Holographic laser scanning system for omni-directional laser scanning of bar code symbols with 3-D scanning volume having a large depth of field

摘要

A holographic laser scanning system for producing a highly defined 3-D scanning volume for omni-directional laser scanning of bar code symbols therein having a minimum element width on the order of about 0. 017 inches or less. The holographic laser scanning system comprise a housing, a plurality of laser sources, a holographic scanning disc and a plurality of photodetectors. The plurality of lasr sources are disposed within the housing, for producing a plurality of laser beams. The holographic scanning disc is disposed within the housing, and has a plurality of holographic optical elements for scanning the laser beams and producing a plurality of laser scanning planes for scanning a code symbol. Each laser scanning plane has predefined beam characteristics and is spatially confined within a highly-defined 3-D scanning volume having at least three focal zones, a depth of field of at least 10 inches, and a scanning volume of at least 1,440 cubic inches. The plurality of laser scanning planes intersect within the highly defined 3- D scanning volume and the predefined beam characteristics of the laser scanning planes cooperate within the highly defined 3-D scanning volume so as to produce an omnidirectional laser scanning pattern for omnidirectional scanning therewithin, code symbols having a minimum element width on the order of about 0.017 inches or less.