• Applied Science and Convergence Technology
• /
• v.25 no.1
• /
• pp.1-6
• /
• 2016

Quantum dots (QDs) are considered as excellent color conversion and self-emitting materials for display and lighting applications. In this article, various technologies which can be used to realize white light emission with QDs are discussed. QDs have good color purity with a narrow emission spectrum and tunable optical properties with size control capabilities. For white light emission with a color-conversion approach, QDs are combined with blue-emitting inorganic and organic light-emitting diodes (LED) to generate white emission with high energy conversion efficiency and a high color rendering index for various display and lighting applications. Various device structures for self-emitting white QD light-emitting diodes (QD-LED) are also reviewed. Various stacking and patterning technologies are discussed in relation to QD-LED devices.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.25 no.1
• /
• pp.65-80
• /
• 2007

The input and output device requires precise color representation and CMS (Color Management System) because of the increasing number of ways to apply the digital image into electronic publishing. However, there are slight differences in the device dependent color signal among the input and output devices. Also, because of the non-linear conversion of the input signal value to the output signal value, there are color differences between the original copy and the output copy. It seems necessary for device-dependent color information values to change into device-independent color information values. When creating an original copy through electronic publishing, there should be color management with the input and output devices. From the devices' three phases of calibration, characterization and color conversion, the device-dependent color should undergo a color transformation into a device-independent color. In this paper, an experiment was done where the input device used the linear multiple regression and the sRGB color space to perform a color transformation. The output device used the GOG, GOGO and sRGB for the color transformation. After undergoing a color transformation in the input and output devices, the best results were created when the original target underwent a color transformation by the scanner and digital camera input device by the linear multiple regression, and the LCD output device underwent a color transformation by the GOG model.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.28 no.1
• /
• pp.25-42
• /
• 2010

One of the important roles of worflow is color management. In general, color management technique, which is called CMS(color management system), is a method to solve problems that show different characteristics of color regeneration in output devices, and the characteristics of output devices is created in data file called ICC(International Color Consortium) profile. In addition, ICC profile is used to manage color in workflow, and includes other functions, process management and printing quality management. In domestic printing market, workflow is in the pipeline at rapid speed along with CTP, and use of ICC profile required for color management is also in rapid progress. Therefore, this paper produced optimal ICC profile through experiment from the work of linearizing devices used in each field to color conversion work. Moreover, the paper confirmed how ICC profile will be used in printing field. In the profiling experiment based on hardcopy proofing, photographed copy and chrominance were compared by printing out in proof the image created through application and color conversion with the use of camera profile and proof profile produced in colorimetric method. By evaluating if color is expressed accurately from input to output through colorimetric color conversion experiment as above, the paper intended to propose color management method using optimal profile in printing process.

• Journal of the Korean Ceramic Society
• /
• v.53 no.2
• /
• pp.258-262
• /
• 2016

The effect of zirconium dioxide ($ZrO_2$) on the properties of color conversion glasses was examined in the $BaO-ZnO-B_2O_3-SiO_2$ system. The difference in refractive index between glass and phosphor affect the optical properties of the color conversion glass because of light scattering. Reducing the difference in refractive index is a method to improve the luminous efficacy of color conversion glasses. As a reference, a type of glass that contains 25 mol% of each component was used. To increase the refractive index of the glass samples, the BaO content was increased from 25 to 40 mol%, and $ZrO_2$ was added at levels of 1, 3, and 5 mol%. Color conversion glasses were prepared by sintering a mixture of glass and 5 wt% $YAG:Ce^{3+}$ phosphor. As a result, the refractive index of the glass was found to be dependent on the BaO and $ZrO_2$ contents in the BaO-ZnO-$B_2O_3-SiO_2$ system. As the BaO and $ZrO_2$ contents were increased, the luminous efficacy of the color conversion glass was improved because the refractive index difference between the glass and the $YAG:Ce^{3+}$ phosphor decreased.

• Journal of Information Processing Systems
• /
• v.13 no.1
• /
• pp.114-127
• /
• 2017

This paper proposes a color image coding algorithm based on shape-adaptive all phase biorthogonal transform (SA-APBT). This algorithm is implemented through four procedures: color space conversion, image segmentation, shape coding, and texture coding. Region-of-interest (ROI) and background area are obtained by image segmentation. Shape coding uses chain code. The texture coding of the ROI is prior to the background area. SA-APBT and uniform quantization are adopted in texture coding. Compared with the color image coding algorithm based on shape-adaptive discrete cosine transform (SA-DCT) at the same bit rates, experimental results on test color images reveal that the objective quality and subjective effects of the reconstructed images using the proposed algorithm are better, especially at low bit rates. Moreover, the complexity of the proposed algorithm is reduced because of uniform quantization.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.46 no.1
• /
• pp.85-91
• /
• 2009

Recently, the LCD has high market share in TV market. The use of motion images in portable devices like DMB, PMP and Cell Phone is growing rapidly. One of the technique of enhancing the LCD's characteristic which is the slow response time. But, the technique requires a lot of memory usage, because of the requirement of frame memory. In this paper, we propose a reduction method for the frame memory that is required for LCD overdrive. Proposed overdrive architecture based on modified DWT-Inverse DWT and Color Conversion. The proposed architecture has a considerable PSNR. At once, it uses 50% of frame memory size and reduces 15% of frame memory size compare with previous architecture. The design was implemented using Xilinx Vertex4 and had 2172 Slice except Memory.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.26 no.4
• /
• pp.447-453
• /
• 2010

The purpose of this study was to compare the light transmitting ability of halogen light in different colors and thicknesses. A1, A2, A3 colors of Z-250 composite resin(3M ESPE, St. Paul, U.S.A.) were used. Degree of conversion of separated resin specimens under the 2, 3, 4mm thickness resin were measured by FTIR spectroscopy. The result shows that decrease of degree of conversion by increase of resin thickness and decrease of degree of conversion by decrease of lightness of color. Within the limitation of results, it is recommended to use more light color of composite resin in small thickness to improve degree of conversion when use halogen light.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.7
• /
• pp.1464-1468
• /
• 2004

The color conversion and color enhancement on gray image is presented in this paper. The pseudocoloring for RCB color components extraction from gray image is used the 2D U(Fast Wavelet Transform) for fille. bank and re-array. The each post processing is used the median filtering for noise reduction and the discrete color histogram equalization for CIT(Color Intensity Transformation). The experiment result has enhanced pseudocoloring image as PSNR 30dB over compared the processing of normal wavelet transform.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.697-699
• /
• 2009

Optical properties of white organic light-emitting devices (WOLEDs) fabricated utilizing a phosphor layer acting as a color conversion layer were investigated. The WOLEDs were achieved due to the enhancement in the color conversion efficiency of the phosphor layer, and the chromaticity coordinates of WOLEDs were (0.29, 0.33).

• Journal of the Korean Graphic Arts Communication Society
• /
• v.14 no.2
• /
• pp.115-128
• /
• 1996

In this paper, we describe the Color Correction and Preferred Skin Color Reproduction in a ink-jet color printer. The fundamental color correction that converts RGB densities into GMY densities has been ordinarily used. This method can reduce the hue error, but color difference between the preferred skin colors and hardcopy skin colors are large. We have been able to reduce color differences between original skin color and hardcopy skin color by transforming hardcopy skin colors` coordinates into Preferred Skin Colors` coordinates. Experimental results show that the described method is useful and valid for the skin color reproduction in a digital color printer.