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:
May. 31, 1994
Filed:
Jan. 17, 1992
Virgle L Hedgcoth, Pomona, CA (US);
Other;
Abstract
A sputtered magnetic recording disk is formed by a series of sequential sputtering processes within an environment of a low pressure inert gas. A disk substrate is abraded to provide a circumferential texturing of hills and valleys. The height of the hills and valleys are of a dimension not to interfere with a fly characteristic of a recording head, while the arithmetic average of the radial roughness is still sufficient to provide a magnetic switching field distribution of less than 0.20. A chromium nucleating layer is deposited on the textured substrate surface by a first sputtering process. A second sputtering process provide a magnetic layer of a cobalt alloy to provide C-axis orientation parallel to the substrate. A third sputtering process provides a protective carbon film. The output of any signal recorded on the magnetic thin film layer will have an amplitude modulation of less than twenty-five percent (25%).