JP7599993B2 - Meeting support system - Google Patents

Description

The present invention relates to a conference support system that prevents conversations in a meeting space, etc. from being heard by other nearby workers, resulting in reduced productivity for those other workers.

In today's workplaces, spaces for meetings and discussions (meeting spaces) are often located close to spaces where individuals work (work spaces).

In addition, in order to encourage collaboration, the establishment of open work spaces and the introduction of free addresses are being promoted, which make it easier for workers to come into contact with each other and have conversations. Here, an open work space is a large desk that can seat several people, and is a space that each worker can use freely to carry out their work or duties.

For example, Patent Document 1 (JP Patent Publication 2010-4962 A) discloses a furniture system that is primarily comprised of large free-address desks that can be used by multiple workers facing each other.

Additionally, workplaces are often planned with a mix of different spaces to make it easier to transition from individual work to conversations and meetings.

However, in a workplace with a mixture of such diverse spaces, there is an issue that conversations in meeting spaces or open work spaces can be heard by other workers nearby, reducing their productivity.

Therefore, the inventor proposed a conference support system in the application of Patent Document 2 (Japanese Patent Application No. 2020-86764) that collects the voices of conference participants, plays the collected voices on a speaker, and presents them to the conference participants to support the conference, in which a parabolic surface is provided on a part of the ceiling, and the sound played on the speaker is reflected by the parabolic surface. In addition, in the application, a loop such as microphone → amplifier → speaker (→ parabolic ceiling surface) → microphone exists, and howling suppression measures are necessary, so a method for suppressing howling by an electroacoustic device was proposed in the second embodiment of the application.
JP 2010-4962 A Patent Application No. 2020-86764

However, the above application had the problem that it did not specify the frequency characteristics of the speakers and other devices used to play back the audio, and did not describe how the audio recorded by the microphone should be amplified and played back for transmission to the speaker and conference participants.

In addition, although the application proposed measures to suppress feedback, at present, even if feedback is suppressed using the electroacoustic device, the effect is insufficient, and the amplification rate of the sound reproduced from the speaker cannot be increased, resulting in an insufficient volume of the conversation sound transmitted to the speaker and conference participants.

The present invention solves the above-mentioned problems, and the conference support system of the present invention supports a conference by collecting voices of conference participants, playing the collected voices through a speaker and broadcasting them to the conference participants, the conference support system having a microphone that converts an input voice signal into an electrical signal, a filter that passes only an electrical signal corresponding to a component of the electrical signal converted by the microphone that has a predetermined frequency or higher, an amplifier that amplifies the electrical signal that has passed through the filter, a speaker that plays the electrical signal amplified by the amplifier, and a parabolic surface formed on a part of the ceiling that reflects the sound played by the speaker, wherein the predetermined frequency of the component corresponding to the electrical signal passed by the filter is 1 kHz or higher, and a soundproofing panel is arranged flush with a horizontal plane that includes the top end of a structure including the housing of the speaker .

In addition, the conference support system of the present invention supports a conference by collecting voices from conference participants, playing the collected voices through a speaker, and broadcasting them to the conference participants, and is characterized in that it has a microphone that converts an input voice signal into an electrical signal, an amplifier that amplifies the electrical signal converted by the microphone, a tweeter that plays only an electrical signal corresponding to a component of the electrical signal amplified by the amplifier that has a predetermined frequency or higher, and a parabolic surface formed on a part of the ceiling that reflects the sound played by the tweeter , wherein the predetermined frequency of the component corresponding to the electrical signal played by the tweeter is 1 kHz or higher, and a soundproofing panel is arranged flush with a horizontal plane that includes the top end of a structure including the speaker housing .

In addition, the conference support system of the present invention supports a conference by collecting voices of conference participants, playing the collected voices through a speaker, and outputting them to the conference participants, and is characterized in that the conference support system has a microphone that converts an input voice signal into an electrical signal, a filter that passes only an electrical signal corresponding to a component of a predetermined frequency or higher from the electrical signal converted by the microphone, an amplifier that amplifies the electrical signal that has passed through the filter, a tweeter that plays only an electrical signal corresponding to a component of a predetermined frequency or higher from the electrical signal amplified by the amplifier, and a parabolic surface formed in a part of the ceiling that reflects the sound played by the tweeter , wherein the predetermined frequency of the component corresponding to the electrical signal passed by the filter is 1 kHz or higher, the predetermined frequency of the component corresponding to the electrical signal played by the tweeter is 1 kHz or higher, and a sound-proofing panel is arranged flush with a horizontal plane that includes the top end of a structure including the housing of the speaker .

The conference support system according to the present invention has a filter that passes only electrical signals that correspond to components of a predetermined frequency or higher among the electrical signals converted by the microphone. Therefore, with this conference support system according to the present invention, it is possible to provide an indication of how to amplify and play back the sound recorded by the microphone so that it can be properly transmitted to the speaker and conference participants.

In addition, the conference support system according to the present invention makes it possible to increase the amplification rate of the sound reproduced from the speaker by using the above-mentioned filter, thereby sufficiently increasing the volume of the conversation sound transmitted to the speaker and conference participants.

The conference support system according to the present invention also has a tweeter that reproduces only the electrical signal amplified by the amplifier that corresponds to components of a predetermined frequency or higher. This type of conference support system according to the present invention makes it possible to provide guidance on how to amplify and reproduce the sound recorded by the microphone so that it can be properly transmitted to the speaker and conference participants.

In addition, the conference support system according to the present invention makes it possible to increase the amplification rate of the audio reproduced from the tweeter described above, thereby sufficiently increasing the volume of the conversational audio transmitted to the speaker and conference participants.

1 is a diagram illustrating an overview of a conference support system 1 according to an embodiment of the present invention. 2 is a block diagram of an audio processing unit 40 of the conference support system 1 according to the embodiment of the present invention. 1 is a diagram illustrating the geometric arrangement of a speaker 60 and a ceiling in the conference support system 1. FIG. 1 is a diagram illustrating sound reflected by a parabolic ceiling portion 17 of the conference support system 1. FIG. FIG. 1 is a block diagram of a conference support system 1 according to a second embodiment of the present invention. FIG. 11 is a block diagram of a conference support system 1 according to a third embodiment of the present invention. FIG. 13 is a block diagram of an audio processing unit 40 of the conference support system 1 according to a fourth embodiment of the present invention. FIG. 13 is a diagram illustrating an overview of a conference support system 1 according to a fifth embodiment of the present invention. 1 is a diagram illustrating a case where a reflecting object R is placed within a sound emission range. FIG. FIG. 13 is a diagram illustrating an overview of a conference support system 1 according to a sixth embodiment of the present invention. 11 is a diagram for explaining the difference in propagation path based on the height of the focal point F and the height of the sound-proof plate 70. FIG. 1 is a schematic diagram of sound propagation paths when the upper surface of a sound-proofing plate 70 is flat and parallel to a floor surface 20. FIG. FIG. 1 is a diagram illustrating a problem caused by a small speaker 60 aligned at a focal point F. 13A to 13C are diagrams illustrating the effects of the conference support system 1 according to the sixth embodiment of the present invention.

The following describes an embodiment of the present invention with reference to the drawings. The conference support system 1 according to the present invention is expected to be applied to, for example, a meeting space located near a large desk in a free address style where work is carried out, or an open office space.

In addition, it is expected that workers will work at the large desks in the free address style and in the open office space, while meetings will take place in the meeting space and participants will be able to speak.

In this specification, a "worker" is defined as a person who performs desk work such as paperwork and computer input work and who does not generally use voice commands, and is distinguished from a meeting participant who takes part in a meeting in the meeting space and speaks.

The objective of the conference support system 1 of the present invention is to output appropriate audio to the conference participants while preventing the content of the conversation between the participants in the meeting space from being heard as much as possible by other workers at nearby large desks or in open office spaces. To achieve this, the conference support system 1 of the present invention collects the audio of the conference participants (the speakers), plays the collected audio on a speaker, and outputs it to the conference participants to support the conference.

Speech is composed of vowels and consonants, the former consisting mainly of low frequency components and the latter of high frequency components. It is known that in the sense of hearing, low frequency components mask high frequency components, and this masking is also at work when we perceive speech. This type of masking is one of the causes of poor speech audibility.

In the conference support system 1 according to the present invention, when the collected voice of a speaker is played back on a speaker for the conference participants, the frequency of the voice played back from the speaker is specified by focusing on the characteristics of the voice and hearing, thereby preventing a decrease in clarity of the played back sound and solving the problem.

Figure 1 is a diagram for explaining an overview of a conference support system 1 according to an embodiment of the present invention. It shows a situation in which a conference is being held with two participants at a desk 25 placed on a floor surface 20. It is assumed that workers are working near this desk 25 at the aforementioned large free address type desk or in an open office space (neither of which are shown).

A microphone 30 is installed on the desk 25, and this microphone 30 picks up the voices of the conference participants. When an audio signal is input to the microphone 30, it converts it into an electrical signal.

The electrical signal converted by the microphone 30 is input to the audio processing unit 40. In this audio processing unit 40, the electrical signal is converted into an appropriate signal for playback by the speaker 60. FIG. 2 is a block diagram of the audio processing unit 40 of the conference support system 1 according to an embodiment of the present invention. The audio processing unit 40 in FIG. 2 is one example, and various other configurations are possible. In the audio processing unit 40 in FIG. 2, the level of the electrical signal is adjusted by the volume adjustment unit 41, and the electrical signal is amplified by the amplifier 50.

In FIG. 2, the electrical signal converted by the microphone 30 is input to a high-pass filter 42 in the audio processing unit 40. This high-pass filter 42 is a filter that passes only electrical signals corresponding to components of the electrical signal output from the microphone 30 that have a predetermined frequency or higher. It is preferable that the predetermined frequency of the components corresponding to the electrical signal passed by the high-pass filter 42 is 1 kHz.

The majority of Japanese syllables are composed of consonants and vowels, each of which has different frequency characteristics. In Japanese conversation, consonants are said to play an important role in transmitting speech clearly. In this embodiment, the low-frequency components that make up vowels are cut by a high-pass filter 42, and consonants made up of high-frequency components are emphasized, improving the audibility of speech.

The present invention amplifies the components of conversational voice recorded by the microphone 30 that are essentially 1 kHz or higher (reproduction frequency band), and reproduces them from a speaker 60 installed at the focus of the parabolic ceiling portion 17.

In other words, the present invention is a system that amplifies and reproduces the above-mentioned reproduction frequency bands, reproducing audio by emphasizing only the frequency bands that contain a large amount of consonant components.

Compared to vowels, consonants have their main components in a high frequency band (1 kHz to 6 kHz), and the frequency band containing the main components of consonants is 1 kHz to 6 kHz. Therefore, in the conference support system 1 according to the present invention, the playback frequency band may be set to 1 kHz to 6 kHz. In this case, a bandpass filter with a passband of 1 kHz to 6 kHz can be used instead of the highpass filter 42.

However, in the conference support system 1 according to the present invention, the playback frequency band is basically 1 kHz or more, and it is more preferable to include the band of 6 kHz or more. This is because, although it is weaker than the band from 1 kHz to 6 kHz, the frequency band of 6 kHz or more also contains consonant components. Also, even if the energy of consonants is minute, they affect the clarity of conversation, so it is more preferable to include 6 kHz or more in the playback frequency band, even if it does not contain the main components.

The output from the high-pass filter 42 is input to the volume adjustment unit 41. The volume adjustment unit 41 adjusts the volume of the sound reproduced by the speaker 60. This volume adjustment unit 41 may be operated automatically or manually. In the latter case, it is preferable that components such as an input knob and an input slider for adjusting the volume are appropriately provided on the desk 25.

The electrical signal amplified by the amplifier 50 of the audio processing unit 40 is input to the speaker 60, which reproduces the sound. The speaker 60 is installed so that its directivity faces upward, and the sound is emitted from the speaker 60 towards the ceiling 10.

The ceiling 10 has a general ceiling portion 15 having a horizontal surface, and a parabolic ceiling portion 17 having a concave parabolic surface formed as part of the general ceiling portion 15. In the conference support system 1 according to the present invention, the layout is such that the parabolic ceiling portion 17 is disposed above the desk 25. In addition, it is preferable that the size of the parabolic ceiling portion 17 is large enough in plan view to at least include the conference participants seated around the desk 25.

In this embodiment, the parabolic ceiling portion 17 is provided as part of the ceiling 10, but a structure equivalent to the parabolic ceiling portion 17 may be provided separately from the ceiling 10. For example, a parasol-like structure equivalent to the parabolic ceiling portion 17, independent of the general ceiling portion 15 in the ceiling 10, may be provided on the ceiling 10.

The parabolic ceiling portion 17 as described above reflects the sound reproduced by the speaker 60 vertically downward. In the conference support system 1 according to the present invention, the ceiling structure is designed so that sound is emitted to a limited area (the meeting space where the desks 25 are arranged) even when using ordinary speakers. Figure 3 is a diagram explaining the geometric arrangement of the speaker 60 and the ceiling in the conference support system 1, and is a schematic diagram showing a cross section of the ceiling 10 and floor surface 20 of a building.

The ceiling 10 is composed of a general ceiling portion 15 that is parallel to a general floor surface 20, and a parabolic ceiling portion 17 that is formed on part of the ceiling 10. Here, the x-axis is the horizontal direction, the y-axis is the vertical direction, and coordinates (x, y) are defined with the position F of the speaker 60 (not shown in FIG. 3) as the origin.

In the coordinate system defined as above, the parabolic ceiling portion 17 is configured to overlap with the surface of a body of revolution obtained by rotating y= ^-x2 /4L+L around the y axis. In this case, the origin (0,0) of the xy coordinate system coincides with the focal point of the parabolic ceiling portion 17.

If the directional range of the speaker 60 (not shown in FIG. 1) is φ, it is preferable that the cone defined by φ is contained within the parabolic ceiling portion 17.

The sound playback means in the conference support system 1 according to the present invention is composed of a parabolic ceiling portion 17 having a shape that forms part of a paraboloid as described above, and a speaker 60 installed below the parabolic ceiling portion 17 with its direction facing upward. The speaker 60 is also installed so as to be located at the focal point F of the paraboloid of the ceiling 10.

In the above-mentioned relationship, when the speaker 60 is placed at F, as shown in Figure 4, the sound reflected by the parabolic ceiling portion 17 travels vertically downward toward the floor surface 20.

In the conference support system 1 according to the present invention, it is preferable that the range in which the ceiling surface forms a paraboloid is the range in which the sound emitted from the speaker 60 is incident, i.e., the range that can cover the directional range of the speaker 60.

Sound emitted from speaker 60 installed at the focus F of the paraboloid that constitutes parabolic ceiling portion 17 enters parabolic ceiling portion 17, which forms part of the paraboloid, and then reflects vertically downward toward desks 25 around which the conference participants are seated. In the conference support system 1 according to the present invention, the sound emitted from the speaker can be kept within the desired range without using expensive speaker systems such as parametric speakers or flat panel speakers. In this way, the conference support system 1 according to the present invention can be realized inexpensively using general speakers.

The mechanism for supporting audio transmission using the parabolic ceiling portion 17 and the speaker 60 has already been proposed by the inventors in Japanese Patent Application No. 2017-160105 (see Japanese Patent Application Laid-Open No. 2019-39166). This proposal had the effect of providing sound information such as background music and announcements to only a limited area in art galleries and museums.

On the other hand, in the conference support system 1 according to the present invention, it can be considered that conference participants can objectively judge their own voice volume by listening to their own voice reproduced by the speaker 60 and reflected by the parabolic ceiling portion 17. Therefore, conference participants can control and suppress their own voice volume. This makes it possible for the conference support system 1 to suppress conversations at a volume that can be heard by workers nearby the meeting space. This effect is not necessarily easily derived from the previous proposal.

Now, if the parabolic ceiling portion 17 is wider than the main directional range of the speaker 60, the reproduced sound from the speaker 60 will not propagate to the surroundings, but will be emitted only directly below the parabolic ceiling portion 17.

In this way, if the directional range of the parabolic ceiling portion 17 and the speaker 60 is appropriately set to cover the meeting space, the sound recorded by the microphone 30 is reliably transmitted only to the meeting participants who are conversing in the meeting space.

The feature of the voice transmission support provided by the conference support system 1 according to the present invention is that the speaker's own conversation voice is amplified and transmitted not only to the person in the conversation but also to the speaker himself at the same time.

By using the conference support system 1 according to the present invention, the speaker can feel that their voice sounds loud and that their voice is being reliably transmitted to the person they are speaking with, so it is expected that they will naturally adjust their voice volume to be lower. In this way, if the speaker's voice volume is suppressed, the amount of conversation sound propagating from the meeting space to the surrounding area is reduced, reducing the decrease in the work efficiency of other nearby workers and the degree of interference with other conversations.

In this way, sound can be reliably transmitted to conference participants who are conversing only in the meeting space covered by the parabolic ceiling section 17, while guiding the speaker to reduce the volume of their voice. As a result, it is possible to reduce the decrease in the work efficiency of other nearby workers and the degree of interference with other conversations.

The microphone 30 used in the conference support system 1 according to the present invention is preferably installed on the desk 25. However, it is also possible to use a lapel microphone worn by each of the conference participants who will be having a conversation.

The conference support system 1 according to the present invention, configured as described above, can prevent conversations in a meeting space from being heard by other nearby workers, thereby reducing the productivity of those other workers, without the need to take measures such as surrounding the meeting space with a partition.

The conference support system 1 according to the present invention has a high-pass filter 42 that passes only electrical signals that correspond to components of a predetermined frequency or higher among the electrical signals converted by the microphone 30. Therefore, the conference support system 1 according to the present invention can provide an indication of how to amplify and play back the sound recorded by the microphone 30 so that it can be properly transmitted to the speaker and conference participants.

In addition, according to the conference support system 1 of the present invention, by providing the high-pass filter 42 as described above, it is possible to increase the amplification rate of the sound reproduced from the speaker 60, and the volume of the conversation sound transmitted to the speaker and conference participants can be sufficiently increased.

In other words, the effect of making conversational voices clearer by playing back based on the playback frequency band, and thus being able to properly transmit voice to conference participants, can be achieved without increasing the amplification rate of the playback voice. In other words, even with an amplification rate that does not cause feedback, voices can be properly transmitted to conference participants.

In addition, according to the conference support system 1 of the present invention, when the howling frequency is outside the playback frequency band, it is possible to sufficiently increase the amplification rate, which also improves the audio transmission to conference participants.

In addition, the conference support system 1 according to the present invention can guide speakers to reduce their speaking volume while reliably transmitting sound only to conference participants within the range covered by the parabolic surface on the ceiling.

This makes it possible to reduce the amount of conversation sound that propagates to adjacent spaces. As a result, it is possible to reduce the degree of decline in the work efficiency of other workers working in adjacent spaces, reduce the degree of interference with other conversations taking place in adjacent spaces, and reduce the feeling of noise throughout the workplace.

In addition, the conference support system 1 according to the present invention makes it possible to prevent highly confidential conversations from being leaked to those around when they are held in a meeting space.

In addition, in the conference support system 1 according to the present invention, if a microphone installed on a desk is used, there is no need for a wearable device such as an intercom, and the above-mentioned effects can be obtained without compromising convenience. Wearing an intercom or the like not only reduces convenience, but can also lead to a decrease in meeting efficiency due to discomfort for workers who are not accustomed to it.

In addition, in the conference support system 1 according to the present invention, a general speaker can be used as the speaker installed at the focal point, and the above-mentioned effects can be achieved at low cost. Parametric speakers and flat panel speakers exist as speaker systems with narrow directional characteristics for playing back conversation sounds in a limited range, but they have issues with cost and sound quality.

The conference support system 1 according to the present invention is also effective when conversing with people in remote locations, such as via a web conference, as well as when actually conversing face-to-face.

Next, another embodiment of the present invention will be described. In the previous embodiment, the high-pass filter 42 passes only the electrical signal corresponding to the component of a predetermined frequency or higher among the electrical signals output from the microphone 30, and reproduces it from the speaker 60. On the other hand, in the second embodiment, such a filter is not used, and the speaker 60 is replaced with a tweeter 67 to reproduce the component of the predetermined frequency or higher. The other configuration is the same as in the first embodiment. Figure 5 is a block diagram of the conference support system 1 according to the second embodiment of the present invention. As in the previous embodiment, in the second embodiment, the sound reproduced by the tweeter 67 is configured to be reflected by a parabolic ceiling portion 17 formed in a part of the ceiling.

In this specification, the tweeter 67 is defined as a speaker that reproduces sound components of 1 kHz or higher, and does not reproduce sound components below 1 kHz. In other words, the frequency of the sound components corresponding to the electrical signal reproduced by the tweeter 67 in FIG. 5 is 1 kHz or higher, and electrical signals corresponding to sounds with lower frequencies are not reproduced.

In the conference support system 1 according to the second embodiment, the conversational voice recorded by the microphone 30 has its electrical signal level adjusted by the volume adjustment unit 41, and the electrical signal is amplified by the amplifier 50. Then, of the conversational voice, essentially only the components of 1 kHz or higher (reproduction frequency band) are reproduced by the tweeter 67 installed at the focus of the parabolic ceiling portion 17. That is, in the second embodiment, the system amplifies and reproduces the above-mentioned reproduction frequency band by the tweeter 67, so that the voice is reproduced by emphasizing only the frequency band containing a large number of consonant components. According to this second embodiment, it is possible to enjoy the same effects as the previous embodiment.

Next, another embodiment of the present invention will be described. FIG. 6 is a block diagram of a conference support system 1 according to a third embodiment of the present invention. In the conference support system 1 according to the third embodiment,
The audio processing unit 40 employs a high-pass filter 42 that passes only electrical signals corresponding to sound components of 1 kHz or higher. The electrical signal that passes through the high-pass filter 42 has its level adjusted by a volume adjustment unit 41, and is amplified by an amplifier 50. The electrical signal amplified by the amplifier 50 is input to a tweeter 67 that reproduces sound components of 1 kHz or higher.

In this way, in the conference support system 1 according to the third embodiment, both the high-pass filter 42 and the tweeter 67 are used, and this embodiment can also achieve the same effects as the previous embodiment.

Next, another embodiment of the present invention will be described. In the embodiments described so far, a high-pass filter and tweeter are used to reproduce only electrical signals corresponding to sound components above a predetermined frequency (preferably 1 kHz or higher). In contrast, in the fourth embodiment, sounds below a predetermined frequency are cut as necessary, and components above 1 kHz (reproduction frequency band) are reflected by the parabolic ceiling portion 17 and made audible to the conference participants. Figure 7 is a block diagram of the audio processing portion 40 of the conference support system 1 according to the fourth embodiment of the present invention.

In FIG. 7, the electrical signal converted by the microphone 30 is input to a high-pass filter 42, which passes only electrical signals corresponding to components of the electrical signal output from the microphone 30 that are equal to or greater than a predetermined frequency. The electrical signal converted by the microphone 30 is also input to a low-pass filter 43, which passes only electrical signals corresponding to components of the electrical signal output from the microphone 30 that are less than a predetermined frequency.

A variable gain amplifier 44 is provided on the line on which the high-pass filter 42 is provided, and is set to obtain a gain of at least 1x. On the other hand, an open/close switch 45 is provided on the line on which the low-pass filter 43 is provided, and this open/close switch 45 is provided near the desk 25 where it can be operated by the conference participants. The gain in the variable gain amplifier 44 is also configured to be changeable by an adjustment unit (not shown). It is preferable that this adjustment unit is also provided near the desk 25 and configured so that it can be operated and adjusted by the conference participants.

The line output from the high-pass filter 42 and the line output from the low-pass filter 43 are added together and input to the volume adjustment unit 41. The level of the electrical signal is adjusted by the volume adjustment unit 41, and the electrical signal is amplified by the amplifier 50. The electrical signal amplified by the amplifier 50 is input to the speaker 60, and sound is reproduced from the speaker 60 toward the parabolic ceiling portion 17, as in the embodiments described so far.

The line on the low-pass filter 43 side is provided with an open/close switch 45, but even if the open/close switch 45 on the line on the low-pass filter 43 side is closed, the line on the high-pass filter 42 side is provided with a variable gain amplifier 44, so that the level of the electrical signal input to the volume adjustment unit 41, which is the sum of the two, is higher for the line on the high-pass filter 42 side. Therefore, the components of the sound reproduced by the speaker 60 are emphasized at a predetermined frequency or higher (for example, 1 kHz or higher). As a result, even in the conference support system 1 according to the fourth embodiment, the sound is reproduced with the frequency band containing a large number of consonant components emphasized, making it easy to hear the sound.

On the other hand, in order to further improve audibility for the conference participants, the open/close switch 45 can be opened to completely block sound components below a certain frequency. When the open/close switch 45 for the line on the low-pass filter 43 side is opened, the only electrical signal input to the volume adjustment unit 41 is the output from the line on the high-pass filter 42 side. As a result, the conference support system 1 according to the fourth embodiment can achieve the same effects as the previous embodiment.

Next, other embodiments of the present invention will be described. In the embodiments described so far, the microphone 30 is present within the sound emission range (presentation range) of the speaker 60 and the parabolic ceiling portion 17, so howling is predicted to occur due to a loop in which sound is input to the microphone 30, amplified by the amplifier 50, played back from the speaker 60, and then input to the microphone 30. Therefore, in the fifth embodiment, a configuration is adopted that suppresses such howling.

Figure 8 is a diagram illustrating an overview of a conference support system 1 according to a fifth embodiment of the present invention. This conference support system 1 according to the fifth embodiment can be arbitrarily combined with any of the first to fourth embodiments described so far.

In Figure 8, four configurations for suppressing feedback are shown: a soundproofing plate 70 provided below the speaker 60, a cover body 80 provided above the microphone 30, a microphone stand 27 shaped like a truncated cone or a truncated pyramid on which the microphone 30 is placed, and sound-absorbing material 90 laid on the desk 25.

In this embodiment, each configuration may be used alone or in any combination to suppress feedback.

The soundproofing plate 70 is provided to prevent the sound reflected by the parabolic ceiling portion 17 from being picked up again by the microphone 30. It is preferable that the soundproofing plate 70 and the microphone 30 are arranged so that they overlap in a plan view.

In addition, by providing the cover body 80 above the microphone 30, the microphone 30 is prevented from picking up sound from above the microphone 30, and the microphone 30 mainly picks up the voices of the conference participants.

The microphone stand 27 on which the microphone 30 is placed is shaped like a truncated cone or a truncated pyramid, and by reflecting sound from the ceiling side generally to the side, it prevents the microphone 30 from picking up sound reflected by the desk 25 from below.

In addition, the sound-absorbing material 90 laid on the desk 25 absorbs sound incident from above, preventing the microphone 30 from picking up sound reflected by the desk 25 from below.

In the above configuration, the conversational voice recorded by the microphone 30 is amplified, and is reproduced from the speaker 60 installed at the focus of the parabolic ceiling 17. Furthermore, in the conference support system 1 according to the fifth embodiment, the above-mentioned physical feedback suppression measures are implemented, and even if the feedback frequency is within the playback frequency band, the diffraction effect of the sound insulation plate 70 or the sound absorption effect of the cover body 80 and the sound absorbing material 90 is high in the high frequency range, so that the amplification rate can be sufficiently increased and the audibility of the voice can be improved. Furthermore, according to the fifth embodiment, the same effects as those of the previous embodiment can be enjoyed.

Next, a sixth embodiment of the present invention will be described. The conference support system 1 according to the sixth embodiment can be used in any combination with any of the first to fourth embodiments described above.

The conference support system 1 according to the present invention is characterized in that the sound emitted from the speaker 60 installed facing upward at the focus F of the parabolic ceiling portion 17 is reflected vertically downward by the parabolic ceiling portion 17 and is emitted within a limited range covered by the parabolic ceiling portion 17.

In such a conference support system 1 according to the present invention, if reflective objects R are placed in the range where sound is emitted (the area below the parabolic ceiling portion 17 in a plan view) as shown in FIG. 9, the sound reflected by the parabolic ceiling portion 17 will be reflected or scattered by these reflective objects R, causing the sound to propagate outside the range covered by the parabolic ceiling portion 17 from which it is intended to emit sound. Here, the configuration of the microphone 30 and the like is omitted from FIG. 9. Examples of reflective objects R include displays, personal computers, bookshelves, desk lights, etc.

As for the desk 25, the top surface of the tabletop is usually flat and parallel to the floor surface 20, so the sound reflected by the top surface of the tabletop after being reflected by the parabolic ceiling portion 17 returns in the direction of the parabolic ceiling portion 17 and does not propagate outside the range where the sound is desired to be emitted, and therefore is not considered a reflecting object R here.

To solve the above problems, in the conference support system 1 according to the sixth embodiment, a soundproofing plate 70 is arranged flush with the horizontal plane that includes the top end of the structure including the housing 61 of the speaker 60. Figure 10 is a diagram for explaining the overview of the conference support system 1 according to the sixth embodiment of the present invention.

The speaker 60 is composed of a magnet coil section 62 which serves as a vibration source, and a cone section 65 which is vibrated by the vibration source and thus serves as a vibration section which is essentially a sound source.
However, the layout is such that the horizontal plane including the uppermost end of the cone portion 65 is flush with the upper surface of the sound insulating plate 70. The reason for such a layout will be described later.

Generally, the speaker 60 is not used by itself, but is used while housed in a housing 61 such as an enclosure. The upper surface of the soundproofing plate 70 is laid out so as to be flush with the horizontal plane that includes the top end of such housing 61. The reason for this layout will be described later.

The housing 61 does not include a metal mesh or the like that is placed in front of the cone portion 65 of the speaker 60 to protect the cone portion 65. This is because such protective materials such as metal mesh can be considered acoustically transparent. Furthermore, the housing 61 does not include tiny protrusions such as screws or bolts.

The installation range of the soundproofing board 70 is set to overlap with or exceed the reflecting object R in a planar positional relationship, so that the reflecting object R is included within the range of the soundproofing board 70. However, in a planar view, the range of the soundproofing board 70 is set to be narrower than the parabolic ceiling portion 17 and not overlap with the conference participants, who are the targets from which sound is to be emitted.

The material and structure of the sound insulation board 70 need only have a certain degree of sound insulation performance (for example, an acoustic transmission loss of 10 dB or more is desirable) against the frequency components of the sound to be emitted. In addition, in the embodiment shown in FIG. 10, the shape of the sound insulation board 70 is circular in a plan view, but the planar shape of the sound insulation board 70 is not particularly limited to this, and the sound insulation board 70 can be rectangular, polygonal, irregular, etc. in a plan view.

The cross-sectional shape of the sound insulation panel 70 is such that at least the upper surface is flat and parallel to the floor surface 20. However, this is based on the assumption that the general ceiling portion 15 is parallel to the floor surface 20 and the parabolic ceiling portion 17 is installed so that the sound radiated from the speaker 60 is reflected perpendicularly to the floor surface 20.

In the conference support system 1 according to the sixth embodiment, the layout is such that the soundproofing plate 70 is flush with the horizontal plane that includes the top end of the structure including the housing 61 of the speaker 60. This is for the following reasons.

Figure 11 is a diagram explaining the difference in the propagation path based on the height of the focal point F and the height of the sound-proofing plate 70. Figure 11(A) is a schematic diagram of the sound propagation path when the sound-proofing plate 70 is placed below the focal point, and Figure 11(B) is a schematic diagram of the sound propagation path when the top surface of the sound-proofing plate 70 is placed at the same height as the focal point.

As shown in FIG. 11(A), when the top surface of the soundproofing plate 70 is placed below the speaker 60, i.e., the focal point F, the sound that has traveled downward from the speaker is reflected by the top surface of the soundproofing plate 70 and then enters the parabolic ceiling portion 17. At this time, the direction of incidence coincides with the direction of incidence of the sound radiated from the virtual image F' of the focal point, which is symmetrical to the focal point with the top surface of the soundproofing plate 70 as the symmetrical plane. For this reason, the reflection direction of the sound that enters the parabolic ceiling portion 17 is not perpendicular downward to the floor surface 20, and the sound propagates outside the range that is covered by the parabolic ceiling portion 17 and where it is desired to emit sound.

On the other hand, as shown in FIG. 11B, if the top surface of the soundproofing plate 70 is at the same height as the top end of the housing 61 in which the speaker 60 is housed, the virtual image of the focus will be in the same position as the real image (original focus), and such a problem will not occur. For this reason, in the conference support system 1 according to the sixth embodiment, the top side of the soundproofing plate 70 is installed at the same height as the top end of the housing 61 of the speaker 60. Note that installing it in this manner is essentially equivalent to arranging the soundproofing plate 70 whose top surface is flush with the horizontal plane that includes the top end of the housing 61 in which the speaker 60 is housed.

In the conference support system 1 according to the sixth embodiment, the reason why the upper surface of the sound-proofing board 70 is flat and parallel to the floor surface 20 (i.e., the horizontal plane) is as follows. Figure 12 is a schematic diagram of the sound propagation path when the upper surface of the sound-proofing board 70 is flat and parallel to the floor surface 20.

Sound (1) emitted from a speaker 60 installed at focal point F enters the parabolic ceiling portion 17 and is then reflected vertically downward (2). The sound reflected vertically downward from the parabolic ceiling portion 17 enters the top surface of the sound insulation board 70, but if the top surface of the sound insulation board 70 is flat and parallel to the floor surface, the sound that enters the top surface of the sound insulation board 70 is reflected vertically upward (3) and then reflected again from the parabolic ceiling portion 17 toward focal point F (4).

The sound is then reflected repeatedly from the focal point F of the speaker 60 → the parabolic ceiling portion 17 → the top surface of the sound-proofing plate 70 → the parabolic ceiling portion 17 → the focal point F of the speaker 60 → ... so that the sound does not propagate outside the range that is covered by the parabolic ceiling portion 17 and is desired to be emitted. For this reason, the top surface of the sound-proofing plate 70 is made flat and parallel to the floor surface 20.

Next, we will explain the speaker 60 that can be used in the conference support system 1 according to the sixth embodiment of the present invention. According to the technology proposed in this invention, it is required to install the speaker 60 at the focal point F of the parabolic ceiling portion 17, and in order to install the speaker 60 accurately at the focal position, it is preferable that the speaker 60 is small. However, a small speaker 60 generally has a wide directivity range over a wide frequency band, and as shown in Figure 13, there is a problem that sound that has bent over from the speaker vibration portion to the side or downward does not enter the parabolic ceiling portion 17, but instead propagates directly outside the range where the sound is intended to be emitted.

By installing the soundproofing panel 70 of the conference support system 1 according to the sixth embodiment, as shown in FIG. 14, it is possible to obtain the effect of reducing the leakage of sound to the side or below the speaker 60 in a frequency band in which the wavelength is smaller than the size of the soundproofing panel 70. This makes it possible to more reliably limit the emission of sound to the area covered by the parabolic ceiling portion 17.

By using a soundproofing plate 70 like that of the sixth embodiment, it is not necessary to custom-make a speaker with a small speaker unit attached to a large housing in order to obtain the above-mentioned effect. The above-mentioned effect can be obtained by configuring a system using small speakers that are generally available on the market.

In the above configuration, of the conversational voices recorded by the microphone 30, basically the components of 1 kHz or higher (reproduction frequency band) are amplified and reproduced from the speaker 60 installed at the focus of the parabolic ceiling portion 17. Furthermore, according to the conference support system 1 of the sixth embodiment configured as described above, it is possible to prevent the sound reflected by the parabolic ceiling portion 17 from propagating to the area below the sound insulation plate 70 in a plan view. As a result, it is possible to prevent the sound from propagating beyond the range where it is originally intended to be emitted by being reflected or scattered by a reflecting object R such as a display located below the parabolic ceiling.

In addition, in the conference support system 1 according to the sixth embodiment, even if the howling frequency is within the playback frequency band, the diffraction effect of the sound insulation panel 70 is high in the high frequency range, so it is possible to sufficiently increase the amplification rate and improve the audibility of the voice.

Furthermore, according to the fifth embodiment, it is possible to enjoy the same effects as the previous embodiments.

As described above, the conference support system according to the present invention can provide guidance on how to amplify and play back audio recorded by a microphone so that it can be properly conveyed to the speaker and conference participants.

In addition, the conference support system according to the present invention makes it possible to increase the amplification rate of the audio played from the speaker, thereby sufficiently increasing the volume of the conversational audio transmitted to the speaker and conference participants.

In addition, the present invention can prevent sound from propagating beyond the desired range, which makes it more reliable to provide sound information such as background music or announcements within the range covered by the parabolic ceiling portion 17.

In addition, according to the present invention, sound is reliably transmitted only to the conference participants who are having a conversation within the area covered by the parabolic ceiling section 17, while guiding the speaker to suppress the volume of their conversation, thereby more reliably reducing the amount of conversation sound propagating to adjacent spaces. As a result, it is possible to more reliably achieve the effects of reducing the degree of decline in the work efficiency of other workers working in adjacent spaces, reducing the degree of interference with other conversations taking place in adjacent spaces, and reducing the feeling of noise throughout the workplace.

In addition, the present invention makes it possible to more reliably prevent the contents of a conversation from being leaked to those around when a highly confidential conversation is taking place in a meeting space.

Reference Signs List 1: Conference support system 10: Ceiling 15: General ceiling section 17: Parabolic ceiling section 20: Floor surface 25: Desk 27: Microphone stand 30: Microphone 40: Audio processing section 41: Adjustment section 42: High-pass filter 43: Low-pass filter 44: Variable gain amplifier 45: Opening/closing switch 50: Amplifier 60: Speaker 61: Housing 62: Magnet coil section 65: Cone section 67: Tweeter 70: Sound insulation board 80: Cover body 90: Sound absorbing material R: Reflector

Claims (3)

A conference support system that collects audio from conference participants, plays the collected audio through a speaker, and outputs the audio to the conference participants to support the conference,
A microphone that converts an input voice signal into an electrical signal;
a filter that passes only an electrical signal corresponding to a component having a predetermined frequency or higher among the electrical signals converted by the microphone;
an amplifier that amplifies the electrical signal that has passed through the filter;
a speaker that reproduces the electrical signal amplified by the amplifier;
A parabolic surface formed on a part of a ceiling that reflects the sound reproduced by the speaker ;
the predetermined frequency of the component corresponding to the electrical signal to be passed by the filter is 1 kHz or more;
A conference support system comprising : a soundproofing panel that is flush with a horizontal plane that includes the top end of a structure including the housing of the speaker . A conference support system that collects audio from conference participants, plays the collected audio through a speaker, and outputs the audio to the conference participants to support the conference,
A microphone that converts an input audio signal into an electrical signal;
an amplifier for amplifying the electrical signal converted by the microphone;
a tweeter that reproduces only an electrical signal corresponding to a component having a predetermined frequency or higher among the electrical signals amplified by the amplifier;
A parabolic surface formed on a part of a ceiling that reflects the sound reproduced by the tweeter ;
the predetermined frequency of the component corresponding to the electrical signal reproduced by the tweeter is 1 kHz or more;
A conference support system comprising : a soundproofing panel that is flush with a horizontal plane that includes the top end of a structure including the housing of the speaker . A conference support system that collects audio from conference participants, plays the collected audio through a speaker, and outputs the audio to the conference participants to support the conference,
A microphone that converts an input audio signal into an electrical signal;
a filter that passes only an electrical signal corresponding to a component having a predetermined frequency or higher among the electrical signals converted by the microphone;
an amplifier that amplifies the electrical signal that has passed through the filter;
a tweeter that reproduces only an electrical signal corresponding to a component having a predetermined frequency or higher among the electrical signals amplified by the amplifier;
A parabolic surface formed on a part of a ceiling that reflects the sound reproduced by the tweeter ;
the predetermined frequency of the component corresponding to the electrical signal to be passed by the filter is 1 kHz or more;
the predetermined frequency of the component corresponding to the electrical signal reproduced by the tweeter is 1 kHz or more;
A conference support system comprising : a soundproofing panel that is flush with a horizontal plane that includes the top end of a structure including the housing of the speaker .

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