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:
Jun. 19, 2007
Filed:
Aug. 21, 2002
Kenji Yamaga, Chuo-ku, JP;
Tsuyoshi Komaki, Chuo-ku, JP;
Kenji Yamaga, Chuo-ku, JP;
Tsuyoshi Komaki, Chuo-ku, JP;
TDK Corporation, Tokyo, JP;
Abstract
An increase in cost is minimized while realizing larger capacity. An optical discincludes, from the bottom of the drawing: a substrate; a first information recording layerformed on the substrate; and a first light transmission layerhaving a thickness of about 20 μm formed on the first information recording layer. A second information recording layeris formed on the first light transmission layer, and a second light transmission layerhaving a thickness of about 90 μm is formed on the second information recording layer. A laser beam La is irradiated from the side of the second light transmission layerto allow recording and/or reading of an information signal on/from the first and second information recording layersand