JPH10117396A - Speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a compact speaker that is driven by a large power with less distortion by improving a linearity between an external force exerted to a damper and its displacement. SOLUTION: A damper 20 is integrally configured with a flat part 24 with a through-hole 23 for a voice coil bobbin, a roll structure whose cross section is formed to be semi-circular, and a mount piece 22 with respect to a speaker frame. Since the roll structured bodies 21a-21d are independent in a circumferential direction of the voice coil bobbin, they do not require expansion/contraction of the material in the circumferential direction in the case of vertical vibration of a diaphragm. Thus, the roll structure 21 is easily deformed, the amplitude of vibration of the damper 20 is increased, and the linearity in the characteristic of force versus displacement is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small speaker for reproducing a large input sound signal.

[0002]

2. Description of the Related Art In recent years, a small and space-saving sound reproducing apparatus has been used, and many speakers used in such a sound reproducing apparatus have a small diameter. FIG. 13 is a cross-sectional view showing a structural example of a conventional small-diameter speaker. A speaker having such a structure will be described below.

[0003] In a speaker 1 shown in FIG. 13, a center pole 3, a magnet 4,
An annular magnetic circuit 6 including a top plate 5 is formed. Upper peripheral part of center pole 3 and top plate 5
A high-density magnetic flux is generated in the annular gap 7 formed by the inner peripheral portion of the voice coil bobbin 8 and the voice coil bobbin 8 is held so as to vibrate vertically. The voice coil bobbin 8 is generally a member formed by molding thin paper into a cylindrical shape, and a voice coil 9 is wound around the outer periphery of the lower end.

The voice coil 9 generates an electromagnetic force when an acoustic driving current is applied to cause the voice coil bobbin 8 to vibrate with a piston. The voice coil 9 is made of a wire such as aluminum or copper. A reinforcing paper 10 is wound around the outer periphery of the voice coil bobbin 8 except for the lower end, and the voice coil bobbin 8
Stiffness is ensured. A diaphragm 11 and a damper (also called a suspension) are provided on such a voice coil bobbin 8.
12 is fixed. The diaphragm 11 is attached to the frame 2 via the edge 13, and the damper 12 is attached to the frame 2.
It is directly attached to and is held free to vibrate.

In the loudspeaker 1 configured as described above, when a driving current proportional to the audio signal is applied to the voice coil 9, a driving force is generated by the driving current and the magnetic flux in the air gap 7, and the damper 12 and the edge The diaphragm 11 held by 13 vibrates up and down, and outputs sound.

[0006]

However, FIG.
In the conventional small speaker 1 shown in FIG. 1, since the aperture of the diaphragm is small, the vibration amplitude of the diaphragm 11 must be increased in inverse proportion to the diaphragm area to obtain a predetermined sound pressure.
Also, the vibration amplitude must be increased in inverse proportion to the square of the frequency. For this reason, it has been difficult for a small speaker to secure a very large amplitude especially in a low frequency region.

FIG. 14 shows the structure of a conventional damper 12 for supporting a diaphragm. The damper 12 is made of resin-impregnated fibers, and has a large number of concentric cross sections as shown by the central profile line.

[0008] As shown in FIG.
The voice coil bobbin 8 which vibrates up and down is supported. When the amplitude of the diaphragm 11 is large, the waveform shown by the broken line is elongated as shown by the solid line. When stretched, the vertex a of the waveform moves to a '. In order for the vertex a of the waveform to move to a ', the radius r1 of the center circle forming the waveform must be r2.
Have to increase. Since the apex of one waveform is on a concentric circle, it does not originally have a mechanism for increasing the radius. Therefore, in order for the radius r1 to change to r2, the material itself must have elasticity in the circumferential direction.

However, since the material of the damper 12 is a resin-impregnated fiber, the elasticity of the material itself is small. On the other hand, as the amplitude increases, the change in the radius of the concentric circle must also increase. However, the change in the radius becomes difficult because the elongation of the material itself is small, and as a result, the increase in the amplitude is limited.

FIG. 16 shows the relationship between the force applied to the damper 12 and the amplitude. As shown in the figure, the amplitude characteristic becomes non-linear from the force of 3N or more, and the amplitude value is saturated. As described above, the conventional small loudspeaker cannot reproduce high-power sound because the damper has a structure with a large amplitude and is hardly deformed. Was.

The present invention has been made in view of such a conventional problem, and provides a speaker having excellent bass characteristics and less distortion by realizing a damper having a structure capable of large amplitude deformation. Aim to be.

[0012]

In order to solve such a problem, the invention according to claim 1 of the present application is directed to a diaphragm for applying air vibration, a cylindrical voice coil bobbin joined to the diaphragm, and the voice. In a speaker having a damper for supporting a voice coil fixed to an outer peripheral portion of a coil bobbin in a magnetic gap formed by an annular top plate and a center pole, the damper has a polygonal shape having a through hole for a voice coil bobbin in the center. A flat portion, and a plurality of roll-shaped structures each having a semicircular arc-shaped cross section connected to each side of the flat portion, the roll-shaped structure having opposite sides fixed to a speaker frame; Is fixed to the outer periphery of the voice coil bobbin.

According to such a configuration, since the roll-shaped structure is independent in the circumferential direction of the voice coil bobbin when the diaphragm vibrates up and down, there is no need to expand or contract the material in the circumferential direction. Therefore, the roll is easily deformed, the vibration amplitude is large, and the force displacement curve has excellent linearity.

According to a second aspect of the present invention, there is provided a diaphragm for applying air vibration, a cylindrical voice coil bobbin joined to the diaphragm, a voice coil fixed to an outer peripheral portion of the voice coil bobbin, and a voice coil formed on an annular top. In a speaker having a damper supported in a magnetic gap constituted by a plate and a center pole, the damper is made of a natural fiber or a synthetic fiber impregnated with a resin, and the roll-shaped structure is a speaker from the flat portion side. It is characterized in that the resin impregnation concentration is changed with respect to the frame side.

According to such a configuration, the roll-shaped structure has a different resin impregnation concentration from the flat portion side to the speaker frame side, so that the rigidity is not uniform and the resonance of the damper is not achieved. Is less likely to occur.

According to a third aspect of the present invention, there is provided a vibration plate for applying air vibration, a cylindrical voice coil bobbin joined to the vibration plate, and a voice coil fixed to an outer peripheral portion of the voice coil bobbin. In a speaker having a damper supported in a magnetic gap formed by a plate and a center pole, the damper has a polygonal flat portion having a through hole of a voice coil bobbin, and a cross section connected to each side of the flat portion. A roll-shaped structure having a semicircular arc shape, wherein the roll-shaped structure is arranged such that the convex direction thereof is alternately reversed with respect to the vibration direction of the diaphragm, and the opposing sides thereof are fixed to the speaker frame, The through hole is fixed to an outer periphery of the voice coil bobbin.

According to such a configuration, the roll-shaped structure is arranged so that the convex direction thereof is alternately opposite to the vibration direction of the diaphragm, so that the stiffness against the vertical vibration of the diaphragm is increased. Can be made symmetric, and the distortion is reduced.

According to a fourth aspect of the present invention, there is provided a vibration plate for applying air vibration, a cylindrical voice coil bobbin joined to the vibration plate, and a voice coil fixed to an outer peripheral portion of the voice coil bobbin. In a speaker having a damper supported in a magnetic gap formed by a plate and a center pole, the damper has a polygonal flat portion having a through hole of a voice coil bobbin, and a cross section connected to each side of the flat portion. A semicircular roll-shaped structure, the roll-shaped structure having opposite sides fixed to the speaker frame, the through-hole fixed to the outer periphery of the voice coil bobbin, and the flat portion corresponding to the through-hole. It is characterized in that triangular pyramid-shaped projections are provided in the peripheral portion.

According to such a configuration, since the triangular pyramid-shaped projection is provided in the periphery of the through hole of the damper, the joint surface with the voice coil bobbin can be enlarged in the vibration direction, and the strength against rolling can be improved. Will be higher.

According to a fifth aspect of the present invention, there is provided a vibration plate for applying air vibration, a cylindrical voice coil bobbin joined to the vibration plate, and a voice coil fixed to an outer peripheral portion of the voice coil bobbin. In a speaker having a damper supported in a magnetic gap formed by a plate and a center pole, the damper has a polygonal flat portion having a through hole of a voice coil bobbin, and a cross section connected to each side of the flat portion. A roll-shaped structure having a semicircular arc shape, the roll-shaped structure having opposite sides fixed to a speaker frame, and having a radius of an arc changed with respect to a center axis direction of the roll. The through hole is fixed to the outer periphery of the voice coil bobbin.

According to such a configuration, by changing the radius of the arc of the roll-shaped structure with respect to the direction of the center axis of the roll, the rigidity becomes non-uniform and damper resonance hardly occurs.

According to a sixth aspect of the present invention, there is provided a vibration plate for applying air vibration, a cylindrical voice coil bobbin joined to the vibration plate, and a voice coil fixed to an outer peripheral portion of the voice coil bobbin. In a speaker having a damper supported in a magnetic gap formed by a plate and a center pole, the damper has a polygonal flat portion having a through hole of a voice coil bobbin, and a cross section connected to each side of the flat portion. A roll-shaped structure having a semicircular arc shape, wherein the roll-shaped structure has opposite sides fixed to the speaker frame, the roll cross section is elliptical, and the through-hole is fixed to the outer periphery of the voice coil bobbin. It is characterized by having been done.

According to such a configuration, the vibration amplitude can be increased by providing a straight rising in a semicircular arc as the roll cross section of the roll-shaped structure to increase the deformation length of the roll portion. .

According to a seventh aspect of the present invention, there is provided a vibration plate for applying air vibration, a cylindrical voice coil bobbin joined to the vibration plate, and a voice coil fixed to an outer peripheral portion of the voice coil bobbin. In a speaker having a damper supported in a magnetic gap formed by a plate and a center pole, the damper has a polygonal flat portion having a through hole of a voice coil bobbin, and a cross section connected to each side of the flat portion. A roll-shaped structure having a semicircular arc shape, wherein the roll-shaped structure has opposite sides fixed to the speaker frame, the roll cross section is elliptical, and the through-hole is fixed to the outer periphery of the voice coil bobbin. It is characterized by having been done.

According to such a configuration, the roll amplitude of the vibration can be increased by making the roll cross section of the roll-shaped structure elliptical.

The invention according to claim 8 of the present application provides a vibration plate for applying air vibration, a cylindrical voice coil bobbin joined to the vibration plate, and a voice coil fixed to an outer peripheral portion of the voice coil bobbin. In a speaker having a damper supported in a magnetic gap composed of a plate and a center pole, the damper has a flat portion having a through hole of a voice coil bobbin, and a cross section connected to each side of the flat portion having a semicircular shape. And the roll-shaped structures having different cross-sectional radii are alternately arranged, and the opposite sides thereof are fixed to a speaker frame, and the through-hole is formed on the outer periphery of the voice coil bobbin. Characterized in that it is fixed to

According to such a configuration, since the roll-shaped structures having different cross-sectional radii are alternately arranged, the frame mounting portion can be shortened. Therefore, it is optimal for a speaker support system of an elliptical diaphragm.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) A speaker according to a first embodiment of the present invention will be described with reference to the drawings, focusing on the structure of a damper. In the drawings of each embodiment,
The same parts as those in the conventional example are denoted by the same reference numerals, and detailed description is omitted. FIG. 1 is a perspective view showing a structure of a damper 20 used for the speaker of the present embodiment. As shown in this figure, the damper 20 has rolled structures 21a to 21
1d and a substantially square-shaped member in which flat attachment pieces 21a to 21d are formed integrally with the central flat portion 24. A circular through hole 23 is formed in the center of the flat portion 24 to allow the voice coil bobbin 8 to pass therethrough.

Assuming that the vibration direction of the voice coil bobbin 8 is the Z axis and the front of the speaker is + and the rear is-, the four roll-shaped structures 21a to 21d have the same sectional shape, respectively.
An elastic portion having a semicircular cross section that is convex in the −Z direction. The four mounting pieces 21 a to 21 d have the same height as the flat portion 24 and are joined on the mounting surface of the frame 2.
The periphery of the through hole 23 of the flat portion 24 is fixed to the outer peripheral surface of the voice coil bobbin 8 with an adhesive.

FIG. 2 is a half sectional view of the speaker 26 having the damper 20 having such a structure, and its operation will be described. When a drive current flows through the voice coil 9 in FIG.
The driving force of the voice coil bobbin 8 is generated by the electromagnetic force,
The diaphragm 11 vibrates to generate sound. The damper 20 and the edge 13 elastically support the diaphragm 11 when the diaphragm 11 reciprocates. FIG. 3 shows a state of the damper 20 when the diaphragm 11 vibrates in the + Z direction. Since the flat portion 24 of the damper 20 is fixed to the outer peripheral surface of the voice coil bobbin 8, the flat portion 24 vibrates integrally with the voice coil bobbin 8. On the other hand, the mounting side 22 is not displaced because it is fixed to the frame 2 shown in FIG. In FIG. 3, the roll-shaped structure 21 is displaced from A <b> 1 to A <b> 2 upon vibration, and supports the vibration displacement of the diaphragm 11. The roll-shaped structures 21 are formed linearly, and each of the roll-shaped structures 21a to 21d
Since the rolls are elastically independent of each other, they do not involve the contraction or expansion of the material in the circumferential direction when the roll is deformed unlike the conventional corrugated damper. For this reason, the force-displacement characteristics have excellent linearity, and the maximum amplitude of the flat portion 24 can be increased.

FIG. 4 shows an example of a force-displacement characteristic of the damper 20 of the present embodiment. Here, the linearity of the displacement up to an external force of 5N and the displacement of up to 5 mm are ensured. Thus, it can be seen that, as compared with the characteristics of FIG. 16, both the linearity and the maximum amplitude show excellent characteristics. Although the shape of the flat portion 24 is shown as a square, any shape may be used as long as the through hole 23 is ensured, as long as the shape is a polygon having more than a triangle.

(Embodiment 2) Next, a speaker according to a second embodiment of the present invention will be described with reference to the drawings, focusing on the structure of a damper. FIG. 5 is a perspective view showing the structure of a damper 30 used in the speaker of the present embodiment, and the same parts as those of the first embodiment are denoted by the same reference numerals, and detailed description is omitted. The outer shape of the damper 30 is the same as that shown in FIG.
Only the configuration 1 is different.

Each of the four roll-shaped structures 31a to 31d is an elastic body having the same cross-sectional shape and a semi-circular cross-section that is convex in the -Z direction. The roll-shaped structure 31 is made of a natural fiber or a synthetic fiber impregnated with a resin. However, two regions having different densities for impregnating the resin are provided. The portions B1 and B2 in FIG. 5 have different impregnation concentrations of the resin, and the impregnation concentration of B2 near the center is lower.

As in the case of FIG. 1, four mounting pieces 2
1 a to 21 d have the same height as the flat portion 24 and are joined on the mounting surface of the frame 2. Around the through hole 23 of the flat portion 24 is fixed to the outer peripheral surface of the voice coil bobbin 8 with an adhesive.

The characteristics of the damper 30 having such a structure will be described. Since the roll-shaped structure 31 is composed of the B1 portion and the B2 portion having different impregnation concentrations, the B2 portion having a lower impregnation concentration is softer than the B1 portion. When a signal in the audible band is applied, the diaphragm 11, the edge 13, the damper 30, and the like may cause resonance. The frequency and amplitude of these resonances are determined by the shape and material and the state of coupling between the components. In the damper 30 of the present embodiment, since the rigidity of the roll-shaped structure 31 is different between the two regions, the resonance frequencies are dispersed into two. Therefore, the amplitude of the resonance of the damper 30 is small, and the vibration plate 11
Adversely affect the vibration of the vehicle.

(Embodiment 3) Next, a loudspeaker according to a third embodiment of the present invention will be described with reference to the drawings, focusing on the structure of a damper. FIG. 6 is a perspective view showing the structure of a damper 40 used in the speaker of the present embodiment, and the same portions as those of the first embodiment are denoted by the same reference numerals, and detailed description is omitted. The outer shape of the damper 40 is the same as that shown in FIG. 1 except for the bending direction of some roll-shaped structures 41.

Of the four roll-shaped structures 41a to 41d, the roll-shaped structures 41b and 41d are elastic portions having a semicircular cross section that is convex in the -Z direction, and the roll-shaped structures 41a and 41c are The elastic portion has a semicircular cross section that is convex in the + Z direction. As described above, the elastic portions are arranged so as to be convex, concave, convex, and concave along the outer periphery of the square of the flat portion 24. However, the four cross-sectional shapes are the same. As in the case of FIG. 1, the four mounting pieces 21a
21d have the same height as the flat portion 24 and are joined at the mounting surface of the frame 2. Also, the through hole 23 of the flat portion 24
The periphery is fixed to the outer peripheral surface of the voice coil bobbin 8 with an adhesive.

The characteristics of the damper 40 having such a structure will be described. Since the roll-shaped structures 41 are arranged so that their bending directions are alternately different from the vibration direction of the diaphragm 11, the roll-shaped structures 41b and 41 are not affected by vibration.
d and the roll-shaped structures 41a and 41c deform symmetrically. Therefore, the imbalance of the vibration characteristics caused by the non-uniformity of the material and the non-uniformity of the shape is canceled, and the distortion of the speaker at the time of the large amplitude can be further reduced.

(Embodiment 4) Next, a speaker according to a fourth embodiment of the present invention will be described with reference to the drawings, focusing on the structure of a damper. FIG. 7 is a perspective view showing the structure of a damper 50 used in the speaker of the present embodiment. The same parts as those of the first embodiment are denoted by the same reference numerals, and detailed description is omitted. The outer shape of the damper 50 is the same as that shown in FIG. 1 except for the structure of the flat portion 51.

The flat portion 51 is provided with triangular pyramid-shaped projections 52a to 52d around the through hole 23. The other structure is the same as that of FIG. 1, and the roll-shaped structures 21 a to 21 d and the flat mounting pieces 21 a to 21 d are provided in four directions.
Are formed integrally with the central flat portion 51. The four attachment pieces 21 a to 21 d have the same height as the flat portion 51 and are joined on the attachment surface of the frame 2. Especially protrusion 5
Since the end surfaces 2a to 52d hold the outer peripheral surface of the voice coil bobbin 8, straightness between the damper 50 and the voice coil bobbin 8 is easily ensured. If the projections of the projections 52a to 52d are alternately opposite, the adhesive strength to the voice coil bobbin 8 is increased.

The characteristics of the damper 50 having such a structure will be described. Since the damper 50 has a structure in which the joining surface between the voice coil bobbin 8 and the flat portion 51 is enlarged in the vibration direction, the voice coil bobbin 8 can be prevented from being tilted by rolling, and the rolling strength can be increased.

Embodiments 5 and 6 Next, a loudspeaker according to a fifth embodiment of the present invention will be described with reference to the drawings, focusing on the structure of a damper. FIG. 8 is a perspective view showing a structure of a damper 60 used in the speaker of the present embodiment. A semi-circular roll-shaped structure 61 whose cross section changes along the circumferential direction of the flat portion 64 is integrally formed around the rectangular flat portion 64 in which the through hole 63 is formed. The shape of each of the roll-shaped structures 61a to 61d is the same, the radius of curvature at the center of each roll-shaped structure 61 is large, and the radius of curvature at both ends is small.

As in FIG. 1, the roll-shaped structures 61a to 61a-6
On the side opposite to the flat portion side of 1d, there are mounting pieces 62a to 62d that are fixed to the speaker frame 2. Each mounting piece 6
The shapes of 2a to 62d are different from those of FIG. Therefore, the mounting pieces 62a to 62
d is mounted in an annular shape. Mounting piece 62 and flat part 6
4 is on the same plane.

Next, a loudspeaker according to a sixth embodiment of the present invention will be described with reference to the drawings, focusing on the structure of a damper. FIG. 9 is a perspective view showing the structure of a damper 90 used for the speaker according to the sixth embodiment. As shown in the figure, the damper 90 includes a flat portion 94 having a through hole 93, a roll-shaped structure 91 having a semicircular cross section,
A mounting piece 92 for fixing to the speaker frame 2 is integrally formed.

The roll-shaped structures 92a and 92c have the same cross-sectional shape, and are configured so that the radius of curvature increases from the center to both ends. The roll-shaped structure 92
b and 92d have the same cross-sectional shape, and the average radius of curvature is smaller than the roll-shaped structures 92a and 92c. Each roll-shaped structure 92 is configured such that the radius of curvature increases from the center to both ends. Attachment pieces 92a to 92d are formed integrally with the respective roll-shaped structures 92a to 92d.

The flat portion 94 has an outer shape surrounded by four arcs, and the radius of curvature matches the edge of each roll-shaped structure 92. Therefore, compared to the roll-shaped structures 92a and 92c, the roll-shaped structures 92b and 92d
Are narrower.

Since the characteristics of the damper 60 and the damper 90 are almost the same, the characteristics of the damper 60 will be described here. In this embodiment, the winding length of the roll is different at each location. For this reason, the resonance of the damper 60 at a specific frequency determined by the shape of the roll is dispersed not at one resonance frequency but at a plurality. Therefore, the amplitude of the resonance of the damper 60 is reduced, and the vibration of the diaphragm 11 is not adversely affected.

(Embodiments 7 and 8) Next, a speaker according to a seventh embodiment of the present invention will be described with reference to the drawings, focusing on the structure of the damper. FIG. 10 is a partial sectional view showing the structure of a damper 70 used in the speaker of the present embodiment. The damper 70 also has a flat portion 74 in which the through-hole 73 of the voice coil bobbin 8 is formed, and a roll-shaped structure 71 is integrally formed around the flat portion 74. On the side opposite to the flat part side of the roll-shaped structure 71, a mounting piece 72 is formed which is fixed to the speaker frame 2.

Unlike the conventional curved structure, the roll-shaped structure 71 has a semicircular portion C1 and a linear portion C2 rising linearly. Note that the mounting piece 72 and the flat portion 74 are on the same plane as in the past.

Next, a damper of the loudspeaker according to the eighth embodiment will be described with reference to FIG. FIG.
The damper 80 shown in FIG. 1 has a flat portion 74 in which a through hole 73 is formed, similarly to the damper shown in FIG. The speaker frame 2 is provided on the opposite side of the flat portion of the roll-shaped structure 81.
A mounting piece 72 is formed, which is fixed to the mounting piece 72.

The roll-shaped structure 81 of the damper 80
Is characterized in that its cross section has a semi-elliptical arc shape. Here, the minor axis of the ellipse is on the flat part 74 and the mounting piece 72 side, and the major axis is in the vibration direction.

The characteristics of the dampers of the seventh and eighth embodiments will be described. In the damper 70, the roll-shaped structure 71 expands and contracts with the vibration of the diaphragm 11. The limit of the maximum amplitude of the damper 70 is when the roll-shaped structure 71 is straightened. Since the cross section of the roll-shaped structure 71 includes the straight portion C2 in addition to the semicircular portion C1, the maximum amplitude is larger than that of the case of only the semicircle by the addition of the straight portion C2.

On the other hand, also in the case of the damper 80, since the major axis of the ellipse is provided in the vibration direction, the maximum amplitude is larger than that in the case of only a semicircle. On the other hand, since the distance between the periphery of the flat portion 74 and the mounting portion of the frame 2 is determined by the diameter of the semicircular portion or the minor diameter of the elliptical portion, the damper mounting portion of the frame 2 does not become large.

(Embodiment 9) Next, a speaker according to a ninth embodiment of the present invention will be described with reference to the drawings, focusing on the structure of the damper. FIG. 12 is a plan view showing the structure of the damper 100 used for the speaker according to the ninth embodiment. As shown in FIG.
Reference numeral 00 denotes a flat portion 104 having a through hole 103, a roll-shaped structure 101 having a semicircular cross section, and a mounting piece 102 for fixing the speaker frame 2 to the speaker frame 2.

The roll-shaped structures 102 a and 102 c have the same cross-sectional shape, and the radius of curvature is constant along the outer periphery of the flat portion 104. Also, the roll-shaped structures 102b, 10
2d has the same cross-sectional shape, its radius of curvature is smaller than that of the roll-shaped structures 102a and 102c, and its value is the flat portion 1
04 is constant along the outer circumference. Therefore, like the one shown in FIG. 11, the groove width of the roll-shaped structures 102b and 102d is smaller than that of the roll-shaped structures 102a and 102c.

The characteristics of the damper 100 having such a configuration will be described. With the vibration of the diaphragm 11, the roll-shaped structures 102a to 102d expand and contract vertically. Damper 1
The amplitude limit of 00 is when the roll-shaped structures 102a to 102d are linearly stretched. Roll-shaped structure 102a
The cross sections of to 102d are configured such that the maximum amplitudes are equal. Therefore, the maximum amplitude is not limited by the narrow roll-shaped structures 102b and 102d. On the other hand, the distance between the peripheral portion of the flat portion 104 and the frame is large on the side of the roll-shaped structures 102a and 102c,
b, small on the 102d side. For this reason, the size of the damper mounting portion on the side of the roll-shaped structures 102b and 102d of the speaker frame does not increase. Therefore, the maximum amplitude can be increased even when the frame becomes smaller in the minor axis direction as in a speaker using an elliptical diaphragm.

[0057]

As described above in detail, according to the first aspect of the present invention, when the diaphragm is vertically vibrated, the roll-shaped structure can be independently deformed in the circumferential direction of the voice coil bobbin. For this reason, the damper is easily deformed, and the linearity of force versus displacement is excellent. For this reason, the vibration amplitude of the diaphragm can be increased, and a small loudspeaker with little distortion even with a large input can be realized.

According to the second aspect of the present invention, the damper is made of a natural fiber or a synthetic fiber impregnated with a resin,
Since the resin impregnation concentration is changed from the flat portion side of the roll-shaped structure to the frame side, the rigidity of the elastic portion is not uniform. For this reason, resonance of a damper can be made hard to occur.

According to the third aspect of the present invention, the stiffness against the vertical vibration of the diaphragm is provided by arranging the convex portions of the roll-shaped structure so as to be alternately opposite to the vibration direction of the diaphragm. Can be aligned. For this reason, the distortion of the damper is reduced.

According to the fourth aspect of the present invention, since a triangular pyramid-shaped projection is provided around the through hole in the flat portion,
The joint surface with the voice coil bobbin can be enlarged in the vibration direction, and the strength against rolling can be increased.

According to the fifth aspect of the present invention, the rigidity of the damper is not uniform because the radius of the arc of the cross section of the roll is changed with respect to the center axis direction of the roll of the roll-shaped structure. For this reason, resonance of a damper can be made hard to occur.

According to the sixth aspect of the present invention, the amplitude of vibration can be increased by adding a straight portion to a semicircular arc portion in the roll cross section of the roll-shaped structure.

According to the seventh aspect of the present invention, the amplitude of the vibration can be increased by making the roll cross section of the roll-shaped structure elliptical.

According to the eighth aspect of the present invention, since the roll-shaped structures having different cross-sectional radii are alternately arranged,
The shape of the damper can be elongated. Therefore, the present invention can be applied to a speaker having a limited frame width, such as an elliptical diaphragm.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a structure of a damper used for a speaker according to a first embodiment of the present invention.

FIG. 2 is a half sectional view showing a structure of the speaker according to the first embodiment.

FIG. 3 is a half sectional view showing a displacement state of a damper according to the first embodiment.

FIG. 4 is a characteristic diagram of force versus displacement of a damper according to the first embodiment.

FIG. 5 is a perspective view showing a structure of a damper used for a speaker according to a second embodiment of the present invention.

FIG. 6 is a perspective view illustrating a structure of a damper used for a speaker according to a third embodiment of the present invention.

FIG. 7 is a perspective view showing a structure of a damper used for a speaker according to a fourth embodiment of the present invention.

FIG. 8 is a perspective view showing a structure of a damper used for a speaker according to a fifth embodiment of the present invention.

FIG. 9 is a perspective view showing a structure of a damper used for a speaker according to a sixth embodiment of the present invention.

FIG. 10 is a partial cross-sectional view illustrating a structure of a damper used for a speaker according to a seventh embodiment of the present invention.

FIG. 11 is a partial cross-sectional view illustrating a structure of a damper used in a speaker according to an eighth embodiment of the present invention.

FIG. 12 is a plan view showing a structure of a damper used for a speaker according to a ninth embodiment of the present invention.

FIG. 13 is a half sectional view showing an example of the structure of a conventional small speaker.

FIG. 14 is a perspective view showing a structure of a damper of a conventional speaker.

FIG. 15 is a half sectional view showing a deformed state of a damper of a conventional speaker.

FIG. 16 is a characteristic diagram of force versus displacement of a damper of a conventional speaker.

[Explanation of symbols]

2 Frame 3 Center pole 4 Magnet 5 Top plate 6 Annular magnetic circuit 7 Air gap 8 Voice coil bobbin 9 Voice coil 11 Diaphragm 12, 20, 30, 40, 50, 60, 70, 80, 9
0,100 Damper 13 Edge 14 Speaker 21, 21a-21d, 31, 31a-31d, 61,
61a-61d, 71, 81, 91, 91a-91d,
101, 101a to 101d Roll-shaped structure 22, 22a to 22d, 62, 62a to 62d, 72,
92, 92a to 92d, 102, 102a to 102d
Mounting pieces 23, 63, 73, 93, 103 Through holes 24, 51, 64, 74, 94, 104 Flat portions 25 Peripherals 52 a to 52 d Projections 75 Stand up

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tohru Yoshikawa 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (8)

[Claims] 1. A magnetic plate comprising: a vibrating plate for applying air vibration; a cylindrical voice coil bobbin joined to the vibrating plate; and a voice coil fixed to an outer peripheral portion of the voice coil bobbin, comprising an annular top plate and a center pole. In a speaker having a damper supported in an air gap, the damper includes a polygonal flat portion having a through hole of a voice coil bobbin at the center, and a plurality of rolls connected to each side of the flat portion and having a semicircular cross section. A speaker, wherein the roll-shaped structure has opposite sides fixed to a speaker frame, and the through holes are fixed to the outer periphery of the voice coil bobbin. 2. A vibrating plate for applying air vibration, a cylindrical voice coil bobbin joined to the vibrating plate, and a magnetic coil fixed to an outer peripheral portion of the voice coil bobbin, the voice coil comprising an annular top plate and a center pole. In a speaker having a damper supported in an air gap, the damper is made of a natural fiber or a synthetic fiber impregnated with a resin,
2. The speaker according to claim 1, wherein the roll-shaped structure has a resin impregnated concentration changed from the flat portion side to the speaker frame side. 3. A magnetic plate comprising: a diaphragm for applying air vibration; a cylindrical voice coil bobbin joined to the diaphragm; and a voice coil fixed to an outer peripheral portion of the voice coil bobbin, comprising a ring-shaped top plate and a center pole. In a speaker having a damper supported in an air gap, the damper includes: a polygonal flat portion having a through hole of a voice coil bobbin;
The cross section connected to each side of the flat portion is constituted by a semicircular arc-shaped roll-shaped structure, and the roll-shaped structure is arranged such that the convex direction thereof is alternately opposite to the vibration direction of the diaphragm. The opposite side is fixed to a speaker frame, and the through-hole is fixed to the outer periphery of the voice coil bobbin. 4. A magnetic plate comprising a vibrating plate for applying air vibration, a cylindrical voice coil bobbin joined to the vibrating plate, and a voice coil fixed to an outer peripheral portion of the voice coil bobbin, comprising an annular top plate and a center pole. In a speaker having a damper supported in an air gap, the damper includes: a polygonal flat portion having a through hole of a voice coil bobbin;
A cross-section connected to each side of the flat portion is formed of a roll-shaped structure having a semicircular arc shape, and the roll-shaped structure has its opposite side fixed to a speaker frame, and the through-hole is formed on the outer periphery of the voice coil bobbin. And the flat portion is provided with a triangular pyramid-shaped protrusion around the through hole. 5. A magnetic plate comprising: a vibration plate for applying air vibration; a cylindrical voice coil bobbin joined to the vibration plate; and a voice coil fixed to an outer peripheral portion of the voice coil bobbin, comprising a ring-shaped top plate and a center pole. In a speaker having a damper supported in an air gap, the damper includes: a polygonal flat portion having a through hole of a voice coil bobbin;
The cross section connected to each side of the flat portion is constituted by a semicircular roll-shaped structure, and the roll-shaped structure has its opposite side fixed to the speaker frame, and the rolled structure is arranged in the center axis direction of the roll. The radius of the arc is changed,
The through-hole is fixed to the outer periphery of the voice coil bobbin. 6. A magnetic plate comprising: a vibration plate for applying air vibration; a cylindrical voice coil bobbin joined to the vibration plate; and a voice coil fixed to an outer peripheral portion of the voice coil bobbin, comprising a ring-shaped top plate and a center pole. In a speaker having a damper supported in an air gap, the damper includes: a polygonal flat portion having a through hole of a voice coil bobbin;
A cross-section connected to each side of the flat portion is constituted by a semicircular roll-shaped structure, and the roll-shaped structure has its opposite side fixed to the speaker frame, and the cross-section of the semicircular portion is equal to that of the semicircular portion. A speaker having a shape in which a straight portion is added to an end, and the through-hole is fixed to an outer periphery of the voice coil bobbin. 7. A magnetic plate comprising: a vibration plate for applying air vibration; a cylindrical voice coil bobbin joined to the vibration plate; and a voice coil fixed to an outer peripheral portion of the voice coil bobbin, comprising a ring-shaped top plate and a center pole. In a speaker having a damper supported in an air gap, the damper includes: a polygonal flat portion having a through hole of a voice coil bobbin;
The cross section connected to each side of the flat portion is constituted by a semicircular roll-shaped structure, and the roll-shaped structure has an opposing side fixed to the speaker frame, and the roll cross section is elliptical. A speaker, wherein the through hole is fixed to an outer periphery of the voice coil bobbin. 8. A magnetic plate comprising: a vibration plate for applying air vibration; a cylindrical voice coil bobbin joined to the vibration plate; and a voice coil fixed to an outer peripheral portion of the voice coil bobbin, comprising a ring-shaped top plate and a center pole. In a speaker having a damper supported in an air gap, the damper includes a flat portion having a through-hole of a voice coil bobbin, and a roll-shaped structure connected to each side of the flat portion and having a semicircular cross section. The roll-shaped structures are arranged such that the cross-sectional radii are alternately arranged, and the opposite sides thereof are fixed to the speaker frame, and the through holes are fixed to the outer periphery of the voice coil bobbin. Features speaker.