Hand held symbology reader illumination diffuser

摘要

A hand held industrial identification symbol reader projects diffuse illumination onto a region of interest to produce high contrast images of symbols. The diffuse illumination is particularly well suited for producing images of symbols that are marked directly on objects. The diffuse illumination is created through the use of an optically translucent diffuser having a generally tapered shape that distributes diffuse illumination throughout the field of view of the reader. The diffuse illumination can be supplemented with dark field illumination using selectively actuated illumination sources.

主权项

1. An apparatus for imaging a symbol on an object, the apparatus comprising:
a hand held portable imaging system having an imager; a lens disposed between the imager and a region of interest, the region of interest being the intended position of the symbol on the object, the lens and imager defining a field of view and an optical axis; a diffuser concentrically aligned with the optical axis, having a first end surrounding the field of view proximate to the lens, and a second end surrounding the field of view proximate to the region of interest; a dark field illuminating light pipe concentrically aligned with the optical axis and adjacent to the second end of diffuser; and a dark field illuminator directing illumination into the dark field illuminating light pipe.