Imaging micron-sized defects on reflective surfaces
11 Apr 2016
The novel Trevista Surface 50 overcomes the problems of detecting defects on these difficult surfaces by combining a structured lighting arrangement with a set of patented shape from shading algorithms. This allow information on the 3-dimensional shape of an object to be deduced from the shading of the surface illuminated from different directions. Defects of just a few microns diameter and depth can be detected, making the system ideally suited for demanding quality inspection applications.
Supplied complete with dome-shaped structured diffuse illumination, lens, software, industry-compatible PC and a 5 MPixel Genie TS camera from Teledyne DALSA, Trevista Surface 50 allows quick and automatic 100% inspection of objects over a 50 mm measurement field. The rugged design allows the system to be integrated into a manufacturing process or into an automatic tester in the same way as a traditional vision system.
The dome-shaped illumination equipment ensures optimum and even illumination from different directions and also suppresses interference from ambient light. Images are acquired using STEMMER IMAGING’s Common Vision Blox vision library. Input image data for further analysis is then transferred into the Sherlock machine vision software platform from Teledyne DALSA where it is preprocessed, the resultant images generated and measurements made using Sherlock’s comprehensive range of inspection tools.
Not only can defects be located quickly, reliably and free of interference using the topographic images produced, but a ‘texture’ image is also created that makes it possible to show differences in brightness on the object. The Trevista process closes the gap between 2D image processing and optical 3D shape recognition. It combines the speed of 2D image processing and the precision of 3D recognition to provide a highly effective 100% surface inspection system.