| 摘要 |
PURPOSE:To avoid conspicuousness of color noises even when the overall chroma of a dark part is lowered, by using a variable gain amplifying circuit which amplifies a chroma signal while varying the gain in response to the amplitude of a luminance signal. CONSTITUTION:For a color reproduction processing circuit 1, a composite video signal is supplied to a band amplifier 4 and chroma and color burst signals are extracted and amplified to be supplied to a variable gain amplifier 5 and a color synchronizing circuit 6. The outputs of the amplifier 5 and the circuit 6 are supplied to a color demodulating circuit 7, and a color difference signal is demodulated for both outputs respectively. Furthermore the color difference signal is mixed with a signal Y delivered from a video amplifying circuit 2 through a matrix 8 and then applied to each cathode of a picture tube 9 in the form of each primary color signal. A luminance signal obtained by reproducing the DC component delivered from a DC reproducer 10 in the circuit 2 is supplied to a gain control input terminal of the amplifier 5. |
