JP2011004210A - Speaker system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a more reliable speaker system that is made compact and suppresses generation of heat by using a magnetostrictor and suppresses echo, etc. when a microphone is mounted.SOLUTION: The speaker system 1 includes a magnetostrictor 30, a coil 31 for driving the magnetostrictor 30, a control means C1 for controlling the energization of the coil 31, transmission members 20 to 24 for transmitting a displacement of the magnetostrictor 30, and a temperature detecting means TS. The temperature detecting means TS is provided near the magnetostrictor 30. The control means C1 stops energization of the coil or reduces an amount of electricity to the coil 31 when the temperature detected on the basis of a signal from the temperature detecting means C1 is equal to or higher than a predetermined temperature.

Description

  The present invention relates to a speaker device using a magnetostrictive element.

In recent years, various speaker devices using magnetostrictive elements have been developed. A speaker device using a magnetostrictive element can be configured to be very small as compared to a conventional cone type speaker.
For example, in the prior art described in Patent Document 1, a part of a leg portion that supports the video display device on the floor is replaced with a speaker device using a magnetostrictive element, and the installation location is not affected by the video display portion. A speaker device having good acoustic characteristics is disclosed.
In addition, in the related art described in Patent Document 2, a microphone is provided in a hole provided on a table surface, and the waveform of the reverse phase of the background noise picked up by the microphone is measured with the speaker device using a magnetostrictive element. An audio system that is generated by vibrating a table surface to reduce background noise around the table is disclosed.
In addition, since a speaker device using a magnetostrictive element can be miniaturized, it is very convenient if it can be applied to a hands-free call or a telephone conference by mounting a microphone.
For example, in the related art described in Patent Document 3, a speaker is disposed below a hemispherical reflector (acoustic reflector) that is convex downward, and a microphone is disposed above the reflector. And a hands-free communication device having a configuration in which a reflector is disposed between a speaker and a microphone is disclosed.

JP 2007-158752 A JP-T-2006-526921 JP 2000-253134 A

In the prior art described in Patent Document 1, a part of a column supporting the video display device on the floor is replaced with a speaker device using a magnetostrictive element, so that an installation place like the conventional speaker device is not particularly required. However, the speaker device generates a relatively large amount of heat because of its small size and high output. If the operation is continued in a high temperature state, the reliability of the speaker device may be reduced.
Moreover, since the audio system described in Patent Document 2 is a noise canceller that outputs a waveform having an opposite phase from a speaker so as to reduce the sound picked up by a microphone, it is suitable for use as a hands-free device or a telephone conference device. Not.
In addition, when a magnetostrictive element is used in the hands-free communication device described in Patent Document 3 and a speaker and a microphone are provided in the device and the device is miniaturized, even if the periphery of the microphone is surrounded by a reflector, the speaker device using the magnetostrictive element, Since the vibration of the speaker device itself is larger than that of the conventional speaker device that vibrates the cone paper and the vibration of the microphone increases, there is a concern about the occurrence of echoes and the like.
The present invention was devised in view of such points, and by using a magnetostrictive element, it is more compact and suppresses heat generation, and when a microphone is mounted, it suppresses the generation of echoes, etc. It is an object to provide a speaker device with high reliability.

As means for solving the above-mentioned problems, the first invention of the present invention is a speaker device as described in claim 1.
The speaker device according to claim 1 includes a magnetostrictive element, a coil that drives the magnetostrictive element, a control unit that controls energization of the coil, a transmission member that transmits displacement of the magnetostrictive element, and a temperature detection unit. And a speaker device.
The temperature detecting means is provided in the vicinity of the magnetostrictive element. When the temperature detected based on the signal from the temperature detecting means is equal to or higher than a predetermined temperature, the coil is energized. Stop or reduce energization.

A second invention of the present invention is a speaker device as described in claim 2.
The speaker device according to claim 2 is the speaker device according to claim 1, wherein the magnetostrictive element, the coil, and the transmission member are accommodated in a case member, and the transmission member is disposed at a lower end of the case member. Arranged, an opening hole communicating the inside and the outside of the case member is provided in an arbitrary part of the case member, a microphone is provided inside the case member in the opening hole, A thin plate-like elastic body having an opening at the center is sandwiched between the opening hole and the microphone.

  According to the speaker device of the first aspect, when it is detected that the temperature of the magnetostrictive element is equal to or higher than the predetermined temperature, heat generation can be suppressed by stopping energization of the coil or reducing the energization amount. Thus, a more reliable speaker device can be realized.

According to the speaker device of the second aspect, a thin plate-like elastic body having a central portion opened between the opening hole of the case member and the microphone is sandwiched, so that the space between the opening hole and the microphone is sealed. And while making it not to pick up the sound inside a case member with a microphone, the vibration of the case member transmitted to a microphone is reduced by utilizing an elastic body also as an insulator.
Thereby, generation | occurrence | production of an echo etc. can be suppressed and a more reliable speaker apparatus can be implement | achieved.

It is a perspective view explaining the external appearance of one Embodiment of the speaker apparatus 1 of this invention. 3 is a cross-sectional view illustrating an example of an internal structure of the speaker device 1. FIG. It is an assembly drawing explaining the example of the structure of the speaker apparatus 1 (some members are described with sectional drawing). 1 is a schematic block diagram of a speaker device 1. FIG.

EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing. FIG. 1 shows a perspective view from above and a perspective view from below in an embodiment of the speaker device 1 of the present invention.
The speaker device 1 can be used for various applications, and can be used, for example, as a hands-free device for a mobile phone, a conference call device, a speaker for a music playback device, or the like. Note that the microphone can be omitted when used as a speaker for a music playback apparatus.
Hereinafter, in the description of the present embodiment, an example in which the speaker device 1 is used as a hands-free device is shown, and an example of the speaker device 1 on which the microphone M is mounted will be described.

● [Appearance of speaker device 1 (FIG. 1)]
An example of the appearance of the speaker device 1 will be described with reference to FIG.
The speaker device 1 described in the present embodiment has a columnar shape with a height of about 8 cm and is very small. The shape is not limited to a cylindrical shape.
The outer shape of the speaker device 1 is configured by an upper case member 11 and a lower case member 12, and a power button B1, a volume (+) button B2, a volume (−) button B3, a microphone mute are provided on the upper surface of the upper case member 11. Button B4 etc. are arrange | positioned and the cover 13 is attached.
In the speaker device 1 shown in the example of FIG. 1, the upper case member 11, the lower case member 12, and the cover 13 constitute a case member that is the outer shape of the speaker device 1.
The opening hole H1 is a voice input hole, and a microphone is attached to the back side of the opening hole H1.

Further, a transmission ring 21 that transmits the displacement (extension / contraction) of the magnetostrictive element is attached to the lower surface of the lower case member 12 with screws 23, and a sheet member 22 is attached to the lower surface of the transmission ring 21. .
The speaker device 1 is placed on a flat surface such as a table surface or a floor surface so that the sheet member 22 on the bottom surface is in contact therewith, and the displacement (extension / contraction) of the magnetostrictive element is transmitted from the transmission ring 21 via the sheet member 22 to the table surface or the floor surface. The sound is transmitted to the floor surface, etc., and the mounted table surface or floor surface is vibrated to obtain an acoustic effect (the table surface or floor surface is used as a speaker (vibrating body)).

● [Overall configuration of speaker device 1 (FIGS. 2 to 4)]
The speaker device 1 described in the present embodiment includes a communication means C2 such as Bluetooth (registered trademark) as shown in the schematic block diagram of FIG. 4 and can transmit and receive with an external device EX as a communication partner.
Next, the overall structure of the speaker device 1 will be described with reference to the schematic block diagram shown in FIG. 4, the cross-sectional view shown in FIG. 2, and the assembly drawing shown in FIG. In the schematic block diagram shown in FIG. 4, various interface circuits and the like are omitted.
As shown in the schematic block diagram of FIG. 4, the speaker device 1 includes a communication unit C2, an antenna AT, a control unit C1, a microphone M, an amplification unit C3, a coil 31, a magnetostrictive element 30, a temperature detection unit TS, and a disk magnet 24. The transmission rod 20, the transmission ring 21, and the sheet member 22 are provided.
In the speaker device 1 described in the present embodiment, the transmission means is constituted by the transmission rod 20, the transmission ring 21, and the sheet member 22 provided with the disk magnet 24. It is not limited to this configuration.

● [Assembly of each member (Figs. 2 and 3)]
As shown in FIGS. 2 and 3, in the speaker device 1, the members housed in the case constituted by the upper case member 11, the lower case member 12, and the cover 13 are the upper holder 14 and the lower holder 15. The upper holder 14 and the lower boulder 15 are fixed by a long screw NN.
An elastic member 25 (a spring or the like) is disposed at the center bottom of the lower holder 15, and the transmission rod 20 is inserted through the lower holder 15 and the elastic member 25.
A disk magnet 24 is attached to the upper end of the transmission rod 20, a magnetostrictive element 30, a coil 31, and a ring magnet 32 are assembled on the disk magnet 24, and a yoke 33 is assembled thereon. Yes.
Then, the upper holder 14 is assembled from above the yoke 33 so as to be fitted to the lower holder 15 and fixed by a long screw NN. As shown in FIG. 3, the battery BT is sandwiched between the lower holder 15 and the upper holder 14, and a terminal TD is attached to the electrode position of the battery BT.

A central portion of the upper holder 14 is opened so that the yoke 33 is exposed. A sub-board KS having a temperature detecting means TS is attached on the yoke 33, and a control board KM is attached above the sub-board KS.
As shown in FIG. 3, a chip-type small LED (not shown) is arranged on the control board KM, and a transparent acrylic rod 13A is placed on the LED. The rod 13 </ b> A is configured such that the light from the LED is guided to the inside, and the entire rod 13 </ b> A of the acrylic member emits light, thereby improving visibility from the user. The operating state of the speaker device 1 is displayed by the light emitting state (color, blinking state, etc.) of the LED (rod 13A). Reference numeral 13B denotes a switch connected to the volume buttons B2, B3, etc., and a description thereof is omitted.
The upper holder 14 and the lower holder 15 to which the respective members are assembled in this way are accommodated in the lower case member 12, and the upper case member 11 and the cover 13 are attached.
Then, from the back side of the lower case member 12, the transmission ring 21 to which the sheet member 22 is attached is attached with screws 23.

● [Operation and function of each member in schematic block diagram (Fig. 4)]
The communication means C2 is, for example, a Bluetooth (registered trademark) circuit, and is mounted on the control board KM shown in FIGS. The antenna AT is also attached to the control board KM.
The communication unit C2 receives the audio output signal from the external device EX via the antenna AT, and outputs the received audio output signal to the control unit C1. The communication means C2 receives the voice input signal input from the microphone M via the control means C1, and transmits the input voice input signal to the external device EX via the antenna AT.
Note that the communication unit C2 does not have to be wireless communication, and may be a communication unit that performs transmission and reception with the external device EX via a cable such as a LAN.

The control means C1 is, for example, a CPU (central processing unit) and its peripheral circuits, and is mounted on the control board KM shown in FIGS.
The control means C1 converts an audio output signal (for example, digital information) input from the communication means C2 into an analog signal according to a program stored in advance, and outputs the converted audio output signal to the amplification means C3. Further, the control unit C1 converts a voice input signal (for example, an analog signal) input from the microphone M into a digital signal, and outputs the converted voice input signal to the communication unit C2.
The control means C1 can detect the temperature of the magnetostrictive element 30 (temperature around the magnetostrictive element 30) based on the signal from the temperature detecting means TS.

When the control means C1 detects that the temperature of the magnetostrictive element 30 is equal to or higher than a predetermined temperature, the control means C1 stops or attenuates the output of the audio output signal to the amplifying means C3, or instructs the stop of the output to the coil 31 or A signal instructing attenuation of the output to the coil 31 is output to the amplifying means C3.
The speaker device 1 using a magnetostrictive element can be further downsized as compared with a conventional cone type speaker device. However, heat may be trapped by reducing the size, and the temperature may exceed a predetermined temperature (for example, about 70 ° C.). However, when the temperature exceeds a predetermined temperature, the energization of the coil 31 can be stopped or the energization amount can be reduced, and the increased temperature of the magnetostrictive element 30 can be appropriately lowered.
When the detected temperature falls below the return temperature (for example, about 60 ° C. or less), the control means C1 cancels the stop or reduction of energization of the coil 31 and returns to normal energization.
The speaker device 1 described in the present embodiment radiates heat from the lower holder 15 and the upper holder 14 without using heat radiating fins that house the magnetostrictive element 30, the coil 31, and the ring magnet 32 in order to reduce the size. However, a heat radiating fin may be provided.

  The temperature detection means TS is, for example, a thermistor, and is attached to the sub-board KS shown in FIGS. The magnetostrictive element 30 and the coil 31 wound around the bobbin are heat sources. However, as shown in FIGS. 2 and 3, it is a space to directly provide the temperature detecting means TS in the magnetostrictive element 30 or the coil 31. Therefore, a concave portion is formed in the yoke 33 (yoke 33 is made of metal and has high thermal conductivity) in contact with the magnetostrictive element 30 and the coil 31, and the temperature detecting means TS is disposed in the concave portion. is doing. The gap between the concave portion of the yoke 33 and the temperature detecting means TS is filled with a heat conductive filler (such as an adhesive). Thereby, the temperature of the magnetostrictive element 30 can be appropriately detected by the temperature detecting means TS.

The amplification means C3 is mounted on the control board KM shown in FIGS.
As described above, the amplifying unit C3 amplifies the audio output signal input from the control unit C1, and outputs the amplified audio output signal (analog signal) to the coil 31. The amplifying unit C3 includes an input interface circuit and a control circuit for executing stop or attenuation when an instruction to stop or attenuate energization of the coil 31 is input from the control unit C1. When stopping or attenuating on the control means C1 side, a circuit for stopping or attenuating is not necessary on the amplifying means C3 side).

As shown in FIGS. 2 and 3, the coil 31 is accommodated in a cylindrical ring magnet 32, and further accommodates a columnar magnetostrictive element 30.
When the coil 31 is energized, the magnetostrictive element 30 is displaced according to the energization amount (expands (vibrates) in the longitudinal direction).
The magnetostrictive element 30 vibrates the transmission rod 20 and the transmission ring 21 via the disk magnet 24, and the vibration is transmitted to the table surface F (where the speaker device 1 is placed) via the sheet member 22. Sound is generated from the table surface F.
The disk magnet 24 is a magnetic disk, and it was confirmed by experiments that it has an effect of improving the distortion in a specific frequency band (for example, near 2 kHz).
The sheet member 22 is, for example, a silicon rubber sheet having a thickness of about 0.5 mm. The sheet member 22 absorbs irregularities such as a floor surface to improve adhesion, and prevents the main body from jumping up due to vibration. The speaker device 1 described in the present embodiment has very high vibration energy that can be transmitted to a mounted table surface or the like, despite the fact that the size of the main body is as small as about 8 cm and the mass is small. Large, depending on the volume, the body may jump up. However, the sheet member 22 can appropriately prevent jumping.

As shown in FIGS. 2 and 3, the microphone M is attached to the inside of the opening hole H <b> 1 that communicates the inside and the outside of the case (the case is constituted by the upper case member 11, the lower case member 12, and the cover 13). Yes. The opening hole H1 is provided in an arbitrary part of the case, and is provided in the upper surface of the case in the example of the present embodiment.
The microphone M may be attached at a position in contact with the opening hole H1 as shown in a portion surrounded by a dotted line in FIG. 2, or as shown in a drawing drawn out from a portion surrounded by a dotted line in FIG. It may be mounted on the control board KM below the opening hole H1 apart from H1.
In addition, when attaching the microphone M to the position which touches the opening hole H1, as shown in FIG.2 and FIG.3, it is preferable to pinch | interpose the spacer S which is a thin-plate-shaped elastic member opened in the center part.

In the speaker device 1 using the magnetostrictive element, the vibration of the speaker device itself is larger than that of the conventional cone type speaker device, so there is a concern about the occurrence of echoes or the like. However, the spacer S serves as an insulator, and the microphone M The transmitted vibration of the case can be attenuated, and the generation of echoes and noise can be suppressed. Further, by sandwiching the spacer S, the microphone M and the periphery of the opening hole H1 are sealed, so that the sound in the case is hardly picked up by the microphone M, and generation of echoes and noise can be suppressed.
The control unit C1 performs software processing such as echo cancellation processing and noise cancellation processing on the audio input signal input from the microphone M, and outputs the processed audio input signal to the communication unit C2.
As described above, the speaker device 1 described in the present embodiment is configured more compactly using the magnetostrictive element, suppresses heat generation of the magnetostrictive element using the temperature detection means TS, and is connected to the microphone via the spacer S. By attaching M to the case, the occurrence of echo and the like is suppressed, and the reliability is further improved.

The speaker device 1 of the present invention is not limited to the appearance, configuration, structure, and the like described in the present embodiment, and various modifications, additions, and deletions can be made without changing the gist of the present invention.
Further, when the speaker device 1 is used for audio reproduction, the microphone M may be omitted.
Further, the above (≧), the following (≦), the greater (>), the less (<), etc. may or may not include an equal sign.
The numerical values used in the description of the present embodiment are examples, and are not limited to these numerical values.

  The speaker device 1 described in the present embodiment can be applied to various uses such as a hands-free device for a mobile phone, a telephone conference device, a speaker for a music playback device, and the like.

DESCRIPTION OF SYMBOLS 1 Speaker apparatus 11 Upper case member 12 Lower case member 13 Cover 14 Upper holder 15 Lower holder 20 Transmission rod 21 Transmission ring 22 Sheet member 24 Disc magnet 30 Magnetostrictive element 31 Coil 32 Ring magnet 33 Yoke C1 Control means C2 Communication means C3 Amplification means H1 Opening hole KM Control board KS Sub board M Microphone S Spacer TS Temperature detection means EX External equipment

Claims (2)

A magnetostrictive element;
A coil for driving the magnetostrictive element;
Control means for controlling energization to the coil;
A transmission member for transmitting displacement of the magnetostrictive element;
Temperature detection means;
A speaker device comprising:
The temperature detection means is provided in the vicinity of the magnetostrictive element,
When the temperature detected based on the signal from the temperature detection means is equal to or higher than a predetermined temperature, the control means stops energizing the coil or reduces the energization amount.
Speaker device. The speaker device according to claim 1,
The magnetostrictive element, the coil, and the transmission member are accommodated in a case member, and the transmission member is disposed at a lower end of the case member,
An opening hole that communicates the inside and outside of the case member is provided in an arbitrary part of the case member, and a microphone is provided inside the case member in the opening hole,
Between the opening hole and the microphone, a thin plate-like elastic body having a central portion opened is sandwiched,
Speaker device.

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