基于FPGA的液晶显示屏测试用标准白场装置

FPGA based white field apparatus for LCD calibration

针对液晶显示屏生产厂商对标准白场的需求,研制了一种用于现场色彩标定的标准白场装置。介绍了标准白场装置的工作原理,以及该装置的标准定标和用户输出2种工作模式。针对标准白场装置的FPGA主控模块、显示器模块、人机接口模块、探头模块等主要硬件进行了详细说明。以内部显示模块状态机、机械按键去抖和LCM控制器为例说明了标准白场装置的软件设计。对研制的标准白场装置进行了标准定标实验,并对其定标后的性能进行了测试。实验结果表明:该标准白场装置可输出6 500、9 300K和12 500K3种色温的标准白场,具有不依赖标准光源、色温可调和数据存储等功能。标定后的标准白场装置能够生成色温可调的标准白场,24h内输出亮度误差小于0.5%。基本满足液晶显示屏生产厂商对标准白场装置的运行稳定可靠、操作简单方便、精度高等要求。

In order to meet the demand of standard white field of LCD production company, a white field apparatus is developed, with which the calibration of color measurement can be finished. Firstly, the principle of the standard white field, its calibration working mode and output working mode are introduced. Secondly, the FPGA main control unit, the display unit, the man-machine connecting unit, the detecting unit and other hardware units are explained in detail. Thirdly, the software system, for example the display mode controller, the key-press debouncing method and the LCM controller are designed. Finally, the calibration experiment of the apparatus is finished, and its calibrated performance is measured. Experimental results indicate that the apparatus system based on FPGA is able to produce 6 500 K, 9 300 K and 12 500 K three different color temperature white fields. The white field apparatus can work without the standard light, and it has the advantage of color temperature adjusting and data storage. The white field apparatus could provide standard white fields with adjustable color temperature, the luminance error is better than 0.50% within 24 h.It can satisfy the requirements of strong stabilization, good operation and high precision.