Frame sequential color thin film transistor/liquid crystal displays: Display characteristics and grayscale consideration

Abstract

We report a theoretical study on the optical characteristics of a frame sequential color thin film transistor/liquid crystal display (TFT/LCD) operating with the TN LCD. Important liquid crystal (LC) and display parameters (cell gap, LC surface pretilt angle, applied voltage, LC viscosity, frame rate, and operation sequence) are considered and optimized to improve the display performances. Both the modeling and experimental results for a TN LCD using an EM Merck ZLI-3651 LC material are presented. We also present detailed theoretical results for a TFT/LCD operating at frame rates of 30 Hz and 71 Hz. Sufficiently fast switching-on and switching-off dynamic responses can be obtained by raising the temperature to 40-60ŶC to reduce the LC rotational viscosity. A display operating at the 71 Hz frame rate, can obtain a good bi-level display, but it is difficult to obtain a good display with 512 colors. © 1993 The Japan Society of Applied Physics.