| 摘要 |
PURPOSE:To reproduce medium and low sound regions, by arranging the disc shaped 2nd piezoelectric oscillator at the center of each upper surface of a plurality of disc shaped 1st stage piezoelectric oscillators and driving the oscillators through the superimposition of each oscillation amplitude of the 1st and 2nd stage piezoelectric oscillators. CONSTITUTION:Three disc-shaped piezoelectric oscillators 5 made of a piezoelectric plate 52 sticked with a brass thin plate 51 are closely arranged, and legs 53 are bonded at the inside of bottom of a frame 2 and fixed. The disc-shaped 2nd stage piezoelectric oscillator 6 is bonded to the upper surface center of each piezoelectric oscillator 5 with the legs 63. The top of a circular cone type diaphragm 4 made of paper is bonded at the upper surface center of the oscillator 6. When the center of the oscillators 5 is bent, the center of the oscillator 6 is interlockingly bent. That is, the amplitude of the oscillators 5, 6 is superimposed to double the oscillation amplitude of the diaphragm of a speaker. Thus, a driving source enabling large amplitude and vibration can be constituted and medium and low sound region can be reproduced. |
