膽固醇液晶擁有反射、散射、雙折射性等特殊光學性質表現及雙穩態的特性，加上容易利用外加場(例如電場、光場、溫度)去調控，因此常被國內外各研究單位廣泛研究並且應用在不同的光電元件上面，如雙穩態反射式顯示器、光開關、智慧型窗戶等等[1][2]。其中在需要像素化驅動的情況中，被動式驅動比較起主動式驅動由於其製程簡單、花費較低而常被使用在產品上，但有換頁時間過長的問題，因此發展出動態驅動來改善而也已經被廣泛研究。
　　膽固醇液晶在特殊邊界條件下擁有三穩態的特性[3]，其中Planar texture可在特定波段反射特定偏振光、Focal conic texture有強烈散射現象、ULH texture在巨觀下似單光軸晶體，擁有光學上的雙折射性，此三種不同光學特性之狀態可均為穩態且互相切換，切換方式為使用不同低頻電壓，在應用上也更加有價值，例如多穩態顯示元件、利用ULH texture取代Focal conic texture在反射式顯示器中當作暗態使用可增加對比度等等，可達到更多光學上顯示的選擇性。而如欲使之像素化使用，搭配被動式驅動來說也有換頁時間過長的問題，而目前尚無人分析動態驅動三穩態膽固醇液晶之方法，在此研究與實驗中，建制了三穩態膽固醇液晶動態驅動的方式，並建構一套自動化分析與量測的系統，進而在較簡易製程、花費較低的被動式驅動裡改善換頁時間的問題，並可有效的加快整體像素化的換頁時間。

Cholesteric liquid crystal has the optical properties of reflection, scattering, birefringence and the characteristics of bistable. Cholesteric liquid crystal is easy to tune by external field(electric fields, light, temperature), so it has been widely studied and apply in different optical devices, such as bistable reflective display, light switch, smart windows and so on. In the situation which needs pixelated driving, passive driving is more suitable than active driving due to its process and cost. Though passive driving has the advantages, but the whole switching time is too long to use, so it has been improved by the dynamic drive scheme.
Cholesteric liquid crystal can be tri-stable under special boundary conditions. Planar texture can reflect particular polarization light in particular band, Focal conic texture can be scattering, ULH texture like a single optical axis crystal in the macroscopic situation, has the optically birefringence. These three textures can be stable and switchable by low frequency voltage and it’s more valuable in applications. e.g., multi-stable display devices, using the ULH texture replace Focal conic texture in the reflective display in use as a dark state to increase the contrast and so on, can achieve more selective optically displayed. In the use of pixelated, it has the problem of long switching time in passive driving, and now have no research to analyze dynamic drive scheme in tri-stable cholesteric liquid crystal. In this study, we create a dynamic driving scheme for tri-stable cholesteric liquid crystal, and create an automated analysis and measurement systems, and then in a relatively simple process, less expensive passive driving time in improving feed problems can effectively speed up the whole time pixelated paging.

[論文審定書 i]
[摘要 ii]
[目錄 iv]
[圖目錄 v]
[第一章 液晶簡介 1]
[1.1 何謂液晶 1]
[1.2 液晶的分類 2]
[1.3 液晶的物理特性 6]
[第二章 膽固醇液晶簡介 9]
[2.1 膽固醇液晶結構介紹 9]
[2.2 膽固醇液晶各狀態介紹 10]
[2.3 雙穩態膽固醇液晶於電子書的應用與驅動方式 13]
[第三章 實驗方法與過程 17]
[3.1 材料介紹與樣品製作 17]
[3.2 動態驅動架設與量測方法 18]
[第四章 實驗結果與討論 20]
[4.1 Planar texture/ULH texture間動態驅動 20]
[4.2 二段式Selection電壓之膽固醇液晶三穩態動態驅動 30]
[4.3 二段式Selection電壓加上延伸Evolution電壓之膽固醇液晶三穩態驅動 37]
[4.4 結論 44]

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