| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic circuit for a speaker that improves sound characteristics of the speaker by reduction of an eddy current etc., and lowers costs by simplification of the manufacturing processes. SOLUTION: In the magnetic circuit 21 for the speaker which has a radially magnetized ring-shaped magnet 5 coupled with the outer periphery of a center pole 3 or the inner periphery of a yoke 7 surrounding the center pole 3, the magnet 5 has its entire surface covered with a plating layer 23 of a nonmagnetic substance and then the plating layer serves for rust-preventive countermeasures and eddy-current reduction countermeasures, thereby eliminating need to individually take the rust-preventive measures and eddy-current reduction countermeasures. COPYRIGHT: (C)2006,JPO&NCIPI
|
