• Korean Journal of Optics and Photonics
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• v.3 no.3
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• pp.143-147
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• 1992

1)iscussed in this paper are the effects of phase modulation on the line spread functions (LSF) and MTFs of ;I binocular objective system. The binocular objective lens is made in Korea. It has rotationally symmetric aberrations. The LSFs and MTFs are measured experimentally. The phase modulation is carried out by applying phase retardation $\pi$ on the aperture. The area where the phase is not retarded presents a double annular type. The OTF curves of phase modulated aperture are compared with that of unmodulated aperture. The comparison shows that there is the aberration compensation effect in aberration loaded system. Therefore the performance of many optical system can be improved without any loss of light energy by properly modulating the phase on the aperture.

• Proceedings of the Optical Society of Korea Conference
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• 2006.02a
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• pp.113-114
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• 2006

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.96-100
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• 2007

Condenser lens and objective lens are used to demagnify the image of the crossover to the final spot size. In lens, electrons are focused by magnetic fields. This fields is fringing field. It is important in electron focusing. Electron focusing occurs the radial component field and axial component field. Radial component produces rotational force and axial component produces radial force. Radial force causes the electron's trajectory to curve toward the optic axis and corss it. Focal length decreases as the current of lens increases. In this paper, we use the focal length for desiging the hardware of lens current control and present the results.

• Korean Journal of Optics and Photonics
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• v.12 no.6
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• pp.460-462
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• 2001

We have analyzed the characteristics of IR lens mounting with elastomer and applied the results to the mounting of a silicon lens with diameter 117 mm which is the objective of a thermal imaging system. The elastomer, the 577 primerless silicone adhesive (Dow Corning Co.) which is heat cure type, and the mount material, A16061 are used for our analysis. Theoretical analysis gives the result that the space between lens and mount is required to be more than 250 ${\mu}{\textrm}{m}$ under the operational temperature conditions of -40~+6$0^{\circ}C$.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.509-517
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• 2013

Purpose: The purpose of this study is developing the 2.6 ${\times}$ optical scope with a Abbe-K$\ddot{o}$nig prism. Methods: First, considering the size of the effective aperture and the focal length of the objective lens, we designed an Abbe-K$\ddot{o}$nig prism. Next, we calculated the optical and geometric distances of Abbe-K$\ddot{o}$nig prism designed in this way. After allocating the focal length of the objective lens and the eyepiece lens so as to satisfy the magnification and optical effective distance of the entire system by using this calculation result, we completed the entire system by optimizing this optical system. Results: We were able to complete the optical scope of about 2.6 ${\times}$ magnification by designing an objective lens with a focal length of 63.13 mm which was composed of two pieces, an eyepiece with a focal length of 24.3 mm which was composed of four pieces, and an Abbe-K$\ddot{o}$nig prism with a face length 11.5 mm. Conclusions: We designed and fabricated an optical scope with 2.6 ${\times}$ magnification employing an Abbe-K$\ddot{o}$nig prism. Then, this system became the compacted optical system with a barrel diameter of 31 mm, characterized by an effective aperture of 12.0 mm and an effective optical barrel length of 103 mm and a resolution of 200 cycles/rad at 50% MTF criterion within the half viewing field angle of $6.42^{\circ}$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.427-428
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• 2008

• Proceedings of the Optical Society of Korea Conference
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• 2004.07a
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• pp.84-85
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• 2004

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.284-285
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• 2009

• The Science & Technology
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• v.29 no.11 s.330
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• pp.84-85
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• 1996

세계 최초로 1.5m 근거리 물체를 선명하게 관측할 수 있는 근거리관측 겸용 망원경을 개발한 한국 OTC는 특허 출원을 끝내고 세계시장을 무대로한 수출준비에 바쁘다. 대물렌즈를 루비코팅해 눈에 해로운 자외선과 적외선을 차단시키는 기능까지 갖추고 가격도 기존제품의 절반 값으로 공급하고 있어 선풍적 인기를 끌고 있다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.164-167
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• 2006

Micro lens especially for optical pick up(Blu-ray) lens module is one of the key products for IT technology. Specific attention has been given to manufacturing of large radius lens but little to small radius less than 2mm diameter with N.A>0.8. This paper deals with a high precision glass molding technology for mass production of Blu-ray pick up lens. Ultra precisely machined tungsten carbide core and glass molding equipments are utilized for forming process. Evaluation was performed in terms of profile accuracy, surface roughness and thickness of fabricated glass lens.