Method of and system for producing images of objects using planar laser illumination beams and image detection arrays

#1. Technical Field

#The present invention relates generally to an improved method of and system for illuminating the surface of objects during image formation and detection operations, and also to an improved method of and system for producing digital images using such improved methods of object illumination.

#2. Brief Description of the Prior Art

#For a more complete understanding of the present invention, the following Detailed Description of the Illustrative Embodiment should be read in conjunction with the accompanying Drawings, wherein:

#FIG. 1A is a schematic representation of a first generalized embodiment of the planar laser illumination and (electronic) imaging (PLIIM) system of the present invention, wherein a pair of planar laser illumination arrays (PLIAs) are mounted on opposite sides of a linear (i.e. 1-dimensional) type image formation and detection module (IFDM) having a fixed focal length imaging lens, a fixed focal distance and fixed field of view, such that the planar illumination array produces a stationary (i.e. non-scanned) plane of laser beam illumination which is disposed substantially coplanar with the field of view of the image formation and detection module during object illumination and image detection operations carried out by the PLIIM system on a moving bar code symbol or other graphical structure;

#FIG. 1B1 is a schematic representation of the first illustrative embodiment of the PLIIM system of the present invention shown in FIG. 1A, wherein the field of view (FOV) of the image formation and detection module is folded in the downwardly imaging direction by the field of view folding mirror so that both the folded field of view and resulting stationary planar laser illumination beams produced by the planar illumination arrays are arranged in a substantially coplanar relationship during object illumination and image detection operations, and a planar laser illumination beam (PLIB) micro-oscillation mechanism is used to micro-oscillate each beam component within the composite planar laser illumination beam by a relatively small distance with respect to each detector element in the stationary linear image detection array of the PLIIM system, so as to repeatedly illuminate the detector element from a different point in space and at a different moment in time over the photo-integration period of the detector element, thereby destroying the spatial and temporal coherence of the laser illumination beam received at the detector element and reducing the speckle-noise level produced thereat;

#Referring to the figures in the accompanying Drawings, the preferred embodiments of the Planar Laser Illumination and (Electronic) Imaging (PLIIM) System of the present invention will be described in great detail, wherein like elements will be indicated using like reference numerals.

#Overview of the Planar Laser Illumination and Electronic Imaging (PLIIM) System of the Present Invention

#In accordance with the principles of the present invention, an object (e.g. a bar coded package, textual materials, graphical indicia, etc.) is illuminated by a substantially planar laser illumination beam having substantially-planar spatial distribution characteristics along a planar direction which passes through the field of view (FOV) of an image formation and detection module (e.g. realized within a CCD-type digital electronic camera, or a 35 mm optical-film photographic camera), while images of the illuminated object are formed and detected by the image formation and detection module.