close

Вход

Забыли?

вход по аккаунту

?

JP2013172237

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 JP2013172237
Abstract: To provide an electroacoustic transducer capable of fixing a metal vibrating member
and a metal vibrating plate to each other with sufficient strength with high positional accuracy.
An electroacoustic transducer (100) includes a metallic diaphragm (14) and a metallic vibrating
member (15) fixed to the diaphragm (14). The electroacoustic transducer 100 receives a sound
from the vibrating member 15 by vibrating the vibrating element by inputting a signal to the
vibrating element (for example, the piezoelectric vibrator 13) surface-bonded to the vibrating
plate 14 and the vibrating element. And an input unit 20 for oscillating the signal. The vibrating
member 15 has a main body portion 15a and a fixed shaft 15b which protrudes toward the
diaphragm 14 from the main body portion 15a. Fixing holes 14 a are formed in the diaphragm
14. The vibrating member 15 is fixed to the vibrating plate 14 by press-fitting the fixed shaft 15
b into the fixing hole 14 a. [Selected figure] Figure 1
Electro-acoustic transducer and electronic device
[0001]
The present invention relates to an electroacoustic transducer and an electronic device.
[0002]
In Patent Documents 1 and 2, a bimorph vibrator configured by bonding a piezoelectric vibrator
and a metal vibrating plate, and a metal vibrating member fixed to the bimorph vibrator through
a coupling axis (conical of the same document) An ultrasonic ceramic microphone is described.
04-05-2019
1
The coupling axis penetrates the metal vibrating member and the bimorph oscillator in the
direction perpendicular to the surface of the bimorph oscillator, and is adhesively fixed to the
bimorph oscillator.
[0003]
Patent Document 3 describes an ultrasonic transducer having a unimorph vibrator configured by
bonding a piezoelectric vibrator and a metal vibrating plate, and a metal vibrating member (a
conical resonator in the same document). It is done. A protruding hole is formed in the central
portion of the metal diaphragm, and the metal vibrating member is fixed to the protruding hole
via a screw or a rivet. In the structure using a rivet, both ends of the rivet are crimped.
[0004]
Patent Document 4 describes a piezoelectric actuator having a structure in which a vibrating
body is supported on a support by pressing a support shaft into a vibrating body configured to
include a piezoelectric element.
[0005]
Patent Document 1: Japanese Patent Application Publication No. 04-217200 Patent Document 2:
Japanese Utility Model Application Publication No. 59-009695 Patent Document 2: Japanese
Utility Model Application Publication No. 08-000442 Patent Document 2: Japanese Patent
Application Publication No. 11-341843
[0006]
In the techniques of Patent Documents 1 and 2, the metal vibrating member is fixed to the
bimorph vibrator by the adhesive via the coupling shaft.
For this reason, the fixing position accuracy of the metal vibrating member with respect to the
bimorph vibrator is lowered due to the variation of the thickness of the adhesive, and the
variation of the primary resonance frequency and the secondary resonance frequency of the
electroacoustic transducer (ultrasonic ceramic microphone) is large. Could be
04-05-2019
2
[0007]
In the technique of Patent Document 3, in the structure using the rivet, if the outer diameter of
the rivet is smaller than the inner diameter of the protruding hole, the variation in the fixing
position of the metal vibrating member with respect to the unimorph vibrator in the cross
direction to the axial direction of the rivet It may occur.
As a result, variations may occur in the primary resonance frequency and the secondary
resonance frequency of the ultrasonic transducer. Further, in the technology of Patent Document
3, in the structure using a screw, the screw may be loosened by vibration.
[0008]
An object of the present invention is to provide an electroacoustic transducer and an electronic
device capable of fixing a metal vibrating member and a metal vibrating plate to each other with
sufficient strength with high positional accuracy.
[0009]
In the present invention, a metallic diaphragm, a metallic vibrating member fixed to the
diaphragm, a vibrating element surface-joined to the vibrating plate, and a signal input to the
vibrating element And an input unit configured to oscillate a sound wave from the vibrating
member by vibrating the vibrating element, the vibrating member comprising: a main body; and a
fixed shaft protruding from the main body toward the diaphragm. And a fixed hole is formed in
the diaphragm, and the vibrating member is fixed to the diaphragm by pressing the fixed shaft
into the fixed hole. Provide the
[0010]
The present invention also includes an electro-acoustic transducer, wherein the electro-acoustic
transducer comprises: a metallic diaphragm; a metallic vibration member fixed to the diaphragm;
A vibrating element, and an input unit for oscillating a sound wave from the vibrating member by
inputting a signal to the vibrating element to vibrate the vibrating element, the vibrating member
comprising a main body And a fixed shaft protruding from the main body toward the diaphragm,
wherein a fixed hole is formed in the vibration plate, and the vibrating member is press-fit into
the fixed hole by the fixed shaft. An electronic device is characterized in that the electronic device
is fixed to the diaphragm.
04-05-2019
3
[0011]
According to the present invention, it is possible to fix the vibrating member made of metal and
the vibrating plate made of metal to each other with sufficient strength and position accuracy.
[0012]
It is a typical sectional view of an electroacoustic transducer concerning a 1st embodiment.
It is a typical sectional view showing an example of a more concrete composition of an
electroacoustic transducer concerning a 1st embodiment.
It is an exploded view of FIG.
It is a typical top view of the electroacoustic transducer concerning a 1st embodiment.
It is a typical top view at the time of constituting an electroacoustic transducer concerning a 1st
embodiment as an array of a plurality of ultrasonic transducers. It is a schematic diagram of the
electronic device which concerns on 1st Embodiment. It is a typical sectional view of an
electroacoustic transducer concerning modification 1 of a 1st embodiment. It is a typical
sectional view of an electroacoustic transducer concerning modification 2 of a 1st embodiment. It
is a typical sectional view of an electroacoustic transducer concerning modification 3 of a 1st
embodiment. It is a typical sectional view of an electroacoustic transducer concerning
modification 4 of a 1st embodiment. It is a typical sectional view of an electroacoustic transducer
concerning a 2nd embodiment.
[0013]
Hereinafter, embodiments of the present invention will be described using the drawings. In all
the drawings, the same components are denoted by the same reference numerals, and the
description thereof will be omitted as appropriate.
04-05-2019
4
[0014]
First Embodiment FIG. 1 is a schematic cross-sectional view of an electroacoustic transducer 100
according to a first embodiment.
[0015]
The electroacoustic transducer 100 according to the present embodiment includes a metallic
diaphragm 14, a metallic vibrating member 15 fixed to the diaphragm 14, a vibrating element
(for example, a piezoelectric vibrator 13), and an input unit 20. And.
The vibrating element is surface-bonded to the diaphragm 14. That is, the vibrating element is
joined to one surface of the diaphragm 14. The input unit 20 oscillates a sound wave from the
vibrating member 15 by inputting a signal to the vibrating element to vibrate the vibrating
element. The vibrating member 15 has a main body portion 15a and a fixed shaft 15b which
protrudes from the main body portion 15a to the diaphragm 14 side. Fixing holes 14 a are
formed in the diaphragm 14. The vibrating member 15 is fixed to the vibrating plate 14 by pressfitting the fixed shaft 15 b into the fixing hole 14 a.
[0016]
According to the electro-acoustic transducer 100, the vibrating member 15 is fixed to the
diaphragm 14 by press-fitting the fixed shaft 15b into the fixing hole 14a. That is, the vibrating
member 15 is press-fitted and fixed to the diaphragm 14. Therefore, it is possible to easily realize
a structure in which the vibrating member 15 is fixed to the vibrating plate 14 with sufficient
strength. That is, even without using an adhesive, the vibrating member 15 can be fixed to the
diaphragm 14 with sufficient strength. When the vibrating member 15 is fixed to the diaphragm
14 without using an adhesive, simplification of the manufacturing process and cost reduction are
possible. Further, since the fixed shaft 15b of the vibrating member 15 and the peripheral wall of
the fixing hole 14a of the vibrating plate 14 are in close contact with each other, the fixing
position accuracy of the vibrating member 15 with respect to the vibrating plate 14 is improved.
As a result, it is possible to reduce variations in the fundamental resonance frequency (primary
resonance frequency and secondary resonance frequency) of the electroacoustic transducer 100.
Therefore, the electroacoustic transducer 100 can be manufactured with high yield. In short, the
vibrating member 15 made of metal and the diaphragm 14 made of metal can be fixed to each
other with sufficient strength with high positional accuracy.
04-05-2019
5
[0017]
A more detailed description will be given below.
[0018]
FIG. 2 is a schematic view showing an example of a more specific configuration of the electroacoustic transducer 100 according to the first embodiment.
FIG. 3 is an exploded view of FIG. FIG. 4 is a schematic plan view of the electroacoustic
transducer 100 according to the first embodiment.
[0019]
In the case of the present embodiment, the vibration element is the piezoelectric vibrator 13.
That is, the electroacoustic transducer 100 according to the present embodiment is a
piezoelectric electroacoustic transducer. The piezoelectric vibrator 13 is also referred to as a
piezoelectric element.
[0020]
The piezoelectric vibrator 13 is formed in a plate shape. The piezoelectric vibrator 13 is fixed to
the vibrating plate 14 by bonding (for example, bonding) to the surface of the vibrating member
14 opposite to the main body 15 a of the vibrating member 15. The piezoelectric vibrator 13 is
surface-bonded to the vibrating plate 14 without a gap.
[0021]
The input unit 20 inputs a modulation signal to the piezoelectric vibrator 13 to vibrate the
piezoelectric vibrator 13. Thereby, the vibration of the piezoelectric vibrator 13 is transmitted to
the diaphragm 14 and the vibrating member 15, and the ultrasonic wave is oscillated (emitted)
from the diaphragm 14 and the vibrating member 15.
04-05-2019
6
[0022]
More specifically, for example, the input unit 20 inputs a modulation signal for a parametric
speaker to the piezoelectric vibrator 13. That is, the electroacoustic transducer 100 is, for
example, a parametric speaker.
[0023]
The main body 15 a of the vibrating member 15 is, for example, separated from the diaphragm
14. The main body portion 15a is formed, for example, in a conical shape (frustum shape) whose
diameter increases with distance from the diaphragm 14. More specifically, for example, the
main body portion 15a is formed in a conical shape (conical shape). Therefore, the external shape
of the main body portion 15a is, for example, circular (see FIG. 4). The outer shape of the main
body portion 15a may be polygonal.
[0024]
In the main body portion 15a, a conical concave portion 15c is formed on the surface opposite to
the diaphragm 14. As a result, the main body portion 15a is formed in a conical thin plate shape.
That is, the main body portion 15a is formed, for example, in the shape of a hollow cone.
[0025]
The fixed shaft 15b of the vibrating member 15 protrudes toward the diaphragm 14 from the
central portion of the main body portion 15a. The fixed shaft 15b of the vibrating member 15
may be, for example, a cylindrical shape, but may be a prismatic shape or a cylindrical shape
(cylindrical or rectangular cylindrical shape).
[0026]
04-05-2019
7
The vibrating member 15 is integrally formed in its entirety. That is, the main body portion 15a
and the fixed shaft 15b are integrally formed.
[0027]
The vibrating plate 14 is formed in a flat plate shape, for example, by a metal such as phosphor
bronze or 42 alloy.
[0028]
It is preferable that the density of the metal material forming the vibrating member 15 be smaller
than the density of the metal material forming the diaphragm 14.
By doing this, the vibrating member 15 can be made as light as possible. Therefore, stress load
and weight load at the press-fit fixing place between the diaphragm 14 and the vibrating member
15 can be reduced. As a result, an excessive decrease in the resonant frequency of the
electroacoustic transducer 100 can be suppressed.
[0029]
At a central portion of the diaphragm 14, a fixing hole 14a for press-fitting and fixing the
vibrating member 15 is formed. The vibrating member 15 is fixed to the vibrating plate 14 by
press-fitting the fixed shaft 15 b into the fixing hole 14 a.
[0030]
The fixing holes 14 a pass through the front and back of the diaphragm 14, for example. For
example, the tip end surface 15 e of the fixed shaft 15 b is flush with the surface 14 b of the
diaphragm 14 opposite to the main body 15 a. The front end surface 15 e abuts, for example, the
surface on the vibrating plate 14 side of the piezoelectric vibrator 13 and is in contact with it.
[0031]
04-05-2019
8
The piezoelectric vibrator 13 includes, for example, a piezoelectric ceramic (not shown) and an
electrode film (not shown) formed on one surface (the lower surface in FIG. 2) of the piezoelectric
ceramic. The diaphragm 14 also functions as an electrode on the other surface (upper surface in
FIG. 2) of the piezoelectric vibrator 13.
[0032]
The external shape of the piezoelectric vibrator 13 is, for example, circular or polygonal.
Furthermore, the external shape of the diaphragm 14 is, for example, circular or polygonal.
Specifically, for example, the external shapes of the piezoelectric vibrator 13 and the diaphragm
14 have the same shape and the same size. By making the external shape of the piezoelectric
vibrator 13 and the diaphragm 14 circular or polygonal, the vibration mode of the
electroacoustic transducer 100 can be degenerated to suppress the generation of unintended
unnecessary resonance. Specifically, for example, as shown in FIG. 4, the external shape of the
diaphragm 14 and the piezoelectric vibrator 13 (not shown in FIG. 4) can be polygonal (for
example, octagonal). The external shapes of the piezoelectric vibrator 13 and the diaphragm 14
are not limited to these shapes.
[0033]
The piezoelectric vibrator 13 is provided on the bottom plate 11 via a low elasticity support 12.
The piezoelectric vibrator 13 is supported by, for example, a plurality of columns 12. The
support 12 is made of, for example, a low elastic resin material. The bottom plate 11 is made of,
for example, a resin.
[0034]
FIG. 5 is a schematic plan view of the case where the electroacoustic transducer 100 according to
the first embodiment is configured as an array of a plurality of ultrasonic transducers 10.
[0035]
In FIG. 5, each of the ultrasonic transducers 10 has a vibrating member 15, a vibrating plate 14,
a piezoelectric transducer 13, and a support 12.
04-05-2019
9
[0036]
The plurality of ultrasonic transducers 10 are supported by, for example, a common support
portion 101.
The bottom plate 11 is fixed on the support portion 101, for example.
The bottom plate 11 may be configured by a part of the support portion 101.
[0037]
FIG. 5 shows an example in which the plurality of ultrasonic transducers 10 are arranged in a
matrix in plan view. However, the arrangement of the plurality of ultrasonic transducers 10 is not
limited to this example. For example, it is also possible to arrange a plurality of ultrasonic
transducers 10 in a row.
[0038]
Here, the transport wave of the modulation signal input from the input unit 20 to the
piezoelectric vibrator 13 is, for example, an ultrasonic wave having a frequency of 20 kHz or
more, and specifically, for example, an ultrasonic wave of 100 kHz. The input unit 20 controls
the piezoelectric vibrator 13 so as to obtain a predetermined oscillation output.
[0039]
The diaphragm 14 and the vibrating member 15 vibrate by the vibration generated from the
piezoelectric vibrator 13. By this vibration, the vibrating member 15 oscillates a sound wave
having a frequency of, for example, 20 kHz or more. The vibrating member 15 is fixed to a
central portion where the displacement of the vibrating plate 14 and the piezoelectric vibrator
13 is maximum.
04-05-2019
10
[0040]
The parametric speaker emits ultrasonic waves (transport waves) with AM modulation, DSB
modulation, SSB modulation, and FM modulation from the multiple oscillation sources into the
air, and the nonlinear characteristics when the ultrasonic waves propagate in the air , Make an
audible sound appear. Here, non-linear means transition from laminar flow to turbulent flow as
the Reynolds number indicated by the ratio of flow inertia action to viscosity action increases.
The sound waves are non-linear and propagate because the sound waves are finely disturbed in
the fluid. In the ultrasonic frequency band in particular, the nonlinearity of the sound wave can
be easily observed. When ultrasonic waves are radiated into the air, harmonics associated with
the non-linearity of the sound waves are generated notably. In addition, sound waves are in a
dense / dense state in which concentration of molecular density occurs in the air. And, if time is
taken for air molecules to recover more than compression, air that can not be recovered after
compression collides with continuously propagating air molecules and a shock wave is
generated. This shock wave generates an audible sound.
[0041]
FIG. 6 is a schematic view of a portable terminal device 150 as an example of the electronic
device according to the first embodiment.
[0042]
As shown in FIG. 5, the portable terminal device 150 has a housing 151 and the electro-acoustic
transducer 100 provided in the housing 151.
The configuration of the electroacoustic transducer 100 is as described above.
[0043]
The housing 151 is formed with a sound emission hole (not shown) for emitting the sound wave
output from the electroacoustic transducer 100. The support portion 101 is fixed to, for example,
a circuit board (not shown) or the housing 151 of the mobile terminal device 150. The support
portion 101 may be a part of the housing 151.
04-05-2019
11
[0044]
The mobile terminal device 150 is, for example, a mobile phone, a PDA (Personal Digital
Assistant), a small game device, a laptop personal computer, or the like.
[0045]
According to the first embodiment as described above, the following effects can be obtained.
[0046]
The vibrating member 15 is fixed to the vibrating plate 14 by press-fitting the fixed shaft 15 b of
the vibrating member 15 made of metal into the fixing hole 14 a of the vibrating plate 14 made
of metal.
As a result, the junction between the vibrating member 15 and the diaphragm 14 becomes metal.
Therefore, the joint portion can suitably withstand the stress generated by the vibration, and the
reliability and the durability of the electroacoustic transducer 100 are improved. As a result, it is
possible to drive the piezoelectric vibrator 13, the diaphragm 14 and the vibrating member 15
for a long time with a large amplitude.
[0047]
Since the vibrating member 15 is press-fitted and fixed to the vibrating plate 14, a structure in
which the vibrating member 15 is fixed to the vibrating plate 14 with sufficient strength can be
easily realized. The vibrating member 15 can be fixed to the diaphragm 14 with sufficient
strength without using an adhesive. When the vibrating member 15 is fixed to the diaphragm 14
without using an adhesive, simplification of the manufacturing process and cost reduction are
possible.
[0048]
04-05-2019
12
Further, because the fixing shaft 15b is fixed to the fixing hole 14a of the diaphragm 14, the
fixing shaft 15b of the vibrating member 15 and the peripheral wall of the fixing hole 14a of the
diaphragm 14 are in close contact with each other. Therefore, the fixing position accuracy of the
vibrating member 15 with respect to the diaphragm 14 is improved. As a result, it is possible to
reduce variations in the fundamental resonance frequency (primary resonance frequency and
secondary resonance frequency) of the electroacoustic transducer 100. Therefore, the
electroacoustic transducer 100 can be manufactured with high yield. Here, when the vibrating
member is fixed to the fixing hole of the diaphragm simply by the adhesive instead of pressfitting, the fixing position accuracy of the vibrating member with respect to the diaphragm is
reduced due to the variation of the thickness of the adhesive, and the variation of the
fundamental resonance frequency is large. Could be Further, in the case where the vibrating
member is fixed to the vibrating plate using a rivet as in Patent Document 3, for example, there is
a possibility that variation occurs in the fixing position of the vibrating member with respect to
the vibrating plate in the cross direction to the axial direction of the rivet. As a result, there is
also a possibility that the variation of the fundamental resonance frequency becomes large.
[0049]
As described above, according to the present embodiment, the vibrating member 15 made of
metal and the vibrating plate 14 made of metal can be fixed to each other with sufficient strength
and position accuracy.
[0050]
Further, since the fixed shaft 15b of the vibrating member 15 and the peripheral wall of the
fixing hole 14a of the vibrating plate 14 are in close contact with each other, the integrity of the
metal of the vibrating member 15 and the metal of the vibrating plate 14 is improved.
Thereby, the vibration can be favorably transmitted from the diaphragm 14 to the vibrating
member 15.
[0051]
Further, the tip end surface 15 e of the fixed shaft 15 b is flush with the surface 14 b on the
opposite side to the main body portion 15 a of the diaphragm 14. That is, the fixed shaft 15 b
04-05-2019
13
does not protrude from the surface 14 b of the diaphragm 14. For this reason, even without
forming a hole in the piezoelectric vibrator 13, the piezoelectric vibrator 13 and the vibrating
plate 14 can be in close contact without any gap and can be surface-bonded. Therefore, even if a
hole is not formed in the piezoelectric vibrator 13, it is possible to join the piezoelectric vibrator
13 and the diaphragm 14 with sufficient strength. Further, since the contact area between the
diaphragm 14 and the fixed shaft 15b can be secured to the maximum, the bonding strength
between the diaphragm 14 and the fixed shaft 15b can be maximized. In Patent Document 3, in
the structure using the rivet, both ends of the rivet are crimped, and a gap for accommodating
the caulking portion on one end side of the rivet is present between the metal diaphragm and the
piezoelectric vibrator. ing. Therefore, there is a possibility that the bonding strength between the
piezoelectric vibrator and the metal diaphragm can not be sufficiently secured.
[0052]
The electroacoustic transducer 100 according to the first embodiment can be modified as
described below. Also in each modification, the same effect as the above can be obtained.
[0053]
Modified Example 1 FIG. 7 is a schematic cross-sectional view of an electro-acoustic transducer
100 according to a modified example 1 of the first embodiment. Among these, FIG. 7A shows a
state in which the vibrating member 15 is fixed to the vibrating plate 14, and FIG. 7B shows a
state before fixing the vibrating member 15 to the vibrating plate 14.
[0054]
In the case of the first modification, the circumferential surface of the fixed shaft 15b is
roughened. Specifically, for example, knurling is formed on the circumferential surface of the
fixed shaft 15b. In the circumferential surface of the fixed shaft 15b, the roughened portion is
referred to as a roughened portion 15d.
[0055]
The roughened portion 15d may be formed on the entire area of the fixed shaft 15b, or, as
shown in FIG. 7, is selectively formed only on the portion of the fixed shaft 15b that is press-fit
04-05-2019
14
into the fixed hole 14a. Also good.
[0056]
The fixed shaft 15 b is pressed into the fixed hole 14 a, and the roughened portion 15 d is in
close contact with the peripheral wall of the fixed hole 14 a in the diaphragm 14.
Thereby, in the first modification, high frictional resistance between the fixed shaft 15b and the
diaphragm 14 can be obtained. Therefore, according to the first modification, high bonding
strength between the vibrating member 15 and the vibrating plate 14 can be obtained.
[0057]
Modified Example 2 FIG. 8 is a schematic cross-sectional view of an electro-acoustic transducer
100 according to a modified example 2 of the first embodiment. In the case of the second
modification, the fixed shaft 15b is not only pressed into the fixed hole 14a, but also joined to the
peripheral wall of the fixed hole 14a in the diaphragm 14 via the bonding material 16 such as an
adhesive or solder.
[0058]
<Modification 3> FIG. 9 is a schematic cross-sectional view of an electro-acoustic transducer 100
according to a modification 3 of the first embodiment. In the case of the third modification, in the
piezoelectric vibrator 13, through holes 13 a penetrating the front and back of the piezoelectric
vibrator 13 are formed coaxially with the fixing holes 14 a of the diaphragm 14. The fixed shaft
15b of the vibrating member 15 is press-fitted and fixed to the fixed hole 14a, and the tip of the
fixed shaft 15b is inserted into the through hole 13a. For example, the tip end portion of the
fixed shaft 15b is inserted into the through hole 13a (inserted without a gap). The surface 13b of
the piezoelectric vibrator 13 on the opposite side to the diaphragm 14 and the end surface 15e
of the fixed shaft 15b are flush with each other.
[0059]
04-05-2019
15
<Modification 4> FIG. 10 is a schematic cross-sectional view of an electro-acoustic transducer
100 according to a modification 4 of the first embodiment. In the case of the fourth modification,
the fixing hole 14 a does not penetrate the diaphragm 14. The fixing hole 14a has a concave
shape. For this reason, the tip end surface 15 e of the fixed shaft 15 b is located closer to the
main body 15 a than the surface 14 b on the opposite side of the main body 15 a of the vibrating
member 15 in the diaphragm 14.
[0060]
Second Embodiment FIG. 11 is a schematic cross-sectional view of an electroacoustic transducer
200 according to a second embodiment.
[0061]
The electro-acoustic transducer 200 according to the second embodiment is different from the
electro-acoustic transducer 100 according to the above-described first embodiment only in the
points described below, and in the other points, the electro-acoustic transducer 100 It is
configured in the same way.
[0062]
In the first embodiment described above, the piezoelectric electroacoustic transducer 100 has
been described, but the electroacoustic transducer 200 according to the second embodiment is
an electrostatic electroacoustic transducer as described below. It is.
[0063]
In the case of the present embodiment, the vibrating element is a capacitor 17.
The capacitor 17 has a first electrode plate 17a, a second electrode plate 17b, and an insulating
member (dielectric member) 17c.
Each of the first electrode plate 17a and the second electrode plate 17b is a flat metal plate.
[0064]
04-05-2019
16
The first electrode plate 17 a is surface-bonded to the surface 14 b of the diaphragm 14 opposite
to the main body 15 a of the vibrating member 15.
Also in the case of the present embodiment, for example, the surface 14 b of the diaphragm 14
opposite to the vibrating member 15 and the tip surface 15 e of the fixed shaft 15 b are flush
with each other. The first electrode plate 17a is in close contact with the diaphragm 14 without
any gap and is surface-joined. The front end surface 15 e abuts and contacts, for example, the
surface of the first electrode plate 17 a on the side of the diaphragm 14.
[0065]
The second electrode plate 17 b is disposed to face the first electrode plate 17 a. The second
electrode plate 17 b is provided on the bottom plate 11 via the support 12.
[0066]
The insulating member 17c is made of a low elastic insulating material such as a resin. The first
electrode plate 17a is supported on the second electrode plate 17b via the insulating member
17c. The insulating member 17c mutually insulates the first electrode plate 17a and the second
electrode plate 17b. The capacitor 17 has, for example, a plurality of insulating members 17c.
[0067]
The input unit 20 inputs a signal to the capacitor 17 to vibrate the capacitor 17. More
specifically, the input unit 20 inputs a modulation signal (for example, a modulation signal for
parametric speaker) to the capacitor 17 to vibrate the capacitor 17. Thereby, the vibration of the
condenser 17 is transmitted to the diaphragm 14 and the vibrating member 15, and a sound
wave (for example, an ultrasonic wave) is oscillated (emitted) from the diaphragm 14 and the
vibrating member 15.
[0068]
04-05-2019
17
The electronic device according to the present embodiment is different from the electronic device
according to the first embodiment only in that the electronic device according to the present
embodiment includes an electro-acoustic transducer 200 instead of the electro-acoustic
transducer 100.
[0069]
Also by the second embodiment as described above, the same effect as that of the first
embodiment can be obtained.
[0070]
Although the above-mentioned each embodiment explained the example (example whose
oscillating member 15 is a metal cone) whose main part 15a of oscillating member 15 is pyramid
shape, shape of oscillating member 15 is not restricted to this example.
For example, the vibration member 15 may have a flat plate portion (not shown) and a fixed shaft
15b depending from the center of the flat portion.
[0071]
DESCRIPTION OF SYMBOLS 10 ultrasonic transducer 11 bottom plate 12 post 13 piezoelectric
transducer 13a through hole 13b surface 14 diaphragm 14a fixing hole 14b surface 15 vibrating
member 15a main body portion 15b fixing shaft 15c recessed portion 15d roughened portion
15e front end surface 16 bonding material 17 capacitor 17a first electrode plate 17b second
electrode plate 17c insulating member 20 input portion 100 electroacoustic transducer 101
supporting portion 150 portable terminal device 151 housing 200 electroacoustic transducer
04-05-2019
18
Документ
Категория
Без категории
Просмотров
0
Размер файла
28 Кб
Теги
jp2013172237
1/--страниц
Пожаловаться на содержимое документа