PIEZOELECTRIC LOUDSPEAKER

摘要

PROBLEM TO BE SOLVED: To provide a piezoelectric loudspeaker that can output a loud sound by using a piezoelectric laminate made of a polymer and causing a diaphragm to resonate.SOLUTION: There is provided a piezoelectric loudspeaker having a piezoelectric laminate joined to at least one surface of a diaphragm 11, the piezoelectric loudspeaker being characterized in that: (i) the piezoelectric laminate has a conductive layer 2 and an oriented film layer 1 made of polylactic acid laminated alternately and conductive layers adjoining each other with an oriented film layer interposed each have an effective electrode part 6 having one end short-circuited to a negative electrode 10 and the other end short-circuited to a positive electrode 9 and also including a conductive layer between the adjacent oriented film layers and also have immobile parts 7 and 8 where the oriented film layers adjoin each other with no conductive layer interposed; (ii) the piezoelectric laminate and the diaphragm are joined together at both effective electrode part and immobile parts of the piezoelectric laminate; and (iii) oriented film layers sandwiched between respective conductive layers are so laminated as to expand and contract in the same directions when current flows and the diaphragm is caused to resonate through plane-directional expansion and contraction of the piezoelectric laminate.