半穿透式OCB液晶顯示器的光電設計

Abstract

半穿透式顯示器廣泛的運用在可攜帶式的電子產品中，不論外在環境光為亮或暗的情況下，半穿透式都具有良好的光學品質。目前為止大部分的半穿透式顯示器都是利用電控雙折射(Electric Control Birefriengent)或多區域扭轉型/扭轉型(Multi-domainTN/TN)模態，但其缺點為視角不夠廣與反應速度慢。眾所皆知得，OCB顯示器是有快速光學反應且光學自我補償特性，對於攜帶式電子型產品的多媒體運用上，我們提出運用OCB模態的半穿透式顯示器。 在本論文中所設計的半穿透OCB顯示器對每一層模進行最佳化設計，包含廣視角偏光片、寬頻λ/4波片及相位補償片，最後的光學特性具有廣視的特性，而液晶層則是工作在電誘的彎曲狀態，模擬的解結果顯示歸一化的穿透率對電壓曲線圖與反射率對電壓曲線圖能近乎重合，也因如此，只需要相同一顆的TFT驅動IC便能驅動穿透區與反射區，所設計的半穿透式OCB顯示器的視角品質也比一般常見的半穿透式顯示器還要好，除此之外，為了要達到更廣的視角品質在光學系統中加入廣視角偏光片與寬頻λ/4波片是很好的選擇。

Transflective liquid-crystal displays have been widely used in mobile electrical products due to good visibility under both dark and bright environments. Most of the transflective LCDs use ECB or MTN/TN modes have poor viewing angle and response speed. OCB LCD is well known to have fast optical response and optical self-compensation. For multi-media application of mobile electrical product, we propose a transflective LCD with OCB-mode. In this report, we design a transflective OCB LCD with wide viewing angle, which is achieved by optimizing the parameters of the wide-viewing angle polarizers, wide-band quarter wave plates and compensating films to the electrical-induced bend state of liquid crystal layer. Simulated results show the normalized voltage dependence of transmittance and reflectance overlap completely, it can be controlled with the same control circuit and the identical TFT array. The viewing angle performance of the transflective OCB LCD is better than that of conventional transflective LCD. The viewing angle performance will be better if the electro-optical system combines with CFCP and WB-QWP.