| 摘要 |
PURPOSE:To miniaturize resonance without spoiling sound quality by providing a vibrator driving means which drives a driver so as to cancel reaction from a resonator to the diaphragm of the vibrator when the resonator is driven. CONSTITUTION:When a sound generating device 2 generates mechanical vibration, this vibration operates the Helmholtz' resonator consisting of a cavity 5 and a duct 6a and is converted into an electric signal by a sound generating circuit 7. A vibration driving circuit 8 drives the vibrator 4 according to the electric signal supplied from the circuit 7. When a driving signal is supplied from the circuit 8 to the vibrator 4, the vibrator 4 drives the diaphragm 3 forward and backward reciprocally. Atmospheric reaction to the operation of the diaphragm 3 is applied to the rear surface side of the diaphragm 3 from the air in the cavity 5, but the circuit 8 drives the driver 4 so as to cancel the atmospheric reaction. This constitution reduces the capacity of the cavity 5 as the cavity of the Helmholtz's resonator and the musical instrument is miniaturized. |
