| 摘要 |
PURPOSE:To realize a high definition picture and to reduce by cost by modulating a picture signal in the unit of picture elements, arranging the picture signal in time series within a time of one picture element, comparing the obtained picture signal with a reference signal to obtain a pulse width modulation signal. CONSTITUTION:A 4-adic counter 105 generating a conversion data starts counting synchronously with a horizontal synchronizing signal (HSYNC) 12 and counts data synchronously with a conversion data clock 14 to output values '0' - '3' as a conversion data 19 at a period of 1/2 of a video clock 13. A conversion table 106 receives the conversion data 19, a 6-bit video data 17, and a screen data 18 and outputs a conversion video data 20 resulting from the conversion of the video data 17 and a data 22 representing inversion/ noninversion. A comparator 107 compares a conversion video data 20 with a triangle wave of 400 lines and outputs '1' when the conversion video data 20 is larger as the result of comparison. The output is inverted by an exclusive OR circuit 108 when the inverting signal is logical 1 and outputted as a pulse width modulation signal 25. |
