投射电容屏ITO电路检测用线阵CCD成像系统的设计  

Design of Imaging System for PCTP ITO Pattern Inspection by Using Line-Scan CCD

作　　者：姜长城[1] 全燕鸣[1] 彭艳华[1] 

机构地区：[1]华南理工大学机械与汽车工程学院,广东广州510640

出　　处：《华南理工大学学报（自然科学版）》2014年第11期19-24,共6页Journal of South China University of Technology(Natural Science Edition)

基　　金：广东省工业高新技术攻关引导项目(2013B010402003)

摘　　要：为解决线阵CCD用于投射电容屏氧化铟锡(ITO)电路检测时不易获取高对比度图像的问题,根据明场照明反射成像原理,设计并构建了一套基于最大叠加反射系数差值的同轴照明与成像系统.根据投射电容屏ITO电路与玻璃基板的光学特性及ITO电路的几何特征,分析了光源照射及成像方式;根据ITO电路的多层复合结构,分析了影响ITO电路与玻璃基板成像对比度的影响因素;在满足较高生产率的运动速度下,通过对比不同光照亮度下所获取的系列图像,确定了可获得高对比度ITO电路与玻璃基板图像的成像系统工作参数.实验结果表明:检测精度为10μm、ITO基板运动速度为130 mm/s且光照亮度等级为190时,所获图像的灰度直方图具有显著双峰值,易于识别ITO电路缺陷.In order to acquire high-contrast images in the defect inspection of the PCTP（ Projected Capacitive Touch Panel） ITO pattern by using the line-scan CCD,a coaxial illumination and imaging system based on the maximum difference value between superposed reflection coefficients is designed and established according to the brightfield reflection illumination principle. Then,the illumination and imaging patterns are analyzed by taking into account the optical properties of the glass substrate,the PCTP ITO material as well as the geometrical structure of the ITO pattern,and the influence factors of the imaging contrast between the ITO film and the glass substrate are analyzed by considering the multi-layered composite structure of the ITO pattern. Finally,at a higher scan rate which can cause a higher productivity,the imaging parameters of the high-contrast images of the ITO pattern and the glass substrate are determined by comparing a series of images taken at different illumination intensities. Experiment results indicate that,when the ITO substrate scans at a rate of 130 mm / s with an inspection precision of 10 μm and a light intensity of 190,image gray histograms have two apparent peaks,which helps to inspect the defects of ITO patterns.

关 键 词：图像获取 线阵CCD 氧化铟锡电路 玻璃基板 图像对比度 

分 类 号：TH164[机械工程—机械制造及自动化] O439[机械工程—光学工程]