| 摘要 |
PURPOSE:To obtain a color reproducing circuit wherein variance in the phase of a chrominance subcarrier due to IC-implementation exerts no influence upon color reproduction by generating two relative-phase signals by a phase shifting circuit, and using them as a chrominance subcarrier for demodulation. CONSTITUTION:A composite video signal applied to a terminal 41 is supplied to a demodulating circuit 46 through the 1st and 2nd band amplifiers 42 and 43 having selection bands in the frequency bands of a chrominance signal and CR phase shifting circuits 44 and 45, and the chrominance signal is demodulated there to supply a primary-color signal to an image receiving tube 47. The chrominance subcarriers (ER-EY)CW and (EB-EY)CW for demodulation which are applied to the demodulating circuit 46 are generated on the basis of the oscillation frequency of the same frequency as the chrominance subcarriers from an oscillator 51. Namely, the circuit consisting of a CR phase shifting circuit 32, differential amplifiers 33 and 34, and matrix circuits 35 and 36 generates two optional signals having the relative phase theta with each other, and they are applied as the chrominance subcarriers for demodulation to the demodulating circuit 46 through a limiter 55. |
