Abstract: The format of two audio input signals, which may be of either matrixed form wherein each signal comprises two common components or of unmatrixed form wherein each signal comprises a respective independent component, is determined by applying the signals to a first network circuit which linearly combines the signals to produce a resultant audio output signal exhibiting a null condition when the input signals are of matrixed form and a non-null condition when the input signals are of unmatrixed form. A null detector responsive to the resultant signal supplies a control signal to a second decoder matrix which decodes the matrixed signals to independent form and couples the decoded signals to respective first and second output terminals when the null condition is detected and which couples the unmatrixed input signals to respective ones of the first and second output terminals when the non-null condition is detected.

Abstract: In a signal expander, the envelope of an input signal to be expanded is detected and applied as a control signal to the gain control input of a variable gain device which expands the input signal. The control signal is applied to the variable gain device via an adaptive filter having improved ripple reduction and transient performance characteristics to minimize audibility of gain changes. The adaptive filter includes a low pass filter for producing a smoothed control signal essentially free of ripple and an analog gate for coupling the greater of the smoothed signal or a further signal to the variable gain device, the further signal being equal to the detector output signal less a constant. Compression of an input signal is provided by applying the input signal to the non-inverting input terminal of an amplifier and coupling the (compressed) output signal of the amplifier to its inverting input terminal via the expander.

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: 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: 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: 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: 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: The envelope of an input signal to be expanded is detected and applied via an adaptive filter to the gain control input of a variable gain device which expands the input signal. The adaptive filter provides improved ripple reduction and transient response characteristics and comprises a low pass filter for producing a smoothed control signal and an analog gate for coupling the greater of the smoothed control signal or a further signal to the variable gain device, the further signal being equal to the filter input signal less two predetermined constants. The gate further includes plural current paths selectively enabled for different conditions of the low pass filter input and output signals for augmenting the supply of current to the filter.

Abstract: Apparatus is described for automatically depeaking the luminance signal of a television receiver under high noise conditions to improve the subjective appearance of reproduced images. Noise accompanying the luminance signal is sensed by bandpass filtering the signal and applying the filtered signal to a detector via a sampling circuit. The sampling circuit is enabled only during the horizontal blanking interval of the luminance signal to reject the active video portions of the luminance signal. The detector is of the pulse averaging type wherein pulses representative of peaks of the sampled signal above a threshold level are generated and averaged to produce a smoothed control signal that is principally representative of the noise and substantially independent of luminance signal transitions which occur during the sampling interval.

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.

Abstract: The burst component of a video signal recovered from a video disc record is applied to a timebase correction servo for controlling the tangential position of the player pick-up transducer in a sense to minimize timebase errors. The record is rotated at a constant angular velocity whereby, for a given displacement of the pick-up transducer, the servo loop gain tends to vary with the radial position of the transducer which, in turn, undesirably influences the servo sensitivity and dynamic stability. A loop gain compensator, responsive to a second component of the recovered video signal proportional to the playing time of the disc, regulates the servo gain at a substantially constant value thereby improving the loop stability and sensitivity.

Abstract: Luminance and chrominance components of a video input signal are stored at one rate and recovered at a lesser rate, 1/N, by means of a frame store to effect video signal bandwidth reduction. Burst is not stored but rather is regenerated and added to the video output signal to conserve memory space. To avoid undesirable hue changes and the necessity of rephasing the regenerated burst signal when switching between different video sources, the burst regenerator includes means for forming a product signal from two signals. One signal is locked to incoming burst, and the other signal is derived from a reference source having a phase related to that of burst.

Abstract: A filter separates a composite video input signal into luminance and chrominance signal components. DC signals are combined with the luminance signal to produce four control signals, first and fourth ones of which have an AC component inversely proportional to the luminance signal, second and third ones of which having an AC component directly porportional to the luminance signal, each having a respective DC component. The DC components of the first and third control signals are regulated in proportion to a first reference voltage, V1, and the DC components of the second and fourth ones of the control signals are regulated in proportion to a second reference voltage V2.

Abstract: A video disc player includes color burst responsive processing circuitry. A burst killer effectively removes burst from the player output when reproducing monochrome program material whereby an improved quality monochrome picture may be obtained from a color television monitor which may be used with the player. The burst killer is controlled on a field-by-field basis in response to an analog or digital signal manifestation of the reproduced video signal whereby the burst killer is automatically enabled and disabled during reproduction of mixed monochrome-color program material.

Abstract: The input terminal of a voltage follower is coupled to a point of reference potential via a first capacitor. A second capacitor is alternately connected across a source of input signals and connected in parallel with the voltage follower during mutually exclusive time intervals whereby an output voltage is produced across the first capacitor proportional to a differential mode component of the input signal. The arrangement is such that internally generated noise is suppressed, very low frequency breakpoints (lag) may be realized with practical element values and there is substantially no tendency toward saturation in the presence of high frequency input noise components.

Abstract: A video disc record suitable for use with a video disc player apparatus is provided with a label for identifying the program material stored on the surface of the record. The label is formed in a machine readable format which comprises grooves in the surface of the record. In one format whorls of a spiral groove of a first pitch are spaced alternately with whorls of a spiral groove of a second pitch. A readout apparatus comprises a light beam which is arranged to scan the grooved label and a detector which is arranged to sense the light beam reflected from the disc record surface. Light striking a grooved section of first pitch is reflected in a substantially specular direction while light striking a grooved section of second pitch is substantially scattered out of the specular direction. The detector is arranged to collect the light reflected into the specular direction.

Abstract: A video disc player, for use with a television receiving device having a tuner, includes a power switch, a source of baseband video signal and a switchable multi-channel TV modulator. Upon closure of the power switch the baseband signal is modulated on a selected TV channel and supplied to the television tuner. Channel prompting apparatus in the video disc player responds to initial closure of the power switch and to the selected channel of the modulator to produce a message perceptable to a user of the player, the message being indicative of the selected TV channel of the modulator, for prompting the user to select the corresponding channel on the receiving device. The message is communicated to the user by sight or sound upon initial activation of the player and may be subsequently followed by a further message indicative of an operating parameter of the player such as a playing time indication of the disc being played.

Abstract: The luminance component of a video signal subject to overshoot is preemphasized and clipped prior to application as a modulating signal to a frequency modulator. Overshoot of the luminance signal, which tends to cause clipping distortion of the modulating signal is minimized by generating a compensating signal representative of the horizontal detail component of the luminance signal. The luminance signal is delayed relative to the compensating signal and subtractively combined therewith prior to application to the clipping circuitry such that the resultant modulating signal exhibits preshoot and reduced overshoot thereby minimizing the clipping distortion. Compensation is effectively disabled for luminance signal overshoots below the clipping level by means of an adjustable coring circuit in the compensating signal path whereby luminance signals exhibiting overshoot below the clipping level are not distorted by the compensating signal.

Abstract: A composite video signal is separated into luminance and chrominance components which are processed in separate channels having transfer functions which differ in terms of frequency response and large signal amplitude response. The luminance channel subjects the luminance signal to high frequency preemphasis and to hard limiting or clipping at predetermined fixed levels. The chrominance channel exhibits a substantially uniform amplitude response and a variable compression characteristic dependent upon the chrominance signal level, a sum of chrominance and processed luminance signals or a composite output signal formed by a sum of processed chrominance and processed luminance signals. The composite signal is suitable for application to a picture carrier frequency modulator whereby an FM signal is produced suitable for video disc or tape recording and in which a tendency for luminance-chrominance crosstalk or interference is minimized.