• 제목/요약/키워드: Vertical-alignment (VA)

검색결과 52건 처리시간 0.023초

비편광 UV조사에 의한 광배향 VA-LCD의 전기광학특성 (Electro-optical properties of photo-aligned VA-LCD by irradiation of unpolarized UV light.)

  • 박두석;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 추계학술대회 논문집
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    • pp.545-548
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    • 1999
  • The electro-optical characteristics of photo-aligned vertical-alignment (VA)-liquid crystal display (LCD) with non-polarized ultraviolet (UV) light irradiation of 45\`on homeotropic polyimide (Pl) surface were investigated. LC alignment on photo-aligned VA-LCD is attributed to photo-depolymerized reaction of the polymer with non-polarized UV light irradiation on PI surface. We had good voltage-transmittance (V-T) characteristics of photo-aligned VA-LCD. The response time of photo-aligned VA-LCD was slower than that of the rubbing-aligned VA-LCD. Finally, we suggest that the slow response time of photo-aligned VA-LCD depends on the LC domain.

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PDT-VA 셀을 이용한 전기광학 특성 (Electro-optical performance using a PDT-VA cell)

  • 김형규;황정연;서대식;한은주;김재형
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2000년도 추계학술대회논문집
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    • pp.133-136
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    • 2000
  • We investigated the improvement of viewing angle using a patterned double twisted (PDT) vertical-alignment (VA) cell mode on a homeotropic alignment layer. Good voltage-transmittance curves for negative dielectric anisotropic nematic liquid crystal (NLC) using the PDT-VA cell without a negative compensation film were obtained. The viewing angle of the PDT-VA cell without a negative compensation film was wider than that of a conventional VA cell.

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PDT-VA 셀을 이용한 전기광학 특성 (Electro-optical performance using a PDT-VA cell)

  • 김형규;황정연;서대식;한은주;김재형
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.133-136
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    • 2000
  • We investigated the improvement of viewing angle using a patterned double twisted (PDT) vertical-alignment (VA) cell mode on a homeotropic alignment layer. Good voltage-transmittance curves for negative dielectric anisotropic nematic liquid crystal (NLC) using the PDT-VA cell without a negative compensation film were obtained. The viewing angle of the PDT-VA cell without a negative compensation film was wider than that of a conventional VA cell.

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수직 광폴리머 표면을 이용한 VA-IPS 셀의 전기 광학 특성 (EO Characteristics in the Vertical-Alignment (VA)-In Plane Swiching (IPS) Cell on a Homeotropic Photopolymer Surface)

  • 정은아;황정연;김재형;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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    • pp.945-948
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    • 2002
  • We studied electro-optical (EO) performances of a vertical-alignment (VA)-in plane switching (IPS) cell on a photopolymer surfaces. The VA-IPS cell, dark in voltage-off state, reveals bright uniformity in all directions due to the dual domainlike dierector configuration in the voltage-on state. For voltage-transmittance (V-T) measurement, the transmittance characteristics of the VA-IPS cell on the photopolymer surface was better than that of the VA-IPS cell on a polyimide(PI) surface.

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수직 광폴리머를 이용한 VA-1/4$\pi$셀의 전기 광학 특성 (Electro-optical Characteristics of in the Vertical-Alignment 1/4$\pi$ Cell Using Homeotroopic Photopolymer)

  • 황정연;서대식;김재형
    • 한국전기전자재료학회논문지
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    • 제14권8호
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    • pp.670-674
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    • 2001
  • The electro-optical (EO) performance in the vertical-alignment (VA) - 1/4$\pi$ cell photoaligned with polarized UV exposure on a homeotropic photopolymer surfaces was investigated. Excellent voltage-transmittance curve in the VA - 1/4$\pi$ cell photoaligned with polarized UV exposure for 3 min on the photopolymer containing cholesteryl group of 8% can be achieved. The V-T characteristics in the VA-1/4$\pi$ cell photoaligned on the photopolymer surface can be improved by increasing cholesteryl group. For response time measurement, the transmittance characteristics of the VA-1/4$\pi$ cell photopolymer surface was better than that of the VA-1/4$\pi$ cell rubbingaligned on a polyimide(PI) surface.

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새로운 VA-1/6$\pi$셀 모드를 이용한 광시야각 특성 (Wide Viewing Angle Characteristics Using Novel Vertical-Alignment 1/6$\pi$ Cell Mode)

  • 황정연;서대식;한은주;김재형
    • 한국전기전자재료학회논문지
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    • 제13권10호
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    • pp.883-886
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    • 2000
  • We have developed a novel vertical-alignment(VA) - 1/6$\pi$ mode that provides a wide viewing angle for nematic liquid crystal (NLC) with negative dielectric anisotropy on a homeotropic polyimide (PI) surfaces. Good voltage-transmittance curves were achieved with the new VA - 1/6$\pi$ cell model without a negative compensation film. The viewing angle of a new VA -1/6$\pi$ cell without a negative compensation film was wider than that of a conventional VA cell. Finally, the wide viewing angle using the new VA-1/6$\pi$ cell mode can be achieved.

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EO Characteristic of the In-plane Driven VA Cells on a Polymer Layer

  • Lee Sang-Keuk;Hwang Jeoung-Yeon;Seo Dae-Shik
    • Transactions on Electrical and Electronic Materials
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    • 제4권4호
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    • pp.7-9
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    • 2003
  • Viewing angle characteristics of a nematic liquid crystal (NLC) using a in-plane driven (IPD) vertical alignment (VA) cell without a negative compensation film on a homeotropic alignment layer were studied. Good voltage-transmittance (V - T) curves were obtained using the rubbing aligned IPD- VA cell. However, instability and low transmittances of V - T characteristics in photo aligned IPD- VA cell was measured. The EO performance of a rubbingaligned IPD- VA cell without a negative compensation film was wider than that of photoaligned IPD- VA cell and conventional VA cell. Also, the fabrication processes using the rubbing aligned IPD- VA cell mode be carried out with only one-sided rubbing.

광배향법을 이용한 VA-l/4$\pi$셀의 전기 광학 특성 (Electro-optical Characteristics in the Vortical-Alignment 1/4$\pi$ Cell by photoalignment Method)

  • 이윤건;황정연;서대식;김재형
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.369-372
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    • 2001
  • We studied the electro-optical (EO) performance in the vertical-alignment (VA) - l/4$\pi$ cell photoaligned with polarized UV exposure on a homeotropic photopolymer surfaces. Excellent voltage-transmittance curve in the VA - l/4$\pi$ cell photoaligned with polarized UV exposure for 3 min on the photopolymer containing cholesterol group of 8% can be achieved. The V-T characteristics in the VA-l/4$\pi$ cell photoaligned on the photopolymer surface can be improved by increasing cholesteryl group. For response time measurement, the transmittance characteristics of the VA-l/4$\pi$ cell photoaligned on the photopolymer surface was better than that of the VA-l/4$\pi$ cell rubbingaligned on a polyimide(Pl) surface.

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새로운 PDT-VA 셀을 이용한 시야각 개선에 관한 연구 (A Study on the improvment of viewing angle using a new PDT-VA cell)

  • 황정연;서대식
    • 한국전기전자재료학회논문지
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    • 제13권8호
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    • pp.700-703
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    • 2000
  • We investigated the improvement using a new patterned double twisted(PDT) vertical-alignment(VA) cell mode on a homeotropic alignment layer. Good voltage-transmittance curves for negative dielectric anisotropic nematic liquid crystal (NLC) using a new PDT-VA cell without a negative compensation film were obtained. The viewing angle of a new PDT-VA cell without a negative compensation film was sider than that of a conventional VA cell. Finally a few fabrication processes using a new PDT-VA cell mode can be achieved by only one-side rubbed substrate.

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Poly[N-(phenyl)maleimide]계 광폴리머를 이용한 액정배향효과 (Effects of Liquid Crystal Alignment on the Photopolymer based Poly[N-(phenyl)maleimide])

  • 황정연;서대식;김준영;이재호;김태호
    • 한국전기전자재료학회논문지
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    • 제14권10호
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    • pp.845-849
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    • 2001
  • The new phto-alignment material PMI5CA, poly{N-(phenyl)maleimide-co-3-[4-(pentyloxy) cinamate]porpyl-2-hydroxy-1-methacrylate}, was synthesized and the electro-optical (EO)characteristics in the vertical-aligned(VA) liquid crystal display (LCD) photo-aligned on the photopolymer surface were studied. Excellent Voltage-transmittance(V-T) characteristics in the VA-LCD photoaligned with polarized UV exposure of oblique direction on the pohotopolymer surface for 1 min can be achieve. The transmittance of the VA-LCD photoaligned on the photopolymer surface decreased with increasing UV exposure time. We suggest that decrease of transmittance in the VA-LCD photoaligned on the photopolymer surface is attributed to the dissociation of the ester linkage in the photodimerized cinnamate structure with increasing UV exposure time.

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