• 산업기술연구
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• 제31권A호
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• pp.95-101
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• 2011

According to recent technological developments in high-power LEDs, the stage lighting is one of most important areas to apply power LED system. Moving light for color rendering of stage uses the RGBW(red, green, blue, white) color mixing method. LED moving light system needs to have a wide range of dimming control as enough to operate at very low power. Also LED dimming system should not be induced color-shift and flicker in camera. This paper is experimentally verified the LED Moving Light driving circuit of 200Watt level designed to satisfy the above characteristics which applied the DC current-controlled and PWM mixed dimming method.

• 대한화학회지
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• 제47권4호
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• pp.370-375
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• 2003

보라색 발광 다이오드에 의해 여기되어 청색, 녹색, 적색을 발광하는 형광체로 각각 $BaMg_2Al_16O_27:Eu,\SrGa_2S_4:Eu$, ZnCdS:Ag,Cl 형광체를 선택하였다. 보라색 발광 다이오드의 발광에서 형광체에 의해서 완전히 흡수되지 않고 나오는 보라색 발광과 $BaMg_2Al_16O_27:Eu,\SrGa_2S_4:Eu$, ZnCdS:Ag,Cl 형광체에서 나오는 청색, 녹색, 적색 발광을 조합하여 사파장 백색 발광 다이오드를 만들었다. 사파장 백색 발광 다이오드의 발광 특성을 확인하였다.

• 한국기계가공학회지
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• 제13권4호
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• pp.121-129
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• 2014

This study was carried out to develop an efficient plant growth system that can be controlled by altering the wavelength and illumination using a LED module. If it is possible to develop a system that can be controlled in this manner, utilizing different characteristics in the meaningful wavelength band depending on the growth time or type of plant, the plant growth conditions can be optimized. In order to this, red, green, blue and white LEDs are arrayed in a rectangle, consisting of LED modules which can be combined with each other. Consequently, the array can be used to select the optimal light conditions with monochromatic red, green, blue and white LEDs, or mixed LEDs, for plant growth. Experiments on the characteristics of the wavelengths to evaluate the efficiency of the plant growth system were performed. The usefulness of the system was demonstrated through a cultivation test involving several special plants.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2019년도 춘계학술대회
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• pp.142-145
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• 2019

최근 들어 지구 온난화 및 고유가로 인한 에너지 위기로 전 세계적으로 이산화탄소 배출규제가 본격화되고 에너지 소비에 따른 지구환경을 보존하기 위한 대표적인 국제적인 GEF(Green Energy Family) 활동은 이산화탄소 배출 금지를 위한 교토의 정서(Kyoto protocol), RoHS(Restriction of Hazardous Substances directive)에서는 무 수은 조명 사용억제, WEEE(Waste Electrical and Electronice Equipment)에서는 조명 통신융합으로 폐기물 최소화를 목적으로 폐기물 회수를 요구하는 등 다각적 노력을 경지하고 있다. 본 논문에서는 기존의 외부 환경 요인(조도, 피사체와의 거리 등)에 의하여 실시간으로 변동되는 환경 데이터를 마이크로프로세서를 활용하여 외부 환경 요인을 확인하고 또한 퍼지 추론 시스템을 접목하여 RGB LED 모듈 조명 제어가 가능한 제어기를 구성하였다.

• 한국전기전자재료학회논문지
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• 제36권5호
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• pp.494-499
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• 2023

In this paper, in order to apply the CF (color filter) type of the micro light emitting device (Micro LED) display method, a study on the manufacturing process of red and green phosphor inks for the inkjet process was conducted. The blue light-emitting KSF and LuAG phosphors were respectively used to control the phosphor particle size to about 1㎛, and a phosphor ink was prepared by synthesizing with a low-viscosity solution (IPA/Eg). A chemical dispersion method was applied to selectively control the dispersion characteristics in the manufacture of phosphor inks, and in particular, phosphor inks with a dispersant applied a dispersant secured stable dispersion characteristic compared to phosphor inks without a dispersion process. Therefore, it seems possible to manufacture CF for Micro LED through an inkjet process capable of controlling the dispersion characteristics of phosphor ink.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.836-841
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• 2004

This paper describes ASIC design for brightness revision control, A LED Pixel Matrix (LPM) design and LPM in natural color LED vision. A designed chip has 256 levels of gradation correspond to each Red, Green, Blue LED pixel respectively, which have received 8bit image data. In order to maintain color uniformity by reducing the original rank error of LED, we adjusted the specific character value 'a' and brightness revision value 'b' to pixel unit, module unit and LED vision respectively by brightness characteristic function with 'Y=aX+b'. In this paper, if designed custom chip and brightness revision control method are applied to manufacturing of natural color LED vision, we can obtain good quality of image. Furthermore, it may decrease the cost for manufacturing LED vision or installing the plants.

• 전기학회논문지
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• 제61권10호
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• pp.1513-1517
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• 2012

As demands for green industry increase, this paper proposes a power control technique that can substitute pre -existing CCFL(Cold Cathode Fluorescent Lamp) and optimize power consumption of LED BLU. This technique is designing LED driver circuit that make a DC-DC output voltage(VLED) to have a linear control function for a supply voltage of LED string. The proposed LED driver have an advantage that can increase or decrease a DC-DC output voltage compared with conventional LED driver. The designed LED driver circuit was designed using 0.35um CMOS technology. And its operation was verified through simulation.

• 한국인터넷방송통신학회논문지
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• 제11권5호
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• pp.19-25
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• 2011

최근 그린 IT 기술이 이슈화 되면서 전 세계적으로 탄소 배출을 낮추고 에너지 효율을 높일 수 있는 환경 친화적인 광원에 대한 연구가 활발히 진행되고 있으며, 특히 고유가와 환경오염 등의 문제로 기존의 백열등이나 형광등을 대체하기 위한 새로운 광원으로 LED가 크게 주목을 받고 있다. 본 논문에서는 저전력, 고효율, 고휘도의 LED 모듈에 온도, 습도, 조도, 그리고 이동 감지 센서를 포함한 복합 센서 모듈을 조합하여 가로등을 지능화하고, ZigBee 모듈을 이용하여 가로등 간에 IT기술인 USN 망 융합을 통하여, 가로등 시스템을 중앙에서 모니터링하고 지역 특성에 따라 선택적으로 가로등의 점멸을 원격으로 제어함으로써 효과적으로 에너지 절약을 극대화할 수 있는 Ad-Hoc망 기반 LED-IT-Sensor 통합 가로등을 설계하고 구현하였다.

• 식물조직배양학회지
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• 제27권1호
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• pp.71-75
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• 2000

발광다이오우드 (Light emitting diode)를 사용한 적색, 녹색 및 청색광에서 식물생산의 가능성을 조사하기 위하여 도라지 유묘의 생장과 형태형성에 미치는 광질의 효과와 광질에 따른 엽록소함량을 형광등과 비교하여 조사하였다. 식물체의 초장은 형광등에서 3.8 cm로 가장 짧았고 LEDs 에서 생장한 것은 적색광에서 13.4cm로 가장 길었다. 반면에 적색/청색의 혼합광은 5.6cm로 적색 단색광에서 식물체가 도장된 것에 비해 정상적인 식물체의 생장양상을 보여 적색과 청색의 혼합광이 식물체의 생장에 적당하였다. 엽면적은 녹색광에서 24.1 $\textrm{cm}^2$로서 적색광에서 10.1 $\textrm{cm}^2$인 것에 비하여 약 2.4 배가 더 넓어 다른 처리구에 비하여 가장 양호하였다. 건물률은 적색/청색의 혼합광에서 15.3%를 나타내어 다른 광질처리보다 함수율이 적었다. 엽록소함량은 청색 단색광과 적색/청색의 혼합광에서 형광등보다 각각 20%, 10% 적었으나 적색과 녹색의 경우 각각 2%, 7% 적었는데 적색 단색광에서 형광등과 비슷한 엽록소 함량을 보였다.

• Journal of Biosystems Engineering
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• 제39권2호
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• pp.87-95
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• 2014

Purpose: The purpose of this study was to design a variable frequency LED light system for plant factory which combined red, blue, green, white, and UV lights and controlled the ratio of the light wavelength. In addition, this study evaluated the performance of each combination of LED to verify the applicability. Methods: Four combinations of LED (i.e. Red+Blue, Red+Blue+Green, Red+Blue+White, Red+Blue+UV) were designed using five types of LED. The system was designed to control the duty ratio of each wavelength of LED by 1% interval from 0~100%, the pulse by 1Hz interval from 1~20kHz. Response characteristics of the control system, spectral distribution of each combination, light uniformity and uniformity ratio were measured to test the performance of the system. Results: Clean waveforms were measured from 10Hz to 10kHz regardless of duty ratio. Frequency distortion was observed within 5% of inflection point at frequencies above 10kHz regardless of duty ratio, but it was judged negligible. Spectra showed a normal distribution, and maximum PPF with duty ratio of 100% was $271.4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for the Red+Blue combination. PPF of the Red+Blue+Green combination was $258.9{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and that of the Red+Blue+White combination was $273.9{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. PPF of the Red+Blue+UV combination was $267.7{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Uniformity ratio for the area excepting border showed 0.90 for the Red+Blue and Red+Blue+White combinations, 0.87 for the Red+Blue+Green combination, and 0.88 for the Red+Blue+UV combination. The light was irradiated evenly at the area excepting border, so it was suitable for plant growing. Conclusions: From the results of this study, response characteristics of the control system, spectral distribution of each combination, light uniformity and uniformity ratio were suitable for applying into the plant factory.