Patent Number: 6,295,175

Title: Apparatus for recognizing spin valve head failure due to pin layer magneticfield offset

Abstract: When a pin layer magnetic field offset judgment unit judges that a magneticfield in a pin layer of a spin valve head through which a sense currentflows in the interference direction has been deviated from a normaldirection, a recovery processing unit allows a recovery from theabnormality arising from the magnetic field offset. For example, thedirection of the sense current is switched from the interference directionto the assist direction, and the sense current larger than that upon theordinary reading action is allowed to flow so that the temperature of anantiferromagnetic layer exceeds the blocking temperature, whereby thedirection of the magnetic field in the pin layer is modified to the normaldirection by the action of a magnetic field generated from the sensecurrent. After the modification, the sense current is returned to have itsordinary value in the interference direction.

Inventors: Tomita; Isamu (Kawasaki, JP), Koshikawa; Takao (Kawasaki, JP), Hoshino; Toshinori (Kawasaki, JP), Nakamura; Tadashi (Kawasaki, JP), Kanai; Hitoshi (Kawasaki, JP), Ueno; Hiroaki (Kawasaki, JP)


International Classification:

Expiration Date: 09/25/2013