There are several ways to inspect parts using 3D machine vision technology. Of these methods, laser triangulation is the fastest and most cost-effective, but the method isn’t flawless.
Laser triangulation measurement systems have speckle, which creates waviness, or uncertainty, in an object’s profile. Engineers try to reduce its impact in various ways, like shifting to a shorter wavelength and increasing the aperture of the camera. However, these tactics only result in a reduction, not elimination, of the speckle. This has been a fundamental limit of laser measurement systems, until now….
Cognex has patented a speckle-free laser that eliminates the appearance and effects of speckle to produce an extremely straight, clean, and bright profiling line. This paper details how this unique optical design: