Patent 11003875 was granted and assigned to Cognex Corporation on May, 2021 by the United States Patent and Trademark Office.
This provides an ID reader, typically configured for handheld operation, which integrates three types of illumination into a compact package that generates robust performance and resistance to harsh environmental conditions, such as dust and moisture. These illumination types include, direct (diffuse) light, low-angle light and polarized light. The ID reader includes a sealed reader module assembly having the illuminators in combination with an imager assembly (optics and image sensor) at its relative center. Additionally, also an on-axis aimer and a variable focus system with liquid lens have been integrated in this module and is placed on axis using a mirror assembly that includes a dichroic filter. As the optimal distance to read a code with low-angle light is typically shorter than the optimal distance to use the polarized illumination a variable (e.g. liquid) lens can adjust the focus of the reader to the optimal distance for the selected illumination.