• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.248-249
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• 2008

본 논문에서는 원칩 마이크로컨트롤러를 사용한 파워 LED 구동제어 시스템의 설계 및 구현에 대해 중점적으로 기술한다. 파워 LED의 조광제어 및 특정 조도에서의 정전류 구동을 위해 전류피드백을 통한 디지털 PI 전류제어 및 PWM 구동방식을 행하였고, 시각적인 깜박거림 없는 충분한 주파수의 스위칭을 통해 부스트 컨버터를 연속도통모드로 동작시켰다. 본 논문에서 제시한 파워 LED 구동을 위한 디지털 제어시스템은 최근의 에너지 및 환경규제에 적합한 조명관련 응용분야에서 다양하게 적용될 것으로 판단된다.

• Journal of the Korea Society of Computer and Information
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• v.20 no.10
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• pp.7-13
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• 2015

Wearable device, next generation smart device, is consistently growing. The flexible display will be a kind of display in the wearable device. The flexible display technology is now evolving with end-user requirement such as portability and easy installation. Previous wearable display products still have some difficulties in manufacturing and in flexibility whole device. But it can be a flexible display with LED device and utilized in commercial area. In this paper, we propose a driver to control the LED display and implement a flexible LED display system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.21-23
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• 2009

The paper is to evaluate for reliability of LED Modules for Lighting by ALTs(Accelerated Life Tests). The recently, some of KS were established by law of LED Modules for Lighting(KS C 7651, KS C 7652 and KS C 7653), but reliability assessment methods of LED Modules for Lighting were not established. Therefore, the paper aided companies to test methods for accelerated life testing by themselves.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.208-210
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• 2009

The paper is to evaluate for reliability of LED Channel Modules by ALTs(Accelerated Life Tests). The recently, some of KS were established by law of LED Lamps for Lighting(KS C 7651, KS C 7652 and KS C 7653), but reliability assessment methods of LED Channel Modules were not established. Therefore, the paper aided companies to test methods for accelerated life testing by themselves.

• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.159-161
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• 2007

본 논문에서는 버스에 장착되는 LED 번호판의 효율적인 설계에 관한 연구를 보여준다. LED 번호판은 16X16 LED Dot Matrix(LDM)을 사용하여 버스 구간을 번호로 표시하기 위한 것으로 기존의 플라스틱 판을 LDM을 사용하여 표시한 것이다. 본 논문에서는 LDM을 사용하여 효율적인 번호판 설계를 보여주고, 실제 시작품을 버스에 장착하여 그의 타당성을 확인하였다.

• Journal of Digital Convergence
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• v.10 no.4
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• pp.37-43
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• 2012

LED TV integration test unit are the equipment for testing LED BLU as LED BLU's operation, error check, AGING work. The previous test unit were inconvenient because it must change test unit in production line according to LCD's kind and size. This paper develops by integration style test unit that can accommodate various LED TV BLU model of 32 ~ 52 inch that is not one LED TV BLU model. We make that output current is various to dimension of 80 ~ 215 mA. We make functions that are LED BLU state check, Diming and heat occurrence mitigation. Also we develop firmware program and that the program can be upgraded and that can support new panel.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.181-187
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• 2012

LED is just a semiconductor which can produce light. Currently, there are active research works on LED lighting technologies according to the growth of energy-saving environmental industry. Especially, LED communication is one of the active research works in these fields. In this paper, we design a LED communication-based PC-PC transmission system. A transmission circuit system(transmitter) using LED and a receiving circuit system(receiver) using PD(photo detector) and Op-amp are designed, respectively. The experiments for the designed system are performed as follows. One computer is connected at the end of transmitter and receiver, respectively, and text files are transmitted by using text transmission programming. In this experiment, we test the performance with various baud rates, LED colors, transmission ranges.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.289-289
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• 2009

Light emitting diode(LED) has many advantages including lower energy consumption and longer lifetime and eco-friendly in comparison with traditional light sources. Spheric plastic lens generally used in LED lighting occurs aberration and ghost image which give displeasure and deteriorate vision quality in human eyes. Using the optical program (LightTools$^{TM}$, CodeV$^{TM}$), we were confirm the aberration and ghost image in optical simulation and employed aspheric lens form in the lens design to improve these problems. From the comparison of the simulation results between the aspheric lens and the spheric lens, we were ascertain to be improved both aberration and Ghost image.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1735-1736
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• 2006

As developing the information society, Lighting Emitted diode(LED) which is light source for illumination of next generation is attracted public attention. LED have many problem as narrow light view angle, high price, drift phenomenon of color coordinate, high heating problem for lower power, lower weight and small size. So, many researches have continued in a illumination as LED module type. in this problem, heating problem is very important and difficult and that is caused in decreasing phenomenon of brightness and drift phenomenon of color coordinate. so the problem of heating is urgent question for illumination of LED. In this paper, structural design of PCB changed as two type for solving the heating problem. also the properties of heating is analysed and optical properties is measured with heating image camera and spectrometer according to change in this design.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.4
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• pp.253-256
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• 2011

LEDs have small size, long lifespan, high reliability, low power consumption and high color efficiency. Using such a characteristics, LED Back Light Unit has been studying actively. This paper proposes LED driver to minimize power consumption due to LED forward voltage($V_F$) difference and temperature rising. Compared to conventional LED driver, the proposed driver have excellent stability, brief structure and linear output voltage of DC-DC boost converter. Proposed LED Driver circuit was designed using 0.35um CMOS technology. And its operation was verified through simulation.