• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.203-203
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• 2012

The SWCNTs network are formed on various plastic substrates such as poly(ethylene terephthalate) (PET), polyimide (PI) and soda lime glass using roll-to-roll printing and spray process. Selective patterning of carbon nanotubes film on transparent substrates was performed using a femtosecond laser. This process has many advantages because it is performed without chemicals and is easily applied to large-area patterning. It could also control the transparency and conductivity of CNT film by selective removal of CNTs. Furthermore, selective cutting of carbon nanotube using a femtosecond laser does not cause any phase change in the CNTs, as usually shown in focused ion beam irradiation of the CNTs. The patterned SWCNT films on transparent substrate can be used electrode layer for touch panels of flexible or flat panel display instead indium tin oxide (ITO) film.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.223-224
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• 2000

As technology level of TFT-LCD advances, application to TV becomes an emerging important area for LCD makers. In this paper, we review current LCD technology level to be used in TV such as liquid crystal response behavior, color accuracy, contrast ratio, brightness and panel size. Based on the understanding of current limitations in LCD compared with CRT, the improvement plan to render 'near perfect motion picture' reproduction with LCD is proposed. Digital TV is a great opportunity for digital LCD panels, but we have to solve remaining technical and cost issue in order to be competitive with other large size TV technologies such as PDP, CRT or projection type. In preparing the upcoming digital TV era with advanced TFT-LCD, the hurdles and prospect of larger size LCD-TV panels will be discussed.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.71-72
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• 2000

The design of large area thin film transistor liquid crystal displays (TFT-LCDs) requires consideration of cross-talks between the data lines and pixel electrodes. These limits are imposed by the mutual coupling capacitances present in a pixel. The mutual coupling capacitance causes a pixel voltage error. In this study, semi-empirical model, which is adopted from VLSI interconnection capacitance calculations, is used to calculate mutual coupling capacitances. With calculated mutual coupling capacitances and arbitrary given image pattern, the root mean square (RMS) voltage of pixel is calculated to see vertical cross-talk from the first to the last column. The information obtained this study can be utilized to design the larger area and finer image quality panel.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.330-333
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• 2005

We investigated the liquid crystal (LC) alignment phenomena using a-C:H and a-C:F:H thin films. Homogeneous alignment is obtained using ion beam treated hydrogenated amorphous carbon (a-C:H) thin films. Homeotropic alignment is obtained using F treated a-C:H thin films, namely, fluorinated amorphous carbon (a-C:F:H) thin films. We investigated the relationship between the surface properties of amorphous carbon based alignment layer and LC alignment phenomena.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.357-360
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• 1996

MgO protection layer in ac PDP(plasma display panel) prevents the dielectric layer from ion bombarding in discharge plasma. The MgO layer also has the additional important role in lowering the firing voltage due to a large secondary electron emission coefficient. Until now, the MgO protection layer is mainly prepared by E-beam evaporation. In this study, MgO protection layer is prepared on dielectric layer of ac PDP cell by reactive R.F magnetron sputtering with Mg target under various conditions of oxygen partial pressure. Discharge characteristics of PDP is also studied as a parameter of MgO preparation conditions. The sputtered MgO shows the better discharge characteristics compared with MgO deposited by E-beam evaporator.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.12
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• pp.1065-1069
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• 2002

The addressing time should be reduced by modifying cell structure and/or driving method in order to replace the dual scan system by single scan and increase the luminance in large ac plasma display panel(PDP). In this paper, the effects of the addressing time was decreased with decreasing thickness of dielectric layer on the front glass and thickness of white dielectric layer on the rear glass. the decreasing rate were 160ns/10$\mu\textrm{m}$ and 270ns/10$\mu\textrm{m}$, respectively Also in case of decreasing the height of barrier rib, addressing time was decreased at the rate of Sons/10$\mu\textrm{m}$.

• Journal of Power Electronics
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• v.6 no.3
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• pp.205-213
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• 2006

A cost-effective magnetic-coupled AC-PDP sustain driver with low switching loss is proposed. The transformer reduces current stress in the energy recovery switches which affects circuit cost and reliability. The turns-ratio can be used to adjust the sustain pulse slopes which affect gas discharge uniformity. Dividing the recovery paths prevents abrupt changes in the output capacitance and thereby switching losses of the recovery switches is reduced. In addition, the proposed circuit has a more simple structure because it does not use the recovery path diodes which also afford a large recovery current. By reducing the current stress and device count in the energy recovery circuit, the proposed driver may have decreased circuit cost and improved circuit reliability.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1864-1865
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• 2007

In this paper, we proposed pre-filter algorithms which using frequency domain analysis method, for the detections of defects in large-sized Thin Film Transistor-Liquid Crystal Display(TFT-LCD) panel surfaces. We performed frequency analysis with 1-D, 2-D FFT methods for extract periodic patterns of lattice structures in TFT-LCDs. To remove this patterns, band-stop filters were used for eliminating specific frequency components. In order to acquire only defected images, we used 2-D inverse FFT methods which can be reverts images that remains defects.

• Journal of the Korean Vacuum Society
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• v.15 no.3
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• pp.241-245
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• 2006

In this study, the characteristics of large area internal linear ICP sources of 1020mm X 920mm(substrate area is 880 X 660mm) were investigated using two different types of antenna, that is, a conventional serpentine-type antenna and a newly developed multiple U-type antenna. The multiple antenna showed a higher plasma density, a higher radical density, and more plasma stability compared to the serpentine-type antenna, and it appeared from the higher inductively coupling and less standing wave effect compared to the serpentine-type antenna. Using the multiple U-type antenna, the plasma density of $2\times10^{11}/cm^3$ with the plasma uniformity of 4% could be obtained using 15mTorr Ar and 5000W of RF power.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.2 s.179
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• pp.43-50
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• 2006

Recently, with rapid development of semiconductor and flat panel display, the manufacturing equipments are required to have large travel range, high productivity, and high accuracy. In this paper, an ultra precision decoupled dual servo (DDS) system is proposed to meet these requirements. And a control scheme for the DDS is studied. The proposed DDS consists of a $XY{\Theta}$ fine stage for handling work-pieces precisely and a XY coarse stage for large travel range. The fine stage consists of four voice coil motors (VCM) and air bearing guides. The coarse stage consists of linear motors and air bearing guides. The DDS is mechanically decoupled between coarse stage and fine stage. Therefore, both stages must be controlled independently and the performance of the DDS is mainly determined by the fine stage. For high performance tracking, the controller of fine stage consists of time delay control (TDC) and perturbation observer while the controller of coarse stage is TDC alone. With these individual controllers, two kinds of dual-servo control strategies are suggested: master-slave type and parallel type. By simulations and experiments, the performances of two dual-servo control strategies are compared.