• 제목/요약/키워드: LC material

검색결과 544건 처리시간 0.029초

수직 광폴리머를 이용한 MVA 셀의 전기 광학 특성 (EO Characteristics in the Multidomain Vertical-Alignment (MVA) Cell on a Homeotropic Photopolymer)

  • 이경준;황정연;김재형;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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    • pp.953-956
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    • 2002
  • The electro-optical (EO) performances of a multidomain vertical-alignment (MVA) cell on a homeotropic photopolymer have been investigated. In the absence of an electric field, the MVA cell achieved black state as LC alignment is homeotropic. An electric field created by interdigitated electrodes and rib made after photolithograph using the photopolymer on both substrates causes a director deformation of a multidomain type. Good voltage-transmittance curves for a MVA cell on the homeotropic photopolymer were observed. Also, the stable response time of MVA cell on the homeotropic photopolymer can be achieved.

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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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복합 광폴리머 표면을 이용한 광배향 TN 셀의 전기 광학 특성 (Electro-optical Characteristics of the TN Cell Photo-aligned on the Blending Photopolymer Surfaces)

  • 황정연;서대식
    • 한국전기전자재료학회논문지
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    • 제14권7호
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    • pp.600-605
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    • 2001
  • The electro-optical (EO) performances for the twisted-nematic (TN)-liquid crystal display (LCD) photo-aligned with polarized UV exposure on various blending photopolymer surfaces were investigated. Excellent LC alignment and voltage-transmittance (V-T) characteristics for TN-LCD photo-aligned with polarized UV exposure of normal incidence on the blending photopolymer (polyimide (PI) +PM4Ch(poly(4-methacryloyloxy chalcone))) surface containing chalcone group can be achieved. The EO performances for the TN-LCD photo-aligned on the blending photopolymer can be improved due to the photosensitivity by long side chain of the photopolymer.

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필터타입으로 구성한 자기임피던스센서의 특성 (Properties of Filter type Magnetoimpedance Sensor)

  • 사공건;김영학;신광호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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    • pp.337-340
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    • 2004
  • To develop the highly sensitive Magneto-Impedance sensor, the amorphous ribbon was micro-processed to meander type sensor pattern and the filter circuit was constructed with this pattern. Its external magnetic field dependence of impedance and the output properties of the filter circuit were investigated. The impedance of the pattern had a peak value at the magnetic field of 10 Oe and its changing ratio was about 280%. The impedance change per unit magnetic field was about 36%, in which the output with high sensitivity and linearity could be obtained. The output sensitivity was about 7%/Oe at bias field of 6 Oe..

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대면적의 LCD를 위한 갇혀진 Locked Super Homeotropic (LSH) 액정 디바이스 (Locked Super Homeotropic (LSH) liquid crystal device for large size LCD)

  • 박상현;송일섭;김완철;오세태;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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    • pp.146-149
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    • 2004
  • We have studied a liquid crystal (LC) mode (named locked super homeotropic (LSH)) in which the LCs aligned homeotropically are locked by surrounding walls such as cubic, hexagonal and cylinder. In the device, the vertically aligned LCs tilt down symmetrically around the center of the cell when a voltage is applied and thus it exhibits wide viewing angle. The structure of this LSH mode is suitable for large-sized display panels. since the LCs are locked in micro domains the LCs do not flow to the bottom of the panel by gravity. This mode is applicable to achieve high performance TFT-LCD TV because of high performance characteristics such as high contrast, high brightness, wide-viewing angle.

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양의 액정을 이용한 Fringe Field Switching mode의 전기-광학 특성 연구 (Study on electro-optic characteristics of FFS mode using a positive LC)

  • 우창우;하경수;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.171-171
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    • 2010
  • Electro-optic characteristics of liquid crystal display using fringe field switching(FFS) device depend on many parameters such as cell retardation, electrode structure, rubbing angle, cell gap and dielectric anisotropy. In this paper, the light efficiency of FFS mode will be analyzed to confirm the electro-optic characteristics according to positive dielectric anisotropy such as transmittance, operating voltage and response time.

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시야각 조절이 가능한 고개구율 액정 디스플레이 연구 (Study on Viewing angle controllable Liquid Crystal Display with High Aperture Ratio)

  • 신석재;허정화;임영진;이승희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.173-173
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    • 2010
  • We proposed viewing angle switchable liquid crystal display(LCD) associated with fringe-field switching (FFS) mode with high aperture ratio characteristic. In the device, single pixel is separated into two regions, named as main pixel for displaying images and sub pixel for viewing angle control. In sub pixel region, add the common electrode on the top substrate and the initial alignment of liquid crystal is Hybrid Alignment Nematic (HAN) state. In conclusion, we suggested that the device has high aperture ratio characteristic because the LC directors are rotated in which viewing angle control region are generated fringe electric field.

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수평 배향된 양의 액정 내에서의 단일벽 탄소 나노튜브 Stretching 관찰 (Observation of SWCNT Stretching in homogeneously aligned nematic liquid Crystal medium)

  • 양규형;강병균;이승희;이규;이영희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.170-170
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    • 2010
  • In this paper, we observed stretching of single-wall carbon nanotubes (SWCNTs) aggregates driven by the in-plane field in a homogeneously aligned nematic liquid crystal (LC) medium. Aggregates of SWCNTs started to stretch above the 0.5 V/${\mu}m$ and stretched up to $1.83\;{\mu}m$ from original size with $0.74\;{\mu}m$ at 3.5 V/${\mu}m$.

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전파정류 방식의 X선 발생장치에서 조사선량 (Exposure Does of X-ray Generator on Full Wave Rectification Method)

  • 김태곤;김영표;천민우;이호식;박용필
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.138-138
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    • 2010
  • X-ray systems for medical treatment use noninvasive procedures. I fabricated a high tension generator of a full-wave rectification type using a LC resonant inviter. It is said that a full-wave rectifying X-ray equipment such as the fabricated system can shorten initiating period and be precision control because of stable output, compared with the X-ray equipment of a half wave rectifying type used in the usual clinical medicine. In order to evaluate the capability of the fabricated high tension generator, I performed exposure dose characteristics experiments.

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Washing Effects on Generation of Pretilt Angle in NLC, 5CB, on a Polyimide Surface with Trifluoromethyl Moieties

  • Lee, Sang-Keuk;Hwang, Jeoung-Yeon;Seo, Dae-Shik
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 춘계학술대회 논문집 디스플레이 광소자분야
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    • pp.133-135
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    • 2003
  • The washing effects on pretilt angle generation in a nematic liquid crystal (NLC), 4-n-pentyl-4’-cyanobiphenyl (5CB) on a rubbed polyimide (PI) surface with trifluoromethyl moiety have been successfully studied. The pretilt angle of 5CB is increased by the washing process on the rubbed PI surface. The surface tension on the rubbed PI surface increases with the rubbing strength RS and then saturated above RS=150 mm. The pretilt angle of 5CB for all washing processes on the rubbed PI surface decreases with the surface tension. We have found that the pretilt angle of 5CB on the rubbed PI surface may be attributed van der walls (VDW) dispersion interaction between the LC molecules and the polymer surfaces having trifluoromethyl moieties.

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