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:
Nov. 07, 1978
Filed:
Oct. 29, 1974
Pravin K Patel, Los Angeles, CA (US);
David H Johnston, Redondo Beach, CA (US);
John Makaeff, Los Angeles, CA (US);
Poly-Disc Systems, Inc., Torrance, CA (US);
Abstract
It is known to manufacture a recording member having a substrate supporting a magnetic recording alloy on a surface and to locate a protective covering on the surface of the alloy remote from the substrate. An improved protective covering for use in this combination comprises a barrier layer located on the surface of the recording alloy and an oxide layer located on the surface of the barrier layer remote from the recording alloy. The barrier layer preferably consists of a nonmagnetic material. The oxide layer is also nonmagnetic and is sufficiently thick to protect the magnetic alloy layer against surface abrasion. The barrier layer isolates the oxide layer from the magnetic recording layer so as to preserve the character and uniformity of the magnetic recording layer as the oxide layer is created.