A simple inspection technique of visual defects of polymer polarizer

In order to inspect the visual defects of polymer polarizer, an off-line automatic optical system (AOI) is proposed in this paper. It employs a plane CCD camera to capture the image of polarizer, and the Vision-Development-Module (VDM) © to process and analyze the image. Simple algorithm to determine the key parameters, such as the range of gray level equalization and the segmentation threshold, is implemented in the LabVIEW2012©. Experimental results demonstrate the validity of the algorithm, and classification, location and size of visual defects are extracted successfully.