• Proceedings of the Optical Society of Korea Conference
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• 2007.07a
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• pp.205-206
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.463-464
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• 2009

• Journal of the Korean Society for Precision Engineering
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• v.27 no.5
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• pp.22-26
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• 2010

Recently, due to the tremendous growth of media technology, demands of the aspheric glass lens which is a high-performance and miniaturized increase gradually. Generally, the aspheric glass lens is manufactured by Glass Molding Press (GMP) method using tungsten carbide (WC) mold core. In this study, the thermal deformation which was occurred by GMP process was analyzed and applied it to compensate the aspheric glass lens. The compensated lens was satisfied that can be applied to the actual specifications.

• The Optical Journal
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• s.141
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• pp.18-20
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• 2012

"내일 지구가 멸망하더라도 나는 오늘 한 그루의 사과나무를 심겠다" 17세기 네델란드 태생의 철학자인 바뤼흐 스피노자가 이렇게 말했다고 한다. 그는 유럽의 대표적인 합리주의 철학자로 인정받으며 '에티카'를 통해 서양철학계에 커다란 화두를 던지기도 했다. 하지만 스피노자의 직업은 잘 알려져 있지 않았다. 그의 직업은 좀 색다르다. 그는 당시로는 파격적인 사상을 지닌 덕에 유대사회에서 추방됐고 카톨릭은 그의 모든 서적을 금서로 지정했다. 결국 스피노자는 렌즈를 가공하는 일로 생계를 유지하게 된다. 현대적 관점에서 보면 직가공에 의한 구면렌즈 가공이 이미 17세기 이전에 일반화된 것이다. 현대의 광학계 가공은 스피노자의 시대와는 비교할 수 없을 만큼의 다양한 기술적 발전에 힘입어 고정밀화, 비구면화, 양산화의 방향으로 진행되고 있다. 특히 성형 방식에 의한 비구면 렌즈 제조는 관련 분야의 핵심 기술이 되고 있으며 최근에는 적외선 렌즈에도 적용되고 있다.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.5
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• pp.82-88
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• 2008

Conventional aspherical lens polishing methods by the small tool polishing use aspherical profile and the trajectory of the polishing tool is also controlled. In this paper, new full contact polishing mechanism is suggested to polish aspherical glass lens mold by both airbag polishing tool and eccentric motion. Full contact concept by airbag polishing tool and no position control make the easy polishing setup and do not need aspherical design profile. An aspherical lens polishing machine was made for this study and a verification experiment was performed for surface roughness improvements.

• The Optical Journal
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• s.101
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• pp.31-38
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• 2006

디지털카메라, 카메라폰, DVD 픽업 등의 수요가 증가하고 있고, 유리 성형 기술의 자동화가 진보하고 있기 때문에 유리 성형 프로세스의 동아시아 이전·전개가 진행되고 있다. 최근 동아시아에서도 단순한 축대칭비구면의 성형틀은 정밀가공이 가능해져, 더욱 부가가치가 높은 광학부품을 생산해내기 위해, 복잡형상 세라믹틀의 연삭가공기술의 개발이 반드시 필요하다. 그래서 본고에서는 마이크로 복잡형상 광학부품 성형틀의 초정밀 미세가공기술의 일부를 소개하겠다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.217-218
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• 2010

• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.11-18
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• 2003

• Journal of the Korean Society for Precision Engineering
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• v.27 no.12
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• pp.28-32
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• 2010

Technical demands for aspheric glass lens formed in market increases its application from simple camera lens module to fiber optics connection module in optical engineering. WC is often used as a metal core of the aspheric glass lens, but the long life time is issued because it fabricated in high temperature and high pressure environment. High hard thin film coating of lens core increases the core life time critically. Diamond Like Carbon(DLC) thin film coating shows very high hardness and low surface roughness, i.e. low friction between a glass lens and a metal core, and thus draw interests from an optical manufacturing industry. In addition, DLC thin film coating can removed by etching process and deposit the film again, which makes the core renewable. In this study, DLC films were deposited on the SiC ceramic core. The process variable in FVA(Filtered Vacuum Arc) method was the substrate bias-voltage. Deposited thin film was evaluated by raman spectroscopy, AFM and nano indenter and measured its crystal structure, surface roughness, and hardness. After applying optimum thin film condition, the life time and crystal structure transition of DLC thin film was monitored.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.11
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• pp.893-898
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• 2016

Plastic array lens are cheap to manufacture; however, plastic is not resistant to high temperatures and moisture. Optical glass represents a better solution but is a more-expensive alternative. Glass array lens can be produced using lithography or precision-molding techniques. The lithography process is commonly used, for instance, in the semiconductor industry; however, the manufacturing costs are high, the processing time is quite long, and spherical aberration is a problem. To obtain high-order aspherical shapes, mold-core manufacturing is conducted through ultra-precision grinding machining. In this paper, a $4{\times}1$ mold core was manufactured using an ultra-precision machine with a jig for the injection molding of an aspherical array lens. The machined mold core was measured using the Form TalySurf PGI 2+ contact-stylus profilometer. The measurement data of the mold core are suitable for the design criterion of below 0.5 um.