Color demodulation device for use in color television receivers

A color demodulation device for demodulating carrier chrominance signal in a composite video signal, said composite video signal having luminance signal component and carrier chrominance signal component multiplexed in frequency-interleaved relation with the luminance signal component, said chrominance signal component being formed by quadrature modulation (carrier-suppressed AM) of a color subcarrier with an I signal and a Q signal, said I signal having a frequency band wider than the Q signal, comprising:

• signal separation circuit means using a comb filter for separating the composite video signal into the luminance and carrier chrominance signal components, said luminance and chrominance signal components being extracted from first and second outputs of said signal separation circuit means, respectively;
• line correlation detecting means coupled to said first and second outputs of said signal separation circuit means for detecting the correlation between video signals on adjacent horizontal scanning lines;
• I signal demodulation circuit means coupled with said second output of said signal separation circuit means for demodulating the I signal;
• Q signal demodulation circuit means coupled with said second output of said signal separation circuit means for demodulating the Q signal;
• and
• matrix circuit coupled to said I and Q signal demodulation circuit means,
• said I signal demodulation circuit means being responsive to said line correlation detecting means to perform wideband demodulation of the I signal so that the I signal is applied in a wide frequency band to said matrix circuit means where there exists line correlation, and to perform narrowband demodulation of the I signal so that the I signal is applied to said matrix circuit means in a narrow frequency band where there exists no line correlation.