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:
Jun. 28, 1988
Filed:
Mar. 26, 1985
Applicant:
Inventors:
Masatoshi Sato, Tokyo, JP;
Hideki Akasaka, Kanagawa, JP;
Assignee:
Nippon Kogaku K.K., Yokohama, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
428679 ; 428681 ; 428686 ; 428694 ; 428900 ;
Abstract
A double-layered magnetooptical recording medium consists of two exchange-coupled layers that permit perpendicular magnetization, one layer having a low Curie point and a high coercive force and the other layer having a high Curie point and a low coercive force. The layer having low coercive force is made of a transition metal rich amporphous Gd.sub.U (Fe.sub.V Co.sub.100-V).sub.100-U alloy having the following compositional range, and the layer having high coercive force is made of a transition metal rich amorphous Tb.sub.W Fe.sub.100-W alloy having the following compositional range: