WO2007129500A1

WO2007129500A1 - Vibration detection device

Info

Publication number: WO2007129500A1
Application number: PCT/JP2007/053273
Authority: WO
Inventors: Kazuya Fujii
Original assignee: Mitsumi Electric Co., Ltd.
Priority date: 2006-04-14
Filing date: 2007-02-22
Publication date: 2007-11-15
Also published as: JPWO2007129500A1

Abstract

A vibration detection device highly practical and having stable sensitivity and anti-noise characteristics. The vibration detection device (1) has silicone (4), one side of which can be in contact with a vibration source; a microphone element (3) having a vibration diaphragm (33) in contact with the other side of the silicone (4); and an inner case (2) for receiving the silicone (4) and the microphone element (3). On the inner wall of the inner case (2) for receiving the silicone (4) is stretched a rib (23) between the vibration diaphragm (33) and that surface of the silicone (4) which is in contact with the vibration source, and the rib (23) is embedded in the silicone (4).

Description

Specification

Vibration detector

Technical field

The present invention relates to a vibration detection device that detects individual vibrations transmitted through soft tissue of a human body.

Background art

[0002] Conventionally, sound transmission using the bones of the human body as a medium, V, and a speaker utilizing the bone conduction have been developed.

In recent years, attention has been paid to a transmission mechanism called meat conduction, in which the sound medium is the muscles of the human body, soft tissues such as fat and skin, and a microphone device using this meat conduction has been developed. (For example, see Non-Patent Document 1). Meat conduction is a vibration transmission mechanism that conducts mainly soft tissue of the human body after an unvoiced breathing sound that uses airway turbulence noise as a sound source is tuned by changes in acoustic filter characteristics caused by the movement of the speech organs. According to meat conduction, airway sound transmitted through soft tissue is directly sampled, so it is possible to detect with high sensitivity even whispering voices and so on that are much lower than normal utterance volume.

[0003] Products using meat conduction are in the process of development, and various studies are being promoted for practical application. For example, vibration detection devices such as the above-mentioned microphone device are still manufactured manually, and for the purpose of mass production, the tolerance and productivity of the product itself have reached a practical stage. Nah ...

[0004] Fig. 31 shows a configuration example of a conventional microphone device using meat conduction.

The microphone assembly M is formed in a cylindrical shape, fill the surrounding established the microphone element _m 5 in a case ml having an opening at the top in Nono over de silicone m7, soft silicone space freed by the remaining apertures Satisfies with m8. In addition, an o-ring m9 is provided at the outer peripheral end of the case ml.

[0005] When the microphone device M is used, the soft silicone m8 surface that is exposed and exposed is brought into contact with the soft tissue (usually skin) of the human body, and transmitted through the soft tissue of the human body. This is a mechanism for transmitting sound vibrations to the microphone element m5 through the soft silicone m8 layer. A method for manufacturing the microphone device M of FIG. 31 will be described with reference to FIGS. 32A to 32D.

First, as shown in FIG. 32A, a soundproof sheet is processed to create a cylindrical case ml having an open top. Next, a rubber member m3 for sound absorption is laid on the bottom part in the cylinder, and the base is produced by covering it with a soundproof sheet. When the base is completed, set up a pedestal _m 4 formed from hard silicone in the center of the base, placing a microphone element m5 over its pedestal m4. In this microphone element m5, a cable m6 for electrical connection with the outside is disposed through the side of the case ml.

Next, as shown in FIG. 32B, hard silicone m7 is filled around the microphone element m5. The hard silicone m7 is shaped so that its inner diameter decreases toward the microphone element m7 of the opening force of the case m1, in order to act as a sound vibration reflector. Also, because the O-ring m9 is placed at the open end, the open end is molded into a flat surface with a width! RU

[0008] Next, as shown in FIG. 32C, an O-ring m9 is installed at the open end of the upper part of the case ml, and fixed with an adhesive. O-ring m9 is used as a filling frame for soft silicone to be filled later. When the position of the O-ring m9 is fixed, the outer surface of the case ml is coated with the polymerization resin m2. Thereafter, as shown in FIG. 32D, soft silicone m8 is injected into case ml until the upper surface of O-ring m9 is reached. When this soft silicone m8 is cured, the microphone device M is completed.

Non-Patent Document 1: Yuki Nakamura, “NAM Interface Communication”, Nara Institute of Technology, Doctoral Dissertation, February 2, 2005

Disclosure of the invention

Problems to be solved by the invention

[0009] Since the conventional microphone device M is manufactured manually as described above, it is necessary to improve the mass production and quality of the product.

For example, the force that placed the microphone element m5 on the base m4 and filled it with hard silicone m7 to fix the position Hard silicone m7 itself was the microphone element. It did not have sufficient hardness to support the child m5, and the fixation was unstable. Microphone element m5 also detects vibrations caused by its own movement, so if the fixation is unstable, its sensitivity characteristics may be affected.

[0010] In addition, the structure in which the O-ring m9 is fixed on the hard silicone m7 and the soundproof sheet using an adhesive may peel off in long-term use or messy use with insufficient strength. In addition, although the adhesion between hard silicone m7 and soft silicone m8 is good, it is preferable to improve the peel resistance in consideration of the period of use and usage of the product.

[0011] Furthermore, in order to prevent vibration from wrapping around the microphone element m5 from behind, a case ml is created by covering the soundproof sheet, or a rubber material m3 for sound absorption is installed in the case ml. However, with this configuration, the number of manufacturing processes is increased and the production efficiency is poor.

[0012] Further, when such a microphone device M is actually used for voice detection or the like, it is necessary to mount the microphone device M on a mounting part for mounting on a human body or the like. However, the conventional microphone device M has not been considered to be mounted on such mounting parts.

[0013] An object of the present invention is to provide a vibration detection apparatus having high practicality, stable sensitivity, and noise resistance.

Means for solving the problem

[0014] The invention described in claim 1 is

A vibration transmission medium whose one surface can contact the vibration source;

In a vibration detection device comprising: a vibration detection element having a vibration film in contact with the other surface of the vibration transmission medium; and an inner case that houses the vibration transmission medium and the vibration detection element.

An inner wall of the inner case that houses the vibration transmission medium, wherein a rib is stretched between a contact surface of the vibration transmission medium with a vibration source and the vibration film, and the rib is formed in the vibration transmission medium. It is characterized by being buried.

[0015] The invention described in claim 8

A vibration transmission medium whose one surface can contact the vibration source; In a vibration detection device comprising: a vibration detection element having a vibration film in contact with the other surface of the vibration transmission medium; and an inner case that houses the vibration transmission medium and the vibration detection element.

A space is provided between the vibration film and the vibration transmission medium,

A dome-shaped cover or body is provided on an inner wall of the inner case for accommodating the vibration transmission medium, on a boundary surface between the space and the vibration transmission medium.

The invention's effect

[0016] According to the present invention, when a pressure is received when the vibration transmission medium contacts the vibration source, a repulsive force of the rib is generated and the pressure received by the rib is dispersed in the inner case. Since the repulsive force of the rib is proportional to the pressing force, the pressure applied to the vibration detecting element can be made almost constant regardless of the contact pressure, and the sensitivity characteristic of the vibration detecting element can be made constant. In addition, the case that houses the vibration detection element and the vibration transmission medium is separated from the inner case and the outer case, which have different acoustic impedances. It is possible to prevent the vibration detection element from entering, and to improve the noise resistance of the vibration detecting element.

[0017] Further, since the protruding portion formed on the outer case contacts the vibration source prior to the contact surface of the vibration transmission medium with the vibration source, the pressure on the vibration transmission medium can be relieved by the outer case. . In addition, since the outer case is made of silicone, it is possible to reduce the shock at the time of contact and prevent the noise vibration caused by this shock from entering the vibration source and attenuating the vibration from the vibration source that should be detected originally. it can. As a result, vibration detection accuracy can be improved.

In addition, the vibration detection device can be fixed to the surrounding member, is highly practical, and an air layer having an acoustic impedance different from that of the outer case is interposed between the outer case and the outer member. It is possible to suppress external noise that enters.

[0018] Further, according to the present invention, since the space is provided between the vibration film and the vibration transmission medium, the pressing force applied by the contact with the vibration source can also protect the vibration film and prevent the vibration detecting element from being damaged. can do. Further, the protection can be enhanced by providing a dome-shaped cover on the boundary surface between the space and the vibration transmission medium. Space, vibration transmission medium and interface By making the dome shape, the transmission efficiency of vibration to the diaphragm can be improved, and the same sensitivity characteristic as when the vibration transmission medium and the diaphragm are in close contact can be realized.

Brief Description of Drawings

FIG. 1 is a plan view of a vibration detection device according to a first embodiment.

2 is a cross-sectional view taken along the line II of FIG.

FIG. 3 is a cross-sectional view of the inner case.

FIG. 4 is a cross-sectional view of a microphone element.

FIG. 5 is a cross-sectional view of the outer case.

FIG. 6 is a cross-sectional view of a mounting part.

FIG. 7 is a diagram illustrating a method for manufacturing a vibration detection device.

FIG. 8A is a diagram illustrating a silicone filling process.

FIG. 8B is a diagram illustrating a silicone filling process.

FIG. 9 is a cross-sectional view showing a configuration of a vibration detecting apparatus according to a comparative example.

FIG. 10 is a diagram illustrating sensitivity characteristics of the vibration detection device according to the example.

FIG. 11 is a diagram showing sensitivity characteristics of a vibration detection device according to a comparative example.

FIG. 12 is a diagram showing noise immunity of vibration detection devices according to examples and comparative examples.

FIG. 13A is a diagram showing a sound spectrum of the sound detected by the vibration detecting apparatus according to the example when the sound is detected by applying an appropriate pressure.

FIG. 13B is a diagram showing the sound spectrum of the sound detected by the vibration detection apparatus according to the example when the detection is performed by applying a pressure equal to or higher than the appropriate pressure.

FIG. 14A is a diagram showing a sound spectrum of a sound detected by a vibration detection device according to a comparative example, when the sound is detected by applying an appropriate pressure.

FIG. 14B is a diagram showing the sound spectrum of the sound detected by the vibration detection device according to the comparative example when the detection is performed by applying a pressure equal to or higher than the appropriate pressure.

FIG. 15A is a diagram showing a case where the positional relationship between the diaphragm of the microphone element and the back electrode is normal. [15B] FIG. 15 is a diagram showing a case where the positional relationship between the diaphragm of the microphone element and the back electrode is abnormal.

FIG. 16A is a plan view showing a configuration of a rib according to another embodiment.

FIG. 16B is a cross-sectional view of the inner case taken along line II-II in FIG. 16A.

FIG. 17 is a view showing a configuration of an outer case according to another embodiment.

FIG. 18 is a diagram showing a configuration of an outer case according to another embodiment.

FIG. 19 is a cross-sectional view of a vibration detection device according to another embodiment.

20] A plan view of the vibration detecting apparatus according to the second embodiment.

FIG. 21 is a sectional view taken along line XX in FIG.

FIG. 22 is a diagram for explaining a method of manufacturing the vibration detection device according to the second embodiment.

FIG. 23 is a diagram for explaining a method of manufacturing the vibration detection device according to the second embodiment.

[24] FIG. 24 is a diagram showing a measurement environment when measuring sensitivity characteristics of the vibration detection device. 25] This is a diagram showing the mounting position of the vibration detection device when measuring the sensitivity characteristic of the vibration detection device.

FIG. 26A is a diagram showing a measurement result when a sweep sound is output.

FIG. 26B is a diagram showing a measurement result when audio is output.

FIG. 27A is a diagram showing an audio spectrum of a comparative example.

FIG. 27B is a diagram showing an audio spectrum of the example.

[28] FIG. 28 is a diagram for explaining how vibration is transmitted from space to the diaphragm.

FIG. 29 is a plan view of a vibration detecting apparatus using a cover instead of a rib.

FIG. 30 is a cross-sectional view taken along line Y—Y in FIG. 29.

[31] FIG. 31 is a diagram showing a conventional vibration detection device.

FIG. 32A is a diagram illustrating a method for manufacturing a conventional vibration detection device.

FIG. 32B is a diagram illustrating a method for manufacturing a conventional vibration detection device.

FIG. 32C is a diagram illustrating a method for manufacturing a conventional vibration detection device.

FIG. 32D is a diagram illustrating a method for manufacturing a conventional vibration detection device.

Explanation of symbols

1 Vibration detector 2 Inner case

21 Thin section

22 Notch

23 Ribs

24 Second containment

25 First containment

26 Groove

27 Through hole

28 Bulkhead

3 Microphone element

33 Vibration membrane

4 Silicone

5 Outer case

51 Open end

52 Engagement part

53 Engagement part

54 Third containment

6 Mounting parts

61 Engagement part

7 Bottom cover

C signal line

s space

23a Cover

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment

Hereinafter, a vibration detection apparatus to which the present invention is applied will be described with reference to the drawings.

Fig. 1 shows a plan view of the vibration detector 1, and Fig. 2 shows a cross-sectional view taken along line II in Fig. 1. As shown in FIG. 1 and FIG. 2, the vibration detection device 1 includes an inner case 2 accommodated in a cylindrical outer case 5, and a microphone element 3 and silicone 4 accommodated in the inner case 2. Is. The upper part of the microphone element 3 is filled with silicone 4, and the silicone 4 is in contact with the vibration film 33 of the microphone element 3. Further, a signal line C is wired below the microphone element 3. Signal line C is a cable for sending the detection signal from vibration detection device 1 to the outside.

[0023] When the vibration detection device 1 is mounted on a mounting target device (for example, a mobile phone or the like), a mounting part 6 for mounting the vibration detection device 1 on the mounting target device is used. That is, as shown in FIGS. 1 and 2, the vibration detection device 1 is housed in the mounting component 6.

The mounting component 6 is formed in a ring shape, and a plurality (three in this example) of convex engaging portions 61 are provided on the inner peripheral surface at predetermined intervals in the circumferential direction. . Corresponding to these engaging portions 61, a concave engaging portion 53 is provided on the outer peripheral surface of the outer case 5 of the vibration detecting device 1.

[0024] The protruding width of the engaging portion 61 is set to be larger than the depth of the engaging portion 53, and therefore a gap is formed between the outer peripheral surface of the outer case 5 and the inner peripheral surface of the mounting component 6. become. That is, the vibration detection device 1 is supported with a gap between the outer surface of the outer case 5 and the inner surface of the mounting component 6.

As described above, the vibration detection device 1 is supported at a point (for example, supported at three points) with a space between the outer surface of the outer case 5 and the inner surface of the mounting component 6. Vibration transmission between the outer cases 5 can be suppressed. In other words, the mounting component 6 and the outer case 5 are not in contact with each other at the surface but in contact with each other, so that the contact area force is reduced and vibration from the mounting target device is not easily transmitted to the vibration detection device 1 !, It becomes a structure! As a result, external noise can be suppressed.

A bottom lid 7 is attached to the bottom surface of the mounting component 6.

[0025] The inner case 2 is made of a synthetic resin such as ABS resin, polystyrene resin, acrylic resin, rubber or rosin hard silicone, etc., and formed in advance in the shape shown in FIG. It is a molded product. In consideration of impact resistance, use a metal with high hardness instead of grease. However, it is preferable to use a resin for light weight.

As shown in FIG. 3, a second housing portion 24 for housing the microphone element 3 is formed in the lower central portion of the inner case 2. The second housing part 24 has a diameter slightly smaller than the diameter of the microphone element 3, and when the microphone element 3 is press-fitted into the second housing part 24, the microphone element 3 is fitted and fixed in the second housing part 24. Formed like! Further, the bottom surface of the second accommodating portion 24 is opened, and the microphone element 3 can be inserted into this opening partial force.

On the other hand, a first accommodating portion 25 having an opening on the upper end side is formed above the inner case 2. A partition wall 28 having a through hole 27 is provided between the second housing part 24 and the first housing part 25, and the second housing part 24 and the first housing part 25 communicate with each other through the through hole 27. . The partition wall 28 functions as a locking member that locks excessive insertion from the second housing portion 24 to the first housing portion 25 when the microphone element 3 is inserted into the second housing portion 24.

[0028] As shown in FIG. 2, the first accommodating portion 25 is filled with silicone 4 that is a vibration transmission medium and accommodated therein. The silicone 4 is also filled into the microphone element 3 side through the through-hole 27, and adheres to the vibrating membrane 33 of the microphone element 3 when the silicone 4 is cured.

In addition, arched ribs 23 are stretched on the partition wall 28. As shown in FIG. 1, the rib 23 is formed so as to cross the through hole 27, for example, at three points. The rib 23 is embedded in the silicone 4 as shown in FIG. 2 when the silicon 4 is filled.

[0030] The first housing part 25 is formed in a mortar-like shape in which the opening force on the upper end side is directed toward the second housing part 24 to reduce its inner diameter. In the present embodiment, an example of a mortar shape is shown, but a parabolic shape or a hemispherical shape whose inner surface is curved may be used.

The outer peripheral edge of the first housing part 25 is formed thinner than the other parts. The thin portion 21 has a tip portion formed in a shape corresponding to the engaging portion 52 of the outer case 5 and functions as an engaging portion. Further, the width of the thin portion 21 in the radial direction of the first accommodating portion 25 is such that the front end portion of the thin portion 21 is engaged with the engaging portion 52 (see FIG. 5) of the outer case 5 and the opening end of the outer case 5 is opened. 51 (see FIG. 5) is set to such a size that a circumferentially continuous groove 26 is formed between the inner circumferential surface (see FIG. 5).

[0031] Thus, the groove 26 is formed by increasing the surface area of the inner surface of the inner case 2. This is to improve the adhesion between the inner case 2 and the silicone 4.

The thin portion 21 is provided with a plurality of (three in this example) cutout portions 22 at predetermined intervals in the circumferential direction. The notch 22 is provided to improve the fluidity of the silicone 4 into the groove 26. The number is not limited to three, but in order to flow the silicone 4 uniformly and quickly (around), it is preferable to determine in consideration of the properties such as viscosity and curing speed of the silicone 4, .

[0032] Silicone 4 is a vibration transmission medium whose surface serves as a contact surface with a soft tissue of a living body that is a vibration source, and conducts sound vibration transmitted from the soft tissue to microphone element 3. Here, the soft tissue of a living body refers to an individual tissue having a certain degree of elasticity, such as skin tissue, muscle tissue, adipose tissue, and fat.

[0033] Soft silicone or the like having a relatively low hardness is applicable as the material of silicone 4, and a material having an acoustic impedance substantially equivalent to that of a soft tissue of a living body serving as a sound vibration transmission medium is selected. The acoustic impedance is obtained from the product of the medium density p and the propagation velocity C. As long as the acoustic impedance of each material differs between two adjacent materials, sound reflection occurs strongly at the boundary surface where the two materials contact. Therefore, in order to mediate the sound propagating through the soft tissue of the living body to the diaphragm 33 of the microphone element 3 that does not reflect and attenuate as much as possible, it is only necessary to select one having an acoustic impedance equivalent to that soft tissue.

[0034] It is known that the acoustic impedance of the soft tissue shows almost the same value although there is a slight difference depending on the tissue. The specific acoustic impedance value of the soft tissue varies depending on the measurement environment, but the fat tissue is about 1.3 X 106 (kg / m2s). When you actually select the silicone 4 material, choose the one with the best acoustic impedance experimentally and empirically!

The microphone element 3 is a vibration detection element that detects vibrations that are conducted through the silicone 4 filled in the first housing portion 25 and converts the vibrations into electric signals.

FIG. 4 shows an enlarged cross-sectional view of the microphone element 3.

As shown in FIG. 4, the microphone element 3 has a cylindrical case 31 in which a vibrating membrane 33, a spacer 34, a back electrode 35, and an FET (Field Effect Transistor) 36 are accommodated. This is a capacitive microphone element.

[0036] The upper central portion of the case 31 is opened in a circular shape, and a sound receiving hole 37 is formed. A case 32 having the same hole diameter as that of the sound receiving hole 37 is provided inside the upper surface of the case 31, and the diaphragm 33, the spacer 34, and the back electrode 35 are laminated and attached to the washer 32. . If the hole diameter of the washer 32 is smaller than the diameter of the sound receiving hole 37, the diameter is not the same.

[0037] A substrate 38 is disposed above the bottom surface of the case 31 with a gap therebetween, and a spacer 39 is disposed between the substrate 38 and the back electrode 35. A spacer 32 and the like attached to the vibration film 33 are supported by the spacer 39. Further, an FET 36 is installed in the inner hole of the spacer 39 on the substrate 38. The FET 36 has three terminals, which are connected to the back electrode 35, the signal line C, and the ground line, respectively.

[0038] The outer case 5 is a silicone molded product that is pre-molded into a shape shown in FIG. 5 using silicone as a material. Silicone has a higher hardness than silicone 4, such as curable soft silicone, rubber-like, and rosin-like hard silicone (for example, hardness (JIS A) compared to silicone 4 hardness (JIS A) 6). A) Silicone of about 20 to 40), etc., which has little deformation due to pressing. Silicone having an acoustic impedance different from that of the resin forming the inner case 2 is applied.

The outer case 5 has an opening at the upper end of the cylinder, and has a third housing portion 54 formed so that the shape of the inner surface thereof corresponds to the outer shape of the inner case 2. A concave engaging portion 52 corresponding to the thin portion 21 of the inner case 2 is provided on the inner surface of the third accommodating portion 54.

Further, the open end 51 of the third housing portion 54 is molded so as to protrude from the surface of the silicone 4 in a state filled with the silicone 4 as shown in FIG.

[0040] The reason why the open end 51 protrudes in this way is that the surface of the silicone 4 serves as a contact surface to the soft tissue that is a vibration source. This is to alleviate excessive pressing directly applied to the microphone element 3 through the silicone 4.

[0041] Further, the vibration detection device 1 is brought into contact with and pressed against the soft tissue, but the contact portion of the soft tissue with the vibration detection device 1 is hardened by the pressing force at this time, and is transmitted from the soft tissue. May be difficult to transmit. Therefore, the material of the outer case 5 that is in direct contact with the soft tissue is made of a low hardness silicone that is made of a hard resin such as grease and metal, thereby reducing the pressure on the soft tissue and preventing the soft tissue from hardening! This makes it easier to transmit vibrations such as soft tissue forces.

A concave portion is formed on the outer surface of the outer case 5 over the entire circumference in the circumferential direction to form an engaging portion 53 that engages with the mounting component 6. As described above, the concave shape of the engaging portion 53 is not that the convex portion of the engaging portion 61 provided corresponding to the mounting component 6 side is engaged with the convex portion of the convex portion. It is formed to engage with a part of the tip. As a result, the outer case 5 is supported at three points so that a gap is created between the outer surface of the outer case 5 and the inner surface of the mounting part 6 when the outer case 5 is stored in the mounting part 6. Become.

[0043] The mounting component 6 is an enclosing member for mounting the vibration detection device 1 to a mounting target device. The mounting component 6 is a molded product that has been previously molded into the shape shown in FIG. As shown in FIG. 6, the mounting part 6 has a hollow inside the cylinder. This hollow portion is a fourth accommodating portion 62 for accommodating the vibration detecting device 1. An engaging portion 61 that engages with the outer case 5 is formed on the inner wall. In addition, a through hole for passing the signal line C of the microphone element 3 is provided in a part of the peripheral edge of the cylinder.

[0044] The bottom cover 7 is a disk-shaped plate material.

With reference to FIG. 7, FIG. 8A, and FIG. 8B, a manufacturing method of the vibration detection device 1 will be described.

FIG. 7 is a diagram for explaining a method of assembling each member. The numbers in the forceps shown in Fig. 7 indicate the order of the assembly process.

First, the signal line C is wired to the microphone element 3 by soldering (see (1) in Fig. 7). The signal line C is preferably wired at an early stage as much as possible. The more the outer case is covered with the inner case 2 and the outer case 5, etc., the heat at the time of soldering tends to be trapped inside the cases 2 and 5, and as a result, the microphone element 3 may be destroyed by heat. is there. Another reason is that when soldering is performed after the silicone 4 is filled, the adhesion between the silicone 4 and the diaphragm 33 of the microphone port device 3 is deteriorated by the heat. Heat If measures are taken, soldering can be performed at the final stage.

Next, the microphone opening phone element 3 to which the signal line C is also inserted is inserted into the bottom opening force of the inner case 2 which is a resin molded product.

This is inserted into the third housing portion 54 of the outer case 5, and the thin portion 21 of the inner case 2 is engaged with the engaging portion 52 of the outer case 5 (see (2) in FIG. 7).

Next, silicone 4 is filled in the first housing portion 25 of the inner case 2 (see (3) in FIG. 7).

The filling process of silicone 4 will be described with reference to FIGS. 8A and 8B.

The filling amount of the silicone 4 is determined in advance so as to be filled up to a position which becomes a filling reference. The position serving as the filling reference is determined to be a position (see FIG. 1) lower than the protruding portion, for example, 1 mm below the protruding portion of the opening end 51 of the first housing portion 25.

[0048] At the time of filling, an inclined partial force is applied to the inner surface of the first housing portion 25 so that the silicone 4 does not drop directly onto the microphone element 3. At this time, as shown in FIG. 8A, the interface of the silicone 4 rises according to the amount of dripping and gradually fills the first accommodating portion 25. When the interface reaches the notch 22, the silicone 4 flows into the notch 22 and enters the groove 26. Meanwhile, when the interface of the silicone 4 in the first housing part 25 rises due to further filling, the silicone 4 filling the first housing part 25 and the silicone 4 entering the groove 26 merge and are shown in FIG. 8B. It will be in such a state.

[0049] Here, consider the case where the notch 22 is provided.

When the silicone 4 reaches the boundary with the groove 26, the silicone 4 temporarily enters the groove 26 due to its surface tension. In addition, by applying a pressure higher than the surface tension by increasing the amount of dripping onto the silicone 4, the force that causes the silicone 4 to enter the groove 26. During that time, the fluidity of the silicone 4 decreases around the groove. Silicone 4 is hardened. As a result, there is a possibility that the curing of the silicone 4 in the first housing part 25 will be uneven. If excessive dripping is performed to exceed the surface tension, when the groove 26 is filled with silicone 4, the interface may exceed the position that should be originally filled.

[0050] However, since the inner case 2 in the present embodiment is provided with the notch 22 in the groove 26, as shown in FIG. Progress Will enter. As a result, the surface tension of the silicone 4 is relaxed, and the silicone 4 that has entered from the notch 22 enters the groove 26, so that the fluidity of the silicone 4 generated by the formation of the groove 26 can be improved.

[0051] When all of the predetermined amount of silicone 4 has been filled, this is left to cure and the silicone 4 is cured. The vibration detector 1 is completed by curing the silicone 4.

Next, the completed vibration detection device 1 is inserted into the mounting component 6 from the bottom opening of the mounting component 6 as shown in FIG. 7 (step indicated by (4) in the figure). When the engaging part 53 provided on the outer surface of the vibration detecting device 1 and the engaging part 61 provided on the inner surface of the mounting part 6 are engaged, the bottom cover of the mounting part 6 is 7 is attached (step shown by (5) in the figure).

When using the vibration detection device 1, the user holds the outer surface of the mounting part 6 and makes the side where the silicone 4 is exposed contact the soft tissue of the living body. At this time, since the sensitivity of the vibration detection device 1 changes depending on the contact position, it is only necessary to find a position with good sensitivity empirically. Experimental results show that the area immediately below the mastoid, which is the back of the ear, is optimal.

[0054] At the time of contact, the open end 51 of the outer case 5 protruding from the surface of the silicone 4 first comes into contact with the soft tissue. Next, the soft tissue inside the open end 51 rises due to the contact pressure, and comes into contact with the surface of the silicone 4. The vibration transmitted from the soft tissue of the living body that is in contact is conducted to the microphone element 3 via the silicone 4. In the microphone element 3, an electric signal is generated by the FET 36 in response to the vibration received by the vibration film 33, and this electric signal is transmitted to the outside via the signal line C.

[0055] As a comparative example, a vibration detection device 10 as shown in Fig. 9 was produced for the vibration detection device 1, and the performance was evaluated by measuring the sensitivity characteristics, noise resistance, voice spectrum, and the like. .

In the vibration detection device 10 shown in FIG. 9, the microphone element 3 and silicone 4 (the microphone element and silicone 4 are the same as the vibration detection device 1 and are therefore given the same reference numerals). It is housed in one molded case 11. The vibration detection device 1 has a mortar-shaped opening formed at one end of the case 11 where silicone 4 A point where the microphone element 3 is accommodated via the silicone 4 accommodating part and the partition wall 28 via the through hole 27 at the other end, and the vibration film of the silicone 4 and the microphone element 3 Are in contact with each other, and the opening end of the case 11 is formed so as to protrude from the surface of the silicone 4. However, the vibration detection device 10 has a different configuration in that the case 11 is formed integrally with the exterior, the rib is not provided, and the mounting component 6 is used.

[0056] <Experiment>

The material of the silicone 4 of the vibration detection device 1 according to this embodiment and the material of the silicone 4 of the vibration detection device 10 according to the comparative example, the material of the case 2 of the vibration detection device 1 and the case 11 of the vibration detection device 1 The following measurements were performed on the same basis.

[0057] (1) Measurement of sensitivity characteristics

The vibration detection device 1 according to the example and the vibration detection device 10 according to the comparative example were brought into contact with an experimental vibration source, and the sensitivity (dB) was measured by changing the frequency of the sound of the vibration source force. Sensitivity is measured using two patterns with different pressures per contact area: 100 (g) and 200 (g).

[0058] (2) Measurement of noise immunity

The vibration detection device 1 according to the example and the vibration detection device 10 according to the comparative example are arranged at a distance of 5 cm for the vibration source for the experiment, and the air conduction sound from the vibration source is treated as noise. Sensitivity (dB) to air conduction sound was measured. Sensitivity is measured by changing the frequency of the sound.

[0059] (3) Measurement of audio spectrum

With the vibration detection device 1 and the vibration detection device 10 in contact with the soft tissue of the human body, the same phrase “Human has bent all reality toward him” is uttered. Then, an audio spectrum was created based on detection signals from the vibration detection device 1 and the vibration detection device 10. The experiment was performed for two patterns of proper pressure and excessive pressure with additional pressure added to the appropriate pressure per contact area. Here, “appropriate pressure” means the pressure included in the pressure range where the signal detection tolerance at the low frequency (800 (Hz) or less) and high frequency (800 (Hz) to 4k (Hz)) is the best. Say. In the experiment The result shows that the proper pressing range of the vibration detection device 10 is about 0 to 40 (g), and the proper pressing range of the vibration detection device 1 is about 0 to 200 (g). In particular, in the vibration detection apparatus 1, a balance of about 100 ± 50 (g) was the best.

[0060] <Evaluation>

(1) Evaluation of sensitivity characteristics

As a measurement result of the sensitivity characteristic of the vibration detection apparatus 1, the result shown in FIG. 10 was obtained. In contrast, the vibration detection apparatus 10 obtained the results shown in FIG.

In Fig. 10 and Fig. 11, the sensitivity characteristics when the pressure at the time of contact is 100 (g) are shown as a solid line,

The sensitivity characteristics at) are indicated by dotted lines.

As shown in FIG. 10, in the vibration detection device 1 according to the example, there is no great difference in sensitivity characteristics between 100 (g) and 200 (g).

On the other hand, in the vibration detection device 10, as shown in FIG. 11, in the region where the frequency is 4000 (Hz) or less, the pressure is about 6 to 7 (dB) when the pressure is 100 (g) and 200 (g). There is a difference. In particular, the human voice range is often included in the frequency band of about 100 (Hz) to 4 (kHz) (mostly depending on the language used), but the vibration detection device 10 according to the comparative example is not capable of listening. It can be seen that in the high frequency range of 2 to 4 (kHz), which has a large effect on the intelligibility (easy to hear), the sensitivity tends to vary due to V and pressing.

[0062] (2) Evaluation of noise tolerance

FIG. 12 is a diagram showing measurement results of noise tolerance of the vibration detection device 1 and the vibration detection device 10. In FIG. 12, the solid line shows the noise sensitivity characteristic of the vibration detection device 1 according to the embodiment, and the dotted line shows the noise sensitivity characteristic of the vibration detection device 10 according to the comparative example.

As shown in FIG. 12, it is clear that the vibration detection device 10 has a higher sensitivity to noise and lower noise resistance than the vibration detection device 1 at about 3.5 (kHz) or less.

[0063] (3) Evaluation of audio spectrum

13A and 13B are diagrams showing audio spectra obtained by the vibration detection device 1. FIG. 14A and 14B are diagrams showing a sound spectrum by the vibration detection device 10. FIG. In these audio spectrums, the level of the signal level is indicated by density, and the higher the density, the higher the signal level. Figures 13A and 14A show that the human body is pushed with proper pressure. Fig. 13B and Fig. 14B show the audio spectrum when overpressed.

[0064] Comparing Fig. 13A and Fig. 13B, it can be seen that the signal is attenuated slightly in the frequency band of 500 (Hz) to 1 (kHz) when overpressing is applied (circle in Fig. 13B). Only in the enclosed area), the sound spectrum characteristics hardly change. From this, it can be seen that the vibration detection device 1 performs stable voice detection regardless of the magnitude of the pressure.

On the other hand, comparing FIG. 14A and FIG. 14B, in the vibration detection device 10, the signal amount in the high frequency region increases due to excessive pressing, and the sound spectrum changes greatly. From this, it can be seen that the vibration detection device 10 cannot cope with the change in the pressure, and the voice detection becomes unstable. Further, since signal detection is performed over the entire frequency band, the frequency components (100 (Hz) to 4 (kHz)) of the sound that is the original detection target are diluted. Furthermore, the signal level exceeds the allowable input value because the input amount of the signal becomes excessive. When the audio in this case is viewed, the sound becomes muffled and difficult to view.

[0066] Possible causes of the above evaluation are as follows.

As shown in FIG. 9, when the vibration detecting device 10 is brought into contact with the soft tissue, the pressure due to the contact is directly applied to the vibrating membrane of the microphone element 3 through the silicone 4. For this reason, the sensitivity may vary depending on the pressure, and the appropriate pressure range will be narrowed.

[0067] Further, when the pressure is excessive, there is a case where vibration detection of the microphone element 3 is not normally performed. As shown in FIG. 15A, in order for the microphone element 3 to perform normal vibration detection, there must be a gap between the vibrating membrane 33 and the back electrode 35 of the microphone element 3. This is because the microphone element 3 can exert a capacitor function due to this gap. However, when excessive pressing is performed, the vibrating membrane 33 is pressed against the back electrode 35 as shown in FIG. 15B, and the gap is lost. If the gap is lost, the function as a capacitor cannot be performed, and the detection operation of the microphone element 3 becomes abnormal.

[0068] Further, the case 11 of the vibration detecting device 10 is a molded resin product having a high hardness. Therefore, when the vibration detecting device 10 is pressed against the soft tissue, the case 11 comes into contact with the soft tissue to harden the soft tissue portion, and is transmitted to the soft tissue force vibration detecting device 10. It is conceivable to suppress vibration. This makes it impossible to accurately detect vibrations.

[0069] Furthermore, since the case 11 is integrally formed as an exterior, it has low resistance to external noise! This is because the vibration of noise transmitted to the case 11 from the outside causes the microphone element 3 to vibrate.

In addition, since the case 11 is not particularly structured to be fixed to a mounting part, vibration is detected by the mounting part, such as forming the mounting part so that it is fitted and fixed when stored in the mounting part. It is considered that the device 10 is sandwiched, but depending on the material, shape, etc. of the mounting parts, it may be a sound collecting plate and noise vibration of external force is transmitted to the microphone element 3.

[0070] In addition, in the vibration detection device 10, the fixing of the silicone 4 to the case 11 relies only on the adhesion between the case 11 and the silicone 4, and the adhesion strength is high. .

In response to such a problem, according to the vibration detection device 1 according to the present embodiment, the inner surface of the inner case 2, the contact surface with the vibration source (soft tissue) of the silicone 4, and the microphone element 3. A rib 23 is stretched on a partition wall 28 between the diaphragm 33 and the diaphragm 4 and is embedded in a silicon 4 that is in direct contact with the vibration source. When the silicone 4 is pressed, the repulsive force of the ribs 23 acts, and the pressure received by the ribs 23 is dispersed in the inner case 2, so that excessive pressing on the microphone element 3 can be suppressed. Thus, the appropriate pressing range can be expanded and the pressing can be prevented until the vibrating membrane 33 comes into contact with the back electrode 35, and the abnormal operation of the microphone mouthphone element 3 can be prevented.

[0072] Further, when the pressure is small, the rebound of the rib 23 is small. Conversely, when the pressure is large, the rebound is large. In this way, the repulsive force of the rib 23 is proportional to the pressure at the time of contact, so that the pressure applied to the microphone element 3 can be made almost constant. Therefore, it is possible to always keep the sensitivity characteristic of the micro-on element 3 constant regardless of the pressing at the time of contact.

[0073] According to the vibration detection device 1, the outer case 5 having the open end 51 in contact with the soft tissue is formed of silicone. As a result, the pressure applied to the soft tissue when the vibration detection device 1 is pressed against the soft tissue can be reduced. By reducing the pressure, it is possible to prevent the vibration transmission from the soft tissue from being hindered. [0074] In the vibration detection device 1, the case housing the microphone element 3 has a separate configuration of the inner case 2 and the outer case 5 having different acoustic impedances. As a result, the vibration transmitted to the outer case 5 can be reflected at the boundary between the inner case 2 and the outer case 5, and noise resistance can be improved.

[0075] Further, when the vibration detection device 1 is actually used, the mounting component 6 for mounting the vibration detection device 1 on the vibration source is required, but the mounting component 6 is required for the outer case 5. Therefore, when the vibration detection device 1 is housed in the mounting part 6, the position can be fixed. Further, since the outer case 5 is engaged with the mounting part 6 by the three engagement portions 53 and 61 so that a gap is maintained between the outer case 5 and the mounting part 6, the outer case 5 and the mounting part 6 And the noise vibration transmitted from the mounting component 6 to the vibration detecting device 1 can be reduced.

[0076] Further, in the vibration detection device 1, the adhesion between the inner case 2 and the silicone 4 is high. This is because the silicone 4 is locked by the tension of the ribs 23. In addition, the area in contact with the silicone 4 is increased by the surface area of the groove 26 and rib 23 formed in the inner case 2, and the adhesion is increased.

[0077] The above-described embodiment is a preferred example to which the present invention is applied, and the present invention is not limited to this.

For example, the rib 23 is shaped like a dome, and the bridge formed at three points arranged at equal intervals in the communication portion between the first housing portion 25 and the second housing portion 24 is used as shown in FIGS. 16A and 16B. It is also possible to stretch a rib 231 that crosses four points in a loss shape. 16A is a front view, and FIG. 16B is an enlarged cross-sectional view of case 2 of FIG. 16A along the line II. Further, the tensioning position may be any position as long as it is on the inner surface of the inner case 2 not between the partition walls 28 and between the contact surface of the silicone 4 with the vibration source and the vibration film 33.

Further, in the above embodiment, the shape is not particularly limited as long as it corresponds to the engaging portion 61 of the force mounting component 6 in which the concave engaging portion 53 is provided on the outer surface of the outer case 5. For example, a convex engaging portion 531 as shown in FIG. 17 may be used, or as an engaging portion 532 having an umbrella-shaped cross section as shown in FIG. 18, it may be provided on the bottom surface of the outer case 5. In the case of the umbrella type, the engagement with the mounting part 6 can be further strengthened, and the vibration detection device 1 is the mounting part 6. Therefore, it is difficult to peel off and a structure can be obtained.

[0079] Sarako, force used to directly connect signal line C to microphone element 3 in the above configuration, as shown in Fig. 19, terminal Tl is connected to microphone element 3, terminal Τ2 is connected to bottom cover 7, and terminal Τ2 is connected to A terminal Τ3 connected to the signal line C is provided, and when the bottom cover 7 is attached to the mounting part 6, the terminal T1 of the microphone element 3 and the terminal Τ2 of the bottom cover 7 come into contact with each other, so that the wiring is performed. It is good also as a possible structure. That is, when the bottom cover 7 with the signal line C wired to the terminal Τ3 is attached to the mounting part 6, the terminal T1 of the microphone element 3 and the terminal Τ2 of the bottom cover 7 are in contact, and the terminal Τ2 is connected to the terminal Τ3. Therefore, it is possible to easily perform wiring simply by attaching the bottom lid 7. According to this configuration, it is possible to protect the high-heat-power microphone element 3 by soldering or the like during wiring that does not require the signal line C to be directly wired to the microphone element 3.

[0080] Second Embodiment

In the second embodiment, an example will be described in which a space is provided between the vibration film and the vibration transmission medium to prevent direct pressure from being applied to the vibration film via the vibration transmission medium due to contact with the vibration source. .

FIG. 20 shows a plan view of the vibration detection device la according to the second embodiment, and FIG. 21 shows a cross-sectional view taken along the line XX of FIG. The vibration detection device la according to the second embodiment is such that a space is provided between the silicone 4 and the vibration film 33 of the vibration detection device 1 according to the first embodiment, and other configurations are the same. Therefore, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted, and the components different from those in the first embodiment will be mainly described.

As shown in FIGS. 20 and 21, the vibration detecting device la has a space s between the silicone 4 and the vibrating membrane 33. The boundary surface between the space s and the silicone 4 is formed in a dome shape along the shape of the rib 23. In this way, by providing the space s, the silicone 4 force that receives the pressure from the vibration source can also separate the vibration film 33, and the pressure is not directly applied to the vibration film 33 through the silicone 4. be able to.

With reference to FIGS. 22 and 23, a method of manufacturing the vibration detection device la will be described. In the production of the vibration detection device la, a shaft 8 and a shaft base 9 are used as shown in FIG. The shaft 8 has a convex cross section, and the tip of the convex portion is formed in a dome shape so as to coincide with the shape of the rib 23. Further, the shaft base 9 is formed with an installation base for the outer case 5 accommodating the inner case 2 in the upper part, and is configured to accommodate the shaft 9 therein.

As shown in FIG. 22, first, the inner case 2 is assembled into the outer case 5, and this is installed on the upper part of the shaft base 9 (step (1) in FIG. 22). In this state, the lower force of the shaft base 9 also inserts the shaft 8 into the shaft base 9 (step shown by (2) in FIG. 22). FIG. 23 is a view after the shaft 8 is inserted. As shown in FIG. 23, the shaft 8 is inserted until the tip of the convex portion is in contact with the rib 23. Then, with the shaft 8 inserted, the silicone 4 is filled into the first housing portion 25 of the inner case 2 (step (3) in FIG. 23). Since the filling method of silicone 4 is the same as that of the first embodiment, description thereof is omitted here.

[0084] When the filled silicone 4 is cured, the shaft 8 and the shaft base 9 are separated from the outer case 5. Then, the microphone element 3 to which the bottom opening force signal line C of the inner case 2 is wired is inserted. After that, the vibration detecting device la is completed by attaching the mounting part 6 and the bottom lid 7 in order.

[0085] <Operation of vibration detection device la>

Since the operation of the vibration detection device la is the same as the operation of the vibration detection device 1 in the first embodiment, the description thereof is omitted here.

Example

[0086] With respect to the vibration detection apparatus la, a vibration detection apparatus 1 was produced as a comparative example, and performance evaluation was performed by measuring the sensitivity characteristics, noise resistance, voice spectrum, and the like.

(1) Measurement of sensitivity characteristics

In the measurement environment shown in FIG. 24, the detection values in the vibration detection device la according to the present example and the vibration detection device 1 according to the comparative example were measured. As shown in FIG. 24, the measurement was performed with a speaker installed at one end of a cylindrical silicone pipe having a hardness of 30 and a vibration detector la, 1 installed on the side of the silicone pipe. Measurement is (i) speaker or When a sweep sound (-20dB) of 20 (Hz) to 20 (kHz) is output, (ii) "A, Ue, Sashisuseso" sound is output from the speaker, and two patterns are used.

In addition, a weight for pressing is arranged on the upper part of the vibration detecting device la, 1 in order to reproduce the pressing when contacting the vibration source. The silicone pipe has a thickness of 5 mm and a length of 100 mm, and the distance between the speaker and the vibration detection device la, 1 is 50 mm. In addition, a reference microphone is installed at the other end facing the speaker to detect sound vibrations as a reference for sensitivity evaluation.

[0087] (2) Audio spectrum measurement

At the mounting position shown in FIG. 25, the vibration detection device 1 according to this example and the vibration detection device 1 according to the comparative example were mounted, and “Aiueo, Sashisoseso” was uttered. And the vibration detection device la,

An audio spectrum was created based on the detection signal from 1.

[0088] <Evaluation>

(1) Evaluation of sensitivity characteristics

FIG. 26A is a diagram showing a measurement result when (i) sweep sound is output, and FIG. 26B is a diagram showing a measurement result when (ii) sound is output. The measurement results of the examples are indicated by solid lines, and the measurement results of the comparative examples are indicated by dotted lines. As shown in FIGS. 26A and 26B, it can be seen that the sweeping sound and the sound have almost the same characteristics in the example and the comparative example. That is, even when a space s is provided between the vibration membrane 33 and the silicone 4 as in the vibration detection device la (example), the vibration detection device 1 (comparative example) and the vibration membrane 33 and the silicone 4 are in close contact with each other. It can be divided that it is possible to realize the sensitivity characteristic of the same degree.

[0089] (2) Evaluation of audio spectrum

FIG. 27A shows an audio spectrum according to the embodiment, and FIG. 27B shows an audio spectrum according to a comparative example. Since any sound has almost the same audio spectrum in the example and the comparative example, the vibration detection device la having the space s is also the same as the vibration detection device 1 having no space s. It can be seen that the characteristics are obtained.

[0090] Although the space s is provided between the vibrating membrane 33 and the silicone 4 as described above, the contact surface between the space s and the silicone 4 can achieve the same sensitivity characteristics as the case where the space s is not provided. This is thought to be due to the dome shape. For example, as shown in Figure 28, the contact surface is planar In this case, the vibration transmitted through the silicone force source 4 travels perpendicular to the contact surface. That is, the vibration is transmitted to the vibration film 33 perpendicularly to the surface of the vibration film 33. In this case, the vibration transmitted to the vibration film 33 is dispersed depending on the position where the vibration enters. On the other hand, in the case of the dome shape, the vibration enters the normal line with respect to the curved surface of the dome, so that the vibration is likely to collect at the central portion of the vibration film 33. Therefore, the dome shape has better vibration transmission efficiency than the flat shape, and as a result, the detection accuracy increases.

[0091] As described above, according to the second embodiment, since the space s is provided between the vibration film 33 and the silicone 4, the vibration film 33 and the silicone 4 are separated by the space s, and the vibration detection device la is vibrated. It is possible to prevent pressure from being directly applied to the vibrating membrane 33 via the silicone 4 when contacting the source. Therefore, it is possible to make the vibration film 33 difficult to break.

Further, the boundary surface between the space s and the silicone 4 is formed in a dome shape. As a result, even when the space s is provided, it is possible to achieve the same sensitivity characteristics as when the space s is not provided.

Note that the second embodiment is merely a preferred example to which the present invention is applied, and the present invention is not limited to this.

For example, as shown in FIGS. 29 and 30, instead of the ribs 23, a dome-shaped cover 23a may be provided on the boundary surface between the silicone 4 and the space s. In this case, the protection of the vibrating membrane 33 can be strengthened.

Industrial applicability

[0094] It can be used in the field of acoustic technology and can be applied to a microphone device of a mobile phone.

Claims

The scope of the claims

[1] a vibration transmission medium in which one surface can contact a vibration source;

An inner wall of the inner case that accommodates the vibration transmission medium, wherein a rib is stretched between a contact surface of the vibration transmission medium with a vibration source and the vibration film, and the rib is used as the vibration transmission medium. A vibration detecting device embedded in the inside.

[2] It further comprises an outer case for accommodating the inner case,

2. The vibration detecting apparatus according to claim 1, wherein an engaging portion that engages with each other is provided on the outer case and the inner case.

[3] The vibration detection device according to claim 2, wherein the inner case and the outer case have different acoustic impedances.

4. The outer case is formed of silicone, and a part of the outer case is formed so as to protrude from a contact surface with the vibration source of the vibration transmission medium. The vibration detection apparatus according to 1.

[5] The outer case can be stored in an outer member,

An outer surface of the outer case is an engagement portion with the outer member, and holds a gap between the outer surface of the outer case and the inner surface of the outer member when engaged with the outer member. The vibration detecting device according to any one of claims 2 to 4, further comprising an engaging portion formed to support the outer case.

6. A space provided between the vibrating membrane and the vibration transmission medium.

6. The vibration detection device according to any one of items 1 to 5.

7. The vibration detection device according to claim 6, wherein a boundary surface between the space and the vibration transmission medium has a dome shape.

[8] —Vibration transmission medium whose surface can contact the vibration source;

A vibration detection element comprising: a vibration detection element having a vibration film in contact with the other surface of the vibration transmission medium; and an inner case that houses the vibration transmission medium and the vibration detection element. In the dispensing device,

A vibration detection apparatus comprising a dome-shaped cover on an inner wall of the inner case that houses the vibration transmission medium, at a boundary surface between the space and the vibration transmission medium.