薄膜晶体管液晶显示器相位调制特性的测试

Measurement of Phase Modulation Properties of TFT-LCD

采用双光束干涉测量装置,对SONY公司的LCX023CMT的薄膜晶体管液晶显示器(TFT-LCD)进行了测试.利用计算机对得到的干涉条纹图像进行滤波、二值化、条纹细化和二值图像的滤波等一系列处理,计算出干涉条纹因LCD相位调制而移动的相位.把参考灰度分别为255和0时测得的数据做了比较并取平均值绘制出LCD相位调制特性曲线.通过定性的分析,该方法能够在一定程度减少系统误差和随机误差.在相移干涉测量中,用LCD代替PZT相移器能大大简化光路系统,同时避免机械运动,实现相移量的全数字化控制.

Two-beam interference device was used to measure phase modulation properties of SONY TFT-LCD. By using image processing techniques such as filter, binarization, image thinning and removing noise from binary image, the shifting of the pattern which was caused by phase modulation was calculated. The experimental results when the reference gray is 255 are compared with the results when the reference gray is 0, and the phase modulation curve of LCD is figured by the average of them. The analysis results show that the system and random error are redueed with this method. In phase shift interferometry measurement,optical system is simplified greatly when PTZ is replaced by LCD. At the same time, the mechanical movement is avoided and phase shift controlled digitally is realized.