Comprehensive defect-detection method for a small-sized curved optical lens

During quality-assurance procedures in the mass production of small-sized curved optical lenses, fine defects are usually detected via manual observation, which is not recommended owing to the associated drawbacks of high error rate, low efficiency, and nonamenability to quantitative analysis. To address this concern, this paper presents a comprehensive defect-detection system based on transmitted fringe deflectometry, dark-field illumination, and light transmission. Experimental results obtained in this study reveal that the proposed method demonstrates efficient and accurate detection of several microdefects occurring in small-sized optical lenses, thereby providing valuable insights into the optimization of parameters concerning the mass production of optical lenses. The proposed system can be applied to the actual mass production of small-sized curved optical lenses.