Abstract: A protective or purge enclosure provides a positive atmosphere around an operating device such as a hand-held computer or calculator contained therein. The protective enclosure has sufficient flexibility, even though providing a positive, sealed atmosphere, to enable the user to operate the functional features of the device sealed within the enclosure, and the material forming the device is sufficiently transparent to enable the user to view the functional features of the device for operation. A visible indicator provided on the enclosure enables the user to determine if the enclosure is maintaining the positive atmosphere sealed therein.

Abstract: Apparatus is disclosed for remotely sensing the unknown subsurface temperature T.sub.s of a bulk transparent medium, such as ocean water, using a cw laser beam and a pulsed laser beam. In one embodiment the cw output of a continuous laser is split into two sub-beams. An optical amplifier periodically amplifies the first such sub-beam thereby generating an intense pulsed laser beam having a plurality of pulses with the same wavelength as the cw laser beam. The intensity level of the pulses is sufficient to produce stimulated Brillouin scattering when focussed into the ocean water. The pulsed laser beam is directed into the water thereby generating an intense return phase-conjugate beam propagating along the path of the pulsed laser beam but in the opposite direction thereto. The phase-conjugate beam and the second sub-beam are mixed at the cathode of a photodetector to produce a heterodyne frequency proportional to the temperature T.sub.s.

Abstract: A TV video signal synchronization signal system enables a video device such as a digital special effects system to operate synchronously in response to an input video signal and still produce an output video signal synchronized to a television studio locking reference signal. The video device and the synchronization signal generating subsystem thereof operate in response to a pixel rate clock of approximately 70 ns and in response to a phase command to generate timing for the horizontal sync pulse, color burst signal and video data of the output video signal. The output color burst signal remains phase locked to the locking reference signal with output gating being responsive to the phase command. A ROM interpolator provides subpixel accuracy for the output horizontal sync pulse while output line buffering and interpolation permits the output video data to the phase matched to the reference master sync signal.

Abstract: To remotely measure the unknown subsurface temperature T.sub.s of a bulk transparent medium such as ocean water, a high intensity pulsed laser beam is split into two sub-beams, a probe beam and a reference beam. The probe beam is directed into a sample of ocean water of unknown temperature, and the reference beam into a reference sample of water having a known temperature T.sub.r. The irradiance of the two pulse beams exceeds a predetermined threshold sufficient to cause stimulated Brillouin scattering (SBS) within the two samples and produce therefrom two return phase-conjugate (PC) beams. A photodetector mixes the two PC beams and produces a heterodyne frequency that is proportional to the difference in temperatures T.sub.s and T.sub.r. A frequency measuring instrument converts the heterodyne frequency into a temperature value equal to T.sub.s.

Abstract: A method and apparatus detects synchronizing sequences in a digital data stream. The apparatus comprises a plurality of candidate sequence generators and associated vote counters which are used in conjunction with comparators to test the order of received synchronizing symbols of a predefined sequence of predefined symbols against a plurality of corresponding candidate symbols of candidate sequences. A candidate generators begins a new candidate sequence when an ambiguity in the input symbol sequence is detected, i.e., when a received symbol does not match a candidate symbol of one of the previous candidate sequences. The apparatus includes a voter decision logic circuit which selects a winner among the candidates based upon the number of votes or matches tallied for each candidate sequence.

Abstract: Plural magnetic transducing heads are employed to record and reproduce video information that is stored in a segmented format. One head is in contact with the magnetic recording tape while the other head is out of contact with it. The position of the head which is in contact with the tape is controlled by a suitable ramp voltage generated in accordance with the ratio of actual tape speed to normal play speed, to maintain the head generally aligned with a track on the tape. The other head, which is out of contact with the tape, is also positioned in the same fashion. When a repositioning of the heads is required, a determination is made whether the track of information being reproduced by the head in contact with the tape relates to a particular segment of a field, for example the last field.

Abstract: A telescopic mast system has a base tube, a plurality of axially movable coaxial inner tubes nestable successively within each other and within the base tube, and a winch supported at the lower end of the base tube with a pair of preferably wire ropes driven thereby for extending and retracting the inner tubes. The base and inner tubes have collars at their respective ends, the collars of adjacent tubes engaging each other to limit extension thereof and to provide additional structural support during application of bending loads on the mast system. The ropes are connected to pulleys mounted near or within tube collars so that the ropes and pulleys are totally enclosed within the mast system. As the winch is rotated in one direction, the ropes axially move the inner tubes from a nested or stowed position within the base tube to a fully vertically extended operational position.

Abstract: A technique for recovering helical audio using the standard synchronous reference clock of the video tape recorder system to conventionally clock the transport and the video signal processor, including the video timebase corrector. A modified audio signal processor clock is generated which is varied commensurate with the desired rate of tape speed override, varying accordingly the flow of audio data through an audio timebase recorder. The speed of a helical scanner is varied in accordance with the rate of tape speed override, to lock the scanner angular position to the audio timebase corrector. In turn, a capstan servo adjusts the tape position in respsonse to the scanner angular position to lock the tape to the scanner. Meanwhile, the video signal processing proceeds conventionally by skipping or repeating fields or frames via a frame store to match the rate of tape speed override.

Abstract: A linkage device connectable between adjacent ends of a tubular support member and payload member is adapted to rotate the payload member through approximately 180.degree. about the end of the support member between inoperative and operative positions by movement of an actuating rod longitudinally within the tubular member. The linkage device comprises first and second frames secured to adjacent ends of the members and four bars pivotally connected at opposite ends to corners of the frames, the first pair of bars extending within the frames and the second pair extending outside the frames. The actuating rod is connected to the first pair of bars and rotates them about their pivotal connection to the first frame when the rod is moved longitudinally within the tubular member. Both pairs of bars cause the payload member to rotate about the end of the support member through 180.degree. and into an operative position in longitudinal alignment with the support member.

Abstract: A winch having a torodially-shaped drum with an axis of rotation and at least one cable wound on the drum having a cable length extending from the drum parallel to and substantially equally spaced from said axis at all times during rotation of the winch. The drum has negatively-curved and positively-curved surfaces joined at a common edge, the cable being wound on the negatively-curved surface and directed therefrom over the positively-curved surface in a direction parallel to the drum axis. This drum is used advantageously with the mast system described in application Ser. No. 246,112.

Abstract: The etendue (throughput or area-solid angle product) of a high resolution interferometer is maintained at a substantially high level by use of a transparent chamber defined by a highly reflective internal surface, the chamber being located at the input to the interferometer. The chamber has an input aperture to admit light into the chamber and an output aperture or exit opening to pass light to the interferometer. By integrating the input light through multiple reflections thereof within the chamber until it exits to the interferometer, the etendue of the latter is substantially enhanced.

Abstract: A pair of interface devices, mounted externally to a pair of residential telephones, can place a temporary hold on the associated telephone line circuit. Each interface device interconnects a standard residential telephone with an associated telephone line circuit. In a two telephone arrangement to place the telephone circuit in a hold condition, the user throws a switch mounted on the interface device, and hangs up the handset (goes on hook). The switch places two indicator lamps across the two-wire line circuit to simulate an off-hook condition. To remove the hold condition, the user merely throws the same switch or the switch associated with one of the other phones in the residence. There is no need to return to the original phone first used to establish the hold.

Abstract: Subsurface waves in an ocean are created by the turbulence in a submarine's wake. These waves can be remotely detected by a search submarine by monitoring subsurface water temperatures using a laser. A pulsed laser beam is directed into the water to at least the depth of the thermocline and an analysis is made of the resultant Brillouin and Rayleigh backscatter components. Wavelength shifted Brillouin scatter is mixed with the unshifted Rayleigh scatter in a self-heterodyne manner for each volume element of illuminated water, and the frequency of the heterodyne signal is measured and converted into equivalent temperature values. This produces the desired temperature-depth profile of the water enabling detection of the first submarine by tracking the internal waves at or near the ocean thermocline.

Abstract: The pulse signal generator produces a repetitive pulse output signal consisting of repetitive pulse groups which may have either constant pulse intervals or staggered pulse intervals. Each pulse in the group also has an adjustable pulse width and may be time referenced to a clock pulse signal. The pulse generator employs cascaded stages of individual pulse generators: one stage for each pulse in the group. The first stage generates the first pulse in each group of n pulses and additionally controls the pulse group repetition interval and the pulse width of each pulse.A first counter/comparator generates a first start-pulse, when it counts N.sub.1 clock pulses. The start-pulse resets the first counter and triggers an output bistable (multivibrator) circuit, which initiates the leading edge of the first output pulse of the group. When N.sub.

Abstract: A technique for accurately controlling both the pulse repetition interval and pulse width of a pulse signal generator which uses a crystal oscillator to maintain a very accurate time base. Two separate digital counters clock-in the clock pulses. When the desired number of clock pulses are registered by the first counter, a first digital comparator generates a start pulse which resets the first counter and triggers an output flip-flop. The change of state in the flip-flop enables the second counter to begin its count. When the desired number of clock pulses are registered by the second counter, a second digital comparator generates an end pulse which resets the second counter and triggers the flip-flop a second time. The second change of state of the flip-flop disables the second counter until the first comparator generates a new start pulse.

Abstract: Subsurface waves in a body of water such as an ocean caused by a submarine are remotely nonacoustically detected by monitoring subsurface water temperatures using a laser. A pulsed laser beam is directed into the water to at least the depth of the thermocline and an analysis is made of the resultant Brillouin and Rayleigh backscatter components. Wavelength shifted Brillouin scatter is mixed with the unshifted Rayleigh scatter in a self-heterodyne manner for each volume element of illuminated water, and the frequency of the heterodyne signal is measured and converted into temperature. This produces the desired temperature-depth profile of the water enabling detection of internal waves generated by submarines.

Abstract: The subsurface temperature of a body of water such as an ocean is measured remotely by directing a laser beam deeply into the water and analyzing the resultant Brillouin and Rayleigh backscatter components. Wavelength shifted Brillouin scatter is mixed with the unshifted Rayleigh scatter in a self-heterodyne manner for each volume element of illuminated water and the frequency of the heterodyne signal is measured. This produces the desired temperature-depth profile of the water.

Abstract: A universal demodulator programmable for any digitally modulated carrier signal having a known constellation format which can be characterized by a unique constellation pattern of phase-amplitude states. The demodulator also generates phase and gain-error signals for locking onto the phase and amplitude of the digitally modulated carrier. The demodulator splits the received digitally modulated carrier signal into an inphase component, D.sub.x, and a quadrature-phase component, D.sub.y. Using a preprogrammed memory device keyed to the identified modulation format, each D.sub.x signal is mapped into one of a plurality of one-dimensional zones each having R.sub.x center values. Using a second preprogrammed memory device also keyed to the identified modulation format, each D.sub.y signal is similarly mapped into a plurality of orthogonal one-dimensional zones having R.sub.y centers. Each pair of R.sub.x and R.sub.

Abstract: The efficiency of an optically pumped solid state laser is substantially improved with a controlled geometry fluorescent converter between the pump light source and the lasing medium. Fluorescent materials have the capability of absorbing broadband pumping radiation, shifting it in wavelength and re-emitting it in the absorption band of the selected solid state laser medium. Use of angular formations having the converter surface facing the laser medium reduces fluorescent light trapping within the converter due to internal reflection thereby greatly increasing the total light output of the converter and thus the efficiency of the laser.

Abstract: An adjustable optical mounting assembly, particularly suited for folding or periscope optics, provides for optical beam motion in three axes using a bearing having a spherical surface. This invention greatly simplifies the mount mechanism and operting procedure, reduces the size, and provides enhanced stability and lockability relative to comparable conventional devices.