Permanent magnet member for voice coil motor and voice coil motor

摘要

A magnetic head is controlled more stably when retracted from above a magnetic disk. When a permanent magnet member 10 having a protrusion projecting from the longer periphery to a side opposite to the center of a fan is mounted on a yoke 15, the end part P side where the sum of thicknesses (P1+P2) is the largest, i.e., the upper face side of a magnet matrix 111 on the protrusion side, is higher than the upper face side of the magnet matrix in the other area. Therefore, since the magnet matrix 111 in the protrusion is located closer to a lock pin 21, the magnetic attraction force between the lock pin 21 and the permanent magnet member 10 becomes stronger, so that the permanent magnet member 10 is locked more firmly when retracted from above the magnetic disk (at the time of locking), whereby the stability can be enhanced.