ELECTROMAGNETIC-ACOUSTIC TRANSDUCER

摘要

PROBLEM TO BE SOLVED: To provide a small electromagnetic-acoustic transducer with high sound pressure which can certainly fix a small magnet while securing a back surface space of a diaphragm. SOLUTION: The electromagnetic-acoustic transducer 1 is composed of: a base 24 formed of magnetic material; a core 22 which is formed of magnetic material and is erected on the base 24; the diaphragm 20 which is formed of magnetic material and is supported leaving a gap from a core tip; a magnetic field generating member 25 which composes a magnetic circuit with the base 24, the core 22 and the diaphragm 20 and supplies a static magnetic field; and a coil 23 which is placed at the peripheral of the core and supplies an oscillating magnetic field to the magnetic circuit. In the magnetic field generating member 25, a magnet 25a and a support ring 26 are formed integrally and a multiple ring structure having a magnetic pole of the same polarity is composed in the surface opposed to the diaphragm 20.