• Title/Summary/Keyword: Light-emitting diode (LED)

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Optic Characteristics Comparison and Analysis of SMD Type Y/G/W HB LED (SMD형 Y/G/W HB LED의 광특성 비교분식)

  • 황명근;허창수;서유진
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.4
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    • pp.15-21
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    • 2004
  • The optical characteristics; luminous flux, correlated color temperature, and CIE -chromaticity coordinate etc., of HB LED(high brightness light emitting diode) of yellow/green/white SMD(surface mounted device) type were tested with integrating sphere photometer and monochromator, and the results were comparatively evaluated And, for the white LED, color rendering indices were considered to analyze.

LED IT-based System sensor network transceiver module research (LED IT 기반 시스템 센서 네트워크 송수신 모듈 연구)

  • Jang, Tae-Su;Lee, Jun-Myung;Choi, Jung-Won;Kim, Yong-kab
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.10a
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    • pp.11-12
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    • 2012
  • In this paper, efficient visible light communication technology LED (Light Emitting Diode) lighting through the existing infrared sensor used for performance analysis of transmitting and receiving is possible. LED utilizes lighting by changing light into electricity. Lighting features while maintaining the basic principles of flashing LED and PD (Photo Diode) to send and receive communications from LED lighting communication convergence principle be realized simultaneously enabling. Multiple IT applications under the basic structure of LED technology development, and the current was encountered in real life. LED lighting anywhere with wireless communication technology that can, in order to ~ 1m above the initial value by taking advantage of the system H/W and infrared sensors(PD) are widely used in the entire system that can improve the speed of visible light data transmission system is finished. LED module that is used to communicate whether the performance analysis, For forecasting and communication distance on the LED and infrared sensor configuration of the implementation of the research is to study about the possibility of application methods and indicates.

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Efficiency of LED Trap on Controlling Tobacco Whitefly, Bemisia tabaci Adults in Greenhouse (온실에 발생하는 담배가루이 성충에 대한 LED 트랩 방제효과)

  • Jeon, Ju-Hyun;Lee, Sang-Guei;Lee, Hoi-Seon
    • Journal of Applied Biological Chemistry
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    • v.57 no.3
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    • pp.243-245
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    • 2014
  • To evaluate light-emitting diode (LED) as potential attractants for Bemisia tabaci adults, attractiveness of white and yellow LED traps were investigated in greenhouse. The yellow LED trap showed the most attractive to B. tabaci adults, followed by a similarly attraction to the white LED trap, whereas the control (no light trap) was little attractive to B. tabaci adults. These results suggested that yellow and white LED traps could be used for environment-friendly insect pest control.

Implementation of Transceiver for Optical Wireless Communication System (광무선통신 시스템의 송수신기 구현)

  • Lee, Sun Yui;Kim, Jin Young
    • Journal of Satellite, Information and Communications
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    • v.8 no.1
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    • pp.71-76
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    • 2013
  • In this paper, a transceiver of VLC (Visible Light Communication) using LED white lighting has been implemented. The transmitted waveforms of LED and PD (Photo Diode) of the received signal are analyze to restore VLC data. Audio signal was successfully transmitted to demonstrate possibility and potential of optical wireless communication systems. Various modulation formats are considered to evaluate and compare performance in diverse channel conditions.

Indoor positioning system of 50 cm resolution based on LED (50cm의 resolution을 가지는 LED 조명 기반의 실내 측위 시스템)

  • Jung, Soo-Yong;Hann, S-Wook;Park, Chang-Soo
    • Journal of Satellite, Information and Communications
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    • v.5 no.2
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    • pp.69-74
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    • 2010
  • In this paper, we present an indoor positioning system based on light emitting diode (LED). Because LED is a semiconductor light emitting device, we can easily switch and modulate electrical signals into lightwave signals at high speed using LEDs. We assigned unique 8-bit ID address to each LED lights. Photo diode receives data from 16-LED lights and takes correlation coefficient beteween received data and each LED-ID. Using correlation coefficient, proposed positioning system shows resolution of 50 cm in dimensions of $4\;m\;{\times}\;4\;m\;{\times}\;2\;m$.

Performance Investigation of Visible Light Communication Using Super Bright White LED and Fresnel Lens (조명용 고출력 백색 LED와 프레넬 렌즈를 이용한 가시광 통신 성능연구)

  • Kim, Min-Soo;Sohn, Kyung-Rak
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.1
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    • pp.63-67
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    • 2015
  • White light-emitting diode (WLED) is growing interest in using both illumination and communications. This paper reports visible light communication (VLC) composed of a super bright white light-emitting diode, low cost commercial photo-diode and a Fresnel lens. LED driver is consisted of the power MOSFET and MOSFET driver that switches the LED on and off. The modulation bandwidth of the LED used was determined to be 8 MHz. However, it was possible to communicate up to 1 Mbps under illumination of 500 lx because of the weak signal power and a low spectral sensitivity of the SHF213 as a PIN photodiode. In order to enhance the system bandwidth, the LED light was focused on the PIN photodiode by use of the Fresnel lens. As a result of that, visible light link was operated up to modulation bandwidth of the LED. The signal to noise ratio can be improved by 40 dB using an optical concentration at the receiver.

A SPICE-based 3-dimensional circuit model for Light-Emitting Diode (SPICE 기반의 발광 다이오드 3차원 회로 모델)

  • Eom, Hae-Yong;Yu, Soon-Jae;Seo, Jong-Wook
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.2
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    • pp.7-12
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    • 2007
  • A SPICE-based 3-dimensional circuit model of LED(Light-Emitting Diode) was developed for the design optimization and analysis of high-brightness LEDs. An LED is represented as an array of pixel LEDs with small preassigned areas, and each of the pixel LEDs is composed of circuit networks representing the thin-film layers(n-metal, n- and p-type semiconductor layers, and p-metal), ohmic contacts, and pn-junctions. Each of the thin-film layers and contact resistances is modeled by a resistance network, and the pn-junction is modeled by a conventional pn-junction diode. It has been found that the simulation results using the model and the corresponding parameters precisely fit the measured LED characteristics.

2D Slab Silicon Photonic Crystal for Enhancement of Light Emission in Visible Wavelengths

  • Cui, Yonghao;Lee, Jeong-Bong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.887-890
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    • 2008
  • We present 2D slab silicon-based photonic crystal optical insulator to enhance light emission efficiency of light-emitting diode (LED). A 2D slab silicon photonic crystal is designed in such a way that light emitting diode die can be placed in the middle of the silicon photonic crystal. The device creates light propagation forbidden region in horizontal plane for Transverse Electric (TE) light with the wavelength range of 450 nm to 600 nm.

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Burn Wound Successfully Treated with 830-nm Light Emitting Diode Phototherapy Combined with Epidermal Growth Factor Solution

  • Lee, Hae-Jin;Kim, Young Koo
    • Medical Lasers
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    • v.8 no.2
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    • pp.94-96
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    • 2019
  • Burns are one of the most extensive injuries of soft tissues as well as skin, occasionally resulting in extensive, deep wounds and death. Burn wounds can lead to severe physical and psychological distress because of excessive scarring and skin contractures. Treatment of burn wounds has always been a challenging problem and many different methods have been used to treat such injuries. We report here on treating a patient with a burn wound using 830-nm light emitting diode (LED) phototherapy combined with epidermal growth factor (EGF) solution. After five daily sessions of LED with EGF solution treatment, the patient demonstrated nearly complete improvement with no remarkable side effects. We suggest that LED phototherapy combined with EGF solution could be an effective and safe treatment option for treating burn wounds.

Cultivation of Chlorella sp. under Different Aeration Conditions Illuminated by Light Emitting Diode (LED 조명을 이용한 광생물 반응기에서 공기 주입량에 따른 클로렐라 성장 연구)

  • Choi, Bo-Ram;Lee, Tae-Yoon
    • KSBB Journal
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    • v.27 no.4
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    • pp.263-267
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    • 2012
  • The purpose of this study was to determine optimum value of aeration rate for the cultivation of Chlorella sp. under illumination of red light emitting diode. The aeration rates varied from 0 to 2.4 vvm under the illumination of 4,400 lux of red light emitting diode. The highest specific growth rate of $1.51\;day^{-1}$ was obtained at the aeration of 0.7 vvm and lower specific growth rates were obtained for other aeration tests. Furthermore, the highest biomass concentration (1.02 g/L) was also obtained at the aeration of 0.7 vvm. Therefore, aeration of 0.7 vvm was determined to be the optimum aeration rate for the cultivation of Chlorella sp. under red light emitting diode.