DARK FIELD ILLUMINATOR AND A DARK FIELD ILLUMINATION METHOD

摘要

A drak field illuminator (51) that includes: (i) a light source (21) adapted to provide a ring of light characterized by uniform intensity distribution; (ii) a collimating ring (22) adapted to receive the ring of light and to direct collimated light beams towards an area of an inspected object such that different points within the area are illuminated by identical cones of light characterized by an incidence angl and wherein the collimating ring and the light source are co-centric to an optical axis of the dark field illuminator.