| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inexpensive and high-efficiency electromagnetic transducer that enhances the magnetic flux density of magnetic flux traversing a voice coil. Ž<P>SOLUTION: This electromagnetic transducer 1 includes: a vibration plate 8 with a voice coil 9 formed on a surface thereof; permanent magnet layers 6, 7 located at both sides of the vibration plate 8; and frames 2, 3 mounted with the permanent magnet layers 6, 7 and catching the vibration plate 8 in the thickness direction so as to be displaceable. The cross section of each permanent magnet of the permanent magnet layers 6, 7 is formed into a flat shape where the ratio of the longitudinal length L to the lateral length B is larger than 100%, and not larger than 200%. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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