• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.274-277
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• 1996

This paper describes the realization of the full-color to the degree of nearest white light by compounding high brightness Red, Green and Blue LEDs with appropriate proportional index. Once these three colors; red, green and blue are mixed, they are genearlly additive mixing and produce white light color contrasted to negative mixing. The luminous efficiency is defined as the product of the efficiency(lm/w), which indicates the degree of perceptual response by the human eye to unit energy(W) of light emitted by an active display devises and as the conversion efficiency of the device from electric power consumed to optical energy produced. We will deduce the each number of LEDs theoretically and design several shapes of LED displays for the full-color. Finally theoretical predictions will be compared with the measured data with different type of display designs.

• 한국전기전자재료학회논문지
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• 제36권5호
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• pp.494-499
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• 2023

In this paper, in order to apply the CF (color filter) type of the micro light emitting device (Micro LED) display method, a study on the manufacturing process of red and green phosphor inks for the inkjet process was conducted. The blue light-emitting KSF and LuAG phosphors were respectively used to control the phosphor particle size to about 1㎛, and a phosphor ink was prepared by synthesizing with a low-viscosity solution (IPA/Eg). A chemical dispersion method was applied to selectively control the dispersion characteristics in the manufacture of phosphor inks, and in particular, phosphor inks with a dispersant applied a dispersant secured stable dispersion characteristic compared to phosphor inks without a dispersion process. Therefore, it seems possible to manufacture CF for Micro LED through an inkjet process capable of controlling the dispersion characteristics of phosphor ink.

• 조명전기설비학회논문지
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• 제26권8호
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• pp.8-17
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• 2012

Unlike traditional lightings, LED lighting is one of objects that sends user an emotional segments through brightness control from various color temperature and dimming control. Also, within present interior lighting environment, emotional researches about traditional fluorescent lamp and newly implemented LED lighting environment are in active progress. Despite the fact adjectives describing emotions and scale modeling have been repeatedly used in many cases for a long time, there seems to be a lack of results in reliability, and there is a limitation for applying into actual lighting design. The purpose of this study is to construct an actual sized test-bed, which is used to draw out one's emotional words of behavior patterns from inner emotional experiences about lighting environment in an office space. Also, having fluorescent lamp and LED lighting as the main test subjects, we have tested emotional parts according to the changes of color temperature and adjective vocabularies chosen from user's action, and we have compared and analyzed the drawn out data. Also, having fluorescent lamp and LED lighting as the main test subjects, we have tested emotional parts according to the changes of color temperature and adjective vocabularies chosen from user's action, and we have compared and analyzed the drawn out data.

• 조명전기설비학회논문지
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• 제27권4호
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• pp.1-7
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• 2013

Optical characteristics including the view angle and color temperature uniformity of LED packages with an integrated lens fabricated by compression molding method are investigated according to lens shape, lens materials, and phosphor coating methods. Four types of lens shape are designed and their optical output power dependence on the refractive index of silicone encapsulant are evaluated. Also, spatial color temperature uniformities of packages fabricated with different phosphor coating methods-direct coating on a chip vs. uniformly mixed with silicone encapsulant- are compared at various view angles. As the result, it is found that phosphor coating method is more effective on color temperature uniformity than lens shape. The maximum color temperature difference of a package with direct coating of phosphor on a chip is 1,340K according to the view angle at the color temperature of 5,000K, and that of a package with uniformly mixed phosphor is 250K, which indicates 1,090K improvement of color uniformity for the latter case.

• 조명전기설비학회논문지
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• 제28권3호
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• pp.14-17
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• 2014

We studied visual clarity according to the difference of color temperature by using black and white printed paper and four sheets of colored paper under LEDs. We tested students in their twenties, under 3,000, 4,000, 5,700 and 6,500K LEDs (Ra=80). The results show visual clarity is proportioned to color temperature.

• 감성과학
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• 제13권1호
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• pp.69-78
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• 2010

최근 LED는 친환경적인 에너지 소비와 자유로운 조명 연출의 가능성으로 각광을 받고 있는 가운데, LED조명을 활용한 인간의 감성적 반응을 유도하는 감성조명에 대한 관심이 증가하고 있다. 본 연구에서는 실내에 설치된 LED조명의 색도를 변화해가면서 실내 생활인들이 시간을 인지하는데 영향을 받는 것을 두 개의 실험연구를 통하여 밝히고 있다. 실험 1(N=28)에서는 3초~20초에 이르는 짧은 시간을 인지하는데 LED 색도의 변화에 따른 영향이 있는가를 살펴보았다. 실험 결과, 난색 계열의 색채조명환경에서는 백색광 환경에 비하여 시간이 더 천천히 지난 것으로 인지한 반면 한색 계열의 색채조명환경에서는 백색광 환경에 비하여 시간이 더 빨리 지난 것으로 인지하는 경향을 발견하였다. 이러한 현상은 주어진 시간의 길이가 길어질수록 더 분명하게 나타났다. 동일한 실험환경에서 진행된 실험 2(N=39)에서는 실험참여자가 6가지 색채조명환경에서 별도의 인지 과제를 수행하는 동시에 90초의 시간을 가늠하였다. 실험참여자가 인지한 90초의 소요 시간과 실제 소요된 시간과의 차이에서, 색채조명환경이 영향을 미치는 현상을 밝혀내었는데, 실험 1에서와 마찬가지로 난색 계열보다 한색 계열의 색채조명환경에서 시간이 더 빠르게 지난 것으로 인지하는 경향을 관찰할 수 있었으나 통계적으로는 유의하지 않았다. 그리고 선호색 계열의 색채조명환경에서는 시간이 더 빨리 가는 것처럼 인지하는 경향을 발견할 수 있었다.

• 한국산학기술학회논문지
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• 제11권1호
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• pp.61-66
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• 2010

본 논문은 LED감성조명장치를 개발하여 뇌파 파장과 조명의 색온도 변화에 따른 상관관계를 뇌파실험을 통해 측정하였다. 이를 위해 장치개발을 통한 열 해석과 뇌파실험의 두 부분으로 실험을 하였다. LED감성조명장치의 모듈은 메탈 PCB에 Chip LED를 배치하여 COMSOL Multiphysics로 열 해석 결과 LED와 PCB의 경계면 온도는 약 $80^{\circ}C$이며, PCB의 바닥면까지는 약 $50^{\circ}C$까지 변화함을 검증 하였으며, 결과적으로 실 제작의 근사치에 가까운 방열설계가 가능함이 확인 및 적합한 조명기구로 판정되었으며, 뇌파측정을 위해 색온도를 $2,300^{\circ}K$, $4,000^{\circ}K$, $6,000^{\circ}K$ 세가지 조건으로 피 실험자의 기본상태(휴식, 주의력, 집중력)를 측정 하였으며 그 결과 색온도가 낮을수록 편안함과 안락함을 느낀다는 것을 검증 할 수 있었다. $4,000^{\circ}K$의 조건으로 실험을 했을 때 주의력의 지수가 약간 높아짐을 볼 수 있는데 이는 $4,000^{\circ}K$가 우뇌의 기능을 활성화 시킬 수 있는 추론이 가능하며 $6,000^{\circ}K$이상에서는 일반 형광등 아래의 색온도와 유사함으로 상태가 변화되지 않았음을 알 수 있었다.

• International Journal of Advanced Culture Technology
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• 제4권4호
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• pp.6-12
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• 2016

Due to the development of technology, the modern people became to require not only more convenient life but also more comfortable and emotional environment, and individually suitable living environment is applied to residents in a residential space. Recently, while the LED lighting was variously attempted in every sector in society, it is needed to express differentiated lighting according to the resident's individual lifestyle in a residential space. In this paper, we analyze the role of LED lighting suitable for the digitalized lifestyle of the modern people through the relevant literature survey and case studies. The following results are obtained in summary of the rapidly changed recent trends of LED lighting. First, LED light replace existing light sources due to the advanced new technology in LED industry, and take the spotlight as a new lighting solution with the development of variable color LED bulb and the control technology by the wired and wireless communications. Second, LED lighting can be structurally applicable to every lighting device because of its compact and lightweight units, can produce abundant light environment by expression of variable colors and moods with the easy coloring and dimming control, can be reborn as emotional lighting design. Third, as recently practices are constantly appeared that integrate LED lights in the interior elements, such as object and furniture, and combine advanced LED lighting technology to new materials, the portion of illumination on the indoor environment is further increased after integrating the LED lighting and interior elements make boundaries of lighting and product architecture become blurred. LED lighting is confirmed that is being changed from the external functionality including material, shape, color, and etc. into the contextual emotion design including the lights expression, variable color, brightness control, making image, and etc. as the light source in current smart lighting era.

• 한국재료학회지
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• 제22권12호
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• pp.669-674
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• 2012

Yellow phosphor dispersed color conversion glasses are promising phosphor materials for white LED applications because of their good thermal durability, chemical stability, and anti-ultraviolet property. Six color conversion glasses were prepared with high Tg and low Tg specimens of glass. Luminous efficacy, luminance, CIE (Commission Internationale de l'Eclairage) chromaticity, CCT (Correlated Color Temperature), and CRI (Color Rendering Index) of the color conversion glasses were analyzed according to the PL spectrum. Color conversion glasses with high Tg glass frit, sintered at higher temperature, showed better luminous properties than did color conversion glasses with low Tg glass frit. The characteristics of the color conversion glass depended on the glass composition rather than on the sintering temperature. The XRD peaks of the YAG phosphor disappeared in the color conversion glass with major components of $B_2O_3$-ZnO-$SiO_2$-CaO and, in the XRD results, new crystalline peaks of $BaSi_2O_5$ appeared in the color conversion glass with major components of $Bi_2O_3$-ZnO-$B_2O_3$-MgO. The characteristics of CIE chromaticity, CCT, and the CRI of low Tg color conversion glasses showed worse color properties than those of high Tg color conversion glasses. However, these color characteristics of low Tg glasses were improved by thickness variation. So color conversion glasses with good characteristics of both luminous and color properties were attained.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1153-1155
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• 2008

Color dimming technology has been developed for high color gamut and aggressive power saving. In our new algorithm, we proposed a new concept of 'color class', with which it is possible to control RGB color luminance effectively and exactly. We reached color gamut of 155% of NTSC 1976 and reduced power consumption under 100 watt for 46 inch LCD.