| 摘要 |
<p>PROBLEM TO BE SOLVED: To erase a noise on the edge of a screen which is generated at the time of displaying a video signal on a CRT of a personal computer and to display only information to be displayed on the CRT only by slightly adding circuits while executing upconversion of an NTSC signal by an FIFO system. SOLUTION: A mask signal generating circuit 21 and an output control circuit 22 are added to an up-conversion video signal processor for up-converting frequency at the time of reading out a video signal written in a memory 15. In order to erase a noise generated on the edge of the screen generated at the time of displaying an up-converted output on the CRT by the circuit 21, a mask signal (b) for masking a signal in a noise period is prepared. The mask signal (b) is added to the circuit 22 and an upconverted output passing the circuit 22 is controlled so as not to output horizontal and vertical blanking periods including a noise out of the up-converted output passing the circuit 22.</p> |
