| 摘要 |
PURPOSE:To eliminate effectively ghost signals and display the delay time by controlling automatically the amplitude and the polarity of delay video signals by the detection output which accords to the amplitude and the polarity of ghost signals. CONSTITUTION:Video signal b obtained by adding a ghost signal to transmitting video signal a is supplied to adder circuit 5, and the output becomes signal c through variable delay circuit 6. Signal c is inputted to synthesizer circuit 5 through amplitude polarity adjustment circuit 7 and is synthesized with signal b, and as a result, a video signal with a ghost signal eliminated is outputted to terminal 8. In this case, signals b and c are applied to high-band extractor circuits 9 and 10 to extract only high-band components d and e, and these components are multiplied in 11 to obtain detection output f. This signal f is applied to circuit 7 through LPF 12 to control automatically the amplitude and the polarity. Further, signals b and c are multiplied in 18 through high-band extractor circuits 14 and 15 respectively, so that the delay time of the ghost signal can be displayed on 18. |
