Systems and methods for automatic visual inspection of defects in ophthalmic lenses

Abstract

Automatic visual inspection (AVI) systems and methods are disclosed for inspecting transmissive lenses using a plurality of camera poses to provide deflectometric measurements using fringe patterns from at least two points of view. Phase and/or modulation visibility values of the deflectometric measurements are measured for two sensitivities of the patterns taken through an inspection area of the lens from the points of view. Defects are detected based on the phase and/or modulation visibility values at a defect location as compared to at the local area. A defect type is classified to be prismatic, transmissive, lenslet or cosmetic based on the phase and/or modulation visibility values. The defect is localized on the front or back surface of the lens based on the phase and modulation visibility values, and a geometry of the lens orientation. The lens can be invalidated based on defect types, numbers, relative positions and locations.