Patent ID: 6836269
Filing Date: 2004-12-28
Classification: G09G

Abstract:
A precharge circuit for precharging a signal line to a predetermined voltage before applying a video signal to the signal line, comprising:a precharge control circuit which operates during a shorter period, encompassing a precharge period in horizontal blanking period in a horizontal period, not coinciding with a drive period of the signal line than an effective display period in a horizontal period and which effects such control to output the predetermined voltage; wherein: the precharge control circuit is further configured to control the selective operation of the precharge circuit based on an externally supplied, low-amplitude external input signal which has an amplitude lower than that of a drive voltage of the precharge circuit and to maintain the amplitude during the precharge period, the precharge control circuit includes a level shifter circuit for level-shifting the low-amplitude external input signal, and the precharge control circuit being configured to control the level shifter circuit so as to be activated during a period in which an input of the low-amplitude external input signal is required.