• Korean Journal of Materials Research
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• v.19 no.7
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• pp.376-381
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• 2009

Indium Tin Oxide (ITO) thin films on Polyethylene Terephtalate (PET) substrate were prepared by Roll-to-Roll sputter system with targets of 5 wt% and 10 wt% $SnO_2$ at room temperature. The influence of the chromaticity (b*) and transmittance properties of the ITO Films were investigated. The ITO thin films were deposited as a function of the DC power, rolling speed, and Ar/$O_2$ gas flow ratio, and then characterized by spectrophotometer. Their crystallinity and surface resistance were also analyzed by X-ray diffractometer and 4-point probe. As a result, the chromaticity (b*) and transmittance of the ITO films were broadly dependent on the thickness, which was controlled by the rolling speed. When the ITO films were prepared with the DC power of 300 W and the Ar/$O_2$ gas flow ratio of 30/1 sccm using 10 wt% $SnO_2$ target as a function of the rolling speeds 0.01 through 0.10 m/min, its chromaticity (b*) and transmittance were about -4.01 to 11.28 and 75.76 to 86.60%, respectively. In addition, when the ITO films were deposited with the DC power of 400W and the Ar/$O_2$ gas flow ratio of 30/2 sccm used in 5 wt% $SnO_2$ target, its chromaticity (b*) and transmittance were about -2.98 to 14.22 and 74.29 to 88.52%, respectively.

• Korean Journal of Materials Research
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• v.21 no.5
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• pp.255-262
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• 2011

This paper has relatively high technical standard and experimental skill. The fabrication of TCO film with high transparency, low resistance and low chromaticity require exact control of several competing factors. This paper has resolved these problems reasonably well, thus recommended for publication. Indium tin oxide(ITO) thin films were by D.C. magnetron roll-to-roll sputter system utilizing ITO and $SiO_2$ targets of ITO and $SiO_2$. In this experiment, the effect of D.C. power, winding speed, and oxygen flow rate on electrical and optical properties of ITO thin films were investigated from the view point of sheet resistance, transmittance, and chromaticity($b^*$). The deposition of $SiO_2$ was performed with RF power of 400W, Ar gas of 50 sccm and the deposition of ITO, DC power of 600W, Ar gas of 50 sccm, $O^2$ gas of 0.2 sccm, and winding speed of 0.56m/min. High quality ITO thin films without $SiO_2$ layer had chromaticity of 2.87, sheet resistivity of 400 ohm/square, and transmittance of 88% and $SiO_2$-doped ITO Thin film with chromaticity of 2.01, sheet resistivity of 709 ohm/square, and transmittance of more than 90% were obtained. As a result, $SiO_2$ was coated on PET before deposition of ITO, their chromaticity($b^*$) and transmittance were better than previous results of ITO films. These results show that coating of $SiO_2$ induced arising chromaticity($b^*$) and transmittance. If the thickness of $SiO_2$ is controlled, sheet resistance value of ITO film will be expected to be better for touch screen. A four point probe and spectrophotometer are used to investigate the properties of ITO thin films.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.3
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• pp.51-61
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• 2007

This paper concerns about the requirement analysis for night vision imaging system(NVIS), whose purpose is to intensify the available nighttime near infrared(IR) radiation sufficiently to be caught by the human eyes on a miniature green phosphor screen. The requirements for NVIS are NVIS radiance(NR), chromaticity, daylight legibility/readability, etc. The NR is a quantitative measure of night vision goggle (NVG) compatibility of a light source as viewed through goggles. The chromaticity is the quality of a color as determined by its purity and dominant wavelength. The daylight legibility/readability is the degree at which words are readable based on appearance and a measure of an instrument's ability to display incremental changes in its output value. In this paper, the requirements of NR, chromaticity, and daylight legibility/readability for Type I and Class B/C NVIS are analyzed. Also the rationale is shown with respect to those requirements.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.243-243
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• 2017

Leaf colors of rice can be used to identify stress level due to its adaptation to environmental change. For most leaves green-related colors are sourced from chlorophyll a and b. For most leaves green-related colors are consisted of chlorophyll a and b. Chlorophyll concentration is normally measured using a spectrophotometer in laboratory. In some remote observation fields, it is impossible to collect the leaves, preserve them, and bring them to laboratory to measure their chlorophyll content. The measurement of chlorophyll content is observed through its color. Using CIE chromaticity diagram leaf color information in RGB is transformed into wavelength (in nm). Pheophytin contents were also analyzed in 95% ethanol extracts. In the process of leaf development of rice young seedling, both pigments were compared. Leaf samples from different rice seedling bed is taken, their colors and RGB values are recorded using Photoshop Image Analysis. SPAD-502 values were also measured. The chlorophyll and Pheophytin contents were fully estimated by ${\rightthreetimes}_{avg}$ on CIE chromaticity diagram.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.5
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• pp.986-991
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• 2016

In this study, we prepared ITO thin films on $Nb_2O_5/SiO_2$ double buffer layer using DC magnetron sputtering method and investigated electrical and optical properties with various substrate temperatures (room temperature ~ $400^{\circ}C$). The resistivity showed a decreasing tendency, because crystallinity has been improved due to the enlarged grain size with increasing substrate temperature. ITO thin film deposited at $400^{\circ}C$ showed the most excellent value of resistivity and sheet resistance as $3.03{\times}10^{-4}{\Omega}{\cdot}cm$, $86.6{\Omega}/sq.$, respectively. In results of optical properties, average transmittance was increased but chromaticity ($b^*$) was decreased in visible light region (400~800nm) with increasing substrate temperature. Average transmittance and chromaticity ($b^*$) of ITO thin film deposited at $400^{\circ}C$ exhibited significantly improved results as 85.8% and 2.13 compared to 82.8% and 4.56 of the ITO thin film without buffer layer. Finally, we found that ITO thin film introduced $Nb_2O_5/SiO_2$ double buffer layer has a remarkably improved optical property such as transmittance and chromaticity due to the index matching effect.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.166-169
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• 2007

최근에 정부의 "15/30 LED조명 보급정책"에 힘입어 개발된 8W급 조명용 LED광원의 CIE 색도좌표 (chromaticity coordinate)와 주파장(dominant wavelength)등을 측정 고찰 하였다. 적색(R), 녹색(G), 청색(B), 백색(W)순으로 주파장은 각각 620[nm], 531[nm], 465[nm], 579[nm]이고, 자극순도(excitation purity)는 0.98, 0.82, 0.97, 0.15이며, 휘도순도(colorimetric putity)는 45[%], 16[%], 279[%], 6[%]로 나타났다. Power LED의 최적배치 설계로서, 특히 백색 LED광원의 경우 백열전구(15 lm/W)에 비해 3배 이상의 높은 효율(47.71m/W)을 보였고, 배광측정에서는 78.7%의 효율로 나타났다. 현재 LED광원은 MR16이나 베이스 타입 등의 형태로 제작하여 스탠드, 복도등, 비상유도등, 침실용 등의 용도에 사용되고, 일부는 LED의 원형이나 면(flat)타입으로 가로등이나 투광등으로도 활용되고 있다. 따라서 이들에 대한 각각의 특성들을 제시해 둘 필요성인 인지되어 국내 최초로 개발된 R/G/B/W 8W급 LED광원에 대한 기본적인 광특성 결과를 얻었으며, 이중에서 HB 백색 LED램프의 색도좌표 값을 얻어 CIE표준광과의 색도좌표(x, y) 위치를 비교 검토할 수 가 있었다.

• The KIPS Transactions:PartB
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• v.18B no.2
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• pp.51-56
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• 2011

Algorithms for intrinsic images reduce color differences in RGB images caused by the temperature of black-body radiators. Based on the reference light and detecting single invariant direction, these algorithms are weak in real images which can have multiple invariant directions when the scene illuminant is a colored illuminant. To solve these problems, this paper proposes a method of acquiring an intrinsic image by omnidirectional projection of an ROI and a translation of white patch in the ${\chi}$-chromaticity space. Because it is not easy to analyze an image in the three-dimensional RGB space, the ${\chi}$-chromaticity is also employed without the brightness factor in this paper. After the effect of the colored illuminant is decreased by a translation of white patch, an invariant direction is detected by omnidirectional projection of an ROI in this chromaticity space. In case the RGB image has multiple invariant directions, only one ROI is selected with the bin, which has the highest frequency in 3D histogram. And then the two operations, projection and inverse transformation, make intrinsic image acquired. In the experiments, test images were four datasets presented by Ebner and evaluation methods was the follows: standard deviation of the invariant direction, the constancy measure, the color space measure and the color constancy measure. The experimental results showed that the proposed method had lower standard deviation than the entropy, that its performance was two times higher than the compared algorithm.

• Journal of the Korean Ceramic Society
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• v.48 no.1
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• pp.34-39
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• 2011

Systematic study on relationship between celadon coloring and glaze component was conducted by chromaticity analysis and M$\ddot{o}$ssbauer spectroscopic analysis. The chromaticity ($L^*$, $a^*$, $b^*$ values) and M$\ddot{o}$ssbauer analysis results were correlated to the amount of $Fe_2O_3$, $TiO_2$, MnO, and $P_2O_5$, which are the essential factors influencing celadon coloring. According to chromaticity analysis, celadon glaze color belongs to GY group when the addition of $TiO_2$ was 1.4%, whereas the color belongs to BG group when the addition of $TiO_2$ was 0.1%. For the GY group, the colors change from GY to YR with the decrease of brightness as the addition of $TiO_2$, MnO, and $P_2O_5$ increases. According to M$\ddot{o}$ssbauer analysis results, as the amount of divalent iron ion increases, the $a^*$ and $b^*$ values decrease, on the other hand, $L^*$ value increases. The ratio of divalent iron ion produced in reductive sintering process is found to be 80~95% in this study, which induces the increase of $L^*$ values in celadon glaze.

• Applied Chemistry for Engineering
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• v.27 no.3
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• pp.325-329
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• 2016

Extracting natural dyes have been widely studied since the needs of eco-friendly and non-toxic natural dyes increased. In this paper, the natural dyes were extracted from sappan wood, gardenia, and mugwort containing brazilein, crocin, and chlorophyll process. After the extraction with variables of pH of solvent and reaction time, the chromaticity of extracted natural dyes was analyzed using quantitative values from brightness and color coordinate (L, a, b) based on the target colors of red, yellow and green. For the case of brazilein and crocin, the cadmium red and cadmium yellow, respectively were extracted. In the case of sappan wood and gardenia, the red pigment under pH 12 (${\Delta}$ = 18.2) and the yellow pigment at pH 9 (${\Delta}$ = 18.4) were extracted respectively. However, the color of extracted chlorophyll from mugwort was different from the target chrome green.

• The Journal of Korean Academy of Prosthodontics
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• v.26 no.1
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• pp.185-196
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• 1988

The purpose of this investigation was to analyze the color of natural teeth by means of the OFC-1001 DP colorimeter which could measure in Adams Coordinate System (L,a,b system). The subjects were the 164 persons (82 men and 82 women) ranged from the teen to the sixtieth who had come to infirmary of dental college, Chosun University. The colors of incisal third, middle third and cervical third of maxillary right incisor, maxillary right canine and maxillary right second premolar were examined after the teeth were cleaned, polished and dried. The data were analyzed statistically by means of SPSS (Statistical Package For the Social Science). The results were as follows. 1. The means of L(lightness), a (red chromaticity), b (yellow chromaticity) of all teeth were measured (Table 2,3,4). 2. The color of teeth was yellowish-gray or bluish-gray. 3. The L value and b value of the cervical third was greater than those of the incisal and middle third. 4. The L value of maxillary 2nd premolar was greater than those of maxillary incisor md maxillay canine. 5. The a & b values of maxillary canine were greater than those of maxillary incisor and maxillary 2nd premolar. 6. The average values of L,a,b of teeth between male and female were not significant. 7. The L values of teeth were decreasing and the b values of teeth were increasing as the age was increased, but there was no corelation between the a values and aging.