| 摘要 |
PURPOSE:To avoid the deterioration of the video signal by detecting the area the deterioration such as the resolution lowering or the like and stopping the function as the comb-line filter for the time of the detection to secure the operation as just a passing circuit. CONSTITUTION:The C-type comb-line filter is formed with 1H delay line 2 and adder 6; while the Y-type filter is formed with line 2 and adder 5 respectively. Nonlinear circuit 7 functions to switch the circuit from the C-type comb-line filter to just a passing circuit in accordance with the signal level supplied to input terminal 10. In other words, decision reference level VF is set previously to the output of Y- type comb-line filter 13. And thus the signal is sent directly to output terminal 11 in case the output of filter 13 is larger than VF to secure the function of just a passing circuit; while the output to terminal 11 is blocked when the output is smaller than VF to secure the function of the C-type comb-line filter. |
