| 摘要 |
PURPOSE:To obtain a sound source, for which a sound pressure level corresponding to the number of vibrators is high, with sharp directionality by circularly arranging a rectangular ultrasonic vibrator to be arranged on a printed circuit board, where a through hole for lead wire is provided, and plural vibrators with resonance elements to be arranged on the ultrasonic vibrator. CONSTITUTION:A super-directional loudspeaker is formed by almost circularly arranging plural vibrators, which are formed with a printed circuit board 3 provided with a through hole 4 for lead wire, a rectangular ultrasonic vibrator 1 arranged on the printed circuit board 3 and resonance elements 2 arranged on the ultrasonic vibrator 1. Thus, when an acoustic signal, etc., is inputted through an amplifier for the super-directional loudspeaker, a parametric sound source is formed from the loudspeaker and a sound field space can be made with the almost two degree angle's directionality. Then, information can be transmitted while being limited only to a specified area. |
