• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.337-342
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• 2004

Since 1992, Philips has been developing polymer OLEDs resulting in a first commercial monochrome display just 10 years later. Philips is now focusing on the technology development required to mass-produce full-color polymer OLDE displays, based on passive and active-matrix addressing. High precision inkjet printing has been chosen as the deposition technology for the OLED material. In this paper, we give an overview of the activities of Philips in the area of mobile OLED applications and explore the route towards large screen OLED television.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1759_1760
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• 2009

본 논문에서는 롤투롤 인쇄에서 보편적으로 많이 사용하는 그라비아 방식의 인쇄에 영상처리를 이용하여 해상도가 높고, 속도가 빠른 전자에 인용될 수 있는 마크를 개발하려 한다. 인쇄의 품질은 영상처리용 레지스터 마크 간의 오차에 의해 결정되므로 영상처리용 레지스터 마크의 형상이 중요 하게 된다. 본 논문에서는 다양한 인쇄 조건하에서도 구분점을 명확히 인식할 수 있는 형태를 찾는 방법으로 마크 형상을 연구하여 적합한 형상을 찾아내었다.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.205-208
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• 2006

We report the recent progress and future prospects of flexible, large-area sensors and actuator using organic thin-film transistors (TFTs). In particular, we describe printing technologies to manufacture electronic artificial skins (e-skins) for robots, sheet image scanners suitable for mobile applications, and Braille sheet display with plastic actuator arrays. We also present recent progress of reliability and stability issues.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.697-699
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• 2005

The need for low cost flexible TFT display backplanes has focused attention on new processing techniques and materials. We have developed backplane technology based entirely on jet-printing, using a combination of additive and subtractive processing, and have applied this technique to both amorphous silicon and polymer TFT arrays.

• The Journal of Advanced Prosthodontics
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• v.12 no.5
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• pp.259-264
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• 2020

PURPOSE. The aim of this study was to investigate and compare the color stability of provisional restorative materials fabricated by 3D printing, dental milling, and conventional materials. MATERIALS AND METHODS. For the experimental groups, two commercially available 3D-printing provisional resins (E-Dent 100; EnvisionTEC GmbH, Germany & VeroGlaze™; Stratasys^®, USA), two dental milling blocks (PMMA Disk; Yamahachi Dental Co., Japan & Telio^®CAD; Ivoclar Vivadent AG, Liechtenstein), and two conventional materials (Alike™; GC Co., Japan & Luxatemp automix plus; DMG, Germany) were used. The water sorption and solubility test were (n=10, respectively) carried out according to ISO4049:2000 (International Standards Organization, Geneva, Switzerland). For the color stability test (n=10), coffee and black tea were used as staining solutions, and the specimens were stored for 12 weeks. Data were analyzed by one-way ANOVA and Tukey's HSD using SPSS version 22.0 (SPSS Inc. Chicago, IL, USA) (P<.05). RESULTS. Alike and Veroglaze showed the highest values and Luxatemp showed the lowest water sorption. In the color stability test, the ΔE of conventional materials varied depending on the staining solution. PMMA milling blocks showed a relatively low ΔE up to 4 weeks, and then significantly increased after 8 weeks (P<.05). 3D-printed materials exhibited a high ΔE or a significant increase over time (P<.05). CONCLUSION. The degree of discoloration increased with time, and a visually perceptible color difference value (ΔE) was shown regardless of the materials and solutions. PMMA milled and 3D-printed materials showed more rapid change in discoloration after 8 weeks.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.19.2-19.2
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• 2010

Printed electronics using printing process has broadened in all respects such as electrics (lighting, batteries, solar cells etc) as well as electronics (OLED, LCD, E-paper, transistor etc). Copper is considered to be a promising alternative to silver for printed electronics, due to very high conductivity at a low price. However, Copper is easily oxidized, and its oxide is non-conductive. This is the highest hurdle for making copper inks, since the heat and humidity that occurs during ink making and printing simply accelerates the oxidation process. A variety of chemical treatments including organic capping agents and metallic coating have been used to slow this oxidation. We have established synthetic conditions of copper nanoparticles (CuNPs) which are resistant to oxidation and average diameter of 20 to 50nm. Specific resistivity should be less than $4\;{\mu}{\Omega}{\cdot}cm$ when sintered at lower temperature than $250^{\circ}C$ to be able to apply to conductive patterns of FPCBs using ink-jet printing. Through this study, the parameters to control average diameter of CuNPs were found to be the introduction of additive agent, the feeding rate of reducing agent, and reaction temperature. The CuNPs with various average diameters (58, 40, 26, 20nm) could be synthesized by controlling these parameters. The dispersed solution of CuNPs with an average size of 20 nm was made with nonpolar solvent containing 3 wt% of binder, and then coated onto glass substrate. After sintering the coated substrates at $250^{\circ}C$ for 30 minutes in nitrogen atmosphere, metallic copper film resulted in a specific resistivity of $4.2\;{\mu}{\Omega}{\cdot}cm$.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.11
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• pp.1237-1242
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• 2011

Calcium phosphates are very interesting materials for use as scaffolds for bone tissue engineering. These materials include hydroxyapatite (HA) and tricalcium phosphate (TCP), which are inorganic components of human bone tissue and are both biocompatible and osteoconductive. Although these materials have excellent properties for use as bone scaffolds, many researchers have used these materials as additives to synthetic polymer scaffolds for bone tissue regeneration, because they are difficult to manufacture three-dimensional (3D) scaffolds. In this study, we fabricated 3D calcium phosphate scaffolds with the desired inner and outer architectures using solid freeform fabrication technology. To fabricate the scaffold, the sintering behavior was evaluated for various sintering temperatures and slurry concentrations. After the fabrication of the calcium phosphate scaffolds, in-vitro cell proliferation and osteogenic differentiation tests were carried out.

• Journal of the Korean Graphic Arts Communication Society
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• v.26 no.2
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• pp.65-77
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• 2008

The color reproduction of digital still camera does not, in general, match those of the final prints. Because color gamut of these devices is different, it is therefore necessary to take account of a way to match. The way uses the optimized profile to print an image. This paper proposed a way to create the input profile of digital still camera for standardization printing process. The results of proposed way showed that for input profiles equivalent, good results relatively. In this paper, an experiment was done where the illumination sources used as the standard illumination 5200K and illuminated at a $45^{\circ}$ angle in the best illumination efficiently. The white balance was in mode 'custom': aperture F11, exposure time 1/60s, ISO50, focal length 80mm. The images were exported and saved as 16bit RGB tiff(AdobeRGB, sRGB, ProphotoRGB) images. To do the test, the RGB values of the RGB tiff images are processed through the ICC input profile to arrive at processed $CIEL^*a^*b^*$ values. A profiling tool such as ProfileMaker 5.0 and Monacoprofile 4.8 are used to do this. The processed CIEL*a*b* values are compared to the reference CIEL*a*b* values and these two values are used to calculate a ${\Delta}E$.

• Journal of the Korean Wood Science and Technology
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• v.46 no.3
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• pp.270-277
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• 2018

This study was conducted to identify wood species of two printing woodblocks either from the Park clan's documentary or Ji-dang documentary of Songok clan of the Milseong Park, Songok, Gyeongju, Korea. Eighty-eight woodblocks out of the total 282 woodblocks were randomly selected to compare anatomical features for the identification of wood species, using a light microscope. As a result, seven wood species were identified, and all of them were diffuse-porous hardwood species. The most significant portion, i.e., 39.8% of wood species was Carpinus laxiflora Blume. Then, Pyrus pyrifolia Nakai, Acer mono Maxim, Prunus sargentii Rehder, Tilia amurensis Rupr, Diospyros kaki Thunb, and Betula costata Trautv was 25.0%, 15.9%, 10.2%, 3.4%, 3.4% and 2.3%, respectively, indicating that all diffuse-porous hardwood species had been used for the woodblocks. It was believed that diffuse-porous hardwoods had been used because they provided an easy of engraving complex Chinese letters, of acquiring these wood species in Gyeongju areas, and a high resistance to repeated printing.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.11
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• pp.905-910
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• 2011

To study encapsulation method for large-area organic light emitting diodes (OLEDs), red emitting OLEDs were fabricated, on which LiF and Al were deposited as inorganic protective films. And then the OLED was attached to flat glass by printing method using epoxy. In case of direct coating of epoxy onto OLED by printing method, luminance and current efficiency were remarkably decreased because of the damage to the OLED by epoxy. In case of depositing LiF and Al as inorganic protective films and then coating of epoxy onto OLED, luminance and current efficiency were not changed. OLED lifetime was more increased through inorganic protective films between OLED and flat glass than that without any encapsulation (8.8 h), i.e., 47 (LiF/Al/epoxy/glass), 62 (LiF/Al/LiF/epoxy/glass), and 84 h (LiF/Al/Al/epoxy/glass). The characteristics of OLED encapsulated with inorganic protective films (attached to flat glass) showed the possibility of application of protective films.