• Title/Summary/Keyword: white light source

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High-brightness Phosphor-conversion White Light Source Using InGaN Blue Laser Diode

  • Ryu, Han-Youl;Kim, Dae-Hwan
    • Journal of the Optical Society of Korea
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    • v.14 no.4
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    • pp.415-419
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    • 2010
  • A phosphor-conversion white light source is demonstrated using an InGaN-based blue laser diode (LD) and a yellow-emitting phosphor excited by the blue LD. The photometric and colorimetric properties of this blue-LD-based white light source are characterized. When injection current of the LD is 100 mA, luminous flux and luminous efficiency of the white light are found to be over 5 lm and 10 lm/W, respectively. When injection current is >90 mA, luminance is estimated to be larger than 10 Mcd/$cm^2$. In addition, color characteristics of the white light such as chromaticity coordinates, a correlated color temperature, and a color rendering index are found to be quite stable as current and temperature of the LD varies. The demonstrated LD-based white light source is expected to be used in high-brightness illumination applications with good color stability.

Radiation and Underwater Transmission Characteristics of a High-luminance Light-emitting Diode as the Light Source for Fishing Lamps (집어등 광원으로서 고휘도 발광 다이오우드의 방사 및 수중투과 특성)

  • Choi, Sok-Jin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.39 no.6
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    • pp.480-486
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    • 2006
  • The radiation characteristics of a high-luminance light-emitting diode (LED) light source were studied to evaluate its potential as an energy-saving light source for fishing lamps. The angle of the LED light source with 50% illuminance was $8-15^{\circ}$, and it had strong directional characteristics. The wavelengths at which the radiance and irradiance were maxima were 709, 613, 473, 501, 525, and 465 nm for red, orange, blue, peacock blue, green, and white light, respectively. The underwater transmission characteristics of the LED light source were superior in the order blue, white, peacock blue, and green in optical water type I: blue, peacock blue, white, and green in optical water type II; and blue, peacock blue, green, and white in optical water type III. Setting the underwater transmission characteristics of the LED light source in optical water type I at 100%, the transmission of water types II and III decreased to 67 and 17%, respectively. Based on the underwater transmission characteristics calculated in optical water types I-III, the blue and peacock blue LED light sources can be used as an energy-saving light source for fishing lamps.

The Fabrication and Characteristics of White Emission Using CCM on Flexible Substrate (플렉시블 무기EL 색변환 백색 발광 소자 제작 및 특성평가)

  • Kim, Gi-Ryoung;Ahn, Sung-Il;Kum, Jeong-Hun;Lee, Heung-Ryeol;Yim, Tae-Hong;Lee, Seong-Eui
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.411-412
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    • 2007
  • EL (electro luminescent) is generally studied as a large size plane light emitting device and flexible light source because of it's simple manufacturing process. In this experiment, we manufactured flexible white emitting light source using Ni-foil with blue phosphor and color change materials. With increasing the thickness of color change material, the luminance of white emission is increased and the color coordinate of white color was shifted to pure white of (0.317,0.328) by strong emission of color change materials excited by blue excitation spectra. Also the luminance level was 30% higher in white emitting light device than blue only light source.

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A study on the small Flash Lamp Design using LED (휴대폰용 소형 Flash에 적합한 LED 램프 설계 연구)

  • Jeong, Hak-Geun;Jung, Bong-Man;Han, Su-Bin;Park, Suk-In;Song, Yu-Jin;Lee, Jeong-Hoon
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2007.11a
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    • pp.107-109
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    • 2007
  • LED is expected as an environmentally friendly light source with its good reliability and long lifetime. A few ten mW white LED can substitute for the indicator light source, and it is required to study several watt multi-chip semiconductor light sources in order to replace the light sources for general illumination such as incandescent lights and fluorescent lamps. Since the optical technology used for several mW white LED light source uses only 30% to 50% of the light, it is required to develop the design technology of optical system and lens to improve the efficiency more than 80% for insuring the high power of white LED. In this paper, we designed and fabricated new structure reflector to increase the efficiency.

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The Design and Fabrication of New Structure Reflector for LED Source (LED 광원에 적합한 새로운 구조의 반사경의 설계 및 제작)

  • Jeong, Hak-Geun;Jung, Bong-Man;Han, Su-Bin;Park, Suk-In;Kim, Kyu-Deok
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2006.05a
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    • pp.154-156
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    • 2006
  • A few ten mW white LED can substitute for the indicator light source and it is required to study several watt multi-chip semiconductor light sources in order to replace the light sources for general illumination such as incandescent lights and fluorescent lanes. Since the optical technology used for several mW white LED light source uses only 30% to 52% of the light it is required to develop the design technology of optical system and lens to improve the efficiency more than 80% for insuring the high power of white LED. In this paper, we designed and fabricated new structure reflector to increase the efficiency and is easy to make high power multi-chip LED lamp.

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Power Supply for White GaN LED by Using SMD Type Solar Cell Array (SMD 타입 태양전지 어레이를 이용한 white GaN LED용 전원 공급 장치)

  • Kim, Seong-Il;Lee, Yoon-Pyo
    • New & Renewable Energy
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    • v.5 no.4
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    • pp.34-37
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    • 2009
  • Using six SMD(surface mount device) type AlGaAs/GaAs single junction solar cells connected in series, a power source was fabricated for a white GaN LED. The electrical properties of the power source was measured and analyzed under one sun (100mW/$cm^2$) and various indoor light (300 - 900 lux) conditions. Under 600 lux indoor light condition, output power was 17.06 ${\mu}W$ and it was 30.75 ${\mu}W$ under 900 lux indoor light condition. Using the fabricated solar cell power supply, we have turned on the white GaN LED. It was worked well under 15 ${\mu}W$(at 480 lux) power supplied from solar cell array. This kind of solar cell power supply can be used as a power source for ubiquitous sensor network (USN).

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Characteristics of Spectral Irradiance Based on the Distance from the Light Source and Operating Method for Fishing Lamps with a Combined Light Source (이종(異種) 광원 조합에 의한 복수 광원의 분광 방사특성과 광달(光達) 거리 및 집어등 운용방법)

  • Choi, Sok-Jin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.42 no.6
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    • pp.711-720
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    • 2009
  • Characteristics of spectral irradiance based on the distance from the light source, which combined metal halide lamp and high-luminance light-emitting diode (LED) light, were studied to investigate a suitable operating method for fishing lamps of the next generation. A 380-780 nm wavelength radiation was superior when using 1 W electrical power in the order of metal halide lamp, blue LED, white LED, and combined LED lights. The wavelengths at which the irradiance was at a maximum were fixed to 581 nm for the light source, which was combined for each ratio. If the irradiance characteristics at 300-1100 nm wavelengths were set as 100%, the irradiance rates at 400-599 nm were 100%, 72.7%, 88.9%, and 69.5% for the blue, white, combined LED lights, and metal halide lamp, respectively. This indicated that the color rendering of the LED lights was dependent on the metal halide lamp light source. When the horizontal profiles (450-550 nm wavelength) of irradiances were compared to a different type of light source in the ratio white LED: combined LED lights: blue LED: metal halide lamp, the irradiated area of more than $0.01\;{\mu}mol/s/m^2/nm$ was in the ratio 1.0 : 1.3 : 1.7 : 37.3, respectively. Based on the radiation characteristics and irradiance according to the distance from the light source, LED lights have an estimated economic efficiency if used before and after operation of a metal halide lamp.

Luminescence Property of ZnS:Mn,Mg Phosphor with Excitation of Plasma Blue Light Source

  • Ryu, Si Hong;Kim, Wan Kyu;Lee, Seong Eui
    • Transactions on Electrical and Electronic Materials
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    • v.14 no.1
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    • pp.24-27
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    • 2013
  • In this paper, we investigated the effect of luminescence properties of various concentrations of magnesium-doped ZnS:Mn phosphor excited by plasma luminescence device. The PL intensity was evaluated in the range of 300~500 nm excitation wavelengths. We found the highest PL intensity of the phosphors excited by 365 nm and 450 nm was observed at Mg concentrations of 1.4 wt% and 0.8 wt%, respectively. In addition, an emission peak was distinguished at 580 nm wavelength. With increasing Mg dopant level, enhanced PL intensity was observed, which is possibly applicable to color converting materials by blue emission for white light sources. Finally, we evaluated the luminance properties of color converting ZnS:Mn,Mg phosphors with plasma blue light source. the white luminance of plasma light source with CIE(0.36,0.26) was established by color converting phosphors of ZnS:Mn with 0.8 wt% Mg.

Phase change on reflection considered of the polarization in white-light interferometer (백색광 주사 간섭계에서 편광을 고려한 반사시 위상 변화)

  • 김영식;김승우
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.276-279
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    • 2003
  • The phase change upon reflection from target surfaces in white-light interferometer induces measurement errors when target surfaces are composed of dissimilar materials. We prove that this phase change on reflection considered of the polarization of the white-light causes the shift of both envelope peak position and fringe peak position of several tens of nanometer. In addition, we propose a new equation of white-light interference fringe pertinent to the polarization of source.

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Development of the Fluorescence Endoscope System with Dual Light Source Apparatus (복합 광원을 갖는 형광 내시경 개발)

  • Bae, Soo-Jin;Kang, Uk
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.1
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    • pp.222-226
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    • 2007
  • We suggest the fluorescence endoscope system that has light source apparatus providing selectable white or excitation light. White light source generates normal color images and is easily switched over to excitation light with the wide spectrum range from 380 nm to 580 nm. 5-ALA is deposited selectively in the abnormal tissue like cancer and causes fluorescence in the red spectrum range when excited by blue spectrum range. In addition, the others of excitation light make the color background image by reflected light to allow accurate orientation and visualization of the abnormal tissue and around. According to clinical studies, the fluorescence intensity contrast that defines the fluorescence intensity of lesion over the fluorescence intensity of around has more than 2 in tumour. Proposed system is useful and objective way in early diagnosis. Furthermore, it can be used in the biopsy for tumour classification at the highest fluorescence intensity point.