• Journal of the Optical Society of Korea
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• 제17권2호
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• pp.162-167
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• 2013

A two-dimensional (2D) / three-dimensional (3D) convertible display system based on integral imaging is proposed to adopt a novel switchable point light source array, which is implemented using the polarization modulator and the polarization selective scattering film that transmits or scatters the incident light due to its polarization direction. The 2D and the 3D display modes of the proposed system can be modulated by controlling the polarization direction of back light using the polarization modulator. We explain the basic principles of the proposed system and verify the feasibility of the system through preliminary experiments.

• 대한기계학회논문집A
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• 제28권1호
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• pp.79-84
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• 2004

A light-guide is one of several important components of backlight unit in TFT-LCD. The manufacturing technology and optical system design of the light guide is very sensitive to quality and cost of the TFT-LCD module. In the present study a new manufacturing method which is called as direct surface forming(DSF) has been tested under various conditions. DSF is very similar to the well-known hot embossing except for partial contact between mold and substrate. The final V-groove pattern shows different shapes depend on the temperature of mold surface, contact time of mold and depth of V-groove.

• 한국생산제조학회지
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• 제20권3호
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• pp.361-367
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• 2011

In this paper, it was attempted to analyze the optimal design of light emitting diode (LED), a source of back light unit (BLU). LED is beginning with commercialized red LED which is made by GaAsP compound semiconductor, and has been developed focusing on liquid crystal panel. In order to get the optimal design, optical simulation was made by analyzing luminosity shape, reflector angle, chip depth, and chip position of LED lighting. Final results show that the proposed LED characteristics were useful to increase light efficiency and it has been proven by distribution chart for actual exposed light on the light guide panel (LGP).

• 조명전기설비학회논문지
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• 제28권12호
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• pp.1-5
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• 2014

Since the "Light Pollution Prevention Act" was executed, the installation of the light cutoff panel to the security lightings which caused light trespass has been increased in the local government. The light cutoff panel is effective in reducing the light trespass in term of the cost-benefit. Because the installation of the light cutoff panel is inexpensive than the change of the security lighting. But the reflected light from the surface of the light cutoff panel has been regarded as another light pollution problem to solve. Therefore, we try to improve light cutoff panel by changing the light reflectivity characteristic of the surface of the light cutoff panel. First, we laminated the surface of light cutoff panel by black powder to reduce the light reflectivity of the light cutoff panel. After the black powder lamination, the light reflectivity on the light cutoff panel improved from 85% to 5%. And we compared reflected light caused by black powder laminated light cutoff panel with the one of no surface treatment cutoff panel. The vertical illuminance was measured at 3, 6, 9m in front of the security lighting and 3, 6, 9, 12, 15, 18m in back of the security lighting to evaluate the reflected light. And the measurement height was determined of 1.5m considering the height of the 1th floor of an apartment house. In this study, we found that the reflected light from the light cutoff panel can be reduced about 90% by the black powder lamination method. The results derived from this study will be helpful to develope the various kind of light cutoff panel which minimize the adverse effect like reflected light of light cutoff panel.

• 한국작물학회지
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• 제29권1호
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• pp.89-97
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• 1984

본 연구는 저연생 고려인삼의 재배위치에 따르는 광합성능력과 암호흡에 관련된 몇 가지 생태 및 생리적 특징의 계절적 변이를 구명하기 위하여 수행하였던 바 그 결과를 요약하면 다음과 같다. 1. 묘삼 및 2연근 인삼에서 엽면적은 후열에서 넓은 경향을 보였고, 엽중은 9월에 현저히 증가하였다. 엽록소 함량은 6월에 비해 9월에 현저히 감소하였고, 전열에 비해 후열에서 높은 경향이 뚜렷하였다. 2. 2연근의 경우 광보상점은 6월에는 전후열간 차이가 없었으나 9월에는 초삼 및 2연근에서 후열의 광보상점이 현저히 낮았고, 6월 및 9월에서 광포화점의 열간 및 계절간 차이는 인정되지 않았다. 다만 2연근의 $15^{\circ}C$에서의 광포화점은 6월이, 그리고 $20^{\circ}C$의 광포화점은 9월이 높은 경향이 뚜렷하였다. 3. 2연근에서 6월은 $15^{\circ}C$에서 전후열 모두 최대광합함량이 가장 높았으나 9월에는 $20^{\circ}C$에서 최고를 보였으며, 6월은 전후열간의 차이가 없었는데 반해 9월은 묘삼 및 2연근에서 모두 후열에서 오히려 최대 광합함량의 현저한 증가를 나타내었다. 4. 최대광합성에 적합한 온도는 2연근의 경우 6월은 1$14.0^{\circ}C$~$14.5^{\circ}C$였으나 9월에는, $19.5^{\circ}C$~$20.5^{\circ}C$였고, 묘요에서는 9월의 경우 21.$2^{\circ}C$~21.6$^{\circ}C$로서 전후열간 차이는 거의 없었다. 5. 2연근에 비해 묘삼의 호흡량이 현저히 많았으며, 또한 묘삼은 9월의 경우 전열에 비해 후열에서 호흡량이 적었는데, 2연근에서는 5월에 비해 9월의 호흡량이 증가되었고, 전열에 비해 후열의 호흡량이 약간 많은 경향이었다. 온도 상승에 따르는 호흡량의 증가율은 묘삼이 2연근에 비해 현저히 높았다. 6. 9월에 있어서 묘삼에 비해 2연근의 $Q_{10}$ 현저히 낮았으며, 2연근의 경우 6월에는 $15^{\circ}C$에서 $25^{\circ}C$로 상승시의 $Q_{10}$이, 그리고 9월에는 $20^{\circ}C$에서 $30^{\circ}C$로 상승시의 Q$_{10}$이 각각 현저히 낮았다.

• Journal of Information Display
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• 제13권3호
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• pp.119-123
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• 2012

In this work, we report on a new monitoring method for an organic light-emitting diode (OLED) panel for lighting by optical sensing of the wave-guided light in the substrate. Using microlens array films, the wave-guided light was extracted into the edge or back side of the panel to be monitored by a photodiode. The luminance of the extracted light was measured as linearly proportional to the front light. Thus, by converting the extracted light into photo voltage, monitoring the luminance change occurring in the OLED is possible. Based on the results and concepts, we have proposed a photodiode-equipped driving circuit which can generate compensated driving current for uniform luminance of OLED panels.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 춘계학술대회 논문요약집
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• pp.134-134
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• 2004

LCD-BLU의 고효율 광특성을 유도하기 위한 도광판의 초미세패턴 형상가공기술, 미세사출성형기술과 미세형상패턴 광학해석기술 및 전광특성 측정 및 보완기술이 요구된다. 이러한 기술들을 바탕으로 LCD-BLU의 고단가의 주요요인인 기능성 광학 sheet(prism sheet 등)를 연차적으로 제거 및 도광판에 기능을 결합하는 기술개발이 본 연구의 목적이다.(중략)

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.617-622
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• 2003

Light Flickering of the lamp(fluorescent lamp) with voltage fluctuation operates as an factor harmful to train passengers which is subjective to them. Recently, international flickering standard(IEC61000-3-3) are applied all over the world. However, there are not any study preparing for regulation about light flickering inside running train. In this study, the Flicker phenomenon is investigated from several references and also how the flickermeter is configured and defined. Flicker evaluation using it are studied.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.137.1-137.1
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• 2008

• 한국재료학회지
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• 제20권8호
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• pp.412-417
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• 2010

Mo thin films were used for the back electrode because of the low resistivity in the Mo/$CuInGaSe_2$ contact in chalcopyrite solar cells. $1\;{\mu}m$ thick Mo thin films were deposited on soda lime glass by varying the Ar pressure with the dc-magnetron sputtering process. The effects of the Ar pressure on the morphology of the Mo back electrode were studied and the relationships between the morphology and electro-optical properties, namely, the resistivity as well as the reflectance of the Mo thin films, were investigated. The resitivity increased from $24\;{\mu}{\Omega}{\cdot}cm$ to $11833\;{\mu}{\Omega}{\cdot}cm$; this was caused by the increased surface defect and low crystallinity as the Ar pressure increased from $3{\times}10^{-3}$ to $3{\times}10^{-2}\;Torr$. The surface morphologies of the Mo thin films changed from somewhat coarse fibrous structures to irregular and fine celled structures with increased surface cracks along the cell boundaries, as the Ar pressure increased from $3{\times}10^{-3}$ to $3{\times}10^{-2}\;Torr$. The changes of reflectances in the visible light range with Ar pressures were mainly attributed to the surface morphological changes of the Mo thin films. The reflectance in the visible light range showed the highest value of 45% at $3{\times}10^{-3}\;Torr$ and decreased to 18.5% at $3{\times}10^{-2}\;Torr$.