• 한국전기전자재료학회논문지
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• 제17권4호
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• pp.439-442
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• 2004

In this study, we investigated about electrooptics characteristic of three kinds of TN cell on the polyimide surface. Monodomain alignments of thermal stressed TN cell over temperature of liquid crystal isotropic phase were almost the same as that of no thermal stressed TN cells. However, the thermal stressed TN cells have many defects. Also, threshold voltage and response time of thermal stressed TN cells show the same performances as no thermal stressed TN cells. There were little changes of value in these TN cells. However, transmittances of TN cells on the polyimide surface decrease with increasing thermal stress time. Finally, the residual DC voltage of the thermal stressed TN cell on the polyimide surface shows decrease of characteristics as increasing thermal stress time. Therefore, the thermal stability of TN cell was decreased by high thermal stress for the long times.

• Journal of Information Display
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• 제12권2호
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• pp.101-107
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• 2011

To come up with a bistable liquid crystal (LC) device using unpolarized UV light, single-step laser patterning on a photoalignment layer using a photomask was proposed to achieve an equilibrium configuration of LC molecules in contact with a periodically patterned substrate. The patterns were formed by stripes of alternating random planar and homeotropic anchoring on a submicrometer scale in the order of $0.5{\mu}m$. Two possible configurations of bistable LC cells that can be obtained by combining a micropatterned surface formed with alternating random-planar- and homeotropic-alignment with planar- or homeotropic-alignment surfaces were proposed. The alignment properties of the two proposed models were investigated, along with the microscopic switching behavior of micropatterned nematic LC cells.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.62-62
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• 2007

It is analyzed with regard to LCD in Korea that national patent application, applicant patent application, IPC patent application. The Trends of patent application concentrated LCD manufacturing process and device, case and a cell of liquid crystal. Therefore, the future research and developments must be centralized these ranges. It is needed for competitive power and original technology that the search and analysis of the previous patent.

• 한국광학회지
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• 제8권3호
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• pp.223-229
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• 1997

베레만의 4 * 4행렬방정식을 써서 액정판의 편광투과특성을 분석하는 프로그램을 개발하고, 이를 써서 액정셀과 편광판의 편광투과특성을 살펴보았다. 개발된 프로그램을 써서 정상백색 모우드의 꼬인 네마틱(TNLTwisted Nematic) 액정셀에서 시야각에 따른 명암대비의 변화를 보여주는 등고선을 그려내어 그 특성을 예측할 수 있었다. 또한 편광판의 투과특성은 입사각이 커짐에 따라 투과된 빛의 편광타원의 주축이 투과축 방향에서 벗어나며 타원도가 커지는 것이 밝혀졌는데, 이 결과는 액정표시소자의 명암대비가 액정판만이 아니라 편광판의 특성에 의해서도 제한될 수 있음을 시사한다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.615-618
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• 2003

We developed a new device structure using anisotropic phase sepraration from liquid crystals (LCs) and polymer composite materials for flexible display applications. In the device, the LC molecules are isolated in pixels where LCs are surrounded by polymer layers. These devices show very good mechanical stability against external pressure. The electro-optic characteristics and the mechanical stability of the devices are discussed in view of the flexible display applications.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.293-294
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• 2009

We proposed a novel single gap transflective liquid crystal display (LCD) using liquid crystal with negative dielectric anisotropy. We designed cell structure driven by fringe electric field in the transmissive (T) part and vertical electric field in the reflective (R) part. In the device, high surface pretilt angle of the LC in the R-part is achieved through polymerization of an UV curable reactive mesogen (RM) monomer at surfaces. By optimizing the parameters, a newly developed transflective display has characteristics such as single gap and single gamma curve.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1386-1389
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• 2008

Conventional viewing angle switching electrode requires pixel division and additional liquid crystal panel. Hence the conventional viewing angle switching has low aperture ratio and high thickness. In this paper we proposed new viewing angle switching using hybrid aligned nematic mode by fringe-field electrode field (named HAN-FFS) with single liquid crystal panel. The fringe-field switching electrode is located at the bottom, and the additional common electrode is located at the top of the cell to control viewing angle. The proposed device is free from additional liquid crystal panel and pixel division. Consequently, the suggested structure has not only high aperture ratio but also show an excellent potential for viewing angle switching.

• 한국전기전자재료학회논문지
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• 제33권4호
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• pp.271-275
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• 2020

Smart windows are used as windows and doors to determine the cooling and heating efficiency of a building. They have characteristics that can increase the energy efficiency of a building, which leads to energy savings. In addition, smart windows can control the amount of light transmitted from the external environment of a building to the interior of a building according to the needs of the user. In this study, a 297×210 ㎟ liquid crystal cell capable of controlling light transmittance was fabricated using a liquid crystal device as an optical shutter. The effect of driving voltage on the transmittance and the effect of the thermal environment on the driving stability were analyzed. We confirmed the applicability of using smart windows as exterior building materials.

• 전력전자학회논문지
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• 제14권1호
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• pp.8-14
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• 2009

현재 사용하고 있는 LCD(Liquid Crystal Display) Backlight용 램프는 주로 CCFL(Cold Cathod Fluorescent Lamp)과 EEFL(External Electrode Fluorescent Lamp)이 사용되고 있다. 하지만 이 램프는 수은을 사용하여 RoHS(the Restriction of e use of certain Hazardous Substances in electrical and electronic equipment)규제가 점점 강화되면서 사용이 제한되고 있으며, 이에 따라 수은을 사용하지 않는 램프의 제작이 불가피해지고 있다. 또한 LCD TV는 CRT와 PDP와는 다른 LCD만의 Hold-type 특성과 LC(Liquid Crystal)의 응답속도로 인하여 Motion Blur현상이 나타나는 단점이 있다. 본 논문에서는 RoHS 규제를 만족시키는 무수은 면광원 램프를 구동하기 위한 인버터를 제안한다. 제안한 인버터는 포워드 방식을 사용하여 반도체 소자 및 자기 소자의 수를 줄여서 구동회로가 간단하다. 또한 면광원 램프를 세로방향으로 6블록으로 나누어 스캔구동을 하여 Motion Blur현상을 저감 시켰다. 끝으로 실험을 통하여 제안한 인버터의 유용성을 입증하였다.

• 한국전기전자재료학회논문지
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• 제15권6호
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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.