• 제목/요약/키워드: Liquid crystal alignment layer

검색결과 154건 처리시간 0.021초

폴리이미드 표면에서의 네마틱 액정의 틸트 제어를 이용한 High Tilted OCB(HTOCB) 모드 (A Hight Tilted OCB(HTOCB) Mode using Control of Tilt Angle for Hematic Liquid Crystal on Polyimide Surface)

  • 황정연;정연학;서대식
    • 한국전기전자재료학회논문지
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    • 제18권7호
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    • pp.635-640
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    • 2005
  • In this paper, we have improved a novel high tilted optically compensated bend (OCB) (HTOCB) mode by using high tilt angle that was generated by the unique baking condition on the homeotropic alignment layer. The high tilt angle of liquid crystal (LC) was generated by new alignment process that tilt angle changed homeotropic state to homeogenous state using Hot-plate equipment; we obtained about $40\~50^{\circ}$ tilt angle with negative and positive dielectric anisotropy on the homeotropic polyimide (PI), and then LC tilt angle decreased as increasing baking temperature and time. At last, we obtained about $10^{\circ}$ with positive type NLC $({\Delta}n>0)$. Also, the LC tilt angle of positive type NLC $({\Delta}n>0)$ decreased as increasing rubbing strength at the same baking temperature and time. The novel LC operating mode (HTOCB) that used the high tilt angle by the new alignment method was improved. The response time of the novel HTOCB cell was faster than that of conventional OCB cell. We suggest that the developed the novel HTOCB cell using control of tilt angle on the homeotropic surface is a promising technique for the achievement of a fast response time and a high contrast ratio.

Investigation into the stability of ion beam treated inorganic alignment layer

  • Kim, Kyung-Chan;Ahn, Han-Jin;Kim, Jong-Bok;Hwang, Byung-Har;Baik, Hong-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.328-329
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    • 2005
  • Inorganic alignment layer (IAL) was deposited on an indium-tin-oxide (ITO) by using reactive sputtering deposition method. After deposited, IAL was irradiated by $Ar^+$ ion beam (IB) for liquid crystal (LC) alignment. IAL treated by various conditions such as IB energy, IB incident angle, and IB irradiation time had excellent alignment property and electro-optical property the same as that of PI. We investigated into the stability of ion beam treated IAL after a lapse of long time. However IAL irradiated IB did not occur degradation of electro-optical property. The results implied that IAL irradiated IB was adopted as LC alignment layer instead of rubbed polyimide.

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ITO 박막이 증착된 편광판을 기판으로 하는 액정 셀의 제작 (Fabrication of a Liquid Crystal Cell Using ITO-deposited Polarizers as Substrates)

  • 진혜정;김기한;박경호;손필국;김재창;윤태훈
    • 한국광학회지
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    • 제22권2호
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    • pp.90-95
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    • 2011
  • 본 논문에서는 액정 디스플레이의 구현에 있어서 필수적인 필름인 편광판에 ITO를 증착하여 기존 액정 디스플레이에서 두께의 대부분을 차지하는 유리기판을 제거함으로써 경략 박형 액정 셀을 구현하였다. 저온($40^{\circ}C$)에서 편광판에 sputtering으로 buffer layer와 ITO를 증착하여 높은 투과율과 낮은 비저항 및 편평도를 확보하였다. 최종적으로 저온공정이 가능한 ion-beam 배향법을 이용하여 액정을 배향하고 액정 셀을 제작하고 전기광학특성을 확인하였다.

고분자 필름을 이용한 폴리이미드 표면에서의 프리틸트각 발생 (Generation of Pretilt Angles on the Polyimide Surface using Plymer Flims)

  • 황정연;남기형;서대식
    • 한국전기전자재료학회논문지
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    • 제16권12호
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    • pp.1110-1114
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    • 2003
  • We have investigated the generation of pretilt angle for a nematic liquid crystal (NLC) alignment with rubbing alignment method on polyimide surfaces using thin plastic substrates. It was found that monodomain alignment of NLC is obtained with rubbing alignment method on polyimide surfaces using thin plastic substrates. The NLC pretilt angles generated are about 3$^{\circ}$ by the rubbing alignment method on thin plastic substrates, However, the pretilt angle are at about 1.7$^{\circ}$ lower on the glass substrate than on thin plastic substrate. We obtain that AFM (atomic force microscope) image of rubbed PI surface with polymer film has formed the micro-groove structure at the low curring temperature (120$^{\circ}C$). However, no grooves are obtained on the glass substrate at the same temperature. It is considered that this alignment may be attributed to roughness of micro-groove substrate. The tilt angle increases with increasing baking temperature for making polyimide layer using glass substrate. It was concluded that the pretilt angle in the polyimide surface is attributable to the increasing of imidization rato.

PI와 유기 절연막 과의 전기광학 특성 비교에 관한 연구 (Study on Electro-Optical Specific of Polyimide and Organic Overcoat)

  • 김병용;김종환;한정민;김영환;강동훈;김종연;옥철호;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.376-376
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    • 2007
  • In Liquid Crystal Display (LCD) manufacturing, the organic over coat materials over coat materials for insulation layer of color filter with acryl ate was widely used. Therefore, we approach that the organic overcoat material can use to insulation layer for color filter and liquid crystal (LC) alignment layer in this research. The LC aligning capabilities was successful stuided for the first time. The organic overcoat layer and polymer layer was coated by spin-coating. In order to characterize the LC alignment, electric optic and residual DC and atomic force microscopy (AFM) image was used. The good LCD aligning capabilities treated on the organic overcoat thin film surfaces with ion beam exposure of $45^{\circ}$ above ion beam energy density of 1200 eV can be achieved. Also the good LCD alignment capabilities treated polymer on surfaces with ion beam exposure of $45^{\circ}$ above ion beam energy density of 1800 eV can be achieved. Comparing electro-optical characteristics between the Polyimide (PI) and the overcoat, the resultant transmittance of the overcoat considerably matched that of the PI and the residual DC also exhibited similar features with the PI.

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Electro-optical Properties of Twisted Nematic Liquid Crystal Displays Fabricated with TIPS-pentacene Doping

  • Lee, Jin-Woo
    • Transactions on Electrical and Electronic Materials
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    • 제14권2호
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    • pp.82-85
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    • 2013
  • This paper introduces 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS pentacene) doped liquid crystal (LC) alignment properties on a rubbed polyimide (PI) layer as a function of the doping concentration of TIPS pentacene. Pretilt angles, photomicrographs, and electro-optical properties of TIPS pentacene doped LCs were comparable to those of pure LCs. However, TIPS pentacene in a LC medium supported twisted nematic-liquid crystal displays (TN-LCDs) to improve electro-optical properties. The threshold voltages observed in the TN cells decreased as the TIPS pentacene concentration increased. In addition, suitable response times were observed in TN cells.

23' LCD TV by using ALT plasma beam alignment technology

  • Lee, C.Y.;Tang, H.C.;Chen, C.W.;Shih, Y.J.;Liu, C.H.;Lin, C.H.;Yang, K.H.;Lin, S.H.;Chang, H.C.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.776-779
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    • 2006
  • The alignment of liquid crystal (LC) is one of the key issues of liquid crystal display (LCD) technologies. In this study, we aligned polyimide (as the LC alignment layer) by ALT plasma beam and to realize the stability and characteristics of this technology. The characteristics such as anchoring energy, pre-tilt angle, voltage holding ratio(VHR) and residual direct current(Rdc) were discussed. Besides, we applied it to the in plane switch (IPS) mode 23" WXGA real panel, the performance parameters and electrical properties were measured and compared with those of rubbing alignment. From the result, we demonstrated a successful LC alignment treatment process in real panel by ALT plasma beam.

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스퍼터링으로 경사증착한 $SiO_x$ 박막을 이용한 VA-LCD의 전기광학특성 (Electro-Optical Characteristic for VA-LCD on the $SiO_x$ Thin Film Layer Oblique Deposited by Sputtering Method)

  • 최성호;황정연;김성연;오병윤;명재민;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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    • pp.451-452
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    • 2006
  • We studied the electro-optical characteristic of vertical alignment liquid crystal display(VA-LCD) on the $SiO_x$ thin film deposited $45^{\circ}$ oblique by rf magnetic sputtering system. LC alignment characteristic showed homeotropic alignment, and pretilt angle was about $90^{\circ}$. A uniform liquid crystal alignment effect on the $SiO_x$ thin film was achieved and the electro-optical characteristic of the $SiO_x$ thin film deposited $45^{\circ}$ oblique by rf magnetic sputtering system was excellent.

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광분해성 고분자를 이용한 액정배향에서의 광조사 및 열처리 효과 (Effects of UV Irradiation and Thermal Treatment of Photo-Degradable Polyimide Layer on LC Alignment)

  • 이장주;이원호;신용일;백상현
    • 폴리머
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    • 제36권2호
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    • pp.145-148
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    • 2012
  • 광분해형 CBDA-ODA 폴리이미드의 배향막에 대하여 선편광(LPUV) 조사와 이후의 열처리가 배향막, 액정 배향 그리고 LCD 특성에 어떠한 영향을 미치는지에 대하여 조사하였다. 가장 우수한 액정 배향은 배향막의 이방성을 최대로 발생시키는 광조사 에너지보다 상당히(약 5~10배) 작은 양의 광조사에 의하여 유도되었다. 광조사에 이후에 이어지는 배향막에 대한 열처리는 광분해 반응에 의하여 배향막 표면에 형성된 저분자 부산물들을 효과적으로 제거함과 동시에 광조사된 배향막을 안정화시킴으로써 액정의 배향성과 LCD의 전기적 특성을 향상시키는 결과를 가져왔다.

Soft-lithography for preparing patterned liquid crystal orientations

  • Kim, Hak-Rin;Jung, Jong-Wook;Shin, Min-Soo;Kim, Myung-Eun;Lee, You-Jin;Kim, Jae-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.615-620
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    • 2006
  • We demonstrate novel soft-lithographic techniques for preparing patterned liquid crystal (LC) orientations at an alignment layer. By controlling patterning conditions such as wetting property and operating temperature depending on polymeric materials, multi-directional or modified LC alignment conditions can be simply achieved.

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