OLED/LCD器件中的γ校正  

Gamma Correction in OLED/LCD

作　　者：杨虹[1] 彭俊彪[1] 曹镛[1] 

机构地区：[1]华南理工大学材料科学与工程学院

出　　处：《发光学报》2004年第2期207-211,共5页Chinese Journal of Luminescence

基　　金：国家计委高技术产业化示范工程(计高[2001]2151);国家"863"计划(2002AA303250)

摘　　要：阐述了OLED/LCD器件中γ校正的基本原理,通过考虑人眼视觉非线性和液晶电光非线性,得到了CRT相对于OLED/LCD的灰度级亮度特性曲线。以所设计的26.4cm VGA(行反转)的TFT-LCD为例,采用源驱动器μPD16641芯片,通过γ校正电路和输入数据、灰度级和基准电压的关系,进行了实际的γ校正,得到了驱动电路中的γ校正的外部电压设定值,将设定目标值与实际驱动测定值进行了比较,从比较的结果可以看到,两者十分接近的,解决了实际的TFT液晶驱动电路中Gamma(γ)校正问题,达到了预期的设计目的,使图像的质量满足了用户的要求。In the video images and computer graphics, Gamma correction is an important process realizing images vision information of reproduction source objects truly. So, the principle of Gamma correction in OLED/LCD is described. By considering human being's vision non-linear, get the formula of gray and luminance, that is G=K×(L)^((1/2.2)). At the same time, get the characteristic curve of gray-scale and luminance of CRT relative to OLED and LCD. According to OLED and LCD electro-optical non-linear curves, we adopt normalized method to correction. Besides, in the practical, two conditions are limited. One is the gradient of OLED and LCD electro-op- tical curves. If their gradient is very steep, the adjacent gray-scale voltage will be very close. Thus, maximum noise voltage is limited in the electrical circuit. Another is the complication of the electrical circuit. If each gray-scale voltage depends on driving circuit directly, it will be very difficult to make the driving circuit to multi-gray scale display. Therefore, usually some regulation voltages of gray-scale are selected. But other gray-scale voltages are se- lected by row resistors average between adjacent regulation voltages. In fact, the practical gray-scale voltages are an approximation by gamma correction. The more the quantity of regulation voltage is, the better the gamma correction voltages are. Due to the comparability of OLED and LCD correction, here we have an example of correcting TFT LCD of 26.4 cm VGA (line inversion). Source driver IC is μPD16641 of NEC corporation. It has eleven voltages as regu- lation voltages of Gamma correction. Its driving method is line inversion. We can see its configuration diagram and gamma correction circuit. From the relation diagram of input data, gray-scale and regulation voltages, get external voltage setting values of γ correction in driving circuits were obtain

关 键 词：Γ校正 灰度级 行反转 OLED/LCD器件 基准电压 

分 类 号：TN383.1[电子电信—物理电子学] TN873.3