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DESCRIPTION JP2007214914

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DESCRIPTION JP2007214914
An object of the present invention is to provide a sound collection device capable of performing a
wider variety of sound collection. SOLUTION: Two unidirectional microphones 2 provided so as
to be able to rotate a pointing axis around two rotation axes a and b parallel to each other, and
rotation of the two unidirectional microphones 2. And a supporting portion 21 for movably
supporting a predetermined section on a straight line connecting the axes a and b to each other.
According to this configuration, since the two unidirectional microphones 2 are provided
rotatably around the two rotation axes a and b parallel to each other, the orientation of the main
axis can be changed individually. Makes it possible to adapt the sound collection device 1 to
various sound collection methods. [Selected figure] Figure 1
Sound pickup device
[0001]
The present invention relates to a sound collection device capable of collecting sound in a
plurality of types of sound collection methods using a plurality of microphones whose main axis
can be changed.
[0002]
Conventionally, a sound collection device using a plurality of microphones capable of changing
the sound collection angle has been known.
10-04-2019
1
For example, Patent Document 1 discloses a sound collection device capable of changing a sound
collection angle of a plurality of microphones by rotating a microphone unit including a plurality
of microphones around a rotation axis. In this sound collection device, according to the sound
collection angle of the microphone, the sound signal processing applied to the collected sound
signal can be changed to change the directivity characteristic. JP 2005-277832 A
[0003]
In the above-described conventional microphones, since the plurality of microphones are
integrally rotated, it is not possible to set different sound collection angles individually.
Moreover, the positional relationship of each microphone can not be changed, and the rotation of
each microphone is also one direction, and the variation of the change of the directivity of each
microphone was scarce.
[0004]
For this reason, it was not possible to collect sound suitably according to various sound collection
methods.
[0005]
In order to solve the above-mentioned subject, the present invention aims at providing a sound
collection device which can perform more various sound collection suitably.
[0006]
In order to solve the above-mentioned subject, the following means are adopted in the present
invention.
[0007]
(1) The present invention according to the first means for solving the problem comprises two
unidirectional microphones rotatably provided about two rotational axes parallel to each other,
and the two unidirectional microphones. And a support portion for supporting the rotation axes
of the sex microphones so as to be movable in a predetermined section on a straight line
connecting the rotation axes with each other.
[0008]
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2
According to the above configuration of the present invention, since the two unidirectional
microphones are provided rotatably about two rotational axes parallel to each other, the
orientation of the main axis can be changed individually. It becomes possible to make a sound
collection apparatus correspond to various sound collection systems.
[0009]
Further, the positional relationship between suitable unidirectional microphones differs
depending on the various sound collecting methods.
In the present invention, two single directional microphones are supported movably in a
predetermined section on a straight line connecting the rotation axes of these single directional
microphones.
For this reason, by moving the unidirectional microphones in a predetermined section, it
becomes possible to easily position the two unidirectional microphones in a positional
relationship suitable for each sound collection system.
By this, it becomes possible to perform sound collection suitably by various sound collection
systems.
[0010]
(2) According to the present invention, in the above-described sound pickup apparatus, a bidirectional microphone provided on the straight line so that the straight line and the directivity
axis are at a right angle, and the bi-directional microphone And a second support portion
movably supported in a parallel direction.
[0011]
According to the above configuration of the present invention, it is possible to perform various
sound collection using a bi-directional microphone and a uni-directional microphone.
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3
At the same time, the position of the bi-directional microphone can be moved in the direction
parallel to the rotation axis by the second support.
For this reason, when accommodating a sound collection apparatus, it becomes possible to make
a sound collection apparatus compact by arranging a bi-directional microphone in the position in
line with a unidirectional microphone.
[0012]
Further, in the case of collecting sound, it is possible to arrange the bi-directional microphone at
the position corresponding to the sound collecting method.
For example, if it is desirable to bring a unidirectional microphone close, adjusting the position of
the bidirectional microphone so that it does not line up with the unidirectional microphone will
make the unidirectional microphone a bidirectional microphone. It becomes possible to arrange
in close proximity without blocking.
[0013]
(3) The present invention is characterized in that, in the above-described sound collection device,
the unidirectional microphone is rotatably supported on a second axis perpendicular to the
rotation axis.
[0014]
According to the above configuration of the present invention, since the unidirectional
microphone can be rotated in two axes, it becomes possible to set the orientation of the main axis
of the unidirectional microphone in various variations, which is more versatile. It becomes
possible to perform sound collection by the sound collection method.
In addition, it is possible to finely adjust the direction of the main axis of the unidirectional
microphone in response to various sound collection methods.
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[0015]
(4) The present invention according to the second means for solving the problems comprises two
rotational axes parallel to each other and two rotational axes provided rotatably about a second
axis perpendicular to the rotational axes. A sound collection device comprising: a unidirectional
microphone; a device body; and a supporting unit attached to the device body and supporting the
unidirectional microphone.
[0016]
According to the above configuration of the present invention, since the two unidirectional
microphones are provided rotatably about two rotation axes parallel to each other, the direction
of the main axis can be changed individually, It is possible to make the device compatible with
various sound pickup methods.
Here, since a unidirectional microphone is provided in advance, it is possible to easily position
the microphone at a position required for the user's desired sound collection system.
[0017]
Further, according to the above configuration, since the unidirectional microphone can be rotated
in two axes, it becomes possible to set the orientation of the main axis of the unidirectional
microphone in various variations, and a more diverse collection can be achieved. It becomes
possible to collect sound by sound system. In addition, it is possible to finely adjust the direction
of the main axis of the unidirectional microphone in response to various sound collection
methods.
[0018]
(5) In the sound pickup apparatus according to the present invention, the device main body is a
side parallel to the rotation axis, wherein the distance from the rotation axis is 1/4 or less of the
wavelength of the sound wave of the specific frequency. It is a sound collection device
characterized by things.
[0019]
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5
According to the above configuration of the present invention, when the side surface is arranged
on the floor surface, uni-directionality is achieved at a position where the height from the floor
surface is within 1⁄4 of the wavelength of the specific frequency Since the rotational axis of the
microphone is arranged, it is possible to use the sound collection device as the boundary
microphone.
In addition, since the rotation axis is located in parallel to the floor surface, it is possible to rotate
the unidirectional microphone on the plane parallel to the floor surface by rotating on the second
axis. For this reason, it becomes possible to perform stereo sound collection with a boundary
microphone.
[0020]
(6) The present invention according to the third means for solving the problems comprises two
unidirectional microphones rotatably provided about two rotation axes parallel to each other, and
the two rotation axes A bi-directional microphone in which the straight line and the directional
axis are provided at right angles on a straight line, and a second support portion for movably
supporting the bi-directional microphone in a direction parallel to the rotation axis A sound
collecting device characterized by
[0021]
According to the above configuration of the present invention, since the two unidirectional
microphones are provided rotatably around two rotational axes parallel to each other, the sound
pickup device can be obtained by individually changing the direction of the main axis. It becomes
possible to correspond to various sound collection methods.
[0022]
Moreover, it becomes possible to perform various sound collection using a bi-directional
microphone and a uni-directional microphone.
At the same time, since the position of the bidirectional microphone can be moved in the
direction parallel to the rotation axis by the second support unit, the bidirectional microphone
should be a unidirectional microphone when the sound collection device is housed. By arranging
them in parallel, it is possible to make the sound pickup device compact.
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Further, in the case of collecting sound, it is possible to arrange the bi-directional microphone at
the position corresponding to the sound collecting method.
[0023]
According to the present invention as set forth in claim 1, two directional microphones provided
rotatably about two rotational axes parallel to each other are provided. It can be arranged
individually at a position corresponding to the sound collection method of As a result, sound can
be collected by various sound collection methods.
[0024]
In addition, by moving the unidirectional microphones in a predetermined section, it is possible
to easily position the two unidirectional microphones in a positional relationship suitable for
each sound collection system.
[0025]
Further, according to the present invention as set forth in claim 4, since two unidirectional
microphones provided rotatably about two rotational axes parallel to each other are provided, it
is possible to It can be individually arranged at a position corresponding to the user's desired
sound collection method.
As a result, sound can be collected by various sound collection methods. In addition, since the
unidirectional microphone can be rotated in two axes, it is possible to set the orientation of the
main axis of the unidirectional microphone in various variations, and the sound can be collected
with a wider variety of sound collection methods. It can be carried out. In addition, it is possible
to finely adjust the direction of the main axis of the unidirectional microphone in response to
various sound collection methods.
[0026]
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According to the sixth aspect of the present invention, two unidirectional microphones provided
rotatably about two rotational axes parallel to each other are provided. It can be arranged
individually at a position corresponding to the sound collection method of As a result, sound can
be collected by various sound collection methods.
[0027]
In addition, the position of the bi-directional microphone can be moved in the direction in which
the rotation axis extends by the second support portion. For this reason, when accommodating a
sound collection apparatus, a sound collection apparatus can be made compact by arranging a bidirectional microphone in the position in line with a unidirectional microphone. In addition, in
the case of collecting sound, the bi-directional microphone can be disposed at a position
corresponding to the sound collecting method.
[0028]
The sound pickup apparatus according to the embodiment of the present invention will be
described in detail with reference to FIGS.
[0029]
<Summary of technical idea of the first embodiment> The sound collection device according to
the present embodiment changes the sound collection direction (the direction of the main shaft)
by rotating around two rotation axes parallel to each other. Two possible unidirectional
microphones (hereinafter referred to as "microphones") and one bi-directional microphone
mounted with its directional axis oriented in the direction orthogonal to the straight line
connecting the two rotation axes Prepare.
[0030]
Here, since the sound collection angles of the unidirectional microphones are separately
changeable, it is possible to enrich the variation of how to set the directivity of the two
unidirectional microphones. The first feature is that it is possible to diversify the available sound
collection methods.
[0031]
Along with this, the sound collection device 1 receives from the user a selection operation of one
of the sound collection modes from plural kinds of sound collection modes according to the
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combination of the sound collection directions of the unidirectional microphone and / or the
bidirectional microphone. It is possible.
[0032]
When the sound collection device 1 receives the selection operation, the sound collection device
1 sets the unidirectional microphone to the sound collection direction corresponding to the
selected sound collection mode and switches on / off the bidirectional microphone, and By
performing audio signal processing corresponding to the selected sound collection mode, various
sound collection is realized.
[0033]
Here, the positional relationship between the two unidirectional microphones suitable for each
sound collection mode (distance between the microphones, etc.) and the positional relationship
(distance) between these unidirectional microphones and the bidirectional microphone are
different. .
In the present embodiment, it is a second feature that two unidirectional microphones are
movable in a predetermined section on a straight line connecting the first axes of these
unidirectional microphones.
Therefore, by moving the unidirectional microphones in a predetermined section, it is possible to
easily position the two unidirectional microphones in a positional relationship suitable for each
sound collection system.
[0034]
A third feature is that the unidirectional microphone is rotatable on a second axis perpendicular
to the rotation axis.
As described above, since the unidirectional microphone can be rotated about the second axis as
well as the first axis, the orientation of the main axis of the unidirectional microphone can be set
in various variations, Sound can be collected by a more versatile sound collection method.
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9
In addition, the direction of the main axis of the unidirectional microphone can be finely adjusted
in accordance with various sound collection methods.
[0035]
A fourth feature is that the bi-directional microphone is supported so as to be movable in a
direction parallel to the first axis.
As a result, when the sound collection device is housed, the sound collection device can be made
compact by arranging the bi-directional microphone in a position aligned with the unidirectional
microphone. Further, in the case of collecting sound, it is possible to arrange the bi-directional
microphone at a position corresponding to the sound collecting method.
[0036]
<Configuration of Sound Collection Device> FIG. 1 is a perspective view showing an appearance
of a sound collection device 1 according to an embodiment of the present invention. FIG. 2 is a
front view of the sound collection device 1 shown in FIG. In the following description, the front
direction of the sound collection device 1 is described as the Y direction, the back direction as the
-Y direction, the right side as the -X direction, and the left side as the X direction. The sound
collection device 1 has an apparatus main body 1B provided with an internal configuration
described later with reference to FIG. 4 in a long substantially rectangular parallelepiped casing
1A.
[0037]
Two single directional microphones 2 (first single directional microphones of the present
invention) are arranged side by side in the ± X direction on the upper surface of the device body
1B, and the rotation axis a (indicated by the dashed line in FIG. It is pivotally supported by the
support portion 21 so as to be rotatable 360 degrees in a direction (left and right direction)
indicated by an arrow A-A in FIG.
[0038]
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10
In addition, it is supported so as to be capable of rotating 180 degrees in the direction (height
direction) indicated by the B-B arrow in FIG. 1 around the rotation axis b (corresponding to the
second axis of the present invention) It is pivotally supported by the part 21.
As a result, the user can manually change the sound collection angle of the unidirectional
microphone 2 so that sounds in various directions can be collected. This makes it possible to
realize a variety of sound collection. Furthermore, since the unidirectional microphones 2A and
2B are rotatably supported by two axes, it is possible to set the sound collection angles to various
angles as compared with the configuration that can be rotated only by one axis. It will be
possible. This also makes it possible to realize more colorful sound collection.
[0039]
In addition, about the structure of the support part 21, it mentions later using FIG. 3 in detail.
Also, hereinafter, the unidirectional microphone 2 disposed on the -X side is referred to as a
unidirectional microphone 2A, and the unidirectional microphone 2 disposed on the X side is
referred to as a unidirectional microphone 2B.
[0040]
In addition, between each unidirectional microphone 2, the sound collecting direction is (the
front side and the back side) such that the sound collecting direction is aligned with (in parallel
with the X axis) with each unidirectional microphone 2. The bidirectional microphone 3 is
provided so as to be in the ± Y direction orthogonal to the direction.
[0041]
Thereby, the bi-directional microphone 3 can pick up voice in a direction orthogonal to the
straight line.
The bi-directional microphone 3 is configured by attaching two uni-directional microphones 31,
32 back to back. The microphone disposed on the Y side is the unidirectional microphone 31,
and the microphone disposed on the −Y side is the unidirectional microphone 32. The
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11
unidirectional microphones 31 and 32 are preferably realized, for example, by those having the
same sound collecting characteristic as the unidirectional microphone 2 from the viewpoint of
realizing various sound collecting modes described later.
[0042]
As described above, by turning on only one of the unidirectional microphones 31 and 32, it is
possible to pick up the bidirectional microphone 3 in only one of the Y direction and the -Y
direction. It has become.
[0043]
The bi-directional microphone 3 is attached to the apparatus main body 1B via the support 3A,
and the bi-directional microphone 3 is moved by moving the support 3A in the direction in which
the rotation axis a extends (the direction of the arrow c). It is possible to move in this direction.
The bi-directional microphone 3 is positioned at the same height as the uni-directional
microphone 2 when the support 3A is at the lowest position. For this reason, it is possible to
make compact the sound collection apparatus 1, and it is suitable at the time of storage. In
addition, the bi-directional microphone 3 is positioned at a position higher than the heights of
the unidirectional microphones 2A and 2B at the highest position of the support portion 3A.
[0044]
In addition, a slit 11 is formed on the upper surface of the housing 1A on a straight line
connecting the two unidirectional microphones 2 to each other. The slits 11 are formed in two
places from the X side end of the upper surface to the vicinity of the bi-directional microphone 3
and from the −X side end to the vicinity of the bi-directional microphone 3. The support portion
21B is loosely inserted in the slit 11 (11B) formed on the X side, and the support portion 21 is
guided by the slit 11B so as to be movable between both ends of the slit 11B (FIG. 1, See the
dotted arrow in Figure 2). The support portion 21A is loosely inserted in the slit 11 (11A) formed
on the −X side, and the support portion 21 is guided by the slit 11A to be movable between both
ends of the slit 11A (FIG. 1) , See the dotted arrow in Figure 2).
[0045]
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12
In the state where the height of the bi-directional microphone 3 is the highest, it is higher than
that of the unidirectional microphone 2. For this reason, by sliding the two unidirectional
microphones 2 to the bi-directional Ike 3 side and inserting them into the lower part of the
bidirectional microphone 3, these uni-directional microphones 2 are brought close to each other.
It is possible to arrange.
[0046]
As described above, the positional relationship between the two unidirectional microphones 2
suitable for various sound collection modes and the positional relationship between the
bidirectional microphone 3 and the unidirectional microphone 2A are different. In the present
embodiment, by sliding the two unidirectional microphones 2 in the X-X direction by the slit 11
and the support portion 21, the positional relationship between the two unidirectional
microphones 2A can be easily determined, and It is possible to adjust the positional relationship
between the directional microphone 2A and the bidirectional microphone 3 to a positional
relationship suitable for various sound collection modes.
[0047]
The operation unit 4 is provided on the -X side and the display unit 4A in the center on the Y side
of the sound collection device 1, and the external interface 5 is provided on the X side. The
operation unit 4 includes four operation buttons 42 (42A to 42D) disposed at the top, bottom,
left, and right of one operation button 41 and the operation button 41, and the operation button
41 or the operation button 42 is pressed by the user with a finger or the like. Accept various
operations. This operation includes, for example, a selection operation (mode selection operation)
of the above-described one sound collecting mode.
[0048]
One example of the specific mode selection operation will be described. One of the respective
sound collection modes is displayed on the display unit 4A, and the operation button 42A
arranged at the upper side is arranged at the lower side. The sound collection mode displayed is
switched each time the operation button 42B is pressed.
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[0049]
Here, when the operation button 41 is pressed, the displayed sound collection mode is selected.
As a result, the microphones 2A and 2B are set in the sound collecting direction according to the
selected sound collecting mode, and the bi-directional microphone 3 is switched on / off, and the
audio signal processing setting according to the sound collecting mode is made. A switch is made.
[0050]
The contents of a plurality of types of sound collection modes and the audio signal processing
when each sound collection mode is selected will be described in detail later.
[0051]
The display unit 4A is configured of, for example, an LCD (Liquid Crystal Display) or the like.
The operation unit 4 and the display unit 4A may be integrally provided by providing a touch
panel on the surface of the display unit 4A.
[0052]
The external interface 5 includes a plurality of connection terminals for connecting to an external
audio device (for example, a headphone device, an audio recorder, etc.), which makes it possible
to output the collected audio signal to the external audio device. ing. The sound collection device
1 is configured to be supplied with power from a power supply outlet (not shown) via the power
supply cord 1C.
[0053]
In the present embodiment, the sound collection device 1 can be used as a boundary microphone
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14
by placing the back surface on the floor surface. Here, in order to use the sound collection device
1 as a boundary microphone, the dimension D from the back surface to the rotation axis a of the
unidirectional microphone 2 is a specific frequency (a predetermined frequency in the audible
range, for example, 10 kHz, 5 kHz) Preferably, it is smaller than 1⁄4 wavelength of The reason for
this is to prevent cancellation of the sound to be collected by the reflected sound from the floor
surface. If the dimension D is a value (less than 17 mm) smaller than the 1⁄4 wavelength of 5
kHz, the influence of the reflected sound is small and sound collection can be performed with
sufficient sound quality, and more preferably 1 / l0 kHz. It is a value (less than 8.5 mm) smaller
than four wavelengths.
[0054]
In addition, it is good also as a structure which can be used as a boundary microphone by the
front of the sound collection apparatus 1 being installed in a floor surface. In this case, the
apparatus main body 1B is configured such that the dimension from the front to the rotation axis
a of the unidirectional microphone 2 is smaller than 1⁄4 wavelength of the specific frequency.
[0055]
FIG. 3A shows the attachment of the support 21 and the unidirectional microphone 2. The same
figure (b) is side sectional drawing which shows the structure of the unidirectional microphone 2
shown in FIG. 1, the support part 21, and these peripheral parts. Also, FIG. 6C is an e-e crosssectional view of the unidirectional microphone 2 shown in FIG.
[0056]
As shown in FIG. 6A, the support portion 21 has a shape in which a rectangular parallelepiped
21b is formed on the top of a cylinder 21a having a H-shaped side cross section. Then, in the
unidirectional microphone 2, a notch 2 ′ is formed at an end portion, and the shaft 22 is
inserted from the YY direction in a state in which the upper end of the rectangular parallelepiped
21 b is inserted in the notch 2 ′. It is done. The unidirectional microphone 2 is configured to
rotate in the B-B direction with the axis 22 as the rotation axis b.
[0057]
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Further, the concave portion of the cylinder 21a is fitted in the slit 11, and the support portion
21 is movable along the slit 11 by being guided by the slit 11 by sandwiching the periphery of
the slit 11 in the housing 1A with the convex portion. The unidirectional microphone 2 is
attached to the device body 1B. Thus, the unidirectional microphone 2 can be slid in the X-X
direction. In addition, the unidirectional microphone 2 can be rotated in the A-A direction, with
the center of the cylinder 21a as the rotation axis a.
[0058]
FIG. 4 is a block diagram showing the configuration of the sound collection device 1 shown in
FIG. The sound collection device 1 includes an A / D (analog / digital) converter 6, a storage unit,
in addition to the uni-directional microphone 2, the bi-directional microphone 3, the operation
unit 4, the display unit 4A, the external interface 5 and the like described above. 7, a control unit
8, a signal processing unit 9, and a D / A (digital / analog) converter 10.
[0059]
The A / D converter 6 is connected to each of the unidirectional microphones 2 and the
bidirectional microphone 3 via signal lines (not shown), and the unidirectional microphone 2 and
the bidirectional microphone 3 The analog audio signals of four channels input from the
directional microphones 31 and 32) are converted into digital audio signals and input to the
signal processing unit 9.
[0060]
The storage unit 7 is realized by, for example, a non-volatile semiconductor memory, a hard disk
or the like, and stores various programs for executing various sound signal processing
corresponding to various sound collection modes.
Various programs include MS stereo (0 ° direction) program, MS stereo (−90 ° direction)
program, MS surround (0 ° direction) program, MS surround (−90 ° direction) program,
sound pressure secondary gradient type narrow Directing program, delay addition type narrow
pointing program, MS stereo zoom (sound pressure secondary gradient type) program, MS stereo
zoom (delay addition type) program, monaural opposite pointing axis rotation program, pair
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microphone stereo (combination of level difference and phase difference) There are a program, a
pair microphone stereo (XY level difference) program, an addition type monaural narrow
pointing program, and the like.
[0061]
The MS stereo (0 ° direction) program is a program read out by the control unit 8 when the MS
stereo (0 ° direction) mode is selected. The MS stereo (−90 ° direction) program is a program
read out by the control unit 8 when the MS stereo (−90 ° direction) mode is selected. The MS
surround (0 ° direction) program is a program read out by the control unit 8 when the MS
surround (0 ° direction) mode is selected.
[0062]
The MS surround (−90 ° direction) program is a program read out by the control unit 8 when
the MS surround (−90 ° direction) mode is selected. The sound pressure secondary gradient
type narrow pointing program is a program read out by the control unit 8 when the sound
pressure secondary gradient type narrow pointing mode is selected. The delay addition type
narrow pointing program is a program read by the control unit 8 when the delay addition type
narrow pointing mode is selected.
[0063]
The MS stereo zoom (sound pressure secondary gradient type) program is a program read out by
the control unit 8 when the MS stereo zoom (sound pressure secondary gradient type) mode is
selected. The MS stereo zoom (delayed addition type) program is a program read out by the
control unit 8 when the MS stereo zoom (delayed addition type) mode is selected. The monaural
counter pointing axis rotation program is a program read by the control unit 8 when the
monaural counter pointing axis rotation mode is selected.
[0064]
The pair microphone stereo (combination of level difference and phase difference) program is a
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program read out by the control unit 8 when the pair microphone stereo (combination of level
difference and phase difference) mode is selected. The pair microphone stereo (XY level
difference) program is a program read out by the control unit 8 when the pair microphone stereo
(XY level difference) mode is selected. The addition type monaural narrow pointing program is a
program read out by the control unit 8 when the addition type monaural narrow pointing mode
is selected.
[0065]
Details of the various sound collection modes will be described later with reference to FIGS.
[0066]
The control unit 8 receives an operation signal indicating a mode selection operation from the
operation unit 4.
The control unit 8 performs display control on the display unit 4A, and switches the sound
collection mode to be sequentially displayed each time an operation signal indicating depression
of the operation buttons 42A and 42B is input from the operation unit 4 as described above. .
[0067]
Further, the control unit 8 acquires the selected sound collection mode by the input of the
operation signal indicating the mode selection operation. When acquiring the sound collection
mode, the control unit 8 executes mode setting processing. In the mode setting process, the
control unit 8 reads a program corresponding to the mode selection operation acquired as
described above from the storage unit 7, and executes a process of setting the read program in
the signal processing unit 9. By this, audio signal processing according to the sound collection
mode, that is, audio signal processing according to the combination of the sound collection
angles of the unidirectional microphones 2 and / or the bidirectional microphones 3 is
performed by the signal processing unit 9 It becomes possible to realize a wide variety of sound
collection. The mode setting process will be described later in detail with reference to FIG.
[0068]
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The signal processing unit 9 is realized by, for example, a DSP, and performs audio signal
processing on each audio signal input from each unidirectional microphone 2 and / or
bidirectional microphone 3 via the A / D converter 6. . The signal processing unit 9 changes the
setting of the audio signal processing by the control unit 8, and performs different audio signal
processing according to the setting. The contents of the audio signal processing corresponding to
the various modes will be described later in detail with reference to FIGS. The signal processing
unit 9 inputs the audio signal after the audio signal processing to the external interface 5
through the D / A converter 10. This makes it possible to input the collected audio signal to an
external audio device. Although the D / A converted analog signal is input to the external
interface 5 in FIG. 4, there may be a path in which the digital signal is input to the external
interface 5 as it is.
[0069]
<Description of Various Sound Collection Modes> Hereinafter, the arrangement of the
unidirectional microphones 2A and 2B in each sound collection mode, the direction of the
directional axis, and the audio signal processing will be described. In the present specification, as
shown in FIG. 1, the −Y direction is described as 0 °, the Y direction is 180 °, the −X
direction is 90 °, and the X direction is −90 °. . Also, in the description of some sound
collection modes, the X direction is described as 270 ° direction in order to clearly show the
range of angles. The term -90 ° indicates that the axis is rotated 90 ° counterclockwise from
the 0 ° axis (in the negative direction), but equivalently, it is rotated 270 ° clockwise (in the
positive direction). Show.
[0070]
<< MS stereo (0 direction) mode >> In the MS stereo (0 direction) mode, the audio signal from the
unidirectional microphone 32 is a mid signal, and the audio signals from the unidirectional
microphones 2A and 2B are side signals It is a mode which performs stereo sound collection by
MS stereo method by making -Y direction (0 degree direction) into the front as.
[0071]
<< MS stereo (0 direction) mode: setting of each microphone 2A, 2B, 31 and 32 >> FIG. 5 (a)
shows a sound collection device in which the monodirectional microphone 2 is set in the MS
stereo (0 direction) mode. It is a top view of 1, and (b) is a front view.
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[0072]
In the MS stereo (0 ° direction) mode, the microphone angle of the unidirectional microphone
2B is set to 90 °, and the microphone angle of the unidirectional microphone 2A is set to −90
°.
[0073]
Further, in the MS stereo system, in order to realize uniform sound collection, it is preferable that
the center of the diaphragm of the microphone for Side signal and the center of the diaphragm of
the microphone for Mid signal be arranged the same.
That is, in this mode, in order to realize uniform sound collection in the X-X direction and the -Y
direction, the centers of the diaphragms of the unidirectional microphones 2A and 2B and the
bidirectional microphone 3 are arranged identical. Is ideal.
Therefore, in the MS stereo (0 ° direction) mode, the bi-directional microphone 3 is set to the
highest.
At the same time, the unidirectional microphones 2A and 2B are arranged closest to the
bidirectional microphone 3 so that the microphones 2A and 2B enter below the bidirectional
microphone 3. As a result, the bidirectional microphone 3 and the unidirectional microphones 2A
and 2B can be arranged in a positional relationship close to an ideal.
[0074]
Then, only the unidirectional microphone 32 is turned on and the unidirectional microphone 31
is turned off. This ON indicates that the audio signal input to the signal processing unit 9 is used
for audio signal processing, and OFF indicates that it is not used for audio signal processing.
[0075]
<< MS Stereo (0 Direction) Mode: Audio Signal Processing >> FIG. 6 (a) is a diagram for
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explaining an audio signal in the MS stereo (0 direction) mode, and FIG. FIG. 6 is a block diagram
showing the function of the signal processing unit 9 in the (0 ° direction) mode. In FIGS. 6 (a), 7
(a), 8 (a), 9 (a), 13, 13, 17 (a) (b), 19 (a) and 24 (a), respectively. The directional characteristics of
the unidirectional microphone 2 and the bidirectional microphone 3 are indicated by alternate
long and short dashed lines. Also, the directional characteristics of the synthesized signal after
voice signal processing has been performed on the voices from the unidirectional microphone 2
and the bidirectional microphone 3 are indicated by thick solid lines.
[0076]
In the MS stereo (0 ° direction) mode, the signal processing unit 9 includes a gain adjustment
unit 91, multiplication units 92A and 92B, and addition units 93A, 93B and 93C.
[0077]
The signal processing unit 9 inputs the audio signal from the unidirectional microphone 32 as
the Mid signal to the addition units 93A and 93B.
Further, the signal processing unit 9 inputs an audio signal from the unidirectional microphone
2A to the multiplying unit 92A. The multiplying unit 92A multiplies the input audio signal from
the microphone 2A by -1 and inputs the result to the adding unit 93C. Further, the signal
processing unit 9 inputs an audio signal from the unidirectional microphone 2B to the addition
unit 93C. The addition unit 93C adds the input audio signal × -1 from the microphone 2A and
the audio signal from the microphone 2B to generate a Side signal, and inputs the side signal to
the gain adjustment unit 91. The gain adjustment unit 91 adjusts the level of the input Side
signal to adjust the level balance with the Mid signal, and inputs the result to the addition unit
93A and the multiplication unit 92B.
[0078]
The addition unit 93A adds the input Mid signal and Side signal to generate an R channel audio
signal, and inputs the signal to the D / A converter 10.
[0079]
The multiplication unit 92B multiplies the input Side signal by −1 and inputs the result to the
addition unit 93B.
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[0080]
The addition unit 93 B adds the input Mid signal and Side signal × −1 to generate an L channel
audio signal, and inputs the L channel audio signal to the D / A converter 10.
[0081]
As described above, in the MS stereo (0 ° direction) mode, sound can be collected in the MS
stereo system with 0 ° as the front (directed axis).
[0082]
In addition to the MS stereo (0 ° direction) mode, it is also possible to include the MS stereo
(180 ° direction) mode in various sound collection modes.
In this case, the single directional microphone 31 is turned on instead of the single directional
microphone 32, and the audio signal from the single directional microphone 31 is treated as a
Mid signal in the same manner as the MS stereo (0 ° direction) mode. Audio signal processing is
performed.
In this case, sound can be collected by the MS stereo method with the 180 ° direction as the
front.
[0083]
<< MS stereo (-90 ° direction) mode >> In the MS stereo (-90 ° direction) mode, the audio
signal from the unidirectional microphone 2A is a mid signal, and the audio signal from the
bidirectional microphone 3 is a side signal This is a mode in which stereo sound collection in the
MS stereo system is performed with the -90 ° direction as the front.
[0084]
<< MS stereo (-90 ° direction) mode: setting of each microphone 2A, 2B, 31, 32> As in the MS
stereo (0 ° direction) mode, the microphone angle of the unidirectional microphone 2A is
directed to -90 ° Set to
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In addition, in this mode, since the unidirectional microphone 2B is not used, the microphone
angle of the unidirectional microphone 2B may be set in any way.
[0085]
Further, as described above, in the MS stereo system, in order to realize uniform sound collection,
the center of the diaphragm of the microphone for the Side signal and the center of the
diaphragm of the microphone for the Mid signal are coaxially arranged. Is preferred.
That is, in this mode, it is ideal that the center of the diaphragm of the bi-directional microphone
3 and the center of the diaphragm of the unidirectional microphone 2A are arranged identical.
Therefore, in the MS stereo (-90 ° direction) mode, the bi-directional microphone 3 is set to the
highest.
[0086]
At the same time, the uni-directional microphone 2A is arranged closest to the bi-directional
microphone 3 so that the microphone 2A enters below the bi-directional microphone 3. Thereby,
the bidirectional microphone 3 and the unidirectional microphone 2A can be arranged in a
positional relationship close to an ideal.
[0087]
<< MS Stereo (-90 ° Orientation) Mode: Audio Signal Processing >> FIG. 7A is a diagram for
describing audio signal processing in the MS stereo (−90 ° orientation) mode. FIG. 7B is a block
diagram showing a functional configuration of the signal processing unit 9 in the MS stereo (-90
° direction) mode.
[0088]
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23
The signal processing unit 9 includes a gain adjustment unit 91-1, multiplication units 92-1A and
92-1B, and addition units 93-1A, 93-1B, and 93-1C. The signal processing unit 9 inputs an audio
signal from the unidirectional microphone 2A as an Mid signal to the adding unit 93-1A and the
adding unit 93-1B. On the other hand, the signal processing unit 9 inputs the audio signal from
the bidirectional microphone 3 as a Side signal to the gain adjustment unit 91-1.
[0089]
Here, in order to cause the unidirectional microphones 31 and 32 to function as the bidirectional
microphone 3, the signal processing unit 9 inputs the output of the microphone 32 to the adding
unit 93-1C, and the output of the microphone 31 Input to the multiplication unit 92-1A. The
multiplying unit 92-1A multiplies the input signal of the microphone 31 by -1 and inputs the
signal to the adding unit 93-1C. The addition unit 93-1C adds the output signal of the
microphone 32 and the input signal x-1 of the input microphone 31, and outputs the result as a
Side signal.
[0090]
The gain adjustment unit 91-1 adjusts the level of the Side signal in order to balance the level
with the Mid signal, and inputs the adjusted Side signal to the addition unit 93-1 A and the
multiplication unit 92-1. The multiplication unit 92-1 multiplies the input Side signal by -1 and
inputs the result to the addition unit 93-1B.
[0091]
The addition unit 93-1A adds the input Mid signal and Side signal, and inputs the audio signal
after the addition to the D / A converter 10 as an R channel audio signal. Further, the addition
unit 93-1B adds the input Mid signal and the input Side signal × -1 to generate an L channel
audio signal.
[0092]
Due to sound collection in the MS stereo (-90 ° direction) mode, stereo sound collection can be
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24
performed with the X direction as the front.
[0093]
In addition to the MS stereo (-90 ° direction) mode, it is also possible to include the MS stereo
(90 ° direction) mode in various sound collection modes.
In this case, the microphone angle of the unidirectional microphone 2B is set to 90 °, and the
unidirectional microphone 2B is disposed at the closest position of the bidirectional microphone
3. Then, the audio signal processing is performed using the audio signal from the unidirectional
microphone 2B as the Mid signal. In this mode, stereo sound collection can be performed with
the -X direction as the front.
[0094]
<< MS surround (0 direction) mode >> In MS surround (0 direction) mode, the sound from the
unidirectional microphone 2 and the bidirectional microphone 3 is used with the front surface
set to 0 ° (the directional axis). In this mode, four channels of surround sound collection are
performed.
[0095]
<< MS surround (0 ° direction) mode: settings of each microphone 2A, 2B, 31, 32>
Unidirectional microphones 2A, 2B and bidirectional microphone 3 are set as in the MS stereo (0
° direction) mode (See Figure 5).
Here, as described above, it is preferable that the center of the diaphragm of the microphone for
the Side signal and the center of the diaphragm of the microphone for the Mid signal be arranged
to be the same. For this reason, even in the MS surround (0 ° direction) mode, the bi-directional
microphone 3 is set to be expanded most. At the same time, the unidirectional microphones 2A
and 2B are arranged closest to the bidirectional microphone 3 so that the microphones 2A and
2B enter below the bidirectional microphone 3. In the MS surround (0 ° direction) mode, the
unidirectional microphones 31 and 32 are both turned on.
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[0096]
<< MS Surround (0 ° Orientation) Mode: Audio Signal Processing >> FIG. 8A is a diagram for
describing audio signal processing in the MS surround (0 ° orientation) mode. FIG. 8B is a block
diagram showing a functional configuration of the signal processing unit 9 in the MS surround (0
° direction) mode.
[0097]
In the MS surround (0 ° direction) mode, the signal processing unit 9 includes addition units
93D and 93E in addition to the gain adjustment unit 91, the multiplication units 92A and 92B,
and the addition units 93A, 93B and 93C.
[0098]
The signal processing unit 9 generates an R channel audio signal and an L channel audio signal
in the same manner as in the MS stereo (0 ° direction) mode.
The front side R channel is described as an FR channel, and the front side L channel is described
as an FL channel.
[0099]
Further, the signal processing unit 9 inputs the Side signal output from the gain adjustment unit
91 to the addition unit 93D, and inputs the output signal (Rmid signal) of the unidirectional
microphone 31 to the addition unit 93D. The addition unit 93D adds the input signals (Side
signal and output signal of the unidirectional microphone 31) to generate an audio signal of the
rear side R channel (RR channel), and the D / A is generated. Input to converter 10
[0100]
Further, the signal processing unit 9 inputs the Side signal x-1 output from the multiplying unit
92B to the adding unit 93E, and inputs the output signal (Rmid signal) of the unidirectional
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microphone 31 to the adding unit 93E. The addition unit 93E adds the input signals (Side signal
x -1 and the output signal of the unidirectional microphone 31) to generate a rear side L channel
(RL channel) audio signal, Input to the D / A converter 10.
[0101]
As described above, in the MS surround (0 ° direction) mode, it is possible to perform surround
sound collection of four channels in the MS mode, with the front face at 0 °.
[0102]
In addition to the MS surround (0 ° direction) mode, it is also possible to include the MS
surround (180 ° direction) mode in various sound collection modes.
In this case, an audio signal from the unidirectional microphone 32 is used as an RMid signal,
and an audio signal from the unidirectional microphone 31 is used as an FMid signal, and an
audio signal similar to the above-mentioned MS surround (0 ° direction) mode Processing is
applied. In this case, four channels of sound can be collected by the MS method with the 180 °
direction as the front.
[0103]
<< MS surround (-90 ° direction) mode >> In MS surround (-90 ° direction) mode, the sound
from the uni-directional microphone 2 and the bi-directional microphone 3 is set to -90 ° in the
front (directed axis). This is a mode that uses four channels for surround sound collection.
[0104]
<< MS surround (-90 ° direction) mode: settings for each microphone 2A, 2B, 31, 32> In MS
surround (-90 ° direction) mode, the directivity is the same as MS stereo (-90 ° direction)
mode. Microphones 2A and 2B and a bi-directional microphone are set.
Here, as in the MS stereo (0 ° direction) mode, the unidirectional microphones 2A and 2B and
the bidirectional microphone 3 are set (see FIG. 5). Here, as described above, it is preferable that
the center of the diaphragm of the microphone for the Side signal and the center of the
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27
diaphragm of the microphone for the Mid signal be arranged to be the same. Therefore, the bidirectional microphone 3 is set to the highest in the MS surround (-90 ° direction) mode. At the
same time, the unidirectional microphones 2A and 2B are arranged closest to the bidirectional
microphone 3 so that the microphones 2A and 2B enter below the bidirectional microphone 3.
Incidentally, in the MS surround (-90 ° direction) mode, the unidirectional microphones 31 and
32 are both turned on.
[0105]
<< MS Surround (-90 ° Orientation) Mode: Audio Signal Processing >> FIG. 9A is a diagram for
describing audio signal processing in the MS surround (−90 ° orientation) mode. FIG. 9B is a
block diagram showing a functional configuration of the signal processing unit 9 in the MS
surround (-90 ° direction) mode.
[0106]
In the MS surround (-90 ° direction) mode, the signal processing unit 9 includes gain adjusting
units 91-2A and 91-2B, multiplying units 92-2A, 92-2B and 92-2C, and adding units 93-2A to
And 93-2E.
[0107]
The signal processing unit 9 sets an audio signal from the unidirectional microphone 2A as a Mid
signal (FMid signal) on the front side, and inputs the signal to the adders 93-2A and 93-2B.
Further, the signal processing unit 9 inputs the audio signal from the bidirectional microphone 3
as a Side signal to the gain adjustment unit 91-2A. Here, in order to cause the unidirectional
microphones 31 and 32 to function as a bidirectional microphone, the signal processing unit 9
inputs the output of the microphone 32 to the adding unit 93-2E, and the output of the
microphone 31 is a multiplying unit Input to 92-2C. The multiplication unit 92-2C multiplies the
input signal of the microphone 31 by -1 and inputs the result to the addition unit 93-2E. The
adder 93-2E adds the output signal of the input microphone 32 and the output signal of the
input microphone 31 × -1 to generate a Side signal, and inputs the generated signal to the gain
adjusters 91-2A and 91-2B. .
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[0108]
The gain adjustment unit 91-2A adjusts the level of the Side signal to balance the level with the
FMid signal, and inputs the adjusted signal to the addition unit 93-2A and the multiplication unit
92-2A. The multiplication unit 92-2A multiplies the input Side signal by -1 and inputs the result
to the addition unit 93-2B.
[0109]
The addition unit 93-2A generates an audio signal of an R channel (FR channel) on the front side
by executing an audio signal process of adding the input FMid signal and the Side signal. The
audio signal of this FR channel is input to the D / A converter 10. Further, the addition unit 932B generates an audio signal of the L channel (FL channel) on the front side by executing audio
signal processing of adding the input FMid signal and the input Side signal × -1. The audio
signal of the FL channel is input to the D / A converter 10.
[0110]
The signal processing unit 9 sets an audio signal from the unidirectional microphone 2B as a rear
side Mid signal (RMid signal), and inputs the signal to the adding unit 93-2C and the adding unit
93-2D. In addition, the signal processing unit 9 branches the Side signal input to the gain
adjustment unit 91-2A and inputs the branched Side signal to the gain adjustment unit 91-2B.
The gain adjustment unit 91-2B adjusts the level of the input Side signal and inputs the result to
the multiplication unit 92-2B and the addition unit 93-2D in order to balance the level with the
RMid signal. The multiplication unit 92-2B multiplies the input Side signal by -1 and inputs the
result to the addition unit 93-2C.
[0111]
The addition unit 93-2D performs audio signal processing of adding the input RMid signal and
the input Side signal to generate an audio signal of the rear side R channel (RR channel). The
audio signal of the RR channel is input to the D / A converter 10. Further, the addition unit 93-2C
generates an audio signal of the rear side L channel (RL channel) by executing audio signal
processing for adding the input RMid signal and the side signal x-1. The audio signal of the RL
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29
channel is input to the D / A converter 10.
[0112]
By collecting the sound in the MS surround mode, it is possible to perform surround sound
collection of four channels of the FR channel, the FL channel, the RR channel, and the RL channel.
[0113]
In addition to the MS surround (-90 ° direction) mode, it is also possible to include the MS
surround (90 ° direction) mode in various sound collection modes.
In this case, an audio signal from the unidirectional microphone 2A is used as an RMid signal,
and an audio signal from the unidirectional microphone 2B is used as an FMid signal, and an
audio similar to that in the MS surround (-90 ° direction) mode is used. Signal processing is
performed. In this case, four channels of sound can be collected by the MS method with the 90
° direction as the front.
[0114]
<< Sound pressure secondary gradient type narrow directivity mode >> The sound pressure
secondary gradient type narrow directivity mode is the X direction by adding any one of the
audio signals from the unidirectional microphones 2A and 2B in opposite phase and adding
them. Or it is a mode which performs sound collection with narrow directivity in the -X direction.
[0115]
<< Sound pressure secondary gradient type narrow directivity mode: setting of each microphone
2A, 2B, 31 and 32 >> FIG. 10 (a) shows a collection in which the unidirectional directivity
microphone 2 is set to the sound pressure secondary gradient type narrow directivity mode. It is
a top view of the sound apparatus 1, (b) is a front view.
[0116]
In the sound pressure secondary gradient type narrow directivity mode, the microphone angle of
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the unidirectional microphones 2A and 2B is set to −90 ° in order to provide narrow directivity
in the X direction.
Further, in order to provide narrow directivity in the -X direction, the microphone angles of the
unidirectional microphones 2A and 2B are set to 90 °.
Also, the unidirectional microphones 31, 32 are both turned off.
[0117]
Also, the distance d1 between the unidirectional microphones 2A and 2B is adjusted. Here, the
frequency characteristic changes depending on the distance d1.
[0118]
FIG. 11 is a graph showing the frequency characteristics in the sound pressure secondary
gradient type narrow directivity mode, where (a) is a graph when the distance d1 / 2 is 0.034 m,
and (b) is a distance d1 / 2 Is a graph in the case of 0.068 m.
[0119]
In this graph and the graph of FIG. 12, the horizontal axis represents frequency (Hz) and the
vertical axis represents level (dB).
In addition, x1 indicates the frequency characteristic of voice input at 0 ° to the unidirectional
microphones 2A and 2B, x2 indicates frequency characteristic of voice input at 30 °, and sound
at x3 input at 60 ° Shows the frequency characteristics of
[0120]
As shown in FIGS. 11 (a) and 11 (b), the frequency at which the dip occurs increases as the
distance d1 increases. Since the dip occurs in the high region, the lower the sound level is
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31
collected higher than the high region as the distance d1 increases. In addition, as shown in FIG.
11A, the dip generated in the lowermost range in FIG. 11B is generated in the lowermost range
as compared to the dip generated in the lowermost range in FIG. The dip occurs in the lower
range as the For this reason, the sound quality deteriorates as the distance d1 increases.
[0121]
From the above, it is preferable to set the distance d1 narrower as the high sound is the sound
collection target, and to set the distance d1 wider as far as the poor sound quality is acceptable
when the low band is the sound collection target. Thus, the distance d1 is adjusted according to
the range of the sound to be collected.
[0122]
<< Sound pressure secondary gradient type narrow directivity mode: audio signal processing >>
FIG. 13 is a diagram for describing audio signal processing in the sound pressure secondary
gradient type narrow directivity mode. Further, FIG. 14A is a block diagram showing a functional
configuration of the signal processing unit 9 in the sound pressure secondary gradient type
narrow pointing mode shown in FIG.
[0123]
The signal processing unit 9 includes a multiplication unit 92-3 and an addition unit 93-3. The
signal processing unit 9 inputs the audio signal s1 from the unidirectional microphone 2 (in FIG.
9B, the unidirectional microphone 2B) in the pointing direction to the adding unit 93-3. At the
same time, the audio signal s2 from the unidirectional microphone 2 (in FIG. 9B, the
unidirectional microphone 2A) on the opposite side of the directivity direction is input to the
multiplying unit 92-3. The multiplication unit 92-3 multiplies the input audio signal s2 by -1 (in
reverse phase) and inputs the result to the addition unit 93-3.
[0124]
The addition unit 93-3 executes audio signal processing that adds and synthesizes the input
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audio signal s 1 and the input audio signal s 2 × −1. The audio signal after this addition and
synthesis is input to the D / A converter 10.
[0125]
Here, the voice from the front of the unidirectional microphone 2B is different in phase because
it is inputted to the unidirectional microphone 2A and the unidirectional microphone 2B with a
predetermined time difference, but the voice from the side is almost the same. The phases are
almost the same because they are input at the same timing. For this reason, the voice signal s2 is
reversed in phase and added to the voice signal s1 by the voice signal processing, so that the
phase of the voice from the front side is a predetermined frequency f1 at which the voice
frequency is determined by the two microphone intervals D. At frequencies below (f1 = Vc / (2D),
where Vc is the speed of sound), the phase does not become antiphase, but the phase of the
sound from the side becomes antiphase, and only the sound from the side is cancelled. As a
result, sound can be collected with narrow directivity on the front side (X side or -X side).
[0126]
In addition, since the sound of the low-pitched sound has a longer wavelength than the sound of
the high-pitched sound, the level is also lowered by the above-mentioned sound signal
processing. Therefore, the sound pressure second-order gradient type narrow pointing mode is
suitable for narrow directional sound pickup in an environment with a lot of low-pass noise.
[0127]
<< Delay-and-add type narrow pointing mode >> In the delay-add type narrow pointing mode, the
voice signal s1 is delayed by time t1 and added to the voice signal s2, thereby providing narrow
directivity in the X direction or −X direction. It is a mode to collect sound.
[0128]
The time t1 is the time until the sound from the same sound source located in front of the
unidirectional microphone 2B is input to the unidirectional microphone 2A and the time until the
sound from the same sound source is input to the unidirectional microphone 2B. It is a time
difference.
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[0129]
<< Delay-and-add type narrow directivity mode: setting of each microphone 2A, 2B, 31 and 32 >>
Even in the delay-add type narrow directivity mode, the microphone angle of the unidirectional
microphones 2A and 2B is the same as the sound pressure secondary gradient type narrow
directivity mode Set to
Also, the unidirectional microphones 31, 32 are both turned off.
[0130]
Further, in the delay addition type narrow pointing mode, the degree of narrow pointing changes
depending on the distance d1 between the unidirectional microphones 31 and 32.
[0131]
FIG. 12 is a graph showing frequency characteristics in the delay addition type narrow pointing
mode, where (a) is a graph when the distance d1 / 2 is 0.034 m, and (b) is a graph when the
distance d1 / 2 is 0. It is a graph in the case of 068 m.
[0132]
In the delay-adding type narrow pointing mode, the voice signal s1 is delayed by time t1 and
added to the voice signal s2, but in this processing, a dip occurs because the voice from 0 ° is in
phase in all frequency bands. The sound is collected without changing the frequency
characteristics.
On the other hand, as shown in FIG. 12 (a) (b) that the sound of 60 ° has more dips than 30 °,
more dips occur in the sound in the side direction.
For this reason, the level of the voice in the side direction is lowered, whereby the voice in the
front direction is collected specifically.
[0133]
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34
Here, as shown in FIGS. 12 (a) and 12 (b), as the distance d1 increases, more dips occur in the
sound in the side direction and dips occur in the low frequency range.
Therefore, as the distance d1 increases, the level of the audio in the side direction decreases, so
the degree of narrow pointing becomes high. Also, as the distance d1 increases, the sound quality
deteriorates due to the dip in the audio in the side direction. Therefore, when the degree of
narrowing is set high, the distance d1 can be set widely as far as the deterioration of the sound
quality can be tolerated.
[0134]
As described above, in the delay addition type narrow pointing mode, the degree of narrow
pointing can be adjusted by adjusting the distance d1.
[0135]
<< Delay-and-add type narrow directivity mode: audio | voice signal processing >> The voice
signal processing in delay addition type narrow directivity mode is demonstrated using FIG.13
and FIG.14 (b).
FIG. 13 is a diagram for describing audio signal processing in the delay addition type narrow
directivity mode as well as the audio signal processing in the sound pressure secondary gradient
narrow directivity mode. FIG. 14B is a block diagram showing a functional configuration of the
signal processing unit 9 in the delay addition type narrow directivity mode shown in FIG.
[0136]
The signal processing unit 9 includes an addition unit 93-4 and a delay unit 94-4. The signal
processing unit 9 inputs an audio signal s2 from the unidirectional microphone 2 (here, the
unidirectional microphone 2A) on the opposite side of the pointing direction to the adding unit
93-4. At the same time, the audio signal s1 from the unidirectional microphone 2 (here, the
unidirectional microphone 2B) in the directional direction is input to the delay unit 94-4. The
delay unit 94-4 delays the input audio signal s1 by time t1. The signal processing unit 9 inputs
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the delayed audio signal s1 to the addition unit 93-4.
[0137]
The addition unit 93-4 adds the audio signal s 2 and the delayed audio signal s 1 and inputs the
result to the D / A converter 10.
[0138]
Here, as described above, the audio from the side is input to the unidirectional microphones 2A
and 2B with almost no time difference, but the audio from the front of the unidirectional
microphone 2B is a single time difference of time t1. The signals are respectively input to the
unidirectional microphones 2A and 2B.
Therefore, by being delayed by time t1, the phases of the audio signal s1 and the audio signal s2
match for the audio component from the front side, but for the audio components from the side,
for both audio signals s1 and s2, It is out of phase. Therefore, although the signal level of the
sound component from the front side is amplified by the addition of the sound signal s1 and the
sound signal s2, the level of the sound component from the side is not amplified as compared to
the sound component from the front side. .
[0139]
As a result, the sound component from the front side becomes relatively large, and in the delay
addition type narrow directivity mode, sound from the front side (X side or -X side) can be
collected with narrow directivity. it can.
[0140]
<< MS stereo zoom (sound pressure secondary gradient type) mode and MS stereo zoom (delayed
addition type) mode >> In MS stereo zoom (sound pressure secondary gradient type) mode, audio
signals from the unidirectional microphones 2A and 2B On the other hand, the processing of the
sound pressure secondary gradient type narrow pointing mode is executed, the audio signal after
this processing is taken as the Mid signal, and the audio signal from the bidirectional microphone
3 is taken as the Side signal, the processing of MS stereo system It is a mode.
[0141]
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36
In the MS stereo zoom (delayed addition type) mode, the processing of the delay addition type
narrow directivity mode is executed on the audio signals from the unidirectional microphones 2A
and 2B, and the processed audio signal is made to be a Mid signal. In this mode, processing of
the MS stereo system is performed using the audio signal from the directional microphone 3 as
the Side signal.
[0142]
<< MS stereo zoom (sound pressure secondary gradient type) mode and MS stereo zoom (delayed
addition type) mode: setting of each of the microphones 2A, 2B, 31 and 32 >> FIG. It is a top view
of the sound collection apparatus 1 which set the unidirectional microphone 2 to the next
gradient type | mold mode, (b) is a front view.
[0143]
Even in the MS stereo zoom (sound pressure secondary gradient type) mode, the microphone
angles of the unidirectional microphones 2A and 2B are set in the same manner as the sound
pressure secondary gradient type narrow directivity mode.
Also, the unidirectional microphones 31, 32 are both turned on.
[0144]
Then, the distance d1 between the unidirectional microphones 2A and 2B is set in the same
manner as the above-mentioned sound pressure secondary gradient type narrow directivity
mode.
Furthermore, the distance d2 from the bidirectional microphone 3 to the unidirectional
microphone 2A and the distance d3 from the unidirectional microphone d3 are set to be
substantially the same.
The reason is as follows.
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[0145]
That is, as described above, in the MS stereo system, in order to realize uniform sound collection,
the center of the diaphragm of the microphone for the Side signal and the center of the
diaphragm of the microphone for the Mid signal are arranged the same. Is preferred.
Here, in the MS stereo zoom (sound pressure secondary gradient type) mode, the audio signal s2
and the audio signal s1 reverse phase are added and synthesized. Here, it is assumed that this
composite signal has a condition at the same position (that is, the central position between the
unidirectional microphones 2A and 2B) as viewed from the two microphones (unidirectional
microphones 2A and 2B). It is equivalent to the sound picked up by a typical diaphragm.
[0146]
For this reason, in the MS stereo zoom (sound pressure secondary gradient type) mode, the bidirectional microphone 3 is disposed at the position of this virtual diaphragm, whereby it is
disposed close to an ideal state for the MS system .
[0147]
FIG. 16 (a) is a top view of the sound collection device 1 in which the unidirectional microphone
2 is set in the MS stereo zoom (delayed addition type) mode, and FIG. 16 (b) is a front view.
[0148]
In the MS stereo zoom (delayed addition type) mode, the microphone angles of the unidirectional
microphones 2A and 2B are set in the same manner as in the delayed addition type narrow
pointing mode.
Also, the unidirectional microphones 31, 32 are both turned on.
[0149]
Then, in the MS stereo zoom (delayed addition type) mode, the distance d1 between the
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unidirectional microphones 2A and 2B is set as in the delay addition type narrow pointing mode.
At the same time, a unidirectional microphone 2 (a unidirectional microphone 2A in FIG. 15),
which does not delay the input audio signal, is disposed near the bidirectional microphone 3.
[0150]
As described above, it is ideal that the center of the diaphragm of the bi-directional microphone 3
and the centers of the diaphragms of the unidirectional microphones 2A and 2B be arranged the
same. Since the time t1 is added to the audio signal input from the unidirectional microphone 2
(in FIG. 15, the unidirectional microphone 2B in the example shown in FIG. 15) for delaying the
input audio signal, the method for delaying the input audio signal is simple. The center of the
diaphragm of the unidirectional microphone 2 is equivalent to being disposed at the same
position as the center of the diaphragm of the unidirectional microphone 2A which does not
delay the input audio signal.
[0151]
Therefore, the unidirectional microphones 2A and 2B and the bidirectional microphone 3 are
arranged close to each other by arranging the unidirectional microphone 2 and the bidirectional
microphone 3 close to each other not to delay the input audio signal. It will be in the state. As a
result, the unidirectional microphones 2A and 2B and the bi-directional microphone 3 can be
arranged in a near ideal state.
[0152]
<< MS stereo zoom (sound pressure secondary gradient type) mode and MS stereo zoom (delayed
addition type) mode: audio signal processing >> FIG. 17A shows an audio in the MS stereo zoom
(sound pressure secondary gradient type) mode. It is a figure for demonstrating signal
processing, (b) is a figure for demonstrating the audio | voice signal processing in MS stereo
zoom (delayed addition type | mold type) mode. FIG. 18A is a block diagram showing a functional
configuration of the signal processor 9 in the MS stereo zoom (sound pressure secondary
gradient type) mode. FIG. 18B is a block diagram showing a functional configuration of the signal
processor 9 in the MS stereo zoom (delayed addition type) mode.
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[0153]
In the MS stereo zoom (sound pressure secondary gradient type) mode, the signal processing
unit 9 includes a gain adjustment unit 91-5 and multiplication units 92-5 and 92 in addition to
the multiplication unit 92-3 and the addition unit 93-3. 2C and adders 93-5A, 93-5B, and 93-2E.
In the MS stereo zoom (delayed addition type) mode, the signal processing unit 9 includes a gain
adjustment unit 91-5, a multiplication unit 92-5, 92-2C, and the like in addition to the addition
unit 93-4 and the delay unit 94-4. The adders 93-5A, 93-5B, and 93-2E are provided.
[0154]
In FIG. 18 (a), the signal processing unit 9 uses the multiplication unit 92-3 and the addition unit
93-3 to apply the above-mentioned second-order sound pressure type narrowing to the audio
signal from the unidirectional microphones 2A and 2B. Execute processing in oriented mode.
Further, in FIG. 18B, the signal processing unit 9 uses the addition unit 93-4 and the delay unit
94-4 to perform the above-mentioned delay addition type narrow directivity mode on the audio
signals from the unidirectional microphones 2A and 2B. Execute the process of The audio signals
after these processes are referred to as audio signals s3 and s3 '.
[0155]
Hereinafter, in common with FIGS. 18A and 18B, the signal processing unit 9 inputs the audio
signals s3 and s3 ′ as Mid signals to the addition units 93-5A and 93-5B. At the same time,
similarly to the MS stereo (-90 ° direction) mode, etc., the multiplier unit 92-2C and the adder
unit 93-2E are used to generate a Side signal from the signals from the microphone 31 and the
microphone 32, and the gain adjustment unit 91 Enter -5. The gain adjusting unit 91-5 adjusts
the level of the side signal input to adjust the level balance with the mid signal, and inputs the
adjusted signal to the multiplying unit 92-5 and the adding unit 93-5A. The multiplying unit 92-5
multiplies the input Side signal by -1 and inputs the result to the adding unit 93-5B.
[0156]
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40
The addition unit 93-5A adds the Side signal to the input Mid signal to generate an R channel
audio signal. The audio signal of the R channel is input to the D / A converter 10. Further, the
adding unit 93-5B adds the input Mid signal and the input Side signal × -1 to generate an L
channel audio signal. The audio signal of L channel is input to the D / A converter 10.
[0157]
By collecting sound in the MS stereo zoom (sound pressure secondary gradient type) mode or the
MS stereo zoom (delayed addition type) mode, sound can be collected with narrow directivity in
the X direction and −X direction While being able to do, it is possible to perform sound
collection with a sense of stereo in the YY direction. Also, by adjusting the mixing ratio of the Mid
signal and the Side signal, it is possible to adjust the zoom feeling.
[0158]
<< Mono Opposite Directional Axis Rotational Mode >> The monaural opposite directional axis
rotation mode causes the unidirectional microphones 2A and 2B to function as bi-directional
microphones in the X-X direction. It is a mode to form a bi-directional microphone. Then, in the
monaural opposite directional axis rotation mode, voices from bidirectional microphones in two
directions are added to form opposite directional axes, and the mixing ratio of voices from
bidirectional microphones in two directions is changed. This is a mode in which the bi-directional
countering pointing axis is rotated.
[0159]
<< Mono opposite directional axis rotation mode: setting of each microphone 2A, 2B, 31 and 32
>> In the mono opposite directional axis rotation mode, the microphone angle of the
unidirectional microphone 2A is set to -90 °, and the unidirectional microphone The
microphone angles of 2B are set to face 90 ° (to face each other). Also, the unidirectional
microphones 31, 32 are both turned on.
[0160]
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41
In the monaural opposite directional axis rotation mode, it is preferable to place both
unidirectional microphones 2A and 2B as close as possible in order to cause the unidirectional
microphones 2A and 2B to function like a bidirectional microphone. Further, in order to rotate
the opposite directional axis concentrically by 360 degrees, it is preferable to arrange the bidirectional microphone 3 and the unidirectional microphones 2A and 2B in proximity to each
other. Therefore, in the monaural countering directional axis rotation mode, the unidirectional
microphones 2A and 2B are disposed closest to the bidirectional microphone 3 with the
bidirectional microphone 3 set to the highest. That is, the microphones 2A, 2B, 31, 32 are set in
the same manner as in FIGS. 5 (a) and 5 (b).
[0161]
<< Mono Opposite Directional Axis Rotation Mode: Audio Signal Processing >> FIG. 19A is a
diagram for describing audio signal processing in the monaural opposite direction axis rotation
mode. FIG. 19B is a block diagram showing a functional configuration of the signal processing
unit 9 in the monaural facing directional axis rotation mode shown in FIG. 19A. The signal
processing unit 9 includes gain adjusting units 91-6A and 91-6B, multiplying units 92-6A and
92-6B, and adding units 93-6A, 93-6B and 93-6C.
[0162]
The signal processing unit 9 inputs the audio signal s2 from the unidirectional microphone 2A to
the adding unit 93-6A, and inputs the audio signal s1 from the unidirectional microphone 2B to
the multiplying unit 92-6A. The multiplying unit 92-6A multiplies the input voice signal s1 by -1
(in reverse phase) and inputs the result to the adding unit 93-6A. The addition unit 93-6A adds
the audio signal s2 from the unidirectional microphone 2A and the audio signal s1 × -1 from the
unidirectional microphone 2B, and generates an audio signal with bidirectionality in the X-X
direction. A process of generating s4 is performed.
[0163]
The signal processing unit 9 inputs the audio signal s4 to the addition unit 93-6B via the gain
adjustment unit 91-6A. At the same time, the signal processing unit 9 inputs the audio signal s5
from the bidirectional microphone 3 to the addition unit 93-6B via the gain adjustment unit 916B. Here, in order to cause the unidirectional microphones 31 and 32 to function as a
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bidirectional microphone, the signal processing unit 9 inputs the output of the microphone 32 to
the adding unit 93-6C and multiplies the output of the microphone 31. Input to section 92-6B.
The multiplying unit 92-6B multiplies the input signal of the microphone 31 by -1 and inputs the
signal to the adding unit 93-6C. The addition unit 93-6C adds the output signal of the input
microphone 32 and the input signal x-1 of the input microphone 31 to generate an audio signal
s5.
[0164]
The gain adjusting unit 91-6A and the gain adjusting unit 91-6B adjust the level balance by
multiplying the input audio signal s4 and the audio signal s5 by a predetermined coefficient. The
coefficient of the gain adjustment unit 91-6A and the coefficient of the gain adjustment unit 916B are set to be "1" when added.
[0165]
The addition unit 93-6B receives the audio signal s4 and the audio signal s5 in the state of which
the level balance has been adjusted, and adds the audio signal s4 and the audio signal s5. As a
result, it is possible to pick up sound on a plane including the XX direction and the YY direction
with the bidirectional directional pointing axis. Here, the mixing ratio of the audio signal s4 and
the audio signal s5 can be changed by changing the coefficient of the gain adjusting unit 91-6A
and the coefficient of the gain adjusting unit 91-6B. The axis can be rotated 360 degrees on a
plane that includes the X-X and Y-Y directions.
[0166]
In the above monaural facing pointing axis rotation mode, as described above, a bi-directional
facing pointing axis can be formed on a plane including the X-X direction and the Y-Y direction,
and this pointing axis can be rotated. The pointing direction can be rotated 360 degrees on the
surface by simple processing.
[0167]
<< Pair Mic Stereo (combination of level difference and phase difference) mode >> Pair
Microphone Stereo (combination of level difference and phase difference) mode is a stereo
collection that uses the level difference and phase difference of the audio input to the
unidirectional microphones 2A and 2B. It is a mode to make a sound.
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[0168]
<< Pair Mic Stereo (combination of level difference and phase difference) mode: setting of each
microphone 2A, 2B, 31 and 32 >> FIG. 20 (a) is a unidirectional microphone in pair microphone
stereo (combination of level difference and phase difference) mode. It is a figure which shows the
setting of 2A and 2B.
[0169]
The unidirectional microphone 2A is disposed at the -X side end, and the unidirectional
microphone 2B is disposed at the X side end.
Furthermore, in order to set the opening angle θ between the unidirectional microphones 2A
and 2B to a predetermined opening angle between 90 degrees and 120 degrees (for example,
110 degrees), The microphone angle is set to 0 ° to 90 °.
In addition, the microphone angle of the unidirectional microphone 2B is set to 0 ° to -90 °.
[0170]
When the unidirectional microphones 2A and 2B are disposed at the opening angles θ of the
above-mentioned predetermined angle and at the opposite end portions of each other as
described above, the unidirectional microphones 2A and 2B are The lengths of the slits 11A and
11B and the unidirectional microphones 2A and 2B in the front-rear direction are set such that
the distance d4 between the centers of the front surfaces is approximately 17 cm.
As a result, the unidirectional microphones 2A and 2B can be easily set in the preferred
arrangement (the arrangement shown in FIG. 20A) in the pair microphone stereo mode
(combination of level difference and phase difference) mode.
[0171]
Although the bi-directional microphone 3 is normally turned off, the microphone 32 facing the
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44
directional axis for preventing the middle drop in the case of a middle drop (in the case of FIG.
20A, the microphone 32) It may be configured to be mixed by adjusting only the level and
adjusting the level.
[0172]
In addition, as described above, the back surface of the sound collection device 1 is installed on
the floor surface, whereby the sound collection device 1 is used as a boundary microphone.
[0173]
FIG. 20B is a diagram showing the setting of the unidirectional microphones 2A and 2B in the
pair microphone stereo (combination of level difference and phase difference) mode in the case
of using the sound collection device 1 as the boundary microphone.
[0174]
Also in this case, the unidirectional microphone 2A is disposed at the -X side end, and the
unidirectional microphone 2B is disposed at the X side end.
Then, by rotating the unidirectional microphones 2A and 2B in the BB direction, the opening
angle θ can be adjusted to a predetermined opening angle (for example, 110 °).
By adjusting in this way, it is possible to perform stereo sound collection with the boundary
microphone.
[0175]
Furthermore, as shown in FIG. 20 (c), the sound collecting direction may be set so that the
unidirectional microphone 2A is rotated in the A-A direction and directed to the height of the
sound source.
In this case, the height from the floor surface to the diaphragm of the unidirectional microphone
2 is preferably set to be smaller than the 1⁄4 wavelength of the specific frequency described
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45
above.
[0176]
Note that the main axis of the bi-directional microphone 3 can be directed upward (in the -Y
direction in the state where the back surface is installed on the floor as shown in FIG. 20 (b)). The
sound may be configured to prevent hollowing out of the voice between the unidirectional
microphones 2A and 2B.
[0177]
For example, as shown in FIG. 21, the bi-directional microphone 3 is pivotally supported by an
axis 3B 'extending in the direction of the unidirectional microphones 2A and 2B.
At the same time, the shaft 3B 'is rotatably attached to the end of the wedge-shaped support 3A'.
As a result, by turning the shaft 3B ', the bidirectional microphone 3 (unidirectional microphone
31 to unidirectional microphone 32) is directed upward (in the -Y direction in FIG. 20B). It can be
turned. In this state, by collecting sound also from the bi-directional microphone 3, it is possible
to prevent hollow of the voice from between the uni-directional microphones 2A and 2B as
described above.
[0178]
<< Pair microphone stereo (combination of level difference and phase difference) mode: sound
signal processing >> The sound signal processing in pair microphone stereo (combination of level
difference and phase difference) mode is voice of normal pair microphone stereo (combination of
level difference and phase difference) method Description of the signal processing will be
omitted.
[0179]
By the pair microphone stereo (combination of level difference and phase difference) mode, it is
possible to perform sound collection in stereo (combination of level difference and phase
difference) method by changing the opening angle θ between the unidirectional microphones
2A and 2B. .
[0180]
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46
<< Pair Microphone Stereo (XY Level Difference) Mode >> Pair microphone stereo (XY level
difference) mode is a stereo including only the level difference, with as little as possible phase
differences and time differences of the sound input to the unidirectional microphones 2A and 2B.
It is a mode to collect sound.
[0181]
<< Pair Microphone Stereo (XY Level Difference) Mode: Setting of Each Microphone 2A, 2B, 31,
32 >> FIG. 22 (a) shows a sound collection device in which the unidirectional microphone 2 is set
in the pair microphone stereo (XY level difference) mode. It is a top view of 1, and (b) is a front
view.
[0182]
In the pair microphone stereo (XY level difference) mode, it is possible that the unidirectional
microphones 2A and 2B are disposed as close as possible without causing phase difference and
time difference of the sound input to the unidirectional microphones 2A and 2B. Because it is
preferable.
Therefore, the bidirectional microphone 3 is set to the highest, and the unidirectional
microphones 2A and 2B are slid to the end of the slit 11 on the bidirectional microphone 3 side,
and the lower portion of the bidirectional microphone 3 Will be placed.
[0183]
In this state, the opening angle θ between the unidirectional microphones 2A and 2B is set to a
predetermined angle (for example, 110 °) between 90 ° and 120 °.
Then, the microphone angle of the unidirectional microphone 2A is set to 180 ° to 270 °.
In addition, the microphone angle of the unidirectional microphone 2B is set to 90 ° to 180 °.
The bi-directional microphone 3 is normally turned off, but when the middle drop is anxious, the
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microphone facing the directional axis for preventing the middle drop (in the case of FIG. 22A,
the microphone 31) It may be configured to be mixed by adjusting only the level and adjusting
the level.
[0184]
<< Pair Microphone Stereo (XY Level Difference) Mode: Audio Signal Processing >> Audio signal
processing in the pair microphone stereo (XY level difference) mode is audio signal processing of
a normal XY stereo system, and therefore, the description thereof is omitted.
[0185]
By the pair microphone stereo (XY level difference) mode, the microphone angles of the
unidirectional microphones 2A and 2B can be changed to perform sound collection in the XY
stereo system.
[0186]
<Addition-type monaural narrow pointing mode> In the addition-type monaural narrow pointing
mode, the sound collecting directions of the unidirectional microphones 2A and 2B and the
bidirectional microphone 3 are all directed to the same direction, and these microphones 2A, 2B,
In this mode, the voice signals from 3 are added and collected with narrow directivity in the
direction to which each of the microphones 2A, 2B, 3 faces.
[0187]
<< Additional monaural narrow directivity mode: settings of the microphones 2A, 2B, 31 and 32
>> FIG. 23 is a top view of the sound collection device 1 in which the unidirectional microphone
2 is set to the additive monaural narrow directivity mode.
When sound is collected with narrow directivity in the -Y direction, the sound collection angle of
the unidirectional microphones 2A and 2B is set to 0 °.
[0188]
Furthermore, the unidirectional microphone 32 is turned on and the unidirectional microphone
31 is turned off.
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[0189]
In addition, when sound is collected with narrow directivity in the Y direction, the sound
collection angle of the unidirectional microphones 2A and 2B is set to 180 °.
At the same time, the unidirectional microphone 31 is turned on and the unidirectional
microphone 32 is turned off.
[0190]
Furthermore, the distance d5 in the XX direction between the unidirectional microphone 2A and
the bidirectional microphone 3 and the distance d5 in the XX direction between the
unidirectional microphone 2B and the bidirectional microphone 3 By adjusting the distance d6,
the directivity and the frequency characteristic can be changed and sound can be collected.
[0191]
<< Additional monaural narrow directivity mode: audio signal processing >> FIG. 24A is a
diagram for describing audio signal processing in the additive monaural narrow directivity mode.
FIG. 24B is a block diagram showing a functional configuration of the signal processing unit 9 in
the addition type monaural narrow pointing mode.
The signal processing unit 9 includes a gain adjustment unit 91-7, an addition unit 93-7, and
delay units 94-7A and 94-7B.
[0192]
The signal processing unit 9 inputs an audio signal from the unidirectional microphone 32 to the
gain adjustment unit 91-7.
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The gain adjustment unit 91-7 adjusts the gain of the input audio signal from the unidirectional
microphone 32 to perform level balance with the audio signals from the unidirectional
microphones 2 A and 2 B, and adds the same. Input to 93-7.
[0193]
Further, the signal processing unit 9 inputs an audio signal from the unidirectional microphone
2A to the delay unit 94-7A, and inputs an audio signal from the unidirectional microphone 2B to
the delay unit 94-7B. There is a distance d (of the diaphragm) in the Y-Y direction between the
unidirectional microphone 32 and the unidirectional microphone 2. The delay units 94-7A and
94-7B delay the input audio signal by the time difference t2 of the audio input timing based on
the distance d, and input the delayed audio signal to the addition unit 93-7.
[0194]
An adder 93-7 adds and synthesizes the input audio signal from the unidirectional microphone
32 and the delayed audio signals from the unidirectional microphones 2A and 2B, and inputs the
resultant to the D / A converter 10. Do. Thus, sound can be collected with narrow directivity in
the Y direction or in the -Y direction.
[0195]
Since sound can be collected in the addition type monaural narrow pointing mode, the abovedescribed sound pressure secondary gradient narrow pointing mode, or the delay addition type
narrow pointing mode, in the sound collection device 1, the X direction, −X direction, Sound can
be collected with narrow directivity in the Y direction and the -Y direction.
[0196]
<Description of Mode Setting Process> FIG. 25 is a flowchart showing the mode setting process
performed by the control unit 8.
This process is started when an operation signal (an operation signal corresponding to pressing
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50
of the operation button 41) indicating a mode selection operation is input to the control unit 8.
First, the control unit 8 detects a sound collection mode indicated by the input operation signal
(S1). The control unit 8 reads a program corresponding to the detected sound collection mode
from the storage unit 7 (S2).
[0197]
The control unit 8 sets the read program in the signal processing unit 9, and switches on / off
setting of the unidirectional microphones 31, 32 (S3). After changing the audio signal processing
setting according to the program, the signal processing unit 9 in which the program is set inputs
a completion signal indicating the completion of this processing to the control unit 8.
[0198]
Thereafter, the control unit 8 determines whether the completion signal is input within the
predetermined time (S4), and when it is determined that the completion signal is input within the
predetermined time (YES in S4), this process is performed. End. On the other hand, when it is
determined that the completion signal has not been input within the predetermined time (NO in
S4), for example, the control unit 8 displays an error on the display unit 4A (S5), and then this
process ends. Let
[0199]
As described above, in the sound collection device 1 according to the present embodiment, since
the sound collection angles of the unidirectional microphones 2A and 2B can be changed
individually, variations of the directivity setting pattern of each microphone can be obtained. It
becomes richer than prior art, and this can make the sound collection apparatus 1 respond |
correspond to various sound collection systems.
[0200]
Further, the sound collection angles of the unidirectional microphones 2A and 2B can be
changed in the A-A direction, and the unidirectional microphones 2A and 2B can slide in the X-X
direction.
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For this reason, the positional relationship between the unidirectional microphones 2A and 2B
and the positional relationship between the unidirectional microphone 2 and the bidirectional
microphone 3 are set so as to be optimum for various sound collection modes and easily
positioned. be able to.
[0201]
In addition, the unidirectional microphones 2A and 2B are rotatable in two axes (rotational axes a
and b), and rotate not only in the A-A direction but also in the B-B direction. It becomes possible
to perform stereo sound collection etc. with a microphone, and more versatile sound collection
can be performed.
[0202]
In addition, since the position of the bi-directional microphone 3 can be changed in the height
direction, it can be made compact by arranging it close to the device body 1B side when stored,
and when collecting sounds, each sound collection mode The height of the bi-directional
microphone 3 can be set to a suitable position.
[0203]
Note that the sound collection device according to the present invention may not be compatible
with all of the above various sound collection modes, and further, various microphone modes and
the contents of microphone angles and audio signal processing corresponding to various sound
collection modes. Is not limited to the above.
[0204]
It is a perspective view showing the appearance of the sound collection device concerning the
embodiment of the present invention.
It is a front view of the sound collection apparatus shown in FIG.
(A) is a figure which shows attachment of a support part and a unidirectional microphone, (b) is a
side sectional view which shows the structure of the unidirectional microphone shown in FIG. 1,
a support part, and these peripheral parts (C) is an ee cross-sectional view of the unidirectional
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microphone shown in (b).
It is a block diagram which shows the structure of the sound collection apparatus shown in FIG.
(A) is a top view of the sound collection apparatus which set the unidirectional microphone to MS
stereo (0 degree direction) mode, (b) is a front view. (A) is a figure for demonstrating the audio |
voice signal in MS stereo (0 degree direction) mode, (b) is a block which shows the function of
the signal processing part 9 in MS stereo (0 degree direction) mode FIG. (A) is a figure for
demonstrating the audio | voice signal processing in MS stereo (-90 degree direction) mode, (b) is
a functional of the signal processing part in MS stereo (-90 degree direction) mode It is a block
diagram showing composition. (A) is a figure for demonstrating the audio | voice signal
processing in MS surround (0 direction) mode, (b) is a functional structure of the signal
processing part in MS surround (0 direction) mode. It is a block diagram shown. (A) is a figure for
demonstrating the audio | voice signal processing in MS surround (-90 degree direction) mode,
(b) is a functional of the signal processing part in MS surround (-90 degree direction) mode It is a
block diagram showing composition. (A) is a top view of the sound collection apparatus which set
the unidirectional microphone to the sound pressure secondary gradient type narrow directivity
mode, (b) is a front view. It is a graph which shows the frequency characteristic in sound
pressure secondary gradient type narrow directivity mode, (a) is a graph in case distance d1 / 2
is 0.034 m, (b) is distance d1 / 2 being 0.068 m In the case of It is a graph which shows the
frequency characteristic in delay addition type narrow pointing mode, (a) is a graph in case
distance d1 / 2 is 0.034 m, (b) is in the case where distance d1 / 2 is 0.068 m. It is a graph. It is a
figure for demonstrating the audio | voice signal processing in sound pressure secondary
gradient type | mold narrow pointing mode and delay addition type narrow pointing mode. (A) is
a block diagram which shows a functional structure of the signal processing part in the sound
pressure secondary gradient type narrow directivity mode shown in FIG. 13, (b) is a delay
addition type narrow directivity mode shown in FIG. It is a block diagram which shows the
functional structure of a signal processing part. (A) is a top view of the sound collection
apparatus which set the unidirectional microphone to MS stereo zoom (sound pressure
secondary gradient type) mode, (b) is a front view. (A) is a top view of the sound collection
apparatus which set the unidirectional microphone to MS stereo zoom (delayed addition type)
mode, (b) is a front view. (A) is a figure for demonstrating the audio signal processing in MS
stereo zoom (sound pressure secondary gradient type) mode, (b) is the audio signal processing in
MS stereo zoom (delayed addition type) mode It is a figure for demonstrating.
(A) is a block diagram showing a functional configuration of a signal processing unit in MS stereo
zoom (sound pressure secondary gradient type) mode, (b) is a signal processing unit in MS stereo
zoom (delayed addition type) mode It is a block diagram which shows the functional structure of.
(A) is a figure for demonstrating the audio | voice signal processing of monaural opposing
pointing axis rotation mode, (b) is a functional of the signal processing part in monaural facing
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pointing axis rotation mode shown in Fig.19 (a). It is a block diagram showing composition. (A) is
a figure which shows the setting of the unidirectional microphone in a pair microphone stereo
(level difference and phase difference combined use) mode, (b) is a pair microphone stereo in the
case of using a sound collection apparatus as a boundary microphone It is a figure which shows
the setting of a unidirectional microphone in (a level difference * phase difference combined use)
mode, (c) is a sound collection apparatus shown by (b), Comprising: A-A It is a figure which
shows the thing of the state rotated also by the direction. It is a figure which shows the bidirectional microphone concerning the modification of this embodiment, and its periphery
member. (A) is a top view of the sound collection apparatus which set the unidirectional
microphone to a pair microphone stereo (XY level difference) mode, (b) is a front view. (It is a top
view of the sound collection apparatus which set the unidirectional microphone 2 to the addition
type monaural narrow directivity mode. (A) is a figure for demonstrating the audio | voice signal
processing in addition type | mold monaural narrow pointing mode, (b) is a block diagram which
shows the functional structure of the signal processing part in addition type monaural narrow
pointing mode is there. It is a flowchart which shows the mode setting process which a control
part performs.
Explanation of sign
[0205]
1-Sound Collection Device 1A-Device Body 2 (2A, 2B)-Unidirectional Microphone 3- Bidirectional
Microphone 3A-Support Part (Corresponding to the Second Support Part of the Present
Invention) 21 (21A, 21B)-Support Part a, b-axis of rotation
10-04-2019
54
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