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An effective classification method for TFT-LCD film defect images using intensity distribution and shape analysis  

Noh, Chung-Ho (한국외국어대학교 산업경영공학과)
Lee, Seok-Lyong (한국외국어대학교 산업경영공학부)
Zo, Moon-Shin ((주) 카사테크)
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Abstract
In order to increase the productivity in manufacturing TFT-LCD(thin film transistor-liquid crystal display), it is essential to classify defects that occur during the production and make an appropriate decision on whether the product with defects is scrapped or not. The decision mainly depends on classifying the defects accurately. In this paper, we present an effective classification method for film defects acquired in the panel production line by analyzing the intensity distribution and shape feature of the defects. We first generate a binary image for each defect by separating defect regions from background (non-defect) regions. Then, we extract various features from the defect regions such as the linearity of the defect, the intensity distribution, and the shape characteristics considering intensity, and construct a referential image database that stores those feature values. Finally, we determine the type of a defect by matching a defect image with a referential image in the database through the matching cost function between the two images. To verify the effectiveness of our method, we conducted a classification experiment using defect images acquired from real TFT-LCD production lines. Experimental results show that our method has achieved highly effective classification enough to be used in the production line.
Keywords
TFT-LCD; defect classification; defect inspection; image analysis; shape feature;
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