发明名称 Electromagnetic transducer and portable communication device
摘要 An electromagnetic transducer includes: a first diaphragm; a second diaphragm provided in a central portion of the first diaphragm, the second diaphragm comprising a magnetic material having a first opening in a central portion thereof; a yoke disposed so as to oppose the first diaphragm; a center pole disposed between the yoke and the first diaphragm, wherein the center pole has a shape which allows insertion into the first opening; a coil disposed so as to surround the center pole; and a first magnet disposed so as to surround the coil.
申请公布号 US6920230(B2) 申请公布日期 2005.07.19
申请号 US20010980325 申请日期 2001.11.30
申请人 MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. 发明人 USUKI SAWAKO;SAIKI SHUJI
分类号 H04R13/02;(IPC1-7):H04R25/00 主分类号 H04R13/02
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