JP6678883B2 - Waterproof microphone - Google Patents

Description

  The present invention relates to a waterproof microphone.

  Microphones used in swimming classes and underwater aerobics called aquabics may get splashed. Sometimes the microphone is dropped into the water. The microphone may be required to have a relatively low degree of waterproofness so that the microphone operates without hindrance even if it is splashed or picked up from the water. This level of waterproofness is generally called life waterproofing.

  As a waterproof microphone for daily life waterproofing, Patent Document 1 discloses an example in which a microphone unit is waterproofed with a waterproof film and a restriction means for restricting deformation of the waterproof film is provided. In the waterproof microphone described in Patent Document 1, a mesh is disclosed as an example of the regulation means.

  According to the waterproof microphone described in Patent Document 1, even if the waterproof film is pressed against the regulation means by water pressure, the waterproof film that receives a sound wave propagating in water vibrates, and the diaphragm of the microphone unit also vibrates due to the vibration of the waterproof film. To do. Therefore, sound waves in water can be captured by the microphone unit.

  However, according to the waterproof microphone described in Patent Document 1, almost the entire waterproof film is pressed against the restricting means at the moment when the microphone enters the water from the atmosphere, so that the sound quality deteriorates at once.

  As another technique related to the invention of the present application, there is a sound passage member described in Patent Document 2. The sound-permeable member includes a main body having an opening for allowing sound to pass therethrough, and a waterproof sound-permeable membrane that closes the opening. The waterproof sound-permeable membrane is fixed to the main body of the sound-permeable member in a slack state. It is characterized by being.

  However, the invention described in Patent Document 2 has a clear difference from the present invention in that it does not include a regulating member for regulating the displacement of the waterproof film, unlike the invention of the present application described in detail later.

  Still another technique related to the present invention is a hydrophone described in Patent Document 3. In this underwater microphone, the sound collecting surface side of the microphone unit is airtightly fitted into an opening on one end side of a cylindrical body made of an elastic material, and an airtight air chamber is provided in front of an acoustic terminal of the microphone unit. The tubular body can be deformed in response to a pressure change generated by a sound wave in water, and the other end side of the tubular body is closed by a heat sink. The pressure in the air chamber of the cylinder changes due to the pressure change caused by the sound wave propagating in the water, and the change is converted into an electric signal by the microphone unit.

  The invention described in Patent Document 3 is an underwater microphone that picks up a sound wave propagating in water and converts it into an electric signal, and has a different configuration from the waterproof microphone according to the present application.

Japanese Patent No. 3629084 JP, 2009-111994, A Japanese Patent No. 4443292

  The present invention devises a structure so that the degree of contact of the waterproof film with the restriction member due to the water pressure applied to the waterproof film is gradually increased, and the difficulty of the conventional waterproof microphone in which the sound quality deteriorates at a stroke can be solved. The purpose is to provide.

The waterproof microphone according to the present invention,
A waterproof case with at least one end open,
A microphone unit housed in the waterproof case,
A waterproof film closing the open end of the waterproof case,
A restriction member that restricts the waterproof film from being deformed toward the inside of the waterproof case under pressure,
The most main feature is that the regulation member has a convex surface or a concave surface with respect to the waterproof film having a flat surface.

  When the water pressure applied to the waterproof membrane is low, the degree of contact of the waterproof membrane with the regulating member is small, and the degree of contact increases as the water pressure increases. While the degree of contact is small, the underwater sound can be collected with good sound quality.

It is a longitudinal cross-sectional view showing an embodiment of a waterproof microphone according to the present invention. It is a schematic diagram which shows the waterproofing operation in steps of the Example of the waterproof microphone which concerns on this invention. It is a longitudinal cross-sectional view which shows schematically the various modified examples of the regulation member applicable to this invention. It is a longitudinal section showing another modification of a regulation member applicable to the present invention for every stage of waterproofing operation. Another modification of the regulation member applicable to the present invention is shown, (a) is a longitudinal sectional view and (b) is a plan view. It is a top view which shows another modification of the regulation member applicable to this invention.

  An embodiment of a waterproof microphone according to the present invention will be described below with reference to the drawings.

  The waterproof microphone 10 according to the first embodiment shown in FIG. 1 is an example of a headset microphone used in aerobics in water, for example. The waterproof microphone 10 has a microphone case 11 connected to the headset device. A waterproof case 14 is incorporated in the case 11, and a microphone unit 12 is housed in the waterproof case 14.

  The directivity of the microphone unit 12 in the embodiment shown in FIG. 1 is unidirectional, and the microphone unit 12 has a front acoustic terminal and a rear acoustic terminal. The waterproof case 14 has open front and rear ends (upper and lower ends in FIG. 1) for guiding sound waves to the front and rear acoustic terminals of the microphone unit 12. Sound waves are introduced to the front acoustic terminals from the front open end of the waterproof case 14, and sound waves are introduced to the rear acoustic terminals from the rear open end of the waterproof case 14. External sound waves are introduced from the front side of the waterproof case 14 to the front acoustic terminals, and also through the microphone case 11 from the rear side of the waterproof case 14 to the rear acoustic terminals.

  A waterproof film 17 is attached to the front open end of the waterproof case 14, and the front open end is closed by the waterproof film 17. The waterproof case 14 also has a restriction member 21 fixed to the inside of the waterproof film 17 and near the waterproof film 17. Similarly, a waterproof film 18 is attached to the rear open end of the waterproof case 14, and the rear open end is closed by the waterproof film 18. A restriction member 22 is fixed to the waterproof case 14 inward of the waterproof film 18 and near the waterproof film 18. The waterproof films 17 and 18 in this embodiment are formed of PET (polyethylene terephthalate) material having a thickness of about 4 μm in a predetermined shape.

  In the embodiment shown in FIG. 1, the characteristic components are the restriction members 21 and 22. The restriction members 21 and 22 are provided to restrict the waterproof films 17 and 18 from being deformed inward of the waterproof case 14 under pressure. The restricting members 21 and 22 in this embodiment are meshes made of stainless steel wire rods. The waterproof films 17 and 18 have a flat surface as a whole, while the regulating members 21 and 22 have a convex surface or a concave surface. More specifically, the restricting members 21 and 22 in the embodiment shown in FIG. 1 have a shape in which a part of the spherical surface is cut off so that the restricting members 21 and 22 are projected toward the waterproof films 17 and 18, respectively. The periphery is fixed to the waterproof case 14.

  In the conventional waterproof microphone, the restriction member is also formed on the flat surface with respect to the waterproof film having the flat surface, and the restriction member is arranged in parallel with the waterproof film. Therefore, according to the conventional waterproof microphone, when water pressure is applied to the waterproof film, almost the entire waterproof film is instantly pressed against the restricting means, and the sound quality deteriorates at a stretch. On the other hand, according to the embodiment shown in FIG. 1, even if water pressure is applied to the waterproof films 17 and 18, some of the waterproof films 17 and 18 come into contact with the restricting members 21 and 22, respectively. The entire body is not instantly pressed against the regulation members 21 and 22.

  FIG. 2 shows, in order, the manner in which the waterproof membrane subjected to water pressure is deformed inward of the waterproof case 14. However, FIG. 2 shows an example in which only one end of the waterproof case 14 is released, the waterproof film 17 and the regulating member 21 are provided at the open end, and the directivity of the microphone unit 12 is omnidirectional. The directivity of the microphone applicable to the present invention is arbitrary, and the waterproof film and the regulating member may be provided corresponding to the acoustic terminals.

  Hereinafter, the relationship between the deformation of the waterproof film 17 and the restriction member 21 will be described with reference to FIG. FIG. 2A shows a normal state in which the waterproof film 17 is not subjected to water pressure, and the waterproof film 17 maintains a flat surface. When the waterproof film 17 receives water pressure, the waterproof film 17 deforms inward of the waterproof case 14 as shown in FIG. Since the entire shape of the regulating member 21 is a shape in which a part of a sphere is cut off and is directed toward the waterproof film 17, while the water depth is shallow and the water pressure is small, as shown in FIG. Only the central portion of the waterproof film 17 is in contact with the central portion of the restriction member 21, and the deformation of the waterproof film 17 is restricted. The peripheral edge of the waterproof film 17 does not contact the regulation member 21.

  As described above, since the entire waterproof film 17 under water pressure does not come into immediate contact with the regulating member 21, the sound quality does not fluctuate or deteriorate at once. Further, while the degree of contact (contact area) of the waterproof film 17 with the regulation member 21 is small, the microphone unit 12 can pick up underwater sound with good sound quality.

  When the water depth increases and the water pressure increases, the waterproof film 17 is largely deformed as shown in FIG. 2C, and the degree of contact of the waterproof film 17 with the regulation member 21 increases. Even in this state, since the area of the peripheral portion of the waterproof film 17 which is not in contact with the regulation member 21 is kept relatively large, the underwater sound is transmitted to the microphone unit by the vibration of the peripheral portion of the waterproof film 17, and the sound is emitted. Converted to a signal.

  The present invention is characterized in that the restriction member has a convex surface or a concave surface with respect to the waterproof film having a flat surface so that almost the entire waterproof film under water pressure does not come into contact with the restriction member at once. . The form of the convex surface or the concave surface formed on the regulating member can be arbitrarily changed within the range in which the object of the invention can be achieved. Hereinafter, various aspects of the convex surface or the concave surface formed on the regulation member will be described. In any of the embodiments, a convex surface or a concave surface is formed on a plate-shaped member made of mesh.

  In FIGS. 3 (a), 3 (b) and 3 (c), reference numerals 30, 40 and 50 denote restricting members, respectively. FIG. 3A shows an example in which a protrusion 32 having a rectangular cross section is formed at one central portion of the regulation member 30. FIG. 3B shows an example in which protrusions 42 having a rectangular cross section are formed at a plurality of locations on the regulation member 40. FIG. 3C shows an example in which a protrusion 52 having a dome-shaped cross section, that is, a part of the spherical surface is cut off is formed at one central portion of the regulation member 50.

  In any of the examples shown in FIG. 3, when water pressure is applied to the waterproof film, deformation of the waterproof film first causes a part of the waterproof film to come into contact with the restriction member to restrict the deformation of the waterproof film, and the entire waterproof film is instantaneously restricted. There is no contact with the members. Therefore, the sound quality does not fluctuate or deteriorate at once. Further, even if the waterproof film comes into contact with the restriction member, a large area in which the waterproof film is separated from the restriction member is secured, so that the microphone unit can pick up underwater sound with good sound quality.

  The regulation member is not necessarily limited to the one having the convex surface facing the waterproof film, but may be the one having the concave surface with respect to the waterproof film. FIG. 4 shows an example thereof. As shown in FIG. 4 (a), the regulation member 60 has a shape in which a part of the spherical surface is cut off with respect to the waterproof film 17 having an entirely flat surface, and is recessed when viewed from the waterproof film 17. It has a shape. The curvature of the restriction member 60 is set to be smaller than the curvature of the waterproof film 17 when the waterproof film 17 is deformed by water pressure and the central portion of the waterproof film 17 contacts the restriction member 60.

  Therefore, when the water depth is shallow and the water pressure applied to the waterproof film 17 is relatively small, as shown in FIG. 4B, the central portion of the waterproof film 17 is in contact with the regulating member 60, and other than the central portion of the waterproof film 17 is contacted. The peripheral portion is separated from the regulation member 60. In this state, the microphone unit can pick up underwater sound with good sound quality and convert it into an audio signal.

  When the water depth increases and the water pressure applied to the waterproof film 17 increases, as shown in FIG. 4C, the waterproof film 17 is largely deformed, and many parts of the waterproof film 17 come into contact with the restriction member 60. Even in this case, the peripheral portion of the waterproof film 17 is separated from the regulation member 60, and since this portion vibrates in response to the underwater sound, the underwater sound is transmitted to the microphone unit and the underwater sound is converted into an audio signal. .

  As described above, even if the regulation member 60 has a recessed shape when viewed from the waterproof film 17, it is possible to prevent the sound quality from abruptly changing or deteriorating when the waterproof film 17 receives water pressure.

  The convex surface or the concave surface formed on the regulating member may be linearly continuous. The examples shown in FIGS. 5 and 6 are such examples. The restricting member 70 shown in FIG. 5 is a restricting member 70 having a circular outer circumference, and a jetty-shaped projection 72 is formed along the concentric circle and over the entire circumference in the radial middle portion. The regulation member 80 shown in FIG. 6 is formed by radially forming a plurality of jetty-shaped projections 82.

  In any of the examples shown in FIGS. 5 and 6, when water pressure is applied to the waterproof member facing the restricting members 70 and 80, the central portion of the waterproof film first comes into contact with the central parts of the restricting members 70 and 80, and suddenly increases. There is no change in sound quality. As the water pressure increases, the degree of contact between the waterproof film and the regulating members 70 and 80 increases. Even if the degree of contact between the waterproof film and the restricting members 70 and 80 increases, the underwater sound is transmitted to the microphone unit by the waterproof film and converted into an audio signal.

10 Waterproof Microphone 11 Microphone Case 12 Microphone Unit 14 Waterproof Case 17 Waterproof Membrane 18 Waterproof Membrane 21 Regulatory Member 22 Regulatory Member 30 Regulatory Member 40 Regulatory Member 50 Regulatory Member 60 Regulatory Member 70 Regulatory Member 80 Regulatory Member

Claims (4)

A waterproof case with at least one end open,
A microphone unit housed in the waterproof case,
A waterproof film closing the open end of the waterproof case,
A restriction member that restricts the waterproof film from being deformed toward the inside of the waterproof case under pressure,
A waterproof microphone in which the regulation member has a convex surface or a concave surface with respect to the waterproof film having a flat surface.   2. The waterproof microphone according to claim 1, wherein one end of the waterproof case is opened, the waterproof film and the regulating member are provided at the one end, and the directivity of the microphone unit is omnidirectional.   The waterproof microphone according to claim 1 or 2, wherein the restricting member has a shape in which a part of a spherical surface is cut out and has a protruding shape toward the waterproof film. The waterproof microphone according to claim 1 or 2, wherein the restriction member has a shape in which a part of a spherical surface is cut out and is recessed when viewed from the waterproof film.

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