• 소성∙가공
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• 제24권6호
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• pp.437-442
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• 2015

The development of polishing technology has enabled the production of injection molds with high quality surfaces and shapes. For products such as mobile phones which require high quality performance the use of plastic materials has many constraints such as shrinkage and deflection. The purpose of the current research is to use reverse engineering in order to find and analyze the data of a selected aspherical lens and then creating a process to design an improved lens. Additionally, the improved lenses are subject to molding analysis. In order to solve this problem, the lens construction program, Zemax, was used to analyze and optimize performance. In the case of optimization, the object was to eliminate spherical aberration and to find good MTF data. The result of the optimization data was similar to the MTF data found from a random lens. Specific resin and analysis conditions were selected and CAD modeling was done to enhance the injection molding analysis.

• Current Optics and Photonics
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• 제3권1호
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• pp.27-32
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• 2019

We present an autofocus tracking system implemented by the digital refocusing of digital holographic microscopy (DHM) and the tunability of an electrically tunable lens (ETL). Once the defocusing distance of an image is calculated with the DHM, then the focal plane of the imaging system is optically tuned so that it always gives a well-focused image regardless of the object location. The accuracy of the focus is evaluated by calculating the contrast of refocused images. The DHM is performed in an off-axis holographic configuration, and the ETL performs the focal plane tuning. With this proposed system, we can easily track down the object drifting along the depth direction without using any physical scanning. In addition, the proposed system can simultaneously obtain the digital hologram and the optical image by using the RGB channels of a color camera. In our experiment, the digital hologram is obtained by using the red channel and the optical image is obtained by the blue channel of the same camera at the same time. This technique is expected to find a good application in the long-term imaging of various floating cells.

• 한국공작기계학회논문집
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• 제15권2호
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• pp.24-29
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• 2006

The use electron-beam(E-beam) manufacturing system provides a means to alleviate optic exposure equipment's problems. We are developing an E-beam manufacturing system with scanning electron microscope(SEM) function. The E-beam manufacturing system consist of high voltage generator, beam blanker, condenser lenses, object lenses, stigmator and stage. The development of E-beam manufacturing system is used on the method of remaking SEM's structure. The functions of SEM are developed. It is important for the test of E-beam performance. In E-beam manufacturing system and SEM, beam focus is important function. In this paper, we propose intelligent remote control function for beam focus in E-beam manufacturing system. The function extends the user's function and gives convenience.

• Journal of the Optical Society of Korea
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• 제20권5호
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• pp.633-640
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• 2016

In a dual lens stereoscopic camera, a convergence point determines the stereopsis effects of a video. When a user zooms an object, a convergence point is fixed since it is not coupled with a zoom function. Due to the fixed convergence point, it is possible for a zoom to cause the excessive binocular disparity resulting in visual discomfort. In this paper, to solve this problem, we build the relational model including all phenomena possible to arise and propose the adjustment methods of a convergence point by the positions of a focus, an object and a convergence point. We also evaluate the experiments measuring a binocular disparity and the subjective test to investigate the visual comfort. The results show that one of the proposed methods produced more comfortable 3D images to viewers than the others.

• 천문학회지
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• 제17권1호
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• pp.15-22
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• 1984

The transverse velocities of the gravitational lens system (galaxy plus a 'disturbing star') and their dependences on unkown properties of the source and the deflecting object are discussed. We have derived an analytic expression for the transverse velocity in terms of the velocities of the light source, the gravitational lensing galaxy and the 'disturbing star', and the observer. The results are then further applied to an estimate of the expectation value of the absolute transverse velocity and of the probable time scales of flux changes of the double QSO 0957+561A, B.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.395-398
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• 2002

The spherical aberration and optical integer (f) of the electron gun's main lens in color CRT is obtained, using electron beam trajectory. A spherical aberration is obtained from the relation between the object plane and the image of a beam trajectory. To analyze beam profile, 3rd and 1st order coefficient were obtained and used. It is shown that, in practice, they are applied to electron gun design.

• Journal of the Optical Society of Korea
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• 제10권4호
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• pp.178-183
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• 2006

An in-line phase-shifting digital holographic microscopy system was constructed by inserting a conventional microscope in the object arm of a Mach-Zehnder interferometer. It was used to measure the three dimensional shape of a micro Fresnel lens. It was also shown that both the lateral and the axial resolutions of the in-line phase-shifting system using a self-calibration algorithm were superior to those of the best off-axis system.

• International Journal of Quality Innovation
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• 제5권1호
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• pp.68-84
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• 2004

The measured values of a same object should remain constant regardless of the object's position in the image. In other words, its measured values should not vary as its position in the image changes. However, lens' image distortion, heterogeneous light source, varied angle between the measuring apparatus and the object, and different surroundings where the testing is set up will all cause variation in the measurement of the object when the object's position in the image changes. This research attempts to compensate the machine vision image distortion caused by the object's position in the image by developing the compensation table. The compensation is accomplished by facilitating users to obtain the correcting object and serves the objective of improving the precision of measurement.

• 한국안광학회지
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• 제12권4호
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• pp.77-81
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• 2007

구면 렌즈는 굴절력에 따라 크게 (+)디옵터와 (-)디옵터 렌즈로 구분할 수 있다. 렌즈에 가해지는 외력에 의해 발생되는 변형은 디옵터의 증가 또는 감소에 따라 다르게 발생된다. 본 논문에서는 수년간 광계측 분야에서 널리 사용되고 있는 ESPI를 이용하여 렌즈에 발생되는 변형을 정량적으로 측정 하였다. ESPI(Electronic Speckle Pattern Interferometry: ESPI)는 빛의 가간섭성을 이용하여 대상물의 변형을 비접촉으로 정밀하게 측정할 수 있다는 장점을 지니고 있다. 실험은 총 16종의 플라스틱 안경 렌즈를 대상으로 수행 하였다. 동일한 변위를 주었을 때, (+)렌즈는 디옵터가 증가함에 따라 변형량이 감소하고, (-)렌즈의 경우 (+)디옵터 렌즈와는 반대로 디옵터가 감소함에 따라 변형량이 증가한다는 것을 확인 하였다. 또한 (+)디옵터 렌즈가 (-)디옵터 렌즈에 비해 상대적으로 변형량이 적게 발생한 사실을 알 수 있었다. 따라서 본 논문의 결과는 다양한 렌즈에 외부 변위가 가해지는 경우 렌즈의 변형에 의한 광학적 결함 등을 정량적으로 측정 할 수 있는 가능성을 제시하고 렌즈 산업 분야에 다양하게 응용 될 것으로 기대된다.

• 한국안광학회지
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• 제6권1호
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• pp.93-100
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• 2001

본 논문에서는 기존에 설계된 35mm 카메라 비구면 줌 렌즈계의 구조와 광학적 성능을 조사하여 비구면 패턴을 분석하여 보았다. 이 렌즈계는 무한 물점에 대한 줌 렌즈계로서 viewing system을 갖는 소형 카메라에 사용되어지는 광학계이므로 짧은 back focal length를 허용하여 image plane 가까이에 lens unit을 사용할 수 있게 하였다. 이 광학계의 zoom ratio는 1 : 2이고 +, -의 power 분포를 가지고 있으며, 일반인들이 가장 많이 사용하는 35~70mm 초점거리 영역을 채택함으로써 대중적인 보편화를 고려한 경제성이 있는 광학계라고 할 수 있겠다. 2개의 비구면을 사용함으로써 단지 3장의 렌즈만으로 수차 보정을 이루었고, 렌즈계의 소형, 경량화, 생산단가의 감소효과를 꾀하였다.