JP4075683B2 - Speaker device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a speaker device.
[0002]
[Prior art]
A technology is disclosed in which voices of attendees in a conference are received by a microphone and the voice is diffused over a wide range using a single speaker and a reflector (see Patent Document 1).
In the above technique, a microphone is disposed on a speaker. The speaker is sealed on the back side by a speaker box. A microphone is disposed on the speaker box.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2003-87887
[Problems to be solved by the invention]
By the way, in said technique, since a microphone is arrange | positioned on the speaker (speaker box) which is a vibration source, it is necessary to suppress the propagation of the vibration to a microphone. For this reason, in Patent Document 1, measures against vibration such as providing a shielding plate or a cushioning material between the speaker and the microphone are taken.
However, since there is vibration called so-called box sound of the speaker box due to the back pressure of the speaker, it is difficult to sufficiently suppress the propagation of vibration to the microphone even if the above-described vibration countermeasures are taken. It was.
Moreover, even if a countermeasure against vibration such as providing a cushioning material is taken, it is effective to attenuate vibration in a specific frequency band, but it is difficult to attenuate vibration over a wide band.
[0005]
The present invention has been made in view of the above-described problems, and an object of the present invention is to suppress the propagation of vibration from a speaker as a vibration source to a microphone in a wide frequency band in a speaker device including a microphone on a speaker. An object of the present invention is to provide a speaker device that can be used.
[0006]
[Means for Solving the Problems]
According to the first aspect of the present invention, a single speaker, a speaker box that seals the back of the speaker, a directional microphone disposed in front of an audio output direction of the speaker , the speaker, and the directivity A printed wiring board having a circuit for driving the directional microphone, a holding member provided on the speaker box and holding the printed wiring board, and a path for transmitting vibration from the speaker to the directional microphone , A plurality of different filter members for damping the vibration ,
The plurality of different filter members support a pair of first filter members that support the printed wiring board with respect to the holding member, and support both ends of the directional microphone on the printed wiring board. A speaker device is provided that includes a second filter member that attenuates vibration propagating from the wiring board side.
Preferably, the natural frequency of the pair of first filter members is lower than the natural frequency of the second filter member.
Preferably, the directional microphone has a cylindrical shape.
[0007]
According to the second aspect of the present invention, a single speaker, a speaker box for sealing the back of the speaker, and a directivity provided on the speaker box in front of the sound output direction of the speaker. a microphone, a printed wiring board having a circuit for driving the speaker and the directional microphone, is provided on the speaker box, a speaker apparatus having a holding member for holding the printed circuit board, the speaker The box includes a first wall plate that forms a bottom surface, and a second wall plate that covers the first wall plate so that a space is formed between the first wall plate and the first wall plate. There is provided a speaker device including a restraining means for restraining a predetermined location on the first wall plate and a predetermined location on the second wall plate .
Preferably, the retaining member is connected by a connecting member and the restraining position or the position near by said restraining means.
Preferably, the restraining means includes a female screw portion formed at a predetermined location on the first wall plate and a predetermined location on the second wall plate of the speaker box, and a coupling member screwed into the female screw portion. Have
Preferably, the speaker box is made of resin, and the coupling member is made of metal.
More preferably, the holding member has a female thread portion into which the coupling member is screwed, and the coupling member is a predetermined location on the first wall plate and a predetermined location on the second wall plate of the speaker box. And the relative movement between the second wall plate and the holding member is restrained.
[0008]
In the speaker device according to the first aspect of the present invention, the vibration from the speaker is attenuated by a plurality of different filter members provided in the vibration transmission path from the speaker to the directional microphone. Since the filter members are different, vibrations in different bands are attenuated.
[0009]
In the speaker device according to the second aspect of the present invention, the first wall plate is formed so that a space is formed between the first wall plate constituting the bottom surface of the speaker box and the first wall plate. second relative movement between the wall plate is restrained by restraining means for covering. When the sound pressure fluctuates in the speaker box, the movement of the portion constrained by the constraining means is constrained, and the number of nodes increases as compared with the case where the sound pressure is not constrained. Vibration is greatly suppressed at or near the restraint position of the wall plate restrained by the restraining means. In addition, the increase in nodes increases the frequency of vibration and suppresses the amplitude.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing an appearance of a speaker device according to an embodiment of the present invention.
Note that the speaker device 1 according to the present embodiment is a device in which a microphone and a speaker used in a remote conference such as a video conference are integrated, for example, and the voices of attendees in the conference room are used as a microphone. This is a device that receives and amplifies the voice from the other party through a speaker.
As shown in FIG. 1, the speaker device 1 according to this embodiment includes a cover member 2, a holding member 3, a speaker 15, and a speaker box 20.
The holding member 3 and the speaker box 20 are made of, for example, a resin such as ABS (acrylonitrile-butadiene-styrene).
The cover member 2 is provided on the holding member 3 and covers the upper surface side of the holding member 3. The cover member 2 is made of a material that transmits sound, such as resin fibers, and protects a printed wiring board and a microphone (described later) held on the holding member 3.
The holding member 3 is supported on the speaker box 20 via a plurality of support members 10 erected on the speaker box 20.
[0011]
FIG. 2 is a plan view of the holding member 3 in a state where the cover member 2 provided on the holding member 3 is removed.
FIG. 3 is a cross-sectional view showing the internal structure of the speaker device according to this embodiment.
As shown in FIG. 2, the holding member 3 has a circular outer shape, and the printed wiring board 30 is held in the circular shape.
[0012]
The printed wiring board 30 has a disk shape, and a plurality of directional microphones 40 are provided on the printed wiring board 30.
Various electronic components (not shown) other than the directional microphone 40 are mounted on the printed wiring board 30. The electronic components mounted on the printed wiring board 30 constitute circuits necessary for the electrical operation of the speaker device 1, such as an echo canceller circuit, a directional microphone 40, and a circuit for driving a speaker described later.
[0013]
The plurality of directional microphones 40 have a cylindrical shape and are arranged radially from the center of the printed wiring board 30, that is, arranged radially from the center, and arranged at equal intervals in the circumferential direction. Has been.
The directional microphones 40 have directivity from the center of the printed wiring board 30 toward the radial direction.
Both end portions of the directional microphone 40 are supported on the printed wiring board 30 by the filter member 60. The filter member 60 is an embodiment of the second filter member of the present invention.
The filter member 60 is obtained, for example, by molding rubber or resin into a predetermined shape.
The filter member 60 attenuates the vibration propagating from the printed wiring board 30 side.
[0014]
A wiring is connected to the rear end portion of the directional microphone 40, and this wiring is connected to the printed wiring board 30 via the connector CN. As a result, the audio signal detected by the directional microphone 40 is input to the electric circuit formed on the printed wiring board 30.
[0015]
As shown in FIG. 3, the printed wiring board 30 is held on the upper surface side of the holding member 3.
Specifically, as shown in FIG. 7, a shaft portion 3t protrudes and is integrally formed on the upper surface side of the holding member 3, and a ring-shaped filter member 51 is inserted into the shaft portion 3t. A through hole 30h is formed in the printed wiring board 30, and a shaft portion 3t is inserted into the through hole 30h. The printed wiring board 30 is provided on the filter member 51. Further, the annular filter member 50 is provided on the outer periphery of the shaft portion 3 t and is disposed on the printed wiring board 30.
[0016]
A screw hole is formed at the center of the shaft portion 3t, and a bolt 56 is screwed into the screw hole via an annular presser plate 57. Thereby, the holding plate 57 presses the upper surface of the filter member 50, and the printed wiring board 30 is sandwiched between the filter member 50 and the filter member 51. That is, the printed wiring board 30 is supported by the filter member 50 and the filter member 51.
The filter members 50 and 51 are an embodiment of the first filter member of the present invention.
The filter members 50 and 51 are made of a material such as rubber or resin and have the same shape. Further, the filter members 50 and 51 have a natural frequency different from that of the filter member 60.
[0017]
The speaker box 20 includes an upper side wall plate 21 and a lower side wall plate 22.
The upper side wall plate 21 and the lower side wall plate 22 have a circular outer shape. A single speaker 15 is fixed to the central portion of the upper side wall plate 21.
For the speaker 15, for example, a cone speaker is used. The speaker 15 outputs toward the sound output direction A1 when a diaphragm (not shown) vibrates along the direction of the sound output direction A1 indicated by the arrow.
[0018]
The speaker box 20 seals the back of the speaker 15. A seal member 80 is provided between the upper wall plate 21 and the lower wall plate 22, and the speaker box 20 is a sealed space.
[0019]
On the lower surface side of the upper side wall plate 21, a support portion 21t extending toward the lower side wall plate 22 is integrally formed.
On the upper surface side of the lower wall plate 22, a protruding portion 22a protruding toward the upper wall plate 21 side is formed.
The lower end surface of the support portion 21t is in contact with the upper end surface of the protruding portion 22a.
A through hole 21p is formed at the center of the support portion 21t, and a female screw portion 21h is formed at the upper end side of the through hole 21p.
A female screw portion 22h is also formed on the protruding portion 22a.
[0020]
The coupling bolt 11 is inserted into the through hole 21p of the support portion 21t from the protruding portion 22a side. The coupling bolt 11 is formed on the female thread portion 21h formed on the upper side wall plate 21 and the lower side wall plate 22. It is screwed to both of the female screw portion 22h.
The coupling bolt 11 is made of a metallic material such as steel and has sufficiently higher rigidity than the resin material forming the speaker box 20 and the holding member 3.
The connecting bolt 11 is an embodiment of the connecting member of the present invention. Further, the coupling bolt 11 and the female screw portions 21h and 22h constitute a restraining means of the present invention that partially restrains the relative movement between the opposing wall plates 21 and 22 of the speaker box 20.
[0021]
The coupling bolt 11 is screwed into the female screw portion 3h formed in the holding member 3 through the female screw portion 21h. As a result, the relative positions of the female screw portion 21h of the upper side wall plate 21, the lower side wall plate 22h, and the female screw portion 3h of the holding member 3 are restricted.
A plurality of support members 10 are provided between the lower side surface of the holding member 3 and the upper side wall plate 21. The support member 10 has a through hole 10h formed therein, and a coupling bolt 11 is inserted into the through hole 10h.
[0022]
Next, with reference to FIG. 4, the configuration and operation of the reflecting surface 3f on the holding member 3 side and the reflecting surface 21f on the speaker box side will be described.
[0023]
The reflecting surface 3f and the reflecting surface 21f reflect the sound from the speaker 15, thereby diffusing the sound radially about the speaker 15 in a direction substantially orthogonal to the sound output direction A1 of the speaker 15.
[0024]
As shown in FIG. 4, the reflecting surface 3f is formed of a curved surface that protrudes smoothly toward the speaker 15 side. The reflecting surface 3f is substantially constituted by, for example, a rotating curved surface formed when a hyperbola is rotated with the central axis Ct of the speaker 15 as a rotation axis.
Similarly, the reflecting surface 21f is substantially constituted by a rotating curved surface having the central axis Ct of the speaker 15 as a rotation axis.
[0025]
The radii from the central axis Ct of the speaker 15 are R1, R2, and R3, and the distances between the reflective surface 3f and the reflective surface 21f at the radii R1, R2, and R3 are L1, L2, and L3. As can be seen from FIG. 4, as the distance from the central axis Ct of the speaker 15 increases, the distance between the reflective surface 3f and the reflective surface 21f increases continuously.
[0026]
For example, assuming that the distance between the reflecting surface 3f and the reflecting surface 21f is constant, resonance occurs at a resonance frequency corresponding to the certain distance.
When resonance occurs, the sound becomes very difficult to hear, and the voices of meeting attendees cannot be faithfully reproduced.
[0027]
On the other hand, according to the present embodiment, the distance between the reflecting surface 3f and the reflecting surface 21f continuously increases as the distance from the central axis Ct of the speaker 15 increases, so that the sound output from the speaker 15 has a specific frequency. There is no resonance.
For this reason, it is possible to faithfully reproduce the voices uttered by the attendees of the conference.
Further, according to the present embodiment, the sound output from the speaker 15 is substantially orthogonal to the central axis Ct about the central axis Ct of the speaker 15 in a direction different from the audio output direction A1 of the speaker 15 without resonating. In all directions (360 ° radial). In particular, since a single speaker 15 is used, the sound does not cause interference around the central axis Ct, and the sound is spread evenly.
Furthermore, since there is no resonance between the reflecting surface 3f and the reflecting surface 21f, it is possible to more efficiently diffuse the sound far away.
[0028]
Next, the operation and effect of the coupling bolt 11 will be described.
FIG. 6 is a schematic diagram showing an example of the vibration of the speaker box when the coupling bolt 11 is not present. (A) is a case where the sound pressure in the speaker box is low, and (b) is a case where it is high.
As shown in FIG. 6, when the sound pressure in the speaker box fluctuates, the upper wall plate 21 and the lower wall plate 22 vibrate in opposite directions.
At this time, if the connection position of the support member 10 to the upper side wall plate 21 is Cp, the connection position Cp vibrates due to the sound pressure fluctuation in the speaker box.
[0029]
FIG. 5 is a schematic diagram showing an example of vibration of the speaker box 20 according to the present embodiment.
As shown in FIG. 5, the upper side wall plate 21 and the lower side wall plate 22 are coupled by the coupling bolt 11.
When the sound pressure in the speaker box 20 fluctuates, the upper wall plate 21 and the lower wall plate 22 vibrate in opposite directions, but the connection position Cp is restrained by the coupling bolt 11 and thus does not vibrate.
[0030]
In this embodiment, since the connection position Cp is restrained by the coupling bolt 11 and hardly vibrates, the vibration is less likely to propagate to the holding member 3 connected by the coupling bolt 11 and the support member 10 at this position. That is, the vibration directly transmitted from the speaker box 20 to the holding member 3 on which the microphone 40 is mounted is suppressed.
[0031]
Moreover, the position restrained by the coupling bolt 11 becomes a new node of vibration. That is, when a new node is formed, the vibration frequency of the speaker box 20 also increases.
By actively utilizing the change in the frequency of the vibration, the vibration of the speaker box 20 can be changed to a vibration frequency that does not substantially affect the microphone 40.
Moreover, the vibration suppression by the filter members 50, 51, and 60 can be efficiently performed by changing the vibration frequency of the speaker box 20 to a frequency that is easily attenuated by the filter members 50, 51, and 60 described above.
[0032]
Next, operations and effects of the filter members 50, 51, 60 will be described with reference to FIG.
As shown in FIG. 7, the vibration from the vibration source such as the speaker 15 or the speaker box 20 propagates to the printed wiring board 30 from the reflection surface 3 f of the holding member 3 through the filter members 50 and 51, for example. Further, the vibration propagated to the printed wiring board 30 propagates through the filter member 60, the wiring connecting the connector CN and the microphone 40, and the like.
[0033]
Here, the filter members 50 and 51 support a relatively heavy weight such as the printed wiring board 30 and the plurality of microphones 40. For this reason, the filter members 50 and 51 have an effect of attenuating vibration at a relatively low frequency. However, it is difficult to simultaneously attenuate vibrations having a relatively high frequency.
For this reason, a relatively high frequency vibration is attenuated by the filter member 60 provided between the microphone 40 and the printed wiring board 30. The weight supported by the filter member 60 is relatively small, and vibrations at relatively high frequencies can be damped relatively easily.
[0034]
In this way, when the sound from the speaker 15 is reflected and amplified by the reflecting surfaces 3f and 21f, resonance is not actively generated, so that vibrations in a very wide frequency band are transmitted from the speaker 15 to the microphone 40. Try to propagate.
According to the present embodiment, it is possible to attenuate the vibration in a wide band by combining filter members having different natural frequencies with respect to the vibration in the wide frequency band.
[0035]
The present invention is not limited to the embodiment described above.
In the above-described embodiment, the case where the coupling bolt 11 is used as the restraining means of the present invention has been described. However, any means other than the coupling bolt 11 may be used as long as it can connect the upper wall plate 21 and the lower wall plate 22. Is possible.
Further, the connection position of the holding member 23 and the upper wall plate of the speaker box 20 is set to the position constrained by the coupling bolt 11, but the holding member 23 and the upper wall plate of the speaker box 20 are coupled in the vicinity of this position. It is good also as a structure connected with the connection member different from the volt | bolt 11. FIG.
Further, as the first and second filter members of the present invention, the filter members 50, 51, and 60 have been described as examples. However, filter members other than these can be used, and the number and use thereof are also possible. The location can be changed as appropriate.
[0036]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, propagation of the vibration from the speaker which is a vibration source to a microphone can be suppressed in a wide frequency band.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an external appearance of a speaker device according to an embodiment of the present invention.
FIG. 2 is a plan view showing a structure of a printed wiring board held by a holding member.
FIG. 3 is a cross-sectional view showing the internal structure of the speaker device according to the embodiment of the present invention.
FIG. 4 is a diagram for explaining a positional relationship between a reflection surface on a holding member side and a reflection surface on a speaker box side.
FIG. 5 is a schematic diagram illustrating an example of vibration of a speaker box.
FIG. 6 is a schematic diagram illustrating an example of vibration of a speaker box when no coupling bolt is present.
FIG. 7 is a cross-sectional view for explaining the operation of the filter member.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Speaker apparatus, 2 ... Cover member, 3 ... Holding member, 3f ... Reflecting surface, 3h ... Female thread part, 10 ... Supporting member, 11 ... Connection bolt, 15 ... Speaker, 20 ... Speaker box, 21 ... Upper side wall board, 21f ... reflective surface, 21h ... female threaded part, 22 ... lower side wall plate, 22h ... female threaded part, 30 ... printed wiring board, 40 ... microphone, 50, 51 ... filter member, 60 ... filter member, 80 ... seal member, CN ... connector.

Claims (7)

A single speaker,
A speaker box for sealing the back of the speaker;
A directional microphone disposed in front of the sound output direction of the speaker;
A printed wiring board having a circuit for driving the speaker and the directional microphone;
A holding member provided on the speaker box and holding the printed wiring board;
A plurality of different filter members that are provided in a path for transmitting vibration from the speaker to the directional microphone and attenuate the vibration;
The plurality of different filter members are:
A pair of first filter members that support the printed wiring board with respect to the holding member;
A second filter member for supporting both ends of the directional microphone on the printed wiring board and attenuating vibration propagating from the printed wiring board side;
Speaker device. The directional microphone has a cylindrical shape,
The speaker device according to claim 1 . A single speaker,
A speaker box for sealing the back of the speaker;
A directional microphone provided in front of the speaker audio output direction and provided on the speaker box;
A printed wiring board having a circuit for driving the speaker and the directional microphone;
A holding member provided on the speaker box and holding the printed wiring board;
A speaker device comprising :
The speaker box is
A first wall plate constituting the bottom surface;
A second wall plate covering the first wall plate so that a space is formed between the first wall plate and the first wall plate;
Have
Furthermore, a restraining means for restraining a predetermined location on the first wall plate and a predetermined location on the second wall plate is included.
Speaker device. The retaining member is connected by a connecting member and the restraining position or the position near by said restraining means,
The speaker device according to claim 3 . The restraining means is
A female screw part formed at a predetermined location on the first wall plate of the speaker box and a predetermined location on the second wall plate ;
A coupling member threadably engaged with the female thread portion,
The speaker device according to claim 3 . The speaker box is made of resin,
The coupling member is made of metal.
The speaker device according to claim 5 . The holding member has a female thread portion into which the coupling member is screwed,
The coupling member is relatively moved between a predetermined location on the first wall plate of the speaker box and a predetermined location on the second wall plate, and between the second wall plate and the holding member. The speaker device according to claim 5 .

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