Abstract: A speed-up circuit time compresses and interlaces field delayed and interpolated lines of a video input signal for display in progressive scan fashion. The interpolated lines are produced by adding low and high frequency components derived from the video input signal. The low frequency component is produced by frame-combing and low pass filtering the input signal. The high frequency component is obtained by field delaying, line comb filtering and low pass filtering the input signal. The combined low and high frequency components are spatially and temporally coincident thereby reducing the visibility of motion artifacts (double images) on the display.

Abstract: A frame comb filter separates a luminance signal from a composite video input signal for display on every other line of a progressively scanned display. The filter includes a tap for providing a field delayed luma signal and an interpolator for providing a frame comb filtered and interpolated luma signal. A selector switch selects the field delayed luma signal for display on the intermediate lines of the display when the vertical detail content of the input signal is greater than a minimum threshold value and there is little or no interframe motion and selects the frame comb filtered and interpolated luminance signal for display otherwise thereby providing enhanced vertical detail and reduced field motion artifacts for displayed images.

Abstract: A wide aspect ratio television system includes memories for storing and recovering a video input signal in response to read and write clock pulses, respectively. Write clock pulses are deleted to compress edge regions of a wide aspect ratio input signal and read clock pulses are deleted to restore the signal to its original aspect ratio. The pattern of delected pulses is altered on a line-by-line basis to reduce visible artifacts of signal decimation. Dual mode receivers include provisions for controlling edge blanking, interpolation and the pattern of clock pulses deleted as a function of received signals. Wide and standard aspect ratio images are displayed without altering the width of the display raster.

Abstract: A television receiver receives a scrambled television signal with a suppressed sync pulse which is restored by a decoder coupled to the receiver. The receiver also includes a noise inverter which alters blanking interval noise pulses below a threshold level to prevent the noise pulses from disrupting the operation of other receiver circuits. The operation of the noise inverter is inhibited when the decoder is operative in the presence of a scrambled signal.

Abstract: In memory-based video signal processing systems such as frame recursive filters, for example, system performance is dependent upon critical timing relationships between incoming signals and delayed signals produced from the memory. Video signal from various sources, e.g. VTR's, tend to have jittering time bases that generally have prevented the use of such memory-based processing systems. The jittering signals may be standardized, in sampled data format, by effecting adaptive signal delays responsive to a measure of the relative phase of the sampling clock with respect to horizontal synchronizing pulses. The phase measure is used to control an interpolator which combines successive samples in proportions to develop sample values that should have occurred at the sample times had the signal not been jittering.

Abstract: Apparatus and a method for controlling the field or frame store signal processing of standard and nonstandard video signals is disclosed. The apparatus includes a nonstandard signal detector which compares the received horizontal sync signals to a horizontal sync signal generated internally be counting down a clock signal having a frequency proportional to the color subcarrier frequency. The detector produces a control signal which is in one state when the horizontal sync signals are substantially in coincidence and in a second state otherwise. This control signal is applied to apparatus which switches from field or frame store signal processing apparatus to alternative signal processing apparatus, which does not include a field or frame memory, to minimize distortion of the image when nonstandard signals are processed.

Abstract: A memory reverses the sequence of samples of selected lines of a composite video input signal without separating the color burst and chrominance components of the lines thereby preserving chroma-burst phase integrity of scrambled lines. A burst inserter adds a second color burst component to the normal and reversed sequence lines to preserve the secrecy of the scramble code. A descrambler includes a memory for restoring the sample sequence and removing the extra color burst component.

Abstract: A motion detector for determining image motion in a video signal develops an array of signals representing the difference between pixels from adjacent frames. The array of signals are grouped into subarrays, each of which include the signal corresponding to the pixel under examination for motion. Each of the subarrays are independently examined to determine if the magnitude of all of the pixel differences represented in a particular subarray exceed a predetermined threshold and/or the pixel differences have like polarity. If these conditions are met in any one of the subarrays, a motion signal is produced.

Abstract: A progressively scanned video signal is encoded into temporal sum and difference components for transmission. The sum signal is temporally filtered, decimated and time expended to be compatible with interlaced receivers. The difference signal, also temporally filtered, decimated and time expanded, is conveyed via single or separate channels with the sum signal to a progressive scan receiver for reconstitution of the original progressive scan signal. Modified quadrature amplitude modulation is used to convey the sum and difference signals in a common channel.

Abstract: A wide-aspect-ratio HDTV signal having 1600 luminance pixels/32 .mu.S line and 980 lines/frame is data reduced by deleting odd pixels of each line of TV field #1 and even pixels of each line of TV field #2 to produce 800 pixels per line, and is further data compressed by a form of differential-pulse-code modulation. The DPCM organizes the pixels into groups of five, and for each group transmits or records one reference pixel at full N-bits. The pixels to the right and left of the reference pixel are compared therewith to produce difference signals of M bits, where M<N. The remaining two pixels of each group are compared with reference pixels from the lines above and below to form M-bit difference signals. The difference signals are transmitted. The DPCM coding reduces the 800 pixels/line to the equivalent of 480 pixels/line. The color portion of the wide-aspect-ratio HDTV is similarly coded to produce the equivalent of 240 pixel/line.

Abstract: A companding system for a television audio apparatus includes a compressor and an expander for stereo difference or second audio program signals. The compressor provides variable preemphasis of high frequency signal components and the expander provides complementary variable deemphasis. Due to noise, the amount of deemphasis the expander can provide is limited. To ensure complementary operation of the compressor and expander a clamp means is used in the compressor to set the maximum amount of preemphasis. Similarly, in the expander, a clamp is used to set the maximum deemphasis of the compressor.

Abstract: A first sound filter in a video IF channel of a television receiver exhibits a null response at a frequency slightly less than the 41.25 MHz sound IF carrier signal frequency. A demodulated baseband video signal is filtered by a second sound filter which exhibits a null response at a frequency slightly less than the 4.5 MHz intercarrier sound frequency. The first sound filter provides a nominal amount of attenuation of the sound carrier signal in the video IF channel, while conserving high frequency information as ultimately manifested in the demodulated baseband video signal. The second sound filter assists the first sound filter to assure that sound information is adequately attenuated in the baseband video signal.

Abstract: A television receiver is arranged to selectively display either information from a broadcast television signal, or information from an auxiliary video signal. The black image reference level associated with the broadcast signal information is sampled and used to automatically establish the black image reference level of the auxiliary video signal.

Abstract: In a color television receiver including a color kinescope and plural kinescope driver stages, a control circuit is included for inhibiting the operation of the driver stages for a short interval after the receiver is energized, particularly under "hot start" conditions, to prevent disturbing artifacts from being displayed by the kinescope. In an illustrated embodiment the driver stages are disabled in response to a control signal applied to a bias point common to the plural driver stages.

Abstract: A multiplier for multiplying the modulated sound and picture carriers to produce an intercarrier sound signal in a quasi-parallel sound channel of an IF section has a pair of anti-parallel connected diodes in a limiter for generating an amplitude limited version of the picture carrier. It has been discovered that the varying capacitance of the diodes with picture amplitude can cause phase shifts and hence phase modulation interference in the intercarrier signal. The latter is especially troublesome for stereo sound reproduction. To reduce such interference, a low value resistor is shunt coupled to the diodes to inhibit the capacitance variations of the diodes and resulting undesired phase modulation in the intercarrier sound signal.

Abstract: A television receiver is arranged to selectively display either information from a broadcast television signal or information from an auxiliary video signal, in accordance with the position of a switching network to which the signals are capacitively coupled via respective capacitors. Similar black reference levels are established for the television and auxiliary signals by means of respective clamping circuits, including the coupling capacitors, which operate at different times but with respect to the same clamping reference voltage.

Abstract: A video monitor includes a kinescope driver amplifier AC coupled to a kinescope via a capacitor which is also associated with a video signal clamp. A control signal related to the magnitude of video signals coupled to the kinescope modifies the kinescope bias so as to increase kinescope current conduction and image brightness, to counteract the tendency of a displayed image to exhibit reduced brightness as the amplitude of the video signal increases.

Abstract: A recursive filter for noise reducing composite video signal separately processes the luminance and chrominance components of the composite signal but requires only a single frame of storage. Input composite video signal is separated into luminance and chrominance component signals. The component signals are coupled to separate signal recursion scaling/combining circuits. The outputs from the recursion circuits are summed in an adder to produce noise-reduced composite video signal which is applied to a frame delay element. The output of the delay element is applied to a chroma/luma separator which separates the luminance and chrominance components and applies them to the respective recursion circuits.

Abstract: A pix-in-pix television display includes a memory for holding samples representing one field of the small picture. Samples which are to be written into the memory are developed in a buffer memory one line at a time over intervals corresponding to the three line periods of the signal which produces the small picture. A line of samples is written from the buffer memory into the field memory over three line periods of the small picture signal. The memory write operation is suspended when data is read from the field memory for display. The write operation resumes when a read operation is completed at the address and pixel value which were being written when the write operation was suspended.

Abstract: A pix-in-pix television display includes circuitry for reducing the amount of memory needed to hold one field of the reduced size image. In the display apparatus, digital samples representing the large and small picture signals are developed at substantially equal rates by separate circuitry. Subsampling circuitry stores one out of every five of the samples representing a horizontal line of the small picture. These samples are displayed, synchronous with the large picture at a rate three-fifths times the display rate of the large picture samples to produce an apparent size reduction of one-third in the horizontal direction.