close

Вход

Забыли?

вход по аккаунту

?

JP2000253479

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 JP2000253479
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an
ultrasonic vibration element that emits ultrasonic waves, and more particularly to an ultrasonic
vibration element in a speaker device.
[0002]
2. Description of the Related Art FIG. 8 is a block diagram showing an ultrasonic vibration
element of Conventional Example 1 disclosed in Japanese Patent Application Laid-Open No. 61296897. In the figure, 101 is an ultrasonic vibration element, 102 is a diaphragm made of a
piezoelectric material such as ceramic, 103 is a case having a truncated conical cross section,
104 is an elastic vibration isolator holding case 103, and 105 is an AC signal. Terminal pins 106
are lead wires for connecting the diaphragm 102 and the terminal pins 105, and the case 103
and the terminal pins 105.
[0003]
In the ultrasonic vibration element 101 of the prior art example 1, the vibration plate 102 is
attached to the inside of the bottom portion 103 a of the case 103 to constitute a bimorph
vibrator, that is, an ultrasonic radiation source. Further, the circular holes 104 a formed in the
elastic vibration isolation body 104 form an acoustic pipe 107 at an opposing position across the
04-05-2019
1
bottom surface portion 103 a of the case 103.
[0004]
Next, the operation will be described. When an alternating current signal is input from the
terminal pin 105, the signal is applied to the diaphragm 102 and the case 103 via the lead wire
106, and the bimorph oscillator vibrates. Then, ultrasonic waves are emitted to the outside
through the acoustic tube 107 by this vibration.
[0005]
FIG. 9 is a block diagram showing an ultrasonic vibration element of Conventional Example 2
disclosed in Japanese Patent Application Laid-Open No. 9-327095. In the figure, 201 is an
ultrasonic vibration element, 202 and 203 are diaphragms made of piezoelectric material such as
ceramic, 204 is an intermediate plate made of metal such as stainless steel, 205 is a soft
adhesive, 206 is a cone vibrator, 207 is vibration. A pin for coupling the plate 202 and the cone
vibrator 206, a base 208, a terminal pin 209 for receiving an AC signal, and a terminal 210 for
connecting the diaphragms 202 and 203 and the terminal pin 209, and the intermediate plate
204 and the terminal pin 209 It is a lead wire.
[0006]
In the ultrasonic vibration element 201 of the conventional example 2, the bimorph vibrator, that
is, the ultrasonic radiation source is configured by arranging the diaphragms 202 and 203 with
the intermediate plate 204 interposed therebetween. In addition, when the bimorph oscillator is
flexurally vibrated, a complex of the bimorph oscillator and the cone oscillator 206 is formed on
the conical surface of the cone oscillator 206 so as to form an annular vibration node 206a
centered on the conical axis. Are configured. In addition, the complex of the bimorph oscillator
and the cone oscillator 206 is coupled to the pedestal 208 at the node position of the flexural
vibration of the bimorph oscillator.
[0007]
04-05-2019
2
Next, the operation will be described. When an alternating current signal is input from the
terminal pin 209, the signal is applied to the diaphragms 202 and 203 and the intermediate
plate 204 through the lead wires 210, and the bimorph oscillator is flexurally vibrated. Further,
due to the vibration of the bimorph vibrator, the cone vibrator 206 vibrates in the opposite phase
with the node 206 a of the vibration of the cone vibrator 206 as a boundary. And an ultrasonic
wave is emitted by vibration of these cone vibrator 206 and a bimorph vibrator.
[0008]
FIG. 10 shows the vibration when the frequency of the alternating current signal applied to the
bimorph vibrator is scanned in the conventional ultrasonic vibration element provided with one
ultrasonic radiation source as shown in the above-described Conventional example 1 and
Conventional example 2 It is a sound radiation characteristic view. In FIG. 10, the upper curve
shows the radiation characteristics of the ultrasonic wave emitted from the ultrasonic vibration
element, and the lower curve shows the vibration characteristics of the bimorph oscillator to
which an AC signal is applied. The vertical axis in the upper curve is the output sound pressure
level, and the horizontal axis is the frequency of the ultrasonic wave emitted from the ultrasonic
transducer. The vertical axis in the lower curve is the electrical impedance, and the horizontal
axis is the frequency of the AC signal applied to the bimorph oscillator.
[0009]
As shown in FIG. 10, in the conventional ultrasonic transducer, when the frequency of the AC
signal applied to the bimorph transducer is scanned, the electrical impedance shows a peak at
the frequency f01. In addition, when the frequency of the AC signal applied to the bimorph
oscillator is scanned, an ultrasonic wave with a very narrow frequency width with the frequency
f01 being the maximum sound pressure level is emitted. The frequency f01 is a frequency
dependent on the characteristic value of the diaphragm constituting the bimorph oscillator, that
is, the resonance frequency, and the nature of the material that the diaphragm is made of a
piezoelectric plate such as ceramics and the ultrasonic vibration element is small. Due to the
restriction of the structure, the frequency f01 is located in the high frequency band.
[0010]
Therefore, in the conventional ultrasonic vibration element, an alternating current signal in the
04-05-2019
3
vicinity of the frequency f01 is applied to the bimorph vibrator to vibrate the bimorph vibrator to
emit ultrasonic waves. In short, the AC signal near the frequency f01 is reproduced.
[0011]
As described above, the conventional ultrasonic vibration element has been used as a buzzer in
various electric devices and electronic devices because the frequency band of reproduced sound
is high and the frequency width is narrow.
[0012]
As described above, since the conventional ultrasonic vibration element has a configuration
including only one bimorph transducer, that is, an ultrasonic radiation source, the output sound
pressure of the ultrasonic wave to be emitted is The level is low.
As a result, there is a problem that the reproduction sound can not be provided to the listener at
a distant position.
[0013]
In addition, in the conventional ultrasonic vibration element, the frequency width of the
reproduction sound is narrow, and it is impossible to reproduce an AC signal in a wide frequency
range. As a result, there is a problem that it is not possible to reproduce complex melodies and
the like. In addition, when it is comprised so that the alternating current signal of a wide
frequency range can be reproduced | regenerated by one ultrasonic radiation source which
consists of a bimorph vibrator | oscillator and a diaphragm single-piece, the result of the
characteristic that it is a compact structure will be lost.
[0014]
The present invention has been made to solve the problems as described above, and it is an
object of the present invention to obtain an ultrasonic transducer capable of emitting ultrasonic
waves at a high output sound pressure level.
[0015]
04-05-2019
4
Another object of the present invention is to provide an ultrasonic transducer which has a
compact structure and can reproduce AC signals in a wide frequency range.
[0016]
SUMMARY OF THE INVENTION An ultrasonic vibration element according to the present
invention is provided with a plurality of ultrasonic radiation sources with their radiation
directions aligned.
[0017]
In the ultrasonic vibration element according to the present invention, the ultrasonic radiation
source is an inherent value of the diaphragm and the diaphragm in which the axial direction is
aligned with the direction perpendicular to the plate surface of the diaphragm and the ultrasonic
radiation source faces the diaphragm. And a conical oscillator having the same eigenvalue.
[0018]
The ultrasonic vibration element according to the present invention changes the outer diameter
dimension of the diaphragm for each ultrasonic radiation source, and at the same time shows the
resonance frequency of the diaphragm showing the maximum resonance frequency from the
resonance frequency of the diaphragm showing at least the minimum resonance frequency. The
respective ultrasonic radiation sources are arranged close to one another so that input
alternating current signals in the frequency range up to can be reproduced in the region reached
by the ultrasonic waves emitted from all the ultrasonic radiation sources.
[0019]
The ultrasonic vibration element according to the present invention is a diaphragm, and a cone
having the same eigenvalue as the eigenvalue of the diaphragm, disposed opposite to the
diaphragm with a direction perpendicular to the plate surface of the diaphragm being matched
with the axial direction. And an elastic member inserted in the gap between the diaphragm and
the vibrator.
[0020]
The ultrasonic transducer according to the present invention comprises a plurality of ultrasonic
radiation sources.
[0021]
04-05-2019
5
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present
invention will be described.
Embodiment 1
FIG. 1 is a side view showing an ultrasonic transducer according to Embodiment 1 of the present
invention.
FIG. 2 is a top view showing an ultrasonic transducer according to Embodiment 1 of the present
invention.
In the figure, 1 is an ultrasonic vibration element, 2a to 2c are circular first 1 to 3 diaphragms
(diaphragm) made of a piezoelectric material such as ceramic, and 3a to 3c are conical shapes
made of a piezoelectric material such as ceramic Are the first to third sound radiation
transducers (vibrator).
The first sound radiation vibrator 3a has its short diameter end directed to the first diaphragm
2a side and its long diameter end facing the first diaphragm 2a opposite to the first diaphragm
2a The second sound radiation vibrator 3b has its short diameter end directed to the second
diaphragm 2b side and the long diameter end opposed to the second diaphragm 2b with its long
end opposite to the second diaphragm 2b. The third sound radiation vibrator 3c has its short
diameter end directed to the third diaphragm 2c side and the long diameter end directed to the
opposite side to the third vibration plate 2c. It is opposite to.
[0022]
Also, 4a is a first connection body for fixing the first sound radiation vibrator 3a to the first
diaphragm 2a, and 4b is a second connection body for fixing the second sound radiation vibrator
3b to the second diaphragm 2b. The connection body 4c is a third connection body for fixing the
third sound radiation transducer 3c to the third diaphragm 2c.
[0023]
Further, 5a is a first vibration damping body that holds a complex of the first diaphragm 2a and
04-05-2019
6
the first sound radiation transducer 3a, 5b is a second diaphragm 2b and the second sound
radiation transducer 3b. And a third vibration isolation body 5c for holding a complex of the
third diaphragm 2c and the third sound radiation vibrator 3c.
[0024]
Further, 6a is a first adhesive layer for fixing a composite of the first diaphragm 2a and the first
sound radiation transducer 3a to the first vibration damping body 5a, and 6b is a second
diaphragm 2b and a second A second adhesive layer for fixing the complex of the second sound
radiation vibrator 3b to the second vibration isolation body 5b; 6c a complex of the third
diaphragm 2c and the third sound radiation vibrator 3c It is a third adhesive layer fixed to the
third vibration isolation body 5c.
[0025]
Further, 7 is a first vibration-proof body 5a to which a complex of the first diaphragm 2a and the
first sound radiation vibrator 3a is fixed, a second diaphragm 2b, and a second sound radiation
vibrator 3b. The second vibration isolation body 5b to which the composite of the second
embodiment is fixed, and the third vibration isolation body 5c to which the composite of the third
vibration plate 2c and the third sound radiation vibrator 3c is fixed. .
[0026]
Further, 8a includes a first diaphragm 2a, a first sound radiation vibrator 3a, a first connection
body 4a, a first vibration isolation body 5a, a first adhesive layer 6a, and a frame 7. 1 from the
second vibration plate 2b, the second sound radiation vibrator 3b, the second connection body
4b, the second vibration isolation body 5b, the second adhesive layer 6b, and the frame 7. The
second vibrating structure configured, 8c is a third diaphragm 2c, a third sound radiation
vibrator 3c, a third connection body 4c, a third vibration isolation body 5c, a third adhesive layer
6c, And the gantry 7 is a third vibration structure.
[0027]
Reference numeral 9 denotes a terminal pin to which an AC signal is input. One terminal pin 9 is
connected to the first to third diaphragms 2a to 2c via a lead wire (not shown) or the like, and
the other terminal pin 9 are connected to the first to third sound radiation transducers 3a to 3c
through lead wires (not shown) or the like.
[0028]
04-05-2019
7
As described above, the ultrasonic vibration element 1 according to the first embodiment
includes the three vibration structures 8 a to 8 c.
In the ultrasonic vibration element 1 according to the first embodiment, each of the vibration
structures 8a to 8c is provided with an ultrasonic radiation source including a diaphragm and a
sound radiation vibrator (hereinafter referred to as the first An ultrasonic radiation source
comprising the diaphragm 2a and the first sound radiation transducer 3a is referred to as a first
ultrasonic radiation source 1a, and the second vibration plate 2b and the second sound radiation
transducer 3b An ultrasonic radiation source comprising the second ultrasonic radiation source
1b, an ultrasonic radiation source comprising the third diaphragm 2c and the third sound
radiation transducer 3c is the third ultrasonic radiation Source 1 c.).
[0029]
Further, in the ultrasonic vibration element 1 of the first embodiment, the first sound radiation
vibrator 3a is fixed to the first diaphragm 2a by the first connection body 4a. The second sound
radiation vibrator 3b is disposed so as to face the first diaphragm 2a, and the second sound
radiation vibrator 3b is fixed to the second diaphragm 2b by the second connection body 4b. The
third sound radiation vibrator 3c is fixed to the third vibration plate 2c by the third connection
body 4c, and the third sound radiation vibrator 3c is arranged to be third vibration. It arranges
opposite to board 2c.
Furthermore, the direction perpendicular to the plate surface of the first diaphragm 2a is made to
coincide with the axial direction of the first sound radiation transducer 3a, and the direction
perpendicular to the plate surface of the second diaphragm 2b and the second sound The axial
direction of the radiation vibrator 3b is matched, and the direction perpendicular to the plate
surface of the third diaphragm 2c is matched with the axial direction of the third sound radiation
vibrator 3c.
Furthermore, the eigen value of the first sound radiation transducer 3a is made the same value as
the eigen value of the first diaphragm 2a, and the eigen value of the second sound radiation
transducer 3b is made the same value as the eigen value of the second diaphragm 2b. The
characteristic value of the third sound radiation transducer 3c is made the same as the
characteristic value of the third diaphragm 2c.
04-05-2019
8
Thus, the output sound pressure levels of the ultrasonic radiation sources 1a to 1c are raised.
[0030]
Further, in the ultrasonic vibration element 1 of the first embodiment, the ultrasonic radiation
directions of the ultrasonic radiation sources 1a to 1c are aligned by making the directions
perpendicular to the plate surfaces of the diaphragms 2a to 2c coincide. There is.
[0031]
Furthermore, in the ultrasonic vibration element 1 of the first embodiment, the outer diameter
size of the first to third diaphragms 2a to 2c, that is, the diameter is changed to change the value
of the resonance frequency of each diaphragm 2a to 2c. In addition, the ultrasonic waves emitted
from all the ultrasonic radiation sources reach the input AC signal in the frequency range from
the resonant frequency of the diaphragm exhibiting the minimum resonant frequency to the
resonant frequency of the diaphragm exhibiting the maximum resonant frequency. The
ultrasonic radiation sources 1a to 1c are arranged close to one another so as to be reproducible
in the area.
[0032]
Next, the operation will be described.
When an alternating current signal is input from the terminal pin 9, the signal is applied to the
diaphragms 2a to 2c and the sound radiation transducers 3a to 3c through the lead wires or the
like, and the diaphragms 2a to 2c and the sound radiation transducers 3a to 3c vibrate.
Then, ultrasonic waves are emitted by the vibrations of the diaphragms 2a to 2c and the sound
radiation transducers 3a to 3c.
[0033]
FIG. 3 is a vibration-sound radiation characteristic diagram when scanning the frequency of the
AC signal applied to each ultrasonic vibration source in the ultrasonic vibration element of the
04-05-2019
9
first embodiment.
In FIG. 3, the upper curve shows the radiation characteristic of the ultrasonic wave emitted from
the ultrasonic vibration element, and the lower curve shows the vibration characteristic of each
ultrasonic radiation source to which an AC signal is applied.
The vertical axis in the upper curve is the output sound pressure level, and the horizontal axis is
the frequency of the ultrasonic wave emitted from the ultrasonic transducer.
The vertical axis in the lower curve is the electrical impedance, and the horizontal axis is the
frequency of the AC signal applied to each ultrasonic radiation source.
[0034]
As shown in FIG. 3, in the ultrasonic vibration element 1 according to the first embodiment, when
the frequency of the AC signal applied to each of the ultrasonic vibration sources 1 a to 1 c is
scanned, the first ultrasonic radiation source at the frequency f01 The electrical impedance of 1a
shows a peak (curve a) and the electrical impedance of the first ultrasonic radiation source 1b
shows a peak at a frequency f0 2 (curve b), and the third ultrasonic radiation source 1c has a
frequency f0 3 The electrical impedance shows a peak (curve c).
In addition, when the frequency of the AC signal applied to each of the ultrasonic vibration
sources 1a to 1c is scanned, an ultrasonic wave is emitted from the first ultrasonic radiation
source 1a with the frequency f01 as the maximum sound pressure level (curve d) And an
ultrasonic wave having a frequency f02 as the maximum sound pressure level is emitted from the
second ultrasonic radiation source 1b (curve e), and an ultrasonic wave having the frequency f03
at the maximum sound pressure level from the third ultrasonic wave radiation source 1c. Sound
waves are emitted (curve f), and the ultrasonic waves emitted from the first to third ultrasonic
radiation sources 1a to 1c overlap each other to emit ultrasonic waves having at least a
frequency width from frequency f01 to frequency f03. (Curve g). The frequencies f01, f02 and
f03 are frequencies dependent on the eigenvalues of the first to third diaphragms 2a to 2c
respectively, that is, resonance frequencies, and the outer shapes of the first to third diaphragms
2a to 2c Because the dimensions are changed, the values of the frequencies f01, f02 and f03 are
different.
04-05-2019
10
[0035]
Therefore, in the ultrasonic vibration element 1 according to the first embodiment, when an AC
signal of at least frequency f01 to frequency f03 is applied to each of the ultrasonic radiation
sources 1a to 1c, the ultrasonic wave is emitted. it can. In short, alternating current signals in a
frequency range of at least frequency f01 to frequency f03 can be regenerated in a region
reached by ultrasonic waves emitted from all ultrasonic radiation sources.
[0036]
As described above, the ultrasonic vibration element 1 according to the first embodiment has a
wide frequency width of the reproduction sound, and can reproduce a complicated melody and
the like.
[0037]
As described above, according to the first embodiment, since three ultrasonic radiation sources
are provided, compared to the conventional ultrasonic vibration element provided with one
ultrasonic radiation source, the radiated super An effect of increasing the output sound pressure
level of the sound wave is obtained.
[0038]
Further, according to the first embodiment, since each ultrasonic radiation source comprises the
diaphragm and the sound radiation vibrator, the output sound pressure of the ultrasonic wave
radiated from each ultrasonic radiation source The effect of increasing the level is obtained.
[0039]
Furthermore, according to the first embodiment, the outer diameter size of each diaphragm is
changed, and the ultrasonic radiation sources are arranged close to each other. Therefore, the
maximum resonance from the resonance frequency of the diaphragm exhibiting the minimum
resonance frequency is obtained. The effect is obtained that the input AC signal in the frequency
range up to the resonance frequency of the diaphragm indicating the frequency can be
reproduced in the area reached by the ultrasonic waves emitted from all the ultrasonic radiation
sources.
[0040]
04-05-2019
11
Second Embodiment
FIG. 4 is a side view showing an ultrasonic transducer according to Embodiment 2 of the present
invention.
FIG. 5 is a top view showing an ultrasonic transducer according to Embodiment 2 of the present
invention.
In the figure, 11 is an ultrasonic vibration element, 12 is a circular diaphragm made of a
piezoelectric material such as ceramic, and 13 is a sound emitting vibrator (vibrator) made of a
piezoelectric material such as ceramic.
The sound radiation vibrator 13 faces the diaphragm 12 with its short diameter end directed to
the diaphragm 12 side and the long diameter end opposite to the diaphragm 12.
[0041]
Further, 14 is a connection body for fixing the sound radiation vibrator 13 to the diaphragm 12,
15 is a vibration isolation body for holding a complex of the vibration plate 12 and the sound
radiation vibrator 13, and 16 is sound radiation vibration for the diaphragm 12 An adhesive
layer for fixing the complex with the element 13 to the vibration-proof body 15, and a frame 17
for holding the vibration-proof body 15 to which the complex of the vibration plate 12 and the
sound emission vibrator 13 is fixed.
[0042]
Reference numeral 18 denotes an elastic member made of a damping material such as urethane
foam, inserted in the gap between the diaphragm 12 and the sound radiation vibrator 13. The
elastic member 18 is in contact with the vibration plate 12 and the sound radiation vibrator It
works to reduce the vibration at 13 resonance frequencies.
[0043]
Further, reference numeral 19 denotes a vibration structure composed of the vibration plate 12,
the sound radiation vibrator 13, the connection body 14, the vibration isolation body 15, the
04-05-2019
12
adhesive layer 16, the mount 17, and the elastic member 18.
[0044]
Reference numeral 20 denotes a terminal pin to which an AC signal is input. One terminal pin 20
is connected to the diaphragm 12 via a lead (not shown) or the like, and the other terminal pin
20 is a lead (not shown) ) And the like are connected to the sound radiation vibrator 13.
[0045]
Thus, the ultrasonic vibration element 11 of the second embodiment includes one vibration
structure 19.
Further, in the ultrasonic vibration element 11 of the second embodiment, the vibration structure
19 includes the ultrasonic radiation source 11 a including the diaphragm 12, the sound radiation
vibrator 13 and the elastic member 18.
Further, as in the case of the first embodiment, the sound radiation vibrator 13 is fixed to the
diaphragm 12 by the connector 14 so that the sound radiation vibrator 13 is disposed to face the
diaphragm 12, and the diaphragm 12 is further provided. From the ultrasonic radiation source
by matching the direction perpendicular to the plane of the plate with the axial direction of the
sound radiation transducer 13 and making the characteristic value of the sound radiation
transducer 13 the same as the characteristic value of the diaphragm 12 The output sound
pressure level of the emitted ultrasonic wave is raised.
[0046]
FIG. 6 is a vibration-sound radiation characteristic diagram when scanning the frequency of an
AC signal applied to an ultrasonic vibration source in the ultrasonic vibration element according
to the second embodiment.
In FIG. 6, the upper curve shows the radiation characteristic of the ultrasonic wave emitted from
the ultrasonic vibration element, and the lower curve shows the vibration characteristic of the
ultrasonic radiation source to which an AC signal is applied.
04-05-2019
13
The vertical axis in the upper curve is the output sound pressure level, and the horizontal axis is
the frequency of the ultrasonic wave emitted from the ultrasonic transducer. The vertical axis in
the lower curve is the electrical impedance, and the horizontal axis is the frequency of the AC
signal applied to the ultrasonic radiation source.
[0047]
As shown in FIG. 6, in the ultrasonic vibration element 11 of the second embodiment, when the
frequency of the AC signal applied to the ultrasonic vibration source 11a is scanned, the
electrical impedance of the ultrasonic radiation source 11a is a peak at a frequency f01. (Curve a)
shows that the width of the peak is wider than in the conventional case (curve b). Also, when the
frequency of the AC signal applied to the ultrasonic vibration source 11a is scanned, an
ultrasonic wave with the frequency f01 as the maximum sound pressure level is emitted (curve
c), but the frequency width of the ultrasonic wave is the conventional one. Wider than the case
(curve d). The frequency f01 is a frequency dependent on the characteristic value of the
diaphragm 12, that is, a resonance frequency.
[0048]
Therefore, in the ultrasonic vibration element 11 according to the second embodiment, ultrasonic
waves can be emitted even when an AC signal in a wider frequency range than in the
conventional case is applied to the ultrasonic radiation source 11a. In short, it is possible to
reproduce AC signals in a wider frequency range than in the conventional case.
[0049]
As described above, according to the second embodiment, the ultrasonic radiation source
includes the diaphragm, the sound radiation vibrator, and the elastic member, so that the
ultrasonic radiation source is compared to the conventional ultrasonic vibration element. Thus,
the effect of being able to reproduce AC signals in a wide frequency range is obtained.
[0050]
04-05-2019
14
Third Embodiment
In the third embodiment, the elastic member described in the second embodiment is inserted into
the gap between the diaphragm and the sound radiation transducer in each ultrasonic radiation
source of the ultrasonic vibration element of the first embodiment, and each ultrasonic radiation
is emitted. The source comprises a diaphragm, a sound radiation transducer and an elastic
member.
[0051]
FIG. 7 is a side view showing an ultrasonic transducer according to Embodiment 3 of the present
invention. In the figure, 21 is an ultrasonic vibration element, 22a is a first elastic member
(elastic member) inserted in the gap between the first diaphragm 2a and the first sound radiation
transducer 3a, and 22b is a second vibration. The second elastic member (elastic member)
inserted in the gap between the plate 2b and the second sound radiation oscillator 3b, 22c is
inserted in the gap between the third diaphragm 2c and the third sound radiation oscillator 3c
The first to third elastic members 22a to 22c are made of a damping material such as urethane
foam. Reference numerals 21a to 21c denote first to third ultrasonic radiation sources (ultrasonic
radiation sources). The other components are the same as or similar to those described with the
same reference numerals in the first embodiment, and thus the description thereof is omitted.
[0052]
The vibration-sound radiation characteristic of the ultrasonic vibration element 21 of the third
embodiment is the same as that of the first embodiment, but the frequency width of the
ultrasonic waves emitted from the respective ultrasonic radiation sources 21a to 21c is the same
as that of the first embodiment. The frequency range from the frequency f01 to the frequency
f03 is wider than the case of the first embodiment compared with the case of the first
embodiment.
[0053]
As described above, according to the third embodiment, the same effects as those of the first
embodiment can be obtained, and each ultrasonic wave radiation source includes the diaphragm,
the sound radiation vibrator, and the elastic member. As it comprises, it is possible to reproduce
the input AC signal in a wider frequency range than in the case where the ultrasonic waves
emitted from all the ultrasonic radiation sources reach as compared with the case of the first
embodiment. The effect can be obtained.
04-05-2019
15
[0054]
In the first and third embodiments described above, the case where three ultrasonic radiation
sources are provided has been described, but the number of ultrasonic radiation sources is not
limited to three, and may be an arbitrary number. Also good.
[0055]
Moreover, although the case where a diaphragm is circular was demonstrated in each
embodiment mentioned above, the shape of a diaphragm is not only circular but arbitrary shapes
may be sufficient.
[0056]
As described above, according to the present invention, since the ultrasonic vibration element is
configured to have a plurality of ultrasonic radiation sources with the radiation directions of the
ultrasonic waves aligned in the same direction, the output of the radiated ultrasonic waves It has
the effect of increasing the sound pressure level.
[0057]
According to the present invention, the ultrasonic wave radiation source has the same
characteristic value as the characteristic value of the diaphragm, which is disposed opposite to
the diaphragm with the diaphragm and the direction of the axis perpendicular to the direction
perpendicular to the plate surface of the diaphragm. Since the ultrasonic vibration element is
configured to have a conical transducer having a conical shape, there is an effect that the output
sound pressure level of the ultrasonic wave emitted from each ultrasonic radiation source
becomes high.
[0058]
According to the present invention, since the ultrasonic vibration element is configured to change
the outer diameter dimension of the diaphragm for each ultrasonic radiation source and to
arrange the respective ultrasonic radiation sources close to each other, the diaphragm exhibiting
the minimum resonance frequency The input AC signal in the frequency range from the resonant
frequency of to the resonant frequency of the diaphragm showing the maximum resonant
frequency can be reproduced in the area reached by the ultrasonic waves emitted from all the
ultrasonic radiation sources. is there.
04-05-2019
16
[0059]
According to the present invention, the diaphragm and the conical vibrator having the same
eigen value as the eigen value of the diaphragm are disposed opposite to the diaphragm with the
direction perpendicular to the plate surface of the diaphragm and the axial direction matched.
Since the ultrasonic vibration element is configured to include the ultrasonic radiation source
including the elastic member inserted into the gap between the diaphragm and the vibrator, the
AC signal in a wide frequency range can be reproduced. effective.
[0060]
According to the present invention, since the ultrasonic vibration element is configured to
include a plurality of ultrasonic radiation sources, there is an effect that the output sound
pressure level of the emitted ultrasonic wave becomes high.
04-05-2019
17
Документ
Категория
Без категории
Просмотров
0
Размер файла
27 Кб
Теги
jp2000253479
1/--страниц
Пожаловаться на содержимое документа