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:
Jul. 11, 1989
Filed:
Dec. 03, 1987
Applicant:
Inventors:
Assignee:
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
428329 ; 428336 ; 428694 ; 428900 ;
Abstract
A magnetic recording medium is disclosed which comprises a non-magnetic support having coated thereon two magnetic layers, wherein an under layer of the magnetic layers contains ferromagnetic metal particles having a coercive force of 550 to 700 Oe, and wherein an upper layer of the magnetic layers contains a ferromagnetic particles having a specific surface area determined by the BET method of 25 to 35 m.sup.2 /g, a coercive force of 700 to 800 Oe and a thickness of 0.5 to 2.5 .mu.m, wherein the entire magnetic layer including the upper layer and the under layer have a coervice force of 580 to 750 Oe, a residual magnetic flux density of 2200 to 3200 gauss and a thickness of 3.0 to 5.0 .mu.m.