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. 07, 2011
Filed:
Apr. 16, 2007
Masaru Yamaoka, Osaka, JP;
Mamoru Shoji, Osaka, JP;
Kenji Kondo, Osaka, JP;
Keiji Nishikiori, Kyoto, JP;
Masaru Yamaoka, Osaka, JP;
Mamoru Shoji, Osaka, JP;
Kenji Kondo, Osaka, JP;
Keiji Nishikiori, Kyoto, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An optical disc () to and from which information can be reproduced and recorded by laser irradiation is provided with a first recording layer () and a second recording layer (). The first recording layer () has a first recording mark () that is formed in a spiral track. The second recording layer () is behind or in front of the read-side surface of the first recording layer (), and neither a wobble track nor a track for reproducing or recording information by laser irradiation is formed on the second recording layer (). On the second recording layer () are formed, by laser irradiation, a second recording mark () that is positioned in the radial direction of the optical disc according to a predetermined position on the spiral track of the first recording layer. The optical disc () ensures the secrecy of the copyright protected information that is recorded thereto and the copyright protection function of the optical disc (), and is resistant against illegal copying.