Planar laser illumination and imaging system

Abstract

Methods of and systems for illuminating objects using planar laser illumination beams having substantially-planar spatial distribution characteristics that extend through the field of view (FOV) of image formation and detection modules employed in such systems. Each planar laser illumination beam is produced from a planar laser illumination beam array (PLIA) comprising an plurality of planar laser illumination modules (PLIMs). Each PLIM comprises a visible laser diode (VLD, a focusing lens, and a cylindrical optical element arranged therewith. The individual planar laser illumination beam components produced from each PLIM are optically combined to produce a composite substantially planar laser illumination beam having substantially uniform power density characteristics over the entire spatial extend thereof and thus the working range of the system. Preferably, each planar laser illumination beam component is focused so that the minimum beam width thereof occurs at a point or plane which is the farthest or maximum object distance at which the system is designed to acquire images, thereby compensating for decreases in the power density of the incident planar laser illumination beam due to the fact that the width of the planar laser illumination beam increases in length for increasing object distances away from the imaging optics. By virtue of the present invention, it is now possible to use both VLDs and high-speed CCD-type image detectors in conveyor, hand-held and hold-under type scanning applications alike, enjoying the advantages and benefits that each such technology has to offer, while avoiding the shortcomings and drawbacks hitherto associated therewith.

1 - 32 . (canceled)  
   
   
       33 . A planar laser illumination and imaging (PLIIM) based system, comprising: 
 an image formation and detection module having a field of view (FOV) focused at an image detecting array; and    a planar laser illumination array (PLIA) for producing a planar laser illumination beam that extends the field of view (FOV) of said image formation and detection module, so that laser light reflected off an object illuminated by said substantially planar laser illumination beam is focused along said FOV and onto said image detecting array to form an image of said illuminated object.    
   
   
       34 . The PLIIM-based system of  claim 34 , wherein said PLIA includes a plurality of visible laser diodes (VLDs), and 
 wherein the power density contributions of said VLDs are additively combined to produce said substantially planar laser illumination beam having substantially uniform power density characteristics in near and far field regions of said PLIIM-based system.