Patent ID: 7911745

Claim:
A thin-film magnetic head, comprising: a magneto-resistive effect device of a CPP (current perpendicular to plane) structure including a multilayer film in which a fixed magnetization layer, a non-magnetic layer and a free layer are stacked together in order, with a sense current passing in a thickness direction of said multilayer film; and an upper shield layer and a lower shield layer located such that said magneto-resistive effect device is held between them in the thickness direction, wherein: said free layer functions such that a direction of magnetization changes depending on an external magnetic field, said fixed magnetization layer has a direction of magnetization fixed by an antiferromagnetic layer exerting pinning action, p 1 said fixed magnetization layer, said nonmagnetic layer and said free layer extend rearward from an air bearing surface that is a plane in opposition to a medium, said multilayer film is provided with a bias magnetic field-applying layer at each end in a widthwise direction and a re-magnetizer unit; so that when said bias magnetic field-applying layer malfunctions, said re-magnetizer unit is actuated to re-magnetize said bias magnetic field-applying layer to get it back to normal, and said re-magnetizer unit is a diode formed at a position between said upper shield layer and said lower shield layer and in the rear of said magneto-resistive effect device, so that a voltage higher than a diode operating voltage (a threshold value) is applied between said upper shield layer and said lower shield layer, thereby conducting a current through said diode to generate a magnetic field that in turn re-magnetizes said bias magnetic field-applying field.