• 제목/요약/키워드: Liquid crystal device

검색결과 250건 처리시간 0.025초

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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혼합시뮬레이터를 사용한 액정 표시기용 비정질 실리콘 박막 트랜지스터의 특성 시뮬레이션 (Simulation of Characteristics of Amorphous-Silicon Thin Film Transistor for Liquid Crystal Display Using the Mixed Simulator)

  • 이상훈;김경호
    • 전자공학회논문지A
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    • 제32A권12호
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    • pp.122-129
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    • 1995
  • The most important feature of a-Si TFT is dense localized states such as dangling bonds which exist in tis bandgap. Electrons trapped by localized states dominate the potential distribution in the active a-Si region ,and influence the performance of a-Si TFT. In this paper, we describe the electrical characteristics of a-Si TFT with respect to trap distribution within bandgap, electron mobility and interface states using 2-Dimensional device simulator and compare the result of simulation with measurements. Using the mixed-mode simulator, we can predict the potential variation of pixel which causes residual image problem during the turn-off of a-Si TFT driving circuit. Therefore it is possible to consider trade-off between potential variation of pixel and turn-on current of a-Si TFT for the optimized driving circuit.

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wwMD 프로젝션 TV의 명암비 향상 액츄에이터 개발 (Development of a Contrast Enhancer for MD Projection TV)

  • 김재은;윤기탁;이종진;홍삼열;고의석;주채민;양상식
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2006년도 춘계학술대회논문집
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    • pp.656-659
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    • 2006
  • MD (DLP, LCoS) Projection TV is appropriate for large screen display with high definition at a relatively low price and thus, has been popular in the digital TV market. In order to realize high resolutions in the DLP projection TV, we successfully developed the Pixel Enhancement Actuator. Furthermore, it is also required that the contrast ratio of projected video signals onto a large screen should be improved. Therefore, we propose a contrast enhancer which adjusts the amount of projected lights by a dynamic aperture and a attached position sensor.

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Principles and Analytical Applications of Acousto-Optic Tunable Filters

  • Tran, Chieu D.
    • 분석과학
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    • 제8권4호
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    • pp.1101-1108
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    • 1995
  • Acousto-optic tunable filter is a compact, all solid state electronic dispersive device. It is based on the acousto-optic interaction in an anisotropic crystal. Compared to conventional grating monochromators. the AOTF has no moving parts, wider spectral tuning range (from UV through visible and near-IR to IR), higher throughput, higher resolution, faster scanning (${\mu}s$) and random wavelength access. These features make it possible to use the filter to develop novel instruments which are not possible otherwise. The instrument development and unique advantages of such AOTF based instruments including the multidimensional fluorimeter, the multiwavelength thermal lens spectrometer, and the detectors for HPLC and flow injection analysis are described.

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Pretilt Angle Effects on Electro-Optic Characteristics of the Fringe-Field Switching (FFS) Mode

  • Hong, Seung-Ho;Lim, Kyu-Whan;Kim, Hyang-Yul;Lee, Seung-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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    • pp.43-44
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    • 2000
  • The fringe-field switching (FFS) display is known to exhibit wide-viewing-angle and high transmittance. We have simulated pretilt effects on electro-optic characteristic of the device when a liquid crystal with positive and negative dielectric anisotropy is used. The results show that asymmetry in contour of luminance and light leakage in the dark state are increased but voltage-dependent transmittance curves remain about the same, as the pretilt angle increases to $10^{\circ}$.

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Evaluation of the Surface Anchoring Strength by Means of Renormalized Transmission Spectroscopic Ellipsometry

  • Kimura, Munehiro;Tanaka, Norihiko;Bansho, Ryota;Akahane, Tadashi
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.191-194
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    • 2005
  • Evaluating methods of the polar and/or azimuthal anchoring strength coefficients by means of the renormalized transmission spectroscopic ellipsometry are demonstrated. The Anchoring strength coefficients can be evaluated from the measurement of ellipsometric parameters measured by the oblique incident transmission ellipsometry, where the effect of multiplebeam interference is eliminated. The device parameters such as the pretilt angle and cell gap can be determined simultaneously even in the case of the twisted nematic liquid crystal sample cells.

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Stamping Method for Fabrication of Flexible Liquid Crystal Display

  • 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.374-377
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    • 2005
  • We proposed a new fabrication method for stable flexible LCDs using stamping method with durable elastomer such as poly(dimethylsiloxane) (PDMS). In the device, the LC molecules are isolated in pixels where LCs are surrounded by PDMS microstructure, and two substrates are tightly attached by phase separated polymer layer. The electro-optic characteristics of our cell are comparable to those of normal sample without PDMS microstructure. We propose cost-effective roll-to-roll process for large size of plastic LCDs with our method.

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Reduction of an Operating Voltage of Liquid Crystal Display based on Kerr Effect

  • Kim, Min-Su;Kim, Mi-Young;Kang, Byeong-Gyun;Kim, Mi-Kyung;Yoon, Su-Kin;Choi, Suk-Won;Lee, Gi-Dong;Lee, Seung-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.637-640
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    • 2009
  • The LCD based on Kerr effect is highly interesting because it uses an optically isotropic state with no need of alignment layer and it shows sub-millisecond response time. The problem of the device is that it requires very high operating voltage and the transmittance is relatively low compared with other LCDs that use nematic LC. In this work, we study on various electrode structures and driving method which can lower operating voltage.

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Display power analysis and design guidelines to reduce power consumption

  • Issa, Joseph
    • Journal of Information Display
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    • 제13권4호
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    • pp.167-177
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    • 2012
  • Cold cathode fluorescent lamps (CCFLs) are used to provide lighting for liquid crystal displays (LCDs). This paper presents a set of guidelines for measurement characterization and design to reduce the power consumption of CCFL LCD backlight inverters and panel electronics. The proposed methods aim to reduce the backlight power consumption by fine-tuning a back-light inverter for a specific LCD, using several methods. First, the authors describe their power measurement methodology; and next, they identify different areas for tuning a backlight inverter for a given display. The experiment results showed that power savings can range from 50 to 200mW if the backlight inverter is properly tuned. This paper also proposes an optimized configuration for light-emitting device (LED) panels to reduce power loss by selecting a LED with a specific input voltage and number of cells to help minimize power loss.

연X선 Ionizer에 의한 대전물체의 제전특성에 관한 연구 (A Study of De-electrification Characteristics of Charged Body By Soft X-Ray Ionizer)

  • 이동훈
    • 한국안전학회지
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    • 제13권3호
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    • pp.67-73
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    • 1998
  • The technology for neutralizing static electricity by soft X-ray radiation has been newly developed. This technology involves ionization of gas molecules in the vicinity of a charged substrate to generate ions and electrons to reduce electrostatic potential. The ULSI device substrate and liquid crystal display substrate tend to get charged instantly to a high potential level when they are handled in the manufacturing process. Soft X-ray radiation is adequate in air or $O_2$ gas at atmospheric pressure. This newly developed neutralization method is effective to be superior to the conventional technique, i.e., an ionizer by using corona discharge ,in every aspect. The new method features excellent neutralization capability and is able to completely reduce electrostatic potential to 0 V within a short time. Moreover, this is a very clean antistatic technology free from particle generation ,ozone generation, and electromagnetic noise, which are problems in using the corona discharge ionizer.

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