Abstract:
Apparatus and method for encoding information and recording same as sets of variably spaced related marks stored in wavelength (color) and/or depth selective layers on the optical record wherein the encoded information is read by illuminating each set of such recorded marks selected by wavelength (color) or focal depth with a coherent read light to cause an optical interference pattern consisting of a varying distribution of amplitude maxima separated by amplitude nulls (or minimas) that change in accordance with the encoded information. This read interference pat-tern is detected by photosensing diode arrays and after decoding, the system outputs an information signal representing the original information.
Abstract:
Apparatus and method are disclosed for encoding information and recording same as sets of variably spaced related marks on the optical record. The encoded information is read by illuminating each set of such recorded marks with a coherent read light to cause an optical interference pattern consisting of a varying distribution of amplitude maxima separated by amplitude nulls (or minimas) that change in accordance with the encoded information. This read interference pattern is detected by photosensing diode arrays and after decoding, the system outputs an information signal representing the original information.
Abstract:
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.
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. 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.
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. 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.
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. 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.
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. 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.
Abstract:
An airway adapter includes a housing and a pressure transducer. The housing includes a flow path having a first end and a second end, a first pressure port that communicates with the flow path, and a second pressure port that communicates with the flow path. The first pressure port is spaced apart from the second pressure port. The flow restriction is disposed in the flow path between the first and second pressure ports that creates a pressure differential therebetween. The pressure transducer generates a signal that reflects the differential pressure created by the flow restriction between the first and second pressure ports, wherein the pressure transducer includes an optical interferometer.