Diffuse bright field illumination system for a barcode reader

摘要

One aspect of the present disclosure is related to a barcode reader that includes a bright field illumination system, a dark field illumination system, and an additional illumination system that is better able to illuminate an area of the reader's field of view between the far zone (where bright field illumination is optimal) and the close zone (where dark field illumination is optimal). In this “center zone,” the dark field illumination may not be bright enough and the bright field illumination may not be diffuse enough for reading a barcode.

主权项

1. A barcode reader, comprising:
a housing; a camera located within the housing configured to capture an image of a barcode within a field of view of the camera, the field of view being directed along an optical axis; and an illumination system configured to illuminate the barcode while the camera captures the image of the barcode, the illumination system comprising:
at least one light source; andan optical substrate, not within the field of view of the camera, having front and back major surfaces arranged generally perpendicular to the optical axis, and between which light introduced from the at least one light source is transferred by total internal reflection primarily in a direction transverse to the optical axis,wherein the optical substrate comprises one or more extraction features configured to extract light from the optical substrate and into the field of view.