• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.603-604
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• 2012

• Current Optics and Photonics
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• v.3 no.2
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• pp.177-180
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• 2019

Based on liquid-lens technology and our previous findings on the optical model of the Chinese eye, the liquid lens is applied in the research of the crystalline-lens optical model. Theoretical models of three-layer liquid lenses are built with COMSOL software, and the effect of voltage on the shape of the interface between two liquids is analyzed. By polynomial fitting, different equations describing the interface shape are set up under different voltages. Finally, the optical system of the human eye with a three-layer liquid lens is built and analyzed with Zemax optical design software, and moreover the optical system models of emmetropia, myopia, and hyperopia are presented. This method to build a model of the human eye with a variable-focus liquid lens can provide a novel idea for more practical human-eye models for clinical regulation and control in the future.

• Journal of the Microelectronics and Packaging Society
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• v.19 no.2
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• pp.47-53
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• 2012

Recently, by the increasing of data transmission rates, PCB is required high-speed data transmission rates and thin packaging. So optical PCB which is the combination of electrical layer and optical layer can be one of the solution to overcome the limitations of conventional electrical PCB. The most important factor in the implementation of optical PCB is optical interconnection. So the research on high-efficiency and passive alignment has been active. In this paper, we suggest built-in lens pluggable waveguide and we simulate its coupling efficiency and structural stability. Optical simulation results show that the proposed structure has higher efficiency than no lens structure about 1.86 times in transmitter and about 1.42 times in receiver. In structure simulation, inner lens has no damage in desorption process. Therefore, we shown that the proposed structure has a high coupling efficiency and structural stability.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.7
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• pp.561-567
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• 2014

Precision injection mold is an essential element in order to manufacture small and precision plastic lenses used for phone camera. There are many critical factors to meet the requested specifications of high quality plastic lenses. One of the main issues to realize high quality is minimizing decenter value, which becomes more critical as pixel numbers increases. This study suggests the method to minimize decenter value by modifying ejecting structure of the mold. Decenter value of injection-molded lens decreased to 1 ${\mu}m$ level from 5 ${\mu}m$ by applying suggested ejecting method. Also, we also developed BIS (Built-in Sensor) based smart mold system, which has pressure and temperature sensors inside of the mold. Pressure and temperature profiles from cavities are obtained and can be used for deduction of optimal injection molding condition, filling imbalance evaluation, status monitoring of injection molding and prediction of lens quality.

• Transactions of the Society of Information Storage Systems
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• v.11 no.2
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• pp.22-25
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• 2015

In this paper, we demonstrate solid-immersion lens based confocal microscopy using super-continuum generation effect. Using super-continuum generation effect, we could diversify the excitation wavelength of confocal microscopy. Further, high refractive index of solid-immersion lens would increase the resolution of confocal microscopy. As a result, by applying the super-continuum generation effect and solid-immersion lens to confocal microscopy, some problems of confocal fluorescent microscopy, the excitation wavelength and the resolution, could be overcome. To verify it, we made home-built solid-immersion lens based confocal microscopy using super-continuum generation effect, and evaluate the performance of the system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.599-600
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• 2012

• International Journal of Advanced Culture Technology
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• v.8 no.3
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• pp.260-268
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• 2020

Currently, it is usually a 3D scanner processing method as a laser method. However, the laser method has a disadvantage of slow scanning speed and poor precision. Although optical scanners are used as a method to compensate for these shortcomings, optical scanners are closely related to the distance and precision of the object, and have the disadvantage of being expensive. In this paper, 3D scanner using variable focus lens-based structured light module with improved measurement precision was designed to be high performance, low price, and usable in industrial fields. To this end, designed a telecentric optical system based on a variable focus lens and connected to the telecentric mechanism of the step motor and lens to adjust the focus of the variable lens. Designed a connection structure with optimized scalability of hardware circuits that configures a stepper motor to form a system with a built-in processor. In addition, by applying an algorithm that can simultaneously acquire high-resolution texture image and depth information and apply image synthesis technology and GPU-based high-speed structured light processing technology, it is also stable for changes to external light. We will designed and implemented for further improving high measurement precision.

• Journal of the Microelectronics and Packaging Society
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• v.19 no.4
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• pp.13-18
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• 2012

By the need for high-speed data transmission in PCB, the studies on the optical PCB has been conducted with optical interconnection and its packaging technology. Particularly, the polymer-based optical interconnection has been extensively studied with the advantages such as cost-effective and ease of process. For high-efficiency and passive alignment, the studies were performed using the 45 degree mirrors, MT connector, and etc. In this work, integrated PLC device and fiber alignment array block was fabricated by using imprint technology to solve the alignment and array problem of optical device and the optical fiber. The fabricated integrated block for optical interconnection of PLC device has achieved higher precision of decreasing the dimensional error of the patterns by optimization of process and its insertion loss has an average value of 4.03dB, lower than criteria specified by international standard. In addition, a optical waveguide with built-in lens has been proposed for high-efficiency and passive alignment. By simulation, it was confirmed that the proposed structure has higher coupling efficiency than conventional no-lens structure and has the broad tolerance for the spatial offset of optical waveguide.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.169-172
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• 2005

Tiny camera module using in modern cellular phone requires precise assembly processes. Higher camera resolution and more functions such as zoom lens make the number of camera parts bigger. As market grows rapidly, automatic assembly process is required. However, diverse product line and short life cycle make it difficult. To attack this, a flexible and expandable lens assembly system is proposed. For the fast manufacturing line formation, modular concept is adopted. Also each module is designed to have intelligence to save system formation time. The assembly system is built up on the standard flat-form which provides vibration free base, air and electric supply, controllers, etc. Futhermore, the assembly cell has the capability of handling tiny, thin, or transparent parts which are very difficult to align with vision.

• Korean Journal of Remote Sensing
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• v.19 no.6
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• pp.431-445
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• 2003

In this paper, we experimentally investigated the precision of 3D positioning using 4S-Van images in photograrmmetric perspective. The 3D calibration target was built over building facade outside and was captured separately by two CCD cameras installed in 4S-Van. After then, we determined the interior orientation parameter for each CCD camera through self-calibration technique. With the interior orientation parameter computed, the bundle adjustment was performed to obtain the exterior orientation parameters simultaneously for two CCD cameras using calibration target image and object coordinates. The reverse lens distortion coefficients were computed and acquired by least squares method so as to introduce lens distortion into epipolar line. It was shown that the reverse lens distortion coefficients could transform image coordinates into lens distorted image coordinates within about 0.5 pixel. The proposed semi-automatic matching scheme incorporated with lens distorted epipolar line was implemented with scene images captured by 4S-Van in moving. The experimental results showed that the precision of 3D positioning from 4S-Van images in photograrmmetric perspective is within 2cm in the range of 20m from the camera.