METHOD AND SYSTEM OF LCD INSPECTION BY PATTERN COMPARISON

摘要

This patent discloses the method and system design of an automated visual inspection system for liquid crystal displays (LCDs). Image defect is detected by comparing the image displayed by an LCD panel under inspection with a template image which the LCD panel is supposed to display. The LCD panel under inspection is allowed to be placed loosely on the inspection platform. The algorithm corrects for the effect of object pose and image perspective to produce a 2-D image of the pattern that appears on the LCD panel. Next, the two patterns are subtracted to obtain an error image. From the error image, pattern discrepancy is evaluated at every pixel location to detect for LCD defects.