JPH1023591A - Speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a speaker without deteriorated sound quality by placing sub magnets whose magnetized direction differs from the facing magnets magnets to their upper and a lower part so as to increase magnetic flux of a repulsion magnetic circuit. SOLUTION: Magnets M1, M2 are placed so that the same poles are opposed to each other and a sub magnet M4 whose magnetized direction differs from that of the magnets M1, M2, that is, magnetized in the radial direction is placed to an upper and a lower part of both the magnets M1, M2. The main magnets M1, M2 are magnetized in the broadwise direction and the same thickness as that of conventional magnets is adopted to ensure magnetic flux capability. They are arranged so that the N poles or the S poles are opposed to each other with a center plate Cp in between and supported by a holder H and an outer ring Or is placed at the outer circumference of the center plate Cp.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loudspeaker using a repulsion type magnetic circuit, and more particularly to a loudspeaker having an improved structure of the repulsion type magnetic circuit.

[0002]

2. Description of the Related Art FIG. 3 shows a voice coil Vc in a repulsive magnetic field generated on the outer periphery of both magnets M1 and M2 by using a repulsive magnetic circuit 11 in which magnets M1 and M2 are arranged so that the same poles face each other. Shows a conventional speaker placed,
A center plate Cp made of a magnetic material is sandwiched between the two magnets M1 and M2, and the magnetic circuit is held by a holder H made of a non-magnetic material. In order to increase the magnetic flux density, an outer ring Or made of a magnetic material may be arranged on the outer peripheral side of the center plate Cp. In the figure, f indicates a magnetic flux.

However, in the conventional loudspeaker shown in FIG. 3, since the same pole (N pole or S pole) is opposed across the center plate Cp, the magnetic flux f from around the center of the magnets M1 and M2. There was a drawback that the direction was reversed, the amplitude was suppressed, and the sound quality was degraded.

In order to solve this problem, we have proposed FIG.
As shown in FIG. 1, a speaker in which an outer peripheral magnet M3 (sub magnet) magnetized in a different direction from the magnets M1 and M2 is arranged outside the facing magnets M1 and M2 (main magnet) was proposed first ( JP-A-6
233379).

[0005]

FIG. 5 is an enlarged sectional view of the lower magnet M2 in FIG. 4. As shown in FIG. 5, the main magnet M1 shown in FIG. , M2 and a radially magnetized sub-magnet M3, a gap g is formed,
As a result, a leakage magnetic flux Lf is generated, and there is a possibility that the magnetic flux in the magnetic gap formed by the center plate Cp and the outer ring Or from which the magnetic flux is originally desired to be reduced.

Further, since the sub magnet M3 is arranged on the outer periphery of the main magnets M1 and M2, the outer diameter of the main magnets M1 and M2 is smaller than the outer diameter of the center plate Cp by the thickness of the sub magnet M3. The magnetic flux was reduced.

It is an object of the present invention to provide a speaker which can increase the magnetic flux of a repulsion type magnetic circuit and does not degrade the sound quality for a speaker unit requiring a wide amplitude.

[0008]

In order to achieve the above object, according to the loudspeaker according to the first aspect of the present invention, the magnets are arranged so that the same poles are opposed to each other, and are generated on the outer periphery of both magnets. In a speaker in which a voice coil is arranged in a repulsive magnetic field, sub-magnets whose magnetization directions are different from those of the opposing magnet are arranged above and below the opposing magnet.

According to a second aspect of the present invention, the sub magnet is magnetized in a radial direction.

[0010]

Since sub magnets whose magnetization directions are different from those of the main magnet are arranged above and below the opposing main magnet, the magnetic flux emitted from the center plate is prevented from returning to the main magnet, and the positive magnetic field is increased. Area spreads in the vertical direction, and the sound quality does not deteriorate even in a speaker unit requiring a large amplitude.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a speaker according to the present invention will be described with reference to FIGS. 1 and 2, and the same components as the conventional components described with reference to FIGS. The sign was attached.

FIG. 1 is a cross-sectional view of the whole speaker using the repulsion type magnetic circuit 1, and FIG. 2 is an enlarged cross-sectional view of the repulsion type magnetic circuit 1. In the present invention, the magnets M1, M2
Are arranged so that the same pole side faces each other, and the voice coil V
c, the magnets M1, M2 above and below the opposing main magnets M1, M2.
The sub-magnet M4 whose magnetization direction is different from that of No. 2 is arranged.

The main magnets M1 and M2 are magnetized in the thickness direction, and have the same thickness as the conventional one in order to secure a magnetic flux capacity.
The N-poles or the S-poles are arranged so as to face each other with p therebetween, are held by the holder H, and the outer ring Or is arranged so as to be located on the outer periphery of the center plate Cp.

The outer periphery of the sub magnet M4 has an N pole or an S pole.
The main magnets M1 and M2 are bonded and fixed to the upper and lower surfaces of the main magnets M1 and M2.
Therefore, the pole portion Ha of the holder H is longer by the thickness of the two sub magnets M4 and M4.

In FIG. 1, 2 is a diaphragm, 3 is a chamber, 4 is a damper, 5 is an edge, and 6 is a frame. In the magnetic flux f of FIG. 2, the direction (arrow) of the magnetic flux crosses the voice coil Vc, that is, the direction from the center plate Cp toward the outer periphery is the + magnetic field, and returns to the inner periphery of the center plate Cp. The magnetic flux is a minus magnetic field,
As is clear from FIG.
It can be prevented from returning to p, and the area of the + magnetic field can be expanded in the vertical direction as shown by arrow 7. Therefore, the sound quality is not deteriorated even in a speaker unit requiring a large amplitude.

[0016]

According to the loudspeaker of the present invention, the sub-magnets whose magnetization directions are different from those of the main magnet opposed to each other are arranged above and below the main magnet facing the main magnet. The return to the magnet is prevented, the area of the + magnetic field expands in the vertical direction, and the sound quality is not deteriorated even in a speaker unit which has a large electric input and requires a relatively large amplitude.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a speaker according to the present invention.

FIG. 2 is an enlarged sectional view of a magnetic circuit section of the speaker according to the present invention.

FIG. 3 is a cross-sectional view of a main part of a speaker using a conventional repulsion type magnetic circuit.

FIG. 4 is a cross-sectional view of a main part of the speaker we previously proposed.

5 is an enlarged sectional view showing a relationship between a main magnet and a sub magnet of the speaker in FIG.

[Explanation of symbols]

 Reference Signs List 1 repulsive magnetic circuit 2 diaphragm M1 magnet M2 magnet M4 sub-magnet Cp center plate Vc voice coil Or outer ring H holder f magnetic flux

Claims (2)

[Claims] A loudspeaker in which magnets are arranged so that the same poles are opposed to each other and a voice coil is arranged in a repulsive magnetic field generated on the outer periphery of both magnets. A speaker comprising a sub-magnet having a different shape. 2. The speaker according to claim 1, wherein the sub-magnet is magnetized in a radial direction.