• 제목/요약/키워드: homeotropic

검색결과 103건 처리시간 0.029초

An integrated elastomer substrate with a lens array and pixel elements for three-dimensional liquid crystal displays

  • Hong, Jong-Ho;Kim, Yeun-Tae;Kim, Yun-Hee;Lee, Byoung-Ho;Lee, Sin-Doo
    • Journal of Information Display
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    • 제13권2호
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    • pp.55-59
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    • 2012
  • In this paper, a concept of an integrated elastomer substrate for a three-dimensional (3D) liquid crystal display based on the integral-imaging method is presented. The elemental lens array and columnar spacers were integrated into one of the two substrates, an elastomer substrate, through an imprinting process. The integrated elastomer substrate was capable of maintaining the uniform liquid crystal (LC) cell gap and promoting homeotropic LC alignment without any surface treatment. The monolithic approach reported herein will provide a key component for 3D displays with enhanced portability through a more than 40% weight reduction compared with the conventional integral-imaging method.

EO Characteristic of the In-plane Driven VA Cells on a Polymer Layer

  • Lee Sang-Keuk;Hwang Jeoung-Yeon;Seo Dae-Shik
    • Transactions on Electrical and Electronic Materials
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    • 제4권4호
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    • pp.7-9
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    • 2003
  • Viewing angle characteristics of a nematic liquid crystal (NLC) using a in-plane driven (IPD) vertical alignment (VA) cell without a negative compensation film on a homeotropic alignment layer were studied. Good voltage-transmittance (V - T) curves were obtained using the rubbing aligned IPD- VA cell. However, instability and low transmittances of V - T characteristics in photo aligned IPD- VA cell was measured. The EO performance of a rubbingaligned IPD- VA cell without a negative compensation film was wider than that of photoaligned IPD- VA cell and conventional VA cell. Also, the fabrication processes using the rubbing aligned IPD- VA cell mode be carried out with only one-sided rubbing.

광배향법을 이용한 VA-l/4$\pi$셀의 전기 광학 특성 (Electro-optical Characteristics in the Vortical-Alignment 1/4$\pi$ Cell by photoalignment Method)

  • 이윤건;황정연;서대식;김재형
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.369-372
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    • 2001
  • We studied the electro-optical (EO) performance in the vertical-alignment (VA) - l/4$\pi$ cell photoaligned with polarized UV exposure on a homeotropic photopolymer surfaces. Excellent voltage-transmittance curve in the VA - l/4$\pi$ cell photoaligned with polarized UV exposure for 3 min on the photopolymer containing cholesterol group of 8% can be achieved. The V-T characteristics in the VA-l/4$\pi$ cell photoaligned on the photopolymer surface can be improved by increasing cholesteryl group. For response time measurement, the transmittance characteristics of the VA-l/4$\pi$ cell photoaligned on the photopolymer surface was better than that of the VA-l/4$\pi$ cell rubbingaligned on a polyimide(Pl) surface.

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Fluorine 계열의 폴리머를 함유한 복합 폴리이미드 표면에서의 네마틱 액정의 고 프리틸트 발생 (Generation of High Pretilt Angle for Nematic Liquid Crystal on Blended Polyimide Surfaces Containing Fluorine Moiety)

  • 황정연;이경준;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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    • pp.949-952
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    • 2002
  • The mechanisms of pretilt angle generation for a nematic liquid crystal (NLC) with negative dielectric anisotropy on the blended polyimide (PI) surface containing trifluoromethyl moiety was studied. High LC pretilt angle on the blended polymer surface with F3 was measured and the pretilt angle increased with rubbing strength. However, the low LC pretilt angle on the blended polymer surface with F1 and F2 was measured. The high LC pretilt angle generated is attributable to trifluoromethyl moiety in backbone structure on the blended PI surface. Therefore, the high pretilt angle of NLC can be achieved by using the blended polymer surface.

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수직 광폴리머 표면을 이용한 VA-IPS 셀의 전기 광학 특성 (EO Characteristics in the Vertical-Alignment (VA)-In Plane Swiching (IPS) Cell on a Homeotropic Photopolymer Surface)

  • 정은아;황정연;김재형;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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    • pp.945-948
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    • 2002
  • We studied electro-optical (EO) performances of a vertical-alignment (VA)-in plane switching (IPS) cell on a photopolymer surfaces. The VA-IPS cell, dark in voltage-off state, reveals bright uniformity in all directions due to the dual domainlike dierector configuration in the voltage-on state. For voltage-transmittance (V-T) measurement, the transmittance characteristics of the VA-IPS cell on the photopolymer surface was better than that of the VA-IPS cell on a polyimide(PI) surface.

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Periodic Boundary Effect on Multi-Domain Formation in Liquid Crystal Devices

  • Yu, Chang-Jae;Park, Jae-Hong;Kim, Jin-Yool;Jung, Min-Sik;Lee, Sin-Doo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.478-481
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    • 2003
  • We studied a periodic boundary effect in liquid crystal (LC) devices with multi-domains consisting of homeotropic and hybrid alignments. In this configuration, the surface anchoring energy was determined using the LC director-distorted length near the domain boundary, in a linear approximation of the director profile based on the continuum theory. The distorted length was measured in the LC binary diffraction grating.

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Fluorine 계열의 폴리머를 함유한 복합 폴리이미드 표면에서의 네마틱 액정의 프리틸트 발생의 메카니즘 (Mechanisms of Pretilt Angle Generation for Nematic Liquid Crystal on Blended Polyimide Surfaces Containing Fluorine Moiety)

  • 황정연;이상극;서대식
    • 한국전기전자재료학회논문지
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    • 제15권11호
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    • pp.981-984
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    • 2002
  • The mechanisms of pretilt angle generation for a nematic liquid crystal (NLC) with negative dielectric anisotropy on the blended polyimide (PI) surface containing trifluoromethyl moiety were studied. High LC pretilt angle on the blended polymer surface with F3 was measured and the pretilt angle increased with rubbing strength. However, the low LC pretilt angle on the blended polymer surface with F1 and F2 was measured. The high LC pretilt angle generated is attributable to trifluoromethyl moiety in backbone structure on the blended PI surface. Therefore, the high pretilt angle of NLC can be achieved by using the blended polymer surface.

반사형 반강유전성 액정 표시장치의 전기광학 특성 (Electro-Optic Characteristics of a Reflective Antiferroelectric Liquid Crystal Display)

  • 김성철;박원상;진현석;이기동;윤태훈;김재창
    • 한국광학회:학술대회논문집
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    • 한국광학회 2000년도 제11회 정기총회 및 00년 동계학술발표회 논문집
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    • pp.112-113
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    • 2000
  • 주변의 광원을 이용하는 단일 편광판 반사형 액정 표시장치는 전력 소모의 70%이상을 차지하는 배면조명이 필요 없으므로 가볍고 얇으며, 소비전력이 적고, 큰 반사효율을 얻을 수 있는 장점으로 인해 큰 주목을 받고 있다. 현재 단일 편광판 반사형 액정 표시장치는 reflective TN(RTN)$^{(1)}$ 과 mixed-mode TN(MTN)$^{(2)}$ 과 같은 TN액정 모드를 기본적으로 사용하고 있다. 하지만 TN액정 모드를 사용한 반사형 액정 표시장치는 좁은 시야각과 느린 응답 특성 등의 문제점이 있다. 이러한 문제점들을 해결하기 위해 reflective-optically compensated bend(R-OCB)$^{(3)}$ 및 reflective homeotropic TN mode$^{(4)}$ , 반사형 BTN$^{(5)}$ 등을 이용한 반사형 액정 표시장치 등이 보고된 바 있다. (중략)

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Vertically Aligned Carbon Film Synthesized from Magnetically Oriented Polyacetylene using Morphology Retaining Carbonization

  • Goh, Munju;Choi, Yong Mun
    • Carbon letters
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    • 제13권4호
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    • pp.226-229
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    • 2012
  • Polyacetylene (PA) films with vertically aligned fibril morphology were synthesized in homeotropic nematic liquid crystal (N-LC) solvent by using a magnetic field of 5 Tesla as an external perturbation. Scanning electron microscope (SEM) photographs indicated that the lengths of fibrils from the substrate were $5-35{\mu}m$, depending on polymerization time. Carbonization was carried out using iodine-doped PA film and a morphology-retaining carbonization method. From the SEM results, we confirmed that the vertical morphology of the PA remains unchanged even after carbonization at $800^{\circ}C$. The weight loss of the films due to carbonization at $800^{\circ}C$ is about 20% of the weight of the film before iodine doping. It is expected that vertically aligned carbon might be a precursor for preparing vertical graphite materials, which materials could be useful for electrochemical energy storage and cell electrodes.

Fabrication of a Dual-Gap Substrate Using the Replica-molding Technique for Transflective Liquid Crystal Displays

  • Kim, Yeun-Tae;Hong, Jong-Ho;Cho, Seong-Min;Lee, Sin-Doo
    • Journal of Information Display
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    • 제10권2호
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    • pp.68-71
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    • 2009
  • A replica-molding method of fabricating a dual-gap substrate for transflective liquid crystal (LC) displays is demonstrated. The dual-gap substrate provides homeotropic alignment for the LC molecules without any surface treatment and embedded bilevel microstructure on one of the two surfaces to maintain different cell gaps between the transmissive and reflective subpixels. The proposed transflective LC cell shows no electro-optic disparity between two subpixels and reduces the panel thickness and weight by 30% compared to the conventional transflective LC cell, which has two glass substrates.