Laser system for measuring spot position on surface - has optical system which stretches or displaces image transversally w.r.t. row of image supporting photodetector elements

摘要

The arrangement uses a laser (10) beam (12) which is directed to a mirror (13) to permit orientation of the beam to ensure that its position on a point (16) of a surface (15) can be controlled. The mirror is orientated from a microprocessor control and processing unit (45) using bus lines (44,46). Two inspection stations (20,21) each comprise optical systems (22,23) directed onto the surface. These systems contain photodetectors in matrices (24,25) on which the optical system forms images (26,27) of the point. The position of each image is detected w.r.t. a reference and depends on the illuminated area. The photodetector outputs are applied to output interfaces (40,41) to permit entry to the microprocessor to calculate the spot coordinates.