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. 21, 1992
Filed:
Oct. 19, 1988
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
A magnetic recording medium for a video tape recorder is disclosed, comprising a nonmagnetic support having thereon in the following order an under magnetic layer containing ferromagnetic particles of metal oxide and an upper magnetic layer containing ferromagnetic particles of metal oxide, wherein said under magnetic layer contains the ferromagnetic particles having a specific surface area by a BET method of from 26 to 50 m.sup.2 /g and a coercive force (Hc.sub.1) of from 500 to 1,000 Oe; said upper magnetic layer contains the ferromagnetic particles having a specific surface area by a BET method of from 30 to 60 m.sup.2 /g and a coercive force (Hc.sub.2) of from 600 to 1,200 Oe; the dry thickness of the upper magnetic layer is from 0.1 to 1.0 .mu.m; and the coercive force (Hc.sub.2) of the ferromagnetic particles for the upper magnetic layer is higher than the coercive force (Hc.sub.1) of the ferromagnetic particles for the under magnetic layer.