| 摘要 |
PROBLEM TO BE SOLVED: To obtain a thin acoustic device in which a receiver and a loudspeaker are integrally formed on the front and rear sides and, at the same time, to improve the sound producing characteristic of the device. SOLUTION: A yoke projection 7a is formed by making the surface-side outer peripheral end section of the yoke 7 which becomes the magnetic path section of the loudspeaker 10b, and in which magnetic saturation is apt to occur of yokes 7 which become the common parts of the receiver 10a and loudspeaker 10b thicker in thickness than the other section. By adjusting the upper limit of the height of the projection 7a to the height or movable height of the vibrating film 1 of the receiver 10a, the sound pressure of the loudspeaker 10b is secured by reducing the magnetic saturation after the thickness of the acoustic device 10 is reduced without increasing the thickness of the device 10 as a whole. COPYRIGHT: (C)2004,JPO
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