• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.1083-1084
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• 2002

We prepared the blend alignment layers made from coumarin based photopolymer and polyimides for liquid crystal(LC) alignment using linearly polarized ultraviolet(UV) exposure. The alignment properties of LC were found to depend on the type of polyimide in the blend alignment layers. The degree of photereaction of polyimide was important factor for LC alignment direction on the blend alignment layers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.271-274
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• 1998

In this paper, the monodomain alignment of nematic liquid crystal(NLC) in the cell fabricated by one side transcription alignment method on PI surface with side chain were investigated. The LC alignment produced by the transcription alignment method is attributable to a memory effect of the NLC on Pl surfaces. We observed that the pretilt angle of NLC is generated about 3.6$^{\circ}$ in a cell with one side transcription alignment on PI surface. Also, the electro-optical(EO) performance of TN-LCD with one side transcription alignment method on PI surface will be discussed.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.263-265
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• 2003

Stressed liquid crystals, SLCs, consist of a lowdensity polymer network dispersed in a nematic host. We induced stress by shearing the material. Alignment layers are not required because the liquid crystal director uniformly aligns along the direction of shear. The shearing stress also eliminates light scattering and results in sub-millisecond switching speeds, making them good candidates for video display applications.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1577-1578
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• 1997

We have studied the effect of the rubbing fabric for liquid crystal alignment and pretilt angle generation in nematic liquid crystals (NLC), 4-cyano-4-n-penthylbiphenyl (5CB), on rubbed polyimide (PI) surfaces. The pretilt angle of 5CB for nylon and rayon fabric is larger than that of cotton fabric in weak rubbing on rubbed PI surfaces. We conclude that the pretilt angle of 5CB is strongly related to the rubbing fabrics on rubbed PI surfaces.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.7
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• pp.695-699
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• 2006

Injection time of liquid crystal (LC) by capillary action in a vertically aligned (VA) nematic LC cell takes longer than that in a homogeneously aligned (HA) LC cell because Miesowicz viscosity in the former is bigger than that in the latter. To reduce liquid crystal injection time in the VA cell, we applied vertical electric field while injecting so that the orientation of LC molecules is changed from vertical alignment to homogeneous alignment. Consequently, the injection speed is improved by 25 % when compared with the cell without an applied field.

• Transactions on Electrical and Electronic Materials
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• v.3 no.2
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• pp.1-5
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• 2002

Alignment effects for nematic liquid crystal (NLC) and electro-optical (EO) characteristics of the ion beam (IB) aligned twisted nematic (TN)-liquid crystal display (LCD) with oblique ion beam exposure on the diamond-like carbon (DLC) thin film surface were studied. A high pretilt angle of 3.5$^{\circ}$ in NLC by ion beam exposure on the DLC thin film layer can be measured. An excellent voltage-transmittance (V-T) curve of the ion beam aligned TN-LCD was observed with oblique ion beam exposure on the DLC thin film surface for 1 min. Also, a faster response time for the ion beam aligned TN-LCD with oblique ion beam exposure on the DLC thin film surface for 1 min can be achieved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.173-173
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• 2010

We proposed viewing angle switchable liquid crystal display(LCD) associated with fringe-field switching (FFS) mode with high aperture ratio characteristic. In the device, single pixel is separated into two regions, named as main pixel for displaying images and sub pixel for viewing angle control. In sub pixel region, add the common electrode on the top substrate and the initial alignment of liquid crystal is Hybrid Alignment Nematic (HAN) state. In conclusion, we suggested that the device has high aperture ratio characteristic because the LC directors are rotated in which viewing angle control region are generated fringe electric field.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.324-327
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• 2001

Liquid crystal alignments on a rubbed polyimide layer were investigated by using optical transmission method. Using this technique, we also studied the pretilt angle of the polymer molecules near the surface of a side-chain polymer layer as a function of the rubbing strength. In particular, we obtained the optical characteristics of liquid crystal orientations and pretilt angles for LC cell photo-aligned by UV as well after rubbing alignment. High pretilt angle of 3.84 degree was obtained on the weekly rubbed polymide layer duribg UV irradation time of 60min.

• Journal of Information Display
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• v.9 no.1
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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.

• Journal of the Optical Society of Korea
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• v.16 no.2
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• pp.166-169
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• 2012

We propose a high-transmittance multi-domain vertical alignment liquid crystal device with a protrusion structure. Disclination lines, which inevitably appear at the boundaries of domains in a multi-domain structure, can be reduced by adding a protrusion structure on the top substrate. The transmittance was improved by 11% using the proposed structure with no change of either the dark state or the operating voltage.