| 摘要 |
PURPOSE:To improve the resolution by leaps and bounds by controlling the phase of a carrier for frequency conversion so that phase relations between a synchronizing signal of a demodulated reproduced low band luminance signal and a high band component of a synchronizing signal included in a high band luminance signal are fixed. CONSTITUTION:The output of a frequency demodulator 5 has the frequency converted with jitter by the carrier for frequency conversion which passes a phase shifter 73 on a basis of a horizontal synchronizing signal obtained by a synchronizing signal separator 11 to take out only a luminance signal by a luminance signal comb line filter 8. This signal and a low band luminance signal YL of the output of the demodulator 5 are synthesized to obtain a chrominance signal without jitter and a luminance signal whose high band component and low band component have the same jitter. Phase relations between the synchronizing signal and the high band component of the synchronizing signal included in the high band luminance signal are detected by a phase detector 70, and the phase shifter 73 is controlled so that they are fixed. Thus, the phase of the carrier is kept correct, and the phase of a high band luminance signal YH and that of a low band luminance signal YL coincide with each other.
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