外差干涉式橢圓儀量測技術在液晶顯示器的應用

Cell Parameter Measurement of a Twisted Nematic Liquid Crystal Device Using Interferometric Polarimeter

劉孟翰(Meng-Han Liu) ； 曾耀騰(Yao-Teng Tseng) ； 游智仁(Chih-Jen Yu) ； 徐桂珠(Kuei-Chu Hsu) ； 周晟(Chien Chou)

《科儀新知》 179期 (2010/12) Pp. 35-43

https://doi.org/10.29662/IT.201012.0004

摘要

隨著液晶顯示器產業的發展，如何掌握液晶的物理特性與製程參數，對於面板產業是一個重要的課題，因為這些特性與參數是影響著顯示器對比度、反應時間、亮度與視角等的重要指標。在此我們提出了一個新的量測架構，利用單一波長及正向入射，即可同時測量扭轉向列型液晶的一些重要參數，這些參數分別為單元間隙、液晶分子預傾角、液晶扭轉角度、配向角與非扭轉相位延遲。我們並利用Yeh和Gu和Lien所提出的數學模型來做曲線擬合，可以非破壞性地快速又準確地得到液晶的物理參數。

並列摘要

Improving the display quality of liquid crystal display (LCD) is a very important topic for the rapid-growth LCD industry. The cell parameters, such as contrast ratio, response time, luminance and view angle, play important roles to identify the quality of a display. In this work, we demonstrate an experimental measurement setup to get the physical parameters of liquid crystal cells. Five cell parameters of a twisted nematic liquid crystal device, namely, cell gap, pretilt angle, twisted angle, rubbing angle, and phase retardation, are precisely measured by the proposed amplitude-sensitive heterodyne polarimeter (ASHP), which integrates Yeh and Gu's transfer matrix method with Lien's transfer matrix method simultaneously. This proposed method can characterize the five cell parameters under the arrangement of a single wavelength at normal incidence. This method presents the advantages of not only having a simple setup but also the possibility to simultaneously measure five cell parameters to characterize TN-LCD at high speed.