• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.97-100
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• 2004

In recent years, a demand for micro-structure machining is increasing by the development of information and optics industries. Micro machining technology is in general well known in the field of lithograghy. However, the requirement of producing micro machine and/or micro mechanism with metal materials will be increased since a variety of workpiece configurations can be easily made. In this paper, ultra precision machine is developed to obtain micro groove and mirror surface using single crystal diamond tool. According to the cutting experiment, no burr was found at the edge of V-grooves, and the surface roughness of copper is about 1～3nm Ra. It is verified that ultra precision machine is effective to high precision machining.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.93-95
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• 2003

We have designed and fabricated a micromirror array using single crystalline silicon (SCS) for data communication applications. The mirror array has $16{\times}16$ micromirrors and each mirror has $120{\mu}m{\times}100{\mu}m$ reflective surface. Electrostatic force was adopted as a driving mechanism. The spring dimensions were determined using relationship between spring dimensions and driving voltage. The designed tilting angle was $9.6^{\circ}$, and measured tilting angle according to applied voltages were experimented. The response time was measured using He-Ne laser and position sensitive diode (PSD), and lifetime was checked for reliability proof.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.24-28
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• 1996

Mirror-like polishing system of hemisphericall high-speed precision bearing for digital VTR drum was developed. Mechamism of the polishing process was analyzed in the view point of polishing contact range and contact length between the tool and the workpiece surface. It was suggested that the two stage polishing process adoptiong the diamond grinding wheel and polishing tool instead of multistage lapping processes, which enables the mass production of the bearing by reduction of polishing time.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.6
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• pp.16-25
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• 1999

In recent years, grinding techniques for precision machining of brittle materials used in die, model and optical parts have been improved by using superfine abrasive wheel and precision grinding machine. The completion of optimum dressing of superfine abrasive wheel makes possible the effective precision grinding of die steel(STD-11). In this study, a new system and the grinding mechanism of optimum in-process electrolytic dressing were proposed. This method can carry out optimum in-process electrolytic dressing of superfine abrasive wheel. Therefore, the optimum in-process electrolytic dressing is a good method to obtain the efficiency and mirror-like grinding of STD-11.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.208.2-208.2
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• 2012

The Slewing Mirror Telescope (SMT) is a key telescope of Ultra-Fast Flash Observatory (UFFO) space project to explore the first sub-minute or sub-seconds early photons from the Gamma Ray Bursts (GRBs) afterglows. The first realization of UFFO is the 20kg UFFO-Pathfinder (UFFO-P) to be launched on board the Russian Lomonosov satellite in 2013 by the Soyuz-2 rocket. Once the UFFO Burst Alert & Trigger Telescope (UBAT) detects the GRBs, Slewing mirror (SM) will rotate to bring the GRB into the SMT's field of view instead of slewing the entire spacecraft. SMT can image the UV/Optical counterpart with about 4-arcsec accuracy. However it will provide a important understanding of the GRB mechanism by measuring the sub-minute optical photons from GRBs. SMT can respond to the trigger over $35^{\circ}{\times}35^{\circ}$ wide field of view within 1 sec by using Slewing Mirror Stage (SMS). SMT has 10-cm Ritchey-Chretien telescope and $256{\times}256$ pixilated Intensified Charge-Coupled Device (ICCD) on focal plane. In this paper, we discuss the overall design of UFFO-P SMT instrument and payloads development status.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.15-16
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• 2012

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.171-173
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• 1991

the poly silicon film was deposited by APCVD. and then the deposition mechanism and electrical characteristics was investigated for that film. The grain phase, the deposition rate, and the etch characteristics were evaluated according to the deposition conditions. The criteria temperature of surface morphology state was $730^{\circ}C {\sim}780^{\circ}C$ between the mirror phase grain and the powder phase grain.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.04a
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• pp.96-101
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• 1997

In recent years, grinding techniques for precision machining of brittle materials used in electric, optical and magnetic parts have been improved by using superabrasive wheel and precision grinding machine. The present dressing system cannot have controll of optimum dressing of the superabrasive wheel. In this study, a new system and the grinding mechanism of optimum in-process electrolytic dressing were proposed. This system can carry out optimum in-process dressing of superabrasive wheel, and give very effective control according to unstable current and gap increase. Therefore, the optimum in-process electrolytic dressing is a good method to obtain the efficiency and mirror-like grinding of brittle materials.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.3
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• pp.56-61
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• 2003

This paper described about on-machine profile measurement of aspheric surfaces using contact probing technique in ultra precision machine. A contact probe has been designed as a sensing device to obtain measuring resolutions in nanometer regime using a circle leaf spring mechanism and a capacitive-type sensor. The contact probe which is installed on the z-axis is In touch with the aspheric objects which is fixed on the spindle of the diamond turning machine(DTM) during the measuring procedure. The x, z-axis motions of the machine are monitored by a set of two orthogonal plane mirror type laser interferometers. As a results, the developed contact probe on-machine measurement system showed 10 nanometers repeatability with a ${\pm}2{\sigma}$ and uncertainty of 200 nmPv.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.90-93
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• 2003

This paper described about the ultra-precision profile measurement of aspheric surfaces using contact probing technique. A contact probe has been designed as a sensing device to obtain measuring resolutions in nanometer regime utilizing a circle leaf spring mechanism and a capacitive-type sensor. The, contact probe is attached on the z-axis during measurement while aspheric object are supported on the diamond turning machine(DTM). The machine xz-axis motions are monitored by a set of two orthogonal plane mirror type laser interferometers. Experimental results show that the contact probing technique developed of on-machine measurement system in this investigation is capable of providing a repeatability of 10 nanometers with a $\pm$20 uncertainty of 200nmPv.