Cognex Corporation
System and method for acquiring images of surface texture

Abstract:

This invention provides a vision system camera assembly that includes an optics and illumination module that is removably attached thereto, and that is arranged to project illumination along an optical axis of the imager. This arrangement allows for short exposure time and a short working distance from an imaged scene/surface under inspection. A semi-reflecting mirror turns a structured illumination beam from an illumination axis onto the optical axis while allowing light from the imaged scene to pass through the mirror and into the imager optics. The front end of the module contains a collimating optics that causes a collimated beam from the mirror to strike the surface at various off-axis angles. The collimating optics can include a telecentric lens assembly that can comprise a pair of stacked lenses having a perimeter that is equal to or greater than the area of interest on the surface.