| 摘要 |
PURPOSE:To miniaturize the sound device by vibrating directly a part of an acoustic device main body by an electromagnetic electroacoustic transducer for reproducing sound so as to eliminate the need for a speaker having a cone diaphragm. CONSTITUTION:An exciting coil 6 is wound on a center pole 5 and a permanent magnet 7 is arranged so as to surround the center pole 5. A nonmagnetic support 8 is arranged to the magnet 7, the center pole 5, the coil 6, the magnet 7 and the support 8 are arranged on a magnetic plate 14. Further, a magnetic diaphragm 9 is supported by the support 8 so as not to contact the upper surface of the center pole 5 and the magnet 7 to constitute an electromagnetic electroacoustic transducer 21. A circumference 12 of a vibrating surface 11 of the transducer 21 is fixed to a fix section 13, and the center of the vibrating surface 11 and the diaphragm 9 are connected by a spacer 10. The transducer 21 is assembled to the main body 16 such as a tape recorder with a radio set, and the thcikness of the part where the vibrating face 11 is fixed is made thinner than the thickness of the other main body 16. |
