• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.446-447
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• 2006

We investigated the electro-optic characteristics of a fringe-field driven twisted nematic (TN) display using a LC with negative dielectric anisotropy depending on electrode structures. The fringe-field driven TN mode known to exhibit wide viewing angle and excellent color characteristics over a wide viewing range and high transmittance. However, when the electrode width and distance between them is large enough, the transmittance is lower than the conventional vertical field-driven TN mode. By narrowing the electrode width and distance, the transmittance reaches the same value of the conventional TN mode.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.440-441
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• 2006

We have studied the narrow viewing angle liquie crystal displays (LCDs) using a hybrid aligned nematic liquid crystal (LC) cell driven by a fringe field. The device using a LC with positive dielectric anisotropy has a relatively low transmittance. This paper describes how to improve light efficiency by optimizing electrode structure. The results show that the device exhibits a high transmittance of 90%, low driving voltage and narrow viewing angle less than $20^{\circ}$ along horizontal direction which is highly effective for private display application.

• International Journal of Internet, Broadcasting and Communication
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• 제15권1호
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• pp.145-149
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• 2023

In this study, the spectrum changes induced from the doping of phosphor micro particles in a twist nematic liquid crystal cell was observed. The experimental results show that the achromatic transmission can be observed with a proper driving condition, which may be applied to the design of an achromatic liquid crystal device. In this paper, we tried to figure out the spectrum changes induced from the doping of phosphor micro particles. The experimental result of the phosphor powder doped twist nematic liquid crystal cell shows that the achromatic transmission and the wavelength linearly dependent transmission both can be observed with some proper driving conditions, respectively. The result is useful on developing an achromatic liquid crystal device and it can be applied for Vihicle lamp.

• International journal of advanced smart convergence
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• 제13권2호
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• pp.103-109
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• 2024

A nonlinear numerical analysis of orientation and velocity fields of the full Ericksen-Leslie theory for a nematic liquid crystal under shear flow is given. We obtained for the first time the three-dimensional orientation and two component velocity profiles evolutions for both in- and out-of-shear plane orientation anchorings. Complex evolution routes to steady state were found even for shear aligning nematic. As the Ericksen number increases monotonic evolution of velocity and orientation shifts towards multi-region nucleating director rotation growth with complex secondary flow generations. We found that contrary to the in-shear-plane anchorings like homeotropic or parallel anchorings, binormal anchoring gives rise to substantial non-planar three-dimensional orientation with nonzero secondary flow.

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 동계학술발표회 논문집
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• pp.347-348
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• 2009

• 대한전자공학회논문지SD
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• 제41권8호
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• pp.59-65
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• 2004

본 논문에서는 IT(In-plane switching foisted nematic) 모드를 기반으로 광 투과 특성을 개선시킨 Pseudo-TN IPS(Pseudo-Twisted Nematic In-Plane Switching) 모드를 새롭게 제안하고 그 광 투과 특성을 분석하였다. PTN-IPS 모드의 경우 개구율을 향상시켜 투과율 면적을 향상시킴으로써 종래의 IT 모드보다 약 25%정도의 높은 광 투과 특성을 나타내었으며, 전압인가에 따른 광 투과율의 변화가 선형적이므로, 광 투과율 조절을 위한 액정의 제어가 IT 모드에 비해 용이함을 확인하였다. 또한, IT 모드에 비해 수평방향 대비비는 약 8%정도 특성이 열화 되었으나 수직 방향에 있어서는 약 20%이상의 특성개선을 확인 할 수 있었다. 이와 더불어, 기존 IT 모드가 가지고 있는 샐 갭에 대한 특성 및 장점을 가지고 있어, 차세대 액정 셀을 개발하는데 유용하게 사용될 것이라 생각된다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.195-198
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• 2005

Using theoretical analysis based on Landau theory, it is shown that only five phenomenological parameters are necessary to describe the twelve bulk elastic constants of a biaxial nematic phase. Further, a simple method for determining the values of these five parameters experimentally is given. Comparison with the values of the well-known splay, twist, and bend elastic constants of the uniaial nematic is made.

• 한국광학회:학술대회논문집
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• 한국광학회 2004년도 제15회 정기총회 및 동계학술발표회
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• pp.142-143
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• 2004

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.14-16
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• 2009

Surface driven switching of the liquid crystal bulk arising from the coupling between an applied electric field and a polarized state of a nematic liquid crystal, both localized at the substrate surface, is reported. Fast switching is demonstrated in a hybrid aligned nematic cell with a fringe electric field generated by comb-like electrode structure.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.972-975
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• 2003

We have performed computer simulation to obtain electro-optic characteristics of reflective hybrid aligned nematic liquid crystal displays driven by fringe field. The results show that the optimal retardation value of the cell is $0.289{\mu}m$, which allows for the cell to have a practical cell gap of larger than $3{\mu}m$ when manufacturing. A reflectance of the dark state is only 0.114% for an incident light 550nm. At this condition, the light efficiency of white state reaches 92.7%. Further, we have studied a new reflective display with polarizer, optical compensation with half plate, LC plus reflector. The display with optimized cell parameters shows low wavelength dispersion and the contrast ratio greater than 5 over exists about $120^{\circ}$ in vertical direction and $160^{\circ}$ in horizontal direction.