Abstract: A write/read head comprises a laser whose resonator faces are formed by the storage medium and by a curved reflective surface which is positioned at a nominal distance from the medium and has a described residual radiant transmittance and a radius of curvature which is greater than the nominal distance. A mode diaphragm is provided between the active medium of the laser and the storage medium. Optical detector elements for the acquisition of position control signals and data read-out signals are arranged outside of the reflective surface and are symmetrically arranged with respect to the optical axis of the laser.

Abstract: The electro-optical method described herein provides adjustable voltage dependent optical properties of a solid whereby the characteristics, i.e., the optical response to applied voltage, are separately adjustable for different laser frequencies. The solid has photo-absorbing centers capable of displaying persistent spectral hole burning; the spectral holes are capable of exhibiting electric-field induced filling. The main fields of application for this method are in integrated optics, image processing, and optical data storage.

Abstract: Disclosed is an optical data storage device having incorporated therein an optical data storage medium. The optical data storage device is switchable between at least two detectable states by the application of projected beam and energy thereto. The optical data storage device has a first substantially transparent substrate with a first polymeric adhesive layer thereon characterized by grooves in the form of lands and valleys, a first inorganic encapsulating layer, a layer of the state changeable chalcogenide memory material, a second inorganic encapsulating layer, an adhesive layer, and a second substantially transparent substrate adherant to the adhesive layer.

Abstract: A semiconductor memory is comprised of four arrays (10), (12), (14) and (16) that have the memory elements therein arranged in accordance with pixel positions on a display. The memory arrays have associated shift registers (34), (36), (38) and (40) which have data loaded in parallel and output in a serial format to the display. Each of the shift registers can be connected in a circulating fashion or a shift register of adjacent arrays can be cascaded. Switches (56), (58), (60) and (62) are provided for configuring the shift registers for either circulation or cascading of data. In the circulating mode, the input and output of the shift registers is multiplexed on one pin whereas in the cascaded configuration, one array receives a dedicated serial input and the other array in the cascaded pair outputs the serial output on a dedicated pin.

Abstract: A laser beam records a digital representation of a medical picture and medical information on an optical data storage strip. The strip is adhered to a medium containing an eye readable picture generated from the same data, such as X-ray pictures, CAT-scan pictures, ultrasonic or NMR images. The medical information may be the image itself, a description or diagnosis related to the picture.

Abstract: An eraseable solid state optical memory has an array of selectively energizeable photoemitters which are imaged by suitable imaging means onto a data mask to optically address data stored thereon. To that end, the data mask is an eraseable optical recording medium, such as a tellurium suboxide or other chalcogenide material. A data writer is provided for programming, erasing and re-programming the data mask in situ while self-aligning the imaging means with the programmed data mask. The data mask may be erased and/or re-programmed in whole or part, thereby extending the utility of these memories to the storage of data that is subject to change.

Abstract: An optical file system in which a command to store data results in a write operation in the next available storage position. A single optical path is used for both reading and writing. By dividing the detector in two equal parts along the direction of relative movement, it is possible to determine whether data has been written at a position which is in advance of the center of the area viewed by the detector. The write operation is conditioned on the output of the first part of the detector. Since the first part of the detector gives advance warning on the status of the oncoming data position, it is possible to switch from reading to writing without the requirement for a wasted revolution or wasted space. By dividing the signal resulting from a change of reflectance sensed during a write operation by a measure of the intensity of the write laser a read signal free of the write modulation is obtained.

Abstract: An optical storage card reading system using a cylindrical lens is disclosed which provides for a large viewing cone at the surface of the optical storage card thus improving the ability to read optically recorded data despite scratches or dust on the optical storage card.

Abstract: A method for recording laser written information on motion picture film includes creating a visual image on the film photographically. A laser records sound information on a direct-read-after-write optical storage strip on an edge of the film. In one embodiment, the strip is made of reflective silver particles in a gelatin matrix. Different tracks may have different sound information such as foreign languages or stereophonic sound. Editing information is also writable on the strip.

Abstract: A method of optical data processing employs a modulable source of light which illuminates an optical assembly. A storage location selector is employed to apply a second modulating signal to an address selected storage location of a charge storage register. A charge storage register provides a selected storage cell with a potential of the modulating signal. After storing the predetermined potential variation in the charge storage register the potential of each cell is applied through an optical modulator to the photocell of a photodetector arrangement. The optical properties of each modular element is controlled through the potential of the associated cell of the charge storage resistor in a manner such that the intensity of the light falling on the photocell is a function of the total intensity incident on the optical assembly and also a function of the voltage applied in the respective modular element.

Abstract: A large scale integrated circuit device such as a random access memory or a read only memory has its top cover removed and information is read into the device in the form of radiation which is selectively applied to the exposed surface of the device. The radiation is of suitable frequency and intensity as to be capable of placing any of the individual devices within the array to a given logic state. The entire device is electrically read out in the normal fashion. The radiation may be modulated in any desired manner and can, for example, be modulated by a transparency containing the desired input information. Gray shades are obtained by employing a plurality of large scale integrated devices which are identical to one another and which receive the same radiation distribution with a different attenuation for each of the devices. The electrical readout process can then compare the state of respective identical devices within each array to determine gray shades.

Abstract: A laser beam scanner system records medical information on a direct-read-after-write optical data storage strip. The strip is adhered to a medium containing a picture, such as X-ray pictures, CAT-scan pictures, ultrasonic or NMR images, or microscope photos of tissue samples. The strip may record information such as a description or diagnosis related to the picture for archival storage.

Abstract: Apparatus for storing and retrieving data, comprising a plurality of electrochromic cells having electrically controllable illumination transparency, a voltage source coupled to each electrochromic cell to provide control and bias signals thereto for electrically controlling the illumination transparency of selected ones of the cells in accordance with data to be stored, a light source providing flood illumination upon the plurality of electrochromic cells, and a charge transfer device comprising a plurality of charge transfer device cells for photodetecting illumination from the light source which passes through the then transparent electrochromic cells to effect the retrieval of data stored in the transparency of the plurality of electrochromic cells.

Abstract: A variable length electro-optic waveguide is used to adjust the input conjugate of a focusing lens, thereby providing a relatively high speed and inexpensive focus control device having a wide dynamic control range for optical memories and the like. A pair of segmented electrodes are deposited in spaced apart relationship on or near a surface of an electro-optic element, and provision is made for individually addressing the electrode segments, whereby the effective length of the waveguide may be increased or decreased by increasing or decreasing, respectively, the number of adjacent electrode segments that are being actively driven at any given time. In keeping with one of the more detailed features of this invention, a multi-layer electrode construction is preferred so that the electrode segments may be interleaved in stacked, overlapping relationship to create a substantially continuous waveguide of controllable length.

Abstract: Spot-focus of a write or read beam upon a flexible optical disc, which is rotated with its neutral plane highly stabilized in space, is maintained precisely by moving the write or read beam source (e.g. a laser diode) in response to focus error signals.

Abstract: In an optical recording system, a media disk for writing information has a plurality of information tracks with preformatted clock location indications written on the tracks. Writing is accomplished by making a written indication at a predetermined location between preformatted clock locations where the predetermined location is representative of the particular data to be written. Proper location of the preformatted clock location indicia on adjacent tracks provides for proper track crossing information when track addressing occurs as well as proper address location on particular tracks.

Abstract: An apparatus for preformatting each track of an optical disk with spaced header patterns using a plurality of overlapping, individually modulated writing laser beams arranged in a line perpendicular to the track. All of the writing laser beams are derived from a single multi-line laser so as to provide high positioning stability, and adjacent beams are chosen to have different wavelengths in order to prevent the deleterious effects of coherent interference between the overlapping beams. A specific header pattern is provided on a single pass by turning on different ones of the writing beams during specific time periods as each header recording area is traversed. A laser read-after-write beam is additionally provided to permit immediate verification of the recorded header pattern.

Abstract: A randomly accessible memory display is disclosed wherein a latching memory panel can be placed in direct optical contact with the triggering electroluminescent panel having a similar matrix. Once the glowing light from the trigger panel shines on the photosensitive resistive layer providing positive feedback, the corresponding region in the latching memory panel is latched. In accordance with the invention, a technique is disclosed for electrically reading the latched state in any one cell. This is done by selectively propagating a high frequency sinusoidal interrogation signal through each of the Y axis lines connected to the cells and measuring any phase alteration in each of the X axis lines connected to the cells, for each Y axis line interrogated. Since the resistance of the photosensitive resistor for a particular latching cell is altered if that cell is emitting light, the impedance of the cell is changed, thereby introducing a phase shift to the interrogation signal.

Abstract: Disclosed is an apparatus for reproducing digitally coded information recorded on a disc-shaped record carrier in the form of optically detectable, unit information areas arranged in accordance with a concentric or spiral track pattern. The apparatus comprises a filter which is tuned to a frequency f=V/L, V being the nominal tangential speed of the record carrier and L the nominal center-to-center distance of said unit areas. This frequency component has a frequency equal to twice the bit frequency of the coded information and is situated at a zero point of the power spectrum of said information, so that the extracted signal may be employed for the generation of a clock signal.

Abstract: A bistable circuit comprises a light-emitting diode connected in series with a phototransistor and so disposed as to illuminate the latter. When current is flowing--i.e. when the phototransistor conducts--light from the LED keeps the phototransistor conductive, and the circuit can be switched to the non-conductive (OFF) state by interrupting the light path between the LED and the phototransistor. When the circuit is OFF it can be switched to the ON state by external light.A data-storage device embodying such bistable circuits is also disclosed; a rotatable disc carries a plurality of such circuits at regular spacings adjacent its periphery, and several setting devices at different positions are each operable to illuminate one of the circuits passing the setting device to switch that circuit to the ON state.

Abstract: The method of, and apparatus for, producing an electrical video signal representing a charge pattern on an insulating dielectric sheet or film, without destroying the charge pattern, including the steps of: placing a transparent electrode on the free top surface of the dielectric film, placing the dielectric film having the charge pattern in close contact with the free top surface of an uncharged photoconductor having a back electrode connected to a load impedance, and scanning the photoconductor through said transparent electrode and said dielectric film with a flying spot of light to produce a video electrical signal across the load impedance during the scanning.

Abstract: The output beam of a read laser for an optical memory is diffracted to provide a plurality of read beams of substantially equal intensity for simultaneously scanning all of the data tracks of a selected data channel with a different one of the read beams, whereby each of the read beams is optically modulated in accordance with the data recorded on a respective one of the data tracks. The optically modulated read beams are applied to respective detectors, whereby the data recorded on the different data tracks is simultaneously converted into corresponding video electrical signals. Those signals are, in turn, output selectively or in parallel.

Abstract: In an optical memory device, such as an optical video disk, an injection laser is used as the source of the light, as the detector of the light reflected from the memory element and as the detector for controlling the proper focus of the light on the memory element. The light reflected from the memory element is fed back into the injection laser and variations in certain characteristics of the injection laser, such as the optical output at constant current, the electrical current through the laser at constant voltage and the voltage drop across the laser at constant current, are used to read the memory device and to maintain the focus.

Abstract: Recording and playback optical scanners are relatively movable with respect to each other and with respect to a movable recording medium such as reel of tape adapted for recording variations in applied light. The playback scanner reproduces recorded information at a time delayed with respect to the time of recording, wherein the amount of delay can vary within wide limits. When the playback scanner is moved relative to recording scanner, the playback rate will be faster or slower than the recording rate.

Abstract: The disclosure describes method and apparatus for optically computing the impulse response h, transfer function H, coherence function .gamma., impulse coherence .GAMMA., product S.sub.y H.sub.r, division 1/S.sub.x, cross-correlation R.sub.yx, cross-power spectrum G.sub.yx, complex conjugate S.sub.x.sup.*, and convolution y*x of signals y and x in real time. The method comprises the steps of computing the mathematical function of a given parameter. The apparatus of the invention comprises the realization of optical elements for performing the tasks of the method.

Abstract: A large number of closely spaced holograms are formed on a sheet, each hologram comprising an information portion and an identification portion. First scan means movably position the sheet relative to a reconstruction beam and a sensor means for reading a selected hologram. The sensor means reads the identification portion of the reconstructed hologram to determine whether said hologram is the selected hologram. If said hologram is the selected hologram, a second scan means is actuated to read the information area. If said hologram is not the selected hologram, the first scan means is actuated to move to the next hologram. The process is continued until the selected hologram is located. The identification area further comprises a density reference section which is read to produce a bias reference signal for combination with the information signals. In digital applications the bias reference signal establishes the quantization threshold.

Abstract: An apparatus for and a method of optically recording or writing data into a thermoplastic layer is disclosed. The recording medium is fabricated as an integral part of the face of a cathode ray tube (CRT) and includes a layer of thermoplastic material that is thermoplastically responsive to a heating light beam having a wavelength within the infrared (IR) range and that is a dielectric capable of storing charges corresponding to a data-containing charging (electron) beam. The thermoplastic layer is first selectively exposed to the charging (electron) beam for spatially selectively electrically charging the exposed surface of the thermoplastic layer and is then softened by the heating (IR) beam causing the charged, softened surface to distort under the forces of the data-bearing charge.

Abstract: An error checking method and apparatus for recording digital data in an optical recording medium. Digital data are written onto the medium by a modulated laser whose beam is detected by a first photodetector means which measures laser output directed toward the recording medium. A second photodetector means measures light scattering from the medium, while a third photodetector detects and measures light transmitted through the recording layer of the medium serving to confirm recording of the data. Amounts of transmitted light or scattered light from the medium are correlated to the laser output and to expected values of light for detecting errors in recording immediately after the time of recording. Reversal processing of the recording medium eliminates a large fraction of potential errors.

Abstract: A rotatable record carrier upon which reproducible information is recorded in the form of spaced apart pits in substantially concentric circular tracks on a surface of the carrier. A method of producing this record carrier is disclosed wherein, although the linear velocity of each track is dependent upon the radius of the track, the length of the pits in the respective tracks does not vary as a function of the change in the radius from one track to the next. A light beam is modulated with a rectangular pulse information signal, the duration of each pulse being controlled as a function of the radius of the track which is being scanned by the modulated light beam. For tracks having a smaller radius, the pulse duration is made larger than for tracks having a larger radius.

Abstract: The optical reader, for information discs of which the items of information are locatable by addresses previously recorded on each of the grooves forming the track, comprises a device for counting the number of grooves traversed during search phases which simultaneously uses the envelope of the reading signal and the signal representing the radial error in the position of the head relative to the nearest track, for algebraically counting the number of tracks traversed. After comparison with the number of grooves to be traversed, the counting device controls the deceleration of the radial advance when the spot is at a predetermined distance from the groove to be reached and also its total stoppage and the closure of the radial servocontrol loop when the groove is reached.

Abstract: An optical data recording system in which during recording the writing beam is made to move at the same velocity as the recording medium whereby motion blur is minimized or reduced. Movement of the writing beam at the same velocity as the recording medium is achieved by supplying a constantly varying frequency RF signal to an acousto-optic device which deflects (diffracts) the writing beam in accordance with the instantaneous frequency of the RF signal. The acousto-optic device can also be utilized to amplitude modulate the writing beam.

Abstract: The output beam of a laser tube is modulated between a maximum intensity (lase) and minimum (no-lase) intensity levels by varying the laser tube current between corresponding values. The device for controlling the output beam comprises a single transistor provided in the current path of the laser tube, the current therethrough being controlled, or modulated, to provide the modulated laser beam. The device is capable of operating in a plurlity of modes. In the preferred mode, an analog signal is coupled to the transistor control circuitry whereby the laser beam intensity is linearly modulated between the maximum and minimum levels to provide a laser beam having grey scale capabilities. In a second operating mode, a digital signal is coupled to the transistor control circuitry whereby the laser beam intensity is modulated to a constant value between minimum and maximum levels.

Abstract: Information which is recorded on a record medium is read therefrom by a main beam of radiant energy, such as a main light beam, which impinges and scans the record medium so as to be modulated with the recorded information. An additional beam of radiant energy also impinges upon the record medium, and both the main and additional beams pass through a common objective lens which focusses the beams. The main beam, after impinging upon the record medium and being modulated with the recorded information, is detected. The transmission path of the main beam, and particularly its impinging location on the record medium, is controlled in accordance with the detection thereof. Also, the additional beam is detected after it impinges upon the record medium. The effective focussing position of the objective lens is adjusted in accordance with the detected additional beam.

Abstract: In a signal play-back device having a substantially flat record carrier or disc provided with first and second oppositely facing reflective surfaces and a signal recorded as variations in at least the second surface, and an optical system in which a first lens directs a laser light beam against the first record carrier surface for reflection by the latter and passage back through the first lens for focussing by the latter at an image point remote from the first record carrier surface, and a second lens effects a predetermined focussing of such image point at the second record carrier surface for scanning the recorded signal variations, with the light beam reflected from the latter, and having corresponding variations in its beam energy, passing back through the second lens toward a light detector for providing an output corresponding to such variations in beam energy, and in which the first and second lenses have magnification factors for maintaining the predetermined focussing of the image point at the secon

Abstract: A semiconductor memory (storage) device is provided using layered semiconductor structures which produce spatially separate electron and hole wells. The state of the device depends upon whether or not charge carriers (electrons and holes) are confined in these wells. Thus, the device has a first state exhibiting one conductance or capacitance when the wells do not have charge carriers in them, and a second state (different conductance or capacitance) when charge carriers are confined in the potential wells. The lifetime of the state in which carriers are confined in the wells depends upon the amount of time required for electron-hole recombination and is expected to be very long since the electrons and holes are spatially separated. A preferred embodiment utilizes a layered heterostructure formed in the space charge region of a p-n junction.

Abstract: An optical storage system for the simultaneous or random storage of digital information in a plurality of channels, comprising a rotating storage disc which is scanned by a light beam. The digital information of each channel is stored in points along a spiral track comprising interruptions. A concentrical guide track is associated with each channel. The light beam being focussed onto both tracks of each channel for optical addressing. The light beams of all channels are controlled via deflection systems so that, during the interruptions, they are briefly directed onto the guide tracks while following the spiral tracks. From the radial deviation of the moving disc, measured by way of a detector system, control signals are derived by the deflection systems to compensate for undesired radial motions of the spiral-shaped tracks.