Partition system with speaker

Abstract

To provide a sound emitting device equipped with a directional speaker that reduces bass components that tend to wrap around in directions other than desired one and prevents sound leakage better than before.SOLUTION: In a sound emitting device, a partition 10 with a speaker comprises: a plurality of wall surfaces having a first wall surface and a second wall surface which, in plan view, constitute a partially open and partially shielded acoustically shielded portion; and a planar speaker 3 which is arranged on the first wall surface and has a sound emission direction toward the acoustically shielded portion. The planar speaker 3 comprises: a vibration unit 30; an enclosure 31 for the vibration unit; and a port 32 comprising a Helmholtz resonator. The enclosure is encased in the first wall.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] An embodiment of the present invention relates to a sound emitting device including a directional speaker. [Background technology]

[0002] Patent Document 1 discloses a speaker structure equipped with a bass reflex port as an example of a Helmholtz resonator. Patent Document 2 discloses a hands-free telephone system that uses a simple partition to improve confidentiality in environments such as call centers or offices. In the hands-free telephone system of Patent Document 2, a sound-absorbing panel is provided at a position spaced apart from the sound emission direction of a planar speaker. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-114934 A [Patent Document 2] JP 2010-091777 A Summary of the Invention [Problem to be solved by the invention]

[0004] The Helmholtz resonator in Patent Document 1 is a bass reflex port for enhancing low-frequency components. The sound emission direction of the planar speaker in Patent Document 2 is toward the outside from each space surrounded by the partition. [Means for solving the problem]

[0005] According to an embodiment of the present invention, a partition system with a speaker comprises a plurality of walls that form an acoustic shielding section that is partially open and partially shielded in a plan view, the walls having a first wall and a second wall, and a directional speaker that is arranged on the first wall and has a sound emission direction relative to the acoustic shielding section, the directional speaker comprising a speaker unit, an enclosure for the speaker unit, and an opening that forms a Helmholtz resonator, the enclosure being contained within the first wall. Effect of the Invention

[0006] According to the embodiment of the present invention, in a sound emitting device, low frequency components that tend to migrate in directions other than the intended direction can be reduced, and sound leakage can be prevented more effectively than in the past. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view showing a sound emitting device 1. [Diagram 2] FIG. 2 is a plan view of the sound emitting device 1. [Diagram 3] FIG. 2 is a front view of the sound emitting device 1. [Figure 4] FIG. 2 is a front view of the sound emitting device 1. [Diagram 5] 2 is a cross-sectional view showing the structure of a flat speaker 3. FIG. [Figure 6] 2 is a block diagram showing the configuration of a flat speaker 3. FIG. [Figure 7] 11 is a diagram showing the relationship between the resonance frequency Fr and the lowest reproducible frequency Fmin of the vibration unit 30. FIG. [Figure 8] FIG. 11 is a cross-sectional view showing an example in which a port 32 is provided on the front side. [Figure 9] 13 is a cross-sectional view of a case where a part of the partition 10 also serves as an enclosure. [Figure 10] 13 is a cross-sectional view of an enclosure 31 having a resonance tube 501 on the rear surface thereof. [Figure 11] 13 is a cross-sectional view showing a modified example of the resonance tube 501. FIG. [Figure 12]FIG. 1 is a front view of a sound emitting device 1A equipped with a plurality of flat speakers 3. [Figure 13] 1 is a perspective view showing the configuration of a sound emitting device 1B having a flat speaker 3 on the top surface. [Figure 14] 1 is a perspective view showing a configuration of a sound emitting device 1C including a display 5 and a microphone 7. FIG. [Figure 15] FIG. 2 is a front view of the sound emitting device 1C. [Figure 16] FIG. 1 is a front view of a sound emitting device 1C when a user is sitting and operating a personal computer (PC) 9. [Figure 17] FIG. 1 is a perspective view of a sound emitting device 1E equipped with casters 110 that are assistive devices for assisting movement. [Figure 18] FIG. 13 is a front view showing a configuration when a masking sound is output. [Figure 19] FIG. 1 is a front view of a sound emitting device 1F having flat speakers 3 on both sides, applied to a semi-private room. [Figure 20] FIG. 1 is a block diagram showing the configuration of a planar speaker 3 that performs signal processing based on a sound signal collected by a microphone (microphone 7 or a microphone of a PC 9). [Figure 21] FIG. 1 shows the results of sound pressure measurement in the 500 Hz frequency band (1 / 1 octave band). [Figure 22] FIG. 1 shows the results of sound pressure measurement in a 1 kHz frequency band (1 / 1 octave band). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Fig. 1 is a perspective view showing a sound emitting device 1 of this embodiment, Fig. 2 is a plan view, and Figs. 3 and 4 are front views.

[0009] The sound emitting device 1 includes a partition 10 and a planar speaker 3. The partition 10 is an example of a plate material for forming a wall surface that is an acoustic shielding portion of the present invention. The planar speaker 3 is an example of a directional speaker of the present invention.

[0010] Partition 10 is a component for defining a semi-private room. A semi-private room has an acoustically shielding portion that is partially acoustically open and partially acoustically shielded. The walls of partition 10 form the acoustic shielding portion of the semi-private room. The walls of partition 10 form acoustic shielding portions at three locations: the right side, left side, and back of the semi-private room. The front and top of the semi-private room are acoustically open.

[0011] In the examples of Figures 1, 2, and 3, the partition 10 is made up of three members. Of the three members, the two partitions 10 constituting the right and left sides of the semi-private room face each other. The remaining one of the three members is disposed at the rear of the semi-private room. However, the partition 10 does not have to be made up of three members. The partition 10 only needs to have parts that face each other. For example, the partition 10 may be a one-piece type. Furthermore, the wall surface of the partition 10 may be flat or curved.

[0012] The planar speaker 3 is disposed on the wall surface of the partition 10. The sound emission direction of the planar speaker 3 faces the part facing the wall surface on which the planar speaker 3 is installed. In other words, the sound emission direction of the planar speaker 3 faces the acoustic shielding part.

[0013] Furthermore, as shown in FIG. 3, the planar speaker 3 outputs sound to a predetermined range including the position of the user's head. For example, the planar speaker 3 outputs sound to a predetermined range at a predetermined height from the floor. As an example, the user stands and listens to the sound of the planar speaker 3 as shown in FIG. 3. When listening to the sound while sitting on a chair as shown in FIG. 4, the mounting position of the planar speaker 3 in the vertical direction relative to the wall surface may be lowered. Also, as shown in FIG. 2, the width of the planar speaker 3 in a plan view is approximately the same as the width (length in the longitudinal direction in a plan view) of the partition 10. Note that the width of the planar speaker 3 corresponds to the width A of the portion in which the vibration unit is arranged among the longitudinal length of the planar speaker 3 in a plan view. Therefore, the user can hear the sound output by the planar speaker 3 no matter where he is in the semi-private room. However, in the present invention, the width of the planar speaker 3 may be shorter than the width of the partition 10. Note that approximately the same does not mean completely the same, but includes being substantially the same. "Approximately the same" also includes a case where the width of the planar speaker 3 is slightly shorter than the width of the partition 10, as long as the effect of being able to hear the sound output by the planar speaker 3 from any position in the semi-private room is achieved.

[0014] The planar speaker 3 is connected to an information processing device (not shown), such as a personal computer. The planar speaker 3 receives an audio signal from the information processing device. The planar speaker 3 reproduces the audio signal and outputs sound. This allows the user to listen to the sound of content, for example. The information processing device may also be connected to an information processing device in a remote location, for example, via a network. The information processing device receives an audio signal from the remote location. This allows the user to listen to the voice of a user in a remote location connected via the network.

[0015] The planar speaker 3 is a thin, flat speaker. Compared to a normal cone speaker which outputs a spherical sound wave, the planar speaker 3 outputs a planar sound wave. The planar speaker 3 outputs a sound with strong directivity in the front direction (normal direction of the main surface) of the planar speaker 3. For example, when the planar speaker 3 is an electrostatic speaker, the minimum reproducible frequency Fmin is about 80 Hz to 250 Hz (the minimum reproducible frequency will be described later with reference to FIG. 7).

[0016] As a result, the sound output from the planar speaker 3 is contained within the semi-private room. The height of the partition 10 is sufficiently longer than the height of the planar speaker 3. Therefore, the sound output from the planar speaker 3 bends upward and downward and does not leak out of the semi-private room. In particular, downward sound is completely blocked by the floor.

[0017] The width of the planar speaker 3 in the left-right direction is approximately the same as the width of the partition 10. Therefore, the sound output from the planar speaker 3 is more likely to bend in the left-right width direction than in the up-down direction. However, as will be described later, the planar speaker 3 further reduces bending in the left-right direction due to the structure of the enclosure.

[0018] This allows the sound emitting device 1 to prevent sound from leaking from the semi-private room. People outside the semi-private room will not hear the sound output from the flat speaker 3. The user of the sound emitting device 1 can listen to the sound of the content or hear the conversation of users in remote locations without worrying about sound leakage. Also, people outside the semi-private room will not be bothered by the sound from the semi-private room.

[0019] Fig. 5 is a cross-sectional view showing the structure of the planar speaker 3. Fig. 6 is a block diagram showing the configuration of the planar speaker 3. The planar speaker 3 includes a vibration unit 30, an enclosure 31, a port 32, and a sound absorbing material 35. The planar speaker 3 also includes an input unit 301, a signal processing unit 302, an amplifier unit 303, and a driver unit 304 as a hardware configuration.

[0020] The input unit 301 includes an analog audio I / F, a digital audio I / F, or a communication I / F such as a USB. The input unit 301 receives a sound signal from an information processing device. The signal processing unit 302 performs signal processing on the sound signal received by the input unit 301. For example, the signal processing unit 302 controls the level or adjusts the frequency characteristics of the sound signal. When the input unit 301 receives an analog sound signal, the signal processing unit 302 converts the signal into a digital sound signal and then processes the signal. The signal processing unit 302 converts the sound signal after signal processing into an analog sound signal and outputs it to the amplification unit 303.

[0021] The amplifier 303 amplifies the sound signal after being signal-processed by the signal processor 302. The driver 304 drives the vibration unit 30 based on the sound signal amplified by the amplifier 303.

[0022] The vibration unit 30 is, for example, an electrostatic speaker unit. The vibration unit 30 has a structure in which a sheet-like vibration plate 30C is sandwiched between two fixed electrodes 30A and 30B. The driving unit 304 generates an electrostatic force by applying a voltage to the fixed electrodes 30A, 30B, and the vibration plate 30C. The driving unit 304 changes the electrostatic force by changing the voltage applied to the fixed electrodes 30A and 30B. The driving unit 304 vibrates the vibration plate 30C due to the change in electrostatic force. As a result, the planar speaker 3 outputs planar sound waves.

[0023] The enclosure 31 has an opening for disposing the vibration unit 30, and is a rectangular box shape having a height in the depth direction. Specifically, the enclosure 31 sandwiches the outer periphery of the vibration unit 30 with the opening on the front side. It is preferable that the enclosure 31 sandwiches the vibration unit 30 via a cushioning material such as rubber, a foaming agent, or a cotton-like material. The vibration unit 30 outputs sounds of opposite phases in the front direction (outward from the enclosure 31) and the rear direction (inward from the enclosure 31) of the enclosure 31. The enclosure 31 confines the sound output in the rear direction inside.

[0024] In the example of Fig. 5, the enclosure 31 includes a sound absorbing material 35 inside. The sound absorbing material 35 absorbs sounds output from the rear direction of the vibration unit 30 that are above a predetermined frequency band. As a result, the sound absorbing material 35 prevents vibration of the wall surface of the enclosure 31, reflected waves, and standing waves that are above the predetermined frequency band. Note that the sound absorbing material 35 is not an essential component of the present invention.

[0025] The enclosure 31 has an opening on the side surface for forming the port 32. The port 32 has an elongated shape in the vertical direction of the planar speaker 3. The port 32 forms a Helmholtz resonator with the plate thickness of the wall surface of the enclosure 31 as the length L in the tube axis direction.

[0026] The resonant frequency Fr of the Helmholtz resonator is given by the following formula (A): Fr=(c / 2π)·(S / VL), where V is the volume of the enclosure 31, c is the sound velocity, L is the length in the axial direction of the tube (the wall thickness of the enclosure 31), and S is the cross-sectional area of ​​the port 32. 1 / 2 The larger the cross-sectional area S of the port 32, the smaller the volume V of the enclosure 31, and the thinner the thickness L of the enclosure 31, the higher the resonance frequency Fr. The volume V of the enclosure 31 is expressed as V=Hw·d, where Hw is the area of ​​the face where the vibration unit 30 is located, and d is the depth of the enclosure 31 (the length in the left-right direction in FIG. 5). Furthermore, if A is the width of the face of the enclosure 31 where the vibration unit 30 is located (width A shown in FIGS. 2 and 5), and H is the height of the enclosure 31 (the length in the up-down direction when viewed from the front), the area Hw is expressed as Hw=A·H.

[0027] The resonant frequency Fr of the Helmholtz resonator of this embodiment is set to a high frequency, unlike a typical bass reflex port. Hereinafter, the point of setting the resonant frequency Fr to be equal to or higher than the minimum reproducible frequency Fmin of the vibration unit 30 will be described with reference to FIG.

[0028] 7 is a diagram showing the relationship between the resonance frequency Fr and the lowest reproducible frequency Fmin of the vibration unit 30. The horizontal axis of the graph represents frequency, and the vertical axis represents level.

[0029] The minimum reproducible frequency Fmin is, for example, a frequency that is −10 dB below the peak level. 2 (equivalent to A0 size), the frequency indicating -10 dB from the peak level is about 80 Hz. When the area of ​​the vibration unit 30 is equivalent to A4 size, the frequency indicating -10 dB from the peak level is about 250 Hz. Note that the reproducible lower limit frequency Fmin is not limited to the frequency indicating -10 dB from the peak level. For example, it may be a frequency indicating -6 dB from the peak level.

[0030] As shown in FIG. 7, the resonance frequency Fr and the lowest reproducible frequency Fmin have the relationship of formula (B): Fr≧Fmin. In a low frequency band below the resonance frequency Fr, the port 32 outputs the sound output toward the rear of the vibration unit 30 as is. The sound output toward the rear of the vibration unit 30 is in opposite phase to the sound output toward the front. Therefore, the port 32 outputs sound of opposite phase in a low frequency band below the resonance frequency Fr. As a result, among the sounds that wrap around from the front of the vibration unit 30 to the sides, sounds of the lowest reproducible frequency Fmin to the resonance frequency Fr are canceled by the opposite phase sound output from the port 32. In addition, sounds of frequencies below the lowest reproducible frequency Fmin are not output at an effective level.

[0031] As a result, even if sound output in the front direction of the vibration unit 30 goes around to the side, it is cancelled by the opposite phase sound from the port 32. Therefore, the sound emitting device 1 can prevent sound leakage.

[0032] The higher the resonant frequency Fr is set, the higher the frequency of the sound that wraps around the sides can be canceled, so it is preferable to set the resonant frequency Fr as high as possible within the structurally possible range. It is preferable to use a material that is thin and has high sound insulation for the enclosure 31. For example, it is preferable to use a metal material that has a high surface density relative to its thickness and is highly rigid for the enclosure 31.

[0033] However, among the sounds output in the direction of the rear of the vibration unit 30, sounds in the high frequency band are absorbed by the sound absorbing material 35. Therefore, when the enclosure 31 is filled with the sound absorbing material 35, it is preferable to set the relationship between the resonance frequency Fr and the effective lower limit frequency of the sound absorbing material 35 so that the effective lower limit frequency of the sound absorbing material 35 or less is reduced by the resonance frequency Fr to the lowest reproducible frequency Fmin. This allows the sound emitting device 1 to deal with sound leakage in a wide frequency band. For example, in the case of urethane foam with an effective lower limit frequency of 1.5 kHz, it is preferable to set the resonance frequency Fr to about 1.5 kHz, and in the case of glass wool with an effective lower limit frequency of 500 Hz, it is preferable to set the resonance frequency Fr to about 500 Hz. The effective lower limit frequency is determined by the thickness (length in the front-rear direction) of the sound absorbing material including the back air layer. The frequency corresponding to four times the length of the thickness of the sound absorbing material corresponds to the effective lower limit frequency. In other words, the thickness of the sound absorbing material corresponds to 0.25 times the wavelength of the sound wave to be absorbed.

[0034] It is preferable that the width A of the enclosure 31 shown in FIG. 2 and FIG. 5 has a certain length with respect to the wavelength of the sound wave corresponding to the resonance frequency Fr so that the sound wave output in the front direction of the vibration unit 30 is unlikely to wrap around to the rear direction. The rear of the enclosure 31 vibrates due to the sound output in the rear direction of the vibration unit 30. However, the sound below the resonance frequency Fr is output as it is from the port 32, so the sound pressure inside the enclosure 31 does not increase. Therefore, the sound below the resonance frequency Fr is unlikely to vibrate the rear. Therefore, it is preferable that the width A of the rear of the enclosure 31 has a certain length with respect to the wavelength λ of the sound wave corresponding to the resonance frequency Fr. Theoretically, in order for the sound wave output in the front direction of the vibration unit 30 to not wrap around to the rear side, the path difference due to the sound wave bypassing the enclosure 31 should be 0.5λ or more. Therefore, when the enclosure 31 itself is a sound insulation wall, it is preferable to at least satisfy the formula (C): A≧0.25λ in order to prevent the sound output in the front direction of the vibration unit 30 from wrapping around. Moreover, it is more preferable that the width A and the resonance frequency Fr satisfy the relationship of the mathematical formula (D)A≧0.5λ.

[0035] Figures 21 and 22 are diagrams showing the results of sound pressure measurement. The sound pressure measurement results shown in Figures 21 and 22 show sound pressure values ​​(relative values) at 30° intervals, with the sound pressure value at 0° in the front direction being the reference (0 dB) when the front direction of the planar speaker 3 is 0° and the rear direction is 180°.

[0036] The width A of the enclosure 31 at the time of measurement in Figures 21 and 22 is 230 mm. Figure 21 shows the measurement results in a sound wave frequency band of about 500 Hz (1 / 1 octave band) (wavelength band of about 680 mm), and Figure 22 shows the measurement results in a sound wave frequency band of about 1 kHz (1 / 1 octave band) (wavelength band of about 340 mm). The solid lines shown in Figures 21 and 22 show the measurement results when the enclosure 31 is equipped with the port 32. The dashed lines show the measurement results when the enclosure 31 is not equipped with the port 32 as a reference example.

[0037] In the example of Fig. 21, the width A of the enclosure 31 is 230 mm for a wavelength λ = 680 mm. In other words, the relationship A ≥ 0.5 λ is not satisfied. In this case, the sound pressure value in the rear direction does not change regardless of the presence or absence of the port 32 of the enclosure 31, since the influence of the sound waves that bend from the front side to the rear side is large. In other words, if the relationship A ≥ 0.5 λ is not satisfied, the effect of the port 32 in suppressing the sound waves in the rear direction cannot be achieved.

[0038] In contrast, in the example of Fig. 22, the width A of the enclosure 31 is 230 mm for a wavelength λ = 340 mm. That is, the relationship A ≥ 0.5 λ is satisfied. In the example of Fig. 22, when the enclosure 31 is provided with the port 32, the sound pressure value in the rear direction is lower than when the port 32 is not provided. That is, when the relationship A ≥ 0.5 λ is satisfied, it can be seen that the port 32 exerts the effect of suppressing sound waves in the rear direction.

[0039] This allows the enclosure 31 to suppress sound output in the rear direction due to vibrations at the rear side.

[0040] The position of the port 32 is not limited to the side of the enclosure 31. FIG. 8 is a cross-sectional view showing an example in which the port 32 is provided on the front side. The enclosure 31 shown in FIG. 8 has a width longer than the width of the vibration unit 30. The enclosure 31 is provided with the ports 32 on the left and right sides of the front side. In this case, the sound output in the front direction of the vibration unit 30 and trying to go around the side is canceled by the sound of the opposite phase output from the port 32 provided on the front side of the enclosure 31. That is, the opening constituting the port 32 is oriented in a direction intersecting the sound emission direction of the speaker unit, in a direction other than the opposite direction to the sound emission direction, or is oriented in the same direction as the sound emission direction of the speaker unit.

[0041] A part of the partition 10 may also serve as an enclosure. Fig. 9 is a cross-sectional view of a case in which a part of the partition 10 also serves as an enclosure. In this case, the enclosure 31 is contained within the partition 10. This prevents the sound emitting device 1 from protruding in the front direction of the flat speaker 3. Therefore, the sound emitting device 1 has a thin thickness and is excellent in design.

[0042] The planar speaker 3 may be covered with an acoustically open cover such as a mesh or punched metal. In this case, the planar speaker 3 is not conspicuous, and the sound emitting device 1 has a more excellent design.

[0043] FIG. 10 is a cross-sectional view of an enclosure 31 provided with a resonance tube 501 on the rear surface thereof. A cylindrical resonance tube 501 is provided on the rear surface of the enclosure 31. The resonance tube 501 has a tube having a certain length in the left-right direction and an opening. Although not shown, a plurality of resonance tubes 501 are provided in the up-down direction. Each of the plurality of resonance tubes 501 constitutes a Helmholtz resonator. The plurality of resonance tubes 501 have different tube lengths.

[0044] The sound that enters the opening resonates at a specific resonance frequency depending on the length of the tube. The resonating sound is in the opposite phase to the incident sound. Therefore, the resonance tube 501 exerts a sound absorbing effect at a specific frequency near the opening. When the resonance frequencies of the multiple resonance tubes 501 are different, the sound absorbing effect is exerted over a predetermined frequency band.

[0045] This further reduces the amount of sound that leaks around the sides, and therefore the sound emitting device 1 can further prevent sound leakage.

[0046] Fig. 11 is a cross-sectional view showing a modified example of the resonance tube 501. The resonance tube 501 may be provided in the partition 10 as shown in Fig. 11. The opening of the resonance tube 501 may be provided on the front or flat side of the partition 10. In this case, the sound waves reflected on the wall surface of the partition 10 interfere with the resonant sound, and a confusion effect can also be achieved. Therefore, the sound emitting device 1 can also have a tuning function that adjusts the resonance of the sound while reducing the sound that wraps around the sides.

[0047] Fig. 12 is a front view of a sound emitting device 1A equipped with a plurality of planar speakers 3. In the example of Fig. 12, the sound emitting device 1A is equipped with a plurality of planar speakers 3 facing each other. In this case, the user can hear the sound of the planar speakers 3 from both the front and rear directions of the user. In this case, the sound emitting device 1A can also prevent sound leakage. Note that the plurality of planar speakers 3 do not need to face each other.

[0048] Fig. 13 is a perspective view showing the configuration of a sound emitting device 1B having a flat speaker 3 on the top surface. As shown in Fig. 13, the flat speaker 3 may be disposed so as to be perpendicular to the main surface of the partition 10, or may be disposed so as to be inclined at a predetermined angle. In this case, the flat speaker 3 outputs a plane wave toward the floor, which is an example of an acoustic shielding part. In this case, the sound emitting device 1B can also prevent sound from leaking.

[0049] FIG. 14 is a perspective view showing the configuration of the sound emitting device 1C when it is equipped with a display 5 and a microphone 7. FIG. 15 is a front view. The display 5 and the microphone 7 are provided on a partition 10 arranged at the back of the semi-private room. The display 5 receives image data from an information processing device installed at a remote location and displays it. The display 5 displays image data captured by a camera at a remote location. The microphone 7 picks up the voice uttered by the user and transmits it to the information processing device at the remote location. The flat speaker 3 receives a sound signal from the information processing device installed at a remote location and emits the sound. In this way, the sound emitting device 1C realizes a remote video conference.

[0050] The microphone 7 is installed near the upper part of the partition 10. That is, the microphone 7 is arranged outside the directivity range of the planar speaker 3 as shown in Fig. 15. Therefore, the microphone 7 does not pick up the sound from a distant place output from the planar speaker 3. Therefore, the sound emitting device 1C suppresses the occurrence of echoes.

[0051] 16, even when a user sits down and operates a personal computer (PC) 9, the microphone provided in the PC 9 is outside the directivity range of the planar speaker 3. In this case as well, the sound emitting device 1C can suppress the occurrence of echoes.

[0052] 17 is a perspective view of a sound emitting device 1E equipped with casters 110, which are auxiliary tools for assisting movement. The sound emitting device 1E is equipped with casters 110 that support the lower part so as to prevent the partition 10 from tipping over in the thickness direction and assist movement. The other configurations are the same as those of the sound emitting device 1.

[0053] A user can easily configure a semi-private room even in an open space by simply moving one or more sound emitting devices 1E to any position using the casters 110 and blocking the view and sound. A semi-private room configured in this way can prevent sound leakage from the semi-private room, similar to the above-mentioned sound emitting device 1, and people outside the semi-private room cannot hear the sound output from the flat speaker 3. A user of the sound emitting device 1 can listen to the sound of the content or hear the conversation of users in remote locations without worrying about sound leakage. Also, people outside the semi-private room do not mind the sound from the semi-private room.

[0054] Since the sound emitting device 1E can be easily moved, the planar speaker 3 may be installed facing outward from the semi-private room. When the planar speaker 3 is installed facing outward from the semi-private room, the planar speaker 3 outputs a masking sound. The sound emitting device 1E may be provided with planar speakers 3 on both walls. In this case, the sound emitting device 1E outputs the sound of the content or the sound of the remote conference from the planar speaker 3, which is a first directional speaker installed facing inward, and outputs the masking sound from the planar speaker 3, which is a second directional speaker installed on the opposite wall (facing outward).

[0055] Fig. 18 is a front view showing a configuration for outputting a masking sound. In the example of Fig. 18, a sound emitting device 1E is placed on the back, right side, and left side of a semi-private room. All of the flat speakers 3 of the sound emitting device 1E are set to face outward.

[0056] The flat speaker 3 outputs a masking sound. The masking sound prevents a third party from understanding what is being said by a person having a conversation in a semi-private room. The masking sound preferably includes a disturbing sound that disturbs the voice, a background sound that occurs continuously, and a performance sound that occurs intermittently. For example, the disturbing sound is a human voice that has been modified on the time axis or the frequency axis to make it lexically meaningless (the content cannot be understood). The disturbing sound has a human voice quality, but cannot be recognized as a conversation voice emitted by a person. Therefore, the confusing sound gives a sense of incongruity to the listener, and may cause discomfort when heard for a long time or at an excessively loud volume. Therefore, it is preferable to combine the background sound and the performance sound with the disturbing sound. The background sound is a sound that is difficult for a third party to notice and does not cause discomfort, such as the murmuring of a stream or the rustling of trees. As a result, the background sound increases the background noise level and makes the disturbing sound less noticeable, thereby reducing the sense of incongruity of the disturbing sound and reducing the discomfort. The special sound is a highly special sound such as musical sound that is generated intermittently. This allows the special sound to draw the attention of third parties to the special sound, making the psychoacoustic discomfort of the disturbing sound less noticeable.

[0057] 18, all of the planar speakers 3 of the sound emitting device 1E are set to face outward. However, the planar speakers 3 may be installed to face inward. The planar speakers 3 installed to face inward output a target sound (such as the sound of the content or the sound of a remote conference).

[0058] Fig. 19 is a front view of a sound emitting device 1F equipped with planar speakers 3 on both sides, when applied to a semi-private room. The sound emitting device 1F is equipped with planar speakers 3 on both sides. In the example of Fig. 19, the sound emitting device 1F is disposed on the right and left sides of the semi-private room. A sound emitting device 1E equipped with a planar speaker 3 on only one side is disposed on the rear of the semi-private room.

[0059] In this case, the sound emission device 1F outputs a masking sound from the planar speaker 3, which is the second directional speaker installed facing outward, and outputs a target sound (such as the sound of content or the audio of a remote conference) from the planar speaker 3, which is the first directional speaker installed facing inward.

[0060] 20 is a block diagram showing the configuration of the planar speaker 3 that performs signal processing based on a sound signal picked up by a microphone (the microphone 7 or the microphone of the PC 9). The hardware configuration is the same as that shown in FIG.

[0061] The input unit 301 receives a sound signal related to a sound picked up by a microphone (microphone 7 or microphone of PC 9). The signal processing unit 302 adjusts the volume of the sound signal to be output to a subsequent stage according to the volume of the sound signal related to the sound picked up by the microphone. For example, the signal processing unit 302 measures in advance the maximum volume at which the sound of the flat speaker 3 does not leak from the semi-private room and the volume of the sound picked up by the microphone at that time. After that, the signal processing unit 302 adjusts the volume based on the volume of the sound signal related to the sound picked up by the microphone and the volume of the sound picked up by the microphone measured in advance. This allows the volume to be adjusted to an optimal volume without the user having to adjust the volume. The signal processing unit 302 may also adjust the frequency characteristics of the sound signal instead of or together with the volume.

[0062] Furthermore, when outputting a masking sound, the signal processing unit 302 may adjust the volume of the masking sound according to the volume of the sound signal related to the sound picked up by the microphone. In this case, the signal processing unit 302 performs processing to suppress the volume to the minimum necessary to exert the effect of the masking sound.

[0063] It is preferable that the signal processor 302 performs a fade-in process when the masking sound starts to be output, and a fade-out process when the masking sound stops, so that the signal processor 302 makes the masking sound less noticeable to third parties.

[0064] Furthermore, when outputting a masking sound, the planar speaker 3 may be divided into a plurality of units. In this case, the signal processor 302 controls the sound emission timing of the plurality of units to control the composite wavefront of the sound waves output from the plurality of units. This allows the signal processor 302 to control the shape of the wavefront and control the directivity. The masking sound can be directed in any direction. The signal processor 302 may delay the sound signals of the plurality of channels by digital signal processing to control the sound emission timing, or may delay the analog sound signals supplied to each planar speaker 3 by an analog circuit.

[0065] Furthermore, the signal processing unit 302 may perform processing to reduce the sense of localization of the planar speaker 3. For example, the signal processing unit 302 convolves the inverse function of a transfer function (head-related transfer function) from the planar speaker 3 to the user's head, which is acquired in advance, into the sound signal. This prevents the sound from the planar speaker 3 installed behind the user from being localized backward, allowing the user to hear the sound with a more natural impression.

[0066] Furthermore, the signal processor 302 may perform low-pass filtering to cut off a band of a predetermined frequency (e.g., 5 kHz) or higher. The localization of sound in the front-rear and up-down directions depends on the frequency characteristics of 5 kHz or higher. Therefore, the signal processor 302 can reduce the sense of localization of the planar speaker 3 by performing low-pass filtering to cut off a band of a predetermined frequency (e.g., 5 kHz) or higher.

[0067] Furthermore, the signal processing unit 302 may perform processing to add reverberation. By adding reverberation, the signal processing unit 302 can also reduce the sense of localization of the direct sound.

[0068] The description of the present embodiment should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims, not by the above-described embodiments. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope of the claims.

[0069] For example, in the present embodiment, a planar speaker is shown as an example of a directional speaker. However, the directional speaker may be, for example, a dynamic speaker. Furthermore, the directional speaker may be an array speaker formed by arranging a plurality of dynamic speakers.

[0070] Also, the sound emitting device of this embodiment has been exemplified as including the partition 10 and the planar speaker 3. However, the partition 10 is not essential. For example, the planar speaker 3 can be suspended from a ceiling. In this case, the sound emitting device includes a speaker unit and an enclosure for the speaker unit. Also, the sound emitting device may include a support member that supports the bottom surface (the lower side surface) of the enclosure from the floor surface.

[0071] This application is based on a Japanese patent application (Patent Application No. 2019-199229) filed on October 31, 2019 and an international patent application PCT / JP2020 / 040439 based on a Japanese patent application (Patent Application No. 2019-199230) filed on October 31, 2019, the contents of which are incorporated herein by reference. [Explanation of symbols]

[0072] 1,1A,1B,1C,1R,1F…Sound emitting device 3... Planar speaker 5. Display 7. Mike 9…PC 10…Partition 30…Vibration unit 30A,30B…Fixed electrode plate 30C…diaphragm 31…Enclosure 32…Port 35…Sound absorbing material 110…Caster 301... Input section 302...signal processing unit 303…Amplification section 304...Drive unit 501…Resonance tube

Claims

1. A plurality of walls constituting an acoustic shielding portion that is partially open and partially shielded in a plan view, the walls having a first wall surface and a second wall surface; a directional speaker disposed on the first wall surface and having a sound emission direction with respect to the acoustic shielding portion; Equipped with The directional speaker includes: A speaker unit; an enclosure for the speaker unit; an opening forming a Helmholtz resonator; Equipped with The enclosure is enclosed within the first wall. Partition system with speaker.

2. The directional speaker is covered with an acoustically released mesh or perforated metal cover.

2. The speaker-equipped partition system according to claim 1.

3. The Helmholtz resonator is provided on the rear surface of the enclosure.

3. A speaker-equipped partition system according to claim 1 or 2.

4. The opening is provided on the front or flat side of the first wall surface.

3. A speaker-equipped partition system according to claim 1 or 2.

5. The enclosure includes a sound absorbing material therein.

3. A speaker-equipped partition system according to claim 1 or 2.

Images