製作具灰階及低色彩偏移之膽固醇液晶顯示器

Abstract

近年來液晶顯示器因為其輕薄便利之優勢，已逐漸取代傳統映像管顯示器。膽固醇液晶由於省電及反射式特性，非常適合於發展電子書的產業應用，只需依賴環境光即可使人眼觀察到色彩並閱讀。

當施加一外加能量驅動膽固醇液晶時，其反射環境光的強度因為內部結構不同而有所差異並得到灰階的效果，但發現色彩偏移會伴隨發生，使得反射光的顏色在驅動前後不能匹配，造成色彩的失真。本篇論文特別針對此色彩偏移的問題做分析，並藉由參雜負型液晶改變膽固醇的介電參數，試圖解決驅動時色彩不均勻的問題。利用此方法，當膽固醇液晶被驅動時，可成功的降低色彩偏移保有單一反射可見光顏色，並同時達到灰階的效果。

Cholesteric Liquid Crystals (CLCs) have great advantages for reflective mode displays because of their lower power consumption and good color visibility. They are suitable for hand held devices or electronic paper.

For CLCs, light is selectively reflected in the planar state and scarred in the focal conic state. The transmittance ratio of these two areas determines the reflective intensity which leads to the gray scale property. The unwanted color shift (or blue shift), however, accompanies with this transition. The reflection color of the CLCs can be turned by varying the voltage leads to a continuous blue shift in the CLCs cell’s appearance color. Here we report a novel method to suppress the color shift by doping negative nematic LCs during the gray scale transition. The color shift ( ) was greatly reduced from 49.89 to 10.80.