P.C.B Inspection System

The system is for inspecting pieces, having a nominally flat surface with undulated areas thereon e.g. PCB's. It comprises a source 6 for a band of light "L" across each piece 15 passed through the system, optical means 5 responsive to undulated areas of each piece passing through the band of light to detect changes in height or depth from the flat surface to produce an optically derived image of the profile of said piece, video imaging means 4 arranged in a line and directed towards the optically derived image, photoelectric conversion means such as a CCD detector 14 for receiving light images detected by the video imaging means and converting them into electric Signals indicative of any height or depth changes, means 3 for moving the or each piece progressively through the band of light to produce a plurality of profile slices of each piece, and means 9 for integrating the electric signals representative of these slices to produce a complete profile of the undulations and their position over the complete surface of each piece for comparison with a reference piece. <IMAGE>