发明名称 Electromagnetic transducer and portable communication device
摘要 <p>An electromagnetic transducer includes: a first diaphragm disposed in a vibratile manner; a second diaphragm provided in a central portion of the first diaphragm, the second diaphragm being formed of a magnetic material; a yoke disposed in a position opposing the first diaphragm; a center pole provided on a face of the yoke that opposes the first diaphragm; a coil substantially surrounding the center pole; a magnet substantially surrounding the coil; and a thin magnetic plate provided between the magnet and the first diaphragm, an inner periphery of the thin magnetic plate being in overlapping relation to an outer periphery of the second diaphragm. &lt;IMAGE&gt;</p>
申请公布号 EP0999722(A2) 申请公布日期 2000.05.10
申请号 EP19990120984 申请日期 1999.11.04
申请人 MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. 发明人 USUKI, SAWAKO;SAIKI, SHUJI
分类号 H04R9/00;H04R13/02;(IPC1-7):H04R9/06 主分类号 H04R9/00
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