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:
Aug. 18, 1987
Filed:
Aug. 19, 1985
Research Development Corporation of Japan, Tokyo, JP;
Abstract
A perpendicular magnetic recording medium is formed of a substrate having 5.times.10.sup.5 -5.times.10.sup.9 fine projections per mm.sup.2 on the surface thereof, said projections having heights in the range of 0.01-10 .mu.m and diameters in the range of 0.01-1 .mu.m, and a ferromagnetic material deposited uniformly in a columnar form on the projections. The recording medium is produced by providing in advance fine projections, the heights and diameters of which are 0.01-10 .mu.m and 0.01-1 .mu.m respectively, on the surface of a substrate to a density of 5.times.10.sup.5 -5.times.10.sup.9 projections per mm.sup.2, and then causing a ferromagnetic material to deposit on the substrate from a vapor phase in such a way that the deposited material is preferentially allowed to adhere onto the projections and then to grow the ferromagnetic material in a direction perpendicular to the plane of the substrate. The present invention has expanded the ranges of usable substrate-forming materials and recording materials, i.e., ferromagnetic materials, and has also simplified the production process.