An optimal design method for minimization of common voltage distortion in large-sized and high-resolution liquid crystal displays

Abstract

This paper proposes an optimal design method that minimizes the common voltage (V-COM) distortion for large-sized and high-resolution liquid crystal displays (LCDs). Three design methods are examined using different architectures of the panel and circuit to compensate for the V-COM distortion. The proposed design method adopts a panel architecture that compensates for the V-COM distortion simultaneously at the top and bottom of the panel using a dual compensation circuit. It is implemented using a 27-in. quad high-definition LCD, and its V-COM distortion is further minimized by optimizing the compensation ratio of the dual compensation circuit. In addition, the minimized V-COM distortion is evaluated by measuring the horizontal crosstalk of the implemented panel according to the decrease in the charging time of the subpixel. As the charging time decreases from 11.6 to 7.8s, the measured crosstalk level varies from 0.10% to 1.06%, respectively, meeting the goal of less than 2%. Therefore, the proposed design method is suitable for large-sized and high-resolution LCDs requiring low V-COM distortion.