| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To improve quality of an output video signal by preventing noise or ripples from superimposing on a negative voltage to be supplied. <P>SOLUTION: A video circuit includes a video processing circuit 10, in which a sync chip and a pedestal of an input video signal S11, containing a synchronizing signal, are clamped by a clamp circuit 11 and outputted as a video drive signal by performing video processing thereon, and a charge pump circuit 20 for generating a negative voltage -V for negative voltage power supply requested to the video processing circuit 10. A synchronizing signal S21 is detected from the output signal of the clamp circuit 11 and inputted to a driving control circuit 21 of the charge pump circuit 20, and switches SW1, SW2 of an output circuit 22 are turned on, only during the synchronizing signal term by a drive control signal S13 outputted from the drive control circuit 21. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
