Abstract: Digital computer data recorded in a spiral track on the surface of a disk using a laser recording head which moves radially across the disk as it revolves at a constant linear velocity. A system for controlling the disk velocity during the recording process includes a device for counting each convolution of the spiral and means for calculating the number of bits of information which should optimally be recorded in that convolution. A counter keeps track of the number of bits which are actually being recorded in that convolution. The calculated number of bits is compared with the number of bits actually recorded to produce a control signal for regulating the speed at which the disk revolves.

Abstract: A predictive coding signal communication arrangement includes at the transmitter a subtractor for subtracting a delayed predicted signal from current signal to produce difference signals. To reduce the data throughput, the difference signals are data reduced or decimated to produce rate-reduced difference signals. The rate-reduced signals are applied to a coder for Huffman coding, run-length coding or the like, and then to a rate buffer for reducing data rate variability. The rate-reduced difference signals are also interpolated back to the original data rate and applied to an adder together with the delayed predicted signal to produce current predicted signal. The current predicted signal is at least delayed to produce the delayed predicted signal. In a particularly advantageous embodiment, the rate buffer is coupled to a fill control circuit which produces a control signal representing the rate buffer fullness.

Abstract: A reduced size and weight beam forming network for a circularly polarized N element array antenna system is achieved by interconnecting quadrature couplers without intermediate phase shifters and adding twisted waveguide phase shifters at the coupler outputs to equalize the phase at the array elements.

Abstract: A television receiver includes an audio signal processing arrangement for expanding a second audio program (SAP) signal compressed in accordance with the "dbx" system in a relatively simple manner. The signal processing arrangement includes a first filter for providing a first amount of deemphasis. A controllable gain amplifier has its input coupled to the filter and its gain controlled by a filtered signal representative of its input signal. A second filter at the amplifier output provides a second amount of deemphasis.

Abstract: A DC-to-AC inverter includes a switched bridge circuit. The bridge is energized by a source of substantially constant direct current. In order to reduce stress on the switches of the bridge, periods of conductivity of the switches of the bridge are overlapped, so that all the legs of the bridge are conductive simultaneously in two operating intervals out of a recurrent operating sequence of four operating intervals. Each switch is associated with a snubber circuit including a snubber capacitor which bypasses or absorbs switch current during turn-off. The charge retained on the snubber capacitor after complete turn-off of the associated switch represents energy which can be reused. The capacitor must be discharged in readiness for the next turn-off of the associated switch.

Abstract: A source of a beam of ions includes in a housing a cathode filament, an anode spaced from the cathode and housing an ion emission opening therethrough and an intermediate electrode between the cathode and anode and having an opening therethrough in alignment with the opening in the anode. An inlet opening extends through the housing into the space between the anode and the intermediate electrode to admit a flow of starting gas and the gas to be ionized into the housing. An outlet opening is through the housing adjacent the cathode and a pump is connected to the outlet opening. In the operation of the ion source a flow of the starting gas is provided through the housing and over the cathode to initiate the discharge. Then the gas to be ionized is admitted into the housing. Some of the gas is ionized to generate the desired ions and the rest of the gas is drawn out of the housing to remove impurities generated at the cathode and thereby increase the lifetime of the cathode.

Abstract: A parcel sorting and distributing apparatus includes a plurality of inclined chutes which receive parcels at their open upper ends. Each parcel slides down a chute into a receptacle such as a mail hamper. The chutes are vertically stacked and arranged in a spoke-like fashion about a circle with the aggregate of their upper ends forming a cylindrical surface. A rotatable vertical mast at the axis of the cylinder includes a pivotally mounted carrier. In one position the carrier retains a parcel; when it pivots to a second position, the parcel spills out into one of the chutes. A first motor causes the mast to rotate and a second motor drives the carrier vertically along the mast. A parcel which has been identified as to its destination is loaded into the carrier, and a controller controls the first motor, the second motor and the carrier pivot so as to convey the parcel to the appropriate receptacle.

Abstract: A television receiver responsive to a broadcast television signal in a normal operating mode includes a television signal channel with high frequency peaking circuits, followed by a display driver to which an auxiliary video signal may be applied. A low pass filter is connected between the output of the television signal channel and the display driver, which exhibits a wide bandwidth when the receiver is intended to display auxiliary video information. The bandwidth of the low pass filter is inversely related to the bandwidth of the driver such that the low pass filter exhibits a narrow bandwidth relative to the bandwidth of a wideband display driver. In addition, the low pass filter exhibits a trapping characteristic at the second harmonic frequency of the chrominance signal in a color television receiver.

Abstract: A rapid acting gas valve for inflated structures employs a slider-crank drive mechanism driven by a pawl and ratchet motor to produce a high closing force in the valve while opening and closing the valve in a partial revolution of the ratchet motor shaft.

Abstract: A reflector antenna system with reduced blockage effects is provided by placing a compensating reflector between the surface of the main curved reflector and its primary feed to intercept illuminating radiation which would otherwise be blocked by the feed. The compensating reflector reflects the intercepted radiation with a beam pattern which is essentially identical to the substractive blockage pattern. The compensating reflector is spaced from the main reflecting surface to place its beam pattern in phase opposition to the blockage pattern to cancel common components from the blockage pattern.

Abstract: A digital phase-lock-loop circuit includes a generator that produces a horizontal rate output signal at a controlled frequency and a phase detector responsive to the output signal and to an incoming synchronizing signal. The phase detector is coupled to the generator control port via a loop filter. When the phase between the output signal and the synchronizing signal that synchronizes the phase-lock-loop circuit changes as a result of, for example, head switching in a two-head VTR that supplies the synchronizing signal, a signal representative of such phase change is produced. The phase change representative signal is fed forward to the generator, by bypassing the loop filter of the phase-lock-loop circuit. The phase change representative signal produces an immediate phase shift of the output signal such that the loop filter is not affected by the head switching.

Abstract: A wideband video signal processor includes a kinescope driver stage which is AC coupled to the kinescope, and an automatic kinescope bias (AKB) control system. During AKB operating intervals, the kinescope is energized so as to produce a cathode output pulse with a magnitude related to the level of black current conducted by the kinescope. Brightness control is achieved by coupling a brightness control voltage to a signal path which conveys the cathode output pulse to AKB signal processing circuits.

Abstract: An auxiliary kinescope beam current limiter in a television receiver includes a control circuit responsive to a sensed signal representative of the combined instantaneous magnitudes of plural color video signals. The control circuit includes, in the order named, a first low pass filter, a first peak detector, a second low pass filter, and a second peak detector which provides a control signal to video signal processing circuits for limiting the amplitudes of the plural color video signals when a given amplitude threshold value is sensed as having been exceeded. The auxiliary beam current limiter is able to prevent warping or blistering of a shadow mask in a color kinescope due to scenes having a high beam current in, for example, an area equal to or greater than five to ten percent of the display screen area of the kinescope in both the horizontal and vertical directions.

Abstract: A printed circuit board assembly is disclosed which includes a printed circuit board having in situ molded members for mechanically securing electrical and mechanical components and the like to the printed circuit board. The printed circuit board is manufactured using a method wherein a printed circuit board is initially prepared with the required printed circuit patterns and with apertures for in situ molded members and for the leads of the electrical components. The required molded members are then molded in situ in specified apertures of the printed circuit board. The electrical components are thereafter mechanically secured in place with the in situ molded members and the leads of the components are connected to the contact pads of the printed circuit pattern.

Abstract: Charge transfer devices typically include a periodically reset floating element output stage coupled to an FET amplifier for sensing the transferred charges. For reducing both low-frequency l/f noise and high-frequency reset noise, the duty factor of the device clocking signals and the reset signal are picked so that at a selected multiple of the clock signal repetition rate, the information component is in phase quadrature with the reset noise component. The charge transfer device output signal is then synchronously detected with a reference signal which is in phase with the selected multiple of the information component.

Abstract: A timing system which includes a timer circuit, a source of first clock pulses for advancing the timer circuit, and a circuit for reading out the timer circuit in synchronism advanced therewith and where there is also included a second source of clock pulses asynchronous with respect to the first source of clock pulses, a synchronizing circuit is provided for storing an indication of the receipt of each second clock source pulse. Then the timer is advanced only when a pulse is produced by the first clock source and the indication is present that a signal has been produced by the second clock source.

Abstract: In a tuning control system for a television receiver, an analog AFT signal is sampled during blanking intervals when the amplitude of the video carrier is relative constant and therefore cannot affect the amplitude of the AFT signal significantly. This reduces the AFT filtering requirements.

Abstract: A process of forming sub-micrometer metallization structures on a substrate is provided. A layer of a photoresist on the structure is pattern irradiated with a reduced dosage of actinic radiation so that, upon development, recesses are formed therein which extend only partially through the photoresist layer. A first layer of metallization is deposited onto the structure at an oblique angle such that it does not completely coat the photoresist in the recesses. The structure is then flood irradiated with actinic light and developed to form openings to the substrate where the photoresist layer is not covered in the recesses. A second layer of metallization is then deposited at normal incidence. The second metallization breaks off and deposits isolated structures on the substrate through the openings. The photoresist layer and overlying layers of metallization are then removed by conventional lift-off technique.

Abstract: A process of forming an epitaxial metal silicide layer on a silicon substrate is disclosed. A thin layer of a first metal that will form an oxide in preference to silicon is initially deposited on the substrate. A preferred first metal is titanium. A layer of palladium, platinum or iridium is deposited thereover. An exceptionally uniform, conductive layer of metal silicide is thereby formed by epitaxial growth without the necessity of a high temperature anneal. The disclosed process is particularly useful in forming ultra thin metal silicide Schottky barriers in devices such as infrared imaging arrays.

Abstract: Parallelled charge transfer channels have multiple-phase-clocked gate electrodes overspanning them in one of a number of arrangements conditioning the transfer of charge packets in opposing directions in adjacent charge transfer channels. Three-phase, four-phase, five-phase and six-phase clocking arrangements constructed in three layers of polysilicon embody the invention.