Title:
MAGNETIC CIRCUIT FOR ACOUSTIC TRANSDUCER AND SPEAKER UNIT
Document Type and Number:
WIPO Patent Application WO/2022/191043
Kind Code:
A1
Abstract:
The purpose of the present invention is to provide a magnetic circuit for an acoustic transducer that can suppress peeling of a surface of a member obtained by compression-molding a soft magnetic composite material. The present invention provides a magnetic circuit for an acoustic transducer comprising a yoke 151, a magnet 152, and a top plate 153. The yoke 151 includes a bottom surface portion 151a, and a pole piece 151b provided vertically to the bottom surface portion 151a. On the bottom surface portion 151a, the magnet 152 and the top plate 153 are provided in this order. A voice coil 14 is disposed in a magnetic gap 141 formed between the pole piece 151a and the top plate 153. The pole piece 151a or the top plate 153 includes a composite material portion 154 opposite the magnetic gap 141, and a protection layer 155 coating a surface of at least the composite material portion 154. The composite material portion 154 is formed of a soft magnetic composite material. The material of the protection layer 155 is different from the soft magnetic composite material.
Inventors:
TERADA TAKAHIRO (JP)
WAKUI YUKIO (JP)
SANO TSUNENORI (JP)
NORO MASAO (JP)
WAKUI YUKIO (JP)
SANO TSUNENORI (JP)
NORO MASAO (JP)
Application Number:
PCT/JP2022/009245
Publication Date:
September 15, 2022
Filing Date:
March 03, 2022
Export Citation:
Assignee:
YAMAHA CORP (JP)
International Classes:
H04R9/02
Foreign References:
| JPS5588595U | 1980-06-18 | |||
| JPH0951597A | 1997-02-18 | |||
| JPS53132333U | 1978-10-20 |
Attorney, Agent or Firm:
AMANO Kazunori (JP)
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