VIDEO SIGNAL PROCESSOR

PURPOSE:To decrease the circuit scale while maintaining conventional performance by converting a chroma signal into color difference signals by using a subcarrier at the time of demodulation, and multiplexing and processing the R-Y signal and B-Y signal when the chroma signal is demodulated into the color difference signals and processed. CONSTITUTION:A composite video signal is passed through a BPF 103 to output a color signal. A demodulating and multiplexing circuit 104 demodulates the color signal with phase information sine and cosine generated from a subcarrier signal and filtering is performed. The 2nd higher harmonic component is removed through the filter process of an LPF 105. A 1/2 time thinning processing circuit 106 limits the band of a color difference multiplexed signal through a filter process to decrease the number of thinned-out data to 1/2. The data after being thinned out are processed vertically by using a 3-line color difference comb filter 112 to generate an accurate color difference signal. An interpolating process circuit 113 performs an interpolating process for restoring the thinned-out signal and outputs the color difference signal in dot sequence. A modulating circuit 115 modulates the color difference signal with the phase information of the subcarrier signal and outputs a vertical two-phase modulated color signal. This color signal is subtracted from the composite video signal which is delayed by a specific time and a luminance signal Y is outputted.