LED背光源缺陷检测方法的研究  

Research of Detection Method for LED Backlight Defect

作　　者：罗龙[1] 胡泓[2] 杨永生[1] 谭开志 LUO Long;HU Hong;YANG Yong-sheng;TAN Kai-zhi(Institute of Systems Engineering,CAEP,Sichuan Mianyang 621000,China;Shenzhen Graduate School,Harbin Institute of Technology,Guangdong Shenzhen 518000,China;Shenzhen Ke Rui Technology Co.,Ltd,Guangdong Shenzhen 518000,China)

机构地区：[1]中国工程物理研究院总体工程研究所,四川绵阳621000 [2]哈尔滨工业大学深圳研究生院,广东深圳518000 [3]深圳科瑞技术股份有限公司,广东深圳518000

出　　处：《机械设计与制造》2018年第11期74-77,共4页Machinery Design & Manufacture

摘　　要：直下式LED背光源广泛应用于大尺寸液晶显示屏,发光晶片和光学透镜装配于PCB板上形成单个背光源,晶片和透镜间可能存在装配缺陷,即水平、高度、角度偏移,要求偏移量不得超过0.02mm、0.1mm、0.2°,否则会对显示屏显示质量造成不利影响。针对背光源的装配缺陷,提出了基于图像灰度曲线对背光源缺陷进行检测的方法。分析了透镜对晶片光线的作用,在光学软件Tracepro中建立了背光源工作模型并进行了仿真,得到了光线在显示屏上形成光斑的照度分布和照度曲线,获得了偏移类型与照度曲线的关系,设计了相应的图像采集平台,基于VC6.0设计了灰度曲线求取算法,进行了试验。试验结果表明,该检测方法可有效检测LED背光源的水平、高度、角度缺陷,检测精度分别为0.01mm、0.04mm、0.1°。LED backlight of straight down type is widely used in large size LCD screen.Light emitting chip and optical lens are assembled on PCB board.They form a single backlight.Assembly defects,namely horizontal offset,height offset and angle offset,may exist between emitting chip and optical lens.The respective offset is required to be less than 0.02mm,0.1mm,0.2°.Otherwise,the display quality of screen will be adversely affected.In view of the defects,a method of detecting backlight defects based on image gray curve was carried out.The effects of optical lens on the light from emitting chip was analyzed.In the optical software,namely Tracepro,backlight working model was established and simulating was carried out.Illuminance distribution and illumination curve of light spot forming on the display screen was obtained.The relationship between different offset type and illumination curve was acquired.The corresponding platform of collecting images was designed,algorithm for calculating gray curve was designed based on VC 6.0,and the experiment was carried out.The testing results show that the backlight defects detection method can effectively detect LED backlight horizontal,height,and angle offset defects.The detecting precision was 0.01mm and 0.04mm,0.1°respectively.

关 键 词：LED背光源 光学透镜 装配缺陷 灰度曲线 

分 类 号：TH16[机械工程—机械制造及自动化] TH7