水平配向邊緣場效驅動液晶顯示器在三維結構之模擬研究

Abstract

本文主要接續研究蔡永傑博士與陳世睿學長的正型液晶結構設計，探討的顯示器類型為正型液晶PA-FFS水平配向邊緣場效驅動顯示器，透過改變結構上電極寬度與電極彼此間間距，探討穿透率以及快速響應的特性。 透過利用特殊的幹枝結構設計，在電極寬度上設計不同的大小，使得部分的液晶分子受到外加電場時偏轉，產生虛擬牆，加速整體液晶分子的響應時間。 從一開始的對於液晶受到電場影響下，液晶分子如何做旋轉曲討論。發現分子在轉軸上面的差異，為是否能使光穿透的主要原因，也是虛擬牆產生在哪裡的一大主因。針對旋轉軸上面去做液晶結構內部的深層探討。論文中對於結構的部分，探討不同電極寬度、不同電極間距以及不同主幹寬度的大小，了解到各尺寸上的匹配與調整對於整體的穿透率以及響應時間有很大的關係。 討論結構的部分，在本論文中發現，不論是改變電極寬度的比例、電極彼此間寬度的比例、主幹的寬度以及同樣面積上的比例匹配改變，對於整體的穿透率以及響應時間都有明顯的變化。追求高穿透率，選擇上以大寬度電極或者電極間彼此的寬度增加，都可大幅增加穿透率，操作電壓也會大幅下降。因此設計上偏向使用大寬度的電極或加大電極之間的間距。但假如是追求快速響應，則應當選擇電極為小寬度或電極彼此間間距為小間距，這樣下降時間可以縮短。對於主幹上的匹配差異討論，發現主幹越大，穿透率略微減少，下降時間則是略微縮短。 最後以相同面積下，做不同電極與電極間間距上尺寸的匹配，發現電極與電極間間距彼此存在一個最佳匹配，可以達到最佳的下降時間，並且同時在操作電壓與穿透率上都是達到最佳的效果。

In this thesis, we will continue to study the structure and design of PA-FFS liquid crystal display. The liquid crystal used has positive dielectric anisotropy. By changing the electrode width and the distance between the electrodes on the structure, the light transmittance and response time are discussed. By using the special trunk-branch structure design, some of the liquid crystal molecules are deflected by an external electric field. By this way, it can create virtual walls that can help speed up the overall response time. First, we discuss how liquid crystal molecules rotate under the electric field, and we discover the main factor how the liquid crystal molecules rotate in the rotation axis, which causes whether the light can pass through. Then we will see how the liquid crystal molecules rotate on the rotation axis. In this thesis, by changing the width of the electrode, distance between electrodes, width of the trunk, etc, we can understand that size matching has an important effect on light transmittance and response time. Second, it is found that no matter changing the width of electrode, the width of electrodes, the width of the trunk, etc, there are obvious changes to the overall light transmittance and response time. In pursuit of high light transmittance, we must choose to use large electrode width or increase the distance between electrodes, which can greatly increase the light transmittance and reduce the operating voltage. However, to pursue a fast response, we should select to have a small electrode width or small distance between electrodes, so that the fall time can be shortened. For the trunk, it is found that the larger the trunk, the light transmittance and the fall time are both slightly reduced and shortened. Finally, under the same pixel area, we change the size matching between different width of electrode and different distance between electrodes. We found that there is a best match to achieve the best fall time and also to achieve the best results in both operating voltage and light transmittance.