Patent ID: 6211923
Filing Date: 2001-04-03
Classification: H04N

Abstract:
A device for correcting an R-Y chrominance parameter and a B-Y chrominance parameter transmitted by a chrominance subcarrier of a television signal by producing a B demodulation signal and an R demodulation signal produced by shifting an S0 signal and an S90 signal, respectively, a phase shift amount which depends on the phase of the chrominance subcarrier, the S0 signal and the S90 signal being obtained from a phase locked loop including an RC network, the S0 signal and the S90 signal differing in phase by about ninety degrees, the device comprising:a first multiplying unit, having an output, to multiply the S90 signal by a first fraction;a first adder having a first input to receive the S0 signal, a second input coupled to the first multiplying unit output and an output to provide the B demodulation signal;a second multiplying unit, having an output, to multiply the S0 signal by a second fraction, the second fraction being equal in magnitude and opposite in sign to the first fraction;a second adder having a first input to receive the S90 signal, a second input coupled to the second multiplying unit output and an output to provide the R demodulation signal; anda control unit, coupled to the first multiplying unit and the second multiplying unit, to provide at least one reference value corresponding to the value of the first fraction and the second fraction.