| 摘要 |
<p>PURPOSE:To prevent the rise time and fall time of a video signal from being affected by forming the quantized video signal depending on the leading and trailing of a signal whose level is a level or over lowered by a prescribed level from a peak level. CONSTITUTION:A peak level detection circuit 6 detects peak levels P'e P'' e and P'''e sequentially and a delay circuit 5 outputs level information to a measuring signal detection circuit 7 while retarding it by a delay time T more than the rise time of the video signal 1. The measuring signal detection circuit 7 calculates a level Me lower than the peak level measurement by a prescribed level C, awaits the level information from the delay circuit 5 and detects the signal with the calculated circuit 12 is made effective when a measuring signal rise detection signal is effective and outputs a correction quantized video signal 13 being ineffective when a measurement signal fall detection signal from a measurement signal trailing detection circuit 11 is effective.</p> |
