• 한국산업정보학회논문지
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• 제12권3호
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• pp.124-131
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• 2007

3 Megapixel, 2.5배 Zoom 카메라폰 모듈용 광학계 중 비구면과 평면으로 설계된 평볼록형 비구면 Glass렌즈를 고온압축성형법으로 제작하였다. 제작된 비구면 Glass 성형렌즈의 성능은 성형렌즈의 형상정도(PV) 전사성과 해상도로 평가하였다. Glass렌즈 성형용 몰드의 형상정도(PV)는 비구면의 경우 $0.127\;{\mu}m$, 평면의 경우 $0.168\;{\mu}m$이었고, 성형된 렌즈의 형상정도(PV)는 비구면의 경우 $0.205\;{\mu}m$, 평면의 경우 $0.223\;{\mu}m로 $90{\sim}95%$의 전사정도를 보였다. 성형렌즈의 해상도 평가를 위해 렌즈의 MTF[Contrast]를 측정하였다. 공간주파수 80 lp/mm에서 Contrast가 32.9%을 보였으며, 이 값은 렌즈 광학설계의 전산모사에서 얻어진 Contrast 33%에 근사한 값으로 성형렌즈의 해상도 특성이 우수함을 알 수 있었다.

• 한국정밀공학회지
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• 제25권12호
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• pp.39-46
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• 2008

Asymmetric glass lens core for portable projection optic system was designed and simulated. And it was machined by newly developed non-rotational ultra precision grinding method. With the designed lens data which optimized for multi-collimation, we generated the we core surface data. Mold pressing conditions analyzed by FEM. In the machining process, ground profile errors were compensated based on measured data, minimized feed rate and depth of cut. The deviations of machined core profile were acceptable level for glass mold press. Mold pressed glass array lens was coated with $SiO_2\;and\;Ta_2O_5$ for anti-reflection.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.191-192
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• 2006

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.57-57
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• 2007

Aspheric glass lenses have many optical advantages, for glass have superior optical performance and an aspheric form can reduce optical aberrations. Recently, the use of it is rapidly expanding as the mass production becomes possible by glass molding press and so this method is considered as the best method for fabricating an aspheric glass lens, but it is difficult to control many parameters for pressing and cooling process. Design of experiments (DOE) is a very useful tool to design and analyze complicated industrial design problems. This study investigated the pressing conditions to mold aspheric glass lenses for mega pixel phone camera module using DOE method. We have applied fractional factorial design and the response variable was set form accuracy (PV) of aspheric surface of molded lens. The results of analysis indicates that all factors expect for pressing force of each step are available for the form accuracy (PV). It was the optimum condition of the designed pressing conditions for lowering the form accuracy(PV) value of molded lens that all factors were at the low level. The form accuracy (PV) of mold and molded lens under the optimum condition are $0.85\;{\mu}m$ and $0.922\;{\mu}m$ respectively.

• 한국전기전자재료학회논문지
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• 제27권2호
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• pp.91-96
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• 2014

Aspheric lenses used in the thermal imaging are typically fabricated using expensive single-crystal materials (Ge and ZnS, etc.) by the costly single point diamond turning (SPDT) process. As a potential solution to reduce cost, compression molding method using chalcogenide glass has been attracted to fabricate IR optic. Thermal deformation of a molded lens should be compensated to fabricate chalcogenide aspheric lens with form accuracy of the submicron-order. The thermal deformation phenomenon of molded lens was analyzed ant then compensation using mold iteration process is followed to fabricate the high accuracy optic. Consequently, it is obvious that compensation of thermal deformation is critical and useful enough to be adopted to fabricate the lens by molding method.

• Current Optics and Photonics
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• 제7권3호
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• pp.273-282
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• 2023

This paper presents a new method for redistributing effectively the first orders of each lens element to achromatize and athermalize an optical system, by introducing a novel method for adjusting the slope of an achromatic and athermal line. This line is specified by connecting the housing, equivalent single lens, and aberration-corrected point on a glass map composed of available plastic and glass materials for molding. Thus, if a specific lens is replaced with the material characterized by the chromatic and thermal powers of an aberration-corrected point, we obtain an achromatic and athermal system. First, we identify two materials that yield the minimum and maximum slopes of the line from a housing coordinate, which specifies the slope range of the line spanning the available materials on a glass map. Next, redistributing the optical first orders (optical powers and paraxial ray heights) of lens elements by moving the achromatic and athermal line into the available slope range of materials yields a good achromatic and athermal design. Applying this concept to design a mobile-phone camera lens, we efficiently obtain an achromatic and athermal system with cost-effective material selection, over the specified temperature and waveband ranges.

• Transactions on Electrical and Electronic Materials
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• 제9권6호
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• pp.237-242
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• 2008

The effects of the process parameters in the molding of aspheric glass lenses for camera phone modules have been investigated experimentally. The molding conditions were optimized with respect to the form accuracy (PV) (the response variable) of the molded lens. The experimental conditions were obtained by employing a factorial design method. From the analysis of variance (ANOVA) and P-value (significance level), the slow cooling rate was found to affect the response variable most significantly. The lens molded under the optimum molding condition showed a transcription ratio of 93.4%.

• Journal of the Optical Society of Korea
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• 제13권2호
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• pp.213-217
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• 2009

The transcription characteristics of the mold surface in the molding of aspherical glass lenses for camera phone modules have been investigated experimentally. The surface topographies of both the form and the roughness were compared between the mold and the molded lens. For the form topography, the molded lens showed a transcription ratio of 93.4% against the mold, which is obtained by comparing the form error (PV) values of the mold and the molded lens. The transcription characteristics of the roughness topography were ascertained by bearing ratio analysis.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.464-464
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• 2008

This study investigated the slow cooling conditions in the molding of aspheric glass lens using the design of experiment (DOE). The optimization of the slow cooling conditions with respect to the form accuracy (PV) of the molded lens were ascertained by employing full factorial design. As a result of the analysis of variance (ANOVA) and P-value (significance level), it was verified that slow cooling rate represent the most significant operative variables that affect the corresponding response variable. In the optimum condition, the molded lens show 82% of transcription ratio.

• 한국기계가공학회지
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• 제5권4호
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• pp.41-45
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• 2006

In recent years, the demands of the aspheric 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, Co 0.5%) 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.