摘要 |
PROBLEM TO BE SOLVED: To provide a speaker diaphragm and electrodynamic speaker which is the electrodynamic speaker of a long and thin type whose width in a short radial direction is shorter compared to a length in a long radial direction, which has a high efficiency, which is excellent in voice reproduction capability, which receives little impact even if a vibrating diaphragm of the long and thin type speaker carries out splitting vibration, and which is suitable for attaching to an apparatus of a display, etc. SOLUTION: The magnetic circuit for the speaker is provided with: a top plate of the long and thin type; a center pole which forms a circular magnetic air gap; an under plate which arranges the center pole in a center, and is the long and thin type corresponding to the long radical direction and the short radical length direction; and two main magnets which are held between the top plate and the under plate, symmetrically arranged making the center pole as a center in the long radical direction, and magnetized in the same direction. The two main magnets are rare earth magnets which have respectively nearly cylindrical shapes. COPYRIGHT: (C)2009,JPO&INPIT
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