THIN ELECTROMAGNETIC ACOUSTIC TRANSDUCER, USING METHOD THEREOF, AND MOBILE COMMUNICATION APPARATUS PROVIDED WITH THE TRANSDUCER

摘要

PROBLEM TO BE SOLVED: To provide a thin electromagnetic acoustic transducer which is thin so as not to attenuate vibrations by exercising ingenuity with respect to the shape of an exciting coil and the arrangement of a magnetic generating body.;SOLUTION: A first vibration system comprises a thin sound generating plate (1) wherein an outer circumferential part disposed in the magnetic field of the magnetic generating body is supported by a housing (H) and the exciting coil disposed in the sound generating plate and formed in a thin doughnut disk- shaped multiple solenoid. The magnetic generating body (4) as a second vibration system is supported by a plate-like elastic body (6) in such a manner that a top part is fitted with margin into an inner diameter part of the exciting coil, and the outer circumferential part of the plate-like elastic body is supported by the housing so as to be thereby movable vertically.;COPYRIGHT: (C)2004,JPO