Microphone

Abstract

[Problem] To provide a microphone suitable for being installed in a moving object. [Solution] A microphone 1 to be installed in a moving object and configured to collect external sounds on right and left sides in the moving object traveling direction, the microphone 1 including: a pair of microphone units 102; a sound collection unit disposed at a tip of the microphone units 102; and a housing 10 in which an opening 10a communicating with a housing part 101 housing the microphone units 102 is provided on a side surface that follows the moving object traveling direction, wherein in a condition of being installed in the moving object, the microphone units 102 are held in a direction in which the sound collection unit is oriented rearward and obliquely relative to the traveling direction.

Description

microphone

[0001] The present invention relates to a microphone.

[0002] Conventional microphone technologies for use in wind-affected environments include microphone covers that allow sound waves to pass while suppressing pressure fluctuations caused by wind inside the cover, and high-speed airflow noise prevention microphone devices that detect sounds in high-speed airflow without generating self-generated noise in the microphone (see, for example, Patent Documents 1 and 2).

[0003] International Publication WO2015 / 015646 Patent No. 5044798

[0004] Wind is a source of noise for microphones, and avoiding wind is a constant challenge when recording sound outdoors. Especially on high-speed motorsport vehicles, relatively strong air currents occur even when there is no wind due to weather, making it difficult to mount microphones on the vehicle for sound recording. If a microphone is directly hit by strong winds, the resulting sound drowns out the target sound. Conventionally, microphones have been wrapped in porous materials to prevent direct wind impacts. However, this method degrades sound quality due to the sound-absorbing properties of porous materials. Furthermore, compact microphones are preferred in motorsports and other competitive events. Large microphones can interfere with the competition itself, increasing air resistance and weight and interfering with video capture, and in some cases, even making them unsuitable for mounting.

[0005] An object of the present invention is to provide a microphone suitable for mounting on a moving object.

[0006] The microphone of the present invention is a microphone mounted on a moving body and picks up external sounds to the left and right of the moving body's direction of travel, and comprises a pair of microphone units, a sound pickup section arranged at the tip of the microphone units, and a housing having an opening communicating with the storage section that houses the microphone units and provided on the side along the moving body's direction of travel, and when mounted on the moving body, the microphone units are held in a direction so that the sound pickup section faces rearward and diagonally to the side with respect to the moving body's direction of travel.

[0007] The microphone according to the present invention is suitable for mounting on a moving object.

[0008] 1 is a perspective view of a microphone according to a first embodiment of the present invention, as seen from the front side. FIG. 2 is a perspective view of a microphone according to the first embodiment, as seen from the back side. FIG. 3 is a front view of a microphone according to the first embodiment. FIG. 4 is a perspective view of a holder constituting a microphone according to the first embodiment. FIG. 5 is a partial cross-sectional view taken along line A-A, with some of the internal mechanism of the microphone according to the first embodiment omitted. FIG. 6 is a perspective view of a fixing member that fixes a microphone unit within a housing. FIG. 7 is a graph showing the frequency characteristics of the microphone according to the first embodiment.

[0009] A microphone according to an embodiment of the present invention will be described below. The microphone according to the present invention is a device mounted on a moving object to pick up external sounds, and the microphone 1 shown in FIG. 1 is one example. The moving object is an object used for the purpose of moving in a predetermined direction of travel, and includes, for example, two-wheeled or four-wheeled vehicles, snowmobiles, boats, jet skis, aircraft, drones, and autonomous mobile robots. This moving object may be mechanically or man-powered, and may be a person or an animal. Furthermore, the moving object may be passenger-mounted or not, and may travel on land, water, or in the air. In the following description, unless otherwise specified, the direction in which the moving object is intended to move forward will be referred to as the direction of travel. In each figure, the x-direction is the moving direction of the moving object. Furthermore, the side toward which the microphone 1 is moving may be referred to as the front, and the side opposite to the moving direction of the microphone 1 may be referred to as the rear.

[0010] In the present embodiment, the external sound refers to a target sound to be picked up. In an example in which the microphone 1 is used in motor sports, the target sound is expected to be the engine noise of a vehicle, cheers, conversations between drivers and staff, etc.

[0011] Regarding mounting, the microphone 1 may be attached to a moving object as a separate unit, or may be manufactured to be integrated with the moving object. The microphone 1 may also be attached to a helmet or the like worn by a person walking, running, or participating in sports such as skydiving or skiing.

[0012] An imaging unit such as a CCD camera may be provided as another functional unit in the microphone 1. The imaging unit is provided integrally on the upper part of the microphone 1, for example, and captures an image in the traveling direction.

[0013] As shown in FIGS. 1 and 5, a microphone 1 according to one embodiment includes a housing 10, a microphone unit 102, and a windshield 11.

[0014] Housing 10 As shown in FIG. 5, housing 10 has a hollow housing portion 101 that houses microphone unit 102, electrical circuits, etc. Housing 10 is preferably made by cutting out a solid piece of aluminum alloy, for example, and is lightweight and does not easily transmit vibrations caused by wind to microphone unit 102. This housing 10 is attached to the mobile body by placing microphone 1 at a predetermined location on the mobile body and connecting members such as screws to the mobile body or by bonding with an adhesive. Alternatively, housing 10 and the mobile body may be formed integrally.

[0015] The length of the housing 10 in the width direction perpendicular to the direction of travel is shorter than the length in the direction of travel. Furthermore, the end of the housing 10 facing the direction of travel is V-shaped in a plan view, and is formed so that it gradually widens from the front to the rear. This allows the wind blowing against the microphone 1 as the moving object moves to flow smoothly along the surface of the housing 10 from the front to the rear, reducing the air resistance caused by the housing 10 when the moving object moves.

[0016] As shown in Figures 1 and 2, an opening 10a communicating with the storage section 101 is provided on a side surface (y-direction surface) of the housing 10 that is aligned with the direction of travel of the mobile object. The opening 10a is provided perpendicular to the direction of travel of the mobile object or facing rearward of the direction of travel of the mobile object relative to the direction of travel of the mobile object relative to the direction of travel of the mobile object. This prevents wind blowing toward the microphone 1 from the direction of travel as the mobile object moves from directly entering the opening 10a. A pair of openings 10a is provided on both side surfaces in the width direction (y-direction) perpendicular to the direction of travel of the mobile object. This allows the microphone 1 to pick up external sounds on the left and right of the direction of travel of the mobile object and obtain stereo sound.

[0017] The opening 10a may be covered with a mesh member. The mesh member may be, for example, a sheet member made of a breathable fiber material or metal material that allows external sound to reach the microphone unit 102 in the housing portion 101 of the housing 10. The mesh member may also be water-repellent. The water-repellent property may be provided by, for example, the material of the mesh member itself, or may be provided by a water-repellent treatment. This prevents rain from blowing into the opening 10a.

[0018] Microphone Unit 102 As shown in FIG. 5 , the microphone unit 102 is housed in the housing 10 together with the electrical circuit and picks up external sounds. The microphone unit 102 is omnidirectional, and picks up external sounds that enter the housing 101 through the opening 10a within the housing 101. The microphone unit 102 is connected to the electrical circuit, which processes the audio signal electroacoustically converted by the microphone unit 102. The electroacoustic conversion method of the microphone unit 102 is optional, and may be, for example, a capacitor type or a dynamic type. Data processed by the electrical circuit is transmitted to an external device, for example, via wireless communication. A terminal for wired connection to the electrical circuit may be provided at a predetermined location on the housing 10.

[0019] A pair of microphone units 102 are provided corresponding to openings 10a provided on both side surfaces of the housing 10. Each pair of microphone units 102 has a substantially cylindrical shape, and a sound pickup section 1021 that picks up external sounds is disposed at the tip. When mounted on a mobile object, the pair of microphone units 102 are held in a direction such that the sound pickup section 1021 faces rearward and diagonally to the side relative to the direction of travel of the mobile object. Meanwhile, the ends opposite the side where the sound pickup section 1021 is disposed are housed diagonally forward from the opening 10a so as to be close to each other. This allows the width of the housing 10 to be reduced, thereby reducing the wind resistance that the housing 10 experiences when the mobile object moves.

[0020] Furthermore, when the pair of microphone units 102 are mounted on the mobile object, the sound collection section 1021 is held in a direction facing diagonally downward relative to the direction of travel of the mobile object, thereby making it difficult for moisture such as rain to penetrate from the outside into the interior through the opening 10 a.

[0021] The pair of microphone units 102 are held in the housing 101 by a fixing member 103. The fixing member 103 is disposed in the housing 10 so as to fill the space within the housing 101. The fixing member 103 houses the microphone unit 102 in an inner hollow portion 1031. An O-ring 104 is provided between the inner wall of the hollow portion 1031 and the outside of the microphone unit 102. The O-ring 104 fills the gap between the inner wall of the hollow portion 1031 and the outside of the microphone unit 102, fixing the microphone unit 102 within the hollow portion 1031. The O-ring 104 is made of, for example, elastic or flexible rubber. This prevents the microphone unit 102 from wobbling within the hollow portion 1031, and reduces the transmission of fixed vibrations of the housing 10, preventing sound degradation due to fixed vibrations.

[0022] 6 , fixing member 103 is composed of a base 1032 on one end side and a pair of end portions 1033 that branch out in two from base 1032. An opening 1032a is provided in front of base 1032. Wiring connected to microphone unit 102 housed in hollow portion 1031 is led out from opening 1032a to the outside and connected to an electrical circuit housed within housing 10.

[0023] A communication hole 1034 that communicates with the opening 10a and the hollow portion 1031 is formed on the end surface of the end portion 1033. The communication hole 1034 is disposed at the rear end of the hollow portion 1031 in the traveling direction, at a position corresponding to the sound pickup portion 1021. The communication hole 1034 is smaller than the opening 10a, and is exposed to the outside through the opening 10a of the housing 10 when the fixing member 103 is housed in the housing 10. External sound is picked up by the microphone unit 102 in the hollow portion 1031 via the communication hole 1034.

[0024] The communication hole 1034 includes a first communication hole 10341 and a second communication hole 10342. The first communication hole 10341 connects to the opening 10a. The second communication hole 10342 connects the first communication hole 10341 to the hollow portion 1031. The diameter of the second communication hole 10342 is smaller than the diameter of the first communication hole 10341, and the communication hole 1034 forms a step at the boundary between the first communication hole 10341 and the second communication hole 10342. Furthermore, the diameter of at least the second communication hole 10342 is smaller than the diameter of the sound pickup portion 1021. With this configuration, resonance in the communication hole 1034 can be reduced, allowing external sounds to be picked up more accurately. Regardless of this embodiment, the diameter of the communication hole 1034 may be the same over the entire length in the axial direction, and may be smaller than the diameter of the sound collection section 1021.

[0025] The upper and lower surfaces of the fixing member 103 in the accommodated state are each provided with a screw hole 1035 for connecting the fixing member 103 to the accommodation section 101 by screwing or the like. Correspondingly, a screw hole into which a screw inserted through the screw hole 1035 is threaded is provided in the accommodation section 101 of the housing 10. The screw inserted through the screw hole 1035 threads into this screw hole, thereby fixing the fixing member 103 to the accommodation section 101. Note that the screw hole 1035 may be provided on only one of the upper surface or the lower surface of the fixing member 103. Furthermore, the means for fixing the fixing member 103 to the accommodation section 101 may be a connecting means other than screwing, such as adhesion with an adhesive.

[0026] Since fixing member 103 is housed in housing portion 101 to fill the space within housing portion 101 and is fixed within housing portion 101 by O-ring 104, resonance within housing portion 101 can be prevented in microphone 1. Furthermore, fixing member 103 separates microphone unit 102 from housing 10, so that vibrations and temperature of housing 10 are not directly transmitted to microphone unit 102, suppressing the effects of vibrations and temperature and enabling clear pickup of external sounds. Furthermore, since opening 10a and sound pickup portion 1021 are separated by the length of communication hole 1034, moisture such as rain and dust are less likely to reach sound pickup portion 1021, preventing deterioration and damage to sound pickup portion 1021.

[0027] 1 and 2, the windshield 11 is attached to the side of the housing 10 in the direction of travel of the mobile object as seen from the opening 10a. As shown in Figures 3 and 4, the windshield 11 includes a main body 12 and a holder 13 that holds the main body 12.

[0028] The main body 12 is made of a porous material such as urethane foam. The main body 12 is held by a holder 13 and deflects wind that blows toward the microphone 1 as the mobile object moves. As a result of the main body 12 deflecting the wind, the force of the wind is sufficiently attenuated before it reaches the opening 10a, thereby suppressing wind noise. Furthermore, if the main body 12 is made of a flexible material such as urethane foam, vibrations caused by the wind are absorbed by the main body 12, and solid vibrations are not transmitted to the microphone unit 102. Note that the main body 12 may be made of a material such as faux fur.

[0029] The holder 13 is made of a plurality of thin plate-like holding pieces 1311, 1312, 1313, and 1314 and a thin plate-like connecting piece 132 that integrally connects these pieces. The holder 13 is made of a hard material such as metal or plastic. In the description of this embodiment, the plurality of holding pieces 1311, 1312, 1313, and 1314 may be referred to as "holding piece 131" when they are not individually identified.

[0030] Each holding piece 131 has a substantially semicircular shape and is spaced apart from one another in the thickness direction (z direction). Each holding piece 131 is arranged so that its length is aligned with the direction of travel of the moving object. As a result, the wide surface of each holding piece 131 faces substantially vertically (z direction), preventing wind resistance caused by the movement of the moving object.

[0031] Of the side edges of each holding piece 131, side edges 1311a, 1312a, 1313a, and 1314a disposed on the side surface of the housing 10 have a shape that conforms to the shape of the side surface of the housing 10. These side edges 1311a, 1312a, 1313a, and 1314a are connected to a wide first surface of the connecting piece 132. A wide second surface of the connecting piece 132 opposite the first surface has a shape that conforms to the shape of the side surface of the housing 10. This second surface is directly adhered to the side surface of the housing 10 with an adhesive or with adhesive tape. This allows the holding body 13 to be attached tightly to the side surface of the housing 10, so it will not easily come off even when affected by wind accompanying movement of the mobile object.

[0032] Of the retaining pieces 131, retaining pieces 1312 and 1313, which are provided between retaining pieces 1311 and 1314, are formed with locking holes 1312b and 1313b, respectively, for inserting and locking the main body 12. The locking holes 1312b and 1313b open in the vertical direction (z direction) perpendicular to the traveling direction. Furthermore, no holes corresponding to the locking holes 1312b and 1313b are formed in the retaining pieces 1311 and 1314. As a result, the main body 12 is locked in the locking holes 1312b and 1313b from the retaining piece 1311 to the retaining piece 1314 without slipping out in the vertical direction. Furthermore, as shown in FIG. 3 , when the main body 12 is locked in the locking holes 1312b and 1313b, the main body 12 is exposed between the retaining pieces 131 toward the traveling direction, and this portion is exposed to the wind. In this embodiment, four holding pieces 131 are provided, but the number is not limited thereto.

[0033] As shown in Figure 2, windshield 11 is attached in the traveling direction of the mobile body when viewed from opening 10a. As a result, opening 10a is exposed to the outside without being covered by windshield 11. The vertical length of opening 10a is equal to or shorter than the distance between holding pieces 1312 and 1313. When viewed from the traveling direction of the mobile body, opening 10a is located in a position hidden by main body 12 between holding pieces 1312 and 1313. As a result, wind blowing toward opening 10a from the traveling direction of the mobile body is reliably attenuated by main body 12 before reaching opening 10a.

[0034] According to the microphone 1 of this embodiment, the opening 10a is not covered by the windshield 11, which prevents deterioration of the sound quality of the target sound. Furthermore, wind blowing toward the microphone 1 as the mobile object moves is deflected and attenuated by the main body 12, thereby suppressing wind noise. Furthermore, because the holder 13 is made up of multiple holding pieces 131, wind vortices are broken down into smaller vortices by the multiple holding pieces 131, preventing the generation of large vortices. Furthermore, the overall size of the microphone 1 is small, allowing it to be easily mounted on a mobile object. Furthermore, it does not interfere with the use of the mobile object, and air resistance generated during movement is sufficiently suppressed.

[0035] Frequency Characteristics Figure 7 is a graph showing the frequency characteristics of sound during sound collection, illustrating the results of an experiment comparing the acoustic characteristics of microphone 1 with windshield 11 (line m1) with those of a microphone without windshield 11 (line m2). In this experiment, fans were placed in front of both microphone 1 with windshield 11 and microphone 1 without windshield 11 to simulate an environment in which wind blows against a moving object. This shows a difference in sound pressure across a wide frequency range. In particular, a difference in sound pressure of approximately 10 dB occurred at frequencies below 5 kHz, indicating that wind noise was sufficiently reduced. The peak near 10 kHz is the peak of the sound emitted by the fan used in the experiment.

[0036] In the above embodiment, the windshield 11 is attached to the side of the housing 10. However, in other embodiments, it may be formed integrally with the housing 10. Also, in this embodiment, the main body 12 made of a porous material is held by the holder 13. However, in other embodiments, the main body 12 may be directly adhered to the side of the housing 10 without providing the holder 13. Various adhesion methods can be used, such as adhesion with an adhesive or adhesion via adhesive tape.

[0037] Furthermore, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist. The embodiments of the present invention also include embodiments in which multiple embodiments are arbitrarily combined, or embodiments in which partial configurations of various embodiments are arbitrarily combined. The effects of new embodiments resulting from the combination also have the effects of the original embodiments.

[0038] 1: Microphone 10: Housing 10a: Opening 101: Storage section 102: Microphone unit 1021: Sound collection section 103: Fixing member 1031: Hollow section 1034: Communication hole 10341: First communication hole 10342: Second communication hole 11: Windshield 12: Main body 13: Holder 131: Holder piece

Claims

1. A microphone mounted on a moving body for picking up external sounds on the left and right sides in the traveling direction of the moving body, comprising: a pair of microphone units; a sound collection unit disposed at the tip of the microphone unit; and a housing provided with an opening communicating with a housing unit for housing the microphone unit on a side surface along the traveling direction of the moving body. The microphone unit is held in a direction in which the sound collection unit faces rearward and obliquely sideward with respect to the traveling direction when mounted on the moving body. Microphone.

2. The microphone according to claim 1, wherein the microphone unit is held in a direction in which the sound collection unit faces obliquely downward with respect to the traveling direction when mounted on the moving body.

3. The microphone according to claim 1, further comprising a fixing member housed in the housing unit for holding the pair of microphone units. The fixing member includes a hollow portion for housing the pair of microphone units, and a communication hole disposed at the rear end in the traveling direction of the hollow portion and corresponding to the sound collection unit and communicating with the opening.

4. The microphone according to claim 3, wherein the diameter of the communication hole is smaller than the diameter of the sound collection unit.

5. The microphone according to claim 3, wherein the communication hole has a first communication hole connected to the opening, and a second communication hole communicating the first communication hole with the hollow portion and having a smaller diameter than the first communication hole.

6. The microphone according to claim 1, wherein the opening opens in a direction orthogonal to the traveling direction or rearward of the orthogonal direction.

7. The microphone according to claim 1, wherein the opening is provided in pairs on both sides in the width direction substantially orthogonal to the traveling direction.

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