• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1197-1199
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• 2004

We have studied an optically compensated splay (OCS) mode driven by fringe electric field. The OCS configuration obtained by applying voltage to vertically aligned LCs shows a dark state when an optic axis of the OCS cell coincides with one of crossed polarizer axis. When the fringe electric field is applied, the LC director rotates in plane above whole electrode surface, giving rise to the high transmittance, the low operating voltage and wide viewing angle simultaneously.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.6
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• pp.524-528
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• 2002

Conventional hybrid aligned nematic liquid crystal display (HAN-LCD) has several advantages on low operating voltage, fast response time and rubbing free on one substrate. We have fabricated a new hybrid aligned nematic display driven by fringe field. The new device exhibits much wider viewing: angle than that of the conventional HAN mode, owing to almost in-plane rotation of the LC director. Furthermore, we have developed the device that reveals more efficient electro-optic characteristics by placing common electrode on top and bottom substrates. In this paper, the electro-optic characteristics of the novel cell are investigated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.953-956
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• 2002

The electro-optical (EO) performances of a multidomain vertical-alignment (MVA) cell on a homeotropic photopolymer have been investigated. In the absence of an electric field, the MVA cell achieved black state as LC alignment is homeotropic. An electric field created by interdigitated electrodes and rib made after photolithograph using the photopolymer on both substrates causes a director deformation of a multidomain type. Good voltage-transmittance curves for a MVA cell on the homeotropic photopolymer were observed. Also, the stable response time of MVA cell on the homeotropic photopolymer can be achieved.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.310-313
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• 2008

Recently, study on the weak interaction energy between the soft polymer surface and liquid crystals has been a primary topic for new LC device applications. In this paper, to understand the switching property of nematic liquid crystals (LCs) at the interface with a weak anchoring boundary, we investigate experimentally the rotation property of surface nematic director by electric field on non-treated Poly-Methylmethacrylate (PMMA, $T_g=110^{\circ}C$, Sigma Aldrich) film observed under various temperatures including the glass transition temperature ($T_g$) of the polymer layer.

• Journal of Information Display
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• v.4 no.3
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• pp.22-25
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• 2003

In this paper, we propose the bistability the bistability in a chiral-splay nematic liquid crystal cell, which is obtained by adding a chiral additive to a splay cell and introduce a novel switching method for the bistable chiral-splay nematic cell in order to transit the LC director between the non-twisted state with splay and the 180$^{\circ}$ twist state.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.3
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• pp.219-223
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• 2003

The electro-optical (EO) performances of a multidomain verticial-alignment (MYA) cell on a homeotropic photopolymer have been investigated. In the absence of an electric field, the WVA cell achieved black state as LC alignment is homeotropic An electric field created by interdigitated electrodes and rib made after photolithograph using the photopolymer on both substrates causes a director deformation of a multidomain type. Good voltage transmittance curves for a MVA cell on the homeotropic photopolymer were observed. Also, the stable response time of MYA cell on the homeotropic photopolymer 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.172-172
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• 2010

The Patterned vertical alignment (PVA) mode has many advantages such as perfect dark state at the normal direction and wide viewing angle. However, PVA mode needs additional process to pattern electrodes of both substrates and complicated assembly process. Moreover, this mode shows slow response time. To overcome these problems, we use plane shape ITO on top substrate instead of patterned electrode and form proper tilt angle of LC director on the surface while maintaining these original merits. Consequently, we achieve fast response time and improve transmittance.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.518-521
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• 2004

We have investigated about compensation film to reduce the light leakage at an oblique angle in-plane switching mode. It is well known that uncompensated in-plane switching (US) and fringe field switching (FFS) liquid crystal displays (LCDs) have much better viewing angle than other modes owing to the in-plane rotation of the LC director. However, to accomplish optimal viewing angle characteristics in these devices, they must be compensated by one or more films. So, in this paper, we have studied how to reduce the light leakage with viewing angle using discotic film in dark state.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.2
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• pp.344-348
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• 2007

In this paper, we propose the electrode of the Patterned Vertical Aligned (PVA) cell [1] for high transmittance. We use the 'TechWiz LCD' for calculation of the director configuration and optical characteristics to ensure the results of the proposed electrode structure. In general, the transmittance of the PVA cell depends on the shape of the electrode and cell gap. In this work the width of gate line and data line of the improved electrode design is set to be equal to that of the PVA conventional. Instead, we modified the shape of the top and bottom electrode on order to decrease the area of the defect. For verification, we compared the calculated optical transmittance of the PVA cell with the proposed electrode structure to the conventional PVA cell . As a result, we can confirm that the optical loss due to the variation of the retardation the LC cell around electrode can be definitely decreased by the proposed electrode.