Abstract: An apparatus for improving the focus of a digital optical record and playback system is described which provides plural simultaneous focal paths of different lengths for playing back or recording a digital optical data record. These focal paths may interact a common bit portion on a data record, successive bit positions in the same row of data on the record, or bit portions on adjacent tracks of data on the record. In certain embodiments, a selection circuit is utilized for evaluating the focal paths and selecting one which results in an improved focus. Data records having recorded bits of data of extended depth are also described to facilitate focusing during playback of the data record.

Abstract: An optical playback system for reading data from a record includes a focusing system for focusing a scanning light beam onto data on the record without need for precision positioning of the record and optical elements of the system. The light beam is modulated by the data and then transmitted to a light detector to produce a playback data signal corresponding to the recorded data. The focusing system includes a source of light having an axially symmetric intensity distribution and a lens designed to focus such light into a focal zone with a specified intensity distribution along the zone. This distribution is preferably uniform so as to provide the detector with a modulated light beam of uniform average intensity regardless of the position of the record along the focal zone.

Abstract: A track intercept apparatus is described for use in an optical playback machine which plays back data recorded on an optical record in track segments. The apparatus deflects the scanning light beam of such machine so that the light beam intercepts each selected track segment properly when the scan is initiated. A track intercept control circuit is employed having storage means for storage of variable values of track alignment data, adjust means for producing an adjustment signal corresponding to the stored data which is applied to a light beam deflection means, and timing means for controlling gating circuitry and for coordinating events within the circuit with the operation of the playback machine as a whole. One embodiment of the invention includes a circuit which compensates for track-following corrections made during scanning by returning the scanning light beam to a stored starting position. Another embodiment has a circuit for electronically aligning the scanner optics.

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: A system including a sensor and electronic instrumentation for measuring fission gas pressures inside a pressurized system or device or the like, such as a nuclear fuel rod. The system is based primarily on what is commonly known as the Villari effect which is the dependence of the magnetic permeability of certain magnetic materials upon applied stress, and permits pressure measurements to be made without any mechanical or physical penetration of the fuel cladding or end cap of the fuel rod. In a preferred embodiment pressure sensing is implemented by locating a sensor made from Villari sensitive material inside the pressurized system. The pressure places a stress loading on the sensor which in turn produces electrical output signals proportional to the applied stress.

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: Multi-layered optical data records and playback apparatus are described in which a plurality of optical data layers are provided on at least one side of a record substrate and the playback apparatus scans data tracks on such layers with a light beam to produce an electrical readout signal corresponding to the data in the scanned tracks. The playback apparatus includes selection means for selectively playing back data tracks on different ones of the data layers. The data track may be formed by lines of data spots of binary coded digital information or such spots may be frequency modulated or pulse length modulated analog information which are photographically recorded at extremely high data density so that they may be used to record audio or video signals including television signals.

Abstract: Multi-layered optical data records and playback apparatus are described in which a plurality of optical data layers are provided on at least one side of a record substrate and the playback apparatus scans data tracks on such layers with a light beam to produce an electrical readout signal corresponding to the data in the scanned tracks. The playback apparatus includes selection means for selectively playing back data tracks on different ones of the data layers. The data track may be formed by lines of data spots of binary coded digital information or such spots may be frequency modulated or pulse length modulated analog information which are photographically recorded at extremely high data density so that they may be used to record audio or video signals including television signals.

Abstract: A record and playback system for reducing repetition redundancy is described in which during recording, a partially repetitive signal, such as a television signal, is converted into digital data words each representing the signal occurring during a particular TV line subinterval. A comparator unit receives the data words and compares each received word with a word from a recirculating storage that corresponds to the same line subinterval in its frame as that of the compared received data word. When the compared words differ by a predetermined value, the received word replaces the stored word in the storage and is also stored in a changed data memory as an updated data word along with address words. A recording control circuit intermittently causes the read out of data from the changed data memory for recording at selected positions of a data record.

Abstract: Holographic lenses are formed on a substantially transparent scanning disc wherein a line focus is the object for each hologram. Such hologram is then used to reconstruct the line focus at the location of the record to be scanned, thereby alleviating tolerance requirements in regard to the positioning or flatness of the scanned record.

Abstract: An optical extensometer is described using sequentially pulsed light beams for measuring the dimensions of objects by detecting two opposite edges of the object without contacting the object. The light beams may be of different distinguishable light characteristics, such as polarization or wave length, and are time modulated in an alternating manner at a reference frequency. The light characteristics are of substantially the same total light energy and are distributed symmetrically. In the preferred embodiment two light beam segments of one characteristic are on opposite sides of a middle segment of another characteristic. As a result, when the beam segments are scanned sequentially across two opposite edges of the object, they produce a readout signal at the output of a photoelectric detector that is compared with the reference signal by a phase comparator to produce a measurement signal with a binary level transition when the light beams cross an edge.

Abstract: Multi-layered optical data records and playback apparatus are described in which a plurality of optical data layers are provided on at least one side of a record substrate and the playback apparatus scans data tracks on such layers with a light beam to produce an electrical readout signal corresponding to the data in the scanned tracks. The playback apparatus includes selection means for selectively playing back data tracks on different ones of the data layers. The data track may be formed by lines of data spots of binary coded digital information or such spots may be frequency modulated or pulse length modulated analog information which are photographically recorded at extremely high data density so that they may be used to record audio or video signals including television signals.

Abstract: An optical data record playback apparatus is described for simultaneously scanning a plurality of data tracks on the optical record by employing two or more light beams controlled by closed loop servos. First and second optical servo means respectively, are employed to deflect the light beams for tracking of such beams during scanning along the data tracks and for maintaining the proper spacing between beams to cause each beam to follow a different track. In addition, a time adjust means, which may be a third optical servo or an electronic signal delay means, is employed to adjust the time relationship of the two readout signals produced by such light beams. The optical servos may include either movable mirrors or light refraction plates. Alternatively, an electromagnetically deflected bundle of optical fibers can be employed as the first servo and a zoom lens at the output of such fibers as the second servo.

Abstract: The effective resolution of a TV presentation reproduced from digitally encoded samples is improved by shifting the sampling points back and forth at a relatively rapid rate. Alternate lines of the original television raster are sampled at shifted points, wherein the shift is less than the sampling interval and suitably one half the sampling interval. Since a TV raster includes an odd number of horizontal lines, a particular line location on the reproduced raster will be formed of samples which shift back and forth at one half the TV frame rate, i.e. 15 cycles per second.

Abstract: An optical data record copying apparatus is described which includes an array of lenses whose viewing fields do not overlap but are separated by field gaps. The viewing field gaps are aligned with data gaps between data groups in the data tracks on the master record to prevent distortion of the copied data. The optical data is high density digital or analog data, such as digital color television signals recorded on an optical video disc. The lens array may include a plurality of lens pairs which are separated by a light opaque mask having apertures each aligned with different lens pairs for limiting the viewing field of each lens pair. One embodiment of the copying apparatus of the present invention employs a fixed lens array and moves the master record and copy so that such lens array scans the entire length of the master. Another embodiment employs a moving lens array and a fixed master record and copy, such lens array and associated light source being scanned along the length of the master during copying.

Abstract: A digital color television system is described in which only one chrominance component of the video color television signal is transmitted for each television line, and digital delay means is employed for delaying at least one of the two chrominance components I and Q of the color television signal so that the delayed chrominance component can be added to the transmitted television signal to produce output signals having both chrominance components. The system includes a recording apparatus for recording the digital color television signal on a record which may be an optical or magnetic record, and a playback apparatus for playing back the recorded signal to a television receiver or other utilization device. A gate means is provided in the recording apparatus for selectively transmitting a conventional digital color television signal having two chrominance components as an altered digital television signal having only one chrominance component per line which is different on alternate lines.

Abstract: An optical fiber deflection device is described in which an electrical transducer is used for deflecting the fiber in response to an electrical control signal in order to deflect a light beam transmitted through such fiber. The transducer includes a nonmagnetic deflector means attached to the fiber and connected to an electrical current source, for deflection of the fiber by movement of the deflector means. In one embodiment employing an electromagnetic transducer, an electrical conductor is attached along the length of the fiber and is connected to a D.C. current source to produce a magnetic field around the conductor so that they may be deflected by pairs of electromagnetic coils positioned adjacent the side of the conductor when a control signal is applied to such coils. Alternatively, the control signal can be applied to the conductor attached to the optical fiber and a D.C. current caused to flow through the electromagnetic coils.