【作者】 徐晓玲；

【导师】 张志东；

【作者基本信息】 河北工业大学 ， 理论物理， 2008， 硕士

【摘要】 液晶显示器在市场中是否具有竞争力,关键看是否具有优质的显示质量。最近由Seung Hee LEE等提出了一种新的显示模式即HAN-FFS模式。这种显示模式具有制作简单、宽视角、低驱动电压和高透光率的特点,是改善视角特性,提高显示质量很有吸引力的方法。本文基于Seung Hee LEE等人的研究的正性液晶构成的液晶盒的HAN-FFS显示模式。由于在该模式中电场的垂直分量不引起阈值,水平方向电场起主要作用。为了集中解决阈值问题,本文将边缘场简化为水平均匀场。且做单一常数近似。通过两个简化条件:（一）将边缘电场简化为均匀电场。（二）弹性系数K₁₁ = K₂₂ = K₃₃=K。根据液晶弹性理论,得到HAN-FFS显示模式的阈值电压的解析解。且它与液晶盒厚,电场方向盒宽,弹性系数,介电常数有关。并根据液晶光学中琼斯矩阵法利用计算机模拟出指向矢变化情况及电光特性曲线。从结果比较可以看出HAN-FFS简化模型模式在大摩擦角时存在阈值电压,这与Seung Hee LEE提出的HAN-FFS显示模式存在阈值相一致。但阈值电压随着摩擦角的减小而减小,至逐渐消失。HAN-FFS显示模式较好地解决了LCD的视角问题。对于自身存在的色移、开口率低、透光率低、响应速度慢等也有了许多相应的改进方法。相信经过努力,该模式一定能在显示领域占据一定地位。更多还原

【Abstract】 In liquid crystal displays （LCDs）, the improvement of image quality becomes more crucial to the extension of their market and competition with other types of displays.Recently, Seung Hee LEE have reported a new type of displays that is hybrid aligned nematic LCD driven by fringe-field switching （HAN-FFS）,which shows a good viewing angle, high transmission and low driving.Voltage with a reduced number of manufacturing processes.HAN-FFS mode has attraction for improving image qualituy and showing a much wider viewing angle.The article sets up a simplified model based on HAN-FFS mode Seung Hee LEE proposed liquid crystal cell using a liquid crystal with positive dielectric anisotropy.Because ,in that display mode ,the threshold vertical component of electric field not produces voltage .The horizontal component play a main role.In order to resovle voltage problem .The model supposes:Firstly:the electric field of electrode in liquid crystal cell is even.Secondly:bend elastic constant ,twist elastic constant and splay are equal,namely, K₁₁ = K₂₂ = K₃₃=K.By using liquid crystal elastic theory to analyze the simplified model,we found the approximate threshold voltage expression of HAN-FFS mode.It relates to cell gap ,electrode width , elastic constant andε。To fully understand the switching principle when using the LC ,a simulation was performed using computer based on Jones matrix method for optical calculations.We obtain derector distributon and voltage-dependent transmittance curves.From the result ,we can see the simplified model have threshold voltage at bigger rubbing angle .This result is communicate with the HAN-FFS mode Seung Hee LEE proposed which has threshold voltage.As the rubbing angle becoming smaller,the threshold voltage will become lower and lower . It will disappear at the end.The HAN-FFS mode can resolve viewing angle problem very well.And it improves low transmittance ,response time,narrow viewing angle。We believe this mode will play a important role in LCDs field.更多还原