Illumination apparatus for an imaging-based bar code reader

An imaging-based bar code reader comprising:

• an imaging system including a lens and a sensor array for focusing illumination from a target object onto the photosensor array, the imaging system defining a field of view directed toward the target object;
• and
• an illumination apparatus for directing an illumination pattern toward the target object and including:
• an illumination array defining a plurality of spaced apart visible illumination sources;
• an aperture plate spaced from the illumination array in a direction of the field of view and defining a plurality of spaced apart apertures aligned with respective illumination sources of the illumination array such that illumination generated by each illumination source passes through a respective corresponding aperture of the aperture plate;
• and
• a lens array spaced from the aperture plate in a direction of the field of view and defining a plurality of substantially contiguous lens elements aligned with respective apertures of the aperture plate such that for each aperture of the aperture plate illumination passing through the aperture is focused by a respective corresponding lens element, lens elements of the lens array combining to generate a visible illumination pattern substantially corresponding to the field of view of the imaging system.

A method of imaging a target object, the steps of the method including:

• providing an imaging system including a lens and a sensor array for focusing reflected illumination from a target object onto the photosensor array, the imaging system defining a field of view directed toward the target object;
• providing an illumination apparatus including an illumination array defining a plurality of spaced apart visible illumination sources;
• an aperture plate spaced from the illumination array in a direction of the field of view and defining a plurality of spaced apart apertures aligned with respective illumination sources of the illumination array such that illumination generated by each illumination source passes through a respective corresponding aperture of the aperture plate;
• and a lens array spaced from the aperture plate in a direction of the field of view and defining a plurality of substantially contiguous lens elements aligned with respective apertures of the aperture plate such that for each aperture of the aperture plate illumination passing through the aperture is focused by a respective corresponding lens element, lens elements of the lens array combining to generate a visible illumination pattern substantially corresponding to the field of view of the imaging system;
• and
• energizing the illumination system and the imaging system and imaging the target object.

An illumination apparatus for an imaging-based bar code reader including an imaging apparatus defining a field of view directed toward a target object, the illumination apparatus comprising:

• illumination array means defining a plurality of spaced apart visible illumination sources;
• an aperture plate means spaced from the illumination array in a direction of the field of view and defining a plurality of spaced apart apertures aligned with respective illumination sources of the illumination array such that illumination generated by each illumination source passes through a respective corresponding aperture of the aperture plate;
• and
• a lens array means spaced from the aperture plate in a direction of the field of view, lens elements of the lens array combining to generate a visible illumination pattern substantially corresponding to the field of view of the imaging system.

An illumination apparatus for an imaging-based bar code reader having a field of view defined by an imaging system of the bar code reader directed toward a target object, the illumination apparatus comprising:

• an illumination source providing a source of illumination;
• an aperture plate spaced from the illumination source in a direction of the field of view and defining a plurality of spaced apart apertures aligned with the illumination source such that illumination passes through the plurality of apertures of the aperture plate;
• and
• a lens array spaced from the aperture plate in a direction of the field of view and defining a plurality of substantially contiguous lens elements aligned with respective apertures of the aperture plate such that for each aperture of the aperture plate illumination passing through the aperture is focused by a respective corresponding lens element, lens elements of the lens array combining to generate an illumination pattern substantially corresponding to the field of view of the imaging system wherein a sharpness of peripheral edges of the illumination pattern is a maximum at substantially a best in-focus target plane of the imaging system.