| 摘要 |
A plurality of magnetostrictive elements made of ferrite or the like are arranged in a matrix on an upper surface of a circuit board. On the periphery of each of the magnetostrictive elements, a voice coil is arranged. When current flows to the voice coils, the magnetostrictive elements themselves expand and contract in their center axis direction (height direction), and whereby ultrasonic waves (carrier waves) are emitted into the air from the magnetostrictive elements themselves. Since the magnetostrictive elements made of ferrite or the like are used, power consumption can be reduced, compared with the case of using piezoelectric vibrators. Also, the magnetostrictive elements can be made resistant to damage even if subjected to an impact due to falling or the like. Accordingly, in a parametric speaker using ultrasonic waves as carrier waves, power consumption can be reduced and vibrating elements can be made resistant to impact damage. |
