• 제목/요약/키워드: Liquid Crystal Alignment

검색결과 493건 처리시간 0.025초

Optical Compensation Effects Induced by Dielectric Surface Gratings for Wide-Viewing Liquid Crystal Displays

  • Yoon, Tae-Young;Park, Jae-Hong;Jeong, Cherl-Hyun;Kim, Sung-Jin;Lee, Sin-Doo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.563-566
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    • 2003
  • We present wide-viewing characteristics of a twisted nematic liquid crystal display (TN LCD) achieved by adopting dielectric surface gratings (DSGs) as alignment layers. The experimental data and the numerical analyses consistently show that the optical compensation effect inherent to the TN LCD with the DSGs greatly reduces the contrast inversion of the TN LCD.

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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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폴리이미드 표면을 이용한 플라스틱 STN 셀의 전기 광학 특성 (Electro-Optical Characteristics of Plastic STN Cell on the Polyimide Surface)

  • 김종환;김강우;황정연;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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    • pp.1086-1089
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    • 2003
  • We investigated the electro-optical (EO) performances of the super twisted nematic liquid crystal display (STN-LCD) on the polyimide (PI) surface using polymer film. Monodomain alignment of the plastic STN-LCD can be observed. A stable voltage-transmittance (V-T) curve of the plastic STN-LCD was observed on the polyimide (PI) surfaces using polymer film. Also, a faster response time for the plastic STN-LCD on the polyimide (PI) surfaces using polymer film can be achieved. Therefore, the EO performances of the plastic STN-LCD on the polyimide (PI) surfaces using polymer film is almost the same as that of the glass STN-LCD on a polyimide (PI) surface.

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광배향을 이용한 플렉시블 STN 셀의 전기 광학 특성 (Electro-Optical Characteristics of Plastic STN Cell using photoalignment method)

  • 배유한;황정연;김종환;남기형;이휘원;김강우;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.1007-1009
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    • 2004
  • We investigated the electro-optical(EO) performances of the super twisted nematic liquid crystal display(STN-LCD) on the polyimide(PI) surface with polymer film using rubbing and photoalignment method. Monodomain alignment of the plastic STN-LCD can be observed. A faster response time for the photoaligned plastic STN-LCD on the polyimide(PI) surfaces can be achieved than rubbingaligned plastic STN-LCD.

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고내열성 광폴리머 표면을 이용한 광배향 TN 셀의 전기광학 특성의 연구 (Study of Electro-Optical Characteristics on Photoalignment TN Cell using a High Thermal Photopolymer)

  • 이휘원;황정연;남기형;이면길;서동학;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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    • pp.210-213
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    • 2004
  • We synthesized photoalignment material of high thermal resistance with hydroxyl aromatic polyimide, and studied the liquid crystal (LC) aligning capabilities on the photopolymer layers. Also, electro-optical (EO) performances for the twisted-nematic (TN)-liquid crystal display (LCD) photoaligned with linearly polarized UV exposure were investigated. A good LC alignment with UV exposure on the photopolymer surface can be obtained. However, the low pretilt angles were obtained below $1^{\circ}$. The Voltage-transmittance (V-T) curve without backflow bounce in the photoaligned TN cell with UV exposure was observed. The response time of photoaligned TN cell was measured about 24 ms. Finally, The photoaligned TN cell has few hysteresis, and shows the residual DC voltage that is less.

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편광 흡수성 광기전성 고분자 박막 연구 (Polarizing Photovoltaic Polymer Films for Reflective Solar-LCDs)

  • 김영찬;허윤호;박병주
    • 한국전기전자재료학회논문지
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    • 제25권7호
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    • pp.525-530
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    • 2012
  • We present the results of a study of the polarizing photovoltaic (PV) effects in an aligned polymer bulk heterojuction PV layer. The fairly uniform in-plane uniaxial alignment of the PV layer with a macroscopic axial orientational order parameter of 0.40 was achieved by means of a simple rubbing technique. Moreover, reflective polarizing PSCs having the aligned PV layers were applied to power-generating reflective type liquid crystal displays (LCDs), which exhibited a maximum contrast ratio of 1.7. These results form a promising foundation for various energy harvesting polarization dependent opto-electrical LCD device applications.

Optimization of Transflective PVA Cell Structure for High Resolution Display

  • Baek, Jong-In;Park, Sung-Jin;Jhun, Chul-Gyu;Kim, Jae-Chang;Yoon, Tae-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.403-406
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    • 2005
  • We optimized a patterned-vertical-alignment (PVA) transflective liquid-crystal (LC) cell for small pixel application. To achieve the high resolution display performance in the mobile communication equipments such as mobile phones, personal data assistants, and tablet personal computers, we optimized the parameters of liquid crystal and the electrode structure. Both the transmittance and the reflectance are maximized at the same time.

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Basic Principle for Determining Azimuthal Anchoring Strength by using HAN/TN Two Domain Liquid Crystal Cell

  • Tanaka, Norihiko;Kimura, Munehiro;Akahane, Tadashi
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.324-327
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    • 2005
  • We propose a novel technique for evaluating the azimuthal anchoring strength of the alignment film on the nematic liquid crystal (LC). In our evaluation, a unique cell, which has two domain in one cell, was used; one is hybrid aligned nematic (HAN) region, the other is twsited nematic (TN) region (viz. HAN/TN two domain cell). From the comparison of director angles on the front substrate with each region, we are able to determine the angle between easy axis and real director axis on the front substrate. From this evaluation, the azimuthal anchoring strength was obtained accurately.

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High Speed Displays Based on a Nonchiral Smectic C Liquid Crystal in an Antiparallel Planar Geometry

  • Jeong, Cherl-Hyun;Na, Jun-Hee;Yoon, Tae-Young;Yu, Chang-Jae;Lee, Sin-Doo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.571-574
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    • 2005
  • We demonstrated a high speed liquid crystal (LC) display mode based on a nonchiral smectic C LC in an antiparallel planar geometry. In this antiparallel planar nonchiral smectic C (APNSC) LC mode, analog gray scales and wide viewing properties are achieved using a stepwise thermal annealing process (STAP). Because of an initially stable LC alignment in large area through the STAP, the APNSC LC mode exhibits the characteristics of fast response and high contrast ratio. This new APNSC mode is suitable for processing the dynamic image at a video rate in the next-generation LCDs.

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광경화성 단분자를 이용한 Z-shape PVA 모드에서의 투과율 향상에 관한 연구 (Electro-optical characteristics of PVA (Z-shape) mode using the UV curable reactive mesogen (RM))

  • 조인영;황성진;김성민;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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    • pp.437-438
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    • 2008
  • The Conventional patterned vertical alignment (PVA) device shows a very high contrast ratio at normal direction and does not require rubbing process. However it has a disclination area in which the liquid crystal can be collision in the boundary domain region. In this paper, we studied PVA(Z-shape) device in which the liquid crystal can be tilted down in multiple directions stably because the surface pretilt angle is controlled by photopolymerization of the UV - curable reactive mesogen (RM) under a proper condition. Consequently, the device shows improved electro optical properties as compared to conventional PVA mode.

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