| 摘要 |
PROBLEM TO BE SOLVED: To provide a woofer in which a high region is cut off and lateral vibration of a voice coil is prevented. SOLUTION: The woofer is provided with a first diaphragm 18 which is so constituted that internal and external peripheral portions have high flexibility compared with an intermediate portion, a magnetic circuit 15 forming a circular magnetic gap 16, the voice coil 17 which has a coil portion fitted into the gap 16 of the circuit 15 and an upper end joining to the internal peripheral portion of the diaphragm 18, and a frame 24 joined to an external peripheral portion 21 between the circuit 15 and the diaphragm 18. The woofer has a bearing 25 arranged on the concentric center portion of the gap 16 so that an axial direction becomes a vertical direction, and a sliding body 27 fitted into the bearing 25 and having an upper end connected to the voice coil 17. A second diaphragm 23 having a size sufficiently covering an internal peripheral portion 19 of the diaphragm 18 is joined to the diaphragm 18. COPYRIGHT: (C)2004,JPO
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