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:
Jan. 11, 1994
Filed:
Apr. 22, 1992
Noboru Tsuya, Setagaya-ku, Tokyo, JP;
Toshiro Takahashi, Hamamatsu-shi, Shizuoka-ken, JP;
Other;
Abstract
The first invention provides a substrate for a magnetic recording medium, which is prepared by forming a macro-concavo-convex pattern for improving CSS properties and a micro-concavo-convex pattern for improving magnetic properties on the surface, thereby preventing the degradation of the CSS properties brought by the enhancement in friction coefficient and the increase in the area of a protective layer of the medium in contact with a magnetic head, caused by the wearing of the protective layer of the medium. The second invention provides a process of producing a substrate for a magnetic recording medium, which forms the above macro-concavo-convex pattern and micro-concavo-convex pattern in a uniform distribution at the same time. The first invention utilizes, as the texture, protrusions 13P and 15P different in length from the substrate surface, the protrusions being prepared by packing at least two kinds of materials 13 and 15 differing in etching rate into alumite pores 14A and 14B, polishing and then etching. The second process invention comprises the steps of packing the first material into alumite pores of an aluminum alloy by means of electrolytic deposition, packing the second material having an etching rate different from that of the first material by means of dipping method, polishing the resultant surface and etching the polished surface so as to make the respective protrusion lengths of the first and the second materials within the predetermined range.