An optical angular position sensing system determines the angular position of a primary, beam-directing mirror by sensing the position of a beam from a secondary light source reflected from a secondary mirror on the back surface of the primary mirror. The position sensing system includes a photodetector...http://www.google.fr/patents/US5223710?utm_source=gb-gplus-shareBrevet US5223710 - Optical angular position sensing system for use with a galvanometer
Optical angular position sensing system for use with a galvanometer
