• 한국버섯학회지
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• 제15권4호
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• pp.259-263
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• 2017

표고 '농진고'를 LED 혼합광에 따른 갓의 색차 및 경도차를 확인한 결과 갓의 명도값은 형광등 처리구 대비 LED혼합광 처리구 모두 낮아지는 결과를 나타내었다. 적색도는 형광등 처리구에 비해 처리구 모두 높아졌고, 황색도는 낮아지는 결과를 보였다. 광원별 자실체의 생육특성을 조사한 결과 형광등 대조구 대비 처리구 모두에서 갓직경이 컸으며, 자실체들에 대한 균일도는 형광등 처리구 대비 LED를 사용하였을 경우 낮은 값을 나타내어 형광등을 처리하는 것보다 균일도가 있는 것으로 나타났다. 대직경은 처리구간 큰 차이를 보이지는 않았으나 White Green LED에서 다른 처리구보다 높은 것으로 조사되었고, 대길이는 형광등 처리구보다 LED처리구 모두에서 다소 높게 조사되었다. 갓직경과 대길이의 비를 조사한 결과 White Green LED을 제외한 White LED와 White Blue LED에서 형광등 처리구 대비 높은 값을 나타내어 대길이에 비해 갓의 직경이 길어지는 것을 확인할 수 있었다. 자실체 물추출물의 항산화능을 확인한 결과 형광등 처리구에서 가장 높은 항산화능을 확인할 수 있었고 LED 처리는 White LED처리에서 가장 큰 항산화능을 확인하였고 White Green LED, White Blue LED간에는 유의한 차이를 보이지 않았으나 LED처리는 Vitamin C 보다 높은 항산화능을 나타내었다. 위의 결과를 통해 White LED와 White Blue 처리가 표고버섯 자실체의 생육 및 항산화능에 영향을 미치는 광원임을 확인할 수 있었다.

• Journal of the Optical Society of Korea
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• 제17권1호
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• pp.22-26
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• 2013

The author analyzes the luminous efficiency of the phosphor-conversion white light-emitting diode (LED) that consists of a blue LED chip and a yellow phosphor. A theoretical model is derived to find the relation between luminous efficiency (LE) of a white LED, wall-plug efficiency (WPE) of a blue LED chip, and the phosphor absorption ratio of blue light. The presented model enables to obtain the theoretical limit of LE and the lower bound of WPE. When the efficiency model is applied to the measured results of a phosphor-conversion white LED, the limit theoretical value of LE is obtained to be 261 lm/W. In addition, for LE of 88 lm/W at 350 mA, the lower bound of WPE in the blue LED chip is found to be ~34%. The phosphor absorption ratio of blue light was found to have an important role in optimizing the luminous efficiency and colorimetric properties of phosphor-conversion white LEDs.

• Journal of Applied Biological Chemistry
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• 제57권3호
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• pp.243-245
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• 2014

온실에 발생하는 담배가루이 성충에 대한 LED 트랩의 시설재배지내의 이용 가능성을 평가하기 위해 white LED (450-625 nm) 및 yellow LED (590 nm) 트랩과 광원이 장착되지 않은 트랩을 이용하여 유인활성을 비교하였다. 광원별 일일 포획 밀도 변화는 yellow LED 트랩에서 가장 높은 유인활성을 나타내었으며, white LED 트랩 또한 유사한 개체수가 포획되었다. 그러나 대조구로 사용된 광원이 설치되지 않은 트랩의 경우 광원이 설치된 트랩보다 적은 개체수가 포획되었다. 이러한 결과를 바탕으로 white LED 및 yellow LED 트랩이 시설재배지내에서의 친환경적 해충방제법으로의 가능성을 보여주었다.

• 한국전기전자재료학회논문지
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• 제24권1호
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• pp.42-46
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• 2011

Light can be divided into ultraviolet rays, visible rays, and infrared rays depending on the wavelengths. Visible rays with specific wavelength are those predominantly used for would treatment. Especially low level laser irradiates into cells, effectively stimulating cellular tissues and activating cellular function. This study was intended to verify the effect of white LED irradiation therapy on wound recovery in animal tests by applying white LED irradiator, which was independently designed and developed to emit beams of similar wavelength to that of a laser. The designed LED Irradiator was used to find out how white LED light source affected the skin wound of SD-Rat(Sprague-Dawley Rat). We divided the participants into two groups; white LED irradiation group which was irradiated 1 hour a day for 9 consecutive days, and none irradiation group. The results showed that the study group had lower incidence of inflammation and faster recovery, compared with the control group.

• 전기학회논문지P
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• 제58권2호
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• pp.142-147
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• 2009

Conventional HP(high pressure) sodium or Metal-halide lamps have a life span of around one year requiring at least annual replacement and maintenance. High Power LED lights require no regular maintenance further increasing savings on replacement bulbs, access equipment and labour costs. New installations benefit from a substantial reduction in the cost of expensive heavy duty cable required for sodium lighting. Especially, LED light can achieve variable color temperature, high functional performance in the field of street light. There are two main method to achieve variable color temperature function of the street light. one method is using RGB multi-chip LED, the other is using Orange-White LED method. In this paper, it was compare RGB Multi-chip LED with white-orange LED for there characteristics performance.

• 한국수산과학회지
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• 제39권6호
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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.

• Journal of the Optical Society of Korea
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• 제11권2호
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• pp.67-70
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• 2007

A Wide Color Gamut Backlight system was studied using a three-band white Light-Emitting Diode. A three-band white light-emitting diode (LED) was fabricated using an InGaN-based blue LED chip that emits 445-nm blue peak, and a green phosphor and red phosphor that emit 535-nm green and 621-nm red peak emissions, respectively, when excited by 450-nm blue light. Using for this three-band white LED, wide color gamut backlight unit (BLU) was attained. The luminance of BLU and CIE 1931 chromaticity coordinates was $1,700Cd/m^2$ and (0.337, 0.346). Color filter matching simulations for this configuration show that the three-band white LED backlight can be enhanced by up to 16% over conventional white LED backlight color gamut.

• 한국재료학회지
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• 제16권3호
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• pp.145-150
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• 2006

Various colors of light emitting diodes(LED) and four-band white light sources are obtained using a violet LED and various phosphor films. $BaMg_2Al_{16}O_{27}:Eu\;(blue),\;SrGa_2S_4:Eu\;(green),\;and\;Eu(TTA)_3(PTA)$ (red) phosphors are dispersed in poly-vinyl-alcohol aqueous solutions, and phosphor films are prepared by coating the suspensions to PET film. The narrow band emission of $Eu(TTA)_3(PTA)$ phosphor has excellent red luminescent property for four-band white light excited by the violet LED.

• Applied Science and Convergence Technology
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• 제25권1호
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• pp.1-6
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• 2016

Quantum dots (QDs) are considered as excellent color conversion and self-emitting materials for display and lighting applications. In this article, various technologies which can be used to realize white light emission with QDs are discussed. QDs have good color purity with a narrow emission spectrum and tunable optical properties with size control capabilities. For white light emission with a color-conversion approach, QDs are combined with blue-emitting inorganic and organic light-emitting diodes (LED) to generate white emission with high energy conversion efficiency and a high color rendering index for various display and lighting applications. Various device structures for self-emitting white QD light-emitting diodes (QD-LED) are also reviewed. Various stacking and patterning technologies are discussed in relation to QD-LED devices.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 추계학술대회 논문집
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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.