封閉式錐柱腔液晶顯示器內線狀液晶分子指向場分佈及其光電特性之模擬

Abstract

本論文主旨在模擬封閉式錐柱腔液晶顯示器（Conic Closed-Cavities-Liquid-Crystal Display，簡稱CCLCD）內線狀液晶指向矢場分布，並以此分布計算正、斜射之光穿透率，以便分析其視角特性。 在指向矢模擬部份，本論文採用赫斯(S. Hess)根據藍道(L. Landou)的相變觀點兩提出在線狀液晶態可表示其有序參數(order parameter)的取向張量(alignment tensor)，以此取向張量為基本元素來表示液晶自由能密度，再以此自由能密度做變分求得最低能量，並與柏桑方程式(Poisson's equation)聯立求得液晶分子指向矢及電場穩態解。在本文我們對自由能密度取單一形變常數近似(one constant approximation)，而自由能表示法以取向張量為基本元素與一般法蘭克(Frank)自由能以指向矢向量形式表示法有所不同，本論文會將張量形式模擬CCLCD的結果與韋忠光先生以向量形式模擬結果比較其不同之處。 在液晶光學模擬部份，本論文採用葉伯琦博士的廣義瓊斯矩陣法(Extended Jones Matrix Method)，此法可計算光穿過層層均勻分布的單軸晶體之正、斜射穿透率，但在適當的切割方式原本僅適用於液晶指向矢一維變化（如TN）的廣義瓊斯矩陣法方可適用於三維變化的CCLCD，於是利用指向矢模擬結果作輸入計算出CCLCD正、斜射之光穿透率，發現模擬結果與王義方先生的實驗結果相吻合，部顯示出CCLCD具有極佳的廣視角、多灰階、且無灰階反轉特性。

The purpose of this thesis is to simulate the director field distribution of one conic cavity in conic closed-cavity liquid crystal display (CCLCD) so as to calculate the optical transnmittance at any angle of incident light of CCLCD. By using the results of the simulation, we can evaluate the characteristics of the viewing-angle of CCLCD. The simulation of director distribution will be based on the tensorial form formulation of the free energy density. The differential equations satisfied with the steady-state director distribution are derived from this form of free energy and are solved in conjuction with the Poisson's equation. The simulation of the optical propogation and the calculation of the optical transmittance will be based on the extended Jones matrix method. The results of the simulation and the experimentation by Yih-Feng Wang both show that indeed CCLCD can have a wide viewing-angle and can have gray levels but no gray-scale inversion.