Waterproof speaker and damper member for speaker

Abstract

This waterproof speaker comprises: a diaphragm that emits sound; a magnetic circuit for vibrating the diaphragm; a frame that has a bottom surface disposed around the magnetic circuit and supports the diaphragm and the magnetic circuit; at least one waterproof damper that is supported by the frame and is displaced in conjunction with the vibration of the diaphragm; and at least one waterproof elastic membrane that seals a space between the damper and the bottom surface together with the damper. The at least one elastic membrane deforms so as to reduce a pressure change in the space in accordance with displacement of the at least one damper due to the vibration of the diaphragm.

Description

Waterproof Speaker and Damper Member for Speaker

[0001] The present disclosure relates to a waterproof speaker and a damper member for a speaker.

[0002] As disclosed in Patent Documents 1-2, a waterproof speaker having waterproofness against a magnetic circuit is known. Patent Document 1 discloses a waterproof damper impregnated with a thermosetting resin.

[0003] Japanese Utility Model Publication No. 5-11693 US Patent Application Publication No. 2018 / 0206030

[0004] The damper described in Patent Document 1 has no air permeability. Therefore, even if the damper is simply applied to a speaker, the efficiency in the low frequency range of the speaker will decrease due to the influence of the air spring by the sealed space provided on the back side of the damper. As one of the countermeasures, it is conceivable to provide an acoustic space such as a chamber in the sealed space. However, providing such an acoustic space has a problem of causing the speaker to be enlarged and complicated.

[0005] In view of the above circumstances, one aspect of the present disclosure aims to provide a waterproof speaker that can enhance the efficiency in the low frequency range while achieving miniaturization and simplification.

[0006] In order to solve the above problems, a waterproof speaker according to a preferred aspect of the present disclosure includes a diaphragm that emits sound, a magnetic circuit for vibrating the diaphragm, a bottom surface disposed around the magnetic circuit, a frame that supports the diaphragm and the magnetic circuit, at least one waterproof damper that is supported by the frame and is displaced in conjunction with the vibration of the diaphragm, and at least one elastic film that is waterproof and seals the space between the damper and the bottom surface together with the damper. The at least one elastic film is deformed so as to reduce the pressure change in the space as the at least one damper is displaced due to the vibration of the diaphragm.

[0007] A damper member for a speaker according to a preferred embodiment of the present disclosure comprises at least one waterproof damper and at least one waterproof elastic membrane connected to the at least one damper, wherein the modulus of elasticity of the at least one elastic membrane is lower than the modulus of elasticity of the at least one damper.

[0008] This is a cross-sectional view of a waterproof speaker according to the first embodiment. This is an explanatory diagram of the damper, elastic membrane, and fixing member of the waterproof speaker shown in Figure 1. This is an explanatory diagram of the operation of the waterproof speaker shown in Figure 1. This is a cross-sectional view of a waterproof speaker according to the second embodiment. This is an explanatory diagram of the operation of the waterproof speaker shown in Figure 4. This is a cross-sectional view of a waterproof speaker according to the third embodiment. This is a plan view of a speaker damper member according to Modification 1.

[0009] Embodiments of this disclosure will be described below with reference to the drawings. Note that the dimensions and scale of the parts in the drawings have been appropriately altered from those of the actual parts. Furthermore, the embodiments described below are preferred examples of this disclosure. For this reason, these embodiments are subject to various technically preferred limitations. However, the scope of this disclosure is not limited to these embodiments unless otherwise specifically stated in the following description.

[0010] 1. First Embodiment 1-1. Schematic diagram 1 of the speaker device is a cross-sectional view of the waterproof speaker 1 according to the first embodiment. The waterproof speaker 1 is a dynamic speaker unit that emits sound based on an audio signal input from an external device such as an amplifier (not shown), and is waterproof.

[0011] The waterproof speaker 1 is attached to a mounting object, such as a panel on a boat hull (not shown), by screwing it in or the like. The manner in which the waterproof speaker 1 is attached to the mounting object is not limited to direct attachment to the mounting object; for example, it may be attached directly to the mounting object via a mounting device such as a baffle plate.

[0012] As shown in Figure 1, the device comprises a diaphragm 10, a voice coil 20, a magnetic circuit 30, a frame 40, a damper 50, an edge 60, a fixing member 70, and an elastic membrane 80.

[0013] In this embodiment, the damper 50 and the elastic membrane 80 constitute a speaker damper member 100. The speaker damper member 100 is a structure that integrally includes the damper 50 and the elastic membrane 80.

[0014] The parts of the waterproof speaker 1 will be described in order below, based on Figure 1. In the following, the central axis of the waterproof speaker 1 is referred to as axis AX. The relationship between the direction in which axis AX extends and the vertical direction is not particularly limited and is arbitrary. In the following, one direction along axis AX from the back to the front of the waterproof speaker 1 will be referred to as direction X1, and the direction opposite to direction X1, from the front to the back of the waterproof speaker 1 will be referred to as direction X2. In the following, directions X1 and X2 may not be distinguished and will simply be referred to as the axial direction. In addition, one direction along a virtual circle centered on axis AX, or the opposite direction, may be referred to as the circumferential direction. Furthermore, the direction perpendicular to axis AX and away from axis AX, or the opposite direction, may be referred to as the radial direction.

[0015] The diaphragm 10 is a vibrating body composed of a sheet material, and emits sound through vibration. The sheet material constituting the diaphragm 10 is obtained, for example, by impregnating or coating a fibrous substrate with a resin material or rubber material and then curing or solidifying it. Examples of the resin material or rubber material include polyester resin, acrylic resin, polyurethane, melamine resin, modified rubber resin, and phenolic resin. Examples of the fibrous substrate include carbon fiber, aramid fiber, glass fiber, ceramic fiber, silica fiber, metal fiber, potassium titanate fiber, zirconia fiber, polyacrylate fiber, polyphenylene sulfide fiber, vinylon fiber, rayon fiber, nylon fiber, polyester fiber, acrylic fiber, polypropylene fiber, polyethylene fiber, cotton fiber, hemp fiber, and cellulose fiber. The surface of the sheet material may be provided with a coating film composed of, for example, a metal such as aluminum or an inorganic material such as DLC (Diamond-like Carbon).

[0016] The diaphragm 10 has a surface facing the X1 direction and a surface facing the X2 direction, and emits sound by vibrating in a direction along the axis AX. The surface of the diaphragm 10 facing the X1 direction is the sound-emitting surface. In the example shown in Figure 1, the diaphragm 10 is cone-shaped. However, the shape of the diaphragm 10 is not limited to the example shown in Figure 1, and may be dome-shaped, for example.

[0017] The voice coil 20 is fixed to the surface of the diaphragm 10 facing the X2 direction and generates a magnetic field in response to an electrical audio signal input. The voice coil 20 has a bobbin 21 and a coil 22. The bobbin 21 is cylindrical with axis AX as its central axis. One end of the bobbin 21 in the X1 direction is joined to the surface of the diaphragm 10 facing the X2 direction by adhesive or the like. The coil 22 is made up of a wire wound circumferentially along the outer circumference of the bobbin 21. The audio signal is input to the coil 22 via wiring (not shown). As a result, a magnetic field corresponding to the audio signal is generated from the voice coil 20.

[0018] The magnetic circuit 30 is an element for vibrating the diaphragm 10 and generates a magnetic field that acts on the magnetic field from the voice coil 20. The magnetic circuit 30 has a permanent magnet 31 and a yoke 32. The permanent magnet 31 is a ferrite magnet or neodymium magnet, etc., with axis AX as its central axis. The yoke 32 is made of a soft magnetic material and guides the magnetic flux from the permanent magnet 31 to the voice coil 20. As a result, the magnetic field from the voice coil 20 due to the audio signal acts on the magnetic field from the magnetic circuit 30, causing the diaphragm 10 to vibrate in response to the audio signal.

[0019] The frame 40 is a structure that supports the diaphragm 10 and the magnetic circuit 30. The frame 40 is made of, for example, a resin composition. The magnetic circuit 30 is fixed to the frame 40. The voice coil 20 is connected to the frame 40 via a damper 50, and the diaphragm 10 is connected via an edge 60. Furthermore, an elastic membrane 80 is attached to the frame 40 so as to seal the space S2 on the back side of the damper 50.

[0020] To explain in more detail, the frame 40 is divided into three parts along the axis AX: a first part P1, a second part P2, and a third part P3. These three parts are arranged in the order of the first part P1, the second part P2, and the third part P3, facing the X2 direction.

[0021] The first part P1 is part of the frame 40 and supports the diaphragm 10. In the example shown in Figure 1, the first part P1 generally has a shape that follows the side surface of a frustum of a cone that expands in the X1 direction with the axis AX as the center. A flange 41 is provided at the end of the first part P1 in the X1 direction, projecting radially outward. The flange 41 is fixed to an object to be mounted (not shown) by screws or the like. An edge 60 is joined to the portion of the first part P1 near the flange 41 by adhesive or the like. In addition, a plurality of holes 42 are provided in the first part P1 at intervals in the circumferential direction. As a result, the space S1 located in the X2 direction relative to the diaphragm 10 inside the first part P1 communicates with the space S0 outside the first part P1 via the plurality of holes 42. Therefore, the influence of the air spring in space S1 on the diaphragm 10 can be reduced. The second part P2 is connected to the end of the first part P1 in the X2 direction.

[0022] The second portion P2 is part of the frame 40 and forms a recess 43 having a bottom surface FB1 and a side surface FS1. Thus, the frame 40 is provided with a recess 43. The bottom surface FB1 and the side surface FS1 constitute a wall surface that defines the recess 43. The side surface FS1 of the recess 43 extends in the X1 direction from the outer edge of the bottom surface FB1 over the entire circumference of the bottom surface FB1 of the recess 43. The end of the side surface FS1 in the X1 direction defines an opening OP1. In the example shown in Figure 1, the diameter of the opening OP1 is smaller than the inner diameter of the end of the first portion P1 in the X2 direction. Thus, the end of the second portion P2 in the X1 direction is provided with a stepped portion FF that extends radially outward over the entire circumference of the opening OP1. The bottom surface FB1 is provided with an opening OP2. The third portion P3 is connected to the end of the second portion P2 in the X2 direction.

[0023] The third portion P3 is part of the frame 40 and is the portion that fixes the magnetic circuit 30. In the example shown in Figure 1, the third portion P3 forms a recess 44 having a bottom surface FB2 and a side surface FS2. The bottom surface FB2 and the side surface FS2 constitute the wall surface that defines the recess 44. The side surface FS2 extends around the entire circumference of the bottom surface FB2 in the direction X1 from the outer edge of the bottom surface FB2. The end of the side surface FS2 in the direction X1 defines the opening OP2.

[0024] In the frame 40 described above, the magnetic circuit 30 is positioned within the recess 44. In the example shown in Figure 1, the magnetic circuit 30 is fixed to the third portion P3 by screw fastening with screws SC. Note that the method of fixing the magnetic circuit 30 to the third portion P3 is not limited to the illustrated example and is arbitrary; for example, it may be fixed by adhesive or the like.

[0025] Furthermore, as described above, the frame 40 has a bottom surface FB1, and the magnetic circuit 30 is exposed into the recess 43 through the opening OP2. Here, the bottom surface FB1 is positioned around the magnetic circuit 30. The space S2 between the damper 50 and the bottom surface FB1 is sealed by the damper 50 and the elastic membrane 80. As a result, even if moisture enters space S1 from space S0 through the hole 42 in the frame 40, it is prevented from entering space S2. This provides waterproofing for the magnetic circuit 30.

[0026] In this embodiment, the damper 50 and the elastic membrane 80 are arranged to close the opening OP1 of the recess 43. This has the advantage of simplifying the structure of the frame 40 and the arrangement of the elastic membrane 80 compared to the configuration in which the two members are separate components, such as the damper 50A and elastic membrane 80A of the second embodiment described later.

[0027] Furthermore, a fixing member 70 is placed within the recess 43. The fixing member 70 is fixed to the bottom surface FB1 with an adhesive or the like. The outer edge of the damper 50 and the inner edge of the elastic membrane 80 are joined to the fixing member 70 with an adhesive or the like.

[0028] The shape of the frame 40 is not limited to the example shown in Figure 1, but is arbitrary. For example, the shape of the third portion P3 may be such that it does not have a bottom surface FB2 and a part of the magnetic circuit 30 is exposed to the outside of the frame 40. However, in this case, from the viewpoint of ensuring waterproofness for the magnetic circuit 390, it is preferable to apply a waterproof coating to the exposed portion of the magnetic circuit 30 or to fill the gap between the magnetic circuit 30 and the side surface FS2 with a waterproof filler. Also, although the frame 40 is composed of a single member in the example shown in Figure 1, it is not limited to this, and the frame 40 may be composed of multiple members joined to each other by adhesive or the like. For example, the member constituting the first portion P1 and the member constituting the second portion P2 may be joined to each other by adhesive or the like, or the member constituting the second portion P2 and the member constituting the third portion P3 may be joined to each other by adhesive or the like.

[0029] The damper 50 is a waterproof member supported by the frame 40 and displaced in conjunction with the vibration of the diaphragm 10, and is also called a spider. The damper 50 is made of a flexible sheet material that supports the voice coil 20 relative to the frame 40 while allowing the vibration of the diaphragm 10. In the example shown in Figure 1, the damper 50 has an annular shape when viewed in the direction along the axis AX.

[0030] The inner edge of the damper 50 is joined to the voice coil 20 by adhesive or the like. The outer edge of the damper 50 is joined to the fixing member 70 by adhesive or the like, and is supported by the frame 40 via the fixing member 70.

[0031] The damper 50 is obtained, for example, by impregnating or coating a fibrous substrate with a resin material or rubber material, similar to the diaphragm 10, and then curing or solidifying it. Examples of such resin materials or rubber materials include polyester resin, acrylic resin, polyurethane, melamine resin, modified rubber resin, and phenolic resin. Among these, latex materials such as acrylonitrile-butadiene latex, styrene-butadiene latex, acrylate latex, or resin latex, as well as rubber materials such as butyl rubber (IIR), ethylene propylene diene rubber (EPDM), silicone rubber, elastomer, and urethane rubber are preferably used. Examples of the fiber base material include carbon fiber, aramid fiber, glass fiber, ceramic fiber, silica fiber, metal fiber, potassium titanate fiber, zirconia fiber, polyacrylate fiber, polyphenylene sulfide fiber, vinylon fiber, rayon fiber, nylon fiber, polyester fiber, acrylic fiber, polypropylene fiber, polyethylene fiber, cotton fiber, hemp fiber, and cellulose fiber, among which aramid fiber is preferably used. The damper 50 may also be composed solely of rubber materials such as butyl rubber (IIR), ethylene propylene diene rubber (EPDM), silicone rubber, elastomer, and urethane rubber, or it may be aramid fiber such as Conex coated with rubber or resin. "Conex" is a registered trademark. The damper 50 may also be composed of a laminate of a fiber base material such as aramid fiber and a waterproof fabric such as Gore-Tex. "Gore-Tex" is a registered trademark. Furthermore, the surface of the damper 50 may be provided with a coating film composed of a metal such as aluminum or an inorganic material such as DLC.

[0032] The edge 60 is a flexible, membrane-like or sheet-like member that connects the outer edge of the diaphragm 10 to the frame 40, and is also called a surround. Here, the edge 60 seals the gap between the diaphragm 10 and the frame 40. The edge 60 is made of a rubber material such as elastomer, for example.

[0033] The edge 60 is annular when viewed in the direction along the axis AX. The edge 60 has an inner portion fixed to the diaphragm 10, an outer portion fixed to the frame 40, and a connecting portion that connects the inner portion and the outer portion to allow vibration of the diaphragm 10.

[0034] The fixing member 70 is a member fixed to the frame 40 and has the function of supporting the outer peripheral edge of the damper 50. Thus, the damper 50 is supported by the frame 40 via the fixing member 70. In this embodiment, in addition to supporting the outer peripheral edge of the damper 50, the fixing member 70 also has the function of supporting the inner peripheral edge of the elastic membrane 80. This allows the damper 50 and the elastic membrane 80 to be integrated, or the damper 50 and the elastic membrane 80 to be positioned to cover the opening OP1 of the frame 40. The fixing member 70 is made of, for example, a resin composition. An example of the configuration of the fixing member 70 will be described later with reference to Figure 2.

[0035] By using such a fixing member 70, the damper 50 and elastic membrane 80 can be suitably installed even when using an existing frame 40. In other words, by appropriately designing the shape of the fixing member 70, the damper 50 and elastic membrane 80 can be easily installed on various existing frames 40 so as to seal the space S2.

[0036] The elastic membrane 80 is a waterproof, membrane-like elastic member that seals the space S2 between the damper 50 and the bottom surface FB1 together with the damper 50. The elastic membrane 80 deforms in accordance with the displacement of the damper 50 due to the vibration of the diaphragm 10, thereby reducing the pressure change in the space S2. This reduces the effect of the air spring in the space S2, and as a result, it is possible to suppress the decrease in efficiency of the waterproof speaker 1 in the low-frequency range.

[0037] The elastic modulus of the elastic membrane 80 is lower than that of the damper 50. This makes it easier to deform the elastic membrane 80. As a result, the influence of the air spring created by the sealed space S2 provided on the back side of the damper 50 can be effectively reduced. Note that "elastic modulus" refers to, for example, Young's modulus.

[0038] The elastic membrane 80 is composed of rubber materials such as butyl rubber (IIR), ethylene propylene diene rubber (EPDM), silicone rubber, elastomer, urethane rubber, and nylon-rubber copolymer.

[0039] In the example shown in Figure 1, the elastic membrane 80 is formed into a concentric wave shape, similar to the damper 50, and forms an annular shape when viewed along the axis AX. The shape of the elastic membrane 80 is not limited to the example shown, and may be S-shaped, concave, convex, flat, mountain-shaped, balloon-shaped, etc.

[0040] 1-2. Damper, Fixing Member, and Elastic Membrane Figure 2 is an explanatory diagram of the damper 50, elastic membrane 80, and fixing member 70 of the waterproof speaker 1 shown in Figure 1. Figure 2 is an exploded perspective view of the structure consisting of the damper 50, elastic membrane 80, and fixing member 70. For the sake of explanation, in Figure 2, the external shapes of parts of the damper 50, elastic membrane 80, and fixing member 70 are simply shown with dashed lines.

[0041] The fixing member 70 has a fixing portion 71 and a plurality of leg portions 72.

[0042] The fixing portion 71 is part of the fixing member 70 and is the portion for fixing the outer peripheral edge of the damper 50 and the inner peripheral edge of the elastic membrane 80, respectively. In the example shown in Figure 2, the fixing portion 71 forms an annular shape along a circle centered on the axis AX when viewed in the direction along the axis AX. Multiple leg portions 72 are connected to the surface of the fixing portion 71 facing the X2 direction.

[0043] The multiple legs 72 are members for fixing the fixing portion 71 to the bottom surface FB1. The multiple legs 72 are arranged at intervals from each other in the circumferential direction of the fixing portion 71. This interval allows the space on the back side of the damper 50 and the space on the back side of the elastic membrane 80 to communicate with each other. The end of each leg 72 in the X1 direction is connected to the fixing portion 71. The end of each leg 72 in the X2 direction is joined to the bottom surface FB1 by adhesive or the like.

[0044] Note that the shape of the fixing member 70 or each part of the fixing member 70 is not limited to the illustrated example. For example, the fixing part 71 may be composed of a plurality of members divided in the circumferential direction. Also, the number of legs 72 may be three or less or five or more. The fixing position of the fixing member 70 with respect to the frame 40 is determined according to the shape of the fixing member 70 and the like, and is not limited to the illustrated example. For example, it may be the side surface FS1. The fixing member 70 is not limited to a mode configured separately from the frame 40, and may be configured integrally with the frame 40.

[0045] On the surface of the fixing part 71 of the fixing member 70 facing the X1 direction, the outer peripheral edge of the damper 50 and the inner peripheral edge of the elastic film 80 are joined by an adhesive or the like.

[0046] The damper 50 has an inner peripheral part 51, an outer peripheral part 52, and an elastic part 53.

[0047] The inner peripheral part 51 is a part of the damper 50 and is a cylindrical part joined to the voice coil 20 by an adhesive or the like. The outer peripheral part 52 is a part of the damper 50 and is a disk-shaped part joined to the fixing part 71 of the fixing member 70 by an adhesive or the like. The elastic part 53 is a part of the damper 50 and is a deformable part that allows the inner peripheral part 51 to move in the X1 direction or the X2 direction with respect to the outer peripheral part 52, and is formed into a concentric wave shape.

[0048] The elastic film 80 has an inner peripheral part 81, an outer peripheral part 82, and an elastic part 83.

[0049] The inner peripheral part 81 is a part of the elastic film 80 and is a disk-shaped part joined to the fixing part 71 of the fixing member 70 by an adhesive or the like. The outer peripheral part 82 is a part of the elastic film 80 and is a disk-shaped part joined to the step part FF of the frame 40 by an adhesive or the like. The elastic part 83 is a part of the elastic film 80 and is a film-shaped part that deforms to reduce the pressure change in the space S2. In the illustrated example, the elastic part 83 is formed into a concentric wave shape.

[0050] The elastic membrane 80 described above is connected to the damper 50. More specifically, the elastic membrane 80 is, for example, joined to the damper 50 with an adhesive or the like, or integrally molded with the damper 50. This allows the speaker damper member 100 to be handled as a single integrated component of the damper 50 and the elastic membrane 80. As a result, there is an advantage in that the structure of the frame 40 and the arrangement of the elastic membrane 80 can be simplified. For example, the damper 50 and the elastic membrane 80 can be joined together to the fixing member 70 with an adhesive or the like. Therefore, the assembly of the waterproof speaker 1 becomes easier compared to the configuration in which the damper 50 and the elastic membrane 80 are joined separately to the fixing member 70. The speaker damper member 100 may consist only of the damper 50 and the elastic membrane 80, or it may also include the fixing member 70. Furthermore, if the elastic membrane 80 is not integrated with the damper 50, the elastic membrane 80 and the damper 50 are joined separately to the fixing portion 71 of the fixing member 7. In this case, the fixing part 71 works in cooperation with the elastic membrane 80 and the damper 50 to seal the space S2.

[0051] Figure 3 is an explanatory diagram of the operation of the waterproof speaker 1 shown in Figure 1. In Figure 3, a part of the waterproof speaker 1 is shown with the voice coil 20 displaced in the X2 direction.

[0052] The diaphragm 10 vibrates due to the displacement of the voice coil 20 in the X1 or X2 direction. Here, as shown in Figure 3, when the voice coil 20 is displaced in the X2 direction, the damper 50 deforms accordingly so as to move closer to the bottom surface FB1 in the direction indicated by arrow A in the figure.

[0053] At this time, the pressure in space S2 tends to rise as the damper 50 deforms, but to suppress this rise, the elastic membrane 80 deforms so as to move away from the bottom surface FB1 in the direction indicated by arrow B in the figure. In other words, the elastic membrane 80 deforms in such a way that it reduces the volume change in space S2 that occurs as a result of the deformation of the damper 50. As a result, the pressure change in space S2 that occurs as a result of the displacement of the damper 50 can be reduced. Although not shown in the figure, if the damper 50 deforms so as to move away from the bottom surface FB1, the elastic membrane 80 deforms so as to move closer to the bottom surface FB1, thereby similarly reducing the pressure change in space S2 that occurs as a result of the deformation of the damper 50.

[0054] As described above, in the waterproof speaker 1, the waterproof damper 50 and elastic membrane 80 seal the space S2 between the damper 50 and the bottom surface FB1 of the frame 40, thereby achieving waterproofness to the magnetic circuit 30. Furthermore, the elastic membrane 80 deforms in accordance with the displacement of the damper 50 due to the vibration of the diaphragm 10 to reduce the pressure change in space S2, thereby reducing the effect of the air spring in space S2. As a result, the decrease in efficiency of the waterproof speaker 1 in the low-frequency range can be suppressed. In addition, since there is no need to provide an acoustic space such as a chamber in space S2, the waterproof speaker 1 can be made smaller and simpler.

[0055] 2. Second Embodiments The second embodiments of this disclosure will be described below. For elements whose operation and function are the same as in the first embodiment in the embodiments described below, the reference numerals used in the description of the first embodiment will be reused, and detailed descriptions of each will be omitted as appropriate.

[0056] Figure 4 is a cross-sectional view of the waterproof speaker 1A according to the second embodiment. The waterproof speaker 1A is configured similarly to the waterproof speaker 1 of the first embodiment, except that the fixing member 70 of the first embodiment is omitted, and the frame 40A, damper 50A, and elastic membrane 80A of the first embodiment are replaced with a frame 40A, damper 50A, and elastic membrane 80A, respectively.

[0057] Frame 40A is configured similarly to frame 40 of the first embodiment, except that it is provided with a plurality of holes 45 that open into the bottom surface FB1 so as to penetrate the inside and outside of the recess 43. Therefore, frame 40A is provided with a recess 43 having a bottom surface FB1. The number and shape of the holes 45 are not particularly limited and are arbitrary. The holes 45 may also open into the side surface FS1 so as to penetrate the inside and outside of the recess 43.

[0058] The damper 50A is configured in the same way as the damper 50 of the first embodiment, except that it is configured to close the opening OP1 of the recess 43. Here, the inner periphery of the damper 50A is joined to the voice coil 20, similar to the damper 50 of the first embodiment. On the other hand, the outer periphery of the damper 50A is joined to the stepped portion FF with an adhesive or the like.

[0059] The elastic membrane 80A is a waterproof, membrane-like elastic member and is provided to seal each of the holes 45 in the frame 40. As a result, the elastic membrane 80A seals the space S2 between the damper 50A and the bottom surface FB1 together with the damper 50A. The elastic membrane 80A deforms in accordance with the displacement of the damper 50A due to the vibration of the diaphragm 10 in order to reduce the pressure change in the space S2.

[0060] Here, the elastic membrane 80A constitutes the wall surface of the recess 43. In this embodiment, the elastic membrane 80A functions as part of the bottom surface FB1 of the recess 43. This simplifies the structure of the frame 40A and the arrangement of the elastic membrane 80A, while allowing the elastic membrane 80A to be positioned away from the damper 50A.

[0061] The elastic membrane 80A is composed of a rubber material such as butyl rubber (IIR), ethylene propylene diene rubber (EPDM), silicone rubber, elastomer, urethane rubber, or nylon-rubber copolymer, similar to the elastic membrane 80 of the first embodiment.

[0062] In the example shown in Figure 4, the elastic membrane 80A is curved in its natural state, which is the non-operational state of the waterproof speaker 1A. The elastic membrane 80A may be composed of multiple members divided for each hole 45, or it may be composed of an annular member that seals multiple holes 45 together. The shape of the elastic membrane 80A in its natural state is not limited to the illustrated example and is arbitrary.

[0063] As described above, the elastic membrane 80A is positioned closer to the bottom surface FB1 than the damper 50A. That is, the damper 50A is positioned between the diaphragm 10 and the elastic membrane 80A. In this way, by positioning the elastic membrane 80A offset from the diaphragm 10 and the damper 50A in a direction along the axis AX, it is easier to make the damper 50A larger. There is also the advantage of being able to increase the degree of freedom in the shape and position of the elastic membrane 80A.

[0064] Figure 5 is an explanatory diagram of the operation of the waterproof speaker 1A shown in Figure 4. In Figure 5, a part of the waterproof speaker 1A is shown with the voice coil 20 displaced in the X2 direction.

[0065] As shown in Figure 5, when the voice coil 20 is displaced in the X2 direction, the damper 50A deforms in the direction indicated by arrow A in the figure to reduce the volume of the space S2.

[0066] At this time, the pressure in space S2 tends to rise, but the elastic membrane 80A deforms in the direction indicated by arrow B in the figure to suppress this rise. In other words, the elastic membrane 80A deforms in a way that reduces the volume change in space S2. Therefore, the pressure change in space S2 due to the displacement of the damper 50A can be reduced. This reduces the effect of the air spring caused by space S2. As a result, the decrease in efficiency of the waterproof speaker 1A in the low-frequency range can be suppressed. Although not shown in the figure, if the damper 50A deforms so that it moves away from the bottom surface FB1, the elastic membrane 80A deforms so that it enters space S2, and similarly, the pressure change in space S2 due to the deformation of the damper 50A is reduced.

[0067] The second embodiment described above also makes it possible to miniaturize and simplify the waterproof speaker 1A while increasing its efficiency in the low-frequency range.

[0068] 3. Third Embodiments The third embodiments of this disclosure will be described below. For elements whose operation and function are the same as in the first embodiment in the embodiments described below, the reference numerals used in the description of the first embodiment will be reused, and detailed descriptions of each will be omitted as appropriate.

[0069] Figure 6 is a cross-sectional view of the waterproof speaker 1B according to the third embodiment. The waterproof speaker 1B is configured by combining the configuration of the first embodiment and the configuration of the second embodiment described above. The waterproof speaker 1B is configured similarly to the waterproof speaker 1 of the first embodiment, except that it includes a frame 40A in place of the frame 40 of the first embodiment and an elastic membrane 80A is added. In other words, the waterproof speaker 1B is configured similarly to the waterproof speaker 1A of the second embodiment, except that it includes a damper 50 and an elastic membrane 80 of the first embodiment in place of the damper 50A and a fixing member 70 is added.

[0070] Here, elastic membrane 80 is an example of a "first elastic membrane" and is connected to the damper 50. Elastic membrane 80A is an example of a "second elastic membrane" and is located in a direction closer to the bottom surface FB1 than the damper 50. In this configuration in which elastic membranes 80 and 80A are combined, the range of volume change due to the deformation of elastic membranes 80 and 80A in the space S2 between the damper 50 and the bottom surface FB1 of the frame 40 can be increased. This has the advantage of making it easier to reduce the effect of the air spring in space S2.

[0071] The third embodiment described above also makes it possible to miniaturize and simplify the waterproof speaker 1B while increasing its efficiency in the low-frequency range.

[0072] 4. Modifications This disclosure is not limited to the embodiments described above, and various modifications described below are possible. Furthermore, each embodiment and each modification may be combined as appropriate.

[0073] 4-1. Modification 1 Figure 7 is a plan view of the speaker damper member 100C according to Modification 1. The speaker damper member 100C is used, for example, in place of the speaker damper member 100 of the first or third embodiment, and is arranged to close the opening OP1 of the recess 43. However, the fixing member 70 is omitted.

[0074] The speaker damper member 100C comprises an inner circumference 110, a plurality of dampers 50C, and a plurality of elastic membranes 80C. These are joined together by adhesive or other means, and are integrated into a single unit.

[0075] The inner circumference portion 110 is a part of the speaker damper member 100C and is a disc-shaped portion that is joined to the voice coil 20 with an adhesive or the like. The inner circumference portion 110 may also be provided with an inner circumference portion 51, similar to the damper 50 in the previously described embodiment.

[0076] Each of the multiple dampers 50C is a part of the speaker damper member 100C, and is a deformable portion that allows movement of the inner circumference 110 relative to the outer edge of the speaker damper member 100C in the X1 or X2 direction, and is shaped into a corrugated form. Each of the multiple dampers 50C is made of the same material as the damper 50 of the above-described embodiment and is waterproof. The multiple dampers 50C extend radially outward from the inner circumference 51 and are spaced apart from each other in the circumferential direction.

[0077] In the example shown in Figure 7, each of the multiple dampers 50C forms a strip shape in plan view. Note that the plan view shape of C of each damper 50 is not limited to the illustrated example and is arbitrary. Also, the plan view shapes of the multiple dampers 50C may be different from each other. Furthermore, a damper 50C may include a part of the inner circumference 110. In this case, the number of dampers 50C in the speaker damper member 100C can be considered as one.

[0078] Each of the multiple elastic membranes 80C is a part of the speaker damper member 100C and is a membrane-like portion that deforms to reduce pressure changes in the space S2. Each of the multiple elastic membranes 80C is made of the same material as the elastic membrane 80 of the above-described embodiment and is waterproof. The multiple elastic membranes 80C extend radially outward from the inner circumference 51 so as to fill the spaces between the multiple dampers 50C, and are arranged with spacing between them in the circumferential direction.

[0079] In the example shown in Figure 7, each of the multiple elastic membranes 80C forms a fan shape in plan view. Note that the plan view shape of C of each elastic membrane 80 is not limited to the illustrated example and is arbitrary. Also, the plan view shapes of the multiple elastic membranes 80C may be different from each other. Furthermore, the elastic membrane 80C may include a part of the inner circumference 110. In this case, the number of elastic membranes 80C in the speaker damper member 100C can be considered as one.

[0080] Even when using the speaker damper member 100C of the above modified example 1, it is possible to provide a waterproof speaker that can be miniaturized and simplified while improving efficiency in the low-frequency range.

[0081] 3-2. Modification 2 In the above-described embodiment, an example is given in which one or both of the elastic membrane 80 provided to cover the opening OP1 and the elastic membrane 80A that constitutes a part of the bottom surface FB1 are used. However, the embodiment is not limited to this, and for example, the elastic membrane may constitute a part of the side surface FS1. The elastic membrane that constitutes a part of the side surface FS1 may be used in combination of one or both of the above-described elastic membrane 80 and elastic membrane 80A.

[0082] 5. From the forms or modifications exemplified above, the following embodiments can be understood, for example:

[0083] (Note 1) A first embodiment of a preferred example of the waterproof speaker of the present disclosure comprises: a sound-emitting diaphragm; a magnetic circuit for vibrating the diaphragm; a frame having a bottom surface disposed around the magnetic circuit and supporting the diaphragm and the magnetic circuit; at least one waterproof damper supported by the frame and displaced in conjunction with the vibration of the diaphragm; and at least one waterproof elastic membrane that seals the space between the damper and the bottom surface together with the damper, wherein the at least one elastic membrane deforms in accordance with the displacement of the at least one damper due to the vibration of the diaphragm to reduce the pressure change in the space.

[0084] According to the above embodiment, the waterproof damper and elastic membrane seal the space between the damper and the bottom surface of the frame, thereby achieving waterproofing for the magnetic circuit. Furthermore, the elastic membrane deforms in accordance with the displacement of the damper due to the vibration of the diaphragm, thereby reducing the pressure change in the space, and thus reducing the effect of the air spring in that space. As a result, the decrease in efficiency of the speaker in the low-frequency range can be suppressed. In addition, since there is no need to provide an acoustic space such as a chamber in that space, the speaker can be made smaller and simpler.

[0085] (Note 2) In the second embodiment, which is a preferred example of the first embodiment, at least one of the elastic membranes is connected to at least one of the dampers. The above embodiments have the advantage of making it easier to simplify the structure of the frame and the arrangement of the elastic membranes.

[0086] (Note 3) In a third embodiment, which is a preferred example of the second embodiment, a fixing member is further provided that is fixed to the frame, and at least one damper is supported by the frame via the fixing member. In the above embodiments, the damper and elastic membrane can be suitably installed even if an existing frame is used.

[0087] (Note 4) In a fourth embodiment which is a preferred example of the second or third embodiment, the frame is provided with a recess having the bottom surface, and the at least one damper and the at least one elastic membrane are arranged to close the opening of the recess. According to the above embodiment, there is an advantage in that the structure of the frame and the arrangement of the elastic membrane can be easily simplified.

[0088] (Note 5) In the fifth embodiment, which is a preferred example of the first embodiment, the at least one damper is located between the diaphragm and the at least one elastic membrane. According to the above embodiment, it is easy to make the damper larger. Also, it is easy to increase the degree of freedom in the shape and arrangement of the elastic membrane.

[0089] (Note 6) In the sixth embodiment, which is a preferred example of the fifth embodiment, the frame is provided with a recess having the bottom surface, and the at least one elastic membrane constitutes the wall surface of the recess. According to the above embodiment, the elastic membrane can be positioned away from the damper while simplifying the structure of the frame and the arrangement of the elastic membrane.

[0090] (Note 7) In the seventh embodiment, which is a preferred example of any of the first to sixth embodiments, the elastic modulus of the at least one elastic membrane is lower than the elastic modulus of the at least one damper. In this embodiment, the elastic membrane can be easily deformed. As a result, the influence of the air spring due to the sealed space provided on the back side of the damper can be suitably reduced.

[0091] (Note 8) In the eighth embodiment, which is a preferred example of the first embodiment, the at least one elastic membrane includes at least one first elastic membrane connected to any of the at least one damper, and at least one second elastic membrane located in a direction closer to the bottom surface than the at least one damper. In the above embodiments, the range of volume change due to the deformation of the elastic membrane in the space between the damper and the bottom surface of the frame can be increased. This has the advantage of making it easier to enhance the effect of reducing the influence of the air spring in the space.

[0092] (Note 9) A ninth embodiment, which is a preferred example of a speaker damper member of the present disclosure, comprises at least one waterproof damper and at least one waterproof elastic membrane connected to the at least one damper, wherein the elastic modulus of the at least one elastic membrane is lower than the elastic modulus of the at least one damper.

[0093] According to the above embodiment, the space between the damper and the bottom surface of the frame can be sealed by a waterproof damper and an elastic membrane. This makes it possible to achieve waterproofing for the magnetic circuit. Furthermore, the elastic membrane can be deformed to reduce the pressure change in the space in accordance with the displacement of the damper due to the vibration of the diaphragm. This makes it possible to reduce the effect of the air spring in the space. As a result, the decrease in efficiency of the speaker in the low frequency range can be suppressed. In addition, since there is no need to provide an acoustic space such as a chamber in the space, the speaker can be made smaller and simpler.

[0094] 1...Waterproof speaker, 1A...Waterproof speaker, 1B...Waterproof speaker, 10...Diaphragm, 20...Voice coil, 21...Bobbin, 22...Coil, 30...Magnetic circuit, 31...Permanent magnet, 32...Yoke, 40...Frame, 40A...Frame, 41...Flange, 42...Hole, 43...Recess, 44...Recess, 45...Hole, 50...Damper, 50A...Damper, 50C...Damper, 51...Inner circumference, 52...Outer circumference, 53...Elastic part, 60...Edge, 70...Fixing member, 71...Fixing part, 72 ...legs, 80...elastic membrane, 80A...elastic membrane, 80C...elastic membrane, 81...inner circumference, 82...outer circumference, 83...elastic part, 100...speaker damper member, 100C...speaker damper member, 110...inner circumference, A...arrow, AX...axis, B...arrow, FB1...bottom surface, FB2...bottom surface, FF...stepped part, FS1...side surface, FS2...side surface, OP1...opening, OP2...opening, P1...first part, P2...second part, P3...third part, S0...space, S1...space, S2...space, SC...screw.

Claims

1. A waterproof speaker comprising: a sound-emitting diaphragm; a magnetic circuit for vibrating the diaphragm; a frame having a bottom surface disposed around the magnetic circuit and supporting the diaphragm and the magnetic circuit; at least one waterproof damper supported by the frame and displaced in conjunction with the vibration of the diaphragm; and at least one waterproof elastic membrane sealing the space between the damper and the bottom surface together with the damper, wherein the at least one elastic membrane deforms to reduce pressure changes in the space in accordance with the displacement of the at least one damper due to the vibration of the diaphragm.

2. The waterproof speaker according to claim 1, wherein any of the at least one elastic membrane is connected to any of the at least one damper.

3. The waterproof speaker according to claim 2, further comprising a fixing member fixed to the frame, wherein the at least one damper is supported by the frame via the fixing member.

4. The frame is provided with a recess having the bottom surface, and the at least one damper and the at least one elastic membrane are arranged to close the opening of the recess, as described in claim 2.

5. The waterproof speaker according to claim 1, wherein the at least one damper is located between the diaphragm and the at least one elastic membrane.

6. The frame is provided with a recess having the bottom surface, and the at least one elastic membrane constitutes the wall surface of the recess, the waterproof speaker according to claim 5.

7. The waterproof speaker according to claim 1, wherein the modulus of elasticity of the at least one elastic membrane is lower than the modulus of elasticity of the at least one damper.

8. The waterproof speaker according to claim 1, wherein the at least one elastic membrane includes at least one first elastic membrane connected to any of the at least one dampers, and at least one second elastic membrane located in a direction closer to the bottom surface than the at least one damper.

9. A speaker damper member comprising at least one waterproof damper and at least one waterproof elastic membrane connected to the at least one damper, wherein the elastic modulus of the at least one elastic membrane is lower than the elastic modulus of the at least one damper.

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