• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1568-1570
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• 2008

In this paper, fabrication of a $60{\times}48$ polymer TFT array with a top-gate structure on plastic substrates using a low temperature printing process will be presented and the device structure and manufacturing processes will be discussed. The polymer TFT array showed excellent air stability and uniform electrical characteristics over a large area. Finally, a 1.5 inch EPD display with 50 dpi resolution using the polymer TFT array will be demonstrated for e-film device applications.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1119-1121
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• 2006

Using a chemical radical we modified the surface property of PET substrates. The chemically treated substrate surface improved dispersion of CNTs on substrate and provides suitable adhesion of CNTs to substrate. In addition, an ink-jet printed patterning technique effectively improved the transparency of transparent conductive CNT composite films.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.329-333
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• 2003

In micro hole punching process the burr occurs inevitably, but the burr must be minimized in order to improve the quality and accuracy of the product. In this study, magnetic field assisted polishing technique is applied to remove the burr which exists in nozzles for ink-jet printer head and proved to be a feasible for deburring by experiment. The deburring characteristics of sheet metals was investigated changing with polishing time. After the deburring, the burr size has remarkably reduced and roundness of the hole also has improved.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.3
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• pp.295-301
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• 2012

The method for spraying of liquids through an electrical field has become a printing method since it can make very small droplet. For electro-hydrodynamic jet printing to become a reliable jetting tool, the jetting performance should be characterized with respect to various jetting conditions. To optimize jetting conditions, the jetting behavior should be measured. In this study, we present a visualization techniques to measure jetting behavior from electro-hydrodynamic (EHD) inkjet head. Unlike most previous method, we use the CCD camera to measure the jetting behavior. For this purpose, LED light is synchronized with jetting signal and sequential image was obtained by adjusting the delay time of the LED light. Finally, merits and demerits of using CCD camera were discussed to measure jetting image from EHD inkjet head.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.18.1-18.1
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• 2010

Here, we introduce our R&D status and strategies for printed electronics containing the two types of aspects such as materials and process/architectures. Specially, in this talk, we focus on the high-performance polymer thin film transistors (PTFTs) backplanes fabricated by ink-jet printing using new polymer semiconductors for the applications of flexible display.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.441-444
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• 2000

BPA(Black Printer Algorithm)은 잉크젯 프린터에서 사용되는 C(사이안), M(마젠타), Y(옐로우) 잉크에 대한 검정(Black) 잉크의 양을 결정하는 알고리즘이다. CMY 잉크로 인쇄한 이미지의 칼라 품질은 모니터가 재생할 수는 있는 칼라 영역보다 적다. 또한 CMY 잉크를 각각 100% 씩 섞었을 때 이론적으로는 검정 색이 나와야 하나 실제는 검정 색을 정확하게 재현하지 못한다. 그래서 대부분의 프린터는 검정(K) 잉크를 기본으로 제공하며 CMY 잉크로 표현될 회색 영역의 부분을 검정 잉크로 대신 표현해 주기 때문에 프린터의 재현 영역을 확장시킬 수 있다. 또한 검정 잉크의 사용으로 인쇄품질의 색조 대비(contrast)를 증가시킬 수 있고 CMY 잉크를 검정 잉크로 대신 인쇄하기 때문에 CMY 잉크를 절약하는 효과를 얻을 수 있다. 본 논문에서는 본 잉크젯 프린터의 K(black) 잉크와 CMY(cyan, magenta, yellow) 잉크와의 관계를 살펴보았고 이 특성을 이용해 검정 잉크를 조절하는 방법 중에 하나인 3차 다항식의 BPA(Black Printer Algorithm)를 구현하였다. 결과에서는 성능 테스트에 대한 내용과 성능 향상을 위한 방법에 대해 논의하였다.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.7 s.184
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• pp.168-176
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• 2006

Nowadays, Three dimensional printing (3DP) technique that is one of solid freeform fabrication (SFF) technology has been notable issue, and has been applied by various fields. The SFF system can fabricate three dimensional objects of solid freeform with high speed and low cost using ink jet printing technology. In this research, a SFF system to analyze 3DP process technology is developed. We applied sliding mode control with sliding perturbation observer (SMCSPO) algorithm and minimized position error to the developed SFF system. We analyzed and optimized process variables such as jetted volume, layer thickness, powder bed and so on experimentally. Also. the dimensional error of a developed SFF system is evaluated. Finally, the feasibility of application to bio manufacturing is presented through successful fabrication of teeth and cranium model.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.858-860
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• 2009

We have applied self-assembled monolayer to make high performance and stable OTFT on the organic gate dielectric. The ${\beta}$-phenethyltrichlorosilane (SAM) was coated on the organic gate dielectric and then active layer was printed. Significant improvements in on-currents and threshold voltage shift were achieved for the SAM treated devices compared to device without SAM.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10b
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• pp.323-325
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• 2000

정보통신의 발전에 따라 컴퓨터 및 주변 장치간에 칼라를 정확히 재생할 수 있는 능력이 산업 경쟁력에 중요한 요소로 부상하고 있다. 본 논문에서는 모니터 상의 이미지를 프린터로 인쇄하기 위하여 사용되는 기존의 참조테이블(Look Up Table) 방식을 살펴보고 이 기능을 대체할 수 있는 신경회로망에 의한 칼라보정 매핑 방법을 제안하였다. 참조테이블 방식에서는 3차원으로 구성된 테이블을 구성하기가 쉽지 않고 구간 사이의 칼라값은 보간법을 써서 구해야 한다. 신경회로망에 의한 방법에서는 일단 학습을 완료하면 실시간으로 칼라를 보정해 주는 장점이 있다. 실험에서는 두 가지 방법에 의한 칼라 샘플의 모델을 통한 결과 값을 비교해 보고 상호간의 장단점과 성능 향상을 위한 방법을 토의하였다.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.372-373
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• 2006

Modern business trends call for miniaturization of electronic systems. One of the major impedances in this miniaturization is the conductive and inductive components in chips and circuit boards. Direct Write Technology can write these soft magnetic materials, thus allowing for further miniaturization of inductor devices. Another obstacle in electronics fabrication is the size limitations of thick screen-printing and the material limitations in ink jet printing. Direct Write Technologies address both of these limitations by providing feature sizes less than 20 microns with a wide range of materials possibilities. A discussion of the application of these nano-particulate materials by Direct Write Technologies will be presented.