• 제목/요약/키워드: Crystal alignment

검색결과 539건 처리시간 0.025초

비정질 $SiO_x$ 박막을 이용한 nematic 액정의 선경사각 제어 (Pretilt control of nematic liquid crystal by deposition of $SiO_x$ film)

  • 박정훈;손필국;차성수;김재창;윤태훈
    • 한국광학회:학술대회논문집
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    • 한국광학회 2006년도 하계학술발표회 논문집
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    • pp.91-92
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    • 2006
  • Liquid crystal (LC) alignment on $a-SiO_x$ thin film was investigated by means of X-ray photoemission spectroscopy and optical transmittance as we varied the deposition temperature and the target-to-substrate distance. LC molecules can be aligned vertically on $a-SiO_x$ film when the stoichiometric parameter x of $a-SiO_x$ is smaller than 1.56, but they can be aligned homogeneously when x is larger than 1.56. We also found that whether liquid crystals can be aligned vertically or homogeneously on $a-SiO_x$ film can be predicted simply by measuring the change in optical transmittance by deposition of $a-SiO_x$ thin film layers.

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Chalconyl과 Cholesteryl group을 가진 methacryl계 공중합체를 이용한 프리틸트 발생에 관한 연구 (Study on generation of pretilt angle using a methacrylic copolymers having cholconyl and cholesteryl groups.)

  • 황정연;서대식
    • 한국전기전자재료학회논문지
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    • 제13권7호
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    • pp.625-629
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    • 2000
  • We synthesized a new copoly (PM4Ch-ChMA) copoly(poly(4-methacryloyloxy) chalcone-cholesteryl methacrylate) having chalconyl and cholesteryl moiety for homeotropic liquid crystal(LC) alignment. Pretilt angles of nematic(N) LC generated by linearly polarized UV exposure on the copolymer surfaces were investigated. Good thermal stabilities of the synthesized copolymer were obtained by TGA (Thermogravimetric Analysis) measurement. Pretilt angles of the NLC decreased with increasing UV exposure time on the copolymer surfaces. We consider that the pretilt angle of the NLC is attributed to increased chalcone by increased UV exposure time. High pretilt angle of the NLC is attributed to increased chalcone by increased UV exposure time. High pretilt angle of 81$^{\circ}$was observed after the UV exposure for 3 min.

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Flexible 액정디스플레이의 셀갭 변화에 따른 응답 특성 (Response Time Characteristics according to The Variation of Plastic LCD cell gap)

  • 김강우;김종환;황정연;남기형;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.477-480
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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. However, the transmittance of the plastic STN-LCD on the polyimide (PI) surfaces using polymer film decreased greatly as cell gap decreases.

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신경망을 이용한 공정변수에 따른 수평 폴리머 표면의 경사각에 관한 연구 (Neural network modeling of Pretilt Angle on the Homogeneous Polyimide Surface)

  • 이정환;고영돈;강희진;서대식;윤일구
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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    • pp.426-427
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    • 2006
  • In this paper, the neural network model of the pretilt angle in the nematic liquid crystal on the homogeneous polyimide surface with different surface treatments is investigated. The pretilt angle is one of the main factors to determine the alignment of the liquid crystal display. The pretilt angle is measured to analyze the variation of the characteristics on the various process conditions. The rubbing strength and the hard baking temperature are considered as input factors. Latin hypercube sampling was used to generate initial weights and biases.

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쌍안정 TN 액정셀의 스위칭 특성 해석 (Numerical modeling of dynamic switching behavir in a bistable TN LCD)

  • 김병석;김양수;윤태훈;김재창
    • 한국광학회지
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    • 제9권2호
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    • pp.117-122
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    • 1998
  • 쌍안정 TN LCD의 스위칭 특성을 Berreman에 의해 제시된 backflow를 고려한 이론적 모델을 적용하여 해석하였다. 그리고 이 모델을 적용하여 $180^{\circ}$ 쌍안정 TN 액정셀이 쌍안정 특성을 갖기 위해서는 두 유리기판을 서로 반대 방향으로 러빙해야 하고 d/p도 중요한 요소임을 확인하였다.

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액정 디스플레이 공정별 유해요인 및 비접촉식 액정 배향 법 연구동향 (Harmful Factors by Liquid Crystal Display Process and Research Trends on Non-Contact Liquid Crystal Alignment Methods)

  • 김대현
    • 한국재난정보학회:학술대회논문집
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    • 한국재난정보학회 2023년 정기학술대회 논문집
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    • pp.215-216
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    • 2023
  • 본 논문에서는 액정 디스플레이 산업에서 발생하는 공정별 유해요인 및 연구동향에 대해 조사하였다. 액정 디스플레이는 컴퓨터, 텔레비전, 태블릿, 스마트폰 등에서 사용되는 주요 디스플레이 기술로, 빠른 응답속도와 저전력 운영, 높은 해상도 등을 제공한다. 액정 디스플레이 제조에서 중요한 역할을 하는 액정 배향 기술은 러빙 천을 사용하는 물리적 배향법과 같은 기존 방법의 단점을 극복하기 위해 비접촉식 액정 배향법과 같은 연구가 진행 중이다. 액정 디스플레이 제조과정은 TFT, 컬러필터, 액정, 모듈 단계로 이루어져 있으며 이 과정에서 사용되는 다양한 화학물질은 작업자에게 노출 될 수 있다. 그러므로 유해요인의 관리와 분석, 공정의 개선, 그리고 화학 물질 사용 최소화와 같은 기술에 대한 연구가 중요하다. 최근에는 비접촉식 액정 배향법 및 박막 제작 기술에 대한 연구가 활발히 진행 중이며, 소자 오염 및 배향 공정 등에서 발생하는 유해요인을 최소화하기 위한 노력이 계속되고 있다.

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NOVEL SURFACE PROFILER SYTSTEM FOR INSPECTION OF FLAT PANEL DISPLAY

  • Kimura, Munehiro;Akahane, Tadashi;Iwata, Tetsuya
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.325-327
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    • 2004
  • Novel surface profiler system for inspection of the display components is demonstrated In the case of the liquid crystal display, for example, not only the flatness of the alignment film but also the quality of rubbing can be inspected. Furthermore, the shape of the component such as the color filter, electrode and mirror can be inspected without removing each component.

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A Fast Response Smectic LCD using Induced Polarization

  • Mochizuki, Akihiro
    • Journal of Information Display
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    • 제6권3호
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    • pp.6-11
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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 sa me with current nematic base LCDs. Specific initial molecular alignment as well as specific cell design realizes ext remely 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 herein.

3-D FEM Study on the Optical Characteristics of S-IPS Mode

  • Yang, Seung-Su;Park, Soon-Yeol;Won, Tea-Young
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.231-234
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    • 2008
  • In this paper, we propose a novel electrode structure for superb transmittance in super in-plane switching (S-IPS) mode while keeping the features of the conventional SIPS mode such as the capability of initial LC alignment. The optimization of the electrode made it possible to enhance the light transmittance approximately by 14 % in comparison to the conventional S-IPS cell.

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