• Korean Institute of Interior Design Journal
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• v.21 no.6
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• pp.129-136
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• 2012

As the importance of eco-friendly and energy saving issues are emphasized in lighting as consciousness about energy saving is elated worldwide, demand for natural resources such as gas increases, supply of LED lighting is spread. Owing to white LED's development and price fall. It is expected to LED High Luminance Emitting Diode. LED's brightness and long life-time that surpass fluorescent light in the latest as well as is used by back light source of thin film LCD, low electric power attrition rate by advantage do and widen the market at the world lighting lamp market that is potential market. Accordingly, study about suitability of LED lighting is activated but space that apply actual LED lighting fixtures yet is less and advanced researches about LED fixtures' applied apaces are slight compared to existing light source up to now because is not many on this. The result of the experiment shows similar tendency with the existing light sources'. Through a psychological reaction experiment in the LED lighting experiencing space that can control of color temperature and lighting level, this study is wished to use to the data for lighting design of space that LED lighting fixtures are applied hereafter.

• 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.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.19 no.2
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• pp.61-65
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• 2009

In this paper, we report on the growth and optical characteristics of white-LED without fluorescent material. The growth of DH(double heterostructure) with AlGaN active layer was performed on a n-GaN/(0001) $Al_{2}O_{3}$ by the mixed-source HVPE and multi-sliding boat. The CRI(color rendering index) of packaging device charged in the range 72-93 with CIE chromaticity coordinates(x=$0.26{\sim}0.34$, y=$0.31{\sim}0.40$). And CCT(correlated color temperature) values was measured $5126{\sim}10406K$ with increasing injection current. The CIE point of conventional phosphor white LED shifts blue region, but cm point of non-phosphor white LED shifts opposite direction. These results show the mixed-source HVPE can be possible to newly fabricate method of phosphor free white LED with high CRI value.

• Journal of the Semiconductor & Display Technology
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• v.14 no.3
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• pp.13-22
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• 2015

LED (Light Emitting Diode) lighting is gaining more and more market penetration as one of the global warming countermeasures. LED is the next generation of fusion source composed of epi/chip/packaging of semiconductor process technology and optical/information/communication technology. LED has been applied to the existing industry areas, for example, automobiles, TVs, smartphones, laptops, refrigerators and street lamps. Therefore, LED makers have been striving to achieve the leading position in the global competition through development of core source technologies even before the promotion and adoption of LED technology as the next generation growth engine with eco-friendly characteristics. However, there has been a point of view on the cost compared to conventional lighting as a large obstacle to market penetration of LED. Therefore, companies are developing a Chip-Scale Packaging (CSP) LED technology to improve performance and reduce manufacturing costs. In this study, we perform patent analysis associated with Flip-Chip CSP LED and flow chart for promising technology forecasting. Based on our analysis, we select key patents and key patent players to derive the business strategy for the business success of Flip-Chip CSP PKG LED products.

• Journal of Satellite, Information and Communications
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• v.9 no.4
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• pp.69-72
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• 2014

Recently, lighting systems using audio signal of audible frequency and frequency spectrum of visible lighting are studied. And various related products are being sold and released commercially. Also demands of emotional matching algorithm and system which includes effective and methodical designs are being increased. And the importance related with this scheme has increased. In this Paper, we configures a system for digital sound source based LED color control. And we develop algorithm to control LED color for the system configuration. Also we demonstrated the usefulness of the algorithm through experiment with simulation using LED color control system. We expected to be useful in a variety of fields and applications using proposed digital music based LED color control system.

• 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).

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.88.1-88.1
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• 2015

In recent printed electronics technology, Photo-Sintering, a technique for sintering materials using a light source, has attracted attention as an alternative to time-consuming high-temperature thermal processes. The key principle of this technique is the selective heating of a strongly absorbent thin film, while preventing the heating of the transparent substrate by the light source. Many recent studies have used a flash lamp as the light source, and investigated the material-dependent effect of the width or intensity of the pulsed light. However, the flash lamp for sintering is not suitable for industry yet, because of needing too high power to sinter for a large scale. In energy-saving and large-scale sintering, LED technologies would be very useful in the near future. In this work, we investigated a sintering process for silver nanoparticles using UV-LED array. Silver nanoparticles in ink were inkjet-printed on a $1{\times}1cm$ area of a PET film and photo-sintered by 365 nm UV-LED module. A sheet resistance value as low as $72.6m{\Omega}/sq$ (2.3 - 4.5 times that of bulk silver) was obtained from the UV-LED sintering at 300 mW/cm2 for 50 min.

• Korean Journal of Head & Neck Oncology
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• v.26 no.2
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• pp.187-192
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• 2010

Background and Objectives : LED(Light emitting diode) is recently introduced as a energy-saving light source in many area including agriculture and environment. In medical field it is known as bright and safe light source in surgical lighting including headlight. This study is aimed to test effectiveness and cost-saving of mountain-climbing headlight in comparison with xenon headlight. Materials and Methods : Internet market-available mountain-climbing headlight was compared with medical xenon headlight regarding heat generation after 30 minutes' usage, intensity of illumination and possible burn to the perioral skin. To get temperature data, 5 cases of tonsillectomy were done with the aid of LED headlight, while another 5 tonsillectomies were done using xenon headlight. Results : The temperatures of all light sources were below 45 degrees Celcius until finish of the surgery without burn or complications. No differences in operation time with both headlights. The maximal intensities of illumination were 24000 Lux for xenon, 20000 Lux for LED. Conclusion : Mountain-climbing headlight could be safe and helpful light source with low cost in simple oral surgery.

• KIEAE Journal
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• v.8 no.6
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• pp.21-26
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• 2008

According to the tendency of energy efficiency and environment-friendly chracteristics, demend of High-efficiency lighting using LED(Light Emitting Diode)are being increased actively and applied in various fields. However, In order to adequate application of LED light sources, it is necessary to lighting environment and luminous characteristics of LED light sources. This Study aims to characterize the work-plane lighting environment by LED light sources comparing with fluorescent light sources which are widely used. For the sake of this study, a fluorescent light source and 5 LED light sources were introduced and luminance and correlated color temperature were measured to evaluate luminance contrast. The experimental model is Mock-up which is $4.9m{\times}7.2m$ with a height of 2.9m. The test room was set up partition and desks. Luminance and correlated color temperature were measured work-plane on the desk which was set up local lighting by the Radiant Imaging ProMetric 1400. The optical characteristics data of LED can give a lot of advantages to design LED lighting appliances. Hereafter, the object of research will be conducted to evaluate effects of LED light sources on working performance, survey of visual performance, preference and physiology of subjects.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.227-228
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• 2006

there are several methods to raise the LED efficiency. In this paper, we designs a simulation(method) to promote the LED efficiency by attaching another lens to a lead type LED lamp. this concentrates a dispersed light.