• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.04a
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• pp.19-22
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• 2009

It is essential to predict the deformed roll profile for the prediction of the strip profile in rolling process. The work roll of the Sendzimir mill has a small diameter in comparison to a barrel length, so that it is well deformed by the rolling pressure. Also it has a complex roll system, so it is difficult to analyze the roll deflection. In this paper, 3D finite element method is used for the analysis of the roll deflection of the Sendzimir due to the contact between rolls. But it takes much time to get the results, so that the on-line model to evaluate the radial deformation of a roll is developed on the basis of the finite element method.

• Transactions of Materials Processing
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• v.18 no.2
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• pp.107-111
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• 2009

Temperature variation happens in micro prism roll mold processing system during machining the prism pattern roll mold using manufacturing optical films of LCD (liquid crystal display). This temperature variation induces pitch errors of the prism patterns. The temperature variation displaces the positions of the diamond cutting tool on the roll which was coated by the copper. In order to prevent the pitch errors, the stabilizing the temperature of machining environment is needed. Therefore, the researching on the temperature variation of the ultra-precision roll mold processing system on the machining of micro prism rot 1 mold is needed. In this paper, the temperature variation of micro prism roll mold processing system is researched, the influence is analyzed, and the study for reducing the pitch errors carried out.

• Journal of Power System Engineering
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• v.1 no.1
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• pp.154-161
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• 1997

Because of the complexity of the flower design of roll forming process, in which the flat strip is progressively deformed by successive sets of profiled rolls, a computer-aided design system for the flower design has been developed. It is programmed in AutoLISP and DCL(Dialogue Control Language) of AutoCAD. It has been found that the system is helpful in saving the time and effort required to design the flower of the product to be roll-formed.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1255-1258
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• 2008

Roll to roll (R2R) system, known as 'web processing', is the process of producing these electronic devices on a roll of flexible plastic. With the need of improved performance and productivity in R2R industry, effective control and on-line supervision for web quality is essential. In this report, we present a system for on-line measurement of wrinkles, one of defects incurring due to compressive stresses developed in the web. This system is able to capture an image generated when a well defined line shape laser beam passes through a transparent web. The system calculates 3D shape information, including the height of the wrinkle on the web, and displays the images for the shape information of the web in real time. By using area scan camera and machine vision laser, this system takes more advantages of setting up as a simple and low cost system compared to the line scan camera systems that widely used in web manufacturing. Specific calibration method and analysis on the achievable accuracy will be discussed.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.10
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• pp.65-73
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• 2009

For mass production of printed electronics in roll-to-roll fashion, precision tension control is important to reduce register errors. Register error should be minimized within several to tens of microns for many electronic devices to be manufactured through printing technology. In order to achieve this goal, tension disturbance must be attenuated before printing process within a certain range. In this paper, a certain tension range which allows maintaining register error within 10 micron was defined with specific operating conditions. A LQG controller was proposed instead of the conventional PI controller for precision tension control using a multivariable feedback. A guideline to determine design parameters for calculating LQ gain was proposed. The proposed LQG controller was compared to both PI controller and LQ regulator with white noise by numerical simulations. Results showed that the proposed LQG controller was effective for attenuating tension disturbance with white noise.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.8
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• pp.653-658
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• 2014

Roll-to-Roll printing process has become a great issue as a breakthrough for low cost and mass production of electronic devices such as organic thin film transistor, and etc. To print the electronic devices, multi-layer printing is essential, and high precision register control is required for this process. Unlike stop-and-repeat printing process, it is impossible to control the register in a static state since the roll-to-roll process is a continuous system. Therefore, the behavior of web such as polyethylene terephthalate (PET) and polyimide (PI) by the tensile and thermal stress generated in the roll-to-roll process as well as motor control of driven rolls has to be considered for a high precision register control. In this study, the correlation between curing temperature and thermal deformation of PET web is analyzed. Finally, it is verified experimentally that the temperature disturbance generates the more serious register error under the higher curing temperature.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.4
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• pp.327-332
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• 2010

We report on the effect of PET substrate preheating on the characteristics of the flexible and transparent indium tin oxide (ITO) electrode grown by a specially designed roll-to-roll sputtering system for touch panel applications. It was found that electrical and optical properties of the roll-to-roll sputter grown ITO film were critically dependent on the preheating of the PET substrate. In addition, the roll-to-roll sputter-grown ITO film after post annealing test at $140^{\circ}C$ for 90 min showed stable electrical and optical properties. The low sheet resistance and high optical transmittance of the ITO film grown on the preheated PET substrate demonstrate that the preheating process before ITO sputtering is one of the effective way to improve the characteristics of ITO/PET film. Furthermore, the superior flexibility of the ITO electrode grown on the preheated PET substrate indicates that the preheating treatment is a promising technique to obtain robust ITO/PET sample for touch panel applications.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.489-490
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.593-594
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• 2010

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.76.1-76.1
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• 2007