• 제목/요약/키워드: Liquid crystal cell

검색결과 484건 처리시간 0.04초

셀룰로오스 트리아세테이트 액정용액으로 부터 고강도 셀룰로오스 섬유 제조에 관한 연구 (High Tenacity Cellulosic Fiber from Liquid Crystal Solution of Cellulose Triacetate)

  • 홍영근
    • 한국염색가공학회지
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    • 제6권1호
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    • pp.44-48
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    • 1994
  • Cellulose triacetate(CTA) liquid crystal solutions obtained via dissolution of CTA in solvent mixture of triflucroacetic acid and methylene chloride were spun and saponified in various chemicals. Among chemicals, methanol/sodium hydroxide mixture endowed highest tenacity as well as modulus to regenerated cellulosic fiber and the fiber thereof showed Cell I or Cell IV morphology, or mixed morphology of Cell I and IV.

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셀룰로오스 아세테이트와 폴리비닐 피리딘 액정중합체의 박막에 관한 연구 (Membrane from Liquid Crystal Composite of Cellulose Acetate and Poly (4-vinyl pyridine))

  • Hong, Young-Keun;Cho, Bong-Heuy
    • 한국염색가공학회지
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    • 제3권2호
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    • pp.43-48
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    • 1991
  • Cellulose acetate (CA) and poly-4-vinyl pyridine (PVP) in various weight proportions were mixed in a mixed solvent of trifluoroacetic acid: methylene chloride/6:4 (v:v). CA was miscible with PVP in that solvent system. CA/PVP/solvent show liquid crystal in a certain range of concentration and the nature of that liquid crystal was cholesteric. Films of the liquid crystal composite cast from the liquid crystal solutions of CA/PVP were tested in a viewpoint of biomembrane. Results show that considering permselectivity CA/PVP membrane is better than that of CA and CA/PVP membrane is closer to cell membrane.

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Bistable Liquid Crystal Device Realized on Microscopic Orientational Pattern

  • Kim, Jong-Hyun;Yoneya, Makoto;Yokoyama, Hiroshi
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.187-190
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    • 2005
  • Alignment pattern of checkerboard was constructed by the stylus of atomic force microscope. Orientational bistability of the nematic liquid crystal was realized on that frustrated surface alignment. Macroscopic orientational switching between two perpendicular directions took place by an appropriate in-plane electric field. The threshold electric fields decreased in both switching directions as temperature increased. The focused laser heated up only the limited domains in the cell including a light-absorbing medium. Irradiating the laser concurrently with an appropriate electric field, we switched the selected unit domains in the alignment pattern. The switched domains maintained stably the switched direction without the disturbance from the exterior. Extending and repeating this process, we realized extremely fine devices of bistable switching.

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Optimization of Chiral Dopant and Rubbing Direction in Liquid Crystal Display

  • Lee, Kyung-Jun;Park, Jun-Baek;Park, Jong-Min;Kim, Hoe-Chang;Seo, Jae-Ho;Kim, Yoo-Jin;Jung, Byung-Hwan
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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    • pp.948-951
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    • 2007
  • In order to improve the performance of LCD, chiral dopant is added to liquid crystal mixture. When we decide the rubbing direction, we must consider the rotation direction of liquid crystal molecules by chiral dopant. When the rotation direction of liquid crystal molecules caused by dielectric torque decided by rubbing direction and that decided by chiral dopant are coincided, the performance of LCD would be improved along to our initial cell design intentions.

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액정 디스플레이 소자 내에서의 불균일한 표면에 의한 결점의 발생과 모델링 (Numerical modeling of defects nucleation in the liquid crystal devices with inhomogeneous surface)

  • 이기동;강봉순
    • 한국정보통신학회논문지
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    • 제9권8호
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    • pp.1793-1798
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    • 2005
  • 액정 디스플레이 소자의 디렉터 내에서 결점을 모델링 할 수 있는 fast Q-텐서법을 이용하여 불균일한 표면에서 발생할 수 있는 결점의 발생과 움직임에 대한 모델링을 하였다. 결점을 모델링하기 위하여 $1{\mu}m$ 단차의 전극을 가진 수직배향셀을 이용하였다. 모델링을 통하여 단차에서 발생하는 액정 디렉터 내에서의 결점의 발생과 결점선을 확인할 수 있었으며 이러한 결과는 실험을 통하여 확인하였다.

고굴절 네마틱 액정에서의 액정 디스플레이의 고속응답 특성 (Fast Response Characteristics in Liquid Crystal Display in the High birefringence nematic liquid crystal)

  • 김종환;황정연;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.498-501
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    • 2003
  • We investigated response characteristics of twisted nematic (TN) cell with different nematic liquid crystals (NLCs) and cell gap d on a rubbed polyimide (PI) surface. High transmittance and fast response time of the TN cell on the rubbed PI surface were achieved by using high birefringence (${\Delta}n$) and low cell gap d. The transmittance and response time of the TN cell on the rubbed PI surface decreased with decreasing ${\Delta}nd$. The fast response time of TN cell using high birefringence with ${\Delta}nd=0.363$ on the rubbed PI surface was measured 5.1 ms.

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액정을 이용한 반사형 가변 광 감쇠기 (Reflective Variable Optical Attenuator using Liquid Crystals)

  • 이용민
    • 전자공학회논문지
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    • 제51권2호
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    • pp.15-18
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    • 2014
  • 본 논문은 광스위치등에 사용되는 가변 광감쇠기를 위해 반사형 액정셀을 채용한 광감쇠기 구조를 제안하고 특성을 검토한다. 본 제안의 가변 광감쇠기는 반사형구조로 소형화가 가능하고 저전압구동이 가능하다. 광통신용 파장에 적합한 액정셀의 설계방법, 주변온도에 따른 동작특성, 광감쇠기의 응답특성 등을 검토하여 본 제안 구조의 유용성을 검증한다.

Control of liquid crystal pretilt angle using polyimide mixture

  • Kang, Dae-Seung;Lee, Ji-Hoon;Rosenblatt, Charles
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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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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Azo-Dyes Photo-Aligning; Physics and Applications

  • Chigrinov, V.G.;Kwok, H.S.;Takada, Hirokazu;Takatsu, Haruyoshi
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.759-763
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    • 2005
  • This review presents the status of our research in liquid crystal display (LCD) photo-aligning. We present the basic mechanisms of the photo-induced order in various photo-aligning materials and in azo-dye layers in particular and show that photo-aligning methods can provide a controllable pretilt angle and anchoring energy of the liquid crystal cell, as well as its high thermo and UV stability. The photo-aligning of various types of liquid crystal displays is also discussed.

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Twisted Nematic LC Modulator for TFT Array Inspection

  • Bae, B.S.;Park, D.H.;Lee, H.K.;Lee, S.E.;Kim, S.H.;Jeong, D.H.;Rho, B.G.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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    • pp.290-292
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    • 2007
  • A twisted nematic type liquid crystal electro-optic modulator (TN-LC modulator) was developed. The modulator used single polarizer and the reflection on-off ratio was maximized by optimization of twist angle and retardation of liquid crystal cell. The TNLC modulator shows better sensitivity and response time than conventional liquid crystal modulator.

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