| 摘要 |
<p>A speaker, comprising a magnetic circuit having a center plate, first and second magnets disposed on the lower and upper surfaces of the center plate and magnetized in the directions of being magnetically repelled each other, an under plate disposed on the lower surface of the first magnet, and a yoke, a voice coil, a diaphragm, an edge connected to the outer peripheral part of the diaphragm, and a frame, the magnetic circuit further comprising a top plate disposed on the upper surface of the second magnet, wherein the second magnet and the top plate are formed in annular shapes, the inner and outer diameters of the second magnet and the top plate are generally equal to each other, respectively, the outer diameters of the second magnet and the top plate are smaller than the outer diameter of the center plate, and a projected part for positioning the second magnet is provided on the upper surface of the center plate, whereby the speaker having a sufficient drive force can be provided with a reduced size.</p> |
