Abstract: Color television receiving apparatus for receiving and demodulating a composite color television signal including hrozintal synchronizing signals, color burst signals, and luminance and chrominance components. This composite color television signal is of the type which additionally may or may not include a VIR signal which, typically, is broadcasted in a predetermined line interval during the vertical retrace period of the composite color video signal. The apparatus includes the demodulator for demodulating the chrominance component, which has been separated from the composite video signal, into its color signal components. A signal generator generates a signal, such as a gate signal, during the predetermined line interval in which the VIR signal is expected.

Abstract: A relatively broad band automatic fine tuning circuit covering a frequency band at least approximately as broad as a television channel and including means to shift the frequency of the television tuner up or down, as necessary, to the proper frequency within the automatic tuning range. A first control signal is obtained by comparing the average value of the envelope detected signal from the video detector with a voltage equal to the pedestal level if the signal were a properly tuned video signal. If the actual average value of the envelope is between zero volts and the pedestal voltage, the tuner is either correctly tuned or tuned at a somewhat lower frequency than is correct. If the voltage average value has a greater magnitude than the pedestal voltage the tuning of the tuner is too high. A frequency discriminator receiving the video IF signal controls the automatic tuning operation close to the desired frequency.

Abstract: Color television receiving apparatus is provided for receiving a composite television signal which includes horizontal synchronizing signals, color burst signals and luminance and chrominance components. The composite color television signal is of the type which additionally may include a VIR signal which is provided in a predetermined line interval during the vertical retrace interval. The receiving apparatus comprises signal processing circuitry for processing the received composite color television signal so as to produce a video picture therefrom. A sampling signal generator generates sampling signals during the predetermined line intervals in which the VIR signal is provided. A VIR detector is coupled to the signal processing circuitry and is responsive to the sampling signals to detect if the VIR signal is included in the received composite color television signal. At least one component produced by the signal processing circuitry is sampled by the sampling signals to produce sampled control signals.

Abstract: A color television receiver having a color picture tube with a screen for displaying a color picture in response to the reception of a composite color television signal which includes a phase reference signal, such as, the chrominance reference portion of a VIR signal, is provided with a circuit for generating variable reference color signals and for causing the color picture tube to display, on at least a portion of its screen, areas of respective colors corresponding to the variable reference color signals, a demodulating circuit for demodulating the phase reference signal and the chrominance component of the color television signal for obtaining demodulated color signals from such chrominance component, a hue correction circuit responsive to the demodulated phase reference signal for correcting errors in the hue of the color picture displayed on the screen in correspondence to the demodulated color signals due to phase distortions in the chrominance component of the received color television signal, and a

Abstract: A stabilized frequency oscillating circuit comprises a voltage or current controlled variable frequency oscillator, a delay device receiving the output of the oscillator, an adder for adding the output of the oscillator and the delayed output of the delay device, and a detecting circuit which detects the amplitude of the output of the adder to provide a control signal which varies cyclically with changes in the oscillating frequency of the oscillator which is applied to the latter for locking the oscillating frequency of the oscillator to a predetermined or desired frequency. The oscillating circuit may further have a control circuit by which an additional control voltage or current is superimposed on the cyclically varying control signal for selecting the oscillating frequency to which the variable frequency oscillator is to be locked, or by which either the oscillator output or delayed output is phase-shifted before being applied to the adder.