三階電極之半穿半反藍相液晶顯示器

Abstract

目前顯示器以液晶螢幕為主流，其中藍相液晶成為越來越熱門的研究題目，其有相當多的優點，如亞毫秒的響應時間，大幅增加了顯示器的解析度與發光效率，此外不須配向層也是極大的優勢，然而目前的藍相液晶顯示器還是有些不足之處，首要克服的問題在於其高操作電壓與低穿透率，若能改善這樣缺點，藍相液晶仍有深具潛力的發展空間，因此本論文將以藍相液晶作為研究主題，藉由改變結構設計來改善缺點。 本論文以半穿半反式顯示器為研究主軸，結構設計採用三階電極為驅動，加上蝕刻基板結構以及雙邊電極排列的想法，設計出高穿透率、高反射率和低操作電壓的半穿半反式型顯示器。在光電曲線重合為本論文另一項研究主題，對於半穿半反式顯示器，光電曲線的高重合度是一項重要議題，根據本論文的結構設計，在了解參數變化的影響後，提出兩種方式，分別為調整液晶層厚度及平移電極。 最後，本論文將半穿半反式顯示器依穿透區與反射區面積大小分別研究，再經由參數最佳化後，皆可得到光電曲線高重合度且高穿透率、高反射率的成果。

Liquid crystal displays are widely used in our daily life nowadays. Among many types of liquid crystal, blue phase liquid crystal (BPLC) has been under active research and development in recent years. There are many advantages that make BPLC very attractive compared to others LCs, such as lack of alignment layer and sub-millisecond response time. However, BPLC still has problems such as high operation voltage and low transmittance. To overcome these drawbacks, we design new electrode structures for BPLCs in the thesis. Considering the suitability of being used under different environments, we focus on developing transflective BPLC display. In this thesis, we employ three major concepts: i) etching substrate, ii) double-side electrodes and iii) three-level electrode. By utilizing these concepts, we successfully design new structures for transflective BPLC display with low operation voltage and high brightness performance. In this thesis, we also propose two different methods to match the transmission and reflection curves: i) adjusting the cell gap and ii) shifting the electrodes. After optimizing the parameters, we get well-matched performance (gamma curve) of transflective BPLC devices with optical efficiency of higher than 85% and operation voltage of lower than 12V. More details will be discussed in the thesis, including fabrication difficulty, gamma curve matching and deadzone reduction.