| 摘要 |
PURPOSE:To obtain a color encoder from which color difference components coping with a TV receiver of the PAL and NTSC system are obtained easily by inverting the three primary chrominance components in a period twice that of a horizontal synchronizing signal in converting the three primary chrominance components into the color difference components. CONSTITUTION:The three primary chrominance components R, G, B from terminals 1-3 and a burst flag signal from a terminal 4 are inputted to a matrix circuit 5, and an inverted horizontal synchronizing siganl H' is fed from a terminal 8 to an FF9. The siganl having double period that of the signal H fed from the circuit 5 is controlled by a switch circuit 10, and in case of a receiver with the PAL system, the color difference components B-Y from the circuit 5 and an output inverting the phase of the color components R-Y in a period twice the period of the signal H are obtained, and the signal B-Y and R-Y are outputted in case of the NTSC system. The color difference components are fed respectively to orthogonal modulation circuits 6, 7, a chrominance subcarrier signal from a terminal 11 is used to generate a pi/4 lead signal and a pi/4 lag signal from a phase shift circuit 2, which apply orthogonal modulation, and the modulated color difference components are superimosed to output the chrominance components. |
