Piezoelectric vibrating elements and piezoelectric electroacoustic transducers

A piezoelectric speaker including a plurality of piezoelectric vibrating elements, each including a piezoelectric vibrating plate and a weight connected to near the point of center of gravity thereof through a viscoelastic layer, and having the vibramotive force designed to be taken out of the outer edge thereof, which are connected at their peripheral ends to each other through connectors, one of said elements being connected at its peripheral edge directly to a cone type acoustic radiator to give thereto a vibramotive force mainly in a high-frequency portion, and the remaining elements adjacent thereto producing a vibramotive force adapted to share middle- and low-frequency portions for energization of said cone type acoustic radiator.

A piezoelectric speaker including a piezoelectric vibrating element designed in such a manner that a main weight is joined to the vicinity of the central portion of a piezoelectric sound radiator through a viscoelastic layer, so that said radiator is constrained at around the central portion thereof to take a vibromotive force out of the outer end thereof, wherein an auxiliary weight is located inside of the outer end of said radiator, and is joined in place through a viscoelastic layer.

A piezoelectric speaker including a piezoelectric vibrating element, wherein each of two weights is joined to the vicinity of the central portion on each side of a piezoelectric sound radiator through a viscoelastic layer, said weights being joined to each other through the associated viscoelastic layers by means of a connecting shaft extending through a small opening formed in the vicinity of the central portion of the piezoelectric sound radiator, so that said radiator is constrained at around the central portion thereof to take a vibromotive force out of the outer end of said radiator.