close

Вход

Забыли?

вход по аккаунту

?

JP2014127748

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JP2014127748
Abstract: To obtain good sound pressure frequency characteristics. A sound generator according
to an embodiment includes at least an exciter, a flat vibrator, a support on which the vibrator is
stretched, and a damping material. The exciter vibrates when an electrical signal is input. The flat
vibrator is attached with the exciter, and vibrates with the exciter due to the vibration of the
exciter. The supporting body stretches the vibrating body, and the damping material is disposed
in contact with the supporting body. [Selected figure] Figure 3
Acoustic generator, acoustic generator and electronic device
[0001]
Embodiments of the disclosure relate to a sound generator, a sound generator and an electronic
device.
[0002]
Conventionally, a sound generator using an actuator is known (see, for example, Patent
Document 1).
Such a sound generator vibrates the diaphragm by applying a voltage to the actuator attached to
the diaphragm to vibrate, thereby outputting a sound.
11-05-2019
1
[0003]
JP, 2009-130663, A
[0004]
However, since the above-mentioned conventional sound generator actively utilizes the
resonance of the diaphragm, the peak of the frequency characteristic of the sound pressure (the
part where the sound pressure is higher than the surrounding area) and the dip (the sound
pressure is larger than the surrounding area) There is a problem that low parts are likely to occur
and it is difficult to obtain good sound quality.
[0005]
One aspect of the embodiments is made in view of the above, and it is an object of the present
invention to provide an acoustic generator, an acoustic generator and an electronic device
capable of obtaining good frequency characteristics of sound pressure.
[0006]
An acoustic generator according to one aspect of the embodiment includes an exciter that
receives an electric signal and vibrates, and a flat vibrator that is attached with the exciter and
that vibrates with the exciter due to the vibration of the exciter. An acoustic generator
comprising at least a vibrating body and a support which vibrates together with the exciter and
the vibrating body by the vibration of the exciter, wherein a damping material is disposed in
contact with the support. .
[0007]
According to one aspect of the embodiment, good sound pressure frequency characteristics can
be obtained.
[0008]
(A) is a typical top view which shows schematic structure of a basic sound generator, (B) is an AA 'line sectional view of Drawing 1A.
It is a figure which shows an example of the frequency characteristic of sound pressure.
11-05-2019
2
(A) is a typical top view which shows the structure of the sound generator which concerns on
embodiment, (B) is a B-B 'line schematic cross section of FIG. 3A.
(A) is a typical top view (the 1) which shows a specific example of arrangement of a damping
material, (B) is a typical top view (the 2) which shows a specific example of arrangement of a
damping material is there.
(A) is a typical top view (the 3) which shows a specific example of arrangement of a damping
material, (B) is a typical top view (the 4) which shows a specific example of arrangement of a
damping material is there.
(A) is a schematic front view (part 1) showing a specific arrangement example of the damping
material, (B) is a schematic front view (part 2) showing a specific arrangement example of the
damping material, (C) is a damping material It is a front schematic diagram (the 3) which shows
the specific example of arrangement | positioning of. (A) is a figure which shows the structure of
the sound generation apparatus which concerns on embodiment, (B) is a figure which shows the
structure of the electronic device which concerns on embodiment.
[0009]
Hereinafter, embodiments of a sound generator, a sound generator and an electronic device
disclosed in the present application will be described in detail with reference to the attached
drawings. Note that the present invention is not limited by the embodiments described below.
[0010]
First, prior to the description of the sound generator 1 according to the embodiment, a schematic
configuration of a basic sound generator 1 'will be described using FIGS. 1A and 1B. FIG. 1A is a
schematic plan view showing a schematic configuration of the sound generator 1 ′, and FIG. 1B
is a cross-sectional view taken along the line A-A ′ of FIG. 1A.
[0011]
11-05-2019
3
In order to make the description easy to understand, FIGS. 1A and 1B illustrate a threedimensional orthogonal coordinate system including a Z axis in which the vertically upward
direction is a positive direction and the vertically downward direction is a negative direction.
Such an orthogonal coordinate system may also be shown in other drawings used in the
following description. Moreover, in FIG. 1A, illustration of the resin layer 7 is omitted.
[0012]
Also, in order to make the description easy to understand, FIG. 1B shows the sound generator 1
′ in a greatly exaggerated manner in the thickness direction (Z-axis direction).
[0013]
As shown in FIG. 1A, the sound generator 1 ′ includes a frame 2, a diaphragm 3 and a
piezoelectric element 5.
As shown in FIG. 1A, the following description exemplifies the case where one piezoelectric
element 5 is provided unless otherwise specified. However, the number of piezoelectric elements
5 is not limited.
[0014]
The frame 2 is formed of two frame members having the same rectangular frame shape and
functions as a support for holding the peripheral portion of the diaphragm 3 and supporting the
diaphragm 3. The diaphragm 3 has a plate-like or film-like shape, and its peripheral edge portion
is sandwiched and fixed to the frame 2. That is, the diaphragm 3 is supported in a stretched state
within the frame 2. A portion of the diaphragm 3 located inside the frame 2, that is, a portion of
the diaphragm 3 which is not sandwiched by the frame 2 and can freely vibrate is referred to as
a vibrator 3 a. Therefore, the vibrating body 3 a is a portion having a substantially rectangular
shape in the frame of the frame 2.
[0015]
11-05-2019
4
Moreover, the diaphragm 3 can be formed using various materials, such as resin and a metal. For
example, the diaphragm 3 can be made of a resin film of polyethylene, polyimide or the like
having a thickness of about 10 to 200 μm.
[0016]
The thickness, material, and the like of the frame 2 are not particularly limited. The frame 2 can
be formed using various materials such as metal and resin. For example, a stainless steel or the
like having a thickness of about 100 to 1000 μm can be suitably used as the frame 2 because of
excellent mechanical strength and corrosion resistance.
[0017]
Although FIG. 1A shows the frame 2 in which the shape of the inner region is substantially
rectangular, it may be a polygon such as a parallelogram, a trapezoid, and a regular n-gon. In the
present embodiment, as shown in FIG. 1A, an example having a substantially rectangular shape is
shown.
[0018]
The piezoelectric element 5 is provided by being attached to the surface of the vibrating body 3a
or the like, and is an exciter that excites the vibrating body 3a by vibrating upon receiving an
applied voltage.
[0019]
As shown in FIG. 1B, the piezoelectric element 5 is, for example, a laminated body in which
piezoelectric layers 5a, 5b, 5c, and 5d made of four layers of ceramics and three layers of
internal electrode layers 5e are alternately stacked; The laminate includes surface electrode
layers 5f and 5g formed on the upper and lower surfaces of the laminate, and external electrodes
5h and 5j formed on the exposed side surfaces of the internal electrode layer 5e.
Further, lead terminals 6a and 6b are connected to the external electrodes 5h and 5j.
11-05-2019
5
[0020]
The piezoelectric element 5 has a plate shape, and the main surfaces on the upper surface side
and the lower surface side have a polygonal shape such as a rectangular shape or a square shape.
The piezoelectric layers 5a, 5b, 5c and 5d are polarized as shown by arrows in FIG. 1B. That is,
the direction of polarization with respect to the direction of the electric field applied at a certain
moment is polarized such that one side and the other side in the thickness direction (Z-axis
direction in the drawing) are reversed.
[0021]
Then, when a voltage is applied to the piezoelectric element 5 through the lead terminals 6a, 6b,
for example, at a certain moment, the piezoelectric layers 5c, 5d on the side adhered to the
vibrating body 3a shrink and the upper surface of the piezoelectric element 5 The piezoelectric
layers 5a and 5b on the side deform so as to extend. Therefore, by giving an alternating current
signal to the piezoelectric element, the piezoelectric element 5 can be bent and vibrated, and the
bent vibration can be applied to the vibrating body 3a.
[0022]
Further, the main surface of the piezoelectric element 5 is bonded to the main surface of the
vibrating body 3a by an adhesive such as an epoxy resin.
[0023]
As materials for forming the piezoelectric layers 5a, 5b, 5c and 5d, lead-free piezoelectric
materials such as lead zirconate titanate (PZT), Bi layer compounds, tungsten bronze structure
compounds, etc. are conventionally used. Piezoelectric ceramics can be used.
[0024]
Moreover, various metal materials can be used as a material of the internal electrode layer 5e.
11-05-2019
6
For example, in the case of containing a metal component consisting of silver and palladium, and
a ceramic component forming the piezoelectric layer 5a, 5b, 5c, 5d, the piezoelectric layer 5a, 5b,
5c, 5d and the internal electrode layer 5e Since the stress due to the thermal expansion
difference can be reduced, it is possible to obtain the piezoelectric element 5 having no stacking
fault.
Also, the lead terminals 6a, 6b can be formed using various metal materials. For example, when
the lead terminals 6a and 6b are formed using a flexible wiring in which a metal foil such as
copper or aluminum is sandwiched by resin films, the height of the piezoelectric element 5 can
be reduced.
[0025]
Further, as shown in FIG. 1B, the acoustic generator 1 ′ is disposed so as to cover the surfaces
of the piezoelectric element 5 and the vibrating body 3a in the frame of the frame 2, and is
integrated with the vibrating body 3a and the piezoelectric element 5. The resin layer 7 is further
provided.
[0026]
The resin layer 7 is preferably formed, for example, using an acrylic resin so that the Young's
modulus is in the range of about 1 MPa to 1 GPa.
In addition, since the appropriate damping effect can be induced by embedding the piezoelectric
element 5 by the resin layer 7, the resonance phenomenon can be suppressed, and the peak and
dip in the frequency characteristic of the sound pressure can be suppressed small. .
[0027]
Further, FIG. 1B shows a state in which the resin layer 7 is formed to have the same height as the
frame 2, but it is sufficient if the piezoelectric element 5 is embedded, for example, the resin
layer 7 is a frame It may be formed to be higher than the height of the body 2.
[0028]
11-05-2019
7
Moreover, in FIG. 1B, although the bimorph-type laminated piezoelectric element was mentioned
as an example as the piezoelectric element 5, it is not restricted to this.
For example, it may be a unimorph type in which a piezoelectric element that expands and
contracts is attached to the vibrating body 3a.
[0029]
By the way, as shown in FIG. 1A and FIG. 1B, in the sound generator of this example, the
piezoelectric element 5 is attached to the vibrating body 3a stretched on the frame 2 and covered
with the resin layer 7 2. The vibrator 3a, the piezoelectric element 5 and the resin layer 7 are
integrated, and the frame 2, the vibrator 3a, the piezoelectric element 5 and the resin layer 7
vibrate integrally.
[0030]
In the composite vibrator constituted by such a frame 2, the vibrator 3a, the piezoelectric
element 5 and the resin layer 7, the frame 2, the vibrator 3a and the resin layer 7 are vibration of
the piezoelectric element 5 which is a vibration source. Is propagated, each vibrates at its own
frequency depending on its size (longitudinal length, horizontal length, diagonal length and
thickness) and hardness, and these vibrations are summed up to generate sound. Frequencysound pressure characteristics.
[0031]
However, in the case where the composite vibration body constituted by such a frame 2, the
vibration body 3a, the piezoelectric element 5 and the resin layer 7 has symmetry as a whole, the
peaks are concentrated at a specific frequency. , Sharp peaks and dips are likely to occur.
This point is illustrated in FIG.
[0032]
As an example, attention is focused on a portion enclosed by a dashed closed curve PD in FIG.
11-05-2019
8
When such a peak occurs, the sound pressure varies depending on the frequency, which makes it
difficult to obtain good sound quality.
[0033]
In such a case, it is effective to take measures to lower the height of the peak P (see arrow 201 in
the figure) and widen the peak width (see arrow 202 in the figure) to reduce the peak and dip.
[0034]
Therefore, in the present embodiment, first, the sound generator 1 is in contact with the frame 2
and the damping member 8 is disposed.
In addition, that the damping material 8 is disposed in contact with the frame 2 means that the
damping material 8 is disposed so as to be in contact with the upper surface, the side surface,
and the corner portion of the frame 2. It is more preferable that the vibrator is disposed in
contact with the vibrating body 3a and the piezoelectric element 5 as well.
[0035]
Thus, by arranging the damping material 8 in contact with the frame 2, the resonance peak of
the sound pressure is suppressed by the damping material 8, so the peak dip is reduced and the
flatness of the frequency-sound pressure characteristic is improved. Be done.
[0036]
Moreover, it is preferable that the sound generator 1 of this embodiment is arrange | positioned
so that the gravity center may not overlap with the gravity center of the sound generator 1 when
planarly viewed.
This makes it possible to further reduce the peak and dip of the sound pressure.
[0037]
11-05-2019
9
Furthermore, it is preferable that the damping material 8 is plural. By providing a plurality of
damping members 8, it is possible to selectively improve the frequency range targeted for sound
quality improvement, and to obtain better sound quality.
[0038]
In addition, the plurality of damping members 8 may be disposed at an asymmetrical position
with respect to the center of gravity of the sound generator 1, may have different areas, may
have different thicknesses, may have different materials, or may have different masses.
preferable. By arranging such a plurality of damping members 8, it is possible to further
suppress the resonance peak of the sound pressure at the pinpoint, and the flatness of the
frequency-sound pressure characteristic can be improved.
[0039]
The damping material 8 may be disposed in contact with the frame 2, and the effect can be
achieved regardless of the presence or absence of the resin layer 7.
[0040]
Hereinafter, it demonstrates concretely using FIG. 3A-FIG. 4B.
FIG. 3A is a schematic plan view showing the configuration of the sound generator 1 according to
the embodiment, and FIG. 3B is a schematic cross-sectional view taken along the line B-B 'shown
in FIG. 3A. 4A to 4B are layout explanatory views (part 1) to (part 2) of the damping material 8
when the diaphragm 3 is viewed in plan.
[0041]
As shown in FIG. 3A, the sound generator 1 includes a damping material 8 in addition to the
sound generator 1 ′ shown in FIGS. 1A and 1B. In addition, although the case where one
rectangular damping material 8 is in contact with the frame 2 straddling the frame 2 and the
11-05-2019
10
vibrating body 3a is illustrated by FIG. 3A, the area | region of the shape, the number, and
arrangement | positioning are illustrated. And the damping material 8 may be in contact with the
frame 2.
[0042]
The damping member 8 may be any member having mechanical loss, but it is desirable that the
damping member 8 be a member having a high mechanical loss coefficient, in other words, a low
mechanical quality coefficient (so-called mechanical Q).
[0043]
Such a damping material 8 can be formed, for example, using various elastic bodies, but since it
is desirable that it is soft and easily deformed, it can be suitably formed using a rubber material
such as urethane rubber.
[0044]
In particular, porous rubber materials such as urethane foam can be suitably used.
The damping material 8 is attached to the surface of the frame 2 and the resin layer 7 shown in
FIG. 1B and is integrated with the frame 2, the vibrator 3 a, the piezoelectric element 5 and the
resin layer 7.
[0045]
And, by providing the damping material 8 in this manner, the region where the damping material
8 is disposed receives vibration loss due to the damping material 8 through the resin layer 7 and
the frame 2, thereby suppressing the resonance phenomenon. It will be.
[0046]
The outer peripheral shape of the damping member 8 is not limited to an elliptical shape as
shown in FIGS. 4A to 4B, a rectangular shape, a semicircular shape, a crescent shape, an irregular
shape such as a star shape, a pentagonal shape, a hexagonal shape, etc. It may be a polygonal
shape, a circular shape or the like.
11-05-2019
11
[0047]
Moreover, it is preferable that the damping member 8 be disposed so that its center of gravity
does not overlap with the center of gravity of the sound generator 1 in plan view.
If the center of gravity of the damping member 8 and the center of gravity of the sound
generator 1 overlap, there is a risk that the peak or dip of the sound pressure may be increased.
[0048]
Next, the sound generator which concerns on the other one aspect of embodiment has several
damping material 8, as shown to FIG. 5A-FIG. 5B.
FIG. 5A is a plan view in which the two damping members 8 are disposed across the frame 2 and
in contact with the frame 2 between the frame 2 and the vibrating body 3a, and FIG. One of the
damping members 8 is disposed across the frame 2 and the vibrating body 3a, and the other is
disposed in contact with the frame 2 at the upper portion of the vibrating body 3a.
[0049]
By providing a plurality of damping members 8, it is possible to selectively improve the
frequency range targeted for sound quality improvement, and to obtain better sound quality.
[0050]
Further, it is preferable that the plurality of damping members 8 be disposed at a non-target
position with respect to the center of gravity of the sound generator 1.
By arranging the plurality of damping members 8 at a position not symmetrical to the center of
gravity of the sound generator 1, the respective resonance frequencies or the length due to the
diagonal or length or width of the sound generator 1 or the piezoelectric element 5 It is possible
to suppress peaks and dips caused by the antiresonance frequency, and as a result, it is possible
to further reduce the peak and dip levels of the sound pressure.
11-05-2019
12
[0051]
The same effects as described above can be obtained by making the areas of the plurality of
damping members 8 different, making the outer peripheral shape different, making the thickness
different, making the material different, or making the mass different.
[0052]
Subsequently, FIGS. 6A to 6C are cross-sectional views (part 1) to (part 3) showing a specific
arrangement example of the damping material 8.
6A to 6C are cross-sectional views of the sound generator 1 taken along line A-A '(see FIG. 1A).
[0053]
FIG. 6A is an arrangement example in which the damping material 8 is disposed across the frame
2 on the main surface side of the diaphragm 3 on which the piezoelectric element 5 is provided
and the vibrating body 3a. FIG. 6B is a damping material 8 The arrangement example is an
arrangement example in which the vibrating body 3a on the main surface opposite to the main
surface side of the vibration plate 3 provided with the piezoelectric element 5 is in contact with
the frame 2.
[0054]
Further, as shown in FIG. 6C, for example, when the bimorph-type piezoelectric element 5 is
attached by sandwiching the diaphragm 3 from both sides, the resin layer 7 is also formed on the
lower surface side of the diaphragm 3, The damping material 8 may be provided on the side so
as to be in contact with the frame 2.
[0055]
Next, a sound generating device and an electronic device equipped with the sound generator 1
according to the embodiment described above will be described with reference to FIGS. 7A and
7B.
11-05-2019
13
FIG. 7A is a view showing the configuration of the sound generation device 20 according to the
embodiment, and FIG. 7B is a view showing the configuration of the electronic device 50
according to the embodiment.
In both figures, only the components necessary for the description are shown, and the
description of general components is omitted.
[0056]
The sound generation device 20 is a sound generation device such as a so-called speaker, and
includes, for example, a sound generator 1 and a housing 30 for housing the sound generator 1
as shown in FIG. 7A.
The housing 30 resonates the sound emitted by the sound generator 1 internally, and radiates
the sound to the outside from an opening (not shown) formed in the housing 30. By having such
a housing 30, for example, the sound pressure in the low frequency band can be increased.
[0057]
Also, the sound generator 1 can be mounted on various electronic devices 50. For example, in
FIG. 7B shown below, it is assumed that the electronic device 50 is a mobile terminal device such
as a mobile phone or a tablet terminal.
[0058]
As shown in FIG. 7B, the electronic device 50 includes the electronic circuit 60. The electronic
circuit 60 includes, for example, a controller 50a, a transmitting / receiving unit 50b, a key input
unit 50c, and a microphone input unit 50d. The electronic circuit 60 is connected to the sound
generator 1 and has a function of outputting an audio signal to the sound generator. The sound
generator generates a sound based on an audio signal input from the electronic circuit.
11-05-2019
14
[0059]
The electronic device 50 further includes a display unit 50 e, an antenna 50 f, and the sound
generator 1. In addition, the electronic device 50 includes a housing 40 that accommodates each
of these devices.
[0060]
Although FIG. 7B shows a state in which all the devices including the controller 50a are housed
in one housing 40, the housing form of the devices is not limited. In the present embodiment, at
least the electronic circuit 60 and the sound generator 1 may be accommodated in one housing
40.
[0061]
The controller 50 a is a control unit of the electronic device 50. The transmitting and receiving
unit 50b transmits and receives data via the antenna 50f based on the control of the controller
50a.
[0062]
The key input unit 50c is an input device of the electronic device 50, and receives a key input
operation by the operator. The microphone input unit 50d is also an input device of the
electronic device 50, and receives a voice input operation and the like by the operator.
[0063]
The display unit 50 e is a display output device of the electronic device 50, and outputs display
information based on the control of the controller 50 a.
[0064]
11-05-2019
15
The sound generator 1 then operates as a sound output device in the electronic device 50.
The sound generator 1 is connected to the controller 50a of the electronic circuit 60, and emits a
sound in response to the application of a voltage controlled by the controller 50a.
[0065]
By the way, although FIG. 7B described the electronic device 50 as a portable terminal device, it
does not ask the type of the electronic device 50, and may be applied to various consumer
devices having a function of emitting sound. . For example, flat-screen TVs and car audio devices
may be used for various products such as vacuum cleaners, washing machines, refrigerators,
microwave ovens, etc. .
[0066]
In the embodiment described above, the explanation has been made mainly by exemplifying the
case where the piezoelectric element 5 is provided on one main surface of the vibrating body 3a,
but the present invention is not limited to this. The piezoelectric element 5 may be provided.
[0067]
Further, in the above-described embodiment, the case where the shape of the region inside the
frame is substantially rectangular is taken as an example, and it may be any polygon as long as it
is a polygon, but it is not limited thereto. It may be in the form of
[0068]
In the embodiment described above, the case where the resin layer 7 is formed so as to cover the
piezoelectric element 5 and the vibrating body 3a in the frame of the frame 2 is taken as an
example, but such a resin layer is not necessarily formed It is good.
[0069]
Further, in the embodiment described above, the diaphragm is made of a thin film such as a resin
film. However, the present invention is not limited to this. For example, the diaphragm may be
made of a plate-like member.
11-05-2019
16
[0070]
Further, in the embodiment described above, the case where the support for supporting the
vibrating body 3a is the frame 2 and the peripheral edge of the vibrating body 3a is supported is
described as an example, but the present invention is not limited thereto.
For example, only both ends in the longitudinal direction or the short side direction of the
vibrating body 3a may be supported.
In this case, the damping material 8 may be disposed in contact with the member supporting the
vibrating body 3a.
[0071]
In the above-described embodiment, although the case where the exciter is the piezoelectric
element 5 has been described as an example, the exciter is not limited to the piezoelectric
element, and a function of vibrating when an electric signal is input What is necessary is to have.
For example, an electrodynamic exciter, an electrostatic exciter, or an electromagnetic exciter
well known as an exciter for vibrating a speaker may be used.
It is to be noted that the electrodynamic exciter is such that a current is supplied to the coil
disposed between the magnetic poles of the permanent magnet to vibrate the coil, and the
electrostatic exciter is formed of two facing metals The bias and the electrical signal are supplied
to the plate to cause the metal plate to vibrate, and the electromagnetic exciter is to cause the
electrical signal to flow to the coil to cause the thin iron plate to vibrate.
[0072]
Further effects and modifications can be easily derived by those skilled in the art. Thus, the
broader aspects of the invention are not limited to the specific details and representative
embodiments represented and described above. Accordingly, various modifications may be made
11-05-2019
17
without departing from the spirit or scope of the general inventive concept as defined by the
appended claims and their equivalents.
[0073]
1, 1 'Sound generator 2 Frame 3 Vibrator 3a Vibrator 5 Piezoelectric element 5a, 5b, 5c, 5d
Piezoelectric layer 5e Internal electrode layer 5f, 5g Surface electrode layer 5h, 5j External
electrode 6a, 6b Lead terminal 7 Resin layer 8 Damping material 20 Sound generation device 30,
40 Case 50 Electronic device 50a Controller 50b Transmitter and receiver unit 50c Key input
unit 50d Microphone input unit 50e Display unit 50f Antenna 60 Electronic circuit P Peak
11-05-2019
18
Документ
Категория
Без категории
Просмотров
0
Размер файла
28 Кб
Теги
jp2014127748
1/--страниц
Пожаловаться на содержимое документа