| 摘要 |
PURPOSE:To reduce ghosts by simple circuit constitution with only one delay line. CONSTITUTION:Vertical synchronizing part V1 of a video signal, namely, input signal (a-2) has ghost S1 and lags the leading edge of the input signal by mT. The above-mentioned input signal is differentiated to obtain differential values alpha1 and beta1. The above-mentioned differential outputs are delayed by time nT to obtain differential values alpha2 and beta2 by tapped two-way delay line A. When differential value alpha2 is inputted in the period of mask pulse (d-2), on the other hand, peak detection pulse 14 is generated, and consequently switches 1b-nb are turned on; since differential value beta2 of the above-mentioned ghost is being delayed by time mT, it is held at the correspoinding position in memory C via the corresponding switch. Then, the propagation path of delay line A is changed over to supply an amplified-18 input signal, by which the above-mentioned held ghost differential value is multiplied D to obtain a signal delayed mT behind the original input signal. From the input signal, the above-mentioned multiplication output is subtracted 19 to obtain a video signal having the ghost eliminated. |
