| 摘要 |
PURPOSE:To stabilize ghost eliminating operation and to shorten processing time by equivalently judging the amount of noise in a video signal by an IF-AGC voltage, and then varying the mean frequency of waveform information and tap correction ending condition by said voltage. CONSTITUTION:An input video detection output signal E containing a ghost is passed through a transversal filter 5 to remove the ghost, thus obtaining an output video signal F. In about one horizontal period before and after a vertical synchronizing signal, the output video signal F is applied to an A/D converter 7 to process ghost information, but in other periods, an IF-AGC voltage is applied to the A/D converting circuit 7, thereby performing the tap correcting operation of the transversal filter 5. When the detection signal has many noises, A/D-converted waveform information is averaged many times to reduce the influence of the noises and when noises are less, the frequency of averaging is decreased to shorten processing time. |
