Array microphone device

Abstract

To set the front of a main body back further than the front of other panels without impairing the directional characteristics of sound collection.SOLUTION: An array microphone device is placed in place of a ceiling panel in an opening of a system ceiling where a ceiling panel is placed in the opening of a lattice. The array microphone device includes a device main body that houses array microphones, and a frame that is fixed to the device main body and placed in the opening. The frame placed in the opening supports the device main body by retracting the main body front surface of the device main body upward from the panel front surface, which is the vertically lower surface of a ceiling panel placed in another opening that constitutes the system ceiling.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present disclosure relates to an array microphone device.

Background Art

[0002] Patent Document 1 discloses an array microphone system including a substrate and a plurality of microphones arranged in the form of concentrically nested rings of various sizes on the substrate. In this array microphone system, each ring includes a subset of a plurality of microphones positioned at predetermined intervals along the peripheral portion of the ring. This array microphone system is a microphone assembly including an array microphone including a plurality of microphones and a housing configured to support the array microphone. The housing has a size and shape that can be mounted in a suspended ceiling instead of at least one of a plurality of ceiling panels included in the suspended ceiling. The front surface of the housing includes a sound-permeable screen having a size and shape substantially the same as at least one of the plurality of ceiling panels, and has a microphone assembly.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A microphone assembly (hereinafter also referred to as an "array microphone device") is often installed at a high place, so it is preferably safe to be able to work well. However, in the case of an array microphone device, when the front surface of the main body is flush with the front surface of the ceiling panel and is temporarily placed during the installation work, the front surface of the main body contacts the temporary placement surface. When the front surface of the main body contacts the temporary placement surface, it is likely to be soiled or damaged. In addition, if the array microphone device is temporarily placed with the front surface of the main body facing upward, the front surface of the main body is likely to be soiled or damaged due to the fall of foreign objects or the like. For this reason, the handling of the conventional array microphone device during the installation work is complicated, and it is difficult to obtain good workability. Such a problem becomes more prominent in an array microphone device in which the front surface of the main body protrudes downward in the vertical direction from the front surface of the panel. In addition, in an array microphone device in which the front surface of the main body protrudes, the ceiling cannot be made to look neat and good-looking. Furthermore, in an array microphone device in which the front surface of the main body protrudes, shadows are likely to be formed on the ceiling by natural light, illumination light, etc., and the appearance of the ceiling is likely to be deteriorated.

[0005] In view of the above-described conventional circumstances, the present disclosure has been devised, and an object thereof is to provide an array microphone device that can retract the front surface of the main body behind the front surface of other panels without impairing the directivity characteristics of sound collection.

Means for Solving the Problems

[0006] The present disclosure is an array microphone device arranged in the opening of a suspended ceiling system in which a ceiling panel is arranged in the opening of a lattice body, having a device main body that houses an array microphone, and a frame that is fixed to the device main body and placed on the opening, wherein the frame arranged in the opening supports the device main body by retracting the front surface of the device main body upward from the front surface of the panel, which is the lower surface in the vertical direction of the ceiling panel arranged in the other opening that constitutes the suspended ceiling system.

Effects of the Invention

[0007] According to the present disclosure, the front surface of the main body can be retracted behind the front surface of other panels without impairing the directivity characteristics of sound collection.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0009] Hereinafter, with appropriate reference to the drawings, embodiments specifically disclosing the array microphone device according to the present disclosure will be described in detail. However, a more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and duplicate descriptions of substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate the understanding of those skilled in the art. It should be noted that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and it is not intended to limit the subject matter described in the claims thereby.

[0010] FIG. 1 is a perspective view of a system ceiling 15 with an array microphone device 11 according to Embodiment 1 disposed in an opening 13, as seen from the vertically downward side. In other words, the state where the array microphone device 11 is disposed in the opening 13 can also be said to be the state where the array microphone device 11 is placed on the opening 13, and the same applies in the following description.

[0011] The array microphone device 11 according to Embodiment 1 is an array microphone device 11 that is disposed inside the opening 13 of the system ceiling 15 where the ceiling panel 19 is disposed in the opening 13 of the lattice body 17, replacing the ceiling panel 19. The array microphone device 11 can be suitably used, for example, in a conference room of an office building or a lecture hall of a university. However, it goes without saying that the place where the array microphone device 11 is disposed is not limited to the places described above.

[0012] In the system ceiling 15, the lattice body 17 is assembled by T-bars 21 that are equally spaced and parallel in both the vertical and horizontal directions. The lattice body 17 is suspended and supported by a building structure or the like so as to be in a horizontal plane. Each opening 13 of the lattice body 17 is a quadrangle of the same size and the same shape. In Embodiment 1, the opening 13 is square. However, the shape of the opening 13 is not limited to square.

[0013] In this opening 13, horizontal mounting piece portions 23 project inward on each of the four sides by an inverted T-shaped T-bar 21. The ceiling panel 19 is disposed on each of the mounting piece portions 23 in a state of being placed thereon. The array microphone device 11 can be disposed in the opening 13 in place of the ceiling panel 19 at any of these positions. The array microphone device 11 has a device body 25 that houses a plurality of microphone elements (not shown) constituting the array microphone, and a frame 27 that is fixed to the device body 25 and is placed and disposed in the opening 13.

[0014] The frame 27 placed on the opening 13 supports the apparatus main body 25 by retracting the main body front surface 31 of the apparatus main body 25 upward and rearward from the panel front surface 29, which is the vertically lower surface of the ceiling panel 19 placed on the other opening 13. In Embodiment 1, the main body front surface 31 is a punching sheet 35 attached to the front surface of the main case 33 of the apparatus main body 25 formed of a square frame. In the array microphone apparatus 11, the frame 27 is assembled by connecting four brackets 37 having the same width and the same length to the respective sides of the square frame constituting the outer shape of the apparatus main body 25 and connecting them to each other.

[0015] In addition, in this specification, the front surfaces of the array microphone apparatus 11 and the ceiling panel 19 are the vertically lower surfaces.

[0016] FIG. 2 is a perspective view of the array microphone apparatus 11 shown in FIG. 1 disposed in the opening 13 as viewed from the upper vertical side. The four brackets 37 constituting each side of the frame 27 are each formed in the same shape. The four brackets are inclined end portions in which both ends of the long side in the longitudinal direction of the horizontal portion 39 are cut at an inclination of about 45° (including exactly 45°). That is, the bracket 37 is a member having a trapezoidal shape. The inclined end portions of the respective brackets 37 are abutted against each other in their orthogonal directions and connected.

[0017] Each bracket 37 is formed with a fixing piece portion 41 that bends upward at a right angle from the horizontal portion 39 at the inclined end portions at both ends of the long side (refer to the above). Both ends of the bracket 37 are connected and assembled to the square frame constituting the outer shape of the apparatus main body 25 by fastening and fixing these fixing piece portions to each other using screws 43 or the like. An inner hole 45 is formed in the frame 27 assembled to the square frame. A convex portion 47 of the apparatus main body 25 is inserted into the inner hole 45 of the frame 27 from the vertically lower side. The convex portion 47 is formed by a connector case 49. A connector cover 51 is detachably attached to the connector case 49. An edge guard 53 is attached to the connector cover 51.

[0018] Figure 3 is a cross-sectional view taken along the line X-X of Figure 2. The frame 27 has a horizontal flange portion 55 formed on each bracket 37, and this flange portion 55 rests on the mounting piece portion 23 of the T-bar 21. The bracket 37 has a crank bending portion 57, which will be described later, formed above the flange portion 55. In the apparatus main body 25, the lower side in the vertical direction of the front surface 31 of the main body becomes the sound collection region 59 of the array microphone device 11. The sound collection region 59 of the array microphone device 11 is generated inside the sound collection boundary 61 determined by the microphone directivity angle θ.

[0019] The array microphone device 11 has a microphone directivity angle, which is the apex angle of a substantially straight circular cone surrounding the sound collection region 59 of the microphone, and is, for example, 150°. This angle does not have to be limited to 150°.

[0020] Figure 4 is an exploded perspective view of the state where the apparatus main body 25 floats vertically upward from the opening 13 of the lattice body 17. The lattice body 17 is configured by arranging a plurality of T-bars 21 with both the vertical and horizontal directions extending horizontally at equal intervals. The lattice body 17 has a plurality of square openings 13 surrounded by the vertical and horizontal T-bars 21. A square ceiling panel 19 (see Figure 1) that rests on the mounting piece portion 23 formed on the T-bar 21 is dropped into each opening 13. The array microphone device 11 can be placed (in other words, arranged) on the opening 13 instead of any of the ceiling panels 19 placed on these plurality of openings 13.

[0021] The array microphone device 11 has the convex portion 47 of the apparatus main body 25 inserted downward into the inner hole 45 of the frame 27 formed by connecting four-sided brackets 37 as a square frame, and the apparatus main body 25 and the frame 27 are integrally assembled. The array microphone device 11 is supported and attached to the opening 13 by the flange portion 55 formed on the outer periphery of the frame 27 resting on the mounting piece portion 23 of the T-bar 21 protruding inward from the four sides in the opening 13.

[0022] FIG. 5 is a perspective view of the front surface 31 of the apparatus main body 25 as viewed from the lower side in the vertical direction. The array microphone device 11 has a flange portion 55 placed on the mounting piece portion 23 of the T-bar 21 shown in FIG. 4. Therefore, the flange portion 55 and the ceiling panel 19 are placed on the same plane. The array microphone device 11 has the apparatus main body 25 fixed to a frame 27 formed with the flange portion 55. The frame 27 supports the apparatus main body 25 at a position where the front surface 31 of the apparatus main body 25 retreats upward from this flange portion 55. That is, the front surface 31 is arranged to retreat upward in the vertical direction from the panel front surface 29 of the ceiling panel 19 placed in the other opening 13 in the system ceiling 15. The frame 27 has a square outer shape similar to the opening 13. The length s of one side of the frame 27 can be, for example, 604 mm. This length s is not limited to 604 mm.

[0023] FIG. 6 is an exploded perspective view of the array microphone device 11. The array microphone device 11 forms a square frame with four brackets 37, and this square frame corresponds to the outer shape of the apparatus main body 25. Each bracket 37 has a flange portion 55 placed on the mounting piece portion 23 of the opening 13, an upright portion 63 bent at a right angle upward from the flange portion 55, and a horizontal portion 39 bent at a right angle from the upright portion 63 and overlapping the apparatus main body 25 in parallel with the front surface 31. The flange portion 55, the upright portion 63, and the horizontal portion 39 form a crank bending portion 57.

[0024] As described above, the longitudinal ends of the horizontal portions 39 of the respective brackets are inclined end portions cut at an inclination of 45°. From these inclined end portions, fixing piece portions 41 bent at a right angle upward stand up. That is, the fixing piece portions 41 are provided on both longitudinal sides of the bracket 37. The bracket 37 has a horizontal main body fixing piece portion 65 in the vicinity of one of the fixing piece portions 41 on both sides. That is, since the frame 27 has one main body fixing piece portion 65 for each bracket 37, it has a total of four main body fixing piece portions 65. These four main body fixing piece portions 65 have screw insertion holes. The frame 27 is fastened to a screw hole 71 (see FIG. 7) formed in the inner chassis 69 (see FIG. 7) by a main body fixing screw 67 inserted through the screw insertion hole of the main body fixing piece portion 65.

[0025] More specifically, the screw hole 71 of the inner chassis 69 is covered by a rear case 73 attached to a part of the inner chassis 69. The main body fixing screw 67 is fastened to the screw hole 71 by passing through a through hole 75 formed in the rear case 73.

[0026] FIG. 7 is an exploded perspective view of the apparatus main body 25. The apparatus main body 25 is assembled by laminating functional parts, substrates, structural parts, electronic parts, cover members, etc. of the array microphone 83. A square punching sheet 35 is attached to a main body front surface 31 which is a vertically lower surface of the apparatus main body 25. As an example, aluminum is used as the material of the punching sheet 35. The punching sheet 35 has a thickness of about 1 mm and a large number of small holes are formed. A plurality (for example, four) of locking claws 77 protruding upward are provided on each side of the punching sheet 35. The locking claws 77 are locked to locking grooves 79 formed in the main case 33 overlapping in the upper layer.

[0027] On the upper layer of the punching sheet 35, a square microphone filter 81 is overlaid. The microphone filter 81 captures dust and the like that passes through the punching sheet 35 and adheres to the array microphone 83. In addition, the microphone filter 81 eliminates unwanted noise and reflections caused by, for example, air flow, and makes it easier to detect sound from a sound source such as a speaker. As an example, non-woven fabric is used for the material of the microphone filter 81.

[0028] On the upper layer of the microphone filter 81, a square main case 33 is provided. As an example, ABS resin is used for the material of the main case 33. The main case 33 is formed in a flat box shape with an open upper surface. At the bottom of the main case 33, a circular hole 85 centered on the intersection of a pair of diagonals is formed. The circular hole 85 is formed close to the side wall 87 of the main case 33. That is, the circular hole 85 is formed in a size close to the inscribed circle of the main case 33.

[0029] In the main case 33, a square array microphone 83 is accommodated from above. The array microphone 83 is fixed to the lower surface of the internal chassis 69 overlaid on the upper layer by array fixing screws 89. As an example, ABS resin is used for the material of the internal chassis 69. The array microphone 83 fixed to the lower surface of the internal chassis 69 has its sound collecting surface 91 coaxially arranged with the circular hole 85 when the internal chassis 69 is accommodated in the main case 33. The main body front surface 31 (see FIG. 1) is formed in a square shape. The array microphone 83 is arranged in a square smaller than the main body front surface 31, parallel and coaxially with the main body front surface 31.

[0030] Coaxial means that the array center axis 93 (see FIG. 8) perpendicular to the array microphone 83 passing through the center of the array microphone 83 passes through the center of the main body front surface 31. The center of the array microphone 83 is the intersection of two orthogonal diagonals in the array microphone 83 formed in a square shape. The array microphone 83 and the main body front surface 31 arranged coaxially and parallel are further arranged with each side parallel.

[0031] The array microphone 83 is provided with a plurality of microphones 95 in the circumferential direction of at least one concentric circle centered on the array central axis 93. Each microphone 95 is mounted on the upper surface of the array microphone 83, and the vertical lower side penetrating the array microphone 83 is the sound collection direction. Further, the array microphone 83 may be provided with an indicator for displaying the operation mode of the array microphone device 11. The indicator has a light-emitting diode (not shown) such as an LED mounted on the upper surface of the array microphone 83, an LED lens 97, etc.

[0032] A substrate accommodation space 99 is formed on the upper surface of the internal chassis 69. The control substrate 101 is accommodated in the substrate accommodation space 99. The control substrate 101 is fixed to the internal chassis 69 by the substrate fixing screws 103. The control substrate 101 controls the operations of the array microphone 83 and the indicator. The control substrate 101 performs parameter control such as the sound collection characteristics, directivity, gain, noise suppression, and muting of the array microphone 83.

[0033] The upper surface of the internal chassis 69 that houses the control substrate 101 in the substrate accommodation space 99 is covered by a pair of rear cases 73 at the parts along a pair of parallel side edges. As an example, aluminum is used as the material of the rear case 73. Various connectors (not shown) constituting the external interface are fixed to the upper surface of the internal chassis 69. Examples of the connectors include a Universal Serial Bus (USB) connector, a mini-USB connector, an HDMI (registered trademark) connector, a power connector, etc.

[0034] The control substrate 101, the rear case 73, and the connectors are covered by a connector case 49 fixed to the internal chassis 69 from above the internal chassis 69. A connector window 105 for exposing the connectors provided on the internal chassis 69 is formed in the connector case 49. A connector cover 51 is attached to the connector window 105. An edge guard 53 for protecting the edge terminals of the connectors is attached to the connector cover 51. The connector cover 51, the connector case 49, the rear case 73, etc. are fixed to the adherends such as the internal chassis 69 by screws 43.

[0035] Figure 8 is a Y - Y cross - sectional view of FIG. 2 including the array central axis 93. Each microphone 95 arranged on the concentric circles of the array microphone 83 has a vertex angle of a substantially straight circular cone with a circular bottom surface on the lower side with the microphone 95 as the vertex, and the vertex angle is the microphone directivity angle θ. The array microphone 83 is such that each of the plurality of microphones 95 arranged in the circumferential direction of the concentric circles centered on the array central axis 93 has the microphone directivity angle θ. Therefore, as a whole, the array microphone 83 generates a cardioid - type beam pattern inside the conical surface passing through the vertex with the array central axis 93. In an example of Embodiment 1 where the vertex angle of this conical surface is equal to the microphone directivity angle θ, it is 150°.

[0036] The relative position between the microphone 95 and the apparatus main body 25 of the array microphone device 11 is set so that the sound - collecting boundary 61 of the microphone directivity angle θ that the entire array microphone 83 has does not interfere with the lower end of the T - bar 21 constituting the lattice body 17 or the flange portion 55 of the frame 27. Thereby, the array microphone 83 makes it easier to remove unnecessary sound sources and reflected sounds in the environment.

[0037] More specifically, the length s1 of one side of the main case 33 can be set to 400 mm. The length d from the main case 33 to the flange portion 55 can be set to 88 mm. The length w in the width direction of the bracket 37 can be set to 145 mm. The length h from the mounting piece portion 23 of the T - bar 21 to the front surface 31 of the main body can be set to 5 mm. The height h3 from the mounting piece portion 23 of the T - bar 21 to the upper end of the main case 33 can be set to 27.3 mm. The height h5 from the front surface 31 of the main body to the upper surface of the convex portion 47 can be set to 42.3 mm.

[0038] Figure 9 is an enlarged view of part A in Figure 8. In the array microphone device 11, the device body 25 has a convex portion 47 that protrudes upward from the inner hole 45 in the square frame of the frame 27. On the convex portion 47, an overhanging portion 107 that protrudes horizontally outward from the outer periphery of the convex portion 47 and overlaps the lower side of the horizontal portion 39 is formed. The overhanging portion 107 protrudes from each side of the quadrangular convex portion 47. The overhanging portion 107 has a space sandwiched between the overhanging plate 109 of the connector case 49 and the case bottom plate 111 of the main case 33. This space becomes an annular space 113 surrounded by the main case 33.

[0039] The inner side of the convex portion 47 of the device body 25 is a housing space for electronic components. The array microphone 83 has an outer size larger than this housing space. The outer edge 115 of the array microphone 83 protruding from the housing space is inserted and housed in the annular space 113 inside the overhanging portion 107.

[0040] Specifically, the height h1 from the front surface 31 of the main body to the array microphone 83 can be set to 6.3 mm. The height h2 from the mounting piece portion 23 to the array microphone 83 can be set to 11.3 m. The height h4 from the flange portion 55 to the lower end of the T-bar 21 can be set to 7 mm. The height h6 from the front surface 31 of the main body to the upper surface of the convex portion 47 can be set to 42.3 mm. The shortest distance s2 from the lower end of the T-bar 21 to the sound collection boundary 61 can be set to 21 mm. The shortest distance s3 from the flange portion 55 to the sound collection boundary 61 can be set to 24.4 m.

[0041] Note that the above values of d, h, h1, h2, h3, h4, h5, h6, s, s1, s2, s3, and w are examples, and the configuration of the array microphone device 11 according to Embodiment 1 is not limited only to those values.

[0042] Next, the operation of the above-described configuration will be described.

[0043] The array microphone device 11 according to Embodiment 1 is arranged in the opening 13 of the suspended ceiling 15 where the ceiling panel 19 is arranged in the opening 13 of the grid body 17, replacing the ceiling panel 19. The array microphone device 11 includes a device body 25 that houses the array microphone 83, and a frame 27 that is fixed to the device body 25 and placed on the opening 13. The frame 27 arranged in the opening 13 supports the device body 25 by retracting the front surface 31 of the device body 25 upward and rearward from the panel front surface 29, which is the vertically lower surface of the ceiling panel 19 arranged in the other opening 13 that constitutes the suspended ceiling.

[0044] In the array microphone device 11 according to Embodiment 1, it can be placed in any opening 13 of the suspended ceiling 15 without being fixed. The array microphone device 11 has a device body 25 and a frame 27. The device body 25 houses the array microphone 83. The array microphone 83 is a microphone substrate on which a plurality of microphones 95 are arranged on a printed wiring board (PC). The frame 27 is fixed to the device body 25 and placed on the opening 13.

[0045] The frame 27 placed on the opening 13 supports the device body 25 by retracting the front surface 31 of the device body 25 upward and rearward from the panel front surface 29, which is the vertically lower surface of the ceiling panel 19 placed on the other opening 13. The frame 27 has a flange portion 55 formed on each of its four sides to be placed on the mounting piece portion 23 of the T-bar 21. The frame 27 is placed in a state of being placed on the opening 13 by placing this flange portion 55 on the mounting piece portion 23 of the T-bar 21.

[0046] In the flange portion 55, a standing portion 63 is bent upward at a right angle from the flange portion 55, and a horizontal portion 39 is bent in a horizontal direction parallel to the flange portion 55 from the upper end of the standing portion 63. The device body 25 is fixed to this horizontal portion 39 of the frame 27.

[0047] Therefore, in the array microphone device 11, as the height of the upright portion 63 increases, the distance by which the front surface 31 of the main body retreats upward increases, and as the height of the upright portion 63 decreases, the distance by which the front surface 31 of the main body retreats upward decreases. In the array microphone device 11, mainly by setting the distance of this upright portion 63, the main body front surface 31 is retreated upward from the panel front surface 29 of the ceiling panel 19 placed on the other opening 13 without impairing the sound collection directivity characteristics, and the device main body 25 is supported.

[0048] Note that the structure for retreating the front surface 31 of the main body upward by the upright portion 63 is an example. The front surface 31 of the main body may have a structure for retreating upward by changing the height of other parts, for example, the main case 33.

[0049] In the array microphone device 11, since the front surface 31 of the device main body 25 retreats upward from the flange portion 55 of the frame 27, even when temporarily placed on a flat temporary placement surface during the installation work, the front surface 31 of the main body does not come into contact with the temporary placement surface. That is, a gap is secured between the front surface 31 of the main body and the temporary placement surface by retreating the front surface 31 of the main body upward.

[0050] For this reason, the front surface 31 of the main body does not get dirty or damaged due to contact with the temporary placement surface. Further, since the array microphone device 11 can be temporarily placed with the front surface 31 of the main body facing downward, the front surface 31 of the main body does not get dirty or damaged due to the fall of foreign objects or the like. As a result, the array microphone device 11 is easy to handle and good installation workability can be obtained.

[0051] Also, compared with a conventional array microphone device in which the front surface 31 of the main body protrudes, since the front surface 31 of the main body retreats upward from the panel front surface 29, the ceiling can be made to look neat and good-looking.

[0052] Furthermore, compared with a conventional array microphone device in which the front surface 31 of the main body protrudes, no shadow is formed on the ceiling by natural light, illumination light, etc., and the appearance of the ceiling is not deteriorated.

[0053] In the array microphone device 11, the frame 27 is assembled by connecting four brackets 37 having the same width and the same length to the respective sides of a square frame forming the outer shape of the device main body 25.

[0054] In this array microphone device 11, the frame 27 is assembled by connecting four brackets 37 to the respective sides of a square frame. That is, the frame 27 is a square frame having a square inner hole 45. A part of the device main body 25 is inserted into and fixed to the inner hole 45. On each side of this frame 27, a flange portion 55 that is bent horizontally outward is formed. The frame 27 of the square frame has this flange portion 55 placed on the mounting piece portion 23 of the T-bar 21 in the opening 13 of the lattice body 17. Thereby, the device main body 25 is placed on the opening 13 of the system ceiling 15 via the frame 27.

[0055] The frame 27 of the square frame is formed such that one side s is 604 mm as an example. The bracket 37 constituting each side is formed such that the width w orthogonal to the length direction of one side s is 145 mm as an example. That is, the bracket 37 is a long plate having a length of approximately 600 mm and a width of 145 mm. The bracket 37 can be manufactured by sheet metal processing.

[0056] Thereby, the array microphone device can separate the device main body 25 and the frame 27, and further package the frame 27 in a state where it is separated into four. Therefore, the array microphone device can reduce the packaging size compared to packaging the assembled 604 mm × 604 mm product. Thereby, the transportation cost can be reduced, and the labor for storage and loading / unloading can be reduced.

[0057] Also, in the array microphone device 11, the bracket 37 has a crank bending portion 57 including a flange portion 55 that is placed on the mounting piece portion 23 of the opening 13, a standing portion 63 that bends upward at a right angle from the flange portion 55, and a horizontal portion 39 that bends at a right angle from the standing portion 63 and overlaps the device main body 25 in parallel with the front surface 31 of the main body.

[0058] In this array microphone device 11, a bracket 37 in the form of a long plate has a crank bent portion 57 formed by a flange portion 55, a standing portion 63, and a horizontal portion 39. In the crank bent portion 57, the end of the horizontal flange portion 55 is connected to the vertical standing portion 63, and the standing tip of the standing portion 63 is connected again to the horizontal horizontal portion 39. That is, the flange portion 55 forms a crank bent portion 57 where two right-angle bends in opposite directions are close to each other.

[0059] Incidentally, the bracket 37 in the form of a long plate can also be manufactured with a structure having a Z-bent portion formed by a flange portion 55, an inclined portion (not shown), and a horizontal portion 39. That is, the standing portion 63 can be manufactured as the inclined portion. However, such a Z-bent portion where both ends in the inclined direction are bent at obtuse angles in two opposite directions is difficult to achieve dimensional accuracy, has low strength, and is difficult to maintain its shape. On the other hand, in the bracket 37 having the crank bent portion 57 where two right-angle bends in opposite directions are close to each other, high dimensional accuracy can be easily obtained, the strength is also high, and shape deformation after manufacturing due to springback can be suppressed.

[0060] Also, in the array microphone device 11, the bracket 37 has fixing piece portions 41 that bend upward at a right angle from the horizontal portion 39 at both ends in the direction along one side of the square frame, and the four brackets 37 are assembled into the square frame by fastening the fixing piece portions to each other.

[0061] In this array microphone device 11, the frame 27 is assembled by connecting four brackets 37 which are long plates along each side of the square frame. In this frame 27, the four divided brackets 37 can be easily fixed from one surface side of the square frame by fixing the fixing piece portions at the four corners to each other. In addition to this, the two fixed fixing piece portions 41 are along the diagonal lines that are orthogonal to each other, resulting in a high-strength assembly in which the square frame is difficult to deform.

[0062] In the array microphone device 11, the front surface 31 of the main body is formed in a square shape, the array microphone 83 is arranged in a square shape smaller than the front surface 31 of the main body, parallel and coaxial with the front surface 31 of the main body. The array microphone 83 is provided with a plurality of microphones 95 in the circumferential direction of at least one concentric circle centered on the array center axis 93 perpendicular to the array microphone 83 passing through the center of the array microphone 83. The sound collection region 59 surrounded by the conical surface of a substantially straight circular cone with the lower side being a circular bottom surface with the microphone 95 as the apex does not interfere with the lower end of the T-bar 21 constituting the lattice body 17.

[0063] In this array microphone device 11, the array microphone 83 is housed in the device main body 25. The array microphone 83 and the front surface 31 of the main body are square. The array microphone 83 and the front surface 31 of the main body are arranged parallel and coaxial.

[0064] The array microphone 83 is provided with a plurality of microphones 95 in the circumferential direction of at least one concentric circle centered on the array center axis 93. Each microphone 95 has a sound collection region 59 surrounded by the conical surface of a substantially straight circular cone with the lower side being a circular bottom surface with the microphone 95 as the apex.

[0065] The array microphone device 11 has a structure in which, in a state of being placed on the opening 13 of the lattice body 17, the sound collection region 59 passing through the front surface 31 of the main body does not interfere with the lower end of the T-bar 21 constituting the lattice body 17. This non-interference structure is determined by the microphone directivity angle θ, the horizontal distance w1 between the microphone 95 and the T-bar 21 (see FIG. 8), and the height difference (h + h1 + h4) between the microphone 95 and the lower end of the T-bar. Since the horizontal distance w1 between the microphone 95 and the T-bar 21 can be a variable value within a range where the sound collection region 59 does not interfere with other members, specific examples of dimensions are omitted.

[0066] In the array microphone device 11, by adopting a structure in which the sound collection region 59 does not interfere with the frame 27 or the lattice body 17, the front surface 31 of the main body can be retracted more than the front surface 29 of other panels without impairing the microphone directivity angle of the microphone 95.

[0067] In the array microphone device 11, the microphone directivity angle, which is the apex angle of a substantially straight circular cone surrounding the sound collection region 59 of the microphone 95, is 150°.

[0068] In this array microphone device 11, a plurality of microphones 95 are provided in the circumferential direction of at least one concentric circle centered on the array central axis 93 that passes through the center of the array microphone 83 and is perpendicular to the array microphone 83. Each microphone 95 has a microphone directivity angle θ as the apex angle of a substantially straight circular cone with a circular bottom surface on the lower side with the microphone 95 as the apex. The array microphone 83 is arranged in the circumferential direction of concentric circles centered on the array central axis 93, and each of the plurality of microphones 95 has a microphone directivity angle θ. Therefore, as a whole, the array microphone 83 generates a cardioid-polarity beam pattern inside the conical surface with the array central axis 93 passing through the apex. The apex angle of this conical surface is 150°, which is equal to the microphone directivity angle θ. Thereby, the array microphone 83 makes it easier to remove unnecessary sound sources and reflected sounds in the environment.

[0069] Also, in the array microphone device 11, the device main body 25 has a convex portion 47 that protrudes upward from the inner hole 45 in the square frame of the frame 27. On the convex portion 47, an overhanging portion 107 is formed that protrudes outward from the outer periphery of the convex portion 47 and overlaps the lower side of the horizontal portion 39. Inside the overhanging portion 107, the outer edge 115 of the array microphone 83 is accommodated.

[0070] In this array microphone device 11, the convex portion 47 of the device main body 25 is inserted into the inner hole 45 of the frame 27 formed of a square frame from the lower side. The convex portion 47 has an overhanging portion 107 that protrudes outward from the outer periphery. The overhanging portion 107 overlaps the lower side of the horizontal portion 39 of each bracket 37 that constitutes the four sides of the frame 27. The overhanging portion 107 has an annular space 113. The device main body 25 accommodates the outer edge 115 of the array microphone 83 that protrudes beyond the accommodation space of the convex portion 47.

[0071] As a result, in the array microphone device 11, the sound collection area 59 of the microphone 95 can be set to have a small distance w1 between the microphone 95 and the T-bar 21 within a range where the sound collection area 59 does not interfere with the T-bar 21. That is, by providing the annular space 113, the sound collection area 59 (specifically, the radius r of the concentric circles) can be secured to the maximum extent without degrading the directivity characteristics of sound collection. In this case (when securing to the maximum extent), the case bottom plate 111 is set to an appropriate length at the design stage so as not to block the sound collection area 59.

[0072] Therefore, according to the array microphone device 11 according to the first embodiment, the front surface 31 of the main body can be retracted behind the front surface 29 of the other panel without degrading the directivity characteristics of sound collection.

[0073] <Regarding the technology of the present disclosure> As described above, the following technical ideas are disclosed in the present disclosure.

[0074] (Technology 1) An array microphone device placed in the opening of a suspended ceiling system where a ceiling panel is placed on the opening of a lattice body, instead of the ceiling panel, the array microphone device comprising: a device main body that houses an array microphone; a frame fixed to the device main body and placed on the opening, and having: the frame placed on the opening supports the device main body by retracting the front surface of the device main body upward relative to the panel front surface, which is the lower surface in the vertical direction of the ceiling panel placed on the other opening. Array microphone device.

[0075] (Technology 2) The frame is assembled by connecting four brackets of the same width and the same length corresponding to each side of a square frame to each other. The array microphone device according to (Technology 1).

[0076] (Technology 3) The bracket has a crank bent portion formed by a flange portion that rests on the mounting piece portion of the opening, an upright portion that bends upward at a right angle from the flange portion, and a horizontal portion that bends at a right angle from the upright portion and overlaps the apparatus main body in parallel with the front surface of the main body. The array microphone device according to (Technology 1) or (Technology 2).

[0077] (Technology 4) The bracket has fixed piece portions that bend upward at a right angle from the horizontal portion at both ends in the direction along one side of the square frame. Four of the brackets are assembled to the square frame by fastening the fixed piece portions to each other. The array microphone device according to any one of (Technology 1) to (Technology 3).

[0078] (Technology 5) The front surface of the main body is formed in a square shape. The array microphone is arranged in a square shape that is smaller than the front surface of the main body, parallel to and coaxial with the front surface of the main body. The array microphone is provided with a plurality of microphones in the circumferential direction of at least one concentric circle centered on an array central axis perpendicular to the array microphone. The sound collection region surrounded by the conical surface of a substantially straight circular cone having a circular bottom surface on the lower side with the microphone as the apex does not interfere with the lower end of the T-bar constituting the lattice body. The array microphone device according to any one of (Technology 1) to (Technology 4).

[0079] (Technology 6) The microphone directivity angle, which is the apex angle of the substantially straight circular cone surrounding the sound collection region of the microphone, is 150°. The array microphone device according to (Technology 5).

[0080] (Technology 7) The apparatus main body has a convex portion that protrudes upward from the inner hole in the square frame of the frame. The convex portion is formed with an overhanging portion that protrudes outward from the outer periphery of the convex portion and overlaps the lower side of the horizontal portion. Inside the protruding portion, the outer edge of the array microphone is accommodated. The array microphone device according to (Technology 3).

[0081] As described above, various embodiments have been described with reference to the accompanying drawings, but the present disclosure is not limited to such examples. It is obvious that those skilled in the art can conceive of various change examples, correction examples, substitution examples, addition examples, deletion examples, and equivalent examples within the scope described in the claims, and it is understood that these also belong to the technical scope of the present disclosure. Also, within the scope not departing from the gist of the invention, the components in the above-described various embodiments may be arbitrarily combined.

Industrial Applicability

[0082] The present disclosure is useful as an array microphone device that can retract the front surface of the main body behind the front surface of other panels without degrading the sound collection directivity characteristics.

Explanation of Signs

[0083] 11…Array microphone device 13…Opening 15…System ceiling 17…Lattice body 19…Ceiling panel 21…T-bar 23…Mounting piece part 25…Device main body 27…Frame 29…Panel front surface 31…Main body front surface 37…Bracket 39…Horizontal part 41…Fixed piece part 45…Inner hole 47…Protrusion 55…Flange part 57…Crank bending part 59…Sound collection area 63…Upright part 83…Array microphone 93…Array central axis 95…Microphone 107…Protruding portion 115... Outer edge θ... Microphone directivity angle

Claims

1. An array microphone device disposed in the opening of a suspended ceiling system where a ceiling panel is disposed in the opening of a lattice body, instead of the ceiling panel, comprising: A device body that houses an array microphone; A frame fixed to the device body and disposed in the opening, and The frame disposed in the opening supports the device body by retracting the front surface of the device body upward in the vertical direction from a panel front surface, which is a lower surface in the vertical direction of a ceiling panel disposed in another opening constituting the suspended ceiling system. An array microphone device.

2. The frame is assembled by connecting four brackets of the same width and the same length to each side of a square frame constituting the outer shape of the device body and connecting them to each other. The array microphone device according to claim 1.

3. The bracket has a crank bent portion including a flange portion that rests on a mounting piece portion of the opening, an upright portion that bends upward at a right angle from the flange portion, and a horizontal portion that bends at a right angle from the upright portion and overlaps the device body in parallel with the front surface of the body. The array microphone device according to claim 2.

4. The bracket has fixing piece portions that bend upward at a right angle from the horizontal portion at both ends in the direction along one side of the square frame, The four brackets are assembled into the square frame by fastening the fixing piece portions to each other. The array microphone device according to claim 3.

5. The front surface of the body is formed in a square shape, The array microphone is disposed in a square smaller than the front surface of the body, parallel and coaxial with the front surface of the body, The array microphone is provided with a plurality of microphones in the circumferential direction of at least one concentric circle centered on an array central axis perpendicular to the array microphone. The sound collection area surrounded by the conical surface of a substantially straight circular cone with a circular bottom surface on the lower side with the microphone as the apex does not interfere with the lower ends of the T-bars constituting the grid body. The array microphone device according to any one of claims 1 to 4.

6. The microphone directivity angle, which is the apex angle of the substantially straight circular cone surrounding the sound collection area of the microphone, is 150°. The array microphone device according to claim 5.

7. The device body has a convex portion that protrudes upward from the inner hole in the square frame of the frame. On the convex portion, an overhanging portion that protrudes outward from the outer periphery of the convex portion and overlaps the lower side of the horizontal portion is formed. Inside the overhanging portion, the outer edge of the array microphone is accommodated. The array microphone device according to claim 3.

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