• Title/Summary/Keyword: LCD response time

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A Study on Electro-optical Characteristics of a-TN-LCD with Polarization of Orientation Film (배향막의 극성에 따른 a-TN-LCD의 전기광학특성에 관한 연구)

  • 서대식;이창훈
    • Electrical & Electronic Materials
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    • v.10 no.10
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    • pp.1011-1015
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    • 1997
  • In this paper we investigated the electro-optical characteristics of amorphous (a)- twisted nematic (TN)-liquid crystal display(LCD) on polymide (PI) surfaces with different molecular structure. It was found that the domaine size of a-TN-LCD on PI with high polarization is small compared to a-TN-LCD on PI with medium polarization. It is considered that the response time of a-TN-LCd contributes to surface effect between the substrate surfaces and the LC molecules. Finally we obtained that the viewing angle of a-TN-LCD on PI surfaces increases with decreasing the domain size.

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Response Time Characteristics according to The Variation of Plastic LCD cell gap (Flexible 액정디스플레이의 셀갭 변화에 따른 응답 특성)

  • Kim, Kang-Woo;Kim, Jong-Hwan;Hwang, Jeoung-Yeon;Nam, Ki-Hyung;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.477-480
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    • 2003
  • We investigated the electro-optical (EO) performances of the super twisted nematic liquid crystal display (STN-LCD) on the polyimide (PI) surface using polymer film. Monodomain alignment of the plastic STN-LCD can be observed. A stable voltage-transmittance (V-T) curve of the plastic STN-LCD was observed on the polyimide (PI) surfaces using polymer film. Also, a faster response time for the plastic STN-LCD on the polyimide (PI) surfaces using polymer film can be achieved. However, the transmittance of the plastic STN-LCD on the polyimide (PI) surfaces using polymer film decreased greatly as cell gap decreases.

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Two Approaches in LCDs With Fast Electro-optic Response: PSV-mode FLCDs and FM-TN-LCDs

  • Kobayashi, Shunsuke
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.911-914
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    • 2004
  • This paper discusses on new two LCD technologies featured by the fast electro-optic response:one is polymer-stabilized FLCDs that exhibit V-shaped electro-optic (EO) switching called PSV-mode FLCDs with response time of 400 ${\mu}$ s; and the other is TN-mode LCDs that exhibit a frequency modulation response (called PM-TN LCDs)and a peculiar sensitivity to the high frequency component of driving voltage waveforms resulting in a short decay time constant of 5ms and an enhancement in the over-driving that yields short response time of 1ms between two gray levels.

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Liquid crystal alignment by photo-dimerization reaction of PCEMA photo polymer (PCEMA 광폴리머의 광중합 작용을 이용한 액정배향)

  • 황정연;서대식
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.541-544
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    • 1999
  • We synthesised a novel photo-alignment material of PCEMA (poly(cinnamolyethyl methacrylate)) on photo-dimerization reaction. Next we investigated the electro-optical (EO) characteristics of photo-aligned twisted nematic (TN)-liquid crystal display (LCD) with linearly polarized ultraviolet (UV) light irradiation on PCEHA surface. The excellent voltage-transmittance characteristics of photo-aligned TN-LCD on PCEMA surface were obtained. The threshold voltage of photo-aligned TN-LCD decreases with increasing the UV light irradiation time on PCEMA surface. Also, the response time of photo-aligned TN-LCD on PCEMA surface is almost the same as rubbing-aligned TN-LCD.

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Fast Response Time in IPS Mode Using LC mixtures with High Elastic Constant

  • Lim, C.S.;Lee, J.H.;Choi, H.C.;Oh, C.H.;Yeo, S.D.;Lee, Seung-Eun;Jin, Min-Ok;Kang, Doo-Jin;Klasen-Memmer, M.;Tarumi, K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.843-846
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    • 2004
  • For the fast growing Liquid Crystal Display (LCD) TV market, it is essential to make the LCD panels to show moving images without any visual difficulties such as blurring or tailing. Owing to reduction of the cell gap and the improved Liquid Crystal (LC) mixtures with low viscosity, it is possible that our S-IPS TFT-LCDs feature a response time (R/T) as fast as 1-frame time (16ms) for a white-black operation and less than a 16rns in all gray levels without Over Driving Circuit (ODC) technology. Currently, mass production of the large size IPS panels with high speed has been successfully achieved. In order to achieve faster response time, new LC mixtures have been developed, optimizing the physical properties of rotational viscosity (${\gamma}$1) and elastic constants (Kii). Also, the LC mixtures with high elastic constant allow us to increase the cell gap. In this paper, realization of fast switching time in IPS mode with optimized '${\gamma}$1/Kii' parameter in the LC mixtures forms the core of this paper.

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Motion Blur Reduction in LCDs

  • Hong, Sun-Kwang;Oh, Jae-Ho;Park, Po-Yun;Park, Jin-Hyeok
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.1108-1110
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    • 2004
  • LCDs show motion image blur due to slow response time and a hold-type driving method. In this paper, we investigate motion blur phenomena and quantitatively show that the motion blur can be significantly reduced through a combination of dynamic capacitance compensation (DCC) and black data insertion.

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Design of a transflective-type LCD using twisted vertical aligned mode (Twisted VA 모드를 이용한 반투과형 LCD의 설계)

  • 백봉진;도희욱;이서헌;윤태훈;김재창
    • Korean Journal of Optics and Photonics
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    • v.14 no.5
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    • pp.565-569
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    • 2003
  • We designed a transflective-type LCD using a twisted VA mode. Generally, a VA mode had a blue shift due to intrinsic properties. We solved this problem using spectroscopic compensation film. We used the front scattering film and negative C-plate to improve characteristics of the viewing angle and contrast ratio. As a result, we found that proposed the transflective-type TVA mode had a contrast ratio of about 80:1, a response time of 22 ms, and a reflectance of 25% in comparison with the standard MgO reflector.

A New Controller for Improvement of Response Time by Data Compression Using Color Space Conversion

  • Koo, Sung-Jo;Kim, Chang-Gon;An, Jong-Ki;Park, Man-Hyo;Yeo, Sang-Deog
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.863-864
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    • 2005
  • In recent years, we use overdriving scheme to improve the response time of the liquid crystal. Since conventional overdriving scheme uses memory to perform ideal processing, it is desired to reduce system cost by decreasing the data stored in these SDRAMs. As a general compression method, quantization, sub-sampling and Block Truncation Coding ( BTC ) are used, which process data in block base and cause block effect. So we proposed new data compression method by color space conversion. Because this method compresses luminance and chrominance signal by different ratio, it can efficiently reduce error of block effect in decompression image.

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A Study on Electro-Optical Characteristics of the Ion Beam Aligned TN Cell on the DLC Thin Film (DLC 박막을 이용한 Ion Beam 배향 TN 셀의 전기광학특성에 관한 연구)

  • 황정연;조용민;노순준;이대규;백홍구;서대식
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.8
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    • pp.726-730
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    • 2002
  • Electro-optical (EO) performances of the ion beam (IB) aligned twisted-nematic (TN)-liquid crystal display (LCD) with ion beam exposure on the new diamond-like carbon (DLC) thin film surface were investigated. A good voltage-transmittance (V-T) curve of the ion beam aligned TN-LCD with oblique ion beam exposure on the DLC thin film surface for 1 min was observed. Also, the fast response time of the ion beam aligned TN-LCD with oblique ion beam exposure on the DLC thin film surface for 1 min can be achieved. Finally, the residual DC voltage of the ion beam aligned TN-LCD on the DLC thin film surface is almost the same as that of the rubbing aligned TN-LCD on a polyimide (Pl) surface.

Fast Optical Response Time based on Transient LC Director Control in the Liquid Crystal Display

  • Hong, Seung-Ho;Ma, Jung-Ho;Shin, Seong-Wook;Choi, Soo-Young;Shim, Hoan-Su;Choi, Sang-Un;Son, Gon;Park, Hae-Sung
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.423-426
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    • 2002
  • New driving waveform which can be inferred by analyzing fundamental LC mechanism is suggested. The main idea of the new waveform is the stabilizing LC layer fast in the cell by controlling the middle director of LC layer. Consequently, we can get not only numerical reduction of optical response merely but also the change of dynamic transmittance from applied voltage exactly

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