WO2021261164A1

WO2021261164A1 - Acoustic device

Info

Publication number: WO2021261164A1
Application number: PCT/JP2021/020222
Authority: WO
Inventors: 篤史山本; 大善小林; 弘之白川; 芳雄大橋; 一泰本郷; 祐輔馬田
Original assignee: ソニーグループ株式会社
Priority date: 2020-06-23
Filing date: 2021-05-27
Publication date: 2021-12-30

Abstract

Provided is an acoustic device having a diaphragm to which the displacement part of a voice coil unit is connected, a housing having a flat part facing the diaphragm across a prescribed space, and a vibration unit arranged between the diaphragm and the flat part. The vibration unit has a stationary part connected to the flat part, a voice coil unit support part for supporting the voice coil unit, and a connection part for connecting the stationary part and the voice coil unit support part. The connection part extends in the prescribed space so as to be oriented toward the diaphragm from the flat part and is displaced in the same direction as the vibration direction of the diaphragm.　FIG. 5

Description

Audio equipment

This disclosure relates to audio equipment.

A technique relating to a speaker device having a structure for ensuring sound pressure has been proposed (see, for example, Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2005-354297

Japanese Unexamined Patent Publication No. 2003-324795

In such a field, a structure of an acoustic device capable of lowering the resonance frequency and increasing the sound pressure in the bass region is desired.

One of the purposes of the present disclosure is to provide an acoustic device having a structure that realizes a decrease in resonance frequency and an increase in sound pressure in the bass region.

The present disclosure is, for example,
The diaphragm to which the displacement part of the voice coil unit is connected and
A housing having a flat portion facing the diaphragm across a predetermined space,
It has a vibration unit placed between the diaphragm and the flat part,
The vibration unit is
The fixed part connected to the flat part and
The voice coil unit support part that supports the voice coil unit and
It has a connecting part that connects the fixed part and the voice coil unit support part, and has a connecting part.
The connecting portion is an acoustic device that extends from the flat portion toward the diaphragm in a predetermined space and is displaced in the same direction as the vibration direction of the diaphragm.

1A and 1B are diagrams referenced in explaining the issues to be considered in the present disclosure. FIG. 2 is a diagram referenced in explaining the issues to be considered in the present disclosure. FIG. 3 is a perspective view of the sound bar according to the embodiment. FIG. 4 is an exploded perspective view of the sound bar according to the embodiment. FIG. 5 is a partially enlarged view of the sound bar according to the embodiment. 6A to 6C are diagrams showing a shape example of the vibration unit according to the embodiment. 7A to 7C are views showing a shape example of the vibration unit according to the embodiment. 8A and 8B are diagrams for explaining a state in which the voice coil unit is supported by the vibration unit. 9A and 9B are diagrams showing the sound bar according to the embodiment as a vibration model. FIG. 10 is a diagram showing a sound bar according to an embodiment as a vibration model. FIG. 11 is a diagram for explaining an example of the effect obtained in one embodiment. FIG. 12 is a diagram for explaining an example of the effect obtained in one embodiment. FIG. 13 is a diagram for explaining a modified example. FIG. 14 is a diagram for explaining a modified example. FIG. 15 is a diagram for explaining a modified example. FIG. 16 is a diagram for explaining a modification. FIG. 17 is a diagram for explaining a modified example. FIG. 18 is a diagram for explaining a modification.

Hereinafter, embodiments and the like of the present disclosure will be described with reference to the drawings. The explanation will be given in the following order.
<Background of this disclosure and issues to be considered>
<One Embodiment>
<Modification example>
The embodiments and the like described below are suitable specific examples of the present disclosure, and the contents of the present disclosure are not limited to these embodiments and the like.

<Background of this disclosure and issues to be considered>
First, the background of this disclosure and the issues to be considered will be described in order to facilitate the understanding of this disclosure. As a function of audio products, bass reduction is evaluated as one performance index. Therefore, in order to reproduce the bass, a large speaker or additional equipment such as a subwoofer is generally used.

On the other hand, there is a need for a sense of unity that integrates with a thin TV as an audio need for home entertainment, and there is a need for a thinner speaker itself. In addition, it is possible to increase versatility by applying the technology for configuring a thin speaker to other speakers. Furthermore, by applying it to an in-vehicle speaker with a limited design space, it is expected that a lower frequency band can be reproduced than the conventional range and a new experience can be brought to the user.

In a general configuration, it is necessary to increase the size of the speaker itself in order to reduce the resonance frequency, so the speaker itself becomes a thick configuration. Therefore, the bass is supplemented by using the speaker of the subwoofer.

The configuration that divides the above functions requires a space for arranging the subwoofer when reproducing the sound field. Therefore, it is necessary to configure a space-saving speaker in addition to the decrease in resonance frequency and the increase in sound pressure in the low frequency range. Generally, the performance and size of the bass region of a speaker are in conflict with each other, but it is required to achieve both of them, which is an important performance required for audio equipment such as a next-generation sound bar.

In view of this aspect, in the embodiment of the present disclosure, the resonance frequency is lowered and the sound pressure in the low frequency range is increased, and the audio equipment in which the size of the device is not increased as much as possible is realized.

Next, as is known, a general dynamic speaker, which describes the problems to be considered in the embodiment of the present disclosure, has a configuration in which a voice coil is wound around a magnet supported by a yoke. The magnetic circuit including the yoke, magnet and voice coil is connected to the speaker housing via a damper. Further, the peripheral edge of the diaphragm is connected to the housing via an edge.

FIG. 1A is a diagram showing a general dynamic speaker as a simplified model. The magnetic circuit 2 is connected to the housing 1. The magnetic circuit 2 and the diaphragm 3 are connected to each other via a damper 4, and the diaphragm 3 is connected to the housing 1 via an edge 5. Let the spring component of the damper 4 be k ₀ and the spring component of the edge 5 be k ₁ . In fact, k ₀ is because it is very small with respect to k _1, as shown in FIG. 1B, to understand the spring component of the damper 4 the spring component of k ₀ and the edge 5 as one spring component with k ₁ be able to.

The model shown in FIG. 1B can be considered as a vibration model of a one-degree-of-freedom system as shown in FIG. The resonance frequency in the vibration model of the one-degree-of-freedom system shown in FIG. 2 can be expressed by the following mathematical formula (1). However, in the formula (1), k represents the spring constant and m represents the mass of the diaphragm.

In order to reduce the resonance frequency f shown by the mathematical formula (1), it is necessary to increase the spring constant k or increase the weight of the diaphragm. However, due to the increase in the weight of the diaphragm, the center of gravity of the voice coil motor deviates from the drive shaft, which causes distortion of sound. Therefore, in order to increase the sound pressure, it is necessary to increase the thrust. Based on the above points, one embodiment of the present disclosure will be described in detail.

<One Embodiment>
[Configuration example of audio equipment]
(Overall configuration example)
In this embodiment, a sound bar will be described as an example of an audio device. FIG. 3 is a perspective view of the sound bar (sound bar 100) according to the present embodiment, FIG. 4 is an exploded perspective view of the sound bar 100, and FIG. 5 is a partially enlarged view of the sound bar 100.

The sound bar 100 has, for example, a housing 10, an edge 11, and a diaphragm 12. As shown in FIG. 4, the housing 10 has a flat portion 10A having a rectangular shape (rectangular shape).

Flat portions

10B, 10C, 10D, and 10E are planted from the peripheral edges (4 sides) of the flat portion 10A in substantially orthogonal directions. Each of the flat portion 10A to the flat portion 10E is a plate-shaped member, and is integrally configured. The tips of the

flat portions

10B, 10C, 10D, and 10E are connected to the diaphragm 12 via the edge 11, whereby the entire housing 10 and the diaphragm 12 are connected.

The diaphragm 12 is a plate-shaped member like the flat portion 10A, and has a rectangular shape (rectangular shape). As shown in FIG. 5, a voice coil 31A (an example of a displacement portion) including a voice coil bobbin is connected to one main surface of the diaphragm 12.

The sound bar 100 has four vibration units 21A to 21D. When it is not necessary to distinguish between individual vibration units, it is appropriately referred to as a vibration unit 21. The vibration unit 21 is arranged in a predetermined space (opposing gap) SP (see FIG. 5) formed between the flat portion 10A of the housing 10 and the diaphragm 12. The vibration unit 21 is generally connected to the flat portion 10A by an appropriate method such as adhesion or welding, and supports the voice coil unit 31 including the voice coil 31A. Although the details will be described later, the vibration unit 21 functions as a resonance damper. That is, the vibration unit 21 has a spring component and applies a reaction force to the voice coil 31A to increase the amplitude of the diaphragm 12.

The voice coil unit 31 has a voice coil 31A and a magnet yoke portion 31B. Further, a damper (damper 31C, see FIG. 8) is connected to the voice coil bobbin of the voice coil 31A.

(Example of vibration unit shape)
Next, a shape example of the vibration unit 21 will be described with reference to FIGS. 6 and 7.
The vibration unit 21 has a frame-shaped base 201. The base 201 corresponds to an example of a fixed portion fixed to the flat portion 10A. From the longitudinal direction of the base 201, plate-shaped

side surface portions

202 and 203 to be planted upward are planted. Further, from the lateral direction of the base 201, plate-shaped

inclined portions

204 and 205 extending in a direction toward the vicinity of the center of the base 201 extend. The arm portion 210 extends from the tip of the inclined portion 204. Further, the arm portion 211 extends from the tip of the inclined portion 205. A ring-shaped voice coil unit support portion 215 is formed at the tips of the

arm portions

210 and 211. The voice coil unit support portion 215 accommodates and supports the voice coil unit 31 inside.

The

side surface portions

202 and 203, the

inclined portions

204 and 205, and the

arm portions

210 and 211 correspond to the connecting portion 220 that connects the base 201 and the voice coil unit support portion 215. The connecting portion 220 is arranged in the facing gap SP, and as a whole, extends from the flat portion 10A toward the diaphragm 12 in the facing gap SP. The connecting portion 220 is a leaf spring having a spring component as a whole, and is displaced in the same direction as the vibration direction of the diaphragm 12 due to the displacement of the voice coil 31A. In the present embodiment, the hole portion 202A is formed in the side surface portion 202 in order to facilitate the displacement. Similarly, the hole 203A is formed in the side surface 203, the hole 204A is formed in the inclined portion 204, and the hole 205A is formed in the inclined portion 205.

Since the base 201 needs to be fixed to the flat portion 10A, it is formed of, for example, resin. On the other hand, the connecting portion 220 and the voice coil unit supporting portion 215 are formed of a flexible material, for example, a metal material such as aluminum or titanium. The base 201, the voice coil unit support portion 215, and the connecting portion 220 may all be made of different materials.

8A and 8B are diagrams showing a state in which the voice coil unit 31 is supported by the vibration unit 21. FIG. 8A is a diagram showing a cross section cut along the cutting line AA in FIG. 3, and FIG. 8B is a diagram showing an end face cut along the cutting line AA in FIG.

As shown in FIGS. 8A and 8B, the voice coil 31A of the voice coil unit 31 is connected to the diaphragm 12. Further, the voice coil unit 31 is supported by the voice coil unit support portion 215. The voice coil unit 31 may be simply housed in the circular frame of the voice coil unit support portion 215, or may be attached by an appropriate component such as a screw.

[Vibration model]
9A and 9B are diagrams showing the configuration of the sound bar by a vibration model. As shown in the figure, in the present embodiment, by adding the vibration unit 21, the housing 10 and the voice coil unit 31 are separated, and the spring component (spring constant k ₂ ) of the vibration unit 21 is added between them. To. Note that k ₀ is the spring constant of the edge 11, and k ₁ is the spring constant of the damper 31C of the voice coil unit 31.

In the sound bar 100 according to the present embodiment, four vibration units 21 are used, and the same diaphragm 12 is driven by the voice coil 31A supported by each vibration unit 21. Therefore, the configuration of the sound bar 100 is more accurately represented by a vibration model as shown in FIG.

[Soundbar operation example]
The sound bar 100 operates as follows, for example. An audio signal is supplied to the voice coil 31A supported by each vibration unit 21, and the voice coil 31A vibrates. Along with the vibration of the voice coil 31A, the diaphragm 12 to which the voice coil 31A is connected vibrates and the sound corresponding to the audio signal is reproduced. The force (reaction force) due to the spring component mainly possessed by the connecting portion 220 of the vibration unit 21 is applied to the vibration of the voice coil 31A, and the force (thrust) in the direction toward the diaphragm 12 increases.

[Effects obtained by this embodiment]
As described above, the resonance frequency can be lowered by adding the spring component of the vibration unit 21. FIG. 11 is a diagram showing that the resonance frequency can be lowered by the configuration according to the present embodiment. In the graph of FIG. 11, the horizontal axis represents frequency and the vertical axis represents amplitude. In FIG. 11, the line L1 shows the resonance frequency of a general configuration (for example, the configuration shown in FIG. 1), and the line L2 shows the resonance frequency of the configuration according to the present embodiment. As shown in FIG. 11, according to the configuration according to the present embodiment, a two-degree-of-freedom vibration system can be realized, whereby the resonance frequency (peak) can be lowered.
Further, the thrust of the voice coil 31A (the force in the direction of pushing the diaphragm 12) can be increased by the spring component of the vibration unit 21. This makes it possible to increase the sound pressure. FIG. 12 shows the simulation results regarding the sound pressure level. In FIG. 12, the horizontal axis shows the frequency and the vertical axis shows the sound pressure level. The solid line L3 in FIG. 12 shows the sound pressure level with respect to the frequency in the case of the configuration (with the vibration unit 21) according to the present embodiment, and the dotted line line L4 shows the sound pressure level with respect to the frequency without the vibration unit 21. show. As shown in FIG. 12, the result that the maximum sound pressure can be increased by about 8 dB was obtained.
According to this embodiment, the above effect can be obtained without using a component such as a bearing that receives a coil spring.

<Modification example>
Although one embodiment of the present disclosure has been specifically described above, the content of the present disclosure is not limited to the above-described embodiment, and various modifications based on the technical idea of the present disclosure are possible.

[First modification]
As described above, the connecting portion 220 may be configured by combining different materials, more specifically members having different spring constants. In this case, as shown in FIG. 13, the spring constant k ₂ of the vibration unit 21 can be represented by the sum of the spring constants of the different members _{^{(k '2 + ··· k n}} 2).

By applying a plurality of different materials, the degree of freedom regarding the shape of the vibration unit 21 such as the connecting portion 220 can be increased, and the entire vibration unit 21 can be made into a compact shape that easily fits in the facing gap SP.

[Second modification]
As shown in FIG. 14, the flat portion 10A may be displaced in the same direction as the vibration direction (direction indicated by the arrow) of the diaphragm 12. With this configuration, the entire voice coil unit 31 that receives the reaction force can be moved. However, in this case, a certain rigidity is required in order to transmit the force of the vibration unit 21 to the voice coil unit 31 as a thrust. Therefore, as shown in FIG. 14, for example, the vibration unit 21 is fixed to each of the

flat portions

10B and 10C extending in a direction substantially orthogonal to the vibration direction of the diaphragm 12 with respect to the flat portion 10A. Is preferable.

[Third variant]
In the above-described embodiment, the plane to which the base 201, which is the fixed portion of the vibration unit 21, is connected is one flat portion 10A, but even if the base 201 is connected to a plurality of different members (flat portions). good. For example, the base 201 may be fixed to each of the plurality of members, such as a door of an automobile, for a member composed of the plurality of members. The shape of the base 201 may be a shape other than the frame shape so that it can be fixed to each of the plurality of members.

FIG. 15 shows a vibration model according to this modification. As shown in FIG. 15, the base 201 of the vibration unit 21 may be fixed to each of _{different members (members 10A 1} to 10A _3).

[Fourth variant]
In the above-described embodiment, the same diaphragm 12 is driven by the four voice coils 31A, but the present invention is not limited to this. FIG. 16 shows a configuration example of a sound bar (sound bar 100A) according to this modification. The sound bar 100A has, for example, four diaphragms 12A to 12D, as shown in FIG. The voice coil 31A supported by the vibration unit 21A is connected to the diaphragm 12A and vibrates the diaphragm 12A. The voice coil 31A supported by the vibration unit 21B is connected to the diaphragm 12B and vibrates the diaphragm 12B. The voice coil 31A supported by the vibration unit 21C is connected to the diaphragm 12C and vibrates the diaphragm 12C. The voice coil 31A supported by the vibration unit 21D is connected to the diaphragm 12D and vibrates the diaphragm 12D. Each vibration unit 21 is fixed to the same flat portion 10A.

FIG. 17 is a diagram showing the sound bar 100A as a vibration model. The voice coil 31A supported by each vibration unit 21 is connected to a different diaphragm.

[Fifth variant]
The vibration unit may have a configuration having an electromagnet or a permanent magnet, or may have a configuration having a spring component similar to that of the vibration unit in a non-contact state. For example, as shown in FIG. 18, the vibration unit may be an electromagnet 51 connected to the flat portion 10A and an electromagnet 52 attached to the voice coil unit support portion. In such a configuration, control is performed to alternately switch the polarities of the

electromagnets

51 and 52. According to this modification, it is possible to realize a spring constant that is difficult to realize with an elastic body and increase the bass region. Further, since the inelastic effect of the elastic body can be removed, it is possible to reproduce a sound with less distortion.

[Other variants]
Other modifications will be described. In the above-described embodiment, the drive system in which the voice coil is displaced (moving coil system) has been described as an example, but the present disclosure can also be applied to a drive system in which a magnet is driven (moving magnet system). That is, the displacement portion in the voice coil unit may be a magnet instead of the voice coil.

In one embodiment described above, the voice coil unit may have a damperless structure without a mechanical damper. For example, the present disclosure can be applied to a voice coil unit using a magnetic fluid instead of a mechanical damper.

From the viewpoint of lowering the resonance frequency and increasing the sound pressure, it is preferable to use a plurality of vibration units as described in one embodiment, but one vibration unit may be used.

The present disclosure is not limited to the sound bar, and can be applied to a speaker device or the like provided in a television device.

The configurations, methods, processes, shapes, materials, numerical values, etc. given in the above-described embodiments and modifications are merely examples, and different configurations, methods, processes, shapes, materials, numerical values, etc. may be used as necessary. It may be replaced with a known one. In addition, the configurations, methods, processes, shapes, materials, numerical values, and the like in the embodiments and modifications can be combined with each other as long as there is no technical contradiction.

It should be noted that the contents of the present disclosure are not limitedly interpreted due to the effects exemplified in the present specification.

The present disclosure may also adopt the following configuration.
(1)
The diaphragm to which the displacement part of the voice coil unit is connected and
A housing having a flat portion facing the diaphragm with a predetermined space,
It has a vibration unit arranged between the diaphragm and the flat portion, and has a vibration unit.
The vibration unit is
A fixed portion connected to the flat portion and
A voice coil unit support portion that supports the voice coil unit,
It has a connecting portion that connects the fixing portion and the voice coil unit support portion, and has a connecting portion.
The connecting portion is an acoustic device that extends from the flat portion toward the diaphragm in the predetermined space and is displaced in the same direction as the vibration direction of the diaphragm.
(2)
The acoustic device according to (1), wherein at least the fixing portion and the connecting portion are made of different materials.
(3)
The acoustic device according to (2), wherein the fixing portion, the voice coil unit support portion, and the connecting portion are all made of different materials.
(4)
The acoustic device according to any one of (1) to (3), wherein the flat portion is displaced in the same direction as the vibration direction of the diaphragm.
(5)
The acoustic device according to (4), wherein the fixed portion is fixed to another flat portion extending in a direction substantially orthogonal to the vibration direction of the diaphragm with respect to the flat portion.
(6)
The acoustic device according to (5), wherein the fixed portion is connected to each of a plurality of different flat portions.
(7)
The acoustic device according to (1), which has a plurality of the vibration units, the fixed portion of the vibration unit is connected to a common flat portion, and the displacement portion of the vibration unit is connected to different diaphragms.
(8)
The acoustic device according to (1), which has a plurality of the vibration units, the fixed portion of the vibration unit is connected to a common flat portion, and the displacement portion of the vibration unit is connected to a common diaphragm. ..
(9)
The acoustic device according to any one of (1) to (8), wherein the displacement portion of the voice coil unit is a voice coil or a magnet of the voice coil unit.
(10)
The acoustic device according to any one of (1) to (8), wherein the voice coil unit has a damperless structure.

10 ... Housing 11 ... Edge 12 ... Diaphragm 10A ... Flat part 21 ...

Vibration unit

100, 100A ... Sound bar 201 ... Base 215 ... Voice coil unit support Part 220 ・・・ Connecting part

Claims

The diaphragm to which the displacement part of the voice coil unit is connected and
A housing having a flat portion facing the diaphragm with a predetermined space,
It has a vibration unit arranged between the diaphragm and the flat portion, and has a vibration unit.
The vibration unit is
A fixed portion connected to the flat portion and
A voice coil unit support portion that supports the voice coil unit,
It has a connecting portion that connects the fixing portion and the voice coil unit support portion, and has a connecting portion.
The connecting portion is an acoustic device that extends from the flat portion toward the diaphragm in the predetermined space and is displaced in the same direction as the vibration direction of the diaphragm.
The acoustic device according to claim 1, wherein at least the fixing portion and the connecting portion are made of different materials.
The acoustic device according to claim 2, wherein the fixing portion, the voice coil unit support portion, and the connecting portion are all made of different materials.
The acoustic device according to claim 1, wherein the flat portion is displaced in the same direction as the vibration direction of the diaphragm.
The acoustic device according to claim 4, wherein the fixed portion is fixed to another flat portion extending in a direction substantially orthogonal to the vibration direction of the diaphragm with respect to the flat portion.
The acoustic device according to claim 5, wherein the fixed portion is connected to each of a plurality of different flat portions.
The acoustic device according to claim 1, wherein the acoustic device has a plurality of the vibration units, the fixed portion of the vibration unit is connected to a common flat portion, and the displacement portion of the vibration unit is connected to a different diaphragm.
The acoustic device according to claim 1, which has a plurality of the vibration units, the fixed portion of the vibration unit is connected to a common flat portion, and the displacement portion of the vibration unit is connected to a common diaphragm. ..
The acoustic device according to claim 1, wherein the displacement portion of the voice coil unit is a voice coil or a magnet included in the voice coil unit.
The acoustic device according to claim 1, wherein the voice coil unit has a damperless structure.