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:
Jul. 20, 2010
Filed:
Jun. 12, 2008
Hiroshi Shinngai, Tokyo, JP;
Hideki Hirata, Tokyo, JP;
Tatsuya Kato, Tokyo, JP;
Hiroshi Takasaki, Tokyo, JP;
Yasuhiro Takagi, Tokyo, JP;
Masaki Sobu, Tokyo, JP;
Masanori Kosuda, Tokyo, JP;
Hiroshi Shinngai, Tokyo, JP;
Hideki Hirata, Tokyo, JP;
Tatsuya Kato, Tokyo, JP;
Hiroshi Takasaki, Tokyo, JP;
Yasuhiro Takagi, Tokyo, JP;
Masaki Sobu, Tokyo, JP;
Masanori Kosuda, Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
A rewritable phase-change optical recording medium is provided, which includes a substrate, a first information layer, a spacer layer, a second information layer, and a cover layer. The second information layer includes a recording film containing Sb as a main component and V or V and In as second components. When an amorphous mark formed in the recording film is irradiated with a reproduction beam, crystallization of the amorphous mark occurs only in a central portion in the width direction of the amorphous mark. The width direction is orthogonal to the scanning direction of the laser beam. The recording film is formed of a material that exhibits a change in degree of modulation of 5% or less when recorded information is repeatedly reproduced. The change in degree of modulation is a change from when the number of times of reproduction is 100,000 to when it is 400,000.