PIEZOELECTRIC SPEAKER

• US 20100290650A1
• Filed: 02/02/2009
• Published: 11/18/2010
• Est. Priority Date: 02/07/2008
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Ogura, Takashi, Tokuda, Tatsuhiko
• Granted Patent: US 8,340,329 B2
• Time in Patent Office: Days
• US Class Current: 381/190
• CPC Class Codes: H01Q 1/44 using equipment having another main function to serve additionally as an antenna , e.g. means for giving an antenna an aesthetic aspectH01Q1/27 - H01Q1/34 take precedence
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• 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 purpose of the invention is to provide a piezoelectric speaker that can serve as an antenna and can be used for frequencies in the MHz band, thereby it is possible to suppress enlarging of the size due to use of the piezoelectric speaker also as the antenna to a minimum level. The antenna (4) is provided on a frame (2a) that is a peripheral edge portion of the diaphragm (2). With this configuration, enlarging of the size can be suppressed to a minimum level while using the piezoelectric speaker also as the antenna, and it is possible to achieve space saving in a miniature electronic apparatus such as a mobile phone or the like when the piezoelectric speaker is adopted to the miniature electronic apparatus. In addition, the antenna (4) is a loop antenna formed in a loop shape. With this configuration, the piezoelectric speaker can be used for frequencies in the MHz band, which is used in, for example, a noncontact IC card technology. Further, a magnetic material sheet (5) is provided on the other face of the frame (2a) so as to oppose to the antenna (4). With this configuration, it is possible to suppress reduction of the reception sensitivity at a time when a metallic material is placed in the vicinity of the antenna (4).

Claims

1. (canceled)

2. A piezoelectric speaker, comprising:

a diaphragm; and

a piezoelectric element that is laminated on the diaphragm,

wherein an antenna is formed on a plane being identical with a plane of the piezoelectric element and is formed so as to surround the piezoelectric element; and

wherein the antenna is supported by a magnetic material sheet.

4. The piezoelectric speaker according to claim 2, wherein the antenna is a loop antenna formed in a loop shape.

5. The piezoelectric speaker according to claim 2, wherein the antenna is a plate-like antenna formed in a plate shape.

6. The piezoelectric speaker according to claim 2, wherein an elastic member is provided between the diaphragm and the antenna.

7. A mobile communication terminal, comprising:

the piezoelectric speaker according to claim 2.

3. (canceled)