| 摘要 |
PROBLEM TO BE SOLVED: To reduce the leak current at the upper part of the magnetic circuit yoke of a voice coil motor by adhering a tabular permanent magnet to a magnetic yoke, magnetizing it in a magnetizing direction and applying an external magnetic field to the magnetic yoke in the direction of the flux of the permanent magnet across the magnetic yoke, thereby magnetizing it. SOLUTION: After adhering a voice coil motor magnetic circuit yoke (up yoke) 41 to a permanent magnet 42, both are held between an upper and lower magnetizing heads 43a, 43b, a current 45 from a pulse power source is fed to a magnetizing coil 44 to generate fluxes 46a, 46b in the direction parallel to the magnetizing direction of the permanent magnet 42, thereby magnetizing this magnet 42. Then the lower magnetizing head 43b is removed with the upper magnetizing head 43a left, a reverse current 47 is fed to the magnetizing coil 44 to generate a flux 48, and an external magnetic field is applied to the up yoke 41a in the direction of the flux of the permanent magnet 42a across the up yoke 41a, thereby magnetizing it. |
