Apparatus for and method of uniformly illuminating fields of view in a point-of-transaction workstation

摘要

Indicia are imaged at a workstation having windows arranged in intersecting planes. The workstation also has solid-state imagers with fields of view that are split into intersecting subfields that look out through the windows, as well as illumination assemblies each having multiple light sources that illuminate each subfield with illumination light over an illumination field that overlaps a respective subfield. Light-modifying elements, such as lenses or baffles that are radially offset from the multiple light sources, condition the illumination light from the multiple light sources to be generally uniform in light intensity over at least one illuminated subfield.

主权项

1. An apparatus for imaging indicia, comprising:
a housing; a window supported by the housing; a solid-state imager supported by the housing and having an array of image sensors with a field of view; an optical system supported by the housing and operative for splitting the field of view of the imager into a plurality of intersecting subfields of view that extend through and past the window to the indicia to be imaged; a plurality of illumination assemblies each comprising at least one LED, and arranged over each of said respective LEDs is a respective lens, one or more for each subfield view, each illumination assembly having a plurality of illumination light sources for illuminating a respective subfield of view with illumination light over an illumination field that overlaps the respective subfield of view, the optical system being further operative for capturing the illumination light returned from the indicia in each illuminated subfield of view; a controller operatively connected to the imager and the illumination assemblies, for processing the captured illumination light in at least one of the illuminated subfields of view; a plurality of light-modifying elements, one for each illumination assembly, each light-modifying element being operative for conditioning the illumination light from the plurality of illumination light sources to be generally uniform in light intensity over the at least one illuminated subfield of view; and wherein each illumination light source emits an illumination light beam, wherein each illumination assembly has a pair of the illumination light sources in close adjacent relationship, wherein each light-modifying element includes either (1) a pair of lenses having respective optical axes and at least partly overlying the closely adjacent pair of the illumination light sources with each illumination light source being offset from a respective lens in a direction radially of a respective optical axis or (2) a pair of lenses having respective optical axes and overlying the closely adjacent pair of the illumination light sources, and a pair of baffles at least partly overlying the closely adjacent pairs of the illumination light sources and the lenses with each baffle being offset from a respective illumination light source and a respective lens in a direction radially of a respective optical axis, wherein the light-modifying elements are operable to combine the illumination light beams in a corresponding subfield of view into a combined light beam having an intensity that is generally uniform over the corresponding subfield of view.