| 摘要 |
PURPOSE:To make high-speed recording and erasing possible by forming the center part of a device, whose section has two recessed parts in one side, with semihard magnetic materials and forming the other parts with soft magnetic materials and winding a coil around one side of the center and flowing a pulse current corresponding to recording/erasing signal. CONSTITUTION:The center part of this device is formed with semihard magnetic materials 5, and the other parts are formed with soft magnetic materials 6, and a magnetic path having not a magnetic path length A-B but having a magnetic path length A-B-C is formed by magnetic materials; and since magnetic poles A and C or D different from each other are arranged close, demagnetizing fields acting among magnetic poles A, B, and C and among magnetic poles A, B, and D are reduced considerably because magnetic resistances between magnetic poles are very low, and a stable powerful magnetic field is generated just under the magnetic pole A. The surface of the magnetic pole A consisting of semihard magnetic materials 5 is arranged orthogonally to a track to record and reproduce information on and from the track. Since the intensity of the magnetic field impressed to a recording medium is determined by the sectional area and the residual magnetic flux density of the semihard magnetic materials 5, the inductance of the magnetic circuit is reduced without requiring the increase of the number of turns of the coil. |
