JPH07264569A - Remote conference device - Google Patents

Abstract

PURPOSE:To reduce the size and cost of a remote conference device capable of preventing the generation of acoustic coupling and effectively recognizing speaker's expression through a monitor. CONSTITUTION:Plural microphones 2 are fixed to the periphery of a board 1 and the voice of each participator sitting on a chair oppositely to one of the microphones 2 is applied from the microphone 2 to a controller 3 built in the board 1. A speaker box 5 supported by a supporting board 12 connected to the upper end of a supporting leg 11 is arranged on the upper part of the center of the board 1 and a speaker is upward fixed to the box 5. A stepping motor 7 is arranged on the bottom part of the inside of the box 5 and a video camera 10 is fixed to a camera fixing device 9 fixed to the lower end of a rotary shaft 8 connected to the motor 7. The controller 3 controls the motor 7 based upon an inputted voice level so as to turn the image pickup direction of the camera 10 to the direction of a speaker.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a teleconferencing device for connecting a conference room distant from each other by communication means and transmitting and receiving voices and images of the participants of the conference to conduct the conference.

[0002]

2. Description of the Related Art Comprehensive service digital network (hereinafter IS
With the development of (DN), the conference rooms that are far apart from each other are connected by ISDN, and images and voices are transmitted and received to hold a conference even if it is between remote places, as if it were the same conference room. The teleconferencing device to obtain is practically used.

The configuration of such a conventional teleconference device is as follows, for example. In each conference room, a table and chairs are arranged so that about 6 participants can sit in a horizontal row, and microphones for inputting voices are arranged between the participants. A monitor that displays images from other conference rooms is placed at a position visible to all participants, and a group camera whose angle is fixed to each participant's right half or left half is placed near that monitor. Has been done.

A speaker for outputting a sound from another conference room is arranged at a distance from the microphone so that no sound is produced, and the speaker, the microphone, the monitor, and the group camera are arranged together with the other conference room. Each is connected to a transmission / reception device that performs bidirectional communication. The transmitting / receiving device digitizes the audio signal from the microphone and the image signal from the group camera, and transmits them to another conference room by superimposing them, and a reception signal from the other conference room into an audio signal and an image signal. It is provided with a receiving means for outputting as an analog signal after separation, and the transmitting / receiving device is connected to the transmitting / receiving device in another conference room by ISDN.

As a result, since the conference rooms are connected to each other in real time by voice and image, it is possible to hold a conference even between remote locations as if they were the same conference room. Therefore, the time required to participate in the conference can be saved even in a remote place, and the efficiency of the conference and the quick decision making can be achieved.

However, in the conventional teleconferencing device, the sound output from the speaker may be input to the microphone to cause acoustic coupling, which may cause ringing or echo.
As described above, the distance between the speaker and the microphone has to be increased, and there is a drawback that the voice transmitting / receiving unit becomes large. On the other hand, at a tabletop meeting,
It is an important factor that the facial expression of the speaker can be sufficiently read by others, and it is required to realize it even in the teleconference. However, in the conventional teleconferencing device, the participants are displayed on the monitor for each group, so that participants in other conference rooms may be able to fully read the facial expressions of the speakers who are changing their opinions. It had the drawback of not having it.

Therefore, Japanese Patent Publication No. Sho 63-22702 discloses the following device. A hole is formed in the center of the upper surface of the speaker box in the shape of a polygonal shell, and the speaker is fitted into the hole so that the speaker faces upward. A plurality of pairs of unidirectional microphones are attached to the peripheral surface on the bottom side of the speaker box so as to be symmetrical to each other with respect to the center axis of the speaker.
The tangents of a circle centered on the central axis of the speaker are provided so that their directivity directions are opposite to each other. As a result, the voice from the speaker is hardly collected by the microphone, so that the voice transmitting / receiving unit is downsized without causing acoustic coupling.

Further, Japanese Patent Publication No. 61-20190 discloses the following device. In each conference room, a video device including a monitor and a camera and a microphone are provided for all participants, and a speaker is placed at a suitable distance from the microphone. The video device, microphone and speaker are connected to a first control unit, each first control unit being connected to a second control unit. The camera and microphone of the video device output the image and sound of the participant in which they are deployed as image and sound signals to the first control unit, and each first control unit provides an input signal to the second control unit. Then, the second control unit displays an image from the video device corresponding to the microphone having the highest sound level on all video devices via the first control unit. As a result, the participant can sufficiently read the facial expression even if the speaker changes one after another.

[0009]

[Problems to be Solved by the Invention] However, JP-B-63
In the device described in Japanese Patent No. 22702,
Although acoustic coupling is prevented, the participants sit in symmetrical positions on a circle centered on the speaker, corresponding to each microphone, so it is possible to image the participant with a fixed-angle camera. Has a problem that the cost is high because it is necessary to deploy cameras for each participant. Further, in the device as described in Japanese Patent Publication No. 61-220190, there is a problem that the cost is as high as before because the image device including the monitor and the camera is provided to each participant. The present invention has been made in view of the above circumstances, and an object thereof is to prevent acoustic coupling by rotating an imaging device in an imaging direction calculated based on a sound level from a microphone. At the same time, another object of the present invention is to provide a remote conference device capable of recognizing a facial expression of a speaker via a monitor at a small scale and at low cost.

[0010]

A remote conference device according to a first aspect of the present invention converts voices and images of participants of a conference into electric signals by a microphone and an image pickup device, and transmits the electric signals to a remote place through a communication means. In a teleconferencing device that transmits and receives an electrical signal from a remote place and outputs a voice and an image with a speaker and an image display device to hold a conference, a plurality of the microphones are arranged at a predetermined interval. The imaging device is rotatably provided so as to image the direction of each microphone, and a driving device that rotationally drives the imaging device, and an imaging direction calculation that calculates the imaging direction of the imaging device based on the signal level from the microphone. It is characterized by comprising a device and a control device for controlling the rotational drive of the drive device so as to be in the calculated imaging direction.

In the teleconference device according to a second aspect of the present invention, in the first aspect, the speaker is disposed above the microphone, and the microphone is provided around the central axis of the speaker at a substantially right angle. The image pickup device is arranged on the central axis side.

A teleconference device according to a third invention is characterized in that, in the first invention, the image pickup direction calculation device is provided with a filter for removing noise.

In addition to the first invention, a remote conference device according to a fourth aspect of the present invention further includes a support device that supports the image pickup device so as to be rotatable in the vertical direction, and a case where the image pickup device is rotated in the vertical direction. A detection device which detects this and gives a detection signal to the control device, wherein the control device is configured to stop the rotational drive of the drive device when the detection signal is given. To do.

[0014]

In the remote conference device of the first aspect of the invention, a plurality of microphones are arranged at a predetermined interval, and the image pickup device is rotatably provided so as to pick up an image of the direction of each microphone. The imaging direction calculation device calculates, for example, the position of the highest-level microphone by comparing the signal levels from the respective microphones, and gives a signal to the control device so that the calculated direction is obtained. The control device controls the rotational drive of the drive device that rotates the imaging device based on the given signal, and rotates the imaging device in the direction calculated by the imaging direction calculation device. Then, successive speakers are individually displayed on the image display device, and the participant at the remote place can recognize the expression of the speaker well through the image display device.

In the teleconference device of the second aspect of the invention, the speaker is arranged above the microphone in an upward direction, and the microphone is arranged around the center axis of the speaker in an outward direction at a right angle thereto. Since the imaging device is arranged on the central axis side, the device scale is small, and the sound output from the speaker is suppressed from being input to the microphone, and acoustic coupling is prevented.

In the teleconference device of the third aspect of the invention, the image pickup direction calculation device for calculating the image pickup direction of the image pickup device based on the sound level from the microphone is provided with a filter for removing noise. Is eliminated, and the speaker is accurately imaged.

In the teleconference device of the fourth aspect of the invention, the supporting device supports the image pickup device so as to be rotatable in the vertical direction, and rotates the image pickup device in the vertical direction so as to capture a drawing or the like placed therebelow. In this case, the detection device detects this and gives a detection signal to the control device. Then, when the detection signal is given, the control device stops the rotation drive of the drive device that rotates the imaging device. As a result, the image of the speaker and the image of the drawing can be taken by one image pickup device.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments thereof. FIG. 1 is a schematic view showing the configuration of a remote conference device according to the present invention, in which 1 is a hollow disk-shaped mount. The gantry 1 is placed on the placing table 17, and the placing table
Attendees of the conference are seated around 17. A plurality of microphones 2, 2, ... Are attached to the peripheral surface of the gantry 1 at predetermined angles, and a participant sits facing the microphones 2, 2 ,. A support leg 11 is erected on the edge of the top surface of the gantry 1, and the support leg 11 is inclined above the center of the gantry 1. A support plate 12 parallel to the gantry 1 is provided on the upper ends of the support legs 11, and a substantially rectangular parallelepiped speaker box 5 having a circular hole at the center of the upper surface is mounted on the support plate 12. Has been. The speaker box 5 has a speaker 6 having its back fitted in the hole and is fixed so that sound can be output upward.

A stepping motor 7 is provided on the bottom of the speaker box 5 with its output shaft facing down. The output shaft of the stepping motor 7 penetrates the speaker box 5 and the support plate 12 and has an appropriate length. The rotary shaft 8 of is connected. A camera fixing device 9 is attached to the lower end of the rotary shaft 8, and a video camera 10 is fixed to the camera fixing device 9 at a right angle to the rotary shaft 8. The rotary shaft 8 is rotated by the rotation drive of the stepping motor 7, and the video camera 10 fixed to the camera fixing device 9 images the participant seated facing the microphones 2, 2, .... .

A control device 3 is disposed inside the gantry 1, and the control device 3 includes the above-mentioned microphones 2, 2, 2.
..., a video camera 10, a stepping motor 7, a speaker 6, and a monitor 15 mounted on a mounting table 17 are connected to each other. Then, the ISDN is connected to the control device of the remote conference device installed in another conference room.

FIG. 2 is a block diagram showing the configuration of the above-mentioned control device. In the figure, 31 is an audio interface unit for inputting and outputting audio signals to and from the microphones 2, 2, ... And the speaker 6, 32 is a video camera 10 and a monitor. An image interface unit for inputting and outputting image signals to and from 15. Microphone 2,
The voice signals from 2, ... Are converted into voltage signals via the voice interface unit 31 and given to the sound source direction calculation unit 33 and the voice encoding / decoding unit 34, respectively. The sound source direction calculation unit 33 includes a low-pass filter (LPF) having a pass frequency of 300 to 3400 Hz, and a voice interface.
The rotation angle of the video camera 10 is calculated on the basis of the signal given from 31 and passed through this LPF, as described later. The sound source direction calculation unit 33 gives the calculated rotation angle as a sound source direction signal to the system control unit 38, and the system control unit 38 gives it to the stepping motor control unit 41.

The stepping motor control section 41 obtains a rotation direction and a rotation angle of the video camera 10 based on the given sound source direction signal, and obtains the rotation direction and the rotation angle of the video camera 10.
Then, the stepping motor drive unit 42 drives the stepping motor 7 based on the given command, and the video camera rotated in the sound source direction by the stepping motor 7
10 images the speaker who is speaking.

The signal from the video camera 10 is given to the image encoding / decoding unit 35 as an image voltage signal via the image interface unit 32, encoded by a predetermined encoding logic, and then multiplexed / demultiplexed. Given to 36. The voice voltage signal applied to the voice encoding / decoding unit 34 is also encoded as before and is applied to the multiplexing / demultiplexing unit 36. And both are 1
It is multiplexed for each frame and output from the line interface unit 37 to the ISDN 39. Note that this multiplexing is, for example,
It is based on H.261 recommended by the International Telegraph and Telephone Consultative Committee (CCITT).

On the other hand, the multiplexed signal input from the other conference room to the line interface unit 37 via the ISDN 39 is multiplexed / multiplexed.
After the separation unit 36 separates the audio signal and the image signal, the audio encoding / decoding unit 34 and the image encoding / decoding unit.
It is given to each of the decoding units 35 and decoded there.
The decoded audio voltage signal and image voltage signal are applied to the speaker 6 and the monitor 15 via the audio interface unit 31 and the image interface unit 32, respectively, where audio output and image display are performed.

The voice interface unit 31, the image interface unit 32, the voice encoding / decoding unit 34, the image encoding / decoding unit 35, the multiplexing / demultiplexing unit 36, the line interface unit 37, and the system control unit 38 described above. Each is controlled by the following. Voice interface section
For the 31, the control relating to the balance adjustment of the input signals from the microphones 2, 2, ... And the adjustment of the sound signal strength of the microphones 2, 2 ,. A video camera for the image interface unit 32.
Controls such as focus adjustment and brightness adjustment of the screen are performed. Further, the audio encoding / decoding unit 34 and the image encoding / decoding unit 35 are subjected to control relating to addition and reset of parameters and clocks used for encoding / decoding. Then, the multiplexing / demultiplexing unit 36 is controlled in accordance with the transmission rate of the audio data and the image data, such as the allocation of bits in the frame. For the line interface unit 37, refer to CCITT Recommendation H.242.
Based on the above, control related to line connection with other conference rooms is performed.

FIG. 3 is a layout diagram of microphones, and illustrates a method of calculating a rotation angle by the sound source direction calculation unit 33. As shown in FIG. 3, the microphones 2, 2 and 2 have a center O.
On the arc of, from the reference line L, θ ₁ , θ ₂ , θ ₃ (θ ₁ <θ
_They are arranged at an angle of ₂ <θ ₃ ). Now, assuming that the voltage signal levels input from the microphones ₂ , ₂ and ₂ are I ₁ , I ₂ and I ₃ , respectively, and the threshold value of the voltage signal level that is considered to be unvoiced is THD ₁ , the sound source direction calculation unit 3
3 outputs a sound source direction signal obtained as follows based on the input voltage signal level.

(A) When the voltage signal levels I ₁ , I ₂ , and I ₃ are all less than the threshold value THD ₁ (I ₁ , I ₂ and I ₃ <THD ₁ ), the sound source direction calculation unit 33 is in the unvoiced state. Judge that there is and do not output the sound source direction signal.

(B) Any _{one of} the voltage signal levels I ₁ , I ₂ , and I ₃ is greater than or equal to the threshold value THD ₁ (I ₁ , I ₂ or I ₃ ≧ TH
If it is D ₁ ), the sound source direction calculation unit 33 selects the arrangement angle θ _n (θ _n = θ ₁ , θ ₂ or θ ₃ ) of the microphone to which it is input. Then, the difference from the angle θ _L related to the sound source direction signal output immediately before is calculated by the following equation (1), and when the positive value is _equal to or more than the threshold value THD ₂ , the selected arrangement angle θ _{n is set} to the sound source direction signal. Output as. │θ _n −θ _L │ ≧ THD ₂ … (1)

(C) Voltage signal level I₁, I₂, I₃of
Any two are threshold THD₁ Or more (I₁And I₂, I₁as well as
I₃, I₂And I₃≧ THD₁ ), The sound source direction
The calculator 33 calculates the angle formed by both microphones. That
The calculated angle is the threshold THD ₃ If less than
The source direction calculation unit 33 calculates the angle θ according to the following equation (2)._RSeeking
It On the other hand, the threshold THD₃ If exceeded, voltage signal level
Angle of microphone with higher angle θ_nSelect. So
Then the angle θ_ROr placement angle θ_nInstead of the above equation (1)
The calculated value is the threshold THD₂ When it is above, the angle
θ_ROr placement angle θ_nIs output as a sound source direction signal.

[0030]

[Equation 1]

(D) All voltage signal levels I ₁ , I ₂ ,
I ₃ is greater than or equal to the threshold THD ₁ (I ₁ , I ₂ , and I ₃ ≧ THD
_In the case of ₁ ), the sound source direction calculation unit 33 selects the arrangement angle θ _n of the microphone having the highest voltage signal level. When the value calculated by the equation (1) is equal to or greater than the threshold value THD ₂ , the arrangement angle θ _n is output as the sound source direction signal. The thresholds THD ₁ , THD ₂ , and THD ₃ described above are determined based on experiments.

FIG. 4 is a partial schematic view showing another embodiment of the present invention, which is also adapted for imaging a chart or the like at a conference. In the figure, the portions corresponding to those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. The camera fixing device 19 is adapted to rotate the video camera 10 fixed thereto in a direction in which an image pickup field thereof is parallel to the pedestal 1 or a direction opposite to the pedestal 1, and the pedestal 1 is substantially centered in the drawing. And so on.

The camera fixing device 19 is provided with a micro switch (not shown) which is activated when the video camera 10 is rotated in a direction in which its imaging field of view faces the gantry 1. The signal is supplied to the control device 3 provided in the gantry 1. When this signal is given, the system control unit provided in the control device 3 stops the output of the sound source direction signal input from the sound source direction calculation unit to the stepping motor control unit, and the video camera
The angle of 10 is fixed and the image pickup screen of the video camera 10 is displayed on the monitor 15 for a predetermined time to prompt confirmation of the direction of the displayed chart. Then, the speaker confirms the direction of the drawing placed on the gantry 1 on the monitor 15 and corrects it.
When the display of 15 is an image from another meeting room, the meeting is held while instructing the drawing.

[0034]

As described above in detail, in the teleconference device according to the first aspect of the invention, the image is displayed because the image of the speaker is picked up by the image pickup device which is rotatably provided based on the sound level from the speaker. A teleconferencing device capable of recognizing a facial expression of a speaker through the device can be manufactured at a small scale and at low cost. Further, in the teleconferencing device according to the second aspect of the invention, it is possible to manufacture a teleconferencing device that can recognize the facial expression of the speaker well and prevent acoustic coupling at a small scale and at low cost.

In the remote conference device according to the third invention,
Avoiding excessive rotation of the imager due to noise,
The number of malfunctions is reduced, the progress of the conference is not hindered, and the breakdown of the device is prevented. Further, in the teleconference device according to the fourth aspect of the invention, since the image of the speaker and the image of the drawing can be taken by one image pickup device, the efficiency of the facility is improved and the present invention is excellent. Produce the effect.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of a remote conference device according to the present invention.

FIG. 2 is a block diagram showing a configuration of a control device.

FIG. 3 is a layout diagram of microphones.

FIG. 4 is a partial schematic view showing another embodiment of the present invention.

[Explanation of symbols]

 1 Stand 2 Microphone 3 Control Device 5 Speaker Box 6 Speaker 7 Stepping Motor 8 Rotation Axis 9 Camera Fixing Device 10 Video Camera 11 Supporting Leg 12 Support Plate 15 Monitor 19 Camera Fixing Device 33 Sound Source Direction Calculator 38 System Controller 39 ISDN 41 Stepping Motor control unit 42 Stepping motor drive unit

Claims (4)

[Claims] 1. A speaker which converts voices and images of conference participants into an electric signal by a microphone and an image pickup device, transmits the electric signal to a remote place through a communication means, and receives the electric signal from the remote place. Also, in the teleconferencing device that outputs a voice and an image on the image display device to hold a conference, the plurality of microphones are arranged at a predetermined interval, and the imaging device is rotatable so as to capture the direction of each microphone. A driving device that is provided to rotate and drive the imaging device, an imaging direction calculation device that calculates the imaging direction of the imaging device based on a signal level from the microphone, and the driving device that makes the calculated imaging direction. A remote conference device, comprising: a control device that controls rotational drive of the device. 2. The speaker is arranged above the microphone in an upward direction, the microphone is arranged outward about a central axis of the speaker at a right angle thereto, and the imaging device is in the center. The teleconference device according to claim 1, wherein the teleconference device is arranged on the axis side. 3. The teleconference device according to claim 1, wherein the imaging direction calculation device includes a filter for removing noise. 4. A supporting device for rotatably supporting the image pickup device in a vertical direction, and a detection device for detecting the detected rotation of the image pickup device when the image pickup device is rotated in the vertical direction and giving a detection signal to the control device. 2. The remote conference device according to claim 1, further comprising: and the control device, when the detection signal is given, to stop the rotation drive of the drive device.