| 摘要 |
PURPOSE:To simplify circuit constitution, by switching a chrominance subcarrier at a prescribed coefficient with a digital three-primary color signal and summing the switched chrominance subcarrier. CONSTITUTION:An amplitude and input selecting circuit 10 produces a chrominance subcarrier (R-Y)' subject to amplitude modulation by switching a chrominance subcarrier Sc1 and its inversion Sc1' with the digital three-primary color signals R, G, B. Similarly, an amplitude and input selecting circuit 11 produces a chrominance subcarrier (Y-B)' by switching the carrier Sc2 and its inversion Sc2' having different phase by 90 deg. with the signals R, G, B. An adder 12 adds the chrominance subcarrier and the burst signal to produce the summing signal between a chrominance signal and the burst signal. Further, a matrix circuit 13 synthesizes a luminance signal Y from the signals R, G, B. The adder 14 adds the signal Y to the output of the adder 12 together with the synchronizing signal to produce a video signal. Since most of circuit parts are digitized, the circuit constitution is simplified. |
