| 摘要 |
PROBLEM TO BE SOLVED: To provide a dynamic electroacoustic transducer capable of preventing in advance a diaphragm from being excessively deformed due to wind pressure even when the diaphragm is made of a thin film. SOLUTION: In the dynamic electroacoustic transducer 10 wherein the film thickness of the diaphragm 12 is set to be a value of 15μor below, a diaphragm stopper 30 as a deformation preventing structure is provided to the upper face of the center of a yoke 26. When the diaphragm 12 is deformed by a prescribed amplitude or larger in excess of the maximum amplitude at ringing, the stopper 30 is pressed into contact with the inner circumferential side 12A of the diaphragm 12 located at the inner circumferential side of a voice coil 16. When a foldable mobile communication apparatus with the electroacoustic transducer 10 installed therein is folded, although wind pressure acts on the diaphragm 12 via a sound hole 20a formed in its cover 20, the press contact action of the diaphragm stopper 30 prevents the diaphragm 12 from being excessively deformed. COPYRIGHT: (C)2005,JPO&NCIPI
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