• 제목/요약/키워드: Liquid crystal displays(LCD)

검색결과 121건 처리시간 0.027초

Dielecrtric and Voltage Holding Properties of the Half-V-shaped Switching Ferroelectric Liquid Crystal Mode Driven by Active Matrix

  • Choi, Suk-Won;Kim, Hong-Chul;Jeong, Woo-Nam;Seo, Chang-Ryong
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.1121-1124
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    • 2003
  • For high quality displays, analog responding liquid crystals with spontaneous polarization ($P_{s}$) need to be coupled with active matrix driving schemes. We have characterized the half-V-shaped switching ferroelectric liquid crystal mode (half-V FLC mode) in terms of dielectiric and voltage holding properties. Research on these switching properties provided us with the technology for switching half-V FLC mode FLCs by using amorphous silicon TFTs.

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Optical Configurations for an Achromatic Transflective Liquid Crystal Cell

  • Lee, Gak-Seok;Kim, Jae-Chang;Yoon, Tae-Hoon;Kim, Young-Sik;Kang, Tae-Hoon;Kang, In-Byeong
    • Journal of Information Display
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    • 제7권1호
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    • pp.19-24
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    • 2006
  • We propose optical configurations of a double-cellgap liquid crystal cell for transflective displays with wide viewing angle and high contrast ratio. The reflective part is designed in the wide-band quarter wave structure to achieve good dark state. For the transmissive part, the compensation method is applied to achieve the super-achromatic dark state, and three switching methods are used : which are vertical switching, horizontal switching to $30^{\circ}$and horizontal switching to $120^{\circ}$, to achieve the bright state.

Optically isotropic liquid crystal composite incorporating with in-plane electric field geometry

  • Yamamoto, Shin-Ichi;Haseba, Yasuhiro;Iwata, Takashi;Higuchi, Hiroki;Choi, Suk-Won;Kikuchi, Hirotsugu
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.1593-1595
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    • 2009
  • We demonstrate an intriguing liquid crystal display (LCD) mode that comprises an optically isotropic liquid crystal (LC) composite incorporating with inplane electric field geometry. No surface treatment, such as rubbing, is required to fabricate the LCD mode because it is based on an optically isotropic state. The measured response time was of submillisecond order. The LCD mode has several unique features such as fast response, continuous grayscale capability, and a high contrast ratio.

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Azo-Dyes Photo-Aligning; Physics and Applications

  • Chigrinov, V.G.;Kwok, H.S.;Takada, Hirokazu;Takatsu, Haruyoshi
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.759-763
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    • 2005
  • This review presents the status of our research in liquid crystal display (LCD) photo-aligning. We present the basic mechanisms of the photo-induced order in various photo-aligning materials and in azo-dye layers in particular and show that photo-aligning methods can provide a controllable pretilt angle and anchoring energy of the liquid crystal cell, as well as its high thermo and UV stability. The photo-aligning of various types of liquid crystal displays is also discussed.

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Modified Half-V Switching Ferroelectric Liquid Crystal Displays (FLCDs) for Quasi Impulsive Driving

  • Choi, Suk-Won;Kim, Hong-Chul;Yoon, Sung-Hoe
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.571-574
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    • 2002
  • We propose modified concept that enables LCDs quasi-impulsive operations, and demonstrated a prototype AM-LCD that is suitable for displaying moving pictures combined with '2-Domain Half-V shaped switching mode' FLCD.

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폐 중형 (40인치와 42인치) LCD (Liquid Crystal Display) 제품 해체 후 분리된 유가자원에 대한 분석 (Analysis for Valuable Materials Disassembled from 40- and 42-inched Waste LCDs (Liquid Crystal Displays))

  • 박헌수;김용;홍현선
    • 자원리싸이클링
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    • 제25권2호
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    • pp.42-48
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    • 2016
  • 국내 전자 디스플레이 산업의 고도화된 기술과 평판 디스플레이 제품의 글로벌 점유율은 세계 최고 수준이지만 사용 후 버려지는 폐 디스플레이 제품에 대한 재활용 기술 및 재활용 현황은 아직 글로벌 리더 수준에는 못 미치고 있다. 평판 디스플레이 제품의 짧은 순환주기를 고려할 때, 폐 디스플레이 제품의 재자원화는 전 세계적으로 경제와 환경측면에서 이슈가 되고 있다. 본 연구는 향후 폐 LCD (Liquid Crystal Display) 제품 재활용 플랜트에서 활용할 수 있는 재자원화 데이터베이스를 구축하기 위한 기초연구로 40인치와 42인치 크기의 폐 LCD 제품의 분리해체 방법과 해체 모듈과 부품에서 회수 가능한 유용자원의 종류와 구성비를 분석하였다. 폐 LCD 해체 분석결과를 보면 무게비로 플라스틱은 약 22%, PCB (Print Circuit Board)는 약 9%, 패널부는 약 34%, 이 외 금속류를 포함한 기타는 약 35%의 구성비를 가지고 있었다. 본 연구에서 얻어진 폐 LCD 데이터베이스는 폐 제품의 재활용률 향상은 물론 효율적 재자원화를 통한 경제적 해체 공정 시스템을 구축하는데 기여할 것으로 판단된다.

LCD의 Leakage 현상을 고려한 색재현 (Color Reproduction Based on Leakage Effect of LCD)

  • 허태욱;이상훈;한찬호;송규익
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 추계종합학술대회 논문집(4)
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    • pp.243-246
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    • 2000
  • Recently, PC monitor users have been replacing cathode ray tubes (CRT) with liquid crystal displays (LCD). But the chromaticity of the primaries are dependent on RGB input signals. And the colorimetry of LCD changes with gray scale and has a poor peformance in color reproduction. In this paper we propose the enhanced algorithm of color reproduction considering color leakage error and black subpixel error in LCD. In order to test peformance of this algorithm we use the colors of Macbeth colorcheck. As a result of experiments, it was confirmed that the color difference of the LCD using the proposed algorithm was considerably reduced.

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Energy Reduction in LCD Displays

  • Liu, Tao;O'Neill, Mark;Hoffman, Kevin M.;Sanford, Quinn D.;Serres, Alan M.;Schiller, Robert
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.780-783
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    • 2008
  • Low-loss optical films can be used in LCD backlights to improve the display efficiency. Improvements can be used to enhance display performance, increase functionality and reduce energy costs.

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반사형 LCD의 광학설계 (Optical Configurations for a Reflective LCD)

  • Yoon, Tae-Hoon;Lee, Gi-Dong;Kim, Jae-Chang
    • 한국광학회:학술대회논문집
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    • 한국광학회 2001년도 제12회 정기총회 및 01년도 동계학술발표회
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    • pp.127-134
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    • 2001
  • With the increasing demands for hand-held devices with lightweight and low-power-consumption displays, the role of reflective liquid crystal displays (LCDs) is becoming more and more important. Especially, the single polarizer mode is considered as a suitable structure for reflective LCDs because it can provide high brightness. However, the single-polarizer LCDs have demerit in that the contrast is lower than double-polarizer LCDs because of the light leakage in thedark state. (omitted)

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Temperature Dependence of the Electro-optic Characteristics in the Liquid Crystal Display Switching Modes

  • Jeon, Eun-Jeong;Srivastava, Anoop Kumar;Kim, Mi-Young;Jeong, Kwang-Un;Choi, Jeong-Min;Lee, Gi-Dong;Lee, Seung-Hee
    • Journal of Information Display
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    • 제10권4호
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    • pp.175-179
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    • 2009
  • As the physical properties of nematic liquid crystals vary with respect to temperature, the performances of liquid crystal displays (LCDs) are highly dependent on temperature. Additionally, it is well known that the electro-optic characteristics of LCDs, such as transmittance and threshold voltage, also rely on the LCD switching modes. The temperature dependence of the electro-optic characteristics of the wide-viewing-angle LCD modes, such as in-plane switching (IPS), multidomain vertical alignment by patterned electrode (PVA), and fringe-field switching (FFS), have been studied, and the results showed that the FFS mode has lower temperature dependence compared to the IPS and PVA modes. Since the liquid crystal (LC) reorients in different ways in each mode, this result is associated with the temperature dependence of LC's bend and twist elastic constants, and also with the position of the main reorientation, either in the middle or on the surface of the LC layer.