• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.564-569
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• 2021

In this paper, for the typical LED and the tilted LED, when there is no electrode, when 20% absorption (80% reflection) occurs at the electrode, and when 60% absorption (40% reflection) occurs at the electrode, the effect of the absorption at the electrode and the height of the active region on the photon extraction efficiency and the mean photon path length was investigated, and an appropriate height of the active region was proposed. In a typical LED, as the absorption of the electrode increases, the photon extraction efficiency decreases from 18% to 15% and 13%, and the photon extraction efficiency is highest when the height of the active area is located in the center between the two electrodes. In the tilted LED, as the absorption of the electrode increases, the photon extraction efficiency decreases from 38% to 33% and 25%, and the photon extraction efficiency is highest when the height of the active area is located in the center between the two electrodes. The tilted LED can increase the photon extraction efficiency more than twice than that of a typical LED, where photons are trapped inside the chip due to total reflection.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.196-198
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• 2008

본 논문에서는 LED의 고출력화가 이루어지면서 많이 사용되고 있는 LED MR 타입과 PAR 타입의 램프 배광을 설계하였다. 1W와 5W급의 High power LED를 적용하였고, 1개의 LED가 사용된 빔각 30도의 MR16 램프부터 9개의 LED가 사용된 빔각 60도의 PAR30 램프까지 총 6가지 배광을 구현하고 최대광도로 각각의 성능을 평가하였다. 빔 각을 구현하고 집광시키기 위하여 LED dome 측면부에 소형의 반사판을 설계하였다.

• Clean Technology
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• v.16 no.2
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• pp.88-94
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• 2010

The physiological roles of various wavelength of light emitting diode (LED) on ‘Hayward’ kiwifruit experiencing after-ripening were investigated. Various wavelengths from LED light source were irradiated on kiwifruits kept in plastic bags or under open air at $25^{\circ}C$. During two weeks of storage, firmness of Hayward kiwifruits was decreased by $25^{\circ}C$ treatment than by $4^{\circ}C$ treatment. In the $25^{\circ}C$ storage condition, the firmness of kiwifruits was decreased by the treatment of 380 nm UV and 470nm white LED light source. Sweetness of kiwifruits treated with 380 nm UV LED and dark condition at $25^{\circ}C$ increased higher than $15^{\circ}$Brix. The acidity of kiwifruits under open air was decreased 52% by incubating at $25^{\circ}C$ with 660 nm red LED treatment. The acidity of kiwifruits in plastic bags was decreased 52.6, 55.6, 52.8% by the treatment of 440 nm blue, 470 nm white and 660 nm red LED light source, respectively, compared to that of kiwifruits incubated in darkness at $25^{\circ}C$. Decreased acidity irradiated by 660 nm red LED light source can be applied for regulating periods of the kiwifruit after-ripening process. LED light sources emit very narrow wavelength with a power-saving mode, therefore, the usage of these LED light source for regulating the after-ripening process can be classified as a clean biotechnology producing safe and environment-friendly kiwifruits.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.281-285
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• 2010

We propose new identification method of LED location in indoor environment. It can transmit and receive position information and additional data, as applying OOK-SS watermarking method for LED transmission signal. Especially, we use a unipolar form code for watermarking spread code, because LED signal has unipolar characteristic. we analysis LED signal influence and interference with watermarking code, demonstrate usefulness of LED-ID using OOK-SS Watermarking.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.813-814
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• 2012

Recently, along with a development to promote low-carbon green growth, LED control IT convergence technology that can create environmentally-friendly emotional lighting is receiving attention. This is an interface control technology that includes a multi-sensor, switching technology, LED optics, and Internet-based remote lighting control, all of which utilize the lighting characteristics of LED lighting. The proposed system is a study on an intelligent LED control technology, and aims to use a multi-switching sensor in order to control LED discharge current so as to improve energy-charging method, to use a battery's SoC sensor, and to improve efficiency in the winter according to a section.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.5
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• pp.933-940
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• 2017

This thesis shows the emotional light that stabilizes various human heart rates through the three elements of LED. This experiments confirm the change of heart rates when subjects see the static LED, fluid LED That was controlled by the guitar chord and beat in a given music and without light Consequently, the experiment proved that the bpm slope of test subject during specific time in liquid LED, -12.85, was steeper than -12.05 in static LED and -11.05 without light, which showed that fluid LED is more effective to stabilize heart rate than other conditions.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.5
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• pp.587-592
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• 2015

According to increase in the use of the LED, the demand for low power consumption LED display design of the controller block has increased. In this paper, the low power LED controller block was designed through the power source supply that leads adiabatic operation from constant current source circuit operated by digital signal control. The proposed circuit was implemented using a 0.35um CMOS process. and it demonstrated linear operation of the circuit. From the simulation result, the proposed circuit was evaluated with about 82% power consumption reduction effect in comparison with conventional LED controller block. This research is expected to be helpful for the low power operation and the solution for heat problem of LED display.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.12
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• pp.1-8
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• 2012

The performance and lighting characteristics of the LED depend on cooling condition because the power LED generates lots of heat. In this paper, the effect of the generated heat from power LED module on lighting characteristics and performance is measured and evaluated. For experiments, the transient temperature of a power LED module with cooling condition is measured. In addition, the temperature and lighting characteristics of the LED module are measured during the steady state. As a result, the cooling condition is less effective on the lighting characteristics of the LED module at rated current but the cooling condition extremely affects those of the LED module over the rated current. Because high temperature of the power LED module causes the low phosphor conversion, luminance efficiency becomes low and color temperature becomes high. When power LED module are driven over the rated condition, higher temperature is directly related to lighting characteristics and performance of the LED module rather than higher current.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.4
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• pp.1203-1209
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• 2010

LED lights as a newly-growing industry are highly energy-efficient and have drawn lots of attention due to higher illuminance and longer life compared to other light sources. In this study, MR16 lights with one high-power LED were considered for the replacement of the previous halogen lights or LED lamps with many LEDs. Thus, fundamental experiments of LED on a MCPCB, 3-dimensional numerical analysis for heatsink design and performance tests of the prototype lights have been done and the MR16 LED lights have been successfully developed.

• Photonics industry news
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• s.38
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• pp.10-13
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• 2007

현재 조명용 LED 광원모듈의 세계시장규모는 약 200억불로 Osram, GE, Philips 등의 다국적기업이 시장의 70-80%를 독점하고 있으며, 국내업체는 기술력 부족 등으로 세계 시장진입을 못하고 있는 실정이다. 국내시장 규모는 약 6,000억원 규모로 약 80%이상을 Osram, GE, Philips 등으로부터 수입하고 있는 실정이다. 특히, 백색조명용 LED 광원모듈은 세계적으로 기술개발 단계이거나 시장진입 초기로서 동 개발제품의 기술을 국내업체가 이전해 온다면 반도체 조명시장 조기진입 및 세계시장 선점에도 크게 기여 할 것으로 예상된다. 우리나라에서도 차기 LED조명시장을 염두에 두고 한국광기술원을 중심으로 연구에 박차를 가하고 있다. LED/반도체조명연구사업부가 개발한 2,500 루멘급 백색조명용 LED 광원모듈 시제품의 개발 성공은 백색조명용 LED 광원모듈의 핵심 원천기술 확보에 한발 더 나아가 결과이며, 시제품 개발결과가 조명제품으로 이어진다면 2010년에는 3,000억원의 무역역조가 개선될 것으로 전망하고 있다. 또한, 국내 최초로 개발된 3mW급 380nm UV(자외선) LED는 위폐감지기, 살균기 등 의료.환경.바이오산업 등에 적용 가능하며, 조명용 백색 LED 제작을 위한 펌핑광원으로 활용이 가능하다. 아울러 20mW 급 380nm UV LED 개발이 완료되는 2008년에는 반도체조명산업과 의료/환경산업 등에 활용되어 약 연 10억불 이상의 수입대체 효과를 가져 올 수 있을 것으로 예상된다. 한국광기술원 LED/반도체조명연구사업부는 다양한 LED 광원모듈의 연구개발을 통해 원천기술을 확보하고 LED광원 모듈의 국산화에 일익을 담당하고 있다.