| 摘要 |
PURPOSE:To prevent the generation of an unnecessary ghost by stopping data having an enough value to eliminate a ghost from being rewritten once the data is obtained. CONSTITUTION:A video signal inputted from input terminal 1 is inputted to differentiator A2 via transversal filter A1. The output of differentiator A2 is supplied to comparators 21 and 22. Comparators 21 and 22, if a positive or negative ghost is outputted from differentiator A2, detect it to supply pulses to three-input AND circuit 23 and 24, respectively. Once the pulses are supplied from comparators 21 and 22, they are supplied as clear pulses to counter 26 through circuits 23 and 24, so that counter 26 can not go up to its final value as far as the ghost exists. When the ghost disappears and counter 26 goes up to the final value, output terminal 30 is held at the high level. An input to tap gain storage part A8 is controlled by the high-level signal to inhibit data in storage part A8 from being rewritten. |
