| 摘要 |
PURPOSE:To prevent abnormal sound due to the contact with a voice coil with a magnetic circuit from being generated, by joining parts of fluoroplastics on a part in the neighborhood of the tip of a poll piece. CONSTITUTION:The coil 8 of the voice coil 7 is arranged on the magnetic gap 4 of the magnetic circuit consisting of a plate 1 in which the parts 12 of fluoroplastics is joined, a magnet 2, and a top plate 3. At this time, the inner periphery of a voice coil bobbin is brought into contact with only the outer periphery of the parts 12 joined on the tip of the poll piece. The voice 7 is joined with the center of a damper 6, and the outer periphery of the damper is fixed on a frame 5, and furthermore, a diaphragm 9 is coupled with the voice coil 7, and the outer periphery of the diaphragm is coupled with the frame via an edge. In such a way, contact resistance between the voice coil 7 and the poll piece is reduced to 1/10-1/20, and the abnormal sound generated due to the contact and the friction of them can be reduced.
|
