close

Вход

Забыли?

вход по аккаунту

?

JP2008258904

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 JP2008258904
The present invention provides a high quality microphone unit which is small in size and capable
of deep noise removal, an audio input device, and an information processing system. A
microphone unit (1) has a housing (10) having an internal space (100), and an internal space
provided in the housing that divides the internal space into a first space (102) and a second
space (104). It includes a partition member 20 made of a film 30, and an electric signal output
circuit 40 that outputs an electric signal based on the vibration of the vibrating film. In the
housing 10, a first through hole 12 for communicating the first space 102 with the external
space of the housing, and a second through hole 14 for communicating the second space 104
with the external space of the housing. And are formed. [Selected figure] Figure 2
Microphone unit, close-talking type voice input device, and information processing system
[0001]
The present invention relates to a microphone unit, a close-talking voice input device, and an
information processing system.
[0002]
It is preferable to pick up only the target voice (user's voice) at the time of a telephone call or the
like, voice recognition, voice recording and the like.
However, in the use environment of the voice input device, sounds other than the intended voice
03-05-2019
1
such as background noise may be present. Therefore, development of a voice input device having
a function of removing noise, which enables accurate extraction of the user's voice even when
used in an environment where noise is present, is in progress.
[0003]
As a technology to remove noise in a use environment where noise is present, the microphone
unit should be made to have a sharp directivity, or noise arrival directions may be identified
using signal arrival time differences to remove noise by signal processing. The way to do it is
known.
[0004]
Further, in recent years, the miniaturization of electronic devices has progressed, and techniques
for miniaturizing voice input devices have become important.
JP-A-7-312638 JP-A-9-331377 JP-A-2001-186241
[0005]
In order to make the microphone unit have a sharp directivity, it is necessary to arrange a large
number of vibrating membranes, and miniaturization is difficult.
[0006]
In addition, in order to detect the arrival direction of the sound wave with high accuracy by
utilizing the difference in arrival time of sound wave, it is necessary to install a plurality of
diaphragms at intervals of about a few wavelengths of the audible sound wave. Is difficult.
[0007]
An object of the present invention is to provide a high quality microphone unit which is small in
size and capable of deep noise removal, a close-talking type voice input device, and an
information processing system.
[0008]
(1) A microphone unit according to the present invention includes: a case having an inner space;
03-05-2019
2
and the inner space provided in the case, which divides the inner space into a first space and a
second space, at least a part of which vibrates. A partition member made of a film, and an electric
signal output circuit that outputs an electric signal based on the vibration of the vibrating film,
and the case includes the first space and an external space of the case And a second through hole
communicating the second space with the external space of the housing.
[0009]
According to the present invention, user voice and noise are incident on both sides of the
diaphragm.
Of the sound incident on both sides of the diaphragm, noise components have almost the same
sound pressure, and thus cancel each other out with the diaphragm.
Therefore, the sound pressure for vibrating the diaphragm can be regarded as the sound
pressure indicative of the user's voice, and the electrical signal acquired based on the vibration of
the diaphragm has the noise removed and the electricity indicative of the user's voice. It can be
considered as a signal.
[0010]
From this, according to the present invention, it is possible to provide a high quality microphone
unit capable of deep noise removal with a simple configuration.
[0011]
(2) In this microphone unit, the partition member may be provided so that a medium that
propagates an acoustic wave does not move between the first and second spaces inside the
housing.
[0012]
(3) In this microphone unit, the outer shape of the housing may be a polyhedron, and the first
and second through holes may be formed in one surface of the polyhedron.
[0013]
03-05-2019
3
That is, in this microphone unit, the first and second through holes may be formed in the same
surface of the polyhedron.
In other words, the first and second through holes may be formed in the same direction.
As a result, since the sound pressure of the noise incident on the inside of the housing can be
(approximately) equalized from the first and second through holes, the noise can be removed
with high accuracy.
[0014]
(4) In this microphone unit, the vibrating membrane may be disposed such that a normal is
parallel to the surface.
[0015]
(5) In this microphone unit, the vibrating membrane may be disposed such that a normal is
orthogonal to the surface.
[0016]
(6) In this microphone unit, the vibrating membrane may be disposed so as not to overlap with
the first or second through hole.
[0017]
According to this, even when foreign matter enters the internal space through the first and
second through holes, the possibility that the vibrating membrane is directly damaged by the
foreign matter can be reduced.
[0018]
(7) In this microphone unit, the vibrating membrane may be disposed to the side of the first or
second through hole.
[0019]
03-05-2019
4
(8) In this microphone unit, the vibrating membrane may be arranged such that the distance
from the first through hole and the distance from the second through hole are not equal.
[0020]
(9) In this microphone unit, the partition members may be arranged such that the volumes of the
first and second spaces become the same.
[0021]
(10) In this microphone unit, a distance between centers of the first and second through holes
may be 5.2 mm or less.
[0022]
(11) In this microphone unit, at least a part of the electric signal output circuit may be formed
inside the housing.
[0023]
(12) In this microphone unit, the housing may have a shielding structure that electromagnetically
shields the internal space and an external space of the housing.
[0024]
(13) In the voice input device according to the present invention, there is provided a housing
having an internal space, and at least a part of the internal space provided in the housing for
dividing the internal space into a first space and a second space. Includes a partition member
formed of a vibrating membrane, and an electric signal output circuit that outputs an electric
signal based on the vibration of the vibrating membrane, and the housing includes the first space
and the outside of the housing A microphone unit is mounted in which a first through hole
communicating with the space and a second through hole communicating the second space and
the external space of the housing are formed.
[0025]
According to this voice input device, it is possible to obtain an electrical signal indicating the
user's voice from which the noise has been accurately removed.
03-05-2019
5
Therefore, according to the present invention, it is possible to provide a voice input device that
can realize high-accuracy voice recognition processing, voice authentication processing,
command generation processing based on input voice, and the like.
[0026]
(14) An information processing system according to the present invention includes: a case having
an internal space; and the internal space provided in the case, which divides the internal space
into a first space and a second space, at least a part of which A partition member made of a
vibrating membrane, and an electric signal output circuit that outputs an electric signal based on
the vibration of the vibrating membrane, wherein the housing includes the first space and an
external space of the housing A microphone unit having a first through hole communicating with
the second space, and a second through hole communicating the second space with the external
space of the housing; And an analysis processing unit that performs analysis processing of voice
incident on the microphone unit.
[0027]
According to this voice input device, it is possible to obtain an electrical signal indicating the
user's voice from which the noise has been accurately removed.
Therefore, according to the present invention, it is possible to provide an information processing
system capable of realizing an analysis process of speech with high accuracy.
[0028]
Hereinafter, embodiments to which the present invention is applied will be described with
reference to the drawings.
However, the present invention is not limited to the following embodiments.
Further, the present invention includes any combination of the following contents.
03-05-2019
6
[0029]
1.
Configuration of Microphone Unit 1 First, the configuration of the microphone unit 1 according
to the present embodiment will be described.
[0030]
The microphone unit 1 according to the present embodiment includes a housing 10 as shown in
FIGS. 1 and 2A.
The housing 10 is a member that constitutes the outer shape of the microphone unit 1.
The outer shape of the housing 10 (microphone unit 1) may have a polyhedral structure.
The outer shape of the housing 10 may be a hexahedron (rectangular parallelepiped or cube) as
shown in FIG.
However, the outer shape of the housing 10 may have a polyhedron structure other than a
hexahedron.
Alternatively, the outer shape of the housing 10 may have a structure other than a polyhedron,
such as a spherical structure (hemispherical structure).
[0031]
The housing 10 has an internal space 100 (first and second spaces 102 and 104), as shown in
FIG. 2 (A).
03-05-2019
7
That is, the housing 10 has a structure for partitioning a predetermined space, and the internal
space 100 is a space partitioned by the housing 10.
The housing 10 may have a shielding structure (electromagnetic shielding structure) that
electrically and magnetically shields the internal space 100 and the space (external space 110)
outside the housing 10.
As a result, the vibrating film 30 and the electric signal output circuit 40 to be described later
can be made less susceptible to the influence of the electronic components disposed outside the
housing 10 (the external space 110), so the noise removal function with high accuracy is
realized. It is possible to provide a microphone unit that can be realized.
[0032]
And as shown to FIG. 1 and FIG. 2 (A), the through-hole which makes the internal space 100 of
the housing | casing 10 and the external space 110 connect is formed in the housing | casing 10.
As shown in FIG.
In the present embodiment, the housing 10 is formed with a first through hole 12 and a second
through hole 14.
Here, the first through hole 12 is a through hole connecting the first space 102 and the external
space 110. The second through hole 14 is a through hole connecting the second space 104 with
the external space 110. The first and second spaces 102 and 104 will be described in detail later.
The outer shapes of the first and second through holes 12 and 14 are not particularly limited,
but may be circular as shown in FIG. 1, for example. However, the outer shape of the first and
second through holes 12 and 14 may be a shape other than a circle, and may be, for example, a
rectangle.
[0033]
03-05-2019
8
In the present embodiment, as shown in FIGS. 1 and 2A, the first and second through holes 12
and 14 are formed on one surface 15 of the casing 10 having a hexahedral structure (polyhedral
structure). It is done. However, as a modification, the first and second through holes 12 and 14
may be formed in different faces of the polyhedron, respectively. For example, the first and
second through holes 12 and 14 may be formed on opposite faces of the hexahedron or may be
formed on adjacent faces of the hexahedron. Further, in the present embodiment, the housing 10
is formed with one first through hole 12 and one second through hole 14. However, the present
invention is not limited thereto, and a plurality of first through holes 12 and a plurality of second
through holes 14 may be formed in the housing 10.
[0034]
The microphone unit 1 which concerns on this Embodiment contains the partition member 20, as
shown to FIG. 2 (A) and FIG. 2 (B). Here, FIG. 2 (B) is the figure which observed the partition
member 20 from the front. The partition member 20 is provided in the housing 10 so as to
divide the internal space 100. In the present embodiment, the partition member 20 is provided to
divide the internal space 100 into the first space 102 and the second space 104. That is, it can be
said that the first and second spaces 102 and 104 are spaces partitioned by the housing 10 and
the partition member 20, respectively.
[0035]
The partition member 20 may be provided so as to prevent the medium for propagating the
sound wave from moving between the first space 102 and the second space 104 inside the
housing 10 (so as not to move). . For example, the partition member 20 may be an airtight
partition that airtightly separates the internal space 100 (the first and second spaces 102 and
104) inside the housing 10.
[0036]
As shown in FIGS. 2A and 2B, at least a part of the partition member 20 is configured by the
vibrating film 30. As shown in FIG. The vibrating film 30 is a member that vibrates in the normal
direction when a sound wave is incident. Then, in the microphone unit 1, the electric signal is
extracted based on the vibration of the vibrating film 30 to obtain the electric signal indicating
the sound incident on the vibrating film 30. That is, the diaphragm 30 may be a diaphragm of a
03-05-2019
9
microphone (an electroacoustic transducer that converts an acoustic signal into an electrical
signal).
[0037]
Hereinafter, the configuration of the condenser microphone 200 will be described as an example
of the microphone applicable to the present embodiment. FIG. 3 is a diagram for explaining the
condenser microphone 200. As shown in FIG.
[0038]
The condenser microphone 200 has a vibrating membrane 202. The vibrating film 202
corresponds to the vibrating film 30 of the microphone unit 1 according to the present
embodiment. The vibrating film 202 is a film (thin film) that vibrates upon receiving an acoustic
wave, has conductivity, and forms one end of an electrode. The condenser microphone 200 also
has an electrode 204. The electrode 204 is disposed to face the vibrating membrane 202.
Thereby, the diaphragm 202 and the electrode 204 form a capacitance. When a sound wave is
incident on the condenser microphone 200, the vibrating membrane 202 vibrates, the distance
between the vibrating membrane 202 and the electrode 204 changes, and the capacitance
between the vibrating membrane 202 and the electrode 204 changes. By extracting the change
in capacitance as, for example, a change in voltage, an electrical signal based on the vibration of
the vibrating membrane 202 can be obtained. That is, the sound wave incident on the condenser
microphone 200 can be converted into an electric signal and output. In the condenser
microphone 200, the electrode 204 may have a structure that is not affected by the sound wave.
For example, the electrode 204 may have a mesh structure.
[0039]
However, the microphone (the vibrating film 30) applicable to the present invention is not
limited to the condenser type microphone, and any microphone already known can be applied.
For example, the diaphragm 30 may be a diaphragm of various microphones, such as an
electrodynamic (dynamic) type, an electromagnetic (magnetic) type, and a piezoelectric (crystal)
type.
03-05-2019
10
[0040]
Alternatively, the vibrating film 30 may be a semiconductor film (for example, a silicon film). That
is, the vibrating film 30 may be a vibrating film of a silicon microphone (Si microphone). By using
a silicon microphone, miniaturization and high performance of the microphone unit 1 can be
realized.
[0041]
The outer shape of the vibrating membrane 30 is not particularly limited. As shown in FIG. 2 (B),
the outer shape of the vibrating membrane 30 may be circular. At this time, the vibrating
membrane 30 and the first and second through holes 12 and 14 may have the same or
substantially the same diameter. However, the vibrating membrane 30 may be larger or smaller
than the first and second through holes 12 and 14. The vibrating membrane 30 also has first and
second surfaces 35 and 37. The first surface 35 is a surface facing the first space 102, and the
second surface 37 is a surface facing the second space 104.
[0042]
In the present embodiment, the vibrating membrane 30 may be provided such that the normal
extends parallel to the surface 15 of the housing 10 as shown in FIG. 2 (A). In other words, the
vibrating film 30 may be provided to be orthogonal to the surface 15. The vibrating film 30 may
be disposed on the side (near the side) of the second through hole 14. That is, the vibrating
membrane 30 may be arranged such that the distance from the first through hole 12 and the
distance from the second through hole 14 are not equal. However, as a modification, the
vibrating membrane 30 may be disposed between the first and second through holes 12 and 14
(not shown).
[0043]
In the present embodiment, the partition member 20 may include a holding portion 32 for
holding the vibrating film 30, as shown in FIGS. 2 (A) and 2 (B). Then, the holding portion 32 may
be in close contact with the inner wall surface of the housing 10. By bringing the holding portion
32 into close contact with the inner wall surface of the housing 10, the first and second spaces
03-05-2019
11
102, 104 can be airtightly separated.
[0044]
The microphone unit 1 according to the present embodiment includes an electrical signal output
circuit 40 that outputs an electrical signal based on the vibration of the diaphragm 30. At least a
part of the electrical signal output circuit 40 may be formed in the internal space 100 of the
housing 10. The electrical signal output circuit 40 may be formed on the inner wall surface of the
housing 10, for example. That is, in the present embodiment, the housing 10 may be used as a
circuit board of an electric circuit.
[0045]
FIG. 4 shows an example of the electric signal output circuit 40 applicable to the present
embodiment. The electric signal output circuit 40 may be configured to amplify and output an
electric signal based on a change in capacitance of the capacitor 42 (a capacitor type microphone
having a vibrating film 30) by the signal amplification circuit 44. The capacitor 42 may, for
example, constitute a part of the diaphragm unit 41. The electric signal output circuit 40 may be
configured to include the charge up circuit 46 and the operational amplifier 48. This makes it
possible to accurately obtain the change in the capacitance of the capacitor 42. In the present
embodiment, for example, the capacitor 42, the signal amplification circuit 44, the charge up
circuit 46, and the operational amplifier 48 may be formed on the inner wall surface of the
housing 10. Further, the electrical signal output circuit 40 may include a gain adjustment circuit
45. The gain adjustment circuit 45 plays the role of adjusting the amplification factor (gain) of
the signal amplification circuit 44. The gain adjustment circuit 45 may be provided inside the
housing 10, but may be provided outside the housing 10.
[0046]
However, when a silicon microphone is applied as the vibrating film 30, the electric signal output
circuit 40 may be realized by an integrated circuit formed on a semiconductor substrate of the
silicon microphone.
[0047]
The electrical signal output circuit 40 may further include a conversion circuit that converts an
analog signal into a digital signal, a compression circuit that compresses (encodes) a digital
03-05-2019
12
signal, and the like.
[0048]
The microphone unit 1 according to the present embodiment may be configured as described
above.
According to the microphone unit 1, it is possible to realize a highly accurate noise removal
function with a simple configuration.
Hereinafter, the noise removal principle of the microphone unit 1 will be described.
[0049]
2. Noise Removal Principle of Microphone Unit 1 (1) Configuration of Microphone Unit 1 and
Vibration Principle of Vibrating Film 30 First, the vibration principle of the vibrating film 30
derived from the configuration of the microphone unit 1 will be described.
[0050]
In the present embodiment, the vibrating membrane 30 receives sound pressure from both sides
(first and second 35, 37). Therefore, when sound pressure of the same magnitude is
simultaneously applied to both sides of the vibrating membrane 30, the two sound pressures
cancel each other out with the vibrating membrane 30, and do not become a force for vibrating
the vibrating membrane 30. Conversely, when there is a difference in the sound pressure
received on both sides, the vibrating film 30 vibrates due to the difference in the sound pressure.
[0051]
Further, the sound pressure of the sound wave incident on the first and second through holes 12
and 14 is uniformly transmitted to the inner wall surfaces of the first and second spaces 102 and
03-05-2019
13
104 (the Pascal's principle). Therefore, the surface (first surface 35) of the diaphragm 30 facing
the first space 102 receives a sound pressure equal to the sound pressure incident on the first
through hole 12, and the second space 104 of the diaphragm 30. The surface (second surface
37) facing the light receiving surface receives a sound pressure equal to the sound pressure
incident on the second through hole 14.
[0052]
That is, the sound pressure received by the first and second surfaces 35 and 37 is the sound
pressure of the sound incident on the first and second through holes 12 and 14, respectively. It
vibrates by the difference of the sound pressure of the sound wave which injected into the 2nd
surface 35, 37 (1st and 2nd through holes 12 and 14).
[0053]
(2) Nature of sound wave The sound wave is attenuated as it travels through the medium, and the
sound pressure (the strength and amplitude of the sound wave) is reduced.
Since the sound pressure is inversely proportional to the distance from the sound source, the
sound pressure P can be expressed as: in relation to the distance r from the sound source. In
equation (1), k is a proportional constant. FIG. 5 shows a graph representing the equation (1), but
as can be understood from this figure, the sound pressure (amplitude of the sound wave) is
rapidly attenuated at a position close to the sound source (left side of the graph) It decays gently
as you leave.
[0054]
When the microphone unit 1 is applied to a close-talking type voice input device, the user's voice
is generated from the vicinity of the microphone unit 1 (first and second through holes 12 and
14). Therefore, the voice of the user is greatly attenuated between the first and second through
holes 12 and 14, and the sound pressure of the user's voice incident on the first and second
through holes 12 and 14, ie, the first and second through holes. A large difference appears in the
sound pressure of the user voice incident on the second surfaces 35 and 37.
[0055]
03-05-2019
14
On the other hand, the noise component is located at a position far from the microphone unit 1
(first and second through holes 12 and 14) as compared to the voice of the user. Therefore, the
sound pressure of noise hardly attenuates between the first and second through holes 12 and 14,
and the sound pressure of noise entering the first and second through holes 12 and 14 is almost
the same. Does not appear.
[0056]
(3) Principle of Noise Removal As described above, the vibrating film 30 vibrates due to the
difference in sound pressure of sound waves simultaneously incident on the first and second
surfaces 35 and 37. The difference in sound pressure of noise incident on the first and second
surfaces 35 and 37 is so small that the noise is canceled by the diaphragm 30. On the other
hand, since the difference between the sound pressures of the user voices incident on the first
and second surfaces 35 and 37 is large, the user voices are not canceled by the diaphragm 30,
and the diaphragm 30 is vibrated.
[0057]
From this, according to the microphone unit 1, the vibrating membrane 30 can be regarded as
vibrating only by the user's voice. Therefore, the electrical signal output from the microphone
unit 1 (electrical signal output circuit 40) can be regarded as a signal representing only the user's
voice from which noise has been removed.
[0058]
That is, according to the microphone unit 1 according to the present embodiment, it is possible
to provide a voice input device capable of obtaining an electrical signal indicating a user voice
from which noise has been removed with a simple configuration.
[0059]
3.
03-05-2019
15
As described above, the microphone unit 1 can obtain an electrical signal representing only the
user's voice from which the noise is removed, as described above. . However, the sound wave
contains a phase component. Therefore, in consideration of the phase difference between the
sound waves incident on the first and second through holes 12 and 14 (the first and second
surfaces 35 and 37 of the diaphragm 30, a more accurate noise removal function is realized. It is
possible to derive possible conditions (design conditions of the microphone unit 1). Hereinafter,
conditions to be satisfied by the microphone unit 1 in order to realize the noise removal function
with higher accuracy will be described.
[0060]
According to the microphone unit 1, as described above, the sound pressure at which the
vibrating film 30 is vibrated (difference in sound pressure received by the first and second
surfaces 35 and 37: hereinafter referred to as “differential sound pressure” as appropriate)
The signal output based on is regarded as a signal indicating user voice. According to this
microphone unit, the noise component included in the sound pressure (differential sound
pressure) for vibrating the diaphragm 30 is smaller than the noise component included in the
sound pressure incident on the first or second surface 35, 37. As a result, it can be evaluated that
the noise removal function has been realized. Specifically, a noise intensity ratio indicating the
ratio of the intensity of the noise component included in the differential sound pressure to the
intensity of the noise component included in the sound pressure incident on the first or second
surface 35, 37 is the differential sound pressure. This noise removal function if the ratio of the
intensity of the contained user voice component to the intensity of the user voice component
contained in the sound pressure incident on the first or second surface 35, 37 is smaller than the
user voice intensity ratio It can be evaluated that
[0061]
Hereinafter, specific conditions to be satisfied by the microphone unit 1 (the housing 10) in order
to realize the noise removal function will be described.
[0062]
First, the sound pressure of the sound incident on the first and second surfaces 35 and 37 (the
first and second through holes 12 and 14) of the diaphragm 30 will be considered.
03-05-2019
16
Assuming that the distance from the sound source of the user voice to the first through hole 12
is R, and the distance between the centers of the first and second through holes 12 and 14 is Δr,
the first and second The sound pressure (intensity) P (S1) and P (S2) of the user's voice incident
on the through holes 12 and 14 can be expressed as follows.
[0063]
Therefore, the intensity of the user voice component included in the differential sound pressure
with respect to the intensity of the sound pressure of the user voice incident on the first surface
35 (the first through hole 12) when the phase difference of the user voice is ignored. The user
voice strength ratio ρ (P) indicating the ratio is expressed as
[0064]
Here, when the microphone unit 1 is used for a close talk type voice input device, Δr can be
regarded as sufficiently smaller than R.
[0065]
Therefore, the above equation (4) can be transformed into
[0066]
That is, it can be seen that the user voice strength ratio when the phase difference of the user
voice is ignored is expressed as Expression (A).
[0067]
By the way, in consideration of the phase difference of the user voice, the sound pressures Q (S1)
and Q (S2) of the user voice can be expressed as
In the equation, α is a phase difference.
[0068]
03-05-2019
17
At this time, the user voice strength ratio ((S) is expressed as
Considering equation (7), the magnitude of the user speech strength ratio ((S) can be expressed
as
[0069]
By the way, in equation (8), the term sin ωt-sin (ωt-α) indicates the intensity ratio of the phase
component, and the term Δr / Rsinωt indicates the intensity ratio of the amplitude component.
Even if it is a user voice component, the phase difference component is noise for the amplitude
component, so that the intensity ratio of the phase component is sufficiently smaller than the
intensity ratio of the amplitude component in order to extract the user voice with high accuracy.
is necessary.
That is, it is important that sin ωt−sin (ωt−α) and Δr / R sin ωt satisfy the following
relationship.
[0070]
Here, since it can be represented as, the above-mentioned formula (B) can be represented as
[0071]
In consideration of the amplitude component of Equation (10), it can be seen that the
microphone unit 1 according to the present embodiment needs to satisfy
[0072]
As described above, since Δr can be regarded as sufficiently smaller than R, sin (α / 2) can be
regarded as sufficiently small, and can be approximated as follows.
[0073]
Therefore, Formula (C) can be transformed into
03-05-2019
18
[0074]
Further, if the relationship between the phase difference α and Δr is expressed as, the equation
(D) can be transformed into
[0075]
That is, in the present embodiment, if the microphone unit 1 satisfies the relationship shown in
equation (E), it is possible to extract the user's voice accurately.
[0076]
Next, the sound pressure of noise incident on the first and second surfaces 35 and 37 (first and
second through holes 12 and 14) will be considered.
[0077]
Assuming that the amplitudes of noise components incident on the first and second surfaces 35
and 37 are A and A ′, sound pressures Q (N1) and Q (N2) of noise considering phase difference
components are represented by Noise intensity ratio ((N) indicating the ratio of the intensity of
the noise component included in the differential sound pressure to the intensity of the sound
pressure of the noise component incident on the first surface 35 (the first through hole 12) , It
can be expressed as.
[0078]
As described above, the amplitudes (intensity) of the noise components incident on the first and
second surfaces 35 and 37 (first and second through holes 12 and 14) are substantially the
same, and A = It can be treated as A '.
Therefore, the above equation (15) can be transformed into
[0079]
And, the magnitude of the noise intensity ratio can be expressed as
[0080]
03-05-2019
19
Here, considering the above equation (9), equation (17) can be transformed into
[0081]
Then, considering equation (11), equation (18) can be transformed into
[0082]
Here, referring to equation (D), the magnitude of the noise intensity ratio can be expressed as
Here, Δr / R is an intensity ratio of the amplitude component of the user's voice, as shown in
equation (A).
From equation (F), it can be seen that in this microphone unit 1, the noise intensity ratio is
smaller than the intensity ratio Δr / R of the user voice.
[0083]
From the above, according to the microphone unit 1 in which the intensity ratio of the phase
component of the user voice is smaller than the intensity ratio of the amplitude component (see
equation (B)), the noise intensity ratio is smaller than the user voice intensity ratio ( Formula (F)).
Conversely, according to the microphone unit 1 designed so that the noise intensity ratio is
smaller than the user voice intensity ratio, a highly accurate noise removal function can be
realized.
[0084]
4.
Method of Manufacturing Microphone Unit 1 Hereinafter, a method of manufacturing the
03-05-2019
20
microphone unit 1 according to the present embodiment will be described.
In the present embodiment, the value of Δr / λ indicating the ratio of the distance Δr between
the centers of the first and second through holes 12 and 14 to the wavelength λ of noise, and
the noise intensity ratio (the intensity based on the phase component of noise The microphone
unit 1 may be manufactured using data indicating the correspondence relationship with the
ratio).
[0085]
The intensity ratio based on the phase component of noise is expressed by the above-mentioned
equation (18).
Therefore, the decibel value of the intensity ratio based on the phase component of noise can be
expressed as
[0086]
Then, if each value is substituted for α in equation (20), the correspondence between the phase
difference α and the intensity ratio based on the phase component of noise can be clarified.
FIG. 6 shows an example of data representing the correspondence between the phase difference
and the intensity ratio when the horizontal axis is α / 2π and the vertical axis is the intensity
ratio (decibel value) based on the phase component of noise. .
[0087]
The phase difference α can be expressed as a function of Δr / λ, which is the ratio of the
distance Δr to the wavelength λ, as shown in equation (12), and the horizontal axis in FIG. 6
should be regarded as Δr / λ. Can.
03-05-2019
21
That is, it can be said that FIG. 6 is data indicating the correspondence between the intensity
ratio based on the phase component of noise and Δr / λ.
[0088]
In this embodiment, this data is used to manufacture the microphone unit 1.
FIG. 7 is a flow chart for explaining the procedure of manufacturing the microphone unit 1 using
this data.
[0089]
First, data (see FIG. 6) indicating the correspondence between the noise intensity ratio (intensity
ratio based on the noise phase component) and Δr / λ is prepared (step S10).
[0090]
Next, the noise intensity ratio is set according to the application (step S12).
In the present embodiment, it is necessary to set the noise intensity ratio so that the noise
intensity decreases.
Therefore, in this step, the noise intensity ratio is set to 0 dB or less.
[0091]
Next, based on the data, a value of Δr / λ corresponding to the noise intensity ratio is derived
(step S14).
[0092]
Then, the condition of Δr to be satisfied is derived by substituting the wavelength of the main
noise for λ (step S16).
03-05-2019
22
[0093]
As a specific example, consider the case of manufacturing the microphone unit 1 in which the
noise intensity decreases by 20 dB in an environment where the main noise is 1 KHz and the
wavelength is 0.347 m.
[0094]
First, conditions for the noise intensity ratio to be 0 dB or less will be examined.
Referring to FIG. 6, it can be seen that the value of Δr / λ may be set to 0.16 or less in order to
set the noise intensity ratio to 0 dB or less.
That is, it is understood that the value of Δr may be 55.46 mm or less, which is a necessary
condition of the microphone unit 1 (the housing 10).
[0095]
Next, conditions for reducing the intensity of 1 KHz noise by 20 dB will be considered.
Referring to FIG. 6, it can be seen that the value of Δr / λ may be set to 0.015 in order to
reduce the noise intensity by 20 dB. Then, assuming that λ = 0.347 m, it is understood that this
condition is satisfied when the value of Δr is 5.199 mm or less. That is, if Δr is set to about 5.2
mm or less, it becomes possible to manufacture a microphone unit having a noise removal
function.
[0096]
When the microphone unit 1 according to the present embodiment is used for a close-talking
type voice input device, the distance between the sound source of the user's voice and the
microphone unit 1 (first and second through holes 12 and 14) is It is usually 5 cm or less.
Further, the distance between the sound source of the user's voice and the microphone unit 1
03-05-2019
23
(first and second through holes 12 and 14) can be set by the design of the housing in which the
microphone unit 1 is housed. Therefore, it can be seen that the value of Δr / R, which is the
intensity ratio of the user's voice, becomes larger than 0.1 (noise intensity ratio), and the noise
removal function is realized.
[0097]
Generally, noise is not limited to a single frequency. However, noise having a frequency lower
than the noise assumed as the main noise has a longer wavelength than the main noise, so the
value of Δr / λ becomes smaller and is removed by this microphone unit 1. Also, the higher the
frequency of sound waves, the faster the energy decays. Therefore, noise higher in frequency
than noise assumed as main noise attenuates earlier than the main noise, so the influence on
microphone unit 1 (vibration film 30) can be ignored. From this, the microphone unit 1
according to the present embodiment can exhibit an excellent noise removal function even in the
presence of noise of a frequency different from the noise assumed as the main noise.
[0098]
Further, in the present embodiment, as can be understood from the equation (12), noise incident
from a straight line connecting the first and second through holes 12 and 14 is assumed. This
noise is noise in which the apparent distance between the first and second through holes 12 and
14 is the largest, and in the actual usage environment, the phase difference is the largest. That is,
the microphone unit 1 according to the present embodiment is configured to be capable of
removing the noise with the largest phase difference. Therefore, according to the microphone
unit 1 according to the present embodiment, noise incident from all directions can be removed.
[0099]
5. The effects of the microphone unit 1 are summarized below.
[0100]
As described above, according to the microphone unit 1, it is possible to obtain an electrical
03-05-2019
24
signal representing a voice from which noise components have been removed, simply by
acquiring an electrical signal (electrical signal based on the vibration of the diaphragm 30)
representing the vibration of the diaphragm 30. It can be acquired. That is, in the microphone
unit 1, the noise removal function can be realized without performing complicated analysis and
arithmetic processing. Therefore, it is possible to provide a high quality microphone unit capable
of deep noise removal with a simple configuration. In particular, by setting the center-to-center
distance Δr of the first and second through holes 12 and 14 to 5.2 mm or less, it is possible to
provide a microphone unit capable of realizing a more accurate noise removal function. it can.
[0101]
Further, in the microphone unit 1, the housing 10 (the positions of the first and second through
holes 12 and 14) so as to be able to remove the incident noise so that the noise intensity ratio
based on the phase difference becomes the largest. It becomes possible to design. Therefore,
according to this microphone unit 1, it is possible to remove noise incident from all directions.
That is, according to the present invention, it is possible to provide a microphone unit capable of
removing noise incident from all directions.
[0102]
In addition, according to the microphone unit 1, it is also possible to remove the user's voice
component incident on the vibrating film 30 (the first and second surfaces 35, 37) after being
reflected by the wall or the like. Specifically, user sound reflected by a wall or the like propagates
long distance and then enters the microphone unit 1, so it can be regarded as sound generated
from a sound source present farther than normal user sound, and Since the energy is largely
dissipated by the reflection, the sound pressure is not greatly attenuated between the first and
second through holes 12 and 14 as in the noise component. Therefore, according to the
microphone unit 1, the user's voice component incident after being reflected by the wall or the
like is also removed (as a kind of noise) as noise.
[0103]
And if the microphone unit 1 is used, the signal which shows a user's voice which does not
contain noise can be acquired. Therefore, by using the microphone unit 1, highly accurate voice
recognition, voice authentication, and command generation processing can be realized.
03-05-2019
25
[0104]
6. Voice Input Device Next, the voice input device 2 having the microphone unit 1 will be
described.
[0105]
(1) Configuration of Voice Input Device 2 First, the configuration of the voice input device 2 will
be described. FIG. 8 and FIG. 9 are diagrams for explaining the configuration of the voice input
device 2. The voice input device 2 described below is a close-talking type voice input device, and
for example, an information processing system using a voice communication device such as a
mobile phone or a transceiver, or a technology for analyzing input voice. It can be applied to
voice recognition systems, voice recognition systems, command generation systems, electronic
dictionaries, translators, voice input remote controllers, etc., or recording devices, amplifier
systems (loudspeakers), microphone systems, etc. .
[0106]
FIG. 8 is a diagram for explaining the structure of the voice input device 2.
[0107]
The voice input device 2 has a housing 50.
The housing 50 is a member that constitutes the outer shape of the voice input device 2. A basic
posture may be set in the case 50, which makes it possible to restrict the traveling path of the
user's voice. The case 50 may have an opening 52 for receiving the voice of the user.
[0108]
In the voice input device 2, the microphone unit 1 is installed inside the housing 50. The
03-05-2019
26
microphone unit 1 may be installed in the housing 50 such that the first and second through
holes 12 and 14 communicate (overlap) with the opening 52. The microphone unit 1 may be
installed in the housing 50 via the elastic body 54. As a result, the vibration of the case 50 is less
likely to be transmitted to the microphone unit 1 (the case 10), so that the microphone unit 1 can
be operated with high accuracy.
[0109]
The microphone unit 1 may be installed in the housing 50 such that the first and second through
holes 12 and 14 are arranged to be offset along the traveling direction of the user voice. Then,
the through hole disposed on the upstream side of the traveling path of the user voice may be
the first through hole 12 and the through hole disposed on the downstream side may be the
second through hole 14. When the microphone unit 1 in which the diaphragm 30 is disposed to
the side of the second through hole 14 is arranged as described above, the user's voice is
displayed on both sides of the diaphragm 30 (first and second surfaces 35, 37). Can be incident
simultaneously. Specifically, in the microphone unit 1, the distance from the center of the first
through hole 12 to the first surface 35 is substantially equal to the distance from the first
through hole 12 to the second through hole 14. The time required for the user voice passing
through the first through hole 12 to enter the first surface 35 is the second user sound wave
passing over the first through hole 12 via the second through hole 14. The time required for the
light to be incident on the surface 37 of the That is, the time taken for the voice uttered by the
user to enter the first surface 35 is equal to the time taken for the voice to be input to the second
surface 37. Therefore, the user's voice can be simultaneously made incident on the first and
second surfaces 35 and 37, and the vibrating film 30 can be vibrated so that noise due to phase
shift does not occur. In other words, since α = 0 and sin ωt-sin (ωt-α) = 0 in the equation (8)
described above, it can be understood that the Δr / R sin ωt term (only the amplitude
component) is extracted. Therefore, even when user voice of about 7 KHz, which is a high
frequency band, is input as human voice, the influence of phase distortion between the sound
pressure incident on the first surface 35 and the sound pressure incident on the second surface
37 Can be ignored and it is possible to obtain an electrical signal that accurately indicates the
user's voice.
[0110]
(2) Function of Voice Input Device 2 Next, the function of the voice input device 2 will be
described with reference to FIG. FIG. 9 is a block diagram for explaining the function of the voice
input device 2.
03-05-2019
27
[0111]
The voice input device 2 has a microphone unit 1. The microphone unit 1 outputs an electrical
signal generated based on the vibration of the vibrating membrane 30. The electrical signal
output from the microphone unit 1 is an electrical signal representing a user's voice from which
noise components have been removed.
[0112]
The voice input device 2 may have an arithmetic processing unit 60. The arithmetic processing
unit 60 performs various arithmetic processing based on the electrical signal output from the
microphone unit 1 (electrical signal output circuit 40). The arithmetic processing unit 60 may
perform analysis processing on the electrical signal. The arithmetic processing unit 60 may
perform processing (so-called voice authentication processing) of identifying a person who has
issued a user voice by analyzing an output signal from the microphone unit 1. Alternatively, the
arithmetic processing unit 60 may perform processing (so-called voice recognition processing)
for specifying the content of the user's voice by analyzing and processing the output signal of the
microphone unit 1. The arithmetic processing unit 60 may perform processing to create various
commands based on the output signal from the microphone unit 1. The arithmetic processing
unit 60 may perform processing for amplifying the output signal from the microphone unit 1.
Also, the arithmetic processing unit 60 may control the operation of the communication
processing unit 70 described later. The arithmetic processing unit 60 may realize the abovedescribed functions by signal processing by a CPU or a memory. Alternatively, the arithmetic
processing unit 60 may realize each of the above functions by dedicated hardware.
[0113]
The voice input device 2 may further include a communication processing unit 70. The
communication processing unit 70 controls communication between the voice input device 2 and
another terminal (such as a mobile phone terminal or a host computer). The communication
processing unit 70 may have a function of transmitting a signal (output signal from the
microphone unit 1) to another terminal via the network. The communication processing unit 70
may also have a function of receiving signals from other terminals via the network. Then, for
example, even if the host computer analyzes the output signal obtained through the
03-05-2019
28
communication processing unit 70 and performs various information processing such as voice
recognition processing, voice authentication processing, command generation processing, data
storage processing, etc. Good. That is, the voice input device 2 may configure the information
processing system in cooperation with another terminal. In other words, the voice input device 2
may be regarded as an information input terminal that constructs an information processing
system. However, the voice input device 2 may be configured without the communication
processing unit 70.
[0114]
The arithmetic processing unit 60 and the communication processing unit 70 described above
may be disposed in the housing 50 as a packaged semiconductor device (integrated circuit
device). However, the present invention is not limited to this. For example, the arithmetic
processing unit 60 may be disposed outside the housing 50. When the arithmetic processing unit
60 is disposed outside the housing 50, the arithmetic processing unit 60 may obtain the
difference signal via the communication processing unit 70.
[0115]
The voice input device 2 may further include a display device such as a display panel and a voice
output device such as a speaker. In addition, the voice input device 2 may further include an
operation key for inputting operation information.
[0116]
The voice input device 2 may have the above configuration. The voice input device 2 uses the
microphone unit 1. Therefore, the voice input device 2 can acquire a signal indicating an input
voice that does not contain noise, and can realize highly accurate voice recognition, voice
authentication, and command generation processing.
[0117]
Also, if the voice input device 2 is applied to a microphone system, the user's voice output from
03-05-2019
29
the speaker is also removed as noise. Therefore, it is possible to provide a microphone system in
which howling does not easily occur.
[0118]
10 to 12 show a mobile phone 300, a microphone (microphone system) 400, and a remote
controller 500 as examples of the voice input device 2. Further, FIG. 13 shows a schematic view
of an information processing system 600 including a voice input device 602 as an information
input terminal and a host computer 604.
[0119]
7. Modified Example The present invention is not limited to the above-described embodiment,
and various modifications are possible. The present invention includes configurations
substantially the same as the configurations described in the embodiments (for example,
configurations having the same function, method and result, or configurations having the same
purpose and effect). Further, the present invention includes a configuration in which a
nonessential part of the configuration described in the embodiment is replaced. The present
invention also includes configurations that can achieve the same effects as the configurations
described in the embodiments or that can achieve the same purpose. Further, the present
invention includes a configuration in which a known technology is added to the configuration
described in the embodiment.
[0120]
Hereinafter, specific modified examples will be shown.
[0121]
(1) First Modification FIG. 14 shows a microphone unit 3 according to a first modification of the
embodiment to which the present invention is applied.
[0122]
The microphone unit 3 includes a vibrating membrane 80.
03-05-2019
30
The vibrating film 80 constitutes a part of a partition member that divides the internal space 100
of the housing 10 into a first space 112 and a second space 114.
The vibrating film 80 is provided such that the normal is orthogonal to the surface 15 (that is,
parallel to the surface 15). The vibrating membrane 80 may be provided on the side of the
second through hole 14 so as not to overlap with the first and second through holes 12 and 14.
The vibrating film 80 may be spaced apart from the inner wall surface of the housing 10.
[0123]
(2) Second Modified Example FIG. 15 shows a microphone unit 4 according to a second modified
example of the embodiment to which the present invention is applied.
[0124]
The microphone unit 4 includes a vibrating membrane 90.
The vibrating membrane 90 constitutes a part of a partition member that divides the internal
space 100 of the housing 10 into a first space 122 and a second space 124. The vibrating film
90 is provided such that the normal is orthogonal to the surface 15. The vibrating membrane 90
may be provided to be flush with the inner wall surface (surface opposite to the surface 15) of
the housing 10. The vibrating membrane 90 may be provided so as to close the second through
hole 14 from the inside (the internal space 100) of the housing 10. That is, in the microphone
unit 3, only the internal space of the second through hole 14 may be the second space 124, and
a space other than the second space 124 in the internal space 100 may be the first space 122.
According to this, it is possible to design the housing 10 thin.
[0125]
(3) Third Modified Example FIG. 16 shows a microphone unit 5 according to a third modified
example of the embodiment to which the present invention is applied.
[0126]
03-05-2019
31
The microphone unit 5 includes a housing 11.
The housing 11 has an internal space 101. The inner space 101 is divided by the partition
member 20 into a first area 132 and a second area 134. In the microphone unit 5, the partition
member 20 is disposed to the side of the second through hole 14. Further, in the microphone
unit 5, the partition member 20 divides the internal space 101 so that the volumes of the first
and second spaces 132 and 134 become equal.
[0127]
(4) Fourth Modification FIG. 17 shows a microphone unit 6 according to a fourth modification of
the embodiment to which the present invention is applied.
[0128]
The microphone unit 6 has a partition member 21 as shown in FIG.
The partition member 21 has a vibrating film 31. The vibrating film 31 is held inside the housing
10 so that the normal intersects the surface 15 diagonally.
[0129]
(5) Fifth Modification FIG. 18 shows a microphone unit 7 according to a fifth modification of the
embodiment to which the present invention is applied.
[0130]
In the microphone unit 7, as shown in FIG. 18, the partition member 20 is disposed between the
first and second through holes 12 and 14.
That is, the distance between the first through hole 12 and the partition member 20 is equal to
the distance between the second through hole 14 and the partition member 20. In the
microphone unit 7, the partition member 20 may be arranged to equally divide the internal space
03-05-2019
32
100 of the housing 10.
[0131]
(6) Sixth Modification FIG. 19 shows a microphone unit 8 according to a sixth modification of the
embodiment to which the present invention is applied.
[0132]
In the microphone unit 8, as shown in FIG. 19, the housing has a structure having a convex
curved surface 16.
The first and second through holes 12 and 14 are formed in the convex curved surface 16.
[0133]
(7) Seventh Modified Example FIG. 20 shows a microphone unit 9 according to a seventh
modified example of the embodiment to which the present invention is applied.
[0134]
In the microphone unit 9, as shown in FIG. 20, the housing has a structure having a concave
surface 17.
The first and second through holes 12 and 14 may be disposed on both sides of the concave
surface 17. However, the first and second through holes 12 and 14 may be formed in the
concave surface 17.
[0135]
(8) Eighth Modification FIG. 21 shows a microphone unit 13 according to an eighth modification
of the embodiment to which the present invention is applied.
[0136]
03-05-2019
33
In the microphone unit 13, as shown in FIG. 21, the housing is structured to have a spherical
surface 18.
In addition, although the base of the spherical surface 18 may be circular, it is not restricted to
this, and the base may be elliptical. The first and second through holes 12 and 14 are formed in
the spherical surface 18.
[0137]
These microphone units can also provide the same effects as described above. Therefore, by
acquiring the electrical signal based on the vibration of the diaphragm, it is possible to acquire
the electrical signal that does not include the noise component and indicates only the user's
voice.
[0138]
The figure for demonstrating a microphone unit. The figure for demonstrating a microphone unit.
The figure for demonstrating a microphone unit. The figure for demonstrating a microphone unit.
The figure for demonstrating the attenuation characteristic of a sound wave. The figure which
shows an example of the data showing the correspondence of a phase difference and intensity
ratio. The flowchart figure which shows the procedure which manufactures a microphone unit.
The figure for demonstrating a speech input device. The figure for demonstrating a speech input
device. The figure which shows the mobile telephone as an example of a voice input device. The
figure which shows the microphone as an example of a speech input device. The figure which
shows the remote controller as an example of a voice input device. Schematic of an information
processing system. The figure for demonstrating the microphone unit which concerns on a
modification. The figure for demonstrating the microphone unit which concerns on a
modification. The figure for demonstrating the microphone unit which concerns on a
modification. The figure for demonstrating the microphone unit which concerns on a
modification. The figure for demonstrating the microphone unit which concerns on a
modification. The figure for demonstrating the microphone unit which concerns on a
modification. The figure for demonstrating the microphone unit which concerns on a
modification. The figure for demonstrating the microphone unit which concerns on a
modification.
03-05-2019
34
Explanation of sign
[0139]
DESCRIPTION OF SYMBOLS 1 ... Microphone unit, 2 ... Voice input device, 3 ... Microphone unit, 4
... Microphone unit, 5 ... Microphone unit, 6 ... Microphone unit, 7 ... Microphone unit, 8 ...
Microphone unit, 9 ... Microphone unit, 10 ... Housing | casing 11: housing 12: first through hole
13: microphone unit 14: second through hole 16: convex surface 17: concave surface 18:
spherical surface 20: partition member 21: partition member 30: diaphragm, 31: diaphragm, 32:
holding part, 40: electric signal output circuit, 41: diaphragm unit, 42: capacitor, 44: signal
amplification circuit, 45: gain adjustment circuit, 46: charge up circuit , 48: op amp, 50: housing,
52: opening, 54: elastic body, 6 ... Arithmetic processing unit 70 ... Communication processing
unit 80 ... Vibrating film, 100 ... Internal space, 101 ... Internal space, 102 ... First space, 104 ...
Second space, 112 ... First space, 114 ... 2 space 110 external space 112 first space 114 second
space 122 first space 124 second space 132 first space 134 second space , 200: capacitor type
microphone, 202: diaphragm, 204: electrode, 300: mobile phone, 400: microphone, 500: remote
controller, 600: information processing system, 602: voice input device, 604: host computer
03-05-2019
35
Документ
Категория
Без категории
Просмотров
0
Размер файла
49 Кб
Теги
jp2008258904
1/--страниц
Пожаловаться на содержимое документа