Abstract: Dual standard TV receiver includes means for identifying field frequency of received TV signals. A switching system responsive to output of field frequency identifying means alters circuitry of receiver's vertical deflection system in a manner maintaining same picture height for received signals of differing field frequencies. Circuitry alteration additionally effects appropriate alteration of free-running frequency of oscillator.

Abstract: R-Y and B-Y color difference components of an NTSC format input signal are demodulated to base-band and a burst flag is added to the R-Y signal. Both the B-Y signal which includes the original base-band burst component and the R-Y signal with the added burst flag are then remodulated on respective quadrature related PAL subcarriers. Alternate line phase reversal is achieved in one embodiment by switching the phase of the R-Y demodulator and inverting the burst flag every other line. In another embodiment the added flag is of constant polarity and the R-Y remodulator reference phase is switched. The remodulator outputs are combined with a luminance component of the NTSC input signal whereby a non-standard video output signal is produced having an NTSC luminance component and a PAL chrominance component to enable monitoring of the NTSC input signal on a PAL color television monitor operating at 525/60 line/field rate.

Abstract: Video disc player is switchable between two operating modes: (1) for playback of records of color signals of one scanning standard (15,625 Hz. line frequency; 50 Hz. field frequency) encoded in a buried subcarrier format; (2) for playback of records of color signals of another scanning standard (15,734.26 Hz. line frequency; 59.94 Hz. field frequency) also encoded in a buried subcarrier format, but with a different subcarrier frequency. When operating in mode (1), recovered signals are heterodyned with output of a VCO to up-convert chrominance signal and accompanying color synchronizing component. Control of VCO is effected in accordance with output of a phase detector responding to up-converted color synchronizing component and to reference oscillations, whereby up-converted signals are stabilized against time-base errors.

Abstract: Color encoding format for a color picture information record, and recording apparatus therefor, are disclosed for recording of discs for use with both (1) disc players designed to provide PAL-type outputs for driving PAL-type color television receivers, and (2) disc players designed to provide SECAM-type outputs for driving SECAM-type color television receivers. In players, up-conversion of recovered composite signal precedes comb filtering to separate luminance and chrominance components. Decoding of up-converted chrominance component, to obtain baseband color-difference signal information is followed by remodulation of a carrier pursuant to a desired output format. Comb filter arrangements of U.S. Pat. No. 3,969,757 are used when up-conversion shifts color subcarrier to a frequency in vicinity of PAL subcarrier frequency, but bearing odd integral multiple relationship to half the line frequency.

Abstract: A protection circuit for limiting the power dissipation of a video output amplifier when high frequency signals of significant magnitude and with a high density of occurrence (e.g., noise during vacant channel reception) are supplied to the amplifier. The protection circuit includes a control transistor and a sensing network. The sensing network monitors a video signal coupling path to detect the presence of high frequency signals, and derives a voltage representative thereof. The derived voltage is insufficient to render the control transistor operative under normal signal conditions. Under abnormal conditions when significant amounts of high frequency signals with a high density of occurrence are present, the derived voltage is sufficient to render the control transistor operative to develop an output control voltage.