Journal of the Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회논문지)

The Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회)
권호 표지

Pretilt Angle Generation and EO Performance in MLC with Polarized UV Light Irradiation Polyimide surface

폴리이미드막 표면에 직선 편광된 UV광 조사에 의한 프리틸트각 발생과 전기광학특성

  • 서대식 (숭실대학교 공대 전기공학과) ;
  • 이정호 (숭실대학교 공대 전기공학과) ;
  • 이창훈 (숭실대학교 공대 전기공학과)
  • Published : 1998.10.01
Download PDF
⟨ Previous Next ⟩

Abstract

We have investigated that the monodomain alignment of nematic liquid crystal (NLC) is obtained with polarized ultraviolet(PUV) light irradiation on polyimide (PI) surface. The LC alignment capability increases with increasing the UV light irradiation time. The polarized UV light irradiation on oblique angle of 60。 irradiated on PI surface rotated by 90。 at 10 min. after being normally irradiated on PI surface at 30 min., the generated pretilt angle of NLC is about 2.5。. The pretilt angle of NLC is attributed to the interaction between the LC molecules and the asymmetric triangular structure of polymer surface due to photo-depolymerization of polymer with the oblique UV light on PI surface. The voltage -transmittance and response time characteristics of photo-aligned twisted nematic (TN)-LCD with UV light irradiation time 60 min. were almost same in comparison with the rubbing-treated TN-LCD.

Keywords

References

  1. Mol. Cryst. Liq. Cryst. v.1 Alignment of nematic liquid crystals and their mixtures J. Cognard
  2. Jpn. J. Appl. Phys. v.29 A simple model for pretilted nematic liquid crystal medium and its torsional surface coupling strength T. Sugiyasma;S. Kuniyasu;D. -S. Seo;H. Fukuro;S. Kobayashi
  3. Mol. Cryst. Liq. Cryst. v.213 Generation of pretilt angles in nematic liquid crystal, 5CB, media aligned on polyimide films prepared by spin-coating and LB techniques : effect of Rubbing D.-S.Seo;K.Muroi;S.Kobayashi
  4. Appl. Phys. Lett. v.61 Study of the pretilt angle for 5CB on rubbed polyimide films containing trifluoromethyl moiety and analysis of the surface atomic concentration of F/C(%) with an electron spectroscope for chemical analysis D. -S. Seo;S. Kobayashi;M. Nishikawa
  5. Jpn. J. Appl. Phys. v.34 Effect of the molecular structure of weakly rubbed organic solvent soluble polyimide with trifluoromethyl moieties on anchoring strength of liquid crystals D. -S. Seo;N. Yoshida;S. Kobayashi;M. Nishikawa;Y. Yabe
  6. Mol. Cryst. Liq. Cryst. v.264 Estimation of the static electricity and optical retardation produced by the rubbing polyimide and polyamide films with different fabrics H. Matsuda;D. -S. Seo;N. Yoshida;K. Fujibayashi;S. Kobayashi
  7. SID digest paper Relationships between the imagesticking time and electrical characteristics of UV-exposed two-domain wide-viewing-angle LCD M. Hasegawa;H. Takano;Y. Momoi;K. Nakayama
  8. Jpn. J. Appl. Phys. v.31 Surface-induced parallel align ment of liquid crystals by linearly polymerized photo polymers M.Schadt;K.Schmitt;V.Kozinkov;V.Chigrinov
  9. Nature v.351 Surface-mediated alignment of nematic liquid crystals with polarized laser light W. M. Gibbons;P. J. Shannon;S. -T. Sun;B. J. Swelin
  10. SID digest paper Polarized UV-exposed polyimide films for liquid-crystal alignment J. L. West;X. Wang;Y. Ji;J. R. Kelly
  11. SID digest paper Four-domain LCD using high-pretilt photoaligned polyimide substrates X. Wang;D. Subacius;O. Lavrentovich;J. L. West
  12. SID digest paper Mechanism of UV modification of LC pretilt angle and its application to two-domain TN-LCDs K. -W. Lee;A. Lien;J. Stathis
  13. SID digest paper Liquid-crystal alignment by slantwise irradiation of non-polarized UV light on a polyimide layer T. Yamamoto;M. Hasegawa;H. Hatoh
  14. SID digest paper The mechanism of pretilt generation on polarized ultraviolet light aligned polyimide film X. Wang;J. L. West
  15. SID digest paper Prospects of the photo-alignment technique for LCD fabrication Y. Iimura;S. Kobayashi
  16. Liquid Crystals v.23 Investigation of pretilt angle generation in nematic liquid crystal with slanted non-polarized ultraviolet light irradiation on polyimide surfaces D. -S. Seo;L. -Y. Hwang;S. Kobayashi