Abstract: Video disc track numbers are conveyed during each video line by means of a quadrature phase shift keyed data carrier recorded along with the picture and sound carriers on a video disc. Upon playback, the data sequence is processed to identify tracking errors occurring within each video field to thereby enable immediate correction of disc tracking errors on a line-by-line basis thus minimizing picture and sound interruption caused by intra-field tracking errors.

Abstract: A high voltage generator in a television receiver responds to horizontal deflection rate signals from a horizontal oscillator which normally responds to a horizontal sync signal derived from the television signal. A sync validity detector provides a control signal indicative of the validity of the horizontal sync signal to an electronic tuning system in order to identify active channels, and to the deflection system to inhibit the response of the deflection system to false sync signals otherwise capable of causing the oscillator to operate a lower frequency likely to cause the high voltage generator to develop an excessively high voltage.

Abstract: A video sync validity detector comprises a peak detector circuit and an average detector circuit both responsive to output signals from a sync separator network. Sync representative signals are provided from the output of the peak detector. The average detector is coupled to the peak detector for inhibiting sync representative outputs therefrom in the presence of sync separator output signals representative of false sync signals of average value.

Abstract: A filter network suitable for processing a signal such as the demodulated "I" chrominance component of a composite color television signal is disclosed. The filter network comprises plural cascaded mutually interactive resonant LC sections for providing wideband filtering, amplitude peaking over a prescribed range of signal frequencies, and signal delay. Mismatched resistors terminate the filter network and constitute the primary DC impedance of the filter network, and the LC sections exhibit selected impedances at frequencies within the peaking frequency range.

Abstract: As a signal seeking tuner tunes through a number of channels to locate the next active (useable) channel, the display screen of a television receiver is blanked when the receiver is tuned between channels or to an inactive (unuseable) channel for which video signal information is substantially absent. Superimposed over the blanked screen background is a moveable tuning indicator bar, the position of which indicates the channel to which the receiver is tuned. The blanking of the screen prevents the tuning indication from being obscured by background noise.

Abstract: In a television receiver, a horizontal peaking signal is added to a luminance signal to accentuate its horizontal detail. The peaking signal is subject to a coring action with the amount of coring subject to dynamic control as a function of luminance signal content. The sense of coring control is such that a greater amount of coring is associated with dark portions of a scene to be reproduced than is associated with bright portions thereof. The coring control is non-linear and exhibits one control characteristic over a first range of luminance signal levels between a white image limit and a threshold level in the black image direction, and a different control characteristic over a second range of signal levels between the threshold level and the black image limit for restricting the amount of coring produced as the black limit is approached.

Abstract: An input pulse having an amplitude to be sampled is coupled to a sampling amplifier via an input circuit including a capacitance. A switch couples a reference voltage to the capacitance during reference intervals preceding sampling intervals. The reference voltage is decoupled at the end of the reference interval, at which time an auxiliary reference pulse is self-generated at the amplifier input by passive circuit elements associated with the input circuit. The auxiliary pulse exhibits an amplitude and sense for negating the response of the amplifier to the input pulse when the input and reference pulses exhibit mutually equal amplitudes at the amplifier input.

Abstract: A filter network suitable for translating a signal such as a demodulated "I" chrominance component of a composite color television signal is disclosed. The filter network comprises first and second cascaded sections with mutually grossly mismatched terminating impedances, and are passively interconnected via a resistance of a value which substantially precludes interaction between the sections over a given range of frequencies within the passband of the signals being translated. Both sections are separately excited with signals to be translated. The first section provides wideband filtering and a large amount of delay relative to that provided by the second section. The second section provides signal amplitude peaking within a given portion of the frequency passband of the first section.

Abstract: A high-definition camera uses sinuous or line scanning to produce wide bandwidth signals having high-definition in the horizontal and vertical directions. A wobble signal having a wobble chosen at an even integer multiple of one-half the line rate is used to create the sinuous scanning. The phase of the wobble signal is inverted on alternate frames to provide a full raster scan on a high-definition television receiver. A low pass filter produces a limited bandwidth signal from the wide bandwidth signal. The limited bandwidth signal is compatible with standard definition broadcast systems and receivers. At the receiver the high-definition image may be recreated by using a delta signal representative of the difference between the high-definition signal and the standard definition signal in conjunction with the limited bandwidth signal. The delta signal and its addresses may be transmitted during the vertical blanking interval.

Abstract: Hue and saturation are modified in a composite video signal processor by detecting the phase of the chrominance signal component to determine if it possesses phase components at or near a predetermined phase angle. If such components exist, quadrature related saturation and hue modifying signals are added to the composite video signal in controlled proportions and polarities to provide a resultant composite video signal in which a specified color or range of colors is modified. The modifying signals are inhibited by a masking unit to confine the color modification to predetermined areas of the displayed color image. Specific picture locations where color changes occur are identified by substituting an AC signal within the luminance frequency band for the color modifying signals. A desaturation signal derived from the hue modifying signals is added to the composite video signal to minimize changes in saturation level of the composite video signal as hue is changed.

Abstract: A compatible high-definition television system may be achieved by dividing a standard picture element into four arranged sub-picture elements arranged in a parallelo-grammatic fashion. In the system a sum signal which is the sum of the four sub-picture elements is transmitted as a standard luminance signal. Further, the system includes means for computing three difference signals and transmitting these in separate channels. The first difference signal is the horizontal difference signal, the second is a vertical difference signal and the third is the diagonal difference signal. These four signals are an orthogonal set of 2.times.2 Hadamard basis functions. To reconstruct the high-definition television sub-picture element values, the three difference signals and the sum signal are summed to determine the orthogonal sub-pixel values. The system uses simple hardware and does not require a frame buffer.

Abstract: An amplifier, including a pair of emitter coupled non-complementary transistors operated at constant emitter, base and collector potentials, provides a bidirectional output current proportional to an AC signal to be rectified. The output current is applied to a common base connection of a pair of complementary emitter-coupled base-coupled transistors having a common emitter connection coupled via a linearizing feedback resistor to the base electrode of one of the amplifier transistors and via a load to a source of reference potential.

Abstract: A video disc player includes a phase locked loop (PLL) heterodyne converter for providing frequency translation and time base correction of the chrominance component of a composite video signal recovered when a disc is played. Residual time base errors due to the finite loop gain of the PLL are minimized by means of a phase modulator controlled by the PLL error signal. In one illustrative embodiment, the phase modulator is coupled so as to vary the phase of the translated chrominance output signal. In another embodiment, it is coupled to vary the phase of a demodulation carrier wave supplied to a chroma demodulator whereby, in either case, chroma streaking effects due to finite gain limitations of the PLL are minimized with no increase in loop gain thereby avoiding potential loop instabilities.

Abstract: A video FM transmission system includes a transmitter coupled to a receiver by means of an FM transmission path subject to triangular noise effects. The receiver includes a coring circuit for reducing the noise and the transmitter includes a coring compensation circuit having a transfer function different from and not complementary to the transfer function of the coring circuit. The transfer functions are selected so as to effect greater coring of the triangular noise characteristic of the FM transmission system and lesser coring of the desired small-signal high-frequency components of the video signal thereby providing a desired signal-to-noise ratio enhancement of the video. In preferred embodiments of the invention the transfer functions of both the coring circuit and the coring compensation circuit are provided by programmed read only memories having different and non-complementary programs.

Abstract: A charge transfer device (CTD) delay line comb filter for separating the frequency interleaved luminance and chrominance components of a composite video signal is provided wherein signal charges representative of the composite video signal within first and second delay lines are effectively subtracted one from the other by alternately passing them under a common, periodically clamped, normally floating sense electrode. This eliminates the need for a phase inverter, which causes imperfect separation due to having a non-zero time delay and not having exactly unity gain.

Abstract: Switch apparatus including first and second signal switch paths for coupling signal between one of first and second input ports and an output port. Each switch path includes a pair of series-coupled oppositely-poled diodes and a shunt diode having one electrode coupled to the junction of the diode pair, each diode being coupled to the junction by an electrode of like conductivity type. A biasing means selectively biases one of the diode pairs into conduction for coupling signal between one of the input ports and the output port concurrently with the biasing into conduction of the shunt diode coupled to the junction of the other of the diode pairs for biasing the other diode pair into non-conduction, thereby decoupling signal between the other of the input ports and the output port.

Abstract: A digital signal processing system of a television receiver includes a digital to analog converter for converting an analog television signal to representative digital samples at times corresponding to pulses of a sampling signal. Clock signal generating is provided to selectively shift the phase of the sampling signal from that corresponding to the -(B-Y) and (R-Y) color reference vectors to that corresponding to the I and Q, color reference vectors as modified by a tint adjustment, at a time during each horizontal scanning interval before beginning of the image interval. In this manner, digital -(B-Y) chrominance samples corresponding to the peaks of the color burst signal component are made available for digital automatic chrominance gain control and digital I and Q chrominance samples are made available for digital color demodulation.

Abstract: Imbalances in the potential appearing across the drain electrodes of source coupled FET transistors arranged in a differential amplifier configuration tends to produce input offset voltages. Where the drain electrodes of the transistors are coupled to a current mirror load for converting balanced signals to a single ended output which in turn is applied to a common source amplifier, the input offset may be nulled by differentially adjusting the drain current of the common source amplifier against the source current of the differential stage.

Abstract: A ghost signal sampling arrangement is provided which includes a gate coupled to receive a ghost contaminated video signal. The gate passes a portion of the video signal including a main signal component available for use as a training signal and its corresponding ghost signal components. The gated signal portion is applied to a differentiator, which passes a first signal corresponding to the training signal, and subsequent signals corresponding to the ghost signal components when present. A clipping limiter is coupled to receive the signals produced by the differentiator, and produces a sampling signal corresponding to the first, training signal component, to the exclusion of the ghost signal components. A serial shift register is coupled to receive the sampling signal, which passes through the shift register and appears at sequential ones of its parallel outputs.

Abstract: A coring circuit is provided in a system which includes a gain controlled device. The diodes which produce the coring effect are biased by a signal which is related to the gain control signal coupled to the device. In this way, the coring threshold is made to vary relative to changes in the amplitude of the applied signal so that the percentage of coring remains fixed over a range of applied signal amplitude levels.