The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 08, 1986
Filed:
Jul. 19, 1982
Applicant:
Inventors:
Edgar F Steigmeier, Hedingen, CH;
Heinrich Auderset, Horgen, CH;
Assignee:
RCA Corporation, Princeton, NJ (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
356237 ; 250572 ;
Abstract
Apparatus for detecting defects and dust on patterned surfaces, such as patterned wafers, or grooved video disks, utilizes a scanning laser that provides light scattered by defects and dust. The scattered light is detected substantially free of diffracted beams from the pattern by a mask having apertures arranged to pass to the detector only scattered light and to block diffracted light and specular reflections.