• Title/Summary/Keyword: Liquid crystal displays(LCD)

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Real-time reconstruction of complex holograms using LCDs (LCD를 이용한 복소홀로그램의 실시간적 복원)

  • 김수길;김규태;이병호;김은수;손중영
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.34D no.4
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    • pp.54-61
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    • 1997
  • In this paper, a new holographic display system that can in real-time reconstruct the complex hologram without the bias and the conjugate image, which is obtained form the modified triangular interferometer, is presented. The proposed system is made of adding liquid crystal displays(LCDs), a $\lambda$/2 wave plate, and a polarizing beam splitter to the conventional mach-zehnder interferontric configuration. We demonstrate through theoretical analysis and experiment that real-time image reconstruction from the complex hologram is possible using the proposed system.

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Amorphous Diamond for Generating Cold Cathode Fluorescence Light

  • Sung, James-C.;Kan, Ming-Chi;Hu, Shao-Chung
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.913-914
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    • 2006
  • Amorphous diamond has a very low work function (1 eV) at modest temperature ($150^{\circ}C$). It has been coat coated on electron emitting electrodes. Such electrodes are used for cold cathode fluorescence lamps (CCFL) that illuminate liquid crystal displays (LCD) for rnote books and television sets. Amorphous diamond can dramatically reduce the turn-on voltage to lit CCFL so the lamp life can be greatly extended. Moreover, the electrical current can be increased to enhance the brightness of the light.

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Flexible Display i Low Temperature Processes for Plastic LCDs

  • Han, Jeong-In
    • Transactions on Electrical and Electronic Materials
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    • v.4 no.2
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    • pp.10-14
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    • 2003
  • Flexible displays such as plastic-based liquid crystal displays (LCDs) and organic light-emitting diode displays (OLEDDs) have been researched and developed at KETI since 1997. The plastic film substrate is very weak to heat and pressure compared to glass substrate, that its fabrication process is limited to 110$^{\circ}C$ and low pressure. The ITO films were deposited on the bare plastic film substrate by rf-magnetron sputtering. Moreover, in order to maintain uniform cell gap and pressure on the plastic film substrate, we utilized newly-invented jig and fabrication process. Electro-optical characteristics were better than or equivalent to those of typical glass LCDs though it is thinner, lighter-weight, and more robust than glass LCDs.

Phase-Separated Pixel Isolation Method for Roll-to-Roll Processing in Flexible Liquid Crystal Displays

  • Kim, Hak-Rin;Jang, Se-Jin;Jung, Jong-Wook;Jin, Min-Young;Kim, Jae-Hoon
    • Journal of Information Display
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    • v.6 no.1
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    • pp.1-7
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    • 2005
  • We propose new fabrication methods of a pixel-isolated liquid crystal (LC) structure for flexible display applications. In the LC structure fabricated through the proposed method, the patterned interpixel walls for sustaining the cell thickness are supported by the solidified polymer layer through anisotropic phase separation of LC/polymer composite, causing the alignment of the LC molecules to have very good mechanical stability against external pressure. In addition, we show that such pixel-isolating walls can be made by the stamping method which can be applied to fabricate large size plastic LCDs by roll-to-roll processing.

Polarizing Photovoltaic Polymer Films for Reflective Solar-LCDs (편광 흡수성 광기전성 고분자 박막 연구)

  • Kim, Young-Chan;Huh, Yoon-Ho;Park, Byoung-Choo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.7
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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.

Improvement of Viewing Angle Characteristics for OCB LCDs Using the Wide View Film (Wide View Film의 적용을 통한 OCB LCDs의 시야각 개선)

  • Woo, Jong-Hoon;Park, Woo-Sang
    • Proceedings of the KIEE Conference
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    • 2001.11a
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    • pp.41-42
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    • 2001
  • 본 연구에서는 빠른 응답특성과 넓은 시야 각 특성을 갖는 Optically Compensated Bend Mode Liquid Crystal Displays(OCB LCDs)의 전기광학 특성을 계산하였다. 액정의 운동방정식을 시뮬레이션하여 얻은 분자배열 분포로부터 광학적 투과 특성을 계산하였으며, 누설광 차단과 수평 및 수직 방향의 넓은 시야각을 확보하기 위하여 보상필름으로써 Wide View Film을 적용하였다. 이러한 결과를 이축성 필름을 사용한 기존의 OCB LCDs와 비교함으로써 Wide View Film을 적용한 OCB LCDs의 시야의존 특성이 향상됨을 확인하였다.

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Colorimetric Characteristics Evaluation of OLED and LCD

  • Baek, Ye-Seul;Kim, Hong-Suk;Park, Seung-Ok;Kim, Youn-Jin
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.509-512
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    • 2008
  • In this study, colorimetric characteristics of a 2.2-inch iriver MP4 based upon OLED was evaluated and compared with another MP4 based upon Liquid Crystal Display (LCD). According to IEC61966-4, the two displays were tested in terms of spectral power distribution, tone reproduction curve (TRC), luminance, contrast, correlated color temperature, 2D color gamut and spatial uniformity. Consequently, the OLED showed better performance for the first four aspects but a similar quality was observed for the rest.

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Calculation of Pixel and Inter-Electrode Capacitance of In-Plane Switching Liquid Crystal Displays using Three-dimensional Simulation

  • Park, Woo-Sang;Jung, Sung-Min;Jang, Sang-Han
    • Proceedings of the IEEK Conference
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    • 2003.07b
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    • pp.739-742
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    • 2003
  • 본 연구에서는 정전계 에너지를 이용하여 IPS-LCD의 화소와 각 전극간 정전용량을 엄정한 방법으로 계산하였다. 정전계 에너지는 전극의 유한한 크기로 인해 발생하는 측면 전장효과를 고려한 3차원 방향자와 전위분포를 시뮬레이션 함으로써 얻을 수 있었다. 수치해석 방법으로는 유한차분법을 사용하였다. 그 결과 IPS-LCD의 화소 정전용량과 게이트-공통전극간 정전용량은 구조적 특성으로 인해 기존의 TN-LCD와 비교하여 1/16배 가량으로 훨씬 더 작은 값을 나타냄이 확인되었다.

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Optical invariants of LCD 'splay' retardation films

  • Belyaev, S.V.;Malimonenko, N.V.;Yu, J.S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.433-436
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    • 2002
  • Retardation liquid crystal films with a profiled titled optic axis (splay films) of both nematic and discotic types are used as compensation films for twisted nematic displays (TN-LCD). A new method is developed to characterize retardation vs. inclination (retardation profile) of splay films by three parameters: "full retardation" $d^{\ast}{\triangle}n$, "inplane retardation" $R_0$ and "retardation difference" $R_d$ . Splay films with the same retardation profile but with different tilt profile (retardation invariants) are discovered. Splay films with different structure parameters but belong to the same retardation invariant have the same compensation opportunities for TN-LCD.

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Empirical Equations for the Analysis of the Time Dependence of the Luminance Properties of LCD Panels and Backlights for TV Applications

  • Ryu, Jin-Sun;Kim, Su-Jin;Park, Seung-Mi;Ko, Jea-Hyeon
    • Journal of Information Display
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    • v.11 no.2
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    • pp.39-44
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    • 2010
  • The time dependences of the luminance properties of 55-inch CCFL and LED backlights and 32-inch FFL backlights with LCD panels were investigated during the warm-up time from the cold start. The long-term luminance maintenance curve of a standard CCFL was examined in a time window up to 5000 hours. These two time dependences are important characteristics from the viewpoint of initial picture quality and lifetime reliability, respectively. Empirical equations were suggested for the analysis of the time dependence of these luminance data. These approaches are expected to be helpful in predicting the luminance properties of backlights based on the luminance data obtained in a limited time window.