Microphone Equipment
By designing a micro acoustic device with multi-directional acoustic hole and rotary cover structure, the problem that the prior art cannot collect multi-directional sound at the same time is solved, and efficient multi-channel audio recording and flexible sound collection are achieved.
Patent Information
- Application Number
- JP2022029583
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-02-28
- Publication Date
- 2025-05-08
- Estimated Expiration
- 2042-02-28
AI Technical Summary
The prior art cannot effectively collect sound from multiple directions, and it cannot simultaneously collect multi-directional sound when directional changes.
A miniature acoustic device is designed, adopting multiple undirected acoustic holes and a rotary cover structure to ensure that the acoustic holes do not overlap in different directions. The rotary cover opens the corresponding acoustic holes by rotating to collect sound.
Efficient collection of sounds in multiple directions and multi-channel audio recording are achieved, reducing the size of the device and improving the flexibility of sound collection.
Smart Images
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Abstract
Description
[Technical Field]
[0001] The present invention relates to a microphone device. [Background technology]
[0002] Patent document 1 discloses a variable directivity superdirectional microphone that is composed of a first acoustic tube having multiple rows of sound holes, each row having a plurality of sound holes covered with an acoustic resistance material arranged in a straight line from one end of the tube to the other, a microphone unit connected to the first acoustic tube, and a second acoustic tube having a slit-shaped opening inserted tightly into the first acoustic tube, and whose directivity can be changed by rotating the second acoustic tube. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-336588 Summary of the Invention [Problem to be solved by the invention]
[0004] However, although Patent Document 1 can change the directivity, it cannot collect sounds coming from multiple directions.
[0005] The present invention has been made in view of the above circumstances, and has as its object to provide a small microphone device that can pick up sounds coming from a plurality of directions. [Means for solving the problem]
[0006] In order to solve the above problems, the microphone device of the present invention comprises a housing, for example, cylindrical, barrel-shaped, spherical, hemispherical, spherically-detailed, or spherical-frustum-shaped, with an internal space provided near the center of gravity; an omnidirectional microphone provided in the internal space; and a cover provided along the outer peripheral surface of the housing so as to cover at least a portion of the outer peripheral surface, the cover being rotatable around the central axis, wherein the housing has a plurality of sound holes communicating with the internal space and a space outside the housing, the plurality of sound holes being arranged so as not to overlap when viewed along the central axis of the housing, and the cover has a sound collection hole that exposes at least one of the plurality of sound holes.
[0007] In order to solve the above problems, the microphone device of the present invention comprises a housing, for example, in the shape of a cylinder, barrel, sphere, hemisphere, truncated sphere, or spherical trapezoid, having an internal space provided near the center of gravity, an omnidirectional microphone provided in the internal space, and a cover provided along the external surface of the housing so as to cover at least a portion of the external surface, wherein the housing has a plurality of sound holes communicating with the internal space and a space outside the housing, and the plurality of sound holes are provided so as not to overlap when viewed along the central axis of the housing, the cover has a plurality of sound collection sections provided corresponding to the plurality of sound holes, and the sound collection section has a sound collection hole that exposes the sound hole, and an opening / closing door that is provided so as to be movable between a position that covers the sound collection hole and a position that opens the sound collection hole.
[0008] According to these microphone devices of the present invention, an omnidirectional microphone is provided in an internal space provided near the center of gravity of a cylindrical, barrel-shaped, spherical, hemispherical, spherical truncated, or spherically shaped housing. This also exposes at least one of the multiple sound holes through a sound collection hole provided in a cover along the outer periphery so as to cover at least a portion of the outer periphery of the housing. This allows the microphone device to collect sounds coming from multiple directions.
[0009] The sound holes may be n in number, spaced apart at 360 / n° intervals when viewed along the central axis, and the microphones may comprise n unidirectional microphones corresponding to the n sound holes, each of which collects sound obtained through the corresponding sound hole, and the sound collection holes may have a central angle of approximately 360 / n° when viewed along the central axis. This allows the microphones to collect sounds in all directions in sequence.
[0010] The device may include an actuator that drives the opening / closing door, and a drive control unit that opens and closes the opening / closing door via the actuator so that at least one of the plurality of sound holes is open, wherein n sound holes are provided at intervals of 360 / n° when viewed along the central axis, and the microphones may comprise n unidirectional microphones corresponding to the n sound holes, respectively, and each of the unidirectional microphones may collect sound obtained through the corresponding sound hole. This allows the microphones to collect sound in all directions.
[0011] The system may further include a processing unit that stores sounds picked up by the plurality of unidirectional microphones in different channels, thereby enabling multi-channel recording of sounds from all directions.
[0012] The sound holes may be n in number and arranged at intervals of 360 / n° when viewed along the central axis, the microphone may be a single omnidirectional microphone, the n sound holes may be the same size, and the sound collection hole may have a central angle when viewed along the central axis that is approximately 360 / n° minus the central angle of the sound hole. This allows a single microphone to pick up sounds coming from multiple directions.
[0013] The device may include an actuator that drives the door and a drive control unit that opens and closes the door via the actuator so that one of the sound holes is open, where n sound holes are provided at intervals of 360 / n degrees when viewed along the central axis, and the microphone may be a single omnidirectional microphone, thereby enabling a single microphone to pick up sounds coming from multiple directions.
[0014] The microphone may be configured to record the sound picked up by the microphone through the sound holes in a different channel for each of the sound holes, thereby enabling multi-channel recording of sounds from all directions. [Effects of the Invention]
[0015] According to the present invention, it is possible to provide a small microphone device that can pick up sounds coming from a plurality of directions. [Brief explanation of the drawings]
[0016] [Figure 1] 1A and 1B are diagrams showing an outline of a microphone device 1, in which (A) is a perspective view and (B) is a cross-sectional view taken along a plane P. FIG. [Figure 2] 1 is a block diagram showing a schematic electrical configuration of a microphone device 1. FIG. [Figure 3] 1A and 1B are diagrams showing a schematic diagram of the microphone device 1 performing multi-channel recording, in which (A) shows a state in which only the sound hole 12a is open, (B) shows a state in which the sound holes 12a and 12b are open, and (C) and (D) show a state in which only the sound hole 12b is open. [Figure 4] 4 is a diagram showing the state of sounds picked up by channels 1 to 4 in FIGS. 3(A) to 3(D). FIG. [Figure 5] FIG. 10 is a diagram showing an outline of a microphone device 1A according to a modified example. [Figure 6] 10(A) to 10(D) are diagrams showing an outline of microphone devices 1B to 1E according to modified examples. [Figure 7]1A and 1B are diagrams showing an outline of a microphone device 2, in which (A) is a perspective view and (B) is a cross-sectional view taken along a plane P. FIG. [Figure 8] 2 is a block diagram showing a schematic electrical configuration of the microphone device 2. FIG. [Figure 9] 1A and 1B are diagrams showing an outline of a microphone device 3, in which (A) is a perspective view and (B) is a cross-sectional view taken along a plane P. FIG. [Figure 10] 2 is a block diagram showing a schematic electrical configuration of the microphone device 3. FIG. DETAILED DESCRIPTION OF THE INVENTION
[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a microphone device according to the present invention will be described in detail with reference to the drawings. First Embodiment 1 is a diagram showing an outline of a microphone device 1, where (A) is a perspective view and (B) is a cross-sectional view taken along a plane P (described in detail later). The microphone device 1 mainly includes a housing 10, a cover 20, and a microphone 30.
[0018] Hereinafter, the direction along the central axis ax of the housing 10 is referred to as the z direction. Two directions perpendicular to the z direction are referred to as the x direction and the y direction. The x direction and the y direction are perpendicular to each other. A plane P passes through the center of gravity G of the housing 10 and is along the x direction and the y direction.
[0019] The housing 10 has a cylindrical shape. An internal space 11 is provided near the center of gravity G of the housing 10. In this embodiment, the internal space 11 has a cylindrical shape and is formed inside the housing 10 so as to include the center of gravity G.
[0020] The housing 10 is also provided with sound holes 12. The sound holes 12 include a plurality of (here, four) sound holes 12a, 12b, 12c, and 12d.
[0021] Sound holes 12a, 12b, 12c, and 12d communicate between internal space 11 and the space outside housing 10. That is, sound holes 12a, 12b, 12c, and 12d have one end opening to outer peripheral surface 13 of housing 10 and the other end opening to internal space 11.
[0022] The four sound holes 12a, 12b, 12c, and 12d are provided so as not to overlap when viewed along the central axis ax. In this embodiment, the four sound holes 12a, 12b, 12c, and 12d are provided at 90° (=360 / 4°) intervals when viewed along the central axis ax.
[0023] The sound holes 12a, 12b, 12c, and 12d have a fan-like or partial ring-like shape when viewed along the central axis ax. However, the shapes of the sound holes 12a, 12b, 12c, and 12d are not limited to these. Furthermore, the sizes of the sound holes 12a, 12b, 12c, and 12d (for example, the size of the central angle) are not limited to these.
[0024] The cover 20 is provided along the outer peripheral surface 13 of the housing 10 so as to cover at least a portion of the outer peripheral surface 13. In this embodiment, the cover 20 has a cylindrical shape and covers the entire outer peripheral surface 13.
[0025] The cover 20 has a sound collection hole 21 that exposes at least one of the sound holes 12a, 12b, 12c, and 12d. The sound collection hole 21 has a central angle of approximately 90° (=360 / 4°) when viewed along the central axis ax.
[0026] The cover 20 is rotatable around the central axis ax. For example, a convex portion (not shown) is provided on the inner peripheral surface of the cover 20, a groove (not shown) is provided on the outer peripheral surface 13, and the convex portion of the cover is inserted into the groove and moved inside the groove, thereby allowing the cover 20 to rotate about the central axis ax.
[0027] Microphone 30 is provided in interior space 11 and has omnidirectional characteristics. In this embodiment, microphone 30 is made up of four unidirectional microphones 31a, 31b, 31c, and 31d corresponding to four sound holes 12a, 12b, 12c, and 12d, respectively. Unidirectional (cardioid) microphones with the highest sensitivity to the front can be used for unidirectional microphones 31a, 31b, 31c, and 31d.
[0028] Unidirectional microphones 31a, 31b, 31c, and 31d are arranged with their fronts facing sound holes 12a, 12b, 12c, and 12d, respectively, and pick up sounds obtained through sound holes 12a, 12b, 12c, and 12d, thereby making it possible to give microphone 30 omnidirectional characteristics.
[0029] 2 is a block diagram showing a schematic electrical configuration of the microphone device 1. The microphone device 1 includes an actuator 25 and a control unit 50. The control unit 50 includes at least a processing unit 51 and a drive control unit 52 as software resources, which are implemented by a calculation device such as a CPU (Central Processing Unit) or a storage device.
[0030] The processing unit 51 is a functional unit that stores sounds collected by the unidirectional microphones 31a, 31b, 31c, and 31d in different channels. For example, the processing unit 51 stores the sound collected by the unidirectional microphone 31a in channel 1 (see FIG. 4), the sound collected by the unidirectional microphone 31b in channel 2 (see FIG. 4), the sound collected by the unidirectional microphone 31c in channel 3 (see FIG. 4), and the sound collected by the unidirectional microphone 31d in channel 4 (see FIG. 4). The sounds stored in channels 1 to 4 are stored in a storage unit, storage medium, or the like (not shown).
[0031] The drive control unit 52 is a functional unit that controls the actuator 25 to rotate the cover 20. The actuator 25 is connected to the cover 20 and rotates the cover 20 at an arbitrary speed.
[0032] 3 is a diagram showing a state in which the microphone device 1 performs multi-channel recording, where (A) shows a state in which only the sound hole 12a is open, (B) shows a state in which the sound holes 12a and 12b are open, and (C) and (D) show a state in which only the sound hole 12b is open. Figures 3(A) to 3(D) are arranged in chronological order. In Figure 3, the cover 20 rotates clockwise when viewed from the +z direction.
[0033] FIG. 4 is a diagram showing the state of sounds picked up by channels 1 to 4 in FIGS. 3(A) to 3(D).
[0034] When the rotating cover 20 is in the position shown in Fig. 3(A), the sound collection hole 21 opens only the sound hole 12a, and the sound holes 12b, 12c, and 12d are covered by the cover 20. The edge 12h of the sound hole 12a and the edge 21a of the sound collection hole 21 are aligned, and the central angle when viewed along the central axis ax of the sound collection hole 21 is approximately 90°, so the sound collection hole 21 does not overlap with the sound hole 12b, and the sound collection hole 21 opens only the sound hole 12a. As a result, in the state shown in Fig. 3(A), sound is stored only in channel 1, as shown in Fig. 4.
[0035] When the cover 20 rotates from the state shown in Fig. 3(A) to the state shown in Fig. 3(B), the sound collection hole 21 opens the sound holes 12a and 12b. As a result, in the state shown in Fig. 3(B), sound is stored in channels 1 and 2 as shown in Fig. 4.
[0036] When the cover 20 rotates from the state shown in FIG. 3(B) to the state shown in FIG. 3(C) where the end 12i of the sound hole 12b and the end 21b of the sound collection hole 21 are aligned, the sound collection hole 21 does not overlap the sound hole 12a, and the sound collection hole 21 opens only the sound hole 12b.
[0037] Thereafter, cover 20 rotates from the state shown in Fig. 3(C) until it reaches the state shown in Fig. 3(D) where end 12j of sound hole 12b and end 21a of sound collection hole 21 are aligned, and sound collection hole 21 opens only sound hole 12b. As a result, in the state shown in Figs. 3(C) and (D), sound is stored only in channel 2, as shown in Fig. 4.
[0038] Thereafter, when the cover 20 is rotated from the state shown in FIG. 3(D), the sound collection hole 21 opens the sound holes 12b and 12c, and the sound is stored in the channels 2 and 3.
[0039] According to this embodiment, sounds from multiple directions can be recorded in multiple channels by collecting sounds from multiple directions through sound holes 12a to 12d with microphone 30. Furthermore, since multidirectional microphone 30 is provided in the center of housing 10, the device can be made smaller.
[0040] Furthermore, according to this embodiment, by arranging the four sound holes 12a, 12b, 12c, and 12d at intervals of 90° (=360 / 4°) when viewed along the central axis ax, it is possible for the microphone 30 to pick up sounds from all directions.
[0041] Furthermore, according to this embodiment, sound holes 12a, 12b, 12c, and 12d can be opened in sequence by rotating cover 20 provided with sound collection hole 21. As a result, sounds from all directions can be collected by microphone 30 in sequence.
[0042] Furthermore, according to this embodiment, when viewed along the central axis ax, the four sound holes 12a, 12b, 12c, and 12d are provided at intervals of 90° (=360 / 4°), and the central angle of the sound collection hole 21 is set to approximately 90° (=360 / 4°). This allows sound to be collected by two of the four sound holes 12a, 12b, 12c, and 12d. Then, based on the sounds collected by the two sound holes 12, the sound of a channel where no sound is collected can be complemented. Complementing the sound of a channel where no sound is collected can be achieved, for example, by analyzing the sounds collected by channels 1 and 2 in FIGS. 3 and 4(B), and generating a sound that is considered to have been collected by channel 2 from the sound collected by channel 1 in FIGS. 3 and 4(A) based on these results. Furthermore, because the volume of the collected sound decreases when only some of the four sound holes 12a, 12b, 12c, and 12d are open, the volume stored in each channel may be adjusted based on the maximum value of the collected sound. The sound supplementation and volume adjustment may be performed by the microphone device 1 or by an external device connectable to the microphone device 1.
[0043] In this embodiment, the four sound holes 12a, 12b, 12c, and 12d are provided at intervals of 90° (=360 / 4°), that is, this corresponds to the case where n=4 in the present invention, but n is not limited to 4. In the present invention, n may be any natural number equal to or greater than 2. For example, when n=2, two sound holes are provided in the housing at intervals of 180° (=360 / 2°), the central angle of the sound collection hole in the cover is set to approximately 180° (=360 / 2°), and two unidirectional microphones corresponding to each of the two sound holes are provided in the internal space of the housing.
[0044] Furthermore, in the present embodiment, the microphone device 1 has a cylindrical shape, but the shape of the microphone device 1 is not limited to this. Fig. 5 is a diagram showing an outline of a microphone device 1A according to a modified example. The microphone device 1A mainly includes a housing 10A, a cover 20A, and a microphone 30 (not shown in Fig. 5).
[0045] The housing 10A has a spherical shape, and an internal space 11A is provided near the center of gravity G. In this embodiment, the internal space 11A has a spherical shape. A microphone 30 is provided in the internal space 11A.
[0046] The housing 10A is also provided with sound holes 12A that connect the internal space 11A to the space outside the housing 10A. The sound holes 12A include multiple sound holes that are provided so as not to overlap when viewed along the central axis ax. For example, four sound holes 12A may be provided at intervals of 90° (=360 / 4°) when viewed along the central axis ax.
[0047] The cover 20A is provided along the outer peripheral surface of the housing 10A so as to cover at least a portion of the outer peripheral surface of the housing 10A. In this embodiment, the cover 20A has a spherical band shape (a hollow spherical truncated shape). Note that the spherical truncated shape is a solid formed by cutting a sphere with a pair of parallel planes, and the spherical band is its side surface (curved surface).
[0048] The cover 20A has a sound collection hole 21A that exposes at least one of the sound holes 12A. The cover 20A is rotatable around a central axis ax (see the arrow in Figure 5). By rotating the cover 20A, at least one of the sound holes 12A is exposed in turn, allowing multi-channel recording with the microphone 30.
[0049] The shape of the microphone according to the modified example is not limited to the spherical shape shown in Fig. 5. Fig. 6 is a diagram showing an outline of microphone devices 1B to 1E according to the modified example. Fig. 6(A) is a diagram showing an outline of microphone device 1B having a hemispherical shape. Microphone device 1B may have a hemispherical housing and a cover having a hollow spherical detent shape, a hollow semicircular shape, or a spherical zone shape. The spherical detent shape is a three-dimensional shape that is created when a sphere is cut along a single plane.
[0050] 6(B) is a diagram showing an outline of a spherically-detailed microphone device 1C. The microphone device 1C may have a housing in a spherically-detailed shape and a cover in a hollow spherically-detailed shape, a hollow semicircular shape, or a spherical band shape.
[0051] 6(C) is a diagram showing an outline of a microphone device 1D having a spherical truncated shape. The microphone device 1D may have a housing having a spherical truncated shape and a cover having a spherical belt shape.
[0052] 6(D) is a diagram showing an outline of a barrel-shaped microphone device 1E. The microphone device 1D may have a barrel-shaped housing and a hollow barrel-shaped cover. The barrel shape is a cylinder with curved sides and a three-dimensional shape with the largest diameter near the center in the longitudinal direction.
[0053] <Second embodiment> In the microphone device 1 according to the first embodiment of the present invention, the sound holes 12a, 12b, 12c, and 12d are opened in sequence by rotating the cover 20, but the method of opening the sound holes 12a, 12b, 12c, and 12d in sequence is not limited to this. Below, a microphone device 2 according to a second embodiment will be described. Note that the same parts as those in the first embodiment are given the same reference numerals and description thereof will be omitted.
[0054] 7A and 7B are diagrams showing an outline of the microphone device 2, in which (A) is a perspective view and (B) is a cross-sectional view taken along a plane P. The microphone device 2 mainly includes a housing 10, a cover 20B, and a microphone 30.
[0055] Cover 20B is provided along outer peripheral surface 13 of housing 10 so as to cover at least a portion of the outer peripheral surface of housing 10. In this embodiment, cover 20 has a cylindrical shape and covers the entire outer peripheral surface 13.
[0056] The cover 20B has a plurality of sound collection sections 23 provided corresponding to the plurality of sound holes 12a, 12b, 12c, and 12d, respectively. In the present embodiment, since there are four sound holes 12a, 12b, 12c, and 12d, there are also four sound collection sections 23 (sound collection sections 23a, 23b, 23c, and 23d). The four sound collection sections 23a, 23b, 23c, and 23d correspond to the sound holes 12a, 12b, 12c, and 12d, respectively, and are provided at intervals of 90° (=360 / 4°) when viewed along the central axis ax.
[0057] Sound collection unit 23 has sound collection hole 21A that exposes the sound hole, and opening / closing door 22. Sound collection unit 23a has sound collection hole 21e and opening / closing door 22a, sound collection unit 23b has sound collection hole 21f and opening / closing door 22b, sound collection unit 23c has sound collection hole 21g and opening / closing door 22c, and sound collection unit 23d has sound collection hole 21h and opening / closing door 22d.
[0058] Doors 22a, 22b, 22c, and 22d are provided so as to be movable between a position where they cover sound collection holes 21e, 21f, 21g, and 21h and a position where they open them, respectively. For example, by providing a protrusion (not shown) on door 22 and a groove (not shown) on cover 20B, and inserting the protrusion of door 22 into the groove and moving the protrusion inside the groove, door 22 can be moved along the inner circumferential surface of cover 20B.
[0059] When the doors 22a, 22b, 22c, and 22d are opened, the sound collection holes 21e, 21f, 21g, and 21h are opened, and the sound holes 12a, 12b, 12c, and 12d are exposed. This allows the microphone 30 to collect sound through the sound holes 12a, 12b, 12c, and 12d.
[0060] 8 is a block diagram showing a schematic electrical configuration of the microphone device 2. The microphone device 1 includes an actuator 26 and a control unit 50A. The control unit 50A includes at least a processing unit 51 and a drive control unit 53 as software resources, implemented by a calculation device such as a CPU (Central Processing Unit) or a storage device.
[0061] The actuators 26 drive the opening and closing doors 22a, 22b, 22c, and 22d. In this embodiment, the actuators 26 include four actuators 26a, 26b, 26c, and 26d provided on the opening and closing doors 22a, 22b, 22c, and 22d, respectively.
[0062] The drive control unit 53 is a functional unit that opens and closes the opening and closing doors 22a, 22b, 22c, and 22d via the actuators 26a, 26b, 26c, and 26d so that at least one of the plurality of sound holes 12a, 12b, 12c, and 12d is open.
[0063] For example, the drive control unit 53 may control the actuator 26 to open the doors 22a, 22b, 22c, and 22d in order. Furthermore, for example, the drive control unit 53 may control the actuator 26 to create a state in which sound is picked up by the microphone 30 through one sound hole 12a, 12b, 12c, and 12d, and a state in which sound is picked up by the microphone 30 through two adjacent sound holes 12a, 12b, 12c, and 12d.
[0064] According to this embodiment, sounds from multiple directions can be recorded in multiple channels by collecting sounds from multiple directions through sound holes 12a to 12d with microphone 30. Furthermore, since there is no need to rotate cover 20, the device can be made smaller.
[0065] In the present embodiment, the doors 22a, 22b, 22c, and 22d are provided along the inner peripheral surface of the cover 20B (between the sound collection holes 21e, 21f, 21g, and 21h and the housing 10), but the positions of the doors 22a, 22b, 22c, and 22d are not limited to this. For example, the doors 22a, 22b, 22c, and 22d may be provided along the outer peripheral surface of the cover 20B.
[0066] Furthermore, in this embodiment, the four sound holes 12a, 12b, 12c, and 12d are the same size, but the four sound holes may be different sizes.
[0067] In addition, although the present embodiment has been described taking the cylindrical housing 10 and cylindrical cover 20B as examples, the shape of the housing 10 is not limited to a cylindrical, barrel, spherical, hemispherical, spherically-segmented, or spherical truncated shape, and the cover 20B is not limited to a cylindrical shape. For example, the microphone device may have a polygonal prism-shaped housing and a polygonal cylindrical cover.
[0068] <Third embodiment> Although the microphone device 1 according to the first embodiment of the present invention is configured as an omnidirectional microphone using a plurality of unidirectional microphones, the microphone configuration is not limited to this. Below, a microphone device 3 according to a third embodiment will be described. Note that the same parts as those in the first embodiment are given the same reference numerals and description thereof will be omitted.
[0069] 9A and 9B are diagrams showing an outline of the microphone device 3, where (A) is a perspective view and (B) is a cross-sectional view taken along plane P. The microphone device 3 mainly includes a housing 10B, a cover 20C, and a microphone 30A.
[0070] Housing 10B has a cylindrical shape, and an internal space 11 is provided near center of gravity G. Housing 10B also has sound hole 12A, which has multiple (here, two) sound holes 12e and 12f.
[0071] Sound holes 12e and 12f communicate internal space 11 with the space outside housing 10B. That is, sound holes 12e and 12f have one end opening to outer peripheral surface 13 and the other end opening to internal space 11.
[0072] The two sound holes 12e, 12f are provided so as not to overlap when viewed along the central axis ax. In this embodiment, the two sound holes 12e, 12f are provided at intervals of 180° (=360 / 2°) when viewed along the central axis ax.
[0073] The sound holes 12e, 12f have a fan-shaped or partially annular shape when viewed along the central axis ax. However, the shape of the sound holes 12e, 12f is not limited to this, and the size (for example, the size of the central angle) is not limited to this either.
[0074] Cover 20C is provided along outer peripheral surface 13 of housing 10B so as to cover at least a portion of outer peripheral surface 13. Cover 20C is rotatable around central axis ax. Cover 20 and cover 20C are the same except for the size of the sound collection hole.
[0075] The cover 20C has a sound collection hole 21B that exposes either the sound hole 12e or 12f. The sound collection hole 21B is semicircular. When viewed along the central axis ax, the central angle θ1 of the sound collection hole 21B is approximately 180° (=360 / 2°) minus the central angle θ2 of the sound holes 12e and 12f, and is expressed by the following equation (1): Central angle θ1 = approx. 180° - central angle θ2 (1)
[0076] Microphone 30A is provided in interior space 11 and has omnidirectional characteristics. In this embodiment, microphone 30A is a single omnidirectional microphone.
[0077] 10 is a block diagram showing a schematic electrical configuration of the microphone device 3. The microphone device 3 includes an actuator 25, a sensor 27, and a control unit 50B. The control unit 50B includes at least a processing unit 51A and a drive control unit 52 as software resources, using a calculation device such as a CPU (Central Processing Unit) or a storage device.
[0078] Sensor 27 detects the position of cover 20C in the rotational direction, i.e., the position of sound collection hole 21B. For example, sensor 27 outputs a signal when the edge of sound collection hole 21B coincides with edge 12k of sound hole 12e (see FIG. 9). The detection result by sensor 27 is input to processing unit 51A.
[0079] The processing unit 51A is a functional unit that stores sounds picked up by the microphone 30A through the sound holes 12e and 12f in different channels for each of the sound holes 12e and 12f. For example, based on the detection result of the sensor 27, the processing unit 51A stores the sound picked up by the microphone 30A through the sound hole 12e in channel 1 and stores the sound picked up by the microphone 30A through the sound hole 12f in channel 2.
[0080] Next, the relationship between the rotation of the cover 20C and the sound pickup by the microphone 30A will be described with reference to Fig. 9(B). When viewed from the +z direction, the cover 20C rotates clockwise (see the arrow in Fig. 9(B)).
[0081] 9(B), the edge 21c of the sound collection hole 21B is aligned with the edge 12k of the sound hole 12e. In this case, the sound collection hole 21B opens only the sound hole 12e, and the sound hole 12f is covered by the cover 20C.
[0082] 9(B), cover 20C rotates so that edge 21c of sound collection hole 21B coincides with edge 12l of sound hole 12e, leaving only sound hole 12e open. While sound hole 12e is open, the sound picked up by microphone 30A is stored in channel 1.
[0083] When end 21c of sound collection hole 21B is aligned with end 12l of sound hole 12e, end 21d of sound collection hole 21B is aligned with end 12m of sound hole 12f. When cover 20C is then rotated, sound collection hole 21B opens only sound hole 12f, and sound hole 12e is covered by cover 20C.
[0084] Thereafter, cover 20 rotates, and sound collection hole 21B opens only sound hole 12f until end 21c of sound collection hole 21B coincides with end 12n of sound hole 12f. While sound hole 12f is open, the sound picked up by microphone 30A is stored in channel 2.
[0085] According to this embodiment, by opening sound holes 12e and 12f one by one, it is possible to collect sounds coming from multiple directions with one microphone 30A. Then, by storing the sounds collected through sound holes 12e and 12f in different channels, it is possible to record sounds from all directions in a multi-channel manner.
[0086] In this embodiment, the two sound holes 12e and 12f are provided 180° apart, which corresponds to the case where n=2 in the present invention, but n is not limited to 2. In the present invention, n may be any natural number equal to or greater than 2.
[0087] Furthermore, in the present embodiment, processing unit 51A stores the sound collected by microphone 30A through sound hole 12e in channel 1 and the sound collected by microphone 30A through sound hole 12f in channel 2 based on the detection results of sensor 27. However, the method by which processing unit 51A stores the sound collected by microphone 30A in a different channel for each of sound holes 12e and 12f is not limited to this. For example, if the position and rotation speed of sound collection hole 21B are stored in a storage unit (not shown) or the like in advance without using sensor 27, processing unit 51A can determine which of sound holes 12e and 12f is open at a given time based on this information, and store the sound in the channel based on the open sound hole 12e or 12f. Even in this case, sounds from multiple directions can be collected by microphone 30A through sound holes 12e and 12f.
[0088] Furthermore, in the present embodiment, the cover 20C is rotated to open the sound hole 12e or 12f, but the cover may have a plurality of sound collection units provided for each of the sound holes 12e and 12f. The sound collection units provided for each of the sound holes 12e and 12f may have a sound collection hole that exposes the sound hole and an opening / closing door that is provided so as to be movable between a position that covers the sound collection hole and a position that opens the sound collection hole, and the sound hole 12e or 12f may be opened by alternately opening and closing the opening / closing door. For example, the device may include an actuator (one or more) that drives the opening / closing door provided for each of the sound holes 12e and 12f, and a drive control unit that opens and closes the opening / closing door via the actuator so that one of the sound holes 12e and 12f is opened.
[0089] Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention also includes design modifications and the like within the scope of the gist of the present invention. Those skilled in the art will be able to modify, add, convert, etc., each element of the embodiments as appropriate.
[0090] Furthermore, in the present invention, the term "substantially" is a concept that includes not only cases where the two are strictly identical, but also errors or deformations to the extent that the identity is not lost. For example, "orthogonal" is not limited to cases where the two are strictly orthogonal, but also includes cases where there is an error of several degrees from the orthogonal direction. Furthermore, for example, when simply expressing "orthogonal," "parallel," etc., it includes not only cases where the two are strictly orthogonal or parallel, but also cases where the two are approximately orthogonal or approximately parallel. Furthermore, in the present invention, "nearby" means including a certain range (which can be arbitrarily determined) near a reference position. For example, when referring to the vicinity of A, it is a concept that indicates a certain range near A, which may or may not include A. [Explanation of symbols]
[0091] 1, 1A, 1B, 1C, 1D, 1E, 2, 3: Microphone device 10, 10A, 10B: Housing 11, 11A: Internal space 12, 12A, 12a, 12b, 12c, 12d, 12e, 12f: tone holes 12h, 12i, 12j, 12k, 12l, 12m, 12n: End 13: Outer Peripheral Surface 20, 20A, 20B, 20C: カバー 21, 21A, 21B, 21e, 21f, 21g, 21h: Sound collection holes 21a, 21b, 21c, 21d: End 22, 22a, 22b, 22c, 22d: Opening and closing doors 23, 23a, 23b, 23c, 23d: Collected Sounds 25, 26, 26a, 26b, 26c, 26d:アクチュエータ 27 :センサ 30, 30A: MASKAN 31a, 31b, 31c, 31d: Single directivity MAKONA 50, 50A, 50B: Control Department 51, 51A: Processing Department 52, 53: Control Department
Claims
1. A housing having a cylindrical shape, a barrel shape, a sphere shape, a hemisphere shape, a spherical truncated shape, or a spherical frustum shape, the housing having an internal space provided near a center of gravity; an omnidirectional microphone provided in the internal space; a cover provided along an outer peripheral surface of the housing so as to cover at least a portion of the outer peripheral surface, the cover being rotatable about a central axis of the housing; Equipped with the housing has a plurality of sound holes communicating the internal space with a space outside the housing, The plurality of sound holes are provided so as not to overlap when viewed along the central axis, The cover has a sound collection hole that exposes at least one of the plurality of sound holes. A microphone device comprising:
2. A housing having an internal space provided near the center of gravity; an omnidirectional microphone provided in the internal space; a cover provided along the outer circumferential surface of the housing so as to cover at least a portion of the outer circumferential surface; Equipped with the housing has a plurality of sound holes communicating the internal space with a space outside the housing, The plurality of sound holes are provided so as not to overlap when viewed along a central axis of the housing, the cover has a plurality of sound collecting parts provided for the plurality of sound holes, The sound collection unit has a sound collection hole that exposes the sound hole, and an opening / closing door that is movable between a position that covers the sound collection hole and a position that opens the sound collection hole. A microphone device comprising:
3. The sound holes are provided in a number of n, spaced apart from each other at 360 / n° (n is a natural number of 2 or more) when viewed along the central axis, The microphones include n unidirectional microphones corresponding to the n sound holes, Each of the unidirectional microphones picks up a sound obtained through a corresponding one of the sound holes, The sound collection hole has a central angle of approximately 360 / n° when viewed along the central axis.
2. The microphone device according to claim 1,
4. An actuator that drives the opening and closing door; a drive control unit that opens and closes the opening and closing door via the actuator so that at least one of the plurality of sound holes is opened, The sound holes are provided in a number of n, spaced apart from each other at 360 / n° (n is a natural number of 2 or more) when viewed along the central axis, The microphones include n unidirectional microphones corresponding to the n sound holes, Each of the unidirectional microphones picks up a sound obtained through a corresponding one of the sound holes.
3. The microphone device according to claim 2.
5. 5. The microphone device according to claim 3, further comprising a processing unit for storing sounds picked up by the plurality of unidirectional microphones in different channels.
6. The sound holes are provided in a number of n, spaced apart from each other at 360 / n° (n is a natural number of 2 or more) when viewed along the central axis, the microphone is an omnidirectional microphone, The n sound holes are the same size, The sound collection hole has a central angle of approximately 360 / n° minus the central angle of the sound hole when viewed along the central axis.
2. The microphone device according to claim 1,
7. An actuator that drives the opening and closing door; a drive control unit that opens and closes the opening and closing door via the actuator so that one of the plurality of sound holes is opened, The sound holes are provided in a number of n, spaced apart from each other at 360 / n° (n is a natural number of 2 or more) when viewed along the central axis, The microphone is an omnidirectional microphone.
3. The microphone device according to claim 2.
8. 8. The microphone device according to claim 6, further comprising a processing unit that stores the sounds picked up by the microphone through the sound holes in different channels for each of the plurality of sound holes.
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