3D- and 2D-scanning machine-vision system

Assembly Automation

ISSN: 0144-5154

Article publication date: 1 September 2003




Rigelsford, J. (2003), "3D- and 2D-scanning machine-vision system", Assembly Automation, Vol. 23 No. 3. https://doi.org/10.1108/aa.2003.03323cad.012



Emerald Group Publishing Limited

Copyright © 2003, MCB UP Limited

3D- and 2D-scanning machine-vision system

3D- and 2D-scanning machine-vision system

Keywords: Scanners, Machine vision, Patents

Applicant: PPT Vision, Inc., USAPatent number: US6,522,777Publication date: 18 February 2003Title: Combined 3D- and 2D-scanning machine-vision system and method

A method and apparatus for obtaining two-and three-dimensional inspection data for manufactured parts in a manufacturing environment is described. Manufacturing lines for making semiconductor devices generally inspect each fabricated part.

The invention provides high-speed 2D imaging of the part using interleaved scanning onto spaced-apart linear imaging rows. One embodiment uses three rows of CCD imaging pixels having an 8-pixel center-to-center spacing. As the imager is scanned across the part, a strobe pulse acquires three lines of pixels simultaneously, the imager is moved a 3-pixel distance, and the next three lines of pixels are acquired. Optionally, the same apparatus is used to alternately perform a 2D scan and then a 3D scan in an interleaved fashion. One such method includes scanning the device within unpatterned light to obtain a high-speed interleaved 2D image, and then scanning the device again with sine-wave spatial-modulation patterned light, and receiving image information to derive 3D height information. The system therefore enables faulty parts to be rejected.

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