Scanner with multiple scan units

摘要

To scan indicia on items moving through a predetermined space, without having to manually orient each item so that the indicia faces in a specified direction, a plurality of optical scan units are arranged around the predetermined space. Each scan unit emits light along a different path and receives light reflected from a surface of any item moving along the conveyor. As a result, the scan heads have different lines of sight and fields of view, and the system nominally scans a plurality of different optimal planes oriented to correspond to item surfaces expected to most often bear the indicia. In some embodiments, optical fibers connect the scan units to a central control unit. In such embodiments, the central control unit houses both a laser light generator and a photodetector, and the optical fibers carry the generated laser light to the scan units and carry the reflected light from the scan units back to the photodetector. Circuitry in the central control analyzes signals produced by the photodetector to derive information represented by the optically encoded indicia. <IMAGE>