探討扭曲向列型液晶顯示器之電壓保持率

Abstract

離子效應是影響液晶顯示器最重要的因素，過去的文獻中所探討的離子大部分皆為高解離率的離子，鮮少對低解離率離子進行探討及分析，所以本論文的研究方向是藉由電壓保持率（Voltage Holding Ratio，VHR）的量測來分析高、低解離率離子。 本論文主要研究為藉由VHR的量測可以得到液晶盒中的離子所造成的電壓變化，並由此電壓變化可以得知有多少離子累積在邊界上形成內建電場，而這些離子包括了高、低解離率離子，因此本論文推導出高、低解離率離子在VHR量測過程中之解析解型式，藉由此解析解可以求出高、低解離率離子在液晶盒中的初始濃度以及在VHR量測時高、低解離率離子之離子遷移率。最後，由實驗數據和理論值的比較來驗證此理論的正確性。

Ion concentration is the most important parameter to affect the display qualities of liquid crystal displays. Prior publications on the measurement of ion concentration did not distinguish ions either from high- or low-ionization-rate impurities. In this thesis, for the first time, we have developed theoretical model for the ion generations and transports for HIR (high-ionization-rate) and LIR (low-ionization-rate) impurities within a TN cell. By fitting our experimental result of the measured VHR data to the theoretical model, we have obtained ion concentration and mobility for LIR impurities within three TN cells made from different alignment layers and LC mixtures. The results of our investigation about that most of ions excited in our TN cells came from ions of LIR impurities owing to the maturity of LC-panel-manufacture technology and the usage of high-purity LC mixtures to reduce the HIR ions to a negligible amount. The theoretical model developed in this thesis can be properly expanded to deal with ion generation and transport in the alignment layers of a TN cells.