A Power-Efficient Driving Method for In-Plane Switching-Mode TFT-LCD Using a Negative Liquid Crystal

This paper presents an effective driving method to reduce the power consumption of an in-plane switching (IPS) mode thin-film transistor liquid crystal display (TFT-LCD) with a negative liquid crystal (LC). Despite the higher transmittance efficiency of the negative LC, it is not effective to reduce the power consumption of the IPS mode TFT-LCD because of the driving voltage, which is 30% higher than that of the positive LC. To complement the higher driving voltage, the driving method, which can modulate the amplitude of the common voltage (VCOM) inversion without side effects, is proposed for low power consumption. In addition, a novel pixel structure is developed to reduce the data load. The measured power consumption is 22.5 W at the full white gray level in a 17-in full high-definition (FHD) IPS mode TFT-LCD. The measured result shows that the proposed method can reduce the power consumption by 19% and 10% as compared to that of the conventional method using the negative LC and positive LC, respectively.