• Title/Summary/Keyword: A laser stripe

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Effect of Stripe Width on Threshold in Single Quantum Well Laser Diodes (단일양자우물 Laser Diode에서 Stripe 폭이 문턱치에 미치는 영향)

  • 이성재
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.3
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    • pp.591-596
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    • 1994
  • Threshold dependence on stripe width in gain-guided single quantum well lasers has been examined by complex domain effective index method. It is found, in narrow stripe regime, that the lateral optical confinement estimated by newly introduced parameters decreases very rapidly as the transverse optical confinement factor decreases. Thus, in a single quantum well laser with a usually very small, the optical confinement may become very poor depending on stripe width not only in the transverse but also in the lateral direction, further enhancing the gain saturation and often leading to an anomalously high threshold current. The understanding of rather anomalous threshold dependence on stripe width will be very important in optimization of quantum well laser diode structure.

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A New Profilometry System for Precision Measurement of 3D Shape Using the Directional Magnification Control of a Laser Light Stripe (선모양을 한 레이저빔의 방향성 배율 확대를 이용한 정밀 형상측정 시스템)

  • Park, Seung-Kyu;Baik, Sung-Hoon;KIM, Cheol-Jung
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.5
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    • pp.60-65
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    • 1997
  • This paper proposes a profilometry system for precise surface contouring of 3D objects using a direc- tionally magnified image of a laser light stripe. The resolution of this system can be improved several times comparad with that of conventional systems without loss of spatial resolution and depth of measurement. A pair of cylindrical lens(a convex lens and a concave lens) are used for a directionally magnified image of a laser light stripe maintaining the same focal plane. Also, image processing procedures for image reconstruc- tions are described.

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Development of 3D Scanner Based on Laser Structured-light Image (레이저 구조광 영상기반 3차원 스캐너 개발)

  • Ko, Young-Jun;Yi, Soo-Yeong;Lee, Jun-O
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.3
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    • pp.186-191
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    • 2016
  • This paper addresses the development of 3D data acquisition system (3D scanner) based laser structured-light image. The 3D scanner consists of a stripe laser generator, a conventional camera, and a rotation table. The stripe laser onto an object has distortion according to 3D shape of an object. By analyzing the distortion of the laser stripe in a camera image, the scanner obtains a group of 3D point data of the object. A simple semiconductor stripe laser diode is adopted instead of an expensive LCD projector for complex structured-light pattern. The camera has an optical filter to remove illumination noise and improve the performance of the distance measurement. Experimental results show the 3D data acquisition performance of the scanner with less than 0.2mm measurement error in 2 minutes. It is possible to reconstruct a 3D shape of an object and to reproduce the object by a commercially available 3D printer.

Recognition of Human Body Using Fourier Descriptors and Laser Stripe Signals (푸리에 서술자와 레이저 스트라이프 신호를 사용한 인체의 인식)

  • Kwak Kyung-Sup;Seok Hyun-Tack
    • Journal of Korea Multimedia Society
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    • v.8 no.3
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    • pp.322-327
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    • 2005
  • In this paper we Propose a method that enables to recognize the laser stripe with 3dimensional information of body. Laser stripe has 3-dimensional information. We found out patterns of stripe have features of body. So we made database of it using Fourier Descriptor method and compared it with another stripe of body to recognize bodies. We could recognize standard style of body efficiently It is respected that deep research should be studied on the different style of bodies and then the other features of human will be recognized.

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A Study on the Grating Projection Method using Polygon Mirror (회전다면경을 이용한 줄무늬 격자 영사방법에 관한 연구)

  • Park, Yoon-Chang;Jeong, Kyung-Min;Jang, Seok-Jun;Park, Kyung-Keun
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.6
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    • pp.159-165
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    • 2001
  • Recently Moire and PMP(Phase Measuring Profilometry) are adopted as a practical methodology for non-contact 3-D measurement of free surface. These methods extract the 3-D informations from the images of the object projected with stripe-pattern light. This paper presents a simple projector generating stripe-pattern light using expensive polygon mirror. In this projector, slit-beam is generated with a Laser diode and a rod lens and the laser diode is switched on/off synchronizing with the rotation of the polygon mirror. So its structure is very simple and light-weighted compared to the existent projection methods using several lenses and it is also easy to change the pitch and the phase of the stripe pattern. Experimental results show that the intensity profile of the stripe pattern can be approximated with sinusoidal curve by reducing the pitch of the stripe pattern.

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A Study on the Performance Improvement of a 3-D Shape Measuring System Using Adaptive Pattern Clustering of Line-Shaped Laser Light (선형레이저빔의 적응적 패턴 분할을 이용한 3차원 표면형상 측정 장치의 성능 향상에 관한 연구)

  • Park, Seung-Gyu;Baek, Seong-Hun;Kim, Dae-Gyu;Jang, Won-Seok;Lee, Il-Geun;Kim, Cheol-Jung
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.10
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    • pp.119-124
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    • 2000
  • One of the main problems in 3D shape measuring systems that use the triangulation of line-shaped laser light is precise center line detection of line-shaped laser stripe. The intensity of a line-shaped laser light stripe on the CCD image varies following to the reflection angles, colors and shapes of objects. In this paper, a new center line detection algorithm to compensate the local intensity variation on a line-shaped laser light stripe is proposed. The 3-D surface shape measuring system using the proposed center line detection algorithm can measure 3-D surface shape with enhanced measurement resolution by using the dynamic shape reconstruction with adaptive pattern clustering of the line-shaped laser light. This proposed 3-D shape measuring system can be easily applied to practical situations of measuring 3-D surface by virtue of high speed measurement and compact hardware compositions.

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Distance Measurement Based on Structured Light Image for Mobile Robots (이동로봇을 위한 구조광 영상기반 거리측정)

  • Yi, Soo-Yeong;Hong, Young-Jin;Suh, Jin-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.1
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    • pp.18-24
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    • 2010
  • In this paper, we address an active ranging system based on laser structured light image for mobile robot application. Since the burdensome correspondence problem is avoidable, the structured light image processing has efficient computation in comparison with the conventional stereo image processing. By using a cylindrical lens in the laser generation, it is possible to convert a point laser into a stripe laser without motorized scan in the proposed system. In order to achieve robustness against environmental illumination noise, we propose an efficient integro-differential image processing algorithm. The proposed system has embedded image processing module and transmits distance data to reduce the computational burden in main control system.

The Development of adaptive optical dimension measuring system (적응형 광학 치수 측정 장치 개발)

  • 윤경환;강영준;백성훈;강신재
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.690-695
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    • 2004
  • A new dimension measuring method for the measurement of diameter of an object has been developed using laser triangulation. The 3-D data of an object was calculated from the 2dimensional image information obtained by the laser stripe using the laser triangulation. The system can measure the diameter of hole not only in a normal plane but also in an incline plane. We can experiment with magnification that is optimized according to size of object using zoom lens. In this paper, the theoretical formula and calibration of the system were described. The measuring precision of the system was investigated by experiment.

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Modeling and Calibration of a 3D Robot Laser Scanning System (3차원 로봇 레이저 스캐닝 시스템의 모델링과 캘리브레이션)

  • Lee Jong-Kwang;Yoon Ji Sup;Kang E-Sok
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.1
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    • pp.34-40
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    • 2005
  • In this paper, we describe the modeling for the 3D robot laser scanning system consisting of a laser stripe projector, camera, and 5-DOF robot and propose its calibration method. Nonlinear radial distortion in the camera model is considered for improving the calibration accuracy. The 3D range data is calculated using the optical triangulation principle which uses the geometrical relationship between the camera and the laser stripe plane. For optimal estimation of the system model parameters, real-coded genetic algorithm is applied in the calibration process. Experimental results show that the constructed system is able to measure the 3D position within about 1mm error. The proposed scheme could be applied to the kinematically dissimilar robot system without losing the generality and has a potential for recognition for the unknown environment.