• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.939-942
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• 2000

Single point diamond turning technique for optical crystals is reported in this paper. The main factors influencing the machined surface quality are discovered and regularities of machining process are drawn. Optical crystals have found more and more important applications in the field of modern optics. Optical crystals are mostly brittle materials of poor machinability. The traditional machining method is polishing which has many shortcomings such as low production efficiency, poor ability to be automatically controlled and edge effect of the workpiece. The purpose of our research is to find the optimum machining conditions for ductile cutting of optical crystals and apply the SPDT technique to the manufacturing of ultra precision optical components of brittle material.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.444-447
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• 2005

This paper is described about the technique of ultra-precision machining for a infrared camera aspheric mirror. A 200 mm diameter aspheric mirror was fabricated by SPDTM. Aluminum alloy as mirror substrates is known to be easily machined, but not polishable due to its ductility. Aspheric large reflector without a polishing process, the surface roughness of 5 nm Ra, and the form error of $\lambda/2\;(\lambda=632.8 nm)$ for reference curved surface 200 mm has been required. The purpose of this research is to find the optimum machining conditions for cutting reflector using A16061-T651 and apply the SPDTM technique to the manufacturing of ultra precision optical components of Al-alloy aspheric reflector.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1566-1570
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• 2005

The aspherical lenses are used as optical lens of HMD optical system. The optimum cutting condition of PMMA lens sample with ultra precision SPDT, the diamond tool nose radius, the cutting speed, the feed rate, the depth of cut, and cutting fluid type are found. The demanded surface roughness 10 nm Ra, aspherical form error $1.0\;\mu{m}$ P-V for aspherical lens of optical data storage device are satisfied.

• 한국기계가공학회지
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• 제2권1호
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• pp.63-68
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• 2003

The aspherical lenses are used as objective lens of optical pickup. To examine the design factor the sample product is made before manufacturing of injection mould of lens. The optimum cutting condition of PMMA lens sample with ultra precision SPDT, the roam spindle speed, the depth of cut, the feedrate are found. The demanded surface roughness 100m Ra, aspherical form error $0.5{\mu}m$ P-V for aspherical lens of optical data storage device are satisfied.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.1125-1128
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• 2001

A 110mm diameter aspheric metal secondary mirror for a test model of an earth observation satellite camera was fabricated by ultra-precision single point diamond turning(SPDT). Aluminum alloy for mirror substrates is known to be easily machinable, but not polishable due to its ductility. A harder material, Ni, is usually electrolessly coated on an Al substrate to increase the surface hardness for optical polishing. Aspheric metal secondary mirror without a conventional polishing process, the surface roughness of Ra=10nm, and the form error of Ra=λ/12(λ=632nm) has been required. The purpose of this research is to find the optimum machining conditions for reflector cutting of electroless-Ni coated Al alloy and apply the SPDT technique to the manufacturing of ultra precision optical components of metal aspheric reflector.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.891-894
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• 1997

The asphericals lenses are used as objective lens of optical pickup. To examine the design factor the sample product is made before manufacturing of injection mould of lens. The optimum cutting condition of PMMA lens sample with ultra precision SPDT, he main spindle sped, the depth of cut, the feedrate are found. The demanded surface roughness 10nm Ra, aspherical form error 0.5${\mu}{\textrm}{m}$ P-V for aspherical lens of optical data storage device are satisfied.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.529-532
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• 2003

Machining technique for optical crystals with single point diamond turning tool is reported in this paper. The main factors influencing the machined surface quality are discovered and regularities of machining process are drawn. Optical crystals have found more and more important applications in the field of modern optics. Optical crystals are mostly brittle materials of poor machinability. The traditional machining method is polishing which has many shortcomings such as low production efficiency. poor ability to be automatically controlled and edge effect of the workpiece. The purpose of our research is to find the optimum machining conditions for ductile cutting of optical crystals and apply the SPDT technique to the manufacturing of ultra precision optical components of brittle materials. As a result. the surface roughness is good when spindle speed is 200m/min. and teed rate is small. The influence of depth of cut is very small.

• 한국기계가공학회지
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• 제4권1호
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• pp.43-48
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• 2005

This paper is described about the technique of ultra-precision machining for an aerospace aspheric mirror. The reflection mirror system generates parallel beams inside a thermal vacuum chamber. A 200mm diameter aspheric mirror was fabricated by SPDTM. Aluminum alloy as mirror substrates is known to be easily machined, but not polishable due to its ductility. Aspheric large reflector without a polishing process, the surface roughness of 10nm Ra, and the form error of ${\lambda}/2$ (${\lambda}$=632.8nm) for reference curved surface 200mm has been required. The purpose of this research is to find the optimum machining conditions for cutting reflector using Al6061-T651 and apply the SPDTM technique to the manufacturing of ultra precision optical components of Al-alloy aspheric reflector.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.83-87
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• 2001

A 110 mm diameter aspheric metal secondary mirror for a test model of an earth observation satellite camera was fabricated by ultra-precision single point diamond turning (SPDT). Aluminum alloy for mirror substrates is known to be easily machinable, but not polishable due to its ductility. A harder material, Ni, is usually electrolessly coated on an Al substrate to increase the surface hardness for optical polishing. Aspheric metal secondary mirror without a conventional polishing process, the surface roughness of Ra=10nm, and the form error of $Ra={\lambda}/12({\lambda}=632nm)$ has been required. The purpose of this research is to find the optimum machining conditions for reflector cutting of electroless-Ni coated Al alloy and apply the SPDT technique to the manufacturing of ultra precision optical components of metal aspheric reflector.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.414-417
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• 2005

Single point diamond turning technique for optical crystals is studied in this paper. The main factors which are influential the machined surface quality are discovered and regularities of machining process are drawn. Optical crystals have found more and more important applications in the field of modern optics. Optical crystals are mostly brittle materials of poor machinability. The traditional machining method is polishing which has many shortcomings such as low production efficiency, poor ability to be automatically controlled and edge effect of the workpiece. The purpose of our research is to find the optimal machining conditions for ductile cutting of optical crystals and to apply the SPDT technique to the manufacturing of ultra precision optical components of brittle material(Ge). Many technical challenges are being tried for the large space infrared telescope, which is one of the major objectives of the National Strategic Technology Road Map (NSTRM).