• Title/Summary/Keyword: liquid-crystal-display (LCD)

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A General Performance of PSS-LCDs

  • Mochizuki, Akihiro
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.91-96
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    • 2005
  • In this paper, a general performance of the PSS-LCD or Polarization Shielded Smectic Liquid Crystal Display is discussed. This smectic base LCD does not use any spontaneous polarization, but uses induced polarization just same with current nematic base LCDs. Specific initial molecular alignment as well as specific cell design realizes extremely fast optical response speed with native wide viewing angle. Moreover, this performance is provided by full compatible electronics for current conventional LCDs. A general performance of the PSS-LCD is introduced here.

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A Novel Transflective-type LTPS-LCD with Cap-Divided VA-Mode

  • Kang, Seung-Gon;Kim, Seong-Ho;Song, Seock-Cheon;Park, Won-Sang;Yi, Chung;Kim, Chi-Woo;Chung, Kyu-Ha
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.831-833
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    • 2004
  • A novel transflective-type LC mode with good display performance has been developed In order to drive both transmissive and reflective modes simultaneously without any modulation of gamma in a single-gap structure, we have introduced a new design concept in the reflective region, where the capacitance is separated into liquid crystal($C_{LC}$} and organic layer($C_{OL}$), playing a key role as a voltage divider in our cap-divided VA-mode. With this cap-divided method having both merits of simplifying process and good legibility, we have achieved good optical characteristics such as high contrast ratio and wide viewing angle in a single-gap homeotropic panel design.

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EO Characteristics of the Mew MVA-LCD using a Crossed Stripe Grating-Groove Vertical Alignment (CGVA) Layer

  • Lee, Kyung-Jun;Hwang, Jeoung-Yeon;Lee, Sang-Keuk;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07b
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    • pp.999-1002
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    • 2003
  • Electrooptical (EO) characteristics of a new multidomain vertical-alignment (MVA) liquid crystal display (LCD) with negative dielectric anisotropy on a homeotropic photopolymer were studied. Good voltage-transmittance (V-T) curves of the new MVA-LCD on the homeotropic photopolymer were obtained. Also, the stable response time of the new MVA-LCD on the homeotropic photopolymer was achieved. The viewing angle of the new MVA-LCD could be improved by a crossed stripe grating-groove surface as the alignment layer using a photolithograph method on the photopolymer.

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Liquid crystal alignment by photo-dimerization reaction of PCEMA photo polymer (PCEMA 광폴리머의 광중합 작용을 이용한 액정배향)

  • 황정연;서대식
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.541-544
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    • 1999
  • We synthesised a novel photo-alignment material of PCEMA (poly(cinnamolyethyl methacrylate)) on photo-dimerization reaction. Next we investigated the electro-optical (EO) characteristics of photo-aligned twisted nematic (TN)-liquid crystal display (LCD) with linearly polarized ultraviolet (UV) light irradiation on PCEHA surface. The excellent voltage-transmittance characteristics of photo-aligned TN-LCD on PCEMA surface were obtained. The threshold voltage of photo-aligned TN-LCD decreases with increasing the UV light irradiation time on PCEMA surface. Also, the response time of photo-aligned TN-LCD on PCEMA surface is almost the same as rubbing-aligned TN-LCD.

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Effect of Liquid Crystal Alignment for Photo-Aligned VA-LCD on the Photo-Dimerized Polymer Surface

  • Hwang, Jeoung-Yeon;Seo, Dae-Shik
    • Journal of the Optical Society of Korea
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    • v.5 no.1
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    • pp.16-19
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    • 2001
  • A photopolymer, copoly (M4Ch-ChMA), copoly ((4-methacryloyloxy) chalcone-cholesteryl methacrylate), was synthesized in this study. The electro-optical (EO) characteristics for the photo-aligned vertical-alignment (VA)-liquid crystal display (LCD) were investigated. Excellent voltage-transmittance curves for the VA-LCD photo-aligned by polarized UV exposure on the copoly (M4Ch-ChMA) surface were observed. The response time for the photo-aligned VA-LCD decrease with increasing UV exposure time. consequently, the photo-dimerized chalcone moiety increased with increasing UV exposure time, which then contributed to a low response time for the VA-LCD photo-aligned.

Electro-Optical characteristics of Flexible Liquid Crystal Display using Photoploymer Surface (광폴리머 표면을 이용한 플렉서블 액정디스플레이의 전기광학 특성)

  • Choi, Sung-Ho;Hwang, Jeoung-Yeon;Lee, Whee-Won;Kim, Jong-Hwan;Kim, Young-Hwan;Kim, Tae-Ho;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.05a
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    • pp.189-192
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    • 2005
  • We have investigated the EO characteristics generation of pretilt angle for a nematic liquid crystal (NLC) alignment with photoalignment method on three kinds of photopolymer surfaces using polymer substrates. The LC homogeneous alignment were observed on the PMI3CA (N-(phenyl)maleimide with 3-carbon chain cinnamoyl group) and PMIF (N-(phenyl)maleimide including fluoro cinnamoyl group). However, the homeotropic alignment on the PMI5CA(N-(phenyl)maleimide with 5-carbon chain cinnamoyl group) was obtained. Also, EO characteristics of the flexible photoaligned TN-LCD using PMIF surface are better than that of the flexible TN-LCD using PMI3CA surface. Also, the stable EO performances of flexible photoaligned VA-LCD using the PMI5CA surface was observed.

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Viewing angle controllable liquid crystal display using fringe-field switching mode with high aperture ratio characteristic (고투과율 특성을 갖는 FFS 모드의 시야각 스위칭)

  • Kim, Jin-Ho;Her, Jung-Hwa;Chin, Mi-Hyung;Lim, Young-Jin;Jin, Hyun-Suk;Kim, Byeong-Koo;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.06a
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    • pp.32-33
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    • 2009
  • We propose viewing angle switchable liquid crystal display(LCD) associated with fringe-field switching (FFS) mode with high aperture ratio characteristic. This device is composed of R(red), G(green), B(blue), pixel and W(white) pixel in which R,G,B pixel shows image and white pixel for both viewing angle control and image. Conventional viewing angle controllable liquid crystal display has not transmittance because the liquid crystal only tilts up without rotates in viewing angle control region. In this paper, we suggested that the device has high transmittance characteristic because the LC directors are rotated in which viewing angle control region are generated fringe electric field.

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Backlight for Large-area LCD-TVs using Light Emitting Diodes

  • Choi, Jong-Hyun;Chu, Haang-Rhym;Bang, Ju-Young;Park, Hee-Jeong;Hong, Hee-Jung;Lim, Moo-Jong;Oh, Eui-Yeol;Chung, In-Jae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1153-1156
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    • 2005
  • A backlight for large-area LCD (Liquid Crystal Display)-TVs has been developed using Light Emitting Diodes (LEDs). Performances of the backlight and the methods driving the LEDs are introduced in this research. A spectral relationship between the LEDs and the color filters of a panel were investigated as well. In order to realize a CRT like dynamic effect, the area-focused luminance control (AFLC) technology was adopted in developing the backlight. Thus, a possibility of applying the LEDs to the backlight for large-area LCD-TVs was systematically proved.

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Development of Simulator for a Design of LCD Backlight Unit (광추적 기법에 기반한 LCD Backlight UNIT의 모의실험에 관한 연구)

  • 박은철;최준수;강노경;김성철
    • Proceedings of the Korean Information Science Society Conference
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    • 2001.10b
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    • pp.538-540
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    • 2001
  • 현재 사용하는 LCD(Liquid Crystal Display) 장치는 비발광형 LCD장치를 사용하므로 외부광원이 필요하다. 투과형 LCD의 경우는 Panel의 뒷면이나 측면에 전용광원(Backlight unit)을 사용하여 빛을 투과시킴으로서 발광할 수 있도록 하는 방법을 사용한다. 현재는 이러한 투과명을 사용하는 것이 일반화되는 추세로 광원을 LCD전면으로 효율적으로 반사하는 Panel의 뒷면을 설계하는 다양한 방법이 개발되고 있다. 본 논문에서는 최적화된 설계를 위한 모델링 도구(Modeling Tool)와 주어진 광원으로부터 LCD 전면으로 출력되는 광량의 분포를 예측하는 시뮬레이터(Simulator)를 제안한다.

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