A study on real time inspection of OLED protective film using edge detecting algorithm

Edge Detecting Algorithm을 이용한 OLED 보호 필름의 Real Time Inspection에 대한 연구

  • Han, Joo-Seok (Department of Mechanical Engineering, Inha University) ;
  • Han, Bong-Seok (Department of Mechanical Engineering, Inha University) ;
  • Han, Yu-Jin (Department of Mechanical Engineering, Inha University) ;
  • Choi, Doo-Sun (Department of Mechanical Engineering, Inha University) ;
  • Kim, Tae-Min (Department of Mechanical Engineering, Inha University) ;
  • Ko, Kang-Ho (Department of Mechanical Engineering, Inha University) ;
  • Park, Jung-Rae (Department of Mechanical Engineering, Inha University) ;
  • Lim, Dong-Wook (Department of Mechanical Engineering, Inha University)
  • 한주석 (인하대학교 기계공학과) ;
  • 한봉석 (인하대학교 기계공학과) ;
  • 한유진 (인하대학교 기계공학과) ;
  • 최두선 (인하대학교 기계공학과) ;
  • 김태민 (인하대학교 기계공학과) ;
  • 고강호 (인하대학교 기계공학과) ;
  • 박정래 (인하대학교 기계공학과) ;
  • 임동욱 (인하대학교 기계공학과)
  • Received : 2020.04.10
  • Accepted : 2020.06.30
  • Published : 2020.06.30

Abstract

In OLED panel production process, it is necessary to cut a part of protective film as a preprocess for lighting inspection. The current method is to recognize only the fiducial mark of the cut-out panel. Bare Glass Cutting does not compensate for machining cumulative tolerances. Even though process defects still occur, it is necessary to develop technology to solve this problem because only the Align Mark of the panel that has already been cut is used as the reference point for alignment. There is a lot of defective lighting during panel lighting test because the correct protective film is not cut on the panel power and signal application pad position. In laser cutting process to remove the polarizing film / protective film / TSP film of OLED panel, laser processing is not performed immediately after the panel alignment based on the alignment mark only. Therefore, in this paper, we performed real time inspection which minimizes the mechanism tolerance by correcting the laser cutting path of the protective film in real time using Machine Vision. We have studied calibration algorithm of Vision Software coordinate system and real image coordinate system to minimize inspection resolution and position detection error and edge detection algorithm to accurately measure edge of panel.

Keywords

References

  1. Smith, Joseph T., et al., "Application of flexible oled display technology to point-of-care medical diagnostic testing", Journal of Display Technology 12.3, pp. 273-280, 2016. https://doi.org/10.1109/JDT.2015.2479457
  2. Sugimoto, Akira, et al., "Flexible OLED displays using plastic substrates", IEEE Journal of selected topics in quantum electronics 10.1, pp. 107-114, 2004. https://doi.org/10.1109/JSTQE.2004.824112
  3. Park, Jin-Seong, et al., "Thin film encapsulation for flexible AM-OLED: a review", Semiconductor science and technology 26.3, 034001, 2011. https://doi.org/10.1088/0268-1242/26/3/034001
  4. Y. J. Park, "Display Technologies for Immersive Devices and Electronic Skin", Electronic Communication Trend Analysis, Vol.34, No.2, pp. 10-18, 2019. DOI:https://dx.doi.org/10.22648/ETRI.2019.J.340202
  5. Keyence, Vision system lighting, Available From: https://www.keyence.co.kr/products/vision/vision-sys/ca-d/lineups/lineup-08.jsp (accessed Aug. 9, 2019)