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US 8,475,006 B2Granted
Dark field illuminator and a dark field illumination method
AssigneeCamtek Ltd.
InventorZehava Ben-Ezer
Life of this patent
Estimating the term…
Abstract
A dark field illuminator that includes: (i) a light source adapted to provide ring of light characterized by uniform intensity distribution; (ii) a collimating ring 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 angle; and wherein the collimating ring and the light source are co-centric to an optical axis of the dark field illuminator.
Claims24
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.
4 more elements
A dark field illumination method, comprising:
- illuminating a folding ring reflector by ring of light characterized by a uniform intensity distribution;
- directing, by the folding ring reflector, first reflected light beams towards an area of an inspected object such that different points within the area of the inspected object are illuminated by substantially identical cones of light characterized by a first incidence angle;
- directing, by the folding ring reflector, second reflected light beams towards a refracting ring;
- directing, by the folding ring reflector, third reflected light beams towards an oriented ring reflector;
- altering, by the refracting ring, an angle of incidence of the second reflected light beams so 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;
- and
- reflecting, by the oriented ring reflector the third reflected light beams so 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 ring reflector, the oriented ring reflector and the refracting ring are co-centric to an optical axis of a dark field illuminator that comprises the light source, the folding ring reflector, the oriented ring reflector and the refracting ring.
5 more elements
Dependencies are inferred from the claim text.