• 제목/요약/키워드: nematic LC

검색결과 278건 처리시간 0.024초

Three-Terminal Hybrid-aligned Nematic Liquid Crystal Cell for Fast Turn-off Switching

  • Baek, Jong-In;Kim, Ki-Han;Kim, Jae-Chang;Yoon, Tae-Hoon
    • Journal of Information Display
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    • 제10권1호
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    • pp.16-18
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    • 2009
  • A three-terminal hybrid-aligned nematic liquid crystal (3T-HAN LC) cell capable of fast turn-off switching is proposed in this paper. By employing the relaxation process initiated by an electric-field pulse, a fast turn-off time of less than 1 ms can be obtained through optically hidden relaxation. A low operating voltage and high transmittance were confirmed through simulations and experiments.

Flexible bistable chiral splay nematic display mode using reactive mesogens

  • Bae, Kwang-Soo;Lee, You-Jin;You, Chang-Jae;Kim, Jae-Hoon
    • Journal of Information Display
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    • 제12권4호
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    • pp.195-198
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    • 2011
  • Proposed herein is a flexible bistable chiral splay nematic display mode with an enhanced memory retention time under external distortion. By adopting the polymerized reactive-mesogen structure mixed in a liquid crystal layer, local anchoring energy is generated on the boundary between the polymer structures, and the relaxation from the ${\pi}$-twisted state to the initial splay state could be interrupted. As a result, the memory retention time becomes significantly longer, and the stability against the external distortion is enhanced.

복합 광폴리머 표면을 이용한 광배향 TN 셀의 전기 광학 특성 (Electro-optical Characteristics of the TN Cell Photo-aligned on the Blending Photopolymer Surfaces)

  • 황정연;서대식
    • 한국전기전자재료학회논문지
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    • 제14권7호
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    • pp.600-605
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    • 2001
  • The electro-optical (EO) performances for the twisted-nematic (TN)-liquid crystal display (LCD) photo-aligned with polarized UV exposure on various blending photopolymer surfaces were investigated. Excellent LC alignment and voltage-transmittance (V-T) characteristics for TN-LCD photo-aligned with polarized UV exposure of normal incidence on the blending photopolymer (polyimide (PI) +PM4Ch(poly(4-methacryloyloxy chalcone))) surface containing chalcone group can be achieved. The EO performances for the TN-LCD photo-aligned on the blending photopolymer can be improved due to the photosensitivity by long side chain of the photopolymer.

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양면 전사배향법을 이용한 TN-LCD의 액정배향과 전기광학특성 (Liquid crystal alignment and EO performance of TN-LCD fabricated by transcription alignment method on polymer surface)

  • 서대식;김진호;이창훈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 D
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    • pp.1388-1390
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    • 1998
  • In this paper, we investigated the monodomain alignment of nematic liquid crystal(NLC) in the cell fabricated by transcription alignment method on polyimide(PI) surface with side chain. The LC alignment produced by the transcription alignment method is attributed to a memory effect of the NLC on PI surfaces. We observed that the pretilt angle of NLC is generated about $3.7^{\circ}$ with transcription alignment on PI surface. Also, we obtained the good electro-optical(EO) performance of twisted nematic(TN)-liquid crystal display(LCD) by transcription alignment method on PI surface.

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시야각 조절이 가능한 고개구율 액정 디스플레이 연구 (Study on Viewing angle controllable Liquid Crystal Display with High Aperture Ratio)

  • 신석재;허정화;임영진;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.173-173
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    • 2010
  • We proposed viewing angle switchable liquid crystal display(LCD) associated with fringe-field switching (FFS) mode with high aperture ratio characteristic. In the device, single pixel is separated into two regions, named as main pixel for displaying images and sub pixel for viewing angle control. In sub pixel region, add the common electrode on the top substrate and the initial alignment of liquid crystal is Hybrid Alignment Nematic (HAN) state. In conclusion, we suggested that the device has high aperture ratio characteristic because the LC directors are rotated in which viewing angle control region are generated fringe electric field.

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수평 배향된 양의 액정 내에서의 단일벽 탄소 나노튜브 Stretching 관찰 (Observation of SWCNT Stretching in homogeneously aligned nematic liquid Crystal medium)

  • 양규형;강병균;이승희;이규;이영희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.170-170
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    • 2010
  • In this paper, we observed stretching of single-wall carbon nanotubes (SWCNTs) aggregates driven by the in-plane field in a homogeneously aligned nematic liquid crystal (LC) medium. Aggregates of SWCNTs started to stretch above the 0.5 V/${\mu}m$ and stretched up to $1.83\;{\mu}m$ from original size with $0.74\;{\mu}m$ at 3.5 V/${\mu}m$.

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Washing Effects on Generation of Pretilt Angle in NLC, 5CB, on a Polyimide Surface with Trifluoromethyl Moieties

  • Lee, Sang-Keuk;Hwang, Jeoung-Yeon;Seo, Dae-Shik
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 춘계학술대회 논문집 디스플레이 광소자분야
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    • pp.133-135
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    • 2003
  • The washing effects on pretilt angle generation in a nematic liquid crystal (NLC), 4-n-pentyl-4’-cyanobiphenyl (5CB) on a rubbed polyimide (PI) surface with trifluoromethyl moiety have been successfully studied. The pretilt angle of 5CB is increased by the washing process on the rubbed PI surface. The surface tension on the rubbed PI surface increases with the rubbing strength RS and then saturated above RS=150 mm. The pretilt angle of 5CB for all washing processes on the rubbed PI surface decreases with the surface tension. We have found that the pretilt angle of 5CB on the rubbed PI surface may be attributed van der walls (VDW) dispersion interaction between the LC molecules and the polymer surfaces having trifluoromethyl moieties.

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배향막의 극성에 따른 a-TN-LCD의 전기광학특성에 관한 연구 (A Study on Electro-optical Characteristics of a-TN-LCD with Polarization of Orientation Film)

  • 서대식;이창훈
    • E2M - 전기 전자와 첨단 소재
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    • 제10권10호
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    • pp.1011-1015
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    • 1997
  • In this paper we investigated the electro-optical characteristics of amorphous (a)- twisted nematic (TN)-liquid crystal display(LCD) on polymide (PI) surfaces with different molecular structure. It was found that the domaine size of a-TN-LCD on PI with high polarization is small compared to a-TN-LCD on PI with medium polarization. It is considered that the response time of a-TN-LCd contributes to surface effect between the substrate surfaces and the LC molecules. Finally we obtained that the viewing angle of a-TN-LCD on PI surfaces increases with decreasing the domain size.

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Bistable Property in a Splay Cell with a Chiral Additive

  • Lee, Seo-Hern;Kim, Tae-Jin;Lee, Jong-Lac;Jung, Mi-Jun;Park, Kyoung-Ho;Lee, Gi-Dong;Yoon, Tae-Hoon;Kim, Jae-Chang
    • Journal of Information Display
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    • 제4권3호
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    • pp.22-25
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    • 2003
  • In this paper, we propose the bistability the bistability in a chiral-splay nematic liquid crystal cell, which is obtained by adding a chiral additive to a splay cell and introduce a novel switching method for the bistable chiral-splay nematic cell in order to transit the LC director between the non-twisted state with splay and the 180$^{\circ}$ twist state.

Lateral field effects on the horizontal switching of the bistable chiral splay nematic device

  • Jhun, Chul-Gyu;Kim, Yi-Jun;Min, Kwan-Sik;Shin, Sugn-Sik;Kim, Jae-Chang;Kwon, Soon-Bum
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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    • pp.538-541
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    • 2007
  • In this paper, with a bistable curve of the bistable chiral splay nematic liquid crystal (BCSN LC) device, we clarify how the twist-to-splay transition is achieved under a horizontal field. By a sufficiently high horizontal electric field, the bistable property becomes monostable. The transition can be achieved.

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