Drive circuit for liquid crystal display device

Abstract

Abstract PURPOSE:To prevent luminance change due to polarity inversion of a drive signal of a liquid crystal by driving the liquid crystal symmetrically with respect to an opposite electrode level vertically even when a gate-source capacitance of a thin film transistor(TFT) exists. CONSTITUTION:A bias power supply 8 is inserted between a reference level point and an opposite electrode 4. Thus, the ground level is decreased with respect to a drain reference level (0V) being a center level of a drain signal by an opposite electrode level VB, and even when the drain signal is decreased by V0 ( V0') at the OFF state of the TFT, the waveform symmetrical in the vertical direction with respect to the opposite electrode level is formed. Even with presence of the reduction in the level of an AC drive signal due to a capacitor in existence between the gate and the source of the TFT, no luminance change is caused at the polarity inversion of the drive signal of the liquid crystal.

Inventors

• 👤 Susumu Ooima
• 👤 大今　進
• 👤 Yutaka Senoo
• 👤 妹尾　豊

Bibliographic Details