• Title/Summary/Keyword: reactive mesogen

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Study on PVA mode using the UV curable reactive mesogen (RM) (광경화성 단분자를 이용한 PVA모드의 8-도메인 형성방안 연구)

  • Kim, Woo-Il;Kim, Sung-Min;Cho, In-Young;Kim, Mi-Young;Son, Jong-Ho;Ryu, Jae-Jin;Kim, Kyeong-Hyeon;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.339-340
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    • 2008
  • The Conventional PVA (patterned vertical alignment) mode showed characteristics of 8-domain using T-T type or C-C type. But these methods have disadvantages such as decreasing aspect ratio and transmittance. In order to resolve these problems, in this paper we have studied a new 8-domain method which is partially using the UV curable reactive mesogen (RM) that is a role in surface stabilization. The characteristic of off-axis color shift is decreased because the part of surface stabilized area is compensated to other area in a pixel. Consequently, the device shows improved color shift by 8-domain.

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Polarization-Dependent Microlens Array Using Reactive Mesogen Aligned by Top-Down Nanogrooves for Switchable Three-Dimensional Applications

  • Son, Ki-Beom;Kim, Mugeon;Park, Min-Kyu;Kim, Hak-Rin
    • Journal of the Optical Society of Korea
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    • v.19 no.3
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    • pp.265-271
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    • 2015
  • We propose a reactive mesogen (RM) lens array to obtain good focusing behavior along with a short focal plane, where the focusing behavior is switchable according to the polarization state of incident light. Polarization-dependent focusing behavior is obtained using a planoconvex RM microlens array on a planoconcave isotropic lens template. Even though the sagitta of our RM lens is high, to obtain the short focal length, the RM layer can be aligned well by introducing a top-down alignment effect, using a nanogrooved template. The optical noise due to the $moir{\acute{e}}$ effect generated by the nanogrooves on the surface of the planoconvex RM layer can be removed simply by overcoating a thin RM layer, which is self-aligned by the geometric surface effect, without an additional alignment process. We demonstrate a hexagonal-packed RM lens array that has a very high fill factor and symmetric phase profile, for an ideal lens.

Flexible bistable chiral splay nematic display mode using reactive mesogens

  • Bae, Kwang-Soo;Lee, You-Jin;You, Chang-Jae;Kim, Jae-Hoon
    • Journal of Information Display
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    • v.12 no.4
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    • pp.195-198
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    • 2011
  • Proposed herein is a flexible bistable chiral splay nematic display mode with an enhanced memory retention time under external distortion. By adopting the polymerized reactive-mesogen structure mixed in a liquid crystal layer, local anchoring energy is generated on the boundary between the polymer structures, and the relaxation from the ${\pi}$-twisted state to the initial splay state could be interrupted. As a result, the memory retention time becomes significantly longer, and the stability against the external distortion is enhanced.

광 경화성 단분자를 이용한 수직 배향 액정 표시 소자의 노광 조건에 따른 표면 안정화의 연구

  • Kim, Hye-Yeong;Kim, Dae-Hyeon;Gwon, Dong-Won;Kim, U-Il;Jo, In-Yeong;Kim, Seong-Min;Lee, Seung-Hui;Jeong, Yeon-Hak;Ryu, Jae-Jin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.187-187
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    • 2009
  • The PVA(patterned vertical alignment) mode has a excellent dark state at normal direction. but they has a disclination area at divided domain region at voltage on state. so this disclination make a slow response time and decrease transmittance. To overcome this problem, we research about polymer stabilized vertical alignment (PS-VA) method which was using the UV curable reactive mesogen. According to our research, UV exposure condition which was UV dosage condition effected to rising time and decay time and also threshold voltage.

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UV 경화성 단분자를 이용한 광학 보상 퍼짐 셀의 전기적 특성 향상 연구

  • Gwon, Dong-Won;Jeon, Eun-Jeong;Im, Yeong-Jin;Lee, Myeong-Hun;Lee, Seung-Hui
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.188-188
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    • 2009
  • We have studied the optically compensated splay (OCS) mode using reactive mesogen (RM) monomer to reduce critical voltage, setting voltage and phase transition time from initial bend to splay state. Through the polymerization of UV curable RM monomer, the high pretilt angle from vertical alignment was formed at the surfaces. In this way, orientation of the LC with OCS mode can be achieved without setting voltage and improved electric characteristic.

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Study on electro optic characteristic of pattern free vertical alignment (PFVA) mode using the uv curable reactive mesogen (RM) (광경화성 단분자를 이용한 pattern free vertical alignment 모드의 전기 광학 특성 연구)

  • Cho, In-Young;Hwang, Seong-Jin;Kim, Sung-Min;Hwang, Ji-Hye;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.04a
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    • pp.45-46
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    • 2008
  • The conventional biased vertical alignment (BVA) mode has several advantages such as rubbing- and protrusion-free, wide-viewing angle and stable LC dynamics against external pressure. However manufacturing process of BVA mode is difficult task because the pixel and bias electrode signal are different in each frame. To solve this problem, we investigated the pattern free vertical alignment (PFVA) by using the UV-curable reactive mesogen (RM), in which the LC molecules were made to be pre-tilted. Eventually transmittance and response time in PFVA mode were found to be improved as compared to BVA mode.

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Study on Electro-opt ic Characteristics in the Optically Compensated Splay Cell with UV-curable Reactive Mesogen

  • Kim, Seong-Su;Jeon, Eun-Jeong;Lee, Myong-Hoon;Lee, Seung-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.327-329
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    • 2008
  • We have studied the optically compensated splay (OCS) mode using reactive mesogen monomer to reduce critical voltage, setting voltage and phase transition time from initial bend to splay state. The high pretilt angle from vertical alignment was formed through the polymerization of UV curable RM monomer at the surfaces. In this way, orientation of the LC with OCS can be achieved without setting voltage.

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Reactive Mesogen Mixtures for Integrated Optical Films

  • Lee, Hee-Kyu;Lee, Seung-Eun;Cumming, S.A.;Verrall, M.;Parri, O.;Harding, R.;Marden, S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.266-269
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    • 2003
  • TFT LCD mode has some well-documented performance limitations, namely limited viewing angle, inversion of the gray scale levels and poor luminance efficiency because of the necessity of using crossed polarisers attached to the display cell. During the last few years many initiatives have been undertaken to solve these problems by incorporation birefringent films of various designs into the LCD module. Controlling the optical performance of LCDs often requires combination of liquid crystal material properties, cell parameters and optical films. Such optical films have traditionally been made with stretched polymer materials such as polycarbonate, but recently coated liquid crystalline materials have been used to give improved optical films which can greatly enhance the performance of LCDs. We have now developed reactive mesogen materials to add ultra-thin optical layers into the display structure, and these allow the potential for many new applications.

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Electro-optical characteristics of PVA (Z-shape) mode using the UV curable reactive mesogen (RM) (광경화성 단분자를 이용한 Z-shape PVA 모드에서의 투과율 향상에 관한 연구)

  • Cho, In-Young;Hwang, Seong-Jin;Kim, Sung-Min;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.437-438
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    • 2008
  • The Conventional patterned vertical alignment (PVA) device shows a very high contrast ratio at normal direction and does not require rubbing process. However it has a disclination area in which the liquid crystal can be collision in the boundary domain region. In this paper, we studied PVA(Z-shape) device in which the liquid crystal can be tilted down in multiple directions stably because the surface pretilt angle is controlled by photopolymerization of the UV - curable reactive mesogen (RM) under a proper condition. Consequently, the device shows improved electro optical properties as compared to conventional PVA mode.

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Study on Controlling Pretilt Angle and Electrical Characteristics in ECB cell by Polymerized Reactive Mesogen monomer (ECB 셀에서 UV 경화성 RM 단분자에 의한 선경사각 조절 및 전기적 특성에 관한 연구)

  • Jeon, Eun-Jeong;Kim, Seong-Su;Lim, Young-Jin;Lee, Myoung-Hoon;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.397-398
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    • 2008
  • We have studied the electrically controlled birefringence (ECB) mode using reactive mesogen (RM) monomer to control pretilt angle and improve electrical characteristics. The measure of capacitance confirmed new pretilt angle by RM monomer, and Voltage Holding Ratio (VHR) was increased more than normal ECB cell.

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