• 디지털융복합연구
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• 제10권7호
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• pp.267-272
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• 2012

열악한 광환경의 극복은 원예작물의 생육증대는 물론 고품질 생산에 있어서도 매우 중요한 역할을 할 수 있는데 이때 LED 광시스템을 이용할 경우 광합성산물의 소모를 효과적으로 줄일 수 있게 된다. 따라서 본 연구에서는 농가 비닐하우스의 저효율, 재배연차별 경영비 상승에 따른 소득감소를 개선하고 적정한 작물생육을 유도함으로써 공장형 식물재배 환경을 마련함과 동시에 농가 소득 증대에 기여할 수 있을 것이며 LED 광처리 장치를 이용한 보광을 통해 광합성 촉진 및 생산물의 품질 향상, 식물 생장 조절이 가능할 것으로 판단되며 이를 위한 효율적 LED 광처리 장치를 개발하고 LED 광처리장치를 이용하여 잎상추를 재배한 결과 일반 형광등이나 백열전구에서 재배한 것 보다 성장 속도가 향상된 것을 알 수 있다. 보통 잎상추는 육묘에서 출하까지 수확까지 25일 ~ 30일 걸린데 반해 광처리장치의 적색광(파장:645nm)을 이용하여 재배한 잎상추는 7일 만에 수확할 수 있을 정도로 성장속도가 증가하였다. 또한 적색광(파장:645nm)과 청색광(파장:470nm)을 동시에 점등하여 재배한 칸에서는 5일만에 수확할 수 있을 정도로 빠른 성장속도를 보였다.

• 대한물리의학회지
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• 제9권2호
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• pp.151-159
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• 2014

PURPOSE: The purpose of this study was to evaluate whether light-emitting diodes (LED) irradiation could be effective in a noninvasive, therapeutic device for the treatment of osteoarthritis(OA). METHODS: Twenty-four male Sprague-Dawley rats were divided into four groups: Vehicle control (saline); monosodium iodoacetate-injection (MIA); LED irradiation after MIA injection (MIA-LED); indomethacin-treatment after MIA injection (MIA-IMT). OA was induced by intra-articular injection of 3 mg MIA through the patellar ligament of the right knee. Vehicle control rats were injected with an equivalent volume of saline. The LED was irradiated for 15 min/day for a week after 7 days of MIA treatment. To compare with the effect of LED irradiation, the indomethacin was administrated 20 mg/kg twice a week orally after 7 days of MIA treatment. Knee joints were removed and fixed overnight in 10% neutral buffered formalin and decalcified by EDTA for 2 week before being embedded in paraffin. The assessment of OA induction were monitored by knee movement and radiographic finding. Histologic analysis were performed following staining with hematoxylin and eosin, safranin O-fast green, or toluidine blue, picrosirius red, and histologic changes were scored according to a modified Mankin system. Apoptotic cell in tissue sections was detected using TUNEL method. RESULTS: Radiographic examination could not show the differences between the MIA-treated and the MIA-LED-treated rats. In the histologic analysis, however, LED irradiation prevented cartilage damage and subchondral bone destruction, and significantly reduced mononuclear inflammatory cell infiltration and pannus formation. LED irradiation also reduced apoptosis of cartilage cells, but it prevented apoptosis of infiltrated inflammatory cells in synovium. In addition, LED irradiation showed an increase of collagen production in the meniscus. CONCLUSION: These results suggest that the 840 nm LED irradiation would be a suitable non-thermal phototherapy for the treatment of OA, as a cartilage protection and anti-inflammatory modality.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.676-678
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• 2004

In order to develop new yellow phosphor that emit efficiently under the 450 - 470 nm excitation range, we have synthesized a $Eu^{2+}$-activated $Sr_3SiO_5$ yellow phosphor and investigated an attempt to develop white LEDs by combining it with a InGaN blue LED chip (460 nm). Two distinct emission bands from the InGaN-based LED and the $Sr_3SiO_5$:Eu phosphor are clearly observed at 460 nm and at 570 nm, respectively. These two emission bands combine to give a spectrum that appears white to the naked eye. Our results showed that InGaN (460 nm chip)-based $Sr_3SiO_5$:Eu exhibits a better luminous efficiency than that of the industrially available product InGaN (460 nm chip)-based YAG:Ce.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.23-23
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• 2003

GaN-related semiconductors are of great technological importance for the fabrication of optoelectronic devices, such as blue and ultra violet light emitting diodes (LEDs), laser diodes, and photo-detectors. One of the most important applications of GaN-based LEDs is solid-state lighting, which could replace incandescent bulbs and ultimately fluorescent lamps. For solid-state lighting applications, the achievement of high extraction efficiency in LED structures is essential. For flip-chip LEDs (FCLEDS), the formation of low resistance and high reflective p-GaN contact is crucial. So far, a wide variety of different methods have been employed to improve the ohmic properties of p-type contacts to GaN. For example, surface treatments using different chemical solutions have been successfully used to produce high-quality ohmic contacts, Metallization schemes, such as Ta/Ti contacts to p-GaN, were also investigated. For these contacts, the removal of hydrogen atoms from the Mg atoms doped n the GaN was argued to be responsible for low contact resistances.

• Journal of the Optical Society of Korea
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• 제15권3호
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• pp.272-277
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• 2011

The effect of the M-window color mixing bar on the characteristics of color mixing and hot spots in the edge-lit backlight employing red (R), green (G), blue (G) light emitting diodes (LED) were studied in terms of the structure of the M-window color mixing bar. The rays from RGB LEDs entering the M-window bar were mixed by internal reflection and scattering inside the M-window bar so that the hot spots and color separation were minimized. The M-window bar was designed and fabricated and the simulation results are matched quite well to experimental data.

• 전자공학회논문지 IE
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• 제48권4호
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• pp.25-29
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• 2011

유기 EL소자는 제작이 쉽고 휘도가 높아 CRT와 LED 대신 평판 디스플레이 패널의 광원으로써 많이 연구되어 지고 있으며, OLED 소자중 청색 OLED는 풀컬러 적용 어플리케이션에 적용할 수 있기 때문에 이에 대한 연구가 이루어 지고 있다. 본 연구에서는, 발광 소재로 PBD, Alq3를 사용하여 유기 EL 디바이스의 전기 발광 특성을 측정하였으며, 전류와 휘도는 전압과의 관계에서 알 수 있었고 휘도와 전류의 관계를 제시하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1327-1330
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• 2008

A novel fiber optic solution is provided to efficiently mix visible colors. Full color synthesis was achieved utilizing a novel $3{\times}1$ hard polymer clad fiber (HPCF) coupler along with red, green and blue (RGB) light emitting diode (LED) primaries. Varying the intensities of RGB LEDs that are coupled to three input ports, the device rendered a full color with an ultra wide CIE color gamut. Potential applications in pica-projection displays and LED backlights will be discussed.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1090-1092
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• 2006

There is provided white light illumination system including a radiation source, a first luminescent material having a peak emission wavelength of about 575 to about 620 nm, a second luminescent material having a peak emission wavelength of about 495 to about 550 nm, which is different from the first luminescent material and a third luminescent material having a peak emission wavelength of about 420 to about 480 nm, which is different from the first and second luminescent materials. The LED may be a UV LED and the luminescent materials may be a blend of three phosphors. A human observer perceives the combination of the blue, green and red phosphor emissions as white light.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.531-531
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• 2012

So many groups have been researching the green quantum dots such as InP, InP/ZnS for overcoming the semiconductor nanoparticles composed with heavy metals like as Cd and Pb so on. In spite of much effort to keep up CdSe quantum dots, it does not reach the good properties compared with CdSe/ZnS quantum dots. This quantum dot has improved its properties through the generation of core/shell CdSe/ZnS structure or core/multi-shell structures like as CdSe/CdS/ZnS and CdSe/CdS/ CdZnS/ZnS. In this research, we try to synthesize the InP multi-shell structure by the successiveion layer absorption reaction (SILAR) in the one pot. The synthesized multi-shell structure has improved quantum yield and photo-stability. To generate white light, highly luminescent InP multi-shell quantum dots were mixed with yellow phosphor and integrated on the blue LED chip. This InP multi-shell improved red region of the LEDs and generated high CRI.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.79-82
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• 2009

This work presents a novel lighting technology based on a YAG:$Ce^{3+}$ phosphor converter with micro line lenticular structure, to accompany an array of bare LED chips on a board. This technology is especially effective in TFT-LCD backlight applications as it offers the advantages of high light radiation efficiency, low color deviation, uniform luminance distribution and compact backlight thickness. Additionally, the proposed configuration is low-cost, can be manufactured quickly, and can be mass-produced economically.