JP2011124707A - Microphone unit and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microphone unit that is operable not to pick up any noise while picking up sound from a sound source when it is near the sound source, and can sufficiently pick up sound from the sound source even when it is not near the sound source but away from the sound source. <P>SOLUTION: The differential microphone unit 100 (microphone unit) includes a cover part 30 having a vibration part 11 disposed therein and a surface provided with cover part side sound holes 33 and 35 arranged at a distance D1 and cover part side sound holes 32 and 37 arranged at a distance D2, and sound path switching sections 22 and 34 for switching a sound path between a condition under which sound input from the cover part side sound holes 33 and 35 arranged at the distance D1 is transmitted to one side and the other side of the vibration part 11 and a condition under which sound input from the cover part side sound holes 32 and 37 arranged at the distance D2 is transmitted to one side and the other side of the vibration part 11. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a microphone unit and an electronic device, and more particularly to a microphone unit and an electronic device having a plurality of sound holes.

  Conventionally, a microphone unit and an electronic device having a plurality of sound holes are known (for example, see Patent Document 1).

  In Patent Document 1, a microphone unit (differential microphone) including a housing having an internal space, a vibration film provided inside the housing, and an output unit for outputting an electric signal based on vibration of the vibration film. Unit). In the microphone unit described in Patent Document 1, a first opening (sound hole) and a second opening (sound hole) are provided on the surface of the housing, and input from the first opening. The sound is transmitted to one side of the diaphragm, and the sound input from the second opening is transmitted to the other side of the diaphragm.

  And in the said patent document 1, in the state where a user and a microphone unit are adjoining, the sound pressure of the user's voice input from the first opening and the user's voice input from the second opening The differential pressure with respect to the sound pressure is converted into an electrical signal and output (pick up the user's voice). For noise emitted from a position relatively far from the microphone unit, the differential pressure between the sound pressure of the noise input from the first opening and the sound pressure of the noise input from the second opening is small. Therefore, it is suppressed that noise is converted into an electric signal and output (pick up noise).

JP 2009-135777 A

  However, generally, the distance from the sound source to the microphone unit and the differential pressure of the sound input to the microphone unit are inversely proportional, and in the microphone unit described in Patent Document 1, the user (sound source) and the microphone In the case where the unit is apart from the first opening, the differential pressure between the sound pressure of the user's voice input from the first opening and the sound pressure of the user's voice input from the second opening is Since it is small, there is a problem that the user's voice cannot be picked up sufficiently.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to prevent noise from being picked up while picking up the sound of the sound source when the sound sources are close to each other. It is another object of the present invention to provide a microphone unit and an electronic device capable of picking up sound of a sound source even when the sound source is separated without being close to each other.

Means for Solving the Problems and Effects of the Invention

  In the microphone unit according to the first aspect of the present invention, a vibrating portion that vibrates due to sound pressure is disposed, and a plurality of sound holes are disposed at a first distance and a second distance that is greater than the first distance. A state in which sound input from a plurality of sound holes arranged at a first distance among a plurality of sound holes and a microphone housing provided on the surface is transmitted to one side and the other side of the vibration unit And a sound path switching unit that switches the sound path to a state where sound input from a plurality of sound holes arranged at a second distance is transmitted to one side and the other side of the vibration unit.

  In the microphone unit according to the first aspect, as described above, sound input from the plurality of sound holes arranged at a first distance among the plurality of sound holes is vibrated by the sound path switching unit. By switching the sound path so that it is transmitted to one side and the other side, the sound of the sound source that is close to the microphone unit is transmitted to the one side and the other side of the vibrating part from the plurality of sound holes, respectively. Thus, the sound of the sound source can be picked up based on the differential pressure of the sound transmitted to one side and the other side of the vibration unit. In addition, with respect to noise emitted from a position relatively far from the microphone unit, since the differential pressure of noise input from a plurality of sound holes is small, picking up noise can be suppressed. In general, the distance from the sound source to the microphone unit and the differential pressure of the sound input to the microphone unit are inversely proportional, and the second distance larger than the first distance is set by the sound path switching unit. By switching the sound path so that sound input from a plurality of spaced sound holes is transmitted to one side and the other side of the vibration part, the sound of the sound source that is separated without being close to the microphone unit However, a sufficient differential pressure of the sound of the sound source input from a plurality of sound holes can be obtained. Thereby, the sound of the sound source can be sufficiently picked up. In this way, the sound path is switched between a state in which the sound is input from the plurality of sound holes arranged at the first distance and a state in which the sound is input from the plurality of sound holes arranged at the second distance. Therefore, when the sound source is close, you can pick up the sound of the sound source and not pick up the noise, and also pick up the sound of the sound source enough even when the sound source is away from close Can do.

  In the microphone unit according to the first aspect, preferably, the plurality of sound holes are spaced apart from the first sound hole by which a sound transmitted to one side of the vibrating portion is input, and the first sound hole. Arranged on the other side of the vibration part, the second sound hole to which the sound transmitted to the other side of the vibration part is input, the third sound hole, and the third sound hole are arranged at a second distance from each other. The sound path switching unit transmits the sound input from the first sound hole and the second sound hole to one side and the other side of the vibration unit, respectively. The sound path is switched between a state in which the sound is input and a state in which the sound input from the third sound hole and the fourth sound hole is transmitted to one side and the other side of the vibration unit, respectively. If comprised in this way, when a sound source is adjoining, while picking up the sound of the adjacent sound source input from the 1st sound hole and the 2nd sound hole, the 1st sound hole and the 2nd sound hole It is possible to avoid picking up noises input from. Further, even when the sound sources are separated without being close to each other, it is possible to sufficiently pick up the sounds of the sound sources that are separated from each other and input from the third sound hole and the fourth sound hole.

  In this case, preferably, the sound path switching unit is configured such that when the sound source and the vibration unit are close to each other, sounds input from the first sound hole and the second sound hole are respectively transmitted to one side and the other side of the vibration unit. The sound input from the third sound hole and the fourth sound hole is set to one side and the other side of the vibration part when the sound source and the vibration part are apart from each other without being set close to each other. It is comprised so that it may be set to the state transmitted to. With this configuration, when the sound source and the vibration unit are close to each other, it is possible to easily pick up the sound of the sound source that is in close proximity and not pick up noise. Even when the sound sources are not close to each other, the sound of the sound sources that are not close to each other can be easily picked up.

  In the microphone unit including the first sound hole, the second sound hole, the third sound hole, and the fourth sound hole, it is preferable that the first sound to be transmitted from the opening end of the first sound hole to one side of the vibrating portion. The length of the path and the length of the second sound path through which sound is transmitted from the opening end of the second sound hole to the other side of the vibration part are substantially equal, and the sound from the opening end of the third sound hole to one side of the vibration part. The length of the third sound path for transmitting the sound and the length of the fourth sound path for transmitting the sound from the opening end of the fourth sound hole to the other side of the vibrating portion are configured to be substantially equal. If comprised in this way, the phase of the sound transmitted from the 1st sound path (3rd sound path) to one side of a vibration part and the 2nd sound path (4th sound path) will be transmitted to the other side of a vibration part. Therefore, the directivity of the microphone unit on the first sound path (third sound path) side and the directivity of the microphone unit on the second sound path (fourth sound path) side are set to be substantially equal to each other. Can be approximately equal.

  In the microphone unit including the first sound hole, the second sound hole, the third sound hole, and the fourth sound hole, it is preferable that the sound path switching unit opens and closes the sound hole or the sound path. And the sound input from the second sound hole is transmitted to one side and the other side of the vibration part, respectively, and the sound input from the third sound hole and the fourth sound hole is respectively one side and the other of the vibration part. The sound path is switched to a state transmitted to the side. If comprised in this way, a sound path can be switched easily by opening and closing of a sound path switching part.

  In this case, preferably, a first sound path through which sound is transmitted from the opening end of the first sound hole to one side of the vibration part, and a third sound transmission from the opening end of the third sound hole to one side of the vibration part. The sound path includes a common part, and the sound path switching unit is provided at a part where the first sound path and the third sound path branch from the common part, and the vibration part starts from the opening end of the second sound hole. The second sound path through which sound is transmitted to the other side of the fourth sound path and the fourth sound path through which sound is transmitted from the open end of the fourth sound hole to the other side of the vibration part include a common part, and the sound path switching unit is The second sound path and the fourth sound path are provided at a portion that branches from the common part, and the sound path switching unit closes either the first sound path or the third sound path and It is configured to close either the sound path or the fourth sound path. If comprised in this way, a 1st sound path, a 2nd sound path, a 3rd sound path, and a 4th sound path will be provided separately, and a 1st sound path, a 2nd sound path, a 3rd sound path, and a 4th sound will be provided. Unlike the case where a sound path switching unit is provided on each of the roads (total of four sound path switching units), one sound path switching unit (a total of two sound path switching units) is provided at each branch of the sound path. The number of sound path switching units can be reduced by the amount that only needs to be provided.

  In the electronic device according to the second aspect of the present invention, the vibration unit that vibrates due to the sound pressure is disposed, and the plurality of sound holes disposed at a first distance and a second distance larger than the first distance are disposed. A state in which sound input from a plurality of sound holes arranged at a first distance among a plurality of sound holes and a microphone housing provided on the surface is transmitted to one side and the other side of the vibration unit And a sound path switching unit that switches the sound path to a state in which sound input from the plurality of sound holes arranged at a second distance is transmitted to one side and the other side of the vibration unit With units.

  In the electronic device according to the second aspect, as described above, sound input from the plurality of sound holes arranged at a first distance among the plurality of sound holes is transmitted by the sound path switching unit. By switching the sound path so that it is transmitted to one side and the other side, the sound of the sound source that is close to the microphone unit is transmitted to the one side and the other side of the vibrating part from the plurality of sound holes, respectively. Thus, the sound of the sound source can be picked up based on the differential pressure of the sound transmitted to one side and the other side of the vibration unit. In addition, with respect to noise emitted from a position relatively far from the microphone unit, since the differential pressure of noise input from a plurality of sound holes is small, picking up noise can be suppressed. Further, the sound path switching unit is in a state in which the sound input from the plurality of sound holes arranged at a second distance larger than the first distance is transmitted to one side and the other side of the vibration unit. By switching the sound path, even the sound of a sound source that is far away without being close to the microphone unit, the differential pressure of the sound of the sound source input from multiple sound holes can be obtained sufficiently, so the sound of the sound source is fully picked up be able to. In this way, the sound path is switched between a state in which the sound is input from the plurality of sound holes arranged at the first distance and a state in which the sound is input from the plurality of sound holes arranged at the second distance. Therefore, when the sound source is close, you can pick up the sound of the sound source and not pick up the noise, and also pick up the sound of the sound source enough even when the sound source is away from close Can do.

  The electronic device according to the second aspect preferably further includes an electronic device housing, and the plurality of sound holes are provided so as to penetrate the electronic device housing and the microphone housing. Is arranged with a first sound hole to which sound transmitted to one side of the vibration part is input and a first distance from the first sound hole, and sound transmitted to the other side of the vibration part is input. A second sound hole, a third sound hole, a fourth sound hole that is disposed at a second distance from the third sound hole, and that receives a sound transmitted to the other side of the vibration unit, The sound path switching unit receives sound input from the first sound hole and the second sound hole to the one side and the other side of the vibration unit, and is input from the third sound hole and the fourth sound hole, respectively. The sound path is configured to be switched between a state where sound is transmitted to one side and the other side of the vibration unit. If comprised in this way, when a sound source is adjoining, while picking up the sound of the adjacent sound source input from the 1st sound hole and the 2nd sound hole, the 1st sound hole and the 2nd sound hole It is possible to avoid picking up noises input from. Further, even when the sound sources are separated without being close to each other, it is possible to sufficiently pick up the sounds of the sound sources that are separated from each other and input from the third sound hole and the fourth sound hole.

  In this case, preferably, based on the user's operation, when the sound source switching unit and the vibration unit are close to each other, the sound path switching unit receives the sound input from the first sound hole and the second sound hole, respectively. The sound input from the third sound hole and the fourth sound hole vibrate when the sound source and the vibration part are separated from each other without being close to each other. It is comprised so that it may be set to the state transmitted to the one side and other side of a part. If comprised in this way, based on a user's operation, when a sound source and a vibration part are near, it can avoid picking up noise while picking up the sound of the sound source that is close. In addition, even when the sound source and the vibration unit are separated without being close to each other, the sound of the sound source that is separated without being close to each other can be sufficiently picked up.

It is the figure which showed the whole structure of the IC recorder by 1st Embodiment of this invention. It is sectional drawing of the differential microphone unit by 1st Embodiment of this invention. It is a top view of the surface side of the differential microphone unit by 1st Embodiment of this invention. It is a top view of the back surface side of the differential microphone unit by 1st Embodiment of this invention. 1 is an exploded perspective view of a differential microphone unit according to a first embodiment of the present invention. It is a figure for demonstrating operation | movement of the differential microphone unit by 1st Embodiment of this invention. It is a figure for demonstrating operation | movement of the differential microphone unit by 1st Embodiment of this invention. It is sectional drawing of the differential microphone unit by 2nd Embodiment of this invention. It is sectional drawing of the differential microphone unit by 3rd Embodiment of this invention. It is sectional drawing when the sound source of the differential microphone unit by 4th Embodiment of this invention is adjoining. It is sectional drawing when the sound source of the differential microphone unit by 4th Embodiment of this invention is separated without adjoining. It is sectional drawing of the differential microphone unit by 5th Embodiment of this invention. It is a disassembled perspective view of the differential microphone unit by 5th Embodiment of this invention shown in FIG. It is sectional drawing of the differential microphone unit by 6th Embodiment of this invention. FIG. 15 is an exploded perspective view of the differential microphone unit according to the sixth embodiment of the present invention shown in FIG. 14. It is sectional drawing of the differential microphone unit by the 1st modification of 1st-6th embodiment of this invention. It is a top view of the differential microphone unit by the 1st modification of the 1st-6th embodiment of this invention shown in FIG. It is sectional drawing of the differential microphone unit by the 2nd modification of 1st-6th embodiment of this invention. It is a top view of the differential microphone unit by the 2nd modification of the 1st-6th embodiment of this invention shown in FIG. It is the figure which showed the whole structure of the mobile telephone by the 3rd modification of 1st-6th embodiment of this invention.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.

(First embodiment)
With reference to FIGS. 1-7, the structure of the differential microphone unit 100 by 1st Embodiment of this invention and IC recorder 200 provided with the differential microphone unit 100 is demonstrated. The differential microphone unit 100 is an example of the “microphone unit” in the present invention, and the IC recorder 200 is an example of the “electronic device” in the present invention.

  As shown in FIG. 1, the IC recorder 200 according to the first embodiment of the present invention includes an IC recorder housing unit 1, a recording button 2, a display screen unit 3 including a liquid crystal display, a differential microphone unit 100, and the like. Is provided. Note that the recording button 2 and the display screen unit 3 are provided on the front side of the IC recorder housing unit 1. The differential microphone unit 100 is arranged so that the longitudinal direction of the differential microphone unit 100 is along the X direction. The differential microphone unit 100 has both directivity of the arrow X1 direction side and the arrow X2 direction side. The IC recorder housing 1 is an example of the “electronic device housing” in the present invention.

  Further, as shown in FIG. 2, the differential microphone unit 100 is disposed on the back surface side (arrow Z2 direction side) of the IC recorder housing 1. The differential microphone unit 100 has a structure in which the substrate 10, the cover portion 30, and the gasket 40 are laminated. The substrate 10 and the cover unit 30 are an example of the “microphone housing” in the present invention.

  The substrate 10 is made of an insulating material such as glass epoxy having a thickness of about 0.4 mm or more and about 0.8 mm or less. Further, on the surface of the substrate 10, a MEMS (Micro Electro Mechanical System) chip 12 having a vibrating part 11 that vibrates due to the sound pressure of sound input from the outside is provided. An electric signal output IC 13 is disposed on the surface of the substrate 10 so as to be adjacent to the MEMS chip 12. The electric signal output IC 13 is an integrated circuit for outputting an electric signal based on the vibration of the vibration part 11 of the MEMS chip 12. Further, the MEMS chip 12 and the electric signal output IC 13 are electrically connected by the wiring 14a and the wiring 14b.

  As shown in FIGS. 2 and 3, the substrate 10 is formed with a through hole 15a, a through hole 15b, and a through hole 15c. A wiring 16a, a wiring 16b, and a wiring 16c are embedded in the through hole 15a, the through hole 15b, and the through hole 15c, respectively. Then, as shown in FIG. 4, on the surface of the substrate 10 on the Z2 direction side, an electrode portion 17a, an electrode portion 17b, and an electrode portion 17c are formed so as to be connected to the wiring 16a, the wiring 16b, and the wiring 16c, respectively. ing. The electrode portion 17a, the electrode portion 17b, and the electrode portion 17c are provided to supply power to the electric signal output IC 13, output an electric signal from the electric signal output IC 13, and perform GND (ground) connection, respectively.

  As shown in FIG. 2, the substrate 10 is provided with a substrate-side cavity 18 having a substantially rectangular parallelepiped shape. A MEMS chip side sound hole 19 is provided which is connected to the end of the substrate side cavity 18 on the arrow X1 direction side and connected to the arrow Z2 direction side of the vibrating part 11 of the MEMS chip 12. In addition, the substrate 10 is provided with a substrate-side sound hole 20 that is connected to an end of the substrate-side cavity 18 on the arrow X2 direction side and is connected to a cover-side cavity 36 described later. In addition, the region corresponding to the space between the MEMS chip side sound hole 19 and the substrate side sound hole 20 of the substrate 10 is connected to the substrate side cavity 18 and to a cover part side sound hole 35 described later. A board-side sound hole 21 is provided. The board side sound hole 20 and the board side sound hole 21 have a long round shape (long hole shape) when seen in a plan view, as shown in FIG. The MEMS chip side sound hole 19 has a perfect circle shape when seen in a plan view.

  In the first embodiment, as shown in FIG. 2, the region corresponding to the space between the substrate-side sound hole 20 and the substrate-side sound hole 21 of the substrate-side cavity 18, and the arrow of the substrate-side cavity 18. The sound path switching unit 22 is provided on the inner surface on the Z2 direction side. That is, the sound path switching unit 22 is provided in a portion where sound paths A1 and A3 (see FIGS. 6 and 7) described later branch from a common portion. The sound path switching unit 22 is configured to close one of the board-side sound hole 20 or the sound path A3 (see FIG. 7) by rotating. That is, the sound path switching unit 22 is configured to switch the sound paths A1 and A3 (see FIGS. 6 and 7) by opening and closing the board-side sound hole 20 or the sound path A3.

  As shown in FIG. 2, the cover 30 is bonded to the surface of the substrate 10 on the Z1 direction side using an adhesive layer having a thickness of about 50 μm (about 0.05 mm) (not shown). The cover 30 is made of a heat resistant resin having a thickness of about 0.6 mm or more and about 1.0 mm or less. In addition, a substantially rectangular parallelepiped cover portion side cavity portion 31 is provided on the arrow X1 direction side of the cover portion 30. Then, the MEMS chip 12 and the electric signal output IC 13 are housed inside the cover-side cavity 31 in a state where the cover 30 is bonded onto the surface of the substrate 10. In addition, the cover part 30 is provided with a cover part side sound hole 32 which is connected to the cover part side cavity part 31 and connected to a gasket side sound hole 41 which will be described later. Further, in the area corresponding to the space between the MEMS chip 12 and the cover part side sound hole 32 of the cover part 30, the cover is connected to the cover part side cavity 31 and to a gasket side sound hole 42 described later. A partial sound hole 33 is provided.

  Moreover, in 1st Embodiment, it is the area | region corresponding between the cover part side sound hole 32 and the cover part side sound hole 33 of the cover part side cavity part 31, and the arrow Z2 direction side of the cover part side cavity part 31 is provided. On the inner surface, a sound path switching unit 34 is provided. That is, the sound path switching unit 34 is provided at a part where sound paths A2 and A4 (see FIGS. 6 and 7), which will be described later, branch from a common part. The sound path switching unit 34 is configured to close one of the cover part side sound hole 33 or the sound path A4 (see FIG. 7) by rotating. That is, the sound path switching unit 34 is configured to switch the sound paths A2 and A4 (see FIGS. 6 and 7) by opening and closing the cover part side sound hole 33 or the sound path A4.

  In addition, a cover part side sound hole 35 is provided in an area of the cover part 30 corresponding to the arrow X2 direction side of the MEMS chip 12. The cover side sound hole 35 is connected to the substrate side sound hole 21 and is connected to a gasket side sound hole 43 described later.

  Further, a substantially rectangular parallelepiped cover portion side cavity portion 36 is provided on the cover portion 30 on the arrow X2 direction side. The end of the cover side cavity 36 on the arrow X1 direction side is connected to the board side sound hole 20. The cover 30 is provided with a cover-side sound hole 37 that is connected to the cover-side cavity 36 and to a gasket-side sound hole 44 described later. As shown in FIG. 5, the cover part side sound hole 32, the cover part side sound hole 33, the cover part side sound hole 35, and the cover part side sound hole 37 have a long round shape (long hole). Shape).

  As shown in FIG. 2, the gasket 40 is made of an elastically deformable rubber member or the like, and the gasket 40 is disposed on the surface of the cover portion 30 on the arrow Z1 direction side. The gasket 40 is connected to the cover side sound hole 32, the cover part side sound hole 33, the cover part side sound hole 35, and the cover part side sound hole 37, respectively. A hole 42, a gasket side sound hole 43 and a gasket side sound hole 44 are provided. As shown in FIG. 5, the gasket-side sound hole 41, the gasket-side sound hole 42, the gasket-side sound hole 43, and the gasket-side sound hole 44 have a long round shape (long hole shape) when seen in a plan view. .

  Further, as shown in FIG. 2, the IC recorder casing 1 is connected to the gasket side sound hole 41, the gasket side sound hole 42, the gasket side sound hole 43, and the gasket side sound hole 44, respectively. A housing sound hole 51, an IC recorder housing sound hole 52, an IC recorder housing sound hole 53, and an IC recorder housing sound hole 54 are provided. As shown in FIG. 5, the IC recorder housing sound hole 51, the IC recorder housing sound hole 52, the IC recorder housing sound hole 53, and the IC recorder housing sound hole 54 are oblong as viewed in a plan view. It has a shape (long hole shape). The IC recorder housing sound hole 51 and the cover side sound hole 32 are examples of the “fourth sound hole” in the present invention. The IC recorder housing sound hole 52 and the cover side sound hole 33 are examples of the “second sound hole” in the present invention. The IC recorder housing sound hole 53 and the cover side sound hole 35 are examples of the “first sound hole” in the present invention. The IC recorder housing sound hole 54 and the cover side sound hole 37 are examples of the “third sound hole” in the present invention.

  Moreover, as shown in FIG. 3, the cover side sound hole 32 and the gasket side sound hole 41 have a hole width W1 on the X direction side of about 0.5 mm, and are about 1.5 mm or more and about 2.0 mm or less. It has a hole width W2 on the Y direction side. And as shown in FIG. 2, the inner surface of the cover part side sound hole 32 and the gasket side sound hole 41 becomes flush.

  The cover side sound hole 33 and the gasket side sound hole 42 also have a hole width W1 on the X direction side and a hole width W2 on the Y direction side. And the inner surface of the cover part side sound hole 33 and the gasket side sound hole 42 becomes flush.

  The board side sound hole 21, the cover part side sound hole 35 and the gasket side sound hole 43 also have a hole width W1 on the X direction side and a hole width W2 on the Y direction side. The inner side surfaces of the substrate side sound hole 21, the cover part side sound hole 35, and the gasket side sound hole 43 are flush with each other.

  The cover side sound hole 37 and the gasket side sound hole 44 also have a hole width W1 on the X direction side and a hole width W2 on the Y direction side. And the inner surface of the cover part side sound hole 37 and the gasket side sound hole 44 becomes flush.

  Further, as shown in FIG. 3, the IC recorder housing sound hole 51, the IC recorder housing sound hole 52, the IC recorder housing sound hole 53, and the IC recorder housing sound hole 54 are larger in the X direction than the hole width W1. And a hole width W4 on the Y direction side that is larger than the hole width W2.

  Further, in the first embodiment, as shown in FIG. 2, the cover-side sound hole 33 (gasket-side sound hole 42) and the cover-side sound hole 35 (substrate-side sound hole 21, gasket side) are viewed in plan view. The sound holes 43) are arranged with a distance D1 of about 5 mm along the X direction. Also, as viewed in a plan view, the cover side sound hole 32 (gasket side sound hole 41) and the cover part side sound hole 37 (gasket side sound hole 44) are separated by a distance D2 of about 50 mm along the X direction. Are arranged. The distance D1 is an example of the “first distance” in the present invention. The distance D2 is an example of the “second distance” in the present invention.

  As shown in FIG. 6, in the first embodiment, the IC recorder housing sound hole 53, the gasket side sound hole 43, the cover part side sound hole 35, the substrate side sound hole 21, the substrate side cavity part 18, and the MEMS chip. The length of the sound path A1 constituted by the side sound holes 19 (from the opening end of the IC recorder housing sound hole 53 to the arrow Z2 direction side of the vibration unit 11), the IC recorder housing sound hole 52, the gasket side sound hole 42, The length of the sound path A2 constituted by the cover part side sound hole 33 and the cover part side cavity part 31 (from the opening end of the IC recorder housing sound hole 52 to the arrow Z1 direction side of the vibration part 11) is substantially equal. Further, as shown in FIG. 7, IC recorder housing sound hole 54, gasket side sound hole 44, cover part side sound hole 37, cover part side cavity 36, substrate side sound hole 20, substrate side cavity 18 and MEMS. The length of the sound path A3 constituted by the chip-side sound hole 19 (from the opening end of the IC recorder housing sound hole 54 to the arrow Z2 direction of the vibration part 11), the IC recorder housing sound hole 51, and the gasket-side sound hole 41 The length of the sound path A4 constituted by the cover part side sound hole 32 and the cover part side cavity part 31 (from the opening end of the IC recorder housing sound hole 51 to the arrow Z1 direction side of the vibration part 11) is substantially equal. In the first embodiment, at least the length of the sound path constituted by the cover part side sound hole 35, the substrate side sound hole 21, the substrate side cavity part 18, and the MEMS chip side sound hole 19, and the cover part side sound hole 33 and the cover portion side cavity portion 31 are substantially equal in length, and the cover portion side sound hole 37, the cover portion side cavity portion 36, the substrate side sound hole 20, the substrate side cavity portion 18, and the MEMS chip. It is only necessary that the length of the sound path constituted by the side sound holes 19 and the length of the sound path constituted by the cover part side sound holes 32 and the cover part side cavity part 31 are substantially equal. The sound path A1 is an example of the “first sound path” in the present invention, and the sound path A2 is an example of the “second sound path” in the present invention. The sound path A3 is an example of the “third sound path” in the present invention, and the sound path A4 is an example of the “fourth sound path” in the present invention.

  Next, the operation of the differential microphone unit 100 according to the first embodiment will be described with reference to FIGS.

  As shown in FIG. 6, in a state where the sound path switching unit 22 closes the sound path A3 (see FIG. 7), the vibration unit 11 of the MEMS chip 12 is disposed on the arrow Z2 direction side via the sound path A1. Sound from the outside is transmitted. Further, when the sound path switching unit 34 closes the sound path A4 (see FIG. 7), an external sound is transmitted to the vibration unit 11 of the MEMS chip 12 in the arrow Z1 direction side via the sound path A2. Communicated. Then, the difference between the sound pressure of the sound transmitted to the arrow Z1 direction side of the vibration part 11 and the sound pressure of the sound transmitted to the arrow Z2 direction side of the vibration part 11 is converted into an electric signal by the electric signal output IC13. To do. In addition, since the distance D1 between the cover part side sound hole 33 and the cover part side sound hole 35 is relatively small, about 5 mm, the close-talked state (the state where the sound source and the differential microphone unit 100 are close to each other). ), The sound of the sound source is clearly picked up by the differential microphone unit 100. On the other hand, in the noise emitted from a position away from the differential microphone unit 100, the differential pressure between the noises input to the arrow Z1 direction side and the arrow Z2 direction side of the vibration unit 11 is small. As a result, the differential microphone unit 100 can be prevented from picking up noise.

  Next, as shown in FIG. 7, for example, the sound path switching unit 22 and the sound path switching unit 34 are rotated by a user operation. As a result, the sound path corresponds to a state where the distance from the sound path corresponding to the close-talked state (a state where the sound source and the differential microphone unit 100 are close to each other) to the differential microphone unit 100 is large. Can be switched to. By this switching, the sound path switching unit 22 is in a state of closing the board side sound hole 21, so that the sound from the outside is transmitted to the vibration unit 11 in the direction of arrow Z2 via the sound path A3. . In addition, since the sound path switching unit 34 closes the cover side sound hole 33, the sound from the outside is transmitted to the vibration unit 11 in the direction of the arrow Z1 via the sound path A4.

  In general, the distance from the sound source to the differential microphone unit 100 and the differential pressure of the sound input to the differential microphone unit 100 are in an inversely proportional relationship. When the distance from the sound source to the differential microphone unit 100 is small, it is sufficient even if the interval between the two sound holes for inputting sound to the arrow Z1 direction side and the arrow Z2 direction side of the vibration unit 11 is small. It is possible to obtain a differential pressure of sound. On the other hand, when the distance from the sound source to the differential microphone unit 100 is large, a sufficient sound differential pressure cannot be obtained when the distance between the two sound holes is small. However, in the state shown in FIG. 7, since the distance D2 between the cover part side sound hole 32 and the cover part side sound hole 37 is relatively large at about 50 mm, the sound source and the differential microphone unit 100 are separated from each other. Even in this state, the differential pressure between the sound transmitted to the arrow Z1 direction side of the vibration part 11 and the sound transmitted to the arrow Z2 direction side of the vibration part 11 becomes relatively large. Thereby, the sound of the sound source can be sufficiently picked up by the differential microphone unit 100.

  Note that the characteristics of the differential microphone unit 100 vary depending on the distance (D1 and D2) between the sound holes. At a frequency of 1 kHz, which is considered to have high human auditory sensitivity, for example, the advantage differs when the distance between the sound holes is 5 mm and 50 mm. When the distance between the sound holes is large (D2 = 50 mm), the sound pressure difference and the phase difference of the sound input from the two sound holes (the cover part side sound hole 32 and the cover part side sound hole 37) become large. The vibration amplitude of the vibration unit 11 also increases, and the output amplitude of the differential microphone unit 100 also increases. That is, the differential microphone unit 100 with high sensitivity can be realized.

  In addition, when the distance between the sound holes is short (D1 = 5 mm), the sensitivity as the differential microphone unit 100 is lowered, while the two sound holes (cover side sound hole 33, cover) arrive from a far sound source. The phase difference of the sound input to the part-side sound hole 35) is reduced in all directivity directions. Thereby, when the differential pressure | voltage of the input sound is detected by the vibration part 11, it acts so that it may be almost canceled. That is, the differential microphone unit 100 having a high noise suppression effect can be realized.

  And if you want to pick up a wide range of sounds including the sound around the speaker (sound source), widen the distance between the sound holes, and narrow the sound collection range to suppress the sound of the far sound source. It is better to narrow the interval between. Here, when picking up a wide range of sounds including sounds around the speaker, the distance between the sound holes that can ensure a desired signal-to-noise ratio (SNR) at the maximum distance to be picked up, for example, Set to 50 mm. Further, in order to suppress omnidirectional distant noise in the voice band, it is desirable to set the distance between the sound holes to 5 mm or less.

  In the first embodiment, as described above, sound input from the plurality of sound holes arranged with the distance D1 among the plurality of sound holes by the sound path switching units 22 and 34 is transmitted to one side of the vibration unit 11. By switching the sound path to the state transmitted to the other side and the other side, the sound of the sound source that is close to the differential microphone unit 100 is transmitted from the plurality of sound holes to one side and the other side of the vibration unit 11, respectively. The sound of the sound source can be picked up based on the differential pressure of the sound transmitted and transmitted to one side and the other side of the vibration unit 11. Further, regarding noise emitted from a position relatively far from the differential microphone unit 100, since the differential pressure of noise input from a plurality of sound holes is small, picking up noise can be suppressed. In addition, the sound path switching units 22 and 34 transmit sounds input from a plurality of sound holes arranged at a distance D2 larger than the distance D1 to one side and the other side of the vibration unit 11. By switching the sound path to the state, even if the sound of the sound source that is not close to the differential microphone unit 100 is separated, a sufficient differential pressure of the sound of the sound source input from a plurality of sound holes can be obtained. Can pick up enough sound. In this way, the sound source is switched by switching the sound path between a state input from a plurality of sound holes arranged at a distance D1 and a state input from a plurality of sound holes arranged at a distance D2. When the sound sources are close to each other, it is possible not to pick up noise while picking up the sound of the sound source, and it is possible to sufficiently pick up the sound of the sound source even when the sound source is not close to the sound source.

  In the first embodiment, the sound path switching unit 22 is configured such that sound input from the cover unit side sound hole 35 (gasket side sound hole 43, IC recorder housing sound hole 53) is on the arrow Z2 direction side of the vibration unit 11. Sound transmitted from the cover side sound hole 37 (gasket side sound hole 44, IC recorder housing sound hole 54) to the state transmitted to the arrow Z2 direction side of the vibration part 11 It was configured to switch the way. Further, the sound path switching unit 34 is in a state in which sound input from the cover unit side sound hole 33 (gasket side sound hole 42, IC recorder housing sound hole 52) is transmitted to the arrow Z1 direction side of the vibration unit 11. The sound path is switched to a state where the sound input from the cover side sound hole 32 (gasket side sound hole 41, IC recorder housing sound hole 51) is transmitted to the arrow Z1 direction side of the vibration part 11. did. Thus, when the sound source is close, the cover side sound hole 35 (gasket side sound hole 43, IC recorder housing sound hole 53) and cover part side sound hole 33 (gasket side sound hole 42, IC recorder). While picking up the sound of the adjacent sound source inputted from the housing sound hole 52), the cover side sound hole 35 (gasket side sound hole 43, IC recorder housing sound hole 53) and cover part side sound hole 33 ( The noise input from the gasket side sound hole 42 and the IC recorder housing sound hole 52) can be prevented from being picked up. In addition, even when the sound source is not adjacent but separated, the cover side sound hole 37 (gasket side sound hole 44, IC recorder housing sound hole 54) and cover part side sound hole 32 (gasket side sound hole 41, It is possible to sufficiently pick up the sound of the sound source that is separated from the IC recorder housing sound hole 51) and is not approached.

  Further, in the first embodiment, as described above, when the sound source switching units 22 and 34 are close to the sound source and the vibration unit 11, the cover unit side sound hole 35 (gasket side sound hole 43, IC Sounds input from the recorder housing sound hole 53) and the cover side sound hole 33 (gasket side sound hole 42, IC recorder housing sound hole 52) are respectively directed to the arrow Z2 direction side and the arrow Z1 direction side of the vibration unit 11. The state to be transmitted is set. Further, when the sound source switching units 22 and 34 are separated without the sound source and the vibration unit 11 being close to each other, the cover side sound hole 37 (gasket side sound hole 44, IC recorder housing sound hole 54) and The sound input from the cover side sound hole 32 (gasket side sound hole 41, IC recorder housing sound hole 51) is set to be transmitted to the arrow Z2 direction side and the arrow Z1 direction side of the vibration part 11, respectively. Configured. Thereby, when the sound source and the vibration unit 11 are close to each other, it is possible to easily pick up the sound of the sound source close to the sound source and not to pick up noise, and the sound source and the vibration unit 11 are close to each other. Even when they are separated without being able to do so, it is possible to easily pick up the sound of the sound sources that are separated without approaching.

  In the first embodiment, as described above, the length of the sound path A1 for transmitting sound from the open end of the IC recorder housing sound hole 53 to the arrow Z2 direction side of the vibration unit 11, and the IC recorder housing sound hole The length of the sound path A2 from which the sound is transmitted from the opening end of 52 to the arrow Z1 direction side of the vibration part 11 is substantially equal, and the sound is from the opening end of the IC recorder housing sound hole 54 to the arrow Z2 direction side of the vibration part 11. And the length of the sound path A4 for transmitting sound from the open end of the IC recorder housing sound hole 51 to the arrow Z1 direction side of the vibration part 11 are configured to be substantially equal. Thereby, the phase of the sound transmitted from the sound path A1 (sound path A3) to the arrow Z2 direction side of the vibration part 11 and the sound phase A2 (sound path A4) are transmitted to the arrow Z1 direction side of the vibration part 11. Since the phase of the sound is substantially equal, the directivity of the differential microphone unit 100 on the sound path A1 (sound path A3) side and the directivity of the differential microphone unit 100 on the sound path A2 (sound path A4) side are determined. Can be approximately equal.

  In the first embodiment, the sound input from the cover side sound hole 35 (gasket side sound hole 43, IC recorder housing sound hole 53) is opened and closed as described above. Is transmitted to the direction of arrow Z2 of the vibration part 11, and the sound input from the cover part side sound hole 37 (gasket side sound hole 44, IC recorder housing sound hole 54) is the direction of arrow Z2 of the vibration part 11 The sound path is switched to the state transmitted to the side. Further, when the sound path switching unit 34 is opened and closed, the sound input from the cover unit side sound hole 33 (gasket side sound hole 42, IC recorder housing sound hole 52) is transmitted to the arrow Z1 direction side of the vibration unit 11. And the state where the sound inputted from the cover side sound hole 32 (gasket side sound hole 41, IC recorder housing sound hole 51) is transmitted to the arrow Z1 direction side of the vibration part 11 Configured to switch. Thereby, the sound path can be easily switched by opening and closing the sound path switching units 22 and 34.

  In the first embodiment, as described above, the sound path switching unit 22 is provided in a portion where the sound path A1 and the sound path A3 branch from a common portion, and the sound path switching unit 34 is provided in the sound path A2. And the sound path A4 are provided at a portion branched from the common part, the sound path switching unit 22 is closed with either the sound path A1 or the sound path A3, and the sound path switching unit 34 is connected with the sound path A2 or One of the sound paths A4 was configured to be closed. Thereby, the sound path A1, the sound path A2, the sound path A3, and the sound path A4 are provided separately, and the sound path switching unit is provided for each of the sound path A1, the sound path A2, the sound path A3, and the sound path A4. Unlike (total four sound path switching units), only one sound path switching unit (a total of two sound path switching units 22 and 34) needs to be provided at each portion where the sound path branches. The number of parts can be reduced.

(Second Embodiment)
Next, the configuration of the differential microphone unit 101 according to the second embodiment will be described with reference to FIG. In the second embodiment, unlike the first embodiment configured to open and close the sound hole or the sound path by rotating the sound path switching units 22 and 34, the sound path switching units 22a and 34a An example in which a sound hole or sound path is opened and closed by bending will be described. The differential microphone unit 101 is an example of the “microphone unit” in the present invention.

  As shown in FIG. 8, in the differential microphone unit 101 according to the second embodiment, the substrate-side cavity is a region corresponding to the space between the substrate-side sound hole 20 and the substrate-side sound hole 21 of the substrate-side cavity 18. On the inner surface of the portion 18 on the arrow Z2 direction side, a sound path switching portion 22a is provided. The sound path switching unit 22a has a structure in which two metal plates 221 and 222 having different thermal expansion coefficients are bonded together. Then, by changing the temperature of the sound path switching unit 22a, the sound path switching unit 22a is configured to change between a curved state in the arrow Z2 direction and a flat plate state. Accordingly, the sound path switching unit 22a is configured to open and close the board side sound hole 20 or the sound path A3 (see FIG. 7).

  Moreover, in the area | region corresponding between the cover part side sound hole 32 and the cover part side sound hole 33 of the cover part side cavity part 31, and the inner surface of the cover part side cavity part 31 on the arrow Z2 direction side, A sound path switching unit 34a is provided. The sound path switching unit 34a also has a structure in which two metal plates 341 and 342 having different thermal expansion coefficients are bonded together. Then, by changing the temperature of the sound path switching unit 34a, the sound path switching unit 34a is configured to change between a curved state in the arrow Z2 direction and a flat plate state. Thereby, the sound path switching part 34a is configured to open and close the cover part side sound hole 33 or the sound path A4 (see FIG. 7).

  In addition, the other structure and effect of 2nd Embodiment are the same as that of the said 1st Embodiment.

(Third embodiment)
Next, the configuration of the differential microphone unit 102 according to the third embodiment will be described with reference to FIG. In the third embodiment, unlike the first embodiment configured to open and close the sound hole or the sound path by rotating the sound path switching units 22 and 34, the sound path switching units 22b and 34b An example in which a sound hole or sound path is closed by sliding in the X direction will be described. The differential microphone unit 102 is an example of the “microphone unit” in the present invention.

  As shown in FIG. 9, in the differential microphone unit 102 according to the third embodiment, a sound path switching unit 22b is provided on the inner surface of the substrate side cavity 18 on the arrow Z2 direction side. A sound path switching portion 34b is provided on the inner surface of the cover portion side cavity portion 31 on the arrow Z2 direction side. The sound path switching unit 22b and the sound path switching unit 34b are configured to be slid in the X direction by, for example, an electromagnetic method. Accordingly, the sound path switching unit 22b opens and closes the board side sound hole 20 or the board side sound hole 21, and the sound path switching unit 34b opens and closes the cover part side sound hole 32 or the cover part side sound hole 33. It is configured.

  The other configurations and effects of the third embodiment are the same as those of the first embodiment.

(Fourth embodiment)
Next, the configuration of the differential microphone unit 103 according to the fourth embodiment will be described with reference to FIGS. 10 and 11. In the fourth embodiment, unlike the first embodiment in which the sound path switching parts 22 and 34 are provided in the substrate 10 and the cover part 30, respectively, the sound path switching part 60 is on the surface of the gasket 40. An example of arrangement will be described. The differential microphone unit 103 is an example of the “microphone unit” in the present invention.

  As shown in FIG. 10, in the differential microphone unit 103 according to the fourth embodiment, the sound path switching unit 60 is provided on the surface of the gasket 40 on the arrow Z1 direction side. The sound path switching unit 60 is provided with a sound path switching unit side sound hole 61, a sound path switching unit side sound hole 62, a sound path switching unit side sound hole 63, and a sound path switching unit side sound hole 64. The sound path switching unit 60 is configured to be slidable in the X direction by an electromagnetic method or manually.

  Then, as shown in FIG. 10, when the sound source is close (close state), the sound path switching unit side sound is set by sliding the sound path switching unit 60 to the arrow X2 direction side. The hole 62, the gasket side sound hole 42, and the cover part side sound hole 33 are connected. Further, the sound path switching portion side sound hole 63, the gasket side sound hole 43, the cover portion side sound hole 35, and the substrate side sound hole 21 are connected. As a result, sound is transmitted to the surface on the arrow Z2 direction side of the vibrating portion 11 of the MEMS chip 12 via the sound path B1. In addition, sound is transmitted to the surface of the vibrating portion 11 of the MEMS chip 12 on the arrow Z1 direction side through the sound path B2.

  Also, as shown in FIG. 11, when the sound source is separated without approaching, the sound path switching unit side sound hole 61 is set by sliding the sound path switching unit 60 to the arrow X1 direction side. And the gasket side sound hole 41 and the cover part side sound hole 32 will be in the connected state. Further, the sound path switching portion side sound hole 64, the gasket side sound hole 44, and the cover portion side sound hole 37 are connected. As a result, sound is transmitted to the surface of the vibrating portion 11 of the MEMS chip 12 on the arrow Z2 direction side through the sound path B3. In addition, sound is transmitted to the surface of the vibrating portion 11 of the MEMS chip 12 on the arrow Z1 direction side through the sound path B4.

  The remaining configuration and effects of the fourth embodiment are similar to those of the aforementioned first embodiment.

(Fifth embodiment)
Next, the configuration of the differential microphone unit 104 according to the fifth embodiment will be described with reference to FIGS. 12 and 13. In the fifth embodiment, an example in which the substrate 70 is configured from two substrates will be described, unlike the first to fourth embodiments in which the substrate 10 is configured from the single substrate. The differential microphone unit 104 is an example of the “microphone unit” in the present invention.

  As shown in FIGS. 12 and 13, in the differential microphone unit 104 according to the fifth embodiment, the substrate 70 includes a substrate 72 in which a recess 71 is formed, a substrate-side sound hole 20, and a substrate-side sound hole 21. And a substrate 73. Then, the substrate 72 and the substrate 73 are bonded together. As a result, a substrate-side cavity 74 is formed by a space surrounded by the recess 71 and the substrate 73 of the substrate 72. The substrates 72 and 73 are an example of the “microphone casing” in the present invention. The other configurations and effects of the fifth embodiment are the same as those of the first embodiment.

(Sixth embodiment)
Next, the configuration of the differential microphone unit 105 according to the sixth embodiment will be described with reference to FIGS. 14 and 15. In the sixth embodiment, an example in which the substrate 80 is configured from three substrates will be described, unlike the first to fourth embodiments in which the substrate 10 is configured from the single substrate. The differential microphone unit 105 is an example of the “microphone unit” in the present invention.

  As shown in FIGS. 14 and 15, in the differential microphone unit 105 according to the sixth embodiment, the substrate 80 includes a flat substrate 81, a substrate 83 in which a through hole 82 is formed, a substrate-side sound hole 20 and It is comprised by the board | substrate 84 with which the board | substrate side sound hole 21 is formed. Then, the substrate 81, the substrate 83, and the substrate 84 are bonded together. As a result, the substrate-side cavity 85 is formed by the through hole 82 of the substrate 83 surrounded by the substrate 81 and the substrate 84. The substrates 81, 83, and 84 are examples of the “microphone housing” of the present invention. The remaining configuration and effects of the sixth embodiment are similar to those of the aforementioned first embodiment.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the first to sixth embodiments, an example in which four sound holes are provided in the cover part (gasket, IC recorder housing part) has been shown, but the present invention is not limited to this. For example, as in the first modification shown in FIGS. 16 and 17, the cover portion 30 is provided with three cover portion side sound holes 32, 33, and 35 and one sound path switching portion 34. The sound input from the two cover part side sound holes 33 and 35 that are close to each other with a distance D3 (about 5 mm) among the cover part side sound holes are respectively transmitted to one side and the other side of the vibration part 11. And the sound input from the two cover part side sound holes 32 and 35 separated from each other with a distance D4 (about 50 mm) apart from each other, on one side and the other side of the vibration part 11, respectively. The sound path may be switched using only one sound path switching unit 34 for the state to be transmitted to. Moreover, you may provide five or more sound holes in a cover part.

  In the first to sixth embodiments, the example in which the sound path switching unit opens and closes the sound hole or the sound path by the user's operation is shown, but the present invention is not limited to this. For example, the sound path switching unit may be configured to automatically open and close the sound hole or sound path by detecting the distance of the sound source.

  In the first to sixth embodiments, an example in which sound is transmitted to the vibrating portion of the MEMS chip from a direction (Z direction) perpendicular to the direction along the surface of the substrate is shown. Not limited to this. In the present invention, the vibrating portion of the MEMS chip is arranged along the direction (Z direction) perpendicular to the direction along the surface of the substrate, and the vibrating portion of the MEMS chip is arranged in the direction along the surface of the substrate (X The sound may be transmitted from (direction).

  In the first to sixth embodiments, the distance D1 between the cover portion side sound hole 33 and the cover portion side sound hole 35 is about 5 mm, and the cover portion side sound hole 32 and the cover portion side sound hole. Although the example in which the distance D2 between them is about 50 mm is shown, the present invention is not limited to this. In the present invention, the distance D1 between the cover part side sound hole 33 and the cover part side sound hole 35 and the distance D2 between the cover part side sound hole 32 and the cover part side sound hole 37 are different from the sound source. It is determined optimally depending on the distance from the moving microphone unit 100.

  In the first to sixth embodiments, the example in which the MEMS chip and the electric signal output IC are electrically connected by wiring has been described. However, the present invention is not limited to this. For example, as in the second modification shown in FIGS. 18 and 19, it may be electrically connected by flip chip. Specifically, the MEMS chip 12 and the electric signal output IC 13 are electrically connected by wirings 90 and 91 formed on the surface of the substrate 10. The electric signal output IC 13 is electrically connected to the wirings 16 a, 16 b and 16 c by wirings 92, 93 and 94 provided on the surface of the substrate 10.

  Moreover, although the example which applies this invention to an IC recorder was shown as an example of an electronic device in the said 1st-6th embodiment, this invention is not limited to this. For example, the present invention may be applied to the mobile phone 201 as in the third modification shown in FIG. In the mobile phone 201 shown in FIG. 20, the differential microphone unit 100 is arranged so that the longitudinal direction of the differential microphone unit 100 is along the X direction. The present invention can also be applied to an electronic device having a differential microphone such as a fixed telephone, a PDA (personal digital assistant), and a portable game machine.

1 IC recorder housing (electronic equipment housing)
10, 72, 73, 81, 83, 84 Substrate (microphone housing)
11 Vibration unit 22, 22a, 22b, 34, 34a, 34b, 60 Sound path switching unit 30 Cover unit (microphone housing)
32 Cover side sound hole (4th sound hole)
33 Cover side sound hole (second sound hole)
35 Cover side sound hole (1st sound hole)
37 Cover side sound hole (third sound hole)
51 IC recorder housing sound hole (4th sound hole)
52 IC recorder housing sound hole (second sound hole)
53 IC recorder housing sound hole (first sound hole)
54 IC recorder housing sound hole (third sound hole)
100, 101, 102, 103, 104, 105 Differential microphone unit (microphone unit)
200 IC recorder (electronic equipment)
201 Mobile phone (electronic equipment)

Claims (9)

A microphone housing provided with a plurality of sound holes provided on a surface thereof, wherein a vibrating portion that vibrates due to sound pressure is disposed, and a first distance and a second distance greater than the first distance are disposed;
A state in which sound input from a plurality of sound holes arranged at a first distance among the plurality of sound holes is transmitted to one side and the other side of the vibration unit; and the second A microphone unit, comprising: a sound path switching unit that switches a sound path to a state in which sound input from a plurality of sound holes arranged at a distance is transmitted to one side and the other side of the vibration unit. The plurality of sound holes are arranged with a first sound hole to which a sound transmitted to one side of the vibration part is input, the first sound hole and the first distance, and the other of the vibration parts. The sound transmitted to the other side of the vibration part, the second sound hole to which the sound transmitted to the side is input, the third sound hole, and the third sound hole are spaced apart from the second distance. Including a fourth sound hole,
The sound path switching unit includes a state in which sounds input from the first sound hole and the second sound hole are transmitted to one side and the other side of the vibration unit, and the third sound hole and the fourth sound hole, respectively. 2. The microphone unit according to claim 1, wherein the sound path is switched to a state in which sound input from a sound hole is transmitted to one side and the other side of the vibration unit, respectively.   The sound path switching unit transmits sound input from the first sound hole and the second sound hole to one side and the other side of the vibration unit, respectively, when the sound source and the vibration unit are close to each other. And the sound input from the third sound hole and the fourth sound hole is one of the vibration parts when the sound source and the vibration part are apart from each other without being close to each other. The microphone unit according to claim 2, wherein the microphone unit is configured to be set in a state of being transmitted to the side and the other side. The length of the first sound path through which sound is transmitted from the opening end of the first sound hole to one side of the vibration part, and the second in which sound is transmitted from the opening end of the second sound hole to the other side of the vibration part. The length of the sound path is almost equal,
The length of the third sound path through which sound is transmitted from the open end of the third sound hole to one side of the vibrating part, and the fourth point where sound is transmitted from the open end of the fourth sound hole to the other side of the vibrating part. The microphone unit according to claim 2 or 3, wherein the length of the sound path is configured to be substantially equal.   The sound path switching unit opens and closes the sound hole or the sound path, so that sounds input from the first sound hole and the second sound hole are transmitted to one side and the other side of the vibration unit, respectively. The sound path is configured to be switched between a state in which the sound is input and a state in which sounds input from the third sound hole and the fourth sound hole are transmitted to one side and the other side of the vibration unit, respectively. Item 5. The microphone unit according to any one of Items 2 to 4. A first sound path through which sound is transmitted from the opening end of the first sound hole to one side of the vibration part, and a third sound path through which sound is transmitted from the opening end of the third sound hole to one side of the vibration part. Includes a common part, and the sound path switching unit is provided at a part where the first sound path and the third sound path branch from the common part,
A second sound path through which sound is transmitted from the opening end of the second sound hole to the other side of the vibration part, and a fourth sound path through which sound is transmitted from the opening end of the fourth sound hole to the other side of the vibration part. Includes a common part, and the sound path switching unit is provided in a part where the second sound path and the fourth sound path branch from the common part,
The sound path switching unit is configured to close either the first sound path or the third sound path and close either the second sound path or the fourth sound path. The microphone unit according to claim 5.   A microphone case in which a vibrating portion that vibrates due to sound pressure is disposed, and a plurality of sound holes disposed on a surface at a first distance and a second distance that is greater than the first distance; A state in which sound input from a plurality of sound holes arranged at the first distance among the sound holes is transmitted to one side and the other side of the vibration unit, and the second distance An electronic apparatus comprising: a microphone unit including a sound path switching unit that switches a sound path to a state in which sound input from a plurality of sound holes arranged at intervals is transmitted to one side and the other side of the vibration unit . An electronic device housing;
The plurality of sound holes are provided so as to penetrate the electronic device casing and the microphone casing,
The plurality of sound holes are arranged with a first sound hole to which a sound transmitted to one side of the vibration part is input, the first sound hole and the first distance, and the other of the vibration parts. The sound transmitted to the other side of the vibration part, the second sound hole to which the sound transmitted to the side is input, the third sound hole, and the third sound hole are spaced apart from the second distance. Including a fourth sound hole,
The sound path switching unit includes a state in which sounds input from the first sound hole and the second sound hole are transmitted to one side and the other side of the vibration unit, and the third sound hole and the fourth sound hole, respectively. The electronic device according to claim 7, wherein the sound path is switched to a state in which sound input from a sound hole is transmitted to one side and the other side of the vibration unit, respectively.   Based on the user's operation, the sound path switching unit is configured such that when the sound source and the vibration unit are close to each other, the sounds input from the first sound hole and the second sound hole are respectively transmitted from the vibration unit. The sound input from the third sound hole and the fourth sound hole when the sound source and the vibration part are apart from each other without being close to each other. The electronic apparatus according to claim 8, wherein the electronic devices are configured to be transmitted to one side and the other side of the vibration unit.

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