| 摘要 |
PURPOSE:To make it possible to transmit the small vibrations of a vibration source to a vibration plate after amplification and to make possible high efficiency reproduction by setting a specific relation among the vibrating mass in a driving system relating to a vibration source, the vibrating mass of a sound system relating to the vibrating plate including the added weight of air and the magnification (n) of amplification by a mechanical amplification means. CONSTITUTION:The relation between the vibrating mass MR relating to the vibrating plate 27 acting as the mass of the vibrating system and the vibrating mass MD of the driving system such as the vibrating plate 17, a bearing part 22 and a pulley 21, is set so as to be (MD/MR)<1/2> 2. A bottom plate 11 and a field magnetic part 15 consisting of a magnet 12 and a top plate 13 constitute an annular magnetic gap 14 in which the vibrating member 17 consisting of a voice coil 18 and a voice coil bobbin 16 wound by it is reciprocably disposed in response to input signals. The bearing part 22 attached to the upper end of the vibrating member 17 are able to press a pair of belts (a belt A30 and a belt B31). The each one end of the pair of belts is fixed to a fixing block 32 so that the other end of the belt is displaced by an amount twice that of the vibrating member 17. |
