• Journal of Information Display
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• 제10권3호
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• pp.97-100
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• 2009

A backlight unit for a 42-inch LCD TV was manufactured with red, green, and blue LED lamps. The luminous and light extraction efficiencies of the LED lamps were increased by improving their light reflection structures and thermal properties. The blue, green, and red LED lamps showed different luminous efficiencies as a function of the input current. Compared to the conventional red LED lamp, however, the developed red LED lamp showed very high luminous efficiency in a low drive current. Taking these luminous efficiencies into account, the fabricated backlight unit showed high energy efficiency, low power consumption, and a wide color gamut.

• 한국산학기술학회논문지
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• 제10권7호
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• pp.1484-1488
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• 2009

본 논문은 LED조명기구의 상용화에 가장 큰 문제로 제기되는 방열설계에 관한 논문으로서, COMSOL을 이용한 방열해석을 통하여 문제해결의 방법을 제시한다. COMSOL Multiphysics에 있는 Heat Transfer Module의 Transient Analysis를 활용하여 해석한 결과, 시뮬레이션 값과 시작품 제작 후 측정 온도와의 차이가 10[$^{\circ}C$]이하로 도출되었으며, Led Lamp가 설치되는 실내.외의 환경조건의 온도변화에 따른 제 요소들을 잘 활용하면 실제 작품의 목표치에 근접하는 결과를 얻을 수 있음을 확인할 수 있었다.

• 한국전기전자재료학회논문지
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• 제25권9호
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• pp.738-742
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• 2012

This paper conducted a study on how the heat radiation of light emitting diode(LED) luminaires affects the indoor temperature increase. The effect was compared with that of a 20 W compact fluorescent lamp(CFL) and a 50 W MR16 halogen lamp which are most widely used inside of cruises, a LED downlight and a 4W MR16 LED replacing each of them. We installed a luminarie inside a thermally shielded chamber, measuring the temperature changes under the same volume every 5 minutes and compared the result with theoretically calculated heat radiation. The temperature changes in the chamber was measured four times, on seven hours' period in order to keep sufficient time once the temperature reaches the thermal equilibrium state. The results showed that the temperature of the 20 W E26 CFL and the 10 W LED downlight increased by $21.1^{\circ}C$ and $10.4^{\circ}C$ respectively, while that of the 50 W halogen MR16 and the 4 W LED MR16 increased by $33.9^{\circ}C$ and $4.8^{\circ}C$ respectively. The experimental heat radiation were calculated from the results and the experimental heat radiation of the CFL and the LED downlight were 171.5 cal and 86.5 cal, and those of the halogen MR16 and the LED MR16 were 275.3 cal and 36.5 cal. Therefore, the heat radiation was reduced by 49.5% and 86.7%, respectively, by replacing conventional light source with LED. In conclusion, we can expect a reduction of power consumption in air condition system and the effect on indoor temperature increase by application of LED luminaires.

• 대한기계학회논문집B
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• 제33권12호
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• pp.947-951
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• 2009

LED has the merits of high reliability, semi-permanent life, rapid-response and its small size for use as light source of head lamp. But the dependence of its performance and life on temperature affect on its practical use. Which dependence makes problem when the LED is heated up to a higher temperature level by self-generation of heat, due to "highly integration" to get enough quantity of light. To solve this problem, effective cooling system is needed that consider conduction, convection and radiation. This study points out the limits of natural convection cooling system and propose of forced convection with heat sink. Also, it describes a correlation between heat sink area and fluid velocity using numerical analysis to optimize the cooling system.

• 조명전기설비학회논문지
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• 제30권3호
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• pp.94-105
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• 2016

The objective of the work was to evaluate the impact of lighting energy to cooling and heating consumption in medium scale office building, when currently installed fluorescent lights were replaced with various LED lighting fixtures. This evaluation comes from an integrated approach combining the proper indoor lighting environment and the thermal aspects of cooling & heating consumption in office building. These simulations were performed by coupling an appropriate luminaire analysis for energy consumption and a dynamic thermal simulation software (TRNSYS). To analyze comparative study of effects on the heating, cooling loads, and energy consumption of an LED lamp application, 2 types of LED lamp with low light power watt(LPW) 24W and high LPW 7.5W and a fluorescent lights(FL) with 37W are used respectively. Integrated building energy consumption decreased up to 3.2% when fluorescent lamps were replaced with LEDs. Thus, the high LPW of LED(7.5W) replaced with the same number of FL shows an effective energy saving and cost- effective luminary.

• 한국광학회지
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• 제23권5호
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• pp.222-226
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• 2012

본 논문에서는, LED 조명의 배광 특성의 조절이 용이한 반사컵 설계 방법을 제안하였다. 먼저 개별 반사컵의 구조와 높이에 대한 방사각의 변화 경향성을 파악하여, 높이에 따른 반사 특성을 확인하였다. 그 결과, 높이에 따라 반사 각도를 조절하여 설계함으로써 배광 분포의 세밀한 조절이 가능했다. 가장 간단한 2단 분할 방식의 경우 방사각의 제어나 균일도 개선을 할 수 있었다.

• 한국전기전자재료학회논문지
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• 제27권2호
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• pp.126-131
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• 2014

In this paper, plant crops used in the region to grow crops for the LED lighting area of a rectangle to fit the light distribution to maximize the efficiency of a rectangular distribution was made of LED lights. After the fabrication of LED lamps, light distribution, and in the area of $1.2m{\times}3m$ was the analysis of Illuminance chart. As a result of examining the performance light distribution for total Emin/Eav is 56%, and the target area of the light distribution compared to normal lamps Emin/Eav is improved by about 17%. In addition, plants grown in the area to minimize the outgoing light distribution can be focused on the cultivation area, according to the distance of the plants and be able to have the best luminous efficacy is judged.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 춘계학술대회 논문집
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• pp.167-170
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• 2004

A high light lantern system using LEDs is composed of power supply, flash controller, and daylight controller and proper case considering work condition. The performance of developed LED lantern is better than that of the existing marine lantern using an incandescent electric lamp and that of foreign products(Vega LED lantern made in New Zealand, Tideland system made in America). The electric consumption of our products is 30% compared with that of existing marine lantern using an incandescent electric lamp, and the luminous Intensity of them is 200% to 400% compared with that of existing marine lantern and foreign LED lantern. In addition, our LED lantern system is easy to repairing something wrong and changing the LED module and other controllers on the sea when they are in accident.

• 조명전기설비학회논문지
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• 제30권1호
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• pp.8-13
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• 2016

Public institutions should replace their luminaires with LED lighting by 2020 to save energy. Because the LED lighting installation rate in schools has not yet reached the legal goal, the ESCO program feasibility was investigated. The amount of electricity used, electric rates, times of use in classrooms and fluorescent lighting maintenance costs etc., as well as the elements of lighting maintenance were analyzed. In the case of schools, the lamp usage time was so short that the ESCO projects with only energy savings were impossible. In order to execute the ESCO projects, the maintenance cost savings by replacing an existing luminaire should be considered and the introduction of the relatively cheaper tube type LED lamp than the flat type LED luminaire was required.

• 한국산학기술학회논문지
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• 제11권7호
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• pp.2317-2322
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• 2010

신성장 동력 산업으로 분류된 LED 조명등은 점차 수요가 확대되고 있으나 본격적인 대중화를 이루기 위해서는 여전히 LED 방열 설계 최적화를 통한 긴 수명과 고효율 확보가 매우 중요하다고 하겠다. 본 연구에서는 기존 10W LED 조명등에 비하여 방열 성능이 더욱 개선된 LED 조명등을 개발하고자 하였다. 이를 위하여 기존 램프의 방열 성능 실험을 통하여 수치해석 모델을 완성하였고 이러한 수치 모델을 이용하여 방열핀 형상, PCB 종류 및 LED 개수 등과 같은 방열 설계 인자들을 최적화하였다. 또한, 시제품을 제작한 후 방열 성능을 실험으로 검증함으로써 방열 성능이 획기적으로 개선된 10W LED 조명등을 성공적으로 개발하였다.