Holographic laser scanning system for carrying out laser beam scanning operations with improved scan angle multiplication efficiency and carrying out light collection operations with improved light collection efficiency

Claim 1

A holographic laser scanning system for carrying out laser beam scanning operations with improved scan angle multiplication efficiency and laser light collection operations with improved light collection efficiency, said holographic laser scanning system comprising: a housing of compact construction; a holographic scanning disc disposed within said housing for rotation about an axis; a plurality of laser beam sources disposed within said housing, for producing plurality of laser beams and directing each said laser beam towards said holographic scanning disc at an angle of incidence substantially greater than twenty-three degrees relative to a normal vector drawn to said holographic scanning disc; said holographic scanning disc including a plurality of holographic optical elements, each said holographic optical element having an outer edge portion for focusing and deflecting said laser beams as said laser beams are transmitted through said outer edge portion at said angle of incidence during said laser beam scanning operations, and a total surface area for collecting light rays reflected off a scanned code symbol for subsequent focusing and detection during light collection operations; a plurality of laser beam folding mirrors disposed within housing and about said holographic scanning disc, for folding said deflected laser beams and producing a plurality of laser scanning planes outside of said housing, said plurality of laser scanning planes intersecting to produce a laser scanning pattern within a 3-D scanning volume for scanning a code symbol present therein; wherein, during laser beam scanning operations, each said laser beam produced from said laser beam sources is transmitted through said outer edge portion of each said holographic optical element as said holographic scanning disc rotates about said axis of rotation, and wherein, during light collection operations, a portion of the laser light rays reflected off a code symbol scanned by one said laser scanning plane is collected over said total surface area of said holographic optical element producing said laser scanning plane; a plurality of light focusing surfaces disposed within said housing and beneath said holographic scanning disc, each said light focusing surface focusing towards a focal point the laser light rays collected by one said holographic optical element positioned above said light focusing surface during said light collecting operations; and a plurality of photodetectors, each said photodetector being disposed within said housing and at the focal point of one said light refocusing surface, for detecting the intensity of said focused laser light rays for detection and generation of a scan data signal for subsequent processing, whereby said laser beam scanning operations are carried out with improved scan angle multiplication efficiency and said light collection operations are carried out with improved light collection efficiency.