Patent ID: 7564986

Claim:
An ultrasonic speaker, comprising: an ultrasonic transducer including: a vibration film having a conductive layer; and a pair of fixed electrodes provided oppositely to respective surfaces of the vibration film the ultrasonic transducer adapted to cause the vibration film to generate sound waves by applying a DC bias voltage to the conductive layer of the vibration film while applying an alternating signal between the pair of fixed electrodes, the ultrasonic transducer including a first sound wave output surface and a second sound wave output surface, the second sound wave output surface being opposite from and substantially parallel to the first sound wave output surface, the first sound wave output surface outputting sound waves generated by the vibration film in a first direction that is substantially perpendicular to the first sound wave output surface, the second sound wave output surface outputting sound waves generated by the vibration film in a second direction that is substantially perpendicular to the second sound wave output surface, the first direction opposite the second direction; and a first sound wave reflection plate and a second sound wave reflection plate disposed on opposite sides of the ultrasonic transducer, the first sound wave reflection plate being disposed at an acute angle with respect to the first sound wave output surface, and the second sound wave reflection plate being disposed at an acute angle with respect to the second sound wave output surface, the sound waves outputted from the first sound wave output surface in the first direction being output toward and reflected by the first sound wave reflection plate, and the sound waves outputted from the second sound wave output surface in the second direction being output toward and reflected by the second sound wave reflection plate.