基于ARM和FPGA的LCD灰阶色度自动校正系统  

LCD gray-scale chromaticity automatic correction system based on ARM and FPGA

作　　者：林新泉 林志贤[1] 姚剑敏[1] 郭太良[1] 杨兰[2] 

机构地区：[1]福州大学物理与信息工程学院,福建福州350001 [2]集美大学理学院,福建厦门361021

出　　处：《电视技术》2016年第6期52-56,90,共6页Video Engineering

基　　金：国家"863"重大专项(2013AA030601);福建省科技重大专项(2014HZ0003-1);福建省资助省属高校专项课题(JK2014002);福建省科技厅重点项目(2013H0033)

摘　　要：由于液晶显示器件特殊的电光效应,其输入与输出为非线性关系,又因液晶像素对不同波长的光透过率不同,红绿蓝三通道穿透率特性表现不一致,形成不同灰阶色温的偏移。为使显示器件达到最佳的显示效果,必须对其做显示校正。针对小尺寸TFT-LCD提出了基于ARM和FPGA的LCD灰阶色度自动校正系统,系统使用高性价STM32为核心主控,结合高速FPGA和SSD2828实现8lane MIPI信号的输出,支持高达2K×4K分辨率的LCD。校正算法依据格拉斯曼混色定理,通过较色矩阵实现XYZ与RGB的转换,结合3次样条插值实现RGB穿透率的获取,再根据目标亮度色度计算获取目标穿透率。实验结果表明该系统可实现LCD灰阶色度更为快速、准确的校正,其中校正时间在10 s以内,灰阶亮度精度为1%,色度精度为±0.001 5,且校正系统成本低、体积小、具有广泛的应用性。Because of liquid crystal display device＇ s special electro-optical characteristic, its inputs and outputs present a nonlin- ear relationship. Besides, since the LCD pixel has different transmittances according to the different lights with various wave- lengths, the red, green and blue channels have diverse performances. Those cause the deviations of color temperature between dif- ferent gray scales. In order to achieve the best performance, it is needed for LCD devices to be corrected. In this paper, a TFT- LCD gray-scale chromaticity automatic correction system based on ARM and FPGA is proposed. The system uses cost-effective ARM as the core controller, combines with high-speed FPGA and SSD2828 to realize 8 lane MIPI outputs, supports up to 2K × 4K resolution. Correction algorithm based on Grsassmann color law, utilizes the transform matrix to realize the transformation between XYZ and RGB, combines with the cubic spline interpolation to get the RGB transmittances and then calculates target penetration rates according to the target brightness and chromaticity. Experimental results show that the system can realize a more rapid and ac- curate correction, the correction time is within 10 s, the precision of gray- scale brightness is 1% , chromaticity accuracy is ±0. 001 5, besides, the correction system is low-cost, small-volume and extensively applicable.

关 键 词：GAMMA 色温 灰阶色度 三刺激值 自动校正 MIPI 

分 类 号：TN29[电子电信—物理电子学]