交流電場驅動下扭轉線狀液晶盒

Abstract

閃爍是液晶顯示器中顯示品質的重要因素，其與人眼敏感度有直接的關係。薄膜電晶體和超扭轉液晶顯示器是目前最被廣泛應用的，而兩者都有閃爍的現象，一般而言，顯示器驅動訊號需在一定時間內極性反轉，也就是必須外加交流電場來驅動，在一般的扭轉液晶盒中，由於離子電荷效應，會產生閃爍現象，因此提高外加電場的頻率可以降低閃爍的程度，但外加的電場頻率越高，其功率消耗也會越大。薄膜電晶體由於寄生電容緣故，位移了信號電壓的大小，造成正負半週大小不同，閃爍現象更加發生。超扭轉液晶顯示器由於所採用的多工驅動方式不同也會造成不同的閃爍現象。本文主要探討外加交流電場的頻率、強度大小以及離子濃度對扭轉式液晶盒閃爍之影響，利用一維模擬程式模擬光學動態響應在交流電場下所發生的光學閃爍，並且對照實驗結果。另外視角的改變所造成閃爍程度的不同也會加以討論。

Flicker is one of the major concerns in the performance of displays design. It is easily perceptible by human’s eyes. TFT-LCD and STN-LCD are the frequently used modes nowadays. Both of them have flicker phenomenon. In general, LCD must be droven in AC electrical field, because polarity inversion is needed. In TN-LC cell, we find that flicker is mainly caused by the mobile ion charges. So the lower frequency applies, the more serious flicker occurs. The purpose of this thesis is to study the effects of the material and experimental parameters on the flicker phenomenon in TN-LC cell. The parameters include applied frequency, applied voltage, ion concentration, etc. We use numerical analysis to simulate the optical dynamic response of LC cell under AC electric field. We compare the experimental values with the simulation results. Viewing angle is also a factor that can affect range of flicker. We also discuss it in the last .