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:
Nov. 14, 2000
Filed:
Mar. 27, 1998
Applicant:
Inventors:
Yasuo Bamba, Kawasaki, JP;
Iwao Okamoto, Kawasaki, JP;
Kazunori Yamanaka, Kawasaki, JP;
Wataru Yamagishi, Kawasaki, JP;
Assignee:
Fujitsu Limited, Kawasaki, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01N / ; G01R / ;
U.S. Cl.
CPC ...
324210 ; 360 31 ; 365 58 ;
Abstract
A testing method for a magnetic recording medium which is magnetized measures variation of magnetization with the passage of time and evaluates the magnetic recording medium over its life. The method includes the steps of recording a first pattern at a density to be guaranteed in the magnetic recording medium, the first pattern having a difference between the sum total of areas of +bits and the sum total of areas of -bits, measuring remanence of the first pattern with the passage of time, and evaluating the magnetic recording medium over its life based on a measurement result.