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. 04, 1990
Filed:
Jun. 13, 1989
Ippei Takahashi, Shizuoka, JP;
Takeshi Wakita, Shizuoka, JP;
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
A method and apparatus for scanning a surface of an optical disk which has signal recording pits or bumps covered with a transparent layer, with a flying spot to detect surface defects of the optical disk surface. The optical disk is rotated at a constant speed of rotation and scanned along a scanning line parallel to but spaced at least 10 mm from a line radial to the center of rotation of the optical disk. A light-detecting unit receives diffused light reflected by the disk surface to provide an output corresponding to the intensity of the diffused light and converts it into an electric output which is used to evaluate the surface of the optical disk.