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. 19, 2008
Filed:
Sep. 06, 2006
Masahiro Yasunaga, Kawasaki, JP;
Takuji Furutani, Kawasaki, JP;
Hiroshi Maeda, Kawasaki, JP;
Minoru Sawada, Kawasaki, JP;
Kiyotsune Yoshimatsu, Kawasaki, JP;
Masahiro Yasunaga, Kawasaki, JP;
Takuji Furutani, Kawasaki, JP;
Hiroshi Maeda, Kawasaki, JP;
Minoru Sawada, Kawasaki, JP;
Kiyotsune Yoshimatsu, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
When testing the quality of shield films of magnetoresistive effect heads, a method of testing and a testing apparatus can detect heads where the shield magnetic domain is susceptible to changing that could not be completely detected by conventional methods of testing that use normal magnetization. The method of testing applies an external magnetic field to a magnetoresistive effect head as external stress, measures the output voltage of the head, and repeats the applying of the external magnetic field and the measuring a plurality of times to test the quality of the shield film. The magnetic field is applied in a direction parallel to the shield film and at an angle to a floating surface of the magnetoresistive effect head. The intensity of the applied magnetic field is smaller than the coercive force of a hard bias film and larger than the coercive force of the shield film.