Patent ID: 8081178
Filing Date: 2011-12-20
Classification: G09G

Abstract:
1. A driving circuit included in an electro-optical device, comprising: a plurality of scanning lines, a plurality of data lines, and a plurality of common electrodes provided for the individual scanning lines; pixels which are arranged at intersections of the scanning lines and the data lines, which include pixel switching elements which have first ends connected to the corresponding data lines and which are brought into conduction states when selection voltages are applied to the corresponding scanning lines, which include pixel capacitors having first ends connected to second ends of the corresponding pixel switching elements and second ends connected to the corresponding common electrodes, and which have levels of gradation corresponding to holding voltages of the pixel capacitors; a scanning line driving circuit which applies the selection voltages to the plurality of scanning lines in a predetermined order; a common electrode driving circuit which drives the plurality of common electrodes individually; and a data line driving circuit which supplies, to pixels corresponding to scanning lines to which the selection voltages are applied, data signals having voltages corresponding to levels of gradation for the corresponding pixels through corresponding data lines, wherein the common electrode driving circuit includes switching circuits which are turned on or turned off in accordance with voltages held in gate electrodes of the switching circuits, and which apply voltages of a low-level side or voltages of a high-level side to the corresponding common electrodes when being turned on, includes first voltage-applying circuits which apply on-voltages to the gate electrodes of the switching circuits when the selection voltages are applied to the scanning lines corresponding to the common electrodes so that the switching circuits are turned on, and includes second voltage-applying circuits which apply on-voltages to the gate electrodes of the switching circuits when instruction signals are transmitted through a predetermined control line in a period in which the selection voltages are not applied to-the scanning lines, and wherein the first voltage-applying circuits each include first and second transistors, the switching circuits each include third and fourth transistors, the second voltage-applying circuits each include fifth and sixth transistors, the first transistors have gate electrodes connected to the corresponding scanning lines and source electrodes connected to a first power supply line to which voltages which cause the third transistors to be turned on or off are supplied, the second transistors have gate electrodes connected to the corresponding scanning lines and source electrodes connected to a second power supply line to which voltages which cause the fourth transistors to be turned on or off are supplied, the third transistors have gate electrodes connected to drain electrodes of the first transistors and source electrodes connected to a third power supply line to which one of voltages of the low-level side and voltages of the high-level side-are supplied, the fourth transistors have gate electrodes connected to drain electrodes of the second transistors and source electrodes connected to a fourth power supply line to which the other of the voltages of the low-level side and the voltages of the high-level side are supplied, drain electrodes of the third transistors and drain electrodes of the fourth transistors are connected to the corresponding common electrodes, the fifth transistors have gate electrodes connected to the control line, source electrodes connected to one of the first and second power supply lines, and drain electrodes connected to the gate electrodes of the third transistors, and the sixth transistors have gate electrodes connected to the control line, source electrodes connected to the other of the first and second power supply lines, and drain electrodes connected to the gate electrodes of the fourth transistors.