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:
Mar. 05, 1991
Filed:
Jul. 31, 1990
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
A magnetic recording medium comprising a non-magnetic support having thereon a magnetic layer composed of ferromagnetic iron oxide powder dispersed in a binder, wherein a value of P.sub.10 of optical interference type three dimensional surface roughness on the magnetic layer side of the non-magnetic support is in the range of 15 to 35 nm, Rmax/P.sub.10 is not higher than 2.8 and P.sub.10 of the opposite side to the magnetic layer side is also in the range of 15 to 35 nm, wherein P.sub.10 (nm) represents the difference between an average height of the protrusions of 10 apices extracted in order of greatest height within an area 250 .mu.m square and an average height of all apices within the same 250 .mu.m square area and Rmax (nm) represents the difference between an uppermost height and a lowermost depth within the 250 .mu.m square area.