Abstract: A system for reproducing a luminance signal from a medium containing a previously recorded luminance signal with a high-frequency portion thereof compressed in dynamic range includes a circuit for recovering that luminance signal from the medium. Filtering is done to separate the low-frequency and compressed-in-dynamic-range high-frequency portions of the recovered luminance signal from each other. A corer responds to the separated compressed-in-dynamic-range high-frequency portion of the recovered luminance signal to provide a cored high-frequency portion with expanded dynamic range and reduced noise.

Abstract: An encoder separates luminance and chrominance signal components of a composite video signal. The frame-to-frame changes in the luminance signal are detected, and a motion signal is derived therefrom. The higher frequency portion of the luminance signal is adaptively de-emphasized in amplitude and folded into the spectrum of the lower frequency portion of the luminance signal, to generate a folded-spectrum luminance signal for modulating the frequency of a luma carrier. In a combined signal, suitable for magnetic recording in accordance with a modified VHS standard, the chrominance signal is translated in frequency to generate a color-under signal in a frequency band below that occupied by the FM luma carrier.

Abstract: A system for reproducing a luminance signal from a medium containing a previously recorded luminance signal with a high-frequency portion thereof compressed in dynamic range includes a circuit for recovering that luminance signal from the medium. Filtering is done to separate the low-frequency and compressed-in-dynamic-range high-frequency portions of the recovered luminance signal from each other. A corer responds to the separated compressed-in-dynamic-range high-frequency portion of the recovered luminance signal to provide a cored high-frequency portion with expanded dynamic range and reduced noise.

Abstract: A new VCR recording format, the augmented or "A-" format, such as A-VHS, is described which is fully compatible with the existing standard recording formats, such as VHS. In the new format, the high-frequencies of the luminance component of the television video signal, which are needed for maintaining sharp pictures but which are missing in standard (VHS) recording systems, are recorded on the video tape in an additional luminance channel, or so-called augmentation channel, which utilizes a portion of the recording spectrum which is above the bandwidth occupied by the luminance component in the standard (VHS) system. A new AM-modulated augmentation signal carrier is used to locate and carry the additional luminance spectrum above the standard VHS luminance FM-spectrum. In the preferred embodiment, the luminance high-frequencies are compressed in bandwidth in order to make efficient use of the bandwidth available in the augmentation channel.

Abstract: A system for reproducing a luminance signal from a medium containing a previously recorded luminance signal with a high-frequency portion thereof compressed in dynamic range includes a circuit for recovering that luminance signal from the medium. Filtering is done to separate the low-frequency and compressed-in-dynamic-range high-frequency portions of the recovered luminance signal from each other. A corer responds to the separated compressed-in-dynamic-range high-frequency portion of the recovered luminance signal to provide a cored high-frequency portion with expanded dynamic range and reduced noise.

Abstract: A frequency-multiplexed video signal is generated in which a color-under signal and a second under signal are linearly combined with at least partially overlapping frequency spectra to form a composite under signal for an FM luma signal. The frequency-multiplexed video signal is suited for recording on magnetic tape using helical scanning methods and for being played back from the magnetic tape using helical scanning methods. The second under signal is generated in such way that line-comb filtering can be used during playback to separate color-under signal and second under signal each from the composite signal despite their frequency spectra being at least partially overlapping in the composite signal.

Abstract: In a backward compatible video signal recording and playback system for recording a full bandwidth video signal on a limited bandwidth medium utilizing a luminance signal having high frequencies being folded into low frequencies and unfolded on playback, apparatus includes circuitry for selecting a desired level of high frequency performance for a given degree of reverse compatibility and circuitry for recording a signal indicative of the level.

Abstract: Noise estimation circuitry for estimating the noise in a small number of horizontal scanning lines of a video signal includes a lowpass line comb filter responding to said video signal, but not to chrominance-descriptive components thereof. The video signal free from chrominance-descriptive components is repeatedly sampled during the backporch interval of each horizontal scanning line, and the samples are accumulated to generate a revised noise estimate each successive horizontal scanning line.

Abstract: An improved video signal recording system for recording a full bandwidth video signal on a limited bandwidth medium is disclosed. The recording system includes an encoder, coupled to an input terminal, for adaptively processing a composite video signal in response to a motion representative signal, and producing two signals; a luminance signal, having attenuated high frequencies subsampled so as to be folded into a spectral hole in the low frequencies, and being bandwidth limited to the limited bandwidth of the recording medium; and a combined signal including a chrominance and a motion component. Luminance signal recording circuitry records the folded luminance signal on the medium and chrominance signal recording circuitry records the combined chrominance and motion signal on the medium. An improved video signal playback system for reproducing such a prerecorded video signal is also disclosed.

Abstract: In a video cassette recorder (VCR) including a video signal processing system having a source of a reference signal having a first frequency of 2.517 MHz, a clock signal generating circuit comprises a first frequency multiplier circuit of a balanced modulator type, having an input coupled to the source of a reference signal and having an output for providing a signal including a component having a second frequency of twice the first frequency. A filter arrangement has an input coupled to the output of the first frequency multiplier circuit, has an output, and has a response characteristic peak substantially at the second frequency. A second frequency multiplier circuit of a balanced modulator type, has an input coupled to the output of the bandpass filter arrangement and has an output for providing a signal including a component having a third frequency of twice the second frequency.

Abstract: In an apparatus for displaying the picture information of an incoming interlaced television signal in noninterlaced raster scanning display on the faceplate of a picture tube, each video line of the television signal is separated into R, G and B color component signals. Each video line is compressed, or speeded-up, at a variable rate and delayed by a variable delay time to provide a speeded-up signal that is coupled to the corresponding electron beam gun of the picture tube. Each of the variable rate and delay is controlled in accordance with information relating to distortions of the raster scanning display. In this way, distortion, such as east-west or convergence, is reduced when the speeded-up signal is displayed.

Abstract: A motion detector for detecting interimage motion represented by composite video signals analyzes both the chrominance and luminance components for image motion. Interimage motion represented by the luminance component is determined from interimage signal differences. The interimage signal differences are separated into high and low frequency spectra corresponding to fine and coarse luminance image detail. Selected signal differences from the low frequency spectrum are summed and threshold detected to determine motion in the coarse image detail. The high frequency spectrum of the sample differences are applied to parallel summing circuits which sum different combinations of sample differences in order to discriminate motion signals from non-moving chrominance transitions. The detection signals from the high and low frequency motion detectors are combined to produce a luminance motion signal.

Abstract: A power supply and deflection circuit for a video monitor provides multiple horizontal scan rates. A switch is used to select the desired scan rate. Operation of the switch determines the proper operating voltage level for the horizontal deflection circuit. A zener diode provides a high or low signal in response to the level of the determined operating voltage. The horizontal oscillator frequency and the value of the S-shaping capacitor is determined in response to the high or low signal. The operation of the switch, therefore, provides the necessary circuit parameter changes for each of the horizontal scan rates selected.

Abstract: An inverter operated at the horizontal deflection frequency is coupled to a source of direct voltage for developing an alternating voltage at an output terminal of the inverter. A capacitor AC couples the alternating voltage to the primary winding of a power transformer for developing alternating polarity supply voltages across secondary windings of the transformer. A horizontal generator generates scanning current in a deflection winding. A third winding of the transformer applies to the deflection winding the alternating polarity voltage developed across the third winding. The control circuit of the inverter is responsive to a deflection rate voltage synchronized with scanning current generation for synchronizing operation of the inverter so as to enable the third winding to provide substantial linearity correction to the scanning current.

Abstract: A horizontal oscillator provides switching signals for use by a trace switch of a horizontal deflection circuit and to drive a push-pull output stage. The push-pull output stage provides an AC supply voltage to the primary of a power transformer. The rectified secondary winding voltage of the transformer provides a B+ supply voltage to the deflection circuit. After the elapse of a start-up interval, energization voltage for the horizontal oscillator is provided by either the power transformer or the deflection circuit. During the start-up interval the push-pull output stage self-oscillates as an astable multivibrator to develop the AC supply voltage within that interval.

Abstract: A high efficiency switching regulator for maintaining a constant d.c. voltage is described. An efficiency improvement of better than 20 percent is realized by use of an alternate low impedance current source for supplying base current to the control transistor of a switching regulator.