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:
Apr. 26, 2005
Filed:
Aug. 07, 2000
Gary Cook, Malvern, GB;
Gary Cook, Malvern, GB;
Qinetiq Limited, Farnborough, GB;
Abstract
An optical inspection system () for comparing surface structures of test and reference objects comprises a laser (), a photorefractive crystal () and a detector (). A refractive index grating corresponding to a diffraction pattern of a surface structure of the reference object is present within the photorefractive crystal () and acts as a spatial filter for light diffracted by surface structures of the test objects. If a surface structure of a test object matches that of the reference object, little or no light reaches the detector (). If the surface structure of a text object differs from that of the reference object, light of greater power reaches the detector (). The system () provides a simple pass/fail comparison test and light incident on the detector () requires no interpretation or other processing. The system () may be adapted to allow simple imaging of an edge of an object.