Apparatus for recognizing spin valve head failure due to pin layer magnetic field offset
US6295175A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1998 |
| Grant date | Sep 25, 2001 |
| Priority date | — |
| Expiry date | Dec 22, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/3996
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
When a pin layer magnetic field offset judgment unit judges that a magnetic field in a pin layer of a spin valve head through which a sense current flows in the interference direction has been deviated from a normal direction, a recovery processing unit allows a recovery from the abnormality arising from the magnetic field offset. For example, the direction of the sense current is switched from the interference direction to the assist direction, and the sense current larger than that upon the ordinary reading action is allowed to flow so that the temperature of an antiferromagnetic layer exceeds the blocking temperature, whereby the direction of the magnetic field in the pin layer is modified to the normal direction by the action of a magnetic field generated from the sense current. After the modification, the sense current is returned to have its ordinary value in the interference direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.