Patent ID: 6825593
Filing Date: 2004-11-30
Classification: H04R

Abstract:
A piezoelectric type electric acoustic converter comprising:a plurality of piezoelectric ceramic layers which are laminated to define a laminate, all of the plurality of piezoelectric ceramic layers being polarized in the same direction which is a thickness direction of said laminate; main surface electrodes disposed on front and back main surfaces of said laminate; an internal electrode disposed between a respective pair of said polarized piezoelectric ceramic layers; and a resin layer arranged to cover the front and back surfaces of the laminate; wherein said main surface electrodes, said internal electrode and said polarized piezoelectric ceramic layers are constructed and arranged to cause the piezoelectric type electric acoustic converter to generate bending vibration in response to application of an alternating signal between the main surface electrodes and the internal electrode; and the resin layer is not disposed on side surfaces of the laminate.