• Design & Manufacturing
• /
• v.9 no.2
• /
• pp.20-24
• /
• 2015

Recently, the light guide plate (LGP), a component of the BLU, becomes thinner and larger than ever. In industrial field, specialized injection molding technique is applied to mold the ultra-thin LGP such as a ultra-high speed injection molding. Usually very high melt temperature is used for low viscosity. High injection speed and melt temperature lead to yellowing of LGP. In the present paper a series of injection molding experiment was performed under various injection molding conditions. Yellow index, CIE xy, spectral transmittance of sample were measured using the UV-Visible spectrophotometer. Systematic decrease of spectral transmittance in UV-B range was found as the melt temperature was higher. Yellow index and CIE xy were became higher near the gate location in LGP. From the result of analysis of variance, the main factor to affect for yellow index was mold temperature and that for spectral transmittance(at 315 nm) was melt temperature.

• Proceedings of the IEEK Conference
• /
• 2003.07e
• /
• pp.1763-1766
• /
• 2003

This paper proposes a non-contact color inspection system for plasma display panel (PDP). The red, green, and blue test pattern images are acquired by using the area color CCD camera at the various distance from the PDP. The RGB values are obtained from the region of interest (ROI) which are extracted by applying the image processing to the test pattern image. Finally, the CIE xy and u'v' chromaticity coordinates of the test pattern images according to the distance are acquired from the RGB color coordinates.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.18 no.4
• /
• pp.146-154
• /
• 2008

This study was carried out for the purpose of obtaining the basic data for color identification of amethyst by spectrophotometer. For this, the eleven amethyst stone and one citrine stone from eight countries were prepared in facet cut or plate. The transmittance and reflection of this samples were investigated as a function of wavelength. The transmittance or reflection was transformed to tristimulus value (X, Y, Z) and chromaticity value (x, y, z) and then compared with the results of eye observation which was plotted on cm xyY color space. Finally, the influence of the amethyst's thickness on transmittance or reflection was investigated.

• Proceedings of the Korea Institute of Convergence Signal Processing
• /
• 2003.06a
• /
• pp.106-109
• /
• 2003

This paper presents a hue preserving gamut mapping algorithm for color monitor and printer. The gamuts of monitor and printer are set by the profile of color reproduction media, specified by ICC(International Color Consortium) and provided by vendors, then those gamuts are represented on the CIE xy color space. In case that the color of monitor are located on out-of-gamut of printer, these are clipped on the point of gamut boundary of printer towards a reference white point. On the other hand, colors are in-gamut of printer are unchanged. An image generated by the algorithm keeps a ratio of each pixel of original image. Advantages of the algorithm are easy to implement and fast processing time than other algorithms which involve hue preserving especially in CIELAB color space.

• Journal of the Optical Society of Korea
• /
• v.17 no.4
• /
• pp.344-349
• /
• 2013

This paper proposes a simulation algorithm to assess the gradual yellowing vision of the elderly, which refers to the predominance of yellowness in their vision due to aging of the ocular optic media. This algorithm employed the spectral transmittance property of a yellow filter to represent the color appearance perceived by elderly people with yellow vision, and modeled the changes in the color space through a spectrum change in light using the yellow filter effect. The spectral reflectivity data of 1269 Munsell matte color chips were used as reference data. Under the standard conditions of a D65 illuminant and a $10^{\circ}$ observer of 1964 CIE, the spectrum of the 1269 Munsell colors were processed through the yellow filter effect to simulate yellow vision. Various degrees of yellow vision were modeled according to the transmittance percentage of the yellow filter. The color differences before and after the yellow filter effect were calculated using the DE2000 formula, and the color pairs were selected based on the color difference function. These color pairs are distinguishable through normal vision, but the color difference diminishes as the degree of yellow vision increases. Assuming 80% of yellow vision effect, 17 color pairs out of $(1269{\times}1268)/2$ pairs were selected, and for the 90% of yellow vision effect, only 3 color pairs were selected. The result of this study can be utilized for the diagnosis system of gradual yellow vision, making various types of test charts with selected color pairs.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08b
• /
• pp.1470-1473
• /
• 2007

We have demonstrated the optimization of white organic light-emitting diodes with two separated emissive layers using a blue fluorescent and a red phosphorescent dopant. The maximum luminous efficiency of the devices showed 7.93, 9.70, 11.8, and 14.3 cd/A. The $CIE_{xy}$ coordinates also showed (x = 0.33, y = 0.36), (x = 0.33, y = 0.35), (x =0.31, y = 0.35), and (x = 0.29, y = 0.36) at 6V, respectively.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08b
• /
• pp.1399-1402
• /
• 2007

We have demonstrated efficient white WOLEDs by using three emissive materials for primary colors (red, green, and blue). The characteristics of WOLEDs showed the maximum luminance of $37600\;cd/m^2$ at 13V, the maximum luminous efficiency of 20.6 cd/A, and the $CIE_{xy}$ coordinates of (x = 0.33, y = 0.33) at 10V.