| 摘要 |
<p>On a frame (15), a plurality of strip-like permanent magnets (13), each of which has different polarities at the front and rear, are fixed at prescribed intervals with polarities alternately arranged. On an end surface opposite to the surface fixed to the frame (15) of the magnets (13), an iron plate (16) is bonded. A vibrating plate (11) is attached to the frame (15) to cover the permanent magnets (13) and the iron plate (16). The vibrating plate (11) has an uneven shape which corresponds to an uneven structure composed of the permanent magnets (13) fixed at the prescribed intervals, and a vibrating plate reference surface (11d) to be a recessed section of the uneven shape is at a position at the same height as the iron plate (16), namely, at a high magnetic flux density position, and a voice coil (11b) is formed on the vibrating plate. Furthermore, on the front side of the protruding section (11c) of the vibrating plate, a vibrating plate front side material (17) is bonded to improve rigidity.</p> |
