• 한국측량학회:학술대회논문집
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• 한국측량학회 2009년도 춘계학술발표회 논문집
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• pp.41-48
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• 2009

본 논문에서는 측량용 3차원 레이저 스캐너의 소형화를 위해 광원으로 레이저 다이오드를 사용한 송신부 광학계의 설계를 다루었다. 레이저 다이오드를 사용할 경우 활성층의 특성상 타원형의 Beam shape를 갖게 되고 또한 비점수차를 지닐 수 밖에 없는 문제를 가지고 있다. 본 연구에서는 레이저 다이오드의 비점수차를 제거하기 위하여 시준렌즈와 원통형렌즈를 사용하였으며 1mrad 의 빔 발산각을 갖는 평행광을 만들기 위해 핀홀과 Aperture의 사용을 제안하였다. 이를 바탕으로 실제 제작된 소형 광학계를 사용하여 직경 3.5mm, 0.3mrad 이하의 빔 발산각을 갖는 평행광을 구현하였다.

• 한국통신학회논문지
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• 제34권10B호
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• pp.1117-1123
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• 2009

DMD(Digital Micro-mirror Device)와 갈바노 스캐너를 이용한 두부 고정형 다초점 디스플레이 시스템은 초점조절이 가능하여 스테레오스코픽 디스플레이에서 발생하는 양안의 수렴작용과 단안의 초점조절 작용의 불일치에 의한 눈의 피로 문제를 해결할 수 있는 디스플레이 시스템이다. 이 시스템은 레이저 스캐닝 방법으로 각 시점에 대한 영상의 수렴점을 형성하여 관찰자 동공에 제공함으로 초점조절이 가능토록 한다. 본 논문에서는 이 다초점 디스플레이 시스템의 레이저 스캐닝 방법을 수학적으로 분석하였고, 이러한 분석에 기반 한 다초점 시스템을 제작하여 비디오카메라를 통하여 초점조절이 가능함을 보였고, 결과적으로 레이저 스캐닝 방법에 의한 다초점 시스템의 시점 형성원리가 검증되었다.

• 한국생산제조학회지
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• 제19권4호
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• pp.427-433
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• 2010

With recent increased demand for reverse engineering in dental machining, the 3D laser scanner is widely used for inspection of artificial pontic. In order to overcome the optical drawback of laser scanner, such as irregular scatter, direction of beam, and the influence of surface integrity, it is developed in this study a new 3D measuring system for artificial pontic using spherical coordinate system mechanism by point laser sensor, which keeps the direction of beam normal to surface consistently. The comprehensive integrated system is established to evaluate the improvement of accuracy with data acquisition system. The experimental results for measuring a master ball and pontic models shows the excellent form accuracy and repeatability compared with conventional apparatus. Also, these results shows the possibility to apply this system for the measuring purpose within 0.05mm accuracy of pontic at the sharp edge or margin contour, which was difficult to measure at the conventional systems.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.423-427
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• 2002

Contrary to the traditional text-based information, 4S(GIS,GNSS,SIIS,ITS) information can contribute to the citizen's welfare in upcoming era. Recently, GSIS(Geo-Spatial Information System) has been applied and stressed out in various fields. As analyzed the data from GSIS arena, the position information of objects and targets is crucial and critical. Therefore, several methods of getting and knowing position are proposed and developed. From this perspective, Position collection and processing are the heart of 4S technology. We develop 4S-Van that enables real-time acquisition of position and attribute information and accurate image data in remote site. In this study, the configuration of 4S-Van equipped with GPS, INS, CCD and eye-safe laser scanner is shown and the merits of DGPS/INS integration approach for geo-referencing is briefly discussed. The algorithm of DGPS/INS integration fur determination of six parameters of motion is eccential in the 4S-Van to avoid or simplify the complicated computation such as photogrammetric triangulation. 4S-Van has the application of Laser-Mobile Mapping System for three-dimensional data acquisition that merges the texture information from CCD camera. The technique is also applied in the fields of virtual reality, car navigation, computer games, planning and management, city transportation, mobile communication, etc.

• 한국레이저가공학회지
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• 제8권3호
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• pp.27-30
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• 2005

Nowadays, most automotives companies are making use of laser welding in car body assembly shop. But even though laser welding is better than resistance spot welding in many points, its application has been limited to special technology for manufacturing. The paper introduces in the field of remote welding system (RWS) to improve the process efficiency of laser welding. Positioning time of RWS between welding stitches is dramatically reduced to zero. It is a kind of solutions to generalize laser welding in mass production. This RWS consists of fiber laser, industrial robot and 3-axis scanner.

• Journal of the Optical Society of Korea
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• 제4권1호
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• pp.37-42
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• 2000

In this paper, we propose a super multi-view (SMV) 3-D display system using a vibrating scanner array (ViSA). The parallel beam scanning using a vibrating scanner array is performed by moving back and forth an array of curvature-compensated mirrors attached to two vibrating membranes. The parallel laser beam scanner array can replace the polygon mirror scanner which has been used in the SMV 3-D display system based on the focused light array(FLA) concept. The proposed system has great advantages in the sense that it requires neither huge imaging optics normechanical scanning parts. Some mathematical analyses and fundamental limitations of the proposed system are presented. The proposed vibrating scanner array, after some modifications and refinements, will replace polygon mirror-based scanners in the near future.

• 한국레이저가공학회지
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• 제10권2호
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• pp.17-24
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• 2007

We have studied a laser direct writing lithography(LDWL). This is more important to apply to micro patterning using UV laser. We demonstrate the possibility of LDWL and construct the fabrication system. We use Galvano scanner to process quickly micro patterns from computer data. And laser beam is focused with $F-{\theta}$ lens. AZ5214 and SU-8 photoresist are chosen as experimental materials and a kind of well-known positive and negative photoresist respectively. Laser ablation mechanism depends on the optical properties of polymer. In this paper, therefore we investigate the phenomenon of laser ablation according to the laser fluence variation and measure the shape profile of micro patterned holes. From these experimental results, we show that LDWL is very useful to process various micro patterns directly.

• International Journal of Advanced Culture Technology
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• 제8권3호
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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.

• 한국CDE학회논문집
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• 제17권3호
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• pp.156-163
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• 2012

Real-time three-dimensional shape measurement is becoming increasingly important in various fields, including medical sciences, high-technology industry, and microscale measurements. However, there are not so many 3D profile tools specially designed for specifically narrow space, for example, to scan the tooth shape of a human jaw. In this paper, a real-time 3D intraoral scanner is proposed for the measurement of tooth profile in the mouth cavity. The proposed system comprises a laser diode beam, a micro charge-coupled device, a graticule, a piezoelectric transducer, a set of optical lenses, and a polhemus device sensor. The phase-shifting technique is used along with an accurate calibration method for the measurement of the tooth profile. Experimental and theoretical inspection of the phase-to-coordinate relation is presented. In addition, a nonlinear system model is developed for collimating illumination that gives the more accurate mathematical representation of the system, thus improves the shape measurement accuracy. Experiment results are presented to verify the feasibility and performance of the developed system. The experimental results indicate that overall measurement error accuracy can be controlled within 0.4 mm with a variability of ${\pm}0.01$.

• 한국산학기술학회논문지
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• 제21권12호
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• pp.867-872
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• 2020

유류 저장탱크는 화학 산업단지의 주요한 구조물로서, 자연재해나 관리 부실로 인한 구조물의 손상은 화학물질의 유출, 화재, 폭발 등의 추가적인 피해를 야기하기 때문에 변형에 대한 파악이 필수적이다. 본 연구에서는 3D 레이저스캐너를 이용하여 유류 저장탱크에 대한 데이터를 취득하고, 설계 데이터와 비교하여 저장탱크 관리를 위한 다양한 분석을 수행하였다. 3D 레이저스캐너로 취득된 데이터와 설계 도면을 이용하여 유류 저장탱크의 모델링을 수행하고, 중첩하여 유류 저장탱크의 검사를 효과적으로 수행할 수 있었다. 또한 시설물 변형에 대한 가시적인 데이터 생성을 위해 변형에 대한 단면도 및 전개도를 생성하였으며, 정량적인 분석을 통해 유류 저장탱크가 최대 -7.16mm의 변형이 발생하였음을 제시하였다. 변형이 크게 일어난 부분에 대한 정밀 검측대상 도면을 생성하여 추가적인 업무에 활용할 수 있는 데이터를 생성하였으며, 향후 3D 레이저스캐너를 이용한 유류 저장탱크의 검사는 유류 저장탱크 변형에 대한 정량적이며, 가시적인 자료를 제공함으로써 시설물 관리의 효율성을 크게 향상시킬 것이다.