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:
Mar. 02, 1999
Filed:
Sep. 19, 1997
Pieter J Kerstens, Boca Raton, FL (US);
Huizong Lu, Coconut Creek, FL (US);
Hee Kuwon Park, Boynton Beach, FL (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Optical apparatus is provided for inspecting a textured surface measures a level of scattered reflections from the surface, occurring when an inspection laser beam is directed at the surface. In a first version of the apparatus, the intensity of scattered reflections directed at a single light-sensitive element are compared with the intensity of specular reflections directed at another light-sensitive element. In a second version, diffraction rings formed by the scattered reflections are passed through a mask which attenuates their intensity according to differences between the actual diffraction rings and a predetermined diffraction pattern. In a third version, the scattered light is divided by a beamsplitter to pass through one mask which increases attenuation as the diffraction rings are increased in size compared to a predetermined diffraction pattern or through another mask which decreases attenuation as the diffraction rings are decreased in size compared to the predetermined diffraction pattern.