| 摘要 |
PROBLEM TO BE SOLVED: To provide a gradation voltage signal supply device for driving a liquid crystal display device that can highly accurately set a gradation voltage nearby a center voltage where an influence on picture quality of a liquid crystal display means is large while securing a sufficient output voltage range without specially making a D/A converter high in resolution. SOLUTION: The gradation voltage signal supply device is equipped with a plurality of D/A converters 10 each of which converts an inputted digital signal into an analog voltage and outputs it as a gradation voltage signal to the liquid crystal display device, and signal conversion characteristics of each D/A converter 10 is such nonlinear characteristics that variation of values V1 to Vn of the analog voltage signal with respect to variation of values D1 to Dn of the digital signal monotonously increases (or monotonously decreases) and the gradient of the analog voltage signal within a prescribed range nearby the center value of a range within which values of the digital signal can exist is gentler than those of ranges before and after it. Further, levels of analog voltage signals of the respective D/A converters are made variable (or different). COPYRIGHT: (C)2006,JPO&NCIPI
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