• 제목/요약/키워드: PDLC

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고분자분산 액정(PDLC)을 이용한 광섬유 변조기 제작 및 주파수 응답 특성 연구 (Fabrication and Frequency Responses of Optical-Fiber Modulator by utilizing Polymer-dispersed Liquid Crystal(PDLC))

  • 성기영;경천수;이영락;이상조;김기현;곽종훈
    • 한국광학회:학술대회논문집
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    • 한국광학회 2001년도 제12회 정기총회 및 01년도 동계학술발표회
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    • pp.212-213
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    • 2001
  • 액정은 낮은 전압에서 액정 방향자의 변화에 따른 굴절률 변조를 일으키고 가시광과 근적외선 파장에서 큰 투과도를 가지고 있어 특히 디스플레이 등의 소자에 널리 이용되고 있다. 그러나 현재 액정만을 이용한 디스플레이 등의 응용제품들은 응답속도, 구동특성으로 인해 대화면 구동이 곤란하고 편광판의 사용으로 시야각은 물론 빛 손실량이 크다는 단점과 광변조기로의 응용에 있어서는 큰 파장의존성이 있어 다중 파장의 빛 조절이 어렵고, 또한 입사편광을 왜곡한다는 단점을 가지고 있다. (중략)

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Effect of Liquid Crystal Structures on olymerization-induced Phase Separation Behavior by Simultaneous Resistivity and Turbidity Measurement

  • Park, Su-Cheol;Lee, Sang-Sub;Hong, Jin-Who
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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    • pp.886-889
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    • 2007
  • Photopolymerization and phase separation behavior during the PDLC formation process were investigated by simultaneous resistivity and turbidity measurement. Using this experimental method, we investigated the effect of liquid crystal structure on photopolymerization and phase separation behavior.

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고분자 분산형 액정 셀에서 혼합물의 비율에 따라 노광 온도가 초기 산란도에 미치는 영향 (Study on Initial Scattering State as a Function of Curing Temperature for Polymer Dispersed Liquid Crystal Cells with Different Mixing Ratio)

  • 김미숙;서영현;이명훈;이종문;이택수;이승희
    • 한국전기전자재료학회논문지
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    • 제17권1호
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    • pp.59-64
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    • 2004
  • We have fabricated the polymer dispersed liquid crystal (PDLC) cell where a control of phase separation is very important. The factors to influence the phase separation are mixing ratio of LC and polymer, curing temperature and UV intensity. In this paper, we inspected the change of a phase separation as a function of curing temperature for the mixture of E7 and. NOA65 with different ratios. When the LC concentration is less than polymer such as LC:NOA65 = 40:60wt%, the PDLC cell is influenced strongly by the curing temperature. However, when the LC concentration is much less than polymer such as LC:NOA65 = 80:20wt%, it is influenced slightly by the curing temperature. The reason is because the mixture shows upper critical solution temperature behavior and therefore it is important to know the behavior of phase separation as a function of curing temperature of the mixture.

Enhanced Adhesion and Transmittance Uniformity in Laminated Polymer-Dispersed Liquid Crystal Films

  • Yoo, Seong-Hyeon;Park, Min-Kyu;Park, Ji-Sub;Kim, Hak-Rin
    • Journal of the Optical Society of Korea
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    • 제18권6호
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    • pp.753-761
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    • 2014
  • We propose a two-step UV irradiation procedure to fabricate polymer-dispersed liquid crystal (PDLC) films by lamination. During the first UV treatment, before lamination, the UV-curable monomers coated on one film substrate are solidified through photo-polymerization as the phase separation between the liquid crystals and the monomers. Introducing an adhesion-enhancement layer on the other plastic substrate and controlling the UV irradiation conditions ensure that UV-induced cross-linkable functional groups remain on the surfaces of the photo-polymerized layers. Thereby, the adhesion stability between the top and bottom films is much improved during a second (post-lamination) UV treatment by further UV-induced cross-linking at the interface. Because the adhesion-enhancement and PDLC layers prepared by the bar-coating process are solidified before lamination, the PDLC droplet distribution and the cell gap between the two plastic substrates remain uniform under the lamination pressure. This ensures that the voltage-controlled light transmittance is uniform across the entire sample.

A 0.55" PDLC-LCoS Micro-display for Mobile Projectors

  • Do, Yun-Seon;Yang, Kee-Jeong;Sung, Shi-Joon;Kim, Jung-Ho;Lee, Gwang-Jun;Lee, Yong-Hwan;Chung, Hoon-Ju;Roh, Chang-Gu;Choi, Byeong-Dae
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.1527-1530
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    • 2009
  • A LCoS micro-display using polymer dispersed liquid crystals (PDLCs) for light switching layer was fabricated. The Si backplane of SVGA ($800{\times}600$) with a pixel size of $14{\times}14mm^2$ was prepared by a $0.35{\mu}m$ 18V CMOS process. PDLCs were filled in the gap between backplane and ITO glass by conventional vacuum filling method. The prepared panels were driven by a field sequential color (FSC) scheme at the frequency of 180Hz and were successful in modulating LED lights to show projection images. The preparation and performance of PDLC-LCoS are presented.

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Electroptic Properties of PDLC Film

  • 김선희;최치훈;김병규
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 1994년도 춘계 학술발표 강연 및 논문 개요집
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    • pp.138-138
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    • 1994
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Improvement of Phase Separation Behavior of LC/Polymer Composite by using PDLC Prepolymer

  • Song, Seong-Kyu;Jung, Eun-Ae;Sung, Shi-Joon;Kim, Dae-Hwan;Kang, Jin-Kyu;Ha, Ki-Ryong
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.931-934
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    • 2009
  • EHA(ethylhexyl acrylate), well known for the prepolymer used for PDLC, was used for the LC/polymer composite system for pixel isolated LC (PILC). In order to improve the polymer wall structures of EHA, various acrylate prepolymers were blended with EHA prepolymer.

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Electro-optic Characteristics of Polymer Dispersed Liquid Crystal Films

  • Yang, Kee-Jeong;Kim, Chang-Geun;Lee, Seung-Chul;Do, Yun-Seon;Kim, Bae-In;Choi, Byeong-Dae
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.902-903
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    • 2009
  • Polymer Dispersed Liquid Crystal (PDLC) films were prepared using the phase separation method with liquid crystal and a newly developed prepolymer. This study investigated the electro-optic characteristics of the PDLC film at various temperatures. It was found that as temperatures increased, the voltage varied, and that the ordinary refractive index of the liquid crystal and the polymer refractive index in the composite had similar dependence at various temperatures.

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Flexible audible display(VizDio$^{TM}$) using polymer dispersed liquid crystal on film speaker

  • Bae, Byeong-Taek;Park, Dong-Hee;Jeong, Kwang-Ho;Choi, Won-Kook
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.877-878
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    • 2009
  • To realize the flexible audible display (FAD), polymer dispersed liquid crystal(PDLC) is deposited on PVDF(Poly-vinylidene fluoride) film with piezoelectric property. With applied audio signal, it makes sound more than 70 dB in 700 Hz-10kHz. In case of transparency it is opaque and transmittance is less than 10% at 550nm wavelength without bias voltage. It is turned to be transparent and show transmittance of 66% with driving voltage of 60V.

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고분자 분산형 액정 표시소자의 전기광학적 특성 개선 (Improvement in the electro-optical properties of PDLCs)

  • 최기석;박우상;박세근
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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    • pp.125-128
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    • 1998
  • The electro-optical properties of PDLCs ( Polymer Dispersed Liquid Crystals ) that have been interested for applications to projection display devices lately are significantly improved. For this improvement, we optimized not only the material parameters of liquid crystal and polymer but also the process conditions. Using TL series liquid crystals and polymer PN393 provided from Merck, we obtained the optimized process conditions such as cell gap, LC concentration, curing temperature and curing time. Under these conditions, we have achieved PDLC cells of threshold voltage 2.6V. contrast ratio 260 and negligible hysteresis.

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