• Journal of Information Display
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• 제10권3호
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• pp.97-100
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• 2009

A backlight unit for a 42-inch LCD TV was manufactured with red, green, and blue LED lamps. The luminous and light extraction efficiencies of the LED lamps were increased by improving their light reflection structures and thermal properties. The blue, green, and red LED lamps showed different luminous efficiencies as a function of the input current. Compared to the conventional red LED lamp, however, the developed red LED lamp showed very high luminous efficiency in a low drive current. Taking these luminous efficiencies into account, the fabricated backlight unit showed high energy efficiency, low power consumption, and a wide color gamut.

• Animal Bioscience
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• 제34권11호
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• pp.1870-1878
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• 2021

Objective: The objective of this experiment was to investigate the effects of different colors produced by light emitting diode (LED) on Brown Tsaiya ducks. Methods: A total of 144 female Brown Tsaiya ducks were randomly allocated into three individual cage rearing chambers with different LED illumination colors as treatments. Three different treatments were: i) white color, ii) blue color, and iii) red color. The experiment periods were from ducks 21 to 49 weeks of age, determined traits included i) egg laying performance, ii) feed intake, iii) egg shell breaking strength, iv) egg shell thickness, v) egg Haugh unit, vi) egg weight, vii) serum Estradiol and Progesterone concentration, and viii) behavior pattern. Results: The results indicated that when compared with white and blue color, red color could stimulate ducks sexual maturation and raised the egg laying performance. The red light group was also observed to have the highest feed intake among three treatments. The blue treatment had the lowest egg shell breaking strength and the highest egg weight among three treatments, nevertheless, no significant difference was observed among three treatments on egg shell thickness and egg Haugh unit. The red light group had higher serum estradiol concentration than the white and blue groups, but no significant difference among treatments on the serum Progesterone concentration was found. The results of behavior pattern indicated that red light group showed more feeding and less resting behavior compared to the blue light group. Conclusion: We found a potential of applying red light illumination in the indoor laying duck raising system with positive results on egg laying performance and acceptable egg weight, equivalent egg qualities compared to white and blue light.

• 한국수산과학회지
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• 제42권6호
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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.

• 조명전기설비학회논문지
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• 제29권8호
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• pp.7-17
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• 2015

Changes in melatonin concentration levels by differences in CCT of white LED light focused on Spectral Power Distribution (SPD) differences compared to the same CCT of conventional fluorescent light were analyzed. For this, melatonin concentration levels in saliva samples were taken over four different experiments at seven-day intervals. In 71.4% of participants, it was confirmed that melatonin concentration is suppressed by exposure to light, and a slight difference was observed by different CCTs. In addition, Experiment II with a high CCT was relatively high in terms of the melatonin suppression rate compared to Experiment III. A key finding was the possibility that different SPDs under a particular CCT of white LED light compared to the same CCT of conventional fluorescent light could have the same effect on the melatonin suppression.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 추계학술대회 논문집
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• pp.119-124
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• 2007

24" LCD Monitor용 LED BLU를 개발하기 위하여 1.5W R,G,G,B가 하나의 PKG에 들어있는 LED를 이용하여 Direct type의 Back Light Unit을 개발하였다. 방열 및 휘도 균일도를 고려하여 LED part를 설계, 개발 하였고 LED를 pulse로 구동하기 위하여 Switching circuit이 포함되는 구동회로 부분을 설계, 개발하였다. 또한 Color Sensor와 ICM (Integrated Color Management) IC를 사용하여 Color를 Control하는 제어회로 부분도 개발을 하였다. 제어회로 부분을 개발하기 위하여 MicroController를 사용하였으며 ICM IC와의 통신을 위한 부분도 개발하였다. 이러한 구성을 개발하여 시제품을 직접 제작하였다. 평가를 위하여 성능시험을 실시하였고 광학적인 평가도 시행하였다. 제작된 시제품은 $L558{\times}W359{\times}H30$으로 하였다. 휘도는 목표휘도를 이루었으며 균일도는 85% 이상이 되었다.

• 전자공학회논문지
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• 제51권8호
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• pp.167-171
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• 2014

평판 디스플레이(plate panel display)가 휴대용으로 발전하면서 박막화, 고색재현성, 고휘도에 관한 연구가 활발히 이루어지고 있으며, 광원으로써 LED, OLED가 주로 이용되고 있다. 이러한 광원의 소재로 양자점에 관한 연구가 많이 이루어 지고 있는데, 양자점은 고색재현성과 유연디스플레이 구현에 있어서 주목받는 차세대 반도체 나노형광체 이다. 본 연구에서는 평판 디스플레이를 구현함에 있어서 양자점을 이용하는 방법에 관하여 제시하였다. CdSe/ZnS 양자점을 PET베리어 필름에 $100{\mu}m$ 두께로 도포하고 455nm의 파장을 갖는 청색 LED를 광원으로하여 빛을 조사하는 디바이스를 제작하고 광특성을 평가하였으며, LCD의 색변환 필름으로써 양자점의 적용 가능성을 제시하였다.

• 한국광학회지
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• 제25권5호
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• pp.254-261
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• 2014

본 논문에서는 일반적인 코팅형 형광체와 이격 형광체 등 두 가지의 형광체 구조가 적용된 백색 LED를 제작한 후 온도변화에 따라 각 백색 LED의 발광 특성이 어떻게 변하는지 측정, 비교하였다. 상온에서 80oC 사이의 구간에서 측정된 두 백색 LED의 발광 스펙트럼을 분석하기 위해 Gaussian Lorentz-cross product 함수와 Asymmectic double sigmoidal 함수를 각각 청색 피크와 황색 피크의 곡선맞춤에 활용하였다. 이로부터 각 피크의 중심파장과 진폭, 반치폭 및 비대칭성을 온도의 함수로 구할 수 있었다. 온도에 따른 휘도와 색좌표를 측정한 결과 이격형광체 구조의 백색 LED의 온도에 따른 휘도저하율 및 색좌표 변화율이 훨씬 적었다. 이는 청색 LED 칩과 형광체가 분리됨에 따라 형광체의 온도가 일반 형광체 도포형 LED의 경우에 비해 낮아져서 효율이 상승했고 아울러 형광체에서 발생한 빛의 칩에 의한 흡수가 감소했기 때문인 것으로 해석된다.

• 한국산학기술학회논문지
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• 제21권4호
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• pp.518-524
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• 2020

본 연구에서는 수학영역, 언어영역 및 창의영역에서 학습효과 증진을 위한 교육용 조명체험실의 조명설계를 위한 기초연구를 진행하였다. 조명환경을 직접 체험할 수 있는 공간 내부는 실험자가 자연스럽게 공부할 수 있는 환경으로 설계하였고, 실험 진행 중 설정조명 외의 다른 색의 영향을 최대한 받지 않도록 외부의 빛은 완벽히 차단하였다. LED조명의 색온도와 조도를 변화시키면서 동일한 방식으로 조명변화에 따른 뇌파의 변화를 분석하였다. 이때 사용되어진 뇌파 분석기는 EMOTIV사(社)를 활용하였다. 가변 RGB LED조명에서 색을 변화시키며 상황별에 따른 실험자의 뇌파를 측정하고, 가변 색온도 LED조명에서는 색온도(3000[K], 4500[K]. 6000[K])와 빛의 세기(50%-250[lux], 70%-350[lux], 100%-500[lux])의 값을 변화시키며 상황별에 따른 실험자의 뇌파를 측정하였다. 그결과, 수리영역의 경우 색온도가 높은 경우가 집중도가 좋은 결과를 보였고 6000[K]의 색온도와 350[lux]의 조도인 조명환경에서 집중도가 가장 높은 결과를 얻었다. 언어영역의 경우 4500[K]의 색온도와 500[lux]조도일때 최적조건이고 창의영역의 경우 3000[K]의 색온도와 500[lux]의 조도일 때 최적 조명환경 조건을 얻었다. 감성조명이 가능한 LED조명원을 활용하는 경우 얻어진 색온도와 조도를 기준하여 조명 환경을 설계한다면 언어, 수리, 창의학습시 집중도가 높아짐을 알았다.

• 한국전기전자재료학회논문지
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• 제17권2호
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• pp.217-222
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• 2004

The white-light-emitting organic LED(OLED) with two-wavelength was fabricated using the DPVBi of blue emitting material and a series of orange color fluorescent dye(Rubrene) by vacuum evaporation processes. The basic structure of white-light-emitting OLED was ITO/NPB(150$\AA$)/DPVBi/Rubrene/BCP(100$\AA$)/Alq$_3$(150$\AA$)/Al(600$\AA$). We analyzed the fabricated device through the changes of the DPVBi and Rubrene layer's thickness. We obtained the white-light-emitting OLED with white color light and the CIE coordinate of the device was (0.29, 0.33) at applied voltage of 13V when the thickness of DPVBi layer was 210$\AA$ and the thickness of Rubrene layer was 180$\AA$. At a current of 100㎃/$\textrm{cm}^2$, the quantum efficiency was 0.35％ and at a voltage of 20V, it was 0.405％.

• 한국생산제조학회지
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• 제20권4호
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• pp.452-457
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• 2011

The internal temperature of an operating room had to keep within $20^{\circ}C$. However, the doctor who is wearing operating gown and mask caused to rise temperature because of the thermal occurrence of dental LED light source. At first, the surgery environment is getting worse. And then last, it would increase bleeding rate by the expansion of patient's exposured blood vessel. A surgical operator can distribute the patient's tissue through such surgery environment, exactly. It can do accurate surgery. So, it gave to effect that surgical operator's eye condition is getting better and it could keep a mutual assistance system. For this research, we develop the LED dental light source module of high color rendition. It performed simulation for replacing established the method of Halogen lamp and Plazma lamp of light source. We analyzed intensity of illumination and the change of viability by changing the height of light source module.