ULTRASONIC-WAVE GENERATION DEVICE

摘要

Provided is an ultrasonic-wave generation device having high sound pressure and providing an output sound pressure that is stable with respect to temperature changes and the like. This ultrasonic-wave generation device (100) comprises: an ultrasonic-wave generation element (1) including a frame (2), a first piezoelectric vibrator (3), and a second piezoelectric vibrator (4), the ultrasonic-wave generation element (1) emitting ultrasonic waves by a buckling tuning-fork vibration mode in which the first piezoelectric vibrator (3) and the second piezoelectric vibrator (4) vibrate at the same frequency and in opposite phases from one another; a housing (lid member 8) that houses the ultrasonic-wave generation element (1) and that is provided with an ultrasonic-wave emission opening (8b); a first acoustic path (R1) leading from the vicinity of a vibration surface (F1) of the first piezoelectric vibrator (3) to the vicinity of the ultrasonic-wave emission opening (8b); and a second acoustic path (R2) leading from the vicinity of a vibration surface (F2) of the second piezoelectric vibrator (4) to the vicinity of the ultrasonic-wave emission opening (8b). The frequency/sound-pressure characteristic, which indicates the relationship between the vibration frequency of the first piezoelectric vibrator (3) and the second piezoelectric vibrator (4) (drive signal frequency) and the output sound pressure of ultrasonic waves emitted from the ultrasonic-wave emission opening (8b), has a low-frequency-side peak and a high-frequency-side peak. The difference in frequency between the low-frequency-side peak and the high-frequency-side peak is 10 kHz or greater.