Patent ID: 8475006

Claim:
A dark field illuminator, comprising: a light source adapted to provide ring of light characterized by uniform intensity distribution; a folding ring reflector adapted to receive the ring of light and to: direct first reflected light beams towards an area of an inspected object, direct second reflected light beams towards a refracting ring, and direct third reflected light beams towards an oriented ring reflector; wherein the first reflected light beams illuminate different points within the area of the inspected object by substantially identical cones of light characterized by a first incidence angle; wherein the refracting ring alters an angle of incidence of the second reflected light beams such as to illuminate the different points within the area of the inspected object by substantially identical cones of light characterized by a second incidence angle; wherein the oriented ring reflector reflects the third reflected light beams such as to illuminate the different points within the area of the inspected object by substantially identical cones of light characterized by a third incidence angle; wherein the folding ring reflector, the oriented ring reflector and the refracting ring are co-centric to an optical axis of the dark field illuminator.