| 摘要 |
PURPOSE:To attain the hue adjustment not requiring a capacitive element and to make the system suitable to digitizing by varying the ratio of the 1st and 2nd color burst demodulation outputs summed to adjust the phase difference between the color burst and a chrominance subcarrier. CONSTITUTION:A detecting means 7 detects a chrominance carrier signal and a synthesized color signal S including a color burst at a B-Y demodulating axis and an R-Y demodulating axis, outputs the 1st color burst demodulating output S1 and the 2nd color burst demodulating output S2 and uses the chrominance subcarrier wave given from a voltage controlled oscillator 4 for the B-Y demodulation axis and the R-Y demodulation axis while keeping them to a phase difference of 90 deg. with each other. A control means 8 adds the demodulation output S1 of the B-Y output path 9 and the demodulation output S2 of the R-Y output path 10, and the summed output is given to the voltage controlled oscillator 4 through an LPF 3 as the control signal. Since the adder 11 and the adjusting means 13 are blocked by a burst gate 12 to the LPF 3 at the output of scanning period, no effect is given to the control of the voltage controlled oscillator 4. |
