TY - JOUR AB - Purpose– The purpose of this paper is to apply an on‐line automatic inspection and measurement of surface defect of thin‐film transistor liquid‐crystal display (TFT‐LCD) panels in the polyimide coating process with a modified template matching method and back propagation neural network classification method.Design/methodology/approach– By using the technique of searching, analyzing, and recognizing image processing methods, the target pattern image of TFT‐LCD cell defects can be obtained.Findings– With template match and neural network classification in the database of the system, the program judges the kinds of the target defects characteristics, finds out the central position of cell defect, and analyzes cell defects.Research limitations/implications– The recognition speed becomes faster and the system becomes more flexible in comparison to the previous system. The proposed method and strategy, using unsophisticated and economical equipment, is also verified. The proposed method provides highly accurate results with a low‐error rate.Practical implications– In terms of sample training, the principles of artificial neural network were used to train the sample detection rate. In sample analysis, character weight was implemented to filter the noise so as to enhance discrimination and reduce detection.Originality/value– The paper describes how pre‐inspection image processing was utilized in collaboration with the system to excel the inspection efficiency of present machines as well as for reducing system misjudgment. In addition, the measure for improving cell defect inspection can be applied to production line with multi‐defects to inspect and improve six defects simultaneously, which improves the system stability greatly. VL - 31 IS - 3 SN - 0144-5154 DO - 10.1108/01445151111150587 UR - https://doi.org/10.1108/01445151111150587 AU - Lin Chern‐Sheng AU - Kuo Jung AU - Lin Chi‐Chin AU - Lay Yun‐Long AU - Shei Hung‐Jung PY - 2011 Y1 - 2011/01/01 TI - Automatic inspection and strategy for surface defects in the PI coating process of TFT‐LCD panels T2 - Assembly Automation PB - Emerald Group Publishing Limited SP - 244 EP - 250 Y2 - 2024/04/19 ER -