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:
Mar. 25, 2008
Filed:
Sep. 01, 2004
Enji Fujita, Kashiwa, JP;
Hideaki Yamanaka, Toride, JP;
Tsuyoshi Onuma, Moriya, JP;
Satoshi Matsunuma, Kamakura, JP;
Akira Yano, Moriya, JP;
Tetsunori Koda, Tsukuba, JP;
Katsusuke Shimazaki, Toride, JP;
Enji Fujita, Kashiwa, JP;
Hideaki Yamanaka, Toride, JP;
Tsuyoshi Onuma, Moriya, JP;
Satoshi Matsunuma, Kamakura, JP;
Akira Yano, Moriya, JP;
Tetsunori Koda, Tsukuba, JP;
Katsusuke Shimazaki, Toride, JP;
Hitachi Maxwell Ltd, Osaka, JP;
Abstract
A magnetic recording medium based on the perpendicular magnetic recording system includes a substrate; a back layer which is formed on the substrate and which is formed of a soft magnetic material; an in-plane magnetized layer which is formed on the back layer and which has in-plane magnetization; and a recording layer which is formed on the in-plane magnetized layer and which has perpendicular magnetization, wherein the in-plane magnetized layer has a coercivity in an in-plane direction larger than a magnetic field generated by residual magnetization in a perpendicular direction of the recording layer. The influence on the reproduction output, caused by the mirror image effect of the soft magnetic back layer is reduced in wide range recording densities, thereby improving the resolution by decreasing the difference between the reproduction outputs of the magnetic recording medium at the low recording density and at the high recording density.