Abstract: Systems for scrambling and descrambling video information lines. The scrambling system includes a memory; a storage system for sequentially storing groups of four video information lines in the memory; and a retrieval means for forming groups of four scrambled video information lines by retrieving the stored video information from the memory in a sequence different from the sequence within the stored group in which the information was stored.

Abstract: A television signal is scrambled by suppressing horizontal and vertical synchronizing signals while leaving unsuppressed a reference level during a selected reference interval. Descrambling of the received scrambled signal is achieved by comparing the unsuppressed reference level with the suppressed synchronizing signals and by adding a level representative of that comparison to the suppressed synchronizing signals, thereby to restore the latter to their proper levels.

Abstract: A forward looking infrared (FLIR) energy imaging device has been found to include components which are required by the receiver portion of a long-wavelength rangefinder. For example, the FLIR collecting lens system which focuses energy from a scene onto a sensitive, cooled detector array duplicates the function which must be performed by the laser rangefinder receiver. Thus an integrated laser/FLIR rangefinder comprises a laser transmitter for illuminating a target, and an IR energy optic channel having a FLIR for receiving IR energy and producing a visible image representative thereof, said FLIR including an afocal lens system for collecting and focusing energy from the target and energy from the laser return having a wavelength compatible with the band pass of the IR optics and detector onto a cooled sensitive detector.

Abstract: In an optical distance-measuring apparatus wherein the light modulated with the constant frequency f.sub.o is emitted through an oscillator OSC, an amplifier SA and a light emitting diode LED and is returned by a reflecting prism DP located on the point the distance to which is being measured, and the distance is measured by the phase difference between the emitted light and returned light, a phase control circuit PCC is provided between the oscillator OSC and the amplifier SA for sequentially inverting the phase of the emitted light A. The real phase difference .psi.A is obtained by averaging the phase difference .psi.A of the normal light A and the phase difference .psi.A.sub.2 of the inverted light A. The averaging operation cancels the error component .delta..sub.1 due to the electrical or optical signal leakage in the light transmitting system.

Abstract: An electronic distance meter which makes a distance measurement by phase comparison between measuring signals modulated on an emitted light beam and on a received light beam reflected from a target is provided with a microphone, an amplifier and an extra modulation circuit, which modulates audible information on the measuring signal of the distance meter. A receiver provided with a detector sensible for the optical wavelength region of the emitted light beam is mounted at a reflecting prism mounted at the target. The receiver at the prism is provided with circuits for detecting the audible information modulated on the measuring signal and a loud speaker or an ear phone. At a receiver of the distance meter the audible information is filtered out from the received measuring signal before distance calculation is made by internal circuits of the instrument.

Abstract: Disclosed is a horizontal position detecting device for maintaining the surface of a body to be inspected vertically to the optical axis of a main objective lens. The device includes an illumination optical system and a condenser lens system. The illumination optical system supplies parallel light rays to the surface of the body from the direction oblique to the optical axis of the objective lens. The condenser lens system condenses the light rays supplied by the illumination optical system and reflected by the surface of the body. The optical axes of the illumination optical system and the condenser lens system are arranged substantially symmetrically with respect to the axis of the objective lens.

Abstract: A suppressed sync television decoder includes a phase locked horizontal oscillator for controlling operation of a suppressed sync detector which supplies a circuit for restoring suppressed sync in a television signal. The restored sync is coupled to the phase locked oscillator and to a first four bit counter. A second four bit counter is supplied with the horizontal oscillator signal and inhibits counting in both counters when it counts 16. A reset signal corresponding to the end of the vertical interval initializes both counters. If the number of sync pulses counted by the second counter is less than 16, an error signal is produced. Thirty-two error signals result in generation of a defeat pulse to unlock the oscillator.

Abstract: An optical rangefinder having a transmitter and receiver located closely acent for short range operation allows optimum detection of a target when either or both the target and the rangefinder are moving. An optical window region is established where the transmitter look axis intersects the receiver look axis and is adjustable for providing an output signal when the rangefinder and target are less than approximately ten feet apart. The transmitter may emit either noncoherent or coherent infrared energy. The receiver includes zero crossing detection when a received maximum signal intensity is reached and adequate signal detection means which activates when the signal level exceeds a desired minimum. An output signal is generated when the outputs of these two detection circuits are coincident.

Abstract: An addressable subscription television decoder includes an input stage including an IF amplifier for converting a scrambled RF television signal to a composite baseband video signal. The baseband video signal comprises either a nominal sync component or a sync component having suppressed horizontal sync pulses during video fields and having non-suppressed sync pulses during vertical intervals, the vertical intervals also including selected encoded data signals. An AGC voltage for controlling the gain of the IF amplifier is developed by a circuit exhibiting a relatively short time constant whenever the composite baseband video signal is characterized by nominal level sync pulses, the time constant being increased in response to suppressed horizontal sync pulses. The sync pulses produced during the vertical intervals of the composite baseband video signal are thereby not subjected to excessive IF gain for facilitating processing of the data signals by the decoder.

Abstract: With an electrooptical distance meter impulses of light are transmitted over the distance. The distance is found by counting the duration of gating signals which last between transmission and reception of the light impulses. 10,000 times of travel generated by a first digital circuit (16, 17, 18) are communicated to a second digital circuit (1, 19, 20) for storing and processing. The distance is computed by the second circuit (1, 19, 20) by forming a mean value from the more frequent counts. By evaluation of artificial gating signals of various durations and by generation of gating signals from the light impulses by means of various threshold levels an improved accuracy of distance measurement is achieved, even when measuring on natural, non cooperative objects.

Abstract: A fiber optic amplifier utilizes a crystal fiber of laser material to bidirectionally amplify light signals. This amplifier permits the application of both pumping illumination and the signal to be amplified to the end of the crystal fiber to avoid the disadvantages inherent in side pumping this fiber. End pumping is accomplished by taking advantage of the slow spontaneous fluorescence of the laser crystal to sequentially apply the pumping illumination and then the signal to be amplified to the crystal. This sequential application of signals is made possible through the use of a switchable coupler which allows light to be selectively coupled from either of a pair of input optical fibers to a single output optical fiber which is coupled to the crystal fiber. The pumping illumination is initially supplied to the crystal fiber to invert the ions within the crystal.

Abstract: A test system (10) for a laser rangefinder (12, 14) having signal transmission and reception paths comprises a thick lens collimator (20) which receives energy (18) from a transmitter (12) for input through an optical fiber (32). The fiber has a partial reflector (34) and a full reflector (38) to simulate sites of targets, and the reflected energy is transmitted back through collimator (20) to a receiver (14). Partial reflection of energy is provided by gold (64) placed on a surface (53) of one of two aligned and spaced termini (32a, 32b) of fiber (32).

Abstract: A laser rangefinder, where the laser is of the passive Q-switched type, is functionally tested. In a method and apparatus for functionally testing the laser rangefinder, the excitation voltage for actuating the laser is raised above the normal voltage, so that the laser sends two light pulses where it normally sends a single one. The pulses are respectively interpreted as a pulse sent from the rangefinder and as a received reflected pulse. A high-voltage unit for providing the excitation voltage is coupled with a feedback circuit in which there is included a voltage divider provided with a switch such that during testing the excitation voltage can be increased so that the laser sends the two required light pulses.

Abstract: An optical pulse radar for an automotive vehicle of heterodyne detection-type which can detect an object ahead of the vehicle with an improved S/N radio even under the worst detection conditions in which sunlight or a strong headlight beam from a car is directly incident thereupon. The optical pulse radar according to the present invention comprises a laser system, a beam splitter for obtaining a carrier beam and a heterodyne beam, a beam deflector, a beam modulator, a beam mixer for obtaining a beat beam signal, a beam sensor and, a beat signal processing section, etc. An optical IC may incorporate the beam splitter and mixer, the beam modulator, and the beam deflector in order to miniaturize the system, while improving the sensitivity, reliability, massproductivity, and cost.

Abstract: A periodic structure such as a diffraction grating is disposed on the surface of an object from which acoustic emissions are to be detected. A plane monochromatic light beam is incident on the periodic structure and forms a number of Bragg diffraction orders at predetermined angles. A detector positioned to intercept one of the diffraction orders receives light whose frequency has been Doppler shifted by surface motion on the object. A reference beam, also incident on the detector heterodynes with the Doppler-shifted beam so that the Doppler component can be recovered. In one embodiment, the reference beam is also incident on the surface and itself produces Bragg diffraction orders. The geometry produces up Doppler in the Bragg diffraction orders from one beam and down Doppler from the Bragg diffraction orders from the other beam and selected Bragg diffraction orders from both beams are heterodyned in the detector.

Abstract: Amplified spontaneous emission is substantially reduced in a novel optical amplifier wherein the gain medium is disposed within a converging region of the coherent signal, which converging region terminates in a waist at or near a limiting stop or saturable absorber. In contrast to the converging coherent signal flux, the amplified spontaneous emission flux is nonconverging and therefore most of the latter is removed by a spatial filter or saturable absorber.

Abstract: The present invention comprises a device for generating a modulated intense relativistic electron beam (IREB) with an electronically tunable frequency, comprising: a longitudinally running drift tube; a plurality of gaps in the drift tube including a first gap and a second gap, disposed with a predetermined distance 1 therebetween; and a plurality of cavities, with a first cavity disposed around the drift tube at the location of the first gap, and a second cavity disposed around the drift tube at the location of the second gap. These first and second cavities are provided with volumes and a geometry such as to excite a predetermined frequency band below the plasma frequency for the device. A circuit is provided for generating an IREB and injecting this IREB to propagate within the drift tube with a predetermined plasma frequency. Additionally, a main magnetic field generating means is provided for generating a magnetic field for confining the IREB to a desired beam diameter.

Abstract: An explosive ordnance disposal protective suit which includes trousers, a at with collar, a protective helmet and a combination face shield-chest plate. The face shield-chest plate is supported and held in place by a pocket on the front of the coat. The chest plate is made of laminated layers of woven glass roving fabric. The face shield is a laminate of an optically clear polycarbonate sheet adhesively bonded to an optically clear acrylic sheet.

Abstract: A method of packaging a product includes the use of an inner web of thermoplastic material and a heat shrinkable thermoplastic film, the inner web and film wrapped about a product. One or more apertures introduced at the overlapping longitudinal edge portion of film and communicating with the inner web permit escape of entrapped air inside the package during a subsequent shrinking operation. The resulting package provides a tight close fitting package characterized by extended shelf life and a store-wrapped appearance.

Abstract: The present invention relates to a means for generating a broadband source of picosecond radiation in the visible and near-infrared spectral regions. In operation, picosecond pulses with wavelength .lambda. are supplied by a laser pump source (10) and injected into the liquid core of a single mode optical fiber (18). A broadband continuum is generated in the liquid core by two mechanisms. Stimulated Raman scattering in the liquid core of the optical fiber shifts the wavelength of the incoming radiation by an amount equal to the energy of the vibrations in the liquid molecules, where with sufficient power, multiple shifts are possible. In addition, the pump radiation and the shifted radiation are broadened by self-phase modulation thereby "filling" the region between the discrete shifted lines. The output radiation from the optical fiber is, therefore, a broadband tunable picosecond pulse source.