Pretilt Angles Effect on Critical Voltage and Response Times in Pi-cell Liquid Crystal Displays
The critical voltage and response times of pi-cell with arbitrary pretilt angle is studied theoretically and numerically. An analytical equation to easily calculate the critical voltage is given. Our results show that the critical voltage is dependent on the pretilt angle and the ratio of the bend and splay elastic parameters of liquid crystal material, but independent on the cell gap. The relationship of the critical voltage and the pretilt angle is consistent with the numerical and experimental data. Moreover, our numerical results on the response times show that it depends on the pretilt angle strongly. Using the normal driven method, the rise and off times decreases as the driven voltage increases, however, the off time increases as the driven voltage increase while the cell with nonzero critical voltage as the cell is driven by under-shoot method, the off time using under-shoot method is very faster than that using the normal driven method. Using the normal driven method, the cell with high pretilt has faster response time than the cell with low pretilt. These results have more potential application in designing pi-cell LCDs with faster response speed.
Pi-cell Critical Voltage Response Time
Yubao Sun Hongmei Ma Zaidong Li Zhidong Zhang
Department of Applied Physics, Hebei University of Technology,Tianjin 300130, China
国际会议
上海
英文
1121-1125
2007-03-12（万方平台首次上网日期，不代表论文的发表时间）