Cognex Corporation
Off-axis dual-sensor vision system camera and method for using the same

Abstract:

This invention overcomes disadvantages of the prior art by providing, vision system, typically in the form of a handheld ID reader, which can include two imaging systems, a first imaging system that is off-axis and a second imaging system that is on-axis. The on-axis imaging system is typically standard in configuration, and can be used, for example, with a polarized illumination system. The off-axis imaging system is intended to minimize the camera reflection footprint on a (typically rounded) shiny object to enhance reading of small feature sets (e.g. DMP codes). The off-axis imaging system includes a diffusive illumination source with an emitter in the form of a concave surface, such as a semi-cylinder or dome. Combining images from the two imaging systems allows the contrast of the imaged feature set to be optimized, and provide superior reading and decoding of small codes on shiny rounded surfaces--such as DPM codes.