• Journal of Information Display
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• v.10 no.3
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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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1484-1488
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• 2009

This thesis is about Heat-sink design which is considered as the biggest problems for commercialization of LED lighting and suggests how to solve the problems though analysis on heat-sink using COMSOL. The temperature difference after simulation value and modelling was $10^{\circ}C$by Transient analysis of Heat Transfer Module which is in the COMSOL Multiphysics. The result approximated the object which is close to actual lighting, when various elements are used according to temperature change of interior and exterior surroundings LED lighting is set up.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.9
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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.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.12
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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.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.30 no.3
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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.

• Korean Journal of Optics and Photonics
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• v.23 no.5
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• pp.222-226
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• 2012

The design methods of the reflecting cup employed in an LED lamp are presented. The beam patterns of an LED lamp can be adjusted by functional segmentation of the reflector height. Thus, the reflecting angle of slope was designed according to the height. The analysis of the designed reflecting cup shows that precise adjustable beam patterns can be achieved.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.2
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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.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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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.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.30 no.1
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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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.7
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• pp.2317-2322
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• 2010

Market for LED lights as a newly-growing industry has been growing, and secureness of high efficiency and long life through optimal thermal design are crucial for further popularization. In this study, considerable improvement in thermal performance for a 10W LED light has been done compared to a previous model. For this, numerical model has been established through experiments and used to optimize design factors in heat release such as fin shape, PCB kind or LED number etc. Furthermore, prototype of a LED light has been made and the improved thermal performance was verified with heat release experiments.