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:
Oct. 01, 1985
Filed:
Sep. 30, 1983
Applicant:
Inventors:
Yasutaro Uesaka, Kokubunji, JP;
Sadao Hishiyama, Sayama, JP;
Masahiro Kitada, Tokyo, JP;
Noboru Shimizu, Tokorozawa, JP;
Hideo Tanabe, Hachioji, JP;
Hideo Fujiwara, Tokorozawa, JP;
Assignees:
Hitachi, Ltd, Tokyo, JP;
Hitachi Maxell, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
428 65 ; 428694 ; 428216 ; 428472 ; 428900 ;
Abstract
In a perpendicular magnetic recording medium comprising a high permeability film and a perpendicular magnetization film which are laminated on a non-magnetic substrate, a perpendicular magnetic recording medium is provided wherein a permanent magnet film is further sandwiched between the non-magnetic substrate and the high permeability film, thereby eliminating a spike noise.