Abstract: A video disc comprises a grooved disc having video information in the form of a surface relief pattern within the groove, the disc made from a plastic material containing finely divided conductive particles such that the bulk resistivity at 900 MHz is less than 500 ohm-centimeters.

Abstract: An improved method for fabricating a diamond video disc playback stylus. The method comprises the steps of preparing a bottom surface which contacts the video disc and producing a conductive layer adjacent to the bottom surface by ion implantation. The improvement lies in annealing the diamond at about 850.degree. to about 1500.degree. C.

Abstract: A system for measuring the bulk resistivity or sheet resistance of a sample of material includes a source of r.f. signals, a transmitting device and receiving device. The sample is placed between the transmitter and the receiver. A display is used to monitor the amplitude characteristic of the received r.f. signal at a particular frequency. The amplitude characteristic at the particular frequency is a measure of the bulk resistivity of the sample of the material.

Abstract: Stylus suitable for use in a capacitive disc record playback apparatus comprises a wedge-shaped support material and an electrode formed on a flat longitudinal surface of the support material. Signal pickup qualities of such stylus can be determined by supporting such stylus on a silicon dioxide-silicon wafer where the capacitance formed between the electrode bottom and the wafer can be changed at a cyclical rate by energizing the wafer with a low frequency signal. A tuned resonator circuit coupled to the electrode detects those capacitance variations and additional undesired capacitance variations contributed by fringe capacitance between the whole of the electrode and the wafer. Where the wafer is of an n-type silicon material, the contribution of the fringe capacitance to the detected capacitance variations is reduced by growing a large quantity of positive charge in the silicon dioxide layer of the wafer.

Abstract: Stylus, having a conductive electrode, is mounted at one end of a pivoted stylus support arm within a pickup cartridge body of non-conductive material, removably received in a conductive housing. A conductive spring, with one end in electrical contact with the stylus electrode, is secured at its opposite end to the cartridge body. A printed circuit board, mounted within the conductive housing, comprises a dielectric substrate bearing a conductive coating in several elongated surface regions. The conductive coating in two of said regions defines first and second conductors, lying substantially parallel to each other. When the cartridge is received in the housing, electrical contact is established between the body-secured spring end and one end of the first conductor. Capacitive elements couple the other end of the first conductor to the housing.

Abstract: A bias circuit for a large pulse-width, broad-bandwidth radio-frequency avalanche device comprising a power supply coupled to the device through a bias line. The bias circuit includes a resistive network shunted across the bias line and ground to dampen spurious submicrowave oscillations.

Abstract: A method for making a four-layer P+PNN+ or N+NPP+ diode, and the diode, wherein the impurity profile about the PN junction is optimally graded for TRAPATT operation throughout the span of the avalanche region by ion implantation of the impurities to a depth of 1000A in a semiconductor wafer and wherein these impurities are subsequently thermally diffused.

Abstract: A high repetition rate injection laser modulator wherein a DC bias voltage is applied across a serially connected forwardly-poled-injection laser and carrier-injected avalanche device. The carrier-injected avalanche device generates a current pulse in response to additional carriers injected into the device by a trigger pulse applied across the control junction of the avalanche device. An offset bias is provided across the control junction to remove built-up charges at the junction interface to provide for high repetition rate operation. The current pulse is of sufficient magnitude to effect pumping of the injection laser, the injection laser thus emitting a corresponding pulse of coherent light.

Abstract: Comb filter apparatus for separating interleaved luminance and chrominance components of a composite color video signal employs a clock controlled delay line of the CCD type to which the composite signal is applied. A VCO supplies clock signals to the CCD delay line, and to a frequency divider. The output of the frequency divider is compared in phase with a color synchronizing component of the undelayed composite color video signal to develop an error signal, which is applied to the VCO in a sense opposing departures from a predetermined phase relationship between the divider output and the synchronizing component. Spurious frequency variations of composite signal components (e.g., accompanying recovery of composite signal by playback of a video disc) are followed by the VCO in a manner assuring that accurate combing of the composite signals occurs at the outputs of circuits providing desired combinations of the delay line input and output.

Abstract: A carrier-injected avalanche device series connected to a forwardly-poled injection laser generates a current pulse, which may be as short as one nanosecond, through the injection laser only when both a direct current bias voltage is applied across this series connection from a charge supply and carriers have been injected into the device in response to the leading edge of a modulation trigger pulse. This current pulse through the injection laser is of sufficient magnitude to effect pumping thereof, so that the injection laser emits a corresponding pulse of coherent light, which may also be as short as one nanosecond.

Abstract: A mount for a microwave diode package wherein good thermal contacts, as well as radio frequency contacts to a microstrip circuit are achieved by applying a mechanical force to a face of the mount at an acute angle so that forces are produced along both of the major axes of the mount.