• Title/Summary/Keyword: liquid-crystal-display (LCD)

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Gate Driving Methods to Compensate Feed-Through Voltage for Large Size, High Quality TFT-LCD (대면적 고화질 TFT-LCD의 Feed-through 전압 보상을 위한 Gate Driving 방법)

  • 정순신;윤영준;박재우;최종선
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.99-102
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    • 1999
  • In recent years, attempts have been made to greatly improve the display quality of active-matrix liquid crystal display devices, and many techniques have been proposed to solve such problems as gate signal delay, feed-through voltage and image sticking. To improve these problems which are caused by the fried-through voltage, we have evaluated new driving methods to reduce the fled-through voltage. Two level gate-pulse was used for the gate driving of the cst-on-common structure pixels. And two-gate line driving methods with the optimized gate signals were applied for the cst-on-gate structure pixels. These gate driving methods were better feed-through characteristics than conventional simple gate pulse. The evaluation of the suggested driving methods were performed by using a TFT-LCD array simulator PDAST which can simulate the gate, data and pixel voltages of a certain pixel at any time and at any location on a TFT array. The effect of the new driving method was effectively analyzed.

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The design and FPGA implementation of a general-purpose LDI controller for the portable small-medium sized TFT-LCD (중소형 TFT-LCD용 범용 LDI 제어기의 설계 및 FPGA 구현)

  • Lee, Si-Hyun
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.4
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    • pp.249-256
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    • 2007
  • AIn this paper, a new desist of LDI controller IC for general purpose is proposed for driving the LDI(LCD Driver Interface) controller in $4{\sim}9$ inches sized portable small-medium TFT-LCD(Thin Film Transistor addressed -Liquid Crystal Display) panel module. The designed LDI controller was verified on the FPGA(Reld Programmable Gate Array) test board, and was made the interactive operation with the commercial TFT-LCD panel successfully. The purpose of design is that it is standardized the LDI controller's operation by one LDI controller for driving all TFT-LCD panel without classifying the panel vendor, and size. The main advantage for new general-purpose LDI controller is the usage for the desist of all panel's SoG(System on a Glass) module because of the design for the standard operation. And in the previous method, it used each LDI controller for every LCD vendor, and panel size, but because a new one can drive all portable small-medium sized panel, it results in reduction of LDI controller supply price, and manufacturing cost of AV(Audio Video) board and panel. In the near future, the development of SoG IC(Integrated Circuit) for manufacturing more excellent functional TFT-LCD panel module is necessary. As a result of this research, the TFT-LCD panel can make more small size, and light weight, and it results in an upturn of domestic company's share in the world market. With the suggested theory in this paper, it expects to be made use of a basic data for developing and manufacturing for the SoG chip of TFT-LCD panel module.

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Experimental Investigation on Machining Feasibility of Micro Patterns using a Single Crystal Diamond Tool (단결정 다이아몬드 공구를 이용한 미세 패턴 가공성에 대한 실험적 분석)

  • Kim, Hyun-Chul
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.5
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    • pp.76-81
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    • 2012
  • The continuing demand for increasingly slimmer and brighter liquid crystal display(LCD) panels has led to an increased focus on the role of the light guide panels(LGPs) or optical films that are used to obtain diffuse, uniform light from the backlight unit(BLU). And the most basic process in the production of such BLU components is the micromachining. LCD BLUs comprise various optical elements such as a LGP, diffuser sheet, prism sheet, and protector sheet with micro patterns. High aspect ratio patterns are required to reduce the number of sheets and enhance light efficiency, but there is a limit to the aspect ratio achievable for a given material and cutting tool. Therefore, this study comprised a series of experimental evaluations conducted to determine the machining feasibility in microcutting various aspect ratio patterns on electroless nickel plated die materials when using single-crystal diamond tools. Cutting performance was evaluated at various cutting speeds and depths of cut using different machining methods and machine tools.

A Study of Master Production Scheduling Scheme in TFT-LCD Factory considering Line Balancing (TFT-LCD 공장의 라인 밸런싱을 고려한 MPS 수립에 관한 연구)

  • Won, Dae-Il;Baek, Jong-Kwan;Kim, Sung-Shick
    • IE interfaces
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    • v.16 no.4
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    • pp.463-472
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    • 2003
  • In this study we consider the problem of MPS(master production planning) of TFT-LCD(Thin Film Transistor - Liquid Crystal Display) production factory. Due to the complexities of the TFT-LCD production processes, it is difficult to build effective MPS. This study presents an algorithm having a concept of IDPQ(Ideal Daily Production Quantity) that considers line balancing of TFT-LCD production process. In general, the MPS building procedure does not consider line balancing in non-bottleneck processes. MPS without considering line balancing may make ineffective schedule. We present algorithms for building MPS considering factory capacity and line balancing according to the sales order.

A New Method for Measuring Azimuthal Anchoring Energy of Rubbed and UV-Exposed Polyimide Alignment Layers

  • Park, H.J.;Lee, W.K.;Kim, D.G.;Shin, D.C.;Woo, J.W.;Shin, H.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1619-1621
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    • 2007
  • Novel optical measurement systems and improved cell configurations for measuring of azimuthal anchoring energies were developed. The difference between the mechanical rubbing direction and the optical easy axis that caused errors in the previous azimuthal anchoring energy measurement was compensated. In addition, the measurement accuracy of the twist angle and therefore the azimuthal anchoring energy was greatly enhanced. As a result, we were able to obtain valid azimuthal anchoring energy values for different alignment layers.

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Electro-Optical Characteristics of a-TN-LCD on Photo-alignment Films (광고분자막을 이용한 a-TN-LCD의 전기광학특성)

  • 서대식;박지호;이보호
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.04a
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    • pp.120-122
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    • 1997
  • In this paper, the viewing angle characteristics of amorphous (a) - twisted nematic (TN) - liquid crystal display (LCD) on poly(viny)cirmamate (PVC) alignment surfaces were investigated. It was found that the threshold voltage is increased with increasing the polymerization on PVC surfaces. We suggest that the threshold voltage is affected to the surface anchoring strength with increasing the polymerization of the alignment film. Also, we obtained that the viewing angle of a-TN-LCD is increased with increasing the polymerization on PVC surfaces. Finally, we considered that the viewing angle of a-TN-LCD on PVC surfaces is large compared to TN-LCD on rubbed polyimide (Pl) surface.

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A Study on Electro-optical Characteristics of the Photoaligned VA-LCD on the Polynobornene Derivative Surface (Polynobornene 유도체 표면을 이용한 광배향 VA-LCD의 전기광학특성에 관한 연구)

  • 황정연;서대식;박경선;서동학;남상희
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.3
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    • pp.253-257
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    • 2002
  • A new photoalignment material PNC, pole norbornene-2,3-dicarboxyolyl cholesterol, was synthesized and the electro-optical (EO) characteristics of the vortical-alignment (VA) liquid crystal display (LCD) photoaligned with UV exposure on the PNC surface were studied. EO characteristics of the photoaligned VA-LCD using a UV filter-less method was better than that of the UV filter method on the PNC surface for short UV exposure time. The response time of the photoaligned VA-LCD on the PNC surface without UV filter on the PNC surface is almost the same compared with the rubbing aligned VA-LCD.

Measurement of Cell Gap of Reflective LCD and Study of :Error Rate (반사형 LCD의 Cell Gap 측정 및 오차율 연구)

  • 이서헌;박원상;이기동;김재창;윤태훈
    • Proceedings of the Optical Society of Korea Conference
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    • 2001.02a
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    • pp.142-143
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    • 2001
  • Cell gap은 LCD(Liquid Crystal Display)의 중요한 파라미터들 중의 하나이다. cell gap이 LCD의 광학적인 성능에 영향을 주기 때문에 정확한 cell gap 측정방법은 제조공정을 향상시키는데 중요하다 특히 최근 고속 영상 디스플레이를 제공할 수 있는 장점 때문에 낮은 cell gap의 LCD가 요구되고 있는 시장 추세에 따라 낮은 cell gap을 측정할 수 있는 기술이 요구되고 있다. LCD의 cell gap 측정 방법들 가운데 가장 보편화되어 있는 것으로 회전편광자법(rotating polarizer method)[1, 2]과 위상보상법(phase compensation method)[3,4]을 들 수 있는데 낮은 셀갭을 정확히 측정하기가 어려우며 주기적인 해가 발생한다는 단점이 있다. (중략)

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Development of OCB mode with impulsive driving scheme for improving moving picture quality

  • Kim, J.L.;Lee, C.H.;Park, S.Y.;Yoo, S.W.;Oh, J.H.;Lee, S.H.;Chai, C.C.;Park, C.W.;Ban, B.S.;Ahn, S.H.;Hong, M.P.;Chung, K.H.;Lim, S.K.;Kim, K.H.;Souk, J.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.1049-1052
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    • 2004
  • In general, contrary to the CRTs with impulsive emission, liquid crystal displays have motion artifacts such as blurring. ghost image, decrease of dynamic CR(contrast ratio), and stroboscopic motion due to hold type driving method. In this paper, to improve motion picture quality of LCDs. impulsive driving method of black data insertion was applied to the OCB mode which is well known for its fast LC response time and wide viewing angle properties. Subject evaluation was carried out with CRT, TN, SIPS(Super IPS). and impulsive driving OCB. Moving picture image quality near CRT was obtained in impulsive OCB driving mode

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Design of Projection Optics System for FPD Exposure (FPD Exposure System 용 투영광학계 설계)

  • 배상신;정연욱;김용래;송청호;송준엽;김동훈
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.1290-1294
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    • 2004
  • Exposure System is used for printing a prescribed pattern on a printed board, a liquid crystal substrate or the like. In this paper we are trying to develop projection Optics Exposure System for manufacturing Color Filter of LCD Display. This paper explain the Projection Optics Design and Illumination Optics Design of Color Filter Exposure system.

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