A holographic scanning system for scanning a bar coded label is disclosed in which the light beams of a laser are directed at a set of holograms located on a rotating disk in which each hologram will generate an individual scan beam having a slightly different focal length and direction angle from that...http://www.google.fr/patents/US4794237?utm_source=gb-gplus-shareBrevet US4794237 - Multidirectional holographic scanner
