ADS液晶面板划痕Mura研究

手指滑动ADS(Advanced Super Dimension Switch)液晶面板的L255画面时,由于按压导致的液晶分子形变和电场作用,滑动位置亮度会降低,表现为留下发暗的按压的痕迹。如果该痕迹在按压5 s后不能恢复,我们称之为划痕Mura(Trace Mura)。本文通过对比5种不同像素设计的液晶面板的滑动按压实验的结果,得到了像素电极设计、驱动电压对Trace Mura的影响;进一步模拟分析液晶分子状态,得到判断不同像素设计的Trace Mura风险的模拟方法。主要结论如下首先,像素电极尾部设计对于Trace Mura改善方面,弧角设计优于切角设计,切角设计优于开口设计;像素电极间距(Space)越小,Trace Mura风险越小。其次,Trace Mura需要在高灰阶电压下按压划动液晶面板才能发生;而发生Trace Mura的液晶面板,可以通过降低液晶面板的电压灰阶来消除按压痕迹。最后,对比液晶分子状态模拟结果,确认在电极末端的液晶分子方位角会发生突变(即向相反方向偏转),模拟的突变角度在-15°以上,预测有Trace Mura风险。

Strace Mura of ADS LCD

As for advanced super dimension switch(ADS)LCD,using finger to slide the surface of LCD lighting on L255 image,the luminance of sliding areas on LCD reduces owing to the liquid crystal molecules deformation and electrical field.Usually,the liquid crystal of sliding area recovers due to electrical field,and also the luminance of those sliding area recovers.While the dark area can not recover in 5 s,trace Mura occurs.In this paper,by validating the recovery time after finger sliding 5 kinds of panels with different slit end design and slit space values,the impact of pixel design on trace Mura is investigated.Comparing with simulated LC twist angle,a method for evaluating trace Mura of panel is found.The results are as flow:Firstly,for slit end design,panel with arc angle is the best for trace Mura prevention,and panel with open tilt is the worst,of course,panel with tangent tilt design appears middle risk for trace Mura.Simultaneously,narrower slit space design also appears faster recovery time and also is beneficial to trace Mura prevention.Secondly,reducing gray level of panel by setting a lower driving voltage is beneficial to trace Mura and also a good method for erasing trace Mura.Finally,the results of recovery time after sliding and simulated LC twist variations at slit end show that panel with larger than-15°LC twist variation has higher risk for trace Mura,which could be a method for evaluating trace Mura risk of ADS LCD.