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Optimization of the Dual-layer LGP for Improving Luminance and Uniformity of Edge Type Back Light Unit

에지형 Back Light Unit의 휘도와 균일도 향상을 위한 복합도 광판 최적화

  • Oh, Se-Won (Department of Information and Communication Engineering, Chunbuk University) ;
  • Kim, Nam (Department of Information and Communication Engineering, Chunbuk University) ;
  • Kim, Eun-Suk (Eunsung Display) ;
  • An, June-Won (LMS)
  • 오세원 (충북대학교 정보통신공학과) ;
  • 김남 (충북대학교 정보통신공학과) ;
  • 김은석 (은성디스플레이(주)) ;
  • 안준원 ((주)엘엠에스)
  • Received : 2010.10.11
  • Accepted : 2010.11.29
  • Published : 2010.12.25

Abstract

A dual-layer light guide plate (DLGP) was designed and a simulation was done to optimize the structure of the light guide plates used at backlight units while maintaining the luminance, uniformity and viewing angle by reducing the optical sheet. The characteristic of DLGP with prism pattern with curvature on the top surface is simulated and the luminance and uniformity are obtained. In order to improve the uniformity, the V groove prism pattern on the bottom surface was turned by an angle of $90^{\circ}$. In particular, we used the pitch calculation program to select the value of the ratio (Max : Min) between the pitch at the extreme outside and the pitch at the middle, the number of V groove lines and the variance at the bottom pattern of DLGP. After that, the optimum distance between V grooves was determined. For optimizing the DLGP, we examined the uniformity again by changing the number of pattern grooves on the bottom surface of DLGP. As a result of the simulation, we find that the BLU with DLGP has a uniformity of 90.6% and viewing angle $145^{\circ}$.

본 논문에서는 에지 방식의 BLU(Backlight unit)에 사용되는 도광판의 구조를 최적화하여 광학시트를 줄이면서 휘도와 균일도 및 시야각을 유지하기 위한 이중구조의 도광판을 설계하고 시뮬레이션을 통해 휘도와 균일도를 알아보았다. 여기에 사용된 복합 도광판은 이중구조의 도광판으로 상부에는 곡률 R을 갖는 프리즘패턴을 형성하고 곡률 R에 따른 휘도와 균일도를 시뮬레이션하였다. 하부에는 V groove 패턴을 회전시켜 상부패턴과 $90^{\circ}$를 이루게 하여 균일도를 확보하였다. 특히, 하부 패턴에서는 외곽의 피치 간격과 중심의 피치간격의 비(최대:최소), 패턴의 개수와 패턴의 분산을 정의할 수 있는 프로그램을 설계하여 V groove 사이의 간격을 결정하였다. 복합 도광판(dual-layer light guide plate, DLGP)의 최적화를 위해 다시 하부 패턴의 개수를 변화시켜 균일도를 알아보았다. 시뮬레이션 결과 복합 도광판을 이용한 BLU는 균일도 90.6%, 시야각 $145^{\circ}$인 특성을 갖는 것을 확인하였다.

Keywords

References

  1. Y. S. Kim and S. Lim, “Design of high uniformity LED backlight,” SID International Symposium Digest of Technical Papers 36, 1321-1325 (2005). https://doi.org/10.1889/1.2036248
  2. Y. E. Ryu, T. H. Kim, S. G. Kim, Y. H. Seo, T. J. Jae, and D. S. Choi, “A study on the manufacturing of micro-patterned light guide,” in Proc. Korea Soc. Pre. Eng. 2006 (Gyeongju Kyoyuk Munhwa Hoekwan, Gyeongju, Korea, 2006), pp. 534-535.
  3. M. Anandan, “LCD backlighting,” Society for Informational Display Seminar Lecture Notes, 169-250 (2002).
  4. K. Kalantar, “Optical design of light-guide plates for illumination systems used in mobile phones and PDAs,” Asia display, IDW 2001, 517-520 (2001).
  5. D. M. Brown, R. Dean, and J. D. Brown, “LED backlight design, fabrication, and testing,” Proc. SPIE 3938, 180-187 (2000). https://doi.org/10.1117/12.382830
  6. Y. M. Lee, J. H. Lee, and E. C. Jeon, “ A study on an integrated guide plate,” J. Opt. Soc. Korea 21, 53-60 (2010). https://doi.org/10.3807/KJOP.2010.21.2.053
  7. M. Y. Shin, E. S. Kim, N. Kim, Y. S. Sim, and J. W. Ahn, “Design of optical film for enhance the brightness in direct type BLU,” in Proc. KSPE Annual Meeting (Ramada Jeju Hotel, Korea, Jun. 2009), pp. 1043-1044.
  8. K. M. Choi, MSC thesis, “A study on the luminance improvement sheet in LCD BLU,” Kookmin University (2004).
  9. S. Y. Jang, J. H. Cho, and S. S. Baek, “ New BLU sheet with linear arrays of deformed bar prism for direct back light unit,” J. Opt. Soc. Korea 18, 401-409 (2007). https://doi.org/10.3807/HKH.2007.18.6.401

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