| 摘要 |
PURPOSE:To amplify the oscillation between short distances of straight line of an oscillating body and to obtain the magnified oscillation of a diaphragm by providing the diaphragm which is adhered to the center part of an another straight part of a belt and has a driving bar projecting toward an opposite direction to radiating direction of sound from the diaphragm. CONSTITUTION:A field part 15 that consists of a bottom plate 11, a magnet 12 and a top plate 13 forms an annular magnetic air gap 14 in which a diaphragm 17 consisting of a voice coil 18 and of a voice coil bobbin 19 that winds the voice coil 18 is reciprocated according to an input signal. Therefore, a pedestal 23, bearing parts 21 and 22 and two pulleys 24 and 25 that wind a belt 32, all of which carry out a same reciprocal movement as of an oscillating body. But, because the center part of a straight part of one side of a belt that is wound around the two pulleys 24 and 25 is adhered to a fixing board 33, the center part of the straight part of another side of the belt is displaced by double of the displacement of the diaphragm 17. |
