Saturated Imaging for Inspecting Transparent Aesthetic Defects in a Polymeric Polarizer with Black and White Stripes

• Published in: Materials Vol. 11; no. 5; p. 736
• Main Authors: Yu, Cilong, Chen, Peibing, Zhong, Xiaopin, Pan, Xizhou, Deng, Yuanlong
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 07-05-2018; MDPI
• Subjects: Computer simulation; Defects; Imaging; Inspection; Light; Luminous intensity; Machine vision; Polarizers; Polymer films; polymeric polarizer; Production lines; saturated imaging; transparent aesthetic defect; Vision systems; transparent aesthetic defect; saturated imaging; machine vision; polymeric polarizer
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma11050736

Machine vision systems have been widely used in industrial production lines because of their automation and contactless inspection mode. In polymeric polarizers, extremely slight transparent aesthetic defects are difficult to detect and characterize through conventional illumination. To inspect such defects rapidly and accurately, a saturated imaging technique was proposed, which innovatively uses the characteristics of saturated light in imaging by adjusting the light intensity, exposure time, and camera gain. An optical model of defect was established to explain the theory by simulation. Based on the optimum experimental conditions, active two-step scanning was conducted to demonstrate the feasibility of this detection scheme, and the proposed method was found to be efficient for real-time and in situ inspection of defects in polymer films and products.