臺灣博碩士論文加值系統

本文主要討論BHN(Bistable chiral tilted-homeotropic nematic LC cell)雙穩態型液晶顯示器靜態參數模擬的結果及最佳化參數之選擇。
BHN和一般雙穩態液晶顯示器不同的是，它僅需要Vrms=5V就可驅動，相較於一般所需提供高電壓驅動明顯低很多，又由於BHN之暗態為垂直排列所造成，故穿透率幾乎接近零，使對比度提高，視角也大，且亮態與暗態之間的切換容易，達穩態後亦不需要電壓供應就可維持，大大地降低了功率的消耗。
本文藉由模擬來改變參數進而得到BHN之對於穿透率（transmittance, T）、對比度（contrast ratio, CR）特性，其中液晶盒參數包含屬於製程參數的液晶盒厚度（d），屬於液晶材料參數的預傾角（pretilt angle）、彈性係數（elastic constant, K）、厚度與螺距之比(d/p)、液晶折射率（Δn）等。K33/K11愈大時，液晶盒會愈趨向TH態；K22/K11和預傾角愈大時，液晶盒都愈趨向T態；另外，還發現BHN的能量並不會單獨隨著厚度或螺距而變，是隨著d/p值改變而變。d/p值的增加，液晶盒會愈來愈趨向T態；相反地，d/p值的減少會使TH態愈趨向穩定。預傾角的增加會使可以形成雙穩態的d/p範圍縮小且讓TH態與T態之能量相等時的d/p變大。

In this report, we study the simulation of BHN （Bistable chiral tilted-homeotropic nematic LC cell） in static state and obtaining the optimum parameters of BHN.
BHN is different from other bistable displays. The external voltage we applied to switch between the two stable states was 5 Vrms, which is much lower than most of the bistable devices reported in the literature. The power consumption can be reduced by two bistable states without electric field. The dark state results from the tiltedly homeotropioc （TH）state, which the molecules in TH state are aligned nearly homogeneous with a very high tilt angle.
In this these, BHN have been optimized by the external and internal parameters of LC cells, including the cell gaps, d/p, elastic constant, and pretilt angle etc. When K33/K11 is increasing, it makes the TH-state more stable. When K22/K11 and pretilt angle increase, both they makes the T-state more stable. Further, we find out energy of the BHN changes by varying of the d/p value. T-state is more stable by larger d/p while smaller d/p makes cell tending to TH-state. Both the bistable range of d/p value decreases and the best d/p value becomes large by the increasing pretilt angle.

摘要 i
Abstract iii
致謝 v
目錄 vi
圖目錄 viii
表目錄 xiv
第一章 緒論 1
1.1 前言 1
1.2 文獻探討 2
1.2.1 BiNem雙穩態模型探討 2
1.2.2 BTN雙穩態模型探討 5
1.2.3 BHN雙穩態模型探討 14
1.3 論文研究重點及目的 20
第二章 理論 21
2.1 能量連續體理論 21
2.2 光學機制 23
2.3 模擬軟體LCD Master之介紹 25
第三章 BHN靜態模擬之能量部分 36
3.1 彈性係數對BHN能量之影響 40
3.1.1 K33/K11的影響 42
3.1.2 K22/K11的影響 47
3.2 液晶盒製程參數對BHN能量之影響 49
3.2.1 預傾角的影響 49
3.2.2 d/p的影響 51
3.3 能量部分之總結 60
第四章 BHN靜態模擬之光學部份 61
第五章 結論與未來展望 65
參考文獻 66
附錄A 67
附錄B 70

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