发明申请
US20100290650A1 PIEZOELECTRIC SPEAKER 失效
压电扬声器

PIEZOELECTRIC SPEAKER
摘要:
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).
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