| 摘要 |
PURPOSE:To reduce ghosts by simple circuit constitution with only one delay line. CONSTITUTION:An input signal (vertical synchronizing part of video signal: a-2) is differentiated to obtain differential values alpha1 and beta1. The above-mentioned differential outputs are delayed by time nT through tapped delay line A to obtain differential value alpha2. Then when alpha2 is inputted to peak pulse generating circuit 14, circuit 14 generates peak detection pulse (e-2), since mask pulse (d-2) is previously inputted, to turn on switches 1b-nb, so that differential value beta2 of the ghost will be held at the corresponding position in memory C through the switch that corresponds to delay time mT. The input signal amplified 17 is multiplied the above-mentioned held voltage by multipliers 1d-nd, whose outputs are inputted to the corresponding positions of delay line A and subtracter 19 is applied with the signal delayed time mT behind the original signal, so that a video signal having the ghost eliminated can be obtained from subtracter 19. |
