| 摘要 |
PURPOSE:To obtain two correct color difference signals by one local subcarrier oscillator by controlling the polarity of the subcarrier signal on a basis of the phase relation between the burst signal and the subcarrier signal applied to the other color signal demodulator. CONSTITUTION:Local subcarrier oscillator 11 is driven by the signal taken out by switching alternately the burst signal and the signal, which is obtained by phase inversion of the burst signal, at every one horizontal period, and obtained prescribed-phase and inverted-phase subcarrier signals are switched and taken out correspondingly to switch circuit 8, and these taken-out subcarrier signals are applied to one color signal R-Y demodulator 4. The subcarrier signal applied to the other color signal B-Y demodulator 5 is generated on a basis of the output of local subcarrier oscillator 11, and the polarity is controlled by control circuit 17 on a basis of the phase relation between the burst signal and the subcarrier signal applied to B-Y demodulator 5. |
