• Title/Summary/Keyword: $2{\pi}$ 모호성

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A Study on 3-D Shape Measurement and Application by Using Digital Projection Moire (II) (디지털 영사식 무아레를 이용한 3차원 형상 측정과 응용에 관한 연구(II))

  • Ryu, Weon-Jae;Kang, Young-June;Rho, Hyung-Min;Lee, Dong-Hwan
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.5
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    • pp.62-67
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    • 2007
  • A simple dimension measuring method for the measurement of human bust has been developed using projection moire. The 3-D data of a human bust was calculated from the 2dimensional image information obtained by the stripe using projection moire. The creation of 3-D geometric shape by digitizing real objects has been widely investigated in reverse engineering(RE). This procedure generally consists of three basic steps: data capture, data alignment and model reconstruction. In order to achieve a complete model, multiple scans must be taken and aligned.

Phase unwrapping enhancement of phase shift interferometry by using lateral scanning (횡방향 주사를 이용한 광위상 간섭계의 페이즈 언래핑 향상에 대한 연구)

  • Park, Do-Min;Park, Sung-Lim;Gweon, Dae-Gab
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.22 no.3
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    • pp.684-687
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    • 1998
  • The biggest problem common on to all forms of Phase Shift Interferometer is unwrapping the phase. Simple phase unwrapping algorithms assume that every pixel is within radians of its neighbors. If this is true, any reasonable algorithm will return the correct unwrapped phase. If not, correct unwrapped phase will not be obtained. In rough surface, frequently, neighboring pixels have phase steps greater than. This paper proposes the new method which makes phase steps smaller than by sub-pixel movement.

2D/3D Visual Optical Inspection System for Quad Chip (Quad Chip 외관 불량 검사를 위한 2D/3D 광학 시스템)

  • Han, Chang Ho;Lee, Sangjoon;Park, Chul-Geon;Lee, Ji Yeon;Ryu, Young-Kee;Ko, Kuk Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.1
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    • pp.684-692
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    • 2016
  • In the manufacturing process of the LQFP/TQFP (Low-profile Quad Flat Package/Thin Quad Flat Package), the requirement of a 3 dimensional inspection is increasing rapidly and a 3D inspection of the shape of a chip has become an important report of quality control. This study developed a 3 dimensional measurement system based on PMP (Phase Measuring Profilometry) for an inspection of the LQFP/TQFP chip and image processing algorithms. The defects of the LQFP/TQFP chip were classified according to the dimensions. The 2 dimensional optical system was designed by the dorm illumination to achieve constant light distribution, In the 3 dimensional optical system, PZT was used for moving 90 degree in phase. The problem of 2 ambiguity was solved from the measured moir? pattern using the ambiguity elimination algorithm that finds the point of ambiguity and refines the phase value. The proposed 3D measurement system was evaluated experimentally.