• 제목/요약/키워드: Anchoring energy

검색결과 74건 처리시간 0.026초

Weak Anchoring 에너지를 고려한 TN-LCD의 Simulation (Electro-optical Simulation of Twist Nematic Liquid Crystal Displays considering Anchoring Energy)

  • 정진택;박우상
    • 한국전기전자재료학회논문지
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    • 제20권11호
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    • pp.969-976
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    • 2007
  • In this thesis, an anchoring energy in the upper and lower substrates of TFT-LCD cell has been modeled and applied in the numerical calculation of the molecular orientation of the TN-LCD. The molecular orientation of liquid crystals defined as tilt and twist angles was simulated using the Newton-Raphson method and the Gaussian integration method. From the results, the tilt and twist angles for the strong anchoring energy were proven to be coincide with those of the conventional results. on the other hand, for the weak anchoring energy, azimuth angles of the molecules were changed abruptly from $0^{\circ}\;to\;90^{\circ}$ near the middle area of the cell due to the balance of the anchoring energy and the elastic energy of the liquid crystals.

A New Method for Measuring Azimuthal Anchoring Energy of Rubbed and UV-Exposed Polyimide Alignment Layers

  • Park, H.J.;Lee, W.K.;Kim, D.G.;Shin, D.C.;Woo, J.W.;Shin, H.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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    • pp.1619-1621
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    • 2007
  • Novel optical measurement systems and improved cell configurations for measuring of azimuthal anchoring energies were developed. The difference between the mechanical rubbing direction and the optical easy axis that caused errors in the previous azimuthal anchoring energy measurement was compensated. In addition, the measurement accuracy of the twist angle and therefore the azimuthal anchoring energy was greatly enhanced. As a result, we were able to obtain valid azimuthal anchoring energy values for different alignment layers.

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Effects of Surface Order Parameter on Polar Anchoring Energy in NLC on Weakly Rubbed Polyimide Surface

  • Seo, Dae-Shik
    • 한국전기전자재료학회논문지
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    • 제11권12호
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    • pp.1128-1132
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    • 1998
  • We have investigated the relationship between the polar anchoring energy and the surface order parameter in nematic liquid crystal (NLC), 4-n-pentyl-4-cyanobiphenyl (5CB), on the two kinds of the weakly rubbed polyimide (PI) surfaces. The observed polar anchoring energy of 5CB is approximately 2${\times}10^{-4}(J/m^2$) and then increases with increasing the rubbing strength (RS) on weakly rubbed surface (RS=57mm) with side chain at $30^{\circ}C$; same results are obtained on weakly rubbed PI surface without side chain. The surface order parameter of 5CB on rubbed PI surfaces increases with increasing the RS at a weak rubbing region. The surface order parameter of 5CB is strongly related to the characteristics of PI material. Consequently, we suggest that the polar anchoring energy of NLC is strongly attributed to the surface order parameter on rubbed PI surfaces.

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3차원 전열해석 및 생애비용 분석을 통한 커튼월 앵커링 유닛의 단열성능 향상 방안 평가 (Insulation Performance Evaluation of the Curtain Wall Anchoring Unit by 3D Heat Transfer Simulation and Life Cycle Cost Analysis)

  • 강승희;송승영
    • 한국태양에너지학회 논문집
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    • 제23권4호
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    • pp.63-70
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    • 2003
  • It is very important to improve the insulation performance of curtain wall anchoring unit since it is composed of materials with high thermal conductivity, such as aluminium, steel and so on. This study aims to evaluate the heating energy performance and economical efficiency of various alternatives which are different in position and material of insulation. As results, alternative of inserting the urethane washer & pad and coating the anchoring unit with urethane foam can improve the heating energy performance and L.C.C(Life Cycle Cost) by 6.33% and 0.95%, respectively, as compared with the existing case.

Anchoring Strength Characteristics by the Washing Process after Rubbing on the Polyimide Layers

  • Lee, Sang-Keuk;Lee, Joon-Ung;Han, Jeong-Min;Hwang, Jeoung-Yeon;Paek, Seung-Kwon;Seo, Dae-Shik
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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    • pp.1078-1081
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    • 2003
  • The polar anchoring strength and surface ordering in a NLC, 4-n-pentyl-4'-cyanobiphenyl (5CB), on a rubbed polyimide (PI) surface containing trifluoromethyl moiety were studied. The large extrapolation length de of 5CB for washing process of water was measured at RS=114 mm. The polar anchoring energy of 5CB on the rubbed PI surface is decreased by the washing process. Also, the polar anchoring energy of 5CB increases with the rubbing strength on the PI surface. The surface ordering of 5CB for all washing processes is smaller than the non-washing process; it is attributed to the washing process.

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Development of Low Anchoring Strength Liquid Crystal Mixtures for Bistable Nematic Displays

  • Stoenescu, D.;Lamarque-Forget, S.;Joly, S.;Dubois, J.C.;Martinot-Lagarde, Ph.;Dozov, I.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.97-100
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    • 2005
  • The recent Bistable Nematic ($BiNem{(R)}$) LCD technology presents long term bistability, high level passive matrix multiplexing and high optical quality. The BiNem device, based on anchoring breaking, needs specific low anchoring strength materials - alignment layers and liquid crystal mixtures. We present here our approach to develop nematic mixtures with wide enough temperature range and low zenithal anchoring energy.

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Capillary Force Lithographic Patterning of a Thermoplastic Polymer Layer for Control of Azimuthal Anchoring in Liquid Crystal Alignment

  • Kim, Hak-Rin;Shin, Min-Soo;Bae, Kwang-Soo;Kim, Jae-Hoon
    • Journal of Information Display
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    • 제9권1호
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    • pp.14-19
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    • 2008
  • We demonstrated the capillary force lithography (CFL) method for controlling the azimuthal anchoring energy of a liquid crystal (LC) alignment layer. When a thermoplastic polymer film is heated to over the glass transition temperature, the melted polymer is filled into the mold structure by the capillary action and the aspect ratio of the pattern is determined by the dewetting time of the CFL process. Here, the proposed method showed that the azimuthal anchoring energy of the LC alignment layer could be simply controlled by the surface relief patterns which were determined by the dewetting times during the CFL patterning.

Anchoring Properties in Photo-aligned Periodic Domains for Wide-viewing Liquid Crystal Displays

  • Yu, Chang-Jae;Park, Jae-Hong;Lee, Sin-Doo
    • Journal of Information Display
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    • 제4권1호
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    • pp.24-28
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    • 2003
  • We studied the anchoring properties in photo-aligned periodic domains of liquid crystals (LCs) in an alternating homeotropic and hybrid geometry. In this geometry, the surface anchoring energy was determined in using the director-distorted length of the LC near domain boundary, calculated in a linear approximation of the director profile within the continuum theory. The measurements were made using the LC diffraction grating with the phase profile in the form of a trapezoid.

Development of Low Anchoring Strength Liquid Crystal Mixtures for Bistable Nematic Displays

  • Dozov, Ivan;Stoenescu, Daniel-Nicusor;Lamarque-Forget, Sandrine;Joly, Stephane;Dubois, Jean-Claude;Martinot-Lagarde, Philippe
    • Journal of Information Display
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    • 제6권3호
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    • pp.1-5
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    • 2005
  • The recent Bistable Nematic ($BiNem^{(R)}$) LCD technology presents long term bistability, high level passive matrix multiplexing, gray levels capabilities and high optical quality. The $BiNem^{(R)}$ device, based on anchoring breaking, needs specific low anchoring strength materials - alignment layers and liquid crystal mixtures. We present here our approach to develop nematic mixtures with wide enough temperature range and low zenithal anchoring energy.