Patent attributes
An array speaker device (1A) includes a vibrator (20) arranged on one face of a substrate having a uniform thickness, the vibrator being formed of a base material layer (11), a first electrode layer (12), a piezoelectric element layer (13), and a second electrode layer (14), each of which has a uniform thickness, and which are layered in the order mentioned on the substrate. A hole through which a sound wave is outputted in the thickness direction of the substrate is provided on the substrate at a position corresponding to the vibrator (20), the sound wave being generated by vibration of the vibrator (20) to which a voltage signal is applied via the first electrode layer (12) and the second electrode layer (14). Scallops (S) made of an indentation and a projection alternating in the thickness direction of the substrate are formed on the inner circumferential wall of the hole.
