• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.3
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• pp.52-57
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• 2003

In this paper, stability of ultra precision cutting unit is analyzed and this unit is the kernel unit in ultra precision processing machine. According to alteration of shape and material about hinge, stability investigation is performed Through this stability investigation, trial and error is reduced in design and manufacture, at the same time, we are accumulated foundation data for unit control.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.5 no.1
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• pp.39-44
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• 2006

Ultra precision positioning mechanism has been widely used on semiconductor manufacturing equipments, optical spectrum analyzers and cell manipulations. Ultra precision positioning mechanism consists of several actuators, sensors, guides and control systems. Its efficiency depends on each performance of components. The object of this study is to design and analyze the micro stage that is one of the equipments embodied in ultra precision positioning mechanism. The micro stage consists of PZT actuators and flexure hinges. The structural design of flexure hinge is optimized by using RSM and FEM. The control factors concerned with the design of flexure hinges of stage and arms are optimized by minimizing the equivalent stress on the hinge and maximizing 1st natural frequency based on RSM and FEM simulation under various kinds of design conditions.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.4
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• pp.71-75
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• 2007

Geometrical error of ultra-precision machining due to spherical tool alignment error is analyzed. Deviation of spherical edge, ranged several ten micrometers, generates vertical and horizontal error of tool path and affects profile accuracy of machined surface. Simulation of machined error shows effect of tool alignment error and enables to estimate alignment error. This work provides technical insights into the minimizing of geometrical error of ultra-precision machining.

• Journal of the Optical Society of Korea
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• v.13 no.2
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• pp.213-217
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• 2009

The transcription characteristics of the mold surface in the molding of aspherical glass lenses for camera phone modules have been investigated experimentally. The surface topographies of both the form and the roughness were compared between the mold and the molded lens. For the form topography, the molded lens showed a transcription ratio of 93.4% against the mold, which is obtained by comparing the form error (PV) values of the mold and the molded lens. The transcription characteristics of the roughness topography were ascertained by bearing ratio analysis.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.591-596
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• 2000

The needs of ultra precision machined parts is increase every days. But the experimental data of nonferrous metal is insufficient. The cutting behavior in micro cutting area is different from that of traditional cutting because of the size effect. Al6061 is widely used as optical parts such as LASER reflector's mirror or multimedia instrument. Al6061 opper is machined by ultra precision machine with natural diamond tool. From the experiment and discussion on the cutting force and worked surface roughness as the variable spindle speed, feed rate and depth of cut. As a result, the cutting force increases as the increasing depth of cut, but the worked surface roughness does not increase so much. The surface roughness is good when spindle sped is above 1200rpm, and feed rate is small. The influence of depth of cut is very small.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.5
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• pp.40-45
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• 2003

Optical and electronic industries are using lapping and polishing processing as a final finish rather than grinding, because they need more accurate parts of brittles non-metallic materials such as single crystals. Sapphire has been ground by the ultra-precision surface grinder having a glass -ceramic spindle of extremely-low thermal expansion with various cup-type resinoid-bonded diamond wheels of #400-#3000 in grain size. Sapphire can be ground in the ductile mode. And also, the surface roughness and grinding conditions has been clarified. The smooth surface of Sapphire less than 1nm RMS, 1nm Ra can be obtained by the ultra-precision grinding without any polishing process.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.18 no.1
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• pp.76-82
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• 2009

To obtain the surface roughness with nano order, we need a ultra-precision machine, cutting condition, and materials. In this paper, the cutting condition for getting nano order smooth surface of core have been examined experimentally by the ultra-precision machine and diamond wheels. The effects of the cutting velocity, the feed rate and depth of cut on the surface roughness were studied. And also, the surface roughness was measured by the Form Talysurf series PGI 840. The champion data of developed core was surface roughness Rmax 24.6nm, figure accuracy Rmax 68.9nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.441-441
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• 2007

As Rhenium-Iridium{Re-Ir) coating possesses such features as, high hardness, high elasticity, abrasion resistance and chemical stability, there have been exerted continuous efforts in research works in a variety of fields, and this technology has also been applied widely to industrial areas. In this research, the optimal grinding condition was identified using Microlens Process Machine in order to contribute to the development of aspheric glass lens for mobile phone module having 3 mega pixel and 2.5X zoom, and molding core(WC) was manufactured having performed ultra-precision machining. Effects of Re-Ir coating on form accuracy (P-V) of molding core and surface roughness(Ra) were measured and evaluated.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.73-74
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.317-318
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• 2007