內嵌式液晶相微相位差膜在立體顯示器 上的開發與製作

Abstract

顯示器在人類生活中扮演著舉足輕重的角色,從早期的黑白顯示器,期間經過彩色,高畫質顯示器的演變,人們對於顯示器的依賴不光只在娛樂的用途之上,而是提供人與訊息之間最直接有效率交流的管道。在顯示技術的需求下,平面顯示器尺寸邁入一個大尺寸次元,同時也期待立體顯示器可以更真實並且自然的呈現所需求的影像。本文以較便宜且可行性高的方法,希望可以切入已經成熟的液晶顯示器工業,來達成有效的關鍵元件之研究。 傳統利用微相位差膜作為關鍵元件的立體顯示器,是以特殊塑膠材料製成的相位差膜黏貼於液晶螢幕前側的玻璃之上,影像經過液晶層與微相位差膜之間的轉換,形成立體資訊並經由偏極眼鏡過濾並傳遞到觀測者的眼睛,最後在大腦形成立體的感知。 由於微相位差膜及液晶層中間存在一層玻璃,玻璃的厚度會造成可視角以及可視距離的限制,降低影像品質,本文將對於關鍵微相位差薄膜的與立體顯示系統提出新的想法,利用液晶分子的本身性質佐以特殊的製程步驟,以液晶分子製作出內嵌玻璃內的微相位差膜,同時佐以特殊的偏極膜,不僅大幅增加可視角以及可視距離,同時與液晶顯示器的製程相整合,大大增加了製作的可行性。 本論文將對製作微相位薄膜的不同方法作研究：其中一種為雷射直寫法,另外一種則利用光罩及紫外光照射來製作薄膜。本論文中將對兩種方法作一個完整的介紹,同時討論此兩種方法製作而成的微相位差膜之光學性質。本論文也針對微相位薄膜與液晶面板的製程整合進行探討，實驗發現：微相位薄膜會受後續的偏極膜影響，產生相位誤差，此影響可以在微相位薄膜與偏極膜間加入二氧化矽薄膜，予以改善；偏極膜會受後續製程的影響，產生消光率降低的現象，我們使用特殊的材質製作偏極膜，發現了改良後的偏極膜在高熱下仍可維持良好的光學性質。在完成這些製程改善後，我們相信未來可以在小尺寸下實現此內嵌式微相位差膜立體顯示器樣本，以達成廣視角的立體顯示器。

A microretarder for stereoscopic display is a film consisting of horizontal or vertical stripes with alternating null and half-wave phase retardation states. An LCD with a microretarder attached on the front side can display good-quality stereoscopic images when viewed with polarization glasses. It is now the most possible way to present stereoscopic images on a flat-panel display. However, the space caused by the glass between the retarder layer and the LC layer of the panel seriously limits the vertical view angle, which, in turn, limits the application of this technology. In this thesis, a process for thin-film microretarder is developed using reactive liquid crystal. The material and the process are essentially compatible with current fabrication processes of LC panel. Since the thin-film microretarder is to be fabricated in the cell of an LC panel, the retarder layer and the LC layer can be fabricated as close to each other as possible. Theoretically, A nearly unlimited 3D view angle can be achieved for the display. In this thesis, two fabrication methods for the micro-retarder layer have been studied: one is laser writing, and the other is thermal and UV process. Laser writing method shows better results. For integrating the micro-retarder layer into the LC panel, affecting factors in the fabrication process has been studied. We have found that phase retardation changes after applying the thin-film polarizer and it can be solved by using a SiO2 protecting layer between the microretarder layer and the thin-film polarizer. Moreover, the extinction ratio of the thin-film polarizer will be decreased in the following processes and we use a proprietary material in making the thin-film polarizer to improve the thermal stability under high temperature. With all these improvements, a stereoscopic display using in-cell microretarder will hopefully be demonstrated and show the feasibility for wide-viewing angle 3D display.