• The Journal of the Korea Contents Association
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• v.10 no.5
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• pp.62-69
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• 2010

LCD panel need BLU(Back Light Unit) that is outside source of light because can not emit light voluntarily. BLU is used in LCD module and is used in tester that examine LCD panel's badness. Lately, BLU had changed from CCFL(Cold Cathode Fluorescent Lamp) to LED(Light-Emitting Diode) fast. CCFL need extra-high tension power and produce much heat and is difficult to keep fixed brightness. LED is few electric power wastage and keeps fixed brightness. But, BLU that is used to detector that examine the LCD module is using CCFL until recently. This paper develops LED BLU that can examine LCD panel's badness. Also, this manufactures LED BLU to 24 inch size to examine all LCD panels(12~24 inch), and develops so that LED BLU may operate according to LCD panel's size.

• Korean Journal of Optics and Photonics
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• v.21 no.3
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• pp.118-122
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• 2010

We fabricated a high power LED lamp structure which utilizes the modified COB concept based on an MCPCB with insulation layer partially removed. In the proposed structure, no insulation layer exists between the LED chip and the metal base. As a result, the heat generated in the chip is easily dissipated through the metal base. In actual measurement as well as in thermal simulation, the fabricated LED lamp structure showed superb thermal properties, compared to the SMD LED lamp attached on an MCPCB or the LED lamp based on conventional COB concept.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.4
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• pp.503-508
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• 2010

Common LED (Light Emitting Diode) lamp has many advantages to compare with fluorescent lamp, long life and no pollution matter like the mercury. The LED lamp is a good light source especially for shipboard lighting because of its compact structure which prevents explosion and shock. Also, low maintenance cost is expected due to its longer life time in comparison with conventional lamps. The LED lamp, however, need some estimates that change of voltage and frequency, vibration, moisture on board to definite accommodation of the LED lamp to shipboard. The purpose of this study is to compare physical properties of a fluorescent lamp with one of the common LED lamp so as to analyze accommodation of common LED lamp on board. This study was carried out in two stages. First, temperature, humidity of illumination, voltage, electric current, frequency and electric power were measured by using experimental equipments. Second, a comparative analysis of consumption electric power, annual oil charge, annual CO2 emission and lamp life time, etc of the fluorescent lamp and common LED one was made. As a result of the study, the consumption electric power of fluorescent lamp was 50% higher than one of the common LED lamp. As a result of measuring life time, it was found that life time of common LED lamp was more about 3.5 fold than one of the fluorescent lamp. Considering these results, it's thought that common LED lamp is verified that energy saving is possible and using is possible as substitute for fluorescent lamp on board.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.5
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• pp.561-566
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• 2014

The high power COB(Chip on Board) LED, densely arranged chips on a board, are increasing to resolve heat problems in LED that has luminous semiconductor chips as main materials. In case of high-power COB LED, protection against heat is necessary due to the power consumption is high. Also if the temperature of device increases, the optical emission becomes less efficient and the life rapidly reduces due to thermal stress. This study packaged 13.5W COB LED and heat sink with difference form and produced 13.5W COB LED down-light heat sink by analyzing the thermal modes with Solidworks Flow Simulation. And finally it analyzed and evaluated the thermal modes using contacting and non-contacting thermometers.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.218-220
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• 2008

This paper describes buck converter's MOSFET driver for high-brightness LED strings. The power driving high-side MOSFET is supplied from the power source of control circuit part. The practical considerations and future work are also described.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.5
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• pp.183-189
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• 2015

In this paper, we propose an efficient implementation method that current-voltage sourcing and measuring for LED using (+) single power. this method has the advantage of reducing the error of the circuit and calibration of system, and also improving the complexity of hardware than the method of using a (+)(-) current or voltage sourcing and measuring.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1574_1575
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• 2009

This paper investigates the reduction of RE(Radiated Emission) noise in a high power LED module circuit using PWM(Pulse Width Module) switching controller circuit. Poorly designed LED lighting module can experience the RE and CE(Conducted Emission) noise problem. This paper propose the reduction of noise source and improvement of EMI filter design in a high power LED lighting module. The experimental and simulation results showed that reduce the RE noise level effectively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.9
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• pp.1312-1316
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• 2014

The color and the installation position of the LED lamp for night voyage of the ship are changed by the purpose of it. The power dissipation occurs because a navigation light is on and off or continuously on. In addition, in case that the light is produced by operating generator in the ship, it's very inefficient except that it's on a voyage. Therefore in this dissertation, we construct auxiliary power system for the LED lamp of the ship, producing and developing a module, a panel, and a charging system using Dye-sensitize Solar Cell.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.906-909
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• 2004

Status of high intensity LED, one of the recent issue in industry is reviewed. In a system view, various power supply methods for multiple array construction are introduced rather than one for single LED. Custom IC for driving LED and different circuit for applications are also considered.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1642-1645
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• 2007

The brightness of LED changes according to the current flowing through LEDs. The current mirror was used to drive LEDs effectively. The reference current of the current mirror was usually controlled by the resistor but the size of this resistor is very large and this resistor consumes too much power for high power LED backlight driving. The reference current of the current mirror LED driver was controlled by using flyback converter at small size with low power consumption in this paper. The concept of active current source was presented.