• Journal of Information Display
• /
• v.6 no.3
• /
• pp.26-29
• /
• 2005

Nanosize cobalt aluminate($CoAl_2O_4$) power was coated as filter layer for us to improve the color purity and contrast performances on the inner face of CRT panel. We simulated color properties by measuring the transmittance and thickness of the coated filter layer. Contrast performance could be improved and color gamut was also changed by the selective light absorption of filter layer at 580${\sim}$605 nm.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.48 no.10
• /
• pp.704-709
• /
• 1999

The optical properties such as luminance and color coordinates for phosphor layer were studied with applied voltage and gas pressure, Xe mixing ratio, frequency using He and Xe mixing gas in chamber like AC PDP. The luminance of red phosphor layer at constant pressure(300Toor) is increased with increasing voltage, but color purity is not varied. The luminance of red phosphor layer at constant voltage(280V)is decreased with increasing pressure, but the color purity is not varied. But the luminance is increased with increasing Xe mixing ratio at constant pressure(200Toor). And also the color purity is improved by this process. The luminance is increased up to 40kHz, but the color purity with frequency is not varied.

• Current Optics and Photonics
• /
• v.3 no.1
• /
• pp.78-85
• /
• 2019

The remote phosphor structure has been proven to bear greater luminous efficiency than both the conformal phosphor and in-cup phosphor structures; however, controlling its color quality is much more challenging. To solve this dilemma, various researchers have proposed dual-layer phosphor and triple-layer phosphor configuration as techniques to enhance the display brightness of white LEDs (WLEDs). Likewise, this study picked one of these configurations to utilize in multichip WLEDs with five distinct color temperatures in the range from 5600 to 8500 K, for the purpose of improving the optical properties of WLEDs, such as color rendering index (CRI), color quality scale (CQS), luminous efficacy (LE), and chromatic homogeneity. According to the results of this research, the triple-layer phosphor configuration has superior performance compared to other configurations in terms of CRI, CQS, and LE, and yields higher chromatic stability for WLEDs.

• Journal of the Optical Society of Korea
• /
• v.1 no.2
• /
• pp.116-119
• /
• 1997

Highly quantum efficient and multi-color emissible polymer light emitting devices have been realized utilizing poly (1-dodecyloxy-4-methyl-1, 3-phenylene)(2, 5"-terthienylene)(hereafter, mPTTh polymer) as an emitting layer and tris(8-hydroxyquinoline) aluminum (Alq3) as an electron transport layer. A single layer EL device of mPTTh polymer emits orange-colored light. EL efficiency increases as the thickness of Alq3 layer increases, but the emission color becomes visually broad when the Alq3 layer thickness is greater than 30nm since the relative peak intensity of green EL from Alq3 layer grows. EL color is changed from orange to greenish orange as the thickness of Alq3 layer grows. EL color is changed from orange to greenish orange as the thickness of Alq3 layer increases. EL efficiency of the double layer device was greatly enhanced by 3000 times compared with that of a single layer device. Alq3 layer in device acts as a hole blocking electron transporting layer and an emitting layer as a function of the thickness of Alq3 layer.ayer.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.15 no.1
• /
• pp.31-40
• /
• 1997

The objectives of color reproduction in printing, photography, and digital hard-copy is an important problem. The Color is obsorved differently from illumination an obsorvation condition, and varied according to individual taste. Generally, the color reproduction system is designed with colorimetric color reproduction method. But the color gamut of the color reproduction system is different each other and the one device has nonlinear relationalship between the other. By these reason, to predict the reproduced color based on linear color transform method is difficult. Some methods of non-linear color transform by neural network was proposed. These method was theoretical useful and valid to transform from CIE color to device color. But more studies were needed to realize the non-linear color transform system. In this paper, we described a method to realize the non-linear color transform system by neural network. The optimum structure of the non-linear color transform system was found out. The structure of descrived system has four layer( input, output and two hidden layers.) Input and output layer have 3 units, and a hidden layer has 27 units. We trained 216 color-samples, and estimated the realized color transform system by 1115 color-samples. The average color difference between original color samples and transformed color samples was 2.54.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.35 no.6
• /
• pp.547-555
• /
• 2022

Color conversion layer refers to a layer that converts the blue light emitted from the backlight into the red and green light. Heavy metal-free quantum dots and perovskite nanocrystals have attracted great attention as base materials for color conversion layers due to their outstanding optical characteristics. Here, we review recent advances in the development of color conversion layers based on quantum dots. First, we overview the representative optical characteristics of quantum dots and perovskite nanocrystals, and then introduce printing techniques for color converting layers including photolithography, inkjet printing, and nanoimprinting. Finally, we conclude this review with a brief perspective.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.35 no.2
• /
• pp.71-76
• /
• 2017

The cocoon's color of silkworm, Bombyx mori L. is usually white. But some are yellow, flesh and green colors because of modified characteristics. The yellow and flesh cocoons depend on carotenoid pigments, green cocoons are determined by flavonoid pigments. The cocoon's color is affected by the genes controlling penetration process from midgut to coelom and silk gland. Y (Yellow blood, 2-25.6) and I (Yellow-inhibitor, 9-16.2) genes are involved in the penetration process of carotenoid pigments from midgut to coelom, C (Outer-layer yellow cocoon, 12-7.2) and F (Flesh, 6-13.6) genes from coelom to silk gland. Therefore, the carotenoid cocoon's color depends on the genotype Y, I, C and F genes and their combination. Among them, C gene is sympathetic gene, which are known as C, CI and CD. C (Outer-layer yellow cocoon) genes make yellow cocoons on outer-layer and white cocoons on inter-layer, and CI (Inner-layer yellow cocoon) genes do yellow cocoons on inter-layer and dilute yellow cocoons on outer-layer. CD gene is known as making dilute yellow cocoons all layer. In this study, we have checked the dominance relation of C sympathetic genes among carotenoid genes for color cocoons by using strains related to the genes for color cocoons and investigated the aspect that pigments were penetrated in silk gland by action of each gene.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07b
• /
• pp.1175-1178
• /
• 2005

Nanosize cobalt aluminate($CoAl_2O_4$) power as filter layer was coated to improve the color purityand contrast performances on inner face of CRT panel. We simulated color properties by measuring the transmittance and thickness of the coated filter layer. Contrast performance could be improved and color gamut was also changed because of the selective light absorption of filter layer at $580{\sim}605\;nm$.

• Horticultural Science & Technology
• /
• v.31 no.3
• /
• pp.259-268
• /
• 2013

This study was carried out to evaluate the visual turfgrass's color quality, winter color, and spring green-up under three different soil systems and to make a practical use for sports turf design and construction. Several turfgrasses were evaluated in multi-layer, USGA and mono-layer systems. Turfgrass entries in the study comprised of 3 cultivars from Korean lawngrass (Zoysia japonica Steud.) of typical warm-season grass (WSG) and 3 blends and 3 mixtures from Kentucky bluegrass (KB, Poa pratensis L.), perennial ryegrass (PR, Lolium perenne L.), and tall fescue (TF, Festuca arundinacea Schreb.) of cool-season grass (CSG). Significant differences were observed in the turfgrass's color quality, winter color, and spring green-up in the study. Seasonal variation of visual turf color greatly occurred according to soil systems and turfgrasses. Multi-layer and USGA systems were highly associated with better visual color ratings, as compared with mono-layer system. Regardless of soil system, visual turf color in all entries was better from spring to fall than in winter. Great color differences were observed during a period of early December to early spring. CSG produced a better color quality over WSG in any soil system. Overall color ratings for CSG were KB > PR > Mixtures > TF. As for a winter color, its ranking was USGA > multi-layer > mono-layer system. No difference was found in winter among cultivars of Korean lawngrass, being completely brown, but great differences among CSG. Rated best for winter color was PR, followed by CSG mixtures, KB and finally TF in order. It was generally conceded that fast green-up in spring was greatly related with multi-layer over mono-layer system and also CSG over WSG. Among CSG, TF had a fastest green-up. PR was also fast in green-up, but poor in color uniformity. KB, however, was the slowest due to shallow rooting system, when compared with other CSGs. These results demonstrate color differences were greatly variable according to soil systems and also among turfgrass species. A precise decision should be made in selecting turfgrass species and soil system. Multi-layer and USGA systems were considered as the suitable one for turfgrass color quality, winter color and spring green-up. It is a great necessity to combine proper soil system, right turfgrass species, and appropriate mixing rates by a concept-oriented approach, when establishing garden, parks, soccer field, and golf courses and so on.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.1386-1388
• /
• 2009

We report on a new method of fabricating color filters based on selective wetting of color inks. The reversible formation of a hydrophobic layer provides sequential generation and protection of successive color filter patterns through a simple coating process. The transmittance and geometrical properties of the fabricated color filter were described.