Patent ID: 7079661

Claim:
A speaker for reproducing ultrahigh frequencies comprising: a schematically disk-shaped piezoelectric ceramic vibrator in which a piezoelectric ceramic and a metal substrate are bonded; a dome-shaped diaphragm attached to said piezoelectric ceramic vibrator; a voltage boosting circuit connected to said piezoelectric ceramic vibrator and configured to multiply an input drive voltage and apply a boosted drive voltage to said piezoelectric ceramic vibrator; and a panel which fixes an outer peripheral part of said piezoelectric ceramic vibrator and has an opening part in a front face of said dome-shaped diaphragm; wherein a diameter of a dome part of said dome-shaped diaphragm is made to be 0.5 to 0.8 times an effective movable diameter of said piezoelectric ceramic vibrator; and the diameter of said piezoelectric ceramic is almost identical to that of said dome part.