JP3932928B2 - Loudspeaker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a loudspeaker and a room loudspeaker system for loudening voices and musical sounds.
[0002]
[Prior art]
FIG. 21 is a diagram showing a configuration of a conventional indoor loudspeaker system used in a room space such as a conference room. FIG. 22 is a block diagram showing an electrical configuration of a conventional indoor loudspeaker system. As shown in FIG. 21, a proximity microphone M is installed in the vicinity of each speaker S. Each microphone M picks up the voice of a nearby speaker S. Further, as shown in FIG. 22, each microphone M outputs an electrical signal corresponding to the collected sound to the mixing console MC. The mixing console MC synthesizes the electrical signals output from the microphones M and outputs the synthesized signals to the power amplifier PA.
[0003]
More specifically, the mixing console MC is provided with an amplifier AMP and a switch SW for each microphone M. The amplifier AMP can be set by the operator of the mixing console MC, amplifies the electric signal output from the microphone M according to the gain setting value, and outputs the amplified signal to the switch SW. The switch SW can be turned on / off by the operator. When the switch SW is on, the switch SW outputs the electrical signal output from the amplifier AMP to the mixer MX. The mixer MX combines the electrical signals received from the amplifier AMP that is turned on, and outputs the combined electrical signal to the power amplifier PA. A speakerphone SP is connected to the power amplifier PA. The power amplifier PA amplifies the electrical signal received from the mixer MX and outputs it to the corresponding speakerphone SP. The speakerphone SP is installed at one corner of the conference room, and emits sound corresponding to the received electrical signal into the conference room. The volume of sound emitted from the speakerphone SP is increased according to the amplitude of the input electric signal.
[0004]
In such a configuration, the operator of the mixing console MC sets the gain of the amplifier AMP and adjusts the volume of the sound emitted from the speakerphone SP. Further, the operator turns on / off the switch SW for each speaker S, and sets the gain of the amplifier AMP corresponding to the microphone M of the speaker S to be amplified, so that the utterance sound of the speaker S Is amplified and emitted from the speakerphone SP into the conference room.
[0005]
[Problems to be solved by the invention]
As described above, in the conventional indoor loudspeaker system, it is necessary for the operator to turn on / off the switch SW provided in the mixing console MC and adjust the gain setting of the amplifier AMP. If the gain setting of the amplifier AMP by the operator is not appropriate, the loud sound emitted from the speakerphone SP is picked up again by the microphone M, and returned to the microphone 3, the mixing console MC, and the speakerphone SP. If a loop is formed and the gain of any one of the amplifiers AMP is excessively increased, there is a problem that the intelligibility is reduced due to howling or echo (reverberation extension).
[0006]
The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a loudspeaker and an indoor loudspeaker system that can prevent howling.
[0007]
  In order to achieve the above object, the present invention provides a sound collecting means provided in a room space for outputting an electric signal corresponding to the collected sound, and provided in the room space, in accordance with the electric signal. A sound emitting means for emitting sound, and a plate material for reflecting the sound, sandwiched between the sound collecting means and the sound emitting means,Provided at a position separating a sound collection space area by the sound collection means and a sound emission space area by the sound emission means.There is provided a loudspeaker comprising a plate material.
  In the structure of this loudspeaker, the sound collection means outputs an electrical signal corresponding to the collected sound. The sound emitting means emits sound according to the electrical signal output from the sound collecting means. Here, a plate material is provided so as to be sandwiched between the sound collecting means and the sound emitting means. That is, of the sound from the sound emitting means, most of the sound toward the sound collecting means is reflected by the plate material. As a result, of the sound from the sound emitting means, the sound that returns to the sound collecting means is minimized, and howling is prevented.
[0008]
  It is desirable that the plate material has a concave shape and is supported with the upper surface on the concave surface side and the convex surface side on the lower surface. Further, the sound collecting means is provided on either the lower surface or the upper surface of the plate material, and the sound emitting means is a surface different from the surface on which the sound collecting means is provided. It is desirable to be provided. Further, either the sound collecting means or the sound emitting means is provided on the lower surface of the plate material, and the sound collected by the sound collecting means is below the sound collecting means or the sound emitting means, or It is desirable that a plate for guiding the sound emitted by the sound emitting means is provided.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
<First Embodiment>
FIG. 1 is a diagram showing an aspect of use of the loudspeaker according to the first embodiment of the present invention. Moreover, FIG. 2 is sectional drawing which shows schematic structure of a loudspeaker. As shown in FIG. 1, the loudspeaker 1 is arranged on a table such as a round table arranged in a room space such as a conference room. The loudspeaker 1 includes a parabolic reflector 20. The surface of the reflecting plate 20 is covered with a sound reflective material such as a decorative copper plate, and the reflectance of sound on the surface is increased. The reflector 20 is supported on the table by the three legs 40 in a posture in which the concave side is the upper surface and the swollen side is the lower surface. Here, the three legs 40 are lifted from below from the lower surface of the reflecting plate 20 so that the positions become three vertices when an equilateral triangle is drawn around the lowermost part.
[0011]
A microphone 30 is provided at the bottom of the lower surface of the reflecting plate 20. More specifically, as shown in FIG. 2, the microphone 30 includes a microphone element 300. The microphone element 300 has a non-directional sound collection characteristic. The microphone element 300 is covered and protected by a dome-shaped microphone cover 302 made of metal or the like.
[0012]
On the other hand, a speaker unit 10 is provided at the center of the upper surface of the reflection plate 20. As shown in FIG. 2, the speaker unit 10 includes a speakerphone 104. The speakerphone 104 has a unidirectional sound emission directivity, and is fixed to the reflection plate 20 by a fixing leg 106 so that the directivity direction is upward (indicated by an arrow A in the drawing). ing. The speakerphone 104 is covered with a dome-shaped speaker net 102 made of metal or the like. The edge of the speaker net 102 is attached to the reflection plate 20 via a vibration isolating rubber 108. The anti-vibration rubber 108 absorbs vibration of the speaker net 102 caused by sound emission from the speakerphone 104 and prevents the reflector 20 from vibrating. Thereby, the noise generated by the vibration of the reflecting plate 20 is not picked up by the microphone element 300.
[0013]
As shown in FIG. 2, a signal processing unit 50 is provided below the speakerphone 104. The speakerphone 104 and the signal processing unit 50 and the signal processing unit 50 and the microphone element 300 are connected to each other by a signal cable (not shown) such as a coaxial cable.
FIG. 3 is a block diagram showing the electrical configuration of the signal processing unit 50 together with the microphone element 300 and the speakerphone 104.
As shown in the figure, the microphone element 300 generates an electrical signal according to the collected sound and outputs it to the signal processing unit 50 as a collected sound signal. The signal processing unit 50 includes an amplifier 502, which amplifies the collected sound signal output from the microphone element 300 and outputs the amplified sound signal to the delay circuit 504. The delay circuit 504 delays the received sound collection signal by the time τe, and then outputs it to the equalizer 506. This time τe will be described in detail later.
[0014]
The equalizer 506 performs frequency resolution on the collected sound signal received from the delay circuit 504 and adjusts the gain in the frequency domain in order to bring the tone of the sound emitted from the speakerphone 104 closer to the tone of the raw sound (voiced sound). Output to the power amplifier 508. The power amplifier 508 amplifies the received sound collection signal and outputs it to the speakerphone 104. The speakerphone 104 emits a sound corresponding to the received sound collection signal.
[0015]
The echo canceller 520 prevents acoustic echo generated when the loud sound emitted from the speakerphone 104 returns to the microphone element 300. More specifically, the echo canceller 520 includes an adaptive filter 522 and a subtracter 524. In this adaptive filter 522, adaptive control of the filter coefficient is performed so that the impulse response characteristic is the reverse characteristic of the impulse response characteristic of the acoustic transmission system from the speakerphone 104 to the microphone element 300. Under this adaptive control, if no measures are taken, an electrical signal corresponding to an acoustic echo component that will reach the microphone element 300 from the speakerphone 104 is generated by the adaptive filter 522, and this electrical signal is generated by the subtractor 524. Subtracted from the output signal of the amplifier 502. This operation prevents the generation of acoustic echo.
[0016]
As shown in FIG. 1, many speakers S are seated around the loudspeaker 1. When the speaker S utters, as shown by an arrow B in FIG. 2, the uttered sound of the speaker S travels through the gap between the reflector 20 and the table while being guided by the reflector 20 and the table, and reaches the microphone 30. Sound is picked up by the element 300. The microphone element 300 outputs a collected sound signal corresponding to the collected sound to the signal processing unit 50.
[0017]
In the signal processing unit 50, the collected sound signal is subtracted from the collected sound signal by the echo canceller 520, and the electrical signal corresponding to the acoustic echo is output to the delay circuit 504. Next, the collected sound signal is given a time delay of time τ by the delay circuit 504 and is output to the equalizer 506. Next, the sound collection signal is output to the power amplifier 508 after the gain of the frequency component is adjusted by the equalizer 506. The collected sound signal is amplified by the power amplifier 508 and then output to the speakerphone 104. As a result, the loud sound of the speaker S is emitted from the speakerphone 104. As described above, the speakerphone 104 emits a loud sound toward the direction indicated by the arrow A in FIG. The emitted loud sound is reflected on the ceiling, and this reflected sound reaches the listener (speaker).
[0018]
Further, in this loudspeaker 1, since the reflecting plate 20 is provided between the speakerphone 104 and the microphone element 300, the reflected sound reflected on the ceiling can reach directly from above the microphone element 300. Absent. Therefore, the sound that reaches the microphone element 300 in the loud sound is multiple reflected by the ceiling, floor, side wall, etc., and then guided by the reflector 20 and the table and reaches the microphone element 300 from the direction indicated by arrow B in the figure. Only things. In general, when a sound is reflected by a wall surface or the like, the sound pressure level decreases. Therefore, the sound pressure level of the sound that reaches the microphone element 300 by multiple reflection among the loud sounds becomes sufficiently small.
[0019]
Thus, in the loudspeaker 1, the sound emitting space region of the speakerphone 104 and the sound collection space region of the microphone element 300 are separated by the reflector 20, and the loudspeaker sound from the speakerphone 104 is The microphone element 300 is not reached while the sound pressure level is maintained. As a result, even if the amplification gain of the amplifier 502 or the power amplifier 508 is increased and the sound pressure level of the loud sound is increased, the sound pressure level of the loud sound that reaches the microphone element 300 becomes sufficiently small, and howling occurs. There is nothing to do.
[0020]
In the loudspeaker 1, the reverberation time extension caused by the loud sound emitted from the speakerphone 104 returning to the microphone 30 is suppressed. Hereinafter, this point will be described.
FIG. 4 is a diagram showing the relationship between the time when the utterance sound of the speaker S reaches the listener and the sound pressure level of the utterance sound reaching the listener. FIG. 5 is a diagram illustrating an example of the relationship between the time when the loud sound from the speakerphone 104 reaches the listener and the sound pressure level of the loud sound that reaches the listener.
[0021]
As shown in FIG. 4, in the place where the listener is present, after the utterance sound V of the speaker S arrives, the reverberation sound R attenuated according to the reverberation attenuation characteristic p in the room space arrives. Further, when the sound of the utterance V of the speaker S is amplified using various devices, the loud sound L emitted from the speaker 1 is more than the utterance V of the speaker S as shown in FIG. The sound is emitted from the speakerphone 104 with a delay of time τ and reaches the listener. Thereafter, the reverberant sound of the loud sound L reaches the listener.
In general, when the loud sound L from the speaker returns to the microphone element, the sound pressure level of the reverberation sound R increases by the amount of the returned sound, so that the sound pressure level as in the reverberation attenuation characteristic q shown in FIG. The decay rate of the signal becomes gradual and the reverberation time is extended. Thereby, since reverberation time becomes long, the clarity of the loud sound that the listener listens to deteriorates.
[0022]
On the other hand, according to the loudspeaker 1 of the present embodiment, since the sound pressure level of the loud sound that returns to the microphone element 300 is sufficiently small, an increase in the sound pressure level of the reverberant sound R can be suppressed. As shown in FIG. 5, “′ has substantially the same characteristic as the reverberation attenuation characteristic p in the room space. Therefore, since the reverberation time is not extended, the clarity of the loud sound that the listener listens to does not deteriorate.
[0023]
In the present embodiment, as described above, the collected sound signal output from the microphone element 300 is given the electrical delay τe by the delay circuit 504, and the spatial path through which the uttered sound reaches the listener And the delay time τs due to the difference in the spatial path from the speakerphone 104 to the listener, the time when the loud sound from the speakerphone 104 reaches the listener is higher than the time when the utterance sound of the speaker S reaches the listener It is delayed about time τ (= τe + τs). Due to this delay of time τ, even if the direction of arrival of the loud sound is different from the direction of arrival of the direct sound, the listener feels as if the loud sound has come from the direct sound arrival direction ( Haas effect (preceding sound effect)). Therefore, in the loudspeaker 1, the sound image localization is maintained at the position of the speaker S even if the sound pressure level of the loud sound is increased due to the Haas effect. Feels as if he is speaking at the sound pressure level of loud sound.
[0024]
Here, it is desirable that the above-mentioned time τ is set to a value from about 10 ms to about 50 ms. More specifically, as shown in FIG. 6, if the time τ is set to a value smaller than 10 ms, the listener feels uncomfortable with the tone of the voice of the speaker S that has been heard. This is due to a so-called color change due to frequency interference between the loud sound and the voice sound. Further, when the time τ is set to a value larger than 50 ms, so-called double (echo) in which the loud sound and the uttered sound are heard separated in time becomes prominent for the listener, and the above-mentioned Haas effect Cannot be obtained, and it becomes difficult to hear the voice of the speaker S. That is, the time τ is set to a value in which the hearth effect is obtained for the listener in a time range in which no echo occurs for the listener. Here, the electrical delay time τe is set to be approximately 10 ms <τe + τs <50 ms depending on the positional relationship between the speaker, the listener, and the speakerphone 104.
[0025]
As described above, according to the first embodiment, the reflecting plate 20 is provided between the speakerphone 104 and the microphone element 300, so that the loud sound from the speakerphone 104 maintains its sound pressure level. Since no feedback is made to the microphone element 300, the occurrence of howling is prevented, and the extension of the reverberation time is suppressed.
[0026]
Furthermore, due to the difference between the delay circuit 504 provided in the signal processing unit 50 and the spatial path, the sound collection signal output from the microphone element 300 is given a time delay that can give a hearth effect to the listener. As a result, the sound image localization is maintained at the position of the speaker S, and there is no difference between the direction in which the speaker S is present and the direction in which the voice (loud sound) of the speaker S arrives in a place where the listener is present. The listener can feel as if this speaker S is speaking loudly.
In addition, since the echo canceller 520 is provided in the signal processing unit 50, even if the loud sound from the speakerphone 104 is somewhat returned to the microphone element 300, the feedback can be removed from the collected sound signal.
[0027]
Second Embodiment
In the first embodiment described above, in the loudspeaker 1, the microphone and the speaker are integrated. In this embodiment, an indoor loudspeaker system in which a microphone and a speaker are separated will be described.
[0028]
FIG. 7 is a top view showing the configuration of the indoor loudspeaker system according to the second embodiment of the present invention, and FIG. 8 is a side view showing the configuration of the indoor loudspeaker system. As shown in FIGS. 7 and 8, the indoor loudspeaker system includes a speaker device 10 a, a microphone 30, and a signal processing unit 50.
[0029]
The speaker device 10a is disposed at each of the four corners of the room space. FIG. 9 is a schematic diagram showing the configuration of the speaker device 10a. As shown in the figure, a linear sound source speakerphone 104a formed by cascading sound sources 1040 such as a small-diameter cone type speakerphone is provided inside the speaker device 10a. The speaker device 10a includes a stand 108a extending coaxially with the column axis of the sound source 1040, and the stand 108a supports the speaker device 10a so that the column direction of the sound source 1040 is a vertical direction.
[0030]
In this configuration, the speaker device 10a forms a service zone S as shown in FIG. Specifically, the speaker device 10a emits sound in the horizontal direction, and the sound pressure level of the loud sound in the space above and below the speaker device 10a is sufficiently smaller than the sound pressure level of the loud sound in the service zone S. It is supposed to be. That is, as shown in FIG. 10, the service zone S has a length approximately the same as the vertical length T of the linear sound source speakerphone 104a in the vertical plane, and is substantially omnidirectional in the horizontal plane. Or bi-directional. Therefore, when the speaker device 10a is disposed at a corner of the room, the radiation angle θ in the horizontal plane of the service zone S is approximately 90 degrees. The speaker device 10a is preferably provided at such a height that the service zone S is formed at the height of the listener's ear.
[0031]
As shown in FIG. 8, the microphone 30 includes a microphone element 300a having a unidirectional sound collection characteristic. The microphone 30 is suspended from the ceiling of the room space. Here, the microphone element 300a of the microphone 30 is disposed at a height that does not enter the service zone S formed by each speaker device 10a and whose directing direction is a vertically downward direction.
The signal processing unit 50 is the same as that described in the first embodiment, performs various signal processing on the collected sound signal output from the microphone element 300a, and outputs the processed signal to the linear sound source speakerphone 104a.
[0032]
In the indoor loudspeaker system configured as described above, the uttered sound from the speaker S is collected by the microphone element 300a suspended from the ceiling. The microphone element 300 a generates a sound collection signal corresponding to the collected sound and outputs it to the signal processing unit 50. After the acoustic echo component is removed from the collected sound signal by the echo canceller 520 included in the signal processing unit 50, the delay signal 504 is given a time delay that can give a hearth effect to the listener. The collected sound signal to which the time delay is applied is subjected to gain adjustment in the frequency domain by the equalizer 506, amplified by the power amplifier 508, and output to the line sound source speakerphone 104a of each speaker device 10a. Thereby, a loud sound is emitted in the service zone S of each speaker apparatus 10a.
[0033]
As described above, the microphone element 300a is installed outside the service zone S formed by each speaker device 10a, and the sound pressure level of the loud sound at the installation location of the microphone element 300a is reduced, so that howling is prevented. The
Further, the delay circuit 504 provided in the signal processing unit 50 gives a time delay capable of giving a hearth effect to the listener to the collected sound signal output from the microphone element 300a. Thereby, the sound image localization is maintained at the position of the speaker S.
In addition, since the echo canceller 520 is provided in the signal processing unit 50, even if the loud sound from the line sound source speakerphone 104a is slightly returned to the microphone element 300a, the feedback can be removed from the collected sound signal. .
[0034]
As described above, according to the second embodiment, howling is prevented and the sound image localization can be maintained at the position of the speaker S. Furthermore, since the speaker device 10a and the microphone 30 can be individually arranged, it is easy for the listener to hear the voice of the speaker S depending on the shape of the room space, the arrangement of the listeners (speakers), and the like. The speaker device 10a and the microphone 30 can be arranged in the room space.
[0035]
<Modification of each embodiment>
Each embodiment mentioned above is an illustration to the last, shows one mode of the present invention, and can be changed arbitrarily within the scope of the present invention. Therefore, various modifications will be described below.
[0036]
<Modification 1>
In the first embodiment described above, the loudspeaker 1 is arranged on a table such as a round table, and the utterance sound of the speaker S is guided by the reflector 20 and the table and reaches the microphone 30, but in a room space where there is no table. In order to use the present invention, the first embodiment may be modified as shown in FIG. In other words, the first embodiment may be modified such that a plate 70 is provided below the reflecting plate 20 and the plate 70 is supported by the stand 80.
[0037]
<Modification 2>
In the first embodiment described above, the microphone 30 is provided at the bottom of the bottom surface of the parabolic reflector 20, and the speaker unit 10 is provided at the center of the top surface of the reflector 20. However, the microphone 30 and the speaker unit 10 may be provided so that the sound collection space region of the microphone 30 and the sound emission space region of the speaker unit 10 are separated by the reflection plate 20. For example, the microphone 30 may be provided at the center of the upper surface of the reflecting plate 20, and the speaker unit 10 may be provided at the bottom of the lower surface of the reflecting plate 20.
[0038]
FIG. 12 is a cross-sectional view showing the configuration of the loudspeaker according to this modification. As shown in the figure, the microphone 30 includes a microphone element 300, and the microphone element 300 is attached and fixed to the reflecting plate 20 by legs 304. A signal processing unit 50 is provided below the microphone element 300. The microphone element 300, the signal processing unit 50, and the legs 304 are covered and protected by a dome-shaped microphone cover 302.
On the other hand, the speaker unit 10 is provided with a linear sound source speakerphone 104a to emit a loud sound in the horizontal direction of the drawing, and the loud sound is emitted from the speaker unit 10 in a direction indicated by an arrow A in the figure. The
[0039]
In this configuration, the sound collection space region of the microphone 30 is formed above the reflection plate 20, while the sound emission space region of the speaker unit 10 is formed below the reflection plate 20. Accordingly, the loud sound from the speaker unit 10 is prevented from returning to the microphone 30. Thereby, howling is prevented.
[0040]
<Modification 3>
In the second embodiment described above, the microphone 30 is provided on the ceiling. However, if the microphone element 300a of the microphone 30 is installed outside the service zone S of the speaker device 10a, the microphone 30 can be installed at an arbitrary location in the room space.
(1) For example, as shown in FIGS. 13 and 14, the second embodiment may be modified such that the microphone 30 is positioned above the speaker device 10a. Specifically, a bar member 310 extending in the vertical direction is provided on the upper portion of the speaker device 10a, and the microphone 30 is provided on the upper end of the bar member 310. A microphone element (not shown) included in the microphone 30 has a single directivity, and the microphone element is provided in the microphone 30 so that the directivity direction is obliquely downward.
In this configuration, as indicated by an arrow A in FIG. 14, the loud sound from the speaker device 10 a is emitted in the horizontal direction, so that the loud sound is prevented from returning to the microphone 30.
[0041]
(2) Further, as shown in FIGS. 15 and 16, the second embodiment is modified so that the speaker device 10b is arranged on the ceiling of the room space and the microphones 30b are arranged at the four corners of the room space. May be.
More specifically, each microphone 30b includes a constant directional microphone element, and collects a sound (indicated by an arrow B in FIGS. 15 and 16) that travels parallel to the floor.
On the other hand, the speaker device 10b includes a unidirectional speakerphone and is provided on the ceiling in a posture in which the directivity direction is vertically downward.
In this configuration, the loud sound from the speaker device 10b is emitted from the ceiling toward the floor (indicated by an arrow A in FIG. 16), and this loud sound is not returned to the microphone 30b.
[0042]
(3) Further, as shown in FIG. 17, the second embodiment may be modified so that the speaker device 10a is arranged on a table. In this configuration, since the loud sound is emitted from the speaker device 10a in the horizontal direction, the loud sound is prevented from returning to the microphone 30b.
As shown in FIG. 18, the speaker device 10a is arranged on a table, and the microphone 30b is attached and fixed to the upper end of the speaker device 10a via a bar member 310 for keeping a distance from the upper end. Of course, it may be.
[0043]
<Modification 4>
In the second embodiment described above, the microphone element 300a of the microphone 30 is installed outside the service zone S of the speaker device 10a. Therefore, in this modification, the microphone element 300a is installed in the service zone S of the speaker device 10a.
FIG. 19 is a side view showing the configuration of the indoor loudspeaker system according to this modification. As shown in the figure, a parabolic reflector 20 is disposed on the table, and a microphone 30 is provided at the bottom of the lower surface of the reflector 20. The reflector 20 and the microphone 30 are the same as those described in the first embodiment. A speaker device 10 a is provided on the ceiling located above the reflecting plate 20. The speaker device 10a includes a unidirectional speakerphone inside, and this directivity direction is vertically downward.
[0044]
In this configuration, the microphone 30 collects the utterance sound of the speaker S that has arrived from the horizontal direction (indicated by the arrow B in the figure). On the other hand, the speaker device 10a emits a loud sound in a vertical direction (indicated by an arrow A in the figure). Since this loud sound is reflected toward the ceiling by the reflecting plate 20, the loud sound is prevented from returning to the microphone 30 provided at the bottom of the reflecting plate 20. As shown in FIG. 20, a microphone 30 that picks up sound coming from a vertically downward direction is provided on the ceiling, while the bottom surface of the reflector plate 20 has a horizontal direction (indicated by an arrow A in the figure). A speaker device 10a that emits sound may be provided.
[0045]
<Modification 5>
In 1st and 2nd embodiment mentioned above, although illustrated about the case where the shape of the reflecting plate 20 was a parabolic shape, it is not restricted to this. That is, the shape of the reflecting plate 20 may be a concave shape, and may be, for example, a hyperbolic shape or an exponential curve shape.
[0046]
<Modification 6>
In the first and second embodiments described above, the case where the loudspeaker and the indoor loudspeaker system of the present invention amplify a person's voice is not limited thereto. That is, according to the loudspeaker and the indoor loudspeaker system of the present invention, the extension of reverberation time due to loudspeaking is suppressed, and further, since the sound image localization is kept directly at the sound source, it is preferable that there is no reverberation in chamber music or piano. The present invention may be used when a musical tone such as the above is amplified.
[0047]
【The invention's effect】
As described above, according to the present invention, there is provided a loudspeaker and an indoor loudspeaker system that can prevent a reduction in intelligibility due to howling or echo.
[0048]
[Brief description of the drawings]
FIG. 1 is a diagram showing a mode of use of a loudspeaker according to a first embodiment of the present invention.
FIG. 2 is a sectional view showing a schematic configuration of the loudspeaker.
FIG. 3 is a block diagram showing an electrical configuration of the signal processing unit together with a microphone element and a speakerphone.
FIG. 4 is a diagram showing the relationship between the time when the utterance sound of the speaker S reaches the listener and the sound pressure level of the utterance sound reaching the listener.
FIG. 5 is a diagram illustrating an example of a relationship between a time when a loud sound from a speakerphone reaches a listener and a sound pressure level of the loud sound that reaches the listener.
FIG. 6 is a diagram showing the relationship between the delay time τ and the acoustic effect.
FIG. 7 is a top view showing a configuration of an indoor loudspeaker system according to a second embodiment of the present invention.
FIG. 8 is a side view showing the configuration of the indoor loudspeaker system.
FIG. 9 is a schematic diagram showing a configuration of the speaker device 10a.
FIG. 10 is a conceptual diagram showing a service zone formed by the speaker device 10a.
FIG. 11 is a cross-sectional view showing a configuration of a loudspeaker according to a first modification of the first embodiment.
FIG. 12 is a side view showing the configuration of a loudspeaker according to a second modification of the first embodiment.
FIG. 13 is a top view showing a configuration of an indoor loudspeaker system according to a third modification of the second embodiment.
FIG. 14 is a side view showing the configuration of the indoor loudspeaker system.
FIG. 15 is a top view showing a configuration of an indoor loudspeaker system according to the other modified example.
FIG. 16 is a side view showing the configuration of the indoor loudspeaker system.
FIG. 17 is a side view showing a configuration of an indoor loudspeaker system according to the other modified example.
FIG. 18 is a side view showing the configuration of an indoor loudspeaker system according to the other modification.
FIG. 19 is a side view showing a configuration of an indoor loudspeaker system according to a fourth modification of the second embodiment.
FIG. 20 is a side view showing a configuration of an indoor loudspeaker system according to the other modified example.
FIG. 21 is a diagram showing a configuration of a conventional indoor loudspeaker system.
FIG. 22 is a block diagram showing an electrical configuration of a conventional indoor loudspeaker system.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Loudspeaker, 10 ... Speaker part, 10a, 10b ... Speaker device, 20 ... Reflector, 30 ... Microphone, 40 ... Leg, 50 ... Signal processing unit, 104 ... Speakerphone, 104a ... Line sound source speakerphone, 300, 300a: microphone element, 504: delay circuit, 520: echo canceller.

Claims (4)

Sound collection means provided in the room space for outputting an electrical signal corresponding to the collected sound;
A sound emitting means provided in the room space for emitting sound according to the electrical signal;
A plate material that reflects sound, is sandwiched between the sound collecting means and the sound emitting means, and is provided at a position that separates a sound collecting space area by the sound collecting means and a sound emitting space area by the sound emitting means. A loudspeaker comprising: a plate member. The plate material has a concave shape, and is supported with the concave surface side as an upper surface and the convex surface side as a lower surface.
The loudspeaker according to claim 1. The sound collecting means is provided on either the lower surface or the upper surface of the plate material,
The sound emitting means is provided on the upper surface or the lower surface of the plate member, which is a surface different from the surface on which the sound collecting means is provided.
The loudspeaker according to claim 1 or 2. On the lower surface of the plate material, either the sound collecting means or the sound emitting means is provided,
Below the sound collecting means or the sound emitting means provided on the lower surface of the plate material, a plate for guiding the sound collected by the sound collecting means or the sound emitted by the sound emitting means is provided. ing
The loudspeaker according to any one of claims 1 to 3.

Images