高分子聚合垂直配向液晶之光電特性

Abstract

TFT-LCD (Thin film transistor- liquid crystal displays) 擁有方便、便宜、以及絕佳的顯示質量與解析度，已經廣泛運用於資訊傳遞商品，如筆記型電腦、監視器、電視以及手持通訊器。而LCD顯示器已有許許多多不同的顯示方式，都已發表或是運用於市場端，如扭轉向列型液晶(TN)、橫向電場效應顯示技術(IPS)、(PVA)、(MVA)等等顯示方式，每一種顯示方式都有其優點與缺點，在此不加以贅述。為了達到較高的暗態，以求得較高的對比顯示，進而許多的面板廠商導入垂直配向型(VA)的LCD於大尺寸的顯示面板，而VA型的顯示面板是眾多顯示面板中較成熟且已大量商品化的顯示模式，因為其特殊的液晶排列方式，使的它的光學路徑，幾乎為“零”。故擁有最佳的暗態(於未驅動狀態時，面板呈現光線無法穿透之狀態，為“OFF”state，即為“暗態”)。但此系統上還是有一些面板顯示表現無法滿足，如“廣視角”以及“液晶快速反應速度”。而高分子聚合穩定型垂直配向液晶(Polymer Stabilized Vertical Alignment Liquid Crystals)已於過去的文獻中已有證明可以改善“廣視角”以及“液晶快速反應速度”，但仍還有許多有趣以及有意義的研究項目可以做相關研究。 於這論文報告中，我會以高分子聚合穩定型垂直配向液晶(Polymer Stabilized Vertical Alignment Liquid Crystals)來改善其反應速度，並且分為三大實驗“飽和UV固化條件”、“可調控的操作電壓以及反應速度條件”，最後是“光學彈跳改善”，並以不同的UV光照條件以及UV照光中的施加電壓來做參數進行相關實驗以及討論。

Thin Film Transistor (TFT) Liquid Crystal Displays (LCDs) have been widely utilized especially in informational propagation such as notebook computers, monitors, televisions and mobile phone. They have excellent resolution and quality, much more convenient and cheaper than CRT. The various types of LCDs have been proposed in the past, and each of them has their own advantages and disadvantages, such as Twisted Nematic (TN), In-Plane Switching (IPS), Patterned Vertical Alignment (PVA), and Multi-domain Vertical Alignment (MVA) mode. In order to achieve a good dark state that is very important in display applications. The numerous Display manufacturing companies adopt the VA mode for producing the large-sized displays. The VA mode is one of the best approaches in commercially available LCDs. Because of its special alignment of LC molecular which can make its phase retardation almost “Zero”. So VA type of display have best “dark state”; In the “OFF” state, the phase retardation of VA type cell is almost zero and the backlight cannot path, which state is called “dark state”. However, TFT-LCD’s performance has been unsatisfactory due to a narrow viewing angle and slow response time. And Polymer Stabilized Vertical Alignment Liquid Crystals is one of published modes to improve the above-said problems by different operating processes and conditions. In this thesis, I used Polymer Stabilized Vertical Alignmnet Liquid Crystals to improve Reponse Time. There are three major experiments to investigate and discuss by different UV curing process and voltage holding conditions; “Saturation UV curing condition”, “Controllable Vth and RT” and “Optical bounce improvement”.