• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2431-2436
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• 2012

This paper is implemented simple visible light communication system by combining the communications through LED lighting. It uses a variable PD sensor to the receiver and 1~12 the LED light-emitting device to the transmitter to realize LED visible light communication. Initial distance value of the developed transmission and receiver is more than 0~1.5m for LED visible light communication, the overall system transmission rate is organized with thousands kbps variability visible light media transmission system. It was measured the performance experiment during lens wearing or not wearing in order to increase the overall efficiency of the LED module, configures the LED and PD to existing PC module for the performance analysis of the implemented research, experiments the maximum communication distance of the transmitter/receiver according to LED count and the transmission rate, check about application methods and the possibility.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.5
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• pp.19-25
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• 2011

With the issue of a Green IT Technology, studies on a environment-friendly luminous source that can reduce Carbon discharge and increase energy efficiency are actively progressed all over the world. Especially, with the problems of high oil price and environmental pollution, LED has made a great attention as a new luminous source that can replace the existing incandescent bulbs and fluorescent lights. In this paper, the proposed streetlight system becomes more intellectual by combining the low power consuming, high efficient, and high luminous LED module with a complex sensor module with temperature, humidity, illumination and motion sensors. Then, we design and implement the Ad-Hoc based LED-IT-Sensor integrated streetlight system that can maximize the energy savings efficiently with central monitoring system and selective remote dimming control by connecting them to the wireless ubiquitous sensor network(USN) using a Zigbee module.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.11
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• pp.1-8
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• 2008

In this paper, the optical properties of the 54[W] LED module have confirmed by changing the angles of LED modules for street light applications. The angle of LED module changed from the $0[^{\circ}]$ to $60[^{\circ}]$ varying by $20[^{\circ}]$ as horizontal direction ${\ominus}_1$. Morever, the angle of LED module changed from the $0[^{\circ}]$ to $15[^{\circ}]$ varying by $5[^{\circ}]$ as vertical direction ${\ominus}_2$. As a result of simulation, the average illumination was about 17[lux] and the overall illuminance uniformity was 0.29 for a 10.39[m] long and 6[m] wide illuminance area at height of 6[m], which is acceptable for street lighting illumination in the Illuminating Engineering Society(IES) standard.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.2
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• pp.155-159
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• 2015

Light emitting devices (LEDs) are widely used in the liquid crystal display (LCD) industry, especially for LCD back light units. Therefore, much research has been performed to minimize manufacturing costs. However, the current process does not process LED chips from broken substrates even though the substrate is expensive sapphire wafer. This is because the broken substrates lose their alignment marks. After pre-processing, LED dies are glued onto blue tape to continue post-processing. If auxiliary alignment marks are stamped on the blue tape, post-processing can be performed using some of the LED dies from broken substrates. In this paper, a novel stamper module that can stamp the alignment mark on the blue tape is proposed, designed, and fabricated. In testing, the stamper was reliable even after a few hundred stamps. The module can position the stamp and apply the pattern effectively. By using this module, the LED industry can reduce manufacturing costs.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.2
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• pp.117-122
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• 2013

The distributed power conversion LED driver circuit using parasitic inductance is proposed in this paper. while the conventional LED driver circuit is composed of the large size devices and heatsinks, the proposed circuit can be realized with the small sized no heatsink based. since the processing power can be effectively distributed. Also by using the wire parasitic inductance of the LED string, the proposed circuit can be implemented without external magnetic device. As a result, the proposed circuit which features the small size and volume con be realized even without LED driver module(LDM) board. since, all the device can be attached to the existing LED array Module(LAM) board. Therefore, it features that cost savings and volume reduction of circuit. To confirm the validity of the proposed circuit, theoretical analysis and experimental results from a distributed power conversion LED driver circuit prototype are presented.

• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.1111-1117
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• 2011

We was designed the portable LED light which can shadowless shooting and developed using a high-power LED that medical attention as a new lighting components for structural confirmation of oral dental area, medical and surgical lesions in the local area. LED which applied to the development, was used the 3-color LEDs for possible of implement a variety of colors and adjusted the light intensity. It is being magnified of delicacy expressiveness and three-dimensional for tone of the subject-specific. It has been developed a highly efficient light module that LED is used to consider the electrical characteristics and optical properties. SMPS has We was designed the portable LED light which can shadowless shooting and developed using a high-power LED that medical attention as a new lighting components for structural confirmation of oral dental area, medical and surgical lesions in the local area. LED which applied to the development, was used the 3-color LEDs for possible of implement a variety of colors and adjusted the light intensity. It is being magnified of delicacy expressiveness and three-dimensional for tone of the subject-specific. It has been developed a highly efficient light module that LED is used to consider the electrical characteristics and optical properties. SMPS has produced for use in mobile that can be driven at low voltage. In addition, it was also possible to implement a variety of colors from monochromatic Light to polychromatic light using by PWM control method and were available 32,768.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.557-560
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• 2008

The main goal of this work is to fabricate light emitting diode (LED) module and apply it to mobile handset. We first fabricated the blue-color LED based on the AlInGaN cell structure with size of $200\;{\mu}m\;{\times}\;200\;{\mu}m$. Also we proposed a new $1.0\;mm\;{\times}\;0.5\;mm$ (1005size) packaging procedure for the LED cell. Thus the overall dimension of our LED cell was as small as $1.0\;mm\;{\times}\;0.5\;mm\;{\times}\;0.4\;mm$ ($W\;{\times}\;L\;{\times}\;T$). As far as we knew it was the first time that this small LED cell dimension had been fabricated and operated.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.439-440
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• 2012

최근 LED의 빠른 성장과 새로운 개발이 이루어지면서 이를 이용한 응용제품의 개발과 기존 조명을 대체하려는 연구가 활발히 진행 되고 있다. 기존의 LED PCB Ass'y와 구동드라이브는 분리형으로 Size및 소자의 개수가 많아 cost및 신뢰성 부분에 제약이 따른다. 이에 대한 보완점을 찾기 위하여 본 연구에서는 새로운 LED 구동 드라이브를 제안하였다. 회로의 부하를 LED Module로 구성하여 피크 전류를 완화하여 LED 동작 및 전류제어가 가능 하고, 부하에 저항만 있을 때의 전압, 전류의 출력파형이 플리커 현상을 보이는 부분이 사인파로 조정된 모습을 확인 할 수 있다. 본 연구 에서는 기존 LED 드라이브의 많은 제약적인 부분을 보완하기 위해 출력되는 전압, 전류의 파형이 부하에 따라 변화하는 모습을 시뮬레이션을 통해 검증하였다.

• Convergence Security Journal
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• v.14 no.7
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• pp.29-36
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• 2014

In this study, we design and develop a VLC test-bed system which has been recently issued and focused as good convergence technology in the world. We classify the developed system into transmission part including analog LED driver module, digital signal modulation module, and receiver part with light sensing module and signal demodulation module. Then we introduce important characteristics and components. We analyze some factors for each module. To validate the communication of the designed VLC system, we develop a VLC sender-receiver simulator which can control the dimming factor and flicker-free effect. From the developed system, we observed about 12Mbps of data transmission rate with 0.5m~1m of distance, without packet loss. We verified the real-time communication with multimedia streaming which can be considered as very high date rate. The developed system and technology will be useful for some converged data services like indoor positing, home appliances, and indoor parking system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.797-798
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• 2012

The purpose of this study to embody LED visible light communication visual signal delivery system based on TFT-LCD module and to analyze a performance for digital signals. LED lighting enables to transmit data through light, to embody visible light communication, and to control lights in different wavelengths according to LED materials and structural materials. In this study, we aim to create a transmitting and receiving sensor that has implemented LED and visual sensors to LED efficiency and existing TFT-LCD module so as to estimate and indicate a communication distance and to find out application methods and problems. Also, by implementing TFT-LCD technology and next-generation LED visual communication technology, this study aims to check the possibility of technological realization by applying them to various means of communication including ubiquitous communication.