JP2011223324A - Sound pick-up device and capacitor microphone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound pick-up device and a capacitor microphone that can be easily stored in a narrow tubular space such as a sound conduction tube of an earphone microphone and pick up with high sensitivity sound propagating in the space.SOLUTION: A package 21 of an earphone microphone 14 has acoustic holes 26 and 27 on its bottom face 71. Electroacoustic transducer dies 23 and 24 are provided on the bottom face 71 of the package 21 to convert the sound propagating from the acoustic holes 26 and 27 toward vibration electrodes 34 and 35 into an electric signal. A bonding face 72 of the package 21 is bonded to a bonding face 73 of an external power distribution board 15. A sound conduction path 45 which communicates with the acoustic holes 26 and 27 and extends in the direction orthogonal to the direction from the vibration electrodes 34 and 35 to the acoustic holes 26 and 27 is formed in a gap between the bonding faces 72 and 73.

Description

  The present invention relates to a microphone that is housed and used in a narrow space.

  One of the small microphones that are used by being fixed in a narrow space is a condenser microphone that is formed into a chip using MEMS (Micro Electro Mechanical Systems) technology. There are the following two types of condenser microphones. As shown in FIG. 15A, the first type of condenser microphone 50 has a hole 55 formed in the cover 53 of the package 54 in which the cover 53 is covered on the tray portion 52, and is opposed to the cover 53 in the package 54. The electroacoustic conversion die 57 and the impedance conversion die 58 are fixed to the surface 56 to be processed. As shown in FIG. 15B, the second type condenser microphone 51 has a hole 55 formed in a surface 56 facing the cover 53 in the package 54 in which the cover 53 is covered on the tray portion 52, and the inside of the package 54. The electroacoustic conversion die 57 and the impedance conversion die 58 are fixed to a position overlapping with the hole 55 in FIG.

  In these condenser microphones 50 and 51, the sound transmitted from the hole 55 into the package 54 reaches the electrodes 60 and 61 of the electroacoustic conversion die 57 and changes the capacitance between the electrodes 60 and 61. Then, an electric signal indicating the change in capacitance is taken out by the impedance conversion die 58 and output as a signal indicating the sound collection result. Further, as shown in FIGS. 15A and 15B, the capacitor microphone 50 of the two types of capacitor microphones 50 and 51 includes an electroacoustic conversion die 57 and an impedance conversion die 58 in the package 54. The external power distribution board 62 is bonded to the surface 59 on the back side of the certain surface 56, and is fixed in the accommodation space in this state. Further, the condenser microphone 51 has an external power distribution board 62 having a hole 63 overlapped with the holes 63 and 55 on the surface 59 on the back side of the surface 56 where the electroacoustic conversion die 57 and the impedance conversion die 58 of the package 54 are located. Bonded and fixed in the accommodation space in this state. As a document disclosing the technology related to these condenser microphones 50 and 51, for example, there is Patent Document 1.

JP 2009-1000042 A

  By the way, the condenser microphones 50 and 51 may be housed in a sound guide tube that passes through the center of the earpiece in the earphone microphone, and may be used as a sound collecting device that collects sound in the ear into which the earpiece is inserted. In this case, as shown in FIG. 16A, a sound collecting device is formed by joining capacitor microphones 50 and 51 (capacitor microphone 51 in the example of FIG. 16) and external power distribution board 62, and from electrodes 60 and 61. The sound guide tube 66 is housed in a posture such that the direction toward the hole 55 faces the sound input side of the sound guide tube 66 of the earphone microphone 65. By accommodating in such a posture, the sound propagated from the outside of the sound guide tube 66 into the sound guide tube 66 can be collected with high sensitivity.

  However, the electroacoustic conversion die 57 and the impedance conversion die 58 are arranged side by side on the surface 56 (FIG. 15B) of the condenser microphone 51, and the electroacoustic conversion die 57 and the impedance conversion die 58 on this surface 56 are arranged. The width in the direction is larger than the width in the other direction. Therefore, when the sound collecting device is accommodated in such a posture that the hole 55 faces the sound entering side of the sound guide tube 66, the cross-sectional area when viewed from the sound entering side must be large. This makes it difficult to use the earphone microphone having the sound guide tube 66 having a small diameter.

  On the other hand, as shown in FIG. 16 (B), if the sound collection device is in such a posture that the direction from the electrodes 60 and 61 toward the hole 55 faces the inner peripheral wall of the sound guide tube 66, the sound guide having a small diameter is provided. Housing in the tube 66 is relatively easy. However, in this posture, the sound propagated into the sound guide tube 66 cannot be collected with high sensitivity.

  The present invention has been devised under such a background, and can be easily stored in a thin tubular space such as a sound guide tube of an earphone microphone, and the sound propagated in the space can be transmitted. An object of the present invention is to provide a sound collection device that collects sound with high sensitivity.

  The present invention includes a package having a hollow inside, a plate-like vibrating electrode and a stationary electrode that are accommodated inside the package so as to face each other, and a capacitance change between the vibrating electrode and the stationary electrode is obtained as a result of collecting sound. And an acoustic hole for guiding sound in a direction orthogonal to the vibrating electrode to reach the vibrating electrode and forming sound holes in the package, and for sound coming from outside A sound collecting device is provided in which a hollow sound guide is formed that guides along a direction parallel to the vibrating electrode and the stationary electrode to reach the acoustic hole.

  According to the present invention, since the direction from the electrode toward the acoustic hole faces the inner wall surface of the accommodation space and the outlet of the sound guide guides toward the side where sound enters in the accommodation space, it can be accommodated in the accommodation space. Sound transmitted in the space can be collected with high sensitivity. Therefore, the sensitivity of sound collection can be increased without increasing the cross-sectional area of the accommodation space as viewed from the sound input side in the accommodation space.

It is a figure which shows the structure of the earphone microphone containing the sound collection device which is one Embodiment of this invention. FIG. 2 is an enlarged view of the sound guide tube in FIG. 1 and a sound collecting device in the sound guide tube, and a cross-sectional view taken along line A-A ′ and B-B ′ in FIG. 1. FIG. 3 is a perspective view of the condenser microphone in a state where an external power distribution board in FIG. 2 is peeled off. It is a figure which shows the sound collection device which is other embodiment of this invention. It is a figure which shows the sound collection device which is other embodiment of this invention. It is a figure which shows the sound collection device which is other embodiment of this invention. It is a figure which shows the sound collection device which is other embodiment of this invention. It is a figure which shows the sound collection device which is other embodiment of this invention. It is a figure which shows the sound collection device which is other embodiment of this invention. It is a figure which shows the sound collection device which is other embodiment of this invention. It is a figure which shows the sound collection device which is other embodiment of this invention. It is a figure which shows the sound collection device which is other embodiment of this invention. It is a figure which shows the sound collection device which is other embodiment of this invention. It is a figure which shows the sound collection device which is other embodiment of this invention. It is a figure which shows the structure of the conventional condenser microphone. It is a figure which shows the aspect of the accommodation to the accommodation space of the conventional condenser microphone.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1A and FIG. 1B are diagrams showing a configuration of an earphone microphone 1 including a sound collection device 3 according to an embodiment of the present invention. The earphone microphone 1 is used as an optional device for hands-free calling using a mobile phone. A sound emitting device 2 is accommodated in the housing 11 of the earphone microphone 1. A cylindrical sound guide tube 12 protrudes from the housing 11, and the sound collecting device 3 is accommodated in the sound guide tube 12. The sound guide tube 12 is covered with an earpiece 13. The earphone microphone 1 is attached to the user's ear by inserting the earpiece 13 into the ear canal of the user's ear. In this wearing state, the sound emitting device 2 converts the received sound signal S _RCV supplied from the mobile phone via the cable 70 into sound, and outputs the converted sound. This sound is emitted through the sound guide tube 12 into the ear canal. About the structure of the sound emission apparatus 2, since the relevance with this invention is thin, detailed description is omitted. The sound collection device 3 outputs a transmission sound signal _SSND indicating a sound (user's speech) transmitted from the user's vocal cords through the skull to the external auditory canal via the cable 70 to the mobile phone. The transmitted sound signal S _SND is transmitted from the output destination mobile phone to the other party's mobile phone. Hereinafter, details of the configuration of the sound collection device 3 will be described.

The sound collecting device 3 is a device in which a condenser microphone 14 that picks up sound in the ear canal is mounted on an external power distribution board 15 that transmits an output signal of the condenser microphone 14 to a cable 70 as a transmission sound signal _SSND . FIG. 2A is an enlarged view of the sound guide tube 12 in FIG. 1A and the sound collection device 3 in the tube 12. 2B is a cross-sectional view taken along line AA ′ in FIG. 1A and line BB ′ in FIG. FIG. 3 is a perspective view showing the condenser microphone 14 with the external power distribution board 15 in FIG.

As shown in FIGS. 2A, 2B, and 3, the condenser microphone 14 has a width W1 (for example, W1 = 2.9 mm), a thickness T1 (for example, T1 = 1.1 mm), And a rectangular parallelepiped having a length L1 (for example, L1 = 6.0 mm). The outer shell of the condenser microphone 14 is constituted by a package 21 having a hollow inside, and the package 21 includes two electroacoustic conversion dies 23 and 24 and one impedance conversion die 25. More specifically, the package 21 of the condenser microphone 14 is composed of a box-shaped tray portion 48 that is open on one side and a cover 49 that closes the open side of the tray portion 48. In the center of the bottom surface 71 facing the cover 49 in the package 21, there are two acoustic holes 26 and 27 spaced along the length L1 direction. In a state where the cover 49 is attached to the tray portion 48, the interior of the package 21 is hollow, and only the acoustic holes 26 and 27 serve as air passages. As shown in FIG. 3, a groove 28 that extends from the acoustic hole 27 through the acoustic hole 26 to the end surface 97 that is one of the surfaces intersecting with the joint surface 72 of the package 21 is formed on the joint surface 72 on the back side of the bottom surface 71. Is formed. The groove 28 has a width W _C (for example, W _C = 0.25 mm) sufficiently smaller than the width W 1 of the package 21 and a depth D _C (for example, D _C = 0. 0) sufficiently smaller than the thickness T 1 of the package 21. 15 mm).

  An electroacoustic conversion die 23 is joined to a position overlapping the acoustic hole 26 on the bottom surface 71 in the package 21. In addition, the electroacoustic conversion die 24 is joined to a position overlapping the other acoustic hole 27 on the bottom surface 71. The electroacoustic conversion die 23 includes a stationary electrode 32, a vibrating electrode 34, and a support portion 30. The electroacoustic conversion die 24 includes a stationary electrode 33, a vibrating electrode 35, and a support portion 31. The stationary electrodes 32 and 33 and the vibrating electrodes 34 and 35 are disk-like electrodes made of doped silicon or the like. The support part 30 is a member that plays a role of supporting the stationary electrode 32 and the vibration electrode 34 so as to face each other in a parallel posture. The support portion 31 is a member that plays a role of supporting the stationary electrode 33 and the vibration electrode 35 so as to face each other in a parallel posture.

  More specifically, the support portions 30 and 31 have an annular shape having an inner circumference with substantially the same diameter as that of the acoustic holes 26 and 27. The support portions 30 and 31 extend from the edges of the acoustic holes 26 and 27 toward the cover 49. The stationary electrode 32 is supported by the support portion 30 so as to cover the edge of the support portion 30 on the cover 49 side. The stationary electrode 33 is supported by the support portion 31 so as to cover the edge of the support portion 31 on the cover 49 side. A plurality of rear through holes are formed in the stationary electrodes 32 and 33. The vibration electrode 34 is supported by the support portion 30 so as to close the acoustic hole 26 side relative to the stationary electrode 32 in the support portion 30. The vibration electrode 35 is supported by the support portion 31 so as to close the acoustic hole 27 side relative to the stationary electrode 33 in the support portion 31.

  In the electroacoustic conversion dies 23 and 24, a slight gap in the thickness T1 direction is provided between the stationary electrode 32 and the vibrating electrode 34 and between the stationary electrode 33 and the vibrating electrode 35. A capacitor is formed by each of the stationary electrode 32 and the vibrating electrode 34 and the stationary electrode 33 and the vibrating electrode 35. The inside of the package 21 is separated by a vibrating electrode 34 and 35 into a space communicating with the outside of the acoustic holes 26 and 27 (referred to as acoustic space SS) and an airtight space (referred to as a back air chamber BC) on the opposite side of the acoustic space SS. It is done.

  The acoustic hole 26 plays a role of guiding sound transmitted to the acoustic hole 26 in a direction perpendicular to the stationary electrode 32 and the vibration electrode 34 (thickness T1 direction) and reaching the vibration electrode 34. The acoustic hole 27 plays a role of guiding the sound transmitted to the acoustic hole 27 in a direction orthogonal to the stationary electrode 33 and the vibration electrode 35 (thickness T1 direction) and reaching the vibration electrode 35. The sound waves that are guided to the acoustic holes 26 and 27 and reach the vibration electrodes 34 and 35 cause the vibration electrodes 34 and 35 to vibrate. When the vibrating electrodes 34 and 35 vibrate, the size of the gap between the stationary electrode 32 and the vibrating electrode 34 and the size of the gap between the stationary electrode 33 and the vibrating electrode 35 change, and the capacitance of the stationary electrode 32 and the vibrating electrode 34 and the stationary electrode 33 are changed. And the capacity of the vibrating electrode 35 changes. As a result, the capacitance changes of the stationary electrode 32 and the vibrating electrode 34 and the stationary electrode 33 and the vibrating electrode 35 correspond to the waveform of the sound that reaches the vibrating electrodes 34 and 35.

  In FIG. 2B, the impedance conversion die 25 is disposed at a position away from the electroacoustic conversion die 24 along the direction in which the electroacoustic conversion dies 23 and 24 are arranged on the bottom surface 71. A capacitor composed of a stationary electrode 32 and a vibrating electrode 34 and a capacitor composed of a stationary electrode 33 and a vibrating electrode 35 are connected in parallel to the impedance conversion die 25 (the connection state is not shown). The impedance conversion die 25 generates an electrical signal corresponding to the capacitance change of the two capacitors connected in parallel, and outputs it as a signal indicating the sound collection result.

As shown in FIGS. 2A and 2B, the external power distribution board 15 has dimensions of width W2 (W2 = W1), thickness T2 (T2 <T1), and length L2 (L2> L1). It has a plate shape. A circuit pattern for outputting an electrical signal output from the impedance conversion die 25 to the mobile phone as a transmission sound signal S _SND is formed on the joint surface 73 of the external power distribution board 15 facing the condenser microphone 14.

  As shown in FIG. 3, there are four points inside the four corners of the joint surface 72 of the condenser microphone 14 and a portion of the joint surface 72 that slightly surrounds the edges of the acoustic holes 26 and 27 and the groove 28 with solder. 40, 41, 42, 43, and 44 are arranged, and the condenser microphone 14 and the external power distribution board 15 are joined by welding the solders 40, 41, 42, 43, and 44. Solders 40, 41, 42, and 43 inside the four corners of the joint surface 72 are terminals (not shown) on the joint surface 72 of the condenser microphone 14 and terminals (not shown) on the joint surface 73 of the external power distribution board 15. It plays the role of electrically connecting.

  In addition, the solder 44 in the portion surrounding the outer edges of the acoustic holes 26 and 27 and the groove 28 includes the solder 44, the groove 28 in the joint surface 72, the inner portion of the joint surface 72 surrounded by the solder 44, and A hollow sound guide path 45 is formed together with an inner portion surrounded by the solder 44 in the joint surface 73 of the external power distribution board 15. The sound guide path 45 is a direction parallel to the vibrating electrodes 34 and 35 and the stationary electrodes 32 and 33 for the sound arriving on the end surface 97 side of the package 21 from the outside (sound propagating in the arrow direction in FIG. 2B). Is a path that serves as a sound guide that is guided along the sound path and reaches the acoustic holes 26 and 27. As shown in FIGS. 2A and 2B, the sound collection device 3 is such that the direction from the vibration electrodes 34 and 35 of the electroacoustic conversion dies 23 and 24 toward the acoustic holes 26 and 27 is the sound guide tube. 12 is accommodated in the sound guide tube 12 in such a posture that it faces the inner wall surface 12 and the outlet of the sound guide path 45 faces the sound input side of the sound guide tube 12.

According to the embodiment described above, the following effects can be obtained.
First, in the sound collection device 3 of this embodiment, the electroacoustic conversion dies 23 and 24 and the impedance conversion die 25 are arranged in the length L1 direction of the package 21 (that is, the insertion direction with respect to the ear), and the stationary electrode 32 and The capacitance change of the capacitor composed of the vibration electrode 34 and the capacitor composed of the stationary electrode 33 and the vibration electrode 35 connected in parallel is extracted as the transmission sound signal S _SND . A sound guide path 45 is formed in a gap between the bonding surface 72 of the package 21 and the bonding surface 73 of the external power distribution board 15. The sound arriving on the end surface 97 side of the package 21 (sound propagating in the direction of the arrow in FIG. 2B) is parallel to the vibrating electrodes 34 and 35 and the stationary electrodes 32 and 33 by the sound guide path 45. And reach the acoustic holes 26 and 27. Therefore, in such a posture that the direction from the vibrating electrodes 34 and 35 toward the acoustic holes 26 and 27 faces the inner wall surface of the sound guide tube 12 and the outlet of the sound guide path 45 faces the sound input side of the sound guide tube 12. Even when accommodated in the sound guide tube 12, the sound transmitted from the ear canal to the sound guide tube 12 can be collected with high sensitivity. Therefore, the cross-sectional area of the sound guide tube 12 as viewed from the sound input side of the sound guide tube 12 of the earphone microphone 1 (the cross-sectional area of the sound guide tube 12 viewed from the arrow direction in FIG. 2B) is not increased. , Can increase the sensitivity of sound collection.

Secondly, in the present embodiment, the acoustic holes 26 and 27 are provided in the surface 71 of the package 21 opposite to the cover 49. Therefore, the volume of the back air chamber BC can be made larger than that in which the acoustic holes 26 and 27 are provided in the cover 49. Therefore, it is possible to collect sound with higher sensitivity and S / N than those in which the acoustic holes 26 and 27 are provided in the cover 49.
Thirdly, in this embodiment, since the sound guide path 45 is formed in the gap between the package 21 and the external power distribution board 15, the manufacturing is easy and the overall size of the sound collecting device 3 is reduced. be able to.

Although one embodiment of the present invention has been described above, the present invention may have other embodiments. For example, it is as follows.
(1) In the above embodiment, the number of sets of the acoustic holes 26 and 27 and the electroacoustic conversion dies 23 and 24 in the package 21 may be one, or may be three or more.

(2) In the above embodiment, the acoustic holes 26 and 27 and the electroacoustic conversion dies 23 and 24 are provided on the bottom surface 71 of the package 21, and the joint surface 73 of the external power distribution board 15 is formed on the joint surface 72 on the back side of the bottom surface 71. It was joined. However, the acoustic holes 26 and 27 and the electroacoustic conversion dies 23 and 24 are provided on the cover 49 side of the package 21, and the external power distribution board 15 is joined to the back side of the cover 49 where the electroacoustic conversion dies 23 and 24 are provided. The sound guide path 45 may be formed in the gap between the cover 49 and the external power distribution board 15.

(3) In the above embodiment, the groove 28 is formed on the bonding surface 72 that is the surface on the back side of the bottom surface 71 of the package 21. However, a groove extending in the same direction as the groove 28 in the above embodiment may be provided on the joint surface 73 of the external power distribution board 15, and solder may be disposed so as to cover the periphery of the groove 28 of the joint surface 73. Further, in the above embodiment, the solder 40 and 41 are provided on the four points inside the four corners of the joint surface 72 of the condenser microphone 14 and the portions slightly surrounding the outer edges of the acoustic holes 26 and 27 and the groove 28 on the joint surface 72. , 42, 43, and 44 are arranged. However, the solders 40, 41, 42, and 43 at the four corners may be arranged at different positions, or the package 21 and the external power distribution board 15 may be joined only by the solder 44 outside the edge of the groove 28. . In short, it suffices that solder is disposed on at least a portion of the bonding surface 72 of the package 21 surrounding the groove 28 and the bonding surface 72 is bonded to the external power distribution board 15 by this solder.

(4) In the above embodiment, the sound conduction path 45 extending from the acoustic hole 27 to the end surface 97 of the package 21 through the acoustic hole 26 is formed in the gap between the package 21 and the external power distribution board 15. . However, as in the sound collecting device 3A shown in FIG. 4, the sound guide path 45 extending from the acoustic hole 26 to the end face 97 of the package 21 and the sound guide leading from the acoustic hole 27 to the end face 98 opposite to the end face 97 of the package 21. You may form the path | route 45 '. In the sound collecting device 3A, the sound guide paths 45 and 45 ′ are sealed by the solders 44 and 44 ′, respectively, and the sound guide paths 45 and 45 ′ are spatially separated. In the sound collection device 3A, the electroacoustic conversion die 23 that closes the acoustic hole 26 in the package 21 collects sound that arrives on the end surface 97 side of the package 21 (sound that propagates in the direction of arrow A in FIG. 4). In addition, the electroacoustic conversion die 24 that closes the acoustic hole 27 in the package 21 collects sound that arrives on the end face 98 side of the package 21 (sound that propagates in the direction of arrow B in FIG. 4). In the sound collecting device 3A, for example, the outlet of the sound guide path 45 faces the sound input side (the side in the user's external auditory canal) in the sound guide tube 12, and the outlet of the sound guide path 45 'is the housing of the earphone microphone 1. 11 is accommodated in the sound guide tube 12 in such a posture as to face the inside (the side of the space communicating with the outside of the user's ear). As a result, the first sound transmitted from the user's vocal cords through the skull to the inside of the external auditory canal and the second sound transmitted from the user's mouth to the outside of the ears through the cheeks are individually collected. Then, it is possible to perform control such that the transmission sound signal _SSND is obtained by correcting the sound collection signal of the first sound by the sound collection signal of the second sound.

(5) In the above embodiment, the sound guide path 45 is formed in the gap between the package 21 and the external power distribution board 15. However, like the sound collection device 3B shown in FIG. 5, the outer shell of the condenser microphone 14 is formed by a package 21 ″ having a thickness T1 ″ (T1 ″> T1) larger than that of the sound collection device 3. Between the surface 71 facing the cover 49 and the outer surface 72 in the package 21 ″, a sound guide path 45 ″ extending from the acoustic hole 27 under the acoustic hole 26 to the end surface 97 of the package 21 ″ is provided. Also good.

(6) In the above-described embodiment, the sound guide path 45 has a straight line extending from the acoustic hole 27 in the bonding surface 72 of the package 21 to the end surface 97 of the package 21 through the acoustic hole 26. However, instead of the sound guide path 45, an individual sound guide path connected to each of the two acoustic holes 26 and 27 may be formed, or a sound guide path that is not linear may be formed. Examples of the sound guide path include the following.

  In the first mode shown in FIG. 6, a sound guide path 145 is formed from the acoustic hole 27 through the bottom of the acoustic hole 26 to the end surface 97 of the package 21. The width of the section from the acoustic hole 27 to the acoustic hole 26 in the sound guide path 145 is slightly larger than the diameter of the acoustic holes 27 and 26. The width of the section from the acoustic hole 26 to the end surface 97 increases as the end surface 97 is approached.

  In the second mode shown in FIG. 7, the sound guide path 245 from the acoustic hole 26 to the end face 97 of the package 21 and the sound guide path from the acoustic hole 27 to the end face 98 of the package 21 (end face 98 opposite to the end face 97). 245 ′. The width of the sound guide path 245 increases as it approaches the end face 97, and the width of the sound guide path 245 ′ increases as it approaches the end face 98.

  In the third mode shown in FIG. 8, a sound guide path 345 from the acoustic hole 26 to the end face 97 and a sound guide path 345 'from the acoustic hole 27 to the end face 98 are formed. The width of the sound guide paths 345 and 345 'is slightly larger than the diameter of the acoustic holes 26 and 27. The sound guide path 345 extends from the acoustic hole 26 toward the intersecting position between one end surface 100 and the end surface 97 of the two end surfaces 99 and 100 orthogonal to both the end surface 97 and the joint surface 72. It is bent toward the end face 97 at a position midway up to the intersection position. Further, the sound guide path 345 ′ extends from the acoustic hole 27 toward the intersecting position between the other end face 99 and the end face 98 of the end faces 99 and 100, and is located on the end face 98 side at a position on the way to the intersecting position. Is bent.

  In the fourth mode shown in FIG. 9, sound guide paths 445 and 445 ′ from the acoustic holes 26 and 27 to the end surface 99 of the package 21 are formed. The width of the sound guide paths 445 and 445 ′ is slightly larger than the diameter of the acoustic holes 26 and 27.

  In the fifth mode shown in FIG. 10, a sound guide path 545 from the acoustic hole 26 to the end face 99 of the package 21 and a sound guide path 545 ′ from the acoustic hole 27 to the end face 100 of the package 21 are formed. The width of the sound guide paths 545 and 545 ′ is slightly larger than the diameter of the acoustic holes 26 and 27.

  In the sixth mode shown in FIG. 11, a sound guide path 645 extending from the acoustic hole 26 to the end face 99 of the package 21 and a sound guide path 645 ′ extending from the acoustic hole 27 to the end face 100 of the package 21 are formed. The width of the sound guide path 645 increases as it approaches the end face 99, and the width of the sound guide path 645 ′ increases as it approaches the end face 100.

  In the seventh mode shown in FIG. 12, a sound guide path 745 extending from the acoustic holes 26 and 27 to the end face 99 of the package 21 is formed. The width of the sound guide path 745 is the distance between the acoustic holes 26 and 27 (more specifically, of the two tangents orthogonal to the end surface 99 in the acoustic hole 26 to the end surface 99 in the acoustic hole 27 from the tangent on the end surface 97 side. It is the same as the distance to the tangent on the end face 98 side of two orthogonal tangents.

  In the eighth mode shown in FIG. 13, a sound guide path 845 extending from the acoustic holes 26 and 27 to the end surface 99 of the package 21 is formed. The width of the sound guide path 845 increases as it approaches the end face 99.

  In the ninth mode shown in FIG. 14, a sound guide path 945 extending from the acoustic holes 26 and 27 to the end face 99 of the package 21 is formed. The width of the sound guide path 945 decreases as the end face 99 is approached.

DESCRIPTION OF SYMBOLS 1 ... Earphone microphone, 2 ... Sound emission device, 3 ... Sound collection device, 11 ... Housing, 12 ... Sound pipe, 13 ... Earpiece, 70 ... Cable, 14 ... Condenser microphone, 15 ... External power distribution board, 21, 52 ... Package, 23, 24 ... Electroacoustic conversion die, 25 ... Impedance conversion die, 26, 27 ... Acoustic hole, 30, 31 ... Supporting part, 32, 33 ... Static electrode, 34, 35 ... Vibration electrode, 45, 145, 245 , 345, 445, 545, 645, 745, 845, 945...

Claims (6)

A package with a hollow inside,
It has a plate-like vibrating electrode and a stationary electrode that face each other and are accommodated inside the package, and includes a condenser microphone that outputs a capacitance change between the vibrating electrode and the stationary electrode as an electric signal indicating a sound collection result. ,
Forming an acoustic hole in the package that guides sound in a direction orthogonal to the vibrating electrode and allows the sound to reach the vibrating electrode;
A sound collecting device, characterized in that a hollow sound guide is formed in which sound coming from outside is guided along a direction parallel to the vibrating electrode and the stationary electrode to reach the acoustic hole.   The sound collecting device according to claim 1, wherein the sound guide is formed in a gap between the package and a substrate for mounting the package.   A groove extending from the acoustic hole to one of the surfaces intersecting with the surface provided with the acoustic hole in the package is formed on the surface provided with the acoustic hole in the package, and the acoustic hole is provided. A portion of the surface surrounding at least the outside of the groove is joined to the substrate by solder, and the sound guide is formed by the solder and an inner portion of the package and the substrate surrounded by the solder. The sound collecting device according to claim 2, wherein Two electroacoustic transducer dies each comprising a vibrating electrode and a stationary electrode;
An impedance conversion die that converts a change in capacitance of the two electroacoustic conversion dies, each of which is composed of a vibrating electrode and a stationary electrode connected in parallel, into an electric signal;
The vibrating electrode and stationary electrode of the two electroacoustic transducer dies are parallel to each other;
The impedance conversion die is arranged along the direction in which the two electroacoustic conversion dies are arranged,
The package has two acoustic holes for guiding sound to the vibrating electrodes of the two electroacoustic conversion dies,
The sound collection device according to any one of claims 1 to 3, wherein the sound guide guides sound coming from the outside into the two acoustic holes. Two electroacoustic transducer dies each comprising a vibrating electrode and a stationary electrode;
An impedance conversion die for converting each capacitance change of each capacitor constituted by the vibration electrode and stationary electrode of the two electroacoustic conversion dies into an electric signal,
The vibrating electrode and stationary electrode of the two electroacoustic transducer dies are parallel to each other;
The package has two acoustic holes for guiding sound to the vibrating electrodes of the two electroacoustic conversion dies,
The sound guide is a first sound guide that causes sound coming from outside to reach one of the two acoustic holes, and a sound that comes from outside along a direction different from that of the first sound guide. The sound collecting device according to claim 1, further comprising a second sound guide that guides and reaches the other of the two acoustic holes. A hollow package provided with acoustic holes on one side of the package;
A plate-like vibrating electrode and stationary electrode housed inside the package facing each other;
An impedance conversion die for converting a capacitance change between the vibrating electrode and the stationary electrode into an electrical signal;
A capacitor microphone characterized in that a groove extending from the acoustic hole toward one of surfaces intersecting the surface of the package provided with the acoustic hole is formed on the surface of the package provided with the acoustic hole. .

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