反平行配向液晶盒預傾角之測量方法

Determination of the pretilt angle for anti-parallel alignment liquid crystal cells

葉鈞皓(CHUN-HAO YEH)

指導教授 ： 徐芝珊

中原大學/理學院/應用物理研究所/碩士(2008年)

https://doi.org/10.6840/cycu200900595

摘要

反平行配向液晶盒（anti-parallel alignment liquid crystal cells）模組是近
二十年來蓬勃發展的一種顯示器模組，其液晶盒之玻璃基板為同方向摩擦
配向，與常見之水平排列液晶盒模組相反，因此稱之為反平行配向液晶盒。
由於同方向摩擦配向的關係，液晶盒內部的液晶指向矢為上下對稱分佈，
也稱之為pi-cell。Pi-cell 因其特殊的對稱排列結構，無法使用一般之晶體旋
轉法[5]（尋找光學相位延遲極值所對應之入射角）量測預傾角，而需要非
常複雜的量測系統與方法才能得知pi-cell 的預傾角。
在本論文中，我們將計算光通過均勻排列液晶層之光學相位延遲的方
法[6]，推廣到彎曲排列型pi-cell（bend state）以及延展排列型pi-cell（splay
state），藉由理論計算光學相位延遲與入射角的關係曲線，推導出基板上液
晶指向矢傾角的近似公式，並利用模擬軟體MATLAB 程式，分析此方法用
於測量彎曲排列型pi-cell 預傾角的誤差與適用範圍。在實驗上，我們藉由
混合垂直PI 與水平PI 的方式，嘗試製作不同預傾角的均勻排列液晶盒與
pi-cell，使用光學相位延遲量測系統，測量此二種液晶盒的預傾角，藉由測
量均勻排列液晶盒的預傾角，分析此反平行配向液晶盒預傾角之測量方
法，應用在實驗上之計算結果。

關鍵字

反平行配向 ； 液晶盒

並列摘要

We demonstrate a method to determine the pretilt angle of anti-parallel
alignment liquid crystal cells (pi-cells). We calculate the phase retardation of
the pi-cell as a function of incident angle in splay and bend state, and then derive
the pretilt angle accordingly. In our method, the pretilt angle is determined by
the ordinary and extraordinary indexes and does not require the value of the
thickness of the pi cell.
We use the MATLAB software to simulate the curve of the phase
retardation as a function of incident angle of a pi-cell and get the ratio between
the curvature and the phase retardation value of the normal incident (S value).
The pretilt angle is obtained by substitute the S value into the theoretical derived
formula. The deviation and applicable range of this method are analyzed.
In our experiments, the various pretilt angles for homogeneous cells and
pi-cells are obtained by nanostructure alignment technique. We use the crystal
rotational method to measure the pretilt angle of the homogeneous cell and our
method to determine the pretilt angle of the pi-cell. The result confirms the
applicability of this method.

並列關鍵字

anti-parallel alignment ； liquid crystal cells

參考文獻

[1] Peter J. Collings and Michael Hird, “Introduction to liquid crystals chemistry

switching device”, Mol. Cyst. Liq. Cryst. 113, 329 (1984).

[5] I-An Yao, Hung-Lin Ke, Chiu-Lien Yang, Chueh-Ju Chen, Jia-Pang

Pang, Tien-Jung Chen1 and Jin-Jei Wu, “Electrooptics of Transflective

[6] Hajime Nakmura and Michikazu Noguchi, “Bend Transition in Pi-cell”, JJAP,