Composite speaker device

Abstract

To provide a composite speaker device capable of enhancing utilization efficiency of magnetic flux in a magnetic circuit.SOLUTION: A composite speaker device 1 includes: a bottomed cylindrical yoke 12; a first magnet 13 attached to an inner bottom surface of the yoke 12; a bottomed cylindrical plate 14 attached to the first magnet 13 so as to open a first gap relative to an inner periphery of the yoke 12; a second magnet 15 mounted on an inner bottom surface of the plate 14; a center pole 16 that does not project from the opening of the yoke 12 and the opening of the plate 14 and being mounted on the second magnet 15 so as to open a second gap relative to an inner periphery of the plate 14; a first voice coil 17; a low sound diaphragm 18; a second voice coil 19; and a high sound diaphragm 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a composite speaker device. [Background technology]

[0002] Conventionally, a composite speaker device equipped with a bass diaphragm and a treble diaphragm has been known (see, for example, Patent Document 1). In the composite speaker device described in Patent Document 1, components of a magnetic circuit for vibrating the bass diaphragm also serve as components of a magnetic circuit for vibrating the treble diaphragm, thereby reducing the number of components, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-078086 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned composite speaker device, magnetic flux for both treble and bass passes through the dual-purpose treble / bass component. However, some of the magnetic flux passes in opposite directions, canceling each other out and resulting in insufficient utilization. This leaves room for improvement in the efficiency of magnetic flux utilization. Improving the efficiency of magnetic flux utilization leads to the miniaturization of the magnets and surrounding structures that supply the magnetic flux, which is desirable from the perspective of the size of the composite speaker device.

[0005] Therefore, an object of the present invention is to provide a composite speaker device that can improve the utilization efficiency of magnetic flux in a magnetic circuit, for example. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, a composite speaker device of the present invention includes a yoke made of a magnetic material and formed into a cylindrical shape with a bottom that opens on the sound radiating side, a first magnet attached to the inner bottom surface of the yoke, a plate made of a magnetic material and formed into a cylindrical shape with a bottom that opens on the sound radiating side, attached to the first magnet and housed in the yoke so as to form a first annular gap between it and the inner periphery of the yoke, a second magnet attached to the inner bottom surface of the plate, a center pole made of a magnetic material and attached to the second magnet and housed in the plate so that an end on the sound radiating side does not protrude from either the opening of the yoke or the plate and a second annular gap is formed between it and the inner periphery of the plate, a first voice coil arranged in the first gap to be movable in an axial direction, an annular woofer diaphragm arranged on the sound radiating side of the first gap and coupled to the first voice coil, a second voice coil arranged in the second gap to be movable in the axial direction, and a large opening of the inner periphery of the woofer. and a treble diaphragm formed to a size equal to or smaller than the width of the diaphragm and disposed inside the inner peripheral opening, and coupled to the second voice coil, wherein the yoke, the first magnet, and the plate form a bass magnetic circuit that vibrates the bass diaphragm, and the bass magnetic circuit is a magnetic circuit in which a first magnetic flux emitted from the first magnet passes from the plate through the first gap to the yoke, and then passes through the yoke and returns to the first magnet; and the plate, the second magnet, the center pole, the yoke, and the first magnet form a treble magnetic circuit that vibrates the treble diaphragm, and the treble magnetic circuit is a magnetic circuit in which a second magnetic flux emitted from the second magnet passes from the center pole through the second gap to the plate, and then merges with the first magnetic flux at the plate, passes through the first gap to the yoke, passes through the yoke together with the first magnetic flux, reaches the first magnet, and separates from the first magnetic flux, and then passes through the plate and returns to the second magnet. [Brief explanation of the drawings]

[0007] [Figure 1]1 is a cross-sectional view showing a composite speaker device according to an embodiment of the present invention, taken along a sound emitting direction. [Figure 2] FIG. 2 is an enlarged view of an area A11 in FIG. [Figure 3] 3 is a schematic diagram showing a magnetic circuit for vibrating a voice coil in the composite speaker device shown in FIGS. 1 and 2, together with magnetic flux flowing through the circuit. FIG. [Figure 4] 4 is a diagram showing the difference in the amount of magnetic flux passing through the first gap and the single gap shown in FIG. 3, in terms of the distribution of magnetic flux density in each gap. FIG. [Figure 5] FIG. 4 is an explanatory diagram illustrating, with a comparative example, how the joining of magnetic fluxes shown in FIG. 3 is realized by the housing form of the center pole in the plate shown in FIGS. DETAILED DESCRIPTION OF THE INVENTION

[0008] A composite speaker device according to one embodiment of the present invention will be described below. The composite speaker device according to one embodiment of the present invention includes a yoke, a first magnet, a plate, a second magnet, a center pole, a first voice coil, a woofer, a second voice coil, and a treble diaphragm. The yoke is a magnetic member formed into a cylindrical shape with a bottom that opens on the sound-emitting side. The first magnet is a magnetic member attached to the inner bottom surface of the yoke. The plate is a magnetic member formed into a cylindrical shape with a bottom that opens on the sound-emitting side, attached to the first magnet and housed in the yoke so as to form a first annular gap between the inner periphery of the yoke and the plate. The second magnet is a magnetic member attached to the inner bottom surface of the plate. The center pole is a magnetic member attached to the second magnet and housed in the plate so that the end on the sound-emitting side does not protrude from the openings of either the yoke or the plate and so as to form a second annular gap between the inner periphery of the plate and the center pole. The first voice coil is a coil member disposed in the first gap so as to be movable in the axial direction. The woofer is an annular diaphragm member located closer to the sound emitting side than the first gap and coupled to the first voice coil. The second voice coil is a coil member located in the second gap so as to be movable in the axial direction. The treble diaphragm is a diaphragm member that is formed to be smaller than the size of the inner peripheral opening of the woofer, is located inside the inner peripheral opening, and is coupled to the second voice coil.

[0009] In this composite speaker device, a magnetic circuit that vibrates the bass diaphragm is formed by the yoke, the first magnet, and the plate. Magnetic flux emitted from the first magnet travels from the plate through the first gap to the yoke and then returns to the first magnet through the yoke. On the other hand, a magnetic circuit that vibrates the treble diaphragm is formed by the plate, the second magnet, the center pole, the yoke, and the first magnet. Magnetic flux emitted from the second magnet travels from the center pole to the plate through the second gap. At this time, a flow of magnetic flux from the first magnet is formed in the plate, passing through the first gap and toward the yoke. In this embodiment, the center pole is housed in the plate so that its sound-emitting end does not protrude from the openings of both the yoke and the plate. Therefore, the magnetic flux from the second magnet reaches the plate in approximately the same direction as the flow of magnetic flux from the first magnet. As a result, much of the magnetic flux from the second magnet merges with the magnetic flux from the first magnet at the plate and travels from the plate through the first gap toward the yoke. These two types of magnetic flux pass through the yoke to the first magnet, where the magnetic flux from the second magnet separates from the magnetic flux from the first magnet and returns to the second magnet through the plate. In this manner, in this embodiment, the magnetic flux from the first magnet and the magnetic flux from the second magnet merge at the plate and pass through the first gap. The magnetic flux in the first gap is used to vibrate the bass diaphragm via the first voice coil, and as described above, the merged magnetic flux from the two magnets is used as this magnetic flux, thereby improving the efficiency of magnetic flux utilization in the magnetic circuit. Furthermore, in anticipation of such improved magnetic flux utilization efficiency, the first magnet can be made smaller, which in turn allows for a more compact and lightweight composite speaker.

[0010] Here, it is preferable that the second gap and the first gap are arranged so that they are in the same position relative to each other in the axial direction. With this configuration, the magnetic flux from the second magnet passing through the second gap easily merges with the magnetic flux from the first magnet passing through the first gap toward the yoke, thereby further improving the efficiency of magnetic flux utilization in the magnetic circuit. Furthermore, with the above configuration, the position at which vibration of the bass diaphragm occurs via the first voice coil in the first gap and the position at which vibration of the treble diaphragm occurs via the second voice coil in the second gap coincide with each other in the axial direction. This allows the listener to hear bass and treble sounds as if they are emanating from the same position in the depth direction, thereby improving the sound quality of the composite speaker.

[0011] It is also preferable that the opening in the yoke, the opening in the plate, and the sound-emitting end of the center pole are arranged so as to be in the same position relative to one another in the axial direction. In this configuration, a first gap between the plate and the yoke is formed on the opening side of both. Furthermore, a second gap between the center pole and the plate is formed on the end side of the center pole and the opening side of the plate. In other words, with this configuration, the axial positions of the second gap and the first gap can be effectively aligned, thereby further increasing the utilization efficiency of magnetic flux in the magnetic circuit and improving the sound quality of the composite speaker.

[0012] The following configuration is also suitable. In this configuration, the woofer is an annular cone-shaped diaphragm. On the other hand, the treble diaphragm is a dome / cone-shaped diaphragm having a dome portion and a cone portion that protrudes annularly from the outer periphery of the dome portion. The inclination of the woofer and the inclination of the cone portion of the treble diaphragm match each other. This configuration can improve the appearance of the sound-producing portion of the composite speaker device where the woofer and treble diaphragm are arranged. Furthermore, the matching of the inclinations can also improve the sound quality of the composite speaker.

[0013] The following configuration is even more preferable. In this configuration, the treble diaphragm, including the cone portion, is formed in a shape smaller than the size of the inner peripheral opening of the woofer. The composite speaker device further includes a treble frame that holds the outer periphery of the cone portion of the treble diaphragm and fills the gap between the inner periphery of the inner peripheral opening of the woofer and the outer periphery of the cone portion. The treble frame's sound-emitting end face is inclined in accordance with the inclination of the woofer and the inclination of the cone portion of the treble diaphragm, forming a continuous mortar-shaped surface. With this configuration, the sound-generating portion of the composite speaker device is formed as a continuous mortar-shaped surface, further improving its appearance.

[0014] It is also preferable that the yoke, plate, center pole, bass diaphragm, and treble diaphragm are arranged coaxially. With this configuration, vibration of the bass diaphragm via the first voice coil in the first gap and vibration of the treble diaphragm via the second voice coil in the second gap occur around the same axis. This allows the listener to hear bass and treble sounds as if they are coming from the same position in the up, down, left, and right directions, improving the sound quality of the composite speaker.

[0015] Preferably, the plate has a cylindrical plate body with a bottom and a flange portion that projects annularly from the opening of the plate body, and the first gap is a gap between the outer periphery of the flange portion and the inner periphery of the yoke. With this configuration, the magnetic fluxes from the first magnet and the second magnet that reach the plate can be efficiently joined via the flange portion and guided to the first gap and the yoke, thereby further improving the utilization efficiency of the magnetic flux in the magnetic circuit. [Example]

[0016] An embodiment of a composite speaker device will be described. Fig. 1 is a cross-sectional view of the composite speaker device according to the embodiment, taken along a sound emitting direction. Fig. 2 is an enlarged view of an area A11 in Fig. 1.

[0017] The composite speaker device 1 of this embodiment is a coaxial speaker in which a woofer diaphragm 18 and a treble diaphragm 20 are arranged coaxially with each other. The composite speaker device 1 includes a speaker housing 11, a yoke 12, a first magnet 13, a plate 14, a second magnet 15, a center pole 16, a first voice coil 17, a woofer diaphragm 18, a second voice coil 19, and a treble diaphragm 20.

[0018] The speaker housing 11 comprises an outermost frame 111, an inner frame 112, and a woofer frame 113. The outermost frame 111 is a generally cylindrical portion with a bottom that constitutes the outermost wall of the composite speaker device 1. The inner frame 112 comprises a holding portion 112a that holds speaker internal components such as the yoke 12 inside the outermost frame 111, and a fixing flange 112b that protrudes outward from an opening in the outermost frame 111 and is used to fix the composite speaker device 1 to a fixed location. The woofer frame 113 is an annular frame member that holds an edge 181 (described below) of the woofer diaphragm 18 by sandwiching it between the edge of the opening in the inner frame 112 and the woofer frame 113.

[0019] The yoke 12 is a member made of a magnetic material and formed into a cylindrical shape with a bottom that opens to the sound emitting side, and is fixed to a holding portion 112 a of the inner frame 112 .

[0020] The first magnet 13 is a disk-shaped magnetic member attached to the inner bottom surface 121 of the yoke 12. The first magnet 13 is fixed with one of its front and back surfaces facing the inner bottom surface 121 of the yoke 12.

[0021] Plate 14 is made of a magnetic material and formed into a cylindrical shape with a bottom that opens to the sound emission side, and is attached to first magnet 13 and housed in yoke 12 so that an annular first gap G11 is formed between plate 14 and the inner periphery of yoke 12. In this embodiment, plate 14 has a cylindrical plate main body 141 with a bottom and a flange portion 142 that protrudes in an annular shape from the opening of plate main body 141. The first gap G11 is a gap between an outer periphery 142a of flange portion 142 and the inner periphery of yoke 12 (in this embodiment, the inner periphery 122 on the opening side).

[0022] The second magnet 15 is a disk-shaped magnetic member attached to the inner bottom surface 141a of the plate body 141 of the plate 14. The second magnet 15 is formed in a disk shape that is thinner than the above-mentioned first magnet 13, and one of its front and back surfaces is fixed in face-to-face contact with the inner bottom surface 141a of the plate body 141.

[0023] The center pole 16 is a disk-shaped member made of a magnetic material. The sound-emitting end (circular end face 161) of the center pole 16 is attached to the second magnet 15 and housed in the plate body 141 so that it does not protrude from the openings of either the yoke 12 or the plate body 141. A second annular gap G12 is formed between the outer periphery 162 of the center pole 16 and the inner periphery of the plate body 141 (inner periphery 141b on the opening side in this embodiment).

[0024] In this embodiment, the first gap G11 and the second gap G12 are arranged so as to be in the same position as each other in the axial direction D11, as shown by the dashed-dotted line L11 in Fig. 2. This gap arrangement is achieved by arranging the opening of the yoke 12, the opening of the plate 14, and the end face 161 of the center pole 16 on the sound radiation side so as to be in the same position as each other in the axial direction D11.

[0025] The first voice coil 17 is a coil member disposed in the first gap G11 so as to be movable in the axial direction D11. The first voice coil 17 is formed by winding an electric wire around the outer periphery of a cylindrical first voice coil bobbin 171, near one opening. The first voice coil bobbin 171 is disposed so that an end portion of the first voice coil 17 on the first voice coil bobbin 171 enters the first gap G11 and is movable in the axial direction D11. This arrangement is achieved by holding a midpoint of the circumferential surface of the first voice coil bobbin 171 in the axial direction D11 elastically by a damper member 172, by the inner frame 112.

[0026] The bass diaphragm 18 is an annular, cone-shaped diaphragm member located closer to the sound-emitting side of the first gap G11 and coupled to the first voice coil 17 via the first voice coil bobbin 171. The bass diaphragm 18 has an annular edge 181 that extends radially outward while curving in an arc from its outer periphery. The outermost periphery of this edge 181 is sandwiched and held between the edge of the opening of the inner frame 112 and the bass frame 113. The circular inner periphery of the annular bass diaphragm 18, whose outer periphery is held in this manner, is adhesively fixed to the outer periphery of the first voice coil bobbin 171, near the opening, on the opposite side from the first voice coil 17. The first voice coil bobbin 171 is provided so as to be movable in the axial direction D11 by adhesively fixing the bass diaphragm 18 and by holding it via the damper member 172. When the first voice coil 17 vibrates in the axial direction D11 inside the first gap G11, the vibration is transmitted to the bass diaphragm 18 via the first voice coil bobbin 171, causing the bass diaphragm 18 to vibrate and generate sound.

[0027] The second voice coil 19 is a coil member disposed in the second gap G12 so as to be movable in the axial direction D11. The second voice coil 19 is formed by winding an electric wire around the outer periphery of a cylindrical second voice coil bobbin 191, near one opening. The second voice coil bobbin 191 is disposed so that the end of the second voice coil 19 on the second voice coil bobbin 191 enters the second gap G12 and is movable in the axial direction D11.

[0028] The treble diaphragm 20 is a diaphragm member formed in a circular shape with a small diameter that is equal to or smaller than the size of the inner peripheral opening 18a of the bass diaphragm 18, specifically, smaller than the size of the circular inner peripheral opening 18a. In this embodiment, the treble diaphragm 20 is a dome / cone-shaped diaphragm having a circular dome portion 201 in the center and a cone portion 202 that extends in an annular shape from the outer periphery of the dome portion 201. In this embodiment, the inclination of the cone-shaped bass diaphragm 18 and the inclination of the cone portion 202 of the treble diaphragm 20 are formed to match each other. This treble diaphragm 20 is disposed inside the inner peripheral opening 18a of the bass diaphragm 18.

[0029] In this embodiment, a treble frame 21 is provided to support the outer periphery of cone portion 202 of treble diaphragm 20 and fill the gap between the inner periphery of inner circumferential opening 18a of bass diaphragm 18 and the outer periphery of cone portion 202. A circular edge 203, with an arc-shaped midsection, extends radially outward from the outer periphery of cone portion 202 of treble diaphragm 20. The outermost periphery of this edge 203 is sandwiched and held between treble frame 21 and a circular retaining ring 22 placed on flange portion 142 of plate 14. Treble frame 21 has a sound-emitting end surface 211 that is inclined in accordance with the inclination of bass diaphragm 18 and the inclination of cone portion 202 of treble diaphragm 20, forming a continuous, bowl-shaped surface.

[0030] Such a treble diaphragm 20 is coupled to the second voice coil 19 via the second voice coil bobbin 191. The open edge of the second voice coil bobbin 191 opposite the second voice coil 19 is adhesively fixed to the boundary between the dome portion 201 and the cone portion 202 on the back surface of the treble diaphragm 20. The second voice coil bobbin 191 is adhesively fixed to the treble diaphragm 20, which is held via the above-mentioned edge 203, so that it can move in the axial direction D11. When the second voice coil 19 vibrates in the axial direction D11 inside the second gap G12, the vibration is transmitted to the treble diaphragm 20 via the second voice coil bobbin 191, causing the treble diaphragm 20 to vibrate and generate sound.

[0031] The yoke 12, first magnet 13, plate 14, second magnet 15, center pole 16, first voice coil 17, bass diaphragm 18, second voice coil 19, and treble diaphragm 20 are arranged coaxially with one another. This arrangement of the components constitutes the composite speaker device 1 as a coaxial speaker.

[0032] Here, the vibration of the first voice coil 17 that vibrates the bass diaphragm 18 and the vibration of the second voice coil 19 that vibrates the treble diaphragm 20 are caused by magnetic interaction in the first gap G11 and the second gap G12. A magnetic flux generated by a magnetic circuit described below passes through each magnetic gap. When a signal current corresponding to the reproduced sound flows through the voice coil located inside each gap, the magnetic interaction between the magnetic flux in each gap and the signal current causes the voice coil to vibrate in response to the signal current, and each diaphragm emits a reproduced sound corresponding to the signal current.

[0033] Fig. 3 is a schematic diagram showing a magnetic circuit for vibrating the voice coil in the composite speaker device shown in Fig. 1 and Fig. 2, together with the magnetic flux flowing through the circuit. In Fig. 3, Fig. 3(b) shows the magnetic circuit in the composite speaker device 1, and Fig. 3(a) shows a comparative example to this magnetic circuit.

[0034] In the above-described composite speaker device 1, first, the yoke 12, the first magnet 13, and the plate 14 form a bass magnetic circuit 1a that vibrates the bass diaphragm 18. In this bass magnetic circuit 1a, the magnetic flux φ11 emitted from the first magnet 13 passes from the plate 14 through the first gap G11 to the yoke 12, and then returns to the first magnet 13 through the yoke 12.

[0035] On the other hand, the treble magnetic circuit 1b that vibrates the treble diaphragm 20 is composed of the plate 14, the second magnet 15, the center pole 16, the yoke 12, and the first magnet 13. The magnetic flux φ12 emitted from the second magnet 15 passes from the center pole 16 through the second gap G12 to the plate 14. At this time, a flow of magnetic flux φ11 from the first magnet 13 is formed in the plate 14, passing through the first gap G11 toward the yoke 12. In this embodiment, the center pole 16 is housed in the plate 14 so that the end face 161 on the sound emission side does not protrude from the openings of both the yoke 12 and the plate 14. As a result, the magnetic flux φ12 from the second magnet 15 reaches the plate 14 in approximately the same direction as the flow of the magnetic flux φ11 from the first magnet 13. As a result, most of the magnetic flux φ12a of the magnetic flux φ12 from the second magnet 15 merges with the magnetic flux φ11 from the first magnet 13 at the plate 14 and flows from the plate 14 through the first gap G11 toward the yoke 12. These two types of magnetic flux φ11 and φ12a pass through the yoke 12 to reach the first magnet 13, where the magnetic flux φ12a from the second magnet 15 separates from the magnetic flux φ11 from the first magnet 13 and returns to the second magnet 15 through the plate 14.

[0036] In this manner, in this embodiment, the magnetic flux φ12 from the second magnet 15 passes through the second gap G12, and the magnetic flux φ11 from the first magnet 13 and a large amount of magnetic flux φ12a from the second magnet 15 join together and pass through the first gap G11.

[0037] Here, a comparative example to the magnetic circuit of Fig. 3(b) will be described with reference to Fig. 3(a). The comparative magnetic circuit 5 shown in Fig. 3(a) is a single magnetic circuit corresponding to the bass magnetic circuit 1a shown in Fig. 3(a). In Fig. 3(a), components equivalent to those shown in Fig. 3(b) are assigned the same reference numerals as in Fig. 3(b), and redundant explanations of these equivalent components will be omitted below.

[0038] In the magnetic circuit 5 of the comparative example as a single magnetic circuit, the magnetic flux φ11 emitted from the first magnet 13 passes from the flat plate 54 through the single gap G51 to the yoke 12, and then returns to the first magnet 13 through the yoke 12. In the magnetic circuit 5 of the comparative example, only the magnetic flux φ11 from the first magnet 13 passes through the single gap G51. For this reason, the following difference occurs between the amount of magnetic flux passing through the first gap G11 and the amount of magnetic flux passing through the single gap G51 between the magnetic circuit of FIG. 3(b) and the magnetic circuit 5 of the comparative example of FIG. 3(a).

[0039] FIG. 4 is a diagram showing the difference in the amount of magnetic flux passing through the first gap and the single gap shown in FIG. 3, in terms of the distribution of magnetic flux density in each gap.

[0040] 4 shows a density distribution graph GR1, with the horizontal axis representing position X in the axial direction D11 in each gap and the vertical axis representing magnetic flux density Bg. Note that position X is set to "0" at the center of each gap in the axial direction D11. In this graph GR1, the dotted line GL1 represents the distribution of magnetic flux density Bg in the single gap G51 of the magnetic circuit 5 of the comparative example in FIG. 3(a). The solid line GL2 represents the distribution of magnetic flux density Bg in the first gap G11 of the magnetic circuit of the embodiment in FIG. 3(b).

[0041] As shown by the difference between the dotted line GL1 and the solid line GL2 in this graph GR1, the magnetic flux density in the gap, i.e., the amount of magnetic flux passing through the gap, is greater in the magnetic circuit of the embodiment than in the magnetic circuit of the comparative example 5. This difference in the amount of passing flux occurs because, in the magnetic circuit of the embodiment, the amount of magnetic flux passing through the first gap G11 is greater by the amount of magnetic flux φ12a from the second magnet 15 that joins the gap.

[0042] In this embodiment, the confluence of magnetic fluxes that increases the amount of passing magnetic flux is achieved by storing the center pole 16 in the plate 14 so that the end face 161 on the sound emitting side does not protrude from the openings of both the yoke 12 and the plate 14. This point will be explained below with reference to a further comparative example.

[0043] Fig. 5 is an explanatory diagram illustrating, with a comparative example, how the confluence of magnetic fluxes shown in Fig. 3 is realized by the manner in which the center pole is accommodated in the plates shown in Figs. 1 to 3. Fig. 5(b) schematically shows the flow of magnetic flux in the magnetic circuit of the embodiment also shown in Fig. 3, and Fig. 5(a) schematically shows the flow of magnetic flux in a magnetic circuit 6 of a comparative example compared to the magnetic circuit of this embodiment. Note that, while Fig. 3 above shows the flow of magnetic flux in the right-hand portion of the magnetic circuit of Fig. 1, Fig. 5 shows the flow of magnetic flux in the left-hand portion.

[0044] First, the magnetic circuit 6 of the comparative example shown in FIG. 5(a) will be described.

[0045] The magnetic circuit 6 of this comparative example also constitutes a composite speaker similar to the magnetic circuit of the embodiment shown in FIGS. 1 to 3, and includes a yoke 62, a first magnet 63, a plate 64, a second magnet 65, and a center pole 66. In this comparative example, a cylindrical portion 64a of the plate 64 that houses the second magnet 65 and the center pole 66 is formed to protrude from the opening of the yoke 62. As a result, the sound-emitting end face 661 of the center pole 66 does not protrude from the opening of the plate 64, but does protrude from the opening of the yoke 62. As a result of this arrangement, the magnetic circuit 6 of the comparative example is configured with a bass magnetic circuit 6a and a treble magnetic circuit 6b that are substantially separated as follows: That is, the bass magnetic circuit 6a is composed of the yoke 62, the first magnet 63, and the flat portion 64b of the plate 64 on which the cylindrical portion 64a is placed, while the treble magnetic circuit 6b is composed of the cylindrical portion 64a of the plate 64, the second magnet 65, and the center pole 66. In this case, the boundary between the flat portion 64b and the cylindrical portion 64a of the plate 64 forms the boundary between the bass magnetic circuit 6a and the treble magnetic circuit 6b. As shown in FIG. 5(a), at this boundary, magnetic flux φ61 that passes through the protruding cylindrical portion 64a as described above and returns to the second magnet 65, and magnetic flux φ62 from the first magnet 63 that passes through the flat portion 64b toward the yoke 62 pass in opposite directions. As a result, part of the magnetic flux φ62 from the first magnet 63 is cancelled out by the magnetic flux φ61 in the opposite direction returning to the second magnet 65, and the amount of magnetic flux φ63 passing through the first gap G61 is reduced accordingly.

[0046] 5(b), magnetic flux flows as follows: The magnetic flux φ12 from the second magnet 15 that passes through the center pole 16, whose sound-emitting end face 161 does not protrude from the openings of both the yoke 12 and the plate 14, flows in the same direction as the magnetic flux φ11 from the first magnet 13 at the plate 14. As a result, most of the magnetic flux φ12a from the second magnet 15 merges with the magnetic flux φ11 from the first magnet 13 at the plate 14 and flows toward the first gap G11.

[0047] In the composite speaker device 1 of the embodiment described above, as described above, the magnetic flux φ11 from the first magnet 13 and the magnetic flux φ12a from the second magnet 15 are joined at the plate 14 and pass through the first gap G11. The magnetic flux in the first gap G11 is used to vibrate the woofer diaphragm 18 via the first voice coil 17, and as described above, the joined magnetic flux from the two magnets is used as this magnetic flux, which can improve the efficiency of magnetic flux utilization in the magnetic circuit. In anticipation of such improved efficiency of magnetic flux utilization, the first magnet 13 can be made smaller, which in turn can reduce the size and weight of the composite speaker device 1.

[0048] In this embodiment, the first gap G11 and the second gap G12 are arranged to be in the same position with respect to the axial direction D11. With this configuration, the magnetic flux φ12 from the second magnet 15 passing through the second gap G12 easily merges with the magnetic flux φ11 from the first magnet passing through the first gap G11 toward the yoke 12, thereby further improving the utilization efficiency of the magnetic flux in the magnetic circuit. Furthermore, with the above configuration, the vibration generation position of the bass diaphragm 18 and the vibration generation position of the treble diaphragm 20 coincide with each other in the axial direction D11. This allows the listener to hear bass and treble sounds as if they are emanating from the same position in the depth direction, thereby improving the sound quality of the composite speaker device 1.

[0049] Furthermore, in this embodiment, the opening of the yoke 12, the opening of the plate 14, and the sound-emitting end face 161 of the center pole 16 are arranged so as to be in the same position relative to one another in the axial direction D11. In this configuration, a first gap G11 between the plate 14 and the yoke 12 is formed on the opening side of both, and a second gap G12 between the center pole 16 and the plate 14 is formed on the end side of the center pole 16 and the opening side of the plate 14. In other words, with this configuration, the positions of the first gap G11 and the second gap G12 in the axial direction D11 can be effectively aligned, thereby further increasing the utilization efficiency of the magnetic flux in the magnetic circuit and improving the sound quality of the composite speaker device 1.

[0050] In this embodiment, the bass diaphragm 18 is a cone-shaped diaphragm, and the treble diaphragm 20 is a dome / cone-shaped diaphragm, and the inclination of the bass diaphragm 18 matches the inclination of the cone portion 202 of the treble diaphragm 20. This configuration can improve the appearance of the sound-producing portion of the composite speaker device 1 where the bass diaphragm 18 and the treble diaphragm 20 are arranged. Furthermore, the matching of the inclinations can also improve the sound quality of the composite speaker device 1.

[0051] In this embodiment, the gap between the inner periphery of inner peripheral opening 18a of bass diaphragm 18 and the outer periphery of cone portion 202 is filled by treble frame 21, which holds the outer periphery of cone portion 202 of treble diaphragm 20. End face 211 on the sound emission side of treble frame 21 is inclined to match the inclination of bass diaphragm 18 and the inclination of cone portion 202 of treble diaphragm 20, forming a continuous mortar-shaped surface. With this configuration, the sound-producing portion of composite speaker device 1 is formed from a continuous mortar-shaped surface, further improving the appearance of the device.

[0052] In this embodiment, the yoke 12, plate 14, center pole 16, bass diaphragm 18, and treble diaphragm 20 are arranged coaxially. With this configuration, the vibrations of the bass diaphragm 18 and the treble diaphragm 20 occur around the same axis. This allows the listener to hear bass and treble sounds as if they are coming from the same position in all directions, improving the sound quality of the composite speaker device 1.

[0053] In this embodiment, the first gap G11 is a gap between the outer periphery of the flange portion 142 of the plate 14 and the inner periphery of the yoke 12. With this configuration, the magnetic fluxes φ11 and φ12 of the first magnet 13 and the second magnet 15 that reach the plate 14 can be smoothly joined via the flange portion 142 and guided to the first gap G11 and the yoke 12.

[0054] The present invention is not limited to the above-described embodiment, but includes other configurations that can achieve the object of the present invention, and the following modifications are also included in the present invention.

[0055] For example, in the above-described embodiment, as an example of a composite speaker device, a composite speaker device 1 is shown that includes a speaker housing 11 having a substantially cylindrical outermost frame 111 with a bottom, an inner frame 112 with a fixing flange 112b, and a bass frame 113. However, the composite speaker device is not limited to this, and any shape and configuration can be adopted for the housing shape and configuration.

[0056] In the above-described embodiment, the following composite speaker device 1 is illustrated as an example of a composite speaker device. Specifically, the composite speaker device 1 includes a cylindrical yoke 12 and plate 14 with a bottom, a first magnet 13 and a second magnet 15 with a disk-like shape, a disk-like center pole 16, and a circular bass diaphragm 18 and a circular treble diaphragm 20. However, the composite speaker device is not limited to this. For example, the shapes of the yoke and the plate are not limited to a cylindrical shape as long as they are cylindrical with a bottom, and other cylindrical shapes such as an elliptical cylinder can be used. Furthermore, the shapes of the first magnet, the second magnet, the center pole, the bass diaphragm, and the treble diaphragm are not limited to a circular or disk-like shape, and other shapes such as an elliptical plate or an oval can be used.

[0057] In the above-described embodiment, the composite speaker device 1 is exemplified as an example of a composite speaker device in which the first gap G11 and the second gap G12 are arranged so as to be at the same position with respect to the axial direction D11. However, the composite speaker device is not limited to this, and the positions of the first gap and the second gap may be offset from each other in the axial direction. However, as described above, by arranging the two gaps at the same position, the sound quality of the composite speaker device 1 can be improved.

[0058] Furthermore, in the above-described embodiment, the composite speaker device 1 is exemplified as an example of a composite speaker device in which the opening of the yoke 12, the opening of the plate 14, and the end face 161 of the center pole 16 are arranged so as to be in the same position with respect to the axial direction D11. However, the composite speaker device is not limited to this, and the positions of these components may be offset in the axial direction. However, as described above, by arranging these components in the same position, the sound quality of the composite speaker device 1 can be improved.

[0059] Furthermore, in the above-described embodiment, as an example of a composite speaker device, composite speaker device 1 is shown that includes a cone-shaped woofer diaphragm 18 and a dome / cone-shaped treble diaphragm 20 in which the inclination of the cone portion 202 matches the inclination of the woofer diaphragm 18. However, composite speaker devices are not limited to this, and the shapes of each diaphragm can be set as appropriate. However, as described above, by matching the inclination of the cone portion 202 of the dome / cone-shaped treble diaphragm 20 to the inclination of the woofer diaphragm 18, the appearance of the sound-generating portion can be improved and the sound quality can also be improved.

[0060] Furthermore, in the above-described embodiment, as an example of a composite speaker device, a composite speaker device 1 is shown in which a continuous mortar-shaped surface is formed by the woofer diaphragm 18, the cone portion 202 of the treble diaphragm 20, and the end face 211 of the treble frame 21 between them. However, the composite speaker device is not limited to this, and it may not have a treble frame whose end face forms part of the mortar-shaped surface as described above. However, as described above, providing a treble frame 21 with such an end face 211 can further improve the appearance of the sound-producing portion.

[0061] In the above-described embodiment, the composite speaker device 1 is exemplified as an example of a composite speaker device, in which the yoke 12, the plate 14, the center pole 16, the woofer diaphragm 18, and the treble diaphragm 20 are arranged coaxially with one another. However, the composite speaker device is not limited to this, and any arrangement of the above components may be adopted. However, as described above, adopting a coaxial arrangement in the composite speaker device 1 can improve sound quality.

[0062] Furthermore, in the above-described embodiment, a composite speaker device 1 in which a first gap G11 is opened between the outer periphery of the flange portion 142 of the plate 14 and the inner periphery of the yoke 12 is exemplified as an example of a composite speaker device. However, the composite speaker device is not limited to this, and may be, for example, a device in which the plate is formed as a simple cylinder with a bottom, and a first gap is opened between the peripheral wall of the cylinder and the yoke. However, as described above, by configuring the plate 14 so that the first gap G11 is opened between the flange portion 142 of the plate 14 and the yoke 12, the magnetic flux from each magnet can be effectively joined and guided to the first gap G11 and the yoke 12. [Explanation of symbols]

[0063] 1. Composite speaker system 1a Bass magnetic circuit 1b High-frequency magnetic circuit 11 Speaker housing 12 York 13 First Magnet 14 plates 15 Second magnet 16 Center Pole 17 First voice coil 18 Bass diaphragm 18a Inner opening 19 Second voice coil 20 High-pitched diaphragm 21 Treble Frame 22 Retaining ring 111 outermost frame 112 Inner frame 112a Holding part 112b Fixed flange 113 Bass Frame 121,141a Inner bottom surface 122,141b Inner circumference 141 Plate body 142 flange part 142a, 162 Outer circumference 161,211 End face 171 1st voice coil bobbin 172 Damper member 181,203 Edge 191 Second voice coil bobbin 201 Dome part 202 Cone part Bg magnetic flux density D11 Axial direction G11 First Gap G12 2nd Gap GL1 dotted line GL2 solid line GR1 graph L11 dashed line X position φ11,φ12,φ12a magnetic flux

Claims

1. a yoke made of a magnetic material and formed in a cylindrical shape with a bottom that opens to the sound emitting side; a first magnet attached to the inner bottom surface of the yoke; a plate made of a magnetic material and formed in a cylindrical shape with a bottom that opens to the sound emission side, the plate being attached to the first magnet and housed in the yoke so as to form a first annular gap between the plate and an inner periphery of the yoke; a second magnet attached to the inner bottom surface of the plate; a center pole made of a magnetic material, attached to the second magnet and housed in the plate so as to form a second annular gap between the center pole and an inner periphery of the plate; a first voice coil disposed in the first gap so as to be movable in the axial direction; an annular bass diaphragm disposed on the sound emitting side of the first gap and coupled to the first voice coil; a second voice coil disposed in the second gap so as to be movable in the axial direction; a treble diaphragm that is formed to be smaller than the size of the inner peripheral opening of the woofer, is disposed inside the inner peripheral opening, and is coupled to the second voice coil; Equipped with the yoke, the first magnet, and the plate constitute a bass magnetic circuit that vibrates the bass diaphragm, and the bass magnetic circuit is a magnetic circuit in which a first magnetic flux emitted from the first magnet passes from the plate through the first gap to the yoke, and then passes through the yoke to return to the first magnet, a composite speaker device in which the plate, the second magnet, the center pole, the yoke, and the first magnet constitute a treble magnetic circuit that vibrates the treble diaphragm, and the treble magnetic circuit is a magnetic circuit in which a second magnetic flux emitted from the second magnet passes from the center pole through the second gap to the plate, merges with the first magnetic flux at the plate, passes through the first gap to the yoke, passes through the yoke together with the first magnetic flux, reaches the first magnet and separates from the first magnetic flux, and then passes through the plate to return to the second magnet.

2. 2. The composite speaker device according to claim 1, wherein the end of the center pole on the sound emitting side does not protrude from the openings of either the yoke or the plate.

3. 3. The composite speaker device according to claim 1, wherein the first gap and the second gap are arranged at the same position in the axial direction.

4. The composite speaker device according to any one of claims 1 to 3, characterized in that the opening of the yoke, the opening of the plate, and the end of the center pole on the sound emitting side are arranged so as to be in the same position as each other in the axial direction.

5. the bass diaphragm is an annular cone-shaped diaphragm, the treble diaphragm is a dome / cone type diaphragm having a dome portion and a cone portion that protrudes annularly from the outer periphery of the dome portion, 5. The composite speaker device according to claim 1, wherein the inclination of the woofer and the inclination of the cone portion of the treble diaphragm are the same.

6. the treble diaphragm including the cone portion is formed to have a shape smaller than the size of an inner peripheral opening of the bass diaphragm, The outer periphery of the cone portion of the treble diaphragm is held, and the bass diaphragm is held Further provided is a treble frame that fills the gap between the inner periphery of the inner peripheral opening of the plate and the outer periphery of the cone portion, 6. The composite speaker device according to claim 5, wherein the end face of the treble frame on the sound emitting side is inclined in a manner that matches the inclination of the woofer and the inclination of the cone portion of the treble diaphragm, forming an inclined surface that forms a continuous mortar-shaped surface.

7. 7. The composite speaker device according to claim 1, wherein the yoke, the plate, the center pole, the woofer, and the treble diaphragm are arranged coaxially with each other.

8. The plate has a cylindrical plate body with a bottom and a flange portion that annularly protrudes from an opening of the plate body, 8. The composite speaker device according to claim 1, wherein the first gap is a gap between an outer periphery of the flange portion and an inner periphery of the yoke.

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