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. 24, 1987
Filed:
Mar. 06, 1985
Toshiyuki Suzuki, Yokohama, JP;
Reiji Nishikawa, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
In a magnetic recording disk of a double-sided data recording type according to a perpendicular magnetic recording technique of the invention, recording layers having different film thicknesses are formed on two surfaces of a base layer. The film thickness of one magnetic recording layer is set to be larger than the film thickness of the other magnetic recording layer, thereby preventing a curl phenomenon. In addition, a coercive force of the thicker recording layer is set to be smaller than that of the thinner layer. Thus, differences in a reproduction output voltage and an optimal recording current between the two recording layers of the disk due to a film thickness difference can be compensated for.