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. 08, 2009
Filed:
Nov. 16, 2004
Toshihiko Okamoto, Tokyo, JP;
Toshihiko Okamoto, Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
A method of scanning an information recording medium and a scanning apparatus for an information recording medium that uses the method scan for defects in respective resin layers of an information recording medium that has a plurality of resin layers and a plurality of information layers, which are separated by the respective resin layers, laminated on at least one surface of a substrate. The method includes: an image capture step of emitting scanning light toward the one surface at a predetermined incident angle from a fixed position on the one surface side, rotating the information recording medium in a fixed direction, and simultaneously receiving reflected light for the scanning light at a fixed position on an optical path of the reflected light to capture images at predetermined time intervals; a counting step of counting a number of images of a same defect that have been captured in the image capture step; and a specifying step of specifying that an (N−1)-th resin layer counting from the substrate side is a resin layer in which the defect is present when the counted number of images is N, where N is a natural number of two or higher.