IP Library Granted Patent US 8,744,116
Granted Patent B2
US 8,744,116 · App. 13/823,762 · Granted Jun 3, 2014

Magnetic circuit for speaker and speaker using same

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Quick Facts
Patent No.
US 8,744,116
App. No.
13/823,762
Granted
Jun 3, 2014
Kind
B2
Abstract

A bond magnet according to the present invention is anisotropic, and a magnetic field is oriented from a lowest edge of side surface of the bond magnet toward an upper section of side surface of the bond magnet. Further, the bond magnet is configured such that the upper section of side surface of the bond magnet is disposed closer to a yoke side surface of a yoke than the lower side surface of the bond magnet is, and the upper section of side surface of the bond magnet faces against the yoke side surface. With this, a magnetic gap is provided between the upper section of side surface of the bond magnet and the yoke side surface. Thus, it is possible to improve a magnetism characteristic of the bond magnet, and to achieve both of magnetic efficiency and productivity of a magnetic circuit for a speaker.

Claims (44)

1. A magnetic circuit for a speaker, comprising:

a yoke having a yoke bottom and a yoke side surface provided upright on the yoke bottom;

a bond magnet fixed onto the yoke bottom;

a magnetic gap provided between an upper section of side surface of the bond magnet and an inner surface of the yoke side surface; and

a first connecting section connecting a lowest edge of side surface of the bond magnet with the upper section of side surface, wherein

the upper section of side surface faces against the inner surface of the yoke side surface,

the upper section of side surface is disposed closer to the yoke side surface than the lowest edge of side surface is,

the bond magnet is anisotropic,

a magnetic field is oriented from a bottom surface of the bond magnet toward the upper section of side surface, and

the first connecting section is provided in an inclined manner with respect to the yoke bottom.

2. The magnetic circuit for a speaker according to claim 1 , wherein

an inclination angle between the bottom surface of the bond magnet and the first connecting section is obtuse.

3. The magnetic circuit for a speaker according to claim 2 , wherein

a cross-sectional shape of the first connecting section is in a circular arc shape, and

the first connecting section is provided with a recess.

4. The magnetic circuit for a speaker according to claim 2 , wherein

a second connecting section is provided between the upper section of side surface and an upper end of the first connecting section, and

the second connecting section is provided perpendicularly to the upper section of side surface.

5. The magnetic circuit for a speaker according to claim 2 , wherein

the magnetic field within the bond magnet is oriented following a shape of the first connecting section.

6. The magnetic circuit for a speaker according to claim 1 , wherein

a recess is provided in a central portion of an upper surface of the bond magnet.

7. The magnetic circuit for a speaker according to claim 1 , wherein

a cross-sectional shape of the first connecting section is in a linear shape.

8. The magnetic circuit for a speaker according to claim 7 , wherein

the first connecting section is provided with a bent portion.

9. The magnetic circuit for a speaker according to claim 1 , wherein

the bond magnet is provided by injection molding.

10. The magnetic circuit for a speaker according to claim 1 , wherein

a projection is provided in a central portion of an upper surface of the bond magnet, and

the magnetic field is oriented from the projection toward the upper section of side surface.

11. A speaker, comprising:

a yoke having a yoke bottom and a yoke side surface provided upright on the yoke bottom;

a bond magnet fixed within the yoke bottom;

a magnetic gap provided between an upper section of side surface of the bond magnet and an inner surface of the yoke side surface;

a first connecting section connecting a lowest edge of side surface of the bond magnet with the upper section of side surface;

a frame coupled to the magnetic circuit;

a voice coil operable to be driven based on a magnetic field generated from the magnetic gap; and

a diaphragm, a center of the diaphragm being coupled to the voice coil, and a circumference of the diaphragm being coupled to an outer periphery of the frame, wherein

the upper section of side surface faces against the inner surface of the yoke side surface,

the upper section of side surface is disposed closer to the yoke side surface than the lowest edge of side surface is,

the bond magnet is anisotropic,

a magnetic field is oriented from a bottom surface of the bond magnet toward the upper section of side surface, and

the first connecting section is provided in an inclined manner with respect to the yoke bottom.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 28, 2024
From: PANASONIC HOLDINGS CORPORATION
To: PANASONIC AUTOMOTIVE SYSTEMS CO., LTD.
Reel/Frame 066957/0984 →
CHANGE OF NAME Recorded Feb 21, 2024
From: PANASONIC CORPORATION
To: PANASONIC HOLDINGS CORPORATION
Reel/Frame 066644/0600 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 29, 2013
From: ITANO, TETSUSHI; SUZUMURA, MASAKI
To: PANASONIC CORPORATION
Reel/Frame 030498/0437 →