DOI QR코드

DOI QR Code

Study on the Reverse Twist According to the Rubbing Direction for the Fringe-Field Switching (FFS) Mode

FFS 모드에서 러빙 방향에 따른 Reverse Twist 변화에 대한 연구

  • 김미숙 (BOE TFT LCD SBU 선행기술그룹, 전북대학교 신소재공학부) ;
  • 신승민 (BOE TFT LCD SBU 선행기술그룹) ;
  • 정연학 (BOE TFT LCD SBU 선행기술그룹, 전북대학교 신소재공학부) ;
  • 김향율 (BOE TFT LCD SBU 선행기술그룹) ;
  • 김서윤 (BOE TFT LCD SBU 선행기술그룹) ;
  • 이승희 (전북대학교 신소재공학부)
  • Published : 2006.02.01

Abstract

We studied on the reverse twist near the pixel edge depending on the rubbing direction for the fringe field switching (FFS) mode. Liquid crystal (LC) dynamic and the transmittance near the pixel edge, where the various field directions are generated, depend on the initial rubbing direction because the position of reverse twist is decided by the angle between the electric direction and the LC director at a bias voltage. For example, when the rubbing angle is $7^{\circ}$, the reverse twist appears on the bottom position of the right sharp comer of the pixel edge so that the reverse region exists far away from main active region. But, when the rubbing angle is $-7^{\circ}$, the reverse twist appears on the top position of the right sharp comer of the pixel edge, resulting that the region becomes more close to the main active area and the unstable disclination lines (DLs) easily intrude into the active region. Therefore, it is necessary to keep the reverse twist region far from the active region and it is possible by controlling the rubbing direction in the design of a pixel electrode.

Keywords

References

  1. H. Y. Kim, D. S. Seo, and J. H. Kim, 'Residual DC voltage property in the in-plane switching cell using the voltage -transrnittance hysteresis method', J. of KIEEME(in Korean), Vol. 14, No. 6, p. 487, 2001
  2. H. Y. Kim, I. S. Song, and S. H. Lee, 'Rubbing angle effects on the electro-optic characteristics of in- plane switching liquid crystal display', Trans. EEM, Vol. 4, No. 1, p. 24, 2003
  3. 김미숙, 김향율, 고재완, 이승희, '프린즈 전기장에 의해 구동되는 수평 배향 액정셀에서 black matrix의 전기적 특성이 셀의 전기 광학특성에 미치는 영향에 관한 연구', 전기전자재료학회논문지, 16권, 11호, p.1008, 2003
  4. 김향율, 고재완, 노정동, 서대식, 이승희, '유전율 이방성이 음인 액정을 이용한 이중 도메인 FFS 모드의 전기광학 특성', 전기전자재료학회논문지, 15권, 8호, p. 720, 2002
  5. M. S. Kim, Y. H. Jung, S. M. Seen, H. Y. Kim, S. Y. Kim, Y. J. Lim, and S. H. Lee, 'A novel fringe field switching (FFS) mode with 3 divided pixel slit', Jpn. J. Appl. Phys., Vol. 44, No. 5A, p. 3121, 2005 https://doi.org/10.1143/JJAP.44.3121
  6. A. Lien, 'Extended Jones matrix representation for twisted nematic liquid crystal display at oblique incidence', Appl. Phys. Lett., Vol. 57, No. 26, p. 2767, 1990