| 摘要 |
PURPOSE:To utilize a magnetic field of a permanent magnet effectively, and to improve frequency response characteristics by forming an air gap to a section opposite to a section in the vicinity of the center of the permanent magnet of a magnetic metal section opposite to the permanent magnet. CONSTITUTION:The moving coil type drive device has a loop-shaped magnetic metal core 12, the permanent magnet 11 attached and brought into contact to one inner surface of the core 12, and a coil 10 arranged between the permanent magnet 11 and the opposite core 12. The air gap 13 is formed to the section opposite to the central section or the section in the vicinity of the center of the permanent magnet 11 of the core 12 opposite to the permanent magnet 11. |
