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:
Sep. 30, 1986
Filed:
Apr. 27, 1984
Yasuhiko Hara, Yokohama, JP;
Yoshimasa Ohshima, Yokohama, JP;
Satoru Fushimi, Yokohama, JP;
Hiroshi Makihira, Yokohama, JP;
Hitachi Ltd., Tokyo, JP;
Abstract
A pattern defect is detected in accordance with the difference between a pair of patterns. The patterns are scanned and imaged to obtain first and second binary signals. A positioning error between the patterns is two-dimensionally detected during the scanning with respective first and second binary signals delayed by a prescribed amount so that each of the picture elements in a prescribed area of a two-dimensional image, delayed and cut out two-dimensionally, corresponding to one pattern, is compared with a specified picture element in a predetermined area of an image delayed and cut out two-dimensionally corresponding to another pattern. The result of the comparison is statistically summed to derive a positioning error by detecting the position shown as an extreme value from the summed values. The positioning error is corrected by two-dimensionally shifting at least one of the delayed binary signals. The corrected binary signals are then two-dimensionally compared with each other.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile