Optical scanner for reading bar=code symbols - use two continuous light beams directed by mirror and rotating polygon mirror onto surface of bar=code

摘要

The optical scanner system has two light sources (10,11) with optical focussing stages (12,13). The sources can be laser diodes or helium-neon lasers. The light beams are reflected by mirrors (16) onto the surfaces of a rotating polygon mirror (18). The reflecting mirror has angled surfaces (22) providing a small difference in the reflected beams. The beams reflected off the facets of the rotating polygon are directed onto the code surface and are modulated and reflected back to be directed at a receiver (24). The signals are amplified and received by a comparator (27). USE/ADVANTAGE - Uses two continuous light sources avoiding switching problems.