垂直配向之單間隙半穿透反射液晶顯示器模擬分析

Abstract

本篇論文主要是以垂直配向模態之單間隙半穿透半反射液晶顯示器之設計模擬為主，由於光線穿過穿透式（T part）液晶層一次而外部光源則穿過反射式（R part）液晶層兩次，因此我們分別設計不同的電極以期穿透與反射的光電曲線（T-V and R-V curves）能夠重合。我們設計的結構希望可以在穿透部分產生較強的電場，而反射部分則是較弱電場，這樣就可以在單一驅動電路（single TFT-driving circuit）下使穿透與反射液晶層達到相同的光延遲效果，換句話說則是得到相同的穿透量（transmittance）與反射量（reflectance）。我們知道垂直配向模態先天上的視角表現是較差的，所以我們還利用了補償膜（compensation film）與多域結構（multi-domain）來嘗試使我們設計的結構達到更廣視角的要求。 本篇論文主要分成兩個部分，一是以垂直配向模態（VA mode）為主搭配部分分佈電極的結構，稱為Partial Switching；而另一則是以邊緣電場效應模態（Fringe Field Switching mode）為主並利用垂直配向為初始模態的結構，稱為VA-FFS

This research in this thesis is based on the use of Vertically Aligned (VA) liquid crystal mode in the design and development of single-cell-gap Transflective TFT-LCDs. In particular, we focus on using different electrode designs between T and R part in order to match the corresponding T-V and R-V curves. Since the light passes through the liquid crystal layer twice in the R part but only once in the T part, the structure we design is required to produce stronger electric fields in T part and weaker electric fields in the R part so that similar retardation change in T and R can be obtained. As a result, the transmittance and reflectance can become very similar even when the pixel is driven by a single TFT-driving circuit. Apart from matching the T-V and R-V curves, we also try to use compensation film and multi-domain approaches to simulate and improve the narrow viewing angle property of the VA liquid crystal mode. This thesis is divided into two parts; the first one is based on a Partial-Switching scheme which employs a partial distributed electrode design while the second one is based on the use of a VA-FFS liquid crystal mode which has a VA liquid crystal mode for the original OFF state and FFS mode for the driven ON state.