Mobile Phone Screen Defect Detection System Based On Machine Vision

Mobile phone LCD display production process is complex,complex process,the need for multiple processes to complete the collaboration,it is easy to produce a variety of display defects,including color temperature anomalies,screen flash anomalies,dotted line defects,Mura defects.As the display of the mobile phone output device,the quality of the screen directly related to the end-user experience,so mobile phone screen defect detection is particularly important.Most of the current production line using manual detection methods,vulnerable to subjective factors,and the traditional manual gradually unable to adapt to high-speed production of automated industrial production line,based on the machine vision detection system for its high speed,high efficiency,anti-interference ability and other advantages quickly Occupy the main line of production line detection.In this paper,the paper "based on the industrial vision of the mobile phone screen CELL module defect detection" and the project "based on the visual LCD screen defect detection system",for mobile phone screen defect detection field in-depth study.Based on the technology of mobile phone screen process,combined with the common detection products on the market,the hardware solution of the system is designed to make the defect imaging visible and not be affected by dust.In the specific detection algorithm design,the first part of the image pre-processing operations,and then for different types of defects:color temperature,screen flash,bad bad lines,mura and other specially designed algorithm module.Which Mura defects due to low contrast,irregular shape and other characteristics,is the key point of detection.,Taking into account the Mura is a display defect,combined with the visual perception of the human eye characteristics,the system uses the contrast JND indicator with the judge mode,calculate the human eye contrast sensitivity,and according to its relationship with the area to determine whether the Mura defect.After field verification,the overall detection effect is expected.My main job is:· Combined with the mobile phone screen production process,the design of the system's visual program,making a variety of defects are visible to ensure that the follow-up detection results.At the same time for the dust interference problem,carefully designed the lighting program,which effectively filter out the dust at the same time greatly reduce the defect of the missing test.· For different types of defects were hardware and algorithm design,including bad point bad line detection,display abnormal detection,screen color temperature detection,screen flash detection.· For the mura defect,the contrast-based mura detection method is used to calculate the image contrast into the contrast-sensitive function,and then the JND map is calculated according to the JND index.After normalization,the threshold is compared with the set threshold to effectively detect the mura.The final field verification data show that the system can meet the actual production enterprise testing quality requirements.