| 摘要 |
<p>PURPOSE:To reproduce a color difference signal stably with high accuracy by separating digitally two color difference signals and a pulse coding (PCM) audio or data signal multiplexed with pulse width modulation on a pulse frequency modulation(PFM) signal modulated by a luminance signal Y. CONSTITUTION:A separator 60 inputs a reception multiplex signal 300 and a reproduced PFM signal 301 and uses a detection signal 303 so as to select the signal 300 at a period S and the signal 301 at a period L respectively. As a result, the pulse width of an output signal 400 of the selector 60 is changed analogically the same as the reception multiplex signal 300 for the period S and constant for the period L. Thus, the peak of a reproduced sawtooth wave signal 401 at the period L is also constant. Then the signal amplitude of a peak hold signal 402 and an LPF output signal 403 at the period L is unchanged. Thus, when a pulse width T0 of the selector output signal 400 for the period L is completely coincident with the pulse width resulting from the clamp level of a color difference signal modulated for the period S, the clamp period is sufficiently extended.</p> |
