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. 13, 1998
Filed:
Jun. 07, 1995
Applicant:
Inventors:
Shinji Fukaya, Odawara, JP;
Yoshinori Honda, Hiratsuka, JP;
Akira Kato, Odawara, JP;
Shuichi Kojima, Odawara, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G11B / ; G11B / ;
U.S. Cl.
CPC ...
428 653 ; 428 654 ; 428 655 ; 428332 ; 428337 ; 4286 / ; 4286 / ; 4286 / ; 428900 ;
Abstract
A magnetic recording has very low warp characteristics but excellent film characteristics. Particularly, the recording medium has a high coercivity with a small range of coercivity distribution, with a warp characteristic below 3 .mu.m per radial inch. The medium is formed by heating a substrate at a high temperature with a temperature distribution on the substrate that is improved by the use of a heat distribution mask, which reduces the temperature distribution of the substrate to below .+-.3%.