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, 2012
Filed:
Nov. 19, 2009
Tomoyasu Takaoka, Osaka, JP;
Shigeru Furumiya, Hyogo, JP;
Naoyasu Miyagawa, Hyogo, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An information recording medium, comprising N number (N is an integer fulfilling N≧3) of information layers on which information is recordable, and allowing information to be recorded on each of the information layers and allowing information recorded on each of the information layers to be reproduced by being irradiated with laser light. The N number of information layers include an N'th information layer, an (N−1)th information layer, an (N−2)th information layer, . . . a second information layer and a first information layer sequentially located from a laser light incidence side. A reflectance of the N'th information layer is R, and a reflectance of an M'th information layer (M refers to every integer fulfilling N>M≧1) is R. The laser light used to irradiate the N'th information layer for reproducing information recorded on the N'th information layer has an upper limit reproduction power Pr, and the laser light used to irradiate the M'th information layer for reproducing information recorded on the M'th information layer has an upper limit reproduction power Pr. The following expressions (1) and (2) are concurrently fulfilled:R>R  (1)Pr<Pr  (2).