• 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.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1285-1285
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• 2015

현재 전력난에 의해 에너지 절감이라는 말은 가정 및 산업 현장 곳곳에서 들을 수 있다. 에너지 절감 대책 중 하나가 몇 년전 정부에서 발표한 백열등 수입 및 유통금지가 있다. 그 효과로 LED 산업이 각광 받게 되었다. 다양한 LED 산업 및 기술에서도 신뢰성 및 성능 분야는 항상 진화하고 많은 기업들이 집중하고 있다. LED에서 중요한 요소인 방열성능을 개선시키기 위해 많은 연구를 행하고 있다. 그리고 광원 개발분야에서도, 반도체 광원의 LED PKG의 다량 실장으로 고출력을 행하는 것 보다는 기판위에 Blue Chip을 실장하여 제작하는 고출력 광원의 기술로 집중되고 있다. 이 논문에서는 고출력 광원인 COB(Chip On Board) LED의 방열성능 개선을 다루었다. 기판의 구조 변형으로 방열특성 개선 대안을 제시하였다. Via hole과 Cavity를 이용한 구조를 제안하였다. 그에 대한 해석 방법으로는, 구조적인 해석과 수치적인 해석을 활용하였다. 그 결과로는 약 13~40%의 방열성능 개선을 나타내었다.

• Composites Research
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• v.28 no.5
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• pp.322-326
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• 2015

We developed the high-power LED beacon and investigated the applicability of composite materials for the light-weight design of LED beacon. By means of the application of composite materials, the vertical deformation could be reduced by 17% and the total weight of LED beacon 8.9 kg comparable to 20% light-weighting against aluminum beacon. In thermal radiation test, the maximum temperature of LED package was measured to $63.5^{\circ}C$ under ambient temperature ($20^{\circ}C$), which is acceptable considering both performance and lifespan of LED packages. In this study, the applicability of composite materials was demonstrated for light-weight design of high-power LED beacon.

• Korean Journal of Optics and Photonics
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• v.20 no.4
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• pp.236-240
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• 2009

LED modules, based on MCPCB with a hard barrier oxide layer and an improved thermal dissipation property, are presented. Reflecting cups were also formed on the surface of the MCPCB such that optical coupling between neighboring chips was minimized for improving the photon absorption loss. LED chips were directly attached on the MCPCB by using the COB (Chip On Board) scheme. The LED modules showed significantly enhanced light outputs, compared to the LED modules based on conventional MCPCBs.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.3
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• pp.243-250
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• 2009

This paper provides an novel two-stage LED driver circuit for LED lighting equipment. The proposed driver circuit reduces voltage stress in LED driver circuit by using multi-level output voltage of PFC flyback converter. The proposed circuit satisfies IEC61000-3-2 class C regulation that is applied to lighting equipment over 25W and uses PWM to control brightness of wide extent. In this paper, the principle of proposed driver circuit is presented. A prototype has been built and tested. The experimental results are presented to show the validity of the proposed circuit.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.6
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• pp.15-20
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• 2014

Recently, LED (Light Emitting Diode) application research is studying by using a specific wavelength. LED plant factory produced a lot of green plants in a closed spaces, so it should be taken to guard against harmful microbes. Until today, a lot of studies for green plant production in plant factory is proceed but there were no study on harmful microbes in plant factory. Thus, the analysis on sterilization for harmful microbes in plant factory were experimented using UV (Ultra Violet) LED with 282nm of wavelength. As a results on sterilization of three harmful microbes, 50% of sterilization efficiency was achieved after 2.5 hours, 97% was achieved after 12 hours of UV LED irradiation, respectively.

• Journal of Satellite, Information and Communications
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• v.8 no.2
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• pp.17-21
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• 2013

A building energy-saving have been increased worldwide interest. There is continuing research on IT technology for efficient management of BEMS. Recently, It is able to control of LED and to maximize energy savings to the development of LED lighting technology. We propose the security image processing system to improve efficiency and we implement the real-time status monitoring system to surveil the object in the building energy management system. In this paper, we proposed the system of LED control using Zigbee network for connect the server. User is able to control LED light and monitering by the desktop. We implemented LED light control software on the based of Real-time monitering and LED control. Also detect human body movement.

• Korean Journal of Optics and Photonics
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• v.22 no.3
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• pp.141-150
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• 2011

Although significant amount of research has been done to develop LED lamp packages for improved performance, no standard theories or guidelines have been established yet for designing LED lamp packages. In this paper, the photon extraction efficiency depending on both the InGaN/Sapphire LED chip structure and its attachment schemes for chip mounting has been analyzed by using the Monte Carlo photon simulation method. Based on the results of the analysis, we have derived guidelines for LED lamp package design, which can be utilized in industries or research institutes for designing new LED lamp packages optimized for particular applications.

• Journal of Industrial Technology
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• v.25 no.B
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• pp.183-188
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• 2005

Instead of the incandescent lamps the LED lamps have been used on the traffic signal lamp with the advantages of small loss, no lens and long life. In this paper, we have compared three kinds of the LED controller structures and showed the LED array decision methods. We studied the temperature characteristics on LED and the temperature compensation network. The experimental results showed that the electrical characteristics of three kinds of the LED controller structures were different each other. We concluded that the temperature compensation is the important technique, the best compensation network has the ${\pm}10%$ variation for the luminous intensity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.5023-5028
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• 2010

In this paper, an image based LED design simulator is proposed to reduce LED design cost mostly contingent on a design expert. Current techniques about LED design schemes have mostly treated text-based LED simulators. The proposed method is to provide novel and easy simulator for LED designers. At first, image filters including histogram equalization, bicubic interpolation. and scaling are employed. Color mapping and special effects are added as well. Experimental results classified into several categories along with running times are shown to validate the proposed methods.