Patent ID: 9301044
Filing Date: 2016-03-29
CPC Classification: H04R

Claim Text:
1. An acoustic apparatus comprising: an amplitude modulation unit configured to generate a first signal by modulating an amplitude of a carrier wave signal having a frequency of an ultrasonic band, based on an acoustic signal; a phase control unit configured to generate a second signal and a third signal by controlling a phase of the first signal, respective phases of the second signal and the third signal being approximately opposite; an amplification unit configured to amplify the second signal and the third signal; a first parametric loudspeaker configured to radiate a first sound wave toward a first control point located on a directional axis of the first parametric loudspeaker, based on the amplified second signal, the directional axis being a normal line passing through a center of a radiation surface of the first parametric loudspeaker; a first reflection unit having a first concave to receive a sound wave and reflect the sound wave toward the first control point, a focal point of the sound wave reflected by the first concave being the first control point; and a second parametric loudspeaker configured to radiate a second sound wave toward the first concave, based on the amplified third signal, wherein the amplification unit amplifies the second signal and the third signal so that a sound pressure of the first sound wave is approximately equal to a sound pressure of the second sound wave at the first control point.