Aperture stop in imaging reader

摘要

An aperture stop focuses light from indicia onto a solid-state imager of an imaging reader. The aperture stop has an open aperture with a scan dimension sized to resolve symbol elements, and with a height dimension to allow sufficient light to be captured. A cylindrical lens can be used to collect additional light. The aperture stop provides a large depth of focus and enables symbols to be read over a wide field of view. The need to use an expensive multiple lens assembly with the imager is eliminated.