• Journal of Sensor Science and Technology
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• v.28 no.5
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• pp.294-298
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• 2019

Pulsed laser-based optical sensor monitoring systems for real time microplastic particle counting are proposed and developed in this study. To develop our real time monitoring system, we used a 450 nm pulsed laser and a photomultiplier with very high quantum efficiency. First, we demonstrated that the microplastic particle counting system could detect standard micro bead samples of 100, 250, and $500{\mu}m$ in river water. We then performed research concerning pulsed laser-based optical spectral sensor systems for real time microplastic monitoring. Additionally, we demonstrated that the real time microplastic remote monitoring system using LoRa communications could detect microplastic in the tap water resource protection area.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.10
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• pp.993-998
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• 2007

To verify the 2D or 3D positioning accuracy of a multi-axes stage is not easy, particularly, in the case the moving path of the stage is not linear. This paper is a study on a measuring method for the curved path accurately. A machine vision technique is used to trace the moving path of two-axes stage. To improve the accuracy of machine vision, a zoom lens is used for the 2D micro moving path. The accuracy of this method depends of the CCD resolution and array align accuracy with the zoom lens system. Also, a further study for software algorithm is required to increase the tracing speed. This technique will be useful to trace a small object in the 2D micro path in real-time accurately.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.1148-1150
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• 1999

Fresnel lens는 zone plate에 비해 공정은 쉬우나 회절 효율이 높은 것으로 알려져 있다. 본 논문에서는 micro fresnel lens를 설계하고 각각의 회절 효율 및 focal size를 계산하였으며. 비교적 공정이 용이한 계단 모양의 fresnel lens를 설계하여 회절 효율과 focal size를 계산하였다. 그리고, 광원의 파장과 초점거리에 따른 lens의 회절 효율을 비교하였으며, 계단의 수에 따른 회절 효율도 비교하였다.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.2
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• pp.25-28
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• 2010

The micro fabrication on the mold material using picosecond laser ablation processing has been studied. We used the two kind of system with picosecond laser. First one is two mirror type scanner and telecentric f-theta lens. Second one is X-Y stage and objective lens. By using these system, the $100{\mu}m$ size chess patterning and $2{\mu}m$ size patterning was fabricated. Especially $2{\mu}m$ size patterning on the mold material can be used as the decorative rainbow color logo for industrial field. In this paper, it is proved the picosecond laser is effective tool for the laser ablation processing.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.10
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• pp.817-821
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• 2011

We have proposed an optical thin film and micro lens to improve the luminance of organic light emitting device. The first method, optical thin film was calculated refractive index of dielectric layer material that was modulated refractive index of organic material, ITO (indium tin oxide)and glass. The second method, microlens was applied with lenses on the organic device. Optical thin films were designed with Macleod Simulator and Micro Lenses were calculated by FDTD (finite-difference time-domain) solution. The structure of thin film was designed in organic material/ITO/dielectric layer/glass. The lenses size, height and distance were 5 ${\mu}m$, 1 ${\mu}m$, 1 ${\mu}m$, respectively. The material of micro lenses used silicon dioxide. Result, The highest luminance of OLED which applied with microlens was 11,185 $cd/m^2$, when approval voltage was 14.5 V, applied thin film was 5,857 $cd/m^2$. The device efficiency applying microlens increased 3 times than the device which does not apply microlens.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1422-1425
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• 2003

In the design of optical system, important variables of optical system (including indices, shapes, spaces, stops. etc.) must manipulate in order to balance out offensive aberration. In this paper, it carried out a basic study on the design of micro optical system usable for the acquaintance of visual information in the particular conditions such as capsule type endoscopes. In this study, specification for design of optical system selected voluntarily and the basic design of optical system carried out by using the ray tracing method on the assumption that ideal lenses without aberrations. In the designed optical system, the optimization including aberration correction and the performance evaluation of optical system carried out by using the CODE-V. The final designed optical system consists of seven sheets of lenses. Also the results of performance evaluation. the micro optical system combined with aspherical lenses was confirmed to have improved optical performance as compared with the micro optical system consisted of spherical lenses.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.41.5-41
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• 2002

This paper presents a feature extraction algorithm for vision-based micromanipulation. In order to guarantee of the accurate micromanipulation, most of micromanipulation systems use vision sensor. Vision data from an optical microscope or high magnification lens have vast information, however, characteristics of micro image such as emphasized contour, texture, and noise are make it difficult to apply macro image processing algorithms to micro image. Grasping points extraction is very important task in micromanipulation because inaccurate grasping points can cause breakdown of micro gripper or miss of micro objects. To solve those problems and extract grasping points for micromanipulation...

• Journal of the Optical Society of Korea
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• v.17 no.5
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• pp.447-453
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• 2013

A micro zoom system without moving elements by use of two liquid lenses is designed and optimized in this paper. The zoom equations of the system composed of two liquid lenses are deduced. The structure parameters including radius and thickness of a conical double-liquid electrowetting based lens are analyzed and calculated. Because the liquid thickness varies non-linearly with the radius of the interface, it's very difficult to optimize a real liquid lens using commercial optical design software directly. Through the Application Programming Interface (API) of the optical design software CODE V, a zoom system with two real electrowetting based liquid lenses is modeled and optimized. A two-liquid-lens zoom system without moving elements, with a zoom factor of 1.8 and a compact structure of 10 mm is designed for illustration. This can be useful for the camera design of mobile phones, tablets and so on. And this paper presents a convenient way of designing and optimizing a zoom system including liquid lenses by commercial optical design software.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.956-961
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• 2004

This paper proposes a study on the spherical lens manufacturing by simultaneous 3 axis for NC lathe. We use friction drive system for moving system in experimental diamond turing machine. The diamond turning machine use manufacturing for high quality lens, mirror and many optics products. Especially, the high tech industry require a lot of lens. For example, optical engineering. medical science, space engineering and material engineering etc. The friction drive system is very simple and quiet, compared to ball screw system. We find a problem at the simultaneous 3 axis and suggest a solution. Also, when we manufactured a micro lens. find a problem and solution.

• 연구논문집
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• s.32
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• pp.23-34
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• 2002

Up to now, collimators have teen generally produced by handwork and only a few companies have produced by semi-automatic system. Under this situation, automatic system for assembly of optical collimators has risen as a mast essential technique in the development of optical communication components. In this study, it was constructed to develop optical collimators with high functionality and we manufactured optical collimators with a GRIN rod lens and spherical lens using automatic system. Therefore, we worked a performance test through a comparison of collimators made by automatic system and handwork with angle augment, bean size. Also we selected a optimum assembly condition of GRIN rod lens and spherical lens. As a result, it brought a reduction of the tact time and an improvement of an efficiency and a productivity of optical collimators, therefore it was found that automatic system was indispensable for materialization of optical collimators with high functionality.