Piezoelectric loudspeaker

A piezoelectric loudspeaker comprising:

• a piezoelectric vibrator including a diaphragm and a piezoelectric member provided on at least one face of the diaphragm, the diaphragm being vibrated by the piezoelectric member;
• a frame for supporting the piezoelectric vibrator;
• and
• a visco-elastic member provided on at least one face of the piezoelectric vibrator,
• the visco-elastic member being disposed in a substantial center of the piezoelectric vibrator,
• the visco-elastic member having a bottom face area which accounts for about 11% to about 80% of a bottom face area of the diaphragm,
• the visco-elastic member including two or more visco-elastic members stacked on top of each other, and
• the two or more visco-elastic members comprising different materials or different shapes.

A piezoelectric loudspeaker comprising:

• a piezoelectric vibrator including a diaphragm and a piezoelectric member provided on at least one face of the diaphragm, the diaphragm being vibrated by the piezoelectric member;
• a frame for supporting the piezoelectric vibrator;
• and
• a visco-elastic member provided on at least one face of the piezoelectric vibrator,
• the visco-elastic member being disposed in a substantial center of the piezoelectric vibrator,
• the visco-elastic member having a bottom face area which accounts for about 11% to about 80% of a bottom face area of the diaphragm,
• the visco-elastic member comprising two or more visco-elastic members having mutually different values in at least one of specific gravity, Young's modulus, and internal loss, and
• the two or more visco-elastic members are disposed in a concentric manner.

A piezoelectric loudspeaker comprising:

• a piezoelectric vibrator Including a diaphragm and a piezoelectric member provided on at least one face of the diaphragm, the diaphragm being vibrated by the piezoelectric member;
• a frame for supporting the piezoelectric vibrator;
• and
• a visco-elastic member provided on at least one face of the piezoelectric vibrator,
• the visco-elastic member being disposed in a substantial center of the piezoelectric vibrator,
• the visco-elastic member having a bottom face area which accounts for about 11% to about 80% of a bottom face area of the diaphragm, and
• the piezoelectric vibrator having at least one aperture, the at least one aperture being at least partially filled by the visco-elastic member.

A piezoelectric loudspeaker comprising:

• a piezoelectric vibrator including a diaphragm and a piezoelectric member provided on at least one face of the diaphragm, the diaphragm being vibrated by the piezoelectric member;
• a frame for supporting the piezoelectric vibrator;
• and
• a visco-elastic member provided on at least one face of the piezoelectric vibrator,
• the visco-elastic member being disposed in a substantial center of the piezoelectric vibrator,
• the visco-elastic member having a bottom face area which accounts for about 11% to about 80% of a bottom face area of the diaphragm,
• the frame having a horn-like configuration including an opening, the opening having a gradually increasing cross-sectional area away from the piezoelectric vibrator and toward a final opening at which soundwaves are emitted, and
• the visco-elastic member having a conical configuration having a gradually decreasing cross-sectional area away from the piezoelectric vibrator and toward the final opening.

A piezoelectric loudspeaker comprising:

• a piezoelectric vibrator including a diaphragm and a piezoelectric member provided on at least one face of the diaphragm, the diaphragm being vibrated by the piezoelectric member;
• a frame for supporting the piezoelectric vibrator;
• and
• a visco-elastic member provided on at least one face of the piezoelectric vibrator,
• the visco-elastic member being disposed in a substantial center of the piezoelectric vibrator,
• the visco-elastic member having a bottom face area which accounts for about 11% to about 80% of a bottom face area of the diaphragm,
• the visco-elastic member including notches in at least one portion thereof.

A piezoelectric loudspeaker comprising:

• a voltage applying means for applying a plurality of voltages;
• a piezoelectric vibrator Including a diaphragm and a plurality of piezoelectric members provided on at least one face of the diaphragm, the diaphragm being vibrated by the plurality of piezoelectric members;
• a frame for supporting the piezoelectric vibrator;
• wherein at least two of the plurality or piezoelectric members have a different voltage applied thereto from the voltage applying means;
• and
• an electrically resistant element for interconnecting at least two of the plurality of piezoelectric members.

A piezoelectric loudspeaker comprising:

• a piezoelectric vibrator Including a diaphragm and a piezoelectric member provided on at least one face of the diaphragm, the diaphragm being vibrated by the piezoelectric member;
• a frame for supporting the piezoelectric vibrator;
• a visco-elastic member provided on at least one face of the piezoelectric vibrator, the visco-elastic member being disposed in a substantial center of the piezoelectric vibrator, and the visco-elastic member having a bottom face area which accounts for about 11% to about 80% of a bottom face area of the diaphragm;
• and
• a plate for connecting at least one said visco-elastic member to the frame so as to damp unwanted vibration of the piezoelectric vibrator, an enclosed space being formed by the plate, the frame, and the diaphragm.

A piezoelectric loudspeaker comprising:

• a piezoelectric vibrator including a diaphragm and a piezoelectric member provided on at least one face of the diaphragm, the diaphragm being vibrated by the piezoelectric member;
• a frame for supporting the piezoelectric vibrator;
• and
• a visco-elastic member provided on at least one face of the piezoelectric vibrator,
• the visco-elastic member being disposed in a substantial center of the piezoelectric vibrator,
• the visco-elastic member having a bottom face area which accounts for about 11% to about 80% of a bottom face area of the diaphragm, and
• the visco-elastic member having a conical configuration having a gradually decreasing cross-sectional area away from the piezoelectric vibrator and toward a final opening.