Microphone device

Abstract

A microphone device (10) is provided with: a housing (20) having an opening (200) and a horn (211) including a horn opening (231) and a horn tube (241) extending in one direction from the horn opening (231); a microphone that converts the sound propagated through the opening (200) into an analog signal; a horn microphone (40) that converts the sound propagated through the horn (211) into an analog signal; an analog wiring (45) that outputs an analog signal from the horn microphone (40); an ADC chip (50) that acquires an analog signal from the speaker microphone (40) via a wiring different from the analog wiring (45) and converts the analog signal from the microphone and the speaker microphone (40) into a digital signal; and a processing unit (60) that performs digital signal processing on the digital signal converted by the ADC chip (50).

Description

Technical Field

[0001] The present disclosure relates to a microphone device. Background Art

[0002] Conventionally, as described in Patent Document 1, there is known an audio system including a plurality of audio ports, an audio path connected to each of the audio ports, and a capsule for converting an audio signal transmitted from a sound source through the audio port and the audio path into an electrical signal.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application No. 2005-536113 Summary of the invention

[0006] In the audio system described in Patent Document 1, digital signal processing such as noise reduction is sometimes performed on the electrical signal converted by the microphone. In this case, the delay time of communication (latency) increases. If the delay increases, it becomes difficult to make a call because, for example, the speaking time of the call overlaps, so the quality of the call is reduced. In addition, if digital signal processing is not performed, the noise makes the call difficult, so the quality of the call is reduced.

[0007] An object of the present disclosure is to provide a microphone device that performs digital signal processing while suppressing an increase in delay.

[0008] A microphone device according to one embodiment of the present invention comprises: a housing having an opening and a speaker, wherein the opening is open, and the speaker includes a speaker opening formed at a position different from the opening and opened, and a speaker tube connected to the speaker opening and extending in one direction; a microphone housed in the housing and converting sound propagated in the opening into an analog signal; a speaker microphone housed in the housing and converting sound propagated in the speaker into an analog signal; an analog wiring housed in the housing and outputting an analog signal from the speaker microphone; a conversion unit that obtains the analog signal from the microphone and obtains the analog signal from the speaker microphone via a wiring different from the analog wiring, and converts the analog signals from the microphone and the speaker microphone into digital signals; and a processing unit that performs digital signal processing on the digital signal converted by the conversion unit.

[0009] Since the signal output from the analog wiring is not subjected to digital signal processing, it is a signal with reduced delay. In addition, the processing unit performs digital signal processing. Therefore, the microphone device performs digital signal processing while reducing the increase in delay. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a diagram showing the configuration of the microphone device according to the first embodiment.

[0011] Figure 2 It is a stereogram of a microphone device.

[0012] Figure 3 is from Figure 2 Magnified view of III observation.

[0013] Figure 4 yes Figure 2 Enlarged cross-sectional view of line IV-IV.

[0014] Figure 5 yes Figure 2 Enlarged cross-sectional view of line VV.

[0015] Figure 6 yes Figure 2 Enlarged cross-sectional view of line VI-VI.

[0016] Figure 7 yes Figure 2 Enlarged cross-sectional view along line VII-VII.

[0017] Figure 8 yes Figure 2 Enlarged cross-sectional view of line VIII-VIII.

[0018] Fig. 9 is a top view of the directivity generator of the microphone device.

[0019] Fig.10 is from Fig. 9 Graph of X observations.

[0020] Fig.11 is from Fig. 9 XI Observed Fig.

[0021] Fig.12 It is a schematic diagram showing a situation in which a plane wave sound wave is incident on a directivity generator at a first angle.

[0022] Fig.13 It is a schematic diagram showing a situation in which a plane wave sound wave is incident on a directivity generator at a second angle.

[0023] Fig.14 The first angle is a distribution diagram showing the relationship between the first angle, the second angle, and the gain of the sound waves collected by the speaker microphone of the microphone device at each frequency of the sound waves.

[0024] Fig.15 This is a diagram showing the relationship between the second angle and the gain of the sound waves collected by the speaker microphone at each frequency of the sound waves when the first angle is fixed.

[0025] Fig.16 This is a distribution diagram showing the relationship between the second angle, each frequency of the sound wave, and the gain of the sound wave collected by the speaker microphone when the first angle is fixed.

[0026] Fig.17 It is a perspective view of a microphone device according to a second embodiment.

[0027] Fig.18 It is an exploded perspective view of the microphone device.

[0028] Fig.19 is a cross-sectional view of a microphone assembly.

[0029] Fig. 20 It is an exploded perspective view of a microphone device according to a third embodiment.

[0030] Fig.21 It is an exploded perspective view of a microphone device according to a fourth embodiment.

[0031] Fig. 22 It is a cross-sectional view of a microphone device according to a fifth embodiment.

[0032] Fig.23 This is a diagram showing the structure of a microphone device. DETAILED DESCRIPTION

[0033] Hereinafter, embodiments will be described with reference to the drawings.

[0034] In addition, in each of the following embodiments, the same or equivalent parts are denoted by the same reference numerals, and the description thereof is omitted.

[0035] (First Embodiment)

[0036] The microphone device of this embodiment performs digital signal processing while suppressing an increase in delay. This microphone device is used in a vehicle, for example.

[0037] Specifically, if Figures 1 to 11 As shown, the microphone device 10 includes a housing 20 , a substrate 30 , an isolator 32 , a microphone 35 , a horn microphone 40 , an analog wiring 45 , an ADC chip 50 , a digital wiring 55 , and a processing unit 60 .

[0038] The housing 20 is formed of resin or the like using injection molding, a 3D printer or the like. Figures 1 to 8 As shown, the housing 20 accommodates a substrate 30, a microphone 35, a speaker microphone 40, an analog wiring 45, an ADC chip 50, a digital wiring 55, and a processing unit 60. The housing 20 also has an opening 200 and a directivity generator 210.

[0039] Here, in order to explain the housing 20 and the like, a Cartesian coordinate system based on a position inside or outside the microphone device 10 is set as an absolute coordinate system. In addition, the X-axis, Y-axis, and Z-axis in the absolute coordinate system are orthogonal to each other. Moreover, the absolute coordinate system is represented by a right-hand system. In addition, the direction of the arrow in the figure is set as the positive direction of the X-axis, Y-axis, and Z-axis. In addition, the direction opposite to the direction of the arrow in the figure is set as the negative direction of the X-axis, Y-axis, and Z-axis.

[0040] like Figure 2 to Figure 8 As shown, a plurality of openings 200 are formed. In addition, the openings 200 are opened toward the positive direction of the Z axis. Moreover, the space of the openings 200 extends along the Z axis direction.

[0041] like Figure 2 to Figure 11 As shown, the directivity generator 210 includes a first speaker 211, a second speaker 212, a third speaker 213, a fourth speaker 214, a first audio tube 221, a second audio tube 222, a third audio tube 223, and a fourth audio tube 224. Thus, the directivity generator 210 generates directivity for the sound collected by the microphone device 10 as described later. In addition, here, directivity refers to a property that the difficulty of collecting sound varies depending on the direction.

[0042] The first speaker 211, the second speaker 212, the third speaker 213, and the fourth speaker 214 are, for example, exponential speakers. In addition, the first speaker 211, the second speaker 212, the third speaker 213, and the fourth speaker 214 are not limited to being exponential speakers, and may also be cylindrical speakers, parabolic speakers, conical speakers, hyperbolic speakers, etc.

[0043] In addition, if Figure 2 to Figure 5 , Fig. 9 as well as Fig.10 As shown, the first speaker 211 includes a first speaker opening 231 and a first speaker tube 241 .

[0044] The first horn opening 231 is formed at a position different from the opening 200. In addition, the first horn opening 231 opens toward the positive direction of the Z axis.

[0045] The first horn tube 241 is connected to the first horn opening 231. In addition, the first horn tube 241 extends from the first horn opening 231 in one direction, here, in the negative direction of the Z axis. Moreover, the first horn 211 is set as an exponential curve horn. Therefore, the cross-sectional area of ​​the first horn tube 241 when cut in a direction orthogonal to the one direction increases as it moves from the side of the first horn tube 241 opposite to the first horn opening 231 toward the first horn opening 231 side. Here, the cross-sectional area of ​​the first horn tube 241 when cut in a direction orthogonal to the Z axis, that is, in the XY plane, increases as it moves toward the positive direction of the Z axis.

[0046] like Figure 2 to Figure 4 , Figure 6 as well as Figures 9 to 11 As shown, the second speaker 212 includes a second speaker opening 232 and a second speaker tube 242 .

[0047] The second horn opening 232 is formed at a position different from the opening 200 and the first horn opening 231. The second horn opening 232 opens in the direction in which the first horn opening 231 opens, which is the positive direction of the Z axis.

[0048] The second horn tube 242 is connected to the second horn opening 232. In addition, the second horn tube 242 extends from the second horn opening 232 in one direction, here, in the negative direction of the Z axis. Moreover, the second horn 212 is set as an exponential curve horn. Therefore, the cross-sectional area of ​​the second horn tube 242 when cut in a direction orthogonal to the one direction increases as it moves from the side of the second horn tube 242 opposite to the second horn opening 232 toward the second horn opening 232 side. Here, the cross-sectional area of ​​the second horn tube 242 when cut in a direction orthogonal to the Z axis, that is, in the X axis or Y axis direction, increases as it moves toward the positive direction of the Z axis.

[0049] like Figure 2 , Figure 3 , Figure 5 , Figure 7 as well as Fig. 9 As shown, the third speaker 213 includes a third speaker opening 233 and a third speaker tube 243 .

[0050] The third horn opening 233 is formed at a position different from the opening 200, the first horn opening 231, and the second horn opening 232. The third horn opening 233 opens in the direction in which the first horn opening 231 and the second horn opening 232 open, which is the positive direction of the Z axis.

[0051] The third horn tube 243 is connected to the third horn opening 233. In addition, the third horn tube 243 extends from the third horn opening 233 in one direction, here, in the negative direction of the Z axis. Moreover, the third horn 213 is set as an exponential curve horn. Therefore, the cross-sectional area of ​​the third horn tube 243 when cut in a direction orthogonal to the one direction increases as it moves from the side of the third horn tube 243 opposite to the third horn opening 233 toward the third horn opening 233 side. Here, the cross-sectional area of ​​the third horn tube 243 when cut in a direction orthogonal to the Z axis, that is, in the X axis or Y axis direction, increases as it moves toward the positive direction of the Z axis.

[0052] like Figure 2 , Figure 3 , Figure 6 , Figure 7 as well as Fig.11 As shown, the fourth speaker 214 includes a fourth speaker opening 234 and a fourth speaker tube 244 .

[0053] The fourth horn opening 234 is formed at a position different from the opening 200, the first horn opening 231, the second horn opening 232, and the third horn opening 233. Moreover, the fourth horn opening 234 opens in the direction in which the first horn opening 231, the second horn opening 232, and the third horn opening 233 open, which is the positive direction of the Z axis.

[0054] The fourth horn tube 244 is connected to the fourth horn opening 234. In addition, the fourth horn tube 244 extends from the fourth horn opening 234 in one direction, here, in the negative direction of the Z axis. Moreover, the fourth horn 214 is set as an exponential curve horn. Therefore, the cross-sectional area of ​​the fourth horn tube 244 when cut in a direction orthogonal to the one direction increases as it moves from the side of the fourth horn tube 244 opposite to the fourth horn opening 234 toward the fourth horn opening 234 side. Here, the cross-sectional area of ​​the fourth horn tube 244 when cut in a direction orthogonal to the Z axis, that is, in the X axis or Y axis direction, increases as it moves toward the positive direction of the Z axis.

[0055] In addition, if Figure 2 to Figure 4 , Fig. 9 as well as Fig.10 As shown, the first speaker 211 and the second speaker 212 are arranged along a direction orthogonal to one direction, which is the Y-axis direction. Figure 2 , Figure 3 , Figure 5 as well as Fig. 9 As shown, the first speaker 211 and the third speaker 213 are arranged in a direction that is orthogonal to the direction in which the first speaker 211 and the second speaker 212 are arranged, which is the X-axis direction. Figure 2 , Figure 3 , Figure 6 , Fig. 9 as well as Fig.11 As shown, the second speaker 212 and the fourth speaker 214 are arranged in a direction that is orthogonal to the direction in which the first speaker 211 and the second speaker 212 are arranged, which is the X-axis direction. Figure 2 , Figure 3 , Figure 7 as well as Fig. 9 As shown, the third speaker 213 and the fourth speaker 214 are arranged along the direction in which the first speaker 211 and the second speaker 212 are arranged, which is the Y-axis direction in this case.

[0056] In addition, the first speaker 211, the second speaker 212, the third speaker 213, and the fourth speaker 214 are formed in the same shape and the same size. In addition, the so-called same here includes a manufacturing error range. Moreover, the first speaker 211, the second speaker 212, the third speaker 213, and the fourth speaker 214 are not limited to being formed in the same shape and the same size, and can also be different shapes and different sizes.

[0057] like Figure 2 , Figures 4 to 6 , Figure 8 to Figure 11 As shown, the first acoustic tube 221 is formed in a cylindrical shape and is connected to the first horn tube 241 and the second horn tube 242 in the Z-axis direction. In addition, the first acoustic tube 221 extends in a direction intersecting one direction, here, the Y-axis direction.

[0058] like Figure 2 , Figure 5 , Figure 6 , Figure 8 , Fig. 9 as well as Fig.11 As shown, the second acoustic tube 222 is formed in a cylindrical shape and is connected to the third bell tube 243 and the fourth bell tube 244 in the Z-axis direction. Moreover, the second acoustic tube 222 extends in parallel with the direction in which the first acoustic tube 221 extends, here, in the Y-axis direction. In addition, the second acoustic tube 222 is formed in the same shape and the same size as the first acoustic tube 221. In addition, the second acoustic tube 222 is not limited to being formed in the same shape and the same size, and may be formed in a different shape and size from the first acoustic tube 221.

[0059] like Figure 2 , Figure 4 , Figure 7 to Figure 11As shown, the third acoustic tube 223 is formed in a cylindrical shape and is connected to the first acoustic tube 221 and the second acoustic tube 222 in the Z-axis direction. In addition, the third acoustic tube 223 extends in a direction intersecting one direction and the direction in which the first acoustic tube 221 extends, here, the X-axis direction. Therefore, an H-shaped acoustic tube is formed by the first acoustic tube 221, the second acoustic tube 222, and the third acoustic tube 223.

[0060] like Figure 2 , Figure 8 to Figure 11 As shown, the fourth acoustic tube 224 is formed in a cylindrical shape and is connected to a portion between the first acoustic tube 221 and the second acoustic tube 222 in the third acoustic tube 223 in the Z-axis direction. In addition, the fourth acoustic tube 224 extends in a direction intersecting with the direction in which the third acoustic tube 223 extends, here, from the third acoustic tube 223 to the negative direction of the Z-axis. In addition, the fourth acoustic tube 224 is not limited to extending from the third acoustic tube 223 to the Z-axis direction, and may also extend from the third acoustic tube 223 to the Y-axis direction, etc.

[0061] The substrate 30 is a printed substrate. Figure 2 , Figures 4 to 8 As shown, the substrate 30 is accommodated in the housing 20. In addition, the substrate 30 is fixed to the housing 20 via, for example, a snap assembly, screws, and a spacer 32 described later. Moreover, the thickness direction of the substrate 30 is consistent with the Z-axis direction. Figures 4 to 8 As shown, the substrate 30 has a substrate front side 300 , a substrate back side 302 , and a substrate hole 304 .

[0062] The substrate front surface 300 is a surface of the substrate 30 that is orthogonal to the thickness direction of the substrate 30 , and is located on the positive direction side of the Z axis here.

[0063] The substrate rear surface 302 is a surface of the substrate 30 that is opposite to the substrate front surface 300 , and is located on the negative side of the Z axis.

[0064] The substrate holes 304 are formed at positions corresponding to the positions of the openings 200. Therefore, the number of the substrate holes 304 corresponds to the number of the openings 200. Moreover, the substrate holes 304 communicate with the spaces of the openings 200. In addition, the substrate holes 304 extend in the Z-axis direction and penetrate the substrate front surface 300 and the substrate back surface 302.

[0065] The isolator 32 is disposed between the housing 20 and the substrate front surface 300. The isolator 32 is formed of an elastic body such as a closed-cell sponge, rubber, foamed rubber, clay, or an adhesive, etc. The isolator 32 allows the sound entering from a certain opening 200 to propagate between the housing 20 and the substrate front surface 300, and prevents the propagated sound from propagating to a microphone 35 other than the microphone 35 described later located directly below the opening 200. The isolator 32 prevents the vibration transmitted from the housing 20 from propagating in the substrate 30 and being observed in the microphone 35.

[0066] The microphone 35 is connected to the vicinity of the position of the substrate hole 304 in the substrate back surface 302. Therefore, the number of microphones 35 corresponds to the number of openings 200 and substrate holes 304. And the microphone 35 is accommodated in the housing 20. In addition, the microphone 35 converts the sound propagated in the opening 200 and the substrate hole 304 into an analog signal. In addition, the analog signal is a signal that is expressed as a continuously changing physical quantity, and here is an electrical signal of current, voltage, etc. corresponding to the sound. In addition, the microphone 35 can also be a microphone having a sound hole for taking in sound from the side opposite to the surface installed on the substrate 30. That is, the microphone 35 can also be installed on the substrate front surface 300 between the substrate 30 and the housing 20, and is arranged at a position corresponding to the opening 200 and the sound hole of the microphone 35.

[0067] like Figure 2 as well as Figure 8 As shown, the speaker microphone 40 is connected to the fourth audio tube 224. Moreover, the speaker microphone 40 is accommodated in the housing 20. In addition, the speaker microphone 40 converts the sound propagated in the first speaker 211, the first audio tube 221, the third audio tube 223 and the fourth audio tube 224 into an analog signal. In addition, the speaker microphone 40 converts the sound propagated in the second speaker 212, the first audio tube 221, the third audio tube 223 and the fourth audio tube 224 into an analog signal. In addition, the speaker microphone 40 converts the sound propagated in the third speaker 213, the second audio tube 222, the third audio tube 223 and the fourth audio tube 224 into an analog signal. In addition, the speaker microphone 40 converts the sound propagated in the fourth speaker 214, the second audio tube 222, the third audio tube 223 and the fourth audio tube 224 into an analog signal.

[0068] The analog wiring 45 is connected to the speaker microphone 40. The analog wiring 45 is accommodated in the housing 20. The analog wiring 45 outputs the analog signal from the speaker microphone 40 to the outside of the microphone device 10.

[0069] The ADC chip 50 corresponds to the conversion unit and is mounted on the substrate front surface 300. Therefore, the ADC chip 50 is accommodated in the housing 20. In addition, the ADC chip 50 is connected to the microphone 35 via the wiring and through holes of the substrate 30, which are not shown in the figure. Therefore, the ADC chip 50 obtains the analog signal from the microphone 35 via the wiring and through holes of the substrate 30, which are not shown in the figure. Moreover, the ADC chip 50 is connected to the speaker microphone 40 via the wiring and through holes of the substrate 30, which are not shown in the figure, and the digital wiring 55. Therefore, the ADC chip 50 obtains the analog signal from the speaker microphone 40 via the wiring and through holes of the substrate 30, which are not shown in the figure, and the digital wiring 55.

[0070] In addition, if Figure 1 As shown, the ADC chip 50 has converters 500 corresponding to the microphone 35 and the speaker microphone 40, respectively. Each converter 500 is a circuit that converts an analog signal into a digital signal. The ADC chip 50 uses each converter 500 to convert the analog signal from the microphone 35 and the speaker microphone 40 into a digital signal. In addition, ADC is the abbreviation of Analog to Digital Converter. A digital signal refers to a signal that is discretized with respect to variables such as time and measured values ​​such as current and voltage. Discretization refers to converting an analog signal into a dispersed value.

[0071] The processing unit 60 is mainly composed of a microcomputer, etc., and includes a CPU, ROM, flash memory, RAM, I / O, and a bus connecting these structures. Figure 8 As shown, the processing unit 60 is mounted on, for example, the substrate back surface 302. The processing unit 60 is connected to the ADC chip 50 via wiring and through-holes (not shown) of the substrate 30.

[0072] In addition, the processing unit 60 performs digital signal processing on the digital signal converted by the ADC chip 50. For example, the processing unit 60 performs sound source separation such as BSS on the digital signal converted by the ADC chip 50 using ICA, PCA, etc. Thus, the processing unit 60 makes the noise contained in the digital signal converted by the ADC chip 50 smaller than the noise contained in the analog signal from the speaker microphone 40. Moreover, the processing unit 60 outputs the signal after digital signal processing to the outside of the microphone device 10 via wiring not shown in the figure. In addition, ICA is the abbreviation of Independent Component Analysis. PCA is the abbreviation of Principal Component Analysis. BSS is the abbreviation of Blind Source Separation. In addition, noise here refers to unnecessary sound information or undesirable sound information.

[0073] The microphone device 10 is configured as described above. Next, generation of directivity by the directivity generator 210 will be described.

[0074] Here, if Figures 9 to 11 As shown, the distance from the center of the connection part between the first speaker 211 and the first acoustic tube 221 to the center of the connection part between the first acoustic tube 221 and the third acoustic tube 223 in the Y-axis direction is set as a1. The distance from the center of the connection part between the second speaker 212 and the first acoustic tube 221 to the center of the connection part between the first acoustic tube 221 and the third acoustic tube 223 in the Y-axis direction is set as a2. The distance from the center of the connection part between the first acoustic tube 221 and the third acoustic tube 223 to the center of the connection part between the third acoustic tube 223 and the fourth acoustic tube 224 in the X-axis direction is set as b1. The distance from the center of the connection part between the second acoustic tube 222 and the third acoustic tube 223 to the center of the connection part between the third acoustic tube 223 and the fourth acoustic tube 224 in the X-axis direction is set as b2.

[0075] Furthermore, a distance from the center of the connection portion between the third speaker 213 and the second acoustic tube 222 to the center of the connection portion between the second acoustic tube 222 and the third acoustic tube 223 in the Y-axis direction is referred to as a1. Furthermore, a distance from the center of the connection portion between the fourth speaker 214 and the second acoustic tube 222 to the center of the connection portion between the second acoustic tube 222 and the third acoustic tube 223 in the Y-axis direction is referred to as a2.

[0076] In addition, here, Fig.12 As shown, it is assumed that in the YZ plane, the sound wave of the plane wave reaches the first horn 211 and the second horn 212 from the direction of the first angle θ with the Z axis. The first angle θ is set to -90°≤θ≤90°. The speed of sound is set to c. The center position of the projection when the center of the connection part of the first acoustic tube 221 and the third acoustic tube 223 is projected onto the plane passing through the first horn opening 231 and the second horn opening 232 and orthogonal to the Z axis is set to the first projection position P1.

[0077] At this time, the sound wave reaching the first speaker 211 is shifted by (-a1 / c)×sinθ relative to the sound wave reaching the first projection position P1, and thus arrives earlier.

[0078] In addition, the sound wave reaching the second speaker 212 is shifted by a time of (a2 / c)×sinθ relative to the sound wave reaching the first projection position P1, and thus arrives later.

[0079] Furthermore, the sound waves reaching the first speaker 211 propagate through the first speaker 211 and reach the center of the connection portion between the first speaker 211 and the first acoustic tube 221. In addition, the sound waves reaching the second speaker 212 propagate through the second speaker 212 and reach the center of the connection portion between the second speaker 212 and the first acoustic tube 221. Moreover, here, since the first speaker 211 and the second speaker 212 have the same shape and the same size, the lengths of the first speaker 211 and the second speaker 212 in the Z-axis direction are the same. Therefore, due to the lengths of the first speaker 211 and the second speaker 212 in the Z-axis direction, there is no time difference between the sound waves propagating through the first speaker 211 and the second speaker 212.

[0080] In addition, the sound wave reaching the center of the connection between the first speaker 211 and the first acoustic tube 221 propagates in the first acoustic tube 221 and reaches the center of the connection between the first acoustic tube 221 and the third acoustic tube 223. The time taken for the sound wave to reach the center of the connection between the first speaker 211 and the first acoustic tube 221 and the third acoustic tube 223 from the center of the connection between the first speaker 211 and the first acoustic tube 221 is a1 / c.

[0081] Furthermore, the sound wave reaching the center of the connection between the second horn 212 and the first acoustic tube 221 propagates through the first acoustic tube 221 and reaches the center of the connection between the first acoustic tube 221 and the third acoustic tube 223. The time it takes for the sound wave to reach the center of the connection between the second horn 212 and the first acoustic tube 221 and the third acoustic tube 223 from the center of the connection between the first acoustic tube 221 and the third acoustic tube 223 is a2 / c.

[0082] In addition, the sound wave reaching the center of the connection point between the first acoustic tube 221 and the third acoustic tube 223 propagates through the third acoustic tube 223 and the fourth acoustic tube 224 and reaches the speaker microphone 40. Since the path of the sound wave is shared, there is no time difference in the sound wave reaching the speaker microphone 40 from the center of the connection point between the first acoustic tube 221 and the third acoustic tube 223.

[0083] Therefore, the time deviation of the sound wave propagating through the first speaker 211, the first acoustic tube 221, the third acoustic tube 223 and the fourth acoustic tube 224 and reaching the speaker microphone 40 is (-a1 / c)×sinθ+(a1 / c). Moreover, the time deviation of the sound wave propagating through the second speaker 212 and the first acoustic tube 221 at the center of the connection between the first acoustic tube 221 and the third acoustic tube 223 is (a2 / c)×sinθ+(a2 / c).

[0084] When these time shifts are the same, the sound waves reinforce each other in all frequency regions. At this time, the first angle θ is expressed by a1 and a2 as in the following relational expression (1). Therefore, directivity on the YZ plane is generated based on a1 and a2.

[0085] (-a1 / c)×sinθ+(a1 / c)=(a2 / c)×sinθ+(a2 / c)

[0086] sinθ=(a1-a2) / (a1+a2)

[0087] θ=arcsin{(a1-a2) / (a1+a2)}…(1)

[0088] In addition, in the above calculation, the lengths of the first speaker 211 and the second speaker 212 in the Z-axis direction are not limited to be the same. The lengths of the first speaker 211 and the second speaker 212 in the Z-axis direction may also be different, and the time deviation caused by the lengths of the first speaker 211 and the second speaker 212 in the Z-axis direction may also be considered.

[0089] In addition, in the case of the third speaker 213 and the fourth speaker 214, the directivity on the YZ plane is generated based on a1 and a2, similar to the case of the first speaker 211 and the second speaker 212. In this case, the lengths of the third speaker 213 and the fourth speaker 214 in the Z-axis direction are not limited to be the same. The lengths of the third speaker 213 and the fourth speaker 214 in the Z-axis direction may also be different, and the time deviation caused by the lengths of the third speaker 213 and the fourth speaker 214 in the Z-axis direction may also be considered.

[0090] In addition, here, Fig.13 As shown, it is assumed that in the XZ plane, the sound wave of the plane wave reaches the first horn 211 and the third horn 213 from the direction of the second angle φ with the Z axis. The second angle φ is set to -90°≤φ≤90°. The speed of sound is set to c. The center position of the projection when the center of the connection part of the third acoustic tube 223 and the fourth acoustic tube 224 is projected onto the plane passing through the first horn opening 231 and the third horn opening 233 and orthogonal to the Z axis is set to the second projection position P2.

[0091] At this time, the sound wave reaching the first speaker 211 is shifted by a time of (b1 / c)×sinφ relative to the sound wave reaching the second projection position P2, and thus arrives later.

[0092] In addition, the sound wave reaching the third speaker 213 is shifted by (-b2 / c)×sinφ relative to the sound wave reaching the second projection position P2, and thus arrives earlier.

[0093] Furthermore, the sound wave reaching the first speaker 211 propagates in the first speaker 211 and reaches the center of the connection portion between the first speaker 211 and the first acoustic tube 221. In addition, the sound wave reaching the third speaker 213 propagates in the third speaker 213 and reaches the center of the connection portion between the third speaker 213 and the second acoustic tube 222. Moreover, here, since the first speaker 211 and the third speaker 213 have the same shape and the same size, the lengths of the first speaker 211 and the third speaker 213 in the Z-axis direction are the same. Therefore, due to the lengths of the first speaker 211 and the third speaker 213 in the Z-axis direction, there is no time difference between the sound waves propagating in the first speaker 211 and the third speaker 213.

[0094] In addition, the sound wave reaching the center of the connection part between the first speaker 211 and the first acoustic tube 221 propagates to the center of the connection part between the first acoustic tube 221 and the third acoustic tube 223 via the first acoustic tube 221. Moreover, the sound wave reaching the center of the connection part between the third speaker 213 and the second acoustic tube 222 propagates to the center of the connection part between the second acoustic tube 222 and the third acoustic tube 223 via the second acoustic tube 222. In addition, here, the distance from the center of the connection part between the first speaker 211 and the first acoustic tube 221 to the center of the connection part between the first acoustic tube 221 and the third acoustic tube 223 in the Y-axis direction is set to a1. The distance from the center of the connection part between the third speaker 213 and the second acoustic tube 222 to the center of the connection part between the second acoustic tube 222 and the third acoustic tube 223 in the Y-axis direction is set to a1. Therefore, the distances of both are the same. Therefore, there is no time difference between the sound waves propagating therebetween.

[0095] Furthermore, the sound wave reaching the center of the connection between the first acoustic tube 221 and the third acoustic tube 223 propagates in the third acoustic tube 223 and reaches the center of the connection between the third acoustic tube 223 and the fourth acoustic tube 224. The time taken for the sound wave to reach the center of the connection between the first acoustic tube 221 and the third acoustic tube 223 and the fourth acoustic tube 224 from the center of the connection between the first acoustic tube 221 and the third acoustic tube 223 is b1 / c.

[0096] In addition, the sound wave reaching the center of the connection between the second acoustic tube 222 and the third acoustic tube 223 propagates in the third acoustic tube 223 and reaches the center of the connection between the third acoustic tube 223 and the fourth acoustic tube 224. The time taken for the sound wave to reach the center of the connection between the second acoustic tube 222 and the third acoustic tube 223 and the fourth acoustic tube 224 from the center of the connection between the third acoustic tube 223 and the fourth acoustic tube 224 is b2 / c.

[0097] Furthermore, the sound waves reaching the center of the connection point between the third and fourth acoustic tubes 223 and 224 propagate through the fourth acoustic tube 224 and reach the speaker microphone 40. Since the path of the sound waves is shared, there is no time difference in the sound waves reaching the speaker microphone 40 from the center of the connection point between the third and fourth acoustic tubes 223 and 224.

[0098] Therefore, the time difference of the sound waves propagating through the first speaker 211, the first audio tube 221, the third audio tube 223 and the fourth audio tube 224 and reaching the speaker microphone 40 is (b1 / c)×sinφ+(b1 / c). In addition, the time difference of the sound waves propagating through the third speaker 213, the second audio tube 222, the third audio tube 223 and the fourth audio tube 224 and reaching the speaker microphone 40 is (-b2 / c)×sinφ+(b2 / c).

[0099] When these time shifts are the same, the sound waves reinforce each other in all frequency regions. At this time, the second angle φ is expressed using b1 and b2 as in the following relational expression (2). Therefore, directivity on the XZ plane is generated based on b1 and b2.

[0100] (b1 / c)×sinφ+(b1 / c)=(-b2 / c)×sinφ+(b2 / c)

[0101] sinφ=(-b1+b2) / (b1+b2)

[0102] φ=arcsin{(-b1+b2) / (b1+b2)}…(2)

[0103] In addition, in the above calculation, the lengths of the first speaker 211 and the third speaker 213 in the Z-axis direction are not limited to be the same. The lengths of the first speaker 211 and the third speaker 213 in the Z-axis direction may also be different, and the time deviation caused by the lengths of the first speaker 211 and the third speaker 213 in the Z-axis direction may also be considered.

[0104] In addition, in the case of the second speaker 212 and the fourth speaker 214, the directivity on the XZ plane is generated based on b1 and b2, similar to the case of the first speaker 211 and the third speaker 213. In this case, it is not limited to the second speaker 212 and the fourth speaker 214 having the same length in the Z-axis direction. The lengths of the second speaker 212 and the fourth speaker 214 in the Z-axis direction may also be different, and the time deviation caused by the lengths of the second speaker 212 and the fourth speaker 214 in the Z-axis direction may also be considered.

[0105] Here, for example, a1=a2=b1=b2=20 mm. In this case, Fig.14 , Fig.15 as well as Fig.16 As shown in FIG. 1 , although the directivity pattern differs depending on the frequency of the sound wave, when the first angle θ and the second angle φ are 0°, the gain of the sound wave collected by the speaker microphone 40 is relatively high. Therefore, in this case, directivity is generated in a direction in which the sound waves when the first angle θ and the second angle φ are 0° reinforce each other at all frequencies. Fig.14 , a distribution showing the relationship between the first angle θ, the second angle φ, and the gain of the sound waves collected by the speaker microphone 40 when the frequencies of the sound waves are 10 kHz, 5 kHz, 2 kHz, and 1 kHz. Fig.15 , the relationship between the second angle φ and the gain of the sound waves collected by the speaker microphone 40 when the sound wave frequencies are 20 kHz, 10 kHz, 5 kHz, 2 kHz, and 1 kHz is shown when the first angle θ is fixed. Fig.16 , a distribution showing the relationship between the second angle φ, each frequency of the sound wave, and the gain of the sound wave collected by the speaker microphone 40 when the first angle θ is fixed is shown. In addition, the gain here is a parameter related to the size of the sound signal.

[0106] As described above, the directivity generator 210 generates directivity. Next, the operation of the microphone device 10 used in the vehicle will be described.

[0107] The microphone device 10 is installed, for example, near an interior rearview mirror in a vehicle compartment (not shown). Sound waves generated by the voice of the driver of the vehicle propagate through the directivity generator 210 and reach the speaker microphone 40. The speaker microphone 40 converts the sound into an analog signal. The analog wiring 45 outputs the analog signal from the speaker microphone 40 to a communication system (not shown) outside the microphone device 10. At this time, since digital signal processing is not performed, the delay is relatively small. Therefore, for example, the microphone device 10 is used as a microphone for hands-free communication with a communication system.

[0108] In addition, the sound waves generated by the sound in the vehicle cabin propagate in the directivity generator 210 and reach the speaker microphone 40. The speaker microphone 40 converts the sound into an analog signal. The analog wiring 45 outputs the analog signal from the speaker microphone 40 to the call system. At this time, since digital signal processing is not performed, the delay is relatively small. In addition, since the analog signal does not pass through a relatively complex circuit, the microphone device 10 is resistant to external interference such as impact. Therefore, for example, the microphone device 10 is used as an emergency call microphone between the call system for obtaining the status of the driver based on abnormalities of the vehicle, abnormalities of the driver of the vehicle, etc.

[0109] Furthermore, the sound waves generated by the sound in the vehicle cabin propagate through the opening 200 and the substrate hole 304 and reach the microphone 35. The microphone 35 converts the sound into an analog signal. In addition, the ADC chip 50 converts the analog signal from the microphone 35 into a digital signal, and converts the analog signal from the above-mentioned speaker microphone 40 into a digital signal. Furthermore, the processing unit 60 uses ICA, PCA, etc. to perform sound source separation such as BSS on these converted digital signals. Thus, the processing unit 60 makes the noise contained in the digital signal converted by the ADC chip 50 smaller than the noise contained in the analog signal from the speaker microphone 40. In addition, the processing unit 60 outputs the signal after digital signal processing to an analysis system (not shown) outside the microphone device 10. The analysis system performs, for example, speech recognition on the signal after digital signal processing. Therefore, the microphone device 10 is used as a microphone for speech recognition between the analysis system.

[0110] The microphone device 10 operates as described above. Next, a description will be given of a digital signal processing performed by the microphone device 10 while suppressing an increase in delay.

[0111] Here, in the audio system described in Patent Document 1, digital signal processing such as noise reduction is sometimes performed on the electrical signal converted by the microphone core. In this case, for example, several tens of milliseconds of processing time is required due to AD conversion, buffering between the CPU and DA conversion. In addition, when the CPU is used to convert and process the signal into a frequency region, 160 ms of processing time is required. Therefore, the delay as the delay time of communication increases.

[0112] In addition, here, in the conversation conducted by the phone, the average delay is 150ms. Moreover, if the delay exceeds 200ms, the speaking time will overlap, etc. Therefore, if the delay increases, it becomes difficult to talk, and the quality of the call is reduced. Therefore, it is difficult to use for hands-free calls and the above-mentioned emergency calls.

[0113] In addition, if digital signal processing is not performed, it becomes difficult to make a call due to noise, so the quality of the call is reduced. In addition, the accuracy of speech recognition is reduced, making it difficult to use for speech recognition.

[0114] On the other hand, the microphone device 10 according to the present embodiment includes a housing 20 , a microphone 35 , a speaker microphone 40 , an analog wiring 45 , an ADC chip 50 , and a processing unit 60 .

[0115] The housing 20 has an opening 200 and a first speaker 211. The first speaker 211 includes a first speaker opening 231 and a first speaker tube 241. The microphone 35 is accommodated in the housing 20, and converts the sound propagated in the opening 200 into an analog signal. The speaker microphone 40 is accommodated in the housing 20, and converts the sound propagated in the first speaker 211 into an analog signal. The analog wiring 45 is accommodated in the housing 20, and outputs the analog signal from the speaker microphone 40.

[0116] The ADC chip 50 acquires an analog signal from the microphone 35 and acquires an analog signal from the speaker microphone 40 via the digital wiring 55. The ADC chip 50 converts the analog signals from the microphone 35 and the speaker microphone 40 into digital signals. The digital wiring 55 corresponds to a wiring different from the analog wiring 45.

[0117] The processing unit 60 performs digital signal processing on the digital signal converted by the ADC chip 50. For example, the processing unit 60 performs sound source separation on the digital signal converted by the ADC chip 50. Thus, the processing unit 60 makes the noise contained in the digital signal converted by the ADC chip 50 smaller than the noise contained in the analog signal from the speaker microphone 40.

[0118] Since the signal output from the analog wiring 45 is not subjected to digital signal processing, the increase in delay is suppressed. In addition, in the processing unit 60, digital signal processing is performed. Therefore, the microphone device 10 performs digital signal processing while suppressing the increase in delay. Therefore, the microphone device 10 can be used as any one of a microphone for hands-free calls, a microphone for emergency calls, and a microphone for voice recognition as described above.

[0119] In addition, the microphone device 10 according to the first embodiment also produces the following effects.

[0120] The housing 20 has a first speaker 211 , a second speaker 212 , a third speaker 213 and a fourth speaker 214 , and has a plurality of speakers.

[0121] This makes it easy to collect sound using the speaker microphone 40. Therefore, it is easy to ensure the SNR of the analog signal from the speaker microphone 40. In addition, SNR is an abbreviation of Signal Noise Ratio.

[0122] The housing 20 has a first speaker 211, a second speaker 212, a third speaker 213, a fourth speaker 214, a first audio tube 221, a second audio tube 222, a third audio tube 223, and a fourth audio tube 224. In addition, the speaker microphone 40 converts the sound propagated in the first speaker 211, the first audio tube 221, the third audio tube 223, and the fourth audio tube 224 into an analog signal. In addition, the speaker microphone 40 converts the sound propagated in the second speaker 212, the first audio tube 221, the third audio tube 223, and the fourth audio tube 224 into an analog signal. In addition, the speaker microphone 40 converts the sound propagated in the third speaker 213, the second audio tube 222, the third audio tube 223, and the fourth audio tube 224 into an analog signal. In addition, the speaker microphone 40 converts the sound propagated in the fourth speaker 214, the second audio tube 222, the third audio tube 223, and the fourth audio tube 224 into an analog signal.

[0123] Directivity is generated by the first speaker 211, the second speaker 212, the third speaker 213, the fourth speaker 214, the first acoustic tube 221, the second acoustic tube 222, the third acoustic tube 223, and the fourth acoustic tube 224. In addition, as described above, directivity on the YZ plane is generated based on a1 and a2. Therefore, it is easy to control the directivity on the YZ plane. And, in addition, directivity on the XZ plane is generated based on b1 and b2. Therefore, it is easy to control the directivity on the XZ plane.

[0124] Here, the first speaker 211, the second speaker 212, and the first acoustic tube 221 are made to have the same cylindrical shape, and the cross-sectional areas of each are made the same. In this case, when the sound waves from the outside of the microphone device 10 reach the first speaker 211 and the second speaker 212, the acoustic impedance changes sharply, and thus they are easily reflected by the first speaker opening 231 and the second speaker opening 232. Therefore, in this case, the sound waves from the outside of the microphone device 10 are difficult to enter the first speaker 211 and the second speaker 212.

[0125] In addition, in this case, part of the sound propagated from the first speaker 211 in the first acoustic tube 221 propagates to the second speaker 212. Since the acoustic impedance changes sharply, the sound wave propagated to the second speaker 212 is reflected by the second speaker opening 232. Part of the sound wave reflected by the second speaker opening 232 propagates in the second speaker 212 and the first acoustic tube 221 and propagates to the first speaker 211. Since the acoustic impedance changes sharply, the sound wave propagated to the first speaker 211 is reflected by the first speaker opening 231. Part of the sound wave reflected by the first speaker opening 231 propagates in the first speaker 211, the first acoustic tube 221 and the second speaker 212 and is reflected by the second speaker opening 232. Such sound waves traveling back and forth between the first speaker 211 and the second speaker 212 become reverberation. Due to the reverberation sound, speech recognition is difficult.

[0126] Here, the lengths of the first speaker 211, the second speaker 212, and the first acoustic tube 221 are set to be lengths related to an integral multiple of a half wavelength of the sound wave. At this time, the sound waves traveling back and forth between the first speaker 211 and the second speaker 212 resonate. Due to the resonant sound, the frequency characteristics of the microphone device 10 are reduced, making it difficult to perform voice recognition.

[0127] In addition, the third speaker 213, the fourth speaker 214 and the second acoustic tube 222 are set to the same cylindrical shape, and the cross-sectional areas of each are set to be the same. In this case, as described above, it is difficult for sound waves from the outside of the microphone device 10 to enter the third speaker 213 and the fourth speaker 214. Moreover, the sound waves that travel back and forth in the third speaker 213 and the fourth speaker 214 become echoes. Due to this echo sound, it is difficult to perform voice recognition. In addition, the lengths of the third speaker 213, the fourth speaker 214 and the second acoustic tube 222 are set to a length related to an integer multiple of a half wavelength of the sound wave. At this time, as described above, the sound waves that travel back and forth in the third speaker 213 and the fourth speaker 214 resonate. Due to this resonance sound, the frequency characteristics of the microphone device 10 are reduced, and it is difficult to perform voice recognition.

[0128] In contrast, the cross-sectional area of ​​the first horn tube 241 when cut in a direction perpendicular to one direction increases as it moves from the side of the first horn tube 241 opposite to the first horn opening 231 toward the first horn opening 231. Here, the cross-sectional area of ​​the first horn tube 241 when cut in a direction perpendicular to the Z axis increases as it moves toward the positive direction of the Z axis. In addition, similar to the cross-sectional area of ​​the first horn tube 241, the cross-sectional areas of the second horn tube 242, the third horn tube 243, and the fourth horn tube 244 increase as it moves toward the positive direction of the Z axis.

[0129] Thus, it is possible to suppress changes in acoustic impedance in the first speaker opening 231, the second speaker opening 232, the third speaker opening 233, and the fourth speaker opening 234. Therefore, sound waves from outside the microphone device 10 are less likely to be reflected by the first speaker opening 231, the second speaker opening 232, the third speaker opening 233, and the fourth speaker opening 234. Therefore, sound waves from outside the microphone device 10 easily enter the first speaker 211, the second speaker 212, the third speaker 213, and the fourth speaker 214.

[0130] In addition, the sound waves propagating from the first speaker 211 in the first acoustic tube 221 and propagating to the second speaker 212 are difficult to be reflected by the second speaker opening 232. Moreover, the sound waves propagating from the second speaker 212 in the first acoustic tube 221 and propagating to the first speaker 211 are difficult to be reflected by the first speaker opening 231. Therefore, it is difficult to generate the above-mentioned sound waves that go back and forth between the first speaker 211 and the second speaker 212, and it is difficult to become an echo. Similarly, the sound waves propagating from the third speaker 213 in the second acoustic tube 222 and propagating to the fourth speaker 214 are difficult to be reflected by the fourth speaker opening 234. Moreover, the sound waves propagating from the fourth speaker 214 in the second acoustic tube 222 and propagating to the third speaker 213 are difficult to be reflected by the third speaker opening 233. Therefore, it is difficult to generate the above-mentioned sound waves that go back and forth between the third speaker 213 and the fourth speaker 214, and it is difficult to become an echo. Therefore, voice recognition is easy.

[0131] Furthermore, since the first speaker 211 and the second speaker 212 do not have the same cross-sectional area, it is difficult for the sound waves to resonate between the first speaker 211 and the second speaker 212. In addition, since the third speaker 213 and the fourth speaker 214 do not have the same cross-sectional area, it is difficult for the sound waves to resonate between the third speaker 213 and the fourth speaker 214. Therefore, the frequency characteristic of the microphone device 10 is suppressed from being reduced, and voice recognition is easy.

[0132] (Second Embodiment)

[0133] In a second embodiment, if Fig.17 , Fig.18 as well as Fig.19 As shown in FIG. 1 , the form of the housing 20 is different from that of the first embodiment. Other than that, the present invention is the same as the first embodiment.

[0134] The housing 20 further includes a first layer 251, a second layer 252, a third layer 253, and a fourth layer 254. The second layer 252 is connected to the first layer 251 in one direction, here, the Z-axis direction. The third layer 253 is connected to the side of the second layer 252 opposite to the first layer 251. The fourth layer 254 is connected to the side of the third layer 253 opposite to the second layer 252.

[0135] In addition, a first speaker 211, a second speaker 212, a third speaker 213 and a fourth speaker 214 are formed on the first layer 251. Fig.19 As shown, the first layer 251 covers the substrate 30 , the microphone 35 , the ADC chip 50 and the processing unit 60 .

[0136] return Fig.17 as well as Fig.18 The first acoustic tube 221 and the second acoustic tube 222 are formed in the second layer 252. In addition, the third acoustic tube 223 is formed in the third layer 253. Furthermore, the fourth acoustic tube 224 is formed in the fourth layer 254, and the speaker microphone 40 and the dummy wiring 45 are accommodated.

[0137] The microphone device 10 of the second embodiment is configured as described above. The second embodiment also achieves the same effects as those of the first embodiment. In addition, the second embodiment achieves the following effects.

[0138] The housing 20 further includes a first layer 251 , a second layer 252 , a third layer 253 and a fourth layer 254 .

[0139] Thus, even if the housing 20 has a complex shape as a whole, the housing 20 can be divided into simple shapes and manufactured using injection molding, etc. Therefore, the housing 20 can be easily manufactured, and thus the microphone device 10 can be easily manufactured.

[0140] (Third Embodiment)

[0141] In a third embodiment, if Fig. 20 As shown, the form of the housing 20 is different from that of the second embodiment. Specifically, the housing 20 further includes a first guide portion 261 and a second guide portion 262. Other than this, the housing 20 is the same as the second embodiment.

[0142] The first guide 261 restricts the third layer 253 to move relative to the second layer 252 only in a direction perpendicular to one direction and in the direction in which the first acoustic tube 221 extends, in this case, in the Y-axis direction. For example, the first guide 261 includes a first concave portion 2611 and a first convex portion 2612.

[0143] The first recess 2611 is recessed from the inside of the surface of the second layer 252 that is opposite to the third layer 253, and extends in the Y-axis direction. In addition, a plurality of first recesses 2611 are formed, and here, the number of first recesses 2611 is set to two. Moreover, the first recess 2611 is formed in a triangular prism shape. As a result, stress concentration is difficult to occur, and the second layer 252 is difficult to be damaged. In addition, the first recess 2611 is formed in a manner that does not cross the third acoustic tube 223. In addition, the number of the first recess 2611 is not limited to two, as long as it is at least one. Moreover, the shape of the first recess 2611 is not limited to a triangular prism. The shape of the first recess 2611 may also be a polygonal prism, a circular arc column, etc.

[0144] The first convex portion 2612 protrudes from the inside of the surface of the third layer 253 that is opposite to the second layer 252 toward the second layer 252. In addition, the first convex portion 2612 is formed in a shape corresponding to the first concave portion 2611. Moreover, the first convex portion 2612 moves in the first concave portion 2611. Thus, the first guide portion 261 enables the third layer 253 to move relative to the second layer 252 only in the Y-axis direction. In addition, here the first concave portion 2611 is formed in the second layer 252, and the first convex portion 2612 is formed in the third layer 253, but it is not limited to this. As long as it is a method that can move relative to each other only in the Y-axis direction, the first convex portion 2612 may be formed in the second layer 252, and the first concave portion 2611 may be formed in the third layer 253.

[0145] The second guide 262 restricts the third layer 253 to move relative to the fourth layer 254 only in a direction perpendicular to one direction and in the direction in which the third acoustic tube 223 extends, in this case, in the X-axis direction. For example, the second guide 262 includes a second concave portion 2621 and a second convex portion 2622.

[0146] The second recess 2621 is recessed from the inside of the surface of the third layer 253 that is opposite to the fourth layer 254, and extends in the X-axis direction. In addition, a plurality of second recesses 2621 are formed, and here, the number of second recesses 2621 is set to two. Moreover, the second recess 2621 is formed in a triangular prism shape. As a result, stress concentration is difficult to occur, and the third layer 253 is difficult to be damaged. In addition, the second recess 2621 is formed in a manner that does not cross the third acoustic tube 223. In addition, the number of second recesses 2621 is not limited to two, as long as there is at least one. Moreover, the shape of the second recess 2621 is not limited to a triangular prism. The shape of the second recess 2621 may also be a polygonal prism, a circular arc column, etc.

[0147] The second convex portion 2622 protrudes from the inside of the surface of the fourth layer 254 that is opposite to the third layer 253 toward the third layer 253. In addition, the second convex portion 2622 is formed in a shape corresponding to the second concave portion 2621. Moreover, the second convex portion 2622 moves in the second concave portion 2621. Thus, the second guide portion 262 causes the third layer 253 to move relative to the fourth layer 254 only in the X-axis direction. In addition, here, the second concave portion 2621 is formed in the third layer 253, and the second convex portion 2622 is formed in the fourth layer 254, but it is not limited to this. As long as it is a mode that can move relative to each other only in the X-axis direction, the second convex portion 2622 may be formed in the third layer 253, and the second concave portion 2621 may be formed in the fourth layer 254.

[0148] The microphone device 10 of the third embodiment is configured as described above. The third embodiment also achieves the same effects as those of the second embodiment. In addition, the third embodiment also achieves the following effects.

[0149] The housing 20 has a first guide portion 261. The first guide portion 261 allows the third layer 253 to move relative to the second layer 252 in a direction perpendicular to one direction and in a direction in which the first acoustic tube 221 extends, in this case, the Y-axis direction.

[0150] This makes it easy to adjust the positions of the first acoustic tube 221 and the second acoustic tube 222 formed in the second layer 252 and the third acoustic tube 223 formed in the third layer 253. Therefore, it is easy to adjust a1 and a2. Therefore, it is easy to control the directivity on the YZ plane generated by a1 and a2.

[0151] The housing 20 has a second guide portion 262. The second guide portion 262 allows the third layer 253 to move relative to the fourth layer 254 in a direction perpendicular to one direction and in a direction in which the third acoustic tube 223 extends, in this case, the X-axis direction.

[0152] This makes it easy to adjust the positions of the third acoustic tube 223 formed on the third layer 253 and the fourth acoustic tube 224 formed on the fourth layer 254. Therefore, it is easy to adjust b1 and b2. Therefore, it is easy to control the directivity on the XZ plane generated by b1 and b2.

[0153] (Fourth Embodiment)

[0154] In a fourth embodiment, if Fig.21 As shown in FIG. 1 , the configurations of the first concave portion 2611 , the first convex portion 2612 , the second concave portion 2621 , and the second convex portion 2622 are different from those of the third embodiment. Other configurations are the same as those of the third embodiment.

[0155] The first concave portion 2611 is not recessed from the inside of the surface of the second layer 252 that is opposite to the third layer 253, but is recessed from the corners on both sides of the surface of the second layer 252 that is opposite to the third layer 253 in the direction parallel to the X-axis. As a result, the portion near the first concave portion 2611 in the second layer 252 becomes a step-like shape. In addition, the first concave portion 2611 extends in the Y-axis direction. In addition, the first concave portion 2611 is not limited to being formed on both sides in the direction parallel to the X-axis, and can also be formed on only one side in the direction parallel to the X-axis.

[0156] The first convex portion 2612 does not protrude from the inside of the surface of the third layer 253 that faces the second layer 252 toward the second layer 252, but protrudes from the corner of the surface of the third layer 253 that faces the second layer 252 toward the second layer 252. Therefore, the portion near the first convex portion 2612 in the third layer 253 is stepped. In addition, the first convex portion 2612 is formed in a shape corresponding to the first concave portion 2611, and moves in the first concave portion 2611. Thus, the first guide portion 261 causes the third layer 253 to move relative to the second layer 252 in the Y-axis direction.

[0157] The second concave portion 2621 is not recessed from the inside of the surface of the third layer 253 that is opposite to the fourth layer 254, but is recessed from the corners on both sides of the surface of the third layer 253 that is opposite to the fourth layer 254 in the direction parallel to the Y axis. As a result, the portion near the second concave portion 2621 in the third layer 253 becomes a step-like shape. In addition, the second concave portion 2621 extends in the X-axis direction. In addition, the second concave portion 2621 is not limited to being formed on both sides in the direction parallel to the Y axis, and can also be formed on only one side in the direction parallel to the Y axis.

[0158] The second convex portion 2622 does not protrude from the inside of the surface of the fourth layer 254 that faces the third layer 253 toward the third layer 253, but protrudes from the corner of the surface of the fourth layer 254 that faces the third layer 253 toward the third layer 253. Therefore, the portion near the second convex portion 2622 in the fourth layer 254 is stepped. In addition, the second convex portion 2622 is formed in a shape corresponding to the second concave portion 2621, and moves in the second concave portion 2621. Thus, the second guide portion 262 causes the third layer 253 to move relative to the fourth layer 254 in the X-axis direction.

[0159] The microphone device 10 of the fourth embodiment is configured as described above. In the fourth embodiment, the same effects as those of the third embodiment are achieved.

[0160] (Fifth Embodiment)

[0161] In a fifth embodiment, if Fig. 22 as well as Fig.23 As shown, the form of the directivity generator 210 is different from that of the first embodiment. In addition, the microphone device 10 includes two speaker microphones 40. Other than that, it is the same as the first embodiment.

[0162] The directivity generator 210 includes a fifth audio tube 225 in addition to the first speaker 211 , the second speaker 212 , the third speaker 213 , the fourth speaker 214 , the first audio tube 221 , the second audio tube 222 , the third audio tube 223 and the fourth audio tube 224 .

[0163] The fifth acoustic tube 225 is formed in a cylindrical shape and is connected to a portion between the first acoustic tube 221 and the second acoustic tube 222 in the third acoustic tube 223 in the Z-axis direction. In addition, the fifth acoustic tube 225 extends in a direction intersecting with the direction in which the third acoustic tube 223 extends, here, from the third acoustic tube 223 to the negative direction of the Z-axis. In addition, the fifth acoustic tube 225 is not limited to extending from the third acoustic tube 223 to the Z-axis direction, and may also extend from the third acoustic tube 223 to the Y-axis direction, etc.

[0164] In addition, the fourth acoustic tube 224 is connected to a portion of the third acoustic tube 223 on the first acoustic tube 221 side. Furthermore, the fifth acoustic tube 225 is connected to a portion of the third acoustic tube 223 on the second acoustic tube 222 side. Therefore, the fourth acoustic tube 224 and the fifth acoustic tube 225 are arranged in the direction in which the third acoustic tube 223 extends, in this case, in the X-axis direction.

[0165] The microphone device 10 includes two speaker microphones 40 . Here, one speaker microphone 40 is referred to as a first speaker microphone 401 , and the other speaker microphone 40 is referred to as a second speaker microphone 402 .

[0166] Furthermore, the first speaker microphone 401 is connected to the fourth audio tube 224. Furthermore, the first speaker microphone 401 converts the sound propagated in the first speaker 211, the first audio tube 221, the third audio tube 223, and the fourth audio tube 224 into an analog signal. Furthermore, the first speaker microphone 401 converts the sound propagated in the second speaker 212, the first audio tube 221, the third audio tube 223, and the fourth audio tube 224 into an analog signal. Furthermore, the first speaker microphone 401 converts the sound propagated in the third speaker 213, the second audio tube 222, the third audio tube 223, and the fourth audio tube 224 into an analog signal. Furthermore, the first speaker microphone 401 converts the sound propagated in the fourth speaker 214, the second audio tube 222, the third audio tube 223, and the fourth audio tube 224 into an analog signal. Furthermore, the first speaker microphone 401 outputs the converted analog signal to the outside of the microphone device 10 via the analog wiring 45. Then, the first speaker microphone 401 outputs the converted analog signal to the ADC chip 50 via the digital wiring 55 and the substrate 30 .

[0167] The second speaker microphone 402 is connected to the fifth audio tube 225. In addition, the second speaker microphone 402 converts the sound propagated in the first speaker 211, the first audio tube 221, the third audio tube 223, and the fifth audio tube 225 into an analog signal. In addition, the second speaker microphone 402 converts the sound propagated in the second speaker 212, the first audio tube 221, the third audio tube 223, and the fifth audio tube 225 into an analog signal. In addition, the second speaker microphone 402 converts the sound propagated in the third speaker 213, the second audio tube 222, the third audio tube 223, and the fifth audio tube 225 into an analog signal. In addition, the second speaker microphone 402 converts the sound propagated in the fourth speaker 214, the second audio tube 222, the third audio tube 223, and the fifth audio tube 225 into an analog signal. In addition, the second speaker microphone 402 outputs the converted analog signal to the ADC chip 50 via the digital wiring 55 and the substrate 30. Here, the second speaker microphone 402 does not output the converted analog signal to the outside of the microphone device 10 via the analog wiring 45. On the other hand, the second speaker microphone 402 may output the converted analog signal to the outside of the microphone device 10 via wiring or the like.

[0168] The microphone device 10 of the fifth embodiment is configured as described above. The fifth embodiment also achieves the same effects as those of the first embodiment. In addition, the fifth embodiment also achieves the following effects.

[0169] The housing 20 further includes a fifth audio tube 225. In addition, the microphone device 10 includes a first speaker microphone 401 and a second speaker microphone 402.

[0170] Thus, as for the directivity on the XZ plane, similarly to the case defined by b1 and b2 in the first embodiment, two directivities on the XZ plane can be independently determined by the positions at which the fourth acoustic tube 224 and the fifth acoustic tube 225 are arranged on the third acoustic tube 223. Therefore, for example, when the microphone device 10 is used in a vehicle, the first speaker microphone 401 can collect the voice of the driver of the vehicle, and the second speaker microphone 402 can collect the voice of passengers other than the driver of the vehicle.

[0171] (Other embodiments)

[0172] The present disclosure is not limited to the above-mentioned embodiments, and the above-mentioned embodiments can be appropriately modified. In addition, in the above-mentioned embodiments, the elements constituting the embodiments are not necessarily essential unless they are specifically indicated as essential or are obviously essential in principle.

[0173] The conversion unit, processing unit and method thereof described in the present disclosure may also be implemented by a special-purpose computer, which is provided by a processor and a memory programmed to execute one or more functions embodied by a computer program. Alternatively, the conversion unit, processing unit and method thereof described in the present disclosure may also be implemented by a special-purpose computer, which is provided by a processor composed of one or more special-purpose hardware logic circuits. Alternatively, the conversion unit, processing unit and method thereof described in the present disclosure may also be implemented by one or more special-purpose computers, which are composed of a processor and a memory programmed to execute one or more functions and a processor composed of one or more hardware logic circuits. In addition, a computer program may also be stored as an instruction executed by a computer in a non-removable tangible recording medium that can be read by a computer.

[0174] In the above-mentioned embodiments, the number of the opening 200, the microphone 35, and the converter 500 is six. On the other hand, the number of the opening 200, the microphone 35, and the converter 500 is not limited to six, and may be at least one.

[0175] In the above-mentioned embodiments, four speakers are formed. In contrast, the number of speakers is not limited to four, and may be at least one. In addition, in the above-mentioned embodiments, the speaker microphone 40 is connected to each speaker via the first audio tube 221, the second audio tube 222, the third audio tube 223, and the fourth audio tube 224. In contrast, the speaker microphone 40 may be directly connected to each speaker without passing through the first audio tube 221, the second audio tube 222, the third audio tube 223, and the fourth audio tube 224.

[0176] In the above-mentioned embodiments, the substrate 30, the ADC chip 50 and the processing unit 60 are accommodated in the housing 20. In contrast, the substrate 30, the ADC chip 50 and the processing unit 60 are not limited to being accommodated in the housing 20. The substrate 30, the ADC chip 50 and the processing unit 60 may be arranged outside the housing 20.

[0177] In the above embodiments, the ADC chip 50 is mounted on the substrate front surface 300. In contrast, the ADC chip 50 is not limited to being mounted on the substrate front surface 300, and may be mounted on the substrate back surface 302. In addition, the ADC chip 50 may be mounted on a printed circuit board different from the substrate 30 disposed in the housing 20.

[0178] In the above-mentioned embodiments, the processing unit 60 is mounted on the substrate back surface 302. In contrast, the processing unit 60 is not limited to being mounted on the substrate back surface 302, and may be mounted on the substrate front surface 300. Furthermore, the processing unit 60 may be mounted on a printed circuit board different from the substrate 30 disposed in the housing 20.

[0179] In the first to fifth embodiments, the number of the fourth acoustic tube 224 is one. In the fifth embodiment, the number of the fifth acoustic tube 225 is one. In contrast, the number of the fourth acoustic tube 224 and the fifth acoustic tube 225 is not limited to one, but may be two or more.

Claims

1. A microphone device, characterized in that: have: A housing having an opening and a horn, wherein the opening is open, and the horn includes a horn opening formed at a position different from the opening and open, and a horn pipe connected to the horn opening and extending in one direction; A microphone is housed in the housing and converts the sound propagated in the opening into an analog signal; A speaker microphone is housed in the housing and converts the sound propagated in the speaker into an analog signal; an analog wiring, housed in the housing and outputting an analog signal from the speaker microphone; a conversion unit that obtains an analog signal from the microphone and obtains an analog signal from the speaker microphone via a wiring different from the analog wiring, and converts the analog signals from the microphone and the speaker microphone into digital signals; as well as The processing unit performs digital signal processing on the digital signal converted by the conversion unit.

2. The microphone device according to claim 1, characterized in that: The housing has a plurality of speakers.

3. The microphone device according to claim 1, characterized in that: The horn opening is a first horn opening, The horn tube is a first horn tube, The speaker is a first speaker, The housing also has a second speaker, a third speaker, a fourth speaker, a first audio tube, a second audio tube, a third audio tube and a fourth audio tube. The second speaker includes a second speaker opening and a second speaker tube. The second speaker opening is formed at a position different from the opening and the first speaker opening, and opens toward the direction in which the first speaker opening opens. The second horn tube is connected to the second horn opening and extends along the one direction. The third speaker includes a third speaker opening and a third speaker tube. The third speaker opening is formed at a position different from the opening, the first speaker opening, and the second speaker opening, and opens toward the direction in which the first speaker opening opens. The third horn tube is connected to the third horn opening and extends along the one direction. The fourth speaker includes a fourth speaker opening and a fourth speaker tube. The fourth speaker opening is formed at a position different from the opening, the first speaker opening, the second speaker opening, and the third speaker opening, and opens toward the direction in which the first speaker opening opens. The fourth horn tube is connected to the fourth horn opening and extends along the one direction. The first speaker and the second speaker are arranged in a direction orthogonal to the one direction, The first speaker and the third speaker are arranged in a direction orthogonal to the one direction and the direction in which the first speaker and the second speaker are arranged. The second speaker and the fourth speaker are arranged in a direction orthogonal to the one direction and the direction in which the first speaker and the second speaker are arranged. The third speaker and the fourth speaker are arranged along the direction in which the first speaker and the second speaker are arranged. The first audio tube is connected to the first trumpet tube and the second trumpet tube, and extends in a direction intersecting the one direction. The second audio tube is connected to the third trumpet tube and the fourth trumpet tube, and extends along the direction in which the first audio tube extends. The third acoustic tube is connected to the first acoustic tube and the second acoustic tube, and extends in a direction intersecting the one direction and the direction in which the first acoustic tube extends. The fourth acoustic tube is connected to a portion of the third acoustic tube between the first acoustic tube and the second acoustic tube, and extends in a direction intersecting with a direction in which the third acoustic tube extends. The speaker microphone converts the sound propagated through the first speaker, the first audio tube, the third audio tube and the fourth audio tube, the sound propagated through the second speaker, the first audio tube, the third audio tube and the fourth audio tube, the sound propagated through the third speaker, the second audio tube, the third audio tube and the fourth audio tube, and the sound propagated through the fourth speaker, the second audio tube, the third audio tube and the fourth audio tube into analog signals.

4. The microphone device according to claim 3, characterized in that: The housing also has: First floor; a second layer connected to the first layer in the one direction; a third layer connected to a side of the second layer opposite to the first layer; and a fourth layer connected to a side of the third layer opposite to the second layer, The first layer includes the first speaker, the second speaker, the third speaker, and the fourth speaker. The first acoustic tube and the second acoustic tube are formed on the second layer. The third layer is provided with the third acoustic tube. The fourth acoustic tube is formed on the fourth layer.

5. The microphone device according to claim 4, characterized in that: The speaker microphone is accommodated on the fourth layer.

6. The microphone device according to claim 4, characterized in that: The housing has a guide portion that allows the third layer to move relative to the second layer in a direction that is orthogonal to the one direction and is a direction in which the first acoustic tube extends.

7. The microphone device according to claim 4, characterized in that: The housing has a guide portion that allows the third layer to move relative to the fourth layer in a direction that is orthogonal to the one direction and is a direction in which the third acoustic tube extends.

8. The microphone device according to any one of claims 3 to 6, characterized in that The housing has a fifth acoustic tube, which is connected to a portion of the third acoustic tube between the first acoustic tube and the second acoustic tube and extends in a direction intersecting with a direction in which the third acoustic tube extends. The fourth acoustic tube is connected to a portion of the third acoustic tube on the first acoustic tube side. The fifth acoustic tube is connected to a portion of the third acoustic tube on the second acoustic tube side. The fourth audio tube and the fifth audio tube are arranged along the extending direction of the third audio tube. The loudspeaker microphone is a first loudspeaker microphone, The microphone device also has a second speaker microphone. The first speaker microphone and the second speaker microphone are arranged along the extending direction of the third audio tube. The first speaker microphone converts the sound propagated in the first speaker, the first audio tube, the third audio tube and the fourth audio tube, the sound propagated in the second speaker, the first audio tube, the third audio tube and the fourth audio tube, the sound propagated in the third speaker, the second audio tube, the third audio tube and the fourth audio tube, and the sound propagated in the fourth speaker, the second audio tube, the third audio tube and the fourth audio tube into analog signals. The second speaker microphone converts the sound propagated in the first speaker, the first audio tube, the third audio tube and the fifth audio tube, the sound propagated in the second speaker, the first audio tube, the third audio tube and the fifth audio tube, the sound propagated in the third speaker, the second audio tube, the third audio tube and the fifth audio tube, and the sound propagated in the fourth speaker, the second audio tube, the third audio tube and the fifth audio tube into analog signals.

9. The microphone device according to any one of claims 1 to 3, characterized in that: A cross-sectional area of ​​the horn pipe when cut along a direction perpendicular to the one direction increases from a side of the horn pipe opposite to the horn opening toward the horn opening.

10. The microphone device according to any one of claims 1 to 3, characterized in that: The processing unit separates the sound source of the digital signal converted by the conversion unit, thereby making the noise included in the digital signal converted by the conversion unit smaller than the noise included in the analog signal from the speaker microphone.

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