Loudspeaker and electronic apparatus using the loudspeaker

Patent metadata

Field	Value
Publication number	US-9769571-B2
Application number	US-201514841786-A
Country	US
Kind code	B2
Filing date	Sep 1, 2015
Priority date	Mar 8, 2013
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A loudspeaker includes two first magnetic portions arranged in parallel and a second magnetic portion disposed between the two first magnetic portions on a bottom plate. An annular top plate is provided to the two first magnetic portions and disposed in such a manner as to form a magnetic gap with respect to the second magnetic portion. The first magnetic portions and the second magnetic portion are magnetized in the opposite directions in a direction in which the bottom plate, the first magnetic portions and the top plate are stacked. The top plate includes two main bodies provided to the two first magnetic portions and two bending portions connecting between two first magnetic portions and bending toward the bottom plate.

First claim

What is claimed is:

1. A loudspeaker comprising:
a magnetic circuit including:
a bottom plate,
two first magnets arranged in parallel and coupled to the bottom plate,
a second magnet disposed between the two first magnets and coupled to the bottom plate, and
an annular first top plate provided to the two first magnetic portions at an opposite side to the bottom plate and disposed in such a manner as to form a magnetic gap with respect to the second magnet;

a frame supporting the magnetic circuit;
a diaphragm supported by the frame; and
a voice coil fixed to the diaphragm and inserted into the magnetic gap of the magnetic circuit,
wherein the two first magnets and the second magnet are magnetized in opposite directions to each other in a first direction in which the bottom plate, the two first magnets, and the first top plate are stacked,
the first top plate includes two main bodies each of which is placed on one of the two first magnets, and two bending portions connecting between the two first magnets and bending toward the bottom plate from the main bodies, and
the second magnet includes a second top plate disposed at an opposite side to the bottom plate, and
each of the bending portions includes:
two first regions each of which faces one of the two first magnets;
two connecting portions each of which connects the main body to one of the two first regions;
a second region which faces the second magnet and protrudes toward the second top plate in the first direction, the second region extending in the first direction beyond an interface between the second magnet and the second top plate; and
two cut-away parts each of which is formed between one of the two first regions and the second region.

2. The loudspeaker of claim 1 , wherein each of the two first magnets and the second magnet includes a rectangular parallelepiped shaped magnet having long sides and short sides, and one of the long sides of the magnet included in each of the two first magnets and each of the long sides of the magnet included in the second magnet face each other.

3. The loudspeaker of claim 2 , wherein the second magnet includes two magnets arranged in a parallel in a direction in which the two first magnets are arranged in parallel.

4. The loudspeaker of claim 2 , wherein a dimension of each of the long sides of the second magnet is smaller than a dimension of each of the long sides of the two first magnets.

5. The loudspeaker of claim 2 , wherein the first top plate includes a guide for positioning the two first magnets.

6. The loudspeaker of claim 2 , wherein an outside dimension of the first top plate in the direction in which the two first magnets are arranged in parallel is smaller than an outer dimension of at least one of the two first magnets.

7. The loudspeaker of claim 2 , wherein an outside dimension of the bottom plate in the direction in which the two first magnets are arranged in parallel is smaller than an outer dimension of at least one of the two first magnets.

8. The loudspeaker of claim 1 , wherein the two bending portions bend at a right angle with respect to the two main bodies in the first top plate.

9. The loudspeaker of claim 1 , wherein the two bending portions include a cut-away part through which a lead wire of the voice coil is inserted to pass.

10. The loudspeaker of claim 1 , wherein the frame is made of resin and integrally formed with the magnetic circuit.

11. The loudspeaker of claim 1 , wherein the frame is made of resin, and integrally formed with an outer periphery of the first top plate.

12. An electronic apparatus comprising:
the loudspeaker defined in claim 1 , and
an amplifier for supplying the loudspeaker with an electric signal.

13. The loudspeaker of claim 1 , wherein:
a part of at least one of the two bending portions faces one the two first magnets, and
a face where the bending portion faces the second magnet is larger than a face where the bending portion faces the one of the two first magnets.

14. The loudspeaker of claim 1 , wherein the second magnet is configured with two magnets and a space therebetween.

15. The loudspeaker of claim 1 , wherein the second top plate is configured with two plates and a space therebetween.

16. The loudspeaker of claim 15 , wherein:
the second magnet is configured with two magnets and a space therebetween, and
the two plates of the second top plate are formed on the two magnets of the second magnet.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Asano Akira
• Enomoto Mitsutaka
• Matsunaga Tomoyuki

Classifications

• H04R9/06

  Loudspeakers · CPC title

• H04R9/025 Primary

  Magnetic circuit · CPC title

• H04R2499/11

  Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's · CPC title