• 한국전기전자재료학회논문지
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• 제19권3호
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• pp.260-266
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• 2006

In this paper, We coupled fluid balance and director balance equation from Ericksen-Leslie's continuum theory and observed the motion of Liquid Crystal molecular. We simulated flow velocity and director distribution in which flow effect is considered in switching on and switching off state. We interpreted the dynamic response characteristic caused by the flow. As the result of the simulation, We could see the flow effect. In the case of Twisted Nematic(TN) cell, this flow caused abnormal twist temporarily in switching off state. We could prove that this abnormal twist is a direct cause of optical bounce phenomenon known well until now with the result of simulation. In addition, We analyzed the mechanism of the fast response due to flow in the case of Optically Compensated Bend(OCB) cell.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.411-414
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• 2005

We have developed a transflective liquid crystal display (LCD) with a single cell gap and a low twisted nematic (LTN) mode in combination with a self-integrated retardation layer. The retardation layer was made of UV curable liquid crystalline material in one step of photo masking process and has both the homeotropic and the planar parts. The proposed transflective configuration has advantages in a simple fabrication process, and the possibility for a single driving scheme due to the similarity between the transmittance and the reflectance.

• E2M - 전기 전자와 첨단 소재
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• 제10권10호
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• pp.1011-1015
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• 1997

In this paper we investigated the electro-optical characteristics of amorphous (a)- twisted nematic (TN)-liquid crystal display(LCD) on polymide (PI) surfaces with different molecular structure. It was found that the domaine size of a-TN-LCD on PI with high polarization is small compared to a-TN-LCD on PI with medium polarization. It is considered that the response time of a-TN-LCd contributes to surface effect between the substrate surfaces and the LC molecules. Finally we obtained that the viewing angle of a-TN-LCD on PI surfaces increases with decreasing the domain size.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1462-1465
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• 2009

Because of its weak points that narrow viewing angle and grayscale inversion, 'bare' twisted nematic (TN) LCD has some limits to use as a display device, though its great strong points that low cost, high yield, simple design, high transmittance and normally white. The 'WideView(WV)' film which introduced by Fuji co., has been good solution to extend the viewing angles of TN mode, therefore that film have been used generally for TN panels needed wide viewing angle. This paper introduce the research to find the parameters of the Wide view film and a TN panel which affect viewing angle characteristics and how to adjust those parameters.

• 한국전기전자재료학회논문지
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• 제17권2호
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• pp.207-211
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• 2004

We have performed computer simulation to obtain a globa1 optimization of power consumption and viewing angle characteristic of reflective twisted nematic (R-TN) mode liquid crystal display (LCD) with sin81e polarizer and λ/4 plate. Our studies shout that with increasing the twist angle, a steepness of reflectance-voltage curve increase, operation voltages decreases, the region where contrast ratio (CR) greater than 10 increases but the reflectance of the white state starts to decrease at above the twist angle of 75$^{\circ}$. Above the twist angle of 90$^{\circ}$, the R-TN mode LCD shows the most favorable combination of low consumption and good viewing angle characteristic.

• E2M - 전기 전자와 첨단 소재
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• 제10권1호
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• pp.15-19
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• 1997

The characteristics of the response time and the viewing angle on twisted nematic (TN) liquid crystal display (LCD) and amorphous (a)-TN-LCD without rubbing were investigated. To measure the tansmission-voltage, response time, and viewing angle characteristics, we prepared three kinds of LC cells and then studied the surface liquid crystal alignment effect. It was found that the response time on A-TN-LCD was fast compared to the TN-I-CD, and the weak anchoring strength was attributed to the fast response time on a-TN-LCD. Also, we obtained the wide viewing angle characteristics on a-TN-LCD. The liquid crystal alignment of LCD device for electro-optical characteristics is discussed in the present paper.

• 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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.477-480
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• 2003

We investigated the electro-optical (EO) performances of the super twisted nematic liquid crystal display (STN-LCD) on the polyimide (PI) surface using polymer film. Monodomain alignment of the plastic STN-LCD can be observed. A stable voltage-transmittance (V-T) curve of the plastic STN-LCD was observed on the polyimide (PI) surfaces using polymer film. Also, a faster response time for the plastic STN-LCD on the polyimide (PI) surfaces using polymer film can be achieved. However, the transmittance of the plastic STN-LCD on the polyimide (PI) surfaces using polymer film decreased greatly as cell gap decreases.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.451-452
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• 2005

In this study, the threshold voltage and the response time of thermal stressed TN-LCDs showed the same performances on none thermal stressed TN-LCDs. There was little change in TN cells. Also, while increasing thermal stress time, the transmittances of TN-LCDs on the rubbed PI surface were almost the same, But the thermal stability of TN cell was deteriorated.

• Journal of the Optical Society of Korea
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• 제16권4호
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• pp.443-448
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• 2012

A polarimetric experimental method was developed to determine the Jones matrix elements of transparent optical materials without sign ambiguity. A set of polarization dependent transmittance data of the samples was measured with polarizer - sample - analyzer system and another set of data was measured with polarizer - sample - quarter-wave plate - analyzer. Two data sets were compared and mathematically analyzed to obtain the correct signs of the elements of the matrix. The Jones matrix elements of a quarter-wave plate were determined to check the validity of the method. The experimentally obtained matrix elements of the quarter-wave plate were consistent with the theoretical expectations. The same method was applied to obtain the Jones matrix elements of a twisted nematic liquid crystal panel.