• 제목/요약/키워드: Liquid Crystal Alignment

검색결과 493건 처리시간 0.029초

Flexible Ferroelectric Liquid Crystal Display Devices Using Thin Plastic Substrates Fastened by Polymer Walls and Networks

  • Sato, Hiroto;Fujikake, Hideo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.305-308
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    • 2003
  • We fabricated a flexible ferroelectric liquid crystal (FLC) device containing polymer walls and networks which fix plastic film substrates. The device using 100-${\mu}m$-thick substrates could be bent in a radius of 7mm without disordering the FLC alignment. When sandwiched between polarizers a roll-up display with high-speed grayscale capability for moving-image displays was created.

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Liquid Crystal Technologies for All Organic Displays

  • Lee, Sin-Doo;Yu, Chang-Jae;Choi, Jong-Sun
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.299-304
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    • 2003
  • We discuss several key technologies of liquid crystal displays (LCDs) that share common features of all organic displays (AODs). An overview of the morphological effects associated with molecular ordering at interfaces on the Crystallinity and the carrier mobility in organic thin film transistors (OTFTs) is given from the viewpoint of the alignment mechanism for LCDs. Recent progress of improving the carrier mobility in the OTFTs is also reviewed.

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Wide-Viewing Characteristics of Self-Formed Micro-Domains in a Liquid Crystal Display with Dielectric Surface Gratings

  • Yoon, Tae-Young;Park, Jae-Hong;Yu, Chang-Jae;Lee, Sin-Doo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.452-455
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    • 2002
  • We demonstrate the wide-viewing characteristics of a twisted nematic liquid crystal display (LCD) with self-formed micro-domains through the topographical alignment and fringe field effects of dielectric surface gratings (DSG). The mutual optical compensation between micro-domains within each pixel eliminates the contrast inversion phenomenon of TN mode without complex surface treatments.

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Development of Low Anchoring Strength Liquid Crystal Mixtures for Bistable Nematic Displays

  • Stoenescu, D.;Lamarque-Forget, S.;Joly, S.;Dubois, J.C.;Martinot-Lagarde, Ph.;Dozov, I.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.97-100
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    • 2005
  • The recent Bistable Nematic ($BiNem{(R)}$) LCD technology presents long term bistability, high level passive matrix multiplexing and high optical quality. The BiNem device, based on anchoring breaking, needs specific low anchoring strength materials - alignment layers and liquid crystal mixtures. We present here our approach to develop nematic mixtures with wide enough temperature range and low zenithal anchoring energy.

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Single-Crystal Poly(3,4-ethylenedioxythiopene) Nanowires as Electrodes for Field-Effect Transistors

  • 조보람;성명모
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.637-637
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    • 2013
  • We develop single-crystal poly(3,4-ethylenedioxythiopene nanowires using liquid-bridge-mediated nanotransfer printing via vapor phase polymerization. This direct printing method can simultaneously enable the synthesis, alignment and patterning of the nanowires from molecular ink solutions. Twoor three-dimensional complex structures of various single-crystal organic nanowires were directly fabricated over a large area using many types of molecular inks. This method is capable of generating several optoelectronic devices. LB-nTM is based on the direct transfer of various materials from a mold to a substrate via a liquid bridge between them. To demonstrate its usefulness, we used LB-nTM to fabricate nanowire field-effect transistors and arrays of 6,13-bis (triisopropyl- silylethynyl) pentacene (TIPS-PEN) nanowire field-effect transistors.

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Liquid-Crystal-on-Silicon 소자에서 액정의 프리틸트각에 따른 Disclination Line 발생 (Generation of Disclination Line Dependent on Liquid Crystal's Pretilt Angle in Liquid-Crystal-on-Silicon Devices)

  • 정태봉;오세태;이승희
    • 한국전기전자재료학회논문지
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    • 제16권4호
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    • pp.322-329
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    • 2003
  • We have studied how surface pretilt angle affects generation of disclination line in liquid-crystal-on silicon cells for 45$^{\circ}$-twisted nematic (TN) and vertical alignment (VA) modes with pixel size of 15$\mu\textrm{m}$. Our studies show that when the pretilt angle is increased from 0$^{\circ}$to 3$^{\circ}$ in the 45$^{\circ}$-TN cell, the disclination line at left side of on-pixel becomes weak and is well suppressed with $\theta$$\_$p/=3$^{\circ}$ although the pixel size Is decreased. In the VA cell, when the pretilt angle is decreased from 89$^{\circ}$ to 86$^{\circ}$, the disclination line at right side of the on-pixel is suppressed well and even for a smaller pixel size, it does not exist when $\theta$$\_$p/=86$^{\circ}$. The results inform that the pretilt angle strongly affects the image quality of microdisplays.

Multimode Configuration Doped with a Chiral Agent for Transflective Liquid Crystal Display with a Single Cell Gap

  • Yu, Chang-Jae;Kim, Jin-Yool;Kim, Dong-Woo;Lee, Sin-Doo
    • Journal of Information Display
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    • 제5권3호
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    • pp.8-13
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    • 2004
  • We demonstrate a transflective liquid crystal display (LCD), doped with a chiral agent to produce a low helical twisting power, in a multimode configuration consisting of the homogeneous alignment and the hybrid alignment. The multimode transflective LCD with a single cell gap was fabricated using a single-step photoalignment technique with a self-masking process of an array of metal reflectors in the reflective region. In our configuration, the electro-optical disparity between the transmissive region and the reflective region was found to be significantly reduced by the low helical twisting power of the chiral dopant.

Effect of the Electrode Edge on the Viewing Angle Property of a Patterned Vertical Alignment Liquid Crystal Cell

  • Choi, Jung-Min;Ji, Seung-Hoon;Lee, Gi-Dong
    • Journal of Information Display
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    • 제9권4호
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    • pp.1-5
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    • 2008
  • This paper investigates the effect of the electrode edge of a patterned vertical alignment (PVA) liquid crystal (LC) device on the viewing angle characteristics. In general, a transmissive LCD applies an LC layer with half-wave retardation for a bright state and with zero retardation for a dark state. The retardation of the LC layer would be distorted in each point, however, when a voltage is applied because of the non-uniform voltage distribution in the electrode edge effect. In this paper, the feasibility of the full effect of the electrode edge on the viewing angle property is considered, and the optical viewing angles of the VA LCD with a uniform half-wave LC layer and the PVA LCD with a practical non-uniform LC layer are compared.

폴리이미드막표면위에 경사진 자외선 조사를 이용한 액정셀에서의 고프리틸트각의 발생 (Generation of High Pretilt Angle in a Cell with Oblique non-polarized UV Light Irradiation on Polyimide Surface)

  • 서대식;한정민
    • 한국전기전자재료학회논문지
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    • 제11권6호
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    • pp.481-485
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    • 1998
  • We investigated the generation of high pretilt angle for nematic liquid crystal (NLC) in a cell with obilique non-polarized ultraviolet (UV) light irradiation on mixtured polyimide surface. It was found that the monodomain alignment of NLC is obtained with an angle of incidence of 75∼85 degrees on PI surface. We consider that the monodomain alignment of NLC is attributed to anisotropic dispersion force effect to photo-depolymerization of polymer. We successfully observed that the pretilt angle of NLC is generated above 5 degree with an angle of incidence of 75∼85 degrees. It is considered that the pretilt angle generation NLC is attributed to interaction between the LC molecules and the polymer surfaces.

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Optical Compensation in a Vertical Alignment Liquid Crystal Cell for Elimination of the Off-Axis Light Leakage

  • Ji, Seung-Hoon;Choi, Jung-Min;Lee, Gi-Dong
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1580-1583
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    • 2008
  • We propose an optical configuration for a vertical alignment (VA) liquid crystal (LC) cell to eliminate the off-axis light leakage in the dark state. The proposed compensation configuration consists of a positive A-film, a positive C-film and a negative C-film. The optical design is performed on a Poincar$\acute{e}$ sphere. This configuration has a better tolerance to the wavelength dispersion, as the polarization trace could self-compensate it. From calculations, we show that the proposed VA LC cell can improve the viewing angle characteristics by compensating for the light leakage in the diagonal direction.

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