Imaging reader with non-uniform magnification within a field of view

摘要

An imaging lens assembly captures return light through a window of a vertical slot scanner from a target located in a range of working distances along an optical axis away from the window, and projects the captured return light onto an array of a solid-state imager. The imaging lens assembly is optically modified for non-uniform magnification within, and for increasing resolution at an outer peripheral region of, a field of view of the array, in an imaging plane generally perpendicular to the optical axis. The magnification is at least partly increased in the imaging plane with increasing radial distance away from the optical axis, to enable reading of the target when tilted relative to the optical axis and located at the outer peripheral region of the field of view.

主权项

1. A reader for electro-optically reading a target by image capture, comprising:
a housing having a window; a solid-state imager supported by the housing, and having an array of sensors with a field of view in which the target is located during reading; an imaging lens assembly having an optical axis, and operative for capturing return light through the window from the target located in a range of working distances along the optical axis away from the window, and for projecting the captured return light onto the array, the imaging lens assembly being optically modified for non-uniform magnification within, and increasing resolution at an outer peripheral region of, the field of view in an imaging plane generally perpendicular to the optical axis, the magnification at least partly increasing in the imaging plane with increasing radial distance away from the optical axis, to enable reading of the target when tilted relative to the optical axis and located at the outer peripheral region of the field of view; and wherein the optically modified imaging lens assembly gradually increases the magnification in the imaging plane with increasing radial distance away from the optical axis until the outer peripheral region of the field of view is reached, and then gradually decreases the magnification in the imaging plane with increasing radial distance away from the optical axis as the outer peripheral region of the field of view is traversed.