Patent ID: 6029893
Filing Date: 2000-02-29
Classification: G06K

Abstract:
An optical scanner for scanning a light beam across a target to read optical indicia, the scanner comprising:a light source for producing the light beam;one or more beam-generation optical elements for shaping and directing the light beam;one or more collector optical elements for collecting and shaping light reflected from the target;a photosensor for detecting at least a portion of the light collected by the collector elements, and for generating an electrical signal indicative of the intensity of the light collected,wherein at least one of the beam-generation optical elements comprises an optical diffuser configured to shape the light beam,wherein the optical diffuser comprises a light shaping diffuser comprising a holographic element that accepts incoming light, and homogenizes and redistributes it over a predetermined angular spread;wherein the optical diffuser comprises a plurality of sections, each section configured to shape the light beam differently from another section;wherein at least two of the sections of the optical diffuser have optical characteristics that differ in ways that shape the light beam differently so that the light beam passing through the two sections is given a different beam waist; andwherein the scanner is configured for reading indicia in which information is encoded as differences in reflectivity of portions of the indicia.