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:
Nov. 19, 1985
Filed:
Oct. 12, 1982
Takato Karashima, Nishinomiya, JP;
Hiroshi Zaitsu, Takatsuki, JP;
Hitachi Maxell, Ltd., Osaka, JP;
Abstract
A magnetic recording medium having two magnetic layers, which comprises an upper magnetic layer and a lower magnetic layer, said lower magnetic layer having a coercive force of at least 100 oersteds, preferably 100 to 500 oersteds, lower than that of the upper magnetic layer, the thickness of the upper and lower magnetic layers being in the ratio of the thickness of the upper magnetic layer to that of the lower magnetic layer of 1/1 to 1/9, and the total coercive force of the upper and lower magnetic layers being 1,000 oersteds or more. The magnetic recording medium has excellent sensitivity and frequency characteristics at low and high frequency bands with less noise.