| 摘要 |
PURPOSE:To obtain a device which can apply a magnetic field needed for record/erasion with a simple constitution by using a means which applies a fixed magnetic field to a recording medium and a variable magnetic field applying means which can change the intensity of a magnetic field applied to the recording medium. CONSTITUTION:A photomagnetic recording head 2 is set over a photomagnetic disk 1 which uses a magnetic thin film having the vertical magnetic anisotropy as a recording medium. Then a permanent magnet and an air-core coil are provided between the disk 1 and the head 2 as a fixed magnetic field applying means 3 and a variable magnetic field applying means 4 respectively. The disk 1 is revolved by a rotary motor 5. The air-core coil uses a coated copper wire with 100 turns and a magnetic field of 260Oe is obtained at a place distant from the coil tip by 0.5mm when the coil current is equal to 1A. The disk 1 uses a recording layer of a TbFe film formed on a plastic substrate containing a guide groove by a low-temperature sputtering process. The coercive force of the TbFe film is equal to 2kOe at a room temperature. The coercive force 20Oe and 270Oe can be applied in the magnetization inverting direction in a record mode and an erasion mode respectively.
|
