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:
Feb. 07, 1995
Filed:
Oct. 22, 1992
Takao Nakamura, Yokohama, JP;
Nobuya Sekiyama, Yokohama, JP;
Hiroshi Tani, Atsugi, JP;
Yoshiki Kato, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
There is disclosed a magnetic disk having a surface shape so designed as to satisfy flying characteristics and sliding characteristics in CSS and the head adhesion even in a high-density recording. The surface shape of the contact surface of the magnetic disk for contact with a sliding surface of a magnetic head plays a very important role in the magnetic disk characteristics such as the head flying characteristics, the head adhesion and the CSS characteristics, and it has been found that a three-dimensional load ratio (0.5% to 10%) and a symmetric property Rsk (0.5 to 2) of a cross-section curve representing depressions and projections on the surface are essential as items of evaluation of this surface shape. For example, the surface shape of an aluminum alloy disk plated with Ni-P is processed in such a manner that the load ratio of the three-dimensional load ratio BR5 is 0.5% to 10% and that the symmetric property Rsk of the cross-sectional shape of this surface is 0.5 to 2. Then, a chromium intermediate film, a Co-Cr magnetic film, a carbon protective film and a film of lubricant are formed on the substrate. By doing so, the magnetic disk having the desired characteristics can be obtained.