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. 01, 2011
Filed:
Jan. 26, 2009
Tatsuo Hariyama, Fujisawa, JP;
Hideaki Sasazawa, Yokohama, JP;
Minoru Yoshida, Yokohama, JP;
Shigeru Serikawa, Chigasaki, JP;
Tatsuo Hariyama, Fujisawa, JP;
Hideaki Sasazawa, Yokohama, JP;
Minoru Yoshida, Yokohama, JP;
Shigeru Serikawa, Chigasaki, JP;
Hitachi High-Technologies Corporation, Tokyo, JP;
Abstract
The present invention relates to an apparatus for detecting defects on a disk surface which projects light on the disk surface by a light transmitting system, receives specula reflection light and scattered light by a light receiving system, exposes defects by performing a two-dimensional frequency filter process on a signal, and performs a defect determination process to extract a linear-shaped isolative defect candidate. Next, the present invention performs a periodicity determination process to classify and detect the periodically generated linear and circular arc defects and the isolatively generated linear and circular arc defects.