Projection laser scanner for scanning bar codes within a confined scanning volume

Abstract

A bar code scanner for projecting a scanning pattern comprising a plurality of groups of scan lines, where each scan line in a given group is substantially parallel to other scan lines in the same group. The scanning pattern is provided within a relatively narrow, yet diverging, volume, such as a pyramid, cone, etc., as referenced to a projection axis. The scanner includes a housing having a window. Within the housing are a plurality of stationary mirrors, a laser beam generating mechanism, a rotating reflective polygon for sweeping the laser beam across the mirrors and a window, such that the projection axis intersects the window. The scanner also includes a fixed collecting mirror and a concentrating lens to focus light which is reflected off a bar code to a photodector. One mirror extends along an axis substantially parallel to the transverse axis to produce a first group of scan lines. The second and third mirrors are disposed opposite each other laterally of the polygon and extending along respective axes at a first acute angle, illustratively 8 degrees, to the longitudinal axis to produce respective ones of a second and a third group of scan lines. The fourth and the fifth mirrors, respectively, each extend along a respective axis at a second acute angle, illustratively 48 degrees to the longitudinal axis, to produce respective ones of a fourth and a fifth group of scan lines.

Dependencies are inferred from the claim text.