3D Precise Inspection of Terminal Lead for Electronic Devices by Single Camera Stereo Vision

Takashi WATANABE  Akira KUSANO  Takayuki FUJIWARA  Hiroyasu KOSHIMIZU  

Publication
IEICE TRANSACTIONS on Information and Systems   Vol.E91-D   No.7   pp.1885-1892
Publication Date: 2008/07/01
Online ISSN: 1745-1361
DOI: 10.1093/ietisy/e91-d.7.1885
Print ISSN: 0916-8532
Type of Manuscript: Special Section PAPER (Special Section on Machine Vision and its Applications)
Category: 
Keyword: 
image processing,  single camera stereo vision,  electronic devices,  terminal lead,  soldering defects inspection,  

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Summary: 
It is very important to guarantee the quality of the industrial products by means of visual inspection. In order to reduce the soldering defect with terminal deformation and terminal burr in the manufacturing process, this paper proposes a 3D visual inspection system based on a stereo vision with single camera. It is technically noted that the base line of this single camera stereo was precisely calibrated by the image processing procedure. Also to extract the measuring point coordinates for computing disparity; the error is reduced with original algorithm. Comparing its performance with that of human inspection using industrial microscope, the proposed 3D inspection could be an alternative in precision and in processing cost. Since the practical specification in 3D precision is less than 1 pixel and the experimental performance was around the same, it was demonstrated by the proposed system that the soldering defect with terminal deformation and terminal burr in inspection, especially in 3D inspection, was decreased. In order to realize the inline inspection, this paper will suggest how the human inspection of the products could be modeled and be implemented by the computer system especially in manufacturing process.