Electromagnetic transducer and portable communicating device
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsSawako Usuki, Shuji Saiki
Life of this patent
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Abstract
An electromagnetic transducer according to the present invention includes: a first diaphragm disposed so as to be capable of vibration; a second diaphragm disposed in a central portion of the first diaphragm, the second diaphragm being made of a magnetic material; a yoke disposed so as to oppose the first diaphragm; a center pole disposed between the yoke and the first diaphragm; a coil disposed so as to surround the center pole; a first magnet disposed so as to surround the coil; and a second magnet disposed on an opposite side of the first diaphragm from the center pole.
Claims47
An electromagnetic transducer comprising:
- a first diaphragm;
- a second diaphragm disposed in a central portion of the first diaphragm, the second diaphragm being made of a magnetic material;
- a yoke disposed so as to oppose the first diaphragm;
- a center pole disposed between the yoke and the first diaphragm;
- a coil disposed so as to surround the center pole;
- a first magnet disposed so as to surround the coil;
- and
- a second magnet disposed on an opposite side of the first diaphragm from the center pole.
Dependencies are inferred from the claim text.