設計與製作具光反射影像增強層之新型透反式液晶顯示器

Abstract

由於通訊產業的蓬勃發展，應用於多種通訊產品之透反式液晶顯示器受到廣泛重視。輕薄、高亮度、可讀性、省電、高色彩飽和度都是可攜式透反式液晶顯示器的重要考量。許多種不同架構之透反式液晶顯示器相繼被提出，然而，幾乎都有著開口率低、光使用效率低劣、反應時間慢、色彩飽和度不同的問題。因此，本論文提出一種具光反射影像增強層之透反式液晶顯示器，使得背光源與環境光因為光反射影像增強層的作用而有相似的光路徑，進而提升光使用效率、開口率、反應時間與色彩飽和度。此外，我們亦設計前置型薄膜電晶體與分隔式ITO結構，藉以改善邊場效應對光效率的影響並有效提升光使用效率。 本論文設計與製作出可提供多項優點之具光反射影像增強層之透反式液晶顯示器。首先，我們藉由改變光反射影像增強層寬度與光反射影像增強層到下反射板的距離之模擬來對光反射影像增強層進行最佳化。由模擬結果可知，邊型與中央型光反射影像增強層最佳的寬度分別為14與16□m。最佳化之後的結構，其光使用效率、光分佈、色彩飽和度與邊場效應的影響將與傳統之透反式液晶顯示器進行比較與討論。 根據模擬結果，我們設計出一個簡單的架構來驗證光反射增強層之特性。首先，光反射影像增強層之雙稜鏡結構利用灰階光罩搭配準分子雷射加工系統來進行製作。我們選擇在玻璃基板上塗佈正光阻AZ P4620來當做加工工件。在精確的控制基板光阻的軟烤時間、雷射能量與雷射施打次數，我們可以成功的控制並製作出具有特定高度符合模擬最佳化之雙稜鏡結構。經過蒸鍍鉬與鋁以及一連串的半導體製程，我們可以初步製作出具光反射影像增強層與下反射板之結構。而其穿透與反射之光使用效率以及光分佈，我們利用量測儀器來進行量測，最後並將量測結果與模擬結果以及傳統之透反式液晶顯示器進行比較與討論，並評估具光反射影像增強之透反式液晶顯示器的潛力與可行性。

Transflective LCDs become important with the population of communication industry. Light weight, high brightness, high readability, low power consumption and good color saturation are the main concern. Several configurations have been proposed for the transflective LCDs technology, however, they suffer from the low aperture ratio, low light utilization, slow response time, and different color saturation. Therefore, a novel single cell gap transflective LCD with a biprism structure named IER is proposed to make the backlight and ambient light follow the similar paths, yielding high light utilization efficiency, high area utilization, same response time and same color saturation in both transmissive and reflective sub-pixels. We also design the TFT-On-Top and separated ITO structures to avoid fringing field effect and sustain the high light utilization efficiency. The main contribution of this thesis is to design and fabricate the transflective LCDs with IER structure which can provide several advantages. The biprism IER structure was optimized by varying the IER width and the distance between the IER structure and lower reflector. After optimizing, light utilization efficiency, light distribution, color saturation, and fringing field effect of the novel transflective LCDs with side or center IER structures were compared with the traditional ones. Based on the simulated results, we designed a preliminary configuration to confirm the features of the transflective LCD with IER structure. Half-tone mask equipped with excimer laser micromachining was chosen to carry out the IER structure. The substrate was chosen glass spun coating with photoresist AZ P4620. After properly controlled the soft-baked time of the substrate, laser energy, and # of shot, we successfully fabricated the IER biprism structure with desired width and height. After several semiconductor processes, the prototype of the transflective LCD with IER structure was fabricated, and the light utilization and light distribution were measured by the optical measurement system. The Simulated and fabricated results were compared and discussed.