The Influence of the Driving Waveform on the Performance of LCDs

• Main Authors: Ing-Haur Hsu, 許英豪
• Other Authors: Shu-Hsia Chen
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/25622411430362380640

碩士 === 國立交通大學 === 光電工程所 === 90 === TFT-LCD is very popular In recent years. In order to increase the competitiveness, many people study how to decrease the cost. In the Master thesis of Chia-Chen Lai, National Chiao Tung University, 2001, proposed a method to change the conventional driving waveform by modulating the voltage on the common electrode. Finding that using modulated driving waveform in TN-mode TFT-LCD can decrease the operation voltage of data driver. Thus, we can use cheaper driving IC to design Data Driver, then, we can decrease the cost and increase the competitiveness. Besides, Using modulated driving waveform in TN-mode TFT-LCD can make the gray level easier, without effecting the response time, but will induce the leakage of light on dark state. The aim of the thesis is to study the influence of the driving method on the performance of VA-mode TFT-LCD, hybrid negative mode TFT-LCD and hybrid positive mode TFT-LCD. We began from continuous elastic deformation theory of liquid crystal and Jones Matrix. We studied the electro-optical performance by using a computer simulation. The cell of liquid crystal of a single pixel was also fabricated, and its electro-optical characteristics were measured for various driving waveform and compared it to the simulation results. From the results of simulation and experiment, we found that use modulated driving waveform in VA-mode, hybrid negative mode and hybrid positive mode TFT-LCDs can decrease the operation voltage of data driver. And can make the gray level easier, without effecting the response time. Besides, using modulated driving waveform in hybrid negative mode and hybrid positive mode TFT-LCDs will induce the leakage of light on dark stage, but will not when in VA-mode TFT-LCD. The conclusion is that VA-mode TFT-LCD is the better one for the application of modulated driving waveform.