Device for correcting the color of a television signal according to NTSC standard

摘要

A device corrects the chrominance parameters transmitted by a chrominance subcarrier of a television signal, by shifting the phase of two demodulation signals an angle, which depends upon the phase of the chrominance subcarrier. The demodulation signals are obtained from a phase-locked loop including a resistive and capacitive network having two outputs that differ by 90° with respect to each other. The device may include circuitry for individually shifting the phase of each signal provided by the RC network by adding to each signal a fraction of the other signal provided by the RC network. The fractional coefficients may be opposite to each other and depend upon the phase of the chrominance subcarrier.