Piezoelectric loudspeaker

• US 4,439,640 A
• Filed: 12/31/1981
• Issued: 03/27/1984
• Est. Priority Date: 01/05/1981
• Status: Expired due to Term

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Takaya, Tadashi
• Primary Examiner(s): Rubinson, G. Z.
• Assistant Examiner(s): Schroeder, L. C.
• Application Number:
  US06/336,038
• Time in Patent Office: 817 Days
• Field of Search: 179/110 A, 179/110 R, 179/181 R, 310/321, 310/323, 310/324, 310/325
• US Class Current: 381/190
• CPC Class Codes: H04R 17/00 Piezoelectric transducers; Electrostrictive transducers piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners H10N30/00

Abstract

A piezoelectric loudspeaker thin plate-like shaped and using a piezoelectric ceramic plate for a sound-generating portion, which comprises a disc-shaped diaphragm formed of a metallic plate, a disc-shaped film using a material of a smaller Q-factor and formed about equal in diameter to the disc-shaped diaphragm, and a disc-shaped piezoelectric ceramic plate smaller in diameter than the disc-shaped diaphragm, these three members being stuck concentrically with each other, so that the integral-stuck member is supported at its outer peripheral portion to a frame.

Claims

1. A piezoelectric loudspeaker comprising:

a disc-shaped diaphragm formed of a metallic plate;

a disc-shaped film formed of a material having a smaller Q-factor than and substantially equal in diameter to said diaphragm; and

a disc-shaped piezoelectric ceramic plate smaller in diameter than said diaphragm;

said diaphragm, said film and said piezoelectric ceramic plate being adhered concentrically to each other so as to form an integral member with said piezoelectric ceramic plate located on the outside of said integral member;

said integral member being supported at the outer peripheral portion thereof to a frame.

2. A piezoelectric loudspeaker according to claim 1, wherein said disc-shaped diaphragm is formed of a thin brass plate.

3. A piezoelectric loudspeaker according to claim 1, wherein said disc-shaped film is formed of paper, polyethylene, or the like.

4. A piezoelectric loudspeaker according to claim 1, wherein said piezoelectric ceramic plate is adhered to said disc-shaped diaphragm.

5. A piezoelectric loudspeaker according to claim 1, wherein said piezoelectric ceramic plate is adhered to said disc-shaped film.

6. A piezoelectric loudspeaker according to claim 1, wherein said frame comprises a pair of annular frame members, said frame members sandwiching therebetween the outer peripheral portion of said integral member.