| 摘要 |
The system has a separator (1) for removing a horizontal synchronizing signal from an input video signal. A pulse generator (4) produces a pulse at a given time during the back porch following the horizontal synchronising signal of the video signal. This pulse has a narrower width than that of the back porch. A second generator (5) produces a second pulse with a lower level than that of the first at a given time during the back porch. The second pulse has a narrower width than that of the back porch and an equal pulse area to that of the first pulse. An arrangement (9-15) alternately adds the first and second pulses to the back porch of the video signal for predetermined time. |
