Optical detector for paper handler used for double-sided scanning or printing

摘要

The paper is carried by a rotating drum (13) carrying a circumferential optical track (36) formed with bands having differing coefficients of reflection. An optical detector (34) has a light source (40) directed onto the optical track and a photosensitive cell (41) receiving light reflected from the track. The signal (S1) from the detector is delivered to a controller and used to control operation of the drum and to detect anomalies in its operation.