Patent ID: 7663619
Filing Date: 2010-02-16
Classification: G09G

Abstract:
1. A power supply circuit that supplies voltage to a common electrode that is opposite to a pixel electrode, an electro-optical substance being interposed between the common electrode and the pixel electrode, the power supply circuit comprising: a high-potential-side voltage generation circuit that generates a high-potential-side voltage to be supplied to the common electrode; a low-potential-side voltage generation circuit that generates a low-potential-side voltage to be supplied to the common electrode; a switch circuit that alternately supplies the high-potential-side voltage and the low-potential-side voltage to the common electrode as a common electrode voltage; and a first conductivity type first auxiliary transistor that has a source and a drain, a high-potential-side power supply voltage of the high-potential-side voltage generation circuit being supplied at the source, and the drain being electrically connected to an output of the switch circuit, the power supply circuit performing supply capability control of the common electrode voltage that changes at least one of current drive capability of the high-potential-side voltage generation circuit, an output voltage level of the high-potential-side voltage generation circuit, current drive capability of the low-potential-side voltage generation circuit, and an output voltage level of the low-potential-side voltage generation circuit according to line data including grayscale data for the number of dots of one scan line, each dot corresponding to voltage applied to the pixel electrode, and the supply capability control being preformed by changing a gate voltage of the first auxiliary transistor according to the line data.