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:
Jan. 07, 1992
Filed:
Jun. 30, 1989
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
428 64 ; 428 65 ; 428337 ; 428402 ; 428695 ; 428694 ; 428900 ; 427129 ; 427130 ; 427131 ;
Abstract
In a magnetic recording medium in which a thin film of a magnetic material is disposed on a surface of a base of a non-magnetic material directly or through an undercoated film, powder of a material substantially the same as that of the non-magnetic base or an undercoated film is disposed directly beneath the magnetic thin film to form dispersed projections on the surface of the magnetic recording medium. Thus, the product has surface projections, and its magnetic thin film has a generally uniform thickness and uniform magnetic properties.