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. 10, 1991
Filed:
Jul. 13, 1988
Applicant:
Inventors:
Noboru Tsuya, Tokyo, JP;
Tadao Tokushima, HamamatsuI-shi, Shizuoka-ken, JP;
Toshiro Takahashi, HamamatsuI-shi, Shizuoka-ken, JP;
Assignee:
Other;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
428 64 ; 428694 ; 428695 ; 428900 ; 360135 ; 427128 ;
Abstract
A substrate for a magnetic recording disk, made of anodized aluminum having its pores packed with a non magnetic material and having been subjected to polishing followed by an etching treatment to form a finely roughened surface due to preferential etching of either the aluminum or the non magnetic material.