• Title/Summary/Keyword: Liquid crystal

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Theoretical study of the optical properties of low voltage stacked cholesteric liquid-crystal displays

  • Valyukh, Iryna;Valyukh, Sergiy;Skarp, Kent
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.202-204
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    • 2004
  • We study theoretically optical properties of thin layered stacked monochrome cholesteric liquid-crystal displays. Thin thickness of the layers (${\sim}1{\mu}m$) allows us appreciably to reduce driving voltage and use such displays in smart cards. Good selective reflection is achieved due to stacked structure. Dependence of the reflectivity of this type of displays on the quantity of the layers, their thickness, and liquid crystal birefringence is investigated.

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Thermotropic Liquid Crystal Polymer and PBT Blend

  • Lim, Sung-Tack;Kim, Seong-Hun
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.04a
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    • pp.14-19
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    • 1998
  • Increasing demand for high modulus high strength polymeric materials have drawn considerable interest in industry. Thermotropic liquid crystal polymers (TLCP), differing from lyotropic liquid crystal polymers, have excellent melt processability and mechanical property resulting from the high degree of molecular orientation under a shear flow field in the molten state with relatively low viscosity$\^$1,2/.(omitted)

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Control of liquid crystal pretilt angle using polyimide mixture

  • Kang, Dae-Seung;Lee, Ji-Hoon;Rosenblatt, Charles
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1577-1579
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    • 2008
  • A mixture of two different types of polyimide, one having an alkyl side chain and ordinarily used for homeotropic alignment, and the other without a side chain and ordinarily used for planar alignment, is deposited and baked at high temperatures. When the resulting cell is filled with a nematic liquid crystal, it is found that the pretilt angle is a function of the baking temperature or mixing ratio, and can be controlled continuously over the range 0 to 90.

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Liquid crystal ferroelectric colloids; non-synthetic method of adjusting properties

  • Reznikov, Yuriy;Buchnev, Olexander;Li, Fenghua;West, John
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.163-166
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    • 2006
  • We found dramatic changes of the properties of LCs by dispersing ferroelectric nanoparticles. Specifically, ferroparticles greatly increase the nematic-isotropic transition temperature, birefringence and dielectric anisotropy of the LC. Ferroelectric nanoparticles/LCs colloids offer a simple and effective means to precisely control the physical properties of LC materials and optimize them for display applications.

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Response characteristics and related material properties of modern LCDs for TV applications

  • Naemura, Shohei
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1061-1066
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    • 2005
  • Analytical solutions are obtained for the director reorientation dynamics of both VA and IPS modes by considering a possible effect of the molecular flow, providing a theoretical basis of the relations between the response characteristics of the display and the physical properties of the liquid crystal material used. The relevant properties of practical liquid crystal mixtures are quantitatively reviewed and the features of superior substances, used in formulating those mixtures, are presented.

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CHEMISTRY, PHYSICS AND TECHNOLOGY FOR NEW LIQUID CRYSTAL DISPLAYS

  • Penterman, Roel;Klink, Stephen I.;Koning, Henk de;Vogels, Joost;Huitema, Edzer;Broer, Dirk J.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.273-276
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    • 2003
  • Polymerization induced diffusion has been successfully applied to create new display components. Based on this principle a new technique to produce polymer covered liquid crystal layers on a single substrate, called photo-enforced stratification, allows cost-effective production of ultra-thin LCDs. The two-step photopolymerization-induced phase separation of a liquid crystal and a polymer precursor can be performed on a variety of substrates and provides freedom in display design.

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Imprinting of Liquid Crystal Alignment on Polymer Layers

  • Wook, Jung-Jong;Kim, Jae-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.611-614
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    • 2003
  • We have investigated electric field effect on the formation of phase separated composite organic film structure which is utilized by anisotropic phase separation from LC and prepolymer mixtures. Application of bias field resulted in a significant change in liquid crystal alignment between glass substrate and polymer layer. The liquid crystal molecules segregated into the inter-electrodes and formed twisted structure which is the result of imprinting of LC alignment by the bias field on polymer layers during polymerization process.

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Novel Homeotropic Alignment Materials with Alkylcyclohexylbenzene as Side Chain in Polyimides

  • Lee, H.K.;Kim, Y.B.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.600-603
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    • 2003
  • VA-LCDs is widely used for recent LCD productions owing to wide viewing angle characteristics with an unusually high contrast ratio. To apply for VA-LCDs, the novel homeotropic alignment materials were synthesized, which have the liquid crystal molecule as a side chain at aromatic diamine in a polyimide structure. These polyimides generated a high pretilt angle $90^{\circ}C$. In this paper, the synthesis and alignment properties of new homeotropic alignment materials will be discussed..

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Electro-Optical and Switching Behavior of In-plane Switching Twisted Nematic Liquid Crystal Display

  • Kimura, Munehiro
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.1092-1095
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    • 2003
  • A driving mechanism and excellent features for an in-plane switching twisted nematic liquid crystal mode (IT mode) that could possibly improve the viewing-angle and color shift characteristics and the cell gap error tolerance is proposed. .It is important that the surface azimuthal anchoring strength of the liquid crystal cell differs at the upper and lower substrates. Furthermore. as a rubbing-free LCD. amorphously aligned in-plane switching twisted nematic mode (a-IT mode) is also demonstrated.

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Two dimensional Phase Transition of Liquid Crystal Film (액정박막에서의 2차원 상전이)

  • Jung, C.S.;Xue, J.Z.;Kim, M.W.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1993.05a
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    • pp.119-121
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    • 1993
  • Two dimensional phase transition and three dimensional propagation of layer structures of liquid crystal film are investigated by using surface second harmonic generation method. We have found a distinctive first order phase transition between a monolayer phase and a stable 3-layer phase of 8CB liquid crystal film.

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