LCD Display Flicker Phenomenon Researching & Solution

• Main Authors: Shih-Ming Yang, 楊士明
• Other Authors: Robin Luo
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/26350297878365564702

碩士 === 國立成功大學 === 電機工程學系專班 === 92 === Flicker is a major visual defect in active-matrix liquid crystal display (AMLCD). As the AMLCD becomes more popular, there have been increased research activities on flicker in order to minimize this undesirable effect. However, most of these studies have focused on individual liquid crystal (LC) mixtures or alignment layers. There were also a few studies on novel pixel structures and driving methods. But up to date there has been no systematic approach to identifying the causes of flicker and establishing a complete flicker model for the AMLCD. The AMLCD depends on active devices to apply voltages to pixels during address time and the ability of pixels to conserve the voltage for the rest of the frame time .To avoid chemical degradation of the LC material, an alternating voltage waveform has to be applied to the LC cell. For this purpose, several modes of polarity inversion including frame, column, row and dot inversion are adopted. Each mode has advantages and disadvantages. Frame inversion commonly used in silicon light valves for the purpose of minimizing the lateral electric field in small pixels. The lateral electric field can result in an undesired reverse tilt domain in each pixel and lead to poor contrast of the display. While frame inversion is good for minimizing the lateral field effect, it also produces a higher degree of flicker than other modes of polarity inversion. In this work, we performed systematic characterizations of flicker in silicon light valves. Four experiments were designed to probe the conduction mechanisms within silicon light valves for causes of flicker. Through systematic characterizations of flicker in various silicon light valves, a flicker model was established. Solutions for minimizing this visual defect were obtained to improve the silicon AMLCD quality.