Office space

Abstract

To provide an office space capable of achieving both designability and reduction of leakage sound from a personal booth.SOLUTION: An office space 100 according to the present invention includes a partition 3 that surrounds four sides in a horizontal cross section, a closing plate 13 that closes a part of an upper opening 10 in the partition 3, a gap 17 in the upper opening 10 that is not closed by the closing plate 13, and a sound absorbing material 15 that is disposed on the closing plate 13. A ceiling sound absorbing material 58 is arranged in a part of a ceiling 57 above the personal booth.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an office space in which personal booths are installed. [Background technology]

[0002] In response to the rapid increase in use of online conferences due to the spread of COVID-19, personal booths for one to several people are increasingly being introduced into office spaces. For example, Japanese Patent Application Laid-Open No. 2022-142688 proposes a completely enclosed personal booth equipped with ventilation equipment. However, such personal booths are costly and difficult to install. [Patent Document 1] Japanese Patent Publication No. 2022-142688 Summary of the Invention [Problem to be solved by the invention]

[0003] Therefore, small spaces created by combining partitions (for example, a space surrounded on all sides by four partitions) are sometimes used as personal booths, but in many cases, the opening at the top is left open due to the need for ventilation and smoke exhaust, temperature control, and to reduce the feeling of being closed in, and sounds such as conversations easily leak from these openings into adjacent booths or surrounding meeting or work spaces. Conversely, there is also the issue of it being difficult to prevent sounds from adjacent booths or surrounding spaces from propagating into the booth itself.

[0004] To reduce the amount of conversational sound leaking from a personal booth and to improve the sound environment inside the booth, i.e., to make it easier to talk and hear, methods are sometimes used to sound-absorb the walls of the partitions and other components of the personal booth (the walls inside the personal booth).Such sound-absorption treatment is achieved by incorporating sound-absorbing materials such as urethane into the partition surface to create a sound-absorbing partition, or by installing sound-absorbing panels made of glass wool or the like on the partition walls.

[0005] However, when treating partition walls with sound absorption, a minimum thickness of about 20mm is required to obtain an effect on sound, and about 50mm is required to expect a sufficient effect. In addition, of the four partition walls surrounding the personal booth, at least two sides that do not face each other must be treated with sound absorption. The reason for needing sound absorption treatment on at least two sides that do not face each other is to suppress multiple reflections between parallel opposing walls.

[0006] Therefore, there was a problem with treating the partition walls with sound absorption, as this made the already small personal booths even smaller.

[0007] In order to solve this problem, the inventor proposed a personal booth having a partition surrounding the partition on all four sides in horizontal cross section, a blocking plate blocking part of the upper opening of the partition, a gap in the upper opening that is not blocked by the blocking plate, and sound-absorbing material arranged on the blocking plate, in which, when viewed in a plane, the gap is not located in the direction in which it is desired to reduce the propagation of sound generated within the partition.

[0008] When introducing such personal booths into an office space, it is preferable to have a sound-absorbing finish on the entire ceiling of the office space; however, if, for example, it is not possible to have a sound-absorbing finish on the entire ceiling of the office space for design reasons, there has been no knowledge as to what kind of ceiling surface should be used. [Means for solving the problem]

[0009] This invention solves the above-mentioned problems, and the office space of the present invention comprises a partition surrounding the four sides in a horizontal cross section, a blocking plate that blocks a portion of an upper opening in the partition, a gap in the upper opening that is not blocked by the blocking plate, and sound-absorbing material arranged on the blocking plate, and is characterized in that in an office space in which personal booths are installed such that, when viewed in a plane, the gap is not arranged in a direction in which it is desired to reduce the propagation of sound generated within the partition, ceiling sound-absorbing material is arranged on a portion of the ceiling above the personal booths.

[0010] Moreover, the office space according to the present invention is characterized in that the ceiling sound-absorbing material is arranged between a first line and a second line. however, The first line is a line where an extension line extending upward from the first partition that is not covered by the closing plate intersects with the ceiling surface. The second line is a line where the extension line from the mirror image point of the sound source position within the personal booth to the boundary line formed by the blocking plate and the gap intersects with the ceiling, in mirror symmetry with the first partition as the mirror plane.

[0011] Moreover, the office space according to the present invention is characterized in that the ceiling sound-absorbing material is arranged between a first line and a second point. however, The first line is a line where an extension line extending upward from the first partition that is not covered by the closing plate intersects with the ceiling surface. a third line, which is a mirror image point of the sound source position in the personal booth in mirror symmetry with the first partition as a mirror plane; In mirror symmetry with the ceiling surface as a mirror plane, a line passing through the side of the closing plate that contacts the gap and the mirror image of the side of the closing plate that faces the gap is a line that intersects with the ceiling surface. The second point is the point where sound that originates from the sound source position within the personal booth is mirror-reflected by the first partition and enters the ceiling surface, is mirror-reflected by the third line, and then mirror-reflected by the edge of the closing plate opposite to the edge of the closing plate that contacts the gap, and enters the ceiling surface again.

[0012] In addition, the office space according to the present invention is characterized in that the closing plate is not fixed to the upper opening, but is placed on the upper opening.

[0013] Furthermore, the office space according to the present invention is characterized in that the sound absorbing material is disposed on the underside of the closing plate.

[0014] Furthermore, the office space according to the present invention is characterized in that the sound absorbing material is disposed on the lower and upper surfaces of the closing plate.

[0015] Furthermore, the office space of the present invention is characterized in that, when viewed in a plan view, the blocking plate forms a first rectangle and the gap forms a second rectangle, the area of ​​the first rectangle is larger than the area of ​​the second rectangle. [Effects of the Invention]

[0016] In the office space of the present invention, ceiling sound-absorbing material is arranged in part of the ceiling above the personal booth.With this office space of the present invention, sound that is reflected inside the personal booth and then reflected off the ceiling surface and propagates can be absorbed by the ceiling sound-absorbing material.Even if the entire office ceiling cannot be finished with sound-absorbing material for design reasons, sound leakage from the personal booth can be reduced. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram showing a schematic configuration of a personal booth 1 that can be applied to the present invention. [Figure 2] 1 is a top view of the periphery of a personal booth 1 that can be used in the present invention. [Figure 3] 1 is a diagram showing a schematic diagram of a path along which conversational voices during a Web conference in a personal booth 1 applicable to the present invention propagate to an adjacent meeting space. [Figure 4] FIG. 1 is a plan view showing an outline of the experimental field. [Figure 5] 10A and 10B are diagrams showing variations of experimental patterns for verifying the effectiveness of measures against leakage of conversation voice from personal booth 1. [Figure 6] Experimental result No. 1: A diagram showing the effectiveness of measures against leakage of conversation voice in an adjacent meeting space (sound receiving point R1). [Figure 7] Experimental result No. 2: A diagram showing the effectiveness of measures against leakage of conversation voice in the surrounding general office space (sound receiving point R2). [Figure 8] Experimental result No. 3: A diagram showing the effectiveness of measures against leakage of conversation voice in an adjacent booth (sound receiving point R3). [Figure 9] Experimental result No. 4: A diagram showing the relative sound pressure level in a booth (sound receiving point R0) where a speaker sound source was installed. [Figure 10] FIG. 1 is a diagram showing a schematic configuration of a conventional personal booth 1. [Figure 11] FIG. 1 is a diagram schematically illustrating a path along which conversational voices during a web conference in a conventional personal booth 1 propagate to an adjacent meeting space. [Figure 12] FIG. 10 is a diagram showing a schematic configuration of another personal booth 1 that can be applied to the present invention. [Figure 13] FIG. 10 is a diagram schematically showing a path along which conversational voices during a Web conference in another personal booth 1 to which the present invention can be applied propagate to an adjacent meeting space. [Figure 14] FIG. 10 is a diagram showing an experimental pattern (pattern (D)) for verifying the effectiveness of measures against leakage of conversation voice from personal booth 1. [Figure 15] Experimental result No. 5: A diagram showing the effectiveness of measures against leakage of conversation voice in an adjacent meeting space (sound receiving point R1). [Figure 16] 1 is a diagram showing an office space 100 according to an embodiment of the present invention. [Figure 17] 1 is a diagram illustrating design guidelines for an office space 100 according to an embodiment of the present invention. [Figure 18] 10A and 10B are diagrams illustrating other design guidelines for the office space 100 according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] First, we will explain a personal booth 1 that uses a conventional partition 3. Figure 10 is a diagram showing the general configuration of a conventional personal booth 1. In Figure 10, the partition 3 that makes up the personal booth 1 is shown transparently, while the desk 42 and chair 45 installed within the personal booth 1 are shown visible. A similar drawing method will also be used when explaining the present invention.

[0019] The personal booth 1 is made up of four partitions 3 that surround it on all four sides in horizontal cross section. One of the four partitions 3 (the one at the front of the drawing) is provided with an openable door 7 that serves as an entrance and exit to the personal booth 1. With the above configuration, an upper opening 10 is provided vertically above the four partitions 3 that make up the personal booth 1.

[0020] The following describes the propagation of conversational voices when, for example, a web conference is held in the conventional personal booth 1 configured as described above. Fig. 11 is a diagram showing a schematic diagram of the path along which conversational voices during a web conference in the conventional personal booth 1 propagate to an adjacent meeting space.

[0021] The main propagation paths of conversational voices are shown in Figure 11. These propagation paths are classified as (0) to (4) and are shown below. Propagation path (0): A path that passes through partition 3 that constitutes personal booth 1 Propagation path (1): Diffraction path through the top edge of the partition 3 that constitutes the personal booth 1 Propagation path (2): After being reflected inside personal booth 1, the light is diffracted at the top of partition 3. Propagation path (3): Path reflected by the ceiling 57 of the office space Propagation path (4): A path that is reflected inside the personal booth 1 and then reflected by the ceiling 57 of the office space Note that propagation paths (2) and (4) are shown as paths that reflect once on the wall surface within personal booth 1 and then diffract off partition 3 or reflect off the surface of ceiling 57 of the office space, but they also include paths that reflect multiple times on the walls, floor 55, desk 42, etc. within personal booth 1 and then diffract off partition 3 or reflect off the surface of ceiling 57 of the office space.

[0022] Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the schematic configuration of a personal booth 1 applicable to the present invention. The personal booth 1 applicable to the present invention is similar to a conventional personal booth 1 in that it is composed of four partitions 3. In response to the above-mentioned problems, the personal booth 1 applicable to the present invention is provided with soundproofing measures to prevent leakage of conversational voices from the personal booth 1 and, conversely, to prevent conversational voices from occurring in adjacent personal booths or meeting spaces. For this reason, the personal booth 1 applicable to the present invention is provided with a blocking plate 13 that blocks a portion of the upper opening 10 formed by the four partitions 3.

[0023] Such a blocking plate 13 is not fixed to the upper opening 10, but is placed on the upper opening 10, which makes it possible to arbitrarily set the mounting position of the blocking plate 13. If no future changes to the layout of the office space are expected, the blocking plate 13 may be fixed to the upper opening 10.

[0024] In the personal booth 1 applicable to the present invention, the upper opening 10 is closed by a closing plate 13, but for ventilation, smoke exhaust, etc., it is not completely closed, and a partial gap 17 is provided. Furthermore, in the personal booth 1 applicable to the present invention, the underside of the closing plate 13 at the upper opening 10 is sound-absorbing. Specifically, sound-absorbing material 15 is arranged on the underside of the closing plate 13.

[0025] The sound-absorbing material 15 used for sound absorption treatment can be glass wool, urethane foam, polyester sound-absorbing material, etc., but the material is not limited to these as long as it has sufficient sound-absorbing performance. The sound-absorbing performance of the sound-absorbing material 15 should desirably have a sound absorption coefficient of 0.8 or more in the octave band of a center frequency of 500 Hz, which is the main component of sound. This can be achieved by making the thickness 50 mm or more for porous sound-absorbing materials such as glass wool and polyester sound-absorbing material.

[0026] There are no particular limitations on the material that can be used for the closing plate 13 in the upper opening 10, as long as it has sufficient sound insulation. The higher the sound insulation performance of the material for the closing plate 13, the more desirable it is, but since materials with high sound insulation performance are generally heavy, it is desirable to select a material that balances sound insulation performance and weight, taking into account that it will be installed in the upper opening 10. Examples of materials that can be used for the closing plate 13 include plywood, gypsum board, and steel panels.

[0027] Fig. 2 is a top view of the periphery of a personal booth 1 applicable to the present invention. In a personal booth 1 applicable to the present invention as shown in Fig. 2, when viewed from above, the closing plate 13 generally forms a first rectangle 21 (indicated by a dashed line in the figure) and the gap 17 generally forms a second rectangle 22 (indicated by a dashed line in the figure).

[0028] In such a case, it is preferable that the area of ​​first rectangle 21 (i.e., the area that blocks upper opening 10) be set larger than the area of ​​second rectangle 22 (i.e., the area of ​​the portion of upper opening 10 that is not blocked). Furthermore, it is more preferable that the area of ​​first rectangle 21 be 70% or more of the entire area of ​​upper opening 10 (the area of ​​first rectangle 21 + the area of ​​second rectangle 22). However, due to the need for ventilation, smoke exhaust, etc., it is preferable that the width of gap 17 be 100 mm or more as shown in the figure.

[0029] It is effective to locate the gap 17 in a location where leakage of conversation sounds is not a problem, i.e., far from adjacent booths or meeting spaces. In other words, as shown in Figure 2, in a personal booth 1 applicable to the present invention, gaps 17 are not located in the direction in which it is desired to reduce the propagation of sound generated within the four partitions 3 when viewed from above.

[0030] Furthermore, when using this as a means to prevent sound from surrounding meeting spaces or the like from propagating into the personal booth 1, it is effective to provide the gap 17 in a position far from the surrounding meeting spaces or the like where the sound is generated. Note that, although the example shown in Figure 1 shows a situation in which only a portion of the closing plate 13 that closes the upper opening 10 has been sound-absorbing treated, the entire surface of the closing plate 13 facing the personal booth 1 may also be sound-absorbing treated.

[0031] Next, the effects of the present invention will be described with reference to Fig. 3. Fig. 3 is a diagram schematically showing the path along which conversational voices during a web conference in a personal booth 1 applicable to the present invention propagate to an adjacent meeting space.

[0032] According to the personal booth 1 applicable to the present invention, the blocking plate 13 can prevent sound from being transmitted to adjacent spaces such as meeting spaces via the transmission paths (1) and (3).

[0033] Although propagation path (2) cannot be completely prevented, the presence of the blocking plate 13 causes double diffraction on the path to an adjacent meeting space, etc., which has the effect of achieving a greater diffraction attenuation (reduction in sound waves obtained by diffraction) compared to single diffraction when the blocking plate 13 is not present.

[0034] Incidentally, although the blocking plate 13 has the effect of reducing sound propagation to adjacent spaces as described above, it also causes conversation sounds to become trapped inside the personal booth 1, resulting in an increase in sound pressure inside the personal booth 1. This is because, in conventional personal booths 1, conversation sounds that would otherwise propagate outside the personal booth 1 through the open upper opening 10 are reflected and blocked by the blocking plate 13, remaining inside the personal booth 1.

[0035] When the sound pressure in personal booth 1 increases, the level of the conversation sound propagating to the adjacent space via propagation path (0), propagation path (2), or propagation path (4) also increases, which means that the effect of blocking plate 13 in preventing the leakage of conversation sound becomes smaller (see the experimental results described later). In the personal booth 1 applicable to the present invention, the surface (underside) of the cover plate 13 facing the personal booth 1 is sound-absorbing treated with sound-absorbing material 15 in order to reduce the amount of conversational sound reflected by the cover plate 13 and remaining within the personal booth 1. This sound-absorbing treatment not only reduces the amount of conversational sound reflected by the cover plate 13, but also provides the same effect as the method of applying sound-absorbing treatment to the surface of the wall, such as the partition 3, that faces the personal booth 1 (the inner surface of the personal booth 1) that constitutes the personal booth 1 described above. Furthermore, with the personal booth 1 applicable to the present invention, this effect can be achieved without the sound-absorbing treatment narrowing the interior of the personal booth 1.

[0036] To obtain sufficient sound absorption performance (for example, a sound absorption coefficient of 0.8 or more) in the octave band with a center frequency of 500 Hz, which is the main component of sound, a thickness of 50 mm or more is required for common porous sound-absorbing materials such as glass wool and polyester sound-absorbing materials.

[0037] As mentioned above, it is desirable to use sound-absorbing material that is 50 mm or thicker, but the method of absorbing sound on the inner wall surface of the partition 3 of the personal booth 1 has the disadvantage that the space inside the personal booth 1 becomes narrow, so in practice sound-absorbing material that is 50 mm or less thick (for example, about 20 mm) may be used.

[0038] In the method proposed for the personal booth 1 applicable to the present invention, sound absorption treatment does not change the effective area, particularly in the horizontal direction, inside the personal booth 1. Therefore, there are no particular restrictions on the thickness of the sound-absorbing material 15, and it is possible to use a sound-absorbing material that has sufficient sound-absorbing performance in the octave band with a center frequency of 500 Hz, which is the main component of sound. (Test results) The effectiveness of the personal booth 1 applicable to the present invention was confirmed through a verification experiment conducted in the field, and the results are shown below.

[0039] The experiment was conducted using personal booth 1 for web conferencing set up in an actual office space. An overview of the experiment field is shown in Figure 4. A meeting space was set up adjacent to the personal booth 1, which was set up in succession.

[0040] Personal Booth 1 and the meeting space are separated by a 1.9m high steel partition. The tops of both Personal Booth 1 and the meeting space are open except when the blocking panels shown below are installed.

[0041] Furthermore, the walls of personal booth 1 are steel partitions covered with fabric, with a reflective finish unless sound-absorbing treatment is applied as described below. Although not shown, a steel door is provided as an entrance and exit on the wall on the left side of the drawing of personal booth 1 (the rear side as seen from the worker inside personal booth 1). As shown in the drawing, the dimensions of personal booth 1 are 1.2 m front to back and 1.3 m left to right as seen from the worker.

[0042] The speaker sound source (see sound source point marked with a ●) was installed 1.2 m above the floor at the position of chair 45 in personal booth 1 shown in the diagram, and the test acoustic signals emitted from the speaker were recorded and analyzed at the receiving points R0 to R3 (see receiving points marked with a ○) shown in the diagram. R0 was installed 10 cm away from the speaker sound source within the same personal booth 1 where the speaker sound source was installed. R1 was installed in the adjacent meeting space, R2 was installed in a general office space further away from that meeting space, and R3 was installed at the position of chair 45 within personal booth 1 adjacent to the personal booth 1 where the speaker sound source was installed. The height of all receiving points was 1.2 m above the floor.

[0043] To verify the effectiveness of measures to prevent leakage of conversation voices from personal booth 1, an experiment was conducted using the pattern shown in Figure 5. Pattern (A): Sound-absorbing treatment was performed on the interior walls of Personal Booth 1. The sound-absorbing material used for the sound-absorbing treatment was a ready-made sound-absorbing panel 48 (KOKUYO SOUND ABSORPTION) made of glass wool with a planar size of 900mm x 900mm and a thickness of 20mm. The installation conditions for the sound-absorbing material were "two-wall sound absorption" (A2), where sound-absorbing material was installed on the two walls at the back and left of the drawing; "three-wall sound absorption" (A3), where sound-absorbing material was added to the right-hand side of the drawing; and "four-wall sound absorption" (A4), where sound-absorbing material was added to the front wall on the left side of the drawing. Pattern (B): A blocking plate 13 was installed in the upper opening 10 of the personal booth 1. A 15 mm thick plywood blocking plate 13 was used. The blocking plate 13 blocked the side of the upper opening 10 closest to the adjacent meeting space, and the blocking plate 13 was installed so as to leave a 340 mm wide gap 17 on the side away from the meeting space. In other words, approximately 70% of the area of ​​the upper opening 10 was blocked. Pattern (C): A blocking plate 13 was installed in the upper opening 10 of the personal booth 1, and the surface facing the personal booth 1 was sound-absorbing. The sound-absorbing material 15 was a polyester fiber sound-absorbing material with a thickness of 50 mm and a planar size of 900 mm x 900 mm. In addition to the above, the standard condition: pattern (O) was defined as no sound-absorbing treatment or blocking panels were installed, i.e., no measures were taken to prevent leakage of conversational voices.

[0044] In addition, the experiment was also conducted in a personal booth 1 with a sound receiving point R3 installed adjacent to the personal booth 1 with the speaker sound source, with the same measures against leakage of conversation voices as above taken.

[0045] Figure 6 shows the effectiveness of measures to prevent leakage of conversation voices in the adjacent meeting space (sound receiving point R1), that is, the relative sound pressure levels for each experimental pattern when the standard condition, pattern (O), is used as the reference. The smaller the value, the greater the effect of the measures. Note that, including in the following, the relative sound pressure levels indicate values ​​in an octave band with a center frequency of 500 Hz, which is the main component of speech.

[0046] When the wall surface of partition 3 is treated with sound absorption (pattern (A)), it is shown that the effect of the countermeasure increases as the number of surfaces treated with sound absorption increases.

[0047] Furthermore, when the upper opening 10 of the personal booth 1 is partially blocked (pattern (B)), the effect is the same as that of two wall surfaces absorbing sound (A2).

[0048] Furthermore, it was confirmed that when the surface of the blocking plate 13 that blocks the upper opening 10 proposed in this invention facing the personal booth 1 is treated with sound absorption (pattern (C)), an effect superior to that of four-wall sound absorption (A4) is obtained.

[0049] Figure 7 shows the relative sound pressure levels in a general office space (sound receiving point R2) further away from the meeting space. It can be seen that even at this distance, the effects were similar to those in the meeting space adjacent to the booth.

[0050] The sound absorption area of ​​pattern (C) in this experiment is 1 / 4 of the sound absorption area of ​​pattern (A4) for four-wall sound absorption. Even with a smaller sound absorption area, an effect equal to or greater than that of four-wall sound absorption is obtained, demonstrating that the present invention also has significant advantages in terms of cost.

[0051] The reason why the same or better effect can be achieved with a smaller sound absorption area is that in addition to the shielding effect achieved by blocking the upper opening 10, sound waves that are reflected vertically between the blocking plate 13 and the floor or desk surface and propagate outside the personal booth 1 through the gap 17 (part of propagation paths (2) and (4) in Figure 3) can be efficiently absorbed.

[0052] On the other hand, when sound-absorbing treatment of the wall surface of partition 3 is performed using sound-absorbing panel 48, sound waves that are mainly reflected horizontally between the wall surfaces are absorbed, and therefore sound waves that are reflected vertically and propagate outside personal booth 1 as described above cannot be efficiently absorbed.

[0053] Furthermore, as mentioned above, when sound-absorbing treatment is applied to the surface of the closing plate 13 that closes part of the upper opening 10 of the personal booth 1 on the side facing the personal booth 1, there is no drawback to the sound-absorbing treatment narrowing the interior of the personal booth 1 compared to sound-absorbing treatment of the wall surface of the partition 3. Therefore, as in the experiment shown here, sound-absorbing material 15 of sufficient thickness can be used to obtain sufficient sound-absorbing performance in the octave band with a center frequency of 500 Hz, which is the main component of sound, and this is one of the reasons why the same or better effect can be obtained even with a smaller sound-absorbing area.

[0054] Figure 8 shows the relative sound pressure levels in a booth (sound-receiving point R3) adjacent to the booth where the speaker sound source was installed. It can be seen that the same trends were observed for sound-receiving points R1 and R2 when the wall surface of partition 3 was sound-absorbing treated (pattern (A)) and when part of the upper opening 10 was closed and the surface of the closing plate 13 facing the partition 3 was sound-absorbing treated (pattern (C)).

[0055] On the other hand, when only a portion of the upper opening 10 was blocked (pattern (B)), almost no countermeasure effect was obtained. This is because sound waves that penetrated the partition 3 between the personal booths 1 or propagated into the adjacent personal booth 1 through the upper opening of the personal booth 1 (which was only partially blocked in pattern (B)) were reflected and blocked by the blocking plate 13 that blocked the upper opening 10, and remained inside the adjacent personal booth 1, causing the sound pressure level inside the adjacent personal booth 1 to rise.

[0056] In pattern (C), where the surface of the closing plate 13 facing the personal booth 1 is sound-absorbing, this increase in sound pressure level does not occur, and the same effect as with the four-wall sound absorption (A4) is obtained, as with the other sound-receiving points. From these results, it can be confirmed that the conversation voice leakage countermeasure of pattern (C) proposed by this invention is also effective as a countermeasure against conversation voice leakage between adjacent personal booths 1 with the same countermeasures.

[0057] As reference data, Figure 9 shows the relative sound pressure level inside the personal booth 1 (sound receiving point R0) where a speaker sound source was installed. When the closing plate 13 of the upper opening 10 was not sound-absorbing (pattern (B)), it can be seen that the sound pressure level inside the booth increased compared to the standard conditions (pattern (O)) due to reflection and blocking by the closing plate 13. On the other hand, when the surface of the closing plate 13 facing the personal booth 1 was sound-absorbing (pattern (C)), this increase in sound pressure level was eliminated. [supplement] The above explanation and experiments have been described as a measure to prevent the sound of conversation occurring in the personal booth 1 from leaking into adjacent or surrounding spaces. However, if we consider the propagation direction of sound waves in the opposite direction, the present invention is also effective as a means to prevent the sound of conversation occurring in the surrounding space from propagating into the personal booth 1.

[0058] Furthermore, in the present invention, it is not necessarily required to perform sound absorption treatment on the wall surface of the partition 3 of the personal booth 1. However, this does not preclude the simultaneous application of the present invention and sound absorption treatment on the wall surface of the partition 3. If it is acceptable for the personal booth 1 to be narrow, the effect of preventing leakage of conversational sounds from the personal booth 1 can be more effectively achieved by simultaneously applying sound absorption treatment to the wall surface of the partition 3.

[0059] As described above, the personal booth 1 applicable to the present invention has a blocking plate 13 that blocks part of the upper opening 10 in the partition 3, a gap 17 in the upper opening 10 that is not blocked by the blocking plate 13, and sound-absorbing material 15 arranged on the underside of the blocking plate 13, and is configured so that, when viewed in a plan view, the gap 17 is not arranged in the direction in which it is desired to reduce the propagation of sound generated within the partition 3.Therefore, with such a personal booth 1 applicable to the present invention, it is possible to suppress the propagation of sound in the direction in which it is desired to reduce the propagation of sound without sacrificing the space within the personal booth 1.

[0060] Furthermore, the personal booth 1 applicable to the present invention can prevent or reduce the degree to which conversation voices occurring within the personal booth 1 leak into adjacent or surrounding spaces.

[0061] Furthermore, according to the personal booth 1 applicable to the present invention, it is possible to prevent conversations occurring in adjacent or surrounding spaces from propagating into the partition 3, or to reduce the extent of such propagation.

[0062] These effects of the personal booth 1 applicable to the present invention can reduce the degree of interference with web conferences, meetings, and other work in the personal booth 1, adjacent spaces, or surrounding areas, and reduce the feeling of hustle and bustle throughout the workplace. Furthermore, these effects can be achieved without reducing the effective area of ​​the personal booth 1.

[0063] Furthermore, the personal booth 1 applicable to the present invention can utilize sound-absorbing material 15 of sufficient thickness to obtain sufficient sound absorption performance in the octave band of 500 Hz, which is the main component of sound, without reducing the effective area of ​​the personal booth 1.

[0064] Furthermore, according to the personal booth 1 applicable to the present invention, the same level of effect in preventing leakage of conversational voices can be achieved with a sound absorption area of ​​about 1 / 4 of that of the sound absorption treatment on the partition 3 wall of the existing personal booth 1, which has great economic benefits.

[0065] Next, a personal booth 1 according to another aspect of the present invention will be described. Fig. 12 is a diagram showing the general configuration of another personal booth 1 that can be applied to the present invention. Below, differences from the embodiments described so far will be described. In the previous personal booth 1, sound-absorbing material 15 was arranged on the underside of closing plate 13, but a personal booth 1 according to another aspect employs a configuration in which sound-absorbing material 15' is arranged on the upper surface of closing plate 13 in addition to the lower surface of closing plate 13. That is, in this other embodiment, sound-absorbing treatment is also performed on the upper surface of closing plate 13.

[0066] Like the sound-absorbing material 15 on the underside of the closing plate 13, glass wool, urethane foam, polyester sound-absorbing material, etc. can be used as the material for the sound-absorbing material 15' used on the upper side of the closing plate 13. However, the material that can be used for the sound-absorbing material 15' is not limited to these sound-absorbing materials as long as it has sufficient sound-absorbing performance.

[0067] The sound-absorbing performance of the sound-absorbing material 15' on the upper surface of the closing plate 13 should desirably have a sound absorption coefficient of 0.8 or more in the octave band with a center frequency of 500 Hz, which is the main component of sound. This can be achieved by making the thickness 50 mm or more if the material is a porous sound-absorbing material such as glass wool or polyester sound-absorbing material. In the example shown in Figure 12, only a portion of the upper surface of the closing plate 13 is sound-absorbing treated, but the entire upper surface of the closing plate 13 may also be sound-absorbing treated with the sound-absorbing material 15'.

[0068] FIG. 13 is a diagram showing a schematic diagram of a path along which conversational voices during a Web conference in another personal booth 1 to which the present invention can be applied propagate to an adjacent meeting space.

[0069] The main propagation paths of conversational voices are shown in Figure 13. These propagation paths are classified as (0) to (4) and are shown below. Propagation path (0): A path that passes through partition 3 that constitutes personal booth 1 Propagation path (1): Diffraction path through the top edge of the partition 3 that constitutes the personal booth 1 Propagation path (2): A path that reflects inside the personal booth 1 and then diffracts above the blocking plate 13 Propagation path (3): Path reflected by the ceiling 57 of the office space Propagation path (4): A path that is reflected inside the personal booth 1, then reflected by the surface of the ceiling 57 of the office space and the upper side of the blocking plate 13. Propagation path (2) and propagation path (4) are shown as paths that are reflected once on the wall surface inside the personal booth 1, then diffracted by the partition 3, or reflected on the surface of the ceiling 57 of the office space, but they also include paths that are reflected multiple times on the walls, floor 55, desk 42, etc. inside the personal booth 1, then diffracted by the partition 3, or reflected on the surface of the ceiling 57 of the office space. Propagation path (4) is shown as a path that is reflected twice on the surface of the ceiling 57 of the office space and once on the top surface of the blocking plate, but the number of reflections for each path is not limited to these.

[0070] The effects of the other embodiment will be described in particular with reference to Fig. 13. In the previous embodiment, the propagation path along propagation path (2) is double-diffracted, which has the effect of achieving a larger diffraction attenuation (reduction in sound waves obtained by diffraction) compared to single diffraction when no blocking plate 13 is provided.

[0071] In addition, in another embodiment, by applying a sound-absorbing treatment to the upper surface of the closing plate 13, the amount of diffraction attenuation in the propagation path (2) can be further increased, thereby making it possible to further prevent sound from being transmitted to adjacent spaces via the propagation path (2).

[0072] The technical basis for increasing the amount of diffraction attenuation by applying sound absorption treatment to the upper surface of the blocking plate 13 is shown in the following Non-Patent Document 1. Non-Patent Document 1 shows a method for increasing the amount of diffraction attenuation of a soundproof wall by installing a flat plate at the upper end of the soundproof wall and applying sound absorption treatment to the upper surface of the plate. (Non-Patent Document 1) Non-Patent Document 1: “Performance of noise barriers with various edge shapes and acoustical conditions,” T. Ishizuka, K. Fujiwara, Applied Acoustics, Vol. 65, pp. 125-141, 2004. Furthermore, in another embodiment, sound absorption treatment on the upper surface of the closing plate 13 absorbs sound during propagation along propagation path (4) (path that reflects off the surface of the ceiling 57 of the office space and the upper side of the closing plate 13). This makes it possible to prevent sound from being propagated to adjacent spaces via propagation path (4).

[0073] If the surface of the ceiling 57 in the office space is finished with a sound-absorbing finish such as rock wool sound-absorbing panels, it is possible to obtain substantially the same effect without relying on this embodiment. However, there are cases where the ceiling surface cannot be finished with a sound-absorbing finish, for example, for design reasons. In such cases, the effect of preventing sound propagation achieved by this embodiment can be expected.

[0074] In this embodiment, the upper surface of the blocking plate 13 is not within the field of view of the workers in the office space, so the above effect can be achieved without affecting the design of the office space. Also, if the surface of the ceiling 57 of the office space can be finished with a sound-absorbing material such as rock wool sound-absorbing board, then in addition to the sound-absorbing treatment on the upper surface of the blocking plate 13, sound can be further absorbed during the propagation process of propagation path (4).

[0075] According to this embodiment, the above-mentioned effect can be achieved without the sound-absorbing treatment narrowing the interior of the personal booth 1. In addition, as a result, there are no particular restrictions on the thickness of the sound-absorbing material 15', and it is possible to use a sound-absorbing material with sufficient sound-absorbing performance in the octave band with a center frequency of 500 Hz, which is the main component of sound. (Verification results from experiments with other aspects) In addition to the experimental verification results described in the previous embodiment, we will show the results of demonstration in another embodiment. The experimental pattern in another embodiment is shown in Fig. 14 as additional pattern (D). In the pattern in another embodiment, the effectiveness of the measures to prevent leakage of conversation voices in an adjacent meeting space (receiving point R1) was verified.

[0076] FIG. 15 shows the results of the experiment on the effectiveness of measures to prevent leakage of conversation voices in adjacent meeting spaces shown in FIG. 6, with the results of the above pattern (D) added.

[0077] Like Figure 6, Figure 15 shows the effectiveness of measures to prevent leakage of conversation voices in the adjacent meeting space (sound receiving point R1) as relative sound pressure levels for each experimental pattern when the standard conditions (pattern (O)) are used as the reference. The smaller the value, the greater the effectiveness of the measures. Note that the relative sound pressure levels are shown in the octave band with a center frequency of 500 Hz, which is the main component of speech.

[0078] As shown in Fig. 15, pattern (D), which adds sound-absorbing treatment to the upper surface of the blocking plate 13 in addition to pattern (C), has a greater countermeasure effect than pattern (C). This countermeasure effect is greater than that of any of the other experimental patterns.

[0079] In addition to the effects of the personal booth 1 explained in the first embodiment, the other embodiment has the following effects.

[0080] It is possible to prevent or reduce the degree to which conversation voices occurring within the personal booth 1 leak into adjacent or surrounding spaces.

[0081] Conversely, it is possible to prevent conversations occurring in adjacent or surrounding spaces from propagating into the personal booth 1, or to reduce the extent of such propagation.

[0082] These effects can reduce the degree of disruption to web conferences, meetings, and other work in personal booth 1 and adjacent or surrounding spaces, and can reduce the sense of noise throughout the workplace.

[0083] These effects can be achieved without reducing the effective area of ​​the personal booth 1.

[0084] Depending on the location of the sound absorption treatment on the blocking plate 13, sound absorbing material of sufficient thickness can be used to obtain sufficient sound absorption performance in the octave band with a center frequency of 500 Hz, which is the main component of sound, without reducing the effective area of ​​the personal booth 1.

[0085] Furthermore, the sound absorbing treatment on the upper surface of the blocking plate 13 is not within the field of view of the workers in the office space, so the above effect can be achieved without affecting the design of the office space.

[0086] Next, an office space 100 according to the present invention, to which the above-described personal booth 1 is applied, will be described. When installing the personal booth 1 described above in the office space 100, if the entire surface of the office ceiling 57 can be finished with a sound-absorbing material, the sound-absorbing performance can be further improved. However, for example, for design reasons, it may not be possible to finish the surface of the office ceiling 57 with a sound-absorbing material. In particular, wood-based materials are increasingly being used to finish offices and the like. When such materials are used on the ceiling surface, the surface is basically reflective, making it impossible to improve sound-absorbing performance.

[0087] FIG. 16 is a diagram showing an office space 100 according to an embodiment of the present invention. The office space 100 according to the present invention is characterized in that a ceiling sound-absorbing material 58 is provided in a portion of the ceiling 57 above the personal booth 1. This invention has the advantage that sound that reflects within the personal booth 1 and then reflects off the surface of the ceiling 57 of the office space 100 and propagates thereafter can be further absorbed during the propagation process, in combination with the sound-absorbing treatment on the upper surface of the closing plate 13 of the personal booth 1. This invention can achieve the above-mentioned effect, for example, when the entire ceiling 57 of the office cannot be finished with a sound-absorbing finish for design reasons. As a result, even when the entire ceiling cannot be finished with a sound-absorbing finish, such as when the ceiling surface is finished with wood, it is possible to achieve both design and reduction of sound leakage from the personal booth 1.

[0088] It is preferable that the sound-absorbing material of the personal booth 1 installed in the office space 100 be on the underside and upper side of the closing plate 13, but the effects of the present invention can be expected even if the sound-absorbing material is installed only on the underside of the closing plate 13, and such cases are also within the scope of the present invention.

[0089] Next, we will explain the suitable size of the ceiling sound-absorbing material 58 to be installed in the office space 100 according to the present invention. Figure 17 is a diagram explaining the design guidelines for the office space 100 according to the embodiment of the present invention. From this figure onwards, the partition 3 not covered by the blocking plate 13 will be particularly described as the first partition 3a. In addition, in the figure, the first mirror image of the personal booth 1 is a mirror image of the personal booth 1 in mirror symmetry with the first partition 3a as the mirror surface. Furthermore, the position of the sound source within the personal booth 1 (here, assumed to be the position of the mouth of the worker within the booth) is S, and the mirror image of this S is S'.

[0090] The minimum range of the partial surface of the ceiling 57 that is finished with sound-absorbing properties (i.e., the range where the ceiling sound-absorbing material 58 is arranged) is A to C shown in Figure 17. Here, A is the line (referred to as the "first line") where the line extending upward from the surface of the partition 3 (first partition 3a) that is on the opposite side of the partition 3 that makes up the personal booth 1 in the direction toward the adjacent meeting space, i.e., the direction in which sound propagation is desired to be reduced, intersects with the ceiling 57.

[0091] The second line is defined as follows: The second line is defined as a line (C) where an extension line from the mirror image point (S') of the sound source position (S) in the personal booth 1 to the boundary line (B) formed by the closing plate 13 and the gap 17 intersects with the ceiling 57, in mirror symmetry with the first partition 3a as the mirror plane.

[0092] Based on the above definition, in the office space 100 according to the present invention, the ceiling sound-absorbing material 58 is arranged between the first line and the second line. In this way, it is possible to ensure the effect of reducing sound leakage from the personal booth 1 with the ceiling sound-absorbing material 58 being of a minimum size.

[0093] Next, suitable sizes for other ceiling sound-absorbing materials 58 will be described with reference to Fig. 18. Fig. 18 is a diagram illustrating other design guidelines for an office space 100 according to an embodiment of the present invention. In the figure, a first mirror image of the personal booth 1 is a mirror image of the personal booth 1 in mirror symmetry with the first partition 3a as the mirror surface. Furthermore, a second mirror image of the personal booth 1 is a mirror image of the personal booth 1 in mirror symmetry with the ceiling 57 as the mirror surface.

[0094] Referring to Figure 18, the first line is defined as follows: The first line is the line (A) where an extension line extending upward from the first partition 3a not covered by the closing plate 13 intersects with the surface of the ceiling 57 (similar to the case of Figure 17). Next, the third line is defined as follows: The third line is a line (E) that intersects with the surface of the ceiling 57, the line passing through the mirror image point S' of the sound source position S inside the personal booth 1 in mirror symmetry with the first partition 3a as the mirror surface, and the mirror image (D) of the side (F) of the closing plate 13 that faces the side of the closing plate 13 that contacts the gap 17 in mirror symmetry with the surface of the ceiling 57 as the mirror surface.

[0095] The second point is defined as follows: The second point is the point (G) where sound that originates from the sound source position (S) inside the personal booth 1, is specularly reflected by the first partition 3a, and is incident on the ceiling surface, is specularly reflected by the third line, and then specularly reflected by the edge (F) of the closing plate 13 opposite to the edge of the closing plate 13 that contacts the gap 17, and is again incident on the ceiling surface.

[0096] Based on the above definition, in the office space 100 according to the present invention, the ceiling sound-absorbing material 58 is arranged between the first line and the second point. In this way, the ceiling sound-absorbing material 58 can be arranged at its maximum size to sufficiently reduce the sound leaking from the personal booth 1.

[0097] As described above, the office space 100 of the present invention has ceiling sound-absorbing material 58 arranged on a portion of the ceiling 57 above the personal booth 1. With this office space 100 of the present invention, sound that is reflected inside the personal booth and then reflected and propagates from the surface of the ceiling 57 can be absorbed by the ceiling sound-absorbing material 58. Even if the entire office ceiling 57 cannot be finished with a sound-absorbing material for design reasons, sound leakage from the personal booth 1 can be reduced.

[0098] Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments. Various modifications can be made to the above embodiments, and two or more embodiments can be combined together, within the scope of the same or equivalent to the present invention.

[0099] Furthermore, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention, and all of these modifications are included in the technical concept of the present invention. [Explanation of symbols]

[0100] 1. Personal booth 3. Partition 3a···First partition (partition not covered by a cover plate) 7. Door 10...Upper opening 13. Covering plate 15, 15' sound absorbing material 17. Gap 21...First rectangle 22...Second rectangle 42...desk 45 Chair 48···Sound-absorbing panel 55...Floor 57 Ceiling 58 Ceiling sound absorbing material 100···Office Space

Claims

1. A partition surrounding the four sides in horizontal section; a closing plate that closes a portion of the upper opening in the partition; a gap at the upper opening that is not blocked by the blocking plate; a sound absorbing material disposed on the closing plate; In an office space where personal booths are installed, the gaps are not arranged in a direction in which sound propagation occurring within the partition is desired to be reduced in a plan view, An office space characterized in that ceiling sound-absorbing material is arranged in part of the ceiling above the personal booth.

2. The ceiling sound-absorbing material is The office space according to claim 1 , wherein the office space is disposed between a first line and a second line. however, The first line is a line where an extension line extending upward from the first partition that is not covered by the closing plate intersects with the ceiling surface. The second line is a line where the extension line from the mirror image point of the sound source position within the personal booth to the boundary line formed by the blocking plate and the gap intersects with the ceiling, in mirror symmetry with the first partition as the mirror plane.

3. The ceiling sound-absorbing material is 2. The office space of claim 1, wherein the space is disposed between a first line and a second point. however, The first line is a line where an extension line extending upward from the first partition that is not covered by the closing plate intersects with the ceiling surface. a third line is a mirror image point of the sound source position in the personal booth in mirror symmetry with the first partition as a mirror plane; In mirror symmetry with the ceiling surface as a mirror plane, a line passing through the side of the closing plate that contacts the gap and the mirror image of the side of the closing plate that faces the gap is a line that intersects with the ceiling surface. The second point is the point where sound that originates from the sound source position within the personal booth is mirror-reflected by the first partition and enters the ceiling surface, is mirror-reflected by the third line, and then mirror-reflected by the edge of the closing plate opposite to the edge of the closing plate that contacts the gap, and enters the ceiling surface again.

4. 4. The office space according to claim 1, wherein the closing plate is not fixed to the upper opening but is placed on the upper opening.

5. 4. The office space according to claim 1, wherein the sound absorbing material is disposed on the underside of the closing plate.

6. 4. The office space according to claim 1, wherein the sound absorbing material is disposed on the lower and upper surfaces of the closing plate.

7. When the closing plate forms a first rectangle and the gap forms a second rectangle in a plan view, 4. The office space according to claim 1, wherein the area of ​​the first rectangle is larger than the area of ​​the second rectangle.

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