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:
May. 17, 1988
Filed:
Feb. 28, 1986
Applicant:
Inventors:
Noboru Watanabe, Yokohama, JP;
Yasuo Ishizaka, Yokohama, JP;
Kazuo Kimura, Yokohama, JP;
Eiichiro Imaoka, Sagamihara, JP;
Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
360131 ; 360125 ; 360134 ; 360135 ; 360136 ; 428694 ; 428928 ;
Abstract
A perpendicular magnetic recording and reproducing system records and reproduces a signal on and from a perpendicular magnetic recording medium comprising a magnetic layer which is made from one magnetic material and is constituted by a layer having a low coercivity and a layer having a high coercivity on top of the layer having the low coercivity, by use of a ring core head and utilizes the layer having the low coercivity as a high permeability layer and the layer having the high coercivity as a perpendicular magnetization layer.