| 摘要 |
PROBLEM TO BE SOLVED: To provide an electroacoustic conversion device capable of obtaining a sound pressure equivalent to that of a circular laminated piezoelectric element, even if a polygonal laminated piezoelectric element is used.SOLUTION: An electroacoustic conversion device 11 includes a laminated piezoelectric element 12 where a piezoelectric layer and an electrode layer are laminated alternately, and the piezoelectric layer is arranged between a pair of electrode layers of different polarities, and a diaphragm 13 on which the laminated piezoelectric element is arranged. The laminated piezoelectric element 12 is polygonal, when viewing from the lamination direction, and the surface of the diaphragm 13, where the laminated piezoelectric element 12 is arranged, is circular. Out of the piezoelectric layer sandwiched by the pair of electrode layers, the sum (V) of volumes of effective layers projected from the lamination direction, and where the pair of electrode layers are superposed satisfies a following conditions. 0.2πR×ts≤V≤2.0πR×ts(where, π is a circular constant, R is the radius of the diaphragm, and ts is the thickness of the diaphragm).SELECTED DRAWING: Figure 6 |
