Multi-point drive of common electrode for highly uniform liquid crystal display televisions

A multi-point drive of a common electrode is presented to improve the uniformity of a large-sized liquid crystal display television (LCD-TV). A current drivability of a switching transistor, line delays at both gate and data lines, and a kickback in a pixel are found to be main factors to affect the uniformity of the pixel voltage. A comparison between a single-gate scheme and a dual-gate scheme is given to understand the pixel voltage drop across the whole 40-inch screen. To compensate the uneven voltage drop across the screen, common electrode should be applied by several different voltage sources at different locations. This is the multi-point drive of the common electrode. This work presents valuable analysis results to designers developing highly-uniform LCD-TV panels with large sizes.