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. 30, 1997
Filed:
Jun. 23, 1992
Kenichi Sato, Miyagi, JP;
Kazunobu Chiba, Miyagi, JP;
Yuichi Arisaka, Miyagi, JP;
Yukari Yamada, Miyagi, JP;
Sony Corporation, Tokyo, JP;
Abstract
A magnetic recording medium comprised of a nonmagnetic support; a magnetic metal thin film formed on one major surface of the nonmagnetic support; and a protective film of a corrosion-resistant metal or a multilayer protective film structure consisting of a corrosion-resistant metal film and a durable protective film of a hard material. A multilayer protective film structure is formed by sputtering a corrosion-resistant protective film and a durable protective film over the magnetic metal thin film while the nonmagnetic support travels along the circumference of a cooling cylinder by using at least one target of a corrosion-resistant metal and at least one target of a hard material, or by using a composite target composed of at least one corrosion-resistant metal and one hard material. The protective film suppresses the corrosion of the magnetic metal thin film and improves the corrosion resistance and durability of the magnetic recording medium.