单边侧入光式导光板质量可视化检测方法  

Single Side Entrance Light Guide Plate Quality Visual Inspection Method

作　　者：张沪强 李俊峰[1] 戴文战[2] ZHANG Hu-Qiang;LI Jun-Feng;DAI Wen-Zhan(Faculty of Mechanical Engineering and Automation,Zhejiang Sci-Tech University,Hangzhou 310018,China;School of Information and Electronic Engineering,Zhejiang Gongshang University,Hangzhou 310018,China)

机构地区：[1]浙江理工大学机械与自动控制学院,杭州310018 [2]浙江工商大学信息与电子工程学院,杭州310018

出　　处：《计算机系统应用》2020年第2期219-227,共9页Computer Systems & Applications

基　　金：国家自然科学基金(61374022);浙江省公益性技术应用研究计划(LGG18F030001,GG19F030034)~~

摘　　要：导光板是液晶显示屏背光模组的重要组成部分,在其生产过程中不可避免会出现亮点、划伤、压伤、暗影等缺陷,直接影响显示效果.针对这种问题,根据网点的排列特征、缺陷的成像效果,本文提出了一种基于机器视觉的导光板缺陷检测方法.首先,根据网点的排列疏密程度将图分成疏区和密区;其次,由于疏区网点会对缺陷检测带来极大干扰,提出了网点分离的思想,通过设计滤波器分离网点与背景,分别进行疑似缺陷提取.设计高斯导数滤波器对密区进行滤波,并在此基础上利用灰度形态学、图像运算等处理方法提取密区疑似缺陷;进而,针对导光板不同区域,根据产线质检要求提取缺陷区域的特征,并通过这些特征制定筛选规则判定缺陷;最后,在自主研发的导光板缺陷检测系统上,对提出的检测方法进行了大量的现场测试.测试结果表明,针对亮白点、压伤和划伤缺陷具有较高的检测精度,检测精度可达99%以上,基本可以满足工业检测要求.The light guide plate is an important part of the backlight module of liquid crystal display screen.In the production process,defects such as bright spots,scratches,crushing,and shadows are inevitable,which directly affects the display effect.Aiming at this problem,according to the arrangement characteristics of the dots and the imaging effect of the defects,this study proposes a method based on machine vision for detecting defects of light guide plates.Firstly,according to the degree of density of the dots,the image is divided into a sparse zone and a dense zone.Secondly,because the dot in sparse zone will cause great interference to the defect detection,the idea of separating the dots is proposed,and the filter is used to separate the dots and the background.Suspected defect extraction is performed separately.The Gaussian derivative filter is designed to filter the dense area.On the basis of this,the gray area morphology and image calculation methods are used to extract the suspected defects in the dense area.Further,for different areas of the light guide plate,according to the quality inspection requirements of the production line,the characteristics of the defect area,and the screening rules are used to determine the defects.Finally,a large number of on-site tests are performed on the proposed detection method on the self-developed light guide plate defect detection system.The test results show that the detection precision for bright white spots,crushing and scratching defects has a detection accuracy of over 99%,which can basically meet the requirements of industrial testing.

关 键 词：缺陷检测 导光板 网点分离 高斯导数滤波 机器视觉 

分 类 号：TN873.93[电子电信—信息与通信工程] TP391.41[自动化与计算机技术—计算机应用技术]