| 摘要 |
PURPOSE:To avoid occurrence of the uneven color even in the system featuring the low stability of the time axis, by turning the signal of the secondary carrier to be modulated into the line sequential signal and then modulating only the amplitude of the secondary carrier with the chrominance signal. CONSTITUTION:Video source 1 produces luminance signal Y and color difference signals R-Y and B-Y based on each of the R, G and B signals. Signals R-Y and B-Y turned into the line sequential signals through switch 7 which opens and closes with the 1/2 repetitive frequency of horizontal frequency fH. This output is then divided into two parts, and one of these two parts is inverted at inverter circuit 8. The output and the inverse output of switch 7 are supplied to switch 9 which is opened and closed with the repetitive frequency of 1/4 fH, and thus the time-series signal is led out to the output of switch 9. This signal receives the AM modulation at carrier suppression modulator 10 to be limited to the band of BPF11, and is then added with signal Y which is the output of adder 6 through adder 12 to receive the FM modulation in the form of the composite color video signal for recording. Thus no color shading is caused by fluctuation of the time axis since no hue is transmitted with the phase modulation of the secondary carrier. |
