify execution of a server side CGI program as part of the process of the web browser reconstructing an image of a served web page. Such a HTML reference is typically of the form: <img src=“http://www.target.com/cgi-bin/count.cgi”> Thus, a counter value incremented with each discrete execution of the CGI program (count.cgi) dynamically provides part of the displayable image of the reconstructed web page. The time, remote client requester, client domain, client browser type and other information that may be known through the operation of the HTTP protocol may be logged as part of the CGI program's function. Consequently, a reasonable manner of accounting and auditing for certain web page accesses exists. Access counters, however, fundamentally log only server local web page accesses. The client browser to the CGI program is evaluated by the client in connection with the initial serving of the web page to the client browser. The initial serving of the web page to the client browser can be connected, but any subsequent selection of a URL that provides a hyper-link reference to an external server is not observed and therefore is not counted by a CGI program based access counter. Other limitations of access counters arise from the fact that the implementing CGI program is an independently loadable executable. The CGI program must be discretely loaded and executed by the server computer system in response to each URL reference to the CGI program. The repeated program loading and execution overhead, though potentially small for each individual invocation of the CGI program, can represent a significant if not substantial load to the sever computer system. The frequent execution of CGI programs is commonly associated with a degradation of the effective average access time of the HTTPd server in responding to client URL requests. Since an Internet Business Service providing access to a search engine logs millions of requests each day, even small reductions in the efficiency of serving web pages can seriously degrade the cost efficiency of the Internet Business Service. As of December, 1995, Infoseek Corporation, in particular, handles an average of five million retrievals a day. The execution overhead associated with CGI programs is often rather significant. Many CGI programs are implemented at least in part through the use of an interpreted language such as Peri or TCL. Consequently, a substantial processing overhead is involved in multiple mass storage transfers to load both the interpreter and CGI program scripts, to process the scripts through the execution of the interpreter, and then actually log whatever useful data is generated, typically to persistent mass storage. Finally, the interpreter and/or CGI program may have to be unloaded. In addition, external CGI programs present a significant problem in terms of maintenance, including initial and ongoing server configuration and control, and security in the context of a busy server system. Individual CGI programs will likely be needed for each independent web page in order to separately identify web page service counts. Alternatively, a CGI program can be made sufficiently complex to be able to distinguish the precise manner in which the program is called so as to identify a particular web page and log an appropriately distinctive access count. Maintenance of such CGI programs on a server system where large numbers of page accesses are being separately counted is non trivial. Further, the existence of external programs, particularly of scripts that are interpreted dynamically, represents a potential security problem. In particular, the access and execute permissions of interpreted scripts must be carefully managed and monitored to prevent any unauthorized script from being executed that could, in turn, compromise the integrity of the data being collected if not the fundamental integrity of the server computer system itself. Consequently, known access counters provide no solution directly in full or in part to the need to account or audit URL references to external servers based on hyper-links from previously served web pages. The HTTP protocol itself provides for a basic server based system of URL redirection for servers and clients supporting the 1.5 or later versions of the HTTP protocol. A configuration file associated with an HTTP server (typically srm.cont) can specify a redirect directive that effectively maps a server local directory URL reference to an external URL reference through the use of a configuration directive of the form: Redirect/dir1 http://newserver.widget.com/dir1 When a Version 1.5 or later HTTP server receives a URL reference to a local directory (/dir1) that is specified as above for redirection, a redirect message is returned to the client browser including a new location in the form of an URL (http://newserver.widget.com/dir1). This redirect URL is then used by the client browser as the basis for a conventional client URL request. This existing server based redirection function is insufficient to support external server access tracking since, in its usual form, the redirection is of the entire directory hierarchy that shares a common redirected base directory. Even in the most restricted form, the redirection is performed on a per directory reference basis. Thus, every access to the directory, independent of the particular web page or graphics image or CGI program that is the specific object of an access request is nonetheless discretely redirected without distinction. Any potential use of the existing server redirect function is therefore exceedingly constrained if not practically prohibited by the HTTP protocol defined operation of the redirect directive. Furthermore, the redirect directive capability of the HTTP protocol server does not provide for the execution of a CGI program or other executable coincident with the performance of the redirection thereby essentially precluding any action to capture information related to the redirect URL request. In addition, the complexity of the resource configuration file necessary to specify redirection down to a per directory configuration again raises significant configuration, maintenance and, to a lesser degree, security issues. Thus, server redirection does not possess even the basic capabilities necessary to support external URL hyper-link reference auditing or accounting. Finally, a form of redirection might be accomplished though the utilization of a relatively complex CGI program. Such a redirection CGI program would likely need to perform some form of alternate resource identification as necessary to identify a redirection target URL. Assuming that a unique target URL can be identified, a redirection message can then be returned to a client from the CGI program through the HTTP server as necessary to provide a redirection URL to the client browser. Unfortunately, any such COI program would embody all of the disadvantages associated with even the simplest access counter programs. Not only would problems of execution load and latency, as well as configuration, maintenance and security remain, but such an approach to providing redirection is inherently vulnerable to access spoofing. Access spoofing is a problem particular to CGI programs arising from the fact that the HTML reference to the CGI program may be issued without relation to any particular web page. Consequently, any CGI program implementing an access counter or other auditing or accounting data collecting program can produce an artificially inflated access count from repeated reference to the CGI program HTML statement outside and independent of a proper web page. Access spoofing inherently undermines the apparent if not actual integrity of any data gathered by a CGI program. Since, at minimum, the ability to insure the accuracy of even a simple access count would be of fundamental importance to an Internet service advertiser, the use of CGI programs to provide even basic accounting or auditing functions is of limited practical use. Finally, HTML does not provide a tamper-proof way for two URLs to be accessed in sequence with just one URL reference button, such as, for example, a server CGI counter URL reference followed by external server URL reference. SUMMARY OF THE INVENTION Thus, a general purpose of the present invention is to provide a system and method of reliably tracking and redirecting hyper-link references to external server systems. This is achieved by the present invention through the provision of a message to a tracking server system in response to a client system referencing a predetermined resource locator that corresponds to a resource external to the tracking server system. The tracking server system indirectly provides for the client system to have an informational element selectable by the client system, where the informational element is graphically identified on the client system with informational content obtainable from a content server system through use of a content resource locator. The informational element includes a tracking resource locator, referencing the tracking server system, and data identifying the informational element. The selection of the informational element causes the client system to use the tracking resource locator to provide the data to the tracking server system and to use the content resource locator to obtain the informational content from the content server system. Thus, an advantage of the present invention is that URL reference data is captured in an expedient manner that interposes a minimum latency in returning the ultimately referenced web page while imposing minimum visibility of the redirection protocol on client users. Another advantage of the present invention is that independent invocations of server external support programs and multiple external data references are not required as a consequence of the present invention, thereby minimizing the CPU and disk intensive load on the web server computer system and the resulting latency. A further advantage of the present invention is that the reference identifier and a redirection directive can both be maintained wholly within the URL specification discretely provided by a client HTML request. Thus, the present invention is superior in both efficiency and maintenance requirements to a CGI counter, or any method that incorporates a CGI counter. Still another advantage of the present invention is that program modifications necessary to support the protocol of the present invention are implemented entirely at the server end of a protocol transaction. Client side participation in the transaction is within the existing client side defined HTML protocol. A still further advantage of the present invention is that the implementation of the invention introduces minimum exposure to additional security breaches due to the closed form of the protocol while providing substantial security against inappropriate URL and protocol references. This is accomplished preferably by the inclusion of validation codes inside the URL specification. BRIEF DESCRIPTION OF THE DRAWINGS These and other advantages and features of the present invention will become better understood upon consideration of the following detailed description of the invention when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof, and wherein: FIG. 1 provides a schematic representation of client and server computer systems inter-networked through the Internet; FIG. 2 provides a block diagram of a server computer system implementing an HTTP daemon (HTTPd) server in accordance with a preferred embodiment of the present invention; FIG. 3 provides a flow diagram illustrating the process performed by a preferred embodiment of the present invention in receiving and processing client URL requests; FIG. 4 provides a flow diagram illustrating the server side processing of special redirect URLs in accordance with another preferred embodiment of the present invention; FIG. 5 provides a generalized process representation of client and server computer systems implementing the alternate processes of the present invention; FIG. 6 is a flow diagram illustrating a server-side process that provides for the issuance of a content request message in accordance with a preferred embodiment of the present invention; and FIG. 7 is a flow diagram illustrating a client-side process that provides for the issuance of a tracking message in accordance with a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION A typical environment 10 utilizing the Internet for network services is shown in FIG. 1 . Client computer system 12 is coupled directly or through an Internet service provider (ISP) to the Internet 14 . By logical reference via a uniform resource locator, a corresponding Internet server system 16 , 18 may be accessed. A generally closed hypertext transfer protocol transaction is conducted between a client browser application executing on the client system 12 and an HTTPd server application executing on the server system 16 . In a preferred embodiment of the present invention, the server system 16 represents an Internet Business Service (IBS) that supports or serves web pages that embed hyper-link references to other HTTPd server systems coupled to the Internet 14 and that are at least logically external to the server system 16 . Within this general framework, the present invention enables the tracking of the selection of embedded hyper-link references by client system 12 . That is, an embedded hyper-link reference is associated with a graphical banner or other Web page element that is selectable, or clickable, by a user of the client system 12 . A banner click on a client system is typically made to obtain information, identified in some fashion by the banner graphic that is of interest to the client system user. Tracking is preferably enabled by embedding HTML information in the Web page served to the client system 12 . This information is served from any prearranged HTTPd server system to the client system 12 . The prearrangement is with an IBS to track banner clicks, on Web pages served by or on behalf of a designated tracking HTTPd server system, such as system 16 , that operates to collect the served page provided tracking information. The embedded information is, in accord with the present invention, sufficient to enable the client computer system 12 to provide tracking information to the HTTPd server system 16 . As will be seen, this information is also sufficient, directly or indirectly, to enable the client computer to request the information associated with the banner graphic. As will also be seen, there are a number of possible implementations of the present invention. These implementations can generally be categorized as predominately using either a server-side or client-side process, as involving proprietary, plug-in, and interpreted control processes, and as using any of a number of specific data transfer protocols. The preferred embodiment of the present invention utilizes a server-side process implemented as a proprietary modification to the HTTPd server application executed by the server system 16 and that uses the HTTP redirection directive. Thus, a web page served by an HTTPd server system, such as the server system 16 or another server system (not shown) to the client 12 embeds a URL reference to a web page served by the logically external server system. Selection of this embedded URL through the client browser of the client computer system 12 results initially in an HTTP transaction with the server system 16 rather than the external server. The information stored in the embedded URL first served with the web page to client system 12 is thus provided back to the server system 16 upon selection of the URL even though the apparent target of the URL is the external server system. A redirection response is then provided by the server system 16 to the client system 12 providing the corresponding redirection URL. As shown in FIG. 2 , the server system 16 receives the redirection request information via a network connection 20 to a network interface 22 within the server system 16 . The network interface 22 is coupled through an internal bus 24 to a central processing unit (CPU) 26 . The CPU 26 executes a network operating system 28 in support of the network interface 22 and other functional aspects of the server system 16 . The network operating system 28 supports the execution by the CPU 26 of an HTTPd server application 30 that defines the responsive operation of the server system 16 to HTTP requests received via the network 20 . Finally, the network operating system 28 provides for temporary and persistent storage of data in a mass storage device 32 preferably including a persistent storage media such as provided by a conventional hard disk drive. In accordance with the preferred embodiment of the present invention, the embedded redirection information provided as part of a URL HTTP request is processed by the HTTPd server 30 . Preferably, the processing by the HTTPd server 30 is performed through the execution of the server 30 itself as opposed to the execution of any external CGI programs or the like. The redirection information is processed by the execution of the server 30 to identify and validate the particular URL reference that provided the redirection information and to generate a redirection target URL. In a preferred embodiment of the present invention, an embedded URL containing redirection information is formatted as follows: http://<direct_server>/redirect?<data>?http://<redirect_server> The direct_server portion of the embedded URL specifies the HTTP server target of a transaction that is to be initially established by the client system 12 . The remaining information is provided to the tracking or targeted direct server. The direct server may be any HTTPd server accessible by the client system 12 that has been designated to service redirection requests in accordance with the present invention. The term “redirect” in the embedded redirection URL is a key word that is pre-identified to the HTTPd server 30 to specify that the URL corresponds to a redirection request in accordance with the present invention. Although the term “redirect” is the preferred term, any term or code may be selected provided that the term can be uniquely identified by the HTTPd server 30 to designate a redirection URL. The recognition processing of the “redirect” term is preferably performed through the execution of the server 30 by way of a corresponding modification to the HTTPd server application. That is, the HTTPd server application is modified to recognize the term “redirect” as a key word and to execute a subprogram to implement the server-side process of this preferred embodiment. Alternately, the modification to the HTTPd server application can be implemented as a “plug-in” binary program operative through a conventional interface provided with the HTTPd server application to obtain essentially the same functionality. Although of possibly lesser performance, a server application embedded language, such as Java® or JavaScript®, may be also alternately used to implement the server-side process of recognizing the “redirect” key word and performing the further processing to implement the present invention. The “data” term of the redirection URL provides reference identifier data to the HTTPd server 30 that can be used to further identify and potentially validate a redirection URL to the HTTPd server 30 . The data thus permits an accounting of the redirection URL to be made by the HTTPd server 30 . In the context of an advertisement, the data may encode a particular advertising client for whom access data may be kept, a particular instance of the graphic image provided to a client system 12 in association with the redirection URL, and potentially a validation code that may serve to ensure that inappropriate client uses of a redirection URL can be distinguished and discarded by the HTTPd server 30 . An exemplary redirection URL, constructed using HTML in accordance with a preferred embodiment of the present invention, is as follows: <a href=”http://www.infoseek.com/IS/redirect?NwPg-003- AA?http://www.newspage.com”> Within the redirection data, the data component “NwPg” serves as a client or account identifier. The data component “003” is a series identifier indicating a particular graphic image that was associated with the redirection URL as embedded in the web page served to the client system 12 . Finally, the data component “AA” may be utilized to provide a basic validation identifier that serves to permit the HTTPd server 30 to identify inappropriate repeated submissions of the redirection URL to the server system 16 or those that are determined to be obsolete by convention. In an alternate embodiment of the present invention, the validation data encodes a data representation that can be used in conjunction with the HTTP protocol to provide information regarding the client system 12 that submitted the redirection URL and, optionally, the graphics series identifier data, to limit repeated use of the redirection URL by the same client system 12 within a defined short period of time. Thus, an inappropriate attempt by a third party client to, in effect, tamper with the data collected by the server system 16 with respect to any particular redirection URL can be identified with relative if not complete certainty and blocked. In addition, date codes older than a certain time interval can be declared by computation to be invalid. Consequently, a copy of the embedded redirection URL cannot be stored on a client system 12 and remain viable for use for longer than a period of time defined exclusively by the server computer system 16 . Each of the data terms within a redirection URL may be statically or dynamically created by the HTTPd server 30 as part of the process of originally serving a web page with the embedded redirection URL to a client computer system 12 . With dynamic generation, different graphic images corresponding to a single advertiser or one of any number of advertisers may be effectively served with an otherwise statically defined web page. The data terms of the embedded redirection URL may be dynamically selected based on the identity of the advertiser and graphics image in addition to separately establishing a hypertext link to the graphics image as part of an instance of serving a particular web page by the HTTPd server 30 . Indeed, the selection of advertiser and graphics image could be made at least in part on the identity of the client computer system 12 as established through information provided by the conventional operation of the HTTP protocol, and on the client profile if known. The validation code may also be dynamically generated. In an alternate embodiment of the present invention, the validation code encodes a representation of the day of the year with the account and image identifier data terms to generate an identifier, preferably encoded as two digits, that provides a sufficient degree of uniqueness to allow an embedded redirection URL to be aged on a per day basis. Furthermore, the validation code remains constant on a per day basis and thereby still permits the number of references on a per day per specific client system 12 basis to be tracked by the HTTPd server 30 so as to limit the frequency that a specific instantiation of the web page is repeatedly presented to a specific client 12 . Additionally, the HTTPd server 30 may operate to block operation on a received redirection URL where the corresponding web page has not recently been served to the requesting client 12 . Various bit shift, check sum, and modulo arithmetic algorithms can be utilized to generate the validation code in a consistent manner known to the HTTPd server 30 , but that cannot be readily discerned upon examination of the resulting redirection URL by a specific client computer system 12 . Alternately, the validation code may be an arbitrarily selected value that is implicitly recognized as valid by the HTTPd server 30 for a programmable period of time from one day to several weeks or longer. In the extreme, and consistent with the initially preferred embodiment of the present invention, the validation code is a static value provided as part of the embedded redirection URL. Independent of the particular manner the validation code is generated or the assigned length of time that the code is recognized by the HTTPd server 30 as valid, evaluation of the data terms of a redirection URL is preferably performed completely internally to the HTTPd server 30 . The data terms are preferably sufficiently complete as to be unambiguous in identifying a particular instantiation of an embedded redirection URL without significant, if any, resort to the loading and execution of an external program or even significantly to interrogate look-up files stored by the persistent storage device 32 . Consequently, the burden of evaluating a redirection URL in accordance with the present invention is almost completely computational in nature. As is conventionally appreciated, the performance of a server computer system 16 is not typically computationally bound, but rather bound by the rate of input/output (I/O) access to the persistent storage device 32 and to the network 20 . By substantially if not completely limiting the evaluation of the redirection URL to a computational operation, with only a limited I/O operation to save auditing or accounting data obtained in connection with a redirection URL, an optimally minimal burden on the server computer system 16 is realized by the operation of the present invention. Indeed, the saving of accounting or auditing data may be cached by the network operating system 28 to defer the write I/O operation to the persistent storage device 32 until otherwise excess I/O bandwidth is available in the ongoing operation of the server computer system 16 . The final portion of the preferred structure of a redirection URL is a second URL. This second URL preferably identifies directly the target server system for the redirection. Preferably, any path portion provided as part of the direct server specification of the redirection URL is repeated as a path component of the redirect server portion of the redirection URL. However, path portion identity is not required. In general, all that is required in accordance with the present invention is a one to one correspondence between the direct server and redirect server terms of the redirection URL. A less strict relationship may be used if the impact upon the auditing or accounting data collected by the operation of the present invention is consistent with the desired characteristic of that data. For example, different direct server specifications may correlate to the use of a common redirect server as a means of further identifying a particular instantiation of an embedded redirection URL. Alternately, otherwise identical instantiations of an embedded redirection URL may reference any of a number of redirect servers. Thus, the embedded redirection URL provides only an indirect reference to the ultimately servicing redirect server and relies on the direct server identified server system or the redirect servers themselves to resolve the second URL into a direct reference to an ultimately servicing redirect server. This may be done to distribute load on the cooperatively operating redirect servers or to provide a means for verifying the auditing or accounting data collected by the ongoing operation of the present invention. Indeed, the second URL of a redirection URL can itself be a redirection URL, though care needs to be taken not to create an infinite redirection loop. A preferred method 40 of processing redirection URLs provided to a server computer system 16 by a client computer system 12 is illustrated in FIG. 3 . As each client request is received 42 the data provided as part of the request is examined to determine whether the request embeds the redirect key word 44 . If the URL data does not specify a redirection request consistent with the present invention, the URL data is checked 46 to determine whether the URL data conventionally specifies an existent local web page. If the web page does not exist or, based on the client identification data provided via the HTTP protocol in connection with the URL client request, the particular client is not permitted access to the existent web page, the HTTPd server 30 determines a corresponding error message 48 that is returned to the client computer system 12 . Otherwise, the HTTPd server 30 proceeds and serves the local web page 50 to the client computer system 12 . Where URL data at least specifies a redirection request 52 , the URL data is further checked for validity. A table of valid combinations of client and graphic image identifiers, preferably cached in memory in the server system 16 , may be used to initially establish the validity of the redirection request. The validation code may either be checked by recalculation based on the provided redirection data or checked against another table of validation codes that are current. In either event, the relative timeliness of the redirection request can be determined from the age of the validation code and therefore serve as basis for determining whether the current redirection request is timely or suspect. Furthermore, additional checks may be performed to verify that the corresponding web page has indeed been served recently by the server computer system 16 to the particular requesting client computer system 12 based on a short term log of local web pages actually served by the server computer system 16 . Finally, access permissions enforced by the server computer system 16 can be checked against the identification of the client computer system 12 to categorically limit redirection to defined classes of clients. Where the request is determined to be invalid for any reason, an appropriate denial message is generated and issued 48 . Where a redirection request is determined valid, any or all of the data provided as part of the redirection request or provided to the HTTPd server 30 through the conventional operation of the HTTP protocol can be logged through the network operating system 28 to the persistent storage device 32 for subsequent manipulation, analysis and reporting. The redirection request is then further processed to obtain the second URL identifying the target redirection server 56 . This second URL is then specified in the location field of a redirection message, preferably a temporary redirection message, that is issued 58 back to the client computer system 12 that issued the redirection URL initially. The process 40 in accordance with a preferred embodiment of the present invention, is performed essentially entirely within the HTTPd server 30 . The implementation of the process 40 can be performed through a modification and extension of the processing flow implemented by the HTTPd server 30 , through a corresponding modification of the server source code. These modifications and additions may be made utilizing conventional programming techniques. The redirection capability provided by the present invention is fully consistent with existent de-facto standard redirection capabilities provided by conventional HTTPd servers. A further detailed portion 60 of the process 40 is shown in FIG. 4 . Within the operation of the HTTPd server 30 , the URL data 62 is received and initially parsed 64 to identify the appropriate existence of the redirect key word. Where the specific form of the redirection URL of the present invention is not identified 66 , the URL is further processed in a conventional manner to determine whether any other form of redirection is applicable. In addition, an evaluation of conventional access privileges to a local web page where no conventional redirection is specified can also be performed with, ultimately, an appropriate response message being issued 68 . In the specific instance where the URL request is of the special redirect form consistent with the present invention, as opposed to conventional HTML redirection capabilities, the URL data is processed 70 and, in combination with the HTTP protocol-provided data identifying the client computer system 12 , a database record is created or updated in the persistent mass storage device 32 at 72 . The second URL is then extracted 74 and a redirection message, specifically a type 302 temporary redirection message, is prepared. As before, the second URL may be a direct or literal URL or an indirect redirection target server identification that is resolvable by the HTTPd server 30 into a URL that is at least sufficient to identify the target redirection server. Since the second URL, as embedded in a Web page, is defined through prearrangement with the operation of the HTTPd server 30 , resolution of any indirect redirection target server identification is fully determinable by the HTTPd server 30 through, for example, a database look-up operation. A redirection message including a location field is then created by the HTTPd server 30 . This location field is provided with the direct or resolved target redirection server URL. The redirection message is then issued 58 to the originally requesting client computer system 12 . Other server-side operative embodiments of the present invention can use other specific protocols to transfer the tracking information from the client system 12 to the HTTPd server 30 . These other HTTP protocol methods include, for example, GET, FORMS, OPTIONS, HEAD, PUT, DELETE, AND TRACE. Use of these other protocol methods are generally similar, differing in their requirements for specific browser support for the protocol methods and details of their specific HTML markup coding into Web pages. As an example of the use of these other protocol methods, the HTTP GET method can be implemented by embedding the following HTML code tags in the Web pages served to a client computer system. // HTTP GET <a href=“http://www.infoseek.com/redirect?\ ak = MTCH-2009-1073-GEN&\ rd = http://www.match.com/”> <img src = “http://www.online.com/ads/MTCH1073.gif”> </a> This HTML code defines “MTCH1073.gif” as the Web page banner graphic, “www.infoseek.com” as the direct_URL, “MTCH-2009-1073-GEN” as the data, and “www.match.com” as the target redirection server. When the above HTML tags are served to the client computer system, an initial HTTP GET request is issued to “www.online.com” to obtain the banner graphic. In response to a banner click, a second GET request is directed to “www.infoseek.com” using the URL: /redirect?ak=MTCH-2009-1073-GEN&rd=http://www.match.com/ The complete GET request will be of the form: GET /redirect?ak=MTCH-2009-1073-GEN&\ rd = http://www.match.com/HTTP/1.0 User-Agent: Mozilla/3.0 Accept:image/gif, image/jpeg, */* The HTTPd server 30 records the values of MIME information (such as cookies) and the form variables (in this case ak and rd). An HTTP redirect message is then created by the HTTPd server 30 and returned to the client computer system. A third and final GET request is then issued to “www.match.com” in response to the redirection message. As another example, an HTTP POST method can be used. The Web page embedded HTML tags can be coded as follows: // HTTP POST <FORM method = “POST” \ action = “http://www.infoseek.com/redirect”> <INPUT TYPE = hidden\ NAME = “ak” \ VALUE = “MTCH-2009-1073-GEN”> <INPUT TYPE = hidden \. NAME = “rd”\ VALUE = “http://www.match.com/”> <INPUT TYPE = image\ SRC = “http://www.online.com/ads/MTCH1073.gif”> </FORM> This HTML code will result in a GET request being issued automatically to “www.online.com” to retrieve the banner graphic. A banner click will result in a HTTP POST request being sent to “www.infoseek.com” along with the FORM NAME and VALUE data. In this case, the data is not encoded into the URL, but rather is encoded in the body of the POST request itself. In this example, the POST request will have the form: POST /redirect HTTP/1.0 User-Agent: Mozilla/3.0 Accept: image/gif, image/jpeg, */* Content-type: application/x-www-form-urlencoded Content-length: 54 ak=MTCH-2009-1073-GEN&rd=http://www.match.com/ When the returned redirection message is received, another GET request is issued by the client computer system to the redirection target server, which is again “www.match.com.” In accordance with the present invention, a client-side process can also be utilized to transparently provide notification of the selection of a Web page element by a client computer system. FIG. 5 provides a representation 78 of the data transfer flows involved in both the server-side and client-side processes that implement the present invention. Common to both server-side and client-side process implementations, a client computer system 80 issues an initial Web page request over the Internet (not shown) to a Web page server system 82 . A corresponding Web page 84 including a Web page element 86 is returned to the client computer system 80 . Again, common to both server-side and client-side process implementations of the present invention the Web page element 86 is provided through the embedding of information in the Web page 84 . In the circumstance of a server-side process as generally depicted in FIG. 6 , the process of the present invention following from a banner click 96 results in a client browser action. Specifically, the embedded information controls the operation of the Web browser on the client computer system sufficient to issue a notification URL 98 directed to the redirection target server system 88 , as shown in FIG. 5 . The server process 100 initiated in response to the notification URL receipt produces the redirection message that is returned to the client computer system 80 . In connection with the generation of the redirection message, the server system 88 also logs and optionally processes the data received as part of the notification URL 98 . Based on the redirection message, the client computer system 80 then preferably issues an HTTP request 102 based on the information contained in the redirection message. Referring again to FIG. 5 , the HTTP request 102 is provided via the Internet 14 to another Web page server system 90 that responds in a conventional manner by the serving of Web page 92 to the client computer system 80 as the Web page 104 that was inferentially referenced by the Web page element 86 . The method of the present invention utilizing a client-side process is generally shown if FIG. 7 . The method 106 , for the purposes of explanation here, generally begins in response to a banner click 108 to initiate a client process 110 executing in connection with the operation of the Web browser on the client computer system 80 . In a preferred embodiment of the present invention, the client process 110 is provided with the Web page 84 to the client computer system 80 . The client process 110 is invoked in response to the banner click and operates to first issue a notification URL message 112 and, second, to issue an HTTP request 114 . Both messages are issued through the Internet 14 and to the target server system 88 and Web page server 90 , respectively. The order that the client process 110 issues the notification URL 112 and HTTP request 114 is not significant. Further, acknowledgment of the receipt of the notification URL from the target server system 88 is not required prior to issuing the HTTP request 114 . Indeed, as evident to the user of the client computer system 80 , the only response recognized as significant is the receipt 116 of the Web page 92 . As in the case of the server-side process, the client-side process 110 can be implemented in a number of different manners that, for purposes of the present invention, each result in the delivery of data to the target server system 88 and a URL request to a Web page server system 90 to provide a Web page 92 having a prearranged correspondence with the Web page element 86 . Specifically, the client-side process can be directly coded into the browser application or supplied as a browser plug-in to a conventional browser application. The client-side process can also be implemented through use of Java and JavaScript type applets. An exemplary client-side process is implemented through the use of a Java Applet. The HTML code that is embedded in the Web page 84 , for purposes of this example, is as follows: <applet name = “ad” code = “ad.class” width = 468 height = 60> <param name = img value = “ad.gif”> <param name = notifyurl value = “?MTCH-2009-1073-GEN”> <param name = pageurl value = “http://catalog.online.com/”> </applet> where the three applet parameters are defined as follows: “img”—the URI reference to a graphic banner advertisement “notifyurl”—the “notification” URL holding the accounting data “pageurl”—the “redirection” URL to use The applet source is as follows: import java.applet.Applet; import java.awt.Image; import java.awt.Graphics; import java.net.URL; import java.net.MalformedURLException; import java.io.IOException; public class ad extends Applet { Image image; URL notifyurl; URL pageurl; public void int( ) { image = getImage(getDocumentBase( ), getParameter(“img”)); try{ logurl = new URL(getDocumentBase( ), getParameter(“notifyurl”)); pageurl = new URL(getDocumentBase( ), getParameter(“pageurl”)); } catch (MalformedURLExeception e) { } } public bold paint(Graphics g) { g.drawImage(image, 0, 0, this); } public boolean mouseDown(java.awt.Event evt, int x, int y) { try{ logurl.openStream( ).close( ); } catch (java.io.IOexception e) { } getApplet Context( ).showDocument(pageurl); return true; } } The above example uses two HTTP requests to first issue the “notifyurl” message and, second, to issue the “pageurl” message. Various other protocols, however, can be used in connection with the present invention. For example, the Java applet can be modified to provide the notification data to the target server system 88 through use of a TCP connection. An exemplary implementation of an applet utilizing a TCP connection is provided below. The applet takes four parameters: “img”—the URL of the ad image to show “port”—the TCP port number to use on the target server “data”—the accounting data to send to the target server “pageurl”—the “redirection” URL to use The armlet source is as follows: import java.applet.Applet; import java.awt.Graphics; import java.awt.Image; import java.io.IOException; import java.io.OutputStream; import java.io.PrintStream; import java.lang.Integer; import java.lang.String; import java.net.MalformedURLException; import java.net.Socket; import java.net.URL; public class ad extends Applet { Image image; String host,data; int port; URl url; public void int( ) { image = getImage(getDocumentBase( ), getParameter(“img”)); host = getDocumentBase( ).gethost( ); port = Integer.parseInt(getParameter(“port”)); data = getParameter(“data”); try {url = new URL(getDocumentBase( ), getParameter(“pageurl”));} catch (MalformedURLException e) { } } public void paint(Graphics g) { g.drawImage(image, 0, 0, this); } public boolean mouseDown(java.awt.Event evt, int x, int y) { try { Socket socket = new Socket(host,port); PrintStream ps = new PrintStream(socket.getOutputStream( )); ps.print(data); ps.close( ); } catch (java.io.IOException e) { } getAppletContext( ).showDocument(url); return true; } } Finally, the above applet can be referenced for execution by embedding the following HTML code into the Web page 84 . <applet name=“ad” code=“ad.class” width=468 height=60> <param name=img value=“ad gif”> <param name=port value=“21”> <param name=data value=“MTCH-2009-1073-GEN”> <param name=url value=“http://catalog.online.com/”> </applet> Thus, a comprehensive system and method for accounting or auditing accesses made by client computer systems to external hyper-linked servers has been described. The auditing capabilities of this system process impose optimally minimal overhead burden on the redirection server system while permitting the data that is gathered to be validated and reasonably assured to correspond to bona fide accesses to a redirection target server system. While the invention has been particularly shown and described with reference to preferred embodiments thereof it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of hthe invention.

A message is provided to a tracking server system in response to a client system referencing a predetermined resource locator that corresponds to a resource external to the tracking server system. The tracking server system indirectly provides for the client system to have an informational element selectable by the client system, where the informational element is graphically identified on the client system with informational content obtainable from a content server system through use of a content resource locator. The informational element includes a tracking resource locator, referencing the tracking server system, and data identifying the informational element. The selection of the informational element causes the client system to use the tracking resource locator to provide the data to the tracking server system and to use the content resource locator to obtain the informational content from the content server system.

FIELD OF THE INVENTION This invention relates to a method and apparatus for transferring a pattern formed on a mask or reticle onto a substrate such as a semiconductor wafer or glass plate. More particularly, the present invention is directed to a projection exposure method and apparatus which uses a projection optical system to transfer the patterns formed on a mask or reticle onto another surface, for example a semiconductor wafer or glass plate, with the projection optical system capable of performance as if in an ideal (e.g. atmospheric pressure and temperature) environment when the actual environment in which the apparatus is used is not ideal. BACKGROUND OF THE INVENTION As integrated circuits (ICs) have become finer and more sophisticated, projection exposure apparatus to transfer circuit patterns onto semiconductor wafers or other receptive substrates (e.g. glass plates, etc.) have been required to perform at higher and higher resolutions. Particularly in recent years, systems have been required to perform well not only in an ideal environment but to do so even when the surrounding conditions change. Although current projection exposure systems perform satisfactorily in an ideal environment, such systems typically do not do as well when conditions such as atmospheric pressure and temperature surrounding the projection optical system in the projection exposure system change. In conventional projection exposure systems, magnification errors due to changes in atmospheric pressure are corrected by controlling the air pressure of the medium which fills the gaps between the multiple optical members comprising the projection optical system. However, this corrective measure merely corrects for magnification abnormalities. The deterioration of other imaging performances is merely reduced to an amount where it is not considered a problem in a practical application of the device, with the practical application of the device being defined by the performance guaranteed atmospheric pressure range (the range for which system's operating performance is guaranteed). As for changes caused by deviations in temperature, various temperature controlling devices are known which are used to control the temperature of projection optical system. These devices essentially maintain the temperature of the system at sufficiently close to that of an ideal environment, so the performance required from such conventional systems can be obtained. However, in recent years, such methods to correct for atmospheric pressure changes have become unsuitable for the needs of the users of such exposure systems who are trying to produce the aforementioned finer and more complicated circuit patterns. The greater densities being called for by semiconductor manufacturers are requiring higher resolutions from such projection exposure systems. This, in turn, requires a narrowing in the performance guaranteed atmospheric pressure range to sufficiently satisfy the rigorous performance being called for by the users of these projection exposure systems. Further, recent calls for higher resolution and more rigorous performance from such systems have also resulted in a need for stricter temperature control in such systems. Differences in atmospheric pressure are inevitable due to changes in the altitude, etc. This is due in part to the fact that the manufacturing site of a projection optical system and the location where the projection exposure apparatus into which the optical system is incorporated are not the same. Conventionally, a projection optical system is adjusted until it achieves ideal imaging performance at the manufacturing site. The optical system is then further adjusted at the location of the actual use according to atmospheric conditions, e.g., altitude, in order to obtain the same ideal imaging performance at the use site. This adjustment is typically accomplished by, for example, changing the multiple air gaps within the projection optical system, or exchanging one lens element for another having a slightly different curvature radius, and so forth. Therefore, when the place where the projection optical system is used changes (e.g. different altitude), a significant readjustment of the projection optical system is necessary, resulting in disassembly and re-assembly of the projection optical system. As for temperature control, it is necessary to set the environmental temperature for each actual use site before manufacturing with the projection optical system. Accordingly, there is a need for a projection optical system which is capable of maintaining the performance of an ideal environment, even when the actual use environment differs substantially from the ideal environment. Further, there is a need for a projection optical system which is capable of adapting to the environment in which it is used with relatively minor adjustments to the projection optical system. SUMMARY OF THE INVENTION The present invention solves the above and other problems associated with conventional projection optical systems by maintaining the same performance as in an ideal environment (in terms of atmospheric pressure and temperature) even when the environment changes. In addition, a projection optical system in accordance with the present invention is able to recover the same performance as in an ideal environment through relatively minor adjustment of its projection optical system even when atmospheric pressure significantly changes due to, e.g., a change in location and altitude where the system is used. The above and other objects and advantages of the present invention are attained through a projection exposure apparatus according to one embodiment of the present invention in which specified patterns formed on reticle are transferred onto a substrate. A projection exposure apparatus according to this embodiment of the invention may include an illumination optical system to uniformly illuminate the reticle with a wavelength λ. A first supporting member is included which supports the reticle, and a second supporting member supports the substrate. A projection optical system is disposed between the reticle and the substrate. The projection optical system projects the patterns on reticle onto the substrate with ray bundle having a numerical aperture of at least 0.55 and which satisfies the following conditions: |dSAp|<0.3×λ/(NA)2 |dCOMAp|<0.3×λ/(NA), where, dSAp is an amount of change in spherical aberration of the maximum numerical aperture ray of the projection optical system when the surrounding atmospheric pressure of the projection optical system changes by 30 mmHg, dCOMAp is an amount of change in coma aberration of the maximum numerical aperture ray at the maximum image height of the projection optical system when the surrounding atmospheric pressure of the projection optical system changes by 30 mmHg, and NA is a maximum numerical aperture of the projection optical system. Also in order to attain above mentioned objectives and advantages of the present invention, a projection exposure apparatus of another embodiment of this invention which transfers specified patterns formed on a reticle onto a substrate includes an illumination optical system to uniformly illuminate the reticle with a wavelength λ, a first supporting member to support the reticle, a second supporting member to support the substrate, and a projection optical system disposed between the reticle and the substrate, which projects patterns on the reticle onto the substrate with ray bundle having an NA of at least 0.55, and which satisfies the following conditions: |dSAt|<0.3×λ/(NA) 2 |dCOMAt|<0.3×λ/(NA) |dMt|<0.2×λ/NA) 2 |dYt|<0.05×λ/(NA), where, dSAt is an amount of change in spherical aberration of the maximum numerical aperture ray of the projection optical system when the surrounding temperature of the projection optical system changes by 3° C., dCOMAt is an amount of change in coma aberration by the maximum numerical aperture ray at the maximum image height of the projection optical system when the surrounding temperature of said projection optical system changes by 3° C., dMt is an amount of change in field curvature at the maximum image height of the projection optical system when the surrounding temperature of the projection optical system changes by 3° C., dYt is an amount of change in image height at the maximum image height of the projection optical system when the surrounding temperature of said projection optical system changes by 3° C., and NA is the maximum numerical aperture of the projection optical system. In another embodiment, the projection optical system according to this invention projects an image of first object onto a second object, and includes, from the side of the first object, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, a fifth lens group having a positive refractive power and an aperture stop placed within the fifth lens group. In this embodiment, the third lens group includes first and second meniscus lens elements having a positive refractive power with the concave surface directed to the first object side and third and fourth meniscus lens elements having a positive refractive power with the concave surface directed to the second object side. The lens element having the maximum effective diameter among the lens elements comprising the third lens group is placed between the first and fourth meniscus lens elements. In still another embodiment of a projection optical system according to the present invention in which an image of a first object is projected onto a second object, the projection optical system includes, from the side of the first object, a first lens group having a positive refractive power; a second lens group having a negative refractive power; a third lens group having a positive refractive power; a fourth lens group having a negative refractive power; a fifth lens group having a positive refractive power, and an aperture stop placed within the fifth lens group. In accordance with this embodiment, the fifth lens group has first and second air-spaced doublets comprising a positive lens element and a negative lens element, where the first and second air-spaced doublets are placed on the side closer to the second object from the aperture stop and at least one lens element comprising the first and second air-spaced doublets has the maximum effective diameter among the fifth lens group. These and other advantages of the present invention will become more apparent upon a reading of the detailed description of the preferred embodiments which follows, when considered in conjunction with the drawings of which the following is a brief description. It should be clear that the drawings are merely illustrative of the currently preferred embodiments of the present invention, and that the invention is in no way limited to the illustrated embodiments. The present invention is best defined by the claims appended to this specification. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of an embodiment of a projection optical system according to the invention as used in an exposure system. FIG. 2 is a schematic cross section showing an example of a lens barrel of a projection exposure apparatus incorporating a projection optical system according to the present invention. FIG. 3 is a schematic cross section showing another example of a lens barrel of a projection exposure apparatus incorporating a projection optical system according to the present invention. FIG. 4 is a schematic diagram of the lenses included in a first embodiment of a projection optical system according to this invention. FIG. 5 is a detailed diagram of the lenses included in the third lens group of the projection optical system according to the first embodiment of the present invention. FIG. 6 is a schematic diagram of lenses included in a projection optical system according to a second embodiment of the present invention. FIG. 7 is a graph of the Modulation Transfer Function (MTF) of the first embodiment of the present invention under ideal conditions. FIG. 8 is a graph of MTF of the first embodiment when atmospheric pressure changes by -100 mmHg from ideal conditions. FIGS. 9A-9D illustrate in graphical form longitudinal spherical aberrations, astigmatic field curves, distortion and ray aberrations in millimeters of the first embodiment under ideal conditions. FIGS. 10A-10D illustrate in graphical form the aberrations illustrated in FIGS. 9A-9D, respectively, when atmospheric pressure changes by -30 mmHg. FIGS. 11A-11D illustrate in graphical form the aberrations illustrated in FIGS. 9A-9D, respectively when the temperature changes by -3° C. from ideal conditions. FIG. 12 is a graph of MTF of a second embodiment under ideal conditions. FIG. 13 is a graph of MTF of the second embodiment when the atmospheric pressure changes by -100 mmHg from ideal conditions. FIGS. 14A-14D illustrate in graphical form longitudinal spherical aberrations, astigmatic field curves, distortion and ray aberrations in millimeters of the first embodiment under ideal conditions FIGS. 15A-15D illustrate in graphical form the aberrations illustrated in FIGS. 14A-14D, respectively, when atmospheric pressure changes by -30 mmHg. FIGS. 16A-16D illustrate in graphical form the aberrations illustrated in FIGS. 14A-14D, respectively when the temperature changes by -3° C. from ideal conditions. DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description is of the presently preferred embodiments of the present invention. It is to be understood that while the detailed description is given utilizing the drawings briefly described above, the invention is not limited to the illustrated embodiments. In the detailed description, like reference numbers refer to like elements. Referring to FIG. 1, an illumination optical system IS includes a high pressure mercury lamp and uniformly illuminates reticle R with illumination light of i-line wavelength (365 nm). Examples of such an illumination optical system which may be used can be found in, for example, U.S. Pat. Nos.: 4,497,015, 4,918,583, 5,245,384, 5,335,044 and 5,420,417. Each of these patents is incorporated herein by reference in its entirety. Reticle R has specified circuit patterns formed on the surface and is supported on reticle stage RS. Below the reticle R, wafer W is placed on, and supported by, wafer stage WS. The light from reticle R illuminated by illumination optical system IS enters projection optical system PL, then forms the image of light source within illumination optical system IS at pupil position (the position of the aperture stop) of the projection optical system PL. That is, the illumination optical system IS uniformly illuminates reticle R under the Kohler illumination. The light from the pupil position of the projection optical system PL is emitted from the projection optical system and reaches wafer W as the second object. The projection optical system PL forms the image of the reticle R on this wafer W. Thus, circuit pattern of reticle R is transferred onto wafer W. The projection optical system PL comprises multiple lens elements. These lens elements are supported inside a lens barrel LB in such a way that specified amounts of air gaps are kept in between them. Flange FL is provided outside of the lens barrel LB. The flange FL is supported by carriage CA of the main body of the projection exposure apparatus. Pressure control equipment PC is provided in the projection optical system PL to control the pressure of certain air gaps among those between lens elements. With respect to the pressure control equipment PC, U.S. Pat. No. 4,666,273, which patent is incorporated herein by reference in its entirety, discloses pressure control equipment which can be used with the present invention. The projection optical system PL in the projection exposure apparatus shown in FIG. 1 is structured so as to satisfy the following conditions: (1) |dSAp|<0.3×λ/(NA) 2 (2) |dCOAMp|<0.3×λ/(NA), where, dSAp is an amount of change in spherical aberration of the maximum numerical aperture ray of the projection optical system PL when surrounding atmospheric pressure of the projection optical system changes by 30 mmHg; dCOMAp is an amount of change in coma aberration of the maximum numerical aperture ray at the maximum image height of the projection optical system PL when surrounding atmospheric pressure of the projection optical system changes by 30 mmHg, and NA is the maximum numerical aperture of the projection optical system PL. The above conditions (1) and (2) are both conditions to make the contrast of reticle R image formed by the projection optical system PL favorable. The condition (1) determines the relation between the depth of focus of the projection optical system and the amount of change in spherical aberration which can be allowed as the projection optical system when atmospheric pressure changes. It is undesirable not to have the condition (1) satisfied because, if not, the amount of generated spherical aberration becomes excessively large and MTF of image declines, rendering the image contrast to deteriorate. The condition (2) determines the relation between the resolving power of the projection optical system and the amount of change in coma aberration which can be allowed as the projection optical system when atmospheric pressure changes. It is undesirable not to have the condition (2) satisfied because, if not, the amount of generated coma aberration around the image becomes excessively large and MTF in the surrounding area of the image declines, rendering the image contrast of the area to deteriorate. In projection exposure apparatus such as this embodiment, it is deemed that there is eventually no deterioration of performance due to the change in atmospheric pressure for illumination optical system IS, reticle stage RS and wafer stage WS. Therefore, in this embodiment, deterioration of image contrast is actually prevented by using the projection optical system satisfying above conditions (1) and (2), even if the atmospheric pressure changes. Having this structure, this embodiment makes it possible to transfer patterns of reticle R onto wafer W with excellent imaging performance even when the atmospheric pressure changes. Also, the projection optical system in the projection exposure apparatus shown in FIG. 1 is structured so as to satisfy the following conditions: (3) |dSAt|<0.3×λ/(NA) 2 (4) |dCOMAt|<0.3×λ/(NA) (5) |dMt|<0.2×λ/(NA) 2 (6) |dYt|<0.05×λ/(NA), where, dSAt is an amount of change in spherical aberration of the maximum numerical aperture ray of the projection optical system PL when the surrounding temperature of the projection optical system changes by 3° C., dCOMAt is an amount of change in coma aberration of the maximum numerical aperture ray at the maximum image height of the projection optical system PL when the surrounding temperature of the projection optical system changes by 3° C., dMt is an amount of change in field curvature at the maximum image height of the projection optical system PL when the surrounding temperature of the projection optical system PL changes by 3° C., dYt is an amount of change in image height at the maximum image height of the projection optical system PL when the surrounding temperature of the projection optical system PL changes by 3° C., and NA is the maximum numerical aperture of the projection optical system PL. The above conditions (3) to (6), inclusive, are the conditions to maintain image contrast of reticle R formed by the projection optical system PL, field curvature and image magnification in favorable status. The condition (3) determines the relation between the depth of focus of the projection optical system and the amount of change in spherical aberration which can be allowed as the projection optical system PL when temperature changes. It is undesirable not to have the condition (3) satisfied because, if not, the amount of spherical aberration generated when the surrounding atmospheric temperature of the projection optical system PL changes becomes excessively large, then MTF of image declines, rendering the image contrast to deteriorate. The condition (4) determines the relation between the resolving power of a projection optical system PL and the amount of change in coma aberration which can be allowed as a projection optical system PL when temperature changes. It is undesirable not to have the condition (4) satisfied because, if not, the amount of coma aberration around image generated when the surrounding atmospheric temperature of the projection optical system PL changes becomes excessively large, then MTF around image declines, rendering image contrast at the surrounding area to deteriorate. The condition (5) determines the relation between the depth of focus of the projection optical system PL and change in field curvature which can be allowed as the projection optical system PL when temperature changes. It is undesirable not to have the condition (5) satisfied because, if not, the amount of field curvature generated when the atmospheric temperature surrounding projection optical system PL changes becomes excessively large, then the usable depth of focus becomes too shallow. The condition (6) determines the relation between the resolving power of the projection optical system PL and change in image height which can be allowed as the projection optical system PL when the temperature changes. It is undesirable not to have the condition (6) satisfied because, if not, change of image height generated when the atmospheric temperature surrounding the projection optical system PL becomes excessively large, rendering a magnification error. It is deemed that, in projection exposure apparatus such as this embodiment, there is eventually no deterioration of performance due to change of temperature for illumination optical system IS, reticle stage RS and wafer stage WS. Therefore, in the (systems) of this embodiment, change in imaging performance is practically restricted by using the projection optical system PL satisfying above conditions (1) to (6) inclusive. This embodiment structure makes it possible to transfer patterns on reticle R onto wafer W with excellent imaging performance even when temperature changes. Following is the description of the lens element supporting method according to this embodiment referring to FIG. 2. FIG. 2 is a cross section of a projection optical system PL, where lens elements comprising the projection optical system are roughly divided into five lens elements G1 to G5, for the sake of simplicity. In FIG. 2, each lens element G1 to G5 is placed on supporting members H1 to H5 respectively. The supporting members H1 to H5 having a ring shape support each lens element G1 to G5 by their peripheral area. Between each supporting member H1 to H5, spacers SP1 to SP5 having a ring shape to maintain specified distances between each lens element G1 to G5 are placed, where thickness of each spacer SP1 to SP5 in the direction of optical axis is determined so that the desired distance values between lens elements G1 to G5 are maintained. In this embodiment structure, the lens barrel LB, the supporting members H1 to H5 and the spacers SP1 to SP5 are all made of the same material. This structure prevents a distortion caused by different thermal expansion coefficients which would have been generated if the lens barrel, supporting members and spacers were made of a variety of materials. The projection optical system PL shown in FIG. 1 is structured so as to satisfy the following conditions: (7) |dSAt1|<0.9×λ/(NA) 2 (8) |dSAt2|<0.9×λ/(NA) 2 (9) |dSAt3|<0.9×λ/(NA) 2 (10) |dCOMAt1|<0.9×λ/(NA) (11) |dCOMAt2|<0.9×λ/(NA) (12) |dCOMAt3|<0.9×λ/(NA) (13) |dMt1|<0.6×λ/(NA) 2 (14) |dMt2|<0.6×λ/(NA) 2 (15) |dMt3|<0.6×λ/(NA) 2 (16) |dYt1|<0.15×λ/(NA) (17) |dYt2|<0.15×λ/(NA) (18) |dYt3|<0.15×λ/(NA), where, dSAt1 is an amount of change in spherical aberration of the maximum numerical aperture ray of the projection optical system PL generated according to the change in refractive index of the optical members comprising lens element when the temperature of the projection optical system PL changes by 3° C., dSAt2 is an amount of change in spherical aberration of the maximum numerical aperture ray of the projection optical system PL generated according to the change in the shape of optical members comprising lens element when the temperature of the projection optical system PL changes by 3° C., dSAt3 is an amount of change in spherical aberration of the maximum numerical aperture ray of the projection optical system PL generated according to the expansion and contraction of the lens barrel supporting lens elements when the temperature of the projection optical system PL changes by 3° C., dCOMAt1 is an amount of change in coma aberration of the maximum numerical aperture ray at the maximum image height of the projection optical system PL generated according to the change in refractive index of the optical members comprising lens element when the temperature of the projection optical system PL changes by 3° C., dCOMAt2 is an amount of change in coma aberration of the maximum numerical aperture ray at the maximum image height of the projection optical system PL generated according to the change in shape of the optical members comprising lens element when the temperature of the projection optical system PL changes by 3° C., dCOMAt3 is an amount of change in coma aberration of the maximum numerical aperture ray at the maximum image height of the projection optical system PL generated according to the expansion and contraction of the lens barrel which supports the lens elements when the temperature of the projection optical system PL changes by 3° C., dMt1 is an amount of change in field curvature at the maximum image height of the projection optical system PL generated by the change in the refractive index of the optical members comprising lens element when the temperature of the projection optical system PL changes by 3° C., dMt2 is an amount of change in field curvature at the maximum image height of the projection optical system PL generated by the change in shape of optical members comprising lens element when the temperature of the projection optical system PL changes by 3° C., dMt3 is an amount of change in field curvature at the maximum image height of the projection optical system PL generated by the expansion and contraction of the lens barrel supporting lens element when the temperature of the projection optical system PL changes by 3° C., dYt2 is an amount of change in image height at the maximum image height of the projection optical system PL generated by the change of the refractive index of the optical members comprising lens element when the temperature of the projection optical system PL changes by 3° C., dYt2 is an amount of change in image height at the maximum image height of the projection optical system PL generated by the change of shape of the optical members constituting lens element when the temperature of the projection optical system PL changes by 3° C., dYt3 is an amount of change in image height at the maximum image height of the projection optical system PL generated by the expansion and contraction of the optical members comprising the lens element when the temperature of the projection optical system PL changes by 3° C., λ is a wavelength of illumination light from the illumination optical system, and NA is the maximum numerical aperture of the projection optical system PL. The above conditions (7) to (18), inclusive, are the conditions to favorably maintain the reticle R image contrast formed by the projection optical system PL, field curvature and image magnification. The conditions (7) to (9) correspond to above mentioned condition (3), where they provide that the amount of change in spherical aberration occurring due to the change of the refractive index caused by the temperature change of each lens element itself comprising the projection optical system PL, the amount of change in spherical aberration occurring due to the change of the shape caused by the temperature change of each lens element itself, and the amount of change in spherical aberration occurring due to the expansion and contraction caused by the temperature change of the lens barrel supporting each lens element are three times or less of the amount of change in spherical aberration that above mentioned condition (3) determines as allowable as a projection optical system PL. The conditions (10) to (12) correspond to above mentioned condition (4), where they provide that the amount of change in coma aberration occurring due to the change of the refractive index caused by the temperature change of each lens unit itself comprising the projection optical system PL, the amount of change in coma aberration occurring due to the change in shape caused by the temperature change of each lens unit itself, and the amount of change in coma aberration occurring due to the expansion and contraction caused by the temperature change of the lens barrel supporting each lens element are three times or less of the amount of change in coma aberration that above mentioned condition (4) determines as allowable as a projection optical system PL. The conditions (13) to (15) correspond to above mentioned condition (5), where they provide that the amount of change in field curvature occurring due to the change of the refractive index caused by the temperature change of each lens element itself comprising the projection optical system PL, the amount of change in field curvature occurring due to the change of shape caused by the temperature change of each lens element itself, and the amount of change in field curvature occurring due to the expansion and contraction caused by the temperature change of the lens barrel supporting each lens element are three times or less of the amount of change of field curvature that above mentioned condition (5) determines as allowable as a projection optical system PL. The conditions (16) to (18) correspond to above mentioned condition (6), where they provide that the amount of change in image height occurring due to the change of refractive index caused by the temperature change of each lens element itself comprising the projection optical system PL, the amount of change in image height occurring due to the change of shape caused by the temperature change of each lens element itself, and the amount of change in image height occurring due to the expansion and contraction caused by the temperature change of the lens barrel supporting the lens element, are three times or less of the amount of change of image height that above mentioned condition (6) determines as allowable as a projection optical system PL. Thus, the conditions (7) to (18) inclusive provide that the amount of change in aberration due to the change in refractive index of each lens element, the change in shape of each lens element and the expansion and contraction of the lens barrel are three times or less of the amount of change in aberrations as the total of these parameters (change in refractive index, change in shape and the expansion and contraction of the lens barrel). This structure makes it possible to keep the discrepancy between the amount of change of each aberration caused by the temperature change and the expected values to a minimum, even when there is difference between the values used in designing and the actual value in each parameter. This structure is especially effective when the refractive indexes are different because the glass lots comprising lens element are different, or when there is an error in measuring refractive indexes of glasses. In above mentioned example, the supporting members H1 to H5 which support each lens element G1 to G5 of the projection optical system PL, the spacers SP1 to SP5 which keep specified distances between supporting members H1 to H5 and the lens barrel which contains these supporting members H1 to H5 and spacers SP1 to SP5 are all made of the same material; however, they do not have to be so. As long as the structure satisfies above conditions (1) to (18) inclusive, the supporting members H1 to H5 and the lens barrel LB can be made of the same material while the spacers are made of the different material, or the supporting members H1 to H5, the spacers SP1 to SP5 and the lens barrel LB can be all made of different materials. The lens barrel can be comprised as shown in FIG. 3. FIG. 3 is a cross section showing another structure of a lens barrel. In FIG. 3 as well, the lens elements comprising the projection optical system PL are divided into five lens elements GI to G5 for the sake of simplicity. In FIG. 3, each lens element G1 to G5 is placed on sub lens barrels LB1 to LB5 respectively. These sub lens barrels LB1 to LB5 are ring-shaped members, where there are shelving rings inside on which each lens element is placed. Between each sub lens barrel LB1 to LB5, spacers SP1 to SP5 are placed to maintain specified distances between each sub lens barrel LB1 to LB5 so that the gaps between each lens element G1 to G5 are kept at desired values. These spacers SP1 to SP5 have a ring shape, and their thickness are determined so that the distances between each lens element G1 to G5 become desired values. In the example of FIG. 3, the sub lens barrels LB1 to LB5 and spacers SP1 to SP5 are made of the same material, however, the sub lens barrels LB1 to LB5 and the spacers SP1 to SP5 can be made of the different materials. Of course, the example of FIG. 3 should have the structure to satisfy said conditions (1) to (18). FIG. 4 is a diagram to show optical paths of the projection optical system PL according to the first embodiment. In FIG. 4, the projection optical system PL according to the first embodiment has, from the side of reticle R as the first object, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, a third lens group G3 having a positive refractive power, a fourth lens group having a negative refractive power and a fifth lens group G5 having a positive refractive power; wherein, the third lens group G3 is structured to include, from the side of reticle R, the first and second meniscus lenses L31 and L32 having a positive refractive power and the concave surface directed to the side of reticle R, and the third and fourth meniscus lenses L34 and L35 having a positive refractive power and the concave surface directed to the side of wafer W. In this embodiment, the lens element L33 with the largest effective diameter among the third lens group G3 is placed between the first meniscus lens L31 and the fourth meniscus lens L35. The fifth lens group G5 is structured to have an aperture stop AP within; on the side of wafer W from the aperture stop AP placed is the first air-spaced doublet comprising of a negative meniscus lens L53 with the concave surface directed to the wafer and a double convex positive lens L54, and the second air-spaced doublet comprising of a double convex positive lens L55 and a negative meniscus lens L56 with the concave surface directed to the side of reticle R. Following is the explanation of the operation according to above mentioned structure. The role of each lens group G1 to G5 are as follows: The first lens group G1 has a positive refractive power as a whole, and plays a role to correct astigmatism and distortion. The second lens group G2 has a negative refractive power as a whole, and helps reducing field curvature by having a negative Petzval sum while minimizing the generation of coma aberration and distortion. The third lens group G3 has a positive refractive power as a whole, and corrects negative coma aberration which occurs mainly in the latter half (i.e. the second object side) of the fourth lens group G4 and the fifth lens group G5. Also, the third lens group G3 plays a role to elongate the working distance of the wafer side in the projection optical system by comprising a retro focus system with its (-+) refractive power arrangement with the second lens group G2. The fourth lens group G4 has a negative refractive power as a whole and contributes significantly to the reduction of field curvature by having a negative Petzval sum. The fifth lens group G5 has a positive refractive power as a whole, condenses rays on the surface of the second object and forms image of an object while minimizing the generation of various aberrations as much as possible. The projection optical system PL according to this embodiment has an arrangement of refractive powers (+-+-+) as a whole, where the lens groups with a positive refractive power and those with a negative refractive power are placed alternately. This structure makes it possible to correct the aberrations occurring at the lens groups having a positive refractive power by the adjacent lens groups having a negative refractive power, where aberrations are restricted under an ideal condition. In addition, when the environmental conditions such as atmospheric pressure and temperature change, it is possible to cancel the change of aberrations occurring at the lens groups having a positive refractive power by change of aberrations occurring at the adjacent lens groups having a negative refractive power. In the projection optical system PL according to this embodiment, the first lens group G1, the second lens group G2 and the fifth lens group G5 are structured by combining positive lens elements and negative lens elements. This structure makes it possible to restrict aberrations under an ideal environment by correcting aberrations occurring at the positive lens elements by the negative lens elements, and also cancel aberration changes occurring at the positive lens elements by the negative lens elements when the environment such as atmospheric pressure and temperature change. However, as the projection optical system PL has a positive refractive power as a whole, there is a tendency that the amount of change in aberration occurring at the positive lens groups becomes larger than the amount of change in aberration occurring at the negative lens groups when the environmental condition changes. Especially in this embodiment, where the third lens group G3 comprises positive lenses only, it is essential to control the amount of change in aberration at the third lens group G3 itself in order to keep amount of change of aberration to a minimum when the environmental condition changes. With respect to the disposition of aberrations upon changes in atmospheric pressure, in this embodiment the projection optical system PL having a refractive power arrangement of (+-+-+), when atmospheric pressure surrounding the projection optical system PL changes, the refractive index of air between each lens element comprising the projection optical system PL changes as well. For example, when atmospheric pressure lowers, so does the refractive index of air, causing the refractive index of optical material comprising each lens element to become greater with respect to that of air. Consequently, at the incident surface of each lens element, the incident angle of a ray entering the incident surface becomes greater, and at the emerging surface of each lens element, the emerging angle of the ray out of respective emerging surfaces becomes greater, thus the influence of change in atmospheric pressure becomes greater. As for the third lens group G3, the ray bundle emerging from the second lens group G2 having a negative refractive power enters the third lens group G3. At the third lens group G3 of the projection optical system PL according to this embodiment, divergent ray bundle, i.e. the group of divergent rays from the second lens group G2 is guided to the first and second meniscus lenses with the concave surface directed to the incident side of the ray bundle. At each lens surface of the first and second meniscus lenses, both incident and emergent angles (of the ray bundle) can be reduced with respect to the group of incident rays entering in divergent status from the second lens group G2. Also, the group of rays from the first and second meniscus lenses becomes a convergent ray bundle, i.e. a group of convergent rays and goes to the fourth lens group G4; then, since the third and fourth meniscus lenses have the meniscus shape where the concave surface is directed to the emerging side of the ray bundle, or, in other words, meniscus shape where the convex surface is directed to the incident side of the ray bundle, it is possible to reduce its incident and emergent angles with respect to the group of rays going to the fourth lens group G4 at each lens surface of the third and fourth meniscus lenses. Thus, the lens group is structured in such a way that incident and emergent angles at each lens surface comprising the first to fourth meniscus lenses are small, where, if atmospheric pressure changes, it is possible to keep the amount of change in aberration occurring due to change of refractive index of air small. Also, this embodiment has a structure where the lens with the maximum effective diameter among the third lens group is placed between the first and fourth meniscus lenses. Otherwise, (i.e. if the lens with the maximum effective diameter among the third lens group is placed on the side closer to the reticle from the first meniscus lens, or on the side closer to the wafer from the fourth meniscus lens) the status of the ray bundle which passes through the third lens group G3 will not be a group of divergent rays with respect to the first and second meniscus lenses, or the ray bundle which comes out of the third and fourth meniscus lenses will not become a group of convergent rays. This embodiment has a structure where the third lens group G3 balances aberrations by generating opposite coma aberration against the coma aberration occurring at the fourth lens group G4 and the latter half of the fifth lens group G5. Observing the lower meridional ray among the off-axial ray bundle which passes through the third lens group G3; in the structure where incident and emergent angles of the lower meridional ray at each lens surface of the third lens group G3 becomes greater (e.g., when atmospheric pressure is reduced), coma aberration is excessively corrected at the third lens group G3, rendering outer coma to be generated on image surface. Therefore, the third lens group G3 of this embodiment has the first and second meniscus lenses with the concave surface directed to the reticle R and the third and fourth meniscus lenses with the concave surface directed to the wafer W, which makes it possible to minimize the incident and emergent angles of the lower meridional ray among the off-axial ray bundle passing through the third lens group G3 at each lens surface. As a result, the amount of change in coma aberration due to change of atmospheric pressure can be reduced. For example, having the third lens group G3 include only of double convex lenses is not desirable because the incident and emergent angles of the lower meridional ray with respect to each lens surface of the third lens group G3 are increased, causing coma aberration to change when atmospheric pressure changes. Although it is possible to cancel the amount of change in coma aberration occurring at the third lens group G3 by increasing the incident and emergent angles with respect to each lens surface of a ray passing through the fourth and fifth lens groups G4 and G5 in this case (i.e. when incident and emergent angles of the lower meridional ray with respect to each lens surface of the third lens group G3 are large), it is not desirable because it increases the amount of both higher order spherical aberration and higher order coma aberration occurring under an ideal condition, both of which are difficult to correct. As in this embodiment, by having the third lens group G3 comprised of the first and second meniscus lenses with the concave surface directed to the reticle R and the third and fourth meniscus lenses with the concave surface directed to the wafer W, it is possible to reduce the incident and emergent angles with respect to each lens surface of on-axis ray bundle passing through the third lens group G3. As a result, the amount of change in spherical aberration can be reduced when atmospheric pressure changes. It is desirable for each lens element L31 to L35 included in the third lens group G3 to satisfy the following conditions: (19) |SIN(β)|<0.5 (20) |(α-β)/(α-γ)|<1.5, where, α is an incident angle of the principal ray corresponding to the maximum image height of the projection optical system PL to the first-object-side lens surface of a lens element, and/or an emergent angle of the principal ray corresponding to the maximum image height of the projection optical system PL from the second-object-side lens surface of a lens element, β is an incident angle of the lower meridional ray corresponding to the maximum image height of the projection optical system PL to the first-object-side lens surface of a lens element, and/or an emergent angle of the lower meridional ray corresponding to the maximum image height of the projection optical system PL from the second-object-side lens surface of a lens element, and γ is an incident angle of the upper meridional ray corresponding to the maximum image height of the projection optical system PL to the first-object-side lens surface of a lens element, and/or an emergent angle of the upper meridional ray corresponding to the maximum image height of the projection optical system PL from the second-object-side lens surface of a lens element. The condition (19) determines the incident and emergent angles of the lower meridional ray which passes through lens surfaces of each lens element comprising the third lens group G3. It is not desirable to have the lens surface of each lens element comprising the third lens group G3 out of the range of the above condition (19) because at each lens surface the incident and emergent angles of the lower meridional ray which passes through the third lens group G3 become excessively large, rendering the amount of change of coma aberration excessively large when atmospheric pressure changes. The condition (20) determines the incident and emergent angles of the upper meridional ray, lower meridional ray and principal ray which pass through lens surfaces of each lens element comprising the third lens group G3. It is not desirable to have the lens surface of each lens element comprising the third lens group G3 out of the range of the above condition (20) because the incident and emergent angles of the upper meridional ray at each lens surface become excessively small, rendering the amount of change of coma aberration occurring in the third lens group excessively large when the atmospheric pressure changes. This embodiment has a structure where the aperture stop AS is placed within the fifth lens group G5, which makes it possible to lessen the amount of coma aberration occurring within the fifth lens group G5. This structure also makes it possible to further reduce the amount of change in coma aberration due to the atmospheric pressure change because it can increase the height of the principle ray, which passes through the third lens group G3 with respect to the optical axis. This embodiment has on the wafer W side from the aperture stop AS, the first air-spaced doublet including of a negative meniscus lens L53 with the concave surface directed to the wafer W and a double convex positive lens L54, and the second air-spaced doublet including of a double convex positive lens L55 and a negative lens L56 with the concave surface directed to the reticle R. The first and second air-spaced doublets mainly contributes to the correction of spherical aberration under the ideal environment. When atmospheric pressure changes, the spherical aberrations occurring at the concave surfaces of negative lenses in the first and second air-spaced doublet fluctuates in the opposite direction of the spherical aberrations at the fifth lens group G5 generated by the atmospheric pressure change, which makes it possible to minimize the amount of change in spherical aberration as a whole even when atmospheric pressure changes. When at least one lens element among those comprising the first and second air-spaced doublets does not have the maximum effective diameter among the fifth lens group G5, the correction of spherical aberration becomes difficult under an ideal condition, and dispositions of aberrations at negative lenses of the first and second air-spaced doublets become different. The influence of temperature change upon an optical system is a sum of the change in aberrations brought about as a result of the change in shapes of optical materials due to expansion and contraction, the change in aberrations brought about as a result of the change in the refractive index of optical materials, the change in aberrations brought about as a result of the expansion and contraction of lens supporting members, and the change in aberrations brought about as a result of reciprocal actions among each of these items. As mentioned above, as the projection optical system PL of this embodiment has a refractive power arrangement of (+-+-+), when the temperature of the optical system changes, aberrations which vary in the positive lens groups and those which vary in the adjacent negative lens groups are opposite and tend to cancel each other. Furthermore, the first lens group G1, the second lens group G2 and the fifth lens group G5 of this embodiment are made up of the combination of positive lens elements and negative lens elements. This structure makes it possible to cancel the change in aberration occurring in positive lens elements by negative lens elements when the temperature changes. Let us observe the third lens group G3 practically made up of positive lens elements. The third lens group G3 of this embodiment includes, in order from the side of reticle R, the first and second meniscus lenses L31 and L32 having a positive refractive power with the concave surface directed to the side of reticle R and the third and fourth meniscus lenses L34 and L35 having a positive refractive power with the concave surface directed to the side of wafer W. Due to the structure where the lens having the maximum effective diameter among the third lens group G3 is placed between the first meniscus lens L31 and the fourth meniscus lens L35, the group of divergent rays enters the first and second meniscus lenses L31 and L32, and the group of convergent rays emerges from the third and fourth meniscus lenses L34 and L35. Therefore, incident and emergent angles of the group of divergent rays at each lens surface which passes through the first and second meniscus lenses L31 and L32 can be reduced, and incident and emergent angles of the group of convergent rays at each lens surface which passes through the third and fourth meniscus lenses L34 and L35 also can be reduced. Reducing incident and emergent angles at each lens surface denotes reducing the amount of aberrations occurring at each lens surface; if the temperature changes, the amount of change in aberrations can be kept extremely small since the original aberrations are small. However, it is difficult to balance coma aberration under an ideal environment (i.e. ideal temperature) only by the structure of the third lens group G3 mentioned above. Therefore, this embodiment draws the aperture stop AS nearer to wafer W by having the aperture stop AS in the fifth lens group G5 so as to reduce coma aberration occurring in the fifth lens group itself. Observing the fifth lens group G5 of this embodiment; the first air-spaced doublet includes a negative meniscus lens L53 with the concave surface directed to the wafer side and a double convex positive lens L54 and the second air-spaced doublet includes a double convex positive lens L55 and a negative lens L56 with the concave surface directed to the side of reticle R are placed on the side closer to the wafer W from the aperture stop AS, wherein at least one lens element among those comprising the first and second air-spaced doublets has the maximum effective diameter among the fifth lens group G5. With this structure, when temperature changes, spherical and coma aberrations generated at concave surface of negative lenses of the first and second air-spaced doublets fluctuate in the opposite direction of the spherical and coma aberrations of the projection optical system PL as a whole when temperature changes, which makes it possible to keep the total amount of change in the spherical and coma aberrations small. Furthermore, the concave surfaces of negative lenses in the first and second air-spaced doublets have a function to correct the change in image height at the maximum image height position of the projection optical system PL when temperature changes. It is desirable for the projection optical system PL of this embodiment to satisfy the following conditions: (21) 0.10<f1/L<0.25 (22) -0.09<f2/L<-0.03 (23) 0.05<f3/L<0.20 (24) -0.10<f4/L<-0.02 (25) 0.05<f5/L<0.20, where, f1 is the focal length of the first lens group G1, f2 is the focal length of the second lens group G2, f3 is the focal length of the third lens group G3, f4 is the focal length of the fourth lens group G4, f5 is the focal length of the fifth lens group G5 and L is the distance between object and image (the distance from the first object (reticle R) to the second object (wafer W)). Condition (21) determines the range of optimal focal length of the first lens group G1 having a positive refractive power; it is not desirable to exceed the upper limit because the correction of negative distortion will become difficult. It is not desirable to go below the lower limit because the correction of the spherical aberration of the pupil will become difficult. Condition (22) determines the range of optimal focal length of the second lens group G2 having a negative refractive power; it is not desirable to exceed the upper limit because the correction of negative distortion which occurs in the second lens group G2 will become difficult. It is not desirable to go below the lower limit because reduction of the Petzval sum and reduction of the total length will become difficult. Condition (23) determines the range of optimal focal length of the third lens group G3 having a positive refractive power; it is not desirable to exceed the upper limit because the refractive power of the second or fourth lens group becomes weak, making correction of the Petzval sum difficult. It is not desirable to go below the lower limit because correction of coma and distortion will become difficult. Condition (24) determines the range of optimal focal length of the fourth lens group G4 having a negative refractive power; it is not desirable to exceed the upper limit because coma aberration will be generated. It is not desirable to go below the lower limit because reduction of the Petzval sum will become difficult. Finally, condition (25) determines the range of optimal focal length of the fifth lens group G5 having a positive refractive power. It is not desirable to exceed the upper limit because the refractive power of the fifth lens group becomes too weak, and accordingly the refractive power of the fourth lens group becomes weak, which makes it difficult to keep the Petzval sum small. It is not desirable to go below the lower limit because spherical aberration is generated. Referring to FIGS. 4 and 6, which show the optical paths of the first and second embodiments, respectively, each of the embodiment based on information shown in FIG. 4 and 6 has, in the order from the side of reticle R as the first object, the first lens group Gl having a positive refractive power, the second lens group G2 having a negative refractive power, the third lens group G3 having a positive refractive power, the fourth lens group G4 having a negative refractive power and the fifth lens group G5 having a positive refractive power. In the projection optical system according to the first and second embodiments, the first object side (reticle R side) and the second object side (wafer W side) are practically telecentric, where a reduced image of the first object is transferred onto the second object. Referring more particularly to the projection optical system according to the first embodiment shown in FIG. 4, this embodiment has, in order from the side of the first object, the first lens group G1 having a positive refractive power, the second lens group G2 having a negative refractive power as a whole which includes a negative meniscus lens L21 placed closest to the first object side with the concave surface directed to the second object side and a negative meniscus lens L27 placed closest to the second object side with the concave surface directed to the first object side, the third lens group G3 having a positive refractive power, the fourth lens group G4 having a negative refractive power as a whole which includes a negative meniscus lens L41 placed closest to the first object side with the concave surface directed to the second object side and a plano-concave lens L44 placed closest to the second object side with the concave surface directed to the first object side, and the fifth lens group G5 including a positive lens L51 placed closest to the first object side and an aperture stop placed on the side closer to the second object from the positive lens L51. The first lens group G1 includes, in order from the reticle R side, a plano-convex lens L11 with the convex surface directed to the wafer W side, a negative meniscus lens L12 with the concave surface directed to the wafer W side, a double convex positive lens L13 and a positive meniscus lens L14 with the convex surface directed to the reticle R side. The second lens group G2 includes, in order from the reticle R side, a negative meniscus lens L21 with the concave surface directed to the wafer W side, a double convex positive lens L22 with a strong convex surface directed to the wafer W side, a plano-concave lens L23 with the concave surface directed to the wafer W side, a double concave negative lens L24, a plano-concave lens L25 with the concave surface directed to the reticle R side, a plano-convex lens L26 with the convex surface directed to the wafer W side and a negative meniscus lens L27 with the concave surface directed to the reticle R side. The third lens group G3 includes, in order from the reticle R side, a positive meniscus lens L31 as the first meniscus lens with the concave surface directed to the reticle R side, a positive meniscus lens L32 as the second meniscus lens with the concave surface directed to the reticle R side, a double convex positive lens L33, a positive meniscus lens L34 as the third meniscus lens with the concave surface directed to the wafer W side and a positive meniscus lens L35 as the fourth meniscus lens with the concave surface directed to the wafer W side. As shown in FIG. 5, the positive meniscus lens L31 in the third lens group G3 has the first-object-side lens surface S311 as the incident surface and the second-object-side lens surface S312 as the emergent surface. The positive meniscus lens L32 has the first-object-side lens surface S321 as the incident surface and the second-object-side lens surface S322 as the emergent surface. The double convex positive lens L33 has the first-object-side lens surface S331 as the incident surface and the second-object-side lens surface S332 as the emergent surface. The positive meniscus lens L34 has the first-object-side lens surface S341 as the incident surface and the second-object-side lens surface S342 as the emergent surface. The positive meniscus lens L35 has the first-object-side lens surface S351 as the incident surface and the second-object-side lens surface S352 as the emergent surface. Referring to FIG. 4, the fourth lens group G4 includes, in order from the reticle R side, a negative meniscus lens L41 with the concave surface directed to the wafer W side, a negative meniscus lens L42 with the concave surface directed to the wafer W side similarly, a double concave negative lens L43 and a plano-convex lens L44 with the concave surface directed to the reticle R side. The fifth lens group includes, in order from the reticle R side, a double convex lens L51 with a strong convex surface directed to the wafer W side, a positive meniscus lens L52 with the concave surface directed to the reticle R side, an aperture stop AS, a double convex lens L53, a negative meniscus lens L54 with the concave surface directed to the reticle R side, a negative meniscus lens L55 with the concave surface directed to the wafer W side, a double-convex positive lens L56, a positive meniscus lens L57 with the convex surface directed to the reticle R side, a positive meniscus lens L58 with the convex surface directed to the reticle R side similarly, a positive meniscus lens L59 with the convex surface directed to the reticle R side, a negative meniscus lens L510 with the convex surface directed to the reticle R side, a positive meniscus lens L511 with the convex surface directed to the reticle R side, and a plano-concave lens L512 with concave surface directed to the wafer W side. Table 1 below shows the values of specifications for the above first embodiment. In table 1, the numbers in the left end column indicate the order from the first object side (reticle side), r is the curvature radius of the lens surface (0.000 equals infinity in this table), d is the distance between lens surfaces, n is the refractive index of optical material when exposure wavelength λ is 365 nm, φ is the effective diameter of each lens element, E is the expansion ratio of optical material which comprises the lens element, dn/dt is the thermal refractive index coefficient of optical material which comprises the lens element, and D is the distance from flange to the supporting point of each lens element. Also in table 1, dO is the distance from the first object (reticle) to the closest lens surface on the side of the first object (reticle side), and Bf is the distance from the lens surface which is closest to the second object to the second object (wafer). In the projection optical system of the first embodiment shown in FIG. 4, the distance between object and image (the distance between the object surface to the image surface along the optical axis) L is 1200, the image side numerical aperture is 0.62, the projection magnification B is -1/5 and the diameter of exposure field at wafer W is 31.2. TABLE 1__________________________________________________________________________dO = 89.650Bf = 21.655r d n φ E dn/dT D__________________________________________________________________________1 0.000 24.000 1.61548 178.197 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -694.7282 -531.881 0.500 180.6873 1104.059 18.000 1.61548 181.138 11.0 × 10.sup.-6 5.8 × 10.sup.-6 -662.3524 255.431 5.483 179.9225 327.711 35.384 1.48858 180.689 16.3 × 10.sup.-6 -4.6 × 10.sup.-6 -639.2866 -359.443 0.500 181.5887 185.781 30.655 1.61548 176.930 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -593.6918 1322.182 1.132 171.6299 168.786 20.000 1.61265 158.656 11.1 × 10.sup.-6 5.8 × 10.sup.-6 -564.21910 119.569 21.502 139.54611 1072.143 19.611 1.48858 138.873 16.3 × 10.sup.-6 -4.6 × 10.sup.-6 -540.57312 -360.000 0.538 134.56313 0.000 11.778 1.61548 128.763 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -514.97614 109.248 22.806 114.85115 -326.667 19.026 1.61548 114.746 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -483.73516 265.643 29.341 117.51217 -173.435 16.906 1.61548 122.659 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -443.20618 0.000 1.476 138.43319 0.000 28.000 1.61265 139.865 11.0 × 10.sup.-6 5.8 × 10.sup.-6 -417.08620 -222.691 35.745 148.44821 -111.227 20.000 1.61265 156.260 11.0 × 10.sup.-6 5.8 × 10.sup.-6 -386.30522 -192.996 0.633 184.08723 -279.097 29.000 1.61548 190.595 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -353.51924 -161.834 0.500 199.93425 -1975.662 28.206 1.61548 214.222 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -310.03226 -309.687 0.500 219.77827 440.594 30.177 1.61548 219.590 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -266.36928 -880.644 0.500 218.04829 238.555 28.012 1.61548 205.013 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -224.68730 767.881 0.550 198.02031 194.345 25.000 1.48858 183.229 16.3 × 10.sup.-6 -4.6 × 10.sup.-6 -192.32332 276.460 4.315 169.00733 347.485 15.000 1.61265 167.559 11.0 × 10.sup.-6 5.8 × 10.sup.-6 -180.57634 279.555 6.194 154.36535 431.474 15.091 1.61548 152.216 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -154.18936 115.261 32.234 130.70037 -206.306 11.776 1.61265 130.129 11.0 × 10.sup.-6 5.8 × 10.sup.-6 -122.42438 243.147 29.754 130.48139 -120.027 42.742 1.61265 131.003 11.0 × 10.sup.-6 5.8 × 10.sup.-6 -79.51640 0.000 1.000 174.76141 1483.642 42.880 1.48858 179.469 16.3 × 10.sup.-6 -4.6 × 10.sup.-6 -31.34342 -179.843 1.416 189.00943 -2788.744 30.003 1.48858 201.840 16.3 × 10.sup.-6 -4.6 × 10.sup.-6 0.61544 -265.715 0.846 205.68945 (AS) 0.000 8.000 206.47046 380.423 36.200 1.61548 214.892 6.1 × 10.sup.-6 7.5 × 10.sup.-6 59.83247 -486.693 9.223 215.32948 -297.922 20.000 1.61265 215.089 11.0 × 10.sup.-6 5.8 × 10.sup.-6 89.86949 -543.660 5.000 220.00750 322.369 20.000 1.61265 220.834 1.0 × 10.sup.-6 5.8 × 10.sup.-6 146.18451 202.379 15.117 212.87752 357.384 33.000 1.61548 212.280 6.1 × 10.sup.-6 7.5 × 10.sup.-6 172.34153 -2968.481 0.500 212.83854 199.918 33.785 1.48858 209.863 16.3 × 10.sup.-6 -4.6 × 10.sup.-6 215.37955 772.323 0.500 204.98756 159.448 35.451 1.48858 191.211 16.3 × 10.sup.-6 -4.6 × 10.sup.-6 260.10557 254.318 0.500 175.35458 129.479 42.998 1.48858 163.255 16.3 × 10.sup.-6 -4.6 × 10.sup.-6 288.62759 4229.259 0.500 147.18260 1082.306 15.000 1.61265 142.777 11.0 × 10.sup.-6 5.8 × 10.sup.-6 308.24961 74.634 28.943 106.09362 78.815 28.615 1.61548 93.187 6.1 × 10.sup.-6 7.5 × 10.sup.-6 354.50663 3000.00 2.102 81.00864 0.000 15.007 1.61265 77.889 11.0 × 10.sup.-6 5.8 × 10.sup.-6 378.78065 820.248 (Bf) 64.145__________________________________________________________________________ Table 2 below shows the corresponding values of conditions (1) to (18) and (21) to (25) of the first embodiment. TABLE 2______________________________________ (1) 0.062 um (2) 0.014 um (3) 0.439 um (4) 0.047 um (5) 0.035 um (6) 0.009 um (7) 0.021 um (8) 0.729 um (9) 0.312 um (10) 0.050 um (11) 0.245 um (12) 0.343 um (13) 0.017 um (14) 0.143 um (15) 0.195 um (16) 0.018 um (17) 0.039 um (18) 0.067 um (21) 0.169 (22) -0.059 (23) 0.103 (24) -0.046 (25) 0.143______________________________________ Table 3 below shows values corresponding to conditions (19) and (20) of the first embodiment. TABLE 3______________________________________ corresponding values corresponding valuessurface no. to the condition (19) to the condition (20)______________________________________23 0.037 0.01324 0.222 0.87625 0.082 0.70426 0.166 0.83927 0.139 1.10228 0.167 0.87229 0.116 0.90830 0.139 0.79331 0.041 0.08632 0.093 0.442______________________________________ The projection optical system PL of the second embodiment shown in FIG. 6 has, in order from the side of the first object, the first lens group G1 having a positive refractive power, the second lens group G2 having a negative refractive power as a whole which includes a negative meniscus lens L21 placed closest to the first object with the concave surface directed to the second object side and a negative meniscus lens L27 placed closest to the second object side with the concave surface directed to the first object side, the third lens group G3 having a positive refractive power, the fourth lens group G4 having a negative refractive power as a whole which includes a negative meniscus lens L41 placed closest to the first object side with the concave surface directed to the second object side and a negative meniscus lens L44 placed closest to the second object side with the concave surface directed to the first object, and the fifth lens group G5 including a positive lens L51 placed closest to the first object side and an aperture stop placed on the side closer to the second object from the positive lens L51. The first lens group G1 having a positive refractive power includes, in order from the side of reticle R, a double convex positive lens L11, a double concave lens L12 with a strong concave surface directed to the wafer W side, a double convex positive lens L13 and a double convex lens L14 with a strong convex surface directed to the reticle R side. The second lens group G2 includes, in order from the reticle R side, a negative meniscus lens L21 with the convex surface directed to the reticle R side, a double convex positive lens L22, a plano-concave negative lens L23 with a strong concave surface directed to the wafer W side, a double concave negative lens L24, a plano-concave negative lens L25 with a strong concave surface directed to the reticle R side, a convex meniscus lens L26 with a strong convex surface directed to the wafer W side and a negative meniscus lens L27 with the concave surface directed to the reticle R side. The third lens group G3 includes, in order from the reticle R side, a positive meniscus lens L31 as the first meniscus lens with the concave surface directed to the reticle R side, a positive meniscus lens L32 as the second meniscus lens with the concave surface directed to the reticle R side, a double convex positive lens L33, a positive meniscus lens L34 as the third meniscus lens with the concave surface directed to the wafer W side and a positive meniscus lens L35 as the fourth meniscus lens with the concave surface directed to the wafer W side. The fourth lens group G4 includes, in order from the reticle R side, a negative meniscus lens L41 with the concave surface directed to the wafer W side, a negative meniscus lens L42 with the concave surface directed to the wafer W side similarly, a double concave negative lens L43 and a concave meniscus lens L44 with the concave surface directed to the reticle R side. The fifth lens group G5 includes, in order from the reticle R side, a positive meniscus lens L51 with the convex surface directed to the wafer W side, a positive meniscus lens L52 with the convex surface directed to the wafer W side, an aperture stop AS, a double convex positive lens L53, a negative meniscus lens L54 with the concave surface directed to the reticle R side, a negative meniscus lens L55 with the concave surface directed to the wafer W side, a double convex positive lens L56, a positive meniscus lens L57 with the convex surface directed to the reticle R side, a positive meniscus lens L58 with the convex surface directed to the reticle R side similarly, a positive meniscus lens L59 with the convex surface directed to the reticle R side, a negative meniscus lens L510 with the concave surface directed to the wafer W side, a positive meniscus lens L511 with the convex surface directed to the reticle R side and a plano-concave lens L512 with the concave surface directed to the wafer W side. Table 4 below shows the values of specifications of the above second embodiment. In table 4, the numbers in the left end column indicate the order from the first object side (reticle side), r is the curvature radius of the lens surface (0.000 equals infinity in this table), d is the distance between lens surfaces, n is the refractive index of optical material when exposure wavelength λ is 365 nm, φ is the effective diameter of each lens element, E is the expansion ratio of optical material which comprises the lens element, dn/dt is the thermal refractive index coefficient of optical material which comprises the lens element. Also in table 4, dO is the distance from the first object (reticle) to the closest lens surface on the side of the first object (reticle side), and Bf is the distance from lens surface which is closest to the second object to the second object (wafer). In the projection optical system of second embodiment shown in FIG. 6, the distance between object and image (the distance between the object surface to the image surface along the optical path) L is 1200, the image side numerical aperture is 0.57, the projection magnification B is -1/5 and the diameter of exposure field at wafer W is 31.2. TABLE 4__________________________________________________________________________dO = 89.650Bf = 21.655r d n φ E dn/dT D__________________________________________________________________________1 555.188 24.000 1.61548 178.494 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -692.6832 -631.380 0.000 178.6753 -1314.268 15.000 1.61265 178.104 11.0 × 10.sup.-6 5.8 × 10.sup.-6 -668.2474 308.194 9.512 176.8525 799.387 36.000 1.48858 177.316 16.3 × 10.sup.-6 -4.6 × 10.sup.-6 -637.4956 -337.323 0.000 179.8297 392.053 24.352 1.61548 178.199 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -603.4558 -1296.268 1.132 175.7509 164.687 43.000 1.61265 164.038 11.0 × 10.sup.-6 5.8 × 10.sup.-6 -557.63910 132.580 12.823 136.05611 308.675 25.125 1.48858 135.393 16.3 × 10.sup.-6 -4.6 × 10.sup.-6 -524.55112 -346.757 0.538 130.43713 0.000 11.778 1.61548 124.203 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -500.26814 109.864 22.886 109.91115 -245.687 19.026 1.61548 109.537 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -468.41616 249.948 29.177 111.37517 -133.699 16.906 1.61548 115.225 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -428.04218 0.000 1.840 133.12119 -3783.753 28.000 161.265 134.418 11.0 × 10.sup.-6 5.8 × 10.sup.-6 -402.53720 -184.592 46.411 143.12721 -112.744 21.759 1.61265 157.111 11.0 × 10.sup.-6 5.8 × 10.sup.-6 -359.85722 -170.639 0.937 183.15423 -331.042 29.000 1.61548 193.566 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -321.65124 -175.469 0.601 201.88925 -2161.494 26.575 1.61548 212.404 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -281.02426 -325.080 0.500 215.16227 555.883 26.228 1.61548 214.695 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -240.46128 -1325.450 0.500 212.86829 232.785 28.012 1.61548 202.703 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -201.29130 737.40 0.510 196.08431 171.317 25.000 1.48858 180.462 16.3 × 10.sup.-6 -4.6 × 10.sup.-6 -168.64332 263.216 4.647 168.22533 334.109 15.000 1.61265 166.715 11.0 × 10.sup.-6 5.8 × 10.sup.-6 -151.33434 147.477 6.194 146.51535 179.817 15.874 1.61548 145.159 6.1 × 10.sup.-6 7.5 × 10.sup.-6 -128.08036 118.970 31.868 130.15637 -243.708 11.776 1.61265 128.421 11.0 × 10.sup.-6 5.8 × 10.sup.-6 -99.09638 -295.224 28.997 126.91839 -118.373 15.239 1.61265 127.550 11.0 × 10.sup.-6 5.8 × 10.sup.-6 -70.96540 -816.863 23.427 145.17641 -1141.486 33.144 1.48858 165.190 16.3 × 10.sup.-6 -4.6 × 10.sup.-6 -18.23042 -176.634 0.500 173.22343 -891.966 23.434 1.48858 179.942 16.3 × 10.sup.-6 -4.6 × 10.sup.-6 6.04444 -268.530 10.149 183.58145 (AS) 0.000 5.000 184.27146 696.535 41.200 1.61548 188.228 6.1 × 10.sup.-6 7.5 × 10.sup.-6 68.12947 -294.506 4.852 189.84548 -250.731 18.000 1.61265 189.600 11.0 × 10.sup.-6 5.8 × 10.sup.-6 97.29949 -506.743 0.500 195.82250 415.632 18.000 1.61265 198.709 11.0 × 10.sup.-6 5.8 × 10.sup.-6 136.41851 267.230 6.950 196.09552 374.561 35.000 1.61548 196.561 6.1 × 10.sup.-6 7.5 × 10.sup.-6 167.01453 -9613.854 0.500 196.28054 264.692 24.937 1.48858 195.612 16.3 × 10.sup.-6 -4.6 × 10.sup.-6 200.03955 672.783 0.500 191.95356 160.583 41.955 1.48858 185.603 16.3 × 10.sup.-6 -4.6 × 10.sup.-6 240.09657 848.012 0.500 175.08158 121.040 39.977 1.48858 154.843 16.3 × 10.sup.-6 -4.6 × 10.sup.-6 279.23859 742.443 0.500 138.30160 888.126 15.036 1.61265 138.352 11.0 × 10.sup.-6 5.8 × 10.sup.-6 296.10261 76.259 36.011 105.36062 82.754 32.442 1.61548 90.414 6.1 × 10.sup.-6 7.5 × 10.sup.-6 350.54763 31489.489 1.286 75.13064 0.000 16.135 1.61265 73.228 11.0 × 10.sup.-6 5.8 × 10.sup.-6 378.19865 527.377 (Bf) 59.584__________________________________________________________________________ Table 5 below shows values corresponding to conditions (1) to (18) and (21) to (25) of the second embodiment. TABLE 5______________________________________ (1) 0.002 um (2) 0.005 um (3) 0.427 um (4) 0.044 um (5) 0.076 um (6) 0.004 um (7) 0.006 um (8) 0.691 um (9) 0.258 um (10) 0.081 um (11) 0.307 um (12) 0.347 um (13) 0.014 um (14) 0.143 um (15) 0.234 um (16) 0.008 um (17) 0.003 um (18) 0.001 um (21) 0.230 (22) -0.079 (23) 0.107 (24) -0.054 (25) 0.128______________________________________ Table 6 below shows the values corresponding to conditions (19) and (20) according to the second embodiment. TABLE 6______________________________________ corresponding values corresponding valuessurface no. to the condition (19) to the condition (20)______________________________________23 0.040 0.11824 0.218 0.91325 0.062 0.53626 0.172 0.88327 0.093 0.84728 0.130 0.82429 0.135 1.05630 0.122 0.77531 0.088 0.67432 0.083 0.314______________________________________ Referring to FIGS. 7-16, the operation of the projection optical system of the first and second embodiments when atmospheric pressure and temperature changes will be discussed in conjunction with the data illustrated in graphical form. With respect to the modulation transfer function MTF and aberrations, which are generated when atmospheric pressure changes make the atmospheric pressures in each air gap between lens elements included in the projection optical system PL change; the illustrated data is is based on the refractive indexes of these air gaps. As for MTF and aberrations occurring when temperature changes, the illustrated data is based on lens data calculated according to the relational expressions (A)˜(E) below. With respect to changes in lens parameters when temperature changes, referring again to FIG. 2, this embodiment can maintain the distance between the flange FL and reticle R constant because flange FL of lens barrel LB is supported by carriage CA of the main body of the projection exposure apparatus. This allows the position of reticle R on the optical axis to be freely modified even when temperature changes. In the example shown in FIG. 2, the lens barrel LB, the supporting members H1˜H5 and the spacers SP1˜SP5 are all to be made of the same material. When the curvature radius of the first-object side (reticle R side) lens surface of the lens element G1 shown in FIG. 2 in an ideal environment is r11, the curvature radius of the second-object side (wafer W side) lens surface of the lens element G1 in an ideal environment is r12, the lens thickness of the lens element G1 in an ideal environment is t1, the distance on the optical axis direction between the supporting point where the supporting member H1 supports the lens element G1 and the flange FL in an ideal environment is d1, the refractive index of optical members comprising lens element G1 in an ideal environment is n1, the expansion coefficient of lens element G1 is E1, the expansion coefficient of members comprising the lens barrel LB, supporting members H1˜H5 and the spacers SP1˜SP5 is EM, and the thermal refractive index coefficient of optical member comprising lens element G1 is (dn/dT)1. When temperature changes by +T° C., the curvature radius r11' of the first-object side lens surface of the lens element G1, the curvature radius r12' of the second-object side lens surface of the lens element G1, the lens thickness t1' of the lens element G1, the distance d1' in the optical axis direction between the supporting point where the supporting member H1 supports the lens element G1 and the flange FL, and the refractive index n1' of optical member comprising lens element G1 are expressed as below, respectively: r11'=r11+r11×E1×T t1'=t1+t1×E1×T r21'=r21+r21×E1×T d1'=d1+d1×EM×T n1'=n1+(dn/dT)1×T In the same manner, as for the mth (m is a natural integer) lens element Gm, when the curvature radius of the first-object side (reticle R side) lens surface of the lens element Gm in an ideal environment is rml, the curvature radius of the second-object side (wafer W side) lens surface of the lens element Gm in an ideal environment is rm2, the lens thickness of lens element Gm in an ideal environment is tin, the distance on the optical axis direction between the supporting point where the supporting member Hm supports the lens element Gm and the flange FL in an ideal environment is dm, the refractive index of optical members comprising lens element Gm in an ideal environment is nm, the expansion coefficient of lens element Gm is Em, the expansion coefficient of members comprising the lens barrel LB, supporting members and spacers is EM, and the temperature coefficient of optical member comprising the lens element Gm is (dn/dT)m. When temperature changes by +T° C., the curvature radius rm1' of the first-object side lens surface of the lens element Gm, the curvature radius rm2' of the second-object side lens surface of the lens element Gm, the lens thickness tm' of the lens element Gm, the distance dm' in direction of the optical axis between the supporting point where the supporting member Hm supports the lens element Gm and the flange FL, and the refractive index nm' of optical members comprising lens element Gm are expressed as below, respectively: (A) rml'=rm1+rm1×Em×T (B) tm'=tm+tm×Em×T (C) r2m'=r2m+rm2×Em×T (D) dm'=dm+dm×EM×T (E) nm'=nm+(dn/dT)m×T When a temperature change occurs, the parameters of each lens element at the changed temperature is calculated based on (A) to (E) above, and MTF and aberrations are calculated using the lens data obtained by the result of the calculations. In the example shown in FIG. 3, the above conditions can be applied when the sub lens barrels LB1˜LB5 and spacers SP1˜SP5 are made of the same material. To illustrate the performance of the first embodiment of the present invention, FIG. 7 is a graph of incoherent MTF of the first embodiment scanned in focal direction in an ideal condition. In FIG. 7, the ordinate axis shows MTF contrast and the abscissa axis shows defocusing; T and R represent the tangential and radial directions, respectively. FIG. 8 shows MTF of the first embodiment when atmospheric pressure changes by -100 nmHg from the ideal condition. As FIGS. 7 and 8 clearly indicate, there is almost no deterioration in image contrast due to a change of atmospheric pressure in the first embodiment. FIGS. 9A-9D show various aberrations of the projection optical system of the first embodiment in an ideal condition. FIG. 9A is a graph of spherical aberration, FIG. 9B is a graph of astigmatism, FIG. 9C is a graph of distortion, and FIG. 9D are graphs showing lateral aberration of tangential and sagittal directions at 100%, 70% and 0% image height. FIG. 10A-10D show various aberrations of the projection optical system of the first embodiment in the condition where the atmospheric pressure changes by -30 mmHg from an ideal environment. FIG. 10A is a graph of spherical aberration, FIG. 10B is a graph of astigmatism and FIG. 10C is a graph showing distortion aberration and FIG. 10D are graphs showing lateral aberration of tangential and sagittal directions at 100%, 70% and 0% image height. Table 7 shows the amount of change in spherical aberration, coma aberration, image height and meridional image surface for the first embodiment in the condition where the atmospheric pressure changes by -30 mmHg from an ideal condition. TABLE 7______________________________________spherical aberration 0.062 μmimage height 0.143 μmmeridional image surface -0.010 μmcoma aberration 0.014 μm______________________________________ As FIGS. 9A-9D, 10A-10D and table 7 clearly indicate, there is almost no change in spherical and coma aberrations due to atmospheric pressure change in the projection optical system of the first embodiment, and field curvature is kept to a small amount as well. Table 8 shows changes in the aberrations from the ideal condition when atmospheric pressure within a portion of the multiple air gaps in the optical system is altered in order to correct magnification in the first embodiment. Specifically, the pressure in the gap between surface numbers 15 and 16 in above Table 1 is changed to -53.9 mmHg by the pressure control device PC. TABLE 8______________________________________spherical aberration 0.040 μmimage height 0.001 μmmeridional image surface -0.028 μmcoma aberration 0.016 μm______________________________________ Thus, by conducting magnification correction using the pressure control device PC, performances obtained in an ideal condition can be maintained in spite of significant changes in atmospheric pressure (-30 mmHg) in the actual use. FIGS. 11A-11D show various aberrations of the projection optical system of the first embodiment in the condition where the temperature changes by 3° C. from the ideal condition. FIG. 11A is a graph of spherical aberration, FIG. 11B is a graph of astigmatism, FIG. 11C is a graph of distortion, and FIG. 11D includes graphs of lateral aberrations in tangential and saggital directions at 100%, 70% and 0% image height. Table 9 shows the amount of change in spherical aberration, coma aberration, image height and meridional image surface for the first embodiment in the condition where the temperature changes by 3° C. from the ideal. TABLE 9______________________________________spherical aberration -0.439mimage height 0.009 μmmeridional image surface 0.035 μmcoma aberration -0.047 μm______________________________________ As FIGS. 9A-9D, 11A-11D, and Table 9 clearly indicate, the projection optical system of the first embodiment can maintain the performance it attains in ideal conditions in spite of a temperature change of 3° C. FIG. 12 is a graph of incoherent MTF of the second embodiment scanned in the focal direction in the ideal condition. FIG. 13 is a graph of the same MTF when the atmospheric pressure changes by 100 mmHg in this embodiment. As FIGS. 12 and 13 clearly indicate, there is almost no deterioration of image contrast due to the atmospheric pressure change in the second embodiment. FIGS. 14A-14D show various aberrations of the projection optical system of the second embodiment under the ideal environment. FIG. 14A is a graph of spherical aberration, FIG. 14B is a graph of astigmatism, FIG. 14C is a graph of distortion and FIG. 14D shows lateral aberrations in tangential and sagittal directions at 100%, 70% and 0% image height. FIGS. 15A-15D show various aberrations of the projection optical system of the second embodiment in the condition where atmospheric pressure changes by -30 mmHg from the ideal. FIG. 15A is a graph of spherical aberration, FIG. 15B is a graph of astigmatism, FIG. 15C is a graph of distortion and FIG. 15D shows lateral aberrations in tangential and sagittal directions at 100%, 70% and 0% image height. Table 10 shows the amount of change in spherical aberration, coma aberration, image height and meridional image surface in the condition where atmospheric pressure has changed by -30 mmHg from the ideal. TABLE 10______________________________________second embodiment______________________________________spherical aberration -0.002 μmimage height 0.133 μmmeridional image surface 0.021 μmcoma aberration 0.005 μm______________________________________ As FIGS. 14A-14D, 15A-15D and table 10 clearly indicate, there is almost no change in amount of spherical and coma aberrations due to the atmospheric pressure change in the projection optical system of the second embodiment, and the change of field curvature is kept to a small amount. Table 11 shows the change in the amount of aberrations from the ideal after the atmospheric pressure in a portion of the multiple air gaps within the optical system was modified in order to correct magnification in the second embodiment, where the pressure control device PC changes the pressure in the gap between surface numbers 15 and 16 in above table 2. TABLE 11______________________________________spherical aberration -0.021 μmimage height 0.001 μmmeridional image surface 0.000 μmcoma aberration 0.006 μm______________________________________ Thus, by having the pressure control device PC conduct magnification correction, performance obtained in the ideal condition can be maintained at the actual use site in spite of a significant change in the atmospheric pressure (by -30 mmHg). FIGS. 16A-16D show various aberrations of the projection optical system of the second embodiment in the condition where the temperature changes by 3° C. from the ideal. FIG. 16A is a graph of spherical aberration, FIG. 16B is a graph of astigmatism, FIG. 16C is a graph of distortion and FIG. 16D shows lateral aberrations in tangential and sagittal directions at 100%, 70% and 0% image height. Table 12 shows change in the amount of spherical aberration, coma aberration, image height and meridional image surface for the second embodiment when the temperature has changed by 3° C. from the ideal. TABLE 12______________________________________spherical aberration -0.427 μmimage height -0.004 μmmeridional image surface 0.076 μmcoma aberration 0.044 μm______________________________________ As FIGS. 14A-14D, 16A-16D and table 12 clearly indicate, the projection optical system of the second embodiment can maintain the same performance as in an ideal environment in spite of temperature change of 3° C. The projection optical systems of the first and second embodiments of this invention have a large numerical aperture of 0.55 or more on the image side, have a large exposure field of 30 mm or more on the second object, and their imaging performance either in an ideal environment and in changed atmospheric pressure or temperature conditions is highly favorable. By applying this projection optical system to a projection exposure apparatus as shown in FIG. 1, circuit patterns on reticle can be transferred finely not only under an ideal conditions, but in environments which differ significantly from the ideal. While each embodiment discussed above uses a mercury lamp which supplies i-line (365 nm) as the exposure light source, the present invention is also usable with other light sources, such as a mercury lamp which supplies g-line (465 nm) exposure light, or deep ultra violet (DUV) light source such as excimer laser which supplies 193 nm or 248 nm wavelength. The projection optical system of the present invention is applicable to a variety of lithography systems, including but not limited to a so-called step and repeat exposure system or step and scan exposure system. As those skilled in the art of projection optical systems will readily appreciate, numerous substitutions, modifications and additions may be made to the above design without departing from the spirit and scope of the present invention. It is intended that all such substitutions, modifications and additions fall within the scope of this invention which is best defined by the claims appended below.

A projection exposure system, which is used to transfer a pattern from a reticle or mask onto a substrate, incorporates a projection optical system that is capable of maintaining the same performance as that which can be found in an ideal environment, even when the actual use environment (e.g. atmospheric pressure and temperature) is not ideal. In addition, the projection optical system is able to recover the same performance as in an ideal environment through relatively minor adjustment of its projection optical system even when atmospheric pressure significantly changes due to, e.g., a change in location and altitude where the system is used.

BACKGROUND OF THE INVENTION [0001] The present invention relates to digital frequency generation. In particular, it relates to a method and apparatus for the digital generation of a pulse stream having a desired frequency relative to a reference clock signal and the ratio of two integers. The method applies generally to integers whose ratio is not an integer. The digital frequency generation (DFG) as a device can be integrated onto a simple chip, without need for an off-chip filter. [0002] A number of techniques are used to synthesize signals in the art of direct digital synthesis. Many of these techniques utilize an accumulator to access a sine wave look-up table stored in a memory, which in turn produces a sequence of values representing a sine wave at the desired frequency. Using a digital-to-analog converter (DAC), the sequence of sine wave values is converted to an analog voltage and then passed through a low-pass filter to produce an analog voltage sine wave signal with the desired output frequency. This form of direct digital synthesis provides accurate control of the generation of signals over a wide range of frequencies. Significant portions of its circuitry can be manufactured using integrated circuits. Jones discloses an example of this type of system in U.S. Pat. No. 3,958,191 and Kovalick et al. discloses an accumulator and lookup ROM in U.S. Pat. No. 5,084,681. [0003] In spite of its many advantages, this first method of direct digital synthesis has drawbacks, including the need for a fast high-resolution DAC and a multi-pole low-pass filter requiring precision discrete components. Consequently, the DAC and filter add size and cost to a product because they usually require components external to other integrated circuits. [0004] A second type of direct digital synthesis uses the accumulator carry signal and remainder value to generate an output frequency without requiring a lookup sine table and a low-pass filter. In U.S. Pat. No. 5,195,044, Wischermann discloses an example of this type of system, wherein the carry signal generates an output pulse after a delay that is computed from the value remaining in the accumulator when carry signals an overflow. Like the first type, this second type of system generates an output frequency with a desired fractional relationship to the input reference clock, and it also requires multi-pole filters with physical components external to an integrated circuit. This second type of circuit uses an approximation when computing the carry signal delay, which in turn reduces the accuracy of the output frequency. [0005] An opportunity is apparent to develop alternative digital frequency generator (DFG) circuitry. Simplified circuitry without artifacts tied to the clock that drives the DFG is useful in a variety of tunable electronic devices. SUMMARY OF THE INVENTION [0006] The present invention relates to digital frequency generation. In particular, it relates to a method and apparatus for the digital generation of a pulse stream having a desired frequency relative to a reference clock signal and the ratio of two integers. The method applies generally to integers whose ratio is not an integer. The digital frequency generation (DFG) as a device can be integrated onto a simple chip, without need for an off-chip filter. Particular aspects of the present invention are described in the claims, specification and drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0007] FIG. 1 is a block diagram of a direct digital frequency synthesizer (DDFS) or digital frequency generator (DFG). [0008] FIG. 2 is a state diagram illustrating the operation of the selector function. [0009] FIGS. 3A-3D are timing diagrams illustrating the relative values of the selector output signal in relationship to the operational state of the selector function. [0010] FIG. 4 is a schematic diagram of an embodiment of generic accumulator coupled to a selector. [0011] FIG. 5 is a conceptual diagram of an embodiment of the accumulator with a power of two numerators, without using a divider. [0012] FIG. 6 depicts using a pseudo random binary sequency (PRBS) shift register to implement a fast down counter, instead of using a subtracter. [0013] FIG. 7 illustrates a PRBS shift register embodiment. [0014] FIG. 8 depicts a simple low pass filter. [0015] FIGS. 9-10 depict more elaborate low pass filters. [0016] FIGS. 11A-B depict simulated results of an embodiment of this technology. FIG. 11A is a simulation of a waveform that is output by the digital-to-analog converter and input to the filter. FIG. 11B is a simulation of a waveform that is output by the filter, responsive to the input in FIG. 11A . [0017] FIG. 12 depicts a comparator, which has a transfer function. [0018] FIGS. 13A-B depict simulated results of processing the filtered analog signal through a comparator to produce a pulse stream. FIG. 13A is a simulation of a waveform that is output by the filter. FIG. 13B is a simulation of a waveform that is output by the comparator. DETAILED DESCRIPTION [0019] The following detailed description is made with reference to the figures. Preferred embodiments are described to illustrate the present invention, not to limit its scope, which is defined by the claims. Those of ordinary skill in the art will recognize a variety of equivalent variations on the description that follows. [0020] The technology disclosed pertains to direct digital synthesis methods and apparatus that provide for the generation of an output frequency F OUT from an input clock signal reference F CLK and an integral ratio [0000] N M , [0000] where N and M are integers further discussed below and F OUT is defined by the following formula: [0000] F OUT = ( 1 2 )  ( N M )  F CLK ( 0.1 ) [0021] In certain embodiments, the denominator M is an integer defined by the range of an accumulator. For example, M may be embodied by an m-bit digital accumulator of whose output ACC counts over the following range: [0000] 0 ≦ACC ≦(2 m −1)   (0.2) [0022] In those embodiments where denominator M is implemented as an m-bit digital accumulator ACC, numerator N is an integer that may also be termed F SEL , and whose value may be repeatedly added to the accumulator. Furthermore, F SEL may be defined to have the following range: [0000] 0 ≦F SEL <2 m−1   (0.3) [0023] Consequently, for those embodiments where M is implemented as an m-bit digital accumulator and F SEL is an integer input repeatedly added to the accumulator, the output frequency of the direct digital synthesis disclosed is defined by the formula: [0000] F OUT = ( 1 2 )  ( F SHL 2 m )  F CLK ( 0.4 ) [0024] Substitution of the minimum and maximum F SEL values from equation (1.3) into equation (1.4) shows these embodiments have the following output frequency range: [0000] 0 ≤ F OUT ≤ ( 1 4 )  F CLK ( 0.5 ) [0025] Depending on the embodiment, practical implementations of an accumulator may treat the numerator as fixed and vary the denominator or may treat the denominator as fixed and vary the numerator. Less efficient implementations may vary both the numerator and denominator. Alternative accumulator embodiments are discussed below. [0026] FIG. 1 is a block diagram of a direct digital frequency synthesizer (DDFS) or digital frequency generator (DFG). The components include an accumulator 110 , a selector 120 , a digital to analog converter (DAC) 130 , a low pass filter 140 and a comparator 150 . Inputs to the accumulator include a frequency selector signal 101 and a reference clock 102 . Outputs from the accumulator component include a carry out signal 111 and an accumulator value signal 112 , both of which are coupled as inputs to the selector 120 . A variety of accumulator embodiments are described below. The selector 120 also operates at the speed of the reference clock. Outputs 121 of the selector 120 are digital signals, such as voltage or current signals (current mode logic.) The outputs are coupled to a digital-to-analog converter 130 . The outputs are a value and rising/falling edge indicator, as depicted in FIG. 3A . [0027] FIGS. 3A-3D are timing diagrams illustrating the relative values of the selector output signal in relationship to the operational state of the selector function. FIG. 3A indicates the clock, selector state, selector digital value and the rising/falling edge indicator of the selector 120 and at the selector output 121 , as the selector changes from a rising edge to a falling edge state. The reference clock 102 , at the top of FIG. 3A , is an input to the selector 120 . The selector state alternates among minimum value (DACMIN) 301 A, 301 B, rising value (DACRIS) 302 , maximum value (DACMAX) 303 , and falling value (DACFAL) 304 , with corresponding outputs. More details of the selector state progression are explained below in the context of FIG. 2 . The output signals 121 include both a digital value 311 and an indicator (DACT) 320 of whether the signal edge is rising 321 or falling 322 . The selector digital value output 311 has the same range between a low 313 and high value 316 , whether the digital value corresponds to a rising edge 315 or a falling edge 317 . The interpretation of the digital value by the DAC 130 depends on whether the signal is rising or falling. [0028] In FIG. 3A , the first two outputs of the selector are a low value 313 and a rising intermediate value 314 , both while the edge is rising. The low value is for one or more clock periods 301 A. The intermediate value is for a single clock period 302 . Then, the state shifts to falling edge 322 and a high value signal 316 is output for one or more clock periods 303 . [0029] In FIG. 3B , the first two outputs are a continuing high value 316 and a falling intermediate value 318 . Like the low value, the high value signal 316 lasts one or more clock periods. The rising and falling intermediate values are for one clock period. At the end of FIG. 3B , the digital value output returns to the low value 313 . Returning to FIG. 1 , the selector output 121 is indicated by a digital output signal. [0030] FIG. 1 includes a DAC coupled to the selector. As FIGS. 3A-3B indicate, the DAC receives a pair of signals. Its response depends on the combination of signals. (One of skill in the art will recognize that the signals could be combined by various encodings without changing the principle of operation.) [0031] FIGS. 3C-D indicate the output of the DAC, along the same time line as FIGS. 3A-B indicate its input. Notice that the range of rising edge outputs 355 is offset from the range of falling edge outputs 356 . The subtle difference between inputs and outputs to the DAC is an offset between the maximum output of the DAC 350 and the greatest intermediate output 361 corresponding to the rising intermediate digital value 314 . Aligned with the rising/falling value indicator 321 , 322 , when the edge is rising 321 , a rising intermediate digital value 314 is processed by the DAC 130 . The highest value 310 of the rising intermediate value 314 causes the DAC to generate an output 361 that is less than the maximum DAC output 350 . Similarly, the lowest value 362 output by the DAC in response to a falling intermediate digital value 318 is greater than the minimum DAC output 352 . Returning to FIG. 1 , the DAC output 131 is indicated as an analog signal with a similar form to the digital input, modified by the offset. [0032] FIG. 1 further includes a low-pass filter. In some embodiments, the time constant of the low-pass filter or the band-pass point, the cutoff frequency of the low pass filter is selected to be roughly half of the reference clock, to eliminate high frequency components of the analog output. It is understood from Fourier analysis that harmonic components of the analog output will in the general case be odd harmonic multiples of the desired output frequency, 3f, 5f, 7f etc. where f is the output frequency of the intended signal, the desired output clock. The low pass filter is designed to pass the desired signal, which has a period of 4 clock cycles or greater, but not the higher frequency harmonics or the reference clock frequency. The output 141 of the low-pass filter 140 is a filtered analog signal, which can be presented to a comparator 150 . [0033] The comparator 150 changes the rising and falling analog signal 141 into a digital pulse (FOUT) 151 having the desired frequency. A reference input 142 governs the comparator. A useful property of this approach to DFG is that the pulse output frequency 151 need not be aligned with any pulse of the clock reference 102 . [0034] One of skill in the art will recognize that by adjusting a value in the accumulator, either a starting value or an intermediate value, an offset can be introduced to align FOUT 151 with an external signal of similar frequency. [0035] FIG. 2 is a state diagram that generally describes the state of the selector 120 . Other than the reset state (DFSRESET) 200 , the state flow progresses among four states 210 , 220 , 230 , 240 , which correspond to states 301 - 04 in FIGS. 3A-D . The selector enters the reset state 200 upon assertion of a reset signal 211 . As long as the reset signal remains asserted 202 , the reset state 200 will be in effect. Deassertion 203 of the reset signal will correspond to a negative initial carry indicator, because the accumulator resets during the reset state. Deassertion 203 causes a transition to a first state, which is illustrated in this state diagram as DACMIN 210 . The DACMIN state 210 produces a minimum digital output value from the selector ( 313 A in FIG. 3A ) which is held throughout this state. It also produces a rising edge signal ( 321 FIG. 3A ). The state continues 211 until the accumulator generates a carry signal. When the selector receives the carry signal, a state transition 212 takes place. [0036] Following DACMIN is the rising edge (DACRIS) state 220 . This state preferably lasts one clock cycle. When the accumulator generates a carry signal, it also generates a so-called remainder which is a value between 0 and N−1, where N is the numerator in equation 1.1, above. During DACRIS, the remainder value is output as the rising intermediate value ( 314 in FIG. 3A ) and the rising edge signal 321 is in effect. The carry signal is deasserted 221 in the clock cycle after it is asserted 212 , corresponding to the next state transition. [0037] The DACMAX state 230 , produces a maximum digital output value ( 316 in FIG. 3A ) which is held throughout this state. It also produces a rising edge signal ( 322 FIG. 3A ). The state continues 231 until the accumulator generates a carry signal. When the selector receives the carry signal, a state transition 232 takes place. [0038] Following DACMAX is the falling edge (DACFAL) state 240 . This state preferably lasts one clock cycle. When the accumulator generates a carry signal, it also generates a so-called remainder which is a value between 0 and N−1, where N is the numerator in equation 1.1, above. During DACFAL, the ones complement of the remainder value is output as the falling intermediate value ( 318 in FIG. 3B ) and the falling edge signal 322 is in effect. The carry signal is deasserted 241 in the clock cycle after it is asserted 232 , corresponding to the next state transition, which returns the state cycle to DACMIN 210 . [0039] To remind the reader how ones' complement is implemented, consider the following table excerpt: [0000] Ones' Decimal Binary Complement +15 1111 0000 +14 1110 0001 +13 1101 0010 +12 1100 0011 +11 1011 0100 +10 1010 0101 +9 1001 0110 [0040] On a rising edge, a large remainder from the accumulator and a corresponding large rising intermediate value signals a desired analog output from the DAC that is near the maximum. On a falling edge, a large remainder signals a desired output from the DAC near the minimum output. A ones' complement of the remainder combined with an offset corresponding to the rising/falling edge indicator 320 is one embodiment of providing the appropriate to the DAC. [0041] Note that the range of the remainder can be larger than the precision of the DAC. The DAC can, for instance, take into account just the most significant digits of the remainder or the ones' complement of the remainder. [0042] In operation, at least four cycles of the reference clock 102 are required for the system to cycle through four states, 210 , 220 , 230 and 240 . Therefore, the frequency of a DGF signal FOUT 151 is one-quarter or less than the reference clock frequency 102 . Conversely, the period of the FOUT signal is at least four times the period of the reference clock period. [0043] The overflow and remainder of the accumulator can be thought of as implementing modulo arithmetic. The modulo base is the denominator. The remainder ranges from zero to one less than the numerator (0<=R<N). It works out nicely if the numerator is an integer power of 2(N=2**k). The design of the accumulator and of the DAC both can benefit from a well-chosen numerator, but the technology disclosed can be practiced with most any choice of numerator and denominator that is consistent with a four state cycle (i.e., ½N/M<=¼). The advantage of a well-chosen numerator emerges as we consider alternative embodiments of the accumulator 110 . [0044] The number of cycles in which the state machine remains at DACMIN or DACMAX will fluctuate by one cycle. The following table with a sample numerator of four and denominator of 17 illustrates this fluctuation: [0000] Accumulated Mod 17 Terminal Ratio 0 0 TC 0 4 4 8 8 12 12 16 16 20 3 TC 0.75 24 7 28 11 32 15 36 2 TC 0.5 40 6 44 10 48 14 52 1 TC 0.25 56 5 60 9 64 13 68 0 TC 0 72 4 76 8 80 12 84 16 88 3 TC 0.75 The accumulated column adds the numerator (four) to the prior total. The mod 17 column translates the accumulated value by modular or clock arithmetic into a modulo denominator ( 17 ) value. The terminal condition column indicates when the modulo 17 value has clocked past 16 . The ratio column indicates the ratio of the remainder at the terminal condition to the numerator. In some ranges of rows, it takes five iterations to overflow the accumulator. In other ranges, it takes four iterations. The number of iterations depends on whether the accumulator starts with zero or with a non-zero remainder from the prior overflow. The overflow remainder depends on the prior overflow remainder. Equivalent result patterns are generated by the illustrated up counter that accumulates a positive numerator or a down counter that accumulates a negative numerator. Alternatively, this result pattern can be produced using a pseudo-random binary sequence shift register with a selected starting symbol and calculating the change in the remainder when the terminal condition occurs, as explained below. [0045] FIG. 4 is a schematic diagram of an embodiment of a generic accumulator stage coupled to a selector. We refer to this schematic as a generic accumulator, because the divider runs relatively slowly and more efficient implementations are described below. [0046] The accumulator 410 is coupled to the selector 420 . As inputs, this accumulator has a frequency selector (FSEL) 401 and a reference clock 402 . A generic interpolation generator 413 , 414 is illustrated as part of the accumulator. Not explicitly illustrated is the value at which the accumulator component 411 overflows, generating the carry/overflow signal 416 . In the formulas above, FSEL 401 corresponds to N in the numerator and the value at which the accumulator overflows corresponds to M in the denominator. The accumulator 411 adds the FSEL 401 value to the previous sum that was calculated, which has been buffered 412 and is coupled back as an input to the accumulator 411 . The resulting sum is stored in the buffer 412 , which updates responsive to the reference clock 402 . [0047] The generic interpolation generator 413 , 414 calculates the ratio of the remainder, when the carry/overflow takes place, divided by FSEL 401 , the numerator N. This ratio is buffered 414 responsive to the reference clock 402 and output 417 to the selector 420 . When the numerator is an integer power of 2(N=2**k), the ratio can be calculated using a shift register operation instead of a divide by operation. Or, depending on the DAC precision, a well-chosen numerator allows the remainder to be used directly to represent the ratio. It is useful to note that the divider 413 does not need to produce an output at each cycle of the reference clock 402 . The calculated ratio is used only when an overflow occurs or is about to occur, which is no more than every two clock cycles, depending on how close the ratio ½N/M is to the limit of one-fourth. [0048] FIG. 5 is a conceptual diagram of an embodiment of the accumulator with a power of two numerator, without using a divider. A down counter is implemented with a subtracter 512 that counts down from the value of the denominator M−1 and underflows when it passes zero. Using ones complementary arithmetic to invert FSEL 501 , an adder can operate as a subtracter. The underflow signal 516 is output to the selector and controls a MUX 513 . The MUX 513 controls whether the output of the fast down counter 512 or the output of the adder 511 is clocked into the buffer 514 . The output of adder 511 is used less frequently than the output of the fast down counter 512 , because the limit for the generated frequency is one quarter of the reference clock. A fast down counter can be implemented, for instance, using a PRBS shift register. [0049] FIG. 6 depicts using a pseudo-random binary sequence (PRBS) shift register to implement a fast down counter, instead of using a subtracter. A PRBS is a sequence of symbols that can be calculated from a starting symbol and that reaches a terminal condition (TC) in a known number of steps. A PRBS can be chosen so that the next to last and last (TC) symbols are easily detected, for instance binary 1 and 0. A down counter can be replaced by a PRBS shift register if the number of elements is known and the appropriate starting symbol is chosen. For a given length of sequence, the appropriate symbol can be looked up and used as a starting point for calculating successive symbols. For instance, if the desired sequence length is 21 symbols, selecting the twenty-first symbol and processing the sequence. A micro-controller looks up the value to be loaded into the PRBS. The desired length of the sequence 605 , for a numerator of N=2**k, is found in the high order bits of the denominator, the j-k high order bits, where j is the bus width that carries the denominator value. In some embodiments, the numerator may be configurable, that is, the value k can vary and be configurable. When the numerator is configurable, it may be necessary to use overly wide data paths, to accommodate the maximum values of numerator and denominator allowable. [0050] A difference between using a PRBS shift register and a subtracter to count down is that the symbol-to-symbol transitions of a PRBS require less time to calculate. Compare subtracting N from M. The subtraction involves an arbitrary number of bit carries that must, to some degree, be executed sequentially. A linear feedback shift register, for instance, can be implemented without any bit carries. In the seven state sequence of 001, 100, 010, 101, 110, 111 and 011, the next symbol can be generated by adding without overflow or XORing the two low order bits and shifting the result into the high order bit position. For symbol 010 , the two low order bits combine to generate a “1”, which becomes the high order bit of the next symbol. The two high order bits become the low order bits. The low order bit of “010” shifts out of the sequence. The result is symbol 101 . [0051] FIG. 7 illustrates a PRBS shift register embodiment, but any PRBS embodiment can be used, preferably a fast implementation. The seven single bit registers illustrated handle up to 128 symbols, for a relatively long sequence. More or fewer bits can be implemented. Logic other than the indicated not-XOR of bits from registers U 15 and U 16 can be applied to reset the high order bit in U 10 . To use the PRBS as a fast down counter with an arbitrary sequence length, a long sequence should be available, the starting symbol is loaded initially and reloaded when the desired end of the sequence is reached. It also is useful to be able to detect both the last and next-to-last symbols in the sequence. [0052] Returning to FIG. 6 , the combination of the MUX 613 and register 614 recycle a value that is unchanging, except when the terminal condition (TC) occurs. When the inverted terminal condition signal 616 indicates that the end of the down count has been reached, the signal causes the MUX 613 to select the output of the subtracter 612 to update the buffer 614 with a new value. The shortest PRBS length is two symbols and longer sequences are likely. Even a two-symbol sequence gives the subtracter extra time to settle and generate output that can be buffered through the MUX into the register 614 . Note that the under flow signal from the subtracter 616 is coupled to the carry indicator of the PRBS 611 . Looking to FIG. 7 , one sees that the carry indicator (CIN) signal controls whether the PRBS reports out the last symbol or the next-to-last symbol as the TC. This is because a sequence of remainders occasional produces an underflow, as illustrated above, the length of the DACRIS 220 or DACFAL 240 state is responsive to the remainder underflow or overflow. [0053] Returning to FIG. 4 , the selector 420 includes various components with a state machine and outputs that can be summarized with reference to the states in FIG. 2 : [0000] State State DACT DACIN Name and Ref Registers Output Output DACMIN 210 00 0 All Zeroes DACRISE 220 10 0 Remainder DACMAX 230 11 1 All Ones DACFALL 240 01 1 Remainder Ones' Comp. Registers 422 and 423 are state registers. The output indicator of a rising or falling edge (DACT for DAC trigger) 429 controls an offset applied by the DAC 130 , as indicated in FIGS. 3A-D . The output value (DACIN for DAC input) 439 is as indicated. Updating of the state registers on the reference clock 402 is responsive to the carry out signal 416 from the accumulator 410 , which is processed by a MUX 421 . The state of register 422 represents the high order bit in the table above, which determines whether the reminder value 417 or an inverted 431 version of the reminder value (e.g., a ones' complement) is selected 432 to be buffered 435 and output 439 . The state of register 423 represents the low order bit in the table above, which determines the offset applied by the DAC in conversion. The logic components 424 , 425 , 433 , 434 combine to generate the buffered output 435 to ones or all zeros in the DACMIN and DACMAX states. [0054] Implementation of the DAC 130 is best summarized by its transfer function, as a variation on an R-2R resistor ladder or any other DAC, preferably low cost, can be used. The transfer function is controlled by the signal DACT, which is illustrated in FIGS. 3C-D . It may be thought of as applying an affect, depending on the signal DACT. Alternatively, a digital value may be implemented, responsive to the value of DACT. Or, DACT could be treated as the lowest order bit of the value to be converted. [0000] DAC Input DAC Input DAC Output DAC Output Decimal Binary DACT = 0 DACT = 1 15 1111 15/16 1 14 1110 ⅞ 15/16 13 1101 13/16 ⅞ 12 1100 ¾ 13/16 11 1011 11/16 ¾ 10 1010 ⅝ 11/16 9 1001   9/16 ⅝ 8 1000 ½   9/16 7 0111   7/16 ½ 6 0110 ⅜   7/16 5 0101   5/16 ⅜ 4 0100 ¼   5/16 3 0011   3/16 ¼ 2 0010 ⅛   3/16 1 0001   1/16 ⅛ 0 0000 0   1/16 This transfer function has been simulated and proven to produce low jitter or noise in the digitally generated frequency output. [0055] FIG. 8 depicts a simple low pass filter. FIGS. 9-10 depict more elaborate low pass filters. The desired transfer function is graphically illustrated in FIGS. 11A-B . Other forms of low pass filter or filters in general may be used to convert an analog version of the selector output into a truncated triangular waveform that presents crossing points with the desired frequency/period, a frequency that need not be aligned with the reference clock. [0056] FIGS. 11A-B depict simulated results of an embodiment of this technology. FIG. 11A is a simulation of a waveform that is output by the digital-to-analog converter and input to the filter. Consistent with the modulo arithmetic example table above, a downward trend of intermediate rising values can be seen in the figure. Applying ones' complement math, a upward trend of intermediate falling values can be seen. These patterns may be cyclic. FIG. 11B is a simulation of a waveform that is output by the filter, responsive to the input in FIG. 11A . We refer to this waveform has a truncated triangular waveform because the high and low values of the waveform are limited, responsive to be range of the digital-to-analog converter. A triangular waveform would extend the longer legs of the waveform to higher highs amble or lows than depicted in the figure. A useful feature of this waveform is a consistently-spaced crossing point at or near the middle of the waveform. Even though the bends in the waveform are aligned to the reference clock, the crossing points of the filter to analog signal are essentially free of artifacts resulting from the frequency of the reference clock. The crossing points do not depend on alignment with the reference clock. [0057] FIG. 12 depicts a comparator, which has a transfer function that is illustrated in the following figures. Any comparator may be used. [0058] FIGS. 13A-B depict simulated results of processing the filtered analog signal through a comparator to produce a pulse stream. FIG. 13A is a simulation of a waveform that is output by the filter. It resembles FIG. 11B , with a compressed timeline. FIG. 13B is a simulation of a waveform that is output by the comparator. [0059] Analysis and simulation of the embodiments illustrated has confirmed that this design is suitable for implementation on a single chip, integrated circuit or other device with an on-chip filter. With other designs, an on-chip filter is impractical to use because it introduces significant distortion and does not faithfully construct a sine wave from samples. Constructing a sine wave using samples from a sine wave ROM requires an off-chip filter that is more precise than practical for an on-chip filter. Recovering a sine wave typically involves using a so-called brick wall filter. In contrast, filtering the high/low values with an intermediate rising/falling value generates a truncated triangular wave instead of a sine wave. The truncated triangular wave of the designs taught here can be generated with an on-chip filter. Some Particular Embodiments [0060] The present invention may be practiced as a method or device adapted to practice the method. The invention may be an article of manufacture such as computer readable media impressed with logic to carry out digital frequency generation. [0061] One embodiment is a digital frequency generator (DFG) that produces an output frequency relative to a reference clock. This device includes a reference clock signal having cycles, a numerator value or signal and a denominator value or signal. The numerator and denominator are accessible in memory. The numerator and denominator may be a value stored in memory or a signal input to the device. The device further includes at least an accumulator stage and a selector. There are several alternatives for implementing the accumulator stage, as described above. The accumulator stage could, alternatively, be implemented using a divider, an adder, a subtracter, or a pseudo-random binary sequence shift register. The accumulator stage is coupled to the reference clock, the numerator and the denominator. It iteratively signals a terminal condition signal and a remainder signal. These signals are generated after a number of cycles that it would take to reach an overflow condition by repeatedly accumulating the numerator and overflowing an accumulator that has a range from zero to the denominator minus one. As explained above, this number of cycles fluctuates by one, depending on the starting value of the accumulator, which ranges from zero to the numerator value minus one. Corresponding to when an overflow would happen, the accumulator stage outputs both a terminal condition signal and a remainder signal. [0062] The selector stage is responsive to the accumulator stage and to both the terminal condition signal and the remainder signal. It includes a state machine and output stage. The state machine transitions, responsive to the terminal condition signal, through states such as those illustrated in FIGS. 2 and 3 A-B. For instance, the states may be a low value state, a rising intermediate value state, a high-value state, and a falling immediate value state. Other names could be applied to the states, which might seem to reverse the order. Between high and low states, there will be an intermediate state, both on the rising and the falling side. In some instances, the intermediate state may be full range, that is, equal to the low value or the high value. This depends on the ratio of the numerator and denominator. The output stage outputs a value signal responsive to the state machine. For instance, it may output a low value responsive to the low value state and a rising intermediate value during the rising intermediate value state. The rising intermediate value is responsive to the remainder signal. Similarly, the output stage outputs a high value responsive to the high-value state and a falling value during the falling intermediate value state. The falling intermediate value also is responsive to the remainder signal. As explained above, it may be the one's complement of the remainder. The output stage further outputs a binary rising-or-falling signal responsive to the state machine. A rising signal may be generated during the low value state and the intermediate rising value state, as illustrated in FIG. 3A , and a falling signal may be generated during the high-value state and the intermediate falling value state, as illustrated in FIG. 3B . Alternatively, the rising signal might be generated during the intermediate rising value state and the high value state, with the falling signal generated during the intermediate falling value state and the low value state. The precise definition of the binary rising-or-falling signal will depend on the encoding of the remainder and the operation of successive stages such as digital-to-analog converter (DAC) and comparator stages. The combination of the accumulator stage and the selector produce a useful output signal that might have a variety of uses in digital processing. [0063] The accumulator stage and selector described above may, optionally, be combined with a digital-to-analog converter, filter and comparator. The digital-to-analog converter would be coupled to the value signal and the rising-or-falling signal of the selector. It would produce an analog output responsive to the value signal with an offset responsive to the rising-or-falling signal, for instance, as illustrated in FIGS. 3A-D . The filter would process the output of the digital-to-analog converter and smooth it. Following conversion of digital value signals from the selector, the corresponding analog output of the converter could be filtered into truncated triangular waveforms. We refer to the waveforms as truncated triangles because the peaks and valleys are cut off to keep the signal within the allowable output range of the converter. The peaks and valleys would exceed the range of the converter if not truncated, at least when the truncated triangular waveforms were not aligned with an edge of the reference clock. Filters other than a low pass filter might produce different but equally useful waveforms. The desired property of the filtered waveform is to have some crossing point that can be converted into a periodic pulse stream of a desired frequency. [0064] Embodiments of the accumulator-selector or the whole DFG will vary by whether the numerator or denominator is fixed. In some limited applications, both may be fixed. If only two frequencies are desired, for instance, two implementations of the whole DFG with fixed numerator and denominator might be built on a chip and selected alternatively. Generally, multiple DFGs may be packaged on the same chip. [0065] In the fixed numerator embodiment, it is useful to select a numerator that is a fixed integer power of two. Then, operations related to the ratio of the numerator and denominator can be performed using shift register operations, which are faster than division operations, or even by using a slow running adder or subtracter to calculate a progression of remainders or residues. With a fixed numerator, the denominator may be selectable to tune the ratio. [0066] In some embodiments, the accumulator stage includes a pseudo-random binary sequence processor. This may be a shift register configuration or a so-called linear feedback shift register. A variety of feedback patterns are available that produce a PRBS. It is useful to choose a PRBS that has a pair of easily detectible symbols next to each other, so that sequences that vary by one cycle can be accommodated. The length of the PRBS can be tailored to the ratio of the denominator divided by the numerator by loading and reloading the PRBS shift register with a starting symbol to be responsive to the ratio. The number of cycles can be adjusted, responsive to a pattern of successive remainders. [0067] The filter of the embodiments described above is simple enough (unlike the so-called brick wall filters used to construct sine waves from samples) that it can share device real estate with the accumulator stage, the selector, the DAC and the comparator. It can be implemented on an ASIC, a semi-custom ASIC, a RISC processor, a signal processor, or in a logic array, such as an FPGA. A single integrated circuit can include all five stages, thereby reducing the chip count of a device that takes advantage of the integration. [0068] The data paths between stages can be implemented in a variety of ways, including current mode logic. [0069] In any of the devices described above, the low value state may be held for a number of cycles separating a first terminal condition signal and a second terminal condition signal. The rising intermediate value state may last one cycle (or some other definite number of cycles may work, at a loss of range in the output pulse stream). The high value state may be held for a number of cycles separating the second terminal condition signal and a third terminal condition signal, with the falling intermediate value state lasting one cycle (or some other definite number of cycles). As the device steps through these transitions, the number of cycles between successive terminal condition signals will fluctuate by one cycle, unless the denominator divided by the numerator is an integer value. [0070] Features and aspects of embodiments described above can be combined in a variety of ways which are fairly reflected in multiple dependencies of dependent claims. [0071] Another device embodiment is expressed largely in means-plus-function terms. It includes means for generating a series of digital signals, a digital-to-analog converter with an offset, means for filtering the analog signal to produce a filtered wave form with periodically spaced crossing points, and a comparator that evaluates the crossing points to produce an output pulse stream. [0072] The means for generating a series of digital signals produces an output that cycles among one or more low values, one rising intermediate value, one or more high values and one falling intermediate value. Any combination of the accumulator stage structures described above and selectors described above can be used as the means for generating the series of digital signals. [0073] The transfer function of the digital-to-analog converter with the offset is described in a table, above. [0074] Means for filtering the analog signal is illustrated as a variety of low pass filters in the figures. An integrator with a suitable decay might produce a similarly useful filtered waveform. [0075] A comparator is also described above. [0076] When the means for triangular filtering is a low pass filter, the resulting filtered wave form may be a truncated triangular waveform, with peaks and valleys of the waveform truncated when the crossing points of the filtered wave are not aligned with or of a period that matches the reference clock. Framed slightly differently, at least some of the peaks and valleys will be truncated when the denominator divided by numerator is not an integer. [0077] Method embodiments build upon one another. A first method embodiment is a method of digitally synthesizing a pulse stream from a reference clock responsive to a ratio of the numerator divided by a denominator. This method includes generating a series of digital signals cycling among one or more repetitions of a low value, one rising intermediate value, one or more repetitions of a high value, and one falling intermediate value. The rising intermediate value and the falling intermediate value may be full range. That is, they may sometimes or always equal the low value or the high value, depending on the ratio. [0078] The method further includes converting the series of digital signals to an analog signal. The offset is responsive to whether the cycling among values is rising or falling. This binary state could alternatively be expressed in many ways. The analog signal values are filtered to produce a filtered waveform that has periodically space crossing points of the desired frequency. By crossing points, we mean where the signal value moves from one side of a threshold to another. For instance, a threshold may be drawn across the middle of the analog signal, mid-range between the low value and high value of the signal. The crossing point is where the waveform intersects the threshold. The method continues by evaluating the crossing points of the filtered waveform to produce a pulse stream signal. The pulse stream has the desired frequency, responsive to the ratio of the numerator divided by the denominator. [0079] Optionally, the digital to analog conversion may use an offset in a range of analog signal values produced, responsive to whether the cycling is rising or falling. [0080] Aspects of this method embodiment substantially overlap with aspects of the device embodiments above. For instance, the cycling may be deemed to be rising if the generating is low or rising and deemed to be falling if the generating is high or falling. Alternatively, the cycling may be deemed to be rising if the generating is rising or high and falling if the generating is falling or low. The proper combination of successive states into a binary rising-or-falling signal may depend upon the implementation of the digital-to-analog converter. [0081] As in the device embodiment, the filtered waveform of the methods may be a truncated triangular waveform, with peaks and valleys of the waveform truncated when the crossing points of the filtered waveform do not have a period that is an integer multiple of the reference clock period. The filtered waveform may be produced by applying a low pass filter. [0082] An alternate method embodiment also involves digitally synthesizing a pulse stream from a reference clock responsive to a ratio of a numerator and a denominator. This method includes generating a terminal condition signal and a remainder signal iteratively, after numbers of cycles that it would take to reach an overflow condition by repeatedly accumulating the numerator and overflowing an accumulator that has a range from zero to the denominator minus one. The method further includes shifting a state machine between states, responsive to the terminal condition signal. The states include a low-value state, a rising intermediate value state, a high-value state and falling intermediate value state. Transition among the states is circular. The method further includes outputting a value signal and a binary rising-or-falling signal responsive to the states. This includes outputting a low value responsive to the low-value state and outputting a rising intermediate value, during the rising intermediate value state and responsive to the remainder signal. It includes outputting a high value responsive to the high-value state and outputting a falling intermediate value, during the falling intermediate value state, responsive to the remainder signal. The immediately preceding description may be considered an elaboration upon the generating action of the earlier method embodiment. The additional actions of converting, filtering and processing parallel the converting filtering and evaluating actions in the prior embodiment. Optionally, this method further may include converting the value signal and the binary rising-or-falling signal to an analog signal with an offset. The rising-or-falling signal determines whether an offset is applied to the value signal during digital-to-analog conversion. As a further option, the analog signal may be filtered to produce a filtered analog signal and the filtered analog signal processed through a comparator to produce a pulse stream signal. The resulting pulse stream signal has the desired frequency. [0083] A further aspect of this method embodiment is that the numerator may be a fixed integer power of two and the denominator may be selectable to tune the ratio of the numerator and the denominator. [0084] For both this and the prior method embodiment, the terminal condition signal may result from operating a pseudo-random binary sequence shift register with a starting symbol loaded into the shift register responsive to the ratio of the denominator and the numerator. The one cycle variation in the length of the sequence may be responsive to values of successive remainders. The pattern is illustrated in the table above. The period for which the four states are held may be the same in this method embodiment as in the prior one. [0085] It is contemplated that modifications and combinations will occur to those skilled in the art, which modifications and combinations will be within the spirit of the invention and the scope of the following claims.

An opportunity is apparent to develop alternative circuitry. Simplified circuitry without artifacts tied to the clock that drives a digital frequency generator (DFG) is useful in a variety of tunable electronic devices. The present invention relates to digital frequency generation. In particular, it relates to a method and apparatus for the digital generation of a pulse stream having a desired frequency relative to a reference clock signal and the ratio of two integers. The method applies generally to integers whose ratio is not an integer. The DFG as a device can be integrated onto a simple chip, without need for an off-chip filter.

CROSS REFERENCE TO RELATED APPLICATIONS This is a Divisional of pending U.S. Ser. No. 09/115,879 filed Jan. 30, 2001, now allowed, which in turn is a Continued Prosecution Application of U.S. Ser. No. 09/115,879 filed Jul. 15, 1998, now U.S. Pat. Ser. No. 6,296,825. FIELD OF THE INVENTION The present invention concerns a novel polymeric alumino-silicate and a method for preparing it. Polymeric alumino-silicates in a fibrous form are known. A fibrous, tubular crystallized alumino-silicate known as imogolite is present in the impure natural state in volcanic ash and in certain soils. U.S. Pat. Nos. 4,152,404 and 4,252,779 of Farmer describe an inorganic material similar to natural imogolite. This inorganic material is synthesized by causing silica or a soluble silicate to react with an aluminium compound so as to form a complex hydroxyaluminium silicate in aqueous solution with a pH of 3.2-5.5, and then effecting a digestion of this complex at a pH of 3.1-5.0 so as to form a colloidal dispersion of the inorganic material. This inorganic material can be used as a molecular sieve, a catalyst support, a coagulant or an adsorbent. By evaporating the colloidal solution of imogolite on a flat surface, it is possible to form films which can be used as membranes. If the material is not isolated from its colloidal solution, it can be used as a flocculant, a substance for promoting hydrophilicity or a thickening agent. European Patent 0 250 154 describes a photographic product, comprising a polymer surface on which a layer comprising a gelled lattice of inorganic particles, preferably oxide particles, has been caused to adhere. According to this patent, the gelled lattice forms a porous layer with voids between the inorganic oxide particles. This porous layer is obtained from a dispersion or suspension of finely divided particles in a liquid medium. The oxide particles can be boehmite (aluminium oxide), silica or a silica gel coated with alumina. This gelled lattice is formed by the aggregation of colloidal particles bonded together in order to form a porous three dimensional lattice. This gelled lattice provides a substratum endowed with antistatic properties. European Patent Application 0 741 668 describes a homogeneous polymeric alumino-silicate having antistatic properties, as well as a method for obtaining this alumino-silicate with a high degree of purity. According to European Patent Application 0 741 668, the method for obtaining the polymeric alumino-silicate comprises: (a) the treatment of a mixed aluminium and silicon alkoxide with an aqueous alkali at a pH in the range of 4 to 6.5, maintaining the Al molar concentration between 5×10 −4 and 10 −2 M and the Al/Si molar ratio between 1 and 3; (b) the heating of the mixture obtained from step (a) to a temperature below 100° C. in the presence of silanol groups, for a sufficient period for obtaining a complete reaction and the formation of an inorganic polymer, and (c) the elimination of the residual ions from the reaction medium. The inorganic polymer is a fibrous alumino-silicate of formula AlxSiyOz where x is in the range of from 1 to 3 and z is in the range of from 1 to 10. The object of the present invention is a polymeric alumino silicate, derived from the polymeric alumino-silicate of aforementioned Patent Application 0 741 668, and a method for obtaining this derived material. The material of the invention is a polymeric alumino-silicate material of formula AlxSiyOz, in which x:y is a number from 1 to 3 and z is a number from 1 to 10, this material being substantially comprised of spindles with a length L of between 10 and 100 μm, a maximum width 1 of between 2 and 20 μm, the ratio L:1 being a number from 3 to 10. Preferably, x:y is a number from 1.5 to 2.5, z a number from 2 to 6, L is between 20 and 80 μm and 1 is between 5 and 15 μm. The terms “substantially comprised” mean that the material comprises at least 95 weight % and preferably at least 99 weight % of said alumino silicate spindles, based in the total weight of the material. The method for obtaining the material of the invention comprises the steps of: (a) treating a mixture of an aluminium compound and a silicon compound, both hydrolysable, or a hydrolysable mixed compound of aluminium and silicon, by an aqueous alkali, at a pH in the range of 4 to 6.5, maintaining the Al concentration between 5×10 −4 M and 10 −2 M and the Al:Si molar ratio between 1 and 3; (b) heating the mixture obtained from (a) at a temperature below 100° C. in the presence of silanol groups, for a period sufficient for obtaining, by means of a complete reaction, the formation of a polymeric alumino-silicate in solution; (c) concentrating the solution obtained from (b) so as to obtain an Al+Si concentration of at least approximately 1.5 g/l, (d) settling the concentrated solution obtained from step (c) to produce 2 phases, and collecting the upper (less dense) phase, which represents at least 90% and preferably at least 95% by weight polymeric alumino-silicate with a spindle morphology. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a device for obtaining the material of the invention. FIGS. 2-3 depict electron microscopy photographs showing the structure of the material of the invention, and FIG. 4 shows the difference in viscosity between the two materials (bunches versus fibres). DETAILED DESCRIPTION OF THE INVENTION The steps (a) and (b) of the method are identical to those described in the aforementioned European Patent Application 0 741 668. The product obtained at the end of step (d) can then be concentrated further in order to be transformed into a gel, which can itself be freeze-dried, in the form of a dry powder. This powder can be put back in solution and, in this case, the material put back in solution still has a spindle morphology. It is also possible, after step (d), to eliminate the ions and the small molecules present in the concentrated solution and, essentially from the alkali used. This elimination can be carried out by dialysis. The novel material according to the invention is in the form of spindles. This morphology can be revealed by optical microscopy or atomic force microscopy (AFM), as the photographs in FIGS. 2-3 show. The method of the invention provides, as indicated, a so-called “upper” phase, consisting of the polymeric alumino-silicate in spindle form and a so-called “lower” phase, which consists of the fibrous polymeric alumino-silicate described in the aforementioned European Patent Application 0 741 668. These two materials have the same basic formula AlxSiyOz indicated above, confirmed by the same Raman spectrum, and are distinguished from each other by various characteristics such as the viscosity or wetting angle, as shown by the following examples. According to one embodiment, the solution obtained at b) is concentrated by ultrafiltration on a membrane. The solution obtained at (b) has a polymeric alumino-silicate (Al+Si) concentration which is generally below 0.5 g/l. It is necessary to concentrate it so that the alumino-silicate content is greater than 1.5 g/l and preferably greater than 1.7 g/l. It is possible to use either a tangential ultrafiltration module in which the solution is pumped at high speed along the membrane, or a frontal ultrafiltration module in which the solution is pumped, at a greater pressure, perpendicular to the membrane. The ultrafiltration membranes which can be used for this purpose are for example cellulosic membranes such as the 10 KD membrane sold by AMICON, polyethersulphur membranes such as the membrane 100 KD sold by MILLIPORE, or polyacrylonitrile membranes. According to another embodiment, the solution obtained at the end of the above step (b) can be concentrated by distillation. A preferred embodiment consists of concentrating the solution obtained at step (b) by tangential ultrafiltration on a cellulosic membrane. Such an embodiment is depicted schematically in FIG. 1 . According to this diagram, the solution 10 coming from step (b) is sent by pumping (pumping unit 12 with pump 13 and flowmeter) into an ultrafiltration module 14 fitted with a spiral membrane. The permeate is discharged through the pipe 15 and the enriched retentate of the desired phase of the alumino-silicate is sent at 10 through the duct 16 . The inlet pressure is between 0.5 and 5.0 bars and the concentration factor is between 30 and 60%, advantageously around 40%. EXAMPLE 1 A solution of 5 liters of AlCl 3 , 6H2O (7.3 g/l) and a solution of 5 l of Si(OCH 3 ) 4 (2.56 g/l) in osmosed water were prepared. These solutions were mixed and 370 ml of NaOH 1M were added dropwise. The mixture was kept overnight under stirring. The pH was adjusted to 6.8 with NaOH and a gel was obtained. This gel was diluted in 5 l of osmosed water, acidified by 25 ml of a mixture of HCl 1M and CH 3 CO 2 H 2M. This mixture was stirred until a transparent solution was obtained. The transparent solution was diluted with 11 liters of osmosed water, and then heated at 96° C. for 5 days in the presence of finely divided silica. A solution of 0.3 g/l of polymeric alumino-silicate was obtained. Using a tangential ultrafiltration module as depicted in FIG. 1, the polymeric alumino-silicate solution was concentrated. The ultrafiltration module 14 comprised a regenerated cellulose wound membrane 10 KD sold by AMICON. Ultrafiltration was carried out at a pressure of 0.7 bar. After concentration, the retentate comprised 4.4 g/l of alumino-silicate. After this retentate was allowed to stand overnight, two separate phases were formed. The less dense upper phase was separated from the lower phase. Characterisation of the two phases gave the following results: Refrac- Resistivity Al:Si Al:Si tion Water Decane G ICP TEM index adhesion adhesion ohm/m 2 Upper phase 1.93 2.11 1.335 yes yes 3 containing spindles (invention) Fibrous 2.01 2.14 1.335 no yes 11 lower phase A sample of ESTAR® polyester film support was coated at 100 mg/m 2 , with each of the two phases and then examined under optical microscopy and AFM. Under AFM (Atomic Force Microscopy) microscopy, a fine tip took a reading on the surface of the material by contact. A relief image of the deposition of polymeric alumino-silicate was obtained. The optical and AFM microscopy photographs obtained are shown respectively in FIGS. 2-3. The Al:Si ratio was measured both by atomic emission spectroscopy with inductive coupling plasma (ICP) and by EDX spectrometry. The water/decane adhesion was evaluated by coating an ESTAR® polyethylene terephthalte support film with a layer of the concentrated solution and then by spraying water or decane onto the coated support. The resistivity was measured as follows: calibrated strips (2.7 cm×3.5 cm) of ESTAR support were produced, coated with the concentrated solution at 100 mg/m 2 ; these calibrated strips were placed on electrodes between which a voltage was established whilst maintaining constant humidity and temperature (HR 30%−23° C.). The viscosity was also measured on a CONTRAVES 115 flowmeter as a function of the stresses applied. The speed of flow curves depicted in FIG. 4, for the solutions of alumino-silicate in spindle form and alumino-silicate in fibrous form, showed that the spindle phase had a viscosity greater than the fibrous phase. Given its resistivity, wettability and viscosity, the solution of polymeric alumino-silicate in spindle form can be used for antistatic layers intended for example for photographic materials. The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

An inorganic polymeric aluminosilicate material and a method for preparing the same, are disclosed. Instead of having a fibrous structure, the material has a structure consisting of spindles with a length in the range of from 10 to 100 μm and a width in the range of from 2 to 20 μm. This polymeric alumino-silicate can be used for the production of antistatic layers.

CROSS REFERENCE TO RELATED APPLICATION This application is a continuation of Ser. No. 13/182,575, filed Jul. 14, 2011, which is a continuation-in-part of Ser. No. 11/294,942, filed Dec. 6, 2005 (now U.S. Pat. No. 7,980,856, dated Jul. 19, 2011) which is related to and claims priority from earlier filed provisional patent application Ser. No. 60/675,768, filed Apr. 28, 2005, all of which is incorporated herein by reference. BACKGROUND OF THE INVENTION The present invention generally relates to the human performance, sports medicine and medical rehabilitation field. More specifically, the present invention relates to a method for fall prevention training using a dynamic perturbation platform to improve the study and research of the biomechanics of trip, slip, and laterally-directed postural disturbances by a person and the step recovery thereof. Additionally, the present invention relates to human performance, injury prevention and neuromuscular training using a dynamic perturbation platform to train step responses to anterior, posterior or laterally-directed postural perturbations. Additionally, the present invention relates to neuromuscular training around any body joint response to dynamic perturbations of the body joint or multiple body joints. It is well known in the medical field that a slip or trip during walking or standing can lead to a fall and be a serious cause of injury. This is particularly problematic for elderly people where such injuries are a leading cause of mortality. It is well known that many of these injuries can be prevented or their severity lessened if the person uses an effective strategy and technique for responding to a fall situation. Therapeutic Interventions can reduce the likelihood of a fall from a disturbance event, such as a trip or slip incident. Exercise and physical training can be used to develop strength, balance and coordination. Also, the person's environment can be changed to remove obstacles and other hazards that can cause a slip or trip. Bars and hand rails can be provided to assist walking and standing. Padded garments can be worn by the person to reduce the injury caused by the slip or fall. An alternative approach is to study why a person falls and train them to better recover from a slip or trip to avoid a fall by taking a corrective step response. Therefore, the biomechanics of a slip or fall can be studied to better understand clinically effective ways to prevent such falls due to a slip or trip. As part of the study and analysis of disturbance events, including slip and trip incidents, it is highly desirable to be able to monitor a slip or fall incident in a controlled environment to produce data that is usable for effective training to help persons adapt their strategy for responding to a slip or trip incident. It is also well known in the medical field that dynamic stability of a body joint is important for injury prevention. The ligaments and tendons and musculature that cross body joints prevent excessive motion of the joint that leads to injury of the structures both within and surrounding the joint. The benefits of neuromuscular training are known to provide increased endurance, positional awareness, performance and reduction in injury risk. Specifically with respect to the knee, neuromuscular training also increases dynamic knee stiffness, dynamic knee stability, and athlete agility. Human locomotion uses sensory information and motor reflex to modulate pre-programmed motor control patterns in order to adapt to unexpected changes in the external environment. Proprioceptive information is used to maintain postural and joint stability. In human locomotion there are major kinematic events where joint stability might be needed most. These events differ for walking and running. All around the body, joint stability is attributed to joint stiffness that occurs with co-contraction of antagonistic muscles around a joint. Increased joint stiffness is believed to resist sudden joint displacements more effectively reducing the incidence of joint subluxation. More specifically, it is well known in the medical field that ligament and other soft tissue injuries are a significant problem among people who engage in cutting, jumping, and pivoting activities, particularly young athletes and women. One ligament that is often injured, for example, is the anterior cruciate ligament (ACL) in the knee. For ACL injured athletes, neuromuscular training has improved functional outcome and increased likelihood of return to previous activity levels with decreased likelihood of knee giving way episodes. Similar effects and results can occur following soft tissue injuries to other structures and joints in the body, and are not limited to the ACL. Following ACL or other soft tissue injury, both surgical and non-surgical treatment options exist, with the ultimate goal of regaining dynamic joint stability, and in the case of the knee joint, normal knee kinematics, and symmetrical quadriceps strength between legs. These outcomes are critical for full return of dynamic knee function and returning to pre-injury activity levels, as well as for preventing additional injury to the cartilage and the meniscus in the knee which might lead to an increased likelihood of osteoarthritis (OA). Laboratory research has demonstrated clinically relevant effects of perturbation of support surface training for both ACL-deficient (ACL-D) and ACL-reconstructed (ACL-R) populations, particularly in females. Currently, perturbation training systems and methods are limited to balance boards that are manually pushed or pulled by physical therapists, and may not simulate real-life or sport-specific perturbations. Specifically, balance boards do not allow for perturbations that occur during an actual step. The manual perturbation method does not allow for repeatable timing of perturbations at specific phases of the gait cycle, nor can the perturbations be delivered in less than 500 ms. ACL injuries are extremely common, with approximately 100,000-250,000 ACL reconstructions being performed annually in the United States. While males comprise a majority of all ACL injuries females are at 3-6× greater risk of suffering an ACL rupture than males. Rehabilitation is time-consuming; time from injury to completing postoperative rehabilitation can range from a few months to a year or more, and surgical intervention does not ensure a return to previous activity levels. At an estimated cost of $17,000 per ACL reconstruction and physical therapy services, expenses for this injury may exceed $1 Billion annually in the United States alone. The ACL plays a principal role in maintaining normal knee function and stability. Quadriceps strength deficits and ACL rupture independently increase the likelihood of developing knee osteoarthritis (OA). ACL injury often leads to knee instability, quadriceps weakness, gait deviations, and post-traumatic OA. Aberrant movement and abnormal muscular strategies are common in the ACL-deficient athlete. Snyder-Mackler and colleagues developed and validated a functional screening examination as a clinical tool to identify those who have the potential to compensate well for the injury (potential-copers). Non-candidates, or non-copers, were classified by their poor functional performance and episodes of knee instability. Recurrent give way episodes of the ACL deficient knee in non-copers are likely due to their inability to stabilize their injured knee with appropriate muscle activity. Rudolph et al. defined the neuromuscular behaviors of ACL deficient athletes, and found an ineffective knee stiffening strategy characteristic of non-copers. Non-copers excessively co-contract their thigh and hamstring muscle and truncate their knee motion which may further exacerbate the alterations in joint loading and cause degenerative changes to the underlying cartilage. Persons who present with a combination of aberrant gait patterns, quadriceps weakness, and knee instability in response to an ACL rupture are at significantly increased risk of developing post-traumatic knee OA. Therefore, the importance of restoring normal gait kinematics and kinetics in this population has been underscored by many research groups. Quadriceps weakness and knee instability can also lead to a knee stiffening strategy in an attempt to improve stability during dynamic activities, such as walking, jogging, stair climbing, and balancing on one limb. This strategy is used predominantly by athletes who are non-copers. Hartigan et al. demonstrated that perturbation training was able to restore symmetric knee excursions in this cohort, something that was not achieved by strength training alone. Again, this perturbation training was performed manually. Clinical rehabilitation paradigms for non-operative treatment and post-operative rehabilitation following ACL rupture focus on reducing joint effusion, increasing knee range of motion, increasing quadriceps and hamstring muscle strength, functional activity education and training, agility training, and protective bracing. However, these approaches may only be successful for patients that are more sedentary or are willing to modify their physical activity levels. Common clinical techniques used during rehabilitation after ACL reconstruction are often limited to strength training, task-specific exercises, and static balance exercises. For athletes, proper coordination of muscle activity is also critical for improving dynamic knee stability and ultimately, sport performance. After ACL injury, the quadriceps and hamstrings have diminished ability to dynamically stabilize the knee due to disruption of the mechanoreceptors in and around the knee joint. Task-specific manual perturbation training has been shown to enhance the restoration of dynamic stability in ACL deficient patients. Factors that are modulated during perturbation training include predictability, speed, direction, amplitude, and intensity of the perturbation. Snyder-Mackler and colleagues combine progressively challenging manual perturbation training together with sport-specific task training in order to achieve improvements in dynamic knee stability. Snyder-Mackler and other researchers published the results of their studies and have demonstrated the following: Superior return to functional activity in potential copers when compared to standard rehab programs (e.g. strength training). 93% of patients using manual perturbation training returned to high-level activity without episodes of giving way. In contrast, only 50% of those who received traditional therapy returned to high-level activity. Patients undergoing perturbation training increased their likelihood of success (i.e. no episodes of knee giving way) by 4.9× when compared to standard treatments, including strength and agility training. Improved dynamic knee stability in ACL deficient patients through improved neuromuscular changes. Increased Lysholm Knee Rating Scale scores compared to subjects who received standard strength training rehabilitation. Normal quadriceps and hamstring activations and increased active stiffness. These changes may prophylactically reduce the risk of biomechanical strain injury in high-risk populations. Manual perturbation training significantly improved lower leg dynamic muscle control in healthy young athletes. Young women responded favorably to perturbation training by mitigating their quadriceps dominance and activating their hamstrings earlier in stance, thus restoring healthier muscle activation patterns. Manual perturbation training in conjunction with strength training improved dynamic knee stability, knee range of motion during midstance, and limb symmetry compared to strength training alone. While manual perturbation paradigms are effective at resolving aberrant neuromuscular strategies in ACL-deficient individuals, the time required to administer the treatment may not allow the therapist time to address other patient impairments. Manual perturbation training does not address the idea of providing the perturbation during the walking cycle or while running. Additionally, manual perturbation training may not allow for timed perturbations at specific phases of the gait cycle, or at specific joint positions, velocities or joint forces. Manual perturbation do not allow for timed and controlled perturbations at specific velocities of a given joint. Conversely, the present invention overcomes the limitations of manual perturbation methods. In the present invention, perturbations can be triggered manually, or, when desired, on a timed basis or other pre-set schedule. The timing of perturbations can be based on intrinsic physiologic factors, such as phase of the gait cycle, position, velocity or acceleration of a limb or joint. The timing of perturbations based on specific phases of gait, perturbation and automatic speed adjustments can be based on the timing and phasing of braking and propulsion of the limb being monitored. Additionally, the timing of perturbations can be based on extrinsic factors. There exists relationships among neuromuscular timing and external cues or triggers. Existing systems such as Nike+, a product of Nike, Inc., modify target exercise parameters based on music selected. Alternatively, it is possible to modulate the speed, pitch, volume, beat, and other rhythmic patterns of music played or presented to a user as a function of the exercise being performed or prescribed. In a similar fashion, visual stimuli such as video presentations or tactile stimuli or other external stimuli can be used in either an excitatory or feedback mode in conjunction with neuromuscular training. Such interactions between external stimuli and neuromuscular training specifically are lacking in the prior art. The present invention can be used to address and prevent a wide range of joint related diseases and injuries, such as but not limited to osteoarthritis and ankle sprains. The present invention is not limited to preventing joint-related diseases and injuries in the lower extremity. There is a also a need to be able to provide controlled perturbations to portions of the body other than those in the lower extremity. For example, there is a need to be able to deliver controlled perturbations to areas of the upper body, such as the elbow, wrist or shoulder for the prevention of disease and injury to those regions. In view of the foregoing, there is a need for a system that can accurately simulate a slip or tripping incident. There is a need for a system that can measure the biomechanics of a slip or tripping incident to further assist a person to better respond to the incident to avoid a fall. There is a further need for an apparatus that is well-suited to measure such biomechanics. There is a need for an apparatus that can simulate various trip and slip scenarios that could lead to a fall so an appropriate response can be developed. There is a need for an apparatus and system that can better train a person to avoid a fall following a trip or slip incident. Moreover, there is a need for a method for fall prevention training to better prepare a person for a disturbance event, including, a slip, trip or fall, to avoid injury or death. In view of the foregoing, there is a need for a system that can provide task-specific, neuromuscular, dynamic perturbation training to prevent injury to the soft tissues surrounding body joints There is a need for a system that provides perturbations that induce joint instability that requires a neuromuscular response to retain, maintain or retrain intrinsic body joint stabilization There is a need for a system that provides task-specific, neuromuscular, dynamic perturbation training to prevent the development and progression of osteoarthritis and other joint-related diseases. There is a need for a system to provide perturbations during the stance phase of the gait cycle during locomotion. There is a need for a system to provide perturbations during the different phases of stance in the gait cycle to elicit a specific joint response. There is a need for a system to provide perturbations that are controlled and triggered by detecting the braking, midstance and propulsion phases of control for a given joint. There is a need for a system to provide perturbations to a joint at a preferred kinematic position, velocity, or loading condition to elicit and train a specific joint response. There is a need for a system to provide modulation of the stretch reflex to prevent ankle sprains. There is a need for a system that detects the different phases of the gait cycle, including but not limited to the stance phase, which also includes the braking, midstance, and propulsion phase, and which provides a trigger for delivering the perturbation. There is a need for a system that provides aperiodic perturbations to challenge and train the joint response to perturbations that occur during daily living or during sporting activity. There is a need for a system to provide perturbations during athlete training or physical therapy where the perturbations are delivered automatically, and in some cases repeatedly, without any manual intervention from another individual or medical provider. There is a need for a system that can provide controlled perturbations to any part of the body, including the elbow, wrist and shoulder to help train response to such perturbations and prevent disease and injury to those regions. There is a need for a system that can deliver perturbations very quickly and in an automated and controlled fashion to any part, portion or region of the body. There is a need for a system to provide perturbations during the stance phase of the gait cycle that are synchronized with musical cues and other external stimuli. There is a further need for a system to provide perturbations of varying magnitude, direction and duration that are generated automatically based on the timing of music driving the system. There is a need for a system that selects music to be presented to a user based on the perturbation profile selected for a given neuromuscular training activity There is a need for a system to provide perturbations that stimulates and trains braking and propulsion control for the joint. SUMMARY OF THE INVENTION The present invention preserves the advantages of prior art fall prevention training systems and methods associated therewith. In addition, it provides new advantages not found in currently available fall prevention training systems and methods and overcomes many disadvantages of such currently available systems and methods. In addition, it provides new advantages not found in current injury prevention and neuromuscular training systems and methods and overcomes many disadvantages of such currently available systems and methods. In accordance with the present invention, a new apparatus and system is provided that studies and analyzes the biomechanics of a disturbance event, such as a slip or trip incident or other disturbance to a part of the body, so that an appropriate response can be executed by the person to reduce or eliminate the number of falls or injury to the body part experienced both in real life and in the simulation/disturbance event. With this new apparatus, system and method, a new and novel method for fall and injury prevention training can be delivered which is superior to training methods known in the prior art. The present invention uses a new and unique disturbance event simulation apparatus. The apparatus, in accordance with the present invention, may be in the form of a perturbation platform is provided which is movable to create a disturbance event that induces a response from an individual. Sensors are located proximate to the individual and the platform with data being outputted from the sensors. A device is provided for collecting and storing the data during the disturbance event. There is also a device for outputting the data so that it may be viewed and studied. The apparatus may also be a device, such as one that is mounted to a wall, that delivers a perturbation to a part of the person's body, such as a wrist, elbow and shoulder. Preferably, the perturbation device, such as a platform, is movable to create the disturbance event in less than 500 ms and more preferably in the range of about 100 ms to about 200 ms. In the platform example, it is also preferably a bi-directional motorized belt. Still further, two bi-directional belts can be provided in this embodiment. Also, the apparatus is capable of introducing an obstacle positioned proximate to the platform to induce the response from the individual to the disturbance event. The obstacle, for example, can be a light beam, a three-dimensional object or a hologram. In accordance with the present invention regarding delivering a disturbance event to a person in a walking gait, an embodiment in provided with a new apparatus and method that monitors the phase of the gait cycle for an individual standing or ambulating on the apparatus and which actuates the biomechanics of a disturbance event, so that an appropriate response can be executed by the person to improve measurable quantities such as dynamic stability or improved neuromuscular response that have been linked to ACL injury, OA, and joint instabilities. With this new apparatus, system and method, a new and novel method for dynamic neuromuscular training can be delivered which is superior to training methods known in the prior art. The current invention improves on the existing systems by delivering systematic, progressive perturbations while, if desired, simultaneously recording relevant training data. The perturbations may be timed to events in the gait cycle, such as but not limited to heelstrike or toeoff. The perturbations may be programmed to occur on every occurrence of such a gait cycle event, or at multiples of such a gait cycle event, or at a random number of occurrences of such a gait cycle event, Additionally, the perturbations may occur randomly but not during a specific gait cycle event. The current invention provides a system for perturbations that induce joint instability in one or more body joints, individually or simultaneously, and not limited to lower extremity. This can include the spine. When the perturbation is provided to the lower extremity, the timing of the perturbation within the gait cycle at which the perturbation is induced and the magnitude of the perturbation may affect body joints in different ways, including both the magnitude and activation patterns of the musculature around the joints, and subsequently the response of the body, such as ankle flexion, knee flexion, hip flexion, trunk flexion, or a step response. The present invention can also be modified to address joints that are not in the lower extremity or associated directly with walking and fall prevention. The present invention is envisioned to include an embodiment where a perturbation device is provided, such as mounted to a wall for example, that delivers a perturbation to a part of the body that is not in the lower extremity, such as the wrist, elbow or shoulder. The person may reach out and grasp a handle and perform a certain exercise or movement. Then, at a desired point or points during the motion, a perturbation is delivered in less than 500 ms to the joint involved in the exercise for recordal of results for subsequent training purposes. This unique apparatus can be employed to carry out the new and novel method of disturbance event training of the present invention, which includes fall prevention and other joint movement training. For the fall prevention training aspect of the present invention, it is preferred that the following steps are provided as part of a unique protocol, however, less than all of the steps may be employed and still be within the scope of the present invention. Using the platform of the present invention, from a stop, a sequence of disturbance events are produced with incrementally increasing perturbation distance that establishes a first threshold of that individual's “foot in place” response and not a step response. Next, from a stop, a sequence of disturbance events are produced with incrementally increasing perturbation distance that establishes a second threshold beyond which the individual can not execute a single step response. Next, a first obstacle, having a first obstacle height, is placed proximate to the platform at a first obstacle distance to induce the step response of the individual to the disturbance event. From a stop, a sequence of disturbance events are produced with incrementally increasing perturbation distance that establishes a third threshold beyond which the individual can not execute a single step response while attempting to negotiate the obstacle. Further, from a stop, a sequence of the combination of a disturbance event with incrementally increasing perturbation distance are produced followed by a continuous platform motion simulating walking velocity that establishes a fourth threshold beyond which the individual can not achieve a stable gait response. Next, from a stop, a stable gait response is sought from the individual. If they are able to achieve a stable gait within a predetermined number of steps, the trial is considered successful. If the individual requires more than the predetermined number of steps to achieve stable gait or if the individual falls, the change in velocity is repeated. Trials are be repeated within a session or across sessions until the variability in step response following a given perturbation displacement and profile are below a target value. Next, a second obstacle, having a second obstacle height, is placed proximate to the platform at a second obstacle distance to induce the step response of the individual to the disturbance event. From a stop, a sequence of a combination of a disturbance event with incrementally increasing perturbation distance is produced followed by a continuous platform motion simulating walking velocity that establishes a fifth threshold beyond which the individual can not achieve a stable gait response. Further, from a first walking velocity created by a continuous platform motion, a sequence of the combination of a disturbance event with incrementally increasing perturbation distance is produced followed by a continuous platform motion returning to the first walking velocity that establishes a sixth threshold beyond which the individual can not achieve a stable gait response. Next, the individual starts at an initial steady state locomotion velocity with a large disturbance introduced at a random time. The disturbance causes the platform to accelerate to a prescribed disturbance velocity before returning to a second steady state locomotion velocity. The maximum time for this change in the platform velocity is less than about 500 ms, and is more typically in the range of about 100 to about 200 ms. A stable gait response is sought from the individual. Finally, a third obstacle, having a third obstacle height, is placed proximate to the platform at a third obstacle distance to induce the step response of the individual to the disturbance event. From a second walking velocity created by a continuous platform motion, a sequence of the combination of a disturbance event with incrementally increasing perturbation distance is produced followed by a continuous platform motion returning to the second walking velocity that establishes a seventh threshold beyond which the individual can not achieve a stable gait response. It is therefore an object of the present invention to provide a new and novel apparatus for use with fall prevention training that more accurately simulates a disturbance event, such as a slip or trip incident, more closely than prior art apparatus. It is another object of the present invention to provide an apparatus and system that can measure the biomechanics of a disturbance event to further assist a person to better respond to the incident to avoid a fall. Another object of the invention is to provide an apparatus that is well-suited to measure such biomechanics. An object of the invention is to provide an apparatus that can simulate various disturbance events that could lead to a fall so an appropriate response can be developed. A further object of the present invention is to provide a new and novel method for fall prevention training that train a person to avoid a fall when encountered with a disturbance event. Another object of the present invention is to provide a method for fall prevention training that better prepares an individual for a disturbance event to avoid injury or death. Yet another object of the present invention is to provide a method for fall prevention training that has a protocol that effectively trains the individual while isolating the weaknesses of the individual. An object of the current invention is to provide task-specific, neuromuscular, dynamic perturbation training to prevent injury to the anterior cruciate ligament (ACL) and other soft tissues in the joints of the lower limb and to improve outcomes for athletes who sustain these injuries, either with or without subsequent surgery to repair or replace the injured ligament or ligaments. Previous research has demonstrated that manual perturbation training has been shown to improve outcomes for both ACL-deficient (ACL-D) and ACL-reconstructed (ACL-R) populations compared to the strength training alone. An object of the current invention is to provide perturbations that induce joint instability that requires a neuromuscular response to retain and maintain balance, joint stability, and joint response time to disturbances The joint instability can occur at a single joint, simultaneously at multiple joints throughout the body, or at time-delayed periods at different joints. The instability requires a response, such as a step response or other, anything from the movement of one or more joints to actually physically changing the body's base of support (moving the foot or feet) to maintain balance. The joint(s) affected by the perturbation are a function of the timing in the gait cycle, the body position and body motion (e.g. defined as the motion of the center of mass, or the motion of independent limbs, and the like) at the time of the perturbation, and the magnitude of the perturbation delivered. Any joint in the body can be affected by this. An object of the current invention is to provide perturbations that induce joint instability that requires a neuromuscular response to retain and maintain balance, joint stability, and joint response time to disturbances The joint instability can occur at a single joint, simultaneously at multiple joints throughout the body, or at time-delayed periods at different joints. The instability requires a response, such as a step response or other, anything from the movement of one or more joints to actually physically changing the body's base of support (moving the foot or feet) to maintain balance. The joint(s) affected by the perturbation are a function of the timing in the gait cycle, the body position and body motion (e.g. defined as the motion of the center of mass, or the motion of independent limbs, and the like) at the time of the perturbation, and the magnitude of the perturbation delivered. Any joint in the body can be affected by this. Perturbations can be delivered to any joint in the body, whether or not it is in the lower or upper extremity of the body and whether or not the joint is associated with the act of walking. Another object of the current invention is to provide task-specific, neuromuscular, dynamic perturbation training to prevent the development and progression of osteoarthritis. Another object of the current invention is to provide perturbations, such as those that are continuous or periodic or aperiodic, during the different phases of stance of the gait cycle. Another object of the current invention is to provide perturbations, such as those that are continuous or periodic or aperiodic, during each stance phase of the gait cycle. Another object of the current invention is to provide modulation of the stretch reflex to prevent ankle sprains. Another object of the current invention is to provide perturbations during the athlete training or physical therapy where the perturbations are delivered automatically without any manual intervention from another individual or medical provider. Another object of the current invention is to provide perturbations during the stance phase of the gait cycle that are synchronized with musical cues or other external stimuli, including but not limited to visual, auditory and tactile stimuli. A further object of the present invention is to provide perturbations to any joint of the body to help prevent disease and injury thereto. Another object of the current invention is to provide perturbations of varying magnitude, direction and duration that are generated automatically based on the timing of music driving the system. Another object of the current invention is to provide selection of music or other external cues to be presented to a user based on the perturbation profile selected for a given neuromuscular training activity Another object of the current invention is to provide perturbations that are based on the timing of braking and propulsions of a joint. BRIEF DESCRIPTION OF THE DRAWINGS The novel features which are characteristic of the present invention are set forth in the appended claims. However, the invention's preferred embodiments, together with further objects and attendant advantages, will be best understood by reference to the following detailed description taken in connection with the accompanying drawings in which: FIG. 1 is a perspective view of the apparatus of the present invention; FIG. 2 is a close-up perspective view of the apparatus of the present invention equipped with a physical obstacle; FIG. 3 is a close-up perspective view of the apparatus of the present invention equipped with a virtual obstacle in the form of a laser beam; FIG. 4 is a close-up perspective view of the apparatus of the present invention equipped with a virtual obstacle in the form of a hologram; FIG. 5 is a top plan view of an inertial sensor used in the present invention; FIG. 6 is a graph showing speed against time for executing a standing and walking perturbation in accordance with the present invention; FIG. 7 is a graph showing the increase in recovery percentage in individuals over time as a result of fall prevention training; FIG. 8 is a flow chart illustrating the execution of Stage 1 of the method of the present invention; FIG. 9 is a flow chart illustrating the execution of Stage 2 of the method of the present invention; FIG. 10 is a flow chart illustrating the execution of Stage 3 of the method of the present invention; FIG. 11 is a flow chart illustrating the execution of Stage 4 of the method of the present invention; FIG. 12 is a flow chart illustrating the execution of Stage 5 of the method of the present invention; FIG. 13 is a flow chart illustrating the execution of Stage 6 of the method of the present invention; FIG. 14 is a flow chart illustrating the execution of Stage 7 of the method of the present invention; FIG. 15A is an exploded front view of a lateral deck to provide lateral perturbations controlled by a DC rack-and-pinion drive centered under the deck and slides on a low friction polymer surface that is fixed to an aluminum sub-frame; FIG. 15B is perspective view of a lateral deck shown in FIG. 15A with the sub-frame; FIG. 15C is a perspective view of a motor transmission that is inline with the MR clutch and drive roller; FIG. 16 is a graphical representation of an algorithm according to the present invention that performs real-time event (e.g. heelstrike or toe-off) detection based on motor current; FIG. 17 is a flowchart illustrating a process for detecting gait phase, such as heel strike and toe off, in accordance with the present invention; FIGS. 18A-F illustrate various graphs of data collected for a one step cycle in accordance with the gait phase detection process in accordance with the present invention; FIGS. 19A-D illustrate various graphs of multi-step data relating to operation of the motor of a perturbation platform in accordance with the present invention; FIG. 20 is a flowchart illustrating the interrelation of the components used for delivering and controlling perturbations in accordance with the present invention; FIG. 21 illustrates the effects of delivering perturbations forces at different phases of the gait cycle such as heelstrike and midstance, resulting in different kinetic and kinematic responses. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention includes a unique method that enables individuals, particularly older adults, to rapidly learn how to modify motor performance and improve recovery rates after being subjected to a disturbance event or perturbation that required a response, such as a step response. The method of the present invention achieves a reduction in the probably of falling by repeated exposure to a realistic disturbance event which serves as targeted and effective motor skill training. As seen in FIG. 7 , the recovery percentage increases exponentially over time when they are subjected to trials of fall prevention training. Thus, the method of the present invention provides an invaluable rehabilitation tool for an individual for training how to recover from a large disturbance event, such as a large postural perturbation. To carry out this method, the present invention employs a cost-effective apparatus that can be widely used to reduce the incidence of falling. The present invention includes a new and novel apparatus and a method which can use that apparatus for fall prevention training. It should be understood that it is preferred that the apparatus of the present invention be used to carry out the method of the present invention. However, the method of the present invention can be carried out by a many different types of training apparatus and still be within the scope of the present invention. The preferred embodiment of the apparatus in accordance with the present invention is set forth in detail below in connection with FIGS. 1-6 . Referring first to FIG. 1 , an apparatus 10 for use in carrying out the method of the present invention is provided. Preferably, the apparatus 10 is in the form of a force-treadmill perturbation treadmill 12 , as shown in FIG. 1 , for use in identifying individual risk factors for falling in an individual 14 . The following details of the apparatus 10 are preferred to carry out the method. However, it should be understood that many other different types of apparatus 10 can be employed and the components therein can be modified to suit the application at hand. All of these modifications are deemed to be within the scope of the present invention. The treadmill 12 includes a left belt 16 and a right belt 18 , which are both preferably bi-directional for maximum control and timing of belt position, velocity and acceleration. For example, each belt 16 , 18 preferably has bi-directional displacement control for large perturbations from 6 mm (0.25 in) to infinity (continuous operation) with minimum 6 mm (0.25 in) resolution. The belts 16 , 18 also have bi-directional velocity control from 0-4 m/s (˜9 mph) and bi-directional acceleration control from 0-6 m/s 2 . The belts 16 , 18 are critically tuned to avoid oscillations. As far as preferred dimensions, each belt 16 , 18 is approximately 250 mm (˜10 in) wide with a platform length of approximately 1.6 m (5 ft). It is also possible that a single belt (not shown) may be used instead of the dual belts 16 , 18 shown in FIG. 1 . The apparatus 10 also includes a motor and drive system 20 . A high torque direct drive motor is preferred although other drive systems 20 may be used. Motors for driving belts are well known in the art and need not be discussed further therein. Most importantly, the apparatus 10 is configured to create the disturbance event in less than 500 ms. More preferably, the disturbance event is created in the range of about 100 to about 200 ms. The creation of the disturbance event, such a movement of a belt 16 or 18 , at such a fast speed is not found in the prior art. The relatively short duration of the disturbance event is used so that it simulates a real disturbance event to trigger a more accurate response from the individual 14 . FIG. 6 is a graph of the speed of a belt 16 , 18 against time to illustrate the unique fast creation of a disturbance event. Line 62 represents the speed of creation of a disturbance event for a standing perturbation where the individual 14 is standing still and belts 16 , 18 are ramped up to a 2 MPH speed in the range of about 100 to about 200 ms. Similarly, line 64 Line 64 represents the speed of creation of a disturbance event for a walking perturbation where the individual 14 is walking at about 2 MPH and belts 16 , 18 are accelerated over 4 MPH in the range of about 100 to about 200 ms. Further, multi-axis load transducers 22 , such as low-profile multi-axis load cells with desired range, accuracy, and sensitivity, which support the platform, generally referred to as 24 of treadmill 12 , and drums 26 of the treadmill apparatus 12 . The pressure applied by an individual 14 to the bed of the platform 24 can be measured with such pressure transducers 22 . The apparatus 10 of the present invention also includes a number of sensors 28 that are attached the individual 14 that is being trained and optionally at various locations on the apparatus 10 itself. For example, inertial sensors 28 , which are well known in the art, can be placed on various parts of the body of the individual 14 to sense position and velocity. An example of a prior art inertial sensor 28 is shown in FIG. 5 with circuit board 29 and electrical lead 31 . As a further example, an inertial sensor 28 can be positioned on the trunk of the individual 14 to sense trunk angle and velocity, which are important factors to be studied in connection with fall prevention training. While sensors 28 are preferred, other ways to measure body location can be used, such as video analysis of body movement. Sensors located between the underside of the belts and the deck of the apparatus sense the location of the subject's foot as it contacts the platform. This plurality of sensors is preferably in an array with a sensing element every 1 cm in both the length and width direction of the apparatus. In the preferred embodiment, these sensing elements are made, for example, from a thin pressure sensitive material and are contact sensors whose electrical output is triggered when foot contact pressure to the sensor through the belt exceeds a certain pre-determined level. While this array of thin contact sensing elements is the preferred embodiment, these sensing elements could also produce a voltage whose output was proportional to applied pressure or force. Also, while thin pressure sensitive material is preferred, any type of sensors, which can be either of the digital ON/OFF or proportional analog, can also be used in accordance with the present invention. The sensors 28 gather data regarding the various parameters that are being monitored. This data is, preferably in real-time, sent to a computer 30 for processing and analysis. The data may be sent to the computer 30 wirelessly or by hard wire. Data transmission and computer processing devices are so well known in the art that they need not be discussed in further detail herein. The apparatus 10 itself preferably includes its own central control unit 32 with the appropriate control algorithm and custom motor control software, which provides bilateral, independent bi-directional real-time biofeedback motor control function. The control algorithm is written as a state machine, and responds according to a lookup-table of inputs to determine the next step. A radio frequency (RF) telemetry console 34 is used for many operational functions of the apparatus 10 , including programming and operation of handrails 36 , safety harness 38 , and emergency stop switch 40 . The control algorithm is preferably written in C using LabWindows CVI software and, where appropriate, native microcontroller firmware language. The key elements of the control system 32 include encoders attached to drive motors provide data for motion control of the platform 24 and PID algorithms for smooth, accurate motion. Also, the control system handles triggering of perturbations at specific times during the walking cycle based on force measurements and monitoring and recording of step recovery response and appropriate state-machine response to inputs. There are also safety interlocks to protect the individual 14 . Thus, the treadmill apparatus 10 of the present invention includes two main components, the perturbation platform (PPU) 24 with force measurement capability, safety harness 38 and handrails 36 as well as a central control unit (CCU) 32 with control algorithms, safety interlocks, data storage and transfer protocols, and user interface. Referring back to FIG. 1 , the treadmill apparatus 10 includes a frame 42 to integrate the platforms on the underside of each transducer and provide rigid attachment points for the mounting of the treadmill 10 to the ground. The frame 42 is designed to minimize any mechanical crosstalk that may be induced by the use of a common frame. The belts 16 , 18 and platforms 44 thereunder are separated by a physical width of 0.125 in. to minimize any influence two separate belts 16 , 18 may have on gait patterns of the individual 14 during walking while preventing any belt overlap that may occur. The apparatus 10 , which includes a motor controller and amplifier with associated electronics within the CCU 32 , is preferably PC based with cabling to the amplifiers to enable a development environment for testing. The apparatus 10 , as seen in FIG. 1 , also includes a harness system 38 that embraces the individual 14 and is suspended from support bar 48 via tether 50 . Support bar 48 is positioned by vertical posts 54 . Force transducers 46 , mounted in the training harness 38 , generate use input signals to determine when an individual 14 has fallen. The harness 38 is used as both a safety subsystem and as a control input device to system software, and is integrally attached to the platform 24 through the subsystem frame. Known chest harnesses (e.g. climbing chest harness) are integrated to the subsystem frame using tubular steel. Further, low-profile handrails 36 are included as a safety feature. The handrails 36 are attached to the treadmill 12 base in such a way that the force transducers 52 can identify and quantify when the rails 36 are being used to support the individual's body weight. This data is also used for real-time biofeedback control of the treadmill 12 . Powder coated bent tubular steel and powder coated for each rail 36 , 54 is preferred although other handrail constructions may be used. Software modules are an important component of the apparatus and control thereof of the present invention. Software modules are preferably developed in a high level language, such a C, but are designed for implementation on an embedded microcontroller or dedicated microprocessor. Computational modules are also employed for kinematic measurements derived from numerous markers placed on the body for computations of stepping response to large postural perturbations. For example, 26 markers on the body of the individual 14 may be used. These measures, including trunk angle and trunk velocity, are of assistance to discriminate fallers versus non-fallers. It should be understood that each of the foregoing components are preferably included in the apparatus 10 of the present invention. However some components and features may be omitted from the apparatus and still be within the scope of the present invention. For example, the apparatus 10 employs force transducers 44 , 46 , 54 , however, such force measurements may not be required for the analysis of the kinetic data in order to be effective as a training tool. For example, it may be sufficient to have programmed control algorithms and relatively simple sensing capabilities that perform universal protocols. Referring now to FIGS. 2-4 , the optional use of obstacles with the apparatus 10 of the present invention. The use of such obstacles in the method of training of the present invention improves the overall effectiveness thereof. In FIG. 2 , the treadmill 24 is equipped with a physical obstacle 56 that is placed proximate to the individual. For example, the obstacle 56 is a wall or barrier that is place in front of the walking path of the individual 14 . This obstacle 56 may be place above the belts 16 , 18 or may be placed directly thereon. Or, the obstacle 56 may, upon command, emanate upwardly from the platform 24 to then be proximate to the individual 14 . In FIG. 3 , the obstacle employed, in this embodiment, is a laser beam 58 that passes proximate to the individual 14 , namely, in their walking path. Still further, in FIG. 4 , the obstacle employed, in this embodiment, is a hologram 60 . As will be discussed below, in connection with the method of the present invention, the obstacles 56 , 58 and 60 play an important role in training the individual 14 . The obstacles 56 , 58 and 60 simulate real obstacles that may be faced in a real world non-training setting. The virtual obstacles 58 and 60 may also be used to sense when the individual 14 passes therethrough to serve as an additional sensor. In view of the foregoing, the apparatus 10 of the present invention can measure an individual's step response to a disturbance event, such as trip or slip incident. Therefore, it can be used to evaluate tripping and slipping fall mechanism in anterior and posterior directions. It can also evaluate stepping responses from static positions in the anterior, posterior and lateral directions. Recovery strategies can also be evaluated to reduce occurrences of falls. The complete measurement and computational capabilities of the present invention enables specific individual risk factors to be identified so appropriate training can be developed and carried out to better avoid fall incidents. Thus, novel biomechanical factors can be linked to the prediction and prevention of falling with better accuracy and effectiveness than prior art devices and systems. The data obtained from the system and apparatus of the present invention can then be used to better train a person for a fall in accordance with the new method for fall prevention training of the present invention. As discussed in detail below, the apparatus 10 can be used to execute a unique protocol of fall prevention training that teaches a person how to better react to a disturbance event according to strategies learned from the apparatus and system described above. For example, a succession of simulated trip incidents can be delivered where the velocities and/or accelerations or a combination thereof of each successive event is built up over time to lead up to a trip situation. By using the unique apparatus 10 of the present invention, a method of training can be delivered where a slip incident can be generated from a static position. This simulates a condition where an individual loses their balance when standing still. Also, and most importantly, the present invention can generate a dynamic slip or trip condition where a second velocity is delivery after a first velocity has been delivered. This simulates a condition where the individual is walking (corresponding to the first velocity) and then encounters a trip or slip situation while walking. Thus, a change of velocities can be delivered to better simulate various conditions that cannot be simulated with prior art devices. Such a method of training is preferably carried out using the apparatus of the present invention described above. Referring now to FIGS. 8-14 , details of the method of fall prevention training is shown and described in detail. The method of the present invention provides a protocol to execute and carry out the fall prevention training of the present invention. This is a general protocol employed in the method of the present invention and can be applied to any of the large disturbance events used in the present method of training. As will be discussed in detail below, the method is a multi-stage process that outlines a unique training progression that is used in an attempt to reduce the incidence of falls by an individual. While this is a preferred method, there is no set number of cycles or limits. In general, the method uses a unique protocol that requires the individual to achieve a goal to represent the acquisition of a given skill. Moreover, multiple trials at a given disturbance level represents skill retention and the results of future retesting indicates skill decay. Stage 1—Small Disturbance, No Step Response As represented by FIG. 8 , in the first stage of the protocol, the individual 14 stands with two feet on platform. A small disturbance is introduced at a random time. The platform moves a finite distance and stops. As stated above, the platform moves in less than about 500 ms and, preferably, in the range of about 100 ms to about 200 ms to ensure a realistic disturbance event. The disturbance level in Stage 1 should be small to determine if the individual can use respond to the disturbance with what is commonly referred to as a “feet in place” recovery strategy. This means that the individual adopts a recovery strategy that maintains upright posture and which requires minimal movement of the feet (e.g. no step response). For example, the individual might use what is referred to as an “ankle strategy” or a “hip strategy” whereby the individual alters their ankle and/or hip rotation angle in one or more directions and stabilizes their body with their muscles with no step response. At this stage, the perturbation distance preferably remains the same until the individual has shown that their response is low in variability. The perturbation distance incrementally increases at 64 as the individual successfully completes the feet in-place response. This increase in distance continues until the individual is able to complete a prescribed distance, or threshold, which is determined based on intrinsic parameters of the individual, such as height, body center of mass, age, and flexibility. Once the individual has exceeded the predetermined maximum perturbation threshold without a step response at 66 , the sequence of disturbance events are stopped at 68 and they are moved to the Stage 2 in the protocol at 70 . Stage 2—Step Response to Large Perturbation In FIG. 9 , the individual starts at a standstill and a large disturbance is introduced at a random time. The platform moves a finite distance and stops. The disturbance magnitude preferably exceeds the magnitude of the maximum disturbance in Stage 1 above. The maximum time for this displacement of the disturbance to occur is less than 500 ms, and is more typically in the range of about 100 to about 200 ms, and preferably about 250 ms. In Stage 2, a single step response by the individual is sought. If the individual is able to maintain posture with a single step, the given train within Stage 2 is considered successful. If the individual requires more than one step to maintain posture or falls, the perturbation distance is repeated. Trials are be repeated within a session or across sessions until the variability in step response following a given perturbation displacement and profile are below a target value. For example, a minimization function relating step length and step width might be employed to calculate a residual value for step response. This value is called a target step response. The variance in this computed value for a given trial compared to the previous n trials can be used. Alternative methods of determining a threshold for success for step response to a given perturbation are readily defined, such as the number of trials in a row for achieving the target step response required by Stage 2. After an individual successfully passes the single step response test for a given perturbation distance and acceptably low variability between sessions, that distance is increased at 72 until individual is able to complete a prescribed perturbation distance threshold at 74 . In similar fashion to Stage 1, intrinsic parameters of the individual, such as height, body center of mass, age, and flexibility, are used to determine a maximum perturbation distance, or threshold, for that individual. Once the individual has exceeded the predetermined maximum perturbation with only a single step response, the sequence of disturbance events are stopped at 76 and they are moved to the Stage 3 in the protocol of the method of the present invention at 78 . Stage 3—Step Response with First Obstacle In FIG. 10 , the individual starts at a standstill. A first obstacle is placed proximate to the individual at 80 , such as ahead of the individual in the direction, so that the perturbation forces them to make a step response. A large disturbance is also introduced at a random time. The platform moves a finite distance and stops. The disturbance magnitude exceeds the magnitude of the maximum disturbance in Stage 1. The maximum time for this displacement of the disturbance to occur is less than about 500 ms, and is more typically in the range of about 100 to about 200 ms. The distance and position that the first obstacle is placed from the individual can vary between zero (i.e. touching the individual) and a prescribed maximum obstacle distance from individual. Intrinsic individual parameters, such as height and body center of mass, are used to determine a maximum obstacle distance from individual for that individual. The obstacle can either be real or virtual. For example, the obstacle, which may be made from any material, may be a barrier or wall that emanates up from the floor of the platform. Such an obstacle may be driven by springs or actuators to control its positioning proximate to the individual. For virtual obstacles, 3-D holograms and laser beam systems are a few examples. In the preferred embodiment of the present invention, the obstacle is 5 cm high but it could be of any height. For example, the obstacle may be in the range of only about 1 mm up to about one half of the body height of the individual. A single step response is sought from the individual. If they are able to negotiate the obstacle and to maintain posture with a single step, the trial is considered successful. If the individual requires more than one step to maintain posture or falls, the perturbation distance is repeated. Trials are repeated within a session or across sessions until the variability in step response following a given perturbation displacement and profile are below a target value. For example, a minimization function relating step length and step width might be employed to calculate a residual value for step response. This value is called a target step response. The variance in this computed value for a given trial are compared to the previous n trials can be used. Alternative methods of determining a threshold for success for step response at 84 to a given perturbation are readily defined, such as the number of trials in a row for achieving the target step response. After a individual successfully passes the single step response test for a given perturbation distance, that distance is incrementally increased at 82 until individual is able to complete a prescribed distance. Also, the height of the obstacle is progressively increased at 83 up to a prescribed height and the initial distance of the obstacle from the individual is progressively increased up to a prescribed perturbation distance. The intrinsic individual parameters, such as height, body center of mass, age, and flexibility, are used to determine a maximum perturbation distance for that individual, the maximum obstacle height for that individual and the maximum initial obstacle distance for the individual. Once the individual has exceeded the predetermined maximum perturbation, with only a single step response and acceptably low variability between sessions, the disturbance events are stopped at 86 and they are moved to the Stage 4 at 88 in the protocol outlined below. It should be noted that in the case where the disturbance event is intended to be large and to simulate a slip incident, Stage 3 may be omitted. Stage 4—Stable Gait after Standstill In FIG. 11 , the individual 14 starts at a standstill and a large disturbance is introduced at a random time. The disturbance causes the platform to accelerate to a prescribed (non-zero) velocity. This second velocity is called the velocity change. The maximum time for this change in the platform velocity is less than about 500 ms, and is more typically in the range of about 100 to about 200 ms. A stable gait response is sought from the individual. If they are able to achieve a stable gait within a predetermined number of steps, the trial is considered successful. If the individual requires more than the predetermined number of steps to achieve stable gait or if the individual falls, the change in velocity is repeated. Trials are be repeated within a session or across sessions until the variability in step response following a given perturbation displacement and profile are below a target value. For example, a minimization function relating step length and step width might be employed to calculate a residual value for step response. This value is called a target step response. The variance in this computed value for a given trial compared to the previous n trials can be used. Alternative methods of determining a threshold for success for step response to a given perturbation are readily defined, such as the number of trials in a row for achieving the target step response. After a individual successfully passes the stable gait response test for a given velocity change perturbation, that velocity change is incrementally increased at 90 to produce continuous walking at 92 until individual is able to successfully complete a prescribed velocity change. Intrinsic individual parameters, such as height, body center of mass, age, and flexibility, are used to determine a maximum velocity change threshold at 94 for that individual. Once the individual has exceeded the predetermined maximum velocity change with stable gait step response and acceptably low variability between sessions, the disturbance events are stopped at 96 and they are moved to the Stage 5 in the protocol at 98 . Stage 5—Stable Gait after Standstill with Second Obstacle In FIG. 12 , the individual 14 starts at a standstill. A second obstacle is placed proximate to the individual at 100 , such as ahead, in the direction such that the perturbation forces them to make a step response. This second obstacle may be the same as the first obstacle but also may be a different obstacle. A large disturbance is introduced at a random time. The disturbance causes the platform to accelerate to a prescribed (non-zero) velocity. This second velocity is called the velocity change. The maximum time for this change in the platform velocity is less than 500 ms, and is more typically in the range of about 100 to about 200 ms. The distance that the second obstacle is placed from the individual can vary between zero (i.e. touching the individual) and a prescribed maximum obstacle distance from individual. Intrinsic individual parameters, such as height, body center of mass, age, and flexibility are used to determine a maximum obstacle distance or threshold from individual for that individual. As above, the second obstacle can either be real virtual and preferably 5 cm high, although, the obstacle could be in the range of 1 mm up to about one half of the body height of the individual. A stable gait response is sought in Stage 5. If the individual is able to achieve a stable gait within the predetermined number of steps, the trial is considered successful. If the individual requires more than the predetermined number of steps to achieve stable gait or if the individual falls, the change in velocity is repeated. Trials are be repeated within a session or across sessions until the variability in step response following a given perturbation displacement and profile are below a target or threshold value. For example, a minimization function relating step length and step width may be employed to calculate a residual value for step response. This value is be called a target step response. The variance in this computed value for a given trial compared to the previous n trials can be used. Alternative methods of determining a threshold for success for step response to a given perturbation are readily defined, such as the number of trials in a row for achieving the target step response. After a individual successfully passes the stable gait response test for a given velocity change perturbation, that velocity change is increased until individual is able to successfully complete a prescribed velocity change at 108 . The height of the obstacle is progressively incrementally increased up to a prescribed height at 106 . The initial distance of the second obstacle from the individual is progressively incrementally increased at 102 up to a prescribed distance. Intrinsic individual parameters, such as height, body center of mass, age, and flexibility, are used to determine, for that individual, the maximum velocity change, the maximum obstacle height and the maximum initial obstacle distance for that individual. Once the individual has exceeded the predetermined maximum velocity change with stable gait step response at 108 and acceptably low variability between sessions, the disturbance events are stopped at 110 and they are moved to Stage 6 in the protocol at 112 of the method of the present invention. It should also be noted that in the case where the disturbance event is large and is intended to be a slip incident, Stage 5 may be omitted. Stage 6—Stable Gait after Initial Steady State Locomotion and Large Disturbance In FIG. 13 , the individual starts at an initial steady state locomotion velocity (velocity 1 ). A large disturbance is introduced at a random time. The disturbance causes the platform to accelerate to a prescribed disturbance velocity (velocity 2 ) before returning to a second steady state locomotion velocity (velocity 3 ). The maximum time for this change in the platform velocity (the time between when the change from velocity 1 is initiated and velocity 3 is achieved) is less than about 500 ms, and is more typically in the range of about 100 to about 200 ms. Velocity 3 may or may not be different from velocity 1 . The three velocities and their timing are called the velocity profile. A stable gait response is sought from the individual. If they are able to achieve a stable gait within a predetermined number of steps, the trial is considered successful. If the individual requires more than the predetermined number steps to achieve stable gait or if the individual falls, the velocity profile is repeated. Trials are be repeated within a session or across sessions until the variability in step response following a given perturbation displacement and profile are below a target value or threshold. For example, a minimization function relating step length and step width may be employed to calculate a residual value for step response. This value is be called a target step response. The variance in this computed value for a given trial compared to the previous n trials can be used. Alternative methods of determining a threshold for success for step response to a given perturbation are readily defined, such as the number of trials in a row for achieving the target step response. After a individual successfully passes the stable gait response test for a given velocity profile perturbation, parameters in that velocity profile are incrementally increased until individual is able to successfully complete a prescribed velocity profile. For example, the magnitude of the disturbance (defined as the difference between velocity 1 and velocity 2 ) is progressively and incrementally increased up at 114 to a prescribed disturbance magnitude, velocity 1 is progressively and incrementally increased up to a prescribed velocity and velocity 3 is incrementally increased up to a prescribed velocity to achieve motion to simulate walking at 116 . Intrinsic individual parameters, such as height, body center of mass, age, and flexibility, are used to determine the final velocity profile for that individual. Once the individual has exceeded the predetermined final velocity profile with stable gait step response at 118 , the disturbance events are stopped at 120 and they are moved to Stage 7 in the protocol of the method of the present invention. Stage 7—Stable Gait after Initial Steady State Locomotion and Large Disturbance with Third Obstacle In FIG. 14 , the individual 14 starts at an initial steady state locomotion velocity (velocity 1 ). A large disturbance is introduced at a random time. In concert with the large disturbance, a third obstacle is placed proximate to the individual at 124 , such as ahead of the individual, in the direction so that the perturbation forces them to make a step response. The third obstacle may be the same as the first obstacle and/or the second obstacle. Alternatively, all three obstacles may be different than one another. The disturbance causes the platform to accelerate to a prescribed disturbance velocity (velocity 2 ) before returning to a second steady state locomotion velocity (velocity 3 ). The maximum time for this change in the platform velocity (the time between when the change from velocity 1 is initiated and velocity 3 is achieved) is less than about 500 ms, and is more typically in the range of about 100 to about 200 ms. Velocity 3 may or may not be different from velocity 1 . The three velocities and their timing are called the velocity profile. The distance that the third obstacle is initially placed from the individual can vary between zero (i.e. touching the individual) and a prescribed maximum obstacle distance from individual. Intrinsic individual parameters, such as height, body center of mass, age, and flexibility are used to determine a maximum obstacle distance from the individual for that individual. Similar to the first obstacle and the second obstacle, the third obstacle can either be real or virtual. In the preferred embodiment of the present invention, the third obstacle is about 5 cm high but it can be in the range of about 1 mm up to about one half of the body height of the individual. A stable gait response is sought from the individual. If the individual is able to achieve a stable gait within a predetermined number of steps, the trial is considered successful. If the individual requires more than the predetermined number of steps to achieve stable gait or if the individual falls, the velocity profile is repeated. Trials are be repeated within a session or across sessions until the variability in step response following a given perturbation displacement and profile are below a target value. For example, a minimization function relating step length and step width may be employed to calculate a residual value for step response. This value is called a target step response. The variance in this computed value for a given trial compared to the previous n trials can be used. Alternative methods of determining a threshold for success for step response to a given perturbation are readily defined, such as the number of trials in a row for achieving the target step response. After a individual successfully passes the stable gait response test for a given velocity profile perturbation, parameters in that velocity profile are incrementally increased until the individual is able to successfully complete a prescribed velocity profile. For example, the magnitude of the disturbance (defined as the difference between velocity 1 and velocity 2 ) is incrementally increased at 126 up to a prescribed disturbance magnitude to produce a motion simulating a walking velocity at 128 . Velocity 1 is incrementally increased up to a prescribed velocity and velocity 3 is incrementally increased up to a prescribed velocity. The height of the third obstacle is progressively increased up to a prescribed height at 130 and the initial distance of the third obstacle from the individual is progressively increased up to a prescribed distance. Intrinsic individual parameters, such as height, body center of mass, age, and flexibility, are used to determine the final velocity profile (including maximum velocity 1 , maximum velocity 2 , and maximum magnitude of disturbance), maximum obstacle height, maximum initial obstacle distance for that individual. Once the individual has exceeded the predetermined final velocity profile with stable gait step response at 132 and acceptably low variability between sessions, the disturbance events are stopped at 134 and protocol of the method of the present invention is completed at 136 . It should also be noted that in the case where the disturbance event is large and is intended to be a slip incident, Stage 7 may be omitted. Referring now to FIGS. 15A , 15 B, 15 C and 20 , a lateral deck 200 of the present invention is controlled by a DC rack-and-pinion drive 202 , with center under deck, that slides on a low friction polymer surface 204 that is fixed to an aluminum sub-frame 206 . The drive motor 208 and rollers 210 are all mounted on the deck 200 to maintain alignment of the walkway belt via drive pulleys 211 . A locking mechanism prevents lateral motion when desired. At a specific phase of the gait cycle, the lateral mechanism moves the entire deck assembly 200 relative to the sub-frame 206 using the DC rack-and-pinion drive at a specified velocity and distance delivering a lateral perturbation to the user. The lateral deck 200 of FIGS. 15A , 15 B and 15 C is a further embodiment of the present invention compared to the deck shown in FIG. 1 . To the end user, the system resembles a treadmill and has similar functionality as a traditional treadmill, but with the added highly controlled perturbations that are superimposed with treadmill velocity at, for example, specific phases in the gait cycle or from external triggers, to elicit a targeted user response. Perturbations are high acceleration changes in gait velocity that last less than 500 msec and preferably less than 150 ms. In one embodiment of the present invention, referring to FIGS. 15A , 15 B and 15 C and representationally shown in FIG. 20 , a novel roller/brake clutch system 220 , alternatively referred to as a slip clutch system, such as a electromagnetic (EM) or magnetorheological (MR) roller/brake clutch, connected between drive pulley 213 and drive roller 210 is adapted to existing AC motors currently used in commercial treadmills to provide a microprocessor controlled mechanism for precise control of perturbation displacement, velocity, and acceleration. For example, a roller/break clutch 220 controls the slip characteristics at the desired timing for the perturbation. In this embodiment, the perturbations are achieved by utilizing the horizontal reaction force generated during stance to overpower the low-inertia rollers 210 and coupled slip clutch system 220 in FIG. 15C . It should be understood that alternate embodiments for creating the desired perturbation kinematics exist. The equipment shown and discussed herein are examples of how the method of the present invention can be carried out. In a preferred embodiment of the present invention, motion of the treadmill platform 204 has dimensions 5.08 cm in 0.5 secs minimum in all directions. The maximum response time from trigger to release roller 210 to cause a dynamic perturbation is preferably 100 msec, and the maximum response time to re-engage roller 210 to achieve total desired perturbation motion is preferably 100 msec. In one embodiment, a servo-driven rack-and-pinion drive 202 is provided for lateral translation of the support surface. When coupled with the roller-clutch system 220 and the treadmill with lateral deck 200 itself, multi-axis perturbation is readily achieved and controlled. The treadmill with lateral deck 200 and motor drive 208 can attach to the rack-and-pinion system 202 and rest on ultra-low friction plates 204 for unrestricted motion. The present invention includes a novel system and method for delivering the controlled perturbations of the apparatus in FIGS. 1 and 15 at specific timing based on event detection algorithms that provide information related to the kinematics of the user. The present invention also includes a novel apparatus and method for delivering the controlled perturbations of the apparatus at specific timing based event detection of external triggers, such as a manual switch, audio cues, visual cues, or tactile cues. The perturbation system can be programmed to allow constant or changing amplitude and constant or changing frequency of perturbations that change from step to step or over a period of time. In accordance with the present invention, perturbations that require a response, such as a step, by the user but which do not necessarily induce a fall. These are imbalances for which the body must and does respond to, whatever their direction. In the preferred embodiment using a motor drive 208 , the magnitude and timing of the perturbations delivered by the roller/brake clutch mechanism 220 are pre-programmed for the perturbation profiles desired. Event detection algorithms 258 provide a trigger output that initiates a perturbation profile. FIG. 20 represents one embodiment of this novel system and method of detecting events and delivering controlled perturbations, whereby the roller/brake clutch system 220 in FIG. 15C is integrated with a motor drive 208 and roller encoder 209 to provide the controlled perturbation together with event detection based on real-time feedback from the components, external cues and specific timing relating to various phases of the gait cycle, such as but not limited to heel strike or toe off. When the event detection algorithm 215 detects a trigger, the prescribed perturbation is executed by the perturbation apparatus, for example, the motor drive 208 and the roller-clutch/brake mechanism 220 via the drive pulleys 213 and belt 211 . Detection of heel strike during walking can be used as an example to demonstrate the steps in the novel system and method for delivering the controlled perturbations included in an event detection algorithm. The event detection algorithm is programmed to issues trigger signal or signals to deliver the prescribed perturbation at the 1 st , 2 nd , nth detected event, such as heel strike, or randomly selected based on a normal or other statistical distribution of detected events. Alternatively and additionally, the trigger can occur due to an external input such as from a switch. The process for determining when a perturbation should be delivered is shown in the flow chart of FIG. 17 and is explained herein. In one embodiment, heel strikes can be detected by monitoring motor current. A graph of motor current 240 versus time can be seen in FIG. 16 . At the moment of heel strike 241 , as in FIG. 16 , there is a horizontal resultant force that opposes the treadmill belt normal movement resulting in a decrease in belt velocity. Toe-off 242 is also shown on graph 240 . To maintain the belt at a constant velocity, the motor drive 208 increases the motor current to maintain the constant velocity in the presence of the increased drag. This represents a significant increase in motor current (I) with respect to time (dI/dt), which can be detected so that, for example, the positive peak in motor current derivative (dI/dt) defines when the heel strike occurs. FIGS. 18A-18F show various data derived from motor current motor position which can be used to identify when a heel strike 241 or toe-off 242 event has occurred thereby warranting delivery of a perturbation. FIGS. 19A-19B illustrate such identification of an event using motor current only when heel strike 241 and toe-off 242 events occur resulting from the monitoring the motor current independently alone or together with other variables such as the time rate of change of motor current. In this case, the moment of heel strike 241 and toe-off 242 can be ascertained from monitoring the motor current parameter to identify the detection event and cause a perturbation trigger. In this embodiment, representationally shown in FIG. 17 , the motor current 250 is detected by a sensor 205 in FIG. 15B . This sensor 205 can be any current monitoring sensor such a hall effect sensor. In one embodiment, the output of sensor 205 is passed through an analog filter 253 , such as a single pole RC low pass filter with a −3 db point around 10 Hz. The motor current signal 250 is preferably amplified by a gain, and offset relative the zero current output level of the sensor 205 and, in this embodiment, converted through analog to digital conversion 254 to a digital signal for processing. This digital value is processed through a digital filter 255 , such as a kernel smoothing algorithm which applies half sine coefficients over a variable width range of samples. The heel strike feature is detected from this smoothed output in the event detection algorithm 258 . In this case, heel strike is detected by finding the positive peak of the current signal derivative 257 . Alternate variables that can be used independently or together with the motor current include motor voltage, and motor power. Each of these measured or computed variables provides a time history that provides unique information about the loads and timing of loads applied to the motor 208 , which in turn are representative of different phases of the gait cycle or other information relating to the gait cycle. Similar measurements and computational analysis for detecting kinematic events can be performed for loads placed on motors during motion of other body joints other than lower extremity joints associated with gait. For example, motion of the trunk or upper extremity and phases of the such motion, such as shoulder kinematics or spinal kinematics, can be detected by the algorithm of the present invention. Additional embodiments for detection of kinematic events of the treadmill apparatus incorporate data from other sensors 207 such as linear or rotational encoders which provide data including but not limited to velocity, acceleration, and jerk of the moving elements of the apparatus. These sensors 207 may be, for example, located on the rollers 210 of the treadmill 200 or on other exercise equipment where kinematic motion is measurable. For example, a rotational encoder 209 may be attached to the roller drive 210 to record roller 210 and motor 208 rotational displacement. The time rate of change of the roller drive 210 and motor 208 rotational displacement is the rotational velocity 251 in FIG. 17 and the time rate of change of velocity 251 is the rotational acceleration 256 . These data are used alone, or, as desired, fused with data such as motor current 250 and time rate of change of motor current 257 and other sensor 207 data output 252 and time rate of change of this data output 252 to provide more robust detection algorithms 258 . These algorithms may optionally use digital filtering 255 , such as Kalman or complementary filters. The detection algorithm 258 may use one or more of these variables. For example, linear and rotational encoder data from a motor combined with current and derivatives of these data can be combined to create latent variables, using Independent Component Analysis, Principal Component Analysis or other data reduction techniques, on which feature extraction and feature detection can be performed to simplify data processing for the detection algorithm. Other embodiments of the data algorithm 258 for detecting gait phase events or events related to motion of a body joint incorporate Markov chains, Bayesian statistics, neural networks, or similar approaches that provide sensor fusion and real-time feature extraction. Additionally, user input data 259 , such as user body height, and weight, and/or an external switch, can be input as part of the event detection algorithm 258 . When the event detection algorithm 258 detects an event 260 , a perturbation trigger 261 is initiated. In a preferred embodiment, the detection algorithm 258 detects and triggers a perturbation within 40 ms of the detected event. The event detection algorithm 258 also identifies events that can occur as a percentage of step time (e.g. mid-stance). In one embodiment, this algorithm is, based on average step time based on subject and walking speed during a warm-up phase. During this phase, each step is used (n>30) to determine an average step time. In one use method, the user can select a percent of stance phase, or percent of average step time, at which to issue a trigger (eg. 0-100% from heelstrike to toeoff). Alternatively, such a trigger time can be selected randomly from between 0-100% of the gait cycle from heel strike to toe off, including but not limited to the braking phase and the propulsion phase of stance. Additionally, this gait phase detection system 200 can be used to control and to change the treadmill speed based on braking phase (time and force as measured by motor current and propulsion phase. If the braking phase impulse is greater than propulsion phase impulse (adjusted for treadmill running), then the treadmill belt (not shown) slows down. If the braking phase impulse is less than the propulsion phase impulse (adjusted for treadmill running), then the treadmill belt speeds up. The application of perturbations at various phases of the gait cycle allows for training to modulate the stretch reflex/arc of the muscles crossing a body joint in the lower extremity. The same approach exists for training at different ranges of motion for a body joint in the upper extremity. It should be understood that the algorithms of the present invention are executed by software that is located and stored on a storage device in computer hardware. The computer hardware preferably includes the typical storage, such as hard drive, with operating system thereon, with memory and input and output capability so computer data may be transferred between the computer running the algorithm and another electronic device. The sensors and other equipment electrically and physically interface with the computer hardware. Any type of operating system and computer language may be employed. The perturbations enable individuals to rapidly learn how to modify motor performance Referring now to FIG. 21 , the same perturbation force Fp applied at different phases of the gait cycle, represented here as knee angle theta, results in different forces F applied at the knee, which in turn causes different kinematic response of the knee and other joints. The anterior force F at the knee is dependent on the knee angle theta and the applied perturbation force Fp. For human locomotion, knee angle during walking/running follows a very predictable pattern. Likewise, the perturbations can be applied to any joint based on the current position, velocity, or acceleration of the joint, independent of gait. This is particularly relevant for upper body neuromuscular training paradigms. The invention provides a method of providing a timed perturbation to the apparatus 10 or 200 based on external cues from a musical source or other external source (not shown). Music drives exercise profiles (speed, elevation, perturbation frequency/magnitudes, intensity, and the like)—real-time modification of playlist based on what is being done. Music feedback can be used by the present invention as a behavioral modifier. In view of the foregoing, a new and novel system and apparatus is provided that captures biomechanical data of body movement during a disturbance event, such as a slip or trip incident or other event experience by a part of the body. A disturbance event is simulated by a treadmill-based apparatus or other device. Data collected is used to compute a wide array of parameters associated with body movement to better and more fully understand body movement during a disturbance event. Such parameters are to be studied to determine and evaluate step responses to a disturbance event. As a result, a new and novel method of fall prevention training can be provided to the person to reduce the likelihood of falling following a disturbance event. As a result, a new and novel neuromuscular training system for body joints can be provide to increase dynamic stiffness of the joint, and to reduce the likelihood of injury to the joint caused by excessive motion. It would be appreciated by those skilled in the art that various changes and modifications can be made to the illustrated embodiments without departing from the spirit of the present invention. All such modifications and changes are intended to be covered by the appended claims.

A new apparatus, system and method for fall prevention training is provided that delivers, studies and analyzes the biomechanics of a disturbance event, such as a slip or trip incident, so that an appropriate response can be executed by the person to reduce or eliminate the number of falls experienced. The apparatus includes a platform that delivers a disturbance event in less than about 500 ms and preferably in the range of about 100 ms to about 200 ms. The method includes a unique protocol for fall prevention training using the apparatus. The disturbance event can create instability in the joint of the individual. An individual's walking gait can be monitored with the portions thereof detected. A disturbance event can be triggered when a given portion of the walking gait is detected. Also, the disturbance even can be triggered manually, at preset intervals or according to preset script.

TECHNICAL FIELD [0001] The present invention relates generally to audio-video entertainment systems, and more particularly to video on demand services. BACKGROUND [0002] Today's televisions have various screen sizes, including width to height aspect ratios of 4:3 and 16:9. Interactive television (iTV) software should be able to accommodate video and graphics to fit these different screen sizes. One technique is to simply stretch a normal screen display to fit the new screen size. This technique can lead to non-esthetic distortion of on-screen graphical data objects. A user of iTV may have a heightened recognition of a distorted or misshapen on-screen graphical data object because of the user's interacting with the graphical data object, such as with a radio button, a slide bar, or a box to be checked. Another technique is to employ the cooperative efforts of a screen designer to design a different screen for each screen of a different aspect ratio and of a programmer to accommodate each different screen design with proper functionality. This cooperative effort, however, is costly. It would be an advantage in the art to provide a technique to accommodate video and graphics to fit different screen sizes without non-esthetic distortion of on-screen graphical data objects and without adding significant cost. SUMMARY [0003] Implementations provide for cost savings by permitting a designer to design an original screen that can be transformed, without screen-specific programming, into a target screen having a different resolution or aspect ratio without giving a distorted appearance to graphical data objects on the target screen. The transformation is effected by designating a “limousine” line on the original screen that is normal to and intersects with an axis at a limousine point that is designated by a designer of the original screen. A graphical data object on the original screen that intersects the limousine line is subjected to both a proportional and a non-proportional stretching while other graphical data objects on the original screen are subjected to a proportional stretching. This limousine stretching technique achieves a target screen having on-screen graphical data objects that do not have a distorted appearance. [0004] In one implementation, a substantially rectangular target screen has a different aspect ratio than a substantially rectangular original screen. The original screen has been designed with a limousine or resizing point on one of its edges. A perpendicular line from the resizing point intersects an original graphic data object on the original screen. The original graphic data object is proportionally increased in size to obtain a target graphic data object on the target screen. A stretch distance is also added to the size of the target graphic data object on the target screen. The proportional increase in size is according to the smaller of the width ratio and height ratio of the target and original screens. When the proportional increase in size is according to the height ratio, then the stretch distance is calculated by subtracting the product of the height ratio and the width of the original screen from the width of the target screen. When the proportional increase in size is according to the width ratio, then the stretch distance is calculated by subtracting the product of the width ratio and the height of the original screen from the height of the target screen. Once formed, the target graphic data object can be output on a display of the target screen. BRIEF DESCRIPTION OF THE DRAWINGS [0005] A more complete understanding of the implementations may be had by reference to the following detailed description when taken in conjunction with the accompanying drawings wherein: [0006] FIGS. 1 a and 1 b show a display screen featuring an outline of an automobile respectively before and after a limousine stretching. [0007] FIGS. 2 a - 3 a and FIGS. 2 b and 3 b respectively show a display screen before and after a limousine stretching, where the display screen of FIGS. 2 a - 3 a has an object to the left of a limousine line, an object that is straddling the limousine line, and an object to the right of the limousine line. [0008] FIGS. 4 a - 4 b show a display screen before and after a limousine stretching, where the display screen of FIG. 4 a has an object above a limousine line, an object that is straddling the limousine line, and an object below the limousine line. [0009] FIG. 5 is a flow chart depicting an implementation of a process for limousine scaling the original graphical data objects depicted in FIGS. 2 a , 3 a , and 4 a into the target graphical data objects depicted in FIGS. 2 b , 3 b , and 4 b , respectively. [0010] FIGS. 6 a - 6 b depict a graphical data object on a target screen, respectively before and after the introduction of error by using integer mathematics for the positioning of the graphical data object on the target screen. [0011] FIG. 7 depicts a main television guide or electronic programming guide (EPG) screen having an original 576 pixels by 480 pixels design, where a dashed line denotes a limousine line extending as a normal to a limousine point on a horizontal axis, where the limousine point and limousine line are to be used for limousine scaling. [0012] FIG. 8 a depicts an EPG target screen that has been limousine scaled to a dimension of 576 pixels by 360 pixels, where graphical data objects have been scaled by a factor of 75% and the target screen height has been reduced to 75% of the height of the original screen seen in FIG. 7 . [0013] FIG. 8 b depicts the EPG screen of FIG. 8 a having been scaled non-proportionally to a dimension of 576 pixels by 360 pixels, where space on the screen has not been used as effectively as the space used in the limousine scaled screen depicted in FIG. 8 a. [0014] FIG. 9 depicts an EPG screen having been scaled proportionally to 432 pixels by 360 pixels, where limousine scaling is not needed because the target screen has the same proportions as the original screen and its graphical data objects do not have a distorted appearance. [0015] FIG. 10 a depicts a screen having a dimension of 576 pixels by 360 pixels that has not been subjected to limousine stretching, where objects at the left side of the screen have the appearance of being stretched too wide. [0016] FIG. 10 b depicts, for comparison purposes, the screen of FIG. 9 with different graphical data objects and a dimension of 432 pixels by 360 pixels, which is a proportionally scaled screen. [0017] FIG. 11 depicts a target screen having a dimension of 576 pixels by 360 pixels with limousine scaling having been used to stretch most of graphical elements on the original screen towards the right side of the depicted target screen. [0018] FIG. 12 depicts a target screen having a dimension of 576 pixels by 360 pixels in which limousine scaling has been used. [0019] FIG. 13 depicts a target screen having a dimension of 576 pixels by 360 pixels where limousine scaling has been used such that most of the stretching of graphical elements on the original screen have been stretched toward the right side of the depicted target screen. [0020] FIG. 14 illustrates an exemplary environment in which a viewer may receive content via a client that effects a transformation of an original screen having one resolution or aspect ratio into a target screen of a different resolution. [0021] The same numbers are used throughout the disclosure and figures to reference like components and features. Series 100 numbers refer to features originally found in FIG. 1 , series 200 numbers refer to features originally found in FIG. 2 , series 300 numbers refer to features originally found in FIG. 3 , and so on. DETAILED DESCRIPTION [0022] Various implementations provide a limousine stretching technique for transforming an original screen of an original dimension and having a graphical data object thereon into a target screen having a different target dimension and a resized graphical data object thereon. By use of the limousine stretching technique, the graphical data object in the original screen is scaled non-proportionally into the target screen without giving a distorted appearance to the graphical data object on the target screen. The limousine stretching technique defines a limousine point on a horizontal axis. A normal, called herein a ‘limousine line’, is extended from the limousine point so as to intersect with the graphical data object on the original screen. Each graphical data object on the original screen with which the limousine line intersects will be non-proportionally stretched. Any other graphical data object on the original screen will be proportionally stretched. Stated otherwise, graphical elements to the left or right of the limousine line are scaled proportionally, and graphical elements that straddle the limousine line are stretched non-proportionally. The non-proportional stretching of the graphical data object enables the user interface (UI) to fit the resolution (e.g., dimension or aspect ratio) of the target screen. A designer of an original screen or a template for original screens can select a limousine point to ensure that the graphical data objects to appear on the target screen will be esthetically distorted without a noticeable loss of quality. [0023] To transform the original screen of the original dimensions into the target screen having the target dimensions, the graphical data objects on the original screen are stretched proportionally and non-proportionally as set forth above. The stretched graphical data objects are placed accordingly on the target screen. The limousine stretching technique provides an esthetic presentation of the graphical data objects on the target screen without appearing distorted. [0024] A designer can designate a limousine point on an original screen or on a screen template. The limousine point can be communicated to a client, such as a set top box. When the client receives media having a first resolution or dimension that is to be transformed into a second, different resolution or dimension, the client will execute a routine having the limousine stretching technique. The executed routine will transform the media intended for an original screen into a target screen to which the client is to output a display. In so doing, graphical data objects on the target screen will not have a distorted or misshapen appearance. [0025] Advantageously, with the limousine stretching technique, a designer only needs to design one original screen for one resolution or dimension, instead of having to design an original screen for each possible resolution or dimension. Moreover, a special program is not needed for each type of original screen to transform the same into a special type of target screen. As such, embodiments enable a designer to use one design for a television user interface that, through the use of the limousine stretching technique, can be presented at multiple screen aspect ratios. One original user interface can be designed that can be used to create target screens at any one of the following screen resolutions or dimensions which can in turn be transformed into the other resolutions or dimensions: the NTSC resolution 640 pixels×480 pixels, the PAL resolution 720 pixels×576 pixels, the NTSC resolution 576 pixels×480 pixels, the High Definition TV (HDTV) resolution 1280 pixels×720 pixels, the HDTV resolution 1960 pixels×1080 pixels. The target screens so created have an esthetic appearance in that they do not appear to be stretched, but rather look as if they'd been designed. [0026] Implementations of the limousine stretch technique provide control over how graphical data objects in an original screen design are stretched to make the target scaled user interface look undistorted while also functioning correctly. Some graphical data objects on an original screen can be designed by a designer so as to be exempted from being non-proportionally scaled. These graphical data objects would rather be scaled using special proportional techniques. For example, text characters in an original screen can be re-rendered at a font size that is appropriate for the scaled space of the corresponding target screen. Still other graphical data objects can be designated for other types of stretching with different stretch distances in the horizontal and vertical dimensions. A still further refinement of stretching techniques allow for stretch distances to be applied to graphical data objects differently, depending on an object's position on the original screen. [0027] On-screen graphical data objects can be divided into two classes. In the first class are elements which cannot esthetically be scaled differently in horizontal and vertical directions such that these elements look their best when they retain their original respective aspect ratios. By way of example, these elements include letter forms, scaled picture-in-picture displays, and corporate logos where the preservation of a recognizable commercial impression is desirable. Other of such graphical elements are regular shapes that are commonly recognized as being distorted when changed, such as squares and circles. An eight-side polygon, such as the common traffic stop sign, is another example of a graphical data object for which the aspect ratio should not be altered on a target screen because of the otherwise distorted appearance that will result. For these types of graphical data objects, a proportional scaling technique can be applied to preserve the original aspect ratio. For text, such as letter forms, a new font point size can be identified that will accommodate the required text in the proportionally-scaled text area of the target screen. The text is then drawn on the target screen using the identified font point size. [0028] In the second class are on-screen graphical elements that can be scaled differently (e.g., non-proportionally) in the vertical and horizontal dimensions for the target screen. The second class includes on-screen interactive buttons, text areas, some images, lines, rectangles, and other shapes. The second class of objects is scaled using different scaling factors in the vertical and horizontal dimensions. [0029] The technique of limousine-scaling or limousine stretching is an approach that can be used to scale an automobile into a limousine and can scale rounded rectangles into rounded rectangles having a different aspect ratio. A “limousine point” is defined on a horizontal axis from which a normal limousine line is extended onto the original screen. Graphical data objects to the left of the limousine line are scaled proportionally and placed on the left side of the target screen. Graphical data objects to the right of the limousine line are scaled proportional and placed on the right side of the target screen. Each graphical data object that straddles or intersects the limousine line is stretched non-proportionally across the center area thereof between the left and right sides of the target screen. The stretching is computationally inexpensive so that it can be performed on a thin client, such as a set top box, and yields esthetic, undistorted appearances of the resultant graphical data objects. [0030] A designer of an original screen, or of a template for screens, can be selective about the parts of the screen that are to be distorted. The designer can set or define the limousine point globally for each original screen or for all screens that are designed from a template. The designer can, if needed, identify certain classes of graphical data objects that are to be proportionally stretched when changing the resolution from a designed original screen to a target screen. [0031] The scaling technique also allows reuse of existing designs and design processes. Designs that are tailored to the widely used 4:3 aspect ratio for TV screens can also be used for the 16:9 aspect ratio TV screens. The design process is visual and does not require programming skills. A user interface layout can be described in a simple declarative format, and a software runtime engine that performs the layout and scaling can run in very resource-constrained environments, such as in a conventional set top box. [0032] FIG. 1 shows a profile image of an automobile 102 before a limousine stretch and a profile image of an automobile 104 after a limousine stretch. Automobile 102 has a limousine point on an axis to which a limousine line is drawn as a normal so as to extend to both automobiles 102 - 104 . The area under the limousine line of automobile 102 is stretched by a distance labeled as “limousine stretch” on automobile 104 . As such, automobile 104 appears to be a limousine version of automobile 102 . [0033] FIG. 2 a is an original screen 200 a that is transformed by limousine stretching into the target screen 200 b depicted in FIG. 2 b . The upper left corner of each screen represents the (0,0) point at an intersection of horizontal and vertical axes, where the horizontal axis increments positively to the right of the page, and the vertical axis increments positively towards the bottom of the page. The width and height of the original screen 200 a are, respectively, SW 1 and SH 1 . The width and height of the target screen 200 b are, respectively, SW 2 and SH 2 . The lower right corner of each screen represents, respectively, the (SW 1 , SH 1 ) point and the (SW 2 , SH 2 ) point. The lower left corner of each screen represents, respectively, the (0, SH 1 ) point and the (0, SH 2 ) point. [0034] A limousine point on original screen 200 a is marked at the limousine point (Limousine,0). A limousine line 202 a is drawn normal to the x axis of the original screen 200 a on which limousine point (Limousine,0) is situated. The limousine point (Limousine,0) is to the right of the left edge of original screen 200 a by a distance of represented as “Limousine Distance” in FIG. 2 a . Three (3) graphical data objects 204 a , 206 a , 208 a are seen on original screen 200 a . Object 204 a is to the left of limousine line 206 a , object 206 a straddles limousine line 202 a , and object 208 a is to the right of limousine line 202 a . Object 206 a has a width W 1 and a height H 1 . The top edge of object 206 a is below the top of original screen 200 a by a distance of T 1 . The left edge of object 206 a is to the right of the left edge of original screen 200 a by a distance of L 1 . [0035] FIG. 2 b shows the result of limousine scaling of objects 204 a , 206 a , and 208 a into objects 204 b , 206 b , and 208 b from original screen 200 a to target screen 200 b . Original screen 200 a has been scaled by width and height from SW 1 to SW 2 and from SH 1 to SH 2 , respectively. The area of object 206 a under limousine line 202 a has been non-proportionally stretched by a distance of 202 b , which is also referenced as the distance “C” in FIG. 2 b. [0036] An original screen 300 a in FIG. 3 a is identical to the original screen 200 a in FIG. 2 a , although additional reference numerals and other references have been added. An original screen 300 b in FIG. 3 b is identical to the original screen 200 b in FIG. 2 b , although additional reference numerals and other references have been added. The upper left corner of each of object 204 a , 206 a , and 208 a is, respectively, (X 204 , Y 204 ) , (X 206 , Y 206 ), (X 208 , Y 208 ). The width and height of each of object 204 a , 206 a , and 208 a is, respectively, W 204 and H 204 , W 206 and H 206 , and W 208 and H 20 8 . Limousine line 202 a is a distance of A 1 from the left edge of original screen 300 a and a distance of A 2 from the right edge of original screen 300 a. [0037] An original screen 300 b in FIG. 3 b is identical to the original screen 200 b in FIG. 2 b , although additional reference numerals and other references have been added. The respective area under limousine line 202 a in FIGS. 2 a and 3 b has been stretched as shown in FIGS. 2 b and 3 b to create two lines, one being a distance of B 1 from the left edge of target screen 300 b , and the other being a distance of B 2 from the right edge of target screen 300 b . A factor ‘f’ is used to transform original screen 200 a - 300 a to target screen 200 b - 300 b , where f=B 1 /A 1 =B 2 /A 2 . As such, the upper left corner of each of object 204 b , 206 b , and 208 b is, respectively, (X 204 *f, Y 204 *f), (X 206 *f, Y 206 *f), (X 208 *f+C, Y 208 *f), and the width and height of each of object 204 b , 206 b , and 208 b is, respectively, W 204 *f and H 204 *f, W 206 *f+C and H 206 *f, and W 208 *f and H 208 *f. Preferably, the smallest change between height and width, from the original to the target screen, will be used for the ‘f’ factor. By way of example, if SH 1 and SW 1 were both 10 units and SH 2 and SW 2 were 20 units and 50 units, then a re-sizing ‘f’ factor of ‘2’ would be used in the transformation of the original screen of FIGS. 2 a and 3 a into the target screen of FIGS. 2 b and 3 b. [0038] FIG. 4 a shows show an original display screen 400 a before a limousine stretching. FIG. 4 b shows show a target display screen 400 b after the limousine stretching. The change in the height of the target screen from that of the original screen is greater than change in the width of the target screen from that of the original screen. A limousine line 402 is seen extending between the left and right edges of the original screen. FIG. 4 a shows that the display screen 400 a before the limousine stretching has an object 408 a above the limousine line 402 a , an object 406 a that is straddling the limousine line 402 a , and an object 404 a below the limousine line 402 a . FIG. 4 b shows that the objects above and below the limousine line 402 a have been proportionally re-sized, whereas the object 406 a straddling the limousine line 402 a has been both proportionally and non-proportionally re-sized. The proportional re-sizing of the object 406 a straddling the limousine line 402 a is the same as the other two objects 408 a , 404 a , but the non-proportionally re-sizing of the object 406 a is directed in a stretching in the vertical direction of target screen 400 b . The factors of A 1 , A 2 , B 1 , B 2 , and C are measured similarly as were discussed with respect to FIGS. 2 a , 2 b , 3 a , and 3 b . Accordingly, target screen 400 b in FIG. 4 b shows the case where the height to width aspect ratio is greater than one. In this case, the non-proportionally re-sizing of the object 406 a is subjected to a vertical stretch due to the larger increment in the vertical distance of target screen 400 b. [0039] FIG. 5 shows a flowchart for a process 500 for the limousine scaling of all objects on an original screen to a target screen. Each object on the original screen in subjected to the process 500 which begins at block 502 and proceeds to block 504 at which a query is made as to whether the target screen is proportionally wider than the original screen. This query is determined by a comparison of SW 2 /SW 1 >SH 2 /SH 1 . If the answer to the query at block 504 is affirmative, then process 500 moves to block 506 to begin the scaling of the object's position and size by a height ratio. At block 506 , several calculations are made with the widths and heights seen in FIG. 2 a to arrive at the widths and heights that are seen in FIG. 2 b . The calculations at block 506 are as follows: L 2 =L 1 *SH 2 /SH 1 T 2 =T 1 *SH 2 /SH 1 W 2 =W 1 *SH 2 /SH 1 H 2 =H 1 *SH 2 /SH 1 C=SW 2 −SW 1 *SH 2 /SH 1 [0040] Process 500 then moves control to block 508 . At block 508 , a query determines, by a length comparison of L 1 <Limousine Distance (Limo), if the left most edge of object 206 a is to the left of the limousine line 202 a . If so, then another query is made at block 510 to determine, by a length comparison of L 1 +W 1 <Limo, if the right most edge of object 206 a is to the left of the limousine line 202 a . If so, then it is determined that object 206 a is on the left side on the original screen, so no adjustments are needed to object 206 a . Process 500 then is complete with this aspect of the transformation of object 206 a of the original screen to object 206 b of the target screen. [0041] If the answer is negative to the query at block 508 , then it is determined at block 518 that object 206 a is on the right side on the original screen, and that object 206 a is to be moved to the right side of the target screen. This move is expressed by the calculation L 2 =L 2 +C. Process 500 then is complete with this aspect of the transformation of object 206 a of the original screen to object 206 b of the target screen. [0042] If the answer is negative to the query at block 510 , then it is determined at block 516 that object 206 a straddles the limousine line 202 a on the original screen. For this determination, it is further determined that object 206 a is to be stretched from the left to the right on the target screen. This stretching is expressed by the calculation W 2 =W 2 +C. Process 500 then is complete with this aspect of the transformation of object 206 a of the original screen to object 206 b of the target screen. [0043] If the result of the query at block 504 is that the target screen is not proportionally wider than the original screen, the process 500 encompasses, by way of example, the scaling of the original objects that are seen in FIG. 4 a , where the limousine line 402 a intersects the original object 406 a . Process 500 moves to block 520 at which various calculations are made: L 2 =L 1 *SW 2 /SW 1 T 2 =T 1 *SW 2 /SW 1 W 2 =W 1 *SW 2 /SW 1 H 2 =H 1 *SW 2 /SW 1 C=SH 2 −SH 1 *SW 2 /SW 1 [0044] Process 500 then moves control to block 522 . At block 522 , a query determines, by a height comparison of T 1 <Limo, if the top most edge of the original object is above the limousine point. If so, then another query is made at block 524 to determine, by a height comparison of T 1 +H 1 <Limo, if the bottom most edge of the original object is to above the limousine point If so, then it is determined that the original object does not need to be adjusted because the original object is on the top side of the original screen. Process 500 then is complete with this aspect of the transformation of the original object of the original screen to the target object of the target screen. [0045] If the answer is negative to the query at block 522 , then it is determined at block 530 that object 206 a is on the bottom side of the original screen, and that the original object is to be moved to the bottom side of the target screen. This move is expressed by the calculation T 2 =T 2 +C. Process 500 then is complete with this aspect of the transformation of the original object of the original screen to the target object of the target screen. [0046] If the answer is negative to the query at block 524 , then it is determined at block 528 that the original object straddles the limousine line 402 on the original screen. From this determination, it is further determined that the original object is to be stretched in a direction from the top side of the original screen to the bottom side of the target screen. This stretching is expressed by the calculation H 2 =H 2 +C. Process 500 then is complete with this aspect of the transformation of the original object of the original screen to the target object of the target screen. [0047] Following the transformation of all of the aspects of each object ( 204 a , 206 a , 208 a , 404 a , 406 a , 408 a ) on the original screen to the respective aspects of each object ( 204 b , 206 b , 208 b , 404 b , 406 b , 408 b ) on the target screen, the target screen can be displayed in a display 516 . Implementations provide for an esthetically presented arrangement of the objects ( 204 b , 206 b , 208 b , 404 b , 406 b , 408 b ) on the target screen of the display 516 . [0048] The examples given in FIGS. 2 a through 4 b provide for a shifting of graphical data objects along horizontal and vertical axes. For instance, an original screen can be a square shape having a dimension of 10 units by 10 units. The target screen can have a height of 20 units and a width of 50 units. In this case, the height to width aspect ratio is less than one for the target screen (i.e., 20/50). A horizontal shift of the graphical data objects would be performed due to the larger increment in the horizontal distance, from 10 to 50 as opposed to from 10 to 20, when resizing the original screen to the target screen. Alternatively, the target screen can but have a height of 50 units and a width of 20 units. In this case, the height to width aspect ratio is greater than one for the target screen (i.e., 50/20). A vertical shift of the graphical data objects would be performed due to the larger increment in the vertical distance, from 10 to 50 as opposed to from 10 to 20, when resizing the original screen to the target screen. [0049] The transformation of an original screen of one resolution or aspect ratio into a target screen of a different resolution or aspect via the limousine stretching technique, as described above, can be reduced in computational complexity by use of integer arithmetic. Integer arithmetic can be run with limited computational resources typical of thin clients, such as set top boxes. By comparison, floating point arithmetic is much more expensive, especially on thin client such as set-top boxes that do not have floating point coprocessors. All computation can be done accurately using only integer arithmetic and no floating point arithmetic. Ultimately, the left, top, width and height values of each graphical data object on the target screen must rounded to integer values for display on a pixel-based device. In the examples given below, the “div” operator will be used to represent integer division and the “/” operator will be used to represent real number division. When scaling coordinates of the graphical data object from the original screen to the target screen, multiplication can be done before division to preserve the accuracy of the results. For example, the computation of the left coordinate can be perform as L 2 =(L 1 *SW 2 )div SW 1 instead of L 2 =L 1 *(SW 2 div SW 1 ). On most computer systems, the integer division operation between a positive numerator N and positive denominator D truncates or “rounds down” the result to the nearest integer introducing an error E, where −1<E≦0. By multiplying before dividing, the total error is limited to E a where −1<E a ≦0. If division is done before multiplication, the error of the division operation E b where −1<E b ≦0 gets multiplied by L 1 resulting in a larger total error E c where −L 1 <E c ≦0. Thus, we minimize the total error by performing multiplication before division. Integer division between positive numerator N and positive denominator D truncates or “rounds down” the result to the nearest integer, but it is also easy to achieve the effect of rounding up using integer arithmetic. By adding D-1 to N before doing in integer division by D, we can achieve the effect of rounding up. It is desirable to round up the width and height calculations. By slightly adding to the growth of the object, a visual problem such as clipping can be avoided, such as where a portion of the clipped graphical data object would otherwise not be seen in the scaled target screen. This can be counterbalanced by rounding down the left and top coordinate calculations. This way, the error in the right and bottom coordinates is at most 1 unit in either direction. −1 <E L ≦0 −1 <E T ≦0 0< E W <1 0< E H <1 −1< E R =E L+ E W <1 −1< E B =E T+ E H <1. [0050] The calculations should be modified as follows to incorporate the proper rounding: width ratio>height ratio: left of limo: L 2 =( L 1 *SH 2 )div SH 1 T 2 =( T 1 *SH 2 )div SH 1 W 2 =( W 1 *SH 2 +SH 1 −1)div SH 1 H 2 =( H 1 *SH 2 +SH 1 −1)div SH 1 straddling limo: L 2 =( L 1 *SH 2 )div SH 1 T 2 =( T 1 *SH 2 )div SH 1 W 2 =(( W 1 −SW 1 )*SH 2 +SH 1 −1)div SH 1 +SW 2 H 2 =( H 1 *SH 2 +SH 1 −1)div SH 1 right of limo: L 2 =(( L 1 −SW 1 )* SH 2 )div SH 1 +SW 2 T 2 =( T 1 *SH 2 )div SH 1 W 2 =( W 1 *SH 2 +SH 1 −1)div SH 1 H 2 =( H 1 *SH 2 +SH 1 −1)div SH 1 height ratio>width ratio: above limo: L 2 =( L 1 *SW 2 )div SW 1 T 2 =( T 1 *SW 2 )div SW 1 W 2 =( W 1 *SW 2 +SW 1 −1)div SW 1 H 2 =( H 1 *SW 2 +SW 1 −1)div SW 1 straddling limo: L 2 =( L 1 *SW 2 )div SW 1 T 2 =( T 1 *SW 2 )div SW 1 W 2 =( W 1 *SW 2 +SW 1 −1)div SW 1 H 2 =(( H 1 −SH 1 )* SW 2 +SW 1 −1)div SW 1 +SH 2 below limo: L 2 =( L 1 *SW 2 )div SW 1 T 2 =(( T 1 −SH 1 )* SW 2 )div SW 1 +SH 2 W 2 =( W 1 *SW 2 +SW 1 −1)div SW 1 H 2 =( H 1 *SW 2 +SW 1 −1)div SW 1 [0059] FIGS. 6 a - 6 b provide an example of the foregoing technique for integer arithmetic to simplify mathematics of positioning objects on a target screen. FIG. 6 a shows a graphical data object 602 a on a rescaled target screen 600 a prior to the introduction of rounding error. FIG. 6 b shows a graphical data object 602 b on a rescaled target screen 600 b after to the introduction of rounding error. The rounding error so introduced enlarges object 602 a to the size depicted for object 602 b , where the width is moved from 0.1-3.9 to 0.0-4.0, and where the height is moved from 0.3-2.7 to 0.0-3.0. Thus, the position of object 602 a was rounded down with respect to the top edge of the target screen and the left side of the target screen, and was rounded up with respect to the bottom edge of the target screen and the right side of the target screen. As such, graphical data object 602 b has a resultant height of 3 and a width of 4. In summary, the size of the target graphic data object on the target screen seen in FIG. 6 b has been increased by rounding to an integer value the coordinates of the target graphic data object on the target screen. [0060] A designer can design a template having a height-to-width aspect ratio. The designer also specifies the type of graphical data objects that will appear on a screen that is formed from the template. For each type of graphical data object, the designer can further specify whether or not the object can be subjected to limousine stretching. For instance, the designer may specify that no corporate trademark or logo is to be limousine stretched, but is only to be proportionally stretched so as to maintain the original aspect ratio. The designer may further specify that text that will appear on a re-sized version of the original screen template is to be examined for an appropriate font point size that will appear best on the target screen and that the text will be drawn with the best font point size. Finally, the template designer will specify a limousine point on one of the edges of the screen, such as at the bottom edge. The designer can then specify that all other graphical data objects can be, by default, eligible to be limousine stretched when re-sizing a screen from its originally designed dimensions. Accordingly, the designer can design the original screen template to accommodate likely graphical data objects for likely target screens so as to preserve the esthetic appearance of the original screen template. [0061] FIG. 7 depicts a main television guide or electronic programming guide (EPG) screen having an original design resolution of 576 pixels by 480 pixels. The dashed line in FIG. 7 depicts a limousine line that is designed by a screen designer that can be used for limousine scaling. The limousine line extends as a normal to a limousine point at the bottom edge of screen to intersect with a horizontal axis on the top edge of the screen. [0062] FIG. 8 a depicts an EPG screen that has been limousine scaled to a dimension of 576 pixels by 360 pixels, where objects have been scaled by a factor of 75% and the target screen height has been reduced to 75% of the height of the original screen. FIG. 8 a shows interactive on-screen buttons for a “Video Store” function, a “Search” function, and an “Exit to TV” function. These buttons are seen on the left side of the screen and have the same proportions in the target screen as they do in the original screen so that their appearance on the target screen does not have a distorted appearance. The space on the target screen is used effectively by making the program listing section in the EPG on the right side of the target screen proportionally wider than on the original screen. This technique allows long titles, such as “Moment of Truth: Why My Daughter?”, to be displayed without clipping. [0063] FIG. 8 a shows that graphic characteristics for, and the text attached to, the original graphic data objects on the original screen seen in FIG. 7 have been obtained and used in the target graphic data objects on the target screen of FIG. 8 a . The attached text has been reformatted so as to correspond to the target graphic data objects on the target screen seen in FIG. 8 a . Accordingly, the attached text esthetically fits within opposing top and bottom edges and opposing left and right edges of the target graphic data objects on the target screen of FIG. 8 a . Additionally, the graphic characteristics for the original graphic data objects on the original screen in FIG. 7 (e.g., tone, borders, etc.) have been applied to the target graphic data objects on the target screen of FIG. 8 a. [0064] FIG. 8 b depicts the EPG screen of FIG. 7 having been scaled non-proportionally to a dimension of 576 pixels by 360 pixels, where space on the screen has not been used as effectively as the space used in the limousine scaled screen depicted in FIG. 8 a . The on-screen interactive buttons on the left side of the original screen for a “Video Store” function, a “Search” function, and an “Exit to TV” function have an appearance of being too wide. These buttons would be more esthetically pleasing if they had been stretched proportionally rather than to be rendered non-proportionally. Alternatively, the grid on the right side of the original screen can be stretched non-proportionally without appearing distorted. As such, the space at the right side of the screen in FIG. 8 b is not used as effectively as the space in the limousine scaled target screen depicted in FIG. 8 a . Unlike in FIG. 8 a , the text “Moment of Truth: Why My Daughter?” is truncated in FIG. 8 b. [0065] FIG. 9 depicts an EPG screen having been scaled proportionally to a resolution of 432 pixels×360 pixels. For this EPG screen, limousine scaling is not needed because the target screen has the same proportions as the original screen and thus does not have a distorted appearance. [0066] FIG. 10 a depicts a screen having a dimension of 576 pixels by 360 pixels that has not been subjected to limousine stretching. Graphical data objects at the left side of the screen in the depicted scaled version look stretched and have a distorted appearance of being too wide. FIG. 10 b depicts, for comparison purposes, the screen of FIG. 10 a as having a dimension of 432 pixels by 360 pixels, which is a proportionally scaled screen that has not been subjected to non-proportional limousine stretching. [0067] FIG. 11 depicts a screen having a dimension of 576 pixels by 360 pixels, where non-proportional limousine scaling has been used. Most of the graphical elements on the original screen have been stretched toward the right side of the target screen as depicted in FIG. 11 . Limousine scaling is beneficial here in that the ‘Video Store’ button does not have a distorted appearance. [0068] FIG. 12 depicts a screen having a dimension of 576 pixels by 360 pixels, where non-proportional limousine scaling has been used. The result is that the on-screen graphical data objects do not have distorted or misshapen appearances. [0069] FIG. 13 depicts a screen having a dimension of 576, pixels by 360 pixels, where non-proportional limousine scaling has been used. Limousine scaling has stretched most of the graphical elements toward the right side of the target screen. [0070] Exemplary Environment [0071] Various environments are suitable and contemplated the disclosed embodiments in which a single set of user interface (UI) description data can be broadcast (such as via data carousels) to many clients with different screen resolutions and aspect ratios, and where each client can scale the UI to fit the screen because the limousine scaling uses integer arithmetic which is computationally inexpensive. Moreover, broadcast bandwidth usage is minimized by delivering only a single set of UI description data, rather than multiple sets (e.g., one for each different screen resolution). According, the environments for the various disclosed implementations are not limited to an exemplary implementation discussed below with respect to FIG. 14 regarding a TV network infrastructure. [0072] FIG. 14 illustrates an exemplary environment 1400 in which a viewer may receive content via a client that re-sizes the content to fit on a target screen as has been described above. Exemplary environment 1400 is a television entertainment system that facilitates distribution of content to multiple viewers. The environment 1400 includes one or more content providers 1402 , one or more program data providers 1404 , a content distribution system 1406 , and multiple clients 1408 ( 1 ), 1408 ( 2 ), . . . , 1408 (J) coupled to the content distribution system 1406 via a broadcast network 1410 . Each client 1408 ( 1 through J) and the content distribution system 1406 are in communication with a network 1450 that provides two-way communications there between. The system may have two-way communications, but this is not required for the UI page scaling to work. The content distribution system 1406 services requests from the clients 1408 ( 1 )- 1408 (J). Each client 1408 ( j ) can receive an original screen that has been designed for limousine stretching and can perform limousine stretching and integer rounding to output a display of a target screen, as has been described above. [0073] Content provider 1402 includes a content server 1412 and stored content 1414 , such as movies, television programs, commercials, music, and similar audio and/or video content. Content server 1412 controls distribution of the stored content 1414 from content provider 1402 to the content distribution system 1406 . For example, the content server 1412 may broadcast the stored content 1414 to one or more of the clients 1408 ( 1 )- 1408 (J) in response to a request received from the clients 1408 ( 1 )- 1408 (J). Additionally, content server 1402 controls distribution of live content (e.g., content that was not previously stored, such as live feeds) and/or content stored at other locations to the content distribution system 1406 . [0074] Program data provider 1404 stores and provides an electronic program guide (EPG) database. Program data in the EPG includes program titles, ratings, characters, descriptions, actor names, station identifiers, channel identifiers, schedule information, and so on. The terms “program data” and “EPG data” are used interchangeably throughout this discussion, both of which may be thought of as forms of content that may be requested by one or more of the clients 1408 ( 1 )- 1408 (J). [0075] J The program data provider 1404 processes the EPG data prior to distribution to generate a published version of the program data which contains programming information for all channels for one or more days. The processing may involve any number of techniques to reduce, modify, or enhance the EPG data. Such processes might include selection of content, content compression, format modification, and the like. The program data provider 1404 controls distribution of the published version of the program data to the content distribution system 1406 using, for example, a file transfer protocol (FTP) over a TCP/IP network (e.g., Internet, UNIX, etc.). Further, the published version of the program data can be transmitted from program data provider 1404 via a satellite 1434 directly to a client 1408 by use of a satellite dish 1434 . [0076] Content distribution system 1406 includes a broadcast transmitter 1428 , one or more content processors 1430 , and one or more program data processors 1432 . Broadcast transmitter 1428 broadcasts signals, such as cable television signals, across broadcast network 1410 . Broadcast network 1410 can include a cable television network, RF, microwave, satellite, and/or data network, such as the Internet, and may also include wired or wireless media using any broadcast format or broadcast protocol. Additionally, broadcast network 1410 can be any type of network, using any type of network topology and any network communication protocol, and can be represented or otherwise implemented as a combination of two or more networks. Although broadcast transmitter 1428 is illustrated as within the content distribution system 1406 , the broadcast transmitter may also be included with the content server 1412 . [0077] Content processor 1430 processes the content received from content provider 1402 prior to transmitting the content across broadcast network 1410 . Similarly, program data processor 1432 processes the program data received from program data provider 1404 prior to transmitting the program data across broadcast network 1410 . A particular content processor 1430 may encode, or otherwise process, the received content into a format that is understood by the multiple clients 1408 ( 1 ), 1408 ( 2 ), . . . , 1408 (J) coupled to broadcast network 1410 . Although FIG. 14 shows a single content provider 1402 , a single program data provider 1404 , and a single content distribution system 1406 , exemplary environment 1400 can include any number of content providers and/or program data providers coupled to any number of content distribution systems. [0078] Content distribution system 1406 is representative of a head end service with one or more carousels that provides content to multiple subscribers. For example, the content may include a result of processing that was performed in response to a request sent by one or more of the clients 1408 ( 1 )- 1408 (J). Each content distribution system 1404 may receive a slightly different version of the program data that takes into account different programming preferences and lineups. The program data provider 1404 creates different versions of EPG data (e.g., different versions of a program guide) that include those channels of relevance to respective head end services, and the content distribution system 1406 transmits the EPG data to the multiple clients 1408 ( 1 ), 1408 ( 2 ), . . . , 1408 (J). In one implementation, for example, content distribution system 1406 utilizes a carousel file system to repeatedly broadcast the EPG data over an out-of-band (OOB) channel to the clients 1408 . [0079] Clients 1408 can be implemented in a number of ways. For example, a client 1408 ( 1 ) receives broadcast content from a satellite-based transmitter via satellite dish 1434 . Client 1408 ( 1 ) is also referred to as a set-top box or a satellite receiving device. Client 1408 ( 1 ) is coupled to a television 1436 ( 1 ) for presenting the content received by the client (e.g., audio data and video data), as well as a graphical user interface. A particular client 1408 can be coupled to any number of televisions 1436 and/or similar devices that can be implemented to display or otherwise render content. Similarly, any number of clients 1408 can be coupled to a single television 1436 . [0080] Client 1408 ( 2 ) is also coupled to receive broadcast content from broadcast network 1410 and provide the received content to associated television 1436 ( 2 ). Client 1408 (J) is an example of a combination television 1438 and integrated set-top box 1440 . In this example, the various components and functionality of the set-top box are incorporated into the television, rather than using two separate devices. The functionality of the set-top box within the television enables the receipt of different kinds of signals, such as via a satellite dish (similar to satellite dish 1434 ) and/or via broadcast network 1410 . In alternate implementations, clients 1408 may receive signals via network 1450 , such as the Internet, or any other broadcast medium. [0081] Each client 1408 runs one or more applications. As mentioned above, one such application can enable client 1408 ( j ) to receive an original screen that has been designed for limousine stretching and can enable limousine stretching and integer rounding operations so as to output a display of a target screen, as has been described above. Another application may enable a television viewer to navigate through an onscreen program guide, locate television shows of interest to the viewer, and purchase items, view linear programming as well as pay per view and/or video on demand programming. As such, one or more of the program data providers 1404 can include stored on-demand content, such as Video On-Demand (VOD) movie content, and near VOD such as pay per view movie content. The stored on-demand and near on-demand content can be viewed with a client 1408 through an onscreen movie guide, for example, and a viewer can enter instructions to stream a particular movie, or other stored content, down to a corresponding client 1408 . Each client 1408 receives content and adapts the content for output to a target screen that is displayed on the television 1436 . This adaptation process undertaken by the client 1408 includes the limousine stretching and integer rounding techniques as disclosed in this patent. [0082] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

An adjustment is made to the size of an original graphic data object in a substantially rectangular original screen to obtain a target graphic data object on a substantially rectangular target screen having a different aspect ratio than that of the original screen. The size of the original graphic data object is proportionally increased to obtain the target graphic data object on the target screen. The size of the target graphic data object on the target screen is non-proportionally increased by the addition of a stretch distance thereto where a line projecting from a resizing point on and perpendicular to an edge of the original screen intersects the original graphic data object.

FIELD OF THE INVENTION This invention relates to corrosion monitoring apparatus. BACKGROUND OF THE INVENTION Corrosion due to the environment causes problems in many areas, a particular area being the metal reinforcement members often used in buildings. When such members corrode their dimensions increase, this resulting in damage to the building requiring costly repairs. There is thus a need for corrosion monitoring apparatus which can be used to determine the corrosivity of different environments and to measure displacements caused by corrosion, such information being useful in material selection and in specifying corrosion protection. A known method of monitoring corrosion is to expose a metal plate to an environment, and then examine the plate in order to ascertain the effect of the environment thereon. This method suffers from the disadvantages that the exposure period required is generally very long, ie. of the order of years, and that the examination of the plate is time consuming and expensive. SUMMARY OF THE INVENTION According to this invention there is provided corrosion monitoring apparatus comprising a plurality of corrosible members arranged each with at least one surface in contact with a surface of another member, and measurement means responsive to changes in a dimension of the arrangement of members. Preferably the members are arranged in a stack, in which case the members can be apertured, the apparatus including a support passing freely through an aperture in each member and serving to retain the members in the stack. Metal, for example mild steel, washers are particularly suitable for use as the corrosible members. In the apparatus of this invention a plurality of corrosible surfaces contribute to the displacement sensed by the measurement means, and it has been found that meaningful results can be obtained with the apparatus after only a few days. The sensitivity of the apparatus can be changed by changing the number of corrosible members used. DESCRIPTION OF THE DRAWINGS This invention will now be described by way of example with reference to the drawings, in which: FIG. 1 is a perspective view of apparatus according to the invention; FIG. 2 is a sectional view through part of the apparatus of FIG. 1; FIG. 3 is a sectional view of part of an apparatus according to the invention arranged to indicate the time-of-wetness of the corrosible surfaces in the apparatus; FIG. 4 is a sectional view of part of an apparatus according to the invention arranged to determine the effect of electrical voltages on the corrosion of the corrosible members in the apparatus; FIG. 5 is a sectional view of part of an apparatus according to the invention arranged to determine the effect of stress on the corrosion of the corrosible members of the apparatus; and FIG. 6 is a sectional view of part of an apparatus according to the invention arranged to determine corrosion between surffaces of dissimilar materials. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2 of the drawings, the apparatus here shown comprises a plurality of corrosible members in the form of mild steel washers 1 arranged in a stack, the stack having a PTFE sheathed metal support 2 passing freely through the aperture in each washer 1 and serving to retain the washers 1 in the stack. The stack of washers 1 is supported with one end of the stack on a stainless steel base 3, a PTFE disc 4 being interposed between the stack and the base 3. A measurement means in the form of a dial gauge 5 reading to +or-1 micron is mounted in fixed relationship to the base 3 and adjacent the end of the stack of washers 1 remote from the base 3, by means of three mounting members 6 extending between the base 3 and the gauge 5. The mounting members 6 are formed by PTFE sheathed mild steel rods whereby they ar electrically and corrosivley shielded and have a coefficient of thermal expansion matched to that of the stack of washers 1. As shown, the support 2 terminates at its upper (as seen in the drawing) end in an enlarged head 7, and the gauge 5 has an operating member which engages this head 7. A waterproof seal in the form of a bellows 8 extends between the head 7 and the gauge 5 about the operating member of the gauge 5. For use, the apparatus described above is placed in a corrosive environment which will cause corrosion of the washers 1, the gauge 5 having been zeroed. The gauge 5 is thereafter read at suitable intervals according to the expected corrosivity of the environment and the sensitivity of the gauge 5, for example daily near the sea with a gauge readable to two microns, or weekly in an inland rural site with a similar gauge. From the difference between successive readings of the gauge 5 divided by the time interval between the readings and the total number of washer corrosive surfaces, a corrosion rate in, for example, microns per surface per annum, can be calculated. Although in the apparatus described above the corrosive members are mild steel washers it will be appreciated that members of any other corrosible material or materials of interest can otherwise be used. For example the stack can comprise alternate washers of two different materials, eg iron and zinc, whereby the effect of galvanic action on corrosion can be investigated. By burying at least part of the stack in the earth the corrosive effect of the earth can be determined, this being useful in the design of buried cathodic protection systems for metal and concrete structures. It will be understood that "corrosion" as used herein is not limited to the eating away or similar degradation of metallic members but can include the eating away or similar degradation of members of other materials. Accordingly, if the stack comprises washers of plastics or rubber material and is immersed in a fluid such as a lubricant or a hydraulic pressure fluid, the corrosive effects of such fluid on the plastics or rubber material can be investigated. Although the apparatus described above utilises a dial gauge as the measurement means, other devices responsive to displacement in the washer stack, for example an electro-mechanical displacement transducer and in particular a linear voltage displacement transducer, can otherwise be used whereby automatic logging of readings can be carried out. The apparatus described above can be used either in the open at sites where the corrosivity of the atmosphere is being measured, or otherwise in, for example, environmental cabinets to measure the corrosivity of particular controlled atmospheres. Apparatus according to the invention can be used to measure corrosion in many circumstances other than simple exposure to a corrosive environment, and a number of such uses will now be described with reference to FIGS. 3 to 6 of the drawings. Each apparatus to be described is basically the same as that described with reference to FIGS. 1 and 2, and the same reference numerals have been used for corresponding parts. The measuring means (dial gauge) shown in FIG. 1 has been omitted in each case for reasons of clarity. It will be appreciated that each apparatus to be described when complete includes such a measuring means which serves to indicate any changes in the height of the stack of members resulting from corrosion of the corrosible members. In the apparatus of FIG. 3 the stack comprises a plurality of mild steel washers 1 having at each end an electrically insulating PTFE guide disc 4. An electrical voltage is applied across the stack of washers 1, the top and bottom washers 1 being connected to input terminals 10 and 11, the top washer 1 by way of a resistor 12, while a resistance measuring device (not shown) is connected between terminal 11 and a further terminal 13 which is directly connected to the top washer 1 in the stack. This apparatus serves to determine the time-of-wetness, that is the time for which each corrosible surface in the stack is wet, this being an important variable in corrosion studies. After some corrosion the resistance of the stack will be high during dry conditions and low during wet conditions. Thus, the device connected to terminals 11 and 13 will indicate the time-of-wetness, and this value can be included in the corrosion rate calculations carried out. The apparatus shown in FIG. 4 is similar to that shown in FIG. 3, but simply has a source of AC (or DC) connected between the top and bottom washers 1 in the stack. By logging the voltages applied to the stack the effect of such voltages on corrosion can be determined. In the apparatus shown in FIG. 5, the support 2 extends throught the base 3 and terminates in an eye 5 on which weights can be hung. This apparatus can be used to investigate the effect of the stress imposed by applied weights on the corrosion of the washers 1 as measured by the measuring means (not shown). The apparatus shown in FIG. 6 can be used to determine the corrosion rate of steel in concrete, whereby the processes influencing concrete reinforcement corrosion can be studied, and also control of such corrosion by cathodic protection. In this apparatus the stack comprises corrosible mild steel washers 1 each sandwiched between a pair of concrete washers 1A, with adjacent concrete washers 1A being separated by non-corrosible electrically conductive washers 1B. The corrosible washers 1 are connected to one terminal, and the non-corrosible conductive washers 1B are connected to the other terminal, of a voltage source 6. An electrical supply as described with reference to FIGS. 3 and 4 and/or a stress arrangement as described with reference to FIG. 5, can be used with the apparatus of FIG. 6.

The apparatus comprises a stack of corrosible members retained in position by a support, and measurement means, for example a dial gauge, arranged to measure any change in the height of the stack when exposed to a corrosive environment. Electrical potentials and/or mechanical stress can be applied to the stack in order to ascertian the influence thereof on corrosion. The use of a plurality of corrodible surfaces enables amplification of dimensional changes and enables measurements to be obtained in a relatively short time.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an instruction queue of a microprocessor, used to hold prefetched instructions. 2. Description of the Prior Art FIG. 1 shows a microprocessor having an instruction queue according to a prior art. Components of the microprocessor will be explained. A main memory 100 stores instructions and data. An instruction cache 200 temporarily stores some of the instructions stored in the main memory 100 and is accessible at a high speed. An instruction fetch unit 300 fetches an instruction from the main memory 100 or from the cache 200. An instruction decoder 400 decodes an instruction transferred from the fetch unit 300 into an executable instruction. An execution unit 500 executes the executable instruction sent from the decoder 400. A register file 600 stores data required for executing an instruction. A data cache 700 stores part of data stored in the main memory 100 and is accessible at a high speed. Components of the execution unit 500 will be explained. A branch unit 510 executes a branch instruction. An ALU 520 executes an arithmetic instruction or a logic instruction. A shifter 530 executes a shift instruction. A load unit 540 executes a load instruction. A store unit 550 executes a store instruction. The execution unit 500 loads and stores data with respect to the register file 600 and the data cache 700. An instruction queue 800 is arranged between the decoder 400 and the execution unit 500. The queue 800 serves as a buffer. Variable-length instructions involve different fetch times, and therefore, the decoder 400 sometimes unable to continuously supply executable instructions to the execution unit 500. Accordingly, the queue 800 functions to temporarily store and continuously supply executable instructions to the execution unit 500, to improve the performance of the microprocessor. FIG. 2 shows an example of the queue 800 according to the prior art. The instruction queue of FIG. 2 is designed to hold six instructions. This number is only an example and is optional in practice. Components of the queue 800 will be explained. An instruction memory 810 stores instructions supplied by the decoder 400. A write decoder 820 specifies a write address in the instruction memory 810. A read decoder 840 specifies a read address in the instruction memory 810. A write controller 860 controls a write operation. A read controller 865 controls a read operation. A counter 870 provides the write decoder 820 with write address data. A counter 875 provides the read decoder 840 with read address data. An input buffer 880 holds an instruction from the decoder 400 and sends it to the instruction memory 810 in response to a write enable signal from the write controller 860. An output buffer 885 holds an instruction from the instruction memory 810 and sends it to the execution unit 500 in response to a read enable signal from the read controller 865. A validity memory 890 indicates the validity of each instruction stored in the instruction memory 810. A full-valid-state detector 1000 determines whether or not the instruction memory 810 is full of valid instructions. A full-invalid-state detector 1005 determines whether or not the instruction memory 810 has no valid instruction. The counters 870 and 875 are initialized to the same value in response to a reset signal. At this time, the validity memory 890 is completely zeroed to indicate that the instruction memory 810 is empty. A write operation in the initial state will be explained. The decoder 400 provides the queue 800 with a write request and an instruction to write. The write decoder 820 receives write address data from the counter 870 through a line 871 and specifies a write address in the instruction memory 810 through lines 821 to 826. The write controller 860 supplies a write enable signal to the input buffer 880 through a line 862. Then, the instruction is written into the instruction memory 810 at the specified address. At the same time, the write decoder 820 sends "1" to indicate the validness of the written instruction to a corresponding one of flip-flops 891 to 896 of the validity memory 890 through lines 831 to 836. The write controller 860 increments the counter 870 by one through a line 861. Any instruction from the decoder 400 is written into the instruction memory 810 as long as the memory 810 has a vacancy. When the instruction memory 810 becomes full of valid instructions, the full-valid-state detector 1000 detects it and sends a write prohibition request to the write controller 860. Then, the write controller 860 provides the input buffer 880 with no write enable signal even if the decoder 400 provides an instruction and a write request. If an instruction is read out of the instruction memory 810, the full-valid-state detector 1000 withdraws the write prohibition request. Then, the write controller 860 provides the input buffer 880 with a write enable signal whenever the decoder 400 sends an instruction request and an instruction to write. A read operation will be explained. The execution unit 500 issues a read request. The read decoder 840 receives read address data from the counter 875 through a line 876 and specifies a read address in the instruction memory 810 through lines 841 to 846. The read controller 865 provides the output buffer 885 with a read enable signal through a line 867 so that an instruction is read out of the specified address of the instruction memory 810. At the same time, the read decoder 840 sends "0" to indicate the invalidness of the read address to a corresponding one of the flip-flops 891 to 896 of the validity memory 890 through lines 851 to 856 and OR gates 901 to 906. The read controller 865 increments the counter 875 by one through a line 866. Any read request is met as long as the instruction memory 810 has valid instructions. When the instruction memory 810 becomes empty, the full-invalid-state detector 1005 detects it and provides the read controller 865 with a read prohibition request. Upon receiving the read prohibition request, the read controller 865 provides the output buffer 885 with no read enable signal even if the execution unit 500 issues a read request. If a new instruction is written into the instruction memory 810 so that the memory 810 has at least one valid instruction, the full-invalid-state detector 1005 withdraws the read prohibition request. Consequently, the read controller 865 provides the output buffer 885 with the read enable signal whenever the execution unit 500 issues a read request. If an exception or a branch instruction is effected, valid instructions stored in the instruction memory 810 will be unnecessary. In this case, a reset signal zeroes the validity memory 890. As explained above, write and read operations with respect to the instruction memory 810 are carried out independently of each other. The read counter 875 follows the write counter 870, and therefore, instructions are read out of the instruction memory 810 in written order. If the instruction memory 810 is full of valid instructions, any write request is rejected, and if the memory 810 is empty, any read request is rejected. To explain the problems of the prior art, the operating conditions of the microprocessor and queue 800 will be explained first. The fetch unit 300 fetches hit instructions from the cache 200 at a rate of two instructions in two cycles. The fetch unit 300 fetches cache-missed instructions from the main memory 100 at a rate of two instructions in four cycles. The branch unit 510, load unit 540, and store unit 550 of the execution unit 500 need each two cycles to execute an instruction, and the ALU 520 and shifter 530 thereof need each a cycle to execute an instruction. Only after completely executing a given instruction, the execution unit 500 provides the queue 800 with a read request. Write and read requests to the queue 800 are never simultaneously made. For example, a write request is made in the first half of a cycle and a read request in the second half thereof. When write and read requests continuously occur, they occur only alternately and never simultaneously. If the fetch unit 300 fetches hit instructions from the cache 200 continuously, it will be able to provide the decoder 400 with an instruction every cycle. Then, the decoder 400 may provide the queue 800 with a write request every cycle. If instructions to be executed by the ALU 520 or shifter 530 are continuously supplied to the execution unit 500, the execution unit 500 will provide the queue 800 with a read request every cycle because the instructions are executed cycle by cycle. If load and store instructions each needing two cycles to execute are continuously supplied to the execution unit 500, the execution unit 500 will intermittently provide the queue 800 with read requests. During this period, instructions transferred from the decoder 400 are stored in the queue 800. If the cache 200 does not have an instruction requested by the fetch unit 300, the cache 200 must be refilled. Until the cache 200 is refilled with instructions, the fetch unit 300 is unable to supply instructions to the decoder 400. This causes an idling period of two in four cycles. If a branch instruction comes, the fetch unit 300 must change an instruction fetching address accordingly. Then, the fetch unit 300 will miss the cache 200 and must access the main memory 100. During this operation, a read request from the execution unit 500 is rejected. During a period between receiving a branch instruction by the queue 800 and executing the same by the execution unit 500, the queue 800 accumulates instructions sent from the decoder 400. There is a great probability of these instructions being not executed once the branch instruction is executed. The fetching of these useless instructions deteriorates the CPI (clock cycles per instruction) and performance of the microprocessor. As explained above, the prior art frequently misses the cache 200 when executing a branch instruction and must access the main memory 100 until the cache 200 is refilled with required instructions. This results in idling the execution unit 500 without instructions to execute. Further, the prior art accumulates useless instructions in the queue 800 while passing the branch instruction from the decoder 400 to the execution unit 500 through the queue 800. Due to these problems, the performance of the microprocessor of the prior art drops whenever a branch instruction occurs. SUMMARY OF THE INVENTION An object of the present invention is to provide an instruction queue that quickly determines, whenever a branch instruction is fetched, instructions that have been fetched before the branch instruction and are independent of the branch instruction. The instruction queue puts the independent instructions behind the branch instruction so that a microprocessor that employs the instruction queue may execute the independent instructions until instructions specified by the branch instruction are fetched, thereby improving the operating efficiency of the microprocessor. In order to accomplish the object, the present invention provides an instruction queue having a dependence detector, a branch instruction detector, an order controller, and a mask. The dependence detector detects data dependence between an instruction to be written into an instruction memory and instructions presently stored in the instruction memory. The branch instruction detector determines whether or not the instruction to be written into the instruction memory is a branch instruction. If the branch instruction detector detects a branch instruction, the order controller refers to the data dependence detected by the dependence detector, to find out instructions that are independent of the branch instruction among the instructions stored in the instruction memory. The order controller puts the independent instructions behind the branch instruction so that the branch instruction may be read out of the instruction memory before the independent instructions. The mask excludes the independent instructions from the instructions that are in the instruction memory and are invalidated when the branch instruction is written into the instruction memory. The order controller may consist of a dependence block and an order block. The dependence block generates branch instruction dependence data that clarifies dependence of the instructions stored in the instruction memory on the branch instruction, according to the branch instruction and the data dependence detected by the dependence detector. Whenever an instruction is read out of or written into the instruction memory, the order block determines the order of reading instructions out of the instruction memory and stores the instruction reading order. The order block changes the instruction reading order according to the branch instruction dependence data so that the branch instruction is read out of the instruction memory before the instructions that are independent of the branch instruction. The dependence block may consist of a dependence memory, a dependence generator, a branch instruction dependence provider, and a specifier. The dependence memory stores dependence data. The dependence generator generates dependence data according to the dependence data stored in the dependence memory and the data dependence provided by the dependence detector and stores the generated dependence data in the dependence memory. The branch instruction dependence provider provides the branch instruction dependence data for the instructions stored in the instruction memory, according to the dependence data stored in the dependence memory and a signal informing of detection of the branch signal. The specifier specifies a location in the dependence memory to store the dependence data generated by the dependence generator according to the data dependence provided by the dependence detector. The order block may consist of an order memory, a fore instruction data provider, a hind instruction data provider, an input controller, and a read select signal generator. The order memory stores order data that determines the order of reading instructions out of the instruction memory and specifies a write address in the instruction memory. The fore instruction data provider provides the order memory with fore instruction data for the instructions stored in the instruction memory. The hind instruction data provider provides the order memory with hind instruction data for the instructions stored in the instruction memory. The input controller controls the storing of the fore and hind instruction data into the order memory and changes the order data in the order memory to change the order of reading instructions out of the instruction memory. The read select signal generator generates a read select signal according to the order data stored in the order memory. The read select signal is used to select an instruction to be read out of the instruction memory. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a microprocessor having an instruction queue according to a prior art; FIG. 2 shows an example of the instruction queue of FIG. 1; FIG. 3 shows a microprocessor having an instruction queue according to an embodiment of the present invention; FIG. 4 shows the details of the instruction queue of FIG. 3; FIG. 5 shows an order controller contained in the instruction queue of FIG. 4; FIG. 6 shows an order block contained in the order controller of FIG. 5; and FIG. 7 shows a dependence block contained in the order controller of FIG. 5. DETAILED DESCRIPTION OF THE EMBODIMENTS FIG. 3 shows a microprocessor having an instruction queue according to an embodiment of the present invention. The microprocessor is a single pipeline RISC processor. A main memory 10 stores instructions and data. An instruction cache 20 temporarily stores some of the instructions stored in the main memory 10 and is accessible at a high speed. An instruction fetch unit 30 fetches an instruction from the main memory 10 or from the cache 20. An instruction decoder 40 decodes an instruction transferred from the fetch unit 30 into an executable instruction. An execution unit 50 executes the executable instruction sent from the decoder 40. A register file 60 stores data required for executing an instruction. A data cache 70 stores part of data stored in the main memory 10 and is accessible at a high speed. The fetch unit 30, decoder 40, and execution unit 50 form a pipeline that simultaneously handles a plurality of instructions. Components of the execution unit 50 will be explained. A branch unit 51 executes a branch instruction. An ALU 52 executes an arithmetic instruction or a logic instruction. A shifter 53 executes a shift instruction. A load unit 54 executes a load instruction. A store unit 55 executes a store instruction. The execution unit 50 loads and stores data with respect to the register file 60 and the data cache 70. An instruction queue 80 is arranged between the decoder 40 and the execution unit 50. The queue 80 serves as a buffer. Variable-length instructions involve different fetch times, and therefore, the decoder 40 sometimes unable to continuously supply executable instructions to the execution unit 50. Accordingly, the queue 80 functions to temporarily store and continuously supply executable instructions to the execution unit 50, to improve the performance of the microprocessor. FIG. 4 shows the details of the queue 80. In the figure, the same reference numerals as those of the prior art of FIG. 2 represent like parts, and they are not explained again. The queue 80 does not have the write address counter 870 and read address counter 875 of the prior art. A dependence detector 1100 compares destination register numbers specified by the instruction codes of instructions stored in an instruction memory 810 with source and destination register numbers specified by the instruction code of an instruction to be stored in the instruction memory 810, to detect data dependence between them. A branch instruction detector 1200 determines whether or not the instruction to be written into the instruction memory 810 is a branch instruction. An order controller 1300 provides the functions of the counters 870 and 875 of the prior art and controls the order of reading instructions out of the instruction memory 810 so that instructions that are independent of a branch instruction are read after the branch instruction. A mask 1400 keeps the independent instructions in the instruction memory 810 when the contents of the instruction memory 810 are invalidated in response to the writing of the branch instruction into the instruction memory 810. When the decoder 40 provides the queue 80 with an instruction and a write request, the dependence detector 1100 checks the dependence of valid instructions stored in the instruction memory 810 on the instruction to be written. A result of the checking is transferred to the order controller 1300 through a line 1110. At this time, the detector 1100 compares the source and destination register data of the instruction to be written with the destination register data of the valid instructions in the instruction memory 810. Comparing the source register data of the instruction to be written with the destination register data of the valid instructions is to detect a read after write (RAW) hazard. Comparing the destination register data of the instruction to be written with the destination register data of the valid instructions is to detect a write after read (WAR) hazard and a write after write (WAR) hazard. The branch instruction detector 1200 checks the operation code of the instruction to be written into the instruction memory 810. If the instruction is a branch instruction, the detector 1200 provides a branch instruction detected signal BI to the order controller 1300 through a line 1210. When a given instruction is written into the instruction memory 810, the order controller 1300 writes dependence data provided by the dependence detector 1100 into a location corresponding to an address of the instruction memory at which the instruction has been written. The dependence data is valid until the instruction in question is read out of the instruction memory 810, or until the instruction is invalidated with a disable signal provided by the execution unit 50 due to branching, etc. A validity memory 890 provides the order controller 1300 with validity data through a line 897. The validity data indicates valid instructions in the instruction memory 810. The order controller 1300 holds order data for the valid instructions in the instruction memory 810. The order data indicates the order of reading the instructions from the memory 810. The order data is created by the order controller 1300 in response to a write enable signal provided by a write controller 860 and based on an address of the memory 810 specified by the order controller 1300. More precisely, order data for an instruction just written into the instruction memory 810 indicates lowest read priority, and order data for instructions already stored in the memory 810 indicates higher priority than the just written instruction. When a read controller 865 provides a read enable signal through a line 868, the order controller 1300 specifies a read address according to the order data. The validity memory 890 provides the addresses of valid instructions in the instruction memory 810 through the line 897. If a given instruction in the instruction memory 810 is invalid, the order data for the instruction is also invalid. When the branch instruction detector 1200 provides the signal BI to indicate the reception of a branch instruction, the order controller 1300 refers to the stored dependence data and creates dependence data for the branch instruction and valid instructions stored in the instruction memory 810. When the branch instruction is written into the instruction memory 810, the order controller 1300 stores order data indicating that the branch instruction has lowest priority and that the instructions already stored in the instruction memory 810 have higher priority than the branch instruction. The order data is changed so that some of the instructions in the instruction memory 810 that are independent of the branch instruction are read after the branch instruction. Namely, any instruction stored in the queue 80 that has no data dependence on a given branch instruction is read after the branch instruction. The prior art of FIG. 2 zeroes the validity memory 890 to invalidate the contents of the instruction memory 810 in response to a reset signal that is generated when a branch instruction is written into the instruction memory 810. On the other hand, when a branch instruction is given, the present invention preserves some instructions that are independent of the branch instruction and puts them behind the branch instruction in the instruction memory 810 so that the independent instructions may be read after the branch instruction. For this purpose, validity data in the validity memory 890 for these independent instructions must not be cleared in response to the branch instruction. The mask 1400 is arranged for this purpose. The mask 1400 receives branch instruction dependence data from the order controller 1300 and sets some of sections 1401 to 1406 of the mask 1400 corresponding to the instructions that are independent of the branch instruction, to thereby exclude these instructions from the clearing operation of the validity memory 890. These preserved independent instructions are read and executed after the branch instruction. The dependence detector 1100 is realized by standardizing the register code region of each instruction code and by employing a CAM (content addressable memory) as a part for storing destination register codes in the instruction memory 810 so that columns of bits are retrievable. The branch instruction detector 1200 is realized with a comparator that compares the operation code of an instruction to be written into the instruction memory 810 with each of predetermined branching operation codes. The mask 1400 is realized with AND gates for receiving the branch instruction dependence data and disable signals and flip-flops controlled by the outputs of the AND gates. The order controller 1300 will be explained. FIG. 5 is a general view showing the order controller 1300. The order controller 1300 mainly consists of an order block 2000 and a dependence block 2100. The order block 2000 holds order data and provides a read decoder 840 and a write decoder 820 with data for specifying an address in the instruction memory 810. The dependence block 2100 refers to dependence data provided by the dependence detector 1100, stores dependence data for each valid instruction stored in the instruction memory 810, and supplies branch instruction dependence data to the mask 1400 and order block 2000. The order block 2000 will be explained. An order memory 2010 stores order data for each address of the instruction memory 810. A fore instruction data provider 2020 provides fore instruction data to each column of the order memory 2010. A hind instruction data provider 2030 provides hind instruction data to each row of the order memory 2010. An input controller 2040 controls the writing of data provided by the data providers 2020 and 2030 into the order memory 2010. A read select signal generator 2050 (FIG. 6) provides the read decoder 840 with a read select signal according to the order data stored in the order controller 1300. The numbers of rows and columns of the order memory 2010 are determined based on the maximum number of instructions stored in the instruction memory 810. In this embodiment, the instruction memory 810 stores six instructions at the maximum, and therefore, the order memory 2010 consists of six rows and six columns. FIG. 6 shows the details of the order block 2000. Each row of the order memory 2010 holds order data for a corresponding instruction stored in the instruction memory 810. For the sake of simplicity of explanation, it is assumed that the instruction memory 810 has instruction storage addresses 1 to 6. Rows 1 to 6 of the order memory 2010 correspond to the addresses 1 to 6 of the instruction memory 810, respectively. Each cell in, for example, the row 1 is expressed as (1, *). If a cell (2, 3) in the row 2 is 1, it means that an instruction stored at the address 2 is behind an instruction stored at the address 3. If the cell (2, 3) is 0, the instruction at the address 2 is prior to the instruction at the address 3. Six logic gate sets each including logic gates 2027, 2028, 2051, 2061, 2062, 2063, and 2064 are arranged for the order memory 2010. The row 1 of the order memory 2010 is connected to a storage area 2021 of the fore instruction data provider 2020 through a line 2011. Similarly, the row 2 is connected to a storage area 2022, the row 3 to a storage area 2023, and so on. The operation of the order memory 2010 will be explained. The input controller 2040 provides "1" to allow data to be written into a corresponding row of the order memory 2010 and "0" to prohibit the same. It is assumed that the input controller 2040 provides "1" for every row of the order memory 2010 and that the format of the order memory 2010 is as follows: ______________________________________000000(1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)000000(2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)000000(3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)000000(4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)000000(5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)000000(6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6)______________________________________ If (1, 3)=1 and the other cells are each 0, then the order memory 2010 is expressed as follows: ______________________________________001000(1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)000000(2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)000000(3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)000000(4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)000000(5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)000000(6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6)______________________________________ The order memory 2010 is reset to the following initial state: ______________________________________011111(1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)001111(2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)000111(3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)000011(4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)000001(5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)000000(6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6)______________________________________ In the initial state, the instruction memory 810 is empty. This initial state indicates that an instruction corresponding to the row 6 has highest priority, and the priority decreases in order of the rows 5, 4, 3, 2, and 1. A write operation will be explained. The order controller 1300 provides a write select signal through a line 1310 based on a row of the order memory 2010 having cells of each 0. In the above initial state, the row 6 has "0" in each cell. Accordingly, the write select signal indicates the address 6 that corresponds to the row 6. According to the write select signal, an instruction is written into the address 6 in the instruction memory 810. At the same time, an area 2036 of the hind instruction data provider 2030 corresponding to the row 6 receives "1" to write "1" into each cell (6, *) of the row 6. This indicates that the newly written instruction is the last valid instruction in the instruction memory 810. To write "1" into a proper area (the area 2036 in the above example) of the hind instruction data provider 2030, the write select signal is used. Namely, the write select signal is supplied to the data provider 2030 through a line 2011, an AND gate 2061, and a line 2013 in synchronization with a write enable signal supplied through a line 863b. At this moment, instructions corresponding to the rows 1 to 5 must have data indicating that they are prior to the instruction corresponding to the row 6. This is made by writing "0" in cells (*, 6) in the column 6 of the order memory 2010. To achieve this, "1" is written into an area 2026 of the fore instruction data provider 2020 so that "0" is written into the cells (*, 6) in the column 6 in response to an inversion of the write enable signal supplied to the buffer 2028 through a line 863C. Then, the order memory 2010 is as follows: ______________________________________011110(1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)001110(2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)000110(3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)000010(4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)000000(5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)111110(6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6)______________________________________ Since each cell in the row 5 is "0," a write select signal specifying the address 5 of the instruction memory 810 is provided in the next write operation. If an instruction is written at the address 5 in the same manner as at the address 6, the order memory 2010 will be as follows: ______________________________________011100(1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)001100(2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)000100(3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)000000(4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)111101(5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)111100(6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6)______________________________________ Each cell in the row 4 has "0." If an instruction is written at the address 4 in the instruction memory 810, the order memory 2010 will be as follows: ______________________________________011000(1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)001000(2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)000000(3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)111011(4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)111001(5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)111000(6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6)______________________________________ Each cell in the row 3 has "0." If an instruction is written at the address 3 in the instruction memory 810, the order memory 2010 will be as follows: ______________________________________010000(1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)000000(2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)110111(3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)110011(4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)110001(5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)110000(6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6)______________________________________ Each cell in the row 2 has "0." If an instruction is written at the address 2 in the instruction memory 810, the order memory 2010 will be as follows: ______________________________________000000(1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)101111(2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)100111(3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)100011(4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)100001(5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)100000(6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6)______________________________________ Each cell in the row 1 has "0." If an instruction is written at the address 1 in the instruction memory 810, the order memory 2010 will be as follows: ______________________________________011111(1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)001111(2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)000111(3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)000011(4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)000001(5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)000000(6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6)______________________________________ In this way, the order memory 2010 stores order data for instructions stored in the instruction memory 810. An address corresponding to a row whose cells have each "0" is used as a read address, to form an FIFO. This technique is known as a least recently used (LRU) method, which is described in "bit" Vol. 15, No. 4, pp. 327 to 328. The present invention adds new functions to this technique. The above technique may function when write and read operations alternate with the instruction memory 810 being continuously filled with instructions. The above technique, however, will not properly function if a read request is made when the instruction memory 810 is empty, or if read requests consecutively occur. In addition, the above technique is incapable of changing order of instructions. The read select signal generator 2050 of the present invention has an additional read function. The generator 2050 has AND gates 2051 and 2053 and a NOR gate 2052. Although the generator 2050 is attached to the row 6 in FIG. 6, it is actually attached to every row of the order memory 2010. The NOR gate 2052 is a zero detector. The AND gates 2051 receive order data from the order memory 2010 and validity data from the validity memory 890. If a given instruction stored in the instruction memory 810 is invalid, validity data supplied to the corresponding row of the order memory 2010 is "0" to zero each of the AND gates 2051. Namely, rows of the order memory 2010 corresponding to invalid instructions are masked so that order data is prepared only for valid instructions. If an instruction is written into the instruction memory 810 that is empty and if a read request is made at once, each cell in a corresponding row of the order memory 2010 has 1 except the cell related to the row itself. At this time, the outputs of the AND gates 2051 are each "0" due to validity data, and therefore, the NOR gate 2052 provides "1." The AND gate 2053 calculates an AND of the output of the NOR gate 2052, the validity data, and a read enable signal and provides a read select signal to meet the read request. The reason why the AND gate 2053 employs the validity data in addition to the read enable signal is because the NOR gate 2052 of the next row having "0" in every cell thereof will provide "1" if validity data for the row shows invalidness. In this case, the NOR gates 2052 of the consecutive two rows provide each "1." The validity data to the AND gates 2053 of the two rows serves to select a valid one of the two rows. If the row having "0" in every cell thereof corresponds to a valid instruction stored in the instruction memory 810, a read address is identical to a write address. In this case, only the NOR gate 2052 of the row in question provides "1." In this way, the order memory 2010 is adaptable to the number of valid instructions. The order data stored in the order memory 2010 must be changed depending on situations. For this purpose, an inversion of branch instruction dependence data is supplied to the fore instruction data provider 2020 through an inverter gate 2062, a line 2104, and an OR gate 2027. The branch instruction dependence data is also supplied to the input controller 2040. A technique of putting instructions that are independent of a branch instruction behind the branch instruction will be explained. It is supposed that the order memory 2010 is in the following state: ______________________________________011110(1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)001110(2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)000110(3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)000010(4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)000000(5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)111110(6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6)______________________________________ Then, a branch instruction is going to be written at the address 5 in the instruction memory 810 corresponding to the row 5 of the order memory 2010. It is supposed that the other addresses of the instruction memory 810 have valid instructions and that the instructions stored at the addresses 2 and 4 are independent of the branch instruction. These independent instructions must be put behind the branch instruction. A request for writing the branch instruction occurs in a second half period. Since cells (5, *) in the row 5 of the order memory 2010 have each "0," a write enable signal from the order controller 1300 specifies the address 5 to store the branch instruction. Once the branch instruction is stored at the address 5 in the instruction memory 810, the hind instruction data provider 2030 makes the order memory 2010 as follows: ______________________________________011110(1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)001110(2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)000110(3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)000010(4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)111111(5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)111110(6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6)______________________________________ In a usual operation, the fore instruction data provider 2020 writes "0" into each cell in the column 5 so that each cell in the row 4 has "0" to make an instruction stored at the address 4 in the instruction memory 810 ready to be read. However, the instruction at the address 4 must be read after the branch instruction written at the address 5. Namely, the fore instruction data provider 2020 must exclude cells (2, 5) and (4, 5) when writing "0" into the column 5 so that the instructions at the addresses 2 and 4 are read after the branch instruction at the address 5. Only thereafter, "1" in the cells (2, 5) and (4, 5) must be cleared. Instructions other than the instructions at the addresses 2 and 4 must be executed first. For this purpose, the fore instruction data provider 2020 writes "0" into the columns 2 and 4 in addition to the column 5. At this time, the cells (2, 2), (2, 4), (4, 2), and (4, 4) must be masked so that the instructions at the addresses 2 and 4 are read after the branch instruction. These operations are easy to carry out for the arrangement of FIG. 6. Namely, when writing "0" in the columns 2, 4, and 5, the rows 2 and 4 are masked to maintain their order data. As a result, the order memory 2010 will be as follows: ______________________________________Writing "0" ↓ ↓↓001000(1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)001110(2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)000000(3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)000010(4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)101001(5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)101000(6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6)______________________________________ Since each cell in the row 3 is "0," the instruction corresponding to the row 3 is read by jumping the instruction corresponding to the row 4. If an instruction is written at the address 3, related order data is written into the row 3, and "0" is written into the column 3. Thereafter, the instruction corresponding to the row 2 is skipped, and the instruction corresponding to the row 1 is read. Then, the instruction corresponding to the row 6 is read. Any instruction newly written during the above operation receives the lowest read priority. Namely, the newly written instructions will be read after the instructions corresponding to the rows 2 and 4 that have been put behind the branch instruction. After the instruction stored at the address 6 corresponding to the row 6 is read, the branch instruction at the address 5 corresponding to the row 5 is read. Then, the instruction at the address 4 corresponding to the row 4 is read, and the instruction at the address 3 corresponding to the row 3. In this way, instructions that are independent of a given branch instruction are put behind the branch instruction. Branch instruction dependence data provided by the dependence block 2100 is "1" to indicate dependence and "0" to indicate independence. This data is provided when "0" is written into a corresponding column of the order memory 2010 in response to a branch instruction. To mask a given row, the input controller 2040 receives the branch instruction dependence data through the AND gate 2063 and OR gate 2064 when "0" is written into a corresponding column. Usually, the input controller 2040 provides "1" to each row when "0" is written into a given column. If a branch instruction is detected, the input controller 2040 provides "0" for any row corresponding to an instruction that is independent of the branch instruction, to allow no data to be written into the row. An inversion of the branch instruction dependence data is supplied to the fore instruction data provider 2020 so that "0" is written into columns corresponding to instructions that are independent of the branch instruction when "0" is written into a column corresponding to a newly written instruction. Although the above example puts two instructions behind a branch instruction, any number of instructions may be put behind a branch instruction. In FIG. 6, the input controller 2040 receives the same data as the hind instruction data provider 2030 when writing "1" into a given row. If no branch instruction is detected, the data provider 2030 can specify by itself a row to write "1," and therefore, data provided through the AND gate 2061, line 2014, and OR gate 2064 will not be required. The timing of writing order data will be summarized. The hind instruction data provider 2030 provides the order memory 2010 with data in synchronization with a write request signal that is generated in the second half of a given period of a clock signal. The fore instruction data provider 2020 provides the order memory 2010 with data in the first half of the next period of the clock signal. A write select signal is supplied to both the fore and hind instruction data providers 2020 and 2030. The write select signal is temporarily stored in a corresponding one of the areas 2021 to 2026 of the fore instruction data provider 2020 in the first half of a period of the clock signal and is provided in the second half of the period. Branch instruction dependence data is provided only when a branch instruction is detected at the same timing as the data provided by the fore instruction data provider 2020. The dependence block 2100 will be explained with reference to FIG. 7. A dependence memory 2110 stores dependence data for each instruction stored in the instruction memory 810. A branch instruction dependence provider 2140 has OR gates 2141 and 2142 and a latch circuit 2143. The OR gates 2141 provide each an OR of a corresponding column of the dependence memory 2110. When a branch instruction is detected, the OR gate 2142 provides an OR of the output of the OR gate 2141 and an inversion of the branch instruction detected signal BI, to generate branch instruction dependence data, which is supplied to the order block 2000. A specifier 2130 specifies a column for which the branch instruction dependence provider 2140 provides an OR, according to dependence data provided by the dependence detector 1100 through a line 1111. The specifier 2130 also specifies a row to which the dependence data is written. A dependence generator 2120 has OR gates 2121 that provide each an OR of the output of a corresponding one of the OR gates 2141 and the dependence data provided by the dependence detector 1100. The outputs of the OR gates 2121 are stored in storage areas 2121 to 2126, respectively. The storage areas supply their data to respective columns of the dependence memory 2110 through buffers 2123. The OR gate 2142 is provided for each of the six OR gates 2141, to provide corresponding branch instruction dependence data. There are six OR gates 2121 for the six storage areas 2121 to 2126. Each OR gate 2121 receives corresponding dependence data and the output of the corresponding OR gate 2141. Similar to the order memory 2010, the dependence memory 2110 is an array of 6 rows and 6 columns. The rows 1 to 6 of the dependence memory 2110 correspond to the addresses 1 to 6 of the instruction memory 810, respectively. The dependence memory 2110 has the following initial state with "0" in each cell: ______________________________________000000D(1, 1), D(1, 2), D(1, 3), D(1, 4), D(1, 5), D(1, 6)000000D(2, 1), D(2, 2), D(2, 3), D(2, 4), D(2, 5), D(2, 6)000000D(3, 1), D(3, 2), D(3, 3), D(3, 4), D(3, 5), D(3, 6)000000D(4, 1), D(4, 2), D(4, 3), D(4, 4), D(4, 5), D(4, 6)000000D(5, 1), D(5, 2), D(5, 3), D(5, 4), D(5, 5), D(5, 6)000000D(6, 1), D(6, 2), D(6, 3), D(6, 4), D(6, 5), D(6, 6)______________________________________ If an instruction corresponding to the row 1 is dependent on an instruction corresponding to the row 2, the dependence memory 2110 is as follows: ______________________________________010000D(1, 1), D(1, 2), D(1, 3), D(1, 4), D(1, 5), D(1, 6)000000D(2, 1), D(2, 2), D(2, 3), D(2, 4), D(2, 5), D(2, 6)000000D(3, 1), D(3, 2), D(3, 3), D(3, 4), D(3, 5), D(3, 6)000000D(4, 1), D(4, 2), D(4, 3), D(4, 4), D(4, 5), D(4, 6)000000D(5, 1), D(5, 2), D(5, 3), D(5, 4), D(5, 5), D(5, 6)000000D(6, 1), D(6, 2), D(6, 3), D(6, 4), D(6, 5), D(6, 6)______________________________________ Dependence data provided by the dependence detector 1100 is insufficient to define dependence among all valid instructions stored in the instruction memory 810. It is necessary to consider dependence among the valid instructions already stored in the instruction memory 810. More precisely, the dependence detector 1100 provides information about whether or not an instruction (for example, an instruction A) to be stored in the instruction memory 810 is directly dependent on valid instructions (for example, valid instructions B to F) already stored in the instruction memory 810. On the other hand, the dependence memory 2110 provides information that, for example, the instruction A is directly dependent on the instruction C, and that the instruction C is dependent on the instruction E. Namely, the dependence memory 2110 tells that the instruction A is directly dependent on the instruction C and indirectly on the instruction E. The dependence detector 1100 provides dependence data for a given instruction a half period before the instruction is written into the instruction memory 810. The specifier 2130 sets the dependence data from the dependence detector 1100 to a corresponding one of the storage areas 2131 to 2136. The OR gate 2141 provides an OR of a column of dependence data corresponding to the instruction and transfers it to the dependence generator 2120 through a line 2111. At this time, the dependence data from the dependence detector 1100 is also transferred to the dependence generator 2120 through a line 1112. The corresponding OR gate 2121 of the dependence generator 2120 provides an OR of the data supplied through the lines 1112 and 2111. The output of the OR gate 2121 is temporarily stored in a corresponding one of the storage areas 2121 to 2126. A write select signal for the instruction in question is supplied to the specifier 2130 through a line 2015, to write the temporarily stored dependence data into a specified row of the dependence memory 2110. This operation is carried out for every instruction written into the instruction memory 810. Then, dependence data in the dependence memory 2110 covers every valid instruction stored in the instruction memory 810. Dependence data for a branch instruction is generated in the same manner and is stored in the dependence memory 2110. As soon as the dependence data is stored, the corresponding OR gate 2141 receives a column of dependence data from a corresponding column of the dependence memory 2110. The output of the OR gate 2141 is given to the corresponding OR gate 2142. The branch instruction detected signal BI supplied through the line 1210 is inverted, and the inverted signal is delayed by a half period and supplied to the OR gate 2142 in synchronization with a write enable signal. The output of the OR gate 2142 is temporarily held in the latch circuit 2143. Thereafter, the branch instruction dependence provider 2140 provides branch instruction dependence data related to the branch instruction in question to the order block 2000 through a line 2102 and to the mask 1400 through lines 1330 and 1340. Dependence data in the dependence memory 2110 for a given instruction must be cleared when the instruction is read out. For this purpose, column data in the dependence memory 2110 corresponding to the read instruction is cleared. Namely, the order block 2000 provides the memory 2110 with a read select signal for specifying the instruction through a line 2016 to clear the corresponding column data. The instruction queue 80 having the above-mentioned arrangement is capable of changing the order of reading instructions so that instructions that are independent of a branch instruction are put behind the branch instruction.

An instruction queue 80 maintains the CPI (clock cycles per instruction) and performance of a microprocessor that employs the instruction queue even if a branch instruction is executed. The queue 80 stores valid instructions in an instruction memory 810. When a branch instruction is supplied to the queue 80, the queue 80 detects instructions that are independent of the branch instruction in the memory 810, and an order controller 1300 puts the independent instructions behind the branch instruction in the memory 810. The queue 80 quickly finds a branch instruction, to let a cache start refilling speedily. While the cache is being refilled, the independent instructions put behind the branch instruction are executed to improve the CPI.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a Continuation-In-Part of application Ser. No. 09/757,053 filed Jan. 8, 2001, of Ser. No. 09/970,368 filed Oct. 2, 2001, and of Ser. No. 10/132,331 filed on Apr. 24, 2002. BACKGROUND FIELD OF INVENTION [0002] The field of invention relates to three dimensional signature management or 3-D signature control technology (also known as cloaking) which has been described by the present inventor in related applications cross referenced in the present application. Some advantages can be gained from adapting these prior architectures to provide a system which passively conducts electromagnetic from multiple concurrent background perspectives and presents them to multiple concurrent observer positions as described in the related applications while omitting the need for a conductive fiber-optic or light pipe. [0003] This continuation in part describes a transmissive 3-D camouflaging architecture replaces the internal reflective means of the related applications (fiber optics or light pipes) with an external reflective means (mirrors in series). BACKGROUND DESCRIPTION OF PRIOR INVENTION [0004] The concept of rendering objects invisible has long been contemplated in science fiction. Works such as Star Trek and The Invisible Man include means to render objects or people invisible. Prior Art illustrates the active camouflage approach used in U.S. Pat. No. 5,220,631. This approach is also described in “JPL New Technology report NPO-20706” August 2000. It uses an image recording camera on the first side of an object and a image display screen on the second (opposite) side of the object. This approach is adequate to cloak an object from one known observation point but is inadequate to cloak an object from multiple observation points simultaneously. In an effort to improve upon this, the prior art of U.S. Pat. No. 5,307,162 uses a curved image display screen to send an image of the cloaked object's background and multiple image recording cameras to receive the background image. All of the prior art uses one or more cameras which record two-dimensional pixels which are then displayed on screens which are themselves two-dimensional. These prior art systems are inadequate to render objects invisible from multiple observation points. Moreover, they are too cumbersome for practical deployment in the field. [0005] The process of collecting pictorial information in the form of two-dimensional pixels and replaying it on monitors has been brought to a very fine art over the past one hundred years. More recently, three-dimensional pictorial “bubbles” have been created using optics and computer software to enable users to “virtually travel” from within a virtual bubble. The user interface for these virtual bubble are nearly always presented on a two-dimensional screen, with the user navigating to different views on the screen. When presented in a three-dimensional user interface, the user is on the inside of the bubble with the image on the inside of the bubble's surface. [0006] Also known in the prior art are “three-dimensional” displays which attempt to display a first image stream to the right eye of observers and a second image stream to the left eye of observers. In actuality two streams can only achieve stereoscopic displays. Specifically, stereoscopic displays present the same two image streams to all multiple concurrent observers and are therefore not truly three-dimensional displays. The three-dimensional display as implemented using the technology disclosed herein provides many concurrent image streams such that multiple observers viewing the display from unique viewing perspectives each see unique image streams. [0007] Using concurrent image receiving three-dimensional “cameras” and image sending “displays”, the present invention creates a three-dimensional virtual image bubble on the outside surface of an actual three-dimensional object. By contrast, observers are on the outside of this three-dimensional bubble. This three-dimensional bubble renders the object within the bubble invisible to observers who can only “see through the object” and observe the object's background. The present invention can make military and police vehicles and operatives invisible against their background from nearly any viewing perspective. It can operate within and outside of the visible range. BRIEF SUMMARY [0008] The invention described herein represents a significant improvement for the concealment of objects and people. Thousands of directionally segmented light receiving pixels and directionally segmented light sending pixels are affixed to the surface of the object to be concealed. Each receiving pixel segment receives colored light from one portion or trajectory of the background of the object. Each receiving pixel segment is positioned such that the trajectory of the light striking it determines the angles at which it is reflected such that it reemerges at the proper position and trajectory. [0009] The three-dimensional signature control architecture described herein uses an array of individual reflective pixels and an array of reflecting secondary mirrors in conic section. These two basic elements work in conjunction to collect electromagnetic energy, condense and segment it according to horizontal plane and original trajectory, reflect it to along a parallel (to the original) trajectory, expand it, and emit it at an extension point of its original trajectory in the same horizontal plane. An individual pixel consisting of a cylinder lens and a reflective concave mirror. The reflecting secondary mirrors forming a conic section of arrayed convex mirrors to receive light from receiving pixels and reflected it to sending pixels. [0010] Objects and Advantages [0011] Accordingly, several objects and advantages of the present invention are apparent. It is an object of the present invention to provide a three-dimensional receiver of light. It is an advantage of the present invention to provide a three-dimensional sender of light. It is an object of the present invention to provide an integration architecture to integrate the three-dimensional light receiver function together with the three-dimensional light sender function for passive concurrent real-time operation. It is an object of the present invention to create a three-dimensional virtual image bubble surrounding or on the surface of objects and people. Observers looking at this three-dimensional bubble from any viewing perspective are only able to see the background of the object through the bubble. This enables military vehicles and operatives to be more difficult to detect and may save lives in many instances. Likewise, police operatives operating within a bubble can be made difficult to detect by criminal suspects. The apparatus is designed to be always on. The apparatus is designed to consume no energy. It is rugged, reliable, and light weight. The lens structures can be made from transparent armor. It has relatively few parts. It efficiently redirects light with acceptable losses. It works across a wide range of polychromatic electromagnetic energy. Pixels are duplex, they both send and receive EM. The system does not need to know an enemy's position to be effective. The system conceals objects and people from multiple concurrent observers each located in different positions. No computer processor or electronics are required. It provides very high resolution. [0012] Further objects and advantages will become apparent from the enclosed figures and specifications. DRAWING FIGURES [0013] [0013]FIG. 1 illustrates a single 3-D reflective pixel in top profile view. [0014] [0014]FIG. 2 illustrates a variety of cylinder lens designs for the single pixel of FIG. 1. [0015] [0015]FIG. 3 illustrates a pixel reflector's relationship with a first secondary reflector. [0016] [0016]FIG. 4 a depicts front view of an array of reflective pixels. [0017] [0017]FIG. 4 b illustrates a single column of 3-D reflective pixels. [0018] [0018]FIG. 5 illustrates a 3-D reflective pixel column's working relationship with some secondary reflectors. [0019] [0019]FIG. 6 illustrates a complete 3-D reflective pixel signature control apparatus and process of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0020] [0020]FIG. 1 illustrates a single 3-D reflective pixel in profile view. The single pixel consists of two elements. The first pixel element being a cylinder lens 35 . 35 's focal length is equal to its diameter. The dimensions of the 3-D reflective pixel are variable heights greater or lesser than one inch are possible and operationally practicable. The following calculation describes of a non-gradient cylinder lens at one wavelength. n 1/ s 1+ n 2/ s′ 1=( n 2− n 1)/ R 1 [0021] set n1=1 (refractive index for air) [0022] set n2=1.5 (refractive index for a median wavelength) [0023] set s′1=2R1 (s′1 being the focal length caused by the first surface and R1 being the cylinder lens radius) [0024] set s1=infinity (object distance) [0025] Therefore, by substitution, the focal length (s′1) caused by the first surface equals 6 units and the radius (R1) equals 3 units. Thus incoming electromagnetic radiation with an object focus at infinity is brought to a focal point (by the first surface) just at the second surface of the cylinder lens. Affixed to the rear surface of 35 is a lenticular array 36 . 36 is manufactured from a material transparent in the wavelengths of interest and selected so as to minimize chromatic aberration within the system. These two lens elements thus forming a lens system which compresses the horizontal plane of incoming EM into a number of beams of outgoing EM which respectively reside in the same said horizontal planes. [0026] The second pixel element being a concave mirror 41 conic section with a forty five degree attitude. The mirror comprising a rigid material. The reflective surface of the 35 being on the side of the mirror adjacent to the 35 . Said conic section sharing an axis with the 35 such that all points on the reflective surface of the mirror reside at a forty five degree angle relative to rays emitted from the 35 at a normal to its ( 35 s ) surface. The 35 and the 41 being comprised of materials conducive to respectively refracting and reflecting desirable electromagnetic energy in the visible and/or non-visible wavelengths. [0027] [0027]FIG. 2 illustrates a variety of cylinder lens designs for the single pixel of FIG. 1. The 35 cylinder lens has no gradient refractive. It can be manufactured from transparent armor manufactured and molded by Simula Safety Systems of Phoenix, Ariz. Affixed to its rear surface is a calenderer plastic array of convex lenticular lenses 36 a . The 35 is manufactured such that its focal length (for a median wavelength) from the first surface is less than or equal to its diameter. [0028] A first alternate cylinder lens 35 a has no gradient. It can be manufactured from transparent armor manufactured and molded by Simula Safety Systems of Phoenix, Ariz. Affixed to its rear surface is a calenderer plastic array of concave lenticular lenses 36 a . The 35 a is manufactured such that its focal length (for a median wavelength) from the first surface is greater than its diameter. [0029] A second alternate cylinder lens 35 b has no gradient. It can be manufactured from transparent armor manufactured and molded by Simula Safety Systems of Phoenix, Ariz. Affixed to its rear surface is a calenderer plastic array of concave, and convex lenticular lenses 36 b . The 35 b is manufactured such that its focal length (for a median wavelength) from the first surface is equal to its diameter. [0030] A fourth alternate cylinder lens 35 d has no gradient. It can be manufactured from transparent armor manufactured and molded by Simula Safety Systems of Phoenix, Ariz. It is manufactured such that its focal length (for a median wavelength) from the first surface is equal to its diameter. The equation listed under FIG. 1 describes the first surface of this lens. [0031] A third alternate cylinder lens 35 c having a radial axis gradient (the refractive index varies according to position such that the highest refractive index is along the axis of the cylinder lens and the lowest refractive index is a cylinder closest to the surface of the cylinder lens). The 35 c enables parallel rays in a horizontal plane to be compressed into a beam when the focal length from the first surface is approximately equal to its diameter. Gradient index cylinder lenses are suitable for this application because they can optimize performance across a range of wavelengths while minimizing chromatic aberration. Producers of gradient index lenses include Lightpath Technologies and Hikari Glass. [0032] [0032]FIG. 3 illustrates a pixel reflector's relationship with a first secondary reflector. The 41 single mirror having been described in FIG. 1. A first secondary mirror 61 comprises a conic section whereby the convex surface of said conic section is comprised of materials reflective in desired wavelengths. A vertical line (a line parallel to the center axis of the 61 conic section) drawn through any section of both the 61 and the 41 will subtend a forty five degree angle (with the respective reflective surface of each) which resides in the same plane as electromagnetic energy which passes through the axis of 35 . [0033] [0033]FIG. 4 a depicts the front view of an array of reflective pixels. 35 being the front surface of a cylinder lens single reflective pixel of FIG. 1. Said single pixel being arrayed with and affixed to many similar reflective pixels to form a pixel array 81 covering the surface of an asset to be concealed. [0034] [0034]FIG. 4 b illustrates a single column of 3-D reflective pixels 83 when viewed from the top and side. The 35 with 41 comprising one pixel and being affixed to a second reflective pixel cylinder lens 85 which is identical to 35 . 85 is connected to a second reflective pixel mirror 87 which is identical to 41 . Note that the 85 has an axis that is pushed back from that of 35 . Like wise the 87 is pushed back relative to 41 . Each lower tier is similarly backed off the higher layer's axis by a distance equal to the height of the 41 . [0035] [0035]FIG. 5 illustrates a 3-D reflective pixel column's working relationship with some secondary reflectors. The elements of FIG. 4 b are present in addition to a second secondary reflector 93 and a third secondary reflector 95 . 93 and 95 being identical to 61 . Each of their axis residing in a circular conic section with a forty five degree slope. [0036] [0036]FIG. 6 illustrates a complete 3-D reflective pixel signature control apparatus and process of the present invention. The elements of FIG. 5 are shown integrated into a complete 3-D low observable casing which surrounds an asset 106 . Note that the asset is not to scale and that it would normally conform to the shape of the camouflage system (or vice versa). Also the asset would be affixed to the camouflage (or vice versa). An encompassing reflective pixel array 81 includes 35 and a third reflective pixel 102 as well as a fourth reflective pixel 107 and many other pixels. The 102 , 107 , and 35 each being in the same horizontal plane. An assembled secondary mirror array 104 includes secondary mirrors 61 , 93 , and 95 together with a number of other secondary mirrors to form a circular conic section with forty five degree slop 104 . The surfaces interior to the conic section having reflective properties in desired wavelengths. An electromagnetic absorbing patch 103 is shown. It is manufactured of a material that absorbs electromagnetic energy. In practice the 103 material is used to coat a number of surfaces that otherwise would reflect EM from undesirable trajectories. For example, material coats the surface (not shown) above the 104 and a surface (not shown) below 104 . The material also coats the non reflective sides of all the pixel mirrors. Additionally, the asset itself is coated with the 103 material. [0037] Operation of the Invention [0038] [0038]FIG. 1 illustrates a single 3-D reflective pixel in profile view. A first ray of polychromatic electromagnetic energy 31 is incident upon 35 . A second ray of polychromatic electromagnetic energy 37 is also incident upon 35 . Prior to incidence, 35 and 37 being on parallel trajectories and within the same horizontal plane. 35 compresses 31 and 37 along with all other parallel rays within the same horizontal plane 36 then collimates the light which becomes exiting first compressed beam 37 a . 37 a resides in the same horizontal plane as 37 and has a parallel trajectory prior to being reflected by 41 to become vertical beam 39 . Similarly, a second trajectory of EM 47 , in a second horizontal plane is incident upon 35 , compressed by 35 , collimated by 36 , reflected vertically by 41 to become a second compressed vertical beam 57 . A third trajectory of EM 45 resides in the same plane as 47 but in a non-parallel trajectory. It and all other EM (incident upon 41 ) parallel to 45 and in its plane are compressed into a beam by 35 , collimated by 36 , and be reflected by 41 as a third compressed beam 55 . A horizontal plan of parallel trajectory EM 43 is in the same horizontal plane as 45 and 47 (but non-parallel in trajectory) similarly is incident upon 35 , and compressed to become a fourth compressed beam, collimated by 36 , which is reflected by 41 to become fourth vertical beam 53 . Note that the position of each beam's incidence upon 41 is a direct function of its original trajectory and its original horizontal plane. The system described effectively sorts and processes EM according to its original trajectory and horizontal plane. This is further described in FIG. 3, FIG. 5, and FIG. 6. [0039] [0039]FIG. 2 illustrates a variety of cylinder lens designs for the single pixel of FIG. 1. In a first cylinder lens embodiment, 47 and all parallel EM in its plane are incident upon 35 . 35 causes the EM to focus at its extreme rear edge. The EM is then collimated by 36 . The EM emerges from the 36 as narrow collimated beam of polychromatic EM 57 . The material of 35 and 36 being selected so as to perform achromatically. 57 is parallel to and in the same plane as 47 . Likewise 45 and other parallel rays within its plane are incident upon 35 . 35 compresses them and 36 collimates them into 55 . 55 is parallel to and in the same plane as 45 . [0040] [0040] 35 a functions similarly to 35 except that the incident EM is not brought to a focal point within 35 a . Instead the EM is converging before it passes through 36 a which causes the converging EM to expand into a collimated beam. The material of 35 a and 36 a being matched so as to provide achromatic performance. 35 b has a back focal length equal to its diameter. The 36 b has alternately both concave and convex lenticular surfaces such that a wider range of EM can be collimated. EM with a focal point within the 35 b being collimated by the convex lenticular lenses and EM with a focal point outside of the 35 b being collimated by the concave lenticular lenses. [0041] [0041] 35 c is can be used to further enhance achromatic performance across a wider range of EM within the visible and outside of the visible. It has a gradient index and can be used in conjunction with 36 , 36 a , or 36 b. [0042] [0042]FIG. 3 illustrates a pixel reflector's relationship with a first secondary reflector. P beam 63 leaves the 36 (not shown), is reflected by 41 to become vertical, and then is reflected by 61 to become horizontal again as P″ beam 73 . Note that 63 , and 73 are both in the same vertical plane and they are in parallel horizontal planes. Thus P″ retains its original trajectory information which was present in P. Three additional beams are shown which each share a horizontal plane but differ in trajectory. Note that X, Y, and Z are all incident on 41 in the same horizontal plane and incident upon 61 in a common elevated horizontal plane. The curvature of 61 causes X″, Y″, and Z″ to each respectively continue on trajectories parallel to X, Y, and Z respectively. Thus each collimated beam which emanates from a horizontal plane and that is emitted from 36 retains information relation to its horizontal plane and trajectory throughout the reflective pixel process of the present invention. Note that all arrows can be reversed and in practice EM is always being reflected by this mirror combination in many more planes and trajectories and in both directions. [0043] [0043]FIG. 4 b illustrates a single column of 3-D reflective pixels. The 85 and 87 pixel is offset to enable EM incident upon 85 to pass vertically by 41 unencumbered. Likewise, each lower tier is offset form the one above it. At the middle of the array, the reverse is true. Thus EM is directed vertically upward unencumbered by the upper pixels and directed vertically downward unencumbered. [0044] [0044]FIG. 5 illustrates a 3-D reflective pixel column's working relationship with some secondary reflectors. As previously discussed, 47 EM is compressed and collimated by 35 and 36 and then reflected vertically upward as 57 . When 57 is incident upon 61 , it is directed at a trajectory parallel with 47 just as 55 is directed by 61 on a trajectory parallel with 45 . Thus two beam emanating from the single 35 pixel are directed by a secondary mirror 61 to two different secondary mirrors. 57 is then incident upon 95 which causes it to be reflected down into a reflective pixel (not shown) which spreads it out to be a first spread polychromatic beam 47 a . 47 a being in the same horizontal plane as 47 and on a continuation of the 47 trajectory. Similarly, 55 is then incident upon 93 which causes it to be reflected down into a reflective pixel (not shown) which spreads it out to be a second spread polychromatic beam 45 a . 45 a being in the same horizontal plane as 45 and on a continuation of the 45 trajectory. The 89 EM is incident upon lower pixel 85 as described in FIG. 4 b . Note that the collimated beams from 85 are incident upon the 61 in a higher plane that those from 35 but as they are reflected again, such as off of 93 , they are restored to the proper plane, such as third spread beam 89 a . This demonstrates that the horizontal plane information which is retained in this process is temporarily inverted during the reflected process then restored. A lower path for reflected light is also partially shown, if functions identically to the upper half and concurrently. [0045] [0045]FIG. 6 illustrates a complete 3-D reflective pixel signature control apparatus and process of the present invention. A C ray 101 enters the 35 pixel from a non-horizontal plane, it is collimated by 36 and reflected by 41 to be a non-vertical beam 101 a . 101 a and many other EM which can not be concurrently processed by the present architecture must be absorbed when it is incident upon non-optical surfaces. As previously discussed material such as 103 absorbs the vast majority of such stray EM as it is incident on any non-optical surfaces. 47 enters the systems at 35 , is reflected vertically by 41 to become 57 , is reflected horizontally by 61 , is reflected vertically by 93 , is reflected horizontally by a pixel mirror connected to a first sending pixel 102 , the lens of 102 expanding the EM to become 45 a , 45 a being in the same horizontal plane and parallel in trajectory to 45 . Similarly, 45 enters the systems at 35 , is reflected vertically by 41 to become 55 , is reflected horizontally by 61 , to become 55 a , is reflected vertically by 95 , is reflected horizontally by a pixel mirror connected to a second sending pixel 107 , the lens of 107 expanding the EM to become 47 a , 47 a being in the same horizontal plane and parallel in trajectory to 47 . [0046] Note that all directions are reversible and in practice EM is always concurrently being received, reflected, and emitted by this assembly in many more horizontal planes and trajectories and in both directions than are represented herein. [0047] Conclusion, Ramifications, and Scope [0048] Thus the reader will see that the Three-Dimensional Signature Control Process and Apparatus With Military Application of this invention provides a highly functional and reliable means for using technology to conceal the presence of an object (or asset). [0049] While the above description describes many specifications, these should not be construed as limitations on the scope of the invention, but rather as an exemplification a preferred embodiment thereof. Many other variations are possible. [0050] The description describes a lens, mirror, mirror, mirror, mirror, lens architecture to transport electromagnetic energy from one side of an asset to another side. It is recognized that at least one of these mirrors can easily be eliminated. This may be desirable when a pyramid shaped asset is to be concealed. Eliminating a mirror requires mirror angles other than those specified herein. [0051] It is recognized that other lens and prism structures can intervene in combinations other than that specified herein. [0052] The specification describes a circular arrangement of pixels and secondary mirrors. Many other shapes are possible. No known constraints on the shapes of assets to be concealed exist. [0053] It is possible to substitute other lenses for the cylinder lenses, for example ball lenses or lenticular lenses. Also different combinations of lenses can be constructed to improve achromatic beam formation. [0054] The specification starts with an object light at infinity, other object focus lengths are possible and may at times be desirable. [0055] To achieve achromatic refraction, different lens combinations may be used in place of those specified herein. [0056] Lenses which enable wide angle light segmentation at the pixel level can be designed in many configurations and in series using multiple elements, shapes and gradient indices.

The invention described herein represents a significant improvement for the concealment of objects and people. The three-dimensional signature control architecture described herein uses an array of individual reflective pixels and an array of reflecting secondary mirrors in conic section. These two basic elements work in conjunction to collect electromagnetic energy, condense and segment it according to horizontal plane and original trajectory, collimate it, reflect it to along a parallel (to the original) trajectory, expand it, and emit it at an extension point of its original trajectory and in the same horizontal plane. An individual pixel consisting of a cylinder lens and a reflective concave mirror. The reflecting secondary mirrors forming a conic section of arrayed convex mirrors to receive light from pixels and reflect it to other pixels. The light which was incident on a first side of the object traveling at a series of respective trajectories is thus redirected and exits on at least one second side of the object according to its original incident trajectories. It captures and emits light which mimics trajectory, color, and intensity in many concurrent directions such that multiple concurrent observers, can “see through” the object to the background.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a xerographic fuser architecture which provides two separate fuser rolls about a central common pressure roll, each fuser roll being designed for a different application, i.e., color fusing or black and white fusing requirements. 2. Description of Related Art Most known fuser roll architectures utilize a single fuser roll in conjunction with a pressure roll. If used for a single application, such as black and white printing, the fuser roll design can accommodate the needs of the particular printing that is to be done. For example, typically customer preference for color xerographic prints is a high gloss finish. This usually requires the use of a smooth, conformable fuser roll operating at a high temperature and having a long-dwell nip. However, customer preference for black and white xerographic copies is a matte finish, which requires a different fuser design and operating parameters. In a color copier which can provide either color or black and white xerographic prints, it has been customary to compromise the needs of these different operating parameters and design criteria into a design which can adequately provide moderate capabilities of either type print. There are known fusing systems which provide multiple fusers such as U.S. Pat. Nos. 4,928,148; 5,019,869; 4,791,447; and 5,053,828. There is a need for a multiple fuser system which can accommodate fusing of a developed image on either side of a copy substrate without complicated inversion apparatus. There also is a need for a multiple fuser roll system which can accommodate images having varying fusing characteristics with minimal power requirements. OBJECTS AND SUMMARY OF THE INVENTION It is an object of the present invention to provide a three-roll fuser roll architecture which includes a driven reversible pressure roll and two fuser rolls aligned in a substantially linear fashion, allowing passage of unfused paper through either of two nips. It is another object of the present invention to provide a three-roll fuser architecture which can accommodate images developed on either side of a paper substrate. In particular, a three-roll architecture is provided which can fuse a black image located on a first side of a substrate and can fuse a color image located on an opposite side of a substrate. The above and other objects are achieved by providing a three-roll fuser system for use in a xerographic machine, including a driven reversible central pressure roll, a first fuser roll on one side of the central pressure roll, and a second fuser roll on an opposite side of the central pressure roll. The central pressure roll and the first fuser roll form a first fusing nip. The central pressure roll and the second fuser roll form a second fusing nip. The three rolls are preferably arranged in a substantially linear fashion. The fuser roll system has an inlet sheet path which may be separate or common for each fuser nip provided near an entrance of the fuser roll system and an outlet sheet path provided near an exit of the fuser roll system which may be a common path or separate for each nip. In a preferred embodiment, the first fuser roll is a heated black fuser roll and the second fuser roll is a heated color fuser roll. Each of the first and second fuser rolls are specifically designed for a certain application. For example, the black fuser roll may be semisoft, of a composition such as copper or aluminum which forms a relatively short nip with the central pressure roll and the color fuser roll may be of a smooth, soft material such as silicone rubber which forms a longer nip with the central pressure roll. Both rolls may comprise a layer of Viton or other suitable elastomeric material. Usually, the extra thickness of unfused toner on a color image, due to multiple layers of different colors, requires a higher operating temperature for this fuser than that of a black image fuser roll. These and other objects will become apparent from a reading of the following detailed description in connection with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in detail with reference to the following drawings wherein: FIG. 1 is an end view of a three-roll fuser architecture according to the present invention having a common copy sheet inlet, a sheet diverting mechanism and a rejoined common copy sheet outlet; FIG. 2 is an end view of a three-roll fuser architecture similar to FIG. 1, only having separate outlet paths provided; and FIG. 3 is an end view of a three-roll fuser architecture having separate inlet and outlet paths for a first and second fuser nip. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS With reference to FIG. 1, the present invention provides a three-roll fuser system 10 for use in a xerographic machine, including a driven reversible central pressure roll 12, a first fuser roll 14, and a second fuser roll 16. The central pressure roll 12 and first fuser roll 14 form a first fusing nip 18. The central pressure roll 12 and second fuser roll 16 form a second fusing nip 20. As shown, the three rolls 12, 14, and 16 are arranged in a substantially linear fashion. In a preferred embodiment, the fuser roll system 10 has a common inlet sheet path 22 provided near an entrance of the fuser roll system 10 and a common outlet sheet path 24 provided near an exit of the fuser roll system 10 for passing a copy substrate such as a copy sheet P therethrough, although it is also contemplated that different transport paths may be provided for the copy substrate. The present invention also can be used with alternative copy substrates such as a web fed from a supply roll to a take-up roll. In such an application, a cutter mechanism may be provided to cut the web to appropriate sized sheets. In the above embodiment, developed unfused black images can enter the fuser on a separate inlet sheet path from developed unfused color images (FIG. 3) or each nip may be provided with a separate outlet path (FIG. 2). In a most preferred embodiment, fuser roll 14 is a heated black fuser roll and fuser roll 16 is a heated color fuser roll. Each of fuser rolls 14 and 16 are specifically designed for a certain application. For example, black fuser roll 14 may be semisoft, of a composition such as a copper or aluminum which forms a relatively short nip with pressure roll 12 and color fuser roll 16 may be of a smooth, soft material such as silicone rubber, although other materials may be used, which forms a longer nip with pressure roll 12. Both rolls may comprise a layer of Viton or other suitable elastomeric material. Usually, the extra thickness of unfused toner on a color image, due to multiple layers of different colors, requires a higher operating temperature for this fuser than that of a black image fuser roll. Engagement mechanisms are provided to engage and disengage each fuser roll 14, 16 from the central pressure roll 12. Suitable mechanisms are described in U.S. Pat. No. 4,716,435, assigned to the same assignee as the present invention, and incorporated herein by reference in its entirety. For brevity, the drawings have arrows designating that first fuser roll 14 and second fuser roll 16 are movable toward and away from central pressure roll 12. For example, when first nip 18 is required, first fuser roll 14 can be movably engaged in a contacting position with an outer surface of central roll 12 to provide the first nip 18. At the same time, second fuser roll 16 is moved away from or remains spaced a predetermined distance from central roll 12. The reverse would occur if the second nip 20 is required to fuse toner on a copy sheet. A drive mechanism is provided to enable rotation of the central pressure roll in either direction, at an appropriate speed. A suitable drive mechanism consists of a drive motor 26 which is connected to central roll 12 by a drive belt or drive chain 28. The drive chain or belt 28 mates with appropriate pulleys or sprockets located on drive motor 26 and central roll 12. A suitable drive system for a roll is shown in U.S. Pat. No. 4,967,237 to Sasaki et al., incorporated herein by reference in its entirety. In a simplest form, the drive motor 26 can drive pressure roll 12 at a same predetermined speed in either direction. Alternatively, suitable controls may be provided for controllably adjusting the rotational speed of the central pressure roll 12. This may be desirable since it allows a different speed to be used for transporting a copy sheet through a fuser nip. For example, it may be beneficial to have the pressure roll 12 driven at one speed when driving a first fuser nip to provide optimum fusing, and having the pressure roll 12 driven at another speed when driving a second fuser nip to provide optimum fusing. This changes the total fusing time through which the copy sheet is in contact with the appropriate fusing nip. The fuser rolls 14 and 16 as shown in the drawings are driven by frictional contact with central pressure roll 12, although they may alternatively have their own drive mechanism which operates to rotate each fuser roll in a predetermined direction complementary with the direction of rotation of the central pressure roll to positively feed a copy sheet through the selected fuser nip. The rotational speed of the separately driven fuser roll 14 or 16 is chosen so as to provide a substantially same linear speed to a copy sheet through the nip as the linear speed provided by the driven pressure roll 12. A slight mismatch in relative speed between rolls 14, 16 and central roll 12 may be beneficial to provide a slippage between one of the rolls and the copy sheet to minimize paper rucking. Diverters 30 such as baffles and/or vacuum transports may be provided in a prefusing area between the common sheet inlet and the fuser system 10 to carry unfused copies to either first fuser nip 18 or second fuser nip 20. As shown in FIG. 1, diverter 30 is a baffle which can be selectively positioned between two positions to provide a sheet path from common inlet 22 to nip 18 or nip 20. The baffle 30 can be controlled through appropriate controls or signals known in the art. For example, in a preferred embodiment, a copier is provided which produces black copies on a top side of a copy sheet in one mode and provides color copies on a bottom side of the copy sheet in another mode. Selection of the desired mode, i.e., either color or black, sends a suitable control signal to the baffle 30 such that it is positioned to guide the copy sheet to the required nip 18 or 20. Selection of a desired mode described above can also provide a control signal which controls directional rotation of central roll 12 and engagement or disengagement of fuser rolls 14 and 16 with central roll 12. Similar baffles and/or vacuum transports can also be provided to a post-fusing area between the fuser system 10 and an output 24. This output may be to a common rejoined path such as common outlet 24 shown in FIGS. 1 and 2 or to separate output trays or paths shown in FIG. 3. There may also be a duplex return loop provided for printing on a second side of a copy sheet. One important structural advantage of the present invention is that images can be fused on either side of a copy sheet. This is accommodated by the three roll architecture having a central reversibly-drivable pressure roll and first and second fuser rolls. As shown in the drawings, if an unfused image is developed on a top side of the copy sheet P, the image can be fused by passing the copy sheet P through first nip 18. In this example, the central roll 12 is driven counterclockwise by drive motor 26 such that a copy sheet P can be fed from inlet 22 through nip 18 and into outlet 24. Baffle 30 in FIG. 1 would be positioned in the dashed position to direct the copy sheet to first nip 18. Central roll 12 rotates heated roll 14 in a clockwise direction. As the copy sheet P passes through nip 18, an unfused image on the top side of the copy sheet contacts the heated outer surface of fuser roll 14 and is fused. If an unfused image is located on a bottom side of the copy sheet P, the image can be fused by passing the copy sheet P through the second nip 20. In this example, the central roll 12 is driven clockwise by drive motor 26 such that a copy sheet can be fed from inlet 22 to outlet 24 through second nip 20. Baffle 30 in FIG. 1 would be in the solid line position for this example. Central roll 12 rotates heated fuser roll 16 in a counterclockwise direction. As the copy sheet passes through nip 20, an unfused image on the bottom side of the copy sheet P contacts the heated outer surface of fuser roll 16 and is fused. In the known prior art, this provision was not possible without some form of prefusing sheet inversion step such that all copy sheets were uniform in orientation, i.e., all having an unfused image on a same side of the copy sheet. This particular arrangement can handle fusing of images which are developed by a xerographic or other developing device on either side of the copy sheet. This is highly useful if more than one development station is present in the machine. For instance, there may be one or more modes provided on a copier which allow selection of which side of a copy sheet a developed image is desired. The present invention can accommodate fusing of the copy sheet developed by the copier described above without additional sheet inverting apparatus. Alternatively, if all copy modes, i.e., such as printing in black and white or color, develop an image on a same side, one of nips 18 and 20 can be provided with a pre-nip sheet invertor which properly orients copy sheet P such that an unfused image is correctly oriented when fed through nips 18 and 20. In a preferred embodiment, the first nip 18 provides fusing of a black and white image and the second nip 20 provides fusing of a color image. In a particular known xerographic copier, due to the nature of the intermediate color transfer web utilized, color images are developed on a different side of a copy sheet from those formed using a black only mode. The copier is capable of providing color and black and white printing through the use of a transfer drum or belt. In such a copier, copy sheets can be fed into a transfer nip. For monochrome copies, the transfer device, either a drum or belt, functions as a large bias transfer roll and toner is directly transferred to the copy sheet. When the sheet is transported toward the fuser, the unfused side of the sheet having toner is on a photoreceptor side, i.e. on the top side of the copy sheet. Thus, the sheet can pass through black nip 18 of the fuser system 10 in a proper orientation. For color, however, the individual separations are transferred onto the belt or drum surface, acting as an intermediate transfer belt or drum. Once the three or four color image is assembled on the intermediate, its bias is reversed with respect to the photoreceptor, a copy sheet is fed into the transfer nip and the image is transferred to the copy sheet. Thus, when the copy sheet is transported to fuser system 10, it is transferred directly to the fuser with unfused toner on the intermediate side, i.e. on the bottom side of the copy sheet. Thus, the color image is oriented correctly to be fused with color fuser nip 20 according to the present invention without any additional sheet handling steps such as sheet inversion. Known fuser systems cannot accommodate this particular copier architecture without requiring inversion of either the black image or the color image due to the structural limitations of their design. The present three-roll architecture according to the present invention naturally accommodates such an architecture while also solving the problem of compromise between fuser roll constraints by provision of two fuser rolls, each having different operating parameters and design constraints. As previously discussed, each of the fuser rolls 14 and 16 may be designed according to different criteria such as durometer hardness, heating temperature, pressure roll velocity, nip length, etc. The invention has been described with reference to the preferred embodiments thereof, which are illustrative and not limiting. Various changes may be made without departing from the spirit and scope of the invention as defined in the appended claims.

A three roll fuser system for a xerographic machine includes a reversibly drivable central pressure roll, a first fuser roll located adjacent the central pressure roll forming a first fuser nip with the central roll, and a second fuser roll located adjacent the central pressure roll on a substantially opposite side of the central pressure roll as the first fuser roll forming a second fuser nip with the central roll. Copy sheets having an unfused image on a side thereof are transported from an inlet through one of the first and second nips to fuse the image on the copy sheet and then transported to an outlet. The three roll fuser system is capable of selectively fusing either side of a copy sheet without requiring extra sheet inverting devices. In a preferred embodiment, the fuser rolls have differing physical properties and can be operated under different operating conditions such as fuser temperature and speed.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of European Application No. 13177709.6, filed Jul. 23, 2013, the disclosure of which is incorporated herein by reference. BACKGROUND [0002] 1. Field [0003] The present invention relates to fault-tolerant monitoring of networked computing elements. As computing systems grow increasingly large and complex, there is an increased risk that monitoring of a system may be disrupted by faults in individual computing elements. Fault-tolerant monitoring can be useful in a wide range of application areas, for example from simple computations to sensor networks, image rendering and large-scale, complex simulations, including on-the-fly and offline processing. As some important examples, mission-critical jobs (e.g. operational weather forecasting) or systems (e.g. the internet) with very many computing elements can benefit from fault-tolerant monitoring. This invention addresses the whole gamut of these application areas, and is focused particularly on distributed, parallel computer programs running on very large high-performance computing systems with data distributed over a number of CPUs. [0004] 2. Description of the Related Art [0005] One example of such a distributed parallel application is simulation. In many simulations, an iterative computation or iterative sets of computations are carried out, each computation corresponding to a single element in the situation. Simulations elements may be linked in that a computation for one element of the simulation may require values from other elements of the simulation, so that data transfer between processes carrying out the simulation is considerable. Monitoring of a system carrying out such a simulation or other computational application can allow identification of not only computing elements which are faulty but also of computing elements which are overloaded and/or consume excessive amounts of energy. However, once a computing element has failed it may be impossible to recover the data. [0006] Computationally intense applications are usually carried out on high performance computer systems. Such high performance computer (HPC) systems often provide distributed environments in which there is a plurality of processing units or cores each with its own individual memory and on which processing threads of an executable can run autonomously in parallel. [0007] Many different hardware configurations and programming models are applicable to high performance computing. A popular approach to high-performance computing currently is the cluster system, in which a plurality of nodes each having one or more multicore or single core processors (or “chips”) are interconnected by a high-speed network. Each node is assumed to have its own area of memory, which is accessible to all cores within that node. The cluster system can be programmed by a human programmer who writes source code, making use of existing code libraries to carry out generic functions. The source code is then compiled (or compiled and then assembled) to lower-level executable code. The executable form of an application (sometimes simply referred to as an “executable”) is run under supervision of an operating system (OS). [0008] The latest generation of supercomputers contain hundreds of thousands or even millions of cores. The three systems on the November 2012 TOP500 list with sustained performance over 10 Pflop/s contain 560,640 (Titan), 1,572,864 (Sequoia) and 705,024 (K computer) cores. In moving from petascale to exascale, the major performance gains will result from an increase in the total number of cores in the system (flops per core is not expected to increase) to 100 million or more. As the number of nodes in the system increases (and especially if low-cost, low-energy nodes are used to maintain an acceptable power envelope) the mean-time-to-component-failure of the system will decrease—eventually to a time shorter than the average simulation run (or other application execution) on the system. Hence, it will be necessary for monitoring of exascale software to be resilient to component failure. [0009] The general principle for fault-tolerant provision of data is redundant storage of data to ensure that in the event of a fault, the data is still available from elsewhere. This principle is used in RAID (Redundant Array of Independent Discs), and could be used in conjunction with iSER (iSCSI extensions for RDMA, Remote Direct Memory Access) for data retrieval. [0010] RAID is an umbrella term for computer data storage schemes that can divide and replicate data among multiple physical drives, such as discs. The array of discs can be accessed by the operating system as one single disc. Effectively, this technology primarily addresses large files which benefit from “striping” across discs. This method of “striping” files across discs can be used to aid fault-tolerant data provision. iSER is a computer network protocol that extends the internet small computer system interface (iSCSI) protocol to use RDMA. It permits data to be transferred directly into and out of SCSI computer memory buffers without intermediate data copies. [0011] Remote Direct Memory Access is a technology allowing a computing element to use its network interface controller (or other network access mechanism) to transmit information via the network to modify the storage at a second computing element. This technology is important in high performance computing, where the computing elements may be part of a supercomputer, as it reduces the work placed on the processor of the computing element. RDMA technology is also beneficial to a network-on-chip processor as a computing element in the network is able to modify storage local to a second computing element in a way that minimizes the work placed on the second computing element. [0012] RDMA relies on single-sided communication, also referred to as “third-party I/O” or “zero copy networking”. In single-sided communication, to send data, a source processor or initiator (under control of a program or process being executed by that processor) simply puts that data in the memory of a destination processor or target, and likewise a processor can read data from another processor's memory without interrupting the remote processor. Thus, the operating system of the remote processor is normally not aware that its memory has been read or written to. The writing or reading are handled by the processors' network interface controllers (or equivalent, e.g. network adapter) without any copying of data to or from data buffers in the operating system (hence, “zero copy”). This reduces latency and increases the speed of data transfer, which is obviously beneficial in high performance computing. [0013] Consequently, references in this specification to data being transferred from one computing element or node to another should be understood to mean that the respective network interface controllers (or equivalent) transfer data, without necessarily involving the host processing units of the nodes themselves. [0014] Conventional RDMA instructions include “rdma_put” and “rdma_get”. An “rdma_put” allows one node to write data directly to a memory at a remote node, which node must have granted suitable access rights to the first node in advance, and have a memory (or buffer) ready to receive the data. “rdma_get” allows one node to read data directly from the memory (or memory buffer) of a remote node, assuming again that the required privileges have already been granted. [0015] It is desirable to provide monitoring for network computing elements which is fault-tolerant. SUMMARY [0016] Additional aspects and/or advantages will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention. [0017] According to one embodiment of a first aspect of the invention there is provided a fault-tolerant monitoring apparatus arranged to monitor physical performance properties of a plurality of networked computing elements, each element including a processing unit and individual memory, the monitoring apparatus including a plurality of measurer apparatuses, each arranged to measure the physical performance properties of a single computing element, the physical performance properties being stored as local information in the individual memory of the computing element in which the measurement is made; and one or more collector apparatuses arranged to control collection of remote information representing physical performance properties from individual memory in a plurality of the computing elements; and storage of the remote physical performance information as replicate information in the individual memory of another computing element; wherein the remote physical performance information is collected using third party access. [0018] By provision of a monitoring apparatus with a plurality of measurer apparatuses, one for each computing element and at least one collector apparatus which redistributes information from individual memory of computing elements into a different computing element using third party access, monitoring data can be stored in a way which allows it to be accessed even if one of the computing elements fails. [0019] The advantage of third party access in this aspect is that the computing element from which the remote information is collected is not involved in the collection process and thus collection can continue even if the computing element is faulty. Third party access is able to tolerate a wide variety of faults on the remote computing element, such as on-chip faults in registers or execution units. [0020] Reference herein to physical performance properties is to physical, usually electrical characteristics such as voltage, current, power and energy use of the computing element or part thereof. [0021] Further characteristics include transmission characteristics, possibly in the form of network metrics such as delay/latency, packet loss, retransmission and throughput to and/or from the computing element. [0022] Thus this aspect of the invention refers primarily to physical performance properties, but a fault-tolerant monitoring apparatus may also monitor data performance properties, such as CPU performance metrics (cycles used, instructions committed, floating operations performed, stalled cycles, integer operations performed, cache hits and misses and TLB hits and misses; and/or memory performance metrics (latency, read/write throughput MB/s, number of page faults). Such data performance properties may be written to individual memory when an application includes self monitoring. [0023] Accordingly, in some embodiments, the one or more collector apparatuses are also arranged to control collection of remote information representing data performance properties from individual memory in the plurality of computing elements and to control storage of the remote data performance information as replicate information in the individual memory of the other computing element. The remote data performance information may also be collected using third party access. [0024] As an aside, the fault-tolerant monitoring apparatus may not be involved when the application writes self monitoring information to individual memory, but become involved only later in collecting this type of information for replicate storage. [0025] Any suitable technology can be used in the measurer apparatus to read physical performance properties. In one embodiment, each measurer apparatus includes probe or sampling resistors to estimate one or more of: voltage; current; power; or energy supplied to one or more components of the computing element. [0026] The individual memory present in each computing element can be any suitable type of memory, but in many embodiments is volatile memory such as pinned RAM (which cannot be swapped out to another memory location) or RAM or a cache memory. If “non-pinned” RAM is used, the third party access may be adapted to arrange for the correct location to become available. Cache memory is usually faster than RAM and closer to CPU cores, so may be a good alternative to either form of RAM. [0027] The third party access is also possible by any known method, including remote direct memory access RDMA put and/or remote direct memory access RDMA get. [0028] Although a measurer apparatus may be provided for every computing element in a network of computing elements and usually a plurality of collector apparatuses will also be provided, all these separate components need not be switched on. For example, only collector apparatuses used in a computing element assigned to an executing application may be switched on. However, some applications may not use all assigned computing elements (typically the application will use all assigned nodes but some nodes may be left unused either by design, e.g. for redundancy, or unintentionally, e.g. by user error or due to the minimum allocation units permitted by the system). Thus only the apparatuses currently used in an application may be switched on. In one embodiment, the monitoring apparatus is controlled to switch on a collector apparatus or a measurer apparatus, in accordance with the computing elements currently used in an application. [0029] Further, even if there is more than one collector apparatus, not necessarily every collector apparatus will be used to collect remote information. For example the monitoring apparatus may be controlled to activate collection by a subset of the collector apparatuses (or a sub-set of the collector apparatuses currently used in an application), the replicate information thus being stored in a subset of computing elements. [0030] Each collector apparatus carrying out collection will provide a set of replicate information, for example from all the nodes used in an application. However a collector apparatus may be switched on but not activated for collection, for example if it carries out other roles as will be explained in more detail later. [0031] The invention can be applied to any network of computing elements however closely or loosely linked, the aspects simply being two or more CPUs or other processing units, two or more corresponding memory locations and for connection purposes two or more connection means such as network interface controllers. Thus the invention is applicable to “resource pool architecture” (in brief, pools of hardware components such as CPUs and discs provided and linked together dynamically by high-speed networks). In this case there may be one FTMC apparatus (with one collector) for every four to ten CPUs. [0032] However a plurality of nodes with distributed memory is probably a more typical embodiment. Therefore, in many embodiments the plurality of networked computing elements forms a single computer system or cluster, the computing elements acting as nodes, each node including a processing unit in the form of at least one CPU, individual memory as RAM memory and a network interface controller to link to the network. [0033] In this type of system, the monitoring apparatus may include a measurer apparatus for each node and a plurality of collector apparatuses, each collector apparatus shared between a group of the nodes, and arranged to collect remote information within its group of nodes and for nodes of other groups. Of course, not every collector apparatus need be activated for collection as mentioned above. [0034] Each collector apparatus may be shared between a plurality of nodes and linked to each of these nodes via the network interface controller. One collector apparatus may be provided per “drawer” or system board in the system, or several drawers may share a collector apparatus. Each measurer apparatus may monitor one or more of the network interface, individual memory and CPU in its node. Each measurer apparatus may be directly linked to a single collector apparatus. [0035] Not all of the nodes (and thus not all of the measurer apparatuses) are necessarily used within any application. For this and other reasons the monitoring apparatus can be controlled to activate measurement by a sub-set of the measurer apparatuses. In one arrangement each of the measurer apparatuses activated is directly linked to a collector apparatus that is activated for collection. Thus where measurement takes place, the collector apparatus also stores remote information. [0036] The skilled reader will appreciate that this embodiment can be combined with other embodiments so that a currently activated sub-set of the measurer apparatuses may be directly linked to collector apparatuses activated for collection to provide a lower number of replicates. [0037] In an alternative arrangement, remote information is stored (at nodes) where there is no measurement so that the measurer apparatuses activated are not directly linked to activated collector apparatuses. [0038] In either of these variants, the nodes in the subset may be monitored by different FTMC apparatus components which will function as one FTMC apparatus for the duration of the monitoring (in the same way as the nodes are individual computers but function together as one computer when a parallel application is running). [0039] For a fixed replication strategy the number of replicates of data will be the same whether replicate monitoring data is held on monitored nodes or non-monitored nodes. The difference between monitoring data being held on the monitored nodes and monitoring data being held on different non-monitored nodes is that for the latter option the remote data storage location is separated from all the local data. Thus failures of these locations will not be correlated so that more replicates will survive. This is not the primary reason for choosing this variant: lower monitoring overhead is a better reason. Overhead is lower as monitored RAM is not used both for local storage and for replicate storage. The usual arrangement of holding replicate data locally has the alternative advantage of employing otherwise unused resources (such as CPUs not involved in the computation). [0040] The measurer apparatus can store its local information in individual memory (such as pinned RAM) without the collector apparatus having a role at this stage. However, in other embodiments, the measurer apparatus may have more of a control role, also with respect to the measurer apparatus. For example, in some embodiments the collector apparatus includes a controller and storage and the controller is operable to update the storage with data performance information from collector apparatuses with which it is directly linked (that is without the NIC) and to write information from the storage to the individual memories as location information using third party access. [0041] The invention also extends to method aspects which may be combined with any of the foregoing apparatus aspects and any combination of sub-features thereof. [0042] According to an embodiment of a method aspect there is provided a fault-tolerant monitoring method for monitoring physical performance properties of a plurality of networked computing elements, each element including a processing unit and individual memory, the monitoring method including measuring the physical performance properties of computing elements using measurer apparatuses and storing local information representing the physical performance properties in the individual memory of those computing elements; and collecting remote information representing physical performance properties from individual memory in a particular computing element using a collector apparatus and storing the remote physical performance information as replicate information in the individual memory of another computing element; wherein the remote physical performance information is collected using third party access. [0043] In such a method, if a computing element fails or is otherwise deselected during execution of an application and an application continues or restarts from a check point and omitting the particular computing element, physical performance data for the particular computing element before failure can be provided by other computing elements in which the data was stored as replicate information. [0044] According to an embodiment of a system aspect there is provided a computer system including a plurality of networked computing elements, each element including a processing unit and individual memory, the computer system also including a fault-tolerant monitoring apparatus arranged to monitor physical performance properties of the networked computing elements, the monitoring apparatus including a plurality of measurer apparatuses each arranged to measure the physical performance properties of a single computing element, for storage as local information in the individual memory of the particular computing element; and collector apparatus arranged to collect remote information representing physical performance properties from individual memory in a plurality of the computing elements and to store the remote physical performance information as replicate information in the individual memory of another computing element; wherein the remote physical performance information is collected using third party access. [0045] Thus the monitored computing system includes the networked computing elements as previously defined and the fault-tolerant monitoring apparatus as previously defined. [0046] According to a further aspect there is provided a program which when loaded onto a monitoring apparatus in a distributed memory computer system configures the computing apparatus to carry out the method steps according to any of the preceding method definitions or any combination thereof. [0047] Features and sub-features of any of the different aspects of the invention may be freely combined. For example, preferred embodiments of the computer system may be configured to incorporate functionality corresponding to one or more preferred features of one or more of the apparatus aspects. [0048] The invention can be implemented in computer hardware, firmware, software, or in combinations of them. The invention can be implemented as a computer program or computer program product, i.e., a computer program tangibly embodied in an information carrier, e.g., in a machine-readable storage device or in a propagated signal, for execution by, or to control the operation of, one or more hardware modules. [0049] A computer program can be in the form of a computer program portion or more than one computer program and can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a data processing environment. A computer program can be deployed to be executed on one module or on multiple modules at one site or distributed across multiple sites and interconnected by a communication network. [0050] Method steps of the invention can be performed by one or more programmable processors executing a computer program to perform functions of the invention by operating on input data and generating output. Each processor may have one or more cores. [0051] Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital or biological computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions coupled to one or more memory devices for storing instructions and data. [0052] The invention is described in terms of particular embodiments. Other embodiments are within the scope of the following claims. For example, the steps of the invention can be performed in a different order and still achieve desirable results. [0053] The apparatus according to preferred embodiments is described as configured, operable or arranged to carry out certain functions. This configuration or arrangement could be by use of hardware or middleware or any other suitable system. In preferred embodiments, the configuration or arrangement is by software. BRIEF DESCRIPTION OF THE DRAWINGS [0054] These and/or other aspects and advantages will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: [0055] FIG. 1 is an overview diagram comparing prior art solutions with a representation of an invention embodiment; [0056] FIG. 2 is a flow chart comparison of a prior art method with an invention embodiment; [0057] FIG. 3 is a further diagrammatic view comparing the prior art with invention embodiments; [0058] FIG. 4 is an apparatus overview of an invention embodiment in a network of computing elements; [0059] FIG. 5 is an apparatus overview of a variant of the FIG. 4 embodiment; [0060] FIG. 6 is a schematic diagram of an FTMC apparatus according to invention embodiments; [0061] FIG. 7 is a comparison between RAID technology and the principle of invention embodiments; [0062] FIG. 8 is a comparison between use of iSER technology and the principle of invention embodiments; and [0063] FIG. 9 shows components of an FTMC apparatus within a computer system. DETAILED DESCRIPTION [0064] Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures. [0065] FIG. 1 is a schematic representation of the effect of invention embodiments. [0066] In the prior art methods of monitoring (left), if a fault occurs which is isolated to a node, then a functioning node attempting to use monitoring data from the faulty node is affected. In contrast, the right hand side of FIG. 1 shows the same node-isolated fault occurring but the non-faulty node is able to access correct monitoring data by the use of third party access before or after occurrence of the fault and/or by the use of replicate information stored at the non-faulty node or another node which is still accessible. [0067] FIG. 2 shows a prior art process in a flow chart to the left and an invention embodiment in a flow chart to the right. In the prior art process, detailed self monitoring takes place if this is available in the application executing in step S 10 . In step S 20 ad hoc external monitoring may take place. [0068] In step S 30 , any node may read (that is store) its own monitoring data. [0069] In step S 40 the node can communicate its monitoring data to a remote node. Any faults will result in errors or failure. [0070] According to an invention embodiment shown to the right of FIG. 2 , the software writes any self-monitoring data to pinned RAM in step S 50 . The apparatus of invention embodiments, sometimes referred to as a Fault-Tolerant Measurer Collector (FTMC) apparatus writes external monitoring data (for example physical data useful for system operation) to pinned RAM in step S 60 . In step S 70 the FTMC apparatus issues RDMA gets to distribute monitoring data fault-tolerantly. [0071] In step S 80 software, such as application or system utility software can access monitoring data including data on faulty components or nodes. [0072] The right hand side of FIG. 2 is applicable to a plurality of collectors and a plurality of measurers. That is, FIG. 2 is the process for one FTMC apparatus (one collector and one or more measurers) but more importantly is also the process for when a plurality of FTMC apparatuses are working together as one FTMC apparatus (the usual operational case). [0073] FIG. 3 represents the way in which many prior art monitoring methods function on the left and on the right hand side of the figure, demonstrates how invention embodiments function. [0074] In the prior art the CPU is involved in sending and receiving (putting/getting) monitoring data as mandated by the application currently executing. Thus there is a burden on the user (application programmer) to manage monitoring data and the correctness thereof depends on complex functioning of CPUs. [0075] Conversely in the invention scenario shown to the right the CPU is no longer required for monitoring data because this function is carried out by the FTMC apparatus, without the need for user or CPU intervention. For example and as shown in FIG. 3 an RDMA get is used and there is no need to make any assumption that a remote node from which data is retrieved is functioning correctly. [0076] FIG. 4 is an apparatus overview of an invention embodiment. The FTMC apparatus 10 is shown in this example as including three measurer apparatuses 12 and one collector apparatus 14 . The various part of the FTMC apparatus are shown separately but they may be provided physically separate or together according to how the computer system or network is physically structured. FIG. 4 shows three computing elements 16 , each with the ability to store remote information (RI) in its individual memory as well as local information (LI). The computing elements may each correspond to a node of a group of nodes served by the collector. FIG. 4 shows the use of RDMA gets to redistribute information. The collector uses third party access to store remote information in the two upper computing elements. A RDMA get acquires data from the target. In this example computing element 16 at the bottom of the figure is the target node and third party access allows local information in that computing element to be written up to the two computing elements at the top of the figure using RDMA gets. [0077] In contrast, FIG. 5 which shows the same physical arrangement, uses RDMA puts initiated by the collector. An RDMA put writes data to the target and thus in FIG. 5 remote information is collected in the computing element at the bottom of the figure. [0078] FIGS. 4 and 5 only show some data replication, for simplicity, but remote data can be stored at any or all of the computing elements. Moreover, data from outside the group of nodes can be collected by use of third party access to other nodes (not shown). [0079] For example, the FTMC Collector will issue RMDA Gets to the NIC which will read from nodes outside the drawer (and in the typical case, communication outside the node/drawer follows normal processes). In particular pre-orchestrated gathering of data will take place. Data location 30 shown in FIG. 6 (discussed later) is populated on initialization and this completely determines what gathering (for replication) takes place. A physical analogy would be a postman's list of pillar poxes to empty. Messages may be sent, from outside the drawer, to the FTMC Collector (the same collector which is reading from outside the drawer) to perform initialization of data locations 28 and 30 in FIG. 6 (if initialization does not occur on-node simply by running an executable which performs initialization again via the NIC). [0080] FIG. 6 is a schematic diagram of a FTMC apparatus showing collector apparatus 14 linked to a plurality of measurer apparatuses 12 and NIC 18 . The collector apparatus 14 includes monitoring and communication logic 20 and settings 22 including counters 24 , the activation state of the apparatus 26 , locations to write to 28 , locations to read from 30 and a bitmask of active monitors 32 . The bitmask simply indicates which kind of information is being monitored according to current settings. [0081] The collector apparatus functions as follows. Software initializes the collector apparatus 14 by switching the activation state 26 to on (e.g. changing a bit from zero to one or setting an integer from an off value to a value corresponding to the appropriate version of the monitoring strategy or software). Software sets the bitmask of the monitors to be used 32 . Initialization also zeroes the counter 24 . Software sets the locations to write to 28 and locations to read from 20 . The monitoring and communication logic (MCL) checks the activation state and sleeps if the collector is not active. If the apparatus is active, MCL updates the counters with data from a measurer apparatus (using direct communication, not the NIC). Periodically, MCL writes the counter information to pinned RAM using RMDA Puts (to some of the “Locations to Write to”) through the NIC. Periodically, MCL performs RMDA Gets from the “Locations to Read from” and places this data In the remaining “Locations to Write to”. The read locations may be local (for example within a group of nodes which the collector apparatus is servicing) or remote (for example outside the group). The process is repeated for other active measurer apparatuses. [0082] Other behavior can be provided according to the activation state of the apparatus (e.g. external monitoring could be disabled so that the Counters are unused but self-monitoring may continue, other debugging schemes could be used such checking for failure of Measurer Apparatus and signaling this in some predetermined way such as writing known values in a software-determined location). [0083] One detailed worked example demonstrating invention embodiments may be monitoring execution of an application running a 2D Finite Difference code for scalar diffusion where there is a grid of points one million by one million in size giving one trillion data points. Assuming the value at each point is a double precision floating point number (8 bytes, 64-bits), eight thousand gigabytes (8000 GB or 8 terabytes, 8 TB) of RAM are required. To carry out the computation more quickly, 1000 nodes are used which each hold a piece of the grid. Each node will also have “ghost points” which are required for computation but which the node is not responsible for updating and these points must be periodically updated during a communication phase which is not addressed further in this example. Additionally, 20 further nodes are provisioned in case some nodes fail. The user wishes to monitor the floating points computed (self-monitored) by the application and the energy used in Joules (measured externally) by the measurer apparatuses. Monitoring of these two characteristics is activated on all 1020 nodes with the instantaneous data periodically written to pinned RAM (i.e., which will not be swapped out to disk). Periodically this data is distributed amongst the 1020 nodes. At a certain point in time, one of the nodes fails and the application restarts from a “check-point” which has been written to disk. One of the reserve nodes is utilized to ensure there are 1000 nodes in the computation. Even after the node failure, full access to the monitoring data will be possible from any of the remaining active nodes. [0084] A variation on this may be that the computation uses the monitoring data to see that one node is performing very poorly yet using a huge amount of energy and the computation may completely deactivate the poorly performing node so that the computation as a whole completes more quickly, uses less total electricity and therefore costs less in monetary terms. [0085] Data independent of a faulty node is also useful in determining corrupt data. For example Node A may record a correct value of 10 for some monitor (monitored parameter). This value is replicated to Node B, Node C and Node D. Node B develops a fault so that an incorrect value of 23 is returned when queried but this can be discovered because Nodes C and D specify the correct value of 10. This is additional data independent of the faulty node. However this strategy does not help if Node A records an incorrect value of 32. If independent monitoring by FTMC measurers is available for this same monitor (e.g. energy usage), this external monitoring may have recorded a correct value of 10 at Node A which will be replicated to Nodes B, C and D. Effectively here, there is self monitoring and external monitoring of the same parameter for the same node. This gives a higher chance that the data will be available somewhere. In practice corrupt data is easily distinguishable from correct data so determining the correct value should not be difficult. [0086] FIG. 7 shows to the left a diagrammatic explanation of the RAID technique and to the right the principle of invention embodiments. [0087] According to the RAID method, a RAID controller is used to provide data access to memory stored across several discs or other drives. If one of the discs fails as shown, replicated information on the other discs can be used. [0088] In invention embodiments, there is no need for a RAID controller and instead remote data is copied from a number of prearranged locations in remote memory using the NIC. Thus if one of the memory locations fails, as shown by the third memory block from the left in the right hand side of the figure, the memory block shown directly linked to the apparatus has access to monitoring data from the failed memory block, either from collection by RDMA get before failure or even after failure. [0089] FIG. 8 shows read and write methodologies for iSER techniques used in RAID to the left of the figure and for invention embodiments to the right of the figure. Reading is shown in the upper half of the diagram. In iSER RDMA put is used to write from the target into the memory associated with the initiator. In contrast, according to invention embodiments a NIC initiated RDMA get reads data from the target to the initiator. As an aside, FIG. 8 shows use of an NIC to write to local memory in invention embodiments, but other methods are also possible, for example a NUMA (Non-Uniform Memory Access) arrangement or using Hyper-Transport or Intel QPI (Quick Path Interconnect). [0090] Similarly, in write methodology the iSER technology uses a RDMA get to read from the target to the memory associated with the initiator. According to invention embodiments, the FTMC apparatus writes to memory associated with it, for example using RDMA put and RDMA get is used to read data from remote memory in the target. [0091] FIG. 9 shows components of an FTMC apparatus within a computer system. The system shown is an interconnected cluster of 64 nodes in 16 drawers. One system board is magnified to show 4 nodes in that drawer. The nodes shown are single CPU nodes. However there may be multi socket nodes with a plurality of CPUs preferably with floating point accelerators. Solid lines between the CPU, memory (MEM), interconnect controller or NIC (ICC here) and the FTMC collector represents by directional interactions. Dotted lines from the FTMC measurer represent monitoring. Novel portions are enclosed in dashed lines. The components of the FTMC apparatus are shaded in. [0092] As the skilled reader will appreciate the components shown for a single drawer may be part of a single FTMC apparatus which has components in each drawer of the system. [0093] The Fault-Tolerant Measurer Collector (FTMC) apparatus and method of this embodiment will monitor characteristics such as voltage and energy usage of components of interest and provide this monitoring data to other nodes of the cluster even in the event of faults. Components with additional self-monitoring capabilities, such as monitoring floating point operations performed or packets sent, will be manipulated by the FTMC apparatus and software to provide fault-tolerant access to the data collected. [0094] The monitoring data of the current invention embodiments may consist of a small collection of integer values which may be stored in 64-bits to 128-bits. A subset of nodes in the HPC system can be monitored and a subset of nodes may be chosen to hold the monitoring data. The monitoring data can be replicated across all the nodes chosen to hold the monitoring data or there may be a reduced number of replicates chosen (e.g. every second data-holding node, or every fourth data-holding node) and these locations may be communicated to the apparatus. [0095] Although a few embodiments have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

A fault-tolerant monitoring apparatus is arranged to monitor physical performance properties of a plurality of networked computing elements, each element including a processing unit and individual memory. The monitoring apparatus comprises a plurality of measurer apparatuses, each arranged to measure the physical performance properties of a single computing element, the physical performance properties being stored as local information in the individual memory of the computing element in which the measurement is made; and one or more collector apparatuses arranged to control collection of remote information representing physical performance properties from individual memory in a plurality of the computing elements; and storage of the remote physical performance information as replicate information in the individual memory of another computing element; wherein the remote physical performance information is collected using third party access.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] This invention relates to precision motion stages and more specifically to a stage suitable for use in a photolithography machine and especially adapted for supporting a reticle. [0003] 2. Description of the Prior Art [0004] Photolithography is a well known field especially as applied to semiconductor fabrication. In photolithography equipment, a stage (an X-Y motion device) supports the reticle (i.e., mask) and a second stage supports the semiconductor wafer, i.e., the work piece being processed. Sometimes only a single stage is provided, for the wafer or the mask. [0005] Such stages are essential for precision motion in the X-axis and Y-axis directions and often some slight motion is provided for adjustments in the vertical (Z-axis) direction. A reticle stage is typically used where the reticle is being scanned in a scanning exposure system, to provide smooth and precise scanning motion in one linear direction and insuring accurate, reticle to wafer alignment by controlling small displacement motion perpendicular to the scanning direction and a small amount of “yaw” (rotation) in the X-Y plane. It is desirable that such an X-Y stage be relatively simple and be fabricated from commercially available components in order to reduce cost, while maintaining the desired amount of accuracy. Additionally, many prior art stages include a guide structure located directly under the stage itself. This is not desirable in a reticle stage since it is essential that a light beam be directed through the reticle and through the stage itself to the underlying projection lens. Thus, a stage is needed which does not include any guides directly under the stage itself, since the stage itself must define a fairly large central passage for the light beam. [0006] Additionally, many prior art stages do not drive the stage through its center of gravity which undesirably induces a twisting motion in the stage, reducing the frequency response of the stage. Therefore, there is a need for an improved stage and especially one suitable for a reticle stage. SUMMARY [0007] A precision motion stage mechanism includes the stage itself which moves in the X-Y plane on a flat base. The stage is laterally surrounded by a “window frame” guide structure which includes four members attached at or near their corners to form a rectangular structure. The attachments are flexures which are a special type of hinge allowing movement to permit slight distortion of the rectangle. In one version, these flexures are thin stainless steel strips attached in an “X” configuration, allowing the desired degree of hinge movement between any two adjacent connected window frame members. [0008] The window frame guide structure moves on a base against two spaced-apart and parallel fixed guides in, e.g., the X axis direction, being driven by motor coils mounted on two opposing members of the window frame cooperating with magnetic tracks fixed on the base. [0009] The window frame in effect “follows” the movement of the stage and carries the magnetic tracks needed for movement of the stage in the Y axis direction. (It is to be understood that references herein to the X and Y axes directions are merely illustrative and for purposes of orientation relative to the present drawings and are not to be construed as limiting.) [0010] The stage movement in the direction perpendicular (the Y axis direction) to the direction of movement of the window frame is accomplished by the stage moving along the other two members of the window frame. The stage is driven relative to the window frame by motor coils mounted on the stage and cooperating with magnetic tracks mounted in the two associated members of the window frame. [0011] To minimize friction, the stage is supported on the base by air bearings or other fluid bearings mounted on the underside of the stage. Similarly, fluid bearings support the window frame members on their fixed guides. Additionally, fluid bearings load the window frame members against the fixed guides and load the stage against the window frame. So as to allow slight yaw movement, these loading bearings are spring mounted. The stage itself defines a central passage. The reticle rests on a chuck mounted on the stage. Light from an illuminating source typically located above the reticle passes to the central passage through the reticle and chuck to the underlying projection lens. [0012] It is to be understood that the present stage, with suitable modifications, is not restricted to supporting a reticle but also may be used as a wafer stage and is indeed not limited to photolithography applications but is generally suited to precision stages. [0013] An additional aspect in accordance with the invention is that the reaction force of the stage and window frame drive motors is not transmitted to the support frame of the photolithography apparatus projection lens but is transmitted independently directly to the earth's surface by an independent supporting structure. Thus, the reaction forces caused by movement of the stage do not induce undesirable movement in the projection lens or other elements of the photolithography machine. [0014] This physically isolating the stage reaction forces from the projection lens and associated structures prevents these reaction forces from vibrating the projection lens and associated structures. These structures include the interferometer system used to determine the exact location of the stage in the X-Y plane and the wafer stage. Thus, the reticle stage mechanism support is spaced apart from and independently supported from the other elements of the photolithography machine and extends to the surface of the earth. [0015] Advantageously, the reaction forces from operation of the four motor coils for moving both the stage and its window frame are transmitted through the center of gravity of the stage, thereby desirably reducing unwanted moments of force (i.e., torque). The controller controlling the power to the four drive motor coils takes into consideration the relative position of the stage and the frame and proportions the driving force accordingly by a differential drive technique. BRIEF DESCRIPTION OF THE DRAWINGS [0016] FIG. 1 shows a top view of a window frame guided stage. [0017] FIG. 2 shows a side view of the window frame guided stage and associated structures. [0018] FIGS. 3A and 3B show enlarged views of portions of the structure of FIG. 2 . [0019] FIG. 4 shows a top view of a photolithography apparatus including the window frame guided stage. [0020] FIG. 5 shows a side view of the photolithography apparatus of FIG. 4 . [0021] FIGS. 6A and 6B show a flexure hinge structure as used, e.g., in the window frame guided stage. [0022] FIG. 7 is a perspective view of a microlithography system disclosed in U.S. patent application Ser. No. 08/221,375. [0023] FIG. 7A is a view of a portion of the structure shown in FIG. 7 delineated by line A-A and with the reaction stage which is shown FIG. 7 removed. [0024] FIG. 7B is an elevational view, partially in section, of the structure shown in FIG. 7 . [0025] FIG. 7C is a schematic elevational view, partially in section, of the object positioning apparatus disclosed in U.S. patent application Ser. No. 08/221,375. [0026] FIG. 8 is a plan view of the wafer XY stage position above the reaction stage. [0027] FIG. 9 is a side elevational view of a portion of the structure shown in FIG. 8 taken along line 9 - 9 in the direction of the arrows. [0028] FIG. 9A is an enlarged view of a portion of the structure shown in FIG. 9 delineated by line B-B. [0029] FIG. 10 is a perspective view of the reaction stage showing the XY followers without the means for coupling to the XY stage for positioning of the XY stage. [0030] FIG. 10A is an enlarged perspective view of the XY followers illustrated in FIG. 10 . [0031] FIG. 11 is a schematic block diagram of the position sensing and control system for the preferred embodiment disclosed in U.S. patent application Ser. No. 08/221,375. [0032] FIGS. 12 and 13 are views similar to FIGS. 8 and 9 of an alternative embodiment disclosed in U.S. patent application Ser. No. 08/221,375. [0033] FIGS. 14 and 15 are views similar to FIGS. 8 and 9 of still another embodiment disclosed in U.S. patent application Ser. No. 08/221,375. [0034] FIG. 16 is an enlarged top view of a portion of the structure shown in FIG. 14 . [0035] FIG. 17 is an end view of the structure shown in FIG. 16 taken along line 17 - 17 in the direction of the arrows. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0036] FIG. 1 shows a top view of a stage mechanism in accordance with the invention. See also copending commonly owned and invented U.S. patent application Ser. No. 08/221,375 entitled “Guideless Stage with Isolated Reaction Stage” filed Apr. 1, 1994, original docket no. NPI0500, which is incorporated herein by reference and shows a related method of supporting elements of a stage mechanism so as to isolate reaction forces from the projection lens and other parts of a photolithography apparatus. [0037] The detailed description from U.S. patent application Ser. No. 08/221,375 is reproduced below. FIGS. 1-11 of that application have been renumbered respectively as FIGS. 7-17 , and the reference numerals have been increased by 200 in order to avoid the use of duplicate reference numerals for different elements. [heading-0038] The Detailed Description from U.S. patent application Ser. No. 08/221,375 [0039] While it will be appreciated by those skilled in the art that the guideless stage, with or without its isolating reaction frame, has many applications to many different types of instruments for precise positioning of objects, the invention will be described with respect to a preferred embodiment in the form of a microlitholigraphic instrument for aligning wafers in a system where a lens produces an image which is exposed to the photoresist on the wafer surface. In addition, while the guideless stage with or without its isolation stage can be utilized as a guideless object stage movable in just one direction, such as a X or an Y direction, the preferred embodiment is directed to a guideless XY wafer stage as described below. [0040] Referring now to the drawings, with particular reference to FIGS. 7 and 8 , there is shown a photolithographic instrument 210 having an upper optical system 212 and a lower wafer support and positioning system 213 . The optical system 212 includes an illuminator 214 including a lamp LMP, such as a mercury lamp, and an ellipsoid mirror EM surrounding the lamp LPM. The illuminator 214 comprises optical integrator such as a fly's eye lens FEL producing secondary light source images and a condenser lens CL for illuminating a reticle (mask) R with uniformed light flux. A mask holder RST holding the mask R is mounted above a lens barrel PL of a projection optical system 216 . The lens barrel PL is fixed on a part of a column assembly which is supported on a plurality of rigid arms 218 each mounted on the top portion of an isolation pad or block system 220 . [0041] Inertial or seismic blocks 222 are located on the system such as mounted on the arms 218 . These blocks 222 can take the form of a cast box which can be filled with sand at the operation site to avoid shipment of a massive structure. An object or wafer stage base 228 is supported from the arms 218 by depending blocks 222 and depending bars 226 and horizontal bars 227 (see FIG. 7A ). FIG. 7B is an elevational view, partially in section, of the structure shown in FIG. 7 except that in FIG. 7B the blocks 222 are shown as being a different configuration than in FIGS. 7 and 7 A. Referring now to FIGS. 8 and 9 , there are shown plan and elevational views, respectively, of the wafer supporting and positioning apparatus above the object or wafer stage base 228 including the object or wafer or XY stage 230 and the reaction frame assembly 260 . The XY stage 230 includes a support plate 232 on which the wafer 234 , such as a 12 inch wafer, is supported. The plate 232 is supported in space above the object stage base 228 via vacuum pre-load type air bearings 236 which can be controlled to adjust Z, i.e., tilt roll and focus. Alternatively, this support could employ combinations of magnets and coils. [0042] The XY stage 230 also includes an appropriate element of a magnetic coupling means such as a linear drive motor for aligning the wafer with the lens of the optical system 216 for precisely positioning an image for exposure of a photoresist on the wafer's surface. In the embodiment illustrated, the magnetic coupling means takes the form of a pair of drive members such as X drive coils 242 X and 242 X′ for positioning the XY stage 230 in the X direction and a pair of Y drive members such as drive coils 244 Y and 244 Y′ for positioning the XY stage 230 in the Y direction. The associated portion of the magnetic coupling means on the reaction frame assembly 260 will be described in later detail below. [0043] The XY stage 230 includes a pair of laser mirrors 238 X operative with respect to a pair of laser beams 240 A/ 240 A′ and 238 Y operative with respect to a pair of laser beams 240 B/ 240 B′ of a laser beam interferometer system 292 for determining and controlling the precise XY location of the XY stage relative to a fixed mirror RMX at the lower part of the lens barrel PL of the projection optical system 216 . [0044] Referring to FIGS. 10 and 10 A, the reaction frame assembly 260 has a reaction frame 261 which includes a plurality of support posts 262 which are mounted on the ground or a separate base substantially free from transferring vibrations between itself and the object stage. [0045] The reaction frame 261 includes face plates 264 X and 264 X′ extending between support posts 262 in the X direction and 266 Y and 266 Y′ extending between support posts in the Y direction. Inside the face plates 264 - 266 a plurality of reaction frame rails 267 - 269 and 267 ′- 269 ′ are provided for supporting and guiding an X follower 272 and a Y follower 282 . Inside face plate 264 X are an upper follower guide rail 267 and a lower follower guide rail 268 (not shown) and on the inside surface of the opposite face plate 264 X′ are upper and lower follower guide rails 267 ′ and 268 ′. On the inside surfaces of each of the face plates 266 Y and 266 Y′ is a single guide rail 269 and 269 ′, respectively, which is positioned vertically in between the guide rails 267 and 268 . [0046] The X follower includes a pair of spaced apart arms 274 and 274 ′ connected at their one end by a cross piece 276 . Drive elements such as drive tracks 278 and 278 ′ (see FIG. 8 ) are mounted on the arms 274 and 274 ′, respectively, for cooperating with the drive elements 242 X and 242 X′ of the XY stage. Since in the illustrated embodiment the drive elements 242 X and 242 X′ on the XY stage are shown as drive coils, the drive tracks on the X follower 272 take the form of magnets. The coupling elements could be reversed so that the coils would be mounted on the X follower and the magnets mounted on the XY stage. As the XY stage is driven in the X and Y direction, the laser interferometer system 292 detects the new position of the XY stage momentarily and generates a position information (X coordinate value). As described in greater detail below with reference to FIG. 11 , a servo position control system 294 under control of a host processor (CPU) 296 controls the position of the X follower 272 and the Y follower 282 in response to the position information from the interferometer system 292 to follow the XY stage 230 without any connection between the drive coils 242 X, 242 X′ and the tracks 274 , 274 ′. [0047] For movably mounting the X follower 272 on the reaction frame 261 , the ends of the arms 274 and 274 ′ at the side of the reaction frame 261 ride or are guided on the rail 269 , and the opposite ends of the arms 274 and 274 ′ ride on rail 269 ′ adjacent face plate 266 Y. For moving the X follower 272 a drive member 277 is provided on the cross piece 276 for cooperating with the reaction frame guide 269 for moving the follower 272 in a direction which is perpendicular to the X direction of the XY stage. Since the precision drive and control takes place in the XY stage 230 , the positioning control of the X follower 272 does not have to be as accurate and provide as close tolerances and air gaps as the XY stage 230 . Accordingly, the drive mechanism 277 can be made of a combination of a screw shaft rotated by a motor and a nut engaged by the X follower 272 or a combination of a coil assembly and a magnet assembly to establish a linear motor and each combination can be further combined with a roller guiding mechanism. [0048] Similar to the X follower 272 , the Y follower 282 includes a pair of arms 284 and 284 ′ connected at their one end by a crossbar 286 and including drive tracks 288 and 288 ′ for cooperating with the Y drive members 244 Y and 244 Y. The arms 284 and 284 ′ of the Y follower 282 are guided on separate guide rails. The ends of arm 284 ride or are guided on the upper rails 267 and 267 ′ and the ends of arm 284 ′ are guided on lower rails 268 and 268 ′. A drive mechanism 287 is provided on the cross piece 286 of the Y follower 282 for moving the Y follower 282 along guides 267 , 267 ′, 268 and 268 ′ between the face plates 266 Y and 266 Y′ in a direction perpendicular to the Y direction of the XY stage. [0049] As best illustrated in FIG. 10A , the arms 274 and 274 ′ and crossbar 276 ′ of the X follower 272 all lie within and move in the same plane crossing the Z axis. The center of gravity of the XY stage 230 lies within or is immediately adjacent to this plane. In this construction the drive forces from each of the drive coils 242 X and 242 X′ are in a direction along the length of the arms 274 and 274 ′, respectively. However, the arms 284 and 284 ′ of the Y follower 282 lie within and move in different parallel planes spaced apart along the Z axis from one another respectively above and below and parallel to the plane containing the X follower 272 . In the preferred embodiment, the crossbar 286 lies in the lower plane containing the arm 284 ′ and a spacer block 286 ′ is positioned between the overlapping ends of the arm 284 and crossbar 286 to space the arms 284 and 284 ′ in their respective parallel planes. As with X follower 272 , the drive forces from each of the drive coils 244 Y and 244 Y′ are in a direction along the length of the arms 284 and 284 ′. Also, predetermined gaps in X and Z directions are maintained between the drive coils 244 Y ( 244 Y) and the drive tracks 288 ( 288 ′) to achieve the guideless concept. [0050] In operation of the guideless stage and isolated reaction frame of the invention, the XY stage 230 is positioned in an initial position relative to the projection lens as sensed by the interferometer system 292 , and the XY stage 230 is supported in the desired Z direction from the object stage base 228 by the air bearings 236 with the drive coils 242 X, 242 X′, 244 Y and 244 Y′ spaced from the drive elements in the form of drive tracks 278 , 278 ′, 288 and 288 ′, respectively. There is no direct contact between the XY stage 230 and the reaction frame 261 . That is, there is no path for the vibration of the reaction frame to affect the position of the XY stage and vice versa. There is only indirect contact via the transmission means that deliver the signals to the coils and the laser interferometer position sensing system which then transmits sensed position information to the controller which receives other commands to initiate drive signals which result in movement of the XY stage 230 . [0051] With the known position of the XY stage 230 from the interferometer system 292 , drive signals are sent from the position control system 294 to the appropriate drive coils, 242 X, 242 X′, 244 Y and 244 Y′ to drive the XY stage to a new desired position. The motion of the XY stage is sensed by the interferometer system 292 and position sensors 298 X and 298 Y (see FIG. 11 ), and the X follower 272 and Y follower 282 are driven by the drive members 277 and 287 , respectively, to follow the XY stage. As illustrated in FIG. 11 , the position sensor 298 X detects a variation of the Y direction space between the XY stage 230 and the X follower 272 and generates an electric signal representing the amount of space to the position control system 294 . The position control system 294 generates a proper drive signal for the drive member 277 on the basis of the X position information from the interferometer system 292 and the signal from the position sensor 298 X. [0052] Also, the position sensor 298 Y detects a variation of X direction space between the XY stage 230 and the Y follower 282 and generates an electric signal representing the amount of space, and the drive member 287 is energized on the basis of the Y position information from the interferometer system 292 and the signal from the position sensor 298 Y. [0053] Yaw correction is accomplished by the pairs of linear motors which can be used to hold or offset yaw, or the pairs of linear motors can change the rotational position of the XY stage. The data from either or both pairs of laser beams 240 A/ 240 A′ and 240 B/ 240 B′ are used to obtain yaw information. Electronic subtraction of digital position data obtained from measurement using the laser beams 240 A and 240 A′ or 240 B and 240 B′ is performed or both differences are added and divided by two. [0054] This invention allows the positioning function of the XY stage to be accomplished faster than if XY guides were used. Reaction forces created in moving the XY stage can be coupled away from the image forming optics and reticle handling equipment. [0055] This invention needs no precision X or Y guides as compared to a guided stage, and precision assembly and adjustment of the wafer XY stage is reduced due to the lack of precision guides. The servo bandwidth is increased because the linear motor forces in the XY axes act directly on the wafer stage; they do not have to act through a guide system. [0056] Forces from the XY linear motors can all be sent substantially through the center of gravity of the XY stage thereby eliminating unwanted moments of force (torque). [0057] With the X follower 272 and the Y follower 282 mounted and moved totally independently of one another, any vibration of a follower is not conveyed to the wafer XY stage or to the optical system when using commercially available electromagnetic linear motors for the magnetic coupling between each of the followers 272 and 282 and the XY stage 230 and with clearance between the coils and magnet drive tracks less than about 1 mm. Additionally, with the arms of one of the followers spaced above and below the arms of the other follower, the vector sum of the moments of force at the center of gravity of the XY stage due to the positioning forces of cooperating drive members is substantially equal to zero. [0058] No connection exists between the XY stage and the follower stages that would allow vibrations to pass between them in the X, Y or theta degrees of freedom. This allows the follower stages to be mounted to a vibrating reference frame without affecting performance of the wafer stage. For example, if the reaction frame were struck by an object, the XY stage and the projection optical system would be unaffected. [0059] It will be appreciated by a person skilled in the art that if the center of gravity is not equidistant between either of the two X drive coils or either of the two Y drive coils, that appropriate signals of differing magnitude would be sent to the respective coils to apply more force to the heavier side of the stage to drive the XY stage to the desired position. [0060] For certain applications the drive elements 242 X/ 242 X′ or 242 Y/ 242 Y′ of the actuator or magnetic coupling assembly for supplying electromagnetic force to the movable XY stage may be held stationary (see FIG. 11 ) in a static position with respect to movement of the stage in either the X or Y direction, respectively. [0061] In the last of the explanation of this embodiment, referring to FIG. 7C again, the essential structure of the invention will be described. As illustrated in FIG. 7C , the XY stage 230 is suspended on the flat smooth surface (parallel with the X-Y plane) of the stage base 228 through the air bearings 236 having air discharge ports and vacuum pre-load ports and is movable in X, Y and theta direction on the stage base 228 without any friction. [0062] The stage base 228 is supported on the foundation (or ground, base structure) 221 by the isolation blocks 220 , arms 218 , blocks 222 , the vertical bars 226 and the horizontal bars 227 . Each of the isolation blocks 220 is composed of a vibration absorbing assembly to prevent transmission of the vibration from the foundation 221 . [0063] Since FIG. 7C is a sectional view of the XY stage 230 along a line through the drive coils 242 X, 242 X′ in Y direction, the following description is restricted about the X follower 272 . [0064] In FIG. 7C , the drive coils 242 X are disposed in a magnetic field of drive track (magnet array elongated in X direction) 278 mounted on the follower arm 274 and the drive coils 242 X′ are disposed in a magnetic field of drive track 278 ′ mounted on the follower arm 274 ′. [0065] The two arms 274 , 274 ′ are rigidly assembled to move together in Y direction by the guide rails 269 , 269 ′ formed inside of the reaction frame 261 . Also, the guide rails 269 , 269 ′ restrict the movement of the two arms 274 , 274 ′ in X and Z directions. The reaction frame 261 is directly supported on the foundation 221 by the four support posts 262 independently from the stage base 228 . [0066] Therefore, the drive coils 242 X ( 242 X′) and the drive tracks 278 ( 278 ′) are disposed with respect to each other to maintain a predetermined gap (a few millimeters) in Y and Z directions. [0067] Accordingly, when the drive coils 242 X, 242 X′ are energized to move the XY stage 230 in X direction, the reaction force generated on the drive tracks 278 , 278 ′ is transferred to the foundation 221 , not to the XY stage 230 . [0068] On the other hand, as the XY stage 230 moves in Y direction, the two arms 274 , 274 ′ are moved in Y direction by the drive member 277 such that each of the drive tracks 278 , 278 ′ follows respective coils 242 X, 242 X′ to maintain the gap in Y direction on the basis of the measuring signal of the position sensor 298 X. [0069] While the invention has been described with reference to the preferred embodiment having a pair of X drive members or coils 242 X and 242 X′ and a pair of Y drive members or coils 244 Y and 244 Y, it is possible to construct a guideless stage with an isolated reaction frame in accordance with the invention with just three drive members or linear motors such as shown in FIGS. 12 and 13 . As illustrated in FIG. 12 , a pair of Y drive coils 344 Y and 344 Y′ are provided on the stage 330 and a single X drive coil or linear motor 342 X is mounted centered at the center of gravity CG′ of the XY stage. The Y drive coils 344 Y and 344 Y′ are mounted on the arms 384 and 384 ′ of the Y follower 382 , and the X drive coil 344 X is mounted on an arm 374 ″ of a X follower 372 . By applying appropriate drive signals to the drive coils 342 X and 344 Y and 344 Y, the XY stage can be moved to the desired XY positions. [0070] Referring now to FIGS. 14-17 , there is shown an alternative embodiment of the invention which includes links between the XY drive coils 442 X, 442 X′, 444 Y and 444 Y′ and the attachment to the XY stage 230 ′. These connections include a double flexure assembly 500 connecting the drive coil 444 Y to one end of a connecting member 520 and a double flexure assembly 530 connecting the other end of the connecting member 520 to the XY stage 230 ′. The double flexure assembly 500 includes a flange 502 connected to the coil 444 Y. A clamping member 504 is attached via clamping bolts to the flange 502 to clamp therebetween one edge of a horizontal flexible link 506 . The other end of the flexible link 506 is clamped between two horizontal members 508 which are in turn integrally connected with a vertical flange 510 to which are bolted a pair of flange members 512 which clamp one edge of a vertical flexible member 514 . The opposite edge of the vertical flexible member 514 is clamped between a pair of flange members 516 which are in turn bolted to a flange plate 518 on one end of the connecting member 520 . At the other end of the connecting member 520 a plate 548 is connected to two flange members 236 which are bolted together to clamp one end of a vertical flexible member 544 . The opposite edge of the vertical member 544 is clamped by flange members 542 which are in turn connected to a plate 540 connected to a pair of clamping plates 538 clamping one edge of a horizontal flexible member 536 , the opposing edge of which is in turn clamped onto the XY stage 230 ′ with the aid of the plate 534 . Thus, in each of the double flexure assemblies 500 and 530 vibrations are reduced by providing both a horizontal and a vertical flexible member. In each of these assemblies the vertical flexible members reduce X, Y and theta vibrations and the horizontal flexible members reduce Z, tilt and roll vibrations. Thus, there are eight vertical flex joints for X, Y and theta and eight horizontal flex joints for Z, tilt and roll. [0071] As illustrated in FIG. 17 , the coil 444 Y is attached to a coil support 445 Y which has an upper support plate 446 attached thereto which rides above the top of the magnetic track assembly 488 . Vacuum pre-load type air bearings 490 are provided between the coil support 445 Y and upper support plate 446 on the one hand and the magnetic track assembly 488 on the other hand. [0072] In an operative example of the embodiment illustrated in FIGS. 14-17 the flexible members 506 , 514 , 544 and 536 are stainless steel 1¼″ wide, ¼″ long and 0.012″ thick with the primary direction of flex being in the direction of the thickness. In the embodiment illustrated members 506 and 514 are mounted in series with their respective primary direction of flex being orthogonal to one another; members 544 and 536 are similarly mounted. [heading-0073] The Detailed Description from U.S. patent application Ser. No. 08/416,558 [0074] The stage 10 is (in plan view) a rectangular structure of a rigid material (e.g., steel, aluminum, or ceramic). Two interferometry mirrors 14 A and 14 B located on stage 10 interact conventionally with respectively laser beams 16 A and 16 B. Conventionally, laser beams 16 A are two pairs of laser beams and laser beams 16 B are one pair of laser beam, for three independent distance measurements. The underside of stage 10 defines a relieved portion 22 (indicated by a dotted line, not being visible in the plane of the drawing). A reticle 24 is located on stage 10 and held by conventional reticle vacuum groove 26 formed in the upper surface of chuck plate 28 . Stage 10 also defines a central aperture 30 (passage) below the location of reticle 24 . Central aperture 30 allows the light (or other) beam which penetrates through reticle 24 to enter the underlying projection lens, as described further below. (It is to be understood that the reticle 24 itself is not a part of the stage mechanism.) Moreover, if the present stage mechanism is to be used for other than a reticle stage, i.e., for supporting a wafer, aperture 30 is not needed. [0075] Stage 10 is supported on a conventional rectangular base structure 32 of, e.g., granite, steel, or aluminum, and having a smooth planar upper surface. The left and right edges (in FIG. 1 ) of base structure 32 are shown as dotted lines, being overlain by other structures (as described below) in this view. In operation, stage 10 is not in direct physical contact with its base structure 32 ; instead, stage 10 is vertically supported by, in this example, conventional bearings such as gas bearings. In one embodiment three air bearings 36 A, 36 B and 36 C are used which may be of a type commercially available. [0076] In an alternative air bearing/vacuum structure, the vacuum portion is physically separated from and adjacent to the air bearing portion. It is to be understood that the vacuum and compressed air are provided externally via tubing in a conventional cable bundle and internal tubing distribution system (not shown in the drawings for simplicity). In operation, stage 10 thereby floats on the air bearings 36 A, 36 B, 36 C approximately 1 to 3 micrometers above the flat top surface of base structure 32 . It is to be understood that other types of bearings (e.g., air bearing/magnetic combination type) may be used alternatively. [0077] Stage 10 is laterally surrounded by the “window frame guide” which is a four member rectangular structure. The four members as shown in FIG. 1 are (in the drawing) the top member 40 A, the bottom member 40 B, the lefthand member 40 C, and the righthand member 40 D. The four members 40 A- 40 D are of any material having high specific stiffness (stiffness to density ratio) such as aluminum or a composite material. These four members 40 A- 40 D are attached together by hinge structures which allow non-rigid movement of the four members relative to one another in the X-Y plane and about the Z-axis as shown in the drawing, this movement also referred to as a “yaw” movement. The hinge is described in detail below, each hinge 44 A, 44 B, 44 C and 44 D being, e.g., one or more metal flexures allowing a slight flexing of the window frame guide structure. [0078] The window frame guide structure moves in the X axis (to the left and right in FIG. 1 ) supported on horizontal surfaces of fixed guides 46 A and 46 B, and supported on vertical surfaces of fixed guides 64 A, 64 B. (It is to be understood that each pair of fixed guides 46 A, 64 A and 46 B, 64 B could be, e.g., a single L-shaped fixed guide, or other configurations of fixed guides may be used.) Mounted on window frame guide member 40 A are two air bearings 50 A and 50 B that cause the member 40 A to ride on its supporting fixed guide member 46 A. Similarly, air bearings 52 A and 52 B are mounted on the member 40 B, allowing member 40 B to ride on its supporting fixed guide member 46 B. Air bearings 50 A, 50 B, 52 A, 52 B are similar to air bearings 36 A, etc. [0079] The window frame guide is driven along the X axis on fixed guides 46 A and 46 B, 64 A and 64 B by a conventional linear motor, which includes a coil 60 A which is mounted on window frame guide member 40 A. Motor coil 60 A moves in a magnetic track 62 A which is located in (or along) fixed guide 64 A. Similarly, motor coil 60 B which is mounted on window frame guide member 40 B moves in magnetic track 62 B which is located in fixed guide 64 B. The motor coil and track combinations are part no. LM-310 from Trilogy Company of Webster Tex. These motors are also called “linear commutator motors”. The tracks 62 A, 62 B are each a number of permanent magnets fastened together. The electric wires which connect to the motor coils are not shown but are conventional. Other types of linear motors may be substituted. It is to be understood that the locations of the motor coils and magnetic tracks for each motor could be reversed, so that for instance the magnetic tracks are located on stage 10 and the corresponding motor coils on the window frame guide members, at a penalty of reduced performance. [0080] Similarly, stage 10 moves along the Y axis in FIG. 1 by means of motor coils 68 A and 68 B mounted respectively on the left and right edges of stage 10 . Motor coil 68 A moves in magnetic track 70 A mounted in window frame guide member 40 C. Motor coil 68 B moves in magnetic track 70 B mounted in window frame guide member 40 D. [0081] Also shown in FIG. 1 are air bearings 72 A, 72 B and 72 C. Air bearing 72 A is located on window frame guide member 40 A and minimizes friction between window frame guide member 40 A and its fixed guide 64 A. Similarly, two air bearings 72 B and 72 C on window frame guide member 40 B minimize its friction with the fixed guide 64 B. The use of a single air bearing 72 A at one end and two opposing air bearings 72 B and 72 C at the other end allows a certain amount of yaw (rotation in the X-Y plane about the Z-axis) as well as limited motion along the Z-axis. In this case, typically air bearing 72 A is gimbal mounted, or gimbal mounted with the gimbal located on a flexure so as to allow a limited amount of misalignment between the member 40 A and fixed guide 64 A. [0082] The use of the air bearing 72 A opposing bearings 72 B and 72 C provides a loading effect to keep the window frame guide in its proper relationship to fixed guides 64 A, 64 B. Similarly, an air bearing 76 A loads opposing air bearings 76 B and 76 C, all mounted on side surfaces of the stage 10 , in maintaining the proper location of stage 10 relative to the opposing window frame guide members 40 B and 40 D. Again, in this case one air bearing such as 76 A is gimbal mounted to provide a limited amount of misalignment, or gimbal mounted with the gimbal on a flexure (spring). Air bearings 72 A, 72 B, 72 C and 76 A, 76 B, and 76 C are conventional air bearings. [0083] The outer structure 80 in FIG. 1 is the base support structure for the fixed guides 46 A, 46 B, 64 A, 64 B and the window frame guide members 40 A, . . . , 40 D of the stage mechanism, but does not support stage base structure 32 . Thus, the underlying support is partitioned so the reaction force on base support structure 80 does not couple into the stage base structure 32 . Base support structure 80 is supported by its own support pillars or other conventional support elements (not shown in this drawing) to the ground, i.e., the surface of the earth or the floor of a building. An example of a suitable support structure is disclosed in above-referenced U.S. patent application Ser. No. 08/221,375 at FIGS. 1, 1B , 1 C ( FIGS. 7, 7B , 7 C of the present application). This independent support structure for this portion of stage mechanism provides the above-described advantage of transmitting the reaction forces of the reticle stage mechanism drive motors away from the frame supporting the other elements of the photolithography apparatus, especially away from the optical elements including the projection lens and from the wafer stage, thereby minimizing vibration forces on the projection lens due to reticle stage movement. This is further described below. [0084] The drive forces for the stage mechanism are provided as close as possible through the stage mechanism center of gravity. As can be understood, the center of gravity of the stage mechanism moves with the stage 10 . Thus, the stage 10 and the window frame guide combine to define a joint center of gravity. A first differential drive control (not shown) for motor coils 60 A, 60 B takes into account the location of the window frame guide to control the force exerted by each motor coil 60 A, 60 B to keep the effective force applied at the center of gravity. A second conventional differential drive control (not shown) for motor coils 68 A, 68 B takes into account the location of stage 10 to control the force exerted by each motor coil 68 A, 68 B to keep the effective force applied at the center of gravity. It is to be understood that since stage 10 has a substantial range of movement, that the differential drive for the motor coils 60 A, 60 B has a wide differential swing. In contrast, the window frame guide has no CG change, hence the differential drive for the motor coils 68 A, 68 B has a much lesser differential swing, providing a trim effect. Advantageously, use of the window frame guide maintains the reaction forces generated by movement of the reticle stage mechanism in a single plane, thus making it easier to isolate these forces from other parts of the photolithography apparatus. [0085] FIG. 2 shows a cross-sectional view through line 2 - 2 of FIG. 1 . The structures shown in FIG. 2 which are also in FIG. 1 have identical reference numbers and are not described herein. Also shown in FIG. 2 is the illuminator 90 which is a conventional element shown here without detail, and omitted from FIG. 1 for clarity. Also shown without detail in FIG. 2 is the upper portion of the projection lens (barrel) 92 . It is to be understood that the lower portion of the projection lens and other elements of the photolithography apparatus are not shown in FIG. 2 , but are illustrated and described below. [0086] The supporting structure 94 for the projection lens 92 is also shown in FIG. 2 . As can be seen, structure 94 is separated at all points by a slight gap 96 from the base support structure 80 for the reticle stage mechanism. This gap 96 isolates vibrations caused by movement of the reticle stage mechanism from the projection lens 92 and its support 94 . As shown in FIG. 2 , stage 10 is not in this embodiment a flat structure but defines the underside relieved portion 22 to accommodate the upper portion of lens 92 . Magnetic track 70 A is mounted on top of the window frame guide 40 B, and similarly magnetic track 70 B is mounted on top of the opposite window frame guide member 40 D. [0087] FIGS. 3A and 3B are enlarged views of portions of FIG. 2 , with identical reference numbers; FIG. 3A is the left side of FIG. 2 and FIG. 3B is the right side of FIG. 2 . Shown in FIG. 3A is the spring mounting 78 for air bearing 76 A. Air bearing 78 A being spring mounted to a side surface of stage 10 , this allows a certain amount of yaw (rotation in the X-Y plane about the Z-axis) as well as limited motion along the Z-axis. A gimbal mounting may be used in place of or in addition to the spring 78 . The spring or gimbal mounting thereby allows for a limited amount of misalignment between stage 10 and members 40 C, 40 D (not shown in FIG. 3A ). [0088] FIG. 4 is a top view of a photolithography apparatus including the stage mechanism of FIGS. 1 and 2 and further including, in addition to the elements shown in FIG. 1 , the supporting base structure 100 which supports the photolithography apparatus including frame 94 except for the reticle stage mechanism. (Not all the structures shown in FIG. 1 are labeled in FIG. 4 , for simplicity.) Base structure 100 supports four vertical support pillars 102 A, 102 B, 102 C and 102 D connected to structure 94 by respective bracket structures 106 A, 106 B, 106 C and 106 D. It is to be appreciated that the size of the base structure 100 is fairly large, i.e., approximately 3 meters top to bottom in one embodiment. Each pillar 102 A, 102 B, 102 C, 102 D includes an internal conventional servo mechanism (not shown) for leveling purposes. Also shown in FIG. 4 are the supports 108 and 110 for respective laser interferometer units (beam splitter etc.) 112 A, 112 B, 112 C. FIG. 4 will be further understood with reference to FIG. 5 which shows a view of FIG. 4 through cross-sectional line 5 - 5 of FIG. 4 . [0089] In FIGS. 4 and 5 the full extent of the supporting structure 94 can be seen along with its support pillars 102 A, 102 C which rest on the base structure 100 which is in contact with the ground via a conventional foundation (not shown). The independent support structure for the reticle stage base support structure 80 is shown, in FIG. 4 only (for clarity) and similarly includes a set of four pillars 114 A, 114 B, 114 C, 114 D with associated bracket structures 116 A, 116 B, 116 C, 116 D, with the pillars thereby extending from the level of base support structure 80 down to the base structure 100 . [0090] The lower portion of FIG. 5 shows the wafer stage 120 and associated support structures 122 , 124 . The elements of wafer stage 120 conventionally include (not labeled in the drawing) a base, the stage itself, fixed stage guides located on the base, magnetic tracks located on the fixed stage guides, and motor coils fitting in the magnetic tracks and connected to the stage itself. Laser beams from laser 124 mounted on support 126 locate lens 92 and the stage itself by interferometry. [0091] FIG. 6A shows detail of one of the window frame guide hinged flexure structures, e.g., 44 C, in a top view (corresponding to FIG. 1 ). Each of hinges 44 A, 44 B, 44 C and 44 D is identical. These flexure hinges have the advantage over a mechanical-type hinge of not needing lubrication, not exhibiting hysteresis (as long as the flexure is not bent beyond its mechanical tolerance) and not having any mechanical “slop”, as well as being inexpensive to fabricate. [0092] Each individual flexure is, e.g., ¼ hard 302 stainless steel approximately 20 mils (0.02 inch) thick and can sustain a maximum bend of 0.5 degree. The width of each flexure is not critical; a typical width is 0.5 inch. Two, three or four flexures are used at each hinge 44 A, 44 B, 44 C and 44 D in FIG. 1 . The number of flexures used at each hinge is essentially determined by the amount of space available, i.e., the height of the window frame guide members. The four individual flexures 130 A, 130 B, 130 C, 130 D shown in FIG. 6A (and also in a 90 degree(s) rotated view in FIG. 6B ) are each attached by clamps 136 A, 136 B, 136 C, 136 D to adjacent frame members (members 40 B and 40 D in FIGS. 6A and 6B ) by conventional screws which pass through holes in the individual flexures 130 A, 130 B, 130 C, 130 D and through the clamps and are secured in corresponding threaded holes in frame members 40 B and 40 D. [0093] Note that the frame members 40 B, 40 D of FIGS. 6A and 6B differ somewhat from those of FIG. 1 in terms of the angular (triangular) structures at the ends of frame members 40 B, 40 D and to which the metal flexures 130 A, 130 B, 130 C, 130 D are mounted. In the embodiment of FIG. 1 , these angular structures are dispensed with, although their presence makes screw mounting of the flexures easier. [0094] In an alternate embodiment, the window frame guide is not hinged but is a rigid structure. To accommodate this rigidity and prevent binding, one of bearings 72 C or 72 B is eliminated, and the remaining bearing moved to the center of member 40 B, mounted on a gimbal with no spring. The other bearings (except those mounted on stage 10 ) are also gimballed. [0095] This disclosure is illustrative and not limiting; further modifications will be apparent to one skilled in the art in light of this disclosure and are intended to fall within the scope of the appended claims.

A lithographic device and an exposure method utilize mask and substrate tables, and a projection system. A mask having a mask pattern is provided on the mask table. A substrate having a radiation-sensitive layer is provided on the substrate table. The mask is irradiated to project an image of at least a portion of the mask pattern onto the radiation-sensitive layer of the substrate using the projection system. Before or during the projecting, at least one of the mask and substrate tables is positioned using a drive unit that includes a stationary part coupled to a reaction frame of the lithographic device. A position of at least one of the mask and substrate tables is measured using a measuring system having a plurality of measurement sensors that have a stationary part and a movable part. The movable part of one of the sensors is coupled to the one of the mask table and the substrate table whose position is measured, and the stationary parts of the sensors are coupled to a support frame mechanically isolated from the reaction frame.

TECHNICAL FIELD [0001] The present invention relates to a production method of reduced coenzyme Q10, a stabilizing method thereof and a composition containing the same. As compared to oxidized coenzyme Q10, reduced coenzyme Q10 shows high oral absorbability, and is a compound useful as a superior food, health food, food with nutrient function claims, food for specified health use, supplement, nutritional supplement, nutritional product, drink, feed, animal drug, cosmetic, pharmaceutical product, therapeutic drug, prophylactic drug and the like. BACKGROUND ART [0002] As compared to oxidized coenzyme Q10, reduced coenzyme Q10 shows high oral absorbability and is a compound highly useful as an antioxidant substance. [0003] Reduced coenzyme Q10 can be obtained, for example, by subjecting oxidized coenzyme Q10 obtained by a conventionally known method such as synthesis, fermentation, extraction from a naturally-occurring substance and the like to a reduction reaction (patent document 1). [0004] As a component (reducing agent) effective for reducing oxidized coenzyme Q10 to reduced coenzyme Q10, sodium borohydride (non-patent document 1), sodium dithonite (non-patent document 2), sulfite type substance (sodium sulfite etc.) (non-patent document 3), ascorbic acids and many other components (patent document 2) and the like have been reported. [0005] However, these components do not necessarily satisfy preferably the requested conditions, since they are compounds requiring attention in production and handling because they have a risk of ignition, are expensive, are associated with a concern about safety to the body, and are influential on the flavor when used for food and the like. In many cases, a step of removing reduced coenzyme Q10 from the above-mentioned reducing agent and by-products thereof by separation after completion of the reduction reaction is required. There is a strong demand, therefore, on a component whose reducing agent and by-product can be directly used as a component effective for stabilization, or applicable to food, health food, supplement and the like, after completion of the reduction reaction, has been desired. [0006] Among the components effective for reducing oxidized coenzyme Q10 are those effective for stabilizing reduced coenzyme Q10, i.e., those utilizable as antioxidants. [0007] It is known that reduced coenzyme Q10 is easily oxidized by oxygen in the air to give oxidized coenzyme Q10. Thus, a method of stabilizing a preparation and a combination agent of reduced coenzyme Q10 by protecting them from oxidization is extremely important. [0008] As a compound effective for stabilizing reduced coenzyme Q10, citric acid and ascorbic acids are known (patent document 3). In addition, as a solvent for stabilizing reduced coenzyme Q10, hydrocarbons, fatty acid esters, ethers and nitriles are known to be preferable (patent document 4). [0009] However, these components and solvents effective for stabilizing reduced coenzyme Q10 do not necessarily satisfy preferably the requested conditions, since the components and solvents themselves or by-products thereof are associated with a concern about safety to the body, influential on the flavor when used for food, are expensive and the like, and further stabilization is sometimes desired depending on the needs. [0010] Under such background, a component that can be used as a component effective for reducing oxidized coenzyme Q10 and/or a component effective for stabilizing reduced coenzyme Q10, and preferably satisfies characteristics of low risk in production and handling, and being economical and functional has been strongly desired. DOCUMENT LIST Patent Documents [0000] patent document 1: JP-A-H10-109933 patent document 2: WO01/52822 patent document 3: WO03/032967 patent document 4: WO03/006408 Non -Patent Documents [0000] non-patent document 1: Journal of Applied Toxicology, 28(1), 55-62, 2008 non-patent document 2: Pharmaceutical Research, 23(1), 70-81, 2006 non-patent document 3: the 7th edition of Japanese Standards of Food Additives SUMMARY OF THE INVENTION Problems to be Solved by the Invention [0018] In view of the above, the present invention aims to provide a production method of reduced coenzyme Q10 utilizing a component that is highly safe, easily applicable to food, health food, food with nutrient function claims, food for specified health use, supplement, nutritional supplement, nutritional product, animal drug, drink, feed, pet food, cosmetic, pharmaceutical product, therapeutic drug, prophylactic drug and the like, and does not need to be removed by separation after production, further a preferable method capable of stabilizing the reduced coenzyme Q10 by protecting from oxidation, and a stabilized composition. Means of Solving the Problems [0019] The present inventors have conducted intensive studies and clarified that conventionally-reported reducing agents of oxidized coenzyme Q10 include many that in deed have poor reducing ability and are not practical. On the other hand, they have surprisingly found that a particular component derived from a naturally-occurring substance, which has not been conventionally considered to have a reducing ability, has an ability to reduce oxidized coenzyme Q10 to produce reduced coenzyme Q10, and reduced coenzyme Q10 is preferably protected from oxidization by a molecular oxygen in the presence of the particular component derived from a naturally-occurring substance, which resulted in the completion of the present invention. [0020] Accordingly, the present invention relates to a production method of reduced coenzyme Q10, comprising reducing oxidized coenzyme Q10 by using a component derived from a naturally-occurring substance, wherein the component derived from a naturally-occurring substance is any one or more selected from the group consisting of an acerola extract, a tea extract, a rosemary extract, a pine bark extract and a Vaccinium vitis - idaea extract. [0021] Furthermore, the present invention also relates to a method of stabilizing reduced coenzyme Q10, comprising co-presence of reduced coenzyme Q10 and an acerola extract and/or a Vaccinium vitis - idaea extract, as a component effective for stabilization of reduced coenzyme Q10, as well as a composition containing reduced coenzyme Q10 and acerola extract and/or a Vaccinium vitis - idaea extract, which is obtained by the stabilizing method. Effect of the Invention [0022] According to the present invention, a convenient production method of reduced coenzyme Q10, which comprises reducing oxidized coenzyme Q10 by using a component safe for the body, can be provided, and a stabilizing method of reduced coenzyme Q10 which uses said component can also be provided. Furthermore, since such component effective for reducing oxidized coenzyme Q10 and/or a component effective for stabilizing reduced coenzyme Q10, which are/is used in the present invention, can also be expected to function as a nutrition and supplement material. Therefore, a composition obtained by the above-mentioned production method and/or the above-mentioned stabilization method is extremely useful particularly as a pharmaceutical product, supplement, food with nutrient function claims, food for specified health uses, nutritional supplement, nutritional product, animal drug, cosmetic, therapeutic drug or the like, which are required to have various effects. DESCRIPTION OF EMBODIMENTS [0023] The present invention is explained in detail in the following. First, the production method of reduced coenzyme Q10 of the present invention is explained. The production method of the present invention is a production method of reduced coenzyme Q10 comprising reducing oxidized coenzyme Q10 by using a particular component derived from a naturally-occurring substance. [0024] Oxidized coenzyme Q10 to be a starting material in the production method of the present invention may be oxidized coenzyme Q10 alone or a mixture thereof with reduced coenzyme Q10. When the above-mentioned oxidized coenzyme Q10 is a mixture thereof with reduced coenzyme Q10, the ratio of oxidized coenzyme Q10 in the total amount of coenzyme Q10 (i.e., total amount of reduced coenzyme Q10 and oxidized coenzyme Q10) is not particularly limited and is, for example, not less than 1 wt %, normally not less than 5 wt %, preferably not less than 10 wt %, more preferably not less than 20 wt %, further preferably not less than 50 wt %, particularly preferably not less than 60 wt %, most preferably not less than 80 wt %. While the upper limit is not particularly limited, when a mixture with reduced coenzyme Q10 is used as oxidized coenzyme Q10, it is normally not more than 99.9 wt %. Needless to say, when oxidized coenzyme Q10 is 100 wt %, oxidized coenzyme Q10 alone can be used. Oxidized coenzyme Q10 to be used here can be obtained by a conventionally known method, for example, synthesis, fermentation, extraction from a naturally-occurring substance and the like. Preferably, it is obtained by fermentation or extraction from a naturally-occurring substance. [0025] In the production method of the present invention, a particular component derived from a naturally-occurring substance is used as a component for reducing oxidized coenzyme Q10 to give reduced coenzyme Q10. The component derived from a naturally-occurring substance, which is used for reduction of oxidized coenzyme Q10 in the production method of the present invention, is an acerola extract, a tea extract, a rosemary extract, a pine bark extract or a Vaccinium vitis - idaea extract (hereinafter these 5 kinds are sometimes to be generically referred to as “the component derived from a naturally-occurring substance of the present invention”). Here, while the tea extract is not particularly limited, specific examples include green tea extract, oolong tea extract, ten tea extract and the like. As the pine bark extract, commercially available pycnogenol, flavangenol and the like can also be used. Vaccinium vitis - idaea to be the starting material of Vaccinium vitis - idaea extract may be any of Cowberry and Lingonberry. [0026] While any of the above-mentioned components derived from naturally-occurring substances of the present invention is an extract from a plant, the extraction method thereof is not particularly limited. Extracts obtained by a known extraction method can be utilized, of which an extract with actual use performance as a supplement material is preferably used. Any of the above-mentioned components derived from a naturally-occurring substance may be used alone, or two or more kinds may be used in combination. [0027] Among the above-mentioned components derived from a naturally-occurring substance, an acerola extract or a Vaccinium vitis - idaea extract is preferable for the production method of the present invention, in view of the reducing ability thereof or effectiveness of the component itself. [0028] In the production method of the present invention, the weight ratio of the above-mentioned component derived from a naturally-occurring substance of the present invention to oxidized coenzyme Q10 (when plural components are used in combination as a component derived from a naturally-occurring substance, a weight ratio of the total amount thereof) is not particularly limited as long as it is an amount effective for reducing oxidized coenzyme Q10 to reduced coenzyme Q10. Generally, the weight ratio of the component derived from a naturally-occurring substance to oxidized coenzyme Q10, that is, weight of the component derived from a naturally-occurring substance to be used/weight of oxidized coenzyme Q10 to be the starting material, is normally about 1/1000 or more, preferably about 1/100 or more, more preferably about 1/10 or more, particularly preferably about 1/1 or more. While its upper limit is not particularly limited, it is about 10000/1 or less, preferably about 1000/1 or less, more preferably about 100/1 or less, particularly preferably about 10/1 or less, from the aspects of economic aspect and effectiveness as a nutrient. [0029] In the production method of the present invention, oxidized coenzyme Q10 to be the starting materials and the above-mentioned component derived from a naturally-occurring substance of the present invention only need to be in contact with each other in the reaction system, where the system may be homogeneous or nonhomogeneous and is not particularly limited. For example, it may be a reaction system wherein oxidized coenzyme Q10 and the component derived from a naturally-occurring substance of the present invention are in contact with each other as a solid, wherein one is present in a liquid layer and dissolved in a solvent and the like, and the other is present as a solid in the liquid layer, wherein oxidized coenzyme Q10 is present as a melt, and the component derived from a naturally-occurring substance of the present invention is present as a solid in the melt, wherein both are present in different phases, forming liquid-liquid two layers, wherein both are present in the same liquid phase and the like. Needless to say, a system showing high contact efficiency between oxidized coenzyme Q10 and the component derived from a naturally-occurring substance of the present invention is effective for the reduction of oxidized coenzyme Q10. From this aspect, most preferred is the coexistence of oxidized coenzyme Q10 and the component derived from a naturally-occurring substance of the present invention in the same liquid phase. [0030] From the above aspects, when a reduction reaction is performed in the production method of the present invention, a solvent is preferably used to allow presence of oxidized coenzyme Q10 and/or the component derived from a naturally-occurring substance of the present invention in the liquid phase. The solvent to be used for reduction reaction in the production method of the present invention is not particularly limited, and organic solvents such as hydrocarbons, fatty acid esters, ethers, alcohols, ketones, nitrogen compounds (including nitriles, amides), sulfur compounds, fatty acids, terpenes and the like, fats, oils, water and the like can be mentioned. These may be used alone or as a mixed solvent of 2 or more kinds thereof. [0031] While the above-mentioned hydrocarbons are not particularly limited, for example, aliphatic hydrocarbon, aromatic hydrocarbon, halogenated hydrocarbon and the like can be mentioned. Particularly, aliphatic hydrocarbon and aromatic hydrocarbon are preferable, and aliphatic hydrocarbon is especially preferable. [0032] While aliphatic hydrocarbon may be cyclic or acyclic, saturated or unsaturated and is not particularly limited, acyclic aliphatic hydrocarbon is particularly preferably used. In addition, aliphatic hydrocarbon having 3 to 20 carbon atoms, preferably 5 to 12 carbon atoms, can be generally used. [0033] Specific examples of the aliphatic hydrocarbon include propane, butane, isobutane, pentane, 2-methylbutane, cyclopentane, 2-pentene, hexane, 2-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, methylcyclopentane, cyclohexane, 1-hexene, cyclohexene, heptane, 2-methylhexane, 3-methylhexane, 2, 3-dimethylpentane, 2,4-dimethylpentane, methylcyclohexane, 1-heptene, octane, 2,2,3-trimethylpentane, isooctane, ethylcyclohexane, 1-octene, nonane, 2,2,5-trimethylhexane, 1-nonene, decane, 1-decene, p-menthane, undecane, dodecane and the like. [0034] Among these, saturated aliphatic hydrocarbon having 5 to 8 carbon atoms is preferable, and pentane, 2-methylbutane, cyclopentane, hexane, 2-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, methylcyclopentane, cyclohexane, heptane, 2-methylhexane, 3-methylhexane, 2,3-dimethylpentane, 2,4-dimethylpentane, methylcyclohexane, octane, 2,2,3-trimethylpentane, isooctane, ethylcyclohexane and the like are particularly preferable. [0035] While the aromatic hydrocarbon is not particularly limited, normally, aromatic hydrocarbon having 6 to 20 carbon atoms, particularly 6 to 12 carbon atoms, especially 7 to 10 carbon atoms, is preferably used. Specific examples of the aromatic hydrocarbon include benzene, toluene, xylene, o-xylene, m-xylene, p-xylene, ethylbenzene, cumene, mesitylene, tetralin, butylbenzene, p-cymene, cyclohexylbenzene, diethylbenzene, pentylbenzene, dipentylbenzene, dodecylbenzene, styrene and the like. It is preferably toluene, xylene, o-xylene, m-xylene, p-xylene, ethylbenzene, cumene, mesitylene, tetralin, butylbenzene, p-cymene, cyclohexylbenzene, diethylbenzene or pentylbenzene, more preferably, toluene, xylene, o-xylene, m-xylene, p-xylene, cumene or tetralin, and most preferably cumene. [0036] The halogenated hydrocarbon may be cyclic or acyclic, saturated or unsaturated, and is not particularly limited. In general, acyclic one is preferably used. Normally, chlorinated hydrocarbon and fluorinated hydrocarbon are preferable, and chlorinated hydrocarbon is particularly preferable. A halogenated hydrocarbon having 1 to 6 carbon atoms, particularly 1 to 4 carbon atoms, especially 1 or 2 carbon atoms, is preferably used. [0037] Specific examples of the halogenated hydrocarbon include dichloromethane, chloroform, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane, 1,1,1,2-tetrachloroethane, 1,1,2,2-tetrachloroethane, pentachloroethane, hexachloroethane, 1,1-dichloroethylene, 1,2-dichloroethylene, trichloroethylene, tetrachloroethylene, 1,2-dichloropropane, 1,2,3-trichloropropane, chlorobenzene, 1,1,1,2-tetrafluoroethane and the like. [0038] It is preferably dichloromethane, chloroform, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane, 1,1-dichloroethylene, 1,2-dichloroethylene, trichloroethylene, chlorobenzene or 1,1,1,2-tetrafluoroethane, more preferably dichloromethane, chloroform, 1,2-dichloroethylene, trichloroethylene, chlorobenzene or 1,1,1,2-tetrafluoroethane. [0039] While the above-mentioned fatty acid esters are not particularly limited, for example, propionate, acetate, formate and the like can be mentioned. Particularly, acetate and formate are preferable, and acetate is especially preferable. While ester group is not particularly limited, in general, alkyl ester or aralkyl ester having 1 to 8 carbon atoms, preferably alkyl ester having 1 to 6 carbon atoms, more preferably alkyl ester having 1 to 4 carbon atoms, is preferably used. [0040] Examples of propionate include methyl propionate, ethyl propionate, butyl propionate and isopentyl propionate. [0041] Examples of acetate include methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, pentyl acetate, isopentyl acetate, sec-hexyl acetate, cyclohexyl acetate, benzyl acetate and the like. It is preferably methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, pentyl acetate, isopentyl acetate, sec-hexyl acetate or cyclohexyl acetate, more preferably methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate or isobutyl acetate, and most preferably ethyl acetate. [0042] Examples of formate include methyl formate, ethyl formate, propyl formate, isopropyl formate, butyl formate, isobutyl formate, sec-butyl formate, pentyl formate and the like. It is preferably methyl formate, ethyl formate, propyl formate, butyl formate, isobutyl formate or pentyl formate, and most preferably ethyl formate. [0043] The above-mentioned ethers may be cyclic or acyclic, saturated or unsaturated, and are not particularly limited. Generally, saturated ones are preferably used. Normally, ether having 3 to 20 carbon atoms, particularly 4 to 12 carbon atoms, especially 4 to 8 carbon atoms, is preferably used. [0044] Specific examples of the ethers include diethyl ether, methyl tert-butyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, dihexyl ether, ethylvinyl ether, butylvinyl ether, anisole, phenetole, butylphenyl ether, methoxytoluene, dioxane, furan, 2-methylfuran, tetrahydrofuran, tetrahydropyran, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dibutyl ether and the like. [0045] Preferred as the ethers are diethyl ether, methyl tert-butyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, dihexyl ether, anisole, phenetole, butylphenyl ether, methoxytoluene, dioxane, 2-methylfuran, tetrahydrofuran, tetrahydropyran, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, more preferred are diethyl ether, methyl tert-butyl ether, anisole, dioxane, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, more preferably, diethyl ether, methyl tert-butyl ether, anisole and the like, and most preferably, methyl tert-butyl ether. [0046] The above-mentioned alcohols may be cyclic or non-cyclic, saturated or unsaturated, and are not particularly limited, and generally, saturated ones are preferably used. Normally, a monovalent alcohol having 1 to 20 carbon atoms, particularly 1 to 12 carbon atoms, especially 1 to 6 carbon atoms, among others 1 to 5 carbon atoms, is preferable, a divalent alcohol having 2 to 5 carbon atoms is preferable, and a trivalent alcohol having 3 carbon atoms is preferable. [0047] Examples of the monovalent alcohol include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 4-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 2-ethyl-1-hexanol, 1-nonanol, 1-decanol, 1-undecanol, 1-dodecanol, allyl alcohol, propargyl alcohol, benzyl alcohol, cyclohexanol, 1-methylcyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol, 4-methylcyclohexanol and the like. [0048] Preferred as the monovalent alcohol are methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1-hexanol, 2-methyl-1-pentanol, 4-methyl-2-pentanol, 2-ethyl-1-butanol and cyclohexanol, more preferred are methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, further preferably, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutyl alcohol, 2-methyl-1-butanol, isopentyl alcohol, and most preferred is ethanol. [0049] Examples of the divalent alcohol include 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol and the like. Preferred are 1,2-ethanediol, 1,2-propanediol and 1,3-propanediol, and most preferred is 1,2-ethanediol. [0050] As the trivalent alcohol, glycerol and the like can be preferably used. [0051] The above-mentioned ketones are not particularly limited, and normally, ketone having 3 to 6 carbon atoms is preferably used. Specific examples of the ketones include acetone, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone and the like. Preferred are acetone and methyl ethyl ketone, and most preferred is acetone. [0052] Nitriles may be cyclic or acyclic, saturated or unsaturated, and is not particularly limited. In general, saturated one is preferably used. Normally, nitrile having 2 to 20 carbon atoms, particularly 2 to 12 carbon atoms, especially 2 to 8 carbon atoms, is preferably used. Specific examples of the nitriles include acetonitrile, propionitrile, malononitrile, butyronitrile, isobutyronitrile, succinonitrile, valeronitrile, glutaronitrile, hexanenitrile, heptyl cyanide, octyl cyanide, undecanenitrile, dodecanenitrile, tridecanenitrile, pentadecanenitrile, stearonitrile, chloroacetonitrile, bromoacetonitrile, chloropropionitrile, bromopropionitrile, methoxyacetonitrile, methyl cyanoacetate, ethyl cyanoacetate, tolunitrile, benzonitrile, chlorobenzonitrile, bromobenzonitrile, cyanobenzoic acid, nitrobenzonitrile, anisonitrile, phthalonitrile, bromotolunitrile, methylcyanobenzoate, methoxybenzonitrile, acetylbenzonitrile, naphtonitrile, biphenylcarbonitrile, phenylpropionitrile, phenylbutyronitrile, methylphenylacetonitrile, diphenylacetonitrile, naphthylacetonitrile, nitrophenylacetonitrile, chlorobenzyl cyanide, cyclopropanecarbonitrile, cyclohexanecarbonitrile, cycloheptanecarbonitrile, phenylcyclohexanecarbonitrile, tolylcyclohexanecarbonitrile and the like. It is preferably acetonitrile, propionitrile, succinonitrile, butyronitrile, isobutyronitrile, valeronitrile, methyl cyanoacetate, ethyl cyanoacetate, benzonitrile, tolunitrile or chloropropionitrile, more preferably acetonitrile, propionitrile, butyronitrile or isobutyronitrile, most preferably acetonitrile. [0053] Examples of the nitrogen compounds other than nitriles include nitromethane, acetonitrile, triethylamine, pyridine, formamide, N-methylformamide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and the like. [0054] Examples of the sulfur compounds include dimethyl sulfoxide, sulfolane and the like. [0055] Examples of the above-mentioned fatty acids include formic acid, acetic acid, propionic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, behenic acid, eicosapentaenoic acid, docosahexaenoic acid, docosapentaenoic acid and the like, formic acid, acetic acid, caprylic acid, capric acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, or docosapentaenoic acid is preferable, particularly, acetic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, or docosapentaenoic acid is preferable, furthermore, oleic acid, linoleic acid, linolenic acid, eicosapentaenoic acid, or docosahexaenoic acid is preferable, and most preferably is oleic acid. [0056] The above-mentioned terpenes may be cyclic or acyclic, or saturated or unsaturated, and are not particularly limited. Generally, hemiterpene, monoterpene, sesquiterpene, diterpene, triterpene, tetraterpene and the like can be mentioned. [0057] Specific examples of the terpenes include purenoru, 3-methyl-3-buten-2-ol, tiglic acid, angelic acid, seneshio acid, isovaleric acid, alloocimene, α-bisabolene, bisabolene, β-bourbonene, δ-cadinene, δ-3-carene, α-caryophyllene, β-caryophyllene, p-cymene, dehydro-p-cymene, menthol, limonene, d-limonene, 1-limonene, cis-3,7-dimethyl-1,3,6,-octatriene, δ-elemene, β-elemene, α-farnesene, β-farnesene, farnesene, germacrene D, β-guaiene, longifolene, myrcene, β-ocimene, α-phellandrene, α-pinene, β-pinene, pinocamphone, sabinene, α-terpinene, γ-terpinene, terpinolen, thujopsis, valencene, α-copaene, hydrogenated limonene dimer, isocaryophyllene, pinene dimer, dipentene dimer, dipentene trimer, geraniol, citral, citronellal, citronellol, 1,8-cineol, hydroxycitronellal, linalool, cosmene, nerol, myrcenol, lavandulol, ipsdienol, neral, geranial, perylene, rose furan, geranyl acid, thioterpineol, α-terpineol, β-terpineol, γ-terpineol, δ-terpineol, carveol, thelepin, perillaldehyde, perillylalcohol, carvone, ascaridole, anethole, thujone, thujanol, α-ionone, β-ionone, γ-ionone, farnesol, nerolidol, α-sinensal, β-sinensal, bissabol, phytol, squalene, citronellioxyacetoaldehyde, myrtenal, perillaaldehyde, 2-p-cymenol, 2-ethoxy-p-cymene, carvenol, 4-carvomenthenol, carvyl acetate, carvyl propionate, caryophyllenealcohol, caryophyllenealcohol acetate, 1,4-cineol, eugenol, d-selinene, thymol, d-camphene, linaloolacetate and the like. [0058] Preferred as terpenes are purenoru, 3-methyl-3-butene-2-ol, tiglic acid, angelic acid, seneshio acid, isovaleric acid, alloocimene, α-bisabolene, bisabolene, P-bourbonene, δ-cadinene, δ-3-carene, α-caryophyllene, β-caryophyllene, p-cymene, dehydro-p-cymene, limonene, d-limonene, 1-limonene, cis-3,7-dimethyl-1,3,6,-octatriene, δ-elemene, β-elemene, α-farnesene, β-farnesene, farnesene, germacrene D, β-guaiene, longifolene, myrcene, β-ocimene, α-phellandrene, α-pinene, β-pinene, pinocamphone, sabinene, α-terpinene, γ-terpinene, terpinolen, thujopsis, valencene, α-copaene, hydrogenated limonene dimer, isocaryophyllene, pinene dimer, dipentene dimer, dipentene trimer, geraniol, citral, citronellal, citronellol, 1,8-cineol, hydroxycitronellal, linalool, nerol, myrcenol, neral, geranial, carvone, anethole, thujone, phytol, squalene, eugenol, d-selinene, thymol and linalool acetate, particularly preferred are α-bisabolene, bisabolene, δ-cadinene, α-caryophyllene, β-caryophyllene, limonene, d-limonene, 1-limonene, myrcene, α-phellandrene, α-pinene, β-pinene, α-terpinene, γ-terpinene, geraniol, citral, citronellol, 1,8-cineol, linalool, carvone, anethole, thujone, eugenol, d-selinene, thymol and linalool acetate, and most preferred are limonene and d-limonene. [0059] In addition, an essential oil containing the above-mentioned terpenes can be used as a solvent. While the essential oil is not particularly limited, orange oil, capsicum oil, mustard oil, garlic oil, callaway oil, clove oil, cinnamon oil, cocoa extract, coffee bean extract, ginger oil, spearmint oil, celery-seed oil, thyme oil, onion oil, nutmeg oil, parsley seed oil, mint oil, vanilla extract, fennel oil, pennyroyal oil, peppermint oil, eucalyptus oil, lemon oil, rose oil, rosemary oil, almond oil, ajowan oil, anise oil, amyris oil, angelica route oil, ambrette seed oil, estragon oil, origanum oil, orris root oil, olibanum oil, cassia oil, cascarilla oil, cananga oil, chamomile oil, calamus oil, cardamom oil, carrot seed oil, cubeb oil, cumin oil, grapefruit oil, cinnamon leaf oil, cade oil, pepper oil, costus root oil, congnac oil, copaiba oil, cilantro oil, perilla oil, musk, juniper berry oil, star anis oil, sage oil, 35 savory oil, geranium oil, tangerin oil, dill oil, neroli oil, tolu balsam oil, basil oil, birch oil, patchouli oil, palmarosa oil, pimento oil, petitgrain oil, bay leaf oil, bergamot oil, peru balsam oil, benzoin resin, Bois de Rose oil, hop oil, boronia absolute, marjoram oil, mandarin oil, myrtle oil, Chinese lemon flavor, lime oil, lavandin oil, lavender oil, rue oil, lemongrass oil, lenthionine, lavage oil, laurel leaf oil, worm wood oil and the like can be mentioned. [0060] Of the above-mentioned organic solvents, alcohols, fatty acids and terpenes are preferable, alcohols are more preferable, and among alcohols, ethanol is most preferable. [0061] The above-mentioned fat or oil may be natural fat or oil from animals and vegetable, synthetic fat or oil, or processed fat or oil. Examples of the vegetable fat or vegetable oil include coconut oil, palm oil, palm kernel oil, flaxseed oil, camellia oil, brown rice germ oil, rape seed oil, rice oil, peanuts oil, corn oil, wheat germ oil, soybean oil, perilla oil, cottonseed oil, sunflower seed oil, kapok oil, evening primrose oil, Shea butter, sal butter, cacao butter, sesame oil, safflower oil, olive oil, avocado oil, poppyseed oil, burdock fruit oil and the like. Examples of the animal fat and animal oil include lard, milk fat, fish oil, beef fat and the like. Furthermore, fat or oil (e.g., hydrogenated oil) obtained by processing the above by fractionation, hydrogenation, transesterification and the like can also be mentioned. Needless to say, medium-chain triglyceride (MCT), partial glycerides of fatty acid and the like can also be used. In addition, a mixture thereof may be used. [0062] The medium-chain triglyceride is not particularly limited and, for example, triglyceride wherein fatty acid has 6 to 12 carbon atoms, preferably 8 to 12 carbon atoms, and the like can be mentioned. [0063] Of the above-mentioned fats or oils, vegetable fat, vegetable oil, synthetic fat, synthetic oil, processed fat, and processed oil are preferable from the aspects of easy handling, odor and the like. Among these, specifically, coconut oil, palm oil, palm kernel oil, rape seed oil, rice oil, soybean oil, cottonseed oil, safflower oil, olive oil, medium-chain triglyceride (MCT), partial triglyceride of fatty acid and the like are preferable, and rice oil, soybean oil, rape seed oil, safflower oil, medium-chain triglyceride, partial triglycerides of fatty acid and the like are particularly preferable. [0064] Among the above-mentioned solvents, those acceptable to foods, pharmaceutical products, cosmetics and the like are preferable, and those acceptable for foods are more preferable. [0065] In view of direct ingestion without processing of the reaction product and reactivity, alcohols, water, fats, oils, fatty acids, terpenes and mixtures thereof are preferable, and ethanol, fats and oils, terpenes and mixtures thereof are most preferable. [0066] In the production method of the present invention, the reduction reaction of oxidized coenzyme Q10 to be the starting material and a component derived from a naturally-occurring substance of the present invention only needs to be performed in the presence of the above-mentioned solvent as necessary, and the method therefor is not limited. [0067] In the production method of the present invention, a surfactant can also be added to the reaction system during the reduction reaction, and the addition is preferable in many cases. [0068] Examples of the above-mentioned surfactant include, but are not limited to, glycerol fatty acid ester, sucrose ester of fatty acid, organic acid monoglyceride, sorbitan ester of fatty acid, polyoxyethylene sorbitan fatty acid ester, propylene glycol ester of fatty acid, condensed ricinoleic acid glycerides, saponin, phospholipid and the like. [0069] Examples of the above-mentioned glycerol fatty acid ester include, but are not limited to, glycerol having a polymerization degree of 1-10. While the fatty acid residue constituting glycerol fatty acid ester is not particularly limited, fatty acid having a carbon number of 6-18 can be preferably used and, for example, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, linoleic acid, linolenic acid and the like can be mentioned. [0070] Examples of the above-mentioned sucrose ester of fatty acid include, but are not limited to, one wherein fatty acid having a carbon number of 6-22 is ester-bonded to one or more hydroxyl groups of sucrose, such as sucrose laurate, sucrose myristate, sucrose palmitate, sucrose stearate, sucrose oleate, sucrose behenate, sucrose erucate and the like. [0071] Examples of the above-mentioned organic acid monoglyceride include, but are not limited to, caprylic acid and succinic acid ester of monoglycerol, stearic acid and citric acid ester of monoglycerol, stearic acid and acetic acid ester of monoglycerol, stearic acid and succinic acid ester of monoglycerol, stearic acid and lactic acid ester of monoglycerol, stearic acid and diacetyltartaric acid ester of monoglycerol, oleic acid and citric acid ester of monoglycerol and the like. [0072] Examples of the above-mentioned sorbitan ester of fatty acid include, but are not limited to, sorbitan wherein one or more of the hydroxyl groups are ester bonded to fatty acid each having a carbon number of 6-18, such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate and the like. [0073] Examples of the above-mentioned polyoxyethylene sorbitan fatty acid ester include, but are not limited to, sorbitan polyoxyethylene monopalmitate, sorbitan polyoxyethylene monostearate, sorbitan polyoxyethylene monooleate, sorbitan polyoxyethylene tristearate and sorbitan polyoxyethylene trioleate, wherein 6-20 mol of an ethyleneoxide chain is added, and the like. [0074] Examples of the above-mentioned polyglycerol ester of interesterified ricinoleic acid include, but are not limited to, one wherein polyglycerol has an average polymerization degree of 2-10, and polyricinoleic acid has an average condensation degree (average number of condensed ricinoleic acid) of 2-4, such as tetraglycerol condensed ricinoleate, pentaglycerol condensed ricinoleate, hexaglycerol condensed ricinoleate and the like. [0075] As the above-mentioned propylene glycol ester of fatty acid, any of monoester or diester can be used. While the fatty acid residue constituting the propylene glycol ester of fatty acid is not particularly limited, fatty acid having a carbon number of 6-18 can be preferably used, and for example, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, linoleic acid, linolenic acid and the like can be mentioned. [0076] Examples of the above-mentioned phospholipid include, but are not limited to, egg-yolk lecithin, purified soybean lecithin, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, sphingomyelin, dicetyl phosphoric acid, stearylamine, phosphatidylglycerol, phosphatidic acid, phosphatidylinositolamine, cardiolipin, ceramide phosphoryl ethanolamine, ceramide phosphoryl glycerol and a mixture thereof and the like. Needless to say, a phospholipid after processing of hydrogenation, enzyme degradation and the like can also be used. To improve absorbability of reduced coenzyme Q10, an enzymatically degraded phospholipid is preferably used. [0077] Examples of the above-mentioned phospholipid include, but are not limited to, enju saponin, quillaja saponin, purification soybean saponin, yucca saponin and the like. [0078] In the production method of the present invention, the concentration of oxidized coenzyme Q10 to the reaction system at the time of start of the reduction reaction (the total weight of the whole reaction mixture) is not particularly limited. It is normally about 0.01 wt % or more, preferably about 0.1 wt % or more, more preferably about 0.2 wt % or more, particularly preferably about 1 wt % or more, further preferably about 2 wt % or more and, among these, about 3 wt % or more. [0079] While the reaction temperature of the reduction reaction in the production method of the present invention is not particularly limited, the reaction is performed generally at 20° C. or more, preferably 30° C. or more, more preferably 40° C. or more, further preferably 50° C. or more, particularly preferably 60° C. or more, most preferably 75° C. or more. [0080] To exhibit the effect of the present invention at the maximum, the above-mentioned reduction reaction is preferably performed, for example, under a deoxygenation atmosphere. The deoxygenation atmosphere can be formed by inert gas replacement, reducing pressure, boiling and combining them. At least, inert gas replacement, that is, use of inert gas atmosphere, is preferable. Examples of the above-mentioned inert gas include nitrogen gas, helium gas, argon gas, hydrogen gas, carbon dioxide gas and the like, preferably nitrogen gas. [0081] In the production method of the first of the present invention, the reduction reaction may be performed in a preparation. In other words, production of reduced coenzyme Q10 by preparing a mixture containing oxidized coenzyme Q10, the component derived from a naturally-occurring substance of the present invention and a solvent where necessary, processing the mixture into a preparation form, and reducing oxidized coenzyme Q10 to reduced coenzyme Q10 in the preparation is within the scope of the present invention. The reduction in this case is performed by preservation over a predetermined period, heating and the like. In the present invention, the preparation means an oral administration form such as capsule (hard capsule, soft capsule, microcapsule), tablet, syrup, drink and the like, or a form such as cream, suppository, toothpaste and the like. The preparation in which the reduction reaction is performed is preferably the above-mentioned oral administration form, which is more preferably capsule and particularly preferably soft capsule. [0082] Reduced coenzyme Q10 can be conveniently produced by the production method of the present invention as mentioned above. [0083] Here, the ratio of reduced coenzyme Q10 to the total amount of coenzyme Q10 at the time of completion of the reaction (i.e., total amount of reduced coenzyme Q10 and oxidized coenzyme Q10) is normally about 5 wt % or more, preferably about 10 wt % or more, more preferably 20 wt % or more, particularly preferably 30 wt % or more, especially 40 wt % or more, most of all 50 wt % or more, and further, 70 wt % or more. [0084] The reduced coenzyme Q10 obtained by the production method of the present invention can be obtained as crudely purified or pure reduced coenzyme Q10 by appropriately performing, after completion of the reduction reaction, removal of solvent and isolation and purification operation. The mixed composition after the completion of the reduction reaction can be directly used as a composition containing reduced coenzyme Q10 and the component derived from a naturally-occurring substance, or followed by formulation into a preparation, and used in the fields of pharmaceutical products, foods and the like. [0085] Now the stabilization method of the present invention is explained. In the present invention, reduced coenzyme Q10 can be stabilized by the co-presence of reduced coenzyme Q10 and a particular component derived from a naturally-occurring substance in the composition. [0086] In the stabilization method of the present invention, reduced coenzyme Q10 to be the object of stabilization may be reduced coenzyme Q10 alone, or a mixture thereof with oxidized coenzyme Q10. When the above-mentioned reduced coenzyme Q10 is a mixture thereof with oxidized coenzyme Q10, the ratio of reduced coenzyme Q10 to the total amount of coenzyme Q10 (i.e., total amount of reduced coenzyme Q10 and oxidized coenzyme Q10) is not particularly limited and, for example, it is 3 wt % or more, normally about 10 wt % or more, preferably about 20 wt % or more, more preferably 30 wt % or more, particularly 40 wt % or more, especially 50 wt % or more, most of all 60 wt % or more, and further, 80 wt % or more. While the upper limit is not particularly limited, it is normally 99.9 wt % or less. Needless to say, when reduced coenzyme Q10 is 100 wt %, reduced coenzyme Q10 alone can be used. [0087] The reduced coenzyme Q10 to be used in the stabilization method of the present invention can be obtained by synthesis, fermentation, extraction from a naturally-occurring substance and the like, or by utilizing a conventionally-known method such as reduction of oxidized coenzyme Q10 and the like. Preferred are those obtained by reducing oxidized coenzyme Q10 such as existing high pure coenzyme Q10 and the like, or a mixture of oxidized coenzyme Q10 and reduced coenzyme Q10 with a general reducing agent, such as sodium hydrosulfite (sodium dithionite), sodium borohydride, ascorbic acids and the like. More preferred are those obtained by reducing oxidized coenzyme Q10 such as existing high pure coenzyme Q10 and the like, or a mixture of oxidized coenzyme Q10 and reduced coenzyme Q10 with ascorbic acids. In addition, needless to say, reduced coenzyme Q10 obtained by the above-mentioned production method of the present invention can also be used preferably. [0088] The component derived from a naturally-occurring substance to be used in the stabilization method of the present invention is an acerola extract or a Vaccinium vitis - idaea extract. These two components may be used in combination. A detailed explanation of the Vaccinium vitis - idaea extract is the same as that presented for the above-mentioned production method of the present invention. [0089] In the stabilization method of the present invention, the weight ratio of reduced coenzyme Q10 to be the target of stabilizing, and the above-mentioned acerola extract and/or Vaccinium vitis - idaea extract is not particularly limited. Generally, the weight ratio of the above-mentioned extract to reduced coenzyme Q10, that is, the ratio of total weight of the above-mentioned extract to be used/weight of reduced coenzyme Q10 is normally about 1/1000 or more, preferably about 1/100 or more, more preferably about 1/10 or more, particularly preferably about 1/1 or more. While the upper limit is not particularly set, it is about 10000/1 or less, preferably about 1000/1 or less, more preferably about 100/1 or less, particularly preferably about 10/1 or less. [0090] In the stabilization method of the present invention, reduced coenzyme Q10 and an acerola extract and/or a Vaccinium vitis - idaea extract are co-present in the composition. Here, “co-present” only requests that the both be in contact in some form. The manner of contact is not particularly limited, and the system of the composition may be homogeneous or nonhomogeneous. For example, it may be reaction system wherein reduced coenzyme Q10 and an acerola extract and/or a Vaccinium vitis - idaea extract are in contact with each other as a solid, wherein one is present in a liquid layer and dissolved in a solvent and the like, and the other is present as a solid in the liquid layer, wherein reduced coenzyme Q10 is present as a melt, and an acerola extract and/or a Vaccinium vitis - idaea extract is present as a solid in the melt, wherein both are present in different phases, forming liquid-liquid two layers, wherein both are present in the same liquid phase and the like. Needless to say, a system showing high contact efficiency between reduced coenzyme Q10 and an acerola extract and/or a Vaccinium vitis - idaea extract is effective for stabilizing reduced coenzyme Q10. From this aspect, most preferred is the co-presence of reduced coenzyme Q10 and an acerola extract and/or a Vaccinium vitis - idaea extract in the same liquid phase. [0091] From the above aspects, in the stabilization method of the present invention, a solvent is preferably co-present to allow presence, in the liquid phase, of reduced coenzyme Q10 and/or an acerola extract or a Vaccinium vitis - idaea extract in the composition. While the solvent to be used in the stabilization method of the present invention is not particularly limited, and specific and preferable examples thereof can be quoted from those mentioned for the production method of the present invention. [0092] In addition, as in the production method of the present invention, a surfactant can also be further co-present or often preferably co-present in the stabilization method of the present invention. Examples of the detailed kind and preferable surfactants to be used in the stabilization method of the present invention are the same as those explained for the production method of the present invention. [0093] In the stabilization method of the present invention, the method for allowing co-presence of reduced coenzyme Q10 and an acerola extract and/or a Vaccinium vitis - idaea extract is not particularly limited. For example, when reduced coenzyme Q10 added from the outside is used, the reduced coenzyme Q10 and an acerola extract and/or a Vaccinium vitis - idaea extract may be simply mixed or, after mixing them, a solvent as mentioned above may be further mixed therewith. Alternatively, a solution containing reduced coenzyme Q10 in the aforementioned solvent may be mixed with an acerola extract and/or a Vaccinium vitis - idaea extract, or a solution containing these extracts in the aforementioned solvent may be mixed with reduced coenzyme Q10, or a solution containing reduced coenzyme Q10 and a solution containing the extracts may be mixed. [0094] Alternatively, reduced coenzyme Q10 obtained by the aforementioned production method of the present invention can be directly utilized, that is, a mixture of reduced coenzyme Q10 after completion of the reduction reaction and the component derived from a naturally-occurring substance of the present invention can be directly utilized for the stabilization method of the present invention, and this embodiment is one of the most preferable embodiments. [0095] In the stabilization method of the present invention, as a substance other than reduced coenzyme Q10, an acerola extract and/or a Vaccinium vitis - idaea extract, and solvent and surfactant where necessary, for example, excipient, disintegrant, lubricant, binder, dye, anticoagulant, absorption promoter, solubilizing agent, stabilizer, flavor, active ingredient other than reduced coenzyme Q10 and the like can also be further co-present, without any particular limitation. [0096] While the above-mentioned excipient is not particularly limited, for example, sucrose, lactose, glucose, starch, mannitol, crystalline cellulose, calcium phosphate, calcium sulfate and the like can be mentioned. [0097] While the above-mentioned disintegrant is not particularly limited, for example, starch, agar, calcium citrate, calcium carbonate, carboxymethylcellulose, tragacanth, alginic acid and the like can be mentioned. [0098] While the above-mentioned lubricant is not particularly limited, for example, talc, magnesium stearate, polyethylene glycol, silica, hydrogenated oil and the like can be mentioned. [0099] While the above-mentioned binder is not particularly limited, for example, ethylcellulose, methylcellulose, hydroxypropylmethylcellulose, hydroxypropylcellulose, tragacanth, shellac, gelatin, pullulan, gum arabic, polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, sorbitol and the like can be mentioned. [0100] While the above-mentioned dye is not particularly limited, for example, dye such as titanium oxide, synthesis colors, colcothar dye, tar pigment and the like can be mentioned. [0101] While the above-mentioned anticoagulant is not particularly limited, for example, stearic acid, talc, light anhydrous silicic acid, hydrated silicon dioxide and the like can be mentioned. [0102] While the above-mentioned absorption promoter is not particularly limited, for example, higher alcohols, higher fatty acids and the like can be mentioned. [0103] While the above-mentioned solubilizing agent for active ingredients is not particularly limited, for example, organic acids such as fumaric acid, succinic acid, malic acid etc., and the like can be mentioned. [0104] While the above-mentioned stabilizer is not particularly limited, for example, benzoic acid, beeswax, hydroxypropylmethylcellulose, methylcellulose and the like can be mentioned. [0105] While the above-mentioned flavor is not particularly limited, for example, orange oil, capsicum oil, mustard oil, garlic oil, caraway oil, clove oil, cinnamon oil, cocoa extract, coffee bean extract, ginger oil, spearmint oil, celery seed oil, thyme oil, onion oil, nutmeg oil, parsley seed oil, peppermint oil, vanilla extract, fennel oil, pennyroyal oil, peppermint oil, eucalyptus oil, lemon oil, rose oil, rosemary oil, almond oil, ajowan oil, anis oil, amyris oil, angelica route oil, ambrette seed oil, estragon oil, origanum oil, orris root oil, olibanum oil, quassia oil, cascarilla oil, cananga oil, chamomile oil, calamus oil, cardamom oil, carrot seed oil, cubeb oil, cumin oil, grapefruit oil, cinnamon leaf oil, cade oil, pepper oil, costus root oil, cognac oil, copaiba oil, cilantro oil, perilla oil, musk, juniper berry oil, star anise oil, sage oil, savory oil, geranium oil, tangerine oil, dill oil, neroli oil, tolu balsam oil, basil oil, birch oil, patchouli oil, palmarosa oil, pimento oil, petitgrain oil, bay leaf oil, bergamot oil, Peru balsam oil, benzoin resin, bois de rose oil, hops oil, Boronia Absolute, marjoram oil, mandarin oil, myrtle oil, Chinese lemon flavor, lime oil, lavandin oil, lavender oil, rue oil, lemongrass oil, lethionine, lovage oil, laurel leaf oil, worm wood oil and the like can be mentioned. [0106] The above-mentioned substances may have plural roles. For example, starch may have roles of excipient and disintegrant. [0107] In the stabilization method of the present invention, the content of an acerola extract and/or a Vaccinium vitis - idaea extract (total amount when the both are used in combination) relative to the total weight of the composition containing reduced coenzyme Q10, and an acerola extract and/or a Vaccinium vitis - idaea extract in co-presence is not particularly limited. To allow sufficient exertion of the stabilizing effect of reduced coenzyme Q10, however, the ratio relative to the total weight of the composition is normally about 0.01 wt % or more, preferably about 0.1 wt % or more, more preferably about 1 wt % or more, particularly preferably about 5 wt % or more. While the upper limit is not particularly set, it is normally about 99 wt % or less, preferably about 95 wt % or less, more preferably about 90 wt % or less, particularly preferably 80 wt % or less, from the economic aspect, effectiveness as a nutrient and the like,. [0108] In the stabilization method of the present invention, the content of reduced coenzyme Q10 relative to the total weight of the above-mentioned composition is not particularly limited. To ensure effectiveness of reduced coenzyme Q10 in the composition, it is normally about 0.001 wt % or more, preferably about 0.01 wt % or more, more preferably about 0.1 wt % or more, particularly preferably about 0.5 wt % or more. While the upper limit is not particularly set, it is preferably about 50 wt % or less, more preferably about 40 wt % or less, particularly preferably about 30 wt % or less. [0109] To exert the maximum effects of the present invention, the stabilization method of the present invention is preferably performed by placing reduced coenzyme Q10 and an acerola extract and/or a Vaccinium vitis - idaea extract in co-presence under deoxygenation atmosphere. The co-presence under the deoxygenation atmosphere may be performed at any stage of preparation, preservation, processing into a preparation, and preservation after processing of the composition in the stabilization method of the present invention, or may be performed at plural or all stages. The deoxygenation atmosphere can be formed by inert gas replacement, reducing pressure, boiling and combining them. At least, inert gas replacement, that is, use of inert gas atmosphere, is preferable. Examples of the above-mentioned inert gas include nitrogen gas, helium gas, argon gas, hydrogen gas, carbon dioxide gas and the like, preferably nitrogen gas. [0110] Now the composition of the present invention is explained. The composition of the present invention is a composition containing reduced coenzyme Q10, and an acerola extract and/or a Vaccinium vitis - idaea extract. [0111] In the composition of the present invention, reduced coenzyme Q10, which is the active ingredient in the composition, is not only protected from oxidation by an acerola extract and/or a Vaccinium vitis - idaea extract and maintained stably, but also a component derived from a naturally-occurring substance superior in safety and effective as a nutrient is contained. Therefore, the composition is safe, expected to show a synergistic effect with reduced coenzyme Q10 and can also be a composition useful as foods and supplement such as food with nutrient function claims, food for specified health uses and the like, drinks, pharmaceutical products, animal drugs, cosmetics, pet foods and the like. [0112] Moreover, when the composition of the present invention is produced by the above-mentioned production method of the present invention, high benefits are provided from the aspect of production, since not only oxidized coenzyme Q10, which is economical, can be utilized as a starting material, but also the component derived from a naturally-occurring substance of the present invention utilized for reduction of oxidized coenzyme Q10 does not require separation and removal after completion of the reduction reaction, since its safety to the body has been established, and the component derived from a naturally-occurring substance remaining in the composition can also be directly utilized for stabilization of reduced coenzyme Q10. Utilizing the present invention capable of obtaining a composition containing reduced coenzyme Q10 in situ, the production cost of a composition containing reduced coenzyme Q10 can be suppressed, and a composition containing reduced coenzyme Q10 can be provided at a low cost. [0113] Specific examples and detailed explanation of reduced coenzyme Q10 to be contained in the composition of the present invention are the same as those explained for the stabilization method of the present invention. From the above-mentioned aspects, one obtained by reducing oxidized coenzyme Q10 with an acerola extract and/or a Vaccinium vitis - idaea extract is particularly preferable from the aspects of production. [0114] In addition, the detailed explanation of the acerola extract and/or Vaccinium vitis - idaea extract to be contained in the composition of the present invention is the same as that for the production method and stabilization method of the present invention. [0115] In the composition of the present invention, the amount ratio of reduced coenzyme Q10, and an acerola extract and/or a Vaccinium vitis - idaea extract that are contained in the composition is not particularly limited. Generally, as the ratio of the weight of reduced coenzyme Q10/total weight of the above-mentioned extracts, it is normally about 1000/1 or more, preferably about 100/1 or more, more preferably about 10/1 or more, particularly preferably about 1/1 or more, and about 1/10000 or less, preferably about 1/1000 or less, more preferably about 1/100 or less, particularly preferably about 1/10 or less. [0116] In the composition of the present invention, reduced coenzyme Q10, and an acerola extract and/or a Vaccinium vitis - idaea extract are co-present in the composition. The “co-present” here means that they need to be in contact with each other in some form. The manner of contact is not particularly limited, and the system of the composition may be homogeneous or nonhomogeneous. Examples thereof include contact of reduced coenzyme Q10, and an acerola extract and/or a Vaccinium vitis - idaea extract each as a solid, the presence of one as a solid in a liquid layer of the other dissolved in a solvent and the like, the presence of an extract as a solid in a melt of reduced coenzyme Q10, each present in a different liquid phase, forming liquid-liquid two layers, and each present in the same liquid phase and the like. Needless to say, a system showing high contact efficiency of reduced coenzyme Q10, and an acerola extract and/or a Vaccinium vitis - idaea extract is effective for stabilization of reduced coenzyme Q10 and, from this aspect, reduced coenzyme Q10 and these extracts are most preferably present in the same liquid phase. [0117] From the above-mentioned aspects, it is preferable in the composition of the present invention to use a solvent to contain reduced coenzyme Q10, and an acerola extract and/or a Vaccinium vitis - idaea extract in liquid phase in the composition. The solvent to be used for the composition of the present invention is not particularly limited, and specific examples, detailed kind and preferable examples thereof are the same as those mentioned for the aforementioned production method and stabilization method of the present invention. [0118] In addition, as in the production method and stabilization method of the present invention, the composition of the present invention can also further contain or often preferably contain a surfactant. Specific examples, detailed kind and preferable examples of the surfactant to be used in the composition of the present invention are the same as those explained for the aforementioned production method and stabilization method of the present invention. [0119] In the composition of the present invention, a method for preparing a composition containing reduced coenzyme Q10, and an acerola extract and/or a Vaccinium vitis - idaea extract is not particularly limited. For example, when reduced coenzyme Q10 added from outside is used, the reduced coenzyme Q10, and an acerola extract and/or a Vaccinium vitis - idaea extract may be simply mixed or, after mixing them, a solvent as mentioned above may be further mixed therewith. Alternatively, a solution containing reduced coenzyme Q10 in the aforementioned solvent may be mixed with an acerola extract and/or a Vaccinium vitis - idaea extract, or a solution containing these extracts in the aforementioned solvent may be mixed with reduced coenzyme Q10, or a solution containing reduced coenzyme Q10 and a solution containing the extracts may be mixed. [0120] Alternatively, reduced coenzyme Q10 obtained by the aforementioned production method of the present invention can be directly utilized, that is, a mixture of reduced coenzyme Q10 after completion of the reduction reaction and, and an acerola extract and/or a Vaccinium vitis - idaea extract can be directly utilized as the composition of the present invention, and this embodiment is one of the most preferable embodiments. [0121] In the composition of the present invention, as a substance other than reduced coenzyme Q10, an acerola extract and/or a Vaccinium vitis - idaea extract, and solvent and surfactant where necessary, for example, excipient, disintegrant, lubricant, binder, dye, anticoagulant, absorption promoter, solubilizing agent, stabilizer, flavor, active ingredient other than reduced coenzyme Q10 and the like can also be further contained, without any particular limitation. Specific examples, detailed kind and preferable examples thereof are the same as those explained for the stabilization method of the present invention. [0122] The content of an acerola extract and/or a Vaccinium vitis - idaea extract (total amount when the both are used in combination) in the composition of the present invention is not particularly limited. To allow sufficient exertion of the stabilizing effect of reduced coenzyme Q10, however, the ratio to the total weight of the composition is normally about 0.01 wt % or more, preferably about 0.1 wt % or more, more preferably about 1 wt % or more, particularly preferably about 5 wt % or more. While the upper limit is not particularly set, it is normally about 99 wt % or less, preferably about 95 wt % or less, more preferably about 90 wt % or less, particularly preferably 80 wt % or less, from the economic aspect, effectiveness as a nutrient and the like. The content of reduced coenzyme Q10 in the composition is not particularly limited. To ensure effectiveness of reduced coenzyme Q10 in the composition, it is normally about 0.001 wt % or more, preferably about 0.01 wt % or more, more preferably about 0.1 wt % or more, particularly preferably about 0.5 wt % or more. While the upper limit is not particularly set, it is preferably about 50 wt % or less, more preferably about 40 wt % or less, particularly preferably about 30 wt % or less. [0123] While the composition of the present invention can be used directly, it can also be used after processing into a preparation as described for the production method of the present invention, such as oral administration forms such as capsules (hard capsule, soft capsule, microcapsule), tablets, syrups, drinks and the like, and a form for cream, suppository, toothpaste and the like. Of these, processing into the above-mentioned oral administration form is preferable. Particular preferred is the form of a capsule, particularly a soft capsule. [0124] A capsule base material in this case is not particularly limited, and gelatin derived from beef bones, cattle skin, pig skin, fish skin and the like, as well as other base materials (e.g., viscosity increasing stabilizers of seaweed-derived products such as carrageenan and alginic acid, vegetable seed-derived products such as locust bean gum and guar gum, and the like, and cellulose-containing agents for production material can also be used. EXAMPLES [0125] While the present invention is explained in more detail in the following by referring to Examples, the present invention is not limited to those Examples alone. Moreover, the purity of reduced coenzyme Q10, the weight ratio of reduced coenzyme Q10/oxidized coenzyme Q10, and the like in the Examples were measured by the following HPLC analysis. However, the purity of the obtained reduced coenzyme Q10 does not define the critical value of the purity in the present invention, and similarly, the weight ratio of reduced coenzyme Q10 and oxidized coenzyme Q10 does not define the upper limit thereof. To conveniently indicate the weight ratio of reduced coenzyme Q10 and oxidized coenzyme Q10 in the present Example, the ratio of reduced coenzyme Q10 to the total amount of coenzyme Q10 (total amount of oxidized coenzyme Q10 and reduced coenzyme Q10) is shown in percentage as a “weight ratio of reduced coenzyme Q10”. For example, “the weight ratio of reduced coenzyme Q10 is 20%” means that the weight ratio of reduced coenzyme Q10 and oxidized coenzyme Q10 is 20/80. (HPLC analysis conditions) column; SYMMETRY C18 (manufactured by Waters) 250 mm (length) 4.6 mm (inner diameter), mobile phase; C 2 H 5 OH:CH 3 OH=4:3 (v:v), detection wavelength; 210 nm, flow rate; 1 ml/min, retention time of reduced coenzyme Q10; 9.1 min, retention time of oxidized coenzyme Q10; 13.3 min. Example 1 [0133] Oxidized coenzyme Q10 crystal (0.1 g) and a component derived from a naturally-occurring substance (plant extract, 1.0 g, 10-fold weight) described in Table 1 were respectively added to 99% ethanol (15 g), and the mixture was stirred at 78° C. for 16 hr under a nitrogen atmosphere. The weight ratio of reduced coenzyme Q10 in the reaction mixture after the reaction is shown in Table 1. Comparative Example 1 [0134] Oxidized coenzyme Q10 crystal (0.1 g, 0.12 mmol) and the compound described in Table 1 (0.69 mmol) were respectively added to 99% ethanol (15 g), and the mixture was stirred at 78° C. for 16 hr under a nitrogen atmosphere. The weight ratio of reduced coenzyme Q10 in the reaction mixture after the reaction is shown in Table 1. [0000] TABLE 1 weight ratio of reagent name reduced coenzyme Q10 (Example 1) acerola extract 100%  Vaccinium vitis - idaea extract 61% pine bark extract 48% tea extract 30% rosemary extract 14% (Comparative Example 1) retinol acetate  4% retinal  4% carnitine  0% NADH  2% Example 2, Comparative Example 2 [0135] Oxidized coenzyme Q10 crystal (0.1 g) and a component derived from a naturally-occurring substance (plant extract, 1.0 g, 10-fold weight) described in Table 2 or a compound (0.69 mmol) were respectively added to limonene (15 g), and the mixture was stirred at 85° C. for 16 hr under a nitrogen atmosphere. The weight ratio of reduced coenzyme Q10 in the reaction mixture after the reaction is shown in Table 2. [0000] TABLE 2 weight ratio of reagent name reduced coenzyme Q10 (Example 2) acerola extract 98% pine bark extract 30% tea extract 19% (Comparative Example 2) grape seed extract  0% R-dihydrolipoic acid  1% L-sodium ascorbate  1% Example 3, Comparative Example 3 [0136] Oxidized coenzyme Q10 crystal (0.1 g) and a component derived from a naturally-occurring substance described in Table 3 (plant extract, 1.0 g, 10-fold weight) or a compound (0.69 mmol) were respectively added to a mixture of Span 80 (0.12 g), glycerol (0.09 g), Tween 80 (1.49 g) and MCT (0.43 g), and the mixture was stirred at 80° C. for 16 hr under a nitrogen atmosphere. The weight ratio of reduced coenzyme Q10 in the reaction mixture after the reaction is shown in Table 3. [0000] TABLE 3 weight ratio of reagent name reduced coenzyme Q10 (Example 3) acerola extract 98%  pine bark extract 84%  tea extract 33%  rosemary extract 17%  (Comparative Example 3) ginkgo leaf extract 5% grapes seed extract 1% retinal 3% NADH 0% α-tocopherol 0% carnitine 0% Example 4, Comparative Example 4 [0137] Oxidized coenzyme Q10 crystal (0.1 g) and a component derived from a naturally-occurring substance described in Table 4 (plant extract, 1.0 g, 10-fold weight) were respectively added to a mixture of condensed ricinoleic acid ester (CR-310, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., 1.25 g) and MCT (1.25 g), and the mixture was stirred at 80° C. for 16 hr under a nitrogen atmosphere. The weight ratio of reduced coenzyme Q10 in the reaction mixture after the reaction is shown in Table 4. [0000] TABLE 4 weight ratio of reagent name reduced coenzyme Q10 (Example 4) acerola extract 100%  rosemary extract 12%  (Comparative Example 4) St. John's wort extract 5% Grape seed extract 0% Example 5 [0138] Reduced coenzyme Q10 crystal (0.02 g) and a component derived from a naturally-occurring substance described in Table 5 (plant extract, 0.2 g, 10-fold weight) were respectively added to 99% ethanol (3.0 g), and the mixture was left standing in the air at 25° C. for 24 hr. The weight ratio of reduced coenzyme Q10 in the reaction mixture after the preservation is shown in Table 5. In addition, the result without addition of a component derived from a naturally-occurring substance is also shown as a control. [0000] TABLE 5 weight ratio of reagent name reduced coenzyme Q10 no addition (control) 38% acerola extract 75% Vaccinium vitis - idaea extract 66% pine bark extract 93% Example 6 [0139] Reduced coenzyme Q10 crystal (0.02 g) and a component derived from a naturally-occurring substance described in Table 6 (plant extract, 0.2 g, 10-fold weight) were respectively added to a mixture of Span 80 (0.17 g), glycerol (0.13 g), Tween 80 (2.10 g) and MCT (0.61 g), and the mixture was left standing in the air at 25° C. for 24 hr. The weight ratio of reduced coenzyme Q10 in the reaction mixture after the preservation is shown in Table 6. In addition, the result without addition of a component derived from a naturally-occurring substance is also shown as a control. [0000] TABLE 6 weight ratio of reagent name reduced coenzyme Q10 no addition (control) 53% acerola extract 100%  pine bark extract 99% Example 7 [0140] Reduced coenzyme Q10 crystal (0.02 g) and an acerola extract (0.2 g, 10-fold weight) were added to a mixture of condensed ricinoleic acid ester (CR-310, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., 1.50 g) and MCT (1.50 g), and the mixture was left standing in the air at 25° C. for 24 hr. The weight ratio of reduced coenzyme Q10 in the reaction mixture after the preservation is shown in Table 7. In addition, the result without addition of a component derived from a naturally-occurring substance is also shown as a control. [0000] TABLE 7 weight ratio of reagent name reduced coenzyme Q10 no addition (control) 48% acerola extract 97%

The present invention aims to provide a component having not only an ability to reduce oxidized coenzyme Q10 and an ability to stabilize reduced coenzyme Q10, but also nutrient, flavor, broad utility and the like, and a utilization method thereof. The present invention relates to a safe and convenient method of producing reduced coenzyme Q10, including reducing oxidized coenzyme Q10 by using, as a component derived from a naturally-occurring substance, which is safe for the body, any one or more components selected from the group consisting of an acerola extract, a tea extract, a rosemary extract, a pine bark extract and a Vaccinium vitis - idaea extract. In addition, the present invention also relates to a method of stabilizing reduced coenzyme Q10 in the co-presence of a component derived from a naturally-occurring substance, and a stabilized composition. Since the above-mentioned components derived from a naturally-occurring substance can also be expected to function as nutrients, the composition of the present invention is particularly useful as a pharmaceutical product, a supplement, a food with nutrient function claims, a food for specified health use, a nutritional supplement, a nutritional product, an animal drug, a cosmetic, a therapeutic drug and the like, which are required to show various effects.

STATEMENT AS TO GOVERNMENT RIGHTS This invention was made with government support under Contract No. DABT 63-93-C-0025 awarded by Advanced Research Projects Agency ("ARPA"). The government has certain rights in this invention. TECHNICAL FIELD The present invention relates to transmission lines, and more particularly, to transmission lines having selected propagation velocities. BACKGROUND OF THE INVENTION Electrical transmission lines are used in a variety of applications, such as carrying communication signals between spaced-apart locations. In some applications, the transmission lines are used as delay lines to induce delay in electrical signals. For example, U.S. patent application Ser. No. 08/019,774 of Gold et al., and assigned to OWL Display, Inc., discloses a tapped microwave transmission line using coincident pulses to control a matrix addressable display. Often, the delay line must be very long to produce adequate delays. For example, the propagation-delay time per unit length for a microstrip line in a non-magnetic medium is T d =1.016√.di-elect cons. r ns/ft where .di-elect cons. r is a relative dielectric constant of the substrate, as described in Liao, "Microwave Devices and Circuits," 2d Ed., Prentice Hall, Inc., 1985. For a relative dielectric constant .di-elect cons. r of 2.0, the propagation-delay time per unit length is 1.437 ns/ft. Thus, for a 100 ns delay, the line would be approximately 69.6 ft. Unfortunately, such long lengths of transmission line are extremely large and lossy making such lines undesirably for many applications. To address such drawbacks, much work has been directed toward decreasing the propagation velocity V P of signals in transmission lines because the propagation delay T d of a signal in a transmission line is inversely proportional to the propagation velocity V P . The propagation velocity V P for a transmission line is inversely proportional to the square-root of the effective dielectric constant .di-elect cons. e , times the effective permeability μ e . Thus, the propagation velocity is ##EQU1## and the propagation-delay time per unit length T d is T d =√μ e .di-elect cons. e . The effective permeability μ e and the effective dielectric constant .di-elect cons. e are determined by the transmission line geometry, the relative permeabilities μ r of the materials, and the relative dielectric constants .di-elect cons. r of the materials. The propagation velocity V P thus increases as a function of the relative dielectric constants .di-elect cons. r and the relative permeabilities μ r of the materials. Previous attempts to reduce propagation velocities V P in transmission lines have focused primarily upon the dielectric medium because increases in the relative dielectric constant .di-elect cons. r of the dielectric medium increase the effective dielectric constant .di-elect cons. e and thereby decrease the propagation velocity V P along the transmission line. For example, for microstrip lines, a variety of substrate materials having extremely large relative dielectric constants .di-elect cons. r have been suggested. Such increases are limited by the availability and cost of high relative dielectric constant materials. To further reduce propagation velocity, the relative permeability μ r of the substrate material and/or the surrounding regions can also be increased. Such increases in relative permeability μ r of the substrate or surrounding regions increases the effective permeability μ e of the transmission line, thereby decreasing propagation velocity V P . However, such increases are limited by relative permeabilities of available materials, physical constraints of the transmission line structure and losses of the available materials. Such constraints can be particularly problematic in small transmission lines, such as microstrip lines in matrix addressable displays. In such displays, spacing between adjacent columns is very small to allow relatively high resolution. Consequently, if the microstrip lines extend between successive columns of the display, the time delay between arrival of pulses of successive columns is very small. To increase the timing separation between adjacent columns, the microstrip line can be formed in a serpentine pattern. However, this approach is limited by the physical constraints of the display and the losses of the serpentine microstrip line. Consequently, additional reductions in the propagation velocity V P remain desirable. SUMMARY OF THE INVENTION A transmission line incorporates a high permeability material as a conductor. In the preferred embodiment of the invention, the high permeability conductor cooperates with a high dielectric constant insulator and a high permeability core material to reduce the propagation velocity V P along the transmission line. In one aspect of the invention, the transmission line is a serpentine microstrip line in a matrix addressable display. Alternating turns of the serpentine microstrip are tapped to drive successive columns of the display. The microstrip line is driven at opposite ends by a pulsed image signal and a control pulse, respectively. The control pulse and image pulses are timed to constructively interfere at successive ones of the taps to produce a tap voltage that is the sum of the image pulse voltage and the control pulse voltage. The constructively interfered voltage breaks down a reverse-biased diode in a discharge circuit to provide an image signal to the column line. The arrival time of the control pulse at each successive tap is determined by the microstrip's length and the propagation velocity V P . The propagation velocity V P is affected by the relative dielectric constant μ r of the microstrip substrate, the relative permeability μ rint of the conductor, and the relative permeability μ rext of the core material partially surrounding the conductor. In one embodiment, the transmission line conductor includes two layers. A first, central layer is formed from a conventional, highly conductive material to provide a low resistivity portion of the conductor. The outer layer is formed from a high permeability conductive material to increase the effective permeability of the conductor. The low permeability of the central layer reduces the effective permeability of the conductor; however, this effect is less noticeable at high frequencies. At high frequencies, the current density of signals carried by the conductor increases near the surface of the conductor, as can be predicted from standard skin depth calculations. Therefore, the thickness of the outer layer of high permeability conductor can be selected based upon the expected operating frequency of the transmission line and the resulting skin depth. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of a portion of a matrix addressable display showing a microstrip delay line having several taps coupled to respective columns of an array. FIG. 2 is a side cross-sectional view of the microstrip transmission line of FIG. 1 along a line 2--2. FIG. 3 is a schematic of a charging and clearing circuit in the matrix addressable display of FIG. 1. FIG. 4A is a tiring diagram showing a composite signal formed from constructive interference of an image signal and control pulse. FIG. 4B is a signal timing diagram showing an image signal and a control pulse traveling in opposite directions on the transmission line of FIG. 1 to form the composite signal of FIG. 4A. FIG. 5 is a cross-sectional view of a coaxial transmission line where the central conductor includes a central layer of high conductivity material and an outer layer of high permeability material. DETAILED DESCRIPTION OF THE INVENTION As shown in FIG. 1, a field emission display 40 includes an emitter substrate 42 including several emitter sets 44 arranged in rows and columns. The emitter sets 44 in each column are coupled to common column lines 46 driven by respective driving circuits 48. The driving circuits 48 are driven in turn by a microstrip transmission line 50. Several parallel conductive extraction grids 52 cover the emitter substrate 42, where each extraction grid 52 is aligned to a row of emitter sets 44 and thus intersects every column. As is known, the emitter set 44 can be selectively activated by producing a voltage differential between a selected one of the extraction grids 52 and one of the emitter sets 44. To create the voltage differential, one of the extraction grids 52 is biased to a voltage of about 30-120V and one of the column lines 46 is driven to a low voltage, such as ground, by the driving circuit 48 to produce a voltage differential at the intersection of the extraction grid 52 and the column. The voltage differential between the extraction grid 52 and the emitter set 44 produces an electric field extending from the extraction grid 52 corresponding to the emitter set 44 and having sufficient intensity to cause the emitter set 44 to emit electrons. The emitted electrons strike a cathodoluminescent layer of a display screen (not shown) causing the cathodoluminescent layer to emit light that is visible to an observer. The intensity of the emitted light is determined in part by the rate at which electrons strike the cathodoluminescent layer. The rate at which electrons are emitted is determined in turn by the voltage differential between the extraction grid 52 and the emitter set 44. The rate at which electrons are emitted by the emitter set 44 can therefore be determined by the voltage of the column line 46, because the extraction grid 52 is biased to a fixed voltage. The driving circuit 48 can therefore control the intensity of light emitted from the emitter set 44 by controlling the voltage of the column line 46. The transmission line 50 supplies signal pulses as shown in FIG. 4A to the driving circuits 48. As shown in FIGS. 1 and 2, the transmission line 50 is a microstrip line formed from an upper conductor 72 and base conductor 73 (FIG. 2) on a substrate 62 having a high relative dielectric constant .di-elect cons. r . To provide adequate transmission line length, the upper conductor 72 is formed in a serpentine pattern. While the transmission line 50 is preferably a microstrip line, other transmission line structures, such as strip lines or coaxial lines, may also be within the scope of the invention. The transmission line 50 is tapped by several equally spaced taps 64 at alternating turns of the serpentine pattern. Each tap 64 provides a column signal V COL to a respective driving circuit 48. The column signal V COL at each tap 64 is a composite signal including a positive pulse 61 and a negative pulse 63, as shown in FIG. 4A. Generation of the composite signal of FIG. 4A is best described with reference to FIGS. 1 and 4B. The transmission line 50 receives an image signal V IM at its left end and a control pulse V CP at its right end. As seen in FIG. 4B, the image signal V IM is a pulse train having equally spaced, variable amplitude, negative-going pulses. As will be explained below, the amplitude of each pulse of the image signal V IM represents the brightness of a pixel in a corresponding column. The control pulse V CP is input to the right end of the transmission line 50 and includes a positive portion 66 followed by a negative portion 68. The negative portion 68 of the control pulse V CP is delayed relative to the positive portion 66 to ease timing control constraints along the transmission line 50 and to allow time for extraction grids 52 (FIG. 1) to go high after clearing, as will be described below. As the control pulse V CP travels from right to left along the transmission line 50, the control pulse V CP intercepts each successive pulse of the image signal V IM . The relative timing of the image signal V IM and the control pulse V CP is tightly controlled such that the positive portion 66 arrives alone at each tap 64 and the negative portion 68 and each successive pulse of the image signal V IM arrive simultaneously at each successive tap 64. Each control pulse V CP constructively interferes with the pulse of the image signal V IM to produce a respective composite signal at each of the taps 64. The composite signal for the leftmost tap 64 is shown in FIG. 4A. Before the composite signal arrives, the tap 64 is biased at an intermediate voltage V INT , by applying a DC voltage to the upper conductor 72. Then, the positive portion 66 of the control pulse arrives at the leftmost tap 64. The positive portion 66 quickly raises the tap voltage to the pulse voltage V POS at time t 1 . When the positive portion 66 passes the tap 64, the tap voltage drops to the intermediate voltage V INT at time t 2 . Later, the negative portion 68 and the last pulse 78 of the image signal V IM arrive at the tap 64 at time t 4 . The last pulse 78 and the negative portion 68 constructively interfere to produce a tap voltage V 1 having a negative-going magnitude that is the sum of the voltages V A , V CL of the last pulse 78 and the negative portion 68. When the last pulse 78 and the negative portion 68 leave the tap 64, the tap voltage returns to the intermediate voltage V INT . One skilled in the art will recognize that each of the taps 64 receives a similar composite signal if each successive pulse of the image signal V IM is timed to intercept the control pulse V CP at each successive tap 64. For example, the second-to-last pulse of the image signal V IM arrives at the second tap 64 from the left simultaneously with the negative portion 68 of the control pulse V CP . Similarly, the first pulse of the image signal V IM arrives at the rightmost tap 64 simultaneously with the negative portion 68 of the control pulse V CP . The constructively interfered image signal pulses and the control pulse V CP thus provide the composite signals to each of the driving circuits 48. The separation between pulses at subsequent taps 64 is determined by the distance (along the transmission line 50) between successive taps 64 and the propagation velocity V P of pulses along the transmission line 50. To slow propagation of the control pulse V CP and the image signal V IM along the transmission line 50, the relative dielectric constant .di-elect cons. r of the substrate 62 is very high. The slowed propagation of the signals V IM , V CP facilitates timing arrivals of pulses at successive taps 64 by increasing the time between arrivals of successive pulses of the image signal V IM at each tap 64 without requiring an excessively long transmission line 50. To further reduce the propagation velocity V P , high permeability cores 75 are bonded to the substrate 62 to increase the relative permeability μ rext of the regions surrounding the upper conductor 72, as best seen in FIG. 2. The relative permeability μ rext of the regions surrounding the upper conductor 72 will be referred to herein as the external relative permeability μ rext . The increased external relative permeability μ rext increases the overall effective permeability μ e of the transmission line 50, because a portion of the B-field of a signal on the transmission line 50 travels through the region surrounding the upper conductor 72. As described above, the propagation velocity V P of the transmission line 50 is inversely proportional to the square root of the effective permeability μ e . Therefore, increasing the external relative permeability μ rext decreases the propagation velocity V P . In addition to increasing the relative dielectric constant μ r and the external permeability μ rext , the inductance-per-length is further increased by forming the upper conductor 72 from a conductive material having a high relative permeability μ r , typically greater than 10. For example, conventional iron typically has a permeability greater than 1,000, pure iron may have a relative permeability μ r of about 280,000, permalloy (78.5% Ni, 21.5% Fe) have been produced with relative permeabilities of about 70,000 and supermalloys (e.g., 79% Ni, 15% Fe, 0.5% Mo, 0.5% Mn) have been shown to have relative permeabilities on the order of 1,000,000. The high relative permeability μ r of such materials increases the internal relative permeability μ rint , i.e., the permeability within the upper conductor 72. The high internal relative permeability μ rint of the upper conductor 72 in turn increases the overall effective relative permeability μ reff (and thus the effective permeability μ e ) of the transmission line 50, because the effective permeability μ reff increases when either the internal permeability μ rint or the external permeability μ rext is increased. Consequently, increasing the relative permeability μ r of the upper conductor 72 decreases propagation velocity V P through the transmission line 50. FIG. 3 shows one suitable driving circuit 48 used in the field emission display 40 of FIG. 1. The driver circuit 48 includes a discharge circuit 60 coupled between the column input 51 and the column line 46. The driving circuit 48 also includes a storage capacitor 57 coupled between the column line 46 and ground. The discharge circuit 60 is formed from a pair of opposed diodes 53, 54 coupled between the input line 51 and the column line 46. The diodes 53, 54 are Zener diodes having well-defined breakdown voltages V BU , V BL , well-defined forward bias voltages V FB , and rapid recovery times. Operation of the display 40 will now be explained with reference to the signal of FIG. 4A. First, at a time t 1 , the positive portion 61 of the first composite signal pulse having the voltage V POS arrives at the upper diode 53. The voltage V POS is greater than the breakdown voltage V BU of the upper diode 53 plus the forward bias voltage V FB of the lower diode 54, so that the positive portion 66 breaks down the upper diode 53. In response, the capacitor 57 quickly charges to a cleared voltage V CL equal to the voltage of the positive-going portion less the breakdown voltage V BU of the upper diode 53 and the forward bias voltage V FB of the lower diode 54. The cleared voltage V CL is greater than the emission voltage V EM of the emitter sets 44. Therefore, the emitter sets 44 coupled to the capacitor 57 will not emit electrons. At time t 2 , the composite signal returns to the intermediate voltage V INT which is between the magnitude V P of the positive-going portion and the capacitor voltage V C . The voltage difference between the column voltage V COL and the capacitor voltage V C is less than the breakdown voltages V BU , V BL of the diode 53, 54. Thus, after the upper diode 53 recovers, current does not flow into the capacitor 57, because the reverse-biased upper diode 53 forms an open circuit. Next, at time t 3 , the grid voltage V ROW1 on a first of the extraction grids 52 (FIG. 1) goes high to approximately 30-120V. The emitter sets 44 at this time are at the capacitor voltage V C , because the emitter sets 44 are electrically connected to the capacitor 57. Because the capacitor voltage V C is relatively high, the emitter set 44 at the intersection of the uppermost extraction grid 52 and the leftmost column is close to the grid voltage V ROW1 and does not emit electrons. Next, the negative portion 63 of the composite signal arrives at a time t 4 with a voltage V 1 , as referenced below the emitter voltage V EM . In response to the negative portion 63, the lower diode 54 breaks down and conducts current, because the difference between the capacitor voltage V C and the voltage V 1 is greater than the breakdown voltage V BL of the lower diode 54 plus the forward bias voltage V FB of the upper diode 53. The capacitor 57 discharges quickly until the voltage difference between the capacitor voltage V C and the voltage V 1 equals the breakdown voltage V BL of the lower diode 54 plus the forward bias voltage V FB of the upper diode 53. The composite pulse then returns to the intermediate voltage V INT at time t 5 and the diodes 53, 54 once again form open circuits, trapping the voltage V 1 minus the upper diode breakdown voltage V BU and the lower diode forward bias voltage V FB on the capacitor 57. The voltages of the emitter sets 44 equal the capacitor voltage V C and the voltage difference between the first extraction grid 52 and the first emitter set 44 causes the first emitter set 44 to emit electrons. The remaining emitter sets 44 on the column line 46 are unaffected, because only the first extraction grid 52 is at a high voltage. As described above, the emitted electrons cause light emission above the emitter set 44. As the first emitter set 44 emits electrons, the emitted electrons are replaced by electrons drawn from the capacitor 57. The capacitor voltage V C rises slightly as the electrons flow from the capacitor 57 to the first emitter set. However, the capacitor 57 is sufficiently large and the total current through the emitter set 44 is sufficiently small that the capacitor voltage V C remains at substantially constant level over the entire time that the first extraction grid 52 is high. The time during which the capacitor 57 provides electrons to the emitter set 44 is substantially longer than the direction of the negative portion 63 of the composite signal. For example, for a typical refresh interval of about 35 μs, each capacitor 57 will be recharged in an interval of about 0.02 μs for a 640 column color display or 0.055 μs for a monochrome display. Consequently, the width of the negative portion 63 of the composite signal can be very short relative to the refresh time of the display. According to aspect of the invention, FIG. 5 shows a coaxial transmission line 80. The coaxial transmission line 80 is formed from a center conductor 82 surrounded by a dielectric 84 that is, in turn, surrounded by an outer conductor 86. The dielectric 84 is a conventional dielectric having a high relative dielectric constant .di-elect cons. r . The center conductor 82 and outer conductor 86 each include radially inner and radially outer layers 88, 90 and 92, 94, respectively. The radially inner layer 88 of the center conductor 82 is a highly conductive material having a relative permeability μ r of approximately 1, i.e., a permeability equal to the permeability of free space μ 0 . The radially outer layer 90 of the center conductor 82 is a high permeability conductor having a relative permeability μ r1 greater than 1. Similarly, the radially inner layer 92 of the outer conductor is a high permeability conductive material having a relative permeability μ r2 greater than 1. The radially outer layer 94 of the outer conductor 86 is a highly conductive material having a relative permeability substantially equal to 1. The use of two layers 88, 90 and 92, 94 for the conductors 82, 86 allows the conductors to be made more cheaply and with higher conductivity than conductors formed solely from high permeability conductive material. Of course, the overall permeability of the center conductor 82 will be lower than the relative permeability μ r1 of the radially outer layer 90, because the overall permeability of the center conductor is partly a function of the permeability μ 0 of the radially inner layer 88. Similarly, the overall relative permeability of the outer conductor 86 will be lower than the relative permeability μ r2 of its radially inner layer 92, because the effective permeability of the outer conductor 86 is, in part, a function of the relative permeability μ 0 of the radially outer layer 94. Thus, the inductance-per-length of the coaxial transmission line 80 will be lower than a transmission line having similar dimensions where the center and outer conductors 82, 86 are made completely of high permeability conductors. However, it is well known that the current density of electric signals in a transmission line is determined using skin depth calculations. For a coaxial transmission line, such as the transmission line 80, the current density will be highest near the outer surface of the center conductor 80, i.e., in the radially outer layer 90. As the frequency of signals carried by the transmission line 80 increase, current density is increasingly confined to the radially outer layer 90. Consequently, as frequency increases, the reduction in effective permeability due to the low permeability inner layer 88 will diminish. Thus, as frequency increases, the effective permeability of the center conductor 82 approaches the relative permeability μ r2 of the high permeability outer layer 90. The effect on the propagation velocity V P will approximate the propagation velocity of a transmission line having a center conductor and outer conductor formed completely of high permeability conductive material. Alternatively, if a particular application makes it desirable to reduce the effect of high permeability conductor at low frequencies, the materials of the coaxial transmission line 80 of FIG. 5 can be reversed so that the outer layer 90 of the center conductor 82 has a relative permeability of 1 and the inner layer 88 has a high relative permeability. Thus, as frequency increases, the effective permeability approaches the permeability of free space μ 0 . One skilled in the art will recognize several variations on the timing of the signals V CP , through V IM that are within the scope of the invention. For example, one skilled in the art will recognize several variations in the timing, magnitude, and approach to constructively interfered pulses along tapped transmission lines. Also, the driving circuit 48 can be realized with alternative circuit structures, such as the field effect transistor-based structure described in U.S. patent application Ser. No. 08/746,965 entitled High Impedance Transmission Line Tap Circuit of Zimlich and Hall which is commonly assigned with the present application and is incorporated herein by reference. Additionally, a variety of other transmission line structures can be realized according to the invention. For example, the two layer, dual-permeability conductor structure described with respect to FIG. 5 can be adapted to the upper conductor 72 and base conductor of the microstrip transmission line 50 of FIGS. 1 and 2, a strip line, a hollow transmission line or to various other transmission line structures. While the present invention has been described by way of an exemplary embodiment, various modifications to the embodiment described herein can be made without departing from the scope of the invention. Accordingly, the present invention is not limited except as by the appended claims.

A transmission line includes a high permeability conductor. The high permeability conductor increases the inductance-per-length of the transmission line to reduce the propagation velocity along the line. The high permeability conductor supplements a high dielectric constant insulator and high permeability core that increase the capacitance-per-length and inductance-per-length, respectively. In one embodiment, the transmission line is a microstrip line that is used in a matrix addressable display. In another embodiment, the transmission line is a coaxial line where the central conductor includes a center layer of nonmagnetic material and an outer layer of high permeability material. The high permeability conductor can be formed from a single layer of high permeability material or may be formed from a central layer of high conductivity material coated with an outer layer of a high permeability conductor.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2011-267118 filed Dec. 6, 2011. BACKGROUND (i) Technical Field The present invention relates to an image recognition information attaching apparatus, an image recognition information attaching method, and a non-transitory computer readable medium. (ii) Related Art One of related art image recognition information attaching apparatuses learns a relation between feature information and identification information (hereinafter referred to as a “label”) in advance if the identification information that is attached in accordance with the feature information resulting from image information or the like is prepared in advance. In accordance with the learning results, the image recognition information attaching apparatus recognizes the label to which input image information belongs. SUMMARY According to an aspect of the invention, an image recognition information attaching apparatus is provided. The image recognition information attaching apparatus includes a retrieving unit that retrieves image information on a per piece basis of identification information, from the image information having the identification information associated thereto in advance, a generator unit that generates feature information from the image information retrieved by the retrieving unit, and a learning unit that provides a learning result by learning a relation between the feature information generated by the generator unit and the identification information of the image information corresponding to the feature information, using a stochastic model including a mixture of a plurality of probability distributions, the learning unit calculating, from a first variable determined from the feature information belonging to one of the probability distributions, and a variable describing a probability distribution determined from a set of the feature information resulting from all the image information retrieved by the retrieving unit regardless of the content of the identification information, a second variable in accordance with a contribution ratio responsive to a density of the feature information belonging to the one of probability distributions, and learning the relation using a distribution described by the second variable. BRIEF DESCRIPTION OF THE DRAWINGS Exemplary embodiments of the present invention will be described in detail based on the following figures, wherein: FIG. 1 illustrates an example of an image recognition information attaching apparatus of one exemplary embodiment of the present invention; FIGS. 2A and 2B illustrate an example of a basic learning operation; FIG. 3A illustrates a relationship of a k-th Gaussian distribution of label c, overall image feature distribution, and mean value μ k C determined by a model learning unit, and FIG. 3B diagrammatically illustrates distributions of feature vectors and ranges of data regions; FIG. 4 is a flowchart illustrating an operation of the image recognition information attaching apparatus; FIG. 5 is a flowchart illustrating a learning algorithm; and FIG. 6 is a flowchart illustrating an operation of the image recognition information attaching apparatus. DETAILED DESCRIPTION FIG. 1 illustrates a configuration of an image recognition information attaching apparatus 1 of an exemplary embodiment of the present invention. The image recognition information attaching apparatus 1 includes controller 10 , storage 11 , and communication unit 12 . The controller 10 controls elements including a central processing unit (CPU), and executes a variety of programs. The storage 11 includes storage units such as a hard disk drive and flash memory. The communication unit 12 communicates with the outside via a network. An image input via the communication unit 12 may include as objects a “river,” a “mountain,” a “child,” and the like. Words such as a “river,” a “mountain,” and a “child” are hereinafter referred to as annotation words. The image recognition information attaching apparatus 1 attaches to the image information the annotation word as identification information (hereinafter referred to as a “label”). The image recognition information attaching apparatus 1 performs a learning process using learning image information with a label attached thereto in advance and stored on the storage 11 or the like. The controller 10 executes an image recognition information attaching program 110 to be discussed, and thus functions as image retrieving unit 100 , image partitioning unit 101 , feature vector generator unit 102 , learning data set retrieving unit 103 , overall image feature distribution estimating unit 104 , model learning unit 105 , likelihood calculating unit 106 , annotation word estimating unit 107 , and output unit 108 . In a learning process, the image retrieving unit 100 selects and retrieves image information for learning from image information 111 stored on the storage 11 . In estimating the label, the image retrieving unit 100 retrieves image information input from an external terminal apparatus via the communication unit 12 . The image partitioning unit 101 partitions the image information retrieved by the image retrieving unit 100 and the image information 111 for learning stored on the storage 11 into multiple regions, thereby generating partial segments. The image partitioning unit 101 may use a method of partitioning the image information in accordance with rectangles arranged in a mesh, or a method of defining near and similar pixels as belonging to the same segment in accordance with a clustering technique, such as k-nearest neighbor algorithm. The feature vector generator unit 102 generates a feature vector from each of the partial segments generated by the image partitioning unit 101 , using a method of Gabor filter, or a method of extracting feature quantity such as RGB, normalized RG, CIELAB, or the like. The feature vector is one example of the feature information. The learning data set retrieving unit 103 retrieves from the image information 111 image information that the same label is imparted to, and retrieves as a learning data set a set of feature vectors included in the retrieved image information. The learning data set retrieving unit 103 also retrieves a feature vector set (hereinafter referred to as a “universal model”) resulting from all the image information 111 regardless of the content of the label. The selection of the learning data set is not limited to a method of retrieving all the learning data. For example, if an amount of learning data is extremely large, another method may be used. For example, in one method, data elements are randomly extracted from all the learning data until a specified number of data elements are obtained. The overall image feature distribution estimating unit 104 learns the universal model as a prior probability model, and estimates learning results (hereinafter referred to as an “overall image feature distribution”). The model learning unit 105 learns the learning data set retrieved by the learning data set retrieving unit 103 , and includes a data density estimating unit 105 a and a parameter optimization unit 105 b. The data density estimating unit 105 a estimates a data density of data in a data region of a given label. The “data region” herein refers to a region in a space of the feature vectors belonging to a k-th Gaussian distribution if the entire space of the feature vectors is segmented into K Gaussian distributions in accordance with Gaussian mixture model (GMM) (see FIG. 3A ). More information is provided in detailed in learning process described below. The “data density” refers to a density of data included in the data region of the k-th Gaussian distribution. The parameter optimization unit 105 b calculates and optimizes a second variable from a first variable determined from the feature information belonging to the data region, and a variable describing the overall feature distribution, in accordance with a contribution ratio. The contribution ratio is determined by the data density of the data region estimated by the data density estimating unit 105 a. The likelihood calculating unit 106 calculates the likelihood of any label of the feature vector of the image information retrieved by the image retrieving unit 100 . The annotation word estimating unit 107 estimates an annotation word corresponding to the label having a high likelihood, as the identification information of the input image information. The output unit 108 outputs, to a display unit, a printer, the storage 11 , or the like, several annotation words having high likelihood, from among those estimated by the annotation word estimating unit 107 . In this way, the output unit 108 presents an annotation word to be output according to the likelihood. The user of the image recognition information attaching apparatus 1 may select an appropriate annotation word from the presented annotation words according to the likelihood. The storage 11 stores image recognition information attaching program 110 , image information 111 , label information 112 , learning information 113 , and the like. The image recognition information attaching program 110 causes the controller 10 to operate as the elements of the controller 10 . The image information 111 is used in the learning process. The label information 112 associates the image information included in the storage 11 with the label. The learning information 113 is the learning result of the model learning unit 105 . Referring to the drawings, the operations of the image recognition information attaching apparatus 1 are described in terms of a basic learning operation, a detailed learning operation, and an annotation estimation operation. FIG. 4 is a flowchart illustrating the operation of the image recognition information attaching apparatus 1 . FIGS. 2A and 2B generally illustrate the basic learning operation. The image retrieving unit 100 receives the image information 111 as the learning data from the storage 11 (S 1 ). For example, the image information 111 includes multiple pieces of image information associated with annotation words a “mountain,” a “sun,” a “car,” and the like as labels. The image partitioning unit 101 partitions a display image of image information 111 a illustrated in FIG. 2A as one example of the image information retrieved by the image retrieving unit 100 into n segments of FIG. 2B . The image partitioning unit 101 thus results in partial segments A 1 -A n (S 2 ). In one example, the display image is partitioned into rectangles arranged in a mesh. That operation may be performed on each of the multiple pieces of image information retrieved by the image retrieving unit 100 . The feature vector generator unit 102 extracts multiple feature quantities f 1 -f D from the partial segments A 1 -A n , for example, using the Gabor filter. The feature vector generator unit 102 thus generates feature vectors x 1 , x 2 , . . . , x n of the partial segments A 1 -A n , each having the feature quantities f 1 -f D as the components thereof (S 3 ). That operation may be performed on each of the multiple pieces of image information retrieved by the image retrieving unit 100 . The learning data set retrieving unit 103 references the label information 112 , and retrieves the image information associated with a label c 1 (for example, the annotation word “mountain”) from the image information 111 . The learning data set retrieving unit 103 retrieves a set of feature vectors generated from the retrieved image information as a learning data set (S 4 and S 5 ). The model learning unit 105 learns the learning data of the label c 1 retrieved by the learning data set retrieving unit 103 (S 6 ), and stores the learning result in the learning information 113 on the storage 11 (S 7 ). Operations in steps S 5 through S 7 are performed on all the labels (M labels) (S 8 and S 9 ). The detailed learning operation performed by the model learning unit 105 in step S 6 is described in detail below. The model learning unit 105 uses GMM as a probability generation model. Let X={x 1 , . . . , x n } represent an input learning data set, and D represent the dimension of the feature vector, and Gaussian mixture model p is defined by expression (1) as follows: p ⁡ ( X | c ) = ∏ i = 1 N ⁢ p ⁡ ( x i | c ) = ∏ i = 1 N ⁢ ∑ k = 1 K ⁢ π k c ⁢ N ⁡ ( x i | μ k c , Σ k c ) ( 1 ) where N is the number of input learning data elements, and K is the number of mixture elements. Let π k c represent a mixture ratio, N(x i |μ k c , Σ k c ) represent a D-dimensional Gaussian distribution having mean value μ k c and variance Σ k c . The mixture ratio satisfies expression (2): ∑ k = 1 K ⁢ π k c = 1 ( 2 ) The overall image feature distribution estimating unit 104 learns as a prior probability common to all the labels a model (universal model) where all the image information 111 is set as the learning data set. The model is referred to as an overall image feature distribution in the present invention. According to the exemplary embodiment, the overall image feature distribution is represented by the following GMM: p u ⁡ ( x i ) = ∑ k = 1 K ⁢ π k u ⁢ N ⁡ ( x i | μ k u , Σ k u ) ( 3 ) The mixture ratio π k c , the mean value μ k c and the variance Σ k c (1≦k≦K) are obtained by performing a learning process in advance through a standard expectation-maximization (EM) algorithm. The learning process is performed using a learning data set of all the labels set in a learning data setting process (or learning data set randomly extracted with no label defined). The parameter optimization unit 105 b performs a first method to correct the Gaussian distribution N(x i |μ k c , Σ k c ) corresponding to a given label using the overall image feature distribution. When the parameter optimization unit 105 b calculates parameters (the mixture ratio, the mean value, and the variance) using the EM algorithm in the first method, the initial values of the parameters are those of the overall image feature distribution. The EM algorithm has a feature of dependence on the initial value. The smaller the number of data elements is, the larger the dependence on the initial value becomes. If the reliability of the learning data is low with a small number of learning data samples, the Gaussian distribution reflecting the overall image feature distribution may be obtained. If the number of learning data samples is large, the Gaussian distribution reflecting the trend of the learning data samples more may be obtained. The model learning unit 105 uses a second method to correct the Gaussian distribution N(x i |μ k c , Σ k c ) corresponding to a given label using the overall image feature distribution. In the second method, the model learning unit 105 uses the overall image feature distribution as a prior distribution. With a specific GMM used as a prior distribution, and the parameters of the Gaussian distribution (second variables) are calculated as follows: π k c = ∑ i = 1 N c ⁢ r ik c + τ N c + τ ⁢ ⁢ K ( 4 ) μ k c = ∑ i = 1 N c ⁢ r ik c ⁢ x i + τμ k u ∑ i = 1 N c ⁢ r ik c + τ ( 5 ) Σ k c = ∑ i = 1 N c ⁢ r ik c ⁢ x i ⁢ x i T + τ ⁢ { Σ k u + μ k u ⁡ ( μ k u ) T } ∑ i = 1 N c ⁢ r ik c + τ - μ k c ⁡ ( μ k c ) T ( 6 ) where r ik c , called shared ratio, is a posterior distribution of mixture elements k if data x i is given, and is defined by the following expression (7): γ ik c ≡ π k c ⁢ N ⁡ ( x i | μ k c , Σ k c ) ∑ k = 1 K ⁢ π k c ⁢ N ⁡ ( x i | μ k c , Σ k c ) ( 7 ) where τ is a real constant number, and N c is the number of learning data elements of label c. From expressions (4) through (6), it is understood that the smaller the amount of learning data is, the more the parameters (second variables) of the Gaussian distribution reflects the parameters of the overall image feature distribution. Expression (5) may be interpreted as follows: ⁢ μ k c = ⁢ ∑ i = 1 N c ⁢ r ik c ∑ i = 1 N c ⁢ r ik c + τ ⁢ ∑ i = 1 N c ⁢ r ik c ⁢ x i ∑ i = 1 N c ⁢ r ik c + τ ∑ i = 1 N c ⁢ r ik c + τ ⁢ μ k u = ⁢ ρ ⁢ ⁢ x _ k c + ( 1 - ρ ) ⁢ μ k u ( 8 ) x _ k c ≡ ∑ i = 1 N c ⁢ r ik c ⁢ x i ∑ i = 1 N c ⁢ r ik c ⁢ : ⁢ ⁢ Sample ⁢ ⁢ mean ⁢ ⁢ value ⁢ ⁢ in ⁢ ⁢ region ⁢ ⁢ k ⁢ ⁢ of ⁢ ⁢ label ⁢ ⁢ c ⁢ ⁢ ( first ⁢ ⁢ variable ) ( 8 ⁢ - ⁢ 1 ) ⁢ ∑ i = 1 N c ⁢ γ ik c ⁢ : ⁢ ⁢ Data ⁢ ⁢ density ⁢ ⁢ in ⁢ ⁢ region ⁢ ⁢ k ⁢ ⁢ of ⁢ ⁢ label ⁢ ⁢ c ( 8 ⁢ - ⁢ 2 ) ⁢ ρ ≡ ∑ i = 1 N c ⁢ γ ik c ∑ i = 1 N c ⁢ γ ik c + τ ⁢ : ⁢ ⁢ Contribution ⁢ ⁢ ratio ⁢ ⁢ in ⁢ ⁢ region ⁢ ⁢ k ⁢ ⁢ of ⁢ ⁢ label ⁢ ⁢ c ( 8 ⁢ - ⁢ 3 ) 1 - ρ ≡ τ ∑ i = 1 N c ⁢ γ ik c + τ ⁢ : ⁢ ⁢ Contribution ⁢ ⁢ ratio ⁢ ⁢ in ⁢ ⁢ region ⁢ ⁢ k ⁢ ⁢ of ⁢ ⁢ the ⁢ ⁢ overall ⁢ ⁢ image ⁢ ⁢ feature ( 8 ⁢ - ⁢ 4 ) Expression (8), if represented in diagram, is illustrated in FIGS. 3A and 3B . FIG. 3A illustrates a relationship of a k-th Gaussian distribution of label c, overall image feature distribution, and mean value μ k c determined by the model learning unit 105 . For simplicity of explanation, the feature vector is one-dimensional, and each small blank circle represents a data sample. The data density estimating unit 105 a estimates a data density N k c in accordance with expression (8-2). Here τ is a predetermined constant, and as the data density N k c is smaller, the model learning unit 105 results in, as a calculation result of the mean value μ k c (second variable), closer to mean value μ k u of the overall image feature distribution. As the data density N k c is larger, the model learning unit 105 results in, as a calculation result of the mean value μ k c (second variable), closer to sample mean x k c (first variable) of a region k of label c. Similarly, ⁢ Σ k c = ρ ⁢ ⁢ x _ k c ⁢ ⁢ 2 + ( 1 - ρ ) ⁢ { Σ k u + μ k u ⁡ ( μ k u ⁢ ) T } - μ k c ⁡ ( μ k c ) T ⁢ ⁢ x _ k c ⁢ ⁢ 2 ≡ ∑ i = 1 N c ⁢ r ik c ⁢ x i ⁢ x i T ∑ i = 1 N c ⁢ r ik c ⁢ : ⁢ ⁢ Root ⁢ ⁢ mean ⁢ ⁢ square ⁢ ⁢ of ⁢ ⁢ the ⁢ ⁢ samples ⁢ ⁢ in ⁢ ⁢ region ⁢ ⁢ k ⁢ ⁢ of ⁢ ⁢ label ⁢ ⁢ c ( 9 ) where π k c defines a data density of the region k of the label c as follows: π k c ∝Σ i=1 N c r ik c +τ  (10) If expression (10) is normalized using expression (2), expression (4) results. In the model learning unit 105 , the data density estimating unit 105 a estimates the data density of the data region, and the parameter optimization unit 105 b determines in response to the data density a contribution ratio that reflects the parameter of the overall image feature distribution. If τ is given, each label c is learned using the EM algorithm. The learning algorithm using the EM algorithm is described in detail below. FIG. 5 is a flowchart illustrating the learning algorithm. FIG. 3B diagrammatically illustrates distributions of feature vectors and ranges of data regions. For simplicity of explanation, the feature vector is two-dimensional, and each small blank circle represents a data sample. The parameter optimization unit 105 b in the model learning unit 105 initializes the parameters {π k c , μ k c , Σ k c } (S 11 ). The parameter optimization unit 105 b determines the initial value of the parameter of the overall image feature distribution using the universal model. In the results of step S 11 , the data sample belongs to any of the data region of the Gaussian distribution. The model learning unit 105 calculates the shared ratio r jk of the data sample belonging to each Gaussian distribution in E step in accordance with expression (7). The model learning unit 105 then updates the parameters {π k c , μ k c , Σ k c } in M step in accordance with expressions (4) through (6) (S 13 ). In the results of step S 13 , the data sample belongs to any of the data regions of the Gaussian distributions governed by the update parameters. The model learning unit 105 determines whether a convergence condition is satisfied or not (S 14 ). If a change in logarithmic likelihood is equal to or lower than a predetermined value (yes from S 14 ), the model learning unit 105 completes the calculation step thereof. If the change in the logarithmic likelihood is higher than the predetermined value (no from S 14 ), the model learning unit 105 returns to step S 12 . The model learning unit 105 stores learned parameters {π k c , μ k c , Σ k c } of the model of each label on the storage 11 as the learning information 113 . FIG. 6 is a flowchart illustrating the annotation estimation operation. The image retrieving unit 100 retrieves via the communication unit 12 image information input from the outside as a label estimation target (S 21 ). The image partitioning unit 101 partitions the image into n segments, thereby generating the partial segments (S 22 ). The feature vector generator unit 102 extracts multiple feature quantities from each of the partial segments, and generates respectively for the partial segments the feature vectors x 1 , x 2 , . . . , x n having these feature quantities as the components thereof (S 23 ). The likelihood calculating unit 106 reads from the learning information 113 the model of each label learned in step S 6 (S 24 ). More specifically, the likelihood calculating unit 106 reads from the storage 11 the parameters {π k c , μ k c , Σ k c } of the model and then expands the parameters {π k c , μ k c , Σ k c } onto a memory (not illustrated). The likelihood calculating unit 106 calculates the posterior probability of the feature vector of each partial segment (S 25 ). When the set X={x 1 , . . . , x n } of the feature vectors extracted from an input image I to be predicted is provided, the likelihood calculating unit 106 calculates the posterior probability p(c|X) of the label c using Baye's theorem as follows: p ⁡ ( c | X ) = p ⁡ ( c | x 1 ⁢ ⁢ … ⁢ ⁢ x n ) = p ⁡ ( c ) p ⁡ ( x 1 ⁢ ⁢ … ⁢ ⁢ x n ) ⁢ ∏ i = 1 n ⁢ p ⁡ ( x i | c ) ( 11 ) where p(c) is the posterior probability of the label c, and relative frequency in the learning data set is used for p(c). p(x 1 . . . x n ) is the posterior distribution of the feature vector set, and takes a constant value with respect to label. The logarithmic likelihood of the label c of the image I is expressed with the constant portion thereof removed as follows: log ⁢ ⁢ p ⁡ ( c ) + ∑ i = 1 n ⁢ log ⁢ ⁢ p ⁡ ( x i | c ) ( 12 ) The larger the magnitude of expression (12) is, the better the label is for the image I. Several results of expression (12) in the order of the large to the small magnitude are used as labels for the image I (annotation words). The likelihood calculating unit 106 calculates the likelihood of the feature vector x i of a partial image of a given label c (S 26 ). When the likelihood is calculated, the annotation word estimating unit 107 retrieves five labels, for example, in the order of the large to the small magnitude, and attaches annotation words to the labels as the identification information of the image information (S 27 ). The output unit 108 outputs annotation word estimation results to a predetermined output device (not illustrated) such as a display, a printer, or a hard disk (S 28 ). The present invention is not limited to the above-described exemplary embodiment, and may be changed into a variety of modifications within the scope of the present invention. The image recognition information attaching program 110 used in the exemplary embodiment may be read onto the storage 11 within the image recognition information attaching apparatus 1 from a recording medium such as compact disk read-only memory (CD-ROM), or may be downloaded onto the storage 11 within the image recognition information attaching apparatus 1 from a server or the like connected to a network such as the Internet. The storage 11 may be arranged external to the image recognition information attaching apparatus 1 . The external storage 11 and the image recognition information attaching apparatus 1 may be connected to via the network. Part or whole of the image retrieving unit 100 through the output unit 108 may be implemented using a hardware structure such as an application specific integrated circuit (ASIC). The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.

An image recognition information attaching apparatus includes a retrieving unit that retrieves image information on a per piece basis of identification information, from the image information having the identification information associated thereto in advance, a generator unit that generates feature information from the image information retrieved by the retrieving unit, and a learning unit that provides a learning result by learning a relation between the feature information generated by the generator unit and the identification information of the image information corresponding to the feature information, using a stochastic model including a mixture of a plurality of probability distributions.