| 摘要 |
PURPOSE:To simplify the circuit constitution and to prevent the generation of the troubles of a cross color, etc., by synthesizing the signals corresponding to the difference between the input and the output of a signal delay circuit through a signal synthesizing circuit and then demodulating the color difference signal contained in the output of the synthesizing circuit. CONSTITUTION:The output of a 1H delay circuit 10 is subtracted from a PAL color video signal through a subtractor circuit 11. Then a signal corresponding to the difference between the video signal and its 1H-preceding video signal is synthesized and supplied to a 1H delay circuit 2, an adder circuit 3 and a subtractor circuit 4 respectively. While a single subcarrier signal is supplied from a subcarrier generator to B-Y and R-Y demodulators 5 and 6 respectively. Then the B-Y signal is delivered from the demodulator 5, and the output of the demodulator 6 and the output of a phase inverter 12 are transmitted with each H by a switch 13 to be turned into an R-Y signal. In such a way, it is possible to obtain both B-Y and R-Y signals from a single subcarrier signal. |
