• Journal of Information Display
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• v.1 no.1
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• pp.48-51
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• 2000

In this work, we proposed a reflective antiferroelectric liquid crystal display (AFLCD) using a half-wave cell whose inplane tilt angle is $22.5^{\circ}$. To check the validity of our design, we fabricated a reflective half-wave AFLC cell of which inplane tilt angle is $24.9^{\circ}$, and measured VIS reflection spectra, contrast ratio and response time. In the results, the half-wave AFLC cell in the reflective configuration exhibits high brightness, high contrast ratio of 20:1, and fast response time of $700{\mu}s$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05a
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• pp.210-213
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• 2004

We synthesized photoalignment material of high thermal resistance with hydroxyl aromatic polyimide, and studied the liquid crystal (LC) aligning capabilities on the photopolymer layers. Also, electro-optical (EO) performances for the twisted-nematic (TN)-liquid crystal display (LCD) photoaligned with linearly polarized UV exposure were investigated. A good LC alignment with UV exposure on the photopolymer surface can be obtained. However, the low pretilt angles were obtained below $1^{\circ}$. The Voltage-transmittance (V-T) curve without backflow bounce in the photoaligned TN cell with UV exposure was observed. The response time of photoaligned TN cell was measured about 24 ms. Finally, The photoaligned TN cell has few hysteresis, and shows the residual DC voltage that is less.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.324-327
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• 2005

We propose a novel technique for evaluating the azimuthal anchoring strength of the alignment film on the nematic liquid crystal (LC). In our evaluation, a unique cell, which has two domain in one cell, was used; one is hybrid aligned nematic (HAN) region, the other is twsited nematic (TN) region (viz. HAN/TN two domain cell). From the comparison of director angles on the front substrate with each region, we are able to determine the angle between easy axis and real director axis on the front substrate. From this evaluation, the azimuthal anchoring strength was obtained accurately.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1130-1132
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• 2009

We propose a novel way for enhancement of efficiency on a quasi solid-state dye-sensitized solar cell (DSSC). It contained gel type electrolyte mixing the liquid crystal (LC) of specific concentration and applied voltage for alignment of the LC. Aligned LC is supported charge transfer inside electrolyte and efficiency is increased in DSSC. We made a quasi solid-state DSSC which applied DC voltage or not and have measured the power conversion efficiency (PCE) and the fill factor. From measurement, we obtain high performances in case of cell applied voltage compare to reference cell.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.496-498
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• 2007

This paper reports our observation that the addition of nanoparticles in the negative dielectric anisotropic liquid crystal (LC) cell can exhibit the properties of vertical alignment without using alignment layers. The electro-optical properties of this nanoparticles-induced vertical alignment in the LC cell are very similar to the conventional homeotropic LC cell with alignment layers. This technique can be used to fabricate a flexible LC display demanding low temperature process

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.954-957
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• 2007

We analyzed conditions for fabricating zero-bias polymer-stabilized liquid crystal (PSLC) pi cells. A high curing voltage and a very low curing intensity are effective in fabricating the cell with a high bright state, a low dark state and therefore a steep T-V curve. However, the response time of the cell is slow. Finally, a dual-frequency PSLC pi cell with fast response time is developed. The obtained result reveals that the dual-frequency PSLC pi cell has a fast response of under 1ms.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.515-518
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• 2000

We studied the viewing angle characteristics of a negative dielectric anisotropy nematic liquid crystal (NLC) using the new vertical-alignment (VA)-1/6 cell on a rubbed polyimide (PI) surface. Good voltage-transmittance (V-T)characteristics using the new VA-1/6 cell without a negative compensation film were obtained. The iso-viewing angle characteristics using the new VA-1/6 cell without the negative compensation film can be achieved.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.3
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• pp.305-310
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• 2004

We have studied the optimal phase retardation value of a homogeneously aligned liquid crystal (LC) driven by fringe-field when using the LC with positive dielectric anisotropy. In general, the transmittance of a homogeneous aligned LC cell under crossed polarizer is maximum when a twist angle of LC by in-plane rotation is 45$^{\circ}$ with polarizer and the cell retardation becomes λ/2. However, the device using the LC with positive dielectric anisotropy does not follow this since the degree of rotation of the LC is dependent on electrode position and in addition the LCs tilt up along the fringe-field. At the center of common and pixel electrode, the LC is most twisted around a middle position of a cell whereas at the edge position of pixel electrode, the LC is most twisted near bottom surface of a cell. Consequently, the optimal phase retardation of the device becomes much larger than λ/2 and the transmittance can be described using the combination of the in-plane switching and twisted nematic mode.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.347-348
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• 2009

• Proceedings of the Optical Society of Korea Conference
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• 2001.08a
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• pp.292-293
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• 2001