• 한국기계가공학회지
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• 제11권2호
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• pp.13-19
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• 2012

Ultra Precision Machining Techniques, such as manufacturing Micro Lens Array(MLA), off-axis mirror, $F-{\theta}$ lens for laser printer, are achieved, based on technologies in consequence of development of modern high-precision machining mechanism. Above all, FTS(Fast Tool Servo) and STS(Slow Tool Servo) are more innovative technologies for reducing time and development costs. In this paper, it is described that MLA machining technique by FTS, off-axis mirror machining technique by STS, optics for observing space, and development of infrared aspheric lens for a thermal imaging microscope.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.221-222
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• 2006

In recent years, the demands of the aspherical glass lenses increase since it is difficult to obtain the desirable performance in the plastic lens. Glass lens is manufactured by the forming with high precision mold core. This paper presents the analysis of optimal grinding condition of tungsten carbide(WC, Co0.5%) using design of experiments(DOE). The process parameters are turbin spindle, work spindle, feedrate and depth of cut. The experiments results are evaluated by MINITAB software.

• 한국생산제조학회지
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• 제21권3호
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• pp.487-492
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• 2012

In this study we researched a spotlight in LED lighting. Ordinary LED spotlight was manufactured with characterized property of traveling straightness of LED light source, but multiple use of shell type LED, a yellow band has formed caused by light source interference between the LED. Also, there was a high miscellaneous light efficiency with losing light source homogeneity and efficiency due to light source control uneasiness. The study uses aspheric reflector and aspheric lens, so we can control the light source of LED spotlight with effectively and we reached surface light source by using COB/COM for LED module. Furthermore it can change its use by a reduced scale of light system. It has been designed to make its various application from low power consumption of bicycle lamp, up to high power consumption of automobile lamps and lighthouse.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.391-395
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• 2002

This paper described about the ultra-precision profile measurement of aspheric surfaces using contact probing technique. A contact probe has been designed as a sensing device to obtain measuring resolutions in nanometer regime utilizing a leaf spring mechanism and a capacitive-type sensor. The contact probe is attached on the z-axis during measurement while aspheric objects are supported on the single point diamond turning machine(SPDTM). The machine xz-axis motions are monitored by a set of two orthogonal plane mirror type laser interferometers. Experimental results show that the contact probing technique developed of On-machine Measurement System in this investigation is capable of providing a repeatability of 20 nanometers with a $\pm$20 uncertainty of 300 nanometers.

• 한국전기전자재료학회논문지
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• 제19권11호
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• pp.1050-1054
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• 2006

There have been intensive and continuous efforts in the field of DLC coating process because of their feature, like high hardness, high elasticity, abrasion resistance and chemical stability and have been applied widely the industrial areas. In this research, optimal grinding condition was investigated using Microlens Process Machine for the development of aspheric glass lens which is to be used for mobile phone module with 3 mega pixel and 2.5X optical zoom, and tungsten carbide(WC) mold cote was manufactured using high performance ultra precision machining and the effects of DLC coating on the form accuracy(PV) and surface roughness(Ra) of WC mold core was evaluated.

• 한국광학회:학술대회논문집
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• 한국광학회 2003년도 제14회 정기총회 및 03년 동계학술발표회
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• pp.298-299
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• 2003

As the demand for high frequency(bandwidth) optical module of reduced cost is increased, there are considerable needs for low cost／ high reliable optical packaging method. In order to meet these requirements, the researches using silicon optical bench(SiOB) technology have been developed as one of the leading technology. In this paper, we discuss optical package using one aspherical lens mounted on SiOB by passive alignment, and present the reliability data for the optical module, which are temperature cycling between 40C and +85C, and high temperature storage 85C(unbiased), 2000hour.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.104-107
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• 2007

An aspheric microlens array to improve the properties of multi optical probes was designed and fabricated. To generate multi optical probes with good qualities, a microlens array with the minimum spherical aberration was designed by ray tracing. Using the reflow process, a master pattern of aspheric microlens array was made and finally with the ultraviolet-imprinting (UV-imprinting) method, the aspheric microlens array was replicated. The reflow condition was optimized to realize the master pattern of the microlens array with the designed aspheric shape. The intensity distribution of the optical probes at the focal plane showed a diffraction-limited shape.

• 한국공작기계학회논문집
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• 제18권1호
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• pp.76-82
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• 2009

To obtain the surface roughness with nano order, we need a ultra-precision machine, cutting condition, and materials. In this paper, the cutting condition for getting nano order smooth surface of core have been examined experimentally by the ultra-precision machine and diamond wheels. The effects of the cutting velocity, the feed rate and depth of cut on the surface roughness were studied. And also, the surface roughness was measured by the Form Talysurf series PGI 840. The champion data of developed core was surface roughness Rmax 24.6nm, figure accuracy Rmax 68.9nm.

• 한국광학회지
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• 제18권4호
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• pp.256-263
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• 2007

SELFOC 소재를 사용하여 높은 수치구경을 가지는 광픽업용 대물렌즈를 설계하였다. SELFOC 소재는 radial gradient-index 분포를 가지며, 이것은 설계에 추가적인 자유도를 제공하므로, 비구면이 아닌 구면만으로 높은 수치구경의 대물렌즈의 설계가 가능하다. 이 연구에서는 quadratic constant와 광축의 굴절률, 광축 두께, 입사동 직경을 변화시키며 rms 스폿 직경 변화를 조사하였으며, Code V를 사용하여 대물렌즈의 최적화와 결상특성을 평가하였다. 이 분석에서는 quadratic constant와 광축의 굴절률이 클수록, 렌즈가 두꺼워질수록, 입사동 직경은 작을수록 더 좋은 특성을 보임을 알 수 있었다. 이 결과를 바탕으로 2매의 구면 SELFOC 렌즈로 구성된 높은 NA의 DVR용 대물렌즈를 설계하였으며, 2가지 형태의 해 Solution I, II가 존재하였다 Solution I은 두 매 모두 양의 굴절능을 가지며 compact한 광학계를 구성하지만, 비축 수차 보정이 Solution II에 비해 부족하였다. Solution II는 음-양의 굴절능으로 조합된 광학계로 비축 수차가 비교적 잘 보정되었지만, 광학계의 전장길이가 길고 렌즈의 직경이 커지는 문제점이 있었다.

• 한국광학회지
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• 제30권1호
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• pp.8-14
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• 2019

본 논문에서는 추가적인 광학부품 및 조립공정 없이 차량용 헤드램프의 cut-off line에서 발생하는 색수차를 보정하는 방법과 이를 평가하는 방법을 제안한다. 기하학적인 방법으로 색수차를 보정하기 위해 비구면 프로젝션 렌즈의 볼록면에 tilt를 적용하여 파장별 최대 출사각도의 차이를 줄였으며, 색수차를 평가하기 위한 위치와 광도를 정하고 색 좌표를 통해 색수차 기준을 제시하였다. 이러한 기하학적인 방법을 이용하여 설계된 자동차용 헤드램프를 평가한 결과 cut-off line의 색수차가 상당히 감소되었음을 확인할 수 있었다.