Abstract: An RF shielding gasket is provided for establishing low impedance paths, in a given frequency range, in the interface area between two conductive surfaces. The gasket includes a first and second plurality of stubs. The stubs are joined to one another by a conductive member. The stubs are open circuited at one end and connected to the conductive member on the other end. Each stub is folded back upon itself between the two ends. In the interface area, portions of each of the conductive surfaces function as ground planes and a first and second plurality of microstrip lines are thus provided. The open circuits are transformed into low impedance paths, in the frequency range of interest, between the second end of the stubs and the portions of the first and second conductive surfaces. In one embodiment, the stubs and conductive member are formed into a substantial U-shape with a resilient core in the central volume to form a compact RF gasket.

Abstract: Selected fields of a redundant field slow motion video tape reproduced video signal are stored in a memory at a given clock rate and recovered from the memory at a clock rate inversely proportional to the number of times each field is repeated so as to produce a non-redundant video output signal of reduced bandwidth yet processing the full informational content of the original video signal. The original signal normally exhibits an ordered color field sequence but is subject to anomalous variations from time to time which causes anomalous variation of the chrominance-burst phase relationship of the video output signal. A detector, responsive to a change of a parameter of the video input signal, detects the anomalous variations of the chrominance-burst phase relationship and produces a control signal that is applied to a circuit which effectively reverses the phase relationship of the chrominance and color burst components of the video output signal of the memory when the control signal is present.

Abstract: A conveyor belt is located along the bottom of a tape bin to support a stack of tape folds. The tape bin contains a U-shaped cradle for shaping the upper run of the conveyor belt. The conveyor belt drives the tape stack around the U-turn from the feed end of the bin to its payout end to present the output end of the tape with very little resistance or pressure from the tape stack.

Abstract: A flaw detection system optically detects defects on the surface of a grooved video disc surface. A beam of light incident on the surface being inspected is reflected thereby into a series of diffraction order cones. A cylindrical lens converges the higher diffraction order cones onto a split photodetector. When the light beam which scans the disc surface passes over a surface defect, such as a hillock, the reflected beam is deflected first to one photosensitive surface of the split photodetector and then to the other, thus providing an output from the photodetector to indicate the presence of such a defect.

Abstract: A 0.degree. and 180.degree. hybrid power divider/combiner includes a first quadrature hybrid and two other quadrature hybrids arranged in tandem with one output port of the first hybrid connected to an input port of the tandem arrangement and the other output port thereof connected to a delay of electrical length equal to that of the tandem arrangement. When an input signal is applied to one input port of the first hybrid with the other port terminated, two signals of reduced amplitude which are either in phase or of opposed phase (dependent on which input port receives the input signal) are produced at the output of the tandem arrangement and delay.

Abstract: Audio signals recovered from a video disc record are applied to a dual mode decoder matrix via track and hold circuits which mute the audio signals in response to defect indicating signals and player mode control signals. A selected one of the mode control signals is applied to the matrix for causing the matrix to form sum and difference output signals at first and second output terminals thereof when at a first logic level and for causing the matrix to produce identical output signals at the output terminals when at a second logic level. Logic circuitry controls the muting and the matrix operating mode to provide compatibility with monophonic, matrixed two channel (e.g., stereophonic) and un-matrixed two channel (e.g., bilingual) video disc records and suppression of record noise in all operating modes.

Abstract: A stylus cartridge is equipped with a pair of integrally-molded flexural retaining fingers for locking a stylus arm within the confines of the cartridge body. When a slider member disposed on the cartridge is acted upon, it spreads the retaining fingers apart to release the stylus arm.

Abstract: A pickup carriage drive for a video disc player comprises a selective-activated motor mounted on a pickup carriage. A drive cord is strung between a pair of anchor points disposed in the player, and has a portion wrapped around the output shaft coupled to the drive motor. The motor, when energized, drives the carriage to follow the pickup stylus across the record during playback.

Abstract: A video disc player designed to play video disc records having either non compressed monophonic wide band audio signals or video disc records having compressed stereophonic limited band audio signals recorded thereon. The player includes expander circuitry which may be selectively operated as a time invariant amplifier in the absence of stereo audio signals and as an amplifier with a time varying transfer function for expanding the stereo signals. The expander circuit operating mode is controlled by a circuit which detects the presence of a second or stereo sound carrier in the signal recovered from the record being played. Concurrently with the amplifier being rendered time invariant during the playback of monophonic records, electronic filter circuitry is switched into the amplifier circuitry to reduce the monophonic audio bandwidth and effectively increase the resultant audio signal-to-noise ratio.

Abstract: An oscillator produces a signal having a frequency equal to a multiple of the turntable speed of a video disc player. A divider, periodically reset by vertical timing signals produced by the player when in a "play" operating mode, divides the oscillator signal and continuously produces a vertical reference signal equal in phase and frequency to a vertical timing component of the player video output signal. Synchronism is maintained between the player and a TV receiver when the player is in a "pause" operating mode (when the video output signal is squelched) by supplying the reference signal to the receiver, thereby preventing undesirable "roll" of the image produced by the receiver when the player is returned to the "play" operating mode.

Abstract: An interface circuit for selectively generating TV RF signals on one of two adjacent TV channels is designed with two independent RF oscillator-modulator circuits. The respective double sideband modulated signals generated by the RF modulators are respectively passed through separate frequency rejection filters designed to attenuate the lower sound sideband of each of the modulated signals. The resultant signals are applied to a common bandpass filter via an isolation network. The pass band of the bandpass filter encompasses substantially the combination of the pass bands of the broadcast TV channels corresponding to the RF signals generated. Consequently the lower frequency RF modulated signal is similar to a conventional vestigal sideband TV signal and the higher frequency RF modulated signal is a double sideband signal minus the lower sound sideband.

Abstract: A video disc playback apparatus for recovering signal from disc records having radially aligned information fields is provided with multiple signal recovery transducers for interactive signal playback. The signal recovery transducers are independently translated to information fields having like synchronization signal components responsive to player program controls and recovered track identification signals. Synchronization signal components recovered by the various transducers are compared to generate an error signal for activating further transducer means to translate the signal recovery transducers tangentially along the prerecorded information tracks and thereby adjust the relative angular location of the signal recovery transducers to reduce the phase differential of the synchronization components of signal between the respective signals and thereby precluding the need for independent frame synchronization apparatus.

Abstract: A video signal is separated into a broad area luminance signal having attenuated vertical and horizontal detail components and a composite detail signal having horizontal and vertical detail components in a predetermined ratio. The broad area luminance signal is combined with the composite detail signal in desired proportions to provide continuous control of the picture detail from soft to sharp in all directions of reproduced images.

Abstract: In video recording apparatus a luminance signal is doubly preemphasized by a cascade connection of two networks prior to clipping and application to a frequency modulator. One network has a non-linear phase characteristic and an amplitude response which increases by a predetermined amount over a lower portion of the luminance band and is substantially constant otherwise. The other network has a substantially linear phase response, and a rising amplitude response within the upper portion of the luminance band. The relative amplitude responses of the networks are in a predetermined relationship such that the combination exhibits a frequency dependent variation dominated by the one network over the lower portion of the luminance band and dominated by the other network over the upper portion of the luminance band whereby the luminance signal receives an increase in preemphasis over both portions of its bandwidth and clipping distortion under transient signal conditions is reduced.

Abstract: Under certain conditions a video disc player can be responsive to externally applied interference signals to provide a defect in the display of the information recovered from the disc. Apparatus is provided to reduce the influence of the extraneous signal to the playback display. The apparatus includes an automatic gain controlled amplifier and a level detector which provides two output signals. One of the output signals is used to control the amplifier gain. When the other output signal reaches a certain level it is used to develop a signal which initiates corrective action in the player.

Abstract: A filter separates a composite video input signal into luminance and chrominance signal components. The luminance signal component is limited to a range of values defined by first and second reference signals. Excursions in either sense of the chrominance signal component are limited to the lesser of two control signals, one control signal being proportional to a potential difference between the limited luminance signal and the first reference signal, the other control signal being proportional to a potential difference between the limited luminance signal and the second reference signal. The limited luminance and limited chrominance signals are combined to provide a composite video output signal limited to the range defined by the reference signals and in which the chrominance component thereof is symmetrically limited with respect to the luminance component thereof, thereby reducing distortion of the chrominance component of the composite output signal under limiting conditions.

Abstract: A video signal processing circuit including signal substitution circuitry for eliminating impulse noise has a signal peaking circuit conditionally operable for the duration of one or more video fields depending upon the presence of noise being detected in the vertical blanking interval. A circuit responsive to enabling pulses generated as a result of impulse noise or defects being detected in a vertical blanking interval provides one of two peaking control signals for controlling the level of peaking applied to the video signal by the peaking circuit.

Abstract: A "freeze frame" video disc player is described for playback of records having an integral number of TV signal frames per circular information track or per convolution of a spiral information track. The player includes a stripe of magnetic material secured to the periphery of the player turntable and magnetic transducer apparatus for repeated recording and recovery of the frozen frame to and from the magnetic stripe.

Abstract: A high performance disc record recording system wherein a digital manifestation of the signal to be recorded modulates a first carrier frequency and a temporally displaced analog manifestation of the same signal modulates a second carrier frequency. The modulated carriers are linearly combined for recording in a single record track. The digital signal is encoded for error detection and/or correction. On playback the modulated carriers are separated and demodulated. One of the separated signals is delayed so that the two signals are returned to temporal coincidence. The digital manifestation of signal is reconverted to analog format and utilized as the primary output signal. However, upon detection of errors in the digital signal the analog manifestation of the signal is substituted for the primary signal.

Abstract: Circuits are disclosed for processing color encoded video signals, encoded per a format wherein a chrominance signal in the form of a modulated subcarrier is buried in spectrum "troughs" in the midband of a wider band luminance signal, an illustrative use of the encoding format being in video disc recording. The processing circuits serve, in use with composite signals developed during video disc playback, to convert an input composite signal of buried subcarrier format to an output composite signal of NTSC format. Comb filtering is employed to separate buried subcarrier chrominance signal from midband luminance signal components. A heterodyning step preceding comb filtering is performed in a manner substantially precluding "jitter" of played back signals from disturbing accuracy of comb filter separating action, enabling use of a single 1H delay line form for the comb filter and enabling use of a relatively inexpensive, narrowband structure for the single delay line.