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:
Feb. 04, 1992
Filed:
Jan. 11, 1991
Applicant:
Inventors:
Kazuaki Taga, Kanagawa, JP;
Takeshi Tsuda, Kanagawa, JP;
Hiroo Inaba, Kanagawa, JP;
Hiroshi Ogawa, Kanagawa, JP;
Assignee:
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
428141 ; 428323 ; 428329 ; 428331 ; 428480 ; 428694 ; 428900 ;
Abstract
A magnetic recording medium which comprises plurality of magnetic layers comprising at least first and second magnetic layers which are successively formed on a surface of a polyethylene terephthalate support, wherein said support contains inert inorganic particles having an average particle size of from 0.5 to 0.7 microns, a standard deviation of 0.1 microns or less and the surface of said support has a center line average roughness (Ra) of 16 nm or less and a density of protrusions (Ds) of 6000/mm.sup.2 or more in the case of protrusions of 0.7 microns of more.