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:
Jun. 20, 1989
Filed:
Jun. 02, 1987
Masaaki Futamoto, Kanagawa, JP;
Yukio Honda, Fuchu, JP;
Shinichiro Saito, Tokyo, JP;
Takashi Nishimura, Kokubunji, JP;
Kazuetsu Yoshida, Kodaira, JP;
Toyoji Okuwaki, Tokyo, JP;
Hitoshi Iwata, Kumagaya, JP;
Hiroyuki Suzuki, Kokubunji, JP;
Kazushige Imagawa, Koganei, JP;
Hideo Daimon, Toride, JP;
Osamu Kitakami, Toride, JP;
Hideo Fujiwara, Ibaraki, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Maxell Ltd., Tokyo, JP;
Abstract
A magnetic recording medium which comprises a non-magnetic substrate, a magnetic film formed on the substrate and a protective film provided on the magnetic film, the protective film being composed of at least two groups of element, the element in one group being at least one of B and C having a smaller atomic size, and a concentration of the element increasing from the interface side of the protective film with the magnetic film toward the opposite face side throughout the protective film has an improved durability against a magnetic head.