JP4867248B2 - Speaker device and audio conference device - Google Patents

Description

  The present invention relates to a speaker device using a speaker array including a plurality of speaker units and an audio conference device to which the speaker device is applied, and particularly relates to a device that emits sound intended for a specific listener. .

2. Description of the Related Art Conventionally, a voice conference device (speaker device) for performing a conference with a remote party through a telephone conference or the like is widely known. Such an audio conference apparatus includes a speaker and a microphone (hereinafter referred to as “microphone”). The voice conference apparatus transmits the voice of the conference attendee collected by the microphone to the voice conference apparatus of the other party, and emits the voice of the other party received from the voice conference apparatus of the other party from the speaker. (See, for example, Patent Document 1). As a result, a call can be made with the other party in the remote place, and the conference attendee can have a voice conference with the other party in the remote place.
JP-A-5-158492

  In a conventional audio conference apparatus, a voice is emitted in a horizontal direction using a non-directional speaker (wide directivity range). For this reason, since the sound propagates horizontally, the reachable range is wide, and it is difficult to emit the sound only for a specific listener. That is, even if sound is emitted toward a specific listener, sound leakage occurs around the specific listener. For this reason, for example, when an audio conference apparatus is used in an office or the like, other staff members of the conference attendee who are specific listeners can hear the voice, which hinders the work of other staff members.

  Therefore, in order to solve the above-described problems, the present invention reduces the sound leakage to the surroundings of a specific listener and can emit a sound for the specific listener, and a voice conference apparatus. The purpose is to provide.

  In order to solve the above problems, the present invention employs the following means.

(1) The present invention includes a speaker array including a plurality of speaker units arranged toward the sound emission direction downward along the longitudinal direction of the apparatus main body, and reflected by the obstacle is below the speaker array A directivity control unit that focuses the sound beam so that the sound beam is directed to a plurality or a specific listener, and the directivity control unit sandwiches the longitudinal direction of the apparatus main body. The speaker device is characterized in that the sound beam is focused on one of a plurality of listeners existing at positions facing each other .
(2) The present invention is directed to the above-described speaker device, wherein the directivity control unit is configured such that when a plurality of listeners are present at positions that do not face each other across the longitudinal direction of the device body, The sound beam is focused so that the sound beam spreads over a predetermined region including the position, or the plurality of sound beams are focused at the position of each listener.

  According to the above configuration, the speaker array including a plurality of arranged speaker units is installed such that the sound emission side of the speaker unit row faces downward. As a result, the sound beam is output downward from the speaker unit row. Then, an audio beam reflected by an obstacle below the speaker array (for example, a desk or a floor when the apparatus is on a desk) propagates obliquely upward of the obstacle.

  Then, the directivity control unit focuses the sound beam so that the sound beam from the speaker unit row reflected by the obstacle is directed to a plurality or one specific listener in the room. As a result, it is possible to output an audio beam with directivity (directivity direction and directivity range) that covers only the position where the specific listener is and its vicinity.

  As described above, in the present invention, the sound beam reflected by the obstacle and directed obliquely upward is controlled so as to be directed to a specific listener. As a result, it is possible to prevent sound leakage for a person who is behind a specific listener (assuming that this listener is facing the direction of arrival of the sound beam). Further, even though the speaker array can control the directivity of the sound beam, some sound leaks in the sound output direction. In the present invention, since the sound beam is output downward from the speaker array, the sound leakage does not cause a person other than the specific listener to hear the sound.

  Note that the arrangement of the speaker units includes a line shape, a circular shape, a matrix shape, a honeycomb shape, and the like.

( 3 ) The present invention is characterized in that, in the speaker device described above, a reflector as the obstacle is provided below the speaker array. As a result, even when there are no obstacles such as a floor surface or a desk that favorably reflect the sound beam below the speaker array, the sound beam can be favorably reflected by the reflector. In addition, the positional relationship between the reflector and the speaker array can be fixed so that the distance from the sound beam to the reflector is a distance suitable for directing the reflected sound beam to a specific listener. As a result, the reflected sound beam can be suitably directed to a specific listener.

( 4 ) The present invention includes the above-described speaker device and a microphone, and the speaker device has a function of transmitting and receiving an audio signal for an audio conference with a remote audio conference device at a remote location. Is an audio conference apparatus characterized by

  Here, when the speaker device is installed in a normal office room instead of a conference room dedicated to voice conference, there are other staff members in the conference. With the configuration of the present invention, it is possible to output a speech voice beam only for conference attendees. In addition, it is possible to reduce sound leakage to the surroundings of the conference attendees. This makes it possible to conduct an audio conference without disturbing the work of other staff members in the office room by speaking.

  According to the present invention, an audio beam can be output in a directivity direction and directivity range that covers only a position where a specific listener is present and the vicinity thereof. Further, it is possible to control so that the sound beam directed obliquely above the obstacle is directed to a specific listener. As a result, when a specific listener is facing the speaker array, it is possible to prevent sound leakage to the person behind the speaker.

  Further, in the present invention, since a sound beam is output downward from the speaker array, it is effective to cause a person other than a specific listener to listen to sound due to sound leakage in a direction orthogonal to the sound emitting surface. Can be prevented.

  With reference to FIGS. 1-6, the audio conference apparatus which is embodiment which applied the speaker apparatus of this invention is demonstrated in detail. FIG. 1 is a cross-sectional view of the audio conference apparatus 1. In addition, in the same figure, the front side of the audio conference apparatus 1 is described as Y side, the opposite side is described as -Y side, the right side is described as -X side, and the left side is described as X side.

  The audio conference apparatus 1 has a long, substantially rectangular parallelepiped shape, and a speaker apparatus that has a long, substantially rectangular parallelepiped shape on the upper portion of a frame 1A having a square shape with open sides in the YY direction in the figure. 2 is provided. A microphone 3 is connected to the speaker device 2 via a connection line 3a. A speaker array 20 is arranged on the lower surface of the speaker device 2 so that the sound emission side faces downward.

  The speaker array 20 includes eight speaker units SP (SP1 to SP8) arranged in a line downward in the longitudinal direction. When an audio signal is input to the speaker units SP1 to SP8, an audio beam is output from the speaker array 20 so as to be directed downward.

  The sound beam output downward is reflected by the lower surface 10A of the frame 1A (hereinafter referred to as the reflecting plate 10A), obliquely upward, and emitted from the side of the frame 1A in the YY direction in the figure. . Note that the reflecting plate 10A is made of, for example, a resin and is formed into a flat plate, and thereby, the sound beam can be favorably reflected. As long as the sound beam can be reflected appropriately, the material of the reflector 10A is not limited to resin, and may be a metal material or the like. Further, the shape of the reflecting plate 10A is not limited to a flat plate, and may be a gently curved shape or the like.

  Then, by controlling the input timing of the audio signals to the speaker units SP1 to SP8, the directivity of the reflected audio beam (the beam width and the directing direction at the pointing point) is changed in the longitudinal direction of the speaker device 2 (in the drawing). (X-X direction).

  The principle by which the beam width at the pointing direction and the pointing point is controlled will be described. Sound is output from each speaker unit SP so as to propagate radially (circular). When these sounds are output at the same time, only the components propagating parallel to each other are in phase and intensified. The components propagating in the other direction interfere with each other from the adjacent speaker units SP and are canceled out. Thereby, the synthesized speech from the speaker units SP1 to SP8 becomes an audio beam.

  The sound beam is directed directly below, and the beam width at the pointing point is substantially the same as the distance between the speaker unit SP1 and the speaker unit SP8. For this reason, the audio beam reflected by the reflecting plate 10 </ b> A also has substantially the same width as the distance between the speaker unit SP <b> 1 and the speaker unit SP <b> 8 and is directed in the front direction of the audio conference apparatus 1.

  On the other hand, by setting the delay times D1 to D8 so that the sound from each speaker unit SP reaches the directional point simultaneously and with a predetermined beam width, the directional direction is set so that the sound beam is directed to the directional point. And the beam width can be controlled to a predetermined beam width.

  FIG. 2 is a diagram for explaining the installation method of the audio conference apparatus 1 shown in FIG. 1 and the directivity control of the audio beam. The room R is not a conference room dedicated to audio conferencing but a normal office room. FIG. 2 is a view of the room R as viewed from the side.

  In the room R, two meeting attendees h1 and h2 (specific listeners) are seated so as to face each other across the meeting desk. On the conference desk, the audio conference apparatus 1 is arranged so that the YY direction (see FIG. 1) is in the direction in which the conference attendees h1 and h2 face each other.

  As a result, as described above, the sound beam output from the hole of the frame 1A is reflected by the reflecting plate 10A and output obliquely upward toward the heads of the conference attendees h1 and h2. . For this reason, compared with outputting an audio beam in the horizontal direction to the conference attendees h1 and h2, it is possible to effectively prevent a person located behind the conference attendees h1 and h2 from listening to the audio. be able to. At the same time, since the directivity of the sound beam can be controlled in the XX direction in FIG. 2, sound leakage in the XX direction can be effectively prevented.

  Further, even though the speaker device 2 can control the directivity of the sound beam, some sound leaks in a direction orthogonal to the sound emitting surface. In this embodiment, since an audio beam is output downward from the speaker array 20, it is possible to prevent a person other than a specific listener from listening to the sound due to the sound leakage.

  Note that the above effect can also be achieved by controlling the directivity so that the sound beam reflected from the ceiling is directed toward the conference attendees h1 and h2, even with the speaker device installed so that the sound output side of the speaker unit SP faces upward. Play. However, in this configuration, the distance from the output of the audio beam to the meeting participants h1 and h2 reflected from the ceiling is long. For this reason, the degree of attenuation of the sound up to the conference attendees h1 and h2 is large, and the sound beam must be output at a loud volume corresponding to the attenuation.

  Since the sound is output at such a large volume, the meeting attendees h1 and h2 may hear the sound leakage of the sound beam in the direction orthogonal to the sound emitting surface as described above. As a result, the meeting attendees h1 and h2 listen to both the sound leakage and the sound reflected from the ceiling, which causes a problem that the sound cannot be suitably heard. In the present embodiment, the above-described effects can be achieved without causing such problems.

  FIG. 3 is a view of the room R shown in FIG. 2 as viewed from above. As described above, the directivity direction and the beam width of the sound beam reflected by the reflecting plate 10A can be controlled in the XX direction. In this embodiment, as shown in FIG. 2, the audio conference apparatus 1 directs the reflected audio beam toward the conference attendees h1 and h2, that is, the pointing point becomes the head of the conference attendees h1 and h2. To control the directivity. Specifically, each speaker unit SP is provided with a delay time (time indicated by an arrow in the figure) such that the sound from each speaker unit SP reaches the conference attendees h1 and h2 at the same timing. Can be directed to the meeting attendees h1 and h2.

  2 and 3, the meeting attendees h1 and h2 are seated at positions facing each other across the conference desk. For this reason, if the directivity of the sound beam is controlled so as to be directed to one of the conference attendees, the narrow orientation covering only the conference attendees h1 and h2 with respect to both the conference attendees h1 and h2. A sound beam can be output in a range.

  However, there are cases where the conference attendees h1 and h2 do not sit opposite to each other. In this case, simply controlling the directivity of the sound beam so as to be directed to one of the conference attendees h1 and h2. The sound beam cannot be directed to both. In this case, as shown in FIG. 4, the speaker device 2 expands so that the sound beam reaches the conference attendees h1 and h2 with a width dimension L that covers both areas of the conference attendees h1 and h2. To output a sound beam.

  That is, it is assumed that an audio beam is output with a spread from the point P, and this audio beam is reflected by the reflecting plate 10A and reaches the positions of the conference attendees h1 and h2 with the width dimension L. Here, the directivity and beam width are controlled so as to output the same sound beam as this sound beam, so that the delay times D1 to D8 are set to values as indicated by solid line arrows in FIG. In this way, by outputting the sound beam with a spread, even when there are many meeting attendees, it is possible to output the sound beam in a directional range covering the many attendees and the vicinity thereof.

  FIG. 5 is a block diagram schematically showing the configuration of the audio conference apparatus 1 shown in FIG. The audio conference apparatus 1 has a function of transmitting and receiving an audio signal such as a voice with the other party's audio conference apparatus 1 (hereinafter referred to as “audio conference apparatus 1 ′” in distinction from the own apparatus). As a result, the audio conference apparatus 1 causes an audio conference to be performed between the meeting attendees h1 and h2 that are the users of the own apparatus and the other party that is the user of the audio conference apparatus 1 ′.

  In addition to the speaker array 20, the speaker device 2 includes an input / output interface 21, an echo canceller 22, a D / A (digital / analog) converter 23, a delay unit 24, an amplifier 25, and a control unit 26.

  The input / output interface 21 transmits and receives digital audio signals to and from the audio conference apparatus 1 ′ connected to the communication cable via a communication cable (not shown) connected to the connection terminal 27. The echo canceller 22 receives an audio signal (received audio signal) received from the audio conference apparatus 1 ′ via the input / output interface 21. The echo canceller 22 uses this input signal to generate a pseudo signal that simulates an echo component output from the speaker array 20 and fed back to the microphone 3. The echo canceller 22 removes an echo component by removing a pseudo signal from an audio signal (described later) input from the microphone 3.

  The delay units 24 correspond to the directivity control unit of the present invention, and are provided by the number of speaker units SP1 to SP8 (eight). Hereinafter, when distinguishing each delay part 24, the same number as the corresponding thing among the speaker units SP1-SP8 is attached as a subscript. For example, the delay unit 24 corresponding to the speaker unit SP1 is referred to as a delay unit 24-1.

  Each of the delay units 24-1 to 24-8 inputs the received voice signal from the echo canceller 22. Delay times D1 to D8 are set in the delay units 24-1 to 24-8, respectively. The delay units 24-1 to 24-8 correspond to the directivity control unit of the present invention, delay the input received audio signal by delay times D1 to D8, and correspond to the amplifier 25 via the D / A converter 23. The sound beam is focused. In other words, depending on the values of the delay times D1 to D8 given to the received reception audio signal, the delay units 24-1 to 24-8 have directivity in the XX direction (see FIG. 1) of the audio beam as described above. That is, the pointing direction and the pointing range (beam width at the pointing point) are controlled.

  There are as many D / A converters 23 as the number of delay units 24. These D / A converters 23 (23-1 to 23-8) receive the received audio signals to which the delay time is added from the corresponding delay units 24, respectively. The D / A converters 23-1 to 23-8 convert the input received audio signal from a digital signal to an analog signal and input the converted signal to the corresponding amplifier 25.

  The amplifier 25 amplifies the signal level of the input audio signal. The number of amplifiers 25 corresponding to the speaker units SP1 to SP8 is provided. Hereinafter, in order to distinguish each amplifier 25, the same number as the corresponding one among the speaker units SP1 to SP8 is attached as a subscript.

  The amplifiers 25-1 to 25-8 receive the received audio signals from the delay units 24-1 to 24-8 via the D / A converter 23 (23-1 to 23-8). The amplifiers 25-1 to 25-8 amplify the signal level of the input received audio signal and input the amplified signal levels to the corresponding speaker units SP1 to SP8. As a result, the voice of the received voice signal is emitted from the speaker units SP1 to SP8, and the voice of the other party from the audio conference apparatus 1 ′ is emitted.

  The control unit 26 includes a storage unit such as a CPU (Central Processing Unit) and a memory, a user interface such as an operation unit, and the like. By executing the program stored in the memory, the control unit 26 controls the operation of each unit of the speaker device 2, such as a call with the audio conference device 1 '. The control unit 26 calculates the delay times D1 to D8 and sets them in the delay units 24-1 to 24-8.

  The delay times D1 to D8 are calculated as follows, for example. The width dimension of the conference desk (dimension in the Y-Y direction in FIG. 2) is input from a user such as conference attendees h1, h2 using an operation unit (not shown). And the seating information on which position (front position, right position, left position) on the XX side of the speaker device 2 is seated by the conference attendee is input from the user using the operation unit. Is done. In FIG. 3, since the front side is the Y side, seating information for sitting at the left position is input.

  Usually, the attendees are seated around the conference desk. Therefore, using these input information, the control unit 26 can calculate the approximate position of the head of the conference attendee. The delay times D <b> 1 to D <b> 8 are calculated so that the calculated head position can be the sound beam directing direction and the beam width can cover the head at the pointing point.

  Note that the user may input the distance from the bottom surface of the speaker device 2 to the head of the conference attendee h1 instead of the width of the conference desk. In this case, the delay times D1 to D8 are calculated using this distance and the seating information.

  The speaker device 2 includes a microphone amplifier 28 and an A / D converter 29 in addition to the above configuration. The microphone amplifier 28 inputs an audio signal (transmission audio signal) from the microphone 3 connected to the connection terminal 30. The microphone amplifier 28 amplifies the input transmission audio signal and inputs it to the A / D converter 29. The A / D converter 29 converts the input analog transmission voice signal into digital and inputs it to the echo canceller 22. The echo canceller 22 removes the echo component by removing the pseudo signal from the input transmission voice signal as described above. Then, the transmission audio signal is transmitted to the audio conference apparatus 1 ′ via the echo canceller 22 -input / output interface 21 -communication cable (not shown).

  As described above, in the present embodiment, the speaker array 20 is disposed so that the sound emission sides of the speaker units SP1 to SP8 are positioned below. Along with this, a reflector 10 </ b> A is disposed below the speaker array 20. As a result, the sound beam output downward from the speaker array 20 and reflected by the reflector 10A is directed obliquely upward. The reflected sound beam is output from the hole of the frame 1A. The delay times D1 to D8 are set so that the sound beam output from the hole has a beam width covering the conference attendees h1 and h2 and is directed to the conference desk and the conference attendees h1 and h2. ing.

  As a result, as shown in FIG. 3, the sound beam propagates only to the conference attendees h1 and h2, or the conference attendees h1 and h2, and the vicinity thereof. For this reason, it is possible to output speech for only the meeting attendees h1 and h2.

  Further, when a horizontal audio beam is output to the conference attendees h1 and h2, sound leakage to a person in the output direction of the audio beam tends to occur. In the present embodiment, an audio beam is output so as to go diagonally upward from below with respect to meeting attendees h1 and h2. For this reason, it is possible to effectively prevent such sound leakage to the surroundings of the conference attendees h1 and h2.

  Further, even though the speaker array 20 can control the directivity of the sound beam, some sound leaks in the sound output direction. In this embodiment, since an audio beam is output downward from the speaker array 20, it is possible to prevent a person other than a specific listener from listening to the sound due to the sound leakage.

  The present embodiment can employ the following modified examples.

  (1) In the present embodiment, as shown in FIG. 4, when the conference attendees h1 and h2 do not sit at the corresponding positions, the beam width at the pointing point covers the conference attendees h1 and h2. The delay times D1 to D8 are set so as to have such a width dimension L. On the other hand, as shown in FIG. 6, a plurality of audio beams having a narrow beam width that covers only the conference attendees may be output to each of the conference attendees h1 and h2. In this case, the speaker units SP1 to SP8 may be divided into a plurality of groups, and a plurality of sound beams directed to different locations may be output from each group. Further, all the speaker units SP1 to SP8 may be shared for each sound beam.

  (2) In the present embodiment, the audio conference apparatus 1 includes the reflector 10A, but is not limited thereto. For example, the frame 1 </ b> A may not have the reflector 10 </ b> A (lower surface) and may be configured to reflect an audio beam on a conference desk where the audio conference apparatus 1 is installed or a floor surface.

  (3) In this embodiment, the number of speaker units SP is eight. However, the number of speaker units SP is not limited to this number. If the number of speaker units SP that can control the directivity and beam width of the sound beam is at least provided. Good.

  (4) In this embodiment, the speaker array 20 in which the speaker units SP are arranged in a line is used. For this reason, the directivity direction and the width dimension in the direction intersecting with the arrangement direction (the Y-Y direction in FIGS. 1 and 5) cannot be controlled. The present invention is not limited to the configuration of the speaker array 20.

  For example, a configuration may be adopted in which the directivity direction and the width dimension in the YY direction are controlled using a speaker array 20A including speaker units SP arranged in a matrix as shown in FIG. Further, the speaker array 20B including the speaker units SP arranged in a honeycomb shape as shown in FIG. Furthermore, the speaker array 20C having speaker units SP arranged in a circle as shown in FIG.

  In this case, by adjusting the output timing to the speaker units SP arranged in the YY direction, the pointing direction and the beam width can be adjusted also in this direction. In the speaker array 20C, since the speaker units SP are arranged in a circle, the same beam shape can be obtained regardless of the location of the sound beam. For this reason, it is possible to provide stable audio without being affected by the difference in the place where the attendees sit.

  (5) In this embodiment, although the case where the speaker apparatus of this invention was applied to the audio conference apparatus was demonstrated, it is not limited to this. The present invention may be applied to a device for outputting sound to a specific listener. For example, an audio device or AV (Audio-Video) device that outputs music, singing sound, or the like to a specific listener. You may apply to.

It is sectional drawing of the apparatus main body of an audio conference apparatus. It is a figure for demonstrating the installation method of the audio conference apparatus shown in FIG. 1, and directivity control of an audio beam. It is the figure which looked at the room shown in FIG. 2 from upper direction. It is a figure for demonstrating the directivity control of an audio beam in case the meeting attendees h1 and h2 are not seated facing each other. It is a block diagram which shows roughly the structure of the audio conference apparatus 1 shown in FIG. It is a figure for demonstrating the directivity control of the sound beam in a modification. (A) is a top view which shows speaker array 20A concerning a modification, (b) is a top view which shows speaker array 20B concerning a modification. It is a top view which shows 20 C of speaker arrays concerning a modification.

Explanation of symbols

1-Voice conference device 20, 20A, 20B-Speaker array 24 (24-1 to 24-8)-Delay unit (directivity control unit) h1, h2- Conference attendee R-room

Claims (4)

A speaker array including a plurality of speaker units arranged toward the sound emission direction downward along the longitudinal direction of the apparatus main body,
A directivity control unit that focuses the sound beam so that the sound beam reflected by the obstacle below the speaker array is directed to a specific listener or a plurality of listeners;
Equipped with a,
The speaker device according to claim 1, wherein the directivity control unit focuses the sound beam at one of a plurality of listeners existing at positions facing each other across the longitudinal direction of the apparatus main body .   When the plurality of listeners are present at positions that do not face each other across the longitudinal direction of the apparatus main body, the directivity control unit is configured to spread the sound beam in a predetermined region including the positions of the plurality of listeners. The speaker device according to claim 1, wherein the sound beam is focused, or a plurality of sound beams are focused on the position of each listener. Below the speaker array, speaker according to claim 1 or 2, characterized in that it comprises a reflector as the obstacle. The speaker device according to any one of claims 1 to 3 ,
With a microphone,
The speaker device has a function of transmitting and receiving audio signals for audio conferencing with a remote audio conference device at a remote location.
An audio conference apparatus.

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