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:
Sep. 24, 1996
Filed:
Dec. 21, 1994
TDK Corporation, Tokyo, JP;
Abstract
A magnetic recording medium having excellent electromagnetic characteristics, still characteristics and cupping, decreased rust generation and high durability, includes a non-magnetic substrate and a magnetic layer formed thereon by oblique deposition, the magnetic layer being composed of at least two ferromagnetic thin films, in which the ferromagnetic thin film of the lowest layer has a saturation magnetization of 300 emu/cc or less, a coercive force of 1000 Oe or less and a thickness of 300 to 1500 .ANG., the ferromagnetic thin layer of the uppermost layer has a saturation magnetization of 300 emu/cc or more, a coercive force of 1000 Oe or more and a thickness of 400 to 1500 .ANG., an average value (.theta.) of angles between growing directions of columnar crystalline particles constituting the ferromagnetic thin film of the lowest layer and a principal plane of the substrate ranges from 50 to 70 degrees, and an average value (.theta.) of angles between growing directions of columnar crystalline particles constituting the ferromagnetic thin film of the uppermost layer and the principal plane of the substrate ranges from 30 to 50 degrees.