| 摘要 |
PURPOSE:To supply a sampling command at any time in one vertical scanning period, by providing a counter which outputs an address signal and a circuit which supplies a video signal corresponding to an optional picture-element position. CONSTITUTION:Counter 2 is reset with vertical synchronizing pulse VSYNC and then counts horizontal synchronizing signal pulses HSYNC successively. Its count value is supplied as address signal A to data buffer BF. Therefore, when timing signal TM is outputted from preset counter 11 at the timing that corresponds to a picture-element position specified with signal HP in each horizontal scanning period, video signal VD is fetched into shift register 12 by signal TM. Then, it is supplied as data SD to buffer BF. Consequently, data SD is stored successively in memory areas of the data buffer specified with signal A. Thus, the sampling start command is supplied at the same period as one vertical scanning time at a maximum. |
