• 제목/요약/키워드: liquid crystal display(LCD)

검색결과 760건 처리시간 0.029초

Electro-optical Characteristics of a Multi-domain Vertical-alignment Liquid Crystal Display on Homeotropic Photopolymer Layer

  • Hwang, Jeoung-Yeon;Lee, Kyung-Jun;Seo, Dae-Shik
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.511-513
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    • 2002
  • Electro-optical characteristics of new multi-domain vertical-alignment (MVA) liquid crystal displays (LCDs) with negative dielectric anisotropy on a homeotropic photopolymer were studied. Good voltage-transmittance (V-T) curves by the new MVA-LCD on the homeotropic photo-polymer were obtained. Also, the stable response time of MVA-LCD on the homeotropic photopolymer can be achieved. The viewing angle of the new MVA-LCD could be improved by the grating groove with UV exposure and development on the photo-polymer.

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FFS 모드를 이용한 광시야각 반투과형 액정 디스플레이 (Wide Viewing Angle Transflective Liquid Crystal Display using Fringe-Field Switching Mode)

  • 송제훈;임영진;박지혁;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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    • pp.567-570
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    • 2004
  • We have designed a single gap transflective liquid crystal display (LCD) driven by a fringe electric field, in which the LCs are homogeneously aligned in the initial state. In the reflective and transmissive areas, the degrees of the rotation of the LC director are $22.5^{\circ}$ and $45^{\circ}$, respectively. Utilizing this mechanism and an in-cell retarder with a quarter-wave plate that is used below the LC layer, the transflective LCD using fringe-field switching (FFS) mode is realized.

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Synthesis and Properties of New Aromatic Polyimides for IPS-mode

  • Kim, Y.B.;Park, J.C.;Park, D.J.;Son, K.C.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.792-795
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    • 2006
  • In-plane-switching (IPS)-mode LCD is one of the most useful technologies for a broad range of viewing angles. To apply for IPS-LCDs, we synthesized novel homogeneous alignment materials, changing dianhydrides (BTDA and BPDA) and bridged diamines (ODA and PACM). We measured their pre-tilt angles using the crystal rotation method with positive LC and their surface properties.

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Synthesis of Three Ring Type Compounds with Fluorine and NCS Groups as Candidates for VA mode Liquid Crystal Display

  • Heo, E.Y.;Kim, Y.B.;Kim, S.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.571-574
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    • 2003
  • Three ring type liquid crystalline compounds having 4-alklycyclohexyl group, 1,2-difluorobenzene and phenylisothiocyanate moieties as main skeleton were designed to have negative dielectricity. However, the compounds with 2,3,2'-trifluoro-3'-isothiocyanated biphenylcyclohexane core did not exhibit the nematic liquid crystalline phase because of two conformers by interaction of isothiocyanate and adjacent fluorine atoms. Also, 4-alkyl-2,2',3'-trifluoro-3-isothiocyanated biphenylcyclohexane core was designed expecting to have uniform conformers of isothiocyanate group. In the course of developing polyimides for VA mode LCD, we synthesized alkyl-3,5-diaminobenzene efficiently with various length of alkyl chains from commercially available di-t-butyl malonate and 3,5-dinitrobenzoyl chloride as starting material.

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베레만의 $4{\times}4$행렬방식을 이용한 액정표시소자의 편광투과특성 분석 (A study on the polarization transmission characteristics of liquid crystal display devices by means of Berreman's $4{\times}4$ matrix method)

  • 양병관;김규석;노봉규;김진승;박희갑;박찬;이형종;김재기
    • 한국광학회지
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    • 제8권3호
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    • pp.223-229
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    • 1997
  • 베레만의 4 * 4행렬방정식을 써서 액정판의 편광투과특성을 분석하는 프로그램을 개발하고, 이를 써서 액정셀과 편광판의 편광투과특성을 살펴보았다. 개발된 프로그램을 써서 정상백색 모우드의 꼬인 네마틱(TNLTwisted Nematic) 액정셀에서 시야각에 따른 명암대비의 변화를 보여주는 등고선을 그려내어 그 특성을 예측할 수 있었다. 또한 편광판의 투과특성은 입사각이 커짐에 따라 투과된 빛의 편광타원의 주축이 투과축 방향에서 벗어나며 타원도가 커지는 것이 밝혀졌는데, 이 결과는 액정표시소자의 명암대비가 액정판만이 아니라 편광판의 특성에 의해서도 제한될 수 있음을 시사한다.

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면광원을 사용한 Scanning Backlight System의 설계 및 제작 (Design and Fabrication of Scanning Backlight System using Flat Fluorescent Lamp)

  • 채형준;허정욱;황선남;이준영;임성규
    • 반도체디스플레이기술학회지
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    • 제7권2호
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    • pp.29-33
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    • 2008
  • LCD panels are increasingly used to show moving image material, for example in LCD television sets. However, moving images become blurred on LCD panels. One of the causes of motion blur is the slow reaction of LC(liquid crystal) cell to change in the pixel value. Another cause of motion blur is the hold-type characteristic of the LCD panel, during the frame time the image is shown continuously. This type of motion blur can be reduced with a scanning backlight. We have designed and fabricated a scanning backlight system that solves the hold-type characteristic problem in a way that Flat fluorescent lamp divided 6 blocks was scanned 60Hz.

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Liquid Crystal Alignment Effect on the Inorganic Thin Film by Sputtering and using Ultraviolet Exposure Mothod

  • Hwang, Jeoung-Yeon;Kang, Hyung-Ku;Seo, Dae-Shik;Oh, Byeong-Yun;Ham, Moon-Ho;Myoungr, Jae-Min
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.460-463
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    • 2005
  • We studied the nematic liquid crystal (NLC) alignment capability by the Ultraviolet (UV) alignment method on a a-C:H thin -film , and investigated electro-optical performances of the UV aligned twisted nematic (TN)- liquid crystal display (LCD) with the UV exposure on a-C:H thin film surface. A good LC alignment by UV irradiation on a a-C:H thin -film surface was achieved. Monodomain alignment of the UV aligned TN-LCD can be observed. The good electro-optical (EO)characteristics of the UV aligned TN-LCD was observed with oblique UV exposure on the a-C:H thin film surface for 1min.

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무기박막표면에 DuoPIGatron 이온소스를 이용한 TN-LCD 셀의 전기광학 특성 (EO performance of TN cell on the inorganic films surface using DuoPIGatron ion source on NDLC thin film)

  • 황정연;김병용;김상훈;한정민;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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    • pp.432-433
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    • 2006
  • Electro-optical (EO) characteristics of twisted nematic (TN) - liquid crystal display (LCD) on the NDLC thin film using obliquely ion beam (IB) exposure as new ion beam (IB) type system (DuoPIGatrion ion source). A good uniform alignment of the nematic liquid crystal (NLC) alignment with the ion beam exposure on the NDLC thin film was observed. In addition, it can be achieved the good EO properties of the ion-beam-aligned TN-cell on polyimide surface ; the stable VT curve in the ion-beam-aligned TN cell on the NDLC thin film with ion beam exposure using new type IB equipment was obtained. and the fast response time in the ion-beam-aligned TN cell on the NDLC thin film with ion beam exposure using new type IB equipment was obtained.

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대형 FPD TV 시장에서의 기술 경쟁: LCD와 PDP간 경쟁에 대한 시스템 다이나믹스 방법론의 응용

  • 이경순;김도훈
    • 한국경영정보학회:학술대회논문집
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    • 한국경영정보학회 2008년도 춘계학술대회
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    • pp.557-562
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    • 2008
  • FPD(Flat Panel Display) 시장은 디지털 기술의 발전으로 급속하게 성장하고 있으며, 이는 TV 시장에서도 마찬가지이다. 많은 전문가들은 LCD(Liquid Crystal Display)와 PDP(Plasma Display Panel)의 기술적 차이로 인해 LCD는 소형 크기의 TV에 적합하고, PDP는 대형 TV에 적합할 것이라 예상하고, 이에 따라 FPD TV 시장에 적용되는 기술이 목표시장(target market)에 따라 양분할 것으로 전망하였다. 그러나 LCD 생산기술상의 예상치 못한 급속한 진전은 PDP가 목표로 하는 대화면 TV 시장에서 LCD가 독자적인 틈새시장을 형성하고 이를 점차 확대할 수 있도록 하였다. 이러한 시장 전개 양상은 LCD와 PDP의 경쟁을 심화시키고, 현재 앞에서 전망한 바와 같은 현상은 발견되지 않고 있으며, 오히려 대화면 TV 시장에서조차 LCD가 우위에 있음을 보여주는 사례가 많다. 본 연구에서는 LCD가 PDP와의 기술적 격차를 줄이고, 결과적으로 LCD와 PDP간 경계를 무너뜨린 보다 근원적인 원인을 분석한다. 특히 이러한 잠재적 메커니즘을 시스템 다이나믹스 방법론을 도입하여 분석한다. 특히 PDP에 대하여 점진적으로 LCD가 우위를 확보하게 되는 피드백 루프들을 밝혀 내고자 한다. 그리고 이러한 피드백 루프 중에서 가장 효과가 큰 메커니즘을 찾아낸다.

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Low Cost, High Performance, and Effective Overdrive Implementation Method for LCD Systems

  • Cho, Young-Min;Park, Chan-Soo;Bhowmik, Achintya;Lee, Seung-Woo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.1168-1171
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    • 2009
  • We propose a low cost, high performance, effective overdrive implementation method for liquid crystal display systems. The technique can calculate all overdrive values using higher order approximation algorithm by only three measurements. We find that our technique can be applied regardless of LCD panels. Due to its simplicity, we can also tune motion performance of the LCD systems without measurements.

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