| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electromagnetic transducer for generating a magnetic flux on even a turning portion of a conductor coil pattern, and highly efficiently generating a sound pressure while further almost fully driving a vibration film. Ž<P>SOLUTION: The electromagnetic transducer includes: a permanent magnet plate having a first magnetization pattern where strip-like different magnetic poles are alternately magnetized, and a second magnetization pattern where strip-like different magnetic poles are each magnetized along both end sides perpendicular to a strip-like longitudinal direction of the magnetic poles of the first magnetization pattern; and a vibration film in which a turning portion of a meandering-shape conductor coil pattern is formed at a position corresponding to the second magnetization pattern and a straight line portion of the conductor coil pattern is formed at a position along the strip-like longitudinal direction of the magnetic poles of the first magnetization pattern, so as to oppose the magnetization forming surface of the permanent magnet plate, and which is electromagnetically coupled to the permanent magnet plate and vibrates in a thickness direction by energizing the conductor coil pattern. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
