以新型電極結構優化六角形電極藍相液晶顯示器之研究

Abstract

藍相液晶顯示器作為備受期待的新一代液晶螢幕，具有超快的響應速度、高對比度與無須配向層等等優點，但卻也有著操作電壓過高和穿透率低等重大缺陷。本論文將藉由加入新的電極結構，對操作電壓以及穿透率進行改善。本論文以學長提出的中空六角型電極結構(Hexagonal Electrode)作為出發點，對結構進行分析並提出改善方法。首先將拉低結構穿透率的原因分為:亮區電場不均勻以及中心與外圍的無效區(Dead zone)，並解釋他們形成的原因。接著，針對中心部分無效區做出改善改善，本論文提出中心六角錐電極(Hexagonal Pyramid Center)的新型結構，成功點亮了原本位於中心的無效區，並大幅降低操作電壓。再來，針對外圍無效區，參考了增強型凸起電極結構(Enhanced Protrusion Electrode)，去掉了它原本凸起物上的反射鏡改用上層電極來補足原本電場不夠的區域，成功地改善電極結構與外圍無效區的問題。最後，我們分別針對結構參數做出比較跟優化，結合中心與外圍結構，提出一個操作電壓為11.3V穿透率為93.88%的雙層六角錐中心六角形電極結構。

Blue Phase Liquid Crystal Displays (BPLCDs) have emerged as promising next-generation LCDs, offering advantages such as ultra-fast response time, high contrast ratio, and wide viewing angle. However, BPLCDs suffer from major drawbacks of high operation voltage and low transmittance. This thesis aims to address these issues by designing an electrode structure to improve both the operation voltage and transmittance. In this thesis, we start with the hollow hexagonal electrode design proposed by our senior colleague and conduct an analysis to propose improvements. Firstly, we identify the reasons for low transmittance in the hollow hexagonal electrode, including the imbalance of electric fields in bright region、 central dead zone and peripheral dead zones. Each factor is explained in detail. Subsequently, we address the improvement of the central dead zone by proposing the Hexagonal Pyramid Center structure, which effectively illuminates the previously ineffective central area and significantly reduces the operating voltage. Next, to tackle the issues with the peripheral ineffective regions, we refer to the Enhanced Protrusion Electrode design. By removing the reflectors on the original protrusions and using upper-layer electrodes to supplement the insufficient electric field region from the lower-layer, we successfully resolve the problems related to the electrode structure and peripheral dead zones. Finally, we perform comparisons and optimizations on the structural parameters, combining the improvements in the central and peripheral regions, resulting in an double-layer hexagonal pyramid center hexagonal electrode structure with an operating voltage of 11.3V and a transmittance of 93.88%.