Sound collecting device

Abstract

The problem to be solved by the present invention is to provide a sound collecting device capable of simultaneously generating resonance in a plurality of frequency bands. In order to solve the problem, this sound collection device (1) is provided with: a plurality of cylindrical resonance tubes (10) having different lengths, each of which has a sound collection opening (20) formed at an opening-side end (22); and a microphone (50) disposed at a microphone-side end portion (24) of the resonance tube (10). Furthermore, the resonance tube (10) is provided with a reflecting surface (28) extending toward the inside of the resonance tube (10) at a position separated from the sound collection opening (20) and the microphone (50) by a predetermined distance.

Description

Technical Field

[0001] The present invention relates to an acoustic microphone for improving signal-noise in different sound ranges. Background Art

[0002] Patent Document 1 discloses a pickup having an open end and a plurality of resonance tubes of different lengths bundled at the other end, which are close to a condenser microphone and assembled in a sealed state to collect sound.

[0003] [Prior Art Literature]

[0004] (Patent Document)

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-223537 Summary of the Invention

[0006] [Problems to be solved by the invention]

[0007] However, the pickup of Patent Document 1 has a structure in which multiple resonance tubes are bundled and connected near the microphone. Therefore, in the pickup of Patent Document 1, each resonance tube does not resonate independently. Instead, resonance occurs over the combined length of the connected tubes. As a result, even though the pickup of Patent Document 1 includes multiple resonance tubes of different lengths, it cannot simultaneously resonate in multiple frequency bands.

[0008] Therefore, an object of the present invention is to provide a sound collecting device capable of simultaneously generating resonance in multiple frequency bands.

[0009] [Technical means to solve the problem]

[0010] The sound collecting device of the present invention comprises: a plurality of resonance tubes of different lengths, formed in a cylindrical shape and having a sound collecting opening formed at one end thereof; and a microphone, arranged at the other end of the aforementioned resonance tube; and the aforementioned resonance tube has a reflecting surface extending toward the inner side of the aforementioned resonance tube at a position at a predetermined distance away from the aforementioned sound collecting opening and the aforementioned microphone.

[0011] (Effect)

[0012] In the above-described sound collection device, the resonance tube includes a reflective surface extending inwardly of the resonance tube at a predetermined distance from the sound collection opening and the microphone. Sound waves entering the sound collection opening are reflected by the reflective surface, thereby generating resonance in the area from the sound collection opening to the reflective surface. This allows each resonance tube to resonate independently, even when multiple resonance tubes are bundled and connected to a microphone. By varying the length of each resonance tube, multiple frequency bands can be amplified and collected simultaneously.

[0013] The above-described sound collection device further facilitates adjustment of microphone characteristics and facilitates listening to different sound ranges through a resonant sound collection tube, thereby improving the SN in different sound ranges and reducing the noise range, thereby achieving abnormal sound detection that surpasses human capabilities. Furthermore, a sound collection device can be provided that can simultaneously resonate in multiple frequency bands.

[0014] In the above-mentioned sound collecting device, optionally, the above-mentioned resonance tube includes: a sound collecting resonance portion formed from the above-mentioned sound collecting opening to the above-mentioned reflecting surface; and a thin tube portion, the cross-sectional area of ​​which is formed to be smaller than the above-mentioned sound collecting resonance portion, and the above-mentioned sound collecting resonance portion is connected to the above-mentioned microphone.

[0015] According to the above-described sound collecting device, since the sound collecting resonance portion and the microphone are connected via the thin tube portion thinner than the sound collecting resonance portion, even if a plurality of resonance tubes are connected to the microphone, an increase in size of the microphone can be suppressed.

[0016] In the above-mentioned sound collecting device, optionally, the cross-sectional area of ​​the thin tube portion is formed to be smaller than the outer shape of the microphone.

[0017] According to the above-described sound collecting device, since the thin tube portion is formed thinner than the outer shape of the microphone, Helmholtz resonance can be generated in the thin tube portion and the space inside the microphone, thereby further amplifying and collecting the target frequency band.

[0018] In the above-mentioned sound collecting device, optionally, the above-mentioned sound collecting opening is formed on a sound collecting surface formed by a plane opposite to the above-mentioned microphone, and the above-mentioned resonance tube is arranged with the above-mentioned microphone as the center. Among the multiple above-mentioned resonance tubes with different lengths, the resonance tube with a shorter total length of the above-mentioned sound collecting resonance part is arranged on the center side, and the resonance tube with a longer total length of the above-mentioned sound collecting resonance part is arranged on the outer side than the resonance tube with a shorter total length of the above-mentioned sound collecting resonance part.

[0019] According to the above-described sound collecting device, since the distance from the microphone to the sound collecting opening can be set short, the device does not increase in size even if sound collecting tubes of different lengths are provided.

[0020] In the above-mentioned sound collecting device, optionally, a plurality of the aforementioned thin tube portions are collected and connected to a microphone.

[0021] According to the above-described sound collecting device, since a plurality of thin tube portions are collected into one and connected to the microphone, the microphone can be miniaturized even if a plurality of resonance tubes are provided.

[0022] (Effects of the Invention)

[0023] According to the present invention, it is possible to provide a sound collecting device capable of simultaneously generating resonance in a plurality of frequency bands. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a perspective view of a sound collecting device according to an embodiment of the present invention.

[0025] Figure 2 It is a drawing Figure 1 A diagram of the sound collecting surface of a sound collecting device.

[0026] Figure 3 It is a drawing Figure 1 Figure 1 shows the back of the sound collection device.

[0027] Figure 4 yes Figure 2 AA line cross-section diagram.

[0028] Figure 5 This is a simplified diagram showing a one-sided closed resonance model.

[0029] Figure 6 yes Figure 4 A partial enlarged view of .

[0030] Figure 7 yes Figure 4 A partial enlarged view of .

[0031] Figure 8 yes Figure 1 AA line cross-section.

[0032] Figure 9 This is an enlarged perspective view of the back of the sound collection device.

[0033] Figure 10 yes Figure 4 A partial enlarged view of .

[0034] Figure 11 It is a perspective cross-sectional view of the sound collecting device.

[0035] Figure 12 yes Figure 11 Cross-sectional view of the sound collection device at line JJ. DETAILED DESCRIPTION

[0036] (Overview of the sound collection device)

[0037] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 1 is a perspective view of a sound collecting device 1 according to an embodiment of the present invention. Figure 1 As shown in FIG, the shape of the sound collecting device 1 is substantially cylindrical. In the sound collecting device 1, one of the two opposing surfaces included in the cylindrical shape is referred to as a sound collecting surface 4. The other of the two surfaces is referred to as a back surface 6. Figure 2 1 is a diagram illustrating the sound collecting surface 4 of the sound collecting device 1 . Figure 3 1 is a diagram showing the back side 6 of the sound collecting device 1 . Figure 4 yes Figure 2 AA line cross-section.

[0038] (One-sided closed resonance model)

[0039] like Figure 4 As shown in FIG, the sound collecting device 1 includes a plurality of resonance tubes 10 and a microphone 50. The resonance tube 10 is a tube in which the collected sound resonates. The sound collecting device 1 is constructed as a one-sided closed resonance model 80. Figure 5 This is a diagram showing a portion of the sound collecting device 1 as a single-sided closed resonance model 80. Figure 5 , a resonance tube 10 and a microphone 50 are described as components of a one-sided closed resonance model 80. One end of the resonance tube 10 is referred to as the opening-side end 22. A sound-collecting opening 20 is formed in the opening-side end 22. The other end of the resonance tube 10 is referred to as the microphone-side end 24. The microphone 50 is disposed at the microphone-side end 24.

[0040] In the sound collecting device 1 of the present embodiment, a portion where the inner diameter of the resonance tube 10 is reduced is formed in the resonance tube 10 . Figure 5 The portion with a reduced inner diameter is shown as the resonance end 26. By forming the portion with a reduced inner diameter in the resonance tube 10, resonance can be generated in the resonance tube 10 even if the resonance tube 10 is not completely closed on one side. Figure 5 The double arrow B in FIG. 2 represents the interval between the opening side end portion 22 and the resonance end 26. Figure 5 In the one-sided closed resonance model 80 shown in FIG, resonance occurs in the section indicated by the double-headed arrow B. Methods for forming a portion with a reduced inner diameter in the resonance tube 10 include, for example, forming a reflecting surface 28 in the resonance tube 10 and forming a narrow tube portion 18 in the resonance tube 10. The reflecting surface 28 and the narrow tube portion 18 will be described later.

[0041] (Multiple resonance frequencies)

[0042] like Figure 1As shown in FIG, the sound collecting device 1 includes 12 resonance tubes 10. Twelve resonance frequencies can be set in the sound collecting device 1. For example, the resonance frequencies can be set to 12 levels from 2.1 kHz to 6.5 kHz at 400 Hz intervals.

[0043] In the sound collector 1 of this embodiment, a single-side closed resonance tube structure is employed, allowing individual resonance tubes 10 to resonate independently. By arranging multiple resonance tubes 10 in parallel, the sound collector 1 of this embodiment achieves overlapping resonances, amplifying signals targeting specific frequencies. Each component is described below.

[0044] (Reflective surface)

[0045] like Figure 1 As shown in , etc., the sound collecting device 1 is formed into a cylindrical shape. Figure 4 As shown in FIG, a sound-collecting opening 20 is formed at one end of the resonance tube 10, namely, the opening-side end 22. Furthermore, the sound collecting device 1 includes a plurality of resonance tubes 10 of varying lengths. The term "length" does not refer to the shortest distance from the opening-side end 22 to the microphone-side end 24, but rather to the actual length of the resonance tube 10 from the opening-side end 22 to the microphone-side end 24. If the resonance tube 10 has a twisted shape, the actual length of the resonance tube 10 corresponds to the length of the twisted tube if it were extended straight.

[0046] In addition, Figure 1 etc., a cylindrical sound collecting device 1 is exemplified as the sound collecting device 1. However, the shape of the sound collecting device 1 is not limited to a cylindrical shape. That is, the so-called cylindrical shape mentioned above includes not only a cylindrical shape but also a cylindrical shape having corners such as a square or a triangle. The sound collecting device 1 may also be a cylindrical shape having corners or a flat surface on the outer surface.

[0047] Figure 6 yes Figure 4 A partial enlarged view of the Figure 6 As shown in FIG, a microphone 50 is disposed at the other end of the resonance tube 10, that is, the microphone-side end 24. The sound collecting device 1 of this embodiment includes a reflecting surface 28 at a position a predetermined distance from the sound collecting opening 20 and a predetermined distance from the microphone 50.

[0048] The reflecting surface 28 extends from the inner wall of the resonance tube 10 toward the inside of the resonance tube 10 . Figure 6Arrow C indicates a direction C toward the inside of the resonance tube 10. Direction C can be perpendicular to the direction from the opening-side end 22 toward the microphone-side end 24. Reflecting surface 28 extends from the inner wall of the tubular resonance tube 10 toward the center of the tube. Sound entering the resonance tube 10 through the sound-collecting opening 20 resonates between the sound-collecting opening 20 and reflecting surface 28. The location where reflecting surface 28 is located is referred to as the resonance end 26.

[0049] Figure 6 The double arrow D indicates the distance D from the sound collecting opening 20 to the reflecting surface 28 . Figure 6 The double-headed arrow E indicates the distance E from the sound collecting opening 20 to the reflecting surface 28. The distance D and the distance E can be determined based on the frequency of the signal to be amplified, etc.

[0050] (microphone)

[0051] The microphone 50 can be set as a capacitor microphone, for example. The resonance frequency of the microphone 50 can be set as 6 kHz, for example. Figure 3 As shown in FIG, the microphone 50 is arranged at the center of the sound collecting device 1 in a plan view from the rear surface 6 .

[0052] In the sound collection device 1 of this embodiment, the resonance tube 10 is provided with a reflective surface 28 extending toward the inside of the resonance tube 10 at a predetermined distance from the sound collection opening 20 and the microphone 50. As a result, sound waves entering the resonance tube 10 from the sound collection opening 20 are reflected by the reflective surface 28. Consequently, resonance can be generated in the area from the sound collection opening 20 to the reflective surface 28. This allows each resonance tube 10 to resonate independently even when multiple resonance tubes 10 are clustered and connected to the microphone 50. Consequently, by varying the length of each resonance tube 10, multiple frequency bands can be amplified and collected simultaneously.

[0053] The sound collector 1 of this embodiment further facilitates adjustment of microphone characteristics and facilitates listening to different sound ranges through a resonant sound collector. This improves the SN of different sound ranges and reduces the noise level, thereby enabling detection of abnormal sounds that surpasses human sensitivity. For example, the sound collector 1 of this embodiment can achieve a sensitivity of 105dB, exceeding the estimated human sensitivity of 95dB.

[0054] (Sound-collecting resonance part and fine tube part)

[0055] Figure 7 and Figure 6 Likewise, Figure 4 A partial enlarged view of the Figure 7As shown in FIG, the resonance tube 10 includes a sound-collecting resonance portion 16 and a thin tube portion 18. The sound-collecting resonance portion 16 is a portion formed from the sound-collecting opening 20 to the reflecting surface 28. In the sound-collecting resonance portion 16, the collected sound resonates by a one-sided closed resonance pattern. The thin tube portion 18 is a portion formed from the reflecting surface 28 to the microphone 50. The thin tube portion 18 is a portion connecting the sound-collecting resonance portion 16 and the microphone 50. The cross-sectional area of ​​the thin tube portion 18 is formed to be smaller than that of the sound-collecting resonance portion 16.

[0056] exist Figure 7 The double arrow G in FIG. 1 shows the outer diameter of the sound collecting resonance portion 16 at the resonance end 26 where the reflection surface 28 is formed. Figure 7 The outer diameter of the thin tube portion 18 at the portion in contact with the inner surface of the reflecting surface 28 is indicated by a double arrow F. The outer diameter F of the thin tube portion 18 is smaller than the outer diameter G of the sound-collecting resonance portion 16. In the sound collecting device 1 of this embodiment, the sound-collecting resonance portion 16 and the microphone 50 are connected by the thin tube portion 18 that is thinner than the sound-collecting resonance portion 16. Therefore, even if a plurality of resonance tubes 10 are connected to the microphone 50, the size of the microphone 50 can be suppressed. In addition, the outer diameter G of the sound-collecting resonance portion 16 at the reflecting surface 28 can be set to 4.8 mm, for example. In addition, the outer diameter F of the thin tube portion 18 at the portion in contact with the reflecting surface 28 can be set to 2 mm, for example.

[0057] (Cross-sectional area of ​​the capillary portion)

[0058] The cross-sectional area of ​​the thin tube portion 18 is formed to be smaller than the outer shape of the microphone 50. Figure 7 The double arrow H in FIG. 1 shows the outer diameter of the thin tube portion 18 at the portion where the thin tube portion 18 and the microphone 50 are connected. Figure 7 The outer diameter of the microphone 50 is indicated by a double arrow I. The outer diameter H of the capillary portion 18 at the portion in contact with the microphone 50 is smaller than the outer shape of the microphone 50. Furthermore, if the microphone 50 is cylindrical, for example, the outer diameter I of the microphone 50 corresponds to the outer diameter of the outer shape of the microphone 50.

[0059] In the sound collecting device 1 of this embodiment, the thin tube portion 18 is formed thinner than the outer shape of the microphone 50. Therefore, Helmholtz resonance can be generated in the thin tube portion 18 and the internal space 54 of the microphone 50. As a result, the target frequency band can be further amplified and sound can be collected.

[0060] (Sound collection surface)

[0061] Figure 8 and Figure 4 Likewise, Figure 1 The plane of the sound collecting device 1 facing the microphone 50 is referred to as the sound collecting surface 4. The sound collecting surface 4 is formed as a plane. The sound collecting opening 20 of each resonance tube 10 is formed on the sound collecting surface 4.

[0062] (Configuration of resonance tube)

[0063] The resonance tubes 10 are arranged around the microphone 50 . Figure 8 The line L1 shows the center of the microphone 50. Figure 8 As shown in FIG, each resonance tube 10 is arranged at a position substantially line-symmetrical with respect to the center line L1 of the microphone 50 in a cross-sectional view. Figure 9 It is an enlarged perspective view of the back side of the sound collecting device 1 . Figure 9 FIG. 4 shows a state where the microphone 50 is removed from the sound collecting device 1. Figure 9 The microphone mounting portion 52 shown in FIG. is provided with a microphone 50. The microphone mounting portion 52 is located at the center of the back surface 6. Figure 9 As shown in FIG, the resonance tubes 10 are radially arranged with the microphone mounting portion 52 as the center.

[0064] (Short resonance tube and long resonance tube)

[0065] The resonance tubes 10 include a plurality of resonance tubes 10 of varying lengths. The plurality of resonance tubes 10 of varying lengths are categorized into resonance tubes 10 having a short total length of the sound-collecting resonance portion 16 and resonance tubes 10 having a long total length of the sound-collecting resonance portion 16. Resonance tubes 10 having a short total length of the sound-collecting resonance portion 16 are referred to as short resonance tubes 12. Resonance tubes 10 having a long total length of the sound-collecting resonance portion 16 are referred to as long resonance tubes 14.

[0066] Figure 8 The double-headed arrows L11 to L14 shown in the figure indicate the total length of the sound-collecting resonance portion 16. The total length of the sound-collecting resonance portion 16 is the length from the opening-side end 22 to the reflecting surface 28. In other words, the total length of the sound-collecting resonance portion 16 is the length from the opening-side end 22 to the resonance end 26. L11 and L12 indicate the length of the short resonance tube 12. L13 and L14 indicate the length of the long resonance tube 14. The lengths of L13 and L14 are longer than the lengths of L11 and L12.

[0067] The term "length" does not refer to the shortest distance from the opening-side end 22 to the reflecting surface 28, but rather refers to the actual length of the sound-collecting resonance portion 16 from the opening-side end 22 to the reflecting surface 28. If the sound-collecting resonance portion 16 is twisted, the actual length of the sound-collecting resonance portion 16 is equivalent to the length of the twisted pipe if it were extended straight.

[0068] Furthermore, the length of L13 is different from the length of L14. Similarly, the length of L11 is different from the length of L12. This is because the resonance tubes 10 are designed to have different resonance frequencies.

[0069] like Figure 8 and Figure 9As shown in FIG, the short resonance tube 12 is positioned closer to the center than the long resonance tube 14. The long resonance tube 14 is positioned further outboard than the short resonance tube 12. This arrangement of the resonance tubes 10 allows the sound collector 1 of this embodiment to shorten the distance from the microphone 50 to the sound collection opening 20. As a result, even with resonance tubes 10 of varying lengths, the sound collector 1 does not become larger.

[0070] (Collection of capillaries)

[0071] Figure 10 and Figure 6 Likewise, Figure 4 A partial enlarged view of . Figure 10 Lines L21 to L23 , lines L31 to L34 , and lines 41 to 42 shown in FIG. 5 are lines indicating the arrangement of the capillary portion 18 . Figure 10 The lines L21 to L23 and L31 to L34 shown in FIG are connected to different sound collecting resonance parts 16. In the sound collecting device 1 of this embodiment, a plurality of thin tube parts 18 are collected and connected to the microphone 50. Figure 10 In the example shown in FIG, the thin tube portions 18 shown by lines L21 to L23 are combined into a single thin tube portion 18 shown by line L41 and connected to the microphone 50. Similarly, the thin tube portions 18 shown by lines L31 to L34 are combined into a single thin tube portion 18 shown by line L42 and connected to the microphone 50.

[0072] Figure 11 It is a perspective cross-sectional view of the sound collecting device 1 taken on a plane perpendicular to the sound collecting surface 4 . Figure 12 yes Figure 11 A cross-sectional view of the sound collecting device 1 at the JJ line. Figure 11 As shown in FIG, the thin tube portion 18 extending from the sound collecting resonance portion 16 is connected to the microphone 50 after being combined with other thin tube portions 18. Figure 12 As shown in FIG, there are 12 thin tube portions 18 as shown in FIG. Figure 11 As shown in FIG, the number of thin tube portions 18 is less than 12, and the thin tube portions 18 are connected to the microphone 50. In this way, in the sound collecting device 1 of this embodiment, the plurality of thin tube portions 18 are collected into one and connected to the microphone 50. Therefore, even if a plurality of resonance tubes 10 are provided, the microphone 50 can be miniaturized.

[0073] The embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various changes, modifications, and combinations are possible.

[0074] Reference numerals

[0075] 1 Sound collection device

[0076] 4 sets of sound surfaces

[0077] 6 Back

[0078] 8 sets of audio

[0079] 10 resonance tubes

[0080] 12 short resonance tubes

[0081] 14 long resonance tube

[0082] 16 Sound Resonance Department

[0083] 18 capillary tube

[0084] 20 sound openings

[0085] 22 Opening side end (one end)

[0086] 24 Microphone side end (other end)

[0087] 26 resonance end

[0088] 28 reflective surfaces

[0089] 50 microphones

[0090] 52 Microphone installation part

[0091] 54 Microphone's internal space

[0092] 80 unilateral closed resonance model

Claims

1. A sound collection device comprising: A plurality of resonance tubes of different lengths are formed in a cylindrical shape and have a sound collecting opening formed at one end thereof; and a microphone disposed at the other end of the resonance tube; and The resonance tube includes a reflecting surface extending toward the inside of the resonance tube at a position separated by a predetermined distance from the sound collecting opening and the microphone.

2. The sound collecting device according to claim 1, wherein: The resonance tube includes: a sound collecting resonance portion formed from the sound collecting opening to the reflecting surface; and The thin tube portion has a cross-sectional area smaller than that of the sound-collecting resonance portion, and connects the sound-collecting resonance portion to the microphone.

3. The sound collecting device according to claim 2, wherein: The cross-sectional area of ​​the thin tube portion is formed to be smaller than the outer shape of the microphone.

4. The sound collecting device according to claim 2 or 3, wherein: The sound collecting opening is formed on a sound collecting surface formed by a plane facing the microphone. The resonance tube is arranged with the microphone as the center. Among the plurality of resonance tubes having different lengths, the resonance tube having a shorter total length of the sound-collecting resonance portion is arranged on the center side, and the resonance tube having a longer total length of the sound-collecting resonance portion is arranged further outward than the resonance tube having a shorter total length of the sound-collecting resonance portion.

5. The sound collecting device according to claim 2 or 3, wherein: The plurality of the aforementioned thin tubes are gathered together and connected to a microphone.

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