ASIAN JOURNAL OF CHEMISTRY ASIAN JOURNAL OF CHEMISTRY INTRODUCTION The display industry has rapidly developed during last decade with the technical convolution of touch pad, smart TV and mobile phone. The expandability and applicability of display technology has changed our lifestyle from home appliance to versatile devices such as mobile touch pad, smart TV and phone. In the display product line, the glass inspection equipment has played a role of preconditioning process to supply the un- tainted glass board for LCD and OLED panels. According to tendency of technical diversification and improvement, the manufacturing technology of large flat panel tends to move to use higher quality glass board. In flat panel manufacturing equipments, the micro-crack inspection system of the large glass board conveyer is an important module to reduce further processing of defective product and overall cost. The optical inspection module especially provides the preliminary process before the main product processes. Many optical methods have been tried to inspect micro-cracks in silicon wafer 1-5 , optical substrate 6,7 , metal surface 8 and others where difficult to use direct inspection 9-11 . The other conventional inspection method of vision system with CCTV could have not offered an expected test error rate due to its insufficient accuracy. The vision system Laser Inspection for Distinguishing Real Crack from Suspected Defects of Glass Boards† JU YONG CHO 1 , JAE WON CHOI 2 and WON KWEON JANG 1,* 1 Division of Electronic, Computer and Communication Engineering, Hanseo University, Seosan-si, Chungnam-do, 356-706, Republic of Korea 2 Westminster School, Simsbury, CT, 06070-1880, USA *Corresponding author: E-mail: jwk@hanseo.ac.kr Published online: 10 March 2014; AJC-14838 We proposed an additional optical algorism to improve the functionality of the conventional in situ glass inspection system of finding out real cracks in the glass boards of LCD and OLED. The modulated pulse laser output was used as an optical probe to investigate glass plates. Two parameters of the attenuated laser pulse counting and the decrease of transmitted optical power were used to modify crack detection algorism. Compared to that of the conventional in situ glass inspection method, the detecting accuracy of real cracks was increased with the additional laser inspection method. The technical parameters for analyzing glass defects were discussed such as pulse repetition rate of the incident laser, moving speed of glass board, and attenuation of the transmitted laser power. We also discussed the field adaptation factors of focal length, spot size and wavelength of the incident laser as well as the experimental field data of the laser inspection added system. Keywords: Fake crack, Real crack, Laser inspection, Glass board. Asian Journal of Chemistry; Vol. 26, No. 6 (2014), 1591-1594 http://dx.doi.org/10.14233/ajchem.2014.17295 †Presented at The 7th International Conference on Multi-functional Materials and Applications, held on 22-24 November 2013, Anhui University of Science & Technology, Huainan, Anhui Province, P.R. China method based on the pixel variation from rapidly conveying glass board and the fake crack and the stain also generate the same pixel variation like that of real crack. This vision inspection module using CCTV executes the distinguishing function for real micro cracks from glass board defects with an algorism developed from accumulated data 12 . The detection algorism of vision inspection system, of course, have improved the accuracy to the considerable level, but the product field still suffer from the unexpected fault detection of fake crack and stain. Though many inspection methods have been tried to reduce the false decision and speed up the inspection, it is not easy to raise the accuracy to the level of the perfect perfor- mance under real operational environment. Considering the loss of productivity that caused by a mistake of distinguishing fake and real cracks in the glass inspection process, the addi- tional and improved detection system is essential and burning problem. The additional algorism and optical inspection module is proposed to reduce the loss of productivity in the product line of LCD and OLED glass boards. The optical inspection system composed of a modulated near infrared laser as a light source and an optical detection module to improve the distinguishing ability of fake and real cracks.