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:
May. 18, 2010
Filed:
Sep. 06, 2005
Morio Nakatani, Shijonawate, JP;
Satoshi Sumi, Gifu, JP;
Masahiro Nakata, Ohgaki, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
A substrate in which a minute ruggedness structure including columnar projections is formed in a track shape is prepared. The pitch of the columnar projections of the ruggedness structure is set such that a plurality of the columnar projections is within a beam spot. A flat portion is disposed between adjacent tracks. A reflecting layer is formed on the substrate. The flat portion becomes a mirror surface because of the formation of the reflecting layer. The reflectance of the ruggedness structure becomes significantly lower than the reflectance of the flat portion. When the ruggedness structure is irradiated with high-power laser light, a portion of the ruggedness structure is raised to a reflecting layer side and flattened. At this time, reflectance of the raised portion becomes higher than reflectance of a non-raised portion. When a track including the ruggedness structure is irradiated with high-power pulse laser light, signal recording based on a change in reflectance is possible.