• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.980-981
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• 2007

Liquid crystal (LC) devices can be operated as amplitude modulators and phase modulators. They usually require two polarizers; therefore the optical efficiency is limited. We introduce two general principles of polarization-free liquid crystal devices and also show several LC devices by applying the principles.

• 한국광학회지
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• 제24권4호
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• pp.168-175
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• 2013

정보디스플레이 기술은 디지털 정보화 사회를 혁신적으로 변화시킨 원동력이다. 액정 디스플레이는 가장 대표적인 평판 디스플레이로서 저소비전력, 경량, 박형 등의 장점을 앞세워 소형에서부터 대형에 이르기까지 다양한 응용분야에 널리 사용되고 있다. 하지만, 더욱 고성능의 디스플레이를 구현하기 위해 끊임없이 연구가 지속되고 있다. 본 논문에서는 액정 디스플레이의 구조 및 구동원리에 대해 설명하고, 액정 모드 기술에 대해 본 연구실에서의 연구를 중심으로 소개하고자 한다.

• Journal of Information Display
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• 제4권1호
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• pp.1-8
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• 2003

Recent progress in both low pretilt and high pretilt defect free C1 surface stabilized ferroelectric liquid crystal (SSFLC) devices is reviewed. First, by numerical calculation to investigate the balance between surface azimuthal anchoring energy and bulk elastic energy within the confined chevron layer geometry of C1 and C2, it is possible to achieve a zigzag free C1 state by low azimuthal anchoring alignment with a low pretilt angle. The critical azimuthal anchoring coefficient for defect free C1 state is calculated. Its relationship with elastic constant, chevron angle as well as surface topography effect are also discussed. Second, using $5^{\circ}$ oblique SiO deposition alignment method a defect free, large memory angle, high contrast ratio and bistable C1 SSFLC display, which has potential for electronic paper applications has also been developed. The electrooptical properties and bistability of this device have been investigated. Various aspects of defect control are also discussed.

• 한국광학회지
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• 제24권4호
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• pp.159-167
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• 2013

액정 디스플레이는 소형에서 대형까지 모두 이용 가능한 가장 확실한 평판 디스플레이 구현 기술로 각광받고 있다. 액정 디스플레이의 동작 원리뿐 만 아니라 성능 개선을 위해, 액정의 비등방성 및 비등방 매질에서 빛의 전파에 대한 이해가 필요하다. 액정 소자의 광학 특성에 영향을 주는 액정의 공간 분포에 관여하는 에너지를 통해 액정 디스플레이의 동작원리를 이해하고, 비등방 매질에서 빛의 편광 해석 방법을 통해 액정 디스플레이의 광학특성에 대해 기술한다.

• Bulletin of the Korean Chemical Society
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• 제33권5호
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• pp.1577-1580
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• 2012

The orientational and dynamic behavior of liquid crystal molecules on the alignment layer surfaces of liquid crystal display (LCD) devices is crucial to their performance, but there are only a few methods of experimentally elucidating the interactions between the liquid crystals and the alignment layers. Inspired by the natural and technical similarities between membrane proteins in lipid bilayers and liquid crystals in LCDs, we employed solid-state NMR methodologies originally developed for the study of membrane proteins in lipid bilayers for the in-situ analysis of liquid crystal display panels. In this article, we present a home-built 500 MHz narrowbore (NB) The orientational and dynamic behavior of liquid crystal molecules on the alignment layer surfaces of liquid crystal display (LCD) devices is crucial to their performance, but there are only a few methods of experimentally elucidating the interactions between the liquid crystals and the alignment layers. Inspired by the natural and technical similarities between membrane proteins in lipid bilayers and liquid crystals in LCDs, we employed solid-state NMR methodologies originally developed for the study of membrane proteins in lipid bilayers for the in-situ analysis of liquid crystal display panels. In this article, we present a home-built 500 MHz narrowbore (NB) $^{19}F-^{13}C$ double resonance solid-state NMR probe with a flat-square coil and the first application of this probe for the in-situ analysis of LCD panel samples. double resonance solid-state NMR probe with a flat-square coil and the first application of this probe for the in-situ analysis of LCD panel samples.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.452-455
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• 2002

We demonstrate the wide-viewing characteristics of a twisted nematic liquid crystal display (LCD) with self-formed micro-domains through the topographical alignment and fringe field effects of dielectric surface gratings (DSG). The mutual optical compensation between micro-domains within each pixel eliminates the contrast inversion phenomenon of TN mode without complex surface treatments.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.191-192
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• 2002

We reported pushing of colloidal particles by a moving isotropic-nematic phase boundary. Here, we report tailoring the structure of 3-dimensional networks formed by these particles by adjusting the rate of phase transition and by application of an electric field. The resulting networks affect the electro-optic performance of liquid crystal devices.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.105-108
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• 2005

We demonstrate an electro-optical device based on the flexoelectric effect of a short-pitched cholesteric liquid crystal. By using a dual-frequency switchable nematic, a small amount of chiral dopant and a small amount of phase-separated polymer localized on the surface, we were able to create a device that operates in amplitude (flexoelectric) and phase(dielectric) modes. At high frequency the dual frequency liquid crystal suppresses the phase mode at higher voltage, which improves the switching speed, and thereby preserving the in-plane-switching mode.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.883-885
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• 2009

We proposed intriguing and simple technique for fabricating flexible plastic liquid crystal (LC) devices. We made a preliminary version of a flexible LC display employing this concept, and we confirmed this technique was useful for the flexible LC display; the electro-optical reproducibility of the flexible LC device fabricated here was remarkably improved against external perturbation compared with the conventional one.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.287-288
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• 2004

We report on the development of ferronematic liquid crystals, new materials that consist of a dilute suspension of ferroelectric particles in a nematic liquid crystal host. The particles share their ferroelectric properties with the nematic liquid crystal and impose a spontaneous dielectric polarization of about 10 nC/$cm^2$ to the entire medium, typical for many ferroelectric liquid crystals. As expected, these new materials have enhanced dielectric anisotropy and are sensitive to the sign of an applied electric field. The potential of their use in a number of devices are discussed.