• 제목/요약/키워드: Liquid crystal device

검색결과 250건 처리시간 0.036초

수직배향 액정 디스플레이의 시야각 스위칭 (Viewing Angle Switching of Vertical Alignment Liquid Crystal Display)

  • 임영진;정은;최민오;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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    • pp.49-50
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    • 2006
  • We have developed vertical alignment liquid crystal display (VA-LCD), of which the viewing angle can be controlled. The VA-LCD has the function of switching between the wide viewing mode and narrow viewing angle mode using one homogeneous aligned (HA) LC layer and one compensation film with a negative C-plate. The retardation of the HA layer at off axis can be controlled by applying an electric field while keeping the retardation value to be zero at normal direction. Consequently, the device exhibits a viewing mode over $170^{\circ}$ in terms of CR = 10 in wide viewing mode and about $60^{\circ}$ in terms of CR = 2 in narrow viewing angle mode m horizontal direction.

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Development of Low Anchoring Strength Liquid Crystal Mixtures for Bistable Nematic Displays

  • Dozov, Ivan;Stoenescu, Daniel-Nicusor;Lamarque-Forget, Sandrine;Joly, Stephane;Dubois, Jean-Claude;Martinot-Lagarde, Philippe
    • Journal of Information Display
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    • 제6권3호
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    • pp.1-5
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    • 2005
  • The recent Bistable Nematic ($BiNem^{(R)}$) LCD technology presents long term bistability, high level passive matrix multiplexing, gray levels capabilities and high optical quality. The $BiNem^{(R)}$ device, based on anchoring breaking, needs specific low anchoring strength materials - alignment layers and liquid crystal mixtures. We present here our approach to develop nematic mixtures with wide enough temperature range and low zenithal anchoring energy.

Effect of the Surface Dielectric Layer on the Electro-Optical Performances of Liquid Crystal Devices

  • Park, Jae-Hong;Jung, Min-Sik;Lee, Sin-Doo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.543-546
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    • 2003
  • We studied the dielectric layer effect on the electro-optical (EO) properties of liquid crystal (LC) devices together with numerical simulations. Recently, it has been reported that the surface dielectric layer affects significantly the EO performances of LC microlens arrays and wide-viewing LC displays. it is found that the operation voltage of the LC device decreases with increasing the dielectric constant or with decreasing the thickness of the dielectric polymer layer. The experimental data agree well with theoretical results predicted in a simple dielectric model within the continuum formalism.

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의료용 초박막 액정의 광배향 제어와 광변위 전류 특성 (Properties of Photo-regulation of Liquid Crystal Alignment and Generation of Maxwell-displacement-current for Application with a Medical Engineering Device)

  • 이호식;안준호;김우연;;이원재
    • 한국전기전자재료학회논문지
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    • 제19권12호
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    • pp.1160-1166
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    • 2006
  • Maxwell-displacement-current (MDC) measuring technique has been applied for the investigation of monolayers of poly(vinyl alcohol)s bearing azobenzene side-chains (6Az5PVA) mixed with p-pentyl-p'-cyano-biphenyls (5CBs) on a water surface. For mixed monolayers containing trans-form 6Az5PVA and LCs, displacement current due to photo isomerization was not generated with alternative photo-irradiation with UV and svisible light. In contrast, for mixed monolaters containing cis-form 6Az5PVA and LCs, displacement current was generated. Finally, it was found that the alignment layers deposited in cis-form could photoregualte the orientation of LCs.

프린지 필드에 의해 구동되는 수직 배향된 광학적 자기 보상 스플레이 액정 소자 (Liquid Crystal Device Associated with Fringe-field Driven Vertically Aligned Optically Compensated Splay (OCS))

  • 정병선;김승재;오상민;김향율;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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    • pp.157-160
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    • 2004
  • We have studied an optically compensated splay (OCS) mode driven by fringe electric field. The OCS LC configuration obtained by applying voltage to vertically aligned LCs shows a dark state when an optic axis of the OCS cell coincides with one of crossed polarizer axis. When the fringe electric field is applied, the LC director rotates in plane above whole electrode surface, giving rise to high transmittance and wide viewing angle simultaneously.

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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.

MIM(Metal-Insulator-Metal)구조의 LCD(Liquid Crystal Display)소자 특성 연구 (A Study on the LCD(Liquid Crystal Display) Device which have MIM (Meta1-lnsulator- Meta1) Structure)

  • 최광남;이명재;곽성관;정관수;김동식
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 하계종합학술대회 논문집(2)
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    • pp.209-212
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    • 2001
  • High quality Taros thin films have been obtained from anodizing. The as-deposited amorphous films have excellent physical and electrical properties: refractive indices ~2.15, dielectric constants ~25, and leakage currents <10$^{-8}$ Ac $m^{-2}$ at 1MV $cm^{-1}$ , 700$\AA$ thickness. We fabricated a MIM element with theses T $a_2$ $O_{5}$ films which had perfect current-voltage symmetry characteristics using a new process technology which was post annealing of whole MIM element instead of conventional annealing conditions (top-electrode metals, annealing conditions) on the capacitor performances were extensively discussed throughout this work.k.

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수직전기장과 프린지 필드에 의해 구동되는 반투과형 FFS 액정소자 (Transflective Fringe-Field Switching Liquid Crystal Device Driven by Vertical- and Fringe-field)

  • 임영진;박상현;최민오;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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    • pp.279-280
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    • 2005
  • We have designed a single gap transflective liquid crystal display (LCD) driven by a fringe electric field and vertical field. The conventional FFS mode does not have an electrode on top substrate, it shows not only slow response time due to weak electric field but also slow discharging problem when electrostatic field is generated after fabricating the cell. To solve these problems, transflective LCD with ITO coated upper substrate was suggested but the transmittance was reduced significantly due to effects from vertical field. Hence, in the present paper, new transflective LCD with ITO coating only in the reflective region was characterized.

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Stability-Enhanced Liquid Crystal Mode for Flexible Display Applications

  • Jung, Jong-Wook;Jang, Se-Jin;Lee, You-Jin;Kim, Hak-Rin;Jin, Min-Young;Kim, Jae-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.687-691
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    • 2005
  • We demonstrated stability-enhanced liquid crystal (LC) displays using pixel-iosolated LC mode in which LC molecules are isolated in pixel by horizontal polymer layer and vertical polymer wall. The device shows good electro-optic properties with external pressure and bending due to the polymer structures. The polymer wall acts as supporting structure from mechanical pressure and maintains the cell gap from bending. Moreover, the polymer layer acts as adhesive for tight attachment of two substrates. We presented various methods to produce the polymer structures by using anisotropic phase separation from LC and polymer composites or patterned micro-structures.

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Method for tight adhesion of two Substrates in Pixel-isolated Liquid Crystal Structure for Flexible Display Application

  • 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.364-367
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    • 2005
  • We developed a method for adhesion of two substrates with stable liquid crystal (LC) structures using patterned microstructure and LC/polymer composite materials. In the device, the LC molecules are isolated in pixels where LCs are surrounded by patterned microstructures, and two substrates are tightly attached each other by the solidified polymer produced by anisotropic phase separation by UV exposure. These devices show very good mechanical stability against external pressure.

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