• Journal of Korean Ophthalmic Optics Society
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• v.14 no.3
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• pp.29-35
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• 2009

Purpose: To develop a relay lens type scope with 70 mm eye relief. Methods: By using Sigma 2000 design program, we designed and manufactured a relay lens type scope with 70 mm eye relief, which is integrated after designing an objective part with relay lenses and an eyepiece part, respectively. Results: The characteristics of the relay lens type scope with 70 mm eye relief whch is designed and manufactured by methods, which integrate after respectively designing an object part with relay lenses and an eyepiece part, have the magnification of $+4{\times}$,the length from 1st lens to last lens of about 105 mm, the barrel diameter of 18mm, and the effective diameter of 13 mm. Also we know that the resolution line width is 275 cycles/rad at the 30% MTF value criterion. Conclusions: We could design and manufacture the relay type scope with 70 mm eye relief, the characteristics of which have the magnification of $+4.0{\times}$the MTF above 30% at 275 cycles/rad, and the length from 1st lens to last lens of about 105 mm.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.678-681
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• 2003

In conventional optical data storage numerical aperture (NA) cannot be over 1 because of diffraction limit. To overcome this limitation. solid immersion lens(SIL) have produced a great interest in near-field optical data storage. In conventional optical recording method, the dual lens system using object lens and SIL had been studied generally. But the conventional SIL system has some critical problems that must be solved. The problems are heat, contamination. alignment of optical components and so on. To solve these problems. this work proposes enhanced SIL which has several advantages for mechanical and optical issues. This new SIL system named elliptic SIL(ESIL) can use evanescent energy in near-field more effectively. In addition. because of applying the inside recording unlike previous surface recording, ESIL can clear up the problems. The design and analysis of ESIL art executed by using CODE V. Also, in this paper we composed actual data recording system and achieved recording experiment by applying ESIL to magneto-optical recording. In conclusion. we analyze the improvement of aerial density and the reasonability of application to real data storage system.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.5 s.305
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• pp.79-84
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• 2005

In this paper, we developed an omni-directional surveillance and motion detection method. The fish-eye lens provides a wide field of view image. Using this image, the equi-distance model for the fish-eye lens is applied to get the perspective and panorama images. Generally, we must consider the trade-off between resolution and field of view of an image from a camera. To enhance the resolution of the result images, some kind of interpolation methods are applied. Also the moving edge method is used to detect moving objects for the object tracking.

• Korean Journal of Optics and Photonics
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• v.18 no.6
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• pp.410-420
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• 2007

We theoretically derive the set of utilizable paraxial zoom locus equations for all complicated zoom lens systems with infinite object distance, such as a camera zoom lens, by using the Gaussian bracket method and the matrix representation of paraxial ray tracing. And we make the zoom locus program according to these equations in Visual Basic. Since we have applied the paraxial ray tracing equations into Gaussian bracket representation, the resultant program systematically simplifies various constraints of the zoom loci of various N group types. Consequently, the solutions of this method can be consistently used in all types of zoom lens in the step of initial design about zoom loci. Finally, in order to verify the usefulness of this method, we show that one example among 4 groups and that among 5 groups, which are very complex zoom lens systems, can be rapidly and with versatility traced through various interpolations by using this program.

• Korean Journal of Optics and Photonics
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• v.29 no.1
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• pp.7-12
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• 2018

In the field of machine vision, a variety of lenses are used to inspect a product for defects. Only part of the appearance of an object can be photographed with a general lens. Optical components such as mirrors, multiple lenses and cameras are required to inspect the entire exterior. This increases the size of the optical system, and has the disadvantage of high cost. In this paper, we design a hypercentric lens, which can photograph the top and side of an object, and various sizes of objects while maintaining the image size. Also, the validity of the design is verified through the performance analysis of the product.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.11
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• pp.979-983
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• 2013

The three-dimensional measurement method of confocal systems is a spot scanning method which has a high resolution and good illumination efficiency. However, conventional confocal systems had a weak point in that it has to perform XY axis scanning to achieve FOV (Field of View) vision through spot scanning. There are some methods to improve this problem involving the use of a galvano mirror [1], pin-hole array, etc. Therefore, in this paper we propose a method to improve a parallel mode confocal system using a micro-lens and pin-hole array in a dual microscope configuration. We made an area scan possible by using a combination MLA (Micro Lens Array) and pin-hole array, and used an objective lens to improve the light transmittance and signal-to-noise ratio. Additionally, we made it possible to change the objective lens so that it is possible to select a lens considering the reflection characteristic of the measuring object and proper magnification. We did an experiment using 5X, 2.3X objective lens, and did a calibration of height using a VLSI calibration target.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.401-404
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• 2004

The electron beam machining provides very high resolution up to nanometer scale, hence the E-beam writing technology is rapidly growing in MEMS and nano-engineering areas. In the optical column of the e-beam writer, there are several lenses condensing and focusing electron beams from electron gun with fringing magnetic fields. To achieve small spot size as 1-2 nm for higher power of electron beam, magnetic lenses should be designed considering their magnetic field distribution. In this paper, the magnetic field at two condenser lenses and object lens are calculated with finite element method and discussed its performances.

• Korean Journal of Optics and Photonics
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• v.15 no.5
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• pp.405-408
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• 2004

In this paper, we used a split-lens speckle shear interferometer using a double speckle interferometer, which enables continuous measurement of the deformation. We made two identical specklegrams corresponding to an object. With this method we could detect the measuring limits of the deformation for various shears. This experimental results showed that the measuring limits of a split-lens speckle shear interferometer are similar to the measuring limits of a double exposure speckle interferometer.

• Journal of the Optical Society of Korea
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• v.18 no.5
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• pp.517-522
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• 2014

In this paper we propose an axially distributed image-sensing method with a wide-angle lens to capture the wide-area scene of 3D objects. A lot of parallax information can be collected by translating the wide-angle camera along the optical axis. The recorded wide-area elemental images are calibrated using compensation of radial distortion. With these images we generate volumetric slice images using a computational reconstruction algorithm based on ray back-projection. To show the feasibility of the proposed method, we performed optical experiments for visualization of a partially occluded 3D object.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.693-696
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• 1998

For camera calibration, this paper describes two steps to camera constants and camera parameters. The former is the radial distortion of lens, image center and focal length etc.. The latter is translation, rotation etc.. Camera calibration use tsai's algorithm. In this paper, the solutions are introduced into overdetermined system as matching points that are acquired from two CCD and measured object depth information.