Ultrasonic sound generator, ultrasonic element, and parametric speaker using the same

摘要

PROBLEM TO BE SOLVED: To provide: an ultrasonic sounder by which a high sound pressure can be obtained efficiently; and a parametric speaker using such an ultrasonic sounder.SOLUTION: An ultrasonic sounder 110 is utilized as an oscillation source of a parametric speaker 100. The ultrasonic sounder 110 comprises: a piezoelectric vibrator formed by a plate-like piezoelectric device and a vibration plate with the piezoelectric device glued to one principal surface thereof; and a resonator which is provided on the other principal surface of the vibration plate and resonates with vibration of the vibration plate to generate ultrasonic waves. The characteristic vibration caused by only the resonator is coincident with a primary resonance of itself in frequency. Therefore, not only the whole ultrasonic wave vibrator 110, but also the resonator resonates and thus, a high sound pressure can be obtained.