• 제목/요약/키워드: LC (Liquid crystal)

검색결과 589건 처리시간 0.026초

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.

양의 액정을 이용한 Fringe Field Switching mode의 전기-광학 특성 연구 (Study on electro-optic characteristics of FFS mode using a positive LC)

  • 우창우;하경수;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.171-171
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    • 2010
  • Electro-optic characteristics of liquid crystal display using fringe field switching(FFS) device depend on many parameters such as cell retardation, electrode structure, rubbing angle, cell gap and dielectric anisotropy. In this paper, the light efficiency of FFS mode will be analyzed to confirm the electro-optic characteristics according to positive dielectric anisotropy such as transmittance, operating voltage and response time.

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High Performance OCB Panel Driven less than 5V for Multi-media Application

  • Chang, H.S.;Lee, C.H.;Ryu, J.J.;Kim, M.S.;Ahn, S.H.;Kim, K.H.;Kim, S.S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.914-917
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    • 2002
  • We have obtained high performance and low voltage driving OCB panel by reducing the critical voltage and retardation matching between liquid crystal layer and compensation films. The critical voltage in the panel has been minimized by flattening color filter layer and optimizing a rubbing process. In addition, an appropriate retardation of the film and LC layer has scanned to achieve low driving voltage and high transmission. The proto-type 17" WXGA OCB panel has demonstrated with less than 5V drive and over 80 degree for all viewing direction except for rubbing direction with over 90% of TN light efficiency.

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Numerical Analysis of One Drop Filling Process with Photo-definable Spacer

  • Lee, Woo-Shik;Yoo, Gi-Chun;Jeon, Baek-Kyun;Kim, Choong-Sik;Kim, Ki-Taek
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.500-503
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    • 2002
  • In this paper, we demonstrate the deformation of TFT-LCD panel using numerical analysis based on the finite element method. To make better uniform cell gap and less stress at a photo-definable spacer (spacer), we have investigated process and design factors such as amount of liquid crystal (LC), spacer density, area, height, and material property. Furthermore we optimized design factors and achieved the robust design through the simulation.

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Design of the OCB mode for the Wide Viewing Angle LCD

  • Noh, Jeong-Dong;Lee, Gi-Dong;Yoon, Tae-Hoon;Kim, Jae-Chang
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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    • pp.47-48
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    • 2000
  • Parameters of a biaxial compensation film and a liquid crystal cell for the optically compensated bend mode LCD with wide viewing angle were optimized. For practical approach, we calculated the optical refractive indices of a retardation film when thickness of a retardation film was fixed at 50 ${\mu}m$. Furthermore, we also optimized optical parameters of LC cell when parameters of a retardation film were different with designed values, because the biaxial compensation film with exact designed values was very difficult to fabricate. In experiments, we achieved the wide viewing angle of over the ${\pm}$ 60 degrees by using a biaxial compensation film with a practical thickness value.

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Stamping Method for Fabrication of Flexible Liquid Crystal Display

  • Jang, Se-Jin;Jin, Min-Young;Kim, Hak-Rin;Lee, You-Jin;Kim, Jae-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.374-377
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    • 2005
  • We proposed a new fabrication method for stable flexible LCDs using stamping method with durable elastomer such as poly(dimethylsiloxane) (PDMS). In the device, the LC molecules are isolated in pixels where LCs are surrounded by PDMS microstructure, and two substrates are tightly attached by phase separated polymer layer. The electro-optic characteristics of our cell are comparable to those of normal sample without PDMS microstructure. We propose cost-effective roll-to-roll process for large size of plastic LCDs with our method.

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FFS 모드에서 표면 엥커링에너지에 따른 전기광학특성의 연구 (A Study on Electro-optical Characteristics Dependent on Surface Anchoring Energy in the Fringe-field Switching Mode)

  • 유인호;총첸신;장원근;이명훈;이승희
    • 한국전기전자재료학회논문지
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    • 제18권11호
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    • pp.1028-1032
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    • 2005
  • Liquid crystal (LC) alignment using a photoalignment method by irradiation of polarized ultraviolet (UV) on an alignment layer has been investigated. Photoalignment method exhibits weaker anchoring energy than rubbing method so that we have studied electro-optic characteristics of fringe-field switching (FFS) mode with alignment layers using the photo and rubbing alignment methods. The cell using photo alignment layer shows lower threshold and operation voltage than those using rubbed alignment layer. Also, the former method shows higher transmittance than that of the latter.

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.

Advanced LCD modes through surface modification using reactive mesogen mixed with alignment layers

  • Lee, You-Jin;Kim, Young-Ki;Jo, Soo-In;Yu, Chang-Jae;Kim, Jae-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.91-94
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    • 2009
  • We propose advanced liquid crystal display (LCD) modes through surface modification using UV curable reactive mesogen (RM) mixed with alignment layers. The LC directors on the modified alignment layer are controlled and memorized by the polymerized RMs under an applied voltage. Using the method proposed here, we can improve the response time and viewing angle characteristics through surface controlled patterned vertical alignment (SC-PVA) mode and 8-domains PVA mode, respectively. Also, we found that the method can be applicable to fabricate multi-domain structures using multiple UV exposure as same as conventional UV alignment method.

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Dual mode LCD with dynamic mode of horizontal switching

  • Lee, Joong-Ha;Lee, Seong-Ryong;Kim, Tae-Hyung;Jhun, Chul-Gyu;Yoon, Tae-Hoon;Kim, Jae-Chang
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.215-217
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    • 2009
  • The authors propose a novel dual mode liquid crystal display (LCD) which has both dynamic and memory operating LCD modes. The mode uses a horizontal switching and bistable chiral splay nematic (BCSN) LCD. The proposed dual mode does not require pixeldivision and has a higher aperture ratio and resolution than the previously proposed dual mode. Experimental results of the memory and dynamic mode show a high contrast ratio of over 100:1.

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