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:
Feb. 11, 1992
Filed:
Oct. 01, 1990
Osamu Kakuchi, Kawasaki, JP;
Mikichi Ban, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A device for measuring depth of a groove formed on an article includes a light source for illuminating the article, a first detector for receiving light from a portion of the article having a groove and being illuminated by the light source, and for detecting a spectral reflectance in relation to the received light, a second detector for receiving light from the article illuminated by the light source and for detecting a spectral reflectance in relation to the received light, the second detector being effective to detect the spectral reflectance in a way not affected or substantially not affected by the groove of the article as compared with the detection by the first detector, and a depth detector for detecting the depth of the groove on the basis of the results of detection by the first and second detectors.