OPTICAL RANDOM ACCESS MEMORY

Abstract: An optical memory (10) is disclosed in which data is stored in an optical data layer (19) capable of selectively altering light such as by changeable transmissivity, reflectivity, polarization, and/or phase. The data is illuminated by controllable light sources (15) and an array of multi-surface imaging lenslets (21) project the image onto a common array of light sensors (27). Data is organized into a plurality of regions or patches (called pages) and by selective illumination of each data page, one of the lenslets (21) images the selected data page onto the light sensors (27). Light in the data image pattern strikes different ones of the arrayed light sensors (27), thereby outputting a pattern of binary bits in the form of electrical data signals. By selectively and sequentially illuminating different ones of the data regions (pages) on the data layer (19), correspondingly different data patterns are imaged by the corresponding lenslets (21) onto the common sensor array (27), thereby enabling many stored data pages to be retrieved by multiplexing at electro-optical speed.

Description: OPTICAL RANDOM ACCESS MEMORY BACKGROUND OF THE INVENTION The invention concerns method and apparatus of opticall storing and retrieving mass digital data stored as light altering characteristics on an optical material and providin fast random access retrieval. Optical memories of the type having large amounts of digital data stored by light modifying characteristics of a film or thin layer of material and accessed by optical addressing without mechanical movement have been proposed bu have not resulted in wide spread commercial application. Th interest in such optical recording and retrieval technology due to its projected capability of faster retrieval of large amounts of data compared to that of existing electro-optical mechanisms such as optical discs, and magnetic storage such tape and magnetic disc, all of which require relative motion of the storage medium. For example, in the case of optical disc memories, it i necessary to spin the record and move a read head radially t retrieve the data, which is output in serial fashion. The serial accessing of data generally requires transfer to a buffer or solid state random access memory of a data process in order to accommodate high speed data addressing and other data operations of modern computers. Solid state ROM and RA can provide the relatively high access speeds that are sough but the cost, size, and heat dissipation of such devices whe expanded to relatively large data capacities limit their applications. Examples of efforts to provide the relatively large capacity storage and fast access of an optical memory of the type that is the subject of this invention are disclosed in the patent literature such as U.S. Patent 3,806,643.for PHOTOGRAPHIC RECORDS OF DIGITAL INFORMATION AND PLAYBACK SYSTEMS INCLUDING OPTICAL SCANNERS and U.S. Patent 3,885,094 for OPTICAL SCANNER, both by James T. Russell? ϋ. S. Patent 3,898,005 for a HIGH DENSITY OPTICAL MEMORY MEANS EMPLOYING A MULTIPLE LENS ARRAY; U. S. Patent No. 3,996,570 for OPTICAL MASS MEMORY; U. S. Patent No. 3,656,120 for READ-ONLY MEMORY; U. S. Patent No. 3,676,864 for OPTICAL MEMORY APPARATUS; U. S Patent No. 3,899,778 for MEANS EMPLOYING A MULTIPLE LENS ARRA FOR READING FROM A HIGH DENSITY OPTICAL STORAGE; U. S. Patent No. 3,765,749 for OPTICAL MEMORY STORAGE AND RETRIEVAL SYSTEM and U. S. Patent No. 4,663,738 for HIGH DENSITY BLOCK ORIENTE SOLID STATE OPTICAL MEMORIES. While some of these systems attempt to meet the above mentioned objectives of the present invention, they fall short in one or more respects. For example, some of the systems proposed above have len or other optical structure not capable of providing the requisite resolution to retrieve useful data density. The optical resolution of the data image by these prior lens systems does not result in sufficient data density and data rate to compete with other forms of memory. Although certain lens systems used in other fields such as microscope objectives are theoretically capable of the needed resolutions, such lens combinations are totally unsuited for reading data stored in closely spaced data fields. Another difficulty encountered with existing designs is the practical effect of temperature and other physical disturbances of the mechanical relationship between the data film or layer, the lens assemblies and the optical sensors that convert the optical data to electrical signals. For example, the thermal expansion effects of even moderate density optical memories o this type can cause severe misregistration between the optica data image and the read out sensors. Similar difficulties ar encountered in the required registration between the recordin process and the subsequent reading operations. Intervening misregistration of the high density optical components can cause significant data errors if not total loss of data. Accordingly, it is an object of this invention to provid an optical mass memory having random accessibility in a relatively compact size comparable to or even smaller than tape and compact disc storage mechanisms and yet still servin data processing equipment in the same manner that solid state random access memories move data into and from the processor' data bus. SUMMARY OF THE INVENTION Data is stored in an optical data layer capable of selectively altering light such as by changeable transmissivity, reflectivity, polarization, and/or phase. In the case of a transmissive data layer, data bits are stored transparent spots on a thin layer of material and are illuminated by controllable light sources. An array of imaging lenslets project an optically enlarged image of the illuminated data onto an array of light sensors. The layer data is organized into a plurality of regions or patches (called pages) and by selective illumination of each data pa one of the lenslets images the data page onto the array of light sensors. Transmitted page data, in this case light passed through the transparent bit locations on the data layer, strike different ones of the arrayed light sensors, thereby outputting a pattern of binary bits in the form of electrical data signals. By selectively and sequentially illuminating different ones of the data regions (pages) on th data layer, correspondingly different data patterns are image by the corresponding lenslets onto the same photosensor array thereby enabling many data pages to be multiplexed at electro optical speed onto the common photosensor array image plane. The data storage and retrieval system of the present invention is embodied in read-only devices, write-only devices, and in read/write configurations as described more fully below in the detailed description. A preferred form of the invention is to fabricate the data layer and lenslet arra as a bonded structural unit or card, much like a sandwich of different layers of material, to thereby fix the optical distances and registration of these elements. This bonded data/lens card structure minimizes the adverse optical effect of differential thermal expansion between the data layer and the lenslets and allows for an exceedingly dense data pattern A further aspect of this sandwiched data and lenslet card structure is to immerse the data layer in the space adjacent the lenslets in a transparent material of select index of refraction relative to air and to the lenslet so as to contro the angle of divergence of data image rays emanating from the data layer and still provide refractive power at the first surface of the lenslet. This immersion material is preferabl also a structural bonding layer made of a transparent polymer described more fully below. The resulting structure, which can be fabricated at a relatively low per unit cost, provides an effective way of achieving the imaging power needed to faithfully form the data image onto the common photosensor array, notwithstanding the very dense, compact arrangement of the data. Still another aspect of this preferred form of the lenslet array is that the first surface of each lenslet, i.e. adjacent the data layer, is aspherically contoured to enhance the optical resolution of the exceedingly small and dense patch of data that is to be imaged. The data layer and lenslet array together with the transparent immersion/bonding layer can be fabricated at a cost that allows the structure t be made and effectively and efficiently used as a replaceable data card. Further still, the preferred form of the write only and read/write embodiments of the invention uses the bonded data lenslet structure as a blank data card in the write systems for recording data through the fixed lenslet array. The recording data pattern is thus projected and condensed by eac lenslet onto the selected data layer page of the record medium. An additional aspect of the preferred form of the invention is the placement of a diffractive corrector adjacen the refractive lenslet surfaces opposite the data layer to correct for optical aberrations introduced by the lenslet optics in the environment of overlapping data image rays from adjacent pages due to the close compact spacing of the data and lenslets. This diffractive corrector, which may take the form of a diffractive grating or a holographic optical element, is formed with optical modifying grating or holographic ringlets, each substantially centered on the optical axis of corresponding lenslets and having overlapping portions at increasing ringlet radius. As a result, the optical ray bundle leaving each lenslet is diffracted in a manner that minimizes effects of various forms of optical aberrations. The data image reaching the photosensor plane is therefore sharp, with minimum distortion in spite of the closely packed multiple lenslet configuration. In a preferred form of the invention, the diffractive corrector is followed by a field lens that has a single common aperture encompassing the entire lenslet array and serves to bend the various rays of light associated with the images of different data pages onto the common image read out plane of the photosensor array. Still another preferred aspect of the data layer, lens array and cooperating photosensor array is to arrange the da pages in a close-packed geometry as contiguous cells, preferably hexagonal in shape. Within each cell the data bi are arrayed in a suitable pattern such as orthogonal rows an columns. The refractive elements of the lenslets are also preferably cellular in shape to conform to the data pages. Complementing the hexagonal cell shape of the individually selectable data pages is the arrangement of the sensor sites on imaged data plane in a correspondingly shaped but substantially larger hexagonal field. The projected image o data bits fills up the hexagonal sensing plane field and mak more efficient use of the lenslet and diffractive corrector optics given the close spacing of these individual elements. In association with this preferred cellular configurati of the data regions or pages and sensor array, the individually energizable light sources, which may be diode emitters, either laser or LED, or may be other solid state o controllable devices, are likewise preferably formed in a hexagonal cell pattern. Each light source is of substantial the same shape and configuration as its associated hexagon data region or page. A preferred form of the array of light sources is to pack into each hexagonal shaped light source cell a plurality of concurrently energized solid state emitters, thereby producing the illumination energy and area coverage best suited for imaging the data layer onto the distant photosensor array. A preferred configuration and several alternative write/read configurations of the invention are disclosed. the preferred form, the read-only assembly is modified to ad a write subassembly by using a diagonal beam splitter in the optical read path to accommodate an assembly of data page recording or composing light sources and light valves, and imaging optics located to the side of the read optics path f injecting a record data image into an entrance pupil of a lenslet (opposite the data layer) . During recording, a blan data/lenslet card is installed in the assembly. An array of write or recording light sources are disposed at a predetermined distance from a write imaging lens which in turn causes a full page of a data light pattern to be projected through a wall of controllable light valves which are set open or closed to compose a data pattern. The resulting illuminated data page composed by the light valves is then transmitted toward and reflected by the diagonal beam splitter in the path of the read optics so that the projected write image is now in the optical path that includes the fiel lens, diffractive corrector, and lenslet array as described above and is condensed and recorded on the blank data layer. Data storage may be by thermal, photochemical or energy storage techniques. For example, known metallic films such a Tellurium, or photochemical films such as silver halide, diazo, or other optical data storage processes such as dye- polymer or magneto-optical are employed for this recording operation. The primary advantage of recording through the data/lenslet card is the substantial elimination of geometric distortion due to intrinsic characteristics of the lens system. Also, since the recording process is substantially the reverse of optical read imaging, optimum position registration, thermal stability and reliability are achieved. Alternative forms of the write/read embodiment are disclosed and include a variation on the forgoing preferred embodiment in which the light valves in the subassembly of th recording optics are replaced by reflective light modulators. Another alternative embodiment of the write/read system is to again place the recording optics and page composer in a side wall or side subassembly of the housing, but using in this case a set of recording light sources that are arrayed i the configuration of a data page. The light sources are energized according to the desired data pattern for each page that is to be recorded. An electromechanical mover or servo mechanism is used to align an array of microlenses, functioning collectively as a field lens, to controllably direct the light ray bundles of the composed data page light sources for maximizing recording light energy through the bea splitter and field lens into a specific one of the lenslets which in turn condense and image the composed data page onto the data layer for recording. A plurality of light shutters, such as an LCD array, are preferably interposed in front of the lenslet array in this embodiment in order to open the optical path for only a single lenslet at a time and to block stray light rays from entering adjacent lenslets. In the read-only and write/read assemblies, the sensor array is preferably provided by a layer of charge coupled devices (CCD) arrayed in the pattern of the projected data page and causing the data light images to generate charge coupled data that is then outputted into data bucket registe underlying the photosensitive elements of the charge coupled devices. Alternatively, other output sensor arrays may be employed, including an array of photosensitive diodes, such a PIN type diodes. Another preferred aspect of the disclosed embodiments of the invention is to provide means for adapting (changing) the light threshold that triggers each photosensor site to switch binary state, e.g., from a "0" to a "1" output bit signal. A preferred form of such adapted threshold is a network of cross-coupled biasing resistors for variably biasing each sensor switching threshold as a function of light sensed at neighboring sensor sites. The biasing resistors are weighted depending on the proximity to the subject sensor site. An alternative form of the invention, preferred for certain applications, combines photosensors and emitters interspersed on the same plane that receives the read image. The sensors read the data image as above. The emitters on th sensor plane are used in a write mode to compose a data page that is to be recorded and the composed page is then imaged back through the optics (reverse from read) to write the data onto selected pages of the data layer using light blocking shutters in the path to screen off the non-selected pages. It is therefore seen that the present invention provides an enormous data storage capability having random access speeds that approach, if not exceed, the fastest solid state RAMs and ROMs. Moreover, the organization of the data output capability of the present invention enables unusually large data words to be accessed virtually at the same instant, such as at a single clock time. Since the entire data page, when imaged on the photosensor array, conditions the array to output all of the data from that page at any given instance, the size of the output word is limited only by the number of bits in the sensor array and the addressing electronics cooperating with the sensor array. Since the array itself ca be interrogated along rows and columns of data, each of which may be on the order of 1,000 bits per row or column, this allows the system of the present invention to output a data word on the order of 1,000 bits, or selected and variable portions thereof as needed. Such relatively large output words provide important applications of the present invention to such systems as computer graphics, "correlation engines" o computer based industrial systems, and other computerized or digital based systems. These and other features, objects, and advantages of the invention will become apparent to those skilled in the art from the following detailed description and appended drawings BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is an isometric view, partly cutaway, of a write/read embodiment of the invention showing a housing for the various electrical and optical components of the optical random access memory of the present invention. FIGURE 2 is a full section view in elevation of the optical memory of Figure 1. FIGURE 3a is a section view in elevation of an embodimen of a read-only optical memory in accordance with the present invention. FIGURE 3b is an isometric view of a preferred assembly o multiple optical memory modules mounted on and electronically connected via a plug-in printed circuit interface and module support board. FIGURE 4 is a plan view showing schematically the layout of individually switchable light sources for illuminating dat regions or pages during readout and showing the arrangement o such light sources as contiguous hexagonal cells. FIGURE 5 is a plan view similar to Figure 4 showing the layout of the data layer and a blow-up of one of the hexagona data pages of the layer depicting the orthogonal array of row and columns of data bits within a single data page. FIGURE 6 is a plan view similar to Figures 4 and 5 showing the array of lenslets in a hexagonal cell pattern tha cooperates in a one-to-one lenslet to page registration with the hexagonal data layer pattern shown in Figure 5. FIGURE 7 is a plan view of the diffractive corrector tha is disposed adjacent the lenslet array on the side opposite the data layer for optically modifying and correcting the image rays projected by the individual lenslets as described more fully in the detailed description. FIGURE 8 is a plan view of the rectangular field lens that encompasses the entire field of data page image rays available from the lenslets of Figure 4 and directs such imag rays to a common sensor plane. FIGURE 9 is a plan view showing the layout of the photo¬ sensors at the image sensing plane but depicted schematically at a greatly reduced density for illustration purposes. FIGURE 10a is a section of the bonded structure of the data layer and lenslet array usable as a replaceable data storage card or unit. FIGURE 10b is an enlarged fragment view of the lenslet and data layer of Figure 10a. FIGURE 10c is another section similar to Figure 10a showing the arrangement of the data layer and lenslet structure mounted in registration and in face-to-face proximity with the multiple read light sources, in this instance LED sets, serving as the read illumination for the embodiments of Figures 1-3. FIGURE 11 is a schematic diagram of the optical characteristics of certain components of the embodiments of Figures 1-3 showing light rays emerging from the plane of the data layer and passing through an immersion polymer layer. then through a registering lenslet and hence through a two surface diffractive corrector. FIGURE 12 is a diagramatic view similar to Figure 11 bu showing the overlapping of the various data bit rays from a pair of adjacent data pages of the data layer and the associated lenslets, followed by the optical treatment of th diffractive corrector. FIGURE 13 is an enlarged schematic view of the arrangement and interaction of certain principal components o the invention including the data/lens bonded structure, the diffractive corrector, a field lens and the photosensor array and showing the optical paths of data bit light rays from the data layer enlarged and imaged on the sensor array through th various optical components. FIGURES 14a and 14b are block diagrams, respectively, of the data write addressing and control, and data read addressing and control electronics associated with the memories of Figures 1, 2 and 3. FIGURE 15a, 15b and 15c are various structural and circuit schematic diagrams of the preferred embodiment of the sensor array and associated electronics. FIGURES 16a, 16b and 16c show various structural components of data write subsystems of the write/read memory of Figures 1 and 2. FIGURE 17 is an alternative embodiment of a write/read system in a section view similar to Figure 2, using many of the same elements as the above briefly described embodiments but having reflective light modulators to compose the data page during a write (recording) mode. FIGURE 18 is another alternative embodiment of a write/read system in a section view similar to Figures 2 and 17, in which the data page is recorded by composing it on an array of selectively energized data record lights and then imaging that composed page onto the data layer through an array of micro lenses and individually selectable LCD light shutters and employing a set of electromechanical movers to variably position the micro lens array for optimum recording light imaging. FIGURE 19 is a plan view of the micro lenses and associated electromechanical movers used in the write mode of the embodiment of Figure 18. FIGURE 20 is another plan view similar to Figure 19 showing the pattern of composed data during write operation o the system of Figure 18, depicted at greatly reduced density. FIGURE 21 shows an alternative embodiment for reading data similar to Figure 13 but differing in that the refractiv field lens has been omitted and its function of bending image rays is replaced by a modified diffractive element that both corrects and functions as a field lens. FIGURE 22 shows a further alternative embodiment using the field lens but without the diffractive corrector. FIGURE 23 is a section view of an alternative write/read embodiment having a composite of interspersed photosensors an photo emitters on a common substrate at the read image plane for composing recording data pages at the same plane as the read image data is sensed. FIGURES 24a and 24b are fragmentary plan views of the circuit layout of the combined photosensor and emitter array of the alternative embodiment of Figure 23, in which Figure 24b is an enlarged plan view of one composite sensor-emitter site of the many sites shown in Figure 24a and illustrating the adapted threshold network and interconnect leads integrated into a common large scale integrated (LSI) circuit. FIGURE 24c is a circuit schematic of the adaptive threshold sensor network integrated into each sensor site on the LSI circuit of the embodiment of Figures 23, 24a and 24b. FIGURE 25 is a schematic diagram similar to Figure 11, of an alternative optical system for use in the embodiments of Figures 1-3 in which the composite refractive-diffractive surfaces of the lens system are replaced by a system of first and second diffractive surfaces interposed by a color correction anomalous lens. FIGURE 26 is an enlarged schematic diagram of the lens system of Figure 25 showing the anomalous color correction lens in its preferred configuration as a Fresnel element. FIGURE 27 is an overall schematic view of the optical system of the alternative embodiment shown in Figures 25 and 26 showing the data layer, first diffractive surface, anomalous lens element, second diffractive surface, and the field lens for imaging the data on the distal sensor plane. FIGURE 28 is a view similar Figure 27 showing an alternative embodiment of the optical system in which the second diffractive surface of the lens system is placed on th first refractive surface of the field lens. FIGURE 29 is a view similar to Figures 27 and 28 showing still a further alternative embodiment of the optical system using all diffractive surfaces including a diffractive field lens and incorporating the color correcting anomalous lens element between the first and second diffractive surfaces tha form the lens system objective. FIGURE 30 is a view similar to Figure 26 above showing a all diffractive lens system including the color correcting anomalous element and further incorporating a shutter LCD layer for shuttering light rays to and from each data page fo recording and reading functions. FIGURE 31 is an overall schematic view on a reduced scal of the all diffractive shuttered lens system of Figure 30 and showing in this view the imaging of data bits on the distal sensor plane. FIGURE 32 is a graph of the index of refraction relative to wave length of a suitable dye used to form the anomalous lens in the embodiments of Figures 25-31. FIGURE 33 sets for the optical equations used in computing the lens prescription for the color correcting anomalous lens. FIGURE 34 is a diagrammatic view similar to Figure 12 of the above embodiment, but having an alternative configuration of a combined refractive and diffractive lens system in whic the first objective surface is a combination curved refracti element having a diffractive surface molded thereon followed by a color correcting anomalous lens region and then a secon diffractive surface. FIGURE 35 is an enlarged schematic view of an arrangeme of lens elements similar in view to Figure 13 above, depictin an alternative objective lens system for imaging data through a succession of diffractive surfaces and interposed variable index gradient lens elements of the longitudinal gradient type. FIGURE 36 is an enlarged schematic view of an arrangemen of lens elements similar to the embodiment of Figure 35 above depicting a further alternative objective lens system for imaging data through a succession of diffractive surfaces and interposed variable index gradient lens elements of the radia variant type. FIGURE 37 is an isometric view of an optical data card read and/or write device in a read only configuration. FIGURE 38 is an isometric view of the internal elements of the embodiment shown Figure 37. FIGURE 39 is a side elevation view of the elements shown in Figure 38. FIGURE 40 is an alternative embodiment of the device of Figure 37 in a read/write configuration. FIGURE 41 is a cutaway side view of a data card with a reflective layer utilized in the read/write configuration of Figure 40. FIGURE 42A is a cutaway isometric view similar to that Figure 38 but depicting multiple data chapters in which each chapter is illuminated by a full chapter light source. FIGURE 42b is an alternative the embodiment of Figure 4 shown in a read/write configuration. FIGURE 43 is a front elevation view of the embodiment o Figure 42A. FIGURE 44 is an isometric view of an embodiment featuri a carousel data card reader. FIGURE 45 is a partial cutaway side elevation view of t embodiment of Figure 44. FIGURE 46 is a plan view of a continuous motion data ta reader. FIGURE 47 is a front elevation view of the embodiment o Figure 46 taken along line A-A. FIGURE 48 is a plan view of an indexed data tape reader. FIGURE 49 is a plan view of one depicting fiducial mark associated with a page of optical data. FIGURE 50 is a cutaway side elevation view of an optica memory module for reading a single chapter of optical data. FIGURE 51 is a cutaway plan view of the module of Figur 50. FIGURES 52A through 52E are various views of registrati adjusters utilizing wax or polymer filled sheaths. FIGURES 53A and 53B are views of a registration adjuste utilizing a solenoid. FIGURES 54A and 54B are cutaway side and plan views respectively of an optical memory module using springs to bi a single chapter of optical data against reference surfaces. FIGURE 55 is a plan view of a 3x3 array of optical data chapters. FIGURES 56 and 57 are alternative embodiments of the array of Figure 55. FIGURE 58 is a side elevation sectional view of an array of optical data chapters embodied in a game cartridge inserte into a game player unit. FIGURE 59 is a rear elevation sectional view of the game cartridge of Figure 58. FIGURE 60A is a vertical section view similar to Figure 18, showing an alternative write/read embodiment in which the electromechanically moved microfield lens array is replaced b a fixed microfield lens array and a dynamic ultrasonic lens module for directing light from each composed data page to select individual pages on the recording media for writing th data. FIGURES 60B, 60C and 60D show, respectively, a front elevation view of the ultrasonic lens module, a block diagram of the control electronics for the ultrasonic lens module, an wave form diagrams of the relative phase of ultrasonic waves launched into the lens module. FIGURES 61A and 6IB are, respectively, a diagrammatic view of an alternative embodiment for selecting data pages t be illuminated and imaged on the sensor array by selective coordinated operation of multiple page light sources and multiple page LCD shutter module shown in the enlarged, fragmentary isometric view of Figure 6IB. FIGURE 62 is an alternative embodiment combining elliptical LED light guides for illuminating multiple, but L shuttered pages in order to conserve on the number of multip LED sources while still obtaining the selectivity of one pag at a time for imaging on the sensor array. FIGURE 63 is an isometric view similar to Figure 62, showing an alternative form of the LED light guide and shuttered page assembly of the type shown in Figure 62. FIGURE 64 is still another isometric view similar to Figures 62 and 63 showing still a further alternative embodiment in which the light guides for each LED illuminate one half of a row of arrayed pages and an LCD shutter assemb responds to a command for opening two columns of pages, one column in registration with only one of the sets of LED ligh guides. FIGURES 65A and 65B show, respectively, a vertical cros section of an alternative embodiment and an enlarged fragmen thereof for submultiplexing each data page by using angled light sources and HOEs (holograpic angle filters) so that on a portion, in this instance one quadrant of a full data page is selectively imaged on the sensor array. FIGURES 65C and 65D diagrammatically illustrate how the angled light sources in conjunction with an HOE filter illuminate selected quadrants of the full data page onto the sensor array. FIGURES 66A, 66B and 66C show an alternative embodiment using color light sources and corresponding color filtering t achieve a functionally similar result to the embodiment of Figures 65B r 65C and 65D above, respectively, FIGURES 67A and 67B are, respectively, an isometric cutaway and an isometric diagram of a holographic beam splitter used in a read only embodiment in which multiple dat chapters forming separate read modules are selectively arranged on the sides and top of the cubical assembly to imag data from selected pages, one page from any one of the given read modules onto a common read sensor array. FIGURE 68 is a block diagram of an alternative data output processing scheme for reading the binary data from the sensor array. FIGURES 69A, 69B, and 69C show an alternative embodiment in which the photo sensitive elements forming sensor array 27 are overlaid by alternating color and/or polarization filters in order to increase the separation of sensor bits for improved readout reliability. FIGURE 70 is an enlarged, cross-sectional fragment of th sensor array overlaid by an array of micro-focal plane lenses to refocus and hence concentrate data image rays onto the sensor elements. FIGURE 71 is a diagramatic view of the optical system embodying an alternative field flattener lens overlying the sensor array to enhance the consistency of the data bit spacing image on the sensor array. FIGURES 72A, 72B, 72C and 72D are, respectively, a sens integrated circuit (IC) layout, an enlarged layout for one sensor bit, a greatly enlarged IC layout of the single bit detection and logic, and a schematic diagram of the detector and logic for a single sensor cell. FIGURES 73A, 73B, and 73C are, respectively, a top plan view of a typical distribution of sensed data in which the information of bit A covers four sensor quadrants or element for reliability and is surrounded by background information illustrated as bits B, Figure 73B is a flow chart of the signal processing of data A (information) and surrounding da B (background) processed from the raw signal outputs develop at the sensor array; and Figure 73C is a top plan view of a data image with corner fiducials used in the signal processi of Figure 73B. DETAILED DESCRIPTION With reference to Figures 1 and 2, a preferred form of write/read configuration of the optical random access memory 10 in accordance with the invention is shown to include a housing 11 of a regular polygon shape, in this instance including top and bottom walls 11a and lib, respectively; opposing side walls lie and lid, and front and back walls li and llf, respectively. Although not critical to the invention, in this embodiment the housing 11 is substantiall bisected into left and right chambers each of a generally cubical configuration in which the right hand chamber as viewed in Figure 2 contains the electronics and optical components for reading data by projecting a data image onto a photosensor array disposed adjacent the bottom wall lib at th right hand side of the housing. The left hand chamber of housing 11 contains the electronics, light sources, and other optics that function to compose and record data images onto a blank data film or layer positioned in the right hand chamber as described more fully below. READ COMPONENTS To more easily understand the construction and operation of the combined write/read system shown in Figures 1 and 2, only those elements of the system used for reading data will be described first, then the write (or record) elements will be introduced and explained. Thus, with reference to the right hand side of the bisected housing 11, there is provided adjacent the upper housing wall 11a, an array of light source drivers 13 formed in an integrated circuit and coupled by micro leads (not shown) to an array of solid state photoem tter elements serving as the read light sources 15. Light sources 15 are mounted on a circuit board or other integrated structural unit to fix the sources in a closely packed dense light pattern that will be described more fully in connection with Figure 4. Immediately beneath and parall to light sources 15, a unitary data/lens card structure 17 i removably mounted for storing on a data layer 19 binary information bits organized in multiple data pages or regions A complementary lens array 21 is bonded to layer 19 and has plurality of lenslets disposed in precise, fixed optical registration with each multi-bit data region or page. Unita data/lens structure 17 is fabricated as a bonded unit so tha the array 21 of lenslets is fixed in spatial relation to the data layer 19 and so that the structure 17 is readily removable as a unit from housing 11 of the optical memory 10 To enhance the resolution of the light image rays emanating from data/lens structure 17, a diffractive correct 23 of generally planar shape is located adjacent second surfaces of lens array 21, i.e., opposite the data layer and first lens surfaces. Following diffractive corrector 23, th data images projected from data layer 19 and lens array 21 upon illumination by light sources 15 are further redirected by field lens 25 having an aperture that encompasses the entire depth and width of the right hand chamber of housing 11. Hence, field lens 25 in this embodiment is of generally rectangular shape about its perimeter as best shown in Figur 8 and otherwise has conventional spherical or piano optical surfaces as described more fully herein. The foregoing elements of the read function of optical memory 10 occupy generally the upper one third of the right hand chamber of housing 11. Beneath the field lens 25 there is an open cavity that allows for the optical convergence of the data image rays which in turn form the data image onto a upwardly facing common image plane of sensor array 27. The data image projected onto array 27 in this preferred embodiment is in the shape of a hexagon, as is shown in Figu 9, to conform to the image generating data pages on layer 19, and the light sources and optics; however, the sensor array itself may have a substantially rectangular or, in this case, square perimeter. Beneath sensor array 27 is located the sensor interface circuitry 29 which is preferably fabricated as an integrated or printed circuit wafer of similar thicknes and rectangular perimeter to complement and lie subadjacent sensor array 27 as shown. The free space that would exist between field lens 25 and sensor array 27 in which the image magnified by lenslet array 21 is occupied in this embodiment by a substantially cubical beam splitter 31 having a diagonal beam splitting plane 31a for cooperating with the writing (record) functions of this optical memory 10 in which a composed record page is generated in the left hand chamber of housing 11 and projected in reverse fashion as described more fully below. Thus, in operation, a single page of binary data selecte on data layer 19 by energizing a chosen cell of light sources 15, causes a data image to be generated that appears generall in the shape of the data image shown in Figure 9 (although it is depicted at a greatly reduced density for -illustration) . The image has roughly the shape of a hexagon and fills the image plane on the upper surface of sensor array 27. The individual data bits within a single data page are here arranged as shown in Figure 5 in closely spaced rows and columns and at densities that use to advantage high resoluti optical films and other record media including but not limit to photochemical films. To provide storage competitive with other types of memory, the data bits must be in a size range of 2.25 to 0.5 microns and a center-to-center spacing also i that range. Each data page is formed by the amount of individual data bits that can be collected and grouped into single hexagon cell as shown in Figure 5 and at the preferre density range of 2 x 10 7 - 4 x 10 8 bits per cm 2 , it has been found that about 10 6 (1 megabit) of data per page (or region) is an advantageous quantity that results in the generation o a data image after magnification that can be reliably sensed by photosensitive elements of sensor array 27. In this case, the preferred embodiment provides an optical magnification through the various lens assemblies of approximately 20 to 3 times. Thus, assuming a magnification of 25, the spacing of the projected image elements on sensor array 27 is on the order of 25 microns and a hexagon cell consisting of a page data will, in this embodiment, contain one million data bits per page that are imaged on a corresponding number of photosensitive elements in array 27. The particular structu and operation of the sensor array 27 and various alternative to the preferred embodiment are described in greater detail below. For the present, however, it will be appreciated tha each data bit which may be represented by spots of light fro the imaged page, causes a photosensitive element of sensor array 27 to either conduct or nonconduct depending on whethe the data is a "1" or a "0" bit. Although different forms of data layer 19 may be employed, in the present preferred embodiment that data layer 19 is a transmissive mask or film in which binary "1" bits are transmissive while binary "0" bits are opaque or light blocking. It will thus be seen that the read elements and operatio of optical memory 10 provide for accessing each of hundreds o pages of data having, for example, one million bits per page at 1 micron bit size. The read out of data from sensor array 27 is described in greater detail in connection with Figures 14b,and 15a, 15b and 15c; however, it is seen that by selecting a single data page on data layer 19 by energizing one cell of the LED or laser diode light sources 15 an entire page of 10 e bits is made available at the interface circuitry 29 associated with sensor array 27 at speeds typical of electro-optical switching, e.g., equal to or less than 50 nanoseconds. Data words that make up different portions of the entire page may be addressed, such as a column or row of data on each page, or the entire page may be output. Each ro or column of data within an accessed page may contain as many as one thousand data bits, hence making fast retrieval of exceedingly long bit words of this magnitude within the capability of the optical memory 10. In terms of dimensions, a one million (10 6 ) bit page imaged on sensor array 27 will occupy a hexagon that would fill an area of 6.5cm 2 or about 1 square inch. Similarly, at the above stated preferred densi range of 2 x 10 7 - 4 x 10 8 bits per cm 2 , an area of 6.5cm 2 (about 1 square inch) contains as many as 640 patches or pag of data, each patch or data page being almost instantaneousl selectable (< 50 nanoseconds) and retrievable by the high speed switching capabilities of electro-optical and electron addressing devices. In effect, the multiple pages of data bits are multiplexed onto the image plane at sensor array 27 by electronic switching of read light sources 15. The outpu data is available in the above-mentioned form for direct (without buffer storage) application to a processor data bus Further details of the construction and operation of th read function of optical memory 10 will be described in conjunction with a separate read-only system shown in Figure and the corresponding electronic and optical components depicted in Figures 4-15. It will be appreciated that these read function components, used separately in the read-only system of Figure 3, correspond to the read elements in the combined write/read optical memory 10 shown in Figures 1 and but for the intervening beam splitter 31. RECORDING COMPONENTS Now with further reference to Figures 1 and 2, the writ or recording function of optical memory 10 is provided primarily by the components located in the left hand chamber of housing 11. These include an array of page illuminating light sources 33, light source imaging lens 35, and an array of LCD light valves 37 located substantially at the bisector of housing 11 and hence to one side of the read-only optics o optical memory 10 described above. The module of recording light sources 33 is formed by an array of light emitters such as LEDs or laser diodes arrayed in a configuration that complements the arrangement of pages on data layer 19 which, in this embodiment, are in the hexagonal cellular pattern as shown in Figure 5. Each element of light sources 33 is hence positioned within the optical path of memory 10 so as to caus light to be imaged by lens 35 over the entire face of light valves 37 which compose a full page of data bits by open or closed condition, onto a single page of data layer 19. More particularly, the recording image is reflected at the beam splitting diagonal plane 31a of beam splitter 31 and is then condensed in reverse optical processing (compared to the read mode) by field lens 25, diffractive corrector 23, and one of the lenslets of lens array 21 that is associated with the selected data page on layer 19 to be recorded. The geometrical and optical positioning of the pattern of light sources 33, when individually energized, cause the data composed by valves 37 to be recorded onto the selected page of layer 19. It is noted that the relative dimensions of light sources 33 are somewhat smaller than might be expected by comparison with the pages on data layer 19 and the lenslets of array 21. The dimensions of sources 33 can be different from the array of pages on data layer 19 because the imaging process changes magnification through source imaging lens 35. In this preferred embodiment, the dimensions of light sources 33, bot as a collection of sources and as individual light elements, s 5 is one half of the size of the pages of the data array on layer 19. A magnification of two times is provided by source imaging lens 35 in order to expand the illuminating recording light rays which are then passed by light valves 37 into the right hand chamber of housing 11. The data image is then 10 deflected by beam splitter 31 up into the image condensing pupils of lens array 21 and onto the plane of data layer 19 for recording. Light valves 37 are preferably liquid crystal device (LCD) shutters interfaced to the data composing registers (see Figure 14a) which sets the shutters according 15 to whether the recorded bits are to be transmissive or opaque Alternatively, light valves 37 may be ferroelectric shutters or other devices that alter the light that then fixes the dat image on layer 19. Since light valves 37 collectively form a full page of data bits, there are in this embodiment 10 £ 20 million light valves fabricated on an integrated LCD shutter wafer that in turn is mounted as a prefabricated layer in the housing 11 as shown. In order to keep the same object-to- image size relationship for recording and reading, the e effective recording and reading path lengths should be the 25 same. In operation of the optical memory 10 of Figures 1 and 2 it will be appreciated that the system may be used for both writing (recording) and reading (data access) operations. Thus, the recording function of optical memory 10, including the imaging optics of lens 35, field lens 25, diffractive corrector 23, and multiple lens 21, causes the composed data image in light valves 37 to be reduced in size (on the same principle as a photographic enlarger except in reverse, i.e., making smaller) with the source imaging lens serving as a condenser. The data light rays to be recorded fill the entrance pupil of one of the lenslets of array 21 where the data pattern is further condensed and imaged onto the data layer forming layer 19 where the data is stored by optical recording processing techniques known per se, such a silver halide, diazo and/or others. The light valves 37 are selectively opened or closed to compose the data page, and serve as the counterpart of a negative in a photographic enlarger while the data layer 19 serves as the print paper. As an alternative to the configuration of optical memory 10 Figures 1 and 2, the data read function can be provided by a modification in which the data layer 19 of structure card 17 is made reflective rather than transmissive. A reflective record can then be used in conjunction with light sources 33 serving both as record lights as described above, and in a read mode as multiplexed read light sources in place of read light sources 15. In such case, during read, a selected one of light sources 33 is turned on, causing a source of illumination to be directed to and reflected off of a selecte page of reflective data on layer 19 and returned through the beam splitter plane 31a of beam splitter 31 to the sensor array 27 where the reflected image would be output by addressing array 27 using interface circuitry 29. READ-ONLY MEMORY Figure 3a shows a preferred form of a read-only optical memory 12 for use in retrieving data that has been stored on data layer 19 and more particularly on a data/lens array card 17 using a data writing technique described above in connection with optical memory 10 or prepared by other recording or reproduction processes including mass copying techniques such as contact printing. Thus, using read-only optical memory 12, a data/lens array card 17 is installed in an optical memory housing 14 similar to housing 11 of optical memory 10 but in this case being provided by a housing consisting of only the right hand chamber of the write/read housing. Using an arrangement of the read electronics and optical components that is substantially the same as in the read section of write/read optical memory 10, read-only optical memory 12 has light source drivers 13, light sources 15, data layer 19 and lens array 21 constituting card 17, diffractive corrector 23 and field lens 25 all arranged in relatively close-layered relation, if not in face-to-face contact, in the upper portion of the optical memory housing 1 near top wall 14a as shown. Similarly, adajcent the bottom 14b of housing 14, sensor array 27 is mounted along with the associated sensor interface circuitry 29. In this form of th invention, the read data image is retrieved from each page o data layer 19 by multiplexing the arrayed light sources 15, causing the images to be projected as described for the read operation, onto the image plane of sensor array 27. As individual sensor sites on array 27, organized in a data pattern such as shown in Figure 9, are either illuminat or dark, depending upon the data bit, the corresponding sens element is conditioned to output a "1" or "0" data bit when addressed. As also discussed, the output data available fro sensor array 27 through associated sensor interface circuitr 29 is at an unusually high data rate in which entire column and row words on the order of 1,000 bits each are retrievable in parallel at a single clock time. Alternatively, individua bits or partial words can be retrieved by high speed random access addressing of array 27 and circuitry 29 without the constraint of slow speed serial read out typical of other optical memories such as Compact Disc and magnetic memories including tape and magnetic disc. Light sources 15 for optical memories 10 and 12 are preferably arranged in a hexagonal cell 43 pattern as shown i Figure 4 and Figure 10c, each cell being composed of a set of multiple photoemitter diodes 41 in order to achieve the required intensity of the illuminating light per data page. Thus, during data read out, each cell of light sources 15 is turned on by multiplexing data retrieval circuitry shown in Figure 14b, firing all the emitter diodes 41 in a given cell for a read out time interval sufficient to condition the photosensor array. Preferably, diodes 41 are laser diodes which have a more intense emission; however, LED diodes may b used in many applications. The light emitting faces of diodes 41 and hence cells 43 are located on a light emitting interface plane 44 as shown i Figure 10c and it is at this interface plane 44 that the data/lens array card 17 is placed in close proximity to the light sources with the data layer 19 adjacent interface 44. In the preferred form of optical memories 10 and 12, card 17 is replaceable. By incorporating guides that accommodate sliding the card sideways into the housing 14 through an access door at the front wall (see Figure 3b) of housing 14, cards with different data are quickly exchanged. Light sourc drivers 13, light sources 15, diffractive corrector 23, field lens 25, sensor array 27, and its interface circuitry 29 are all securely mounted in housing 11 of optical memory 10 and housing 14 of optical memory 12 and are not usually replaceable. Figure 3b shows a plurality of read-only memory 12 modules each provided by one of the read-only optical memorie of Figure 3a. These are mounted on a plug-in memory board 40 having an edge connector 42 with multi-lead conductors to the memory module interface and driver circuits. Each memory module 12 has a front card receiving slot 46 opening to precision card positioning edge guides 48 (see Figure 3a) for receiving a replaceable data/lens card 17 as described above. Now the fabrication of data/lens card 17, and more particularly, the construction of the lenslets of array 21 will be described with reference to Figures lOa-e, 11, 12 an 13. In configuring the lenslets of array 21, the shape of t data pages shown in Figure 5 must be considered. Of course, there needs to be some empty space between data pages of the layer 19 in order to prevent interference (cross-talk) betwe data in adjacent pages. Because a lens is generally axially symmetric, its optimum imaging capability is in a circle, so square array of bits is not optimum. That is, for a given refractive lens complexity in terms of its contouring and the cost of fabricating such a lens, there is a maximum circular area that will be imaged to maximum resolution, and the cost/complexity of a lens will increase dramatically as the radius (field of view) increases, assuming other parameters are held constant. The most efficient use of each lens subsystem in array 2 is to make the data array, i.e., the pages of data layer 19, circular so that the diameter of each data field makes maximu use of the available lens imaging power. However, if the lenses and data patches are arranged in a regular array of columns and rows, there will be a significant fraction of are lost in the corners between the circular data regions. With this in mind, the present invention is preferably embodied by forming each of pages 47 of data layer 19 in a close-packed cellular pattern, here each cell being hexagonal as best shown in Figure 5. Each cell is filled substantially by the data bits at a uniform density as indicated by the enlarged fragmentary view of a single cell page 47' in Figur 5. Thus the cellular shape of the data pages 47 serves to accommodate maximum density of data and efficient use of the circular configuration of lenses. Since the data pages are hexagonal profile then the preferable configuration of the light source cells 43 of light sources 15 is also hexagonal complement the hexagonal shaped and arrayed data pages. Giv this preferred configuration of data pages 47, light illuminating sources cells 43, lenslets 51 of array 21, and the projected data image on the sensor array 27, a single da page contains one million bits each of approximately 1 micro size organized into 640 pages, each page being about 0.8 to 1.0mm in diameter, for a total storage capacity per data/len card 17 of 640 megabits and 80 megabytes (assuming 8 bit wor per byte) . LENS CONSTRUCTION Now in order to resolve data bits on layer 19 of requir size and density, namely, between 2.25 and 0.5 microns, preferably about 1 micron, and stored at 2 x 10 7 to 4 x 10 bits per cm 2 , the numerical aperture (NA) of each lens subsystem of array 21 must be relatively large, in the range of about 0.35 to 0.6, and preferably approaches .6 for 1 micron bit size. The focal length of the lenslet should be 1.0mm or less and the spacing of the first lense surface to the data layer also should be 1.0mm or less. Such NA values are normally found only in microscope objectives having a large number of elements. Read heads of Compact Disc system use high power lenses but they only need to resolve one bit a time, as compared to the megabit resolution of a field of data required by preferred embodiment of the present invention. The use of known Compact Disc objective lens designs will not provide adequate imaging resolution of the small, densely stored data bits on layer 19. Furthermore, i is not practical to adopt directly those multi-element objective lenses found in high resolution microscopes because of the cost, physical size and the lateral space requirements of such lens assemblies given the close-packed spacing of the data pages 47 on layer 19. Therefore, in designing each of the lenslets of the lens array 21 in accordance with the preferred embodiment, data/lens card 17 is composed of a continuous layer of lens glass having the contoured optical surfaces of the lenslets molded or otherwise formed thereon in a close-packed array 21 The first active lens surface 52 of each lenslet 51 of array 21 proximate to the data layer 19, i.e., within a distance that is the same order of magnitude as the diameter of the data field in a page 47. This is best illustrated in Figures 10b and 11 in which a single lenslet 51 shown as a subsystem of array 21 has its first active lens surface 52 (SI) within spacing s of 1/10 to 3/4 of the field diameter of the lenslet (and the associated data page), which is in the range of 0.8 mm to 1 mm. This close optical coupling of surface 52 of lenslet 51 to the plane of the data layer 19 enables each dat bit of the mask to form light image rays when illuminated by one of sources 15 that strike surface 52 of each lenslet at different locations on first surface 52. This is indicated b the optical ray patterns of Figure 11 and Figure 12 in which extreme data bits 53a and 53c are indicated (on opposite side of a center bit 53b) to form light rays intersecting surface 52 at different contours. Secondly, the diameter of the data page 47 and the field of view of the lenslet 51 are substantially equal, and the first surface 52 (S2) of lenslet 51 is made strongly aspheric. By contouring surface 52 aspherically, the surface provides a unique optical treatment of the ray bundles from diverse data points 53a, b and c. Th unique optical treatment is needed to accommodate the relatively large field angle due to the close spacing of the lens surface to the data layer 19 and the fact that the lens diameter is substantially that of the page 47 which is being resolved. Thirdly, the optical space between data layer 19 and surface 52 of lenslet 51 is filled with a lens immersion material or spacing layer 55 such as a transparent polymer (i.e., plastic) having an index of refraction that is greater than air to provide the needed angle of data bit light rays t resolve each bit and is different from the index of the lenslet material which is preferably glass in order to define the first lens surface 52. For example, a glass having an index of 1.75 will work with a polymer having an index such a 1.5, which is typical of plastics. Furthermore, a plastic spacing layer 55 not only immerses the data field on layer 19 in a material having the desired index of refraction, but als serves to bond and hence fix the relative optical spacing of the lenslet relative to data layer 19. Plastic spacing layer 55 thus has a thickness s less than the diameter of the lens and data fields. Fabrication of spacing layer 55 may, for example, be spin coated. The lenslets 51 of array 21 are preferably formed of a continuous sheet of relatively high index glass having on one surface the circular aspherical contours that form the first lens surface 52. The second surface of the lens glass layer is formed with the plurality of second lens surfaces 54 (S2) of lenslets 51 which are here of substantially spherical convex shape in axial optical alignment with the aspherical first surfaces 52 (S2). The thickness of each lenslet 51 along the optical axis, and hence the approximate thickness of the glass layer, is on the order of the same dimension as the field diameter of a data page, namely 0.8mm to 1 mm. Fourthly, the center-to-center spacing of the lenslets is the same as the center-to-center spacing of the data pages 47 which, because of geometrical constraints, means that the second optical surface 54 (S2) of each lenslet 51 is the effective aperture stop. Coaction of first and second lens surfaces 52 and 54 provides the primary imaging and aberration correcting optical power of the device. As mentioned, spacing layer 55 bonds and fixes the optical space between the data layer and the lens array laye Therefore, differential thermal expansion and other causes misregistration and misalignment of the optics are minimized at the location of maximum optical sensitivity. This resulting sandwich structure that serves as data/lens card 17 is now usable as a unit in either optical memory 10 for writing and reading, or after being recorded once in memory as a read-only card in optical memory 12. The resulting dat image may be projected directly onto a photosensor array 27 from the second surface 54 of lenslet 51 as shown in Figure 11, but in accordance with the preferred form of the invention, the optical images from the second surface 54 of lenslet 51 are further refined through a diffractive correct 23 having third (S3) and fourth (S4) optical surfaces 62 and 64. This additional optical corrector used in optical memor 10 and optical memory 12 and best shown in Figures 11 and 12, serves to correct for residual aberrations in the images projected from the data page in an optical system in which t light rays emanating from adjacent lenslets 51 of array 21 overlap. By using a diffractive corrector 23 that has overlapping diffractive ringlets, this embodiment of the invention provides additional corrective surfaces for treati overlapping light rays emanating from adjacent data pages. Beyond the effective aperture stop of the image rays from refractive lenslet surface 54, adjacent data pages enter the same expansion space and the overlapping diffractive optics corrector 23 provide a way of optically changing and hence correcting aberrations of these comingled image rays while retaining the integrity of each page image. Therefore, diffractive corrector 23, which may be a diffractive grating of generally round overlapping ringlets gratings 59 shown in enlarged form 59' in Figure 7, provides third and fourth surfaces 62 (S3) and 64 (S4) to correct the optical data image rays emanating from second refractive surface 54 (S2) of the lenslet as best shown in Figures 11 an 12. More particularly, with reference to Figure 12, it is seen that adjacent data pages N and N+l of data layer 19 caus image light rays (one in solid lines and the other in dotted lines) to overlap after the second surfaces 54 (S2) of the adjacent lenslets 51 of array 21. As an alternative to the diffractive gratings 62 (S3) and 64 (S4) , a holographic plate may be used in place of the grating plate to function as diffractive corrector 23. The holographic plate would be formed in a manner analogous to the ringlet patterns 59 of th grating shown in Figure 7, by light interference images on a photographic plate using processes known per se. The imaging of the data is enhanced by placing each separate data patch (page) on a slightly concave curvature facing the lenslet, as best seen in Figure 10b, adjacent the first surface (SI) of the lens subsystem in order to reduce field curvature of the image plane. An example of this contouring is given in the following tables as a non-flat surface at SRF=0, being the object surface at the data layer 19. In such case, the data page contouring is formed by a press molding of the bonding layer 55 with a convex or dimple region at each page position prior to forming the data layer emulsion or film. Alternatively, a flat data page may be used with optics reconfigured to adjust for the flat field of the data. LENS PRESCRIPTION The lens system comprising a refractive lenslet 51 having a strong aspheric first surface 52 (SI), a second substantially but not exactly spherical second surface 54 (S2), and followed by spaced diffractive third surface 62 (S3) and a diffractive fourth surface 64 (S4) constitute a preferred objective lens subsystem. A minimum of four surfaces are thus provided in this embodiment with correction for optical aberrations, such as spherical, coma, distortion, astigmatism and field curvature. Such a lens structure is capable of imaging at sufficiently high resolution the 2.25 micron or smaller data bits. In fabricating the elements of this lens subsystem, several examples are given of the optical specifications of each of the four objective or primary surfaces SI, S2, S3, and S4, as well as the additional surfaces S5 and S6 of the spherical field lens and the contour of the data layer at SRF=0. The first example is for a lens system of the preferred embodiment, including a field lens 25 as shown in the following Table 1 in which the first set of data is for the spherical contours and the second set of data is the aspheric numbers. TABLE 1 X 10 - 15 20 25 30 35 40 45 50 55 As an alternative, Table 2 contains the spherical and aspheric data for an embodiment that incorporates the field lens function in the diffractive elements as shown 60 in Figure 21. TABLE 2 LENS SYSTEM HITBOUT FIELD LENS LENS DATA, OFF AXIS CASE: 65 SRF RADIUS THICKNESS APERTURE RADIUS GLASS 0 1.63883 0.46858 0.40000 1.51021 1 1.06770 0.48000 1.730 2 70 -1.08912 0.65696 0.48000 AIR 1.71849 1.00000 LASF9 33.00000 2.00000 AIR 12.00000 IMAGE ASPHERIC DATA BY SRF: LENS DATA, ON AXIS CASE: SRF RADIUS THICKNESS APERTURE RADIUS GLASS 0 1.63883 0.46858 0.40000 1.51021 1 1.06770 0.48000 1.730 2 -1.08912 0.65696 0.48000 AIR 1.71849 1.00000 LASF9 33.00000 2.00000 AIR 12.00000 IMAGE ASPHERIC DATA. BY SRF: PI -0.02894 P2 -1.34813 P3 5.70154 P4 -78.12907 P5 178.56707 P6 2329.44442 P7 -1.7700E+04 PS 3.4026E+04 CC -0.48711 PI -0.01041 P2 -0.06934 P3 0.13071 P4 -0.98380 P5 3.41779 P6 -14.03236 P7 57.27584 P8 -138.09144 P9 132.08888 DFR. COEF: SI -0.15865 S2 0.00257 S3 -0.25194 S4 1.26070 S5 -2.86407 56 2.37729 S7 1.36299 S8 -2.36629 S9 -1.48033 S10 1.20315 Sll 2.25310 S12 0.17190 S13 -2.44329 S14 ■0.03497 S15 0.80123 DFR COEF: SI -0.01076 Ξ2 0.03052 S3 -0.04407 S4 0.12362 S5 -0.16767 S6 0.07931 S7 0.04196 S8 -0.03445 S9 -0.02233 S10 0.00881 Sll 0.01273 S12 3.4632E-05 S13 -0.00673 S14 0.00203 In computing these spherical and aspherical lens data, including the data for the diffraction gratings of corrector 23, the prescriptions are established using known optical design criteria. Conventionally, a lens with an aspheric surface, or with a diffractive surface, is described with a power series. In the present case, all aspheric surfaces are axially symmetric. and the sag of the surface, i.e., the location of a surface point along the optical axis, as a function of the distance R from the axis, is given by: Z - CR 2 + P X R 2 + P 2 R 4 + P 3 R 6 + . . . 1 + (Equation 1) where the P H coefficients are specified in a lens prescription. The term C is the basic curvature of the surface, and K is the conic constant of the surface. Diffractive surfaces are described by a similar equation, where it is the relative phase of the light that is given, as a function of the position on the lens surface. In the present case, both axially symmetric (DFR) and general (DFX) surfaces are used. In the symmetric case, the phase is given by: <j> = 2 Tf (S.R 2 + S 2 R 4 + S 3 R 6 . . . ) (Equation 2) λ It is the S H coefficients that are specified by the prescription. The general case is more complex mathematically, and is given by the relationships: m φ = Σ Q where Q i = 2iτ S L-Y", and (Equation 3) i=l λ i = 1/2 [(j + k) 2 + j + 3k] CONTROL ELECTRONICS With reference to Figures 14a and 14b, control electronics respectively for a write mode and a read mode are shown. In Figure 14a, the light valves 37 (see Figures 1 and 2) that compose each page of data and, in this embodiment, are provided by an array of LCD elements, depicted in Figure 16c, and are addressed on a row by row basis via an address interface 101 connected to an address bus 103, through an address buffer 105 and a row select switches 107 coupled directly to LCD light valves 37. As each page of data is composed by controlling the individual states of light valves 37, part of the address on bus 103 that determines the particular data page is communicated over X and Y source select buses 109 and 111 connected respectively to an X decode 113 and a Y decode 115. These in turn are connected to operate selected ones of recording light sources 33, one source being located in the proper XY position to illuminate a single data page on the recordable data layer 19. Also, taken from bus 103 are data words and word count signals which are passed via bus interfaces 101 to a word assembly register 117 and a timing and sequence control 119. Timing and sequence control 119 is a conventional sequencing device having outputs including clocking assembly register 117 and sequential signals for "load assembled row", "row increment", "pulse light source" and "done" that cooperate with row select switches 107 and recording light sources 33 to sequentially load and flash each page of data composed at light valves 37. The intensity of light imaged through light valves 37 onto data layer 19 is a function of the type of light sources 33 used and the duration and power applied to each source. For laser diodes, sufficient light energy is generated to image the pattern after being condensed through the objective lens optics onto a data layer 19 made of silver halide, dye- polymer, or a thin tellurium (Te) film. This and other materials are known per se in write-once-read-many (worm) records. Once a data layer is written with multiple pages of data, such as by using the foregoing recording processes, or in reading mass copied data cards, an addressing control such as shown in Figure 14b is employed. For this purpose, addressing data from a data bus 121 is connected via an interface bus 123 through an address buffer 125 to select particular rows of data after an image has been formed on sensor array 27. This is done by operating row select switches 127. To illuminate a selected data page, the address available from bus 121 includes page address data fed over X and Y decode buses 131 and 133 which cause X decode 135 and Y decode 137 to select a particular one of the multiple light sources 15 to illuminate a single page of data for imaging onto sensor array 27. A timing control 139 similar to timing and sequence control 119 provides in a manner known per se, a sequence of timing control signals identified as "pulse LED" (controls page light sources 15); "pulse CCD row" (controls the read-out of data from a charge coupled device sensor array 27); "gate MUX" (controls an output multiplexor from sensor array 27); and "data ready" (signals that the data is ready from the data output multiplexor and interface to a data user bus) . As described more fully below in connection with Figures 15a- c, the output of data from sensor array 27 is available through a buffer register 141, a multiplexor 143, an interface to bus 145, and an output data bus 147. SENSOR ARRAY Figure 15a illustrates a preferred sensor array 27 and interface circuitry 29 using photosensitive elements provided by a conventional charge coupled device (CCD) array formed in a large scale integrated circuit. Any of numerous CCD designs used in the video picture imaging field are suitable, such as those configurations disclosed in the article by Walter F. Kosonocky, CHARGE-COUPLED DEVICES—AN OVERVIEW, 1974 Western Electron. Show and Conv. Tech. Papers, Vol. 18, Sept. 10-13, pp. 2/1-2/20. Each sensor site is located to receive a data light image representing a single data bit, either "on" (1) or "off" (0) depending upon the data pattern imaged on sensor array 27. In underlying charge storage regions of the CCD wafer forming array 27, charge coupled elements receive the level of charge (representing the strength of light illumination on the overlying photosensor elements 27a) and store the level of image data. This signal level representing data is then shifted out and converted into binary ones and zeros by a threshold sensing operation in the output electronics shown in Figures 15a, 15b and 15c. Thus, in Figure 15a, array 27 receives row select data from row select switches 127 and dumps the charge level data from each row of the stored image into the analog buffer register 141. In conventional charge coupled devices, analog buffer register 141 is normally outputted serially as may be done using a serial output amplifier 152 as shown. Preferably the charge level data representing image data is withdrawn in parallel from buffer register 141 via a plurality of parallel output amplifiers 153, one for each column of array 27. From buffer register 141 via output amplifers 153, the charge level data, which is still in analog form, is converted to binary data by an interface circuit 145 preferably incorporating a plurality of adaptive threshold networks indicated at 161. Each of adaptive threshold networks 161 serves to automatically adjust the sensor site threshold depending on the amount of incident overlap or fringe light, i.e., light intended for adjacent sensors but partially landing on the subject sensor site. Above the threshold, circuit 145 outputs a "1" signal and below the threshold, circuit 145 outputs a "0" bit for that corresponding sensor site. In Figure 15b, networks 161 are shown with a centermost adaptive threshold network 161b that for illustration corresponds to the sensor site of interest, i.e., subject site, and includes an amplitude/sample circuit (A/S) 171 receiving a charge level signal through multiplexor 173 from buffer register 141 (see Figure 15c) of the sensor array. The output of A/S 171 applies the signal level which represents the amount of light energy illuminating a single one of the sensor sites in array 27 to a signal node 175 which in turn is connected to a summing input of a comparator 177. Node 175 also sends this same level signal outwardly to the laterally adjacent network 161a and 161b in the network of circuit 145 as indicated by interconnective weighted summing resistor 179 going to the left side adjacent network 161a and another weighted summing resistor 181 going to the right hand adjacent network 161c. Additionally, at comparator 177, a subtractive node 183 receives the weighted summing resistor signal levels from eac of the adjacent nodes, there being eight such adjacent nodes, via resistors 191, 192, 193, 194, 195, 196, 197, and 198 as illustrated. It is observed that in this embodiment the uppe and lowermost rows of amplitude/sample circuits corresponding to circuit 171 are needed to provide the level control signal from the above and below adjacent rows of sensor sites but th comparison function provided by comparator 177 is only needed in the middle row of adaptive threshold networks 161a, 161b and 161c. At comparator 177, the sum of the proportionally attentuated light signal levels from the adjacent sensors are subtracted at subtraction node 183 from the primary site signal at node 175 to adjust the switching threshold. If the intensity of light illuminating a particular sensor and represented by a voltage at node 175 exceeds the adjusted threshold of comparator 177, the computer outputs a binary "1". The adaptive threshold adjustment is accomplished by collectively subtracting at subtractive node 183 the weighted signals, then an output "1" or "0" is sent on to the user bus 147 at the time of a strobe signal applied to strobe line 149 Thus, an adaptive threshold is provided depending upon the amount of overlap light impinging the sensor array from adjacent illuminated sensor sites, thereby greatly enhancing the reliability of array 27 to discriminate between true data light and overlap light from data imaged on adjacent sensors. The interconnective resistors are weighted either (A) weight for resistors 191, 193, 195 and 197, being from those closer sensor sites immediately to the side or above or below; or (B) weight for the corner adjacent sites for resistors 192, 194, 196 and 198, which are somewhat further away and have a lower weight according to the fall off of light intensity with distance. The actual values of these weighted resistors are determined empirically by imaging various data patterns on th sensor array and adjusting the resistor values for optimum selectivity. The circuit for one of adaptive threshold sensor circuit 161 is shown in greater detail in Figure 15c. As indicated, each circuit 161 includes an amplitude/sample circuit 171 which in turn is made up of a sample gate 171a, a reset gate 171b, a sample holding capacitor 171c, and an output driver 171d that develops the sampled amplitude signal at node 175. Resistors 179 and 181 feed weighted proportional amounts of this level signal to adjacent networks 161 (see Figure 15b) . Comparator 177 similarly includes a summing junction 177a, a subtractive junction 177b, and a strobed output gate 177c. That output gate 177c, shown as an AND gate, may alternativel be a Schmitt trigger. The positive summing junction 177a receives the same output level signal developed by amplitude/sample 171 at node 175 and from that signal level the summed inputs from adjacent nodes fed over to subtractive node 187 are subtracted and the result is outputted through gate 177c at the time of an output strobe signal applied to strobe lead 177d corresponding to strobe line 149 in Figure 15b. Another amplitude/sample circuit 172 of a network node 162 is shown in Figure 15c for illustration, in this instance network 162 being associated with the sensor site in the row immediately above as illustrated in Figure 15b and having one weighted (A) resistor output feeding one of eight comparative levels to node 187 of comparator 177 for adjusting the threshold of adaptive threshold network 161b as shown in Figure 15b. ALTERNATE EMBODIMENTS The foregoing embodiments represent preferred apparatus and method for writing and/or reading optical data stored at exceedingly high densities, on the order of 625 megabits per square inch of data layer and organized into multiple pages that may be individually selected by optical means for high speed, large word retrieval. Numerous alternative components and design details are contemplated within the scope of the invention disclosed by way of example in the above specific preferred forms. For example. Figure 17 shows an alternative write/read optical memory 210 occupying a more compact configuration than the memory 10 described above (Figures 1 and 2) . Thus, in Figure 17, memory 210 is mounted in a compact, read/write module including a housing 211 containing many of the same elements as in the above described write/read embodiment, but here using reflective light modulators 217 to form the record image pattern. Light modulators 217 are mounted along with a quarter wave plate 219 and a source imaging lens 221 in line with one optical axis of a polarizin beam splitter 223 in which beam splitter 223 is situated in housing 211 between the read optics and the sensor array similarly to beam splitter 31 of memory 10. On the opposite side of housing 211, parallel to and in line with the optical axis of beam splitter 223 is an array of recording light sources 225, replacing light sources 33 shown in memory 10 of Figure 1. The remaining elements of the memory are the same as memory 10 and include light source drivers 13', light sources 15', data layer 19', and multiple lens array 21', together forming data lens card 17', diffractive corrector 23', field lens 25', sensor array 27' and sensor interface circuitry 29'. Polarizing beam splitter 223 includes the diagonal beam splitting plane 227 and in this case, the beam splitter is a polarizing device so that light emitted by sources 225 is polarized as the rays passing through the beam splitter. The light rays are then reflected by modulators 217. The recording process of the optics of memory 210 are similar to that of memory 10 described above accept that the source imaging lens 221 needs to be only one-half as strong as lens 35 and Figures 1 and 2 because the recording data images go through the lens twice prior to being deflected at diagonal plane 227 upwardly into the field lens 25', corrector 23', array 21', onto the recordable data layer 19'. Reflective light modulators 217 may be provided by an array of micro-machined mirrors, but for economy of fabrication, it is preferred to use a conventional LCD array, each LCD site being individually controllable to compose a page of data and using a low loss mirror behind the LCD page composer to reflect the image back toward the imaging lens 221 and beam splitter 223. The use of a beam splitter 223 minimizes the loss of light energy, but this in turn requires the use of a quarter wave length plate 219 between modulators 217 and imaging lens 221 in order to maintain the sense of polarization through the reflection plane 227 of splitter 223. Like memory 10, each of light sources 225 is selectively energized to record one page of data on its corresponding page site on data layer 19'. The orientation of each of sources 225 in the array on the side of housing 211 together with the various optics including source imaging lens 221 serves to direct and condense the image to the proper lenslet and hence page site on layer 19'. A variation of memory 210 shown in Figure 17 would provide for using a reflective data layer 19' or a transmissive data layer 19' with a reflective surface on the upper side thereof to provide an alternative to the read light sources 15' by using the light sources 225 for the dual purpose of recording and/or reading. During a read mode, individual ones of light sources 225 would be turned on or pulsed at a power level below the recording threshold and all of the reflective light modulators 217 would be set to reflec all impinging light which in turn would be condensed to fill one of the lenslets of array 21'. The result is to reflect light off the reflective record at layer 19' which then passe downwardly through beam splitter 223 to form the data image o sensor array 27'. Still another embodiment of the write/read system is shown in Figure 18 as memory 212. In this embodiment, the write mode is implemented by an array of recording light sources 251 arrayed in the pattern of a data field to compose each page of data. Light sources 215 are here mounted to one face of a drive circuitry module 253 in which both the array of sources 251 and circuitry 253 are flat structures such as printed circuit cards or boards disposed within housing 255 parallel to one of the housing side walls adjacent a beam splitter 31'. Between beam splitter 31' and recording light sources 251 is an array of micro lenses 257 functioning as a field lens, and being carried in a set of eight electromechanical X,Y movers serving to adjust the position o the i age forming recording rays onto the preselected data page site of data layer 19' through lens array 21'. Movers 259 are shown in greater details in Figure 19 and, as shown, eight such movers are disposed in pairs at the four corners o field lens array 257 so as to effect X and Y translation of the array plane for moving the image into a position for precise registration of the source rays onto data layer 19. Movers 259 are conventional electro-magnetic transducers— e.g., moving magnet devices—although other suitable known transducer devices for converting electrical positioning signals into movement may be used. These movers need only operate at a relatively slow electromagnetic speed to set the optics prior to the recording of each page of data composed on recording light sources 251. LCD or other light valve type shutters 260 screen out lenslets and hence data pages that are not to be recorded. Figure 21 shows another alternative embodiment in schematic form by which data is imaged from the data/lens system through a diffractive corrector directly onto a sensor array without an intervening field lens. In this embodiment, the four optical surfaces of the lenslet and diffractive corrector are prescribed as, for example, in Table 2 above, to perform the substantially equivalent optical imaging otherwise performed by the omitted field lens of the previously described embodiment in Figure 13, prescribed in Table 1. Figure 22 is still another alternative embodiment of the invention again shown in schematic form depicting a data/lens system with the data being imaged through a field lens but omitting the diffractive corrector resulting in lower density that may be acceptable in certain applications. A higher density variation on this Figure 22 embodiment would provide diffractive gratings placed on one or both of the field lens surfaces in order to provide further correction of the optical aberrations as needed to enhance resolution required by a particular application. Figure 23 shows an alternative version of a write/read memory in which the sensor array is modified to incorporate both sensors and emitters disposed in an interspersed, side- by-side pattern on a common plane. Thus, the same plane serves both to receive the imaged data for sensing, as well as an object plane to compose record data by selective driving of the interspersed emitters. The composed record page is then imaged back onto the data layer through the same optics as the read imaging but in reverse, condensing fashion to write (record) onto the selected record page. The set of Figures 24a, 24b and 24c shows various portions of a large scale integrated (LSI) circuit fabricated for use as the composite sensor and emitter array 315 of memory 310 described above in connection with Figure 23. Thus, as shown in Figure 24a, the array 315 includes a plurality of sensor/emitter units 315' arrayed so that all told there exists a number S of such units equal to the number of bits that are imaged or generated at array 315 for each page or region of data layer 19'. Each such sensor/emitter unit 315' includes juxtaposed sensor 321 and emitter 323 arranged in approximate juxtaposition so that a light bit imaged on unit 315' will strike sensor 321 even though some o the imaged light falls outside of the area of the sensor. Similarly, during a write operation in which emitter 323 is energized at each unit 315', the emitted light from, in this case, the somewhat smaller area emitter surface is sufficiently located within the overall area of unit 315' to create a source image bit at that particular array location. In addition to the semi-conductor areas forming sensor 321 and emitter 323, each unit 315' has integrated therewith the adaptive threshold circuit and the interconnects to the counterpart sensors in adjacent units corresponding to 315' and here including drain follower 331, difference amplifier 333, AND gate 335, and the weighting resistors 337 shown somewhat pictorially in the diagram of Figure 24a. In this embodiment, each sensor 321 has a separate adaptive threshold circuit that alters the switching threshold of that particular sensor unit as a result of the amount of light falling on the immediately surrounding or adjacent unit sensors. The theory and operation is similar to the adaptive threshold sensors described above in connection with the embodiment shown in Figures 15a-15e except that the adaptive threshold circuit and operation is integrated with and co-functions with the operation of each sensor site on array 315. Thus, with reference to Figure 24b, an enlarged fragment of the sensor/emitter unit 315 is shown in a schematic/pictorial diagram to provide sensor 321 as a diode 321a, here being a PIN type diode but which could also be a CID (charge injection diode) or other photosensing element, in which the irregular polygon area 321b depicts that surface area of the semi- conductor material that forms one electrode of the schematically indicated PIN diode 321a. The cathode of diode 321a is then connected as indicated to MOS drain follower 331 (corresponding to MOS drain follower 162 in Figure 15c described above) . The output of drain follower 331 is then fed to difference amplifier 333 (being the counterpart of differential amplifier 177 in Figure 15c described above) which performs the threshold comparison and outputs data through AND gate 335 for data light incident on sensor 321. The adaptive threshold operation which effects the switching threshold of differential amplifier 333 in conjunction with output diode 335 is provided by a network of weighting resistors 337 which feed input signals to differencing amplifier 333 from the adjacent sensor sites in a manner similar to the operation of the weighting resistors A and B described above in connection with Figure 15c. In this embodiment, each unit 315' of the array also includes a light source here in the form of a solid state diode emitter 323. Emitter 323 is shown schematically and pictorially to include an emitter 323 formed by a light emitting diode 323a and a land area 323b constituting an electrode of the diode 323a at which photo emission occurs, forming the source of light. The area of each unit 315' is. in this embodiment, substantially .03mm by .03mm square such that the entire array 315 as shown in Figure 24a will be composed of an array of 1000 x 1000 for a total of 10 6 such units. With reference to Figure 24c, the schematic diagram of the sensor and its associated adaptive threshold circuit, as well as the separate source or emitter circuit are shown to include PIN type diode sensor 321a connected with its cathode to an MOS drain follower 331 and to an MOS reset device 337 for clearing the storage of any signal on follower 331 during a read cycle. The output of drain follower 331 is fed to an input 333a of difference amplifer 333. In addition to sending its output signal to one 333a of difference amplifier 333, follower 331 also sends the output signal for that particular sensor to the A and B weighting resistors 337 that are distributed to the adjacent sensor units of the array as described above. Similarly, the comparison input 333b to difference amplifier 333 receives the weighted light sensing signals from the adjacent sensor sites through the network of weighting resistors 337 to adapt or adjust the switching threshold of amplifier 333 as it responds to the output of PIN diode sensor 321a through follower 331. An output of difference amplifier 333 thus has the switched adaptive thresholded output signal which is applied through a strobed AND gate 335 to a user bus multiplexer representing the output bit signal for that particular sensor site. As a schematically separate circuit from the sensor, the photo emitting source or diode 323a is connected across X and Y address or select leads as shown so as to be energized whenever that particular bit of the array 315 is to be illuminated for a record mode. As an alternative to the composite sensor and emitter array 315 shown in Figures 24a, b and c, a similar LSI circui may be used as a sensor-only array by omitting the source or light emitter 323 from each array unit 315'. In such case, the sensor area 321b, as shown in Figures 24a and 24b, can be enlarged to a regular rectangular shape by shifting some of the adaptive sensor circuitry components down into the space otherwise occupied by the source 323. Otherwise, the circuitry as schematically shown in Figure 24c for the sensor portion of the array and the basic arrangement of elements shown in the plan view of this LSI circuit would remain the same. Another variation on the embodiment of array 315 of Figures 24a, b and c is to provide at each site a single soli state element, using a variation of either diode 321a or diod 323a, which serves as a dual functioning sensor and emitter i the same physical element. During read, the common element i operated as a sensor; during write, the element is driven as an emitter to provide one bit of the page composer. While only particular embodiments have been disclosed herein, it will be readily apparent to persons skilled in the art that numerous changes and modifications can be made to th devices and method steps disclosed herein, including the use of equivalent means and steps, without departing from the spirit of the invention. For example, other optics may be used in place of the preferred and above described refractiv and diffractive lens subsystems, including all refractive an all diffractive lens systems, and different combinations of refractive and diffractive surfaces. Although a preferred form of the lens array 21 uses a sheet or layer of glass for the refractive lenslets as described above, an alternative embodiment may use individually fabricated lenslets mounted a close-packed array held together by a bonding matrix of a suitable bonding polymer. The sensor array similarly may be provided by different structures, including a modified D-RAM array with an overlay of transparent material to allow data image light to strike solid state junctions in the RAM memory storage elements, or by superposing an array of solid state photosensing elements, e.g., diodes, on top of a D-RAM array and then coupling the photodiode outputs by metalization downward from the top photo sensing layer to a storage elemen of the underlying D-RAM for each sensor site. The imaged dat is then output from the D-RAM using conventional addressing circuitry. ADDITIONAL ALTERNATE EMBODIMENTS Achromatizing Diffraction Lens Systems With reference to Figure 25, an alternative embodiment o the invention is shown in which the refractive lens surfaces used in the device of Figure 11 above are replaced by diffractive surfaces and incorporate achromatizing optics. this color correcting or achromatizing diffraction lens syst 400, image rays from data layer 19 pass through a first diffractive surface 402, then through an anomalous or phanto lens 404 that corrects for color aberrations caused by the diffractive surfaces, and then through a second diffractive surface 406 from which the imaging rays extend to the field lens (not shown in Figure 25). The resulting lens system has the advantage of being a diffractive objective system giving rise to a substantially flat field, compact dimensions and light weight. The anomalous or phantom lens 404, which only serves as a color correction factor, can be omitted in those applications in which a narrow band light source is used, such as provided b a laser diode. However, for those systems in which laser diodes are too costly, LEDs and other types of light sources produce a wider band of light and hence may produce undesirable aberrations or distortions in the imaged data du to different source wavelengths interacting with the powerful diffractive surfaces 402 and 406. The reason is that the ra passing through the diffractive element are "bent" (actually, diffracted) by an interaction of the groove spacing and the wavelength of the light. The angle of diffraction is a primary function of the wavelength. In contrast, the chromatic aberration of a refractive lens is due to the chan in the index of refraction with frequency, a secondary effec The classical way to color-correct a diffractive elemen is to combine it with a refractive element, because the effects are in opposite direction. Unfortunately, because t refractive effect is much smaller, the optical system to be corrected must have most of the power in the refractive lenses, leaving the diffractive elements to a roll of correcting for some of the shortcomings of the refractive elements. That can be a good arrangement in many instances, especially where the system has a large f number and/or a small field of view. In this invention, however, the optical system has a relatively small f number and a large field of view for the reasons described above. If a single refractive lens is made strong enough to correct for the chromatic error of a diffractive element in this environment, the field may curve to an unacceptable extent. An obvious solution as mentioned is to avoid color effects by using very narrow bandwidth light sources to image the data pages. A diode laser, even a multi-mode laser, woul be satisfactory. A plasma lamp might be satisfactory depending on the pressure and the gas chosen. An LED when combined with an interference filter would work to narrow the bandwidth, but again that will rob needed intensity. The other devices mentioned are either too costly or lack intensity. The object of this embodiment is to provide new ways to correct a diffractive lens system for color aberrations. The novel feature is to include one or more refractive surfaces within the system, where the surface is the interface between two materials, in effect a buried refractive surface. The tw materials are chosen such that the index of refraction is the same for both at the middle wavelength, but the dispersion is different. That is, at wavelengths different from the center wavelength, there will be a difference in the index, so at th center wavelength (or any other selected wavelength) the lens has no effect at all; it is not there. It is a "phantom" lens. At a wavelength different from the center or selected wavelength, the lens is effective, and will act as a positive lens for wavelengths on one side of the selected one, and a negative lens on the other. Which is which depends on the sign of the curvature of the surface, and which material has the greater dispersion. In this way, the lens corrects primarily for chromatic aberration, and has minimal effect on field flatness or other aberrations. At a wavelength extreme there will be some effect other than color, but it is very small and can be neglected in this embodiment. In selecting a glass or plastic with a high enough dispersion to give enough index change over a small wavelengt range, the following approach is used. As an example, an LED that has a center wavelength of .645 microns, has a bandwidth of about .02 microns. This would be the full width at half maximum. As sources go, (not including lasers) this is a narrow wavelength range. And the index of ordinary glasses does not change enough over that range. The fact that the index changes at all in normal transparent materials is due to absorption bands that are in the infrared and in the ultraviolet. It is a fact of nature that as one approaches a resonance in any system, the phase changes rapidly. In an optical system, this is manifest as change in the index as an absorption band edge is approached The index always decreases as the wavelength increases up to the edge. On the other side of the edge, the index jumps to higher value, but still decreases as the wavelength continue to increase. There is a very rapid change with the opposite slope in the region of the band edge, but at that point the absorption is at a maximum, so the dispersion is very difficult to observe. A discussion of this effect can be found in most physical optics texts often under the subject "anomalous dispersion", e.g., Jenkins and White, "Fundamental of Optics" 2d ed., p. 466, or R.W. Wood "Physical Optics" Chapter 15, 3d edition. The implementing process for the phantom or anomalous lens 404 in Figure 25 is to dissolve a dye in the plastic (glass may also be used as an alternative) , where the dye ban edge is near the light source wavelength. The edge could be either above or below, but for this embodiment, the dye is selected to be on the short wavelength side of the source. With the above LED chosen, the dye would be a green absorber, so it would appear red or purplish. Because the dye will absorb, the thickness of the dyed material must be kept relatively small. This is not an optical problem, as a very thin layer can do the job, although in a particular system there might be constructional problems if it is too thin. Figure 25 is one example of an all diffractive system that has very good characteristics, except for color errors. The addition of the planoconvex phantom lens 404 embedded in plastic between the diffraction surfaces 402 and 406 correct for the color aberration very effectively. The lens is preferable in a Fresnel form, as best shown in Figure 26 so that the absorption loss would be minimized. The dispersion chosen for the lens is thought to be reasonably attainable. For example, as shown in the graph of Figure 32, the index as a function of wavelength is plotted for a dye known as Nitrosodimethylanaline. The "x" marks are taken from experimental data that are given in Wood, page 508, supra. The continuous curved graph is a best match that is based on dispersion theory (see e.g., Born and Wolf, PRINCIPLES OF OPTICS, Pergamon Press, 6th Edition, p.92 eqn 31). The match is not perfect, mainly because the equation assumes a single absoption line, when in fact there are usually several in a typical solid. Further, there may be other bands, particularly in the infra red, that are not accounted for in the simple equation. However, the straight line of Figure 32 shows the dispersion required to make the phantom lens 404 work, and it should be noted that that particular dye is more than adequate from a wavelength range of about .68 microns to .58 microns. The dispersion is much larger at even shorter wavelengths, but absorption would begin to have a more serio effect. With reference to Figure 28, another variation of the embodiment of Figures 25-27 is shown in which the second diffractive surface 406' has been moved from the data lens card to the first surface of field lens 25. The anomalous o phantom lens element 404 for color correction remains embedde in a plastic material that is bonded to the first diffractive surface 402 and to data layer 19 to form a data lens card. With reference to Figure 29, another embodiment of the anomalous or phantom lens for color correction is found in a system that provides the data and objective lens elements as card as in the embodiment of Figures 25-27, but replaces the refractive field lens with an all diffractive field lens system provided by a diffractive field lens surface 410 and another diffractive field lens surface 412 separated by a spacer material of optical plastic. The advantage of this al diffractive system for both the objective and the field lense is that it further enhances the system compactness. Figures 30 and 31 illustrate an embodiment of the all diffractive lens system including the anomalous or phantom lens 404, here again being of Fresnel form, combined with an intervening LCD page shutter element 415 including polarizing layers and being located proximate the first objective diffractive element 402'. For this embodiment, the data lens card is made of data layer 19 and an optical bonding plastic on which the first objective diffractive surface 402' is formed as indicated followed by an air space indicated at 420 separating the next system of LCD shutters and lens elements which include shutter LCD 415, anomalous element 404' for color correction, a second diffractive objective element 406' and then first and second field diffractive elements 410 and 412 all of which are held together by plastic spacer and bonding as indicated. The LCD shutter 415 is located in a region where the light rays from adjacent pages are not overlapping, hence LCD 415 is located adjacent the first diffractive surface 402'. In this lens system and using two objective diffractive elements 402' and 406', the LCD shutter element must go after the first diffractive element so that a single page shutter is not distorting an image by cutting off or letting through rays from adjacent pages. For this purpose, it is efficient to make the data lens card of just the data layer 19' and the first diffractive element 402'. The shutter LCD 415, color corrector anomalous lens element 404', second diffractive layer 406', and the field diffractiv layers 410 and 412 are conveniently bonded together as a unit Either air space or a solid optical plastic may be used between the second diffractive field element 412 and the sensor array. With reference to Figure 34, still another embodiment of the lens system is shown in which a first objective lens element is a composite of refractive and diffractive surfaces indicated at 430. The anomalous or color corrective phantom lens region 404' lies between this composite refractive and diffractive element 430 and the second diffractive surface 406'. By shifting some of the objective imaging power from the first diffractive surface into the refractive component the composite surfaces 430, the grating can be less fine and hence easier to fabricate, and secondarily, the amount of color correction or achromatizing is reduced and hence the prescription for the anomalous or phantom lens region 404' i less stringent, thereby permitting a wider selection of dopi materials or dyes. In making these choices it is also preferable to keep the refractive power relatively small to minimize field curvative. GRIN Lenses Using Anomalous Dispersion Dyes With reference to Figure 35, another embodiment of the objective lens system for imaging the multiplexed data pages uses a gradient index lens system 450 bonded to the data laye 19 as a data lens card 452. The composite card 452 includes first diffractive lens surface or element 454 followed by a second diffractive lens surface or element 456 wherein both diffractive elements are augmented by a gradient index lens effect in the intervening optical plastic areas indicated at 458 and 460. The advantage of the gradient index lens or GRI lens is to allow for the same overall imaging power with less strong and hence less rigorous requirements for the diffractive elements. In other words, some of the imaging power of the lens system is shifted from the diffractive elements over to another type of optical lens element, namel the gradient index lens areas 458 and 460 of lens system 450 used in the card 452. Simplified, the GRIN is fabricated in this instance by a change in the index of refraction of the material in the direction along the lens axis from the data layer toward the field lens and sensor, hence longitudinally of the lens axis. By using a base plastic, or it can be glass, material between the diffractive elements and the dat layer, and then increasing the index of that optical materia longitudinally (axially) from data layer toward the field lens, an optical effect is achieved that is the functional equivalent of a refractive lens element. In this case, the device is fabricated by a build up of different layers of increasingly higher index optical plastics, either by selecting the stock material or by selective doping of the layered material. In an alternative embodiment, a GRIN lens configuration can be used in which the index of refraction varies as a function of radius. In fact, lenses made with a radial GRIN are widely known and used because the optical effect is more similar to a conventional refractive spherical lens element. Thus, in the embodiment shown in Figure 36, a lens system tha is an alternative to the longitudinal GRIN of Figure 35 is shown using a radial gradient variation. In fabricating both a longitudinal (Figure 35) and radial (Figure 36) GRIN lens components of the present invention, the following considerations apply. A gradient index lens (GRIN lens) is an optical element where the index of refraction of the lens material varies as function of distance. One type of GRIN is known per se, and is a device shaped like a right cylinder, with the index of refraction varied as a function of radius. It turns out that if the index decreases as the inverse square of the radius, the cylinder will function like a standard positive spherical lens. The power of the GRIN lens depends on the total change in index (the value of the proportionality constant) , the length of the cylinder, and the diameter. Known GRIN lenses are currently manufactured of glass. The glass that is used is a mixture of two or more components where at least one component is more soluble in some reagent than the others. The technique has been to put a glass cylinder in a leaching bath, which will remove the one component as an inverse function of the square of the distance. In this way, a GRIN lens can be made with the proper radial distribution of index. Alternatively, and in accordance with my novel embodiment, a gradient is generated along the axis of an optical path which will give optical power similar to a conventional lens element and an example of such is used in the embodiment of Figure 25. The preferred fabrication on such lenses is to diffuse a dye into a plastic base material. The dye will increase or decrease the base index depending on the location of the dye absorption band relative to the operating wavelength of the optical system. In the case of a radial index distribution, there are t ways to make an element. The first way is to immerse a plastic cylinder in a bath of dye that is dissolved in a solvent that is compatible with the plastic. The dye will diffuse into the plastic on an inverse square basis without further arrangements. In this case, it is desired to have th lower index at the surface of the cylinder (for a positive lens), so a dye would be chosen such that the absorption band is at a wavelength that is longer than the operating wave band. Alternatively, a radial index distribution could be diffused into a relatively thin section of a cylinder by printing or painting dye/solvent on the cross-section surface of the cylindrical section and diffusing the dye into the plastic, as above. The process would resemble frosting a cookie. The dye will diffuse in a radial direction as well a axial, so the section must be thin relative to the required index variation, i.e., the cookie must be thin. Note that a positive lens can be made by either reducing the index of the outer radii, or by increasing the index of the central regions. The choice depends on the available dye On the other hand, if longitudinal gradient is desired, it is only necessary to uniformly coat the section surface of a cylindrical piece, and again diffuse the dye into the plastic. There is somewhat more flexibility in the manufacturing process in that there is no pattern to worry about, and the diffusion can take place from either side, depending on the type of dye available. In the ray trace programs which may be used to design GRIN lenses, the index is specified as two power series, whe one independent variable is the radius, and the other is the axial (the direction of the light) distance: n(r,z)=n 0 + n zl z + n z2 z 2 + n z3 z 3 +...+ n rl r 2 + n r2 r 4 +n r3 r ε Basic Relative Motion Mechanism Separate Source and Sensor: Figure 37 shows an alternative embodiment in the form of an optical data card read and/or write device 510 (R/W device in a read only configuration for a single optical data card 512. R/W device 510 has a slot 514 for introducing card 512 into R/W device 510. Figure 38 depicts card 512 fully drawn into the internal mechanism of R/W device 510. Card 512 is gripped by translation rollers; upper rollers 516a and 518a cooperating with lower rollers 516b and 518b. The pairs of rollers translate card 512 back and forth in direction "A". Yoke 520 is urged to translate in direction "B" by worm shaft 522 which is driven by stepper motor 524. Yoke 520 is supported by support rail 526 bearing upon support wheels 528 Referring now to Figure 39, yoke 520 has an upper arm 530 and a lower arm 532. Arm 530 has at its distal end light source means 534 while lower arm 532 has at its distal end sensor means 536. The relative position of card 512 and light/senso means 534 and 536 is controlled by conventional devices and methods for this purpose as well as additional features of this invention discussed herein. Single Page Source: Still referring to Figure 39, in one preferred embodiment, light source means 534 is a single light source 537 which illuminates a single page of data on card 512. A sensor means 536 embodies a sensor array 538 which receives light rays from single light source 537. Single Page with Reflective Data Layer: A variation on the embodiment just described is shown in Figure 40 wherein a read/write module 540 with beam splitter 541 is located at the distal end of lower arm 532. Module 54 provides the light sources necessary to read and/or write dat card 512 with a reflective layer 544 as well as the sensor array 538. Figure 41 shows a portion of card 512 illustratin a reflective layer 544 behind data layer 546. The incorporation of read/write module 540 obviates the need for upper arm 530. Multiple Chapters: Both of the immediately previously described methods of reading a single card can be employed in a R/W device 510 tha accommodates an array of data representing multiple cards or chapters 512 as depicted in Figures 42A and 42B. In a preferred embodiment, light source means 534 would be a full chapter light source 548, shown in Figure 43, which can be selectively controlled to illuminate single pages. Alternatively, in some applications a read/write module 540 could be utilized, thus eliminating the need for an overhead full chapter light source as depicted in Figure 42B. Carousel: Another preferred embodiment adapts R/W device 510 into data card carousel reader 550 depicted in Figure 44. Carous 552 stores a plurality of data cards 512. The upper portion of carousel reader 550, as shown in Figure 45, houses R/W device 510. The lower portion of carousel reader 550 houses data card transport means 553 and carousel rotation means 55 Transport means 553 may be a simple rack and pinion device a shown which lifts a card 512 up to a point where rollers 516 can grip the card and further transport it into the grip of rollers 518 and proceed to be read or written to as desired. An alternative embodiment, not depicted, incorporates a transport means in the upper portion of carousel reader 550 which in effect would reach down and lift a data card up int contact with rollers 516, thereby permitting the overall housing size to be made more compact. Diffractive Lower Surface of Data Card: In all of the above described embodiments employing an R/W device utilizing rollers as shown in Figure 37, an alternative formation of data cards 512 incorporates a - r 5 diffractive layer in place of the lenslets 511 depending fro the lower surface of card 512 as shown in Figure 39. The advantage of employing a flat diffractive surface, as oppose to the bumpier lenslet surface, is to enhance the smoothness of translation of card 512 through rollers 516a,b and 518a,b 10 and to aid in maintaining the proper geometry relative to light sources and sensors. Continuous or Indexed Data Tape Relative Movement: An additional preferred embodiment provides for continuous relative movement between a medium supporting a 15 data layer, such as a continuous tape, and corresponding lig sources and sensors. Figure 46 depicts an overhead view of portion of a data tape 560 with rows of data pages 562. Pai of rollers 564a,b and 566a,b assist in feeding the data tape through a read module 568, shown cutaway, and maintaining 20 flatness of the data tape as it passes through the module in direction "C". A light source strip 570 is mounted in the to of module 568 at a skew angle alpha relative the data tape f' edge normal direction "D". The skew angle alpha is chosen to permit light source strip 570 to span from the beginning page 25 in a data page row to a data page at the opposite end of an adjacent row. A cutaway front side view of module 568 is shown in Figure 47. Below data tape 560 is a field lens str 572 and sensor array 538. In this embodiment, lens strip 57 is canted at the same skew angle as light source 570. Readi of data tape 560 is accomplished by multiplexing individual light sources in light source strip 570 sequentially from le to right or vice versa depending on the direction of travel the data tape. The reading of a continuously moving data ta can be accomplished by skewing the data page rows as opposed to the optical components. By maintaining the optics elemen in orthogonal relationship to the direction of tape travel a depicted in Figure 48, a tape can be indexed and whole data page rows can be read at one time then stepped to the next r to be read and so on. An alternative embodiment incorporates a read/write module 540 (described above and shown in FIGS. 40 and 43) so that data can be recorded on data tape 560. Although, in th embodiment, ordinarily only a single row of data pages will written at one time. Tape Synchronization: In either of the data tape embodiments discussed above, continuous or indexed, synchronization of the data page on th tape with the reading mechanism may be accomplished by one of several methods. Multi-flash Indexing: One preferred embodiment flashes the light source 570 a a high rate while the sensor array looks for fiducial data mark images (fiducial data marks are discussed below in relation to FIG. 49), after the tape drive system has transported the tape to approximately the correct position fo the next read. The tape drive system is controlled to provid the correct overall data rate so the position of the next dat page is reasonably well known. An example of the multi-flash technique follows. Assuming the data tape system is designed for TV, the data rate required is approximately 25 Mbit/sec. with "ordinary" compression. Also assume the data tape is 16mm wide, a data page is 1mm in diameter and lMbits of data is stored per page in a 1000 bit by 1000 bit array, yielding 16Mbits/data page row. The suggested data rate of 25Mbits/sec. then requires reading 1.6 data page rows/sec which translates into tape movement of 1.6mm/sec or 1600 rows of bits per second. Flashing the light source at a frequency of 6400 flashes/sec provides control of the reading of the data to within 1/4 of bit which is good enough for an accurate read. Since as mentioned above the overall tape position is reasonably well known, it is only necessary to begin flashing the light sourc in a search for the fiducial marks when the tape is within approximately 5% of the position in which it will be stopped for about .6 seconds before indexing to the next row of data pages. For continuously moving tapes, indexing of a read operation must be accomplished for each data page. As described above, either the light source or the data page ro are skewed in a continuous moving device. The operation of flashing the light source and looking for fiducial marks is repeated in this configuration as described above. Applying this technique to the TV data rate example described above follows. Again approximately 25Mbits/sec is required. Since each data page contains lMbits, 25 pages ar read each second. Since the data rows or the light source is skewed by the diameter of 1 page (1mm) and the tape is 16 pages (16mm) wide the tape must advance 1.56 page diameters (1.56mm) to permit reading 25Mbits of data. This rate of tap advance also translates into 1560 rows of bits per second. A flash rate of about 6250Hz provides for indexing of about 1/4 bit which again is sufficient for an accurate read of a data page. Separate Detector: An alternative preferred embodiment utilizes a separate detector which reads index marks recorded on an edge of the data tape. The marks correspond to the locations of either rows of data pages or individual data pages in the skewed arrangement. The index marks sensor is accurate to approximately 1/4 bit (1/4 micron). A conventional feedback mechanism utilizing the voltage generated by the mark detecto controls the read function. An alternative to this approach incorporates double detectors that would register a balance across a mark thereby permitting the index mark to be larger in size, such as 3 to 4 microns. The multi-flash technique can also take advantage of index marks positioned at the edge of the data tape wherein the detector(s) signal(s) the imminent arrival of the page fiducial, so only a small number of flashes would be required Fiducial Data Marks: Fiducial data marks are used for several purposes including registration adjustment for reading or prior to writing if previously recorded fiducial data marks exist, where the adjustment is provided by electronic and/or mechanical means as described elsewhere and for data tape synchronization. The fiducial data marks may be pre-recorded or recorded at the same time that data pages are recorded. One preferred configuration of fiducial data marks 580 is shown on a single data card in FIG. 49. Slow Registration: The preferred embodiments may employ the aid of mechanical adjusters to achieve the necessary optical registration between the light source, data medium and sensor array elements of the invention. A typical application of registration adjustment means is shown in Figure 50. In the embodiment of Figure 50, registration adjusters 600 are show depending from the top of a read only optical memory module 602. An optical data card (chapter) 604 is shown being held up against a full chapter light source 608 by springs 606. Figure 51 is a top view of module 10 of Figure 50 showing registration adjusters 600 in position proximate the corners of data card 604. Adjusters 600 are controlled via a conventional feedback loop (not shown) to push chapter 604 along orthogonal axis "x" or "y" depending into a position o optical registration. Further, chapter 604 can be urged through an angle Beta into angular alignment by adjusters 600 since the force vectors generated, Fl, F2, F3 and F4, do not act through the center of chapter 604. Figure 52A depicts one preferred type of registration adjuster 600. The device is symmetrical about its central axis "A" and incorporates a resistive heating element 610 which is surrounded by a flexible sheath 612. The space within the sheath is filled with a wax, such as Centowax J, o polymer with a known coefficient of expansion during a phase change from a crystalline state to a liquid state. While undergoing a phase change, the sheath expands as indicated by the phantom lines. The expanding sheath bears upon an edge o a chapter 604 as shown in Figure 51 and discussed above. An alternative to the embodiment shown in Fig 52A is shown in a side view in Figure 52B and a top view in Figure 52C. Depending on space limitations and type of application (to be discussed below) this embodiment may be preferable. The variation shown in top view in Figure 52D and in side view in Figure 52E has the added element of a perforated diaphram 614 which is designed to only permit expansion of adjuster 600 primarily in one direction thus concentrating the forces and movement in a desired direction. Another preferred embodiment of is shown in side view in Figure 53A and partial top view in Figure 53B. Adjuster 600 embodies a solenoid coil 616 and a translating core 618. The rounded end 620 of core 618 pushes upon a beveled edge 622 of chapter 604 when the solenoid is energized. The components N-. fy of the normal forces "N" acting in the plane of chapter 604 provide the required orthogonal and angular registration. Alternative embodiments to the wax filled embodiments or solenoid embodiment described above include using a heated bi¬ metallic strip with a predictable coefficient of expansion or a stack of piezoelectric elements to provide the forces necessary for registration. In other embodiments, the adjusters may provide registration by adjusting the relative position of a sensor array as opposed to a data card, or they may act upon guide means for a continuously moving or indexing data tape. Single Chapter Fixed Registration: Another alternative to utilizing registration adjusters to shift the position of a single chapter is to create a module with precision reference surfaces against which a chapter is brought into contact. Figures 54A and 54B show such an embodiment. Figure 54A is a partial cutaway side vie of a read only module 602 showing a chapter 604 held up against a full chapter light source 608 by upward force springs 624. Figure 54B shows a cutaway top view of a module 600 with front reference surfaces 626 and side reference surfaces 628. Side spring 630 biases chapter 604 against sid references surfaces 628 while rear spring 632 biases the chapter against the front reference surfaces 626. Such a module can be constructed by precision molding processes utilizing filled polymers or metals. Alternatively a rough molded or cast part can be machined to provide the precision reference surfaces. Solid Cube : A further alternative to the module discussed wherein a chapter may be replaceable and module incorporates some registration means is to simply pot the elements of a functional module in polymer of appropriate optical properties. Such a module could be used to permanently store software of the type that is often accessed but not altered such as a computer operating system. Game Cartridge: Another preferred embodiment incorporates an array of data cards or chapters 604 into an array 634, one version of which is shown in plan view in Figure 55. Other versions of chapter arrays are shown in Figures 56 and 57. These will be discussed in more detail below. A preferred application of an array 634 is in a cartridg similar to the type used in video games. A cartridge 636 is shown in a cutaway side elevation view in Figure 58 installed in a game player unit 638. Cartridge 636 is comprised of a case 640 with a top, a bottom, sides and a front. The back of the cartridge is equipped with a door (not shown) similar to those commonly found on VCR cassettes. Array 634 is suspende in the interior of cartridge 636 by elastic suspension members 642 depending from the front and side walls of the cartridge. Abutments 642 are molded as part of case 640 and depend downward from the top of the case. The game player unit 638, in addition to video display drivers and other conventional elements, includes a player sensor array 644 of field lenses 646 and sensor arrays. The player sensor array is cantilevered in the interior of player unit 638 so it can fit into the interior of cartridge 636 underneath the chapter array 634. The player unit also includes a light source array 650 with full chapter light sources. The light source array is flexibly cantilevered in the interior of player unit in a position above an installed chapter array. Attached to the top of light source array 650 by living hinges 652 are pressure bars 654. The pressure bar are cooperatively connected by a pushrod 656. Figure 59 show the pressure bars 654 from the rear of the cartridge in a fully deployed position. Depending downwards from light source array 650 are a plurality of registration pins 658, which mate with registration holes 662, and also depending downwards are a plurality of registration springs 660 which contact angled chapter edges 672. Figure 58 shows cartridge 636 fully inserted in a game player unit. Prior to insertion of a cartridge in a player unit, the light source array 650 is biased upwards by biasing means 664, such as springs. During insertion, the leading edge of the case top contacts flange 666 of pushrod 656. As the pushrod is forced rearwards, the pressure bars begin to raise up and lobes 668 make contact with abutments 642. Further insertion causes the pressure bars to rotate further about living hinges 652 into a vertical position thus forcing light source array 650 downwards in such a manner to sandwich chapter array 634 between it and player sensor array 644. Coincident with the downward motion of the light source array is the passage of registration pins 658 by registration notches 670 (shown in Figures 55, 56 and 57) in the chapter array into registration holes 662 and the contact of registration springs 660 with angled chapter edge 672. Refer now to Figure 55. Registration of array 634 is accomplished as follows. Individual chapters 604 are flexibl interconnected at their edges to other chapters by elastomeri means 674. The flexible interconnection allows for small relative movement between chapters to provide the proper registration between each chapter and associated light sources, lenses and sensor arrays. Refer now to chapter "A" in the lower left hand corner and the associated registration spring "B" and registration pins "C" and "D". During insertion of a cartridge into a game playing unit, a portion of registration spring B exerts a normal force "N" against angled chapter edge 672. The orthogonal components of normal force "N" in the "x" and "y" directions urge chapter "A" against registration pin "D" which establishes the orthogonal registration of chapter "A". Similarly, the component of normal force "N" directed in the "y" direction urges chapter "A" against registration pin "C" which prevents angular displacement of chapter "A" in the planar area it occupies. Each chapter 604 in array 634 is registered in the same manner as just described. A single registration spring 660 may provide normal forces to multiple chapters depending on where it is located in the array.The normal forces generated by registration springs are sufficient to overcome the tendency for the elastomeric means to restore each chapter to its pre-insertion position relative to one another. Figures 56 and 57 are alternative embodiments of array 634 showing alternative chapter geometry, registration spring configuration and placement of the registration springs and pins. The registration springs may also be formed of a resilient non-permanently deforming material, such as silicon rubber, that will generate sufficient normal forces to provide adequate registration when brought into contact with an angle chapter edge. Referring back to Figure 58, an alternative embodiment o the cartridge includes a semiconductor chip 676 on array 634. Such a chip can provide control over the function and capabilities of separate portions of the chapter array, e.g., read only, write and read or erasing functions, as well as providing processing, processing parameters, authorization codes, electronic serial numbers, ID codes or the like. Another preferred embodiment provides for adjusting position of the sensor arrays 648 by incorporating registration adjuster means 600 (discussed above) . This embodiment allows for greater latitude in the tolerances of interacting registration parts such as chapter dimensions and registration pin placement and size. Alternative Recording/Writing Embodiments Yet another apparatus and method is described in connection with Figures 60A through 60C for directing the recording light data page to a selected page on the data layer. This scheme uses an ultrasonic lens module in place o the mechanical movers 259 for the microfield lens array shown in Figure 18 while still providing recording light intensity of that system. Also, while the LCD shutters are retained in the preferred form of this embodiment, certain applications may omit the shutters and rely solely on the selective light guidance of the ultrasonic lens. Thus, with reference to Figure 60A, a write/read or writ only memory 712 is shown having a generally cubical shape similar to memory 212 in the above described write/read syste of Figure 18, but here replacing the movers 259 of that embodiment with a dynamic ultrasonic lens module 715 best shown in the front elevation view of Figure 6OB. Between ultrasonic lens module 715 and a data page composer consistin of recording light sources 251' is an array of fixed field lenses 718 which are similar to the microfield lens array 257 of the embodiment of Figure 18, but in the embodiment of Figure 60A, these field lenses remain stationary, relying on the ultrasonic lens module 715 to selectively guide the recording light from the recording bit sources 251' toward th selected page on data layer 19'. In some applications the ultrasonic lens may provide all of the needed light directing function in which case the fixed field lenses 718 can be omitted. In accordance with the theory of ultrasonic optics, as known per se, a longitudinal (i.e., compressional) ultrasonic pulse is injected into an edge of a glass plate 720 causing the density of the glass to be dynamically increased at the compressed area, hence causing the index of refraction to be increased. At the rarefactions, the density is decreased and there the index of refraction also decreases. By shaping the launched ultrasonic pulse properly, the compression forms a positive lens. And if the rarefactions are used, the lens is negative. Of course, the lens is transitory in time/position, i.e, dynamic, so the ultrasonic waves must be synchronized with the desired motion of the lens through the glass. A continuous ultrasonic sine wave is introduced along tw axes X,Y of glass plate 720 by edge transducers 730 and 732 (see Figure 60B) . The glass plate is placed adjacent the array of laser diodes used as page composer of recording sources 251'. An array of fixed field lenses is positioned between the light sources 251' and the glass plate 720. The sine waves are not standing waves, they are absorbed at the opposite edge by ultrasonic absorbers 734 and 736 (Figure 60B) . At any instant, there will be many points on the glass plate where compressions intersect. At these points, the two waves define an approximation of a positive spherical lens. The ultrasonic frequency applied to transducers 730, 732 is chosen so that the wavelength of the compressions in the glass corresponds in an integral way to the pitch of the sources, and when the compressions are in the correct location, the recording light sources are pulsed. Note that there is a negative lens between each positive lens. With th recording light wavelength equal to the pitch, each ultrasonically created lens diameter will be 1/2 the pitch. Since the source beam diameter from recording sources 251' will be larger than 1/2 the pitch at the glass plate, the ultrasonic wavelength preferably twice as large (or an integral multiple larger) . When twice as large, there will b negative lenses over adjacent sources, so that it is necessar to pulse the sources 251' alternately to coincide with the positive lens in the glass plate 720. The direction of the beam after the lens depends on the location of the center of the lens relative to the center of the source. By timing the source light pulse a little early or late (or by shifting the phase of the ultrasound) , the bea direction is adjusted to direct the source light bit to the position of the chosen page. Furthermore, this is a 2 dimensional system, so that a change in the source timing causes the beam to move on a diagonal across the data card. In order to sweep the beam in 2 dimensions to control the recording bit placement, it is necessary to change one phase plus the timing, or change bot phases with a constant source timing. In this embodiment we change the phase to one transducer 732 and vary the timing of the recording light strobe as shown in Figure 60C. The objective of the system is to direct the light from each source into the desired page microlens. Therefore each source beam must be at a different angle. To do this, the wavelength would be adjusted slightly less than the source pitch. The wavelength in the glass is a function of the temperature of the glass. Therefore the direction of the beams will depend not only on the phases and timing, which are easily controlled, but also on the temperature. There are a number of ways to control this temperature variable including the disclosed feedback 756 described below. Alternatively, the temperature of the glass can be controlled with an oven or other thermal regulated module of known desig for electronic components. The temperature can be measured, and the phases adjusted according to an analytical or empirical dependence. The LED read light sources can be used as light detectors. In the latter case the light intensity through the data mask is compared to a reference and to the intensity through the nearest neighbor data pages. The phase and frequency of the two ultrasonic drive circuits are then adjusted by feedback to maximize the intensity at the desired data page. As an example, the source pitch is given to be 30 microns, and a glass with a velocity of 4000 m/s is used, and a wavelength of 60 microns is desired. Then the frequency o the sinusoid driving the ultrasonic transducers is about 66.6Mhz, with a period of about 15 nanoseconds. The maximum full range of timing or phase adjustment will be half of that, 7.5nsec, corresponding to the time width of a lens. The strength of the lens which is set by the intensity of the ultrasonic wave is then adjusted to give a maximum optical power. The control end ultrasonic drive electronics is shown in Figure 60C and includes an oscillator source 750 generating the primary sine wave which is then passed through an amplifier 752 to drive the X-axis transducer 730 through a matching network 754. Feedback 756 responds to an acoustical sensor (transducer) on the glass opposite transducer 730 and controls the fundamental frequency of oscillator 750 to establish the desired wavelength in the glass; i.e., it requires a specified phase at the edge of the glass. Tapped from oscillator source sine wave source 750, the same fundamental frequency is fed through a phase shifter 760 and an initialization on/off switch 762, amplifier 764 to drive the Y-axis transducer 732 via a matching network 766 as shown Switch 762 is normally off so that feedback 756 calibrates or initializes the circuit in response to X axis waves only. This switch is turned on when activated by data in register 770 and turned off after a delay 774 that allows the ultrasonic waves to fill the glass plate. As described below this delayed activate signal causes gate 776 to be enabled fo strobing by a delay phase shifted oscillator pulse. Phase shift 760 is one of the primary circuits for determining the lens position so as to direct the recording light bit to the desired page and this is achieved through an addressing schem including a page address fed to a register 770 that includes address bits that operate through a digital-to-analog converter 772 to provide the predetermined page directing lens timing by supplying the desired phase shift to phase shifter 760 in accordance with the address. Similarly, the address in register 770 activates the "on" switch 762 and provides a delayed enable logic level to a light source strobe gate 776. Also the delay 774 turns off the switch 762 after the data has been recorded to allow reinitialization. The timing pulse to gate 776 is taken from the main sine wave oscillator 750 through a fixed delay (see + 60° phase shift in the wave form of Figure 60D relative to the master oscillator wave driving the X-axis transducer). Thus, the tapped master sine wave form is fed over line 780 through another fixed delay 782, then through a controlled time phase shift 784 which triggers a pulse generator 786 that provides the strobing or output pulse to gate 776 that in turn strobes the light source associated with that lens address. The timing of phase shift 784 is controlled through a digital-to-analog converter 788 that is addressed by register 770 in manner similar to the addressing of digital-to-analog converter 772 controlling phase shifter 760. The data on bus 790 is fed to the page composer light sources for enabling those particular light source bits that are to be recorded to be illuminated on the page composer. The output from register 770 called lower power read, selects low power for the LED feedback function, and/or for reading the data (rather than the normal writing mode) when a reflection surface is provided behind the data a described above in an alternative embodiment, thereby obviating the need for the usual LED read light sources. Multiplexing The Light Sources In the embodiments of the optical memory shown in Figure 1-24, each page of data has a corresponding LED light source (or group of sources jointly driven) for reading the data in that page. Figures 61A, 6IB and 62-64 illustrate alternative embodiments to conserve on the number of light sources for lower cost applications without sacrificing the number of accessible pages. This is achieved in one aspect of the invention by multiplexing the light sources in conjunction with read LCD shutters or other light valving or direction function. The general scheme is to make one light source serve selectably several data pages. In the embodiment of Figures 61A and 6IB, each light source (e.g., sources 800-805) is arranged to illuminate a 2x array of 4 pages as best shown by source 800 illuminating one of the array of 4 pages in Figure 61A. A matrix of liquid crystal shutters (LCS) 810 is located close to the plane of the data pages. The LCS could be on either side of the page plane, but in this embodiment it is on the side next to the sources 800-805. Each element of the LCS array is the same size as the source illuminated 2x2 page array, but offset one page in both X and Y. That is, each square LCS element can control the light though only one page of the four that are illuminated by a particular source as indicated by LCS contro lead 820 from drivers 822. When source 804 is turned on by the drivers 824, the LCS opened by control lead 820 selects one of 4 pages for reading on the common sensor. This arrangement would reduce the number of sources by factor of 4, and if every other LCS element is on (in both X and Y) then for a particular setting of the LCS, one quarter of the total data can be accessed, one page at a time, by sequencing the sources only. The other three quarters of dat pages can be accessed by the same sources, but after the LCS "checkerboard" has been shifted one element in X or Y or both As an example, where there are 50x50 pages in a chapter, there would need to be 2500 sources on a page/source basis. In this embodiment, only 625 sources are required. In the embodiment of Figure 62 each light source such as an LED is connected to a light pipe or light guide 830. Each guide here is a flat wafer, roughly one half of an ellipsoid in shape, with the source at the focal point and the truncate ellipsoid face congruent with a column of data pages. The outside surfaces are aluminized (reflective) so as to distribute all light to the truncated face in an efficient manner. The thickness of each guide 830-1 n is equal to on page, and the light filled face of the ellipsoid would be as long as a column of pages of a chapter. Between the truncate face of the guide and the pages is a set of LCS 832, where each LCS element is 1 page wide and as long as a full row of pages. Only one element would be on at a time. In the example of a 50x50 page array, 50 sources and 50 LCS elements would be needed. Fifty pages could be accessed with one setting of the LCS array. In the embodiment of Figure 63 guides 840-1, 840-2, through 840-n are 2 pages wide and each element of the LCS array 842 is one page wide and 2 pages long (in the case of a 2-page wide guide), and made to overlap the guides one page. The LCS elements are wired alternately along all columns, so that either the even or odd ones are on. This will select rows two at a time. The particular row is selected by the LE source. Columns are selected separately, so only one column has any open shutters at a time. In the case of, say, 50x50 pages in a chapter, there would be 25 light sources, and 25 guides. With one setting of the LCS, the system could access 25 pages by source sequencing. Alternatively, in Fig. 64, the guides 850A and 850B are 1/2 (but could be 1/3, 1/4, etc.) of the chapter dimension, with a corresponding inverse increase in the number of sources. The advantage is 2x, (or 3x, 4x, etc.), increase in the number of pages that can be accessed with one LCS 852 setting. There would be only one LCS element on (open) in each group of guides. As an alternative to the above light guides, they can be replaced by holographic beam distributor elements, known per se. Such an element is essentially a set of gratings, set at various azimuth angles and periods. A (narrowband) light beam (source) directed into the element is split into as many subbeams as there are gratings, and each subbeam is directed to a specific location. The application here is to apply a matrix of LCS elements near the data pages as before. However, the pattern of the elements can be somewhat arbitra due to the beam output of the holographic distributor, and hence selected to simplify manufacturing. For example, the pattern can be 5x5. In this case, for a chapter as above, each element would cover 2500/25 = 100 pages. Now there wou be 25 gratings on each read light source, so each source wou direct light to one specific page in each LCS element area. But only one element would be on at a time, so a particular source would only illuminate one specific page. By sequenci the sources, 25 pages can then be read without changing the LCS. In this case, 100 sources would be required. In the above multiple guide examples, and the holograph example, a diffractive element near each page is a desirable feature in order to further direct the beam in the proper pag direction. Submultiplexing Of Data Pages With reference to Figures 65A-65D and 66A-66C, a read optical memory embodiment is provided similar to the above described read memory in Figure 3A, in which the multiple rea light sources are modified so as to selectively illuminate an hence read portions of full data pages onto the underlying sensor array. Thus in the embodiment shown in Figures 65A an 65B, read light sources 860 are disposed at selected angles o emission in groups of four as best shown in Figures 65A and 65D, and combined with an array of holographic gratings, HOEs (holographic optical element), 862, that respond to the angle of light sources 860 to cause one of four selective quadran of the data page to be imaged on the underlying sensor array 27. The HOE array 862 array 862 can be located just before just after the first surface of the lens system, and in this case is located between the first and second refractive surfaces of lens array 21 as illustrated. The individual light sources 860a, 860b, 860c and 860d are, in this embodiment, arrayed in a group of four, each group of four corresponding to a single page of the data layer 19 and have an angle of emission canted inwardly toward a central axis as best shown in Figure 65C and 65D. This angle A as shown in Figure 65B of each of the sources 860 relative to a central optical axis through the page lens system coax with HOE 862 t shift the imaging rays that are formed by data layer 19 at each page so that portions of the data page are selectively shifted on the sensor array 27 as best illustrated in Figure 65C and 65D. Thus, in Figure 65C, one of four angled sources 860a, which may be provided by LEDs, is turned on. Imaging light from source 860a in fact picks up data rays for the entire associated data page. However, only quadrant A of the data page is imaged on sensor array 27, the remaining data page quadrants B, C and D, although partially illuminated by source 860a, are shifted outside the sensing area of array 27. Thus, a quarter of the data page is read on sensor array 27, lessening the size requirements of array 27 to only one fourt of the number of sensor bits as contained in the entire four quadrants of the data page 865. In Figure 65D, for comparison, another one of the four sources 860b is turned on causing the same data page 865 to be illuminated; however, by the coaction of the angle of source 860b and the array of HOE 862, quadrant B of page 865 is now imaged on sensor array 27 and read in accordance with the processes described above in connection with the main embodiments. No increase in overall density of the memory is achieved, but for certain applications, there is an important reduction in the overall size of the sensor array 27 while maintaining the same size and density of the recorded pages in data layer 19. In Figure 66A, an alternative embodiment is shown simila to the optical memory of Figure 65A, but here the group of four light sources 870a, b, c, and d, are differently colored light sources or sources of the same broad wavelength augmented by different color filters and combined with a colo selective HOE 872 sandwiched between first and second diffractive lens elements 877 and 879. Light sources 870a, b c, and d, can, for example, be provided by a yellow, green, red and near infra-red LED device available from manufacturer such as Hewlitt Packard Corporation of Palo Alto, California. The HOE diffractive elements in array 872 shift the light ray that carry the data images as a function of source wavelength to achieve the selective reading of different quadrants of th full data page 875 onto sensor array 27 as best shown in Figures 66B and 66C. In Figure 66B, color source 870d acts through HOE array 872 to image quadrant D of data page 875 onto sensor array 27; while in Figure 66C, source 870c images quandrant C onto array 27 with the remaining quadrants of da page 875 being shifted off of array 27 as illustrated. Holographic Beam Splitter For Multiple Read Modules Sharing Common Sensor In the embodiment shown in Figure 67A and 67B, a multip read module memory 890 is provided, formed about the essentially cube-like configuration of the above read memory shown in Figure 3A and described above, but here having a plurality of separate, fully implemented read modules, Rl, R2 and R3, arranged about the top and, in this case, two sides o the central image expansion region now occupied by a multiple way holographic beam splitter 892. Beam splitter 892 is essentially of regular polygon configuration, here a cube, in which data read from any one of multiple separate read module Rl, R2 and R3 is directed onto common sensor array 27. Each of module Rl, R2 and R3 is of like construction shown by the cutaway of Rl, including light source drivers 13, light sources 15, data layer 19, lens array 21, diffractive corrector 23, and field lens 25. Holographic beam splitter 892 has a compound or multiple way beam splitting function illustrated by splitting planes 892-2 and 892-3 for the side read modules R2 and R3 (the imag from read module Rl passing through beam splitter 892 to sensor array 27). The read images for R2 and R3 are turned 90° as illustrated onto sensor array 27, thus enabling the same sensor array 27 to read data from any selected illuminated page from any one of the multiple read modules Rl R2 and R3 without requiring a separate sensor module. In constructing the multiple-way holographic splitter 892, photopolymer materials are used to form separate segment of the beam splitter defined by the splitting planes 892-2 an 892-3 and after such segments are formed using holographic exposure techniques, known per se, the individual pieces of cubical splitter 892 are adhesively reassembled. To expose the materials for forming the splitting planes, each plane is illuminated by a combined reference beam and image beam using coherent wavelength sources and each surface is formed with a operating hologram that causes read data images from each of the read modules Rl, R2 and R3 to be reconstructed on the sensor array 27. Density Increase By Color The data record can also be composed of 2 or more layers of subtractive color filter material forming composite layer 19. The data consists of transparent spots in each layer. The layers are usually presumed thin so that the focal planes for each color substantially coincide. Light sources of different colors are used to read and record. Each layer contains data, thus greatly increasing storage density. In such an alternative embodiment, it is difficult to build a lens system that does not have any lateral chromatic aberration, i.e., the image magnification is a secondary function of the wavelength. A shift in magnification of as little as .1% could mean a mis-match of one bit between the data image and the sensor array. The first part of the solution is to employ a method of recording through the lens (or an equivalent lens) as described above in connection with Figure 1, so that the readback is automatically corrected for magnification. But when the lens system is made up of diffractive elements, the focal length will be inversely proportional to wavelength. With a multicolor system, the selected wavelengths might range from, say, .8 to .4 microns, a factor of 2. Such a shift in focal length would distort the image. The second part of the solution is to make one or more of the diffractive elements that make up the lens system out of binary elements using the same dyes that are used in the data mask. That is, the diffractive elements would be of the absorptive type (such as a classical zone plate) where the absorptive parts are composed of a subtractive color dye. The point is that the element is only effective at the wavelength(s) that is absorbed by the dye. Therefore, several elements may be stacked together, one for each color that is to be used, and where each element is designed to correctly focus a specific color. The disadvantage of this approach is that absorptive diffractive elements are not efficient, so stronger light sources or longer sensor integration times will be required. But this may be acceptable for applications that require higher density, and where speed is not as crucial. Density Increase By Depth Again, as before, this alternative embodiment provides multiple data layers separated by spaces that are substantially larger than the depth of focus of the lens system. Different layers of data are selected by shifting the focus. In previous art, this shifting of focus was mechanical, i.e., an objective lens (there was only one) is moved to focus in on the required layer. This movement can be augmented by color selection. With the present array system, the problem is how to select the proper data layer. Mechanical devices and/or beam splitters have disadvantages for this application and are not preferred. It is preferred to use colored sources for data layer selection. The optical system is constructed so that longitudinal chromatic aberration is not fully corrected. This means that the focal distance of the lens system will vary with wavelength. With appropriate design, the lens will focus each separated data plane on to a single sensor on the basis of color. This system is different from the multi-color record system, in that the data planes are monochrome, probably are inverse sense, i.e., the bits are opaque and the surrounds are transparent, and are spaced a few (3-6) microns apart. Density Increase By Polarization Two different sources are employed to illuminate the data, with polarizations at right angles. Two data planes are composed of polarizing material also set at right angles. The bits are holes in the material. This technique will provide for only two data planes. Spaced Sensor Rows With reference to Figure 68, an alternative embodiment of the sensor and register array 27 is illustrated for improved readout reliability by sacrificing image density. In particular, sensor and register array 27 is provided with spacing between rows of sensor elements to eliminate image overlap in one dimension and the output data is processed from the adjacent elements in common rows by simplified processing circuit 950 that subtracts out the overlap light from adjacent bits. By increasing the space in one dimension, in this sense it's between the rows of array 27, the processing circuit 950 operates on a serial data stream output from parallel-to- serial register 141 to correct for inter-symbol interference (ISI) . In the illustrated embodiment, sensor and register array 27 uses the same array as described above in connection with Figure 15A and data from the record is stored only in alternate rows, bypassing the intervening rows to create the desired inter-row space without requiring fabrication of a different sensor array. Alternatively, the sensor and register array shown in the embodiment of Figure 68 may be specially made to provide a blank space between rows and that blank space may be somewhat less than a full sensor element spacing as exists in the present embodiment but with sufficient inter-row space to substantially eliminate image cross-talk between adjacent data rows. To resolve the data along each row and hence reduce image cross-talk, the data is serially stepped out of register 141 into processor circuit 950 which includes preceding and following subtraction circuits 951 and 952 each being made up of a one bit delay, an attenuating resistor R and an Invertor connected to a summing junction 953 as illustrated. Data imaged on sensor and register array is sequentially down shifted through the array into parallel-to-serial register 141 and then out shifted from register 141 into processing circuit 950 in which the preceding and trailing data bits are subtracted at summing junction 953 with the center or desired data bit existing at the juncture of the one bit delays. Hence raw data signals on the preceding and trailing sensors are subtracted from the desired data bit correcting the serial data which is output on lead 954 and passed on to the downstream data processing. The attenuating resistors R are selected to cause subtraction of only a fraction of the preceding and following data bits to negate the overlap of the fringes of light images that overlap the sensors on array 27. As an example, subtracting a value of 10 percent of the full amplitude of the preceding and trailing data bits is suitable. 1 ,1 ,0 Λ Color and/or Polarization Filtering of Overlapping Data Spots Figure 69A, 69B and 69C show various forms of polarizing and/or color filtering of adjacent sensor cells on array 27 as an embodiment of the invention for improving reliability by reducing cross-talk between sensor cells. Thus in Figure 69A, a two filter scheme is illustrated in which like polarizing or color filters are located along the diagonals representing a greater inter-cell spacing than occurs along rows and columns. The two filter embodiment is constructed by overlaying the filter array 1002 over the sensor sites of array 27 so that the centers of the circular filters in this instance are coincident with the centers of each sensor cell. A two filter screening in this manner may be by using alternate polarizations or two different filter colors. To read out data in this embodiment, each page will be illuminated by two sequentially driven sources either differently polarized or of different colors and the sensors of array 27 are read in synchronization with each source flash. In the case of the polarization of two filter array 1002, the two types of polarizers are at 90° apart, and corresponding light sources would have likewise a 90° or orthogonal polarization. Figures 69B and 69C illustrate variations of differently colored filters, including a three color filter version in array 1004 in Figure 69B and a four filter array 1006, again of a plurality of different colors illustrated in Figure 69C for even greater separation between like filtered elements. The three and four filter versions 1004 and 1006 require a corresponding number of colored light sources flashed in sequence and the data read in synchronization therewith as described above for the two filter embodiment. Focal Plane Lens Array The embodiment shown in Figure 70 enhances the precision by which the data light rays from the imaging optics are directed onto the elements of sensor array 27. Because the rays from the data light are striking the sensor plane at an angle that is usually not normal and because the light rays tend to be somewhat diffracted or dispersed, this embodiment provides a focal plane lens array 1010 provided by an array of single surface refractive lens elements indicated at 1012 and formed by a molding process on an optical plastic or transparent spacer 1014 that lies flush against the sensor image plane. The bundle of light rays associated with each data bit as depicted in Figure 70 are refocused by the refractive surface elements 1012 so that the refocused image bit strikes the sensor elements squarely and with greater sharpness than without the focal plane lens array 1010. The focal length of elements 1012 is relatively short, on the order of the center-to-center spacing of the lens contours and hence on the same order of spacing as the sensor elements as described above. The thickness of the transparent optical spacer 1010, which may be plastic or ordinary glass, is approximately three to four times the center-to-center spacing of the lens surfaces 1012; however, this spacing will change depending upon the type of spacer material used. One advantage of this focal plane array is that each sensor element can be made smaller, thus improving the signal-to- noise, and leaving more room adjacent each element for on site processing elements. Field Flattener Lens at Sensor Plane In Figure 71, an optical system is shown in a view similar to that of above described Figure 13, but with the addition of a piano concave field flattener lens 1020 placed up against the sensor plane of array 27 as illustrated. Also, in this embodiment, the relatively high powered imaging optics are provided by an all diffractive array 1022 (shown for one data page only) which may utilize the all diffractive lens system described above in connection with Figure 25. The field lens 25 remains as a refractive element. The advantage of a field flattener lens 1020 is to reduce the requirements on the imaging optics to produce a flat image field, in turn, the manufacturing of the imaging optics will be less expensive. Alternative Embodiments of Sensor Array and Data Processor With reference to Figures 72A, 72B, 72C, and 72D, an alternative configuration of the sensor is shown as a large scale integrated circuit sensor array 1050 in Figure 72A in which each sensor site or cell appears separately in Figure 72B on an enlarged scale as cell 1050'. The number of cells in array 1050 will depend on the desired data storage capacity of the optical memory and the resolution specifications, but as an example of one embodiment, an array of 512 x 512 IC sensor cells 1050' is formed on the sensor chip. Each cell 1050' as depicted in Figure 72B is shown in a further enlarged and shaded IC topographical layout in Figure 72C and the corresponding schematic diagram is depicted in Figure 72D as cell schematic 1050''. Each of the cells 1050' receive light data in the area of photodiode PD1 shown by the textured region that is roughly three quarters of the overall rectangular cell site and generally centered in the rectangle. The remaining elements, including various input and output metallizations as well as FET transistor gates, are shown in Figure 72C by like reference numerals in the schematic diagram 1050" of Figure 72D. Thus the FET gates appear as ql, q2, q3 and q4 in both figures and the various input supply and output Vdd, rstn (reset), ens (enable side), and enc (enable center), gnd (ground), side and center signal outputs also are indicated in both figures. As explained herein, the side and center outputs, when enabled by ens and enc, respectively, produce the detected light signal in analog form as raw signal information by means of two isolated outputs which are used in an off site processing of these signals to develop the corrected and processed binary data in the manner described below. Alternatively, the processing can be on site in the IC matrix or along the edge of the IC sensor module chip. In order to read information off the sensor placed in th focal plane of the data image, the sensor 1050 and associated signal processing decides where to look for each bit and then determines whether the bit value is (1) or (0). Ideally, the sensor module automatically aligns itself to the data image, suppresses the optical intersymbol interference between bits, and quantizes the optical information into digital (1)s and (0)s. For this embodiment, sensor 1050 uses twice the bit density or size as the image it is trying to discern to prevent image aliasing. Thus, for each nominal optical data spot, a 2x2 array of four sensor cells 1050 is used. The image is initially found by means of peak detectors, the method of which is described in detail below, by searching a known area for fiducial data or special marks in the data image. Once these peak fiducial values are located, the offset and skew (rotation) of the image are known within one sensor cell. This allows the system to locate any particular spot (or bit) that it chooses. When the bit value of a particular address is desired, the processor (see Figure 73B) adds the effective offset value to its programmed address and examines the appropriate data levels at the sensor plane. To suppress optical interference between bits, the processor not only examines the image bit containing the information it wants, but also looks at neighboring bit values. Depending upon the optical spot spread and the orientation of neighboring image bits, a percentage of each is subtracted from the bit of interest. To quantize this analog valve and convert to binary data, a threshold is set. This function is served by looking at peak current values in the region of the cell site that is being examined. Knowing the maximum value and the fact that this value represents a (1) and that the minimum value represents a (0) yields a central current value around which a decision is made. Coding format can assure that there are (l)s and (0)s nearby. This allows the processor to compensate for intensity variation across the data' image and to make the best decision for each bit based on its environment, yielding the best signal-to-noise ratio. An example of the basic sensor cell used for this technique is shown by the circuit schematic of Figure 72D that is the basic unit cell on the array. The circuit 1050" functions to collect photons in the photo-diode and produce a current for processing. The photo diode PD1 is constructed of an N+ diffusion into the substrate of the IC, commonly used for source and drain implants of the N-MOS species of transistor. This diode is back biased an amount equal to the power supply voltage Vdd to maximize its depletion region volume. A percentage of the photons striking the diode surface produce electron-hole pairs as they pass through the depletion region and impact the lattice. In the presence of the depletion region field, the electron-hole pairs do not recombine, and those form a photo current. This current is integrated on the gate capacitor of q2, producing a gate voltage proportional to the intensity of exposure and its duration. With an applied gate voltage, q2 will conduct and pass a current from the supply voltage. To sense the bit value, either q3 (center) or q4 (side) is turned on with a positive voltage. These devices act as switches to enable the photo-proportional current potential of q2 onto one of the two sensing buses. Depending upon whether the processor has determined that this particular bit is a side value or a central value determines which enable line (ens for side, enc for center) will be turned on. When the sensing operation is complete, the enabled FET is turned off and the rstn signal is driven to ground potential, discharging the gate of q2 and re-establishing the full depletion region on the photo diode. When this operation is complete, the rstn line is driven back to the supply voltage and re-exposure can occur. Sensor Processor With reference to Figures 73A and 73B, the sensor processor element provides an interface between the outside world and the data. The processor sits on a parallel digital data bus and talks to a system CPU like an ordinary storage device (such as RAM, ROM or a disk drive) . When the system CPU requests data by presenting the address and appropriate control signals, the processor's actions are set in motion. The first step is to initialize at 1062 by clearing the array of old data, effectively discharging all sensor cells to a known initial state. Having done this, the processor 1060 activates a light source, illuminating the germane data page on the record. This exposes the sensor to the data at which point the information can be accessed electrically. In the next phase of operation, the processor synchronizes at 1064 by determining where exactly on the sensor the data is imaged. This is to account for any mechanical misalignment that may have occurred due to functional tolerances (each new piece of media mounted to the reader will have a new randomly determined alignment) . To do this, the processor initiates a peak detector action which returns the sensor address of known fiducial data from several locations. This gives the processor relative addressing information which is used to modify the word address presented by the system CPU, thus the correct sensor data location may be accessed. At this point, page data may be obtained. The relative address is presented to the sensor from the processor and the analog information from the sensor is input to the de-blurring and threshold circuitry on the side of the sensor. This function removes any interference between bits and then decides whether a location contains a one or a zero. In this way, the processor constructs the word in a digital format. Having done these steps, the processor can then feed the data to the system CPU via the data bus. If another word in the same page is requested by the system CPU, the processor simply goes out and accesses the desired sensor location without re- exposing the sensor to a new data patch (page) . An address on a new page requires that the sensor be cleared and that a new data patch be imaged on the sensor. Peak Detection The image is aligned by means of peak detectors which go out and search a known area for fiducial marks in the data image. Once these peak values are located, the offset and rotation of the image are known within one sensor cell. This allows the device to locate any particular spot (or bit) that it chooses. When the bit value of a particular address is desired, the processor can add the effective offset value to its programmed address and examine the appropriate bits. Since image rotation will be small, any angular calculations degenerate to linear summations not trigonometric operations. This is due to the fact that Sin(x)=x for small x. Thus both offset and rotation can be accounted for by an offset address which varies across the image (depending upon the rotational angle) . Algorithm To suppress the optical interference between bits, the processor must not only examine the bits containing the information it wants, but must also look at neighboring bit values. Depending upon the optical spread and the orientation of neighboring bits, a percentage of each is subtracted from the bit of interest. This may be done in several ways, such as weighted voltage summing, charge summing or current summing. For this discussion, current summing will be described. Presuming that bit values are available as currents, in a randomly accessible fashion, the processor can enable the central bit (the one containing the information desired) and subtract from it portions of the surrounding (side) bit values. This can be done using transimpedance amplifier configurations or simple current mirrors. This difference yields the actual bit current if there were no optical interference. Such an operation is inherently parallel since several bits need to be accessed in order to evaluate a single bit, thus the technique can be applied to a whole word. Also, this method is best applied as the word is read out, and fortunately so since this speeds the access time up. In actuality, three words are accessed at once by parallel read lines. This allows the construction of the local neighborhood for each bit, forming the inputs required for the intersymbol interference inhibition algorithm. Decision Making Now with de-blurred analog information, the processor must decide whether a bit contains a one or a zero. To quantize the signal, a threshold must be set. This function is served by looking at peak current values in the region of the bit that is being discerned. Knowing the maximum value (and the fact that this value represents a one) and that the minimum value represents a zero yields a central current value around which a decision can be made. Coding format can assure that there are ones and zeros nearby. This allows the processor to compensate for intensity variation across the i age and to make the best decision for each bit based on its environment, thereby yielding the best signal to noise ratio. An example of the basic bit cell which can be used for this technique follows. The rationale for the interconnect scheme shown in this embodiment is best understood by considering the nature of the algorithm. Since all bits surrounding the one of interest need to be evaluated, their information must be brought to the edge of the sensor array as well. Thinking in terms of a vertical orientation (with the algorithm circuitry at the bottom of the sensor bit array) , the bit values to the left, right, top and bottom of the desired bit, must be available in addition to the values at the corners of the 3X3 array of bits making up the neighborhood (with the bit of interest at the center) . To accomplish this with the least amount of interconnect one can consider that the values above and below the central bit to have an identical impact upon the algorithm evaluation. Thus they may be summed, and this influence upon the weighting of their contribution can be taken into account in the processing. Summing in this scheme is simply the addition of currents, thus a single interconnect line suffices to bring out the information of two bits. This accounts for the labeling of side bit and the signal name ens, for "enable side". The central bit must be brought out uniquely, so a second line is required. The name for its enable signal enc (for enable center) reflects this. Were these aspects of the algorithm not true, three interconnect lines would be needed to bring out the required information. This would reduce the optical capture area and reduce sensor chip yield. In general, the theory of the processor is as follows. We presume a two dimensional random data source, I, passed through an effective linear space-invariant system which models optical blurring and misalignment. The data is encoded at the baud rate of 1 symbol per unit length T, which we call one baud. However, because each symbol is read out on a two- by-two grid, doubling the baud rate, we artificially view the input as being placed at twice the baud rate, with a single repetition in each dimension. This simplifies the discussion, by allowing us to formulate the problem at a single sample rate, 2/T. This increased sampling rate is crucial to system performance, since it acts to remove spatial frequency domain aliasing. Elimination of aliasing is required to mitigate misalignment. We write Σ I BfX h(x-m, y-1) m,l where the spatial impulse response, h, is sampled with misalignment, and can be assumed known, after measurement in laboratory tests. These tests have shown that a single input data symbol, read-out on a two-by-two grid, falls on a L-by-L grid, with L = 6. The required filtering can be broken down into three steps: realignment or interpolation (INT), equalization (EQ), and matched filtering (MF) . We briefly discuss the role of each filter. Interpolation is required to correct for offset and rotation of the input mask. This is a linear process (L) , b is space variant (SV) . The spatial variation is due to the rotation, as the corrective interpolation would be space- invariant in the presence of offset alone. The offset proble is a common one in data communications, and is referred to as symbol timing error. The rotation effect has no counterpart in one-dimensional data communications. Equalization, or deblurring or pulse sharpening, consist of providing a linear (L) filter to undo the effect of the blurring. When the blurring is space-invariant (SI), so is the filtering. If the blurring function, or optical impulse response, is known in advance through lab tests, the inverse filter can be synthesized in advance, and does not vary with position. The optimal LSI filter depends on the system noise level and on the blurring response, and presumes that the misalignment has been compensated. Matched filtering is a signal processing technique used to combat random Gaussian electronic noise. In effect, it is a weight-and-sum filter acting only on all pixels that contribute to any data value. Based on the lab tests, this will be a two-by-two grid. This filter is LSI, and can be cascaded with the equalizer. Thus, the EQ and MF are effectively a single filter, although they have different functions. THe MF is readout at the baud rate and is sliced or compared to a threshold to make a hard symbol decision on the data symbol value. This data can be FEC (forward error correction) encoded, and the hard decision can be forwarded t an off-chip de-interleaver and FEC decoder as required. Above, we have discussed the basic components of the information retrieval process: initialization, synchronizatio and interpolation, equalization, and matched filtering. In order to alleviate processing complexity, a simplified but effective system has been developed and is described in connection with Figures 73A, 73B and 73C. Misregistration and skew (rotation) forces the retrieval system to resynchronize each time a new mask is inserted. To aid this process, fiducial data or markings have been placed on the mask as described above for mechanical registration systems and again as shown here in Figure 73C, which are easily identified based on their unique signature and gross location. Basically, these are data arrays 1059 that lie at the corners of each page, but alternatively can be embedded i the data such as in the form of a large cross centered on the mask. By reading the offset in the horizontal and vertical w determine misregistration at 1064, and by reading the slope o these fiducial lines, we determine rotation. With computatio of the required trig functions, and multiplies and adds, the group of pixels surrounding information bit A is retrieved. (See Figure 73A) . Because of the gradual slew due to rotation, interpolation at 1066 of nearby intensities is used to correct for offsets of less than one full data bit. This operation requires scaling and adding of adjacent bits after read-out, as shown in the flowchart of Figure 73B. At this point, we have obtained the blurred values of data bits surrounding group A. In fact, this consists only o the adjacent bits marked B in Figure 73A, since far-out data are less relevant in the decision making. The next step in the general procedure is deblurring or equalization, as discussed in the generic procedure. In actuality, we combine equalization with matched filtering and thresholding to develop an expedient algorithm called "bit detection" 1068 shown in Figure 73B. The algorithm 1068 which has been implemented is based o a judicious approximation to ideal equalization. All bits labeled 'A' in Figure 73A are summed; this forming the matche filter, as the input mask is 4:1 oversampled upon readout. The ideal processing in a noise free environment would be the MF cascaded with the equalizer, or inverse filter. We have succeeded in approximating this filtering scheme by that shown in the last block 1068 of Figures 73B, where the sum of all bits at 'A' is compared to the sum of all intensity in the adjacent bits marked 'B'. These bits are further scaled by a factor "t" to properly approximate the ideal filtering scheme. The data then is passed through a threshold determination and the result of decision block 1070 is a (1) or (0) at the corresponding address. This data reading process is now complete and the data passed to a system CPU. As will be apparent, still further alternative embodiments fall within the scope of this invention including the use of reading light sources can be one of a variety of types. The requirements are that the bandwidths should be relatively narrow, turn on and off rapidly, and in practical applications, should be long-lived. For most applications, speed is desirable, so a high flux of photons, i.e. high power, is also desirable. Laser diodes would be best, and they are required for the highest speed systems, but they are the most expensive. LEDs may be used and those made as a monolithic array are preferred. Plasma, or electroluminescent arrays, such as are currently available for computer displays, would be effective, although each element cannot, at present, provide as much power as an LED. Field emission light source arrays, currently available as prototypes, are another alternative. The light elements can consist of a single source with an array of shutters between said source and the pages. In the embodiment shown in Figures 24a and 24b, the light source element on the IC in combination with the photosensor can be a silicon filament-type element which will lend itself to integration with the silicon based sensors more readily than GaAs sources. In alternative implementations of the write/read embodiments a wavelength may be used for recording that is different from that used for reading. In particular, a short wavelength, e.g., blue, recording light, would allow smaller spots to be made because diffraction would be less. In addition, there are desirable recording materials that are sensitive only to short wavelengths, such as photopolymers, diazo materials and energy storage crystals. Alternatively to the storage of binary data described above, the system can be used to store a multiplicity of analog pictures, e.g., patterns, photographs, etc., each randomly accessible at rapid retrieval times. Each page area would contain at least one photograph or pattern. When the page source is activated, a picture image is transferred to the sensor array. Each sensor of the array senses one picture element, i.e., pixel. The sensor array would provide an analog output for each pixel in the same manner as a TV sensor, except that pixels may be addressed randomly or at a non-TV standard rate. These data then may be compared or correlated with other data in a separate processor.

Claims: I claim: 1. An optical data system comprising: an optical data means for storing data as light altering characteristics and being organized into a plurality (P) of juxtaposed data regions each having capacity to store (B) bits of data; controllable light source means for selectively illuminating at least one of said separate data regions of said optical data means; data imaging lens means having a plurality of juxtaposed lenslets each being shaped and arranged in such proximity to and in optical registration with a separate one of said juxtaposed data regions so that the image resolving power thereof is substantially uniform over the field of view of that data region to form an image thereof on a common image surface spaced from said data means and lens means; sensor means having a plurality (S) of juxtaposed light sensors arranged at said image surface for sensing data as a light image corresponding to an illuminated data region; and data signal output means coupled to said sensor means for outputting data signals representing said data of an illuminated and imaged data region. 2. The system of claim 1 further comprising optical means disposed between said sensor means and said lens means and including diffraction means for correcting aberrations in the imaging of each data region by each of said plurality of juxtaposed lenslets. 3. The system of claim 1 wherein said plurality of lenslets of said lens means include contoured refractive surfaces of a continuous layer of optical material and further comprising optical means disposed between said sensor means and said lens means and having diffraction means and field lens means, said diffraction means selectively correcting light rays representing data images from said lenslets, and said field lens means directing light patterns imaged through said diffraction means from different lenslets onto said image surface. 4. The system of claim 2 wherein said diffraction means comprises a plurality of overlapping grating patterns arrayed so that individual grating patterns are in optical axial alignment with separate individual ones of said plurality of juxtaposed lenslets. 5. The system of claim 2 wherein said diffraction means of said optical means comprise holographic means having a plurality of overlapping holographic image correction patterns arrayed so that individual holographic correction patterns are in optical axial alignment with separate ones of said plurality of juxtaposed lenslets. 6. The system of claim 2 wherein said optical means further comprises a field lens disposed between said diffraction means and said sensor means for bending light ray patterns originating from different ones of said data regions and lenslets onto said common image surface containing said sensor means. 7. The system of claim 1 wherein each said lenslet has a Numerical Aperture in a range of 0.35 to 0.6, and a field of view substantially equal to an area of one of said data regions. 8. The system of claim 1 wherein each of said lenslets is comprised of at least one functionally aspherical optical element. 9. The system of claim 8 wherein said aspherical surface of each of said lenslets is disposed adjacent said data means. 10. The system of claim 1 wherein said data means and said lens means are formed as a unitary layered structure so as to maintain optical registration therebetween. 11. The system of claim 10 wherein said unitary layered structure of said data means and said lens means comprises a data layer having said data regions arrayed in juxtaposition thereon, a lenslet layer having said plurality of lenslets formed thereon as an array of juxtaposed lens surface contour having their individual optical axes aligned with registering ones of said data regions, and a transparent spacer layer disposed between said data layer and said lenslet layer. 12. The system of claim 11, wherein said transparent spacer layer optically immerses said data of said data layer to reduce an angle of image ray divergence relative to that of air or free space. 13. The system of claim 11 wherein said lens surface contours of said lenslets adjacent said transparent spacer layer are aspherical to provide substantially uniform resolution across the field of data in the aligned data region. 14. The system of claim 13 wherein each said data region has a contour toward said transparent spacer layer and said lenslet layer has second optical lens surfaces of said lenslets opposite from said transparent spacer that are substantially spherical. 15. The system of claim 14, wherein said second lens surfaces have predetermined aspheric factors on a substantially spherical surface. 16. The system of claim 10 further comprising structura means for receiving and releasably retaining said unitary layered structure of said data means and said lens means relative to said sensor means, whereby said unitary structure can be removed and replaced with a like structure storing different data. 17. The system of claim 1 wherein said sensor means comprises a plurality of sensor elements arrayed in a pattern that complements, on an enlarged image scale, data in one of said data regions of said data means. 18. The system of claim 1 wherein said data regions on said data means are arrayed in juxtaposed close-packed cells and sensor means has a plurality of said sensor elements arrayed to form said common image surface and having a perimeter in the shape of a single cell generally of the shap but larger than one of said data regions. 19. The system of claim 18 wherein said cell has the shape resembling a hexagon. 20. The system of claim 1 wherein said controllable light source means comprises an array of juxtaposed solid state light generating elements. 21. The system of claim 20, wherein said light generating elements are organized into groups, each group for illumination of a different one of said data regions. 22. The system of claim 20 wherein each group of said solid state light generators has a generally hexagonal shaped cell in the array and means for selectively energizing each said group to cause a hexagonal-shaped patch of light for illuminating a corresponding one of said separate data regions of said data means. 23. The system of claim 1 wherein said controllable light source means comprise an array of solid state light generators, said light generators being arranged in multiple- element groups, each such group having multiple elements and being arranged as a group in registration with a separate data region of said data means so that each group of elements is collectively energized to illuminate a separate selected data region. 24. The system of claim 23 wherein said plurality of solid state light generators comprise light emitting diodes. 25. The system of claim 23 wherein said plurality of solid state light generators comprise laser diodes. 26. The system of claim 1 wherein said data means is a light transmissive data means. 27. The system of claim 1 wherein said data means is a light reflective data means. 28. The system of claim 1 wherein said data means is a light polarizing data means. 29. The system of claim 28 wherein said light polarizin data means is a magneto-optic data means. 30. The optical system of claim 1, wherein said data bits are < 2.25 microns across and stored at a density of 2 x 10 7 or greater per cm 2 . 31. The optical system of claim 30, wherein each said data region stores B ≥ 10 6 bits and said plurality (S) of juxtaposed sensors and (B) bits of data stored in each data region has the relationship S > B. 32. The optical system of claim 1, wherein said (B) bit of data is defined by B > 10 s and said plurality of (P) data regions is P >_ 100 for a data capacity of the system equal to or greater than 100 megabits. 33. The optical system of claim 30, wherein said optica data means comprises data supporting means that has a substantially flat surface of area equal to about 6.5 cm 2 . 34. The optical system of claim 1, wherein each said lenslet has an effective focal length of substantially 1.0mm or less and is disposed with its first surface at substantially .6mm or less from said data means. 35. The optical system of claim 34, wherein each said data region has a dimension of d across its area, and each said lenslet has a first surface spaced within 1/10 d to 3/4 of said data means, and wherein said image surface at which said sensors are arranged is spaced from said lenslets by a distance greater than d. 36. The optical data system of claim 1 wherein said sensor means comprises: an array of solid state sensor elements formed in an integrated circuit structure providing said common image surface, and a plurality of adaptive threshold sensing circuit means for providing a variable, adaptive light sensing threshold to data images at each of said sensor elements in response to receipt of light on adjacent sensor elements. 37. The optical data system of claim 36 wherein said array of solid state sensor elements comprises a plurality of charge coupled devices. 38. The optical data system of claim 36 wherein said array of solid state sensor elements comprises at least one PIN diode. 39. The optical data system of claim 1, further comprising adaptive threshold sensing circuit means for providing a variable, adaptive light sensing threshold to data images incident on each of said sensors. 40. An optical data system comprising: an optical data means for storing data as light altering characteristics having a density on the order of one bit per square micron and being organized into a plurality of juxtaposed data regions each adapted to store a field of bits of data; controllable light source means for selectively illuminating at least one of said data regions of said optical data means; lens means having a plurality of juxtaposed lensle configured to resolve objects on the order of one micron or less and each arranged proximate and in optical registration with a separate one of said juxtaposed data regions for forming an image of the bit field thereof on a common image surface spaced from said data means and lens means; sensor means having a plurality of juxtaposed light sensors arranged at said image surface for sensing said data as a light image of an illuminated one or more of said data regions; and data signal output means coupled to said sensor means for outputting data signals representing said data of a illuminated and i aged data region. 41. An optical data system comprising: an optical data means for storing data as light altering characteristics on a substantially planar data storage structure and being organized in an array of close packed, juxtaposed cells and each cell adapted to store data; controllable light source means for selectively illuminating at least one of said cells of said optical data means; data imaging optical means having an array of juxtaposed lens subsystems disposed so that each said lens subsystem is proximate to and in optical registration with a separate one of said cells and has a center-to-center spacing relative to adjacent lens subsystems that is substantially equal to the corresponding spacing between adjacent cells in said data storage structure, and wherein each said lens subsystem has a Numerical Aperture in the range of 0.35 to 0. and a field of view substantially equal to an area of the one of said cells in registration therewith for forming an image of data in said cell on a common image surface; and sensor means having a plurality of juxtaposed light sensors arrayed at said common image surface for sensing data as light imaged from an illuminated said cell. 42. The optical data system of claim 41 wherein each of said lens subsystems has at least one refractive surface that is disposed within a distance d < than said center-to-center spacing of said lens subsystems. 43. The optical data system of claim 42 wherein said on refractive surface is aspherical. 44. The optical data system of claim 42 wherein each said lens subsystem has at least one diffractive surface disposed at a distance greater than d from said cell, and has overlapping diffractive areas so that overlapping data image rays from adajcent cells after passing through said refractiv surface are diffractively altered by overlapping diffractive areas. 45. The optical data system of claim 41 wherein each of said lens subsystems has an optical stop located at a predetermined distance from a registering one of said cells, each of said lens subsystems having at least one refractive means between a registering one of said cells and said stop and having at least one diffractive means at a distance from said cell greater than that of said stop. 46. The optical data system of claim 45 wherein said diffractive means comprises a plurality of over-lapping diffractive patterns, each pattern encompassing an area that is greater than the field of view of each of said lens subsystems so that overlapping data image rays from adjacent cells are diffractively corrected by different but overlapping diffractive patterns. 47. The optical data system of claim 44 wherein said diffractive means includes a grating. 48. The optical data system of claim 44 wherein said diffractive means includes a holographic pattern. 49. An optical data system comprising: an optical data means for storing data as light altering characteristics having a density in a range of the order of 10 7 to 10 8 bits per square cm and being organized into a plurality of (P) juxtaposed data regions each sized to stor a field of (B) bits of data at said density; controllable light source means for selectively illuminating at least one of said data regions of said optica data means; lens means having a plurality of juxtaposed lenslet each arranged in optical registration with a separate one of said (P) juxtaposed data regions and shaped to resolve said field of (B) bits of data thereof at said density substantially uniformly over said region to form an image thereof on a common image surface spaced from said data means and lens means; sensor means having a plurality of juxtaposed light sensors arranged at said image surface for sensing said field of (B) bits of data as a light image of an illuminated one or more of said data regions; and data signal output means coupled to said sensor means for outputting data signals representing said field of (B) bits of data. 50. An optical data system comprising: an optical data means for storing data as light altering characteristics and being organized into a plurality of juxtaposed data regions each having capacity to store bits of data; controllable solid state light generator means for selectively illuminating at least one of said separate data regions of said optical data means; data imaging lens means having a plurality of juxtaposed lenslets each having at least one functionally aspherical surface and arranged in such proximity to and in optical registration with a separate one of said juxtaposed data regions so that the image resolving power thereof is substantially uniform over the field of view of that data region to form an image thereof on a common image surface spaced from said data means and lens means; sensor means having a plurality of juxtaposed solid state light sensors arranged at said common image surface for sensing data as a light image corresponding to an illuminated data region; and data signal output means coupled to said sensor means for outputting data signals representing selective portions of said stored bits of data of an illuminated and imaged data region. 51. An optical data recording and retrieval system comprising: read light source array means; optical data record means disposed proximate to said read light source array means for being illuminated thereby; lens array means comprising a plurality of substantially similar lenslets arrayed in a lens structure disposed proximate to said optical data record means, each said lenslet forming a distal image of a portion of said optical data record means illuminated by said read light, source array means; light sensor array means disposed to receive said image of said portion of said optical data record means illuminated by said read light source means, said sensor arra means responding to said age to output data; and recording light data composer means for producing a recording light data pattern and imaging same onto said optical data record means for storing said data pattern. 52. The optical data recording and retrieval system of claim 51 having a read mode and a recording mode, further comprising beam splitter means that in a read mode causes read data to be imaged in succession through said lens array means and said beam splitter means onto said light sensor array means, and that in a recording mode causes said recording light pattern produced by said recording light data composer means to be imaged in succession through said beam splitter means and said lens array means onto said optical data record means. 53. The optical data recording and retrieval system of claim 51 wherein said recording light data composer means comprises controllable light valve array means and recording light emitter means for generating said recording light data pattern by illuminating said light valve array means so that a recording image thereof is directed onto said optical data record for storage. 54. The optical data recording and retrieval system of claim 53 wherein said recording light emitter means comprises an array of selectively energized record light sources, one for imaging data through separate ones of said lenslets onto an associated portion of said optical data record means, and further comprising a record imaging lens means disposed between said array of selectively energized record light sources and said controllable light valve means. 55. The optical data recording and retrieval system of claim 51 wherein said recording light data composer means comprises controllable reflective modulators arrayed in a data pattern, and recording light means for generating said recording light data pattern by illuminating said controllable reflective modulators so as to cause a reflected recording image thereof, and optical means for directing said reflected recording image through a selected lenslet onto an associated portion of said optical data record means. 56. The optical data recording and retrieval system of claim 51 wherein said recording light data composer means comprises an array of light source elements disposed substantially coplanar with said light sensor array means, and further comprising light shutter means disposed proximate said lens array mean for controllably transmitting said recording light data pattern composed by said array of light source elements through a selected one or more of said lenslets onto the associated portion or portions of said optical data record means. 57. The optical data recording and retrieval system of claim 56 wherein said array of recording light source elements and said light sensor array means comprise solid state devices. 58. The optical data recording and retrieval system of claim 56 wherein said array of recording light source elements and said light sensor array means are mounted on a common circuit board. 59. The optical data recording and retrieval system of claim 58 wherein said common circuit board comprises a large scale integrated circuit. 60. The optical data recording and retrieval system of claim 51 wherein said light sensor array means comprises soli state devices, and said recording light data composer means comprises means for operating said solid state devices as light generators. 61. The optical data recording and retrieval system of claim 51 further comprising controllable optical shutter means for selectively blocking recording light data patterns from selected regions of said data means. 62. The optical data recording and retrieval system of claim 51 wherein said recording light data composer means comprises a plurality of recording light emitters arrayed in a pattern that complements data patterns on said data record means. 63. The optical data recording and retrieval system of claim 51 wherein said recording light data composer means comprises an array of micro lenses and adjacent thereto an array of recording light source means for imaging recording light patterns onto said data record means through said lens array means. 64. A method of recording and reading optical data, comprising the steps of: composing a recording light data pattern by selectively operating light pattern controlling devices; optically forming a recording image of said recording light data pattern through one of a plurality of lenslets of a lens array onto a region of an optical data record, said region being in registration with said one of th plurality of lenslets; storing said recording image formed on said optical data record; and reading said optical data record by illuminating said region thereof storing said recording image. 65. The method of claim 64 wherein the step of reading comprises imaging said illuminated region of said optical dat record onto an array of light sensors using the same one of the plurality of lenslets of the lens array through which sai recording image was formed on said region of said optical dat record. 66. The method of claim 65 further comprising the step of physically bonding said optical data record to said plurality of lenslets by means of a transparent bonding material before the step of optically forming a recording image. 67. The method of claim 65 comprising the step of immersing said optical data record in a transparent material disposed between said optical data record and said lens arra before the step of optically forming a recording image. 68. An optical data recording system comprising: a recording light data composer means for forming pattern of changeable data to be recorded; data storage means having a plurality of separate data storage regions each for storing data imaged thereon; lens array means comprising a plurality of similar lenslets arrayed in a lens structure and disposed proximate t said data storage means so that each separate lenslet is optically in registration with a separate one of said regions of said data storage means; and optical selector means for causing composed data light patterns produced by said recording light data composer means to be imaged by said multiple lens array means onto a separate selected one of said data regions of said data storage means. 69. The optical data recording system of claim 68 wherein said optical selector means comprises controllable optical means for blocking recording light data to all but selected one or more of said regions of said data storage means. 70. The optical data recording system of claim 68 wherein said recording light data composer means comprises a plurality of recording light emitters arrayed in a pattern that complements each of the separate data storage regions on said data storage means. 71. The optical data recording system of claim 68 wherein said recording light data composer means comprises an array of micro lenses and an adjacent array of recording light emitter elements, said array of micro lenses directing recording light data composed on said array of recording light emitter elements into one of said lenslets of said lens array for being imaged thereby onto one of said data regions of said data storage means. 72. The optical data recording system of claim 68 having a read mode and a recording mode, further comprising beam splitter means that in a read mode causes read data to be imaged through said lens array means and said beam splitter means, and that in a recording mode causes said recording light pattern produced by said recording light data composer means to be imaged in succession through said beam splitter means and said lens array means onto said optical data record means. 73. The optical data recording system of claim 68 wherein said recording light data composer means comprises controllable light valve array means and recording light emitter means for generating said recording light data patter by illuminating said light valve array means so that a recording image thereof is directed onto said optical data record for storage. 74. The optical data recording system of claim 68 wherein said recording light emitter means comprises an array of selectively energized record light sources, one for imaging data through separate ones of said lenslets onto a registering portion of said optical data record means, and further comprising a record imaging lens means disposed between said array of selectively energized record light sources and said controllable light valve means. 75. The optical data recording system of claim 68 wherein said recording light data composer means comprises controllable reflective modulators arrayed in a data pattern, and recording light means for generating said recording light data pattern by illuminating said controllable reflective modulators so as to cause a reflected recording image thereof, and optical means for directing said reflected recording image through a selected lenslet onto a registering portion of said optical data record means. 76. The optical data recording system of claim 68 wherein said light sensor array means comprises solid state devices, and said recording light data composer means comprises means for operating said solid state devices as light sources. 77. The optical data recording system of claim 68 further comprising controllable optical shutter means for selectively blocking recording light data patterns from selected regions of said data means. 78. The optical data recording system of claim 68 wherein said recording light data composer means comprises a plurality of recording light emitters arrayed in a pattern that complements data patterns to be stored on said data means. 79. The optical data recording and retrieval system of claim 72 wherein said recording light data composer means comprises an array of micro lenses and adjacent thereto an array of recording light generator means for imaging recording light patterns onto said data regions of said data record means through said beam splitter means and said lens array means. 80. An optical data and lens structure for an optical data system, comprising: a data layer for storing data as light altering characteristics and being organized into a plurality of separate data regions; a lens array comprising a plurality of lenslets disposed adjacent said data layer and each lenslet having an optical field of view respectively aligned with one of said separate data regions so that each lenslet is arranged for imaging optical data associated with one of said data regions; and structural means interposed said data layer and sai lens array so as to optically couple and mechanically fix sai data layer to said lens array to form a structural unit. 81. The optical data and lens structure of claim 80 wherein said structural means comprises a transparent optical layer of bonding material. 82. The optical data and lens structure of claim 80, further comprising: an additional layer of material bonded to said data layer on a side thereof opposite from said first named layer and said lens array. 83. The optical data and lens structure of claim 81, wherein said additional layer is a transparent protective cover material through which data illuminating light may be passed from an external light source to illuminate said data layer. 84. The optical data and lens structure of claim 81 wherein said additional layer is reflective so that light illuminating said data layer through said lens array is reflected back toward said lens array to form a reflected dat image. 85. The optical data and lens structure of claim 80 wherein each said lenslet has first and second optical surfaces at least one of which is substantially aspherical. 86. The optical data and lens structure of claim 80 wherein said data layer at each said data region has an optical contour that optically coacts with the aligned one of said lenslets to image data at a distal image plane. 87. An optical data lens system for reading and/or writing optical data with respect to a data storage medium, comprising: a data imaging lens means having a first surface adapted to be positioned proximate an optical data storage medium, and having a second surface; said first surface having a substantially aspheric prescription so as to selectively alter data image rays from different locations of a data field proximate thereto, and said second surface having a relatively higher degree of spherical prescription compared to said first surface. 88. The optical data lens system of claim 87 wherein said second surface of said lens means is substantially spherical but has a predetermined amount of aspherical conte in its prescription for correcting aberrations in data image rays passing through said surfaces of said lens means. 89. The optical data lens system of claim 87 wherein said first surface of said lens means is refractive and further comprising an optical immersion layer formed between said first surface of said lens means and the optical data storage medium and having an index of refraction that is substantially unequal to that of said lens means at said firs surface. 90. The optical data lens system of claim 89 wherein said second surface of said lens means is also refractive and further comprising a glass material between said first and second surfaces, said immersion layer comprising a transparen polymer having an index of refraction greater than that of air. 91. The optical data lens system of claim 87 wherein said lens means is refractive and is made of a glass material bounded by said first and second surfaces, and said system further comprising a layer of data media for storing optical data as light altering characteristics disposed adjacent said first lens surface, and a transparent immersion and bonding layer interposed said first surface and said data storage layer for bonding said data storage layer to said lens means and having an index of refraction greater than air and substantially less than that of said glass material. 92. The optical data lens system of claim 87 wherein said leans means further comprises a third surface disposed in spaced apart relation to said second surface, and said first and second surfaces being refractive and said third surface being diffractive. 93. The optical data lens system of claim 92 wherein said lens means further comprises a fourth surface disposed in spaced apart relation to said third surface, and wherein said fourth surface is diffractive. 94. The optical data lens system of claim 87 wherein said data imaging lens means comprises a plurality of lenslets juxtaposed in substantially flat array and each said lenslet having said first surface that has a substantially aspherical prescription and a second surface that has said relatively higher degree of spherical prescription whereby " each of said plurality of lenslets cooperates with that optical data on t storage medium in the field of view of such lenslet. 95. An optical data sensor for sensing optical data imaged on a sensing plane, comprising: an array of solid state light sensor elements disposed for receiving imaged data; and a plurality of adaptive threshold sensing circuit means for providing a variable, adaptive light sensing threshold to data at each sensor element in response to receipt of light on adjacent sensor elements. 96. The optical data sensor of claim 95 wherein said array of light sensor elements comprises a plurality of charg coupled devices. 97. The optical data sensor of claim 95 wherein said array of light sensor elements comprises photosensiπg diodes. 98. The optical data sensor of claim 97 wherein at leas one of said photosensing diodes is a PIN diode. 99. The optical data sensor of claim 95 further comprising a plurality of solid state light emitters disposed substantially in juxtaposition with said light sensor elements, and means for selectively energizing said light emitters. 100. The optical data sensor of claim 95 wherein said plurality of adaptive threshold sensing circuit means comprises variable level comparator means, said variable leve comparator means connected to receive sensor output signals from predetermined subgroups of said sensor elements for changing a threshold sensing level at each said variable leve comparator means as a function of the amount of light inciden on said subgroups of said sensor elements. 101. The optical data sensor of claim 95 wherein said array of solid state light sensor elements and said adaptive threshold sensing circuit means are fabricated as an integrated solid state circuit. 102. A method of sensing optical data imaged on a sensin plane, comprising: forming a light image of a data pattern on an array of photo sensitive elements; outputting data from each element when light in sai pattern that is incident on one of said elements has a predetermined intensity threshold; and changing said intensity threshold in response to light incident on elements adjacent to said one of said elements. 103. The system of claim 1, wherein said data imaging means comprises for each said lenslet at least one diffractive element for imaging an associated data region, and at least one anomalous lens means for achromatizing the imaging rays. 104. The system of claim 103, wherein said anomalous lens means comprises an optical medium containing a buried refractive surface formed by a preselected dye that has an anomalous dispersion selected to cancel out color aberration caused by dispersion in the diffractive element. 105. The system of claim 103, wherein said anomalous lens means is in the configuration of a Fresnel lens. 106. The system of claim 1, wherein said data imaging means comprises for each lenslet at least one diffractive element for i aging an associated data region, and at least one anomalous lens characterized by an optical media having embedded therein an optical material exhibiting a predetermined sharp change in index of refraction as a function of wavelength. 107. The system of claim 1, wherein said data imaging means comprises for each lenslet at least one diffractive element for imaging an associated data region, and at least one anomalous lens formed by at least two optical media that exhibit a predetermined and selectable net dispersion such that the optical power introduced by said lens substantially affects color aberration only. 108. The system of claim 1, wherein said data imaging means comprises for each said lenslet at least one diffractive element for imaging an associated data region, and at least one gradient index lens means. 109. The system of claim 1, wherein said gradient index lens means is formed by a gradient of anomalous dispersion dye varying the index of refraction longitudinally of the optical axis. 110. The system of claim 1, wherein said gradient index lens means is formed by a gradient of anomalous dispersion dye varying the index of refraction radially of the optical axis. 111. The optical data system of claim 39, wherein said adaptive threshold sensing circuit means comprises an integrated circuit sensor array having a plurality of subarrays of grouped sensor cells for detecting a single light image bits and sensor processing means for detecting data bits from said light image bits. 112. The optical data system of claim 39, wherein each of said data regions has fiducial data stored thereon for registering the light image on said sensor means, and wherein said adaptive threshold sensing circuit comprises processing means for reading said fiducial data and controlling addressing of said data signal output means for adapting the reading of data from said sensor means according to said fiducial data. 113. The optical data system of claim 1, further comprising means for submultiplexing data from each of said data regions so as to cause portions of each of said regions to be selectively imaged on said sensor means. 114. The optical data system of claim 1, further comprising a field flattener lens means for correcting spherical aberration of said light image incident on said sensor means. 115. The optical data system of claim 1, further comprising a focal plane lens array after said plurality of juxtaposed lenslets and proximate said sensor means for refocusing each imaged data region onto said sensor means. 116. The optical data recording and retrieval system of claim 51, wherein said recording light data composer means comprises ultrasonic leans means for controllably directing said data pattern and imaging it onto said optical data record. 117. The optical data system of claim 1, wherein said controllable light source means comprises at least one light guide means for jointly illuminating a subset of said data regions, and electrically controlled shutter means disposed in a data image path between said light guide and said sensor means for shuttering image light from certain but not all of said subset of said data regions. 118. An optical data reading system comprising: at least one of an optical data storage medium with juxtaposed data regions thereon; a controllable light source means for selectively illuminating a data region on said data storage medium; a data imaging lens means having a plurality of juxtaposed lenslets proximate said data storage medium being shaped and arranged to form an image of an associated data region on a common image surface; and a sensor means having a plurality of juxtaposed light sensors arranged at said common image surface for sensing data as a light image corresponding to an illuminated data region, wherein the relative positions of said optical data storage medium, said controllable light source means, said data imaging lens means and said sensor means are controllably moveable in substantially parallel planes. 119. An optical data reading system comprising: a substantially planar optical data storage medium with juxtaposed data regions thereon wherein said data storage medium is controllably movable within a first planar area occupied by it; a plurality of juxtaposed lenslets proximate a first side of said data storage medium being shaped and arranged to form an image of an associated data region on a common image surface spaced from said first side; a controllable light source means for selectively illuminating a data region of said data storage medium wherein said controllable light source means is controllably moveable within a second plane parallel to said first plane, and a substantially planar sensor means having a plurality of juxtaposed light sensors arranged at said common image surface for sensing data as a light image corresponding to an illuminated data region wherein said sensor means is cooperatively connected to said light source means. 120. An optical data system comprising: an optical data means for storing data as light altering characteristics and being organized into a plurality (P) of juxtaposed data regions each having capacity to store (B) bits of data, said optical data means defining a plane; controllable light source means for selectively illuminating at least one of said separate data regions of said optical data means; data imaging lens means having a plurality of juxtaposed lenslets each being shaped and arranged in such proximity to and in optical registration with a separate one of said juxtaposed data regions so that the image resolving power thereof is substantially uniform over the field of view of that data region to form an image thereof on a common image surface spaced from said data means and lens means; sensor means having a plurality (S) of juxtaposed light sensors arranged at said image surface for sensing data as a light image corresponding to an illuminated data region; data signal output means coupled to said sensor means for outputting data signals representing said data of an illuminated and imaged data region; and registration adjustment means being controlled by a control signal for adjusting the position of said optical data means within said plane for maintaining optical registration of said light image and said sensor means. 121. An optical data cartridge reading system comprising: a cartridge including a housing, said housing suspending in its interior a data array of substantially planar optical data storage medium with juxtaposed data regions thereon, said data array including a plurality of juxtaposed lenslets proximate a first side of said data array being shaped and arranged to form an image of an associated data region on a common image surface spaced from said first side, a reading unit including a controllable light source means for selectively illuminating a data region from a second side of said data array wherein said light source means is supported by said reading unit in a plane parallel to said data array, said reading unit further including a sensing array of substantially planar sensor means having a plurality of juxtaposed light sensors arranged at said common image surface for sensing data as a light image corresponding to an illuminated data region wherein said sensing array is supported by said reading unit in a plane parallel to said data array a clamping means including registration means mounted within said reading unit for clamping said data array and said plurality of lenslets between said light source means and said sensing array.

Inventors: RUSSELL JAMES T, RUSSELL, JAMES, T.
Applicants: INFORMATION OPTICS CORP, INFORMATION OPTICS CORPORATION
Application year: 1992
Main classification: G11C11
IPC codes: G11C7, G11C11, G11C13