Patent ID: 7342562
Filing Date: 2008-03-11
Classification: G09G

Abstract:
1. A liquid crystal drive device for supplying various signals and voltages for effecting display on a liquid crystal display panel comprising a plurality of source electrode interconnects extending in a first direction and juxtaposed in a second direction intersecting the first direction, a plurality of gate electrode interconnects extending in the second direction and juxtaposed in the first direction, an active element constituting a pixel at respective crossover points of the source electrode interconnects and the gate electrode interconnects, a plurality of common electrode interconnects disposed through the intermediary of a liquid crystal layer, and an external terminal coupled in common to the common electrode interconnects, said liquid crystal drive device comprising: a first terminal to which a first reference voltage is supplied; a second terminal to which a second reference voltage is supplied; a third terminal to which a third reference voltage is supplied; a fourth terminal to be coupled to the external terminal of the liquid crystal display panel; a first voltage generation circuit coupled to the first terminal and the second terminal, for generating a first voltage higher than the first reference voltage; and a second voltage generation circuit coupled to the first terminal and the second terminal, for generating a second voltage lower than the second reference voltage, wherein a voltage supplied to the fourth terminal is changed from the second voltage to the third reference voltage and subsequently, changed from the third reference voltage to the first voltage.