• Journal of Satellite, Information and Communications
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• v.10 no.3
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• pp.48-52
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• 2015

In this paper, we develops a domestic and foreign first reinforced cover glass grinding process for large surface TPS and resolves a problem of conventional cover glass grinding process through a research. Also, it is developed in priority to improve a productivity and processing quality emphasis. The development process develops a total process technology through a production and operation of demonstration unit. so, in this paper, we secured cover glass grinding process technology, image processing technology, mechanisms and control algorithms.

• International Journal of Precision Engineering and Manufacturing
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• v.1 no.2
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• pp.61-66
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• 2000

In this paper, we discuss the machining characteristics of HDD glass. Glass is now being used globally as a data storage device, Such glasses are usually machined by lapping by this technique requires a long machining time, resulting in low productivity, For this reason, we examine the possibility of EILD grinding in HDD glass workpieces, A move to ELID grinding may result in substantial cost reduction. Our purpose is to investigate the grinding characteristics of HDD glass in ELID grinding. The bonding materials for fixing the abrasives of cast iron, cobalt and bronze are applied, and grinding conditions such as rotation speed and feeding are varied. Results show that with the use of ELID, mirror surfaces can be achieved with high efficiency.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.6
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• pp.440-444
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• 2016

Owing to the introduction of various IT devices with emphasis on portability and design, the TFT (thin film transistor liquid crystal display) panel applied to IT devices has the same shape as the product, and the portability requirement of IT devices has resulted in a need for panels with higher rigidity. In this study, the effect of grinding conditions such as the feed rate and edge speed of edge grinding on the surface roughness and chipping of the machined surface is investigated using a metal bond wheel. During edge grinding of alkari-free glass, weak mechanical property of glass results in big chipping owing to generation of tensile stress at the end of grining operation. The results of this study show that the grinding characteristics of alkali-free glass are obtained and meet industry requirements.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.2
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• pp.161-168
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• 2000

In this paper, machining characteristics of glass for HDD media are researched. Nowadays HDD media are used globally as a data storage device. In generally, it is machined by the lapping. But the lapping process time is long and the productivity is low. In this reason, 1 examined the possibility of ELID grinding of glass fur HDD media. If the machining process of HDD media can be changed to ELID grinding, a product cost will be largely saved. The machines used in this experiment were a special rotary type grinder and a normal rotary grinder. The one has an air bearing spindle, the other has not. Experimental results show the possibility of highly efficient grinding and mirror surface can be achieved by the ELID grinding.

• Design & Manufacturing
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• v.16 no.1
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• pp.50-54
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• 2022

Coverglass of electronic equipments is thinner and slimmer, so the glass must have good bending strength. In these days, the polishing edge of glass is used by solid tool like grinding wheel. But solid tool leave micro crack or edge chipping in edge of glass. MR polishing is an optimal method by polishing edge of glass. MR polishing is used MR fluid that is a liquid tool. MR polishing doesn't leave tool path or residual stress, micro crack and edge chipping unlike grinding wheel polishing. In this paper, the results of grinding and MR polishing were compared and analyzed to improve bending strength by minimizing edge chipping of cover glass. It was derived that the depth and size of cracks have a significant influence on the bending strength of the glass edge. The edges of the glass using MR grinding were analyzed to have a better surface and higher bending strength than the glass using abrasive wheel grinding. It was confirmed that MR polishing had an effect on strength improvement by effectively removing cracks in the specimen.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.9
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• pp.165-170
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• 2001

In normal grinding abrasive particles of a grinding wheel rotate on planes parallel to the direction of workpiece fred. which may induce continued scratch lines on ground surface as the workpiece feeds. Instead in helical scan grinding the planes make an angle, called a helical angle, with the feeding direction. Thus scratch lines produced by abrasive particles per one revolution are discontinued which implies that the generation of scratch lines are suppressed by the helical scan grinding. In this study some experimental works have been done on the helical scan grinding of glass to find the effects of grinding conditions on the surface roughness and estimate the optimal grinding conditions. The helical angle, fred rate, material removal rate and the wheel speed are taken as factors for three kinds of grinding wheels i.e., coarse(#140 mesh), medium(#400) and fine(#800) diamond wheels. The experiments are scheduled by Taguchi technique and ANOVA has been carried out for the interpretation of the results. As a result of this study effects of the factors are verified quantitatively showing that the major factors are changed according to the wheel's mesh size and the helical angle is one of the influencing factors on the surface quality.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.94-97
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• 2003

A precise fabrication technology of glass is increasingly demanded fer the latest Industrial applications of spherical lenses. micro-optical components, laser applications and so on. Most of cases, the surface roughness of glass is required to be minute for improving the optical characteristics. Then. the machining characteristics of SF-5 glass and quarts glass were studied by using the ELID grinding process to get mirror surface and productivity compared with a general lapping process. A rotary type grinder with ELID generator was used to make the mirror surface of glass and a Mitutoyo surface tester and a nano-hardness tester were also used to measure the grinded surface or glass. As the results of experiments. they showed that the surface roughness(Ra) of SF-5 glass was under 7.8 nm and that of quartz glass was under 3.0 nm using the # 8000 grinder. So, the possibility of highly efficient and accurate surface for optical components can be achieved by the ELID grinding process.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.7
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• pp.56-62
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• 2003

The precision fabrication of glass is increasingly demanded for the latest industrial applications of spherical lenses, micro-optical components, and so on. In many cases, the surface roughness of glass is required to be minute for improving the optical characteristics. In this paper, machining characteristics of SF-5 glass and quarts glass are studied by using the ELID grinding process to get mirror surface and productivity compared with a general lapping process. A rotary type grinder with air spindle was used for the experiments. Mitutoyo surface tester and AFM were also used to measure the grinded surface of glass. As the results of experiments, they showed that the surface roughness (Ra) of SF-5 glass was under 7.8 nm and that of quartz glass was under 3.0 m using the # 8000 grinder. So, the possibility of highly efficient and accurate surface for optical components can be achieved by the ELID grinding process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.57-60
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• 2002

The high precision spindle is essential fer mass and low cost production of aspherical glass lens. Especially, in the grinding process of micro glass lens the performance of the spindle determine the machined surface quality. For the aspheric micro glass lens grinding, we design and make a high precision spindle. We use air bearings for high speed and low motion errors of the spindle. And the driving mechanism is an air turbine to remove heat generation. In this study, we make basic performance requirements of the spindle through benchmarking. And we confirm the requirements by basic machining test. We test air consumption, static stiffness, run-out and vibration of the spindle.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.1
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• pp.85-89
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• 2012

Conventional grinding of BK7 glass will normally result in brittle fracture at the surface, generating severe sub-surface damage and poor surface finish. The precision grinding of BK7 glass in parallel grinding modes has been investigated. Grinding process, maximum chip thickness, ductile/brittle regime, surface roughness and sub-surface damage have been addressed. Special attention has been given to the condition for generating a ductile mode response on the ground surface. Experiments reveal that the level of surface roughness and depth of sub-surface damage vary differently for different condition. This study gives an indication of the strategy to follow to achieve high quality ground surfaces on brittle materials.