| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve sag of a video signal without deteriorating characteristics of the video signal and further without enlarging the capacity of an input coupling capacitor. <P>SOLUTION: The synchronizing signal of a video signal inputted via an input coupling capacitor 4, before and after its Sync Tip term, is clamped to a first voltage V1 by a Sync Tip clamp circuit 1. A Sync detecting circuit 2 is provided to output a control signal to an improved current output circuit 3 when the Sync Tip voltage of this synchronizing signal is lower than a second voltage V2 supplied by a second power source 6, on the other hand, and the improved current output circuit 3 supplies a charging/discharging current of the input coupling capacitor 4 when the control signal is inputted from the Sync detecting circuit 2. The charging/discharging current of the input coupling capacitor 4 is sufficiently secured differently from the conventional circuit, thereby ensuring the sag improvement of the video signal. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
