Reflected light reading station for binary data - uses cylindrical focussing lenses and polarising filters

摘要

The optical reading of multi-digit binary codes using deflected light is greatly enhanced by the use of cylindrical lenses and polarisation filters. The information is stored in coded form on a card that is held against a glass base (12) within a frame (10). Light emitting cells (18) direct light through polarising filters (26) and focussing cylinder lenses (20). The reflected signals are received by photo-transistor stages (22), after processing through a focussing lense (24) and polarising filter (28). The system exhibits a reduced sensitivity to ambient disturbances.