半穿反液晶顯示器之光學配向及高分子散射光電特性研究

Electro-Optical Characteristics of Single Cell Gap Transflective LCD with Photoalignment and Polymer Dispersed LC

朱貴麟(Kuei-Lin Chu)

指導教授 ： 陳殿榮 ； 吳俊傑

國立臺北科技大學/機電學院/光電工程系所/碩士(2007年)

摘要

本研究利用光學配向(Photoalignment) 方法和電控雙折射(Electrically Controlled Birefringence)機制來製作相位型半穿反液晶顯示器(Phase-Retardation Type Transflective Liquid Crystal Display)。將光配向劑以適當的比例與液晶混合後，在光配向時外加curing 電壓並利用光罩(Photo Mask)控制UV 曝光時間，在穿透區形成較低的預傾角(57度)達到π 相位延遲，反射區形成較高的預傾角(67度)相位延遲為π /2。實驗證實此光學配向能有效控制穿透區與反射區液晶分子的預傾角並應用在Single Cell Gap Transflective 液晶顯示器。經由光學配向的偏光圖
(Microscope、Conoscopy)、相位延遲、預傾角、液晶指向矢平均傾角、穿透率、反射率、灰階到灰階響應時間、光譜圖、CIE 色座標之色散測量，評估其光電顯示特性。
此外，也製作扭轉反式高分子散射型液晶(900 Twisted-Reverse mode Polymer Dispersed Liquid Crystal；TN-RPDLC)，應用在散射型半穿反液晶顯示器(Scattering Type Transflective Liquid Crystal Display)。經由外加電場改變液晶及高分子之間折
射率匹配性，用光學散射強弱來調制光學輸出大小。在NW結構中，亮態是利用TN光隨偶性，而暗態是利用PDLC散射特性；在NB結構中，穿透部份是以TN的旋光性來改變亮暗態，而反射部分則利用散射來增加反射效果。

關鍵字

半穿反液晶顯示器 ； 光學配向 ； 相位延遲 ； 預傾角 ； 色散 ； CIE-1931 ； CIE-1976 ； 扭轉向列型-反式高分子散射型液晶

並列摘要

We have demonstrated multi-pretilt angle in multi-domain of a Single Cell Gap electrically controlled birefringence Transflective LCD with photoalignment method. In appropriate photo-monomer/E7wt(%)concentration, Transflective LCD was fabricated by exposure of the un-polarized 365nm UV light through an array of a amplitude
photo-mask. Controlled the curing time and applied curing voltage in the polymerization process give different pretilt angles on the homogeneous LC cells. Dual orientation of LC at an initial state that transmissive regions are stabilized in a low pretilt angle 57(deg.) with a large phase retardationπ , while the reflective regions are stabilized in a high pretilt angle 67(deg.) with a small phase retardationπ /2. It shows that can
be used in the single cell gap and single gamma Transflective LCD. This cell a total on-off response time of less than 4.4 ms. Their optimized optical configuration for high luminance, no scattering, one curing voltage, no residual phase retardation in dark state and no-bias voltage.

並列關鍵字

Single Cell Gap Transflective LCD ； Photoalignment ； Phase retardation ； Pertilt angle ； Color Dispersion ； CIE-1976 ； Single gamma ； No-bias voltage

參考文獻

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