| 摘要 |
PURPOSE:To give a sufficient magnetic field to a recording layer with a small external magnetic field by providing a 2nd magnetic layer having strong coercive force for recording through a 1st magnetic layer having weak coercive force. CONSTITUTION:The 1st magnetic layer 7 which is provided for increasing a magnetic effect is provided between the 2nd magnetic layer 1 for recording and a disk base plate 2. The coercive force of the 1st magnetic layer 7 is made weaker so that no magnetization can remain and a magnetic material having high susceptibility is used for the magnetic layer 7 so that the magnetic effect can be increased. Therefore, the magnetic flux produced from an electromagnet 5 returns to the electromagnet 5 through the 1st magnetic layer 7 and the magnetic flux does not diffuse in a recording area 6. Thus a high magnetic flux density is obtained in the recording area 6 and a highly efficient magnetic bias is obtained. Accordingly, a sufficient magnetic bias can be obtained with a small electromagnet or a less driving current. |
