• Journal of Broadcast Engineering
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• v.15 no.4
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• pp.461-473
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• 2010

Since eco friendly and power saving products recently got into the limelight for the protection of environment, LED light technology has caught much of attention as the next generation broadcasting lighting. The newly introduced light source has such advantages as higher efficiency, longer life and its slim and compact forms leading to conveniency in installations. When combined with digital light control it gives more dynamic and various features to lighting. In this paper, used CIE standard for measuring light sources by their purposes and forms to make a comparative analysis of spectral distribution and color rendition of LED light source to those of existing lighting systems. By means of the cast shadowing and color reproduction tests I also tried to figure out the effects of LED lighting design on TV visuals where higher quality is crucial with the audience's increasing demands for quality image.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.3
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• pp.59-68
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• 2023

Currently, yellow phosphor of Y3Al5O12:Ce3+ (YAG:Ce) fluorescent material is applied to a 450~480nm blue LED light source to implement a white LED device and it has a simple structure, can obtain sufficient luminance, and is economical. However, in this method, in terms of spectrum analysis, it is difficult to mass-produce white LEDs having the same color coordinates due to color separation cause by the wide wavelength gap between blue and yellow band. There is a disadvantage that it is difficult to control optical properties such as color stability and color rendering. In addition, this method does not emit purple light in the range of 380 to 420nm, so it is white without purple color that can not implement the spectrum of the entire visible light spectrum as like sunlight. Because of this, it is difficult to implement a color rendering index(CRI) of 90 or higher, and natural light characteristics such as sunlight can not be expected. For this, need for a method of implementing sunlight with one LED by using a method of combining phosphors with one light source, rather than a method of combining red, blue, and yellow LEDs. Using this method, the characteristics of an artificial sunlight LED device with a spectrum similar to that of sunlight were demonstrated by implementing LED devices of various color temperatures with high color rendering by injecting phosphors into a 405nm deep blue LED light source. In order to find the spectrum closest to sunlight, different combinations of phosphors were repeatedly fabricated and tested. In addition, reliability and mass productivity were verified through temperature and humidity tests and ink penetration tests.

• Journal of Mushroom
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• v.12 no.4
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• pp.375-378
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• 2014

The attractions of Lycoriella ingenua to different LED light sources were investigated in the mushroom cultivations which were located in Yongin of Gyeonggi-do province and Buyeo of Chungcheongnam-do Province. The LED light sources which were used in the investigations were white, green, red, blue and orange. Numbers of Lycoriella ingenua to LED lights in Yongin and Buyeo were 132.9 and 3,272.5 to white LED source, 120.3 and 3,109.5 to green LED source, 105.5 and 1,910.1 to red LED source, 88.3 and 2,708.3 to blue LED source and 46.7 and 2,465.5 to orange LED source, respectively. The numbers of Lycoriella ingenua to LED light sources were 2.7~3.5 times higher than the ones of untreated.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.4
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• pp.16-23
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• 2011

Since the first lighting light source was invented, lighting has turned into superior-quality lighting considering the amenity of occupants, and the characteristics of a light source has developed rapidly. So this research confirmed the lighting performance of a dimmer control system and an ON-OFF control system via the existing light source, and analyzed the basic lighting environment of Permanent Supplementary Artificial Lighting of Interiors(PSALI) through the physical comparison and evaluation of a LED lamp substituted for a fluorescent lamp used in a dimmer control system, showing that the lighting physical quantity characteristics of an ON-OFF control system and a dimmer control system are similar to each other and that they are effective in terms of energy saving. Besides, it was shown that introducing a LED light source to a dimmer control system improves lighting environments and largely reduces energy consumption.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.6
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• pp.433-436
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• 2018

A total internal reflection (TIR) linear lens of size $190(W){\times}5(D){\times}2.1(H)mm^3$ has a directivity of $25^{\circ}$ and was made of a polydimethysiloxane (PDMS) silicone resin with a refractive index of 1.4 and a transmittance of 93% at 365 nm UV wavelength. A light source with a size of $190{\times}25.5mm^2$ was fabricated by installing a TIR linear lens on a chip on board (COB) type LED module mounted with a $1.1{\times}1.1mm^2$ size UV LED. The optical characteristics of the light source showed a maximum irradiation density of $3,840mW/cm^2$ at a working distance of 5 mm and a high uniformity of 91.6% over a $150{\times}25mm^2$ irradiation area. The thermal characteristics of the light source were measured at a supply current of 500 mA. The saturation temperature was reached after 30 min of operation, and measured to be $95^{\circ}C$.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1912-1914
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• 2004

As the characteristics of LED disposition, LED warning light must be designed differently from general incandescent lamp warning light whose light source is located in origin. In this paper, the globe's lens of LED warning light was designed considering the LED intensity distribution and the arrangement of the LED. And prove the appropriateness of that design by simulation in LightTools which is optical design program.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7256-7261
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• 2015

This paper devised a plant growing system As LED light source, three monochromatic lights (red, blue, white) and three mixed lights (red1+blue1, red2+blue1, red1+blue2) were made. According to the optical properties of those LED light sources and change in the amount of light, this author analyzed the characteristics of luminance and PPFD and also plant growth. According to the light efficiency of those LED light sources, it was high in white light as 125 lm/W and was low in red1+blue2 light as 9.9 lm/W. This result shows that monochromatic light has higher light efficiency than mixed light. The PPFD ($25{\mu}mol$, $50{\mu}mol$, $100{\mu}mol$) luminance in different wavelengths of LEDs was high in white LEDs and was low in blue LEDs. therefore, it is possible to devise an efficient LED lighting system appropriate for growing plants by variety monochromatic lights and mixed light wave length combination of LED light source.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.1-5
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• 2023

In the past, display devices have undergone many changes, such as plasma TVs and LCDs, and have continued to develop. Recently, new display technologies, such as Organic Light Emitting Diode displays and Inorganic Light Emitting Diode displays, have been developed. Among them, Micro LED displays have the potential to improve performance more than LCDs and OLEDs, but a lot of effort and time are needed until the mass production technology (transfer and bonding) of Micro LED displays is developed. We have developed a new Micro LED display light source that can be produced using existing transfer and bonding process technologies to enable faster commercialization of Micro LED in the industry. This light source is TFT deposition on LED. TFT deposition on LED has the advantage of being able to produce displays using existing process technology, making early commercialization of display application products possible. In this study, we applied the Active Driving method to verify the performance of TFT deposition on LED as a display to determine its commercialization potential. Additionally, to facilitate faster application of Micro LED in the industry, we applied TFT deposition on LED to Optical Wireless Communication systems, which are widely used in application service areas such as safety/security and sensors, to verify its communication performance. The experimental results confirmed that TFT deposition on LED is not only capable of AM driving but can also be applied to OWC systems.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.1 no.2
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• pp.21-25
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• 2008

A CCFL which commonly used in the back light units for the LCD, possess very high brightness hence, was widely used as a line light source. However, the use of CCFL, caused for several environmental concerns since it contain highly toxic mercury, gradually replaced into a LED. But the LED is a spot light source, the dark area occurs in the surface of the back light units. In this paper, we proposed the lens that can convert the spot light into the line light and it can remove the dark area in the surface of the back light units. The lens is composed with the light condensation part and the light guiding part. The conditions obtained will be helpful to plan an optimum structure for such preparation.

• Journal of the Semiconductor & Display Technology
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• v.23 no.1
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• pp.84-87
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• 2024

A water sterilization system is developed utilizing a 275 nm-wavelength LED light source equipped with a TIR lens. The system's light source is constructed by combining a 275 nm-wavelength UVC LED, known for its germicidal properties, with a TIR lens having a direction angle of 6.8 degrees. The optical simulation software 'LightTools' is employed to design and optimize the intensity of deep ultraviolet sterilizing light irradiation, its distribution, and sterilization capacity. In the inactivation experiment with E. coli, the water sterilizer system achieved a sterilization rate of 78.92 % while maintaining a water flow capacity of 50 L/min. Compared to the conventional mercury lamp light source water sterilizer system, the UVC LED water sterilizer system addresses environmental concerns related to mercury usage and offers advantages in terms of lifespan and durability.