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. 02, 1997
Filed:
May. 27, 1994
Hidetoshi Honda, Miyagi, JP;
Yasumi Sato, Miyagi, JP;
Taketoshi Sato, Miyagi, JP;
Jota Ito, Miyagi, JP;
Yoshihito Ebine, Miyagi, JP;
Toshikazu Sasaki, Miyagi, JP;
Sony Corporation, Tokyo, JP;
Abstract
A magnetic recording medium has a magnetic layer formed by a thin magnetic metal layer and a carbon protective layer on a non-magnetic substrate; the surface of the carbon protective layer has first protrusions formed by first particles and second protrusions formed by second particles; the carbon protective film has a thickness in the range of 3 nm to 30 nm, while the first protrusions have the heights of 65 nm.+-.15 nm to 95 nm.+-.15 nm and the second protrusions have the heights of 18 nm.+-.5 nm to 28 nm.+-.5 nm; since the surface properties of the carbon protective film are controlled, the electro-magnetic conversion characteristics may be prevented from being lowered due to the spacing losses for improving the running durability of the recording medium.