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JP2008061186

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This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
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DESCRIPTION JP2008061186
An object of the present invention is to make it possible to pick up a target sound to be picked up
with a high S / N ratio, even when the position of the sound source changes successively. A
sound collection device comprising two bi-directional microphones and one non-directional
microphone in which main axes of orientation are orthogonal, and adding and outputting signals
output from each microphone at a preset addition ratio A directional characteristic control device
for setting a directional characteristic, wherein storage means in which a plurality of addition
ratios each representing different directional characteristics are stored in advance, and each of
the addition ratios stored in the storage means Control is performed at predetermined time
intervals to add to the sound collection device an addition ratio representing the directivity
characteristic according to the direction of the sound source determined by adding the signals
output from each of the microphones by the ratio A directional characteristic control device is
provided. [Selected figure] Figure 1
Directional characteristic control device, sound collecting device and sound collecting system
[0001]
The present invention relates to a technology for picking up a sound to be picked up at a high S /
N (Signal / Noise) ratio, and in particular, achieves a high S / N ratio by using in combination
microphones having different directional characteristics. Related to technology.
[0002]
Various techniques have been conventionally proposed to realize sharp directivity characteristics
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in order to be able to pick up a target sound to be picked up with a high S / N ratio, and
examples of such techniques include so-called microphone arrays and patents The techniques
disclosed in the documents 1 to 3 can be mentioned.
Here, the microphone array is an array of microphones having the same directivity (for example,
uni-directionality) and realizes sharp directivity by using the arrival time difference of sound
waves to each microphone. It is. On the other hand, Patent Documents 1 to 3 combine
microphones with different directional characteristics (for example, nondirectional microphone
and bidirectional microphone), and appropriately adjust the addition ratio of output signals of
each microphone by DSP (Digital Signal Processor) or the like. There is disclosed a technique for
realizing sharp directional characteristics by Japanese Patent Application Laid-Open No. 5994993 Patent No. 3599 653 Patent No. 3279040
[0003]
However, since the microphone array is configured by arranging a large number of microphones,
the overall size of the microphone array becomes large, making it difficult to handle, and the cost
of the device increases. is there. In addition, in the microphone array, since the arrival time
difference of the sound waves is used, there is a problem that the sound quality of the collected
sound is significantly deteriorated by the Comb filter effect if the sound source deviates from the
directional axis direction. For this reason, it is difficult to pick up the target sound with good
sound quality when the sound source position changes successively. In addition, in the speaker
array, since delay control is added to the audio signal output from each microphone, the signal
waveform becomes discontinuous (that is, the picked up audio becomes discontinuous). There is
also. On the other hand, although the techniques disclosed in Patent Documents 1 to 3 can
appropriately set the directivity characteristic according to the position of the sound source,
when the position of the sound source changes successively, the change is made to follow Can
not change the directional characteristics. An object of the present invention is to provide a
technology that enables a target sound to be collected to be collected at a high S / N ratio even
when the position of the sound source changes sequentially.
[0004]
In order to solve the above problems, the present invention has a non-directional microphone
and two or three bi-directional microphones whose directional axes are orthogonal to each other,
and pre-set addition of signals output from each microphone In a directional characteristic
control device for setting directional characteristics to a sound collection device that adds and
outputs by ratio, storage means in which a plurality of addition ratios representing different
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directional characteristics are stored in advance, and stored in the storage means According to
the first process of determining the direction of the sound source from the signal strength of the
signal obtained by adding the output signals of the microphones according to each of the adding
ratios, and the direction determined in the first process A directional characteristic control device
comprising: a second process of setting an addition ratio representing a directional characteristic
to the sound collection device; and control means for executing at a predetermined timing. That.
[0005]
In a more preferable aspect, the control means is characterized in that the direction of the sound
source is determined from the signal strength of a predetermined frequency component among
the signals obtained by adding the output signals of the respective microphones.
[0006]
Further, in order to solve the above-mentioned problems, according to the present invention, a
nondirectional microphone, two or three bidirectional microphones whose directional axes are
orthogonal to each other, and addition of preset signals output from the respective microphones
Output means for adding and outputting by a ratio, storage means for storing a plurality of
addition rates representing different directional characteristics, and an output of each
microphone according to each addition rate stored in the storage means The first process of
determining the direction of the sound source from the signal strength of the signal obtained by
adding the signals, and the addition ratio representing the directivity characteristic according to
the direction determined in the first process to the sound collection device And a control unit
configured to execute a second process to set at a predetermined timing.
[0007]
Further, in order to solve the above problems, the present invention is provided with a
nondirectional microphone and two or three bidirectional microphones whose directional axes
are orthogonal to each other, and a signal output from each of the microphones is a
communication network A sound collecting device for transmitting to a predetermined
destination via the network and an output signal of each of the microphones transmitted from
the sound collecting device via the communication network are received, added at a preset
addition ratio, and output to a speaker An output device and a plurality of addition ratios
representing different directional characteristics are stored in advance, and output signals of the
microphones transmitted from the sound collection device via the communication network are
stored in the own device. First processing for determining the direction of the sound source from
the signal strength of the signal obtained by adding according to each of the adding ratios, and
the direction determined in the first processing Sound collecting system, characterized in that it
comprises a second process of setting the addition ratio that represents the directivity
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characteristic to the output device, and the directivity characteristic control apparatus for
executing a predetermined timing, provides.
[0008]
In a more preferable aspect, the sound collection system is an imaging device disposed together
with the sound collection device, and includes an imaging device that transmits a signal
corresponding to a captured image via the communication network, while the output device The
display apparatus according to claim 1, further comprising: a display device configured to display
an image according to a signal transmitted from the imaging device via the communication
network, wherein the directional characteristic control device is configured to display the
imaging direction by the imaging device. It is characterized in that a third process which is set
according to the direction determined in the first process is executed.
[0009]
According to the present invention, even when the position of the sound source changes
sequentially, it is possible to collect the target sound to be collected at a high S / N ratio.
[0010]
Hereinafter, an embodiment of the present invention will be described with reference to the
drawings.
(A: Configuration) FIG. 1 is a block diagram showing a configuration example of a sound
collection system 10 including a directivity control apparatus 200 according to an embodiment
of the present invention.
As shown in FIG. 1, the sound collection system 10 collects a target sound to be collected and
outputs an audio signal according to the target sound, and the sound source direction of the
target sound. And a directional characteristic control device 200 for setting the directional
characteristics to the sound collection device 100.
[0011]
As shown in FIG. 1, the sound collection device 100 has microphones 110a, 110x and 110y, and
directional characteristic variable means 120 for adding and outputting audio signals outputted
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from these microphones at a predetermined addition ratio. ing.
[0012]
More specifically, of the three microphones of the sound collection device 100, the microphones
110x and 110y are bi-directional microphones, and the microphone 110a is a nondirectional
microphone.
In the present embodiment, the directivity levels of the three microphones are the same.
These three microphones are microphones 110y and microphones such that the pointing origin
is located on the vertical axis (FIG. 2 (a): Z axis) in the housing of the sound collection device 100
installed substantially perpendicular to the ground. 110a and the microphone 110x are placed in
this order (see FIG. 2A).
In addition, the microphones 110x and the microphones 110y are arranged such that their
directivity axes are orthogonal to each other.
Hereinafter, the directional axis direction of the microphone 110x is referred to as an X direction,
and the directional axis direction of the microphone 110y is referred to as a Y direction.
In the present embodiment, the case where the three microphones are placed in the order of the
microphones 110y, 110a, and 110x will be described. However, it is a matter of course that the
microphones 110x, 110a, and 110y may be placed in order. The point is that the pointing origins
of the three microphones should be located on the Z-axis, and the pointing axis of the
microphone 110x and the pointing axis of the microphone 110y may be disposed orthogonal to
each other.
[0013]
FIG. 2 (b) is a diagram showing the directivity characteristics of the three microphones. In FIG. 2
(b), the directivity characteristic of the microphone 110a is represented by an alternate long and
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short dash line. Further, the directivity characteristic of the microphone 110x is represented by a
solid line, and the microphone 110y is represented by a dotted line. Hereinafter, when it is not
necessary to distinguish each of the microphones 110a, 110x and 110y, the microphones 110a,
110x and 110y are simply referred to as "microphone 110". An audio signal output from the
microphone 110 is converted into a digital signal by an A / D converter (not shown), and further
divided into two as shown in FIG. 1, one of which is supplied to the directivity characteristic
variable means 120, The other is supplied to the directivity control apparatus 200.
[0014]
As shown in FIG. 1, the directivity characteristic changing means 120 of the sound collection
device 100 adds the amplifiers 122a, 122x and 122y and the audio signals outputted from these
three amplifiers and outputs the result to a sound emitting device such as a speaker. And an
adder 124. Here, the amplifier 122a amplifies the audio signal supplied from the microphone
110a by the amplification factor set for the amplifier 122a (in the present embodiment, when the
value of the amplification factor is a negative value) The amplifier 122x performs amplification
and phase inversion), and the amplifier 122x amplifies and outputs the audio signal supplied
from the microphone 110x with the amplification factor set for the amplifier 122x. The amplifier
122 y amplifies and outputs the audio signal supplied from the microphone 110 y at the
amplification factor set for the amplifier 122 y. That is, the sound collection device 100 adds and
outputs the audio signals output from the microphones 110a, 110x, and 110y at an arbitrary
addition ratio by appropriately adjusting the amplification factors of the amplifiers 122a, 122x,
and 122y. It is configured to be able to.
[0015]
For example, the voice signals output from each of the microphones 110a, 110x and 110y are
added in the addition ratio of 0: 1/1/2: 1 / √2 (where √2 is the square root of 2). If the
amplification factor is set, as shown in FIG. 2C, the bi-directional characteristic having the
directivity axis in the direction of 45 ° in the counterclockwise direction from the X-axis
direction (that is, the directivity axis direction of the microphone 110x) The device 100 is set. In
addition, if 1/2: 1 / 2√2: 1 / 2√2 is set as the addition ratio, as shown in FIG. 2 (d),
unidirectivity having a directivity axis in the same 45 ° direction Is set to the sound collection
device 100. As described above, the sound collection device 100 according to the present
embodiment can properly set the amplification factor in each of the amplifiers 122a, 122x and
122y to direct the directivity axis in any direction on the plane on which the sound collection
device 100 is installed. Are configured to be capable of achieving single or bi-directionality.
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[0016]
On the other hand, as shown in FIG. 1, the directivity characteristic control device 200 includes
amplifiers 210a, 210x and 210y, an adder 220, a band pass filter (denoted as “BPF” in FIG. 1)
230, and control means 240. And storage means 250. In the following, when it is not necessary
to distinguish each of the three amplifiers from each other, it is simply referred to as “amplifier
210”.
[0017]
The amplifier 210 amplifies an audio signal supplied from the microphone 110 corresponding to
the amplifier 210 at an amplification factor set by the control means 240 and outputs the
amplified signal to the adder 220. Specifically, the amplifier 210a amplifies and outputs the
audio signal supplied from the microphone 110a, the amplifier 210x amplifies and outputs the
audio signal supplied from the microphone 110x, and the amplifier 210y outputs the audio
signal from the microphone 110y. It amplifies and outputs the supplied audio signal. In the
amplifier 210, similarly to the amplifier 122, when the amplification factor set by the control
means 240 is a negative value, amplification and phase inversion are performed.
[0018]
The adder 220 adds the audio signals output from the amplifiers 210 a, 210 x and 210 y and
outputs the result to the band pass filter 230. As described above, the audio signal output from
the microphone 110 is amplified by the amplifier 210 corresponding to the microphone 110 at
the amplification factor set in the amplifier 210 and then input to the adder 220, so The audio
signals output from the respective microphones 110 are added by the adder 220 at the addition
ratio according to the ratio of the amplification factor set in each of the amplifiers 210.
[0019]
The band pass filter 230 passes only a component of a predetermined frequency band
(hereinafter, a pass band) of the input audio signal, and in the present embodiment, the
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frequency band of the target sound to be collected. Is set as the above-mentioned passband. The
addition signal output from the adder 220 is input to the band pass filter 230. Therefore, among
the addition signals, the frequency component belonging to the pass band (that is, the frequency
component belonging to the frequency band of the target sound) ) Is to be extracted by the band
pass filter 230.
[0020]
The storage unit 250 is, for example, a hard disk, and a directivity characteristic management
table shown in FIG. 3 is stored in advance. In this directivity characteristic management table,
assuming that the directivity axis direction of the microphone 110x is 0 °, each directivity in the
direction is 45 ° in 45 ° in a counterclockwise direction with a directivity axis (see FIG. 2). The
amplification factor to be set to each amplifier 120 is written when setting (d) (see) to the sound
collection device 100. Although the details will be described later, the directivity characteristic
management table controls processing for determining the sound source direction of the target
sound to be collected, and processing for setting the directivity characteristic according to the
sound source direction to the sound collection device 100 It is used when making the means 240
execute.
[0021]
The control means 240 includes a central processing unit (CPU), a read only memory (ROM), a
random access memory (RAM), etc., although the detailed illustration is omitted in FIG. The ROM
determines the sound source direction of the target sound and sets directivity characteristics (in
the present embodiment, a single directivity characteristic having a directional axis in the sound
source direction) according to the sound source direction in the sound collection device 100 A
control program that causes the CPU to execute setting processing, and timing data indicating
timing to execute the directivity characteristic setting processing are stored. In the present
embodiment, the determination of the sound source direction is triggered by the turning on of
the directional characteristic control device 200, and the sound source is generated at
predetermined time intervals (for example, at intervals of 10 seconds) from the time of turning
on the power. Timing data indicating the determination of the direction is stored in the ROM. On
the other hand, the RAM is used as a work area when the CPU executes the control program.
Although the details will be described later, a direction parameter Φ used in the process of
executing the directivity characteristic setting process is stored in the RAM. The above is the
configuration of the directivity control apparatus 200.
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[0022]
(B: Operation) Next, directivity characteristic setting processing performed by the control means
240 will be described with reference to the drawings. At the start of the operation described
below, the sound source of the target sound is a counterclockwise from the above-mentioned Xaxis direction (that is, the directional axis direction of the microphone 110x: see FIG. 2A) with
respect to the sound collection device 100. It shall be located in the direction of 45 ° around.
[0023]
FIG. 4 is a flow chart showing the flow of directivity characteristic setting processing executed by
the CPU of the control means 240. As shown in FIG. 4, the control means 240 determines
whether it is necessary to determine the sound source direction according to the timing data
stored in advance in the ROM (step SA100), and the determination result is “No”. If there is,
the process of step SA100 is repeatedly executed.
[0024]
In step SA110 subsequently executed when the determination result in step SA100 is "Yes",
control means 240 initializes direction parameter Φ. Specifically, the control means 240 sets the
direction parameter Φ to a value indicating 0 °. As described above, in the present embodiment,
the determination of the sound source direction is performed when the directional characteristic
control device 200 is powered on, and the determination of the sound source direction is
performed at predetermined time intervals from the power on time. Since the timing data
indicating that is stored in the ROM, the judgment result of step SA100 becomes “Yes”
immediately when the power of the directional characteristic control device 200 is turned on and
the execution of the control program is started. The process of step SA110 is performed.
[0025]
Next, the control means 240 reads out an amplification factor corresponding to the direction
parameter そ の at that time from the directivity characteristic management table and sets it in
the amplifier 210 (step SA120). As a result, the audio signal output from the adder 220 is output
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from the sound collection device 100 when the single directivity having the directional axis in
the direction indicated by the direction parameter Φ is set in the sound collection device 100.
Match the voice signal.
[0026]
Thus, the audio signal output from the adder 220 is supplied to the band pass filter 230, and
only the passband component of the band pass filter 230 among the audio signal is output to the
control means 240. . On the other hand, the control means 240 measures the signal strength of
the output signal of the band pass filter 230, and writes the measurement result to the RAM in
association with the direction parameter Φ at that time (step SA130). In the present
embodiment, regardless of the magnitude of the signal strength of the audio signal output from
the band pass filter 230, the case of unconditionally writing in the RAM in association with the
direction parameter そ の at that time has been described. Of course, the writing to the RAM may
be performed when the intensity is equal to or higher than a predetermined threshold.
[0027]
Next, the control means 240 adds a value indicating a predetermined angle (45 ° in the present
embodiment) to the direction parameter Φ (step SA140), and determines whether the
measurement of the signal intensity has been completed for all directions. It determines based on
the value of (step SA150). Specifically, when the value of the direction parameter が is a value
indicating 360 °, the control means 240 determines that the measurement of the signal
strength has been completed for all directions. And control means 240 performs processing after
step SA160, when a judged result of step SA150 is "Yes", conversely, when a judged result of step
SA150 is "No", control is carried out. The means 240 repeatedly executes the process after step
SA120. As a result, in the present embodiment, the signal strength is stored in the RAM for each
of eight directions from 0 ° to 45 ° in steps of 315 °.
[0028]
In step SA160 subsequently executed when the determination result in step SA150 is "Yes",
control means 240 is associated with the largest signal strength among direction parameters 記
憶 stored in RAM. The amplification factor corresponding to the direction parameter 読 み 出 し
is read out from the directivity characteristic management table and set in the amplifier 122. As
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a result, in the sound collection device 100, a single directivity having a directional axis in the
direction in which the signal strength is maximized (that is, the sound source direction of the
target sound) is set. At the start of this operation example, the sound source of the target sound
is located in the direction of == 45 °, so the signal strength in this direction is maximum, and the
sound collection device 100 has Φ = 45 °. Unidirectionality with a pointing axis in the direction
will be set.
[0029]
Then, the control means 240 determines whether or not the end of the directivity characteristic
setting process is instructed (step SA170), and when the result of the determination is "No",
repeatedly executes the process after step SA100. On the other hand, when the determination
result is "Yes", the directivity characteristic setting process is ended. In the sound collection
system 10 according to the present embodiment, when the directivity characteristic control
device 200 is powered on, the unidirectionality having the directivity main axis in the sound
source direction of the target sound is set in the sound collection device 100 Since the
determination of the sound source direction at predetermined time intervals and the process of
setting the unidirectionality according to the determination result are repeatedly executed, the
predetermined characteristic is started from the time when the power of the directional
characteristic control device 200 is turned on. Even if the sound source emitting the target sound
has moved in the direction of == 135 ° when the time has elapsed, the processing of step SA110
to step SA170 is executed again, and the pointing axis is moved in the direction of == 135 °. The
unidirectionality which it has will be set to the sound collection apparatus 100. FIG.
[0030]
As described above, according to the present embodiment, even when the sound source direction
of the target sound changes sequentially, the directivity characteristic of the sound collection
device 100 is set following the change and the high S / N ratio is set. It becomes possible to pick
up the target sound. In addition, in the sound collection device 100 of the sound collection
system 10 according to the present embodiment, the delay control as performed by the speaker
array is not performed, so that the collected target sound is discontinuous. Nothing happened. In
the present embodiment, although the case where the predetermined time is set to 10 seconds
has been described, it is needless to say that an appropriate value may be set according to the
moving speed of the sound source.
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[0031]
(C: Modification) Although the embodiment of the present invention has been described above, it
is needless to say that the following modification may be added to the embodiment. (1) In the
above-described embodiment, the processing of determining the direction of the sound source
emitting the target sound to be collected and setting the unidirectionality having the main axis of
orientation in that direction to the sound collection device 100 is predetermined. Even when the
direction of the sound source emitting the target sound changes sequentially by the directivity
characteristic control device 200 executing at time intervals, the target sound is collected with a
high S / N ratio following the change. The case of realizing the sound has been described.
[0032]
However, the direction of the sound source generating the noise that inhibits the collection of the
target sound may be specified, and the directivity characteristic having a blind spot in that
direction may be set in the sound collection device 100. Here, the dead angle of the directional
characteristic is, for example, a direction in which the sound collection sensitivity is a value of
zero or a value close to zero, as in the 90 ° direction and the 270 ° direction in the directional
characteristic of the microphone 110x. In order to specify the direction of the sound source
emitting noise, for example, the pass band of the band pass filter 230 may be set to a frequency
band other than the frequency band of the target sound, and the frequency band of noise is If it
is known, the frequency band may be set as the pass band.
[0033]
Also, by combining two or three bi-directional microphones and one non-directional microphone,
and adjusting the addition ratio of the output signals of each microphone appropriately, it is
possible to realize arbitrary directional characteristics, for example, Both the direction of the
sound source emitting the target sound and the direction of the sound source emitting the noise
are determined, and the direction of the sound source emitting the target sound having a
directional axis in the direction of the sound source and emitting noise It is also possible to set a
directivity characteristic that has a blind spot at
[0034]
(2) In the embodiment described above, the case of determining whether the sound source of the
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target sound is in any of eight directions from 0 ° to 45 ° in steps of 315 ° has been
described, but for example, 30 ° or 15 ° Of course, the sound source direction may be
determined more finely.
For example, when the sound source direction is determined in steps of 30 °, uni-directionality
having a directional axis in each of 12 directions from 0 ° to 30 ° in 330 ° is set in the sound
collection device 100 At the same time, the amplification factor to be set to each amplifier 120
may be stored in the directivity characteristic management table, and the increment of the
directional parameter に お け る in step SA140 of FIG. 4 may be set to 30 °.
[0035]
(3) In the embodiment described above, the case is described where the sound source direction is
determined when the directional characteristic control device 200 is powered on, and then the
direction of the sound source is determined again at predetermined time intervals. However, of
course, the sound source direction may be determined when the signal strength of the target
sound collected by the sound collection device 100 falls below a predetermined threshold. This
means that the threshold is written in the ROM as timing data, and at step SA100 in FIG. 4,
control means is used to determine whether the signal strength of the signal output from the
band pass filter 230 is lower than the threshold. The determination may be made at 240. In the
embodiment described above, the case where only the frequency component belonging to the
frequency band of the target sound is extracted from the output signal of the adder 220 using
the band pass filter 230 has been described, but the movement while emitting the target sound It
goes without saying that it is not necessary to provide the above-mentioned band pass filter
when there is no other sound source other than the sound source in question.
[0036]
(4) In the above-described embodiment, the in-plane is realized by combining two bi-directional
microphones and non-directional microphones arranged so that the directivity axes are
orthogonal on the surface on which the sound collection device 100 is installed. In the sound
pickup apparatus 100 capable of orienting the directional axis in all directions of the above, it
has been described using three bi-directional microphones and one non-directional microphone
arranged with their main axes of orientation orthogonal to each other. A sound collection system
may be configured by combining a sound collection device capable of pointing the directional
axis in the entire sky direction and a directivity control device that sets an arbitrary directivity
04-05-2019
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characteristic to this sound collection device. Specifically, the sound collection system may be
configured by combining the sound collection device 500 shown in FIG. 5 with the directivity
characteristic control device 600 shown in FIG. 5 differs from the sound collection device 100 in
that the sound collection device 500 is different from the sound collection device 100 in that the
microphone 110z which is a bidirectional microphone having a directional axis in the Z-axis
direction of FIG. And an amplifier 122z for amplifying and outputting an audio signal to be
output. On the other hand, the directivity characteristic control device 600 shown in FIG. 5
differs from the directivity characteristic control device 200 in that it has an amplifier 210z for
amplifying and outputting an audio signal outputted from the microphone 110z, and control The
means 240 sets the amplification factor of the amplifiers 122a, 122x, 122y and 122z
appropriately to set the unidirectivity having the directional axis in any direction in the sound
collection device 500.
[0037]
(5) In the embodiment described above, the directivity characteristic management table shown in
FIG. 3 is stored in the storage unit 250 of the directivity characteristic control device 200, and
the directivity characteristic setting process shown in FIG. The case where a single directional
characteristic (FIG. 2D) having a directional axis in the sound source direction of the target sound
is set in the sound collection device 100 has been described. However, for each of eight
directions up to 315 ° in 45 ° steps counterclockwise with the directivity axis direction of the
microphone 110 x as 0 °, there is a directivity characteristic of positive phase in that direction
and negative in the direction opposite to that 180 °. When setting the bi-directional
characteristic (refer to FIG. 2C) having the directional characteristic of the phase to the sound
collection device 100, the directional characteristic management table (refer to FIG. 6) is written
with the amplification factor to be set to each amplifier 120. The directivity characteristic
management table shown in FIG. 3 may be stored in the storage unit 240, and the directivity
characteristic setting process shown in FIG. 4 may be executed by the control unit 240. In this
way, it is possible to set each of the bi-directional characteristics in the sound collection device
100 according to the sound source direction of the target sound. Further, both of the directivity
characteristic management tables shown in FIGS. 3 and 6 are stored in storage means 240, and
in step SA120 of the directivity characteristic setting process shown in FIG. 4, the directivity
characteristic management table shown in FIG. While the directivity characteristic is set and the
sound source direction is searched, when one direction is specified as the sound source direction
in step SA160, the directivity axis is set to the sound source direction with reference to the
directivity characteristic management table shown in FIG. When the unidirectional apparatus
having the above is set in the sound collection device 100 and two opposing directions (for
example, 45.degree. And 225.degree. Directions) are identified as sound source directions, the
directivity characteristic management table shown in FIG. The bi-directional characteristics
04-05-2019
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having directional characteristics in both directions may be set in the sound collection device
100 with reference to FIG. In this way, for example, when one of the conference participants is
speaking when the speech in the conference hall is picked up using the sound collection system
10, the pointing axis is provided in the direction of the conference participant. When the
unidirectional characteristic is set in the sound collection device 100 and the discussion is
started between the conference participant and the meeting participant who is facing, the
directivity characteristic of the sound collection device 100 carries out the above discussion. It
will be automatically switched to a bi-directional characteristic having directional characteristics
in the direction of both participants.
[0038]
(6) In the embodiment described above, the case where the sound collection device 100 and the
directional characteristic control device 200 are configured by respective hardware has been
described. However, it goes without saying that both may be configured as integral hardware.
Specifically, output means for adding and outputting non-directional microphones, two or three
bi-directional microphones whose directional axes are orthogonal to each other, and signals
output from the respective microphones at a preset addition ratio A signal obtained by adding
the output signal of each of the microphones according to each of the storage means in which a
plurality of addition ratios each representing different directional characteristics are stored in
advance and the addition ratio stored in the previous storage means A first process of
determining the direction of the sound source from the signal strength of the second sound
source, and a second process of setting, to the sound collection device, an addition ratio
representing a directivity characteristic according to the direction determined in the first process.
Of course, the sound collection device may be configured by combining with control means that
executes at a predetermined timing.
[0039]
(7) In the above-described embodiment, two bi-directional microphones, one non-directional
microphone, and directional characteristic variable means for adding and outputting signals
output from these three microphones at a predetermined addition ratio The case where the
sound pickup apparatus is configured by combining However, while connecting the sound
collection device configured by combining the microphones 110a, 110x and 110y and the
communication IF unit that transmits the audio signals output from these microphones via the
communication network to a communication network such as the Internet, An output device
configured by combining a communication IF unit for receiving an audio signal transmitted from
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the sound collection device and the directivity characteristic changing means is connected to the
communication network, and the directivity characteristic control device 200 is Of course, it may
be configured in combination to configure a sound collection system.
[0040]
In addition, in the aspect, an imaging device that transmits a signal according to a captured
image via the communication network is disposed together with the sound collection device, and
an image corresponding to the signal transmitted from the imaging device via the communication
network Of course, a display device to be displayed may be disposed together with the output
device, and the directivity characteristic control device may execute processing for setting the
imaging direction of the imaging device according to the sound source direction. A so-called
omnidirectional camera may be used as the above-mentioned imaging device, and each direction
(for example, eight directions from 0 degree to 45 degrees in each direction) which can be set by
the directional characteristic control device may be used. A plurality of cameras, each of which
has its imaging direction fixed, may be used.
[0041]
(8) In the above-described embodiment, the case has been described in which the characteristic
feature of the directivity control apparatus according to the present invention is realized by a
software module, but of course it may be realized by a hardware module. In the embodiment
described above, the control program for causing the CPU of the control unit 240 to execute the
directional characteristic setting process characteristic of the directional characteristic control
apparatus according to the present invention is written in advance in the ROM of the control unit
240 However, the control program may be recorded and distributed in a computer-readable
recording medium such as a CD-ROM (Compact Disk-Read Only Memory) or a DVD (Digital
Versatile Disk), and the telecommunication line such as the Internet Of course, the control
program may be distributed by way of download.
[0042]
It is a block diagram showing an example of composition of sound source separation system 10
concerning one embodiment of the present invention. It is a figure for demonstrating the
directional characteristic of each of microphone 110a, 110x, and 110y. It is a figure which shows
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an example of the directional characteristic management table memorize | stored in the memory
means 250. FIG. It is a flowchart which shows the flow of the directional characteristic setting
process which CPU of the control means 240 performs according to a control program. FIG. 18 is
a block diagram showing an example of configuration of a directivity control apparatus according
to a modification 4; It is a figure which shows an example of the directional characteristic
management table memorize | stored in the memory means 250. FIG.
Explanation of sign
[0043]
DESCRIPTION OF SYMBOLS 10 ... Sound collection system, 100 ... Sound collection apparatus,
110, 110a, 110x, 110y ... Microphone, 120 ... Directionality-variable means, 122, 122a, 122x,
122y ... Amplifier, 124 ... Adder, 200 ... Directional control apparatus , 210, 210a, 210x, 210y ...
amplifier, 220 ... adder, 230 ... band pass filter, 240 ... control means, 250 ... storage means.
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