Electricity: measuring and testing – Magnetic – Magnetic information storage element testing
Reexamination Certificate
2006-09-06
2008-08-19
Patidar, Jay M (Department: 2862)
Electricity: measuring and testing
Magnetic
Magnetic information storage element testing
Reexamination Certificate
active
07414394
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.
REFERENCES:
patent: 6090498 (2000-07-01), Omata et al.
patent: 6340885 (2002-01-01), Hachisuka et al.
patent: 6433540 (2002-08-01), Hachisuka et al.
patent: 6714006 (2004-03-01), Mackay et al.
patent: 7193824 (2007-03-01), Naka
patent: 2008/0061773 (2008-03-01), Otagiri et al.
patent: 10-124828 (1998-05-01), None
Furutani Takuji
Maeda Hiroshi
Sawada Minoru
Yasunaga Masahiro
Yoshimatsu Kiyotsune
Fujitsu Limited
Kratz Quintos & Hanson, LLP
Patidar Jay M
LandOfFree
Method of quality-testing a shield film of a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of quality-testing a shield film of a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of quality-testing a shield film of a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-4012917