An improved bar code reading system for reading bar codes having a wide range of intensity of reflected radiation includes repeatedly scanning a beam of radiation across a bar code containing bar and space code elements; monitoring the number of scans of the beam across the bar code; sensing the radiation...http://www.google.co.uk/patents/US5149948?utm_source=gb-gplus-sharePatent US5149948 - Improved bar code reader system for reading bar codes under high specular reflection conditions with a variety of surface effects
