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:
Nov. 04, 1986
Filed:
Jul. 13, 1983
Applicant:
Inventors:
Yasutaro Uesaka, Kokubunji, JP;
Hideo Fujiwara, Tokorozawa, JP;
Sadao Hishiyama, Sayama, JP;
Kazuo Shiiki, Kanagawa, JP;
Assignees:
Hitachi, Ltd., Tokyo, JP;
Hitachi Maxell, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21C / ;
U.S. Cl.
CPC ...
428607 ; 428611 ; 428621 ; 428678 ; 428679 ; 428680 ; 428681 ; 428928 ; 360134 ; 360135 ;
Abstract
A perpendicular magnetic recording medium free from spike noise having a high permeability magnetic material film, an antiferromagnetic material film and a perpendicularly oriented magnetic material film formed on a substrate in this order. Another high permeability magnetic material film may be formed between the antiferromagnetic material film and the perpendicularly oriented magnetic material film. During the formation of the antiferromagnetic material film, a magnetic field is applied in a direction of a track width.