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:
Mar. 28, 1995
Filed:
Jun. 22, 1992
Applicant:
Inventors:
Assignee:
Sony Corporation, Tokyo, JP;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B32B / ; B32B / ; G11B / ;
U.S. Cl.
CPC ...
428336 ; 4284735 ; 4286 / ; 4286 / ; 4286 / ; 4286 / ;
Abstract
The coefficient k.sub.1 of linear expansion in a temperature range from 50.degree. to 300.degree. C. of a non-magnetic support member of a recording medium, before a Co-Cr alloy film is formed thereon, is less than 0 mm/mm .degree.C., and the coefficient k.sub.2 of linear expansion in a temperature range from 50.degree. to 300.degree. C. of that support member after the Co-Cr alloy film is formed is less than 0.3.times.10.sup.-5 mm/mm .degree.C. The alloy film also includes carbon in the magnetic layer, and a protective film comprised of carbon is further formed on the magnetic layer. The recording medium is particularly adapted for perpendicular magnetic recording.