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:
Feb. 29, 2000
Filed:
Feb. 04, 1999
Masahiro Ito, Kanagawa, JP;
Shohei Mimura, Kanagawa, JP;
Masao Shigeta, Chiba, JP;
Tsutomu Chou, Chiba, JP;
Tokyo Magnetic Printing Co., Ltd., Tokyo, JP;
TDK Corporation, Tokyo, JP;
Abstract
A magnetic recording medium, and a method of making the same, including an irreversible recording layer which undergoes an irreversible change of saturation magnetization upon heating. The magnetic recording medium includes on at least a portion of a substrate an irreversible recording layer which contains an irreversible recording material undergoing an irreversible change of saturation magnetization upon heating. The irreversible recording layer includes at least in part a fixed information recording region for recording the fixed information of the medium. In the fixed information recording region, a plurality of heated bars whose saturation magnetization has been irreversibly changed are arrayed substantially parallel to each other. The array pattern of the heated bars or the array pattern of unheated bars disposed between adjacent ones of the heated bars contains the fixed information encoded in a frequency modulation process or phase modulation process.