• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.24 no.12
• /
• pp.1-8
• /
• 2010

Recently, adjustable CCT(Correlated Color Temperature) luminaire for the human circadian rhythm and room atmosphere has been developed. Accurate CCT control is needed in the luminaire for the human circadian rhythm. Therefore, appropriate CCT calculation method for each of fluorescent lamps and white LEDs was examined using three CCT calculation methods in this study. To make accurate CCT combination, CCT for two different CCT lamps was separately measured. And this study compared and analyzed proportionally calculated CCT value with measured value from the compounded luminaire with the two lamps.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2008.05a
• /
• pp.172-174
• /
• 2008

대표적인 신광으로 일컬어지는 LED는 기존 광원과는 달리 다수의 LED 소자가 모여 하나의 광원을 구성하여 조명기구를 이루는 형태를 가지고 있으며 이에 따라 높은 휘도와 낮은 휘도가 반복되는 발광 형태를 가지게 된다. 이러한 불균일한 휘도를 가지는 광원의 경우 일반적인 균일 휘도 광원에 사용되던 UGR의 평가치가 그대로 적용되는 것은 적절하지 못한 글레어의 평가가 이루어질 수 있다. 따라서 이에 대한 보정이 실행되어야 한다. 본 논문에서는 이러한 불균일한 휘도를 가지는 광원에 대해 UGR 글레어 평가식을 보정하기 위한 실험을 수행할 수 있는 실험실을 구성하고 이에 대한 과정을 서술하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.26 no.4
• /
• pp.6-13
• /
• 2012

In this paper, we took an indirect reflectance type that irradiates light from an LED module, which reflects light from a reflector onto the road. This LED pedestrian lighting design produces minimal glare from a relatively simple structure. Using LightTools 7.2, we conducted a study on the varying shape and curvature of the reflector. In order to further investigate this data, we researched the ratio of the DLOR and ULOR, the average illuminance, and the uniformity of the illumination. Based on this research, we selected optimum conditions to realize the actual LED pedestrian lighting using RELUX software. We found the average illuminance value to be 22[1x] and the illuminance uniformity ratio to be 0.23, which met the criteria of the proposed standards set in KS C 7658. In addition, it also satisfied the criteria of the standards set in KS A 3701 by having TI (Threshold Increment) at 7[%].

• Journal of the Korean Solar Energy Society
• /
• v.31 no.2
• /
• pp.31-36
• /
• 2011

LED is expected as an environmentally friendly next generation light source with its good reliability and long lifetime. The light sources for illumination have a variety of applications in the indoor and outdoor, and the variation of optical power and color rendering of the light source limits their applications. Therefore, it is necessary to research the LED lamp and its luminaire to minimize the variation of dynamic characteristics and to improve the color rendering due to that illuminating environment. Daylight is very good light source to human and can be used as primary or a secondary light source with benefits of energy, productivity and health.This paper presents the design method of LED lighting system to improve poor property in terms of CR(color redering) characteristic to use daylight effectively.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.7
• /
• pp.1484-1488
• /
• 2009

This thesis is about Heat-sink design which is considered as the biggest problems for commercialization of LED lighting and suggests how to solve the problems though analysis on heat-sink using COMSOL. The temperature difference after simulation value and modelling was $10^{\circ}C$by Transient analysis of Heat Transfer Module which is in the COMSOL Multiphysics. The result approximated the object which is close to actual lighting, when various elements are used according to temperature change of interior and exterior surroundings LED lighting is set up.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.28 no.3
• /
• pp.18-25
• /
• 2014

In this paper, tried to find out the proper luminous intensity distribution for the cabin with low-level height by analyzing the changing tendency of discomfort glare according to luminous intensity distribution of marine indoor luminaires using Unified Glare Rating(UGR). First, we analyzed UGR of the indoor luminaires in the existing cabin, and then evaluated influence on luminous intensity distributions of marine indoor luminaire. The results showed that $cos^2{\Theta}$ distribution got almost low UGR results regardless of height and UGR 16.5 in cabin height of 2m. However, Gaussian distribution with the same beam angle showed that UGR results consistently increased by getting lower height and UGR 20.7 in the same height. In conclusion, the $cos^2{\Theta}$ distribution in consideration of luminous intensity on the direction of observer's eye was appropriate for general cabin indoor luminaires because it decreased UGR in the low-level height.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2011.06a
• /
• pp.186-186
• /
• 2011

This paper presents the design guide of a LED red-light for naval vessels. Power consumption, luminous flux and optical characteristics of a conventional FL red-light were analyzed. Spectrum of the red-light is in ranges of 600~780 [nm]. Power consumption and luminous efficacy are 26.9 [W] and 1.1 [lm/W], respectively. From the experimental results, we proposed a 5 [W] LED red-light which save power consumption by 80 [%] and increase luminous flux over 500 [%].

• Journal of Digital Convergence
• /
• v.14 no.4
• /
• pp.419-424
• /
• 2016

In this paper, we studied a light distribution for the LED chips arrangement using an optical design software. The structures of the edge type LED luminaires are reflector plane, LGP(lighting guide plane) and diffuse plane. The reflector plane is on the middle of the overall structure. We had simulation that placing LED chips on the reflector center of the reflector edge by changing the position of LED chips above the reflector center at 1mm, 2mm, and 3mm respectively. In the case, when LED chips are on the center of the reflector, it shows the light distribution of the general diffuse illumination, the semi-direct distribution with 0.56 efficiency and the direct distribution with 0.31 efficiency. And the wedge type LGP shows more efficiency than the flat type. Gradually increasing shape of semi-spherical type by 0.015mm has power of 1.02W, efficiency of 0.25, and maximum luminous intensity of 0.104W/sr, it also and shows the better optical characteristics than the reflector plane that have no patterns. This semi-spherical type shows the better optical characteristics than the reflector plane that have no patterns.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.1
• /
• pp.61-66
• /
• 2010

The purpose of this experiment is to analyze the basic status of brain. Which are consist of rest, attention and concentration, of the brain by measuring the temperature of color by changing RGB color after manufacturing LED-illumination stand. Basic status (rest, attention and concentration) of experimenter were measured temperature of colors having three difference temperature like as $2,300^{\circ}K$, $4,000^{\circ}K$ and $6,000^{\circ}K$. The results was shown that experimenter feels more comfortable and relaxation by decreasing the temperature of color. For example we can see the little increase of concentration index at $4,000^{\circ}K$ condition and we can estimate that right brain can be more activated at the $4,000^{\circ}K$ condition. But we can not find out any different at the $6,000^{\circ}K$ condition. Main cause of no difference from the color temperature was the similarity of color temperature under the general fluorescent lamp. And interface temperature of radiant heat design results LED and PCB was approximately 80 degrees to COMSOL Multiphysics, and changed until approximately 50 degrees until a floor plane of PCB, and verification as arranged chip LED to metal PCB, and it was possible, and a near radiant heat design was confirmed to an approximate value of, as a result, acid manufacture.

• Journal of IKEEE
• /
• v.21 no.4
• /
• pp.368-374
• /
• 2017

In this Paper, we developed a low power type LED security light using LED lighting that substitutes a 220[V] commercial power source for a solar cell module instead of a halogen or a sodium lamp. in addition, a PWM type drive control circuit is designed to minimize the heat generation problem and the drive current of the LED drive controller. in developed system, The light efficiency measurement value is 93.6[lm/W], and a high precision temperature sensor is used inside the controller to control the heat generation of the LED lamp. In order to eliminate the high heat generated from the LED lamp, it is designed to disperse quickly into the atmosphere through the metal insertion type heat sink. The heat control range of LED lighting was $50-55[^{\circ}C]$. The luminous flux and the lighting speed of the LED security lamp were 0.5[s], and the beam diffusion angle of the LED lamp was about $110[^{\circ}C]$ by the light distribution curve based on the height of 6[m].