• Journal of the Korea Convergence Society
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• v.9 no.9
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• pp.183-189
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• 2018

This study deals with the design and development of imaging optics having 24mm focal length for MWIR ($3{\sim}5{\mu}m$) with two symmetrical lenses facing each other. We used CodeV in our optical design, and we performed the optimization process to have the resolution and angle of view satisfying the user's requirements. The materials of lenses were limited to two types, including KCIR035 with a refractive index of 1.7589, developed in Korea. The optical system designed in this way consists of two aspherical lenses made of KCIR035 material having the same shape and one spherical lens made of Si. Here, the arrangement of the two aspherical lenses is characterized by having a symmetrical structure facing each other. And this optical system has a resolution of MTF value of 0.35 or more at a line width of 20 lp / mm. Therefore, it is considered that this optical system has the capability to be applied to a thermal imaging camera using a $206{\times}156$ array MWIR detection device having a pixel size of $25{\mu}m$.

• Journal of Digital Convergence
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• v.11 no.1
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• pp.315-320
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• 2013

We have investigated the variation of spherical aberration of the anterior and posterior surface in a Korean sample population with various age between 20 to 71 years old. We used Pentacam (Oculus Inc., Germany) to measure the corneal radius, asphericity, and spherical aberration of 290 patients with normal cornea. There were negative correlation between corneal anterior radius and spherical aberration(r = -0.22, p<0.0001), and, there were negative correlation between corneal posterior radius and spherical aberration(r=-0.27, p < 0.0001). There were positive correlation between anterior asphericity and spherical aberration(r = 0.24, p < 0.0001), however there were negative correlation between posterior asphericity and spherical aberration(r = -0.17, p=0.00288).The average of anterior spherical aberration and posterior spherical aberration was $0.482{\pm}0.099{\mu}m$ and $-0.098{\pm}0.029{\mu}m$. The average of spherical aberration was $0.385{\pm}0.097{\mu}m$. There were significant positive correlations between anterior spherical aberration and age(r = 0.227, p<0.0001), and there were positive correlations between posterior aberration and age(r = 0.349, p<0.0001). It is considered that this data can be used as basic information for furture studies for improving the quality of vision of modern human and, through the analysis of the spherical aberration of cornea was to provide a better understanding of the optical part of the Korean's eye.

• Korean Journal of Optics and Photonics
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• v.16 no.5
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• pp.440-445
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• 2005

The limitation of measurement accuracy and reliability of autostigmatic null lens system are studied for the cases of using inter-distance of null lenses as the adjustment factor of alignment and fixing the distance by mounting. If we investigate the first case, the wavefront aberration of null lens system is compensated by the adjustment process even though the shape of aspherical surface is not properly fabricated. As the result, it brings about the problem of measurement reliability. However, for the fixing process by mounting null lenses, it doesn't cause the reliability problem because the wavefront aberration of null lens system is not compensated. Further, the fixing process shows nearly same result in measurement accuracy to the adjustment process, that is, $0.0316{\lambda}$ vs. $0.0326{\lambda}$. So, we can conclude the setup for autostigmatic null lens system must be constituted by means of the fixing process. Meanwhile, we introduce and define the alignment aperture on aspheircal mirror, which can be approximated as spherical zone for alignment of null lens system, and besides, we calculate the required fabrication accuracy of the zone for the necessary measurement accuracy.

• Korean Journal of Optics and Photonics
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• v.34 no.4
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• pp.157-169
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• 2023

Augmented reality (AR) using a head mounted display (HMD) is used in various fields such as military, medicine, manufacturing, gaming, and education. In this paper, we discuss the design and fabrication of the AR optical system, which is most essential for HMD. The AR optical system for HMD requires a wide transparent area in which the augmented image of the display and the real world can be viewed at the same time. To this end, an AR optical system was designed and manufactured by dividing it into three parts according to each characteristic. Also, the refractive index of the ultra-violet (UV) adhesive layer required to make the three optical systems into one complete AR optical system was considered from the design stage to minimize the optical path shift phenomenon when the input light source passes through the UV adhesive layer. In addition, when designing the AR optical system, two aspheric surfaces were used to compensate for off-axis aberration and to be suitable for mass production. Finally, for HMD mass production, an aspheric AR optical system with a thickness of 11 mm, a diagonal field of view of 40°, and a weight of 11.3 g was designed and manufactured.

• The Optical Journal
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• s.118
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• pp.25-27
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• 2008

국광학거울을 제작하기 위해서는 가공기술과 초정밀 측정기술이 수반되어야 한다. 국내에서는 100개 이상의 광학렌즈 및 거울 가공업체가 있으나 대부분 직경 1인치 이내의 소형광학계를 주로 생산하고 있고 면 형태 역시 구면이 대부분이다. 최근 휴대폰 카메라 등에 비구면을 사용하고 있지만 대부분 다이아몬드터닝 머신 등을 이용한 정밀급 가공수준이므로 대형 광학거울에 같은 기술을 적용할 수 있다고 보기에는 무리가 따른다. 본 원고에서는 대구경 정밀 광학거울 가공, 평가 및 코팅기술을 설명하고 관련 기술의 전망에 관하여 간단히 언급하고자 한다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.237-237
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• 2004

최근 산업의 급속한 발전과 가공기계의 초정밀화로 인한 초정밀가공품의 수요가 꾸준한 증가를 보이고 있으며, 특히 렌즈 산업에서 초정밀가공기술의 적용이 급속히 증가되고 있는 추세이다. 초정밀가공에서는 공구의 가공물on 대한 상대운동이 그대로 가공물에 전사되므로 생성되는 가공데이터의 정확도가 중요하다. 고정도의 렌즈와 렌즈금형들은 형상정밀도가 수십 나노미터에 이르는 초정밀 제품으로써 가격이 고가이다. 따라서 잘못 생성된 공구 경로는 시간적인 손실뿐만 아니라 고가의 장비를 훼손시킬 수 있으므로 공구경로 보정을 행할 필요가 있다.(중략)

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.149-150
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• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1591-1596
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• 2005

In this paper, we designed the aspheric lens by mathematical methods which are solved by refractive index. Based on these mathematical method, we manufactured the aspheric lens. Because of the usefulness of manufacturing, we used the acryl as the material. And we used a high speed machine to manufacture the aspheric lens. Also it sits in judgment the aberration of spherical distribution by using the grid fringe. Asource of laser produced by laser sheet generator passed the optical system of the aspheric lens. Though a character is to verify that the accuracy of the aspheric lens by experiment of the straight character.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1099-1104
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• 2004

As consumer in optics, electronics, aerospace and electronics industry grow, the demand for ultra precision aspherical surface lens increases higher. To enhance the precision and productivity of ultra precision aspherical surface micro lens, the following specification of ultra precision grinding system is required: the highest rotational speed of the grinder is 100,000rpm and its turning accuracy is $0.1{\mu}m$, positioning accuracy is $0.1{\mu}m$. The development process of the grinding system for the ultra precision aspherical surface micro lens for optoelectronics industry is introduced. In the work reported in this paper, an intelligent grinding system for ultra precision aspherical surface machining was designed by considering the factors affecting the surface roughness and profiles accuracy. An aerostatic form was adopted to build the spindle of the workpiece and the spindle of grinder and ultra precision LM guide way was adopted in this system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.1029-1030
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• 2012