JPH0865784A - Structure for speaker - Google Patents

Abstract

PURPOSE: To make a speaker thinner without damaging a reproducing frequency band by arranging a driving structure composed of a repulsing magnetic circuit and a voice coil on the front surface side of, a diaphragm and providing a sub-cone further. CONSTITUTION: A magnetic circuit 1 is constituted by superimposing two ring- like magnets magnetized in a thickness direction while holding a center plate there between and making the same electrodes face each other and arranging the voice coil 3a in repulsing magnetic fluxes radially generated at the peripheral edge of the center plate. The vibration system of the speaker is constituted of the diaphragm 2 of a cone type, the 5 voice coil 3a attached to the diaphragm through a coil bobbin 3b and a damper 4 for supporting them. By arranging the voice coil 3a and the magnetic circuit 1 on the front surface side of the diaphragm 2, it is prevented that the vertical angle of the cone becomes large and the reproducing frequency band of a high tone area is sacrificed at the time of limiting the height of the entire speaker to be small. Further, the sub- cone 11 is provided and the high tone area is reinforced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a repulsive magnetic circuit type speaker, and more particularly to a structure of a speaker which is suitable for weight reduction and thickness reduction and can improve a reproduction frequency band.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 8, as a magnetic circuit 1, two magnets 5 magnetized in a thickness direction have been used.
A repulsion magnetic circuit is formed by arranging 5 so that the same poles face each other to form a repulsion magnetic circuit utilizing a magnetic field generated by a repulsion magnetic flux generated on the outer peripheral side of the magnet, and the voice coil 3 is arranged in the magnetic field. Type speaker B has been proposed, and we have also proposed various speakers of this type. In the figure, 2 is a cone diaphragm, 4 is a damper, and 6 is a center plate made of a magnetic material sandwiched between magnets 5 and 5 for increasing the magnetic flux density of the repulsive magnetic flux. Reference numeral 7 is a frame, and 8 is a column for coupling and fixing the magnetic circuit members.

[0003]

In a conventional general repulsive magnetic circuit type speaker, as shown in FIG. 8, a diaphragm is provided on the upper end side of the coil bobbin 3b of the voice coil 3 or on the outside of the coil section 3a. Since the inner peripheral portion (neck portion) of 2 is connected, there is a restriction in reducing the overall height of the diaphragm 2, and there is a limit to the reduction in overall height of the speaker. For example, as shown by the phantom line in the figure, when the overall height of the diaphragm 2 is reduced to make the overall height h1 of the speaker h2, the half-vertical angle 2θ1 formed at the joint between the voice coil 3 and the diaphragm 2 is 2θ2.
It became large and was restricted by the expansion of the reproduction frequency band of the treble part.

In order to reduce the overall thickness without increasing the half-vertical angle of the speaker too much, a magnetic circuit is provided in front of the diaphragm 2 and the coil portion 3a of the voice coil 3 is joined to the coil bobbin 3b and the diaphragm 2. It may be possible to position it in front of the portion. However, as shown in FIGS. 9A and 9B, when a general outer magnetic type magnetic circuit or inner magnetic type magnetic circuit is used as the magnetic circuit 21, Has a structure as shown in the figure, and since the front surface of the diaphragm 2 is covered with a large magnetic circuit component such as the magnet 25 and the yoke 23, sound wave interference occurs and smooth frequency characteristics cannot be obtained. In FIGS. 9A and 9B, 22 is a center pole and 26 is a top plate.

Further, there has been proposed a speaker in which the repulsive magnetic circuit as described above is used and the inner peripheral portion of the diaphragm is directly bonded to the voice coil to achieve a thin structure (for example, Japanese Patent Laid-Open No. 5-219592). Gazette).

An object of the present invention is to secure the entire height of the diaphragm for promoting the expansion of the reproduction frequency band, and also to reduce the weight and the thickness of the entire diaphragm so that the front surface of the diaphragm is covered with the magnetic circuit. It is an object of the present invention to provide a speaker structure which does not have such a structure, and in particular, a speaker structure which can widen a reproduction band, particularly a treble range of the speaker according to the conventional proposal.

[0007]

In the structure of the speaker of the present invention, two magnets magnetized in the thickness direction are arranged so that the same poles face each other, and a repulsive magnetic flux is generated on the outer peripheral side of the magnet. In the repulsive magnetic circuit type speaker configured to arrange the voice coil in the magnetic field, the coil portion of the voice coil is located in front of the joint between the coil bobbin and the diaphragm, and the coil bobbin is smaller than the outer diameter of the diaphragm. It has a diameter sub-cone attached.

[0008]

The coil portion of the voice coil is located in front of the joint between the coil bobbin and the diaphragm. In other words, the position of the joint between the coil bobbin and the inner peripheral part of the diaphragm is located behind (below) the coil part of the voice coil, so the coil part that has restricted the overall height of the cone type speaker vibrates. Since it is located within the height range of the plate, there is no restriction on the total height of the speaker.

Further, in FIG. 8, the total height of the speaker is h2.
Compared with the conventional one, most of the full width (winding width) of the coil part is taken into the height range of the diaphragm, and the half apex angle of the speaker is not made too large, so the reproduction high frequency range is expanded. You can expect an effect.

Further, since the magnetic circuit uses a repulsive magnetic circuit, the front surface of the diaphragm is the same as the one in which a normal inner magnet type or outer magnet type magnetic circuit is arranged on the front side of the diaphragm. Since there is nothing blocking the side and there is no interference of sound waves, better frequency characteristics can be obtained.

Since a sub-cone having a diameter smaller than the outer diameter of the diaphragm is attached to the coil bobbin, it is possible to reproduce in a high frequency range, which is effective as a full range speaker.

[0012]

EXAMPLE FIG. 1 shows a specific example of the structure of the speaker according to the present invention.
7 to 10, the same components as those of the conventional one described with reference to FIG. 8 will be assigned the same reference numerals and detailed description thereof will be omitted. FIG. 1 shows a basic structure of a thin speaker using a repulsive type magnetic circuit, and as described above, a similar structure has been conventionally proposed. Reference symbol A denotes the entire speaker, and in the magnetic circuit 1, two ring-shaped magnets 5 and 5 magnetized in the thickness direction are arranged so that the same poles face each other, and a center plate 6 is placed between both magnets. A repulsive magnetic circuit is used which is configured by sandwiching the repulsive magnetic flux and utilizes repulsive magnetic flux radiated radially.

The vibration system of the speaker A is composed of a cone type diaphragm 2, a voice coil 3 having a coil portion 3a, and a damper 4 supporting the voice coil 3. The magnetic circuit 1 is attached to a mounting portion 7a protruding from the bottom of the frame 7, and a sleeve-shaped support 8 having a threaded portion at the bottom is inserted through the center of the magnetic circuit, and a fixing screw 9 is attached from the lower surface of the mounting portion 7a. Fixed.

In the present invention, the inner peripheral portion of the diaphragm 2 is joined to the lower side of the coil bobbin 3b. Therefore, the coil portion 3a of the voice coil 3 is joined to the inner peripheral portion of the diaphragm 2 and the coil bobbin 3b. It will be located in front of the portion 2a. Further, as shown in FIG. 2, in order to obtain better frequency characteristics, a sub-cone 11 having a diameter smaller than the outer diameter of the diaphragm 2 and mainly responsible for middle and high frequency reproduction is attached to the coil bobbin 3b of the voice coil 3. ing. Further, a dustproof cloth 10 is attached for dustproofing the upper surface portion of the magnetic circuit 1, the inside of the voice coil 3 and the coil portion 3a, and the damper 4 is provided with a conductive portion 4a on the surface side in order to facilitate wiring. The one with is used.

In FIG. 2, the sub-cone 11 is attached above the coil portion 3a located above the diaphragm 2, and FIG. 3 is the structure in which the sub-cone 11 is attached below the coil portion 3a. And the dustproof cloth 10
Is joined to the upper portion of the sub-cone 11, and as is clear from the figure, the dustproof cloth 10 can be prevented from projecting upward as much as possible. The diaphragm 2 and the sub-cone 11 are joined to the coil bobbin 3b so as not to contact the coil portion 3a.

In FIGS. 4 and 5, the dustproof cloth 10 has a composite shape consisting of a hemispherical central portion 10a and a semicircular outer peripheral portion 10b, and a connecting portion 10c between the central portion 10a and the outer peripheral portion 10b is a magnet. The total height of the speaker is made small by fixing it to No. 5 and reducing the portion protruding to the front of the speaker A as much as possible. In FIGS. 6 and 7, the dustproof cloth 10 is made only of a semi-circular shape, and the shape of the tip of the pillar 8 for fixing the magnetic circuit portion is made mushroom-shaped, and the inner circumference of the dustproof cloth 10 is provided on the outer peripheral portion thereof. By fixing the ends, as in FIGS. 4 and 5, the total height of the speaker is reduced by reducing the portion protruding to the front of the speaker A as much as possible.

2 to 7, the diaphragm 2 and the sub-cone 11 are joined to the coil bobbin 3b so as not to come into contact with the coil portion 3a.
Also, the sub-cone 11 does not directly transfer to the diaphragm or the sub-cone even when the sub-cone 11 comes into contact with the ill part 3a to generate abnormal noise or the coil part 3a generates heat.

FIG. 10 compares the frequency characteristics of the loudspeaker A according to the present invention according to the embodiment of FIG. 2 and the conventional thinned repulsive magnetic circuit type loudspeaker B shown in FIG. 8 (where the total height of the loudspeaker is h2). In comparison with the conventional speaker B, the speaker A according to the present invention has remarkably improved frequency characteristics in the high frequency range.

[0019]

According to the structure of the speaker of the present invention, the overall height of the speaker can be made smaller than that of the conventional repulsive magnetic circuit type speaker, and the speaker can be made thinner. Further, the same diaphragm as the conventional one can be used, and there is no deterioration in the frequency characteristic particularly in the high frequency range. Further, the diaphragm can be deeper than the conventional one, and the half-vertical angle formed at the joint between the voice coil and the diaphragm can be made smaller, and the reproduction frequency characteristic band can be expanded. . And by providing a sub cone, it is possible to reproduce the high range,
Compared with conventional ones, it exhibits excellent effects as a full-range speaker that covers the entire range.

[Brief description of drawings]

FIG. 1 is a sectional view showing the basic structure of a thin speaker using a repulsive timing circuit.

FIG. 2 is a sectional view showing an embodiment of a speaker structure according to the present invention.

FIG. 3 is a cross-sectional view showing another example of how the sub-cone is attached.

FIG. 4 is a cross-sectional view showing an example in which the shape of the dustproof cloth is changed.

FIG. 5 is a sectional view showing another example in which the shape of the dustproof cloth is changed.

FIG. 6 is a cross-sectional view showing an example in which the shape of a column is changed.

FIG. 7 is a cross-sectional view showing another example in which the shape of the column is changed.

FIG. 8 is a sectional view of a conventional repulsive magnetic circuit type speaker.

FIG. 9 shows an example in which a normal outer magnet type magnetic circuit or inner magnet type magnetic circuit is used as a magnetic circuit, (A) is a cross-sectional view of an example using an outer magnet type magnetic circuit, and (B) is Sectional drawing of the example which uses an inner magnet type magnetic circuit.

FIG. 10 is a frequency characteristic comparing characteristics of a speaker according to the present invention and a conventional repulsive magnetic circuit type speaker.

[Explanation of symbols]

 A speaker 1 magnetic circuit 2 diaphragm 3 voice coil 3a coil part 3b coil bobbin 4 damper 4a conductive part 5 magnet 6 center plate 7 frame 8 pillar 9 fixing screw 10 dustproof cloth 11 subcone

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area H04R 9/06 A

Claims (5)

[Claims] 1. A repulsion magnetic circuit type loudspeaker in which two magnets are arranged so that their same poles face each other and a voice coil is arranged in a magnetic field generated by a repulsion magnetic flux generated on the outer peripheral side of the magnet. The coil is arranged so that a coil portion of the coil is located in front of a joint portion between the coil bobbin and the diaphragm, and a sub-cone having a diameter smaller than an outer diameter of the diaphragm is attached to the coil bobbin. The structure of the described speaker. 2. The structure of the speaker according to claim 1, wherein a dustproof cloth is attached to the front side of the magnetic circuit. 3. The speaker structure according to claim 2, wherein a dustproof cloth is attached between the sub-cone and the magnetic circuit. 4. The structure of the speaker according to claim 2, wherein the dustproof cloth is divided. 5. A pillar for fixing a magnetic circuit portion is formed in a substantially mushroom shape at its tip, and a semicircular dustproof cloth having an inner peripheral edge is fixed at its outer peripheral portion. The structure of the speaker according to claim 3.