| 摘要 |
PURPOSE:To efficiently apply a bias magnetic field by a very small current supplied to an electric conductor thin film, by providing an MR element in the vicinity of a back gap of a ring head, and providing the element, the electric conductor thin film and a high magnetic permeability magnetic substance through an insulator. CONSTITUTION:A ring head 10 constitutes a magnetic circuit of front cores 11, 12, back cores 13, 14, a front gap and a back gap 18. An MR element 20 is installed to a position shown in the figure. On the surface of the back cores 13, 14 and the gap 18, a nonmagnetic insulating layer 19, on which the MR element 20 is formed wider than the gap width. On the MR element 20, an insulating layer 24, an electric conductor thin film 21 and an insulating layer 25 are laminated and provided, on which a high magnetic permeability material 22 is constituted. The MR element 20 has uniaxial anisotropy in the (y) axial direction. Accordingly, the signal magnetic field and the bias magnetic field are applied in the (z) axial direction, but in case of no signal, magnetization M is set so as to be inclined by 45 deg. against the (y) axis by only the bias magnetic field. |
