| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic circuit for speaker of an almost even magnetic flux density in an amplification area of a voice coil with a simple structure, to provide a speaker of high sound quality of acoustic characteristic, and to easily manufacture the magnetic circuit for a speaker without performing complicated processing. SOLUTION: The magnetic circuit for a speaker includes a magnet 21 and a pole piece placed as a magnetic pole. A pole piece 22 composes a laminated body 5 comprising a first plate of a first outer diameter whose cross section shape is formed rectangular and a second plate of a second diameter larger than the first one which is placed concentrically on the first plate and includes a cross section shape formed rectangular. The laminated body 5 forms a projection part on a surface part of an outer circumferential side by a difference in outer diameter between the first plate and the second plate. COPYRIGHT: (C)2010,JPO&INPIT |
