Other

Digital Recording Corporation

Battelle Memorial Institute

Battelle Development Corporation

Exxon Nuclear Company, Inc.

James T Russell

Thomas J Davis

Bernard P Hildebrand

Byron B Brenden

Fred R Reich

Bryon B Brenden

Ray A Walker

John L West

A recording medium utilizing metal azides as an energy amplifying substance is disclosed. A photosensitive material comprises an energy absorptive dye and a metal azide dispersed in an inert binder. Low to moderate pulses of laser light cause the azide particles to react exothermally creating a void in the photosensitive material which can be read by an optical readout device.

Process of using metal azide recording media with laser

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 to focal zone . The lens is but one member of an entire family of nonconical, aspherical axicon-type focusing elements designed in accordance with a method described herein to focus energy from given source to a prescribed focal zone intensity distribution.

Focusing elements and system for producing a prescribed energy

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.

Recording and playback system

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.

Apparatus for improving focus during playback of an optical data record

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. The lens is but one member of an entire family of nonconical, aspherical axicon-type focusing elements designed in accordance with a method described herein to focus energy from given source to a prescribed focal zone intensity distribution.

Optical playback apparatus focusing system for producing a prescribed

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. A third embodiment includes a circuit for using data track addresses to direct the scanning light beam to the correct track. A fourth embodiment has a circuit which combines the first three embodiments.

Optical track segment intercept apparatus

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. By sensing the initial magnetic permeability of the sensor, the difference between that sensed information and subsequently sensed similar information can be obtained, thereby providing an indication of any change in system pressure and the degree of such change. Such measurements can be made sequentially at multiple locations by placing an external electromagnetic search coil adjacent the internal sensor in the pressurized system such that the magnetic field of the search coil penetrates the containment wall of the pressurized system, thus interrogating the sensor and providing an appropriate readout which can be calibrated in terms of system pressure.

Magnetostrictive non-contacting pressure detection system

Compression and expansion circuitry for a recording and playback system

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. While the optical data records may be light transparent, they are preferably light reflective so that the playback light source and associated focusing and scanning means may be supported on the same side of the record as the light detector to provide a more compact playback apparatus. This also enables at least some of the same optical elements to be used for transmitting the reflected light beam to the detector that are used for transmitting the playback light beam from the light source to the record. Selection of one data track for playback may be accomplished by changing the focus of the light beam from one data layer to another, or by making the data tracks of optically different materials, such as using different color dyes or different photoluminescent materials, and selectively positioning corresponding color filters in front of the light detectors.

Record playback apparatus for optical data records

Light beam scanner

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. The storage includes alternately operating first and second recirculating storages which each store a set of data words equal in number to the number of data words of one-half a TV frame. Audio data words are stored for recording during vertical blanking intervals of the signal. On playback, a record pickup intermittently reads data words from the record to a record pickup memory whenever this memory is nearly empty. A composite signal generator reconstructs the recorded television signal from data words it receives from the display storage and display control.

Repetition reduced digital data record and playback system

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.

Method of manufacturing and utilizing holographic lens means

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. The light beams may be of different cross sectional geometries, including two superimposed and concentric circular beam cross sections of different diameter, or two rectangular cross sections which intersect with each other substantially perpendicular so only their central portions are superimposed. Alternately, a row of three light beams can be used including two outer beams on opposite sides and separate from a middle beam. The three beams may all be of the same light characteristic. However it is preferable that the middle beam be of a different characteristic but of the same total energy as the two outer beams.

Growing community of inventors

Richland, WA, United States of America

James T Russell