JP5185430B1 - Transceiver - Google Patents

Abstract

The present invention provides a transmission / reception device in which a contact microphone can be arranged close to a receiving means such as a headphone or a portable wireless device.
A headphone 100 includes contact microphones 1a to 1h and 1j to 1m close to a speaker unit. Specifically, the contact microphones 1a to 1h and 1j to 1m are divided into four parts by a first reference axis in the longitudinal direction of the headband 130 and a second reference axis orthogonal to the first reference axis, and the four parts are divided. Among these, the headband 130 is disposed on the side farther from the headband 130 and in contact with the frontal side of the user than the receiving means.
[Selection] Figure 1

Description

  The present invention relates to a transmission / reception device, and more particularly, to a transmission / reception device equipped with a contact microphone.

  The headset allows hands-free calling to the speaker easily. Headsets are widely used for call center operators, mobile phone options, and voice communication terminals via personal computers (PCs).

  Patent Document 1 discloses a microphone device in which a first microphone is set at a position approaching a close sound source, and a second microphone is set farther than the distance between the first microphone and the close sound source. Is described.

  On the other hand, contact-type microphones have been developed that can clearly pick up the sound of normal utterances that are intended even in noisy environments, as well as weak sounds that cannot be heard by human ears or inaudible murmurs.

  In Patent Document 2, a microphone is brought into contact with the skin surface of the posterior part of the auricle and immediately below the milk leaf process of the skull, and an inaudible muttering sound (hereinafter referred to as “NAM”) is obtained. A contact-type microphone for collecting various voices such as the beginning and conduction sound in the body as a transmission vibration, a so-called NAM microphone is described. Such NAM microphones started with application to voice input / recognition and voiceless telephones with the main purpose of concealing the contents of speech. In recent years, it has been attracting attention as a vibration pickup detector that constantly monitors pulse and heart sounds, which are conduction sounds in a patient, for medical purposes.

JP 2007-300513 A International Publication No. 2004/021738

  In the headset, the speaker uses the headband to place the receiver on the speaker's ear, the microphone attached to the tip of the arm extending from the receiver is positioned near the mouth, and the speaker's voice information is picked up by the microphone. Used when a speaker has a conversation with the other party. That is, the headset has a configuration in which the receiver and the microphone are considerably separated. On the other hand, the speaker unit (receiving unit) of the headphone is in an environment where the sound is very loud, and it is difficult to place a microphone that picks up a weak sound close to each other.

  By the way, if the noise resistance of contact type microphones such as NAM microphones is further improved and only normal voices and non-audible murmuring voices can be easily picked up, a contact type microphone will be installed as a headphone microphone. There is also a possibility. However, at the present stage, a transmission / reception apparatus that can place a microphone close to a speaker unit such as a headphone has not been put into practical use.

  An object of the present invention is to provide a transmission / reception device in which a contact-type microphone can be arranged close to a receiving means such as a headphone or a portable wireless device.

The transmission / reception apparatus of the present invention includes a casing, and a transmission means and a reception means attached to the casing, and the casing includes at least a temporal contact portion that contacts the temporal region of the user. The transmission means includes a condenser microphone element having a diaphragm, a vibration transmission member to the diaphragm, a cover member having an opening and storing the microphone element and the vibration transmission member, A sound collecting contact member including metal or ceramics, which is disposed so as to cover the opening of the cover member, and the vibration transmission member is disposed substantially at the center of the sound collection contact member. Adopts a configuration in which the diaphragm of the microphone element and the sound collection contact member are in contact with each other.

  According to the present invention, the noise resistance of the contact microphone is further improved, and it is easy to clearly pick up only normal voice or inaudible murmur voice, so that the contact type is close to the speaker unit like a headphone. A transmitter / receiver capable of arranging a microphone can be realized.

The perspective view which shows the transmission / reception apparatus which mounts the contact-type microphone of Embodiment 1 of this invention. Side view when the transmitter / receiver equipped with the contact microphone according to the first embodiment is mounted on the head The figure explaining arrangement | positioning of the said contact type microphone in the transmission / reception apparatus which mounts the contact type microphone of this Embodiment 1. FIG. The perspective view which shows the transmission / reception apparatus which mounts the contact-type microphone of this Embodiment 1. FIG. The perspective view which shows the transmission / reception apparatus which mounts the contact-type microphone of this Embodiment 1. FIG. The perspective view which shows the transmission / reception apparatus which mounts the contact-type microphone of this Embodiment 1. FIG. (A) Side sectional view of the contact type microphone in Embodiment 1 of the present invention, (b) Side sectional view of the contact type microphone in Embodiment 2 of the present invention. The figure which shows the method of evaluating S / N ratio of the contact-type microphone of this invention The side sectional view of the contact type microphone in Example 3 of the present invention, (a) the whole side sectional view, (b) the enlarged view of the tip of the vibration transmitting member Side sectional view of contact microphone in comparative example in comparison with embodiment 3 of the present invention (a) Side sectional view of a contact microphone in comparative example 1, (b) Side sectional view of a contact microphone in comparative example 2 Side sectional view of a contact type microphone in a comparative example having a comparative relationship with Example 3 of the present invention (a) Side sectional view of a contact type microphone in Comparative Example 3, (b) Side sectional view of a contact type microphone in Comparative Example 4 Sectional side view in the application example of the contact-type microphone using Example 3 of this invention Side sectional view of a contact-type microphone in Example 4 of the present invention, (a) overall side sectional view, (b) enlarged view of the tip of the vibration transmission member Side sectional view of a contact-type microphone in Comparative Example 5 that is in a comparative relationship with Example 4 of the present invention The exploded perspective view of the contact type microphone in Example 5 of the present invention The side sectional view of the contact type microphone in Example 5 of the present invention, (a) the whole side sectional view, (b) the enlarged view of the tip of the vibration transmitting member The figure which shows the example of the manufacturing method of the contact-type microphone in Example 5 of this invention. The figure which shows the example of the manufacturing method of the contact-type microphone in Example 5 of this invention. The figure which shows the example of the manufacturing method of the contact-type microphone in Example 5 of this invention. The figure which shows the example of the manufacturing method of the contact-type microphone in Example 5 of this invention. The figure which shows the example of the manufacturing method of the contact-type microphone in Example 5 of this invention. Side sectional view of a contact microphone according to a sixth embodiment of the present invention. The perspective view which shows the housing | casing of the transmission / reception apparatus which mounts the contact-type microphone of Embodiment 2 of this invention. Schematic diagram of a transmission / reception device equipped with the contact microphone according to the second embodiment The perspective view which shows the external appearance of the transmission / reception apparatus which mounts the contact-type microphone of this Embodiment 2. FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a perspective view showing a transmission / reception apparatus equipped with a contact microphone according to Embodiment 1 of the present invention. FIG. 2 is a side view of the transmitter / receiver mounted on the head. FIG. 3 is a diagram for explaining the arrangement of the contact microphones in the transmission / reception apparatus.

  This embodiment is an example in which the transmission / reception apparatus of the present invention is applied to headphones in which a speaker unit and a microphone are arranged close to each other.

  As shown in FIGS. 1 and 2, the headphone 100 is a sealed headphone worn on the head so as to cover the ear shell through a headband.

  The headphone 100 mainly includes a left ear covering headphone 110, a right ear covering headphone 120, and a curved headband 130 that connects the left ear covering headphone 110 and the right ear covering headphone 120 to the left and right.

  The headband 130 comes into contact with the heads on both sides via the top of the user's head.

  In the left ear covering headphone 110 and the right ear covering headphone 120, each member is arranged symmetrically in the head.

  The left ear covering headphone 110 is attached to a circular baffle plate 111 as an overall support substrate, an outer peripheral portion on the front surface side of the baffle plate 111, and is supported on an outer pad portion on the back side of the baffle plate 111 and an ear pad 112 covering the ear shell. And a housing 114 fixed through a ring 113. Although not shown, a speaker unit is fixed to the central portion on the back side of the baffle plate 111. The baffle plate 111 has a large number of holes as sound holes in the center.

  The ear pad 112 is formed in a ring shape large enough to surround the ear shell.

  The support ring 113 and the housing 114 cover the back side of the baffle plate 111 and the speaker unit (not shown).

  The housing 114 is larger than the ear shell, the ear pad 112 is in close contact with the temporal region around the ear shell, and the ear shell is completely covered by the ear pad 112 and the speaker unit. This sealed type has a good wearing feeling and can prevent sound leakage to the outside. In addition, bass can be reproduced richly.

  In the present embodiment, the headphone 100 is characterized in that a microphone can be disposed in the vicinity of the speaker unit.

  1 and 2, the left ear covering headphone 110 is characterized in that, in addition to the configuration of the above general sealed headphone, a contact microphone 1a is disposed in the vicinity of the speaker unit. As will be described later with reference to FIGS. 6 to 21, the contact microphone 1a is not the conventional contact microphone but the contact microphone 1a according to the first embodiment. Further, the transmission / reception apparatus of the present invention is characterized in that the contact microphone 1a according to the first embodiment is arranged as follows.

  In this embodiment, the contact microphone 1a is mounted on the left ear covering headphone 110, but may be mounted on the right ear covering headphone 120. It is sufficient that the contact microphone 1 a is disposed on one side of the headphones 100. However, it may be attached to both.

  As shown in FIGS. 1 and 2, the headphone 100 has a central part of a sealed headphone, that is, a central part of a circular baffle plate 111, and the baffle plate 111 is connected to the first reference axis in the longitudinal direction of the headband 130 and the first reference axis. Dividing into four parts by a second reference axis orthogonal to one reference axis, and among the parts divided into four parts, the part that is separated from the headband 130 and is in contact with the frontal side of the user from the receiving means The contact microphone 1a is disposed. That is, as shown in FIGS. 1 and 2, when the contact-type microphone 1a is represented by four regions I to IV, the lower part of the user's frontal region among the four divided regions I to IV. The contact type microphone 1a is arranged in the area III. Further, when the user wears the contact-type microphone 1a on the head in the four-divided portion (region III in FIGS. 1 and 2) that contacts the frontal side, the base of the user's chin or It is arranged at the position that best contacts the cheekbone (hereinafter referred to as the vicinity of the cheekbone) (see the circle in FIG. 3). According to the experiment of the present inventor and the like, when the contact microphone 1a is mounted on the headphones 100, it has been confirmed that the detection accuracy is improved when the contact microphone 1a is disposed near the cheekbone. However, the contact-type microphone 1a is not limited to the vicinity of the cheekbones, and may be disposed at a site (region III in FIGS. 1 and 2) that abuts on the frontal head divided into four parts. Further, since the contact microphone 1a has an excellent S / N ratio, the contact microphone 1a is disposed, for example, in a region (region IV in FIGS. 1 and 2) that is out of the region (region III in FIGS. 1 and 2). It is also possible.

  In this way, the contact microphone 1a is arranged at a position where the general user best contacts the vicinity of the user's cheekbone when the headphone 100 is normally used. In other words, the arrangement position in contact with the vicinity of the user's cheekbone is a region III below the user's forehead.

  FIG. 4 is a perspective view showing a transmission / reception apparatus equipped with the contact microphone according to the present embodiment. FIG. 4A is a perspective view as seen from the front diagonal of the user, and FIG. 4B is a perspective view as seen from the rear diagonal of the user.

  FIG. 4 shows an example in which the transmission / reception apparatus is applied to a single-ear type headphone. The same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description of overlapping portions is omitted.

  As shown in FIG. 4, the one-ear type headphone 100 </ b> A is a sealed headphone that is attached to the head so as to cover the ear shell through the one-ear type headband.

  The single-ear headphone 100A mainly includes a single-ear headphone main body 110A and a single-ear headband 130A for mounting the single-ear headphone main body 110A on the head.

  The one-ear type headband 130A comes into contact with the one-side head via the user's top of the head.

  The one-ear type headphone main body 110A includes a circular baffle plate (not shown) as a whole support substrate, an ear pad 112 attached to the outer peripheral portion on the front surface side of the baffle plate, and an outer peripheral portion on the back surface side of the baffle plate. And a housing 114 fixed via a support ring 113. Moreover, although illustration is abbreviate | omitted, the speaker unit is being fixed to the back side central part of the baffle board. Note that the shapes of the support ring 113 and the housing 114 are optimized for a single-ear type, and thus are slightly different from the support ring 113 and the housing 114 of the headphone 100 shown in FIGS.

  As shown in FIG. 4, the one-ear headphone main body 110A has a sealed headphone central portion, that is, a central portion of a circular baffle plate (not shown) as a center, and the baffle plate is the first in the longitudinal direction of the single-ear headband 130A. A reference axis and a second reference axis that is orthogonal to the first reference axis are divided into four parts. Of the four parts, the part far from the headband 130 and closer to the user's frontal side than the receiving means. The contact type microphone 1a is disposed at the contacted portion. That is, as shown in FIGS. 1 and 2, when the contact-type microphone 1a is represented by four regions I to IV, the lower part of the user's frontal region among the four divided regions I to IV. The contact type microphone 1a is arranged in the area III. When the user wears the contact microphone 1a on the head in a region (region III in FIG. 4) that abuts on the frontal side divided into four parts, the contact microphone 1a is near the user's cheekbone (see FIG. 3). It is arranged at the position where it makes the best contact (see mark).

  As described above, the contact microphone 1a is disposed at a position where the general user makes the best contact with the vicinity of the user's cheekbone when the one-ear type headphone 100A is normally used.

  FIG. 5 is a perspective view showing a transmission / reception apparatus equipped with the contact microphone according to the present embodiment.

  FIG. 5 shows an example in which the transmission / reception apparatus is applied to a neckband type headphone. The same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description of overlapping portions is omitted.

  As shown in FIG. 5, the neckband type headphone 100 </ b> B is a sealed headphone worn on the head so as to cover the ear shell via the neckband.

  The neckband type headphone 100B mainly includes a left ear covering headphone 110, a right ear covering headphone 120, and a neckband 130B for connecting the left ear covering headphone 110 and the right ear covering headphone 120 to the left and right.

  The neckband 130B circulates around the rear neck of the user, and brings the left ear covering headphones 110 and the right ear covering headphones 120 into contact with both heads.

  In the left ear covering headphone 110 and the right ear covering headphone 120, each member is arranged symmetrically in the head.

  The left ear covering headphone 110 is attached to a circular baffle plate 111 as an overall support substrate, a front side outer peripheral portion of the baffle plate, an ear pad 112 covering the ear shell, and a support ring on the rear side outer peripheral portion of the baffle plate. And a housing 114 fixed via 113. Moreover, although illustration is abbreviate | omitted, the speaker unit is being fixed to the back side central part of the baffle board. Since the shapes of the support ring 113 and the housing 114 are optimized for the neckband type, they are slightly different from the support ring 113 and the housing 114 of the headphones 100 of FIGS.

  As shown in FIG. 5, the left ear covering headphone 110 has a central part of the sealed headphone, that is, a center part of the circular baffle plate 111 as a center, and the baffle plate 111 and the third reference axis in the longitudinal direction of the neckband 130B. 3 parts are divided into four by a fourth reference axis orthogonal to the reference axis, and among the parts divided into four parts, the part that is separated from the neckband 130B and that is in contact with the opposite side of the user's head from the center. The contact microphone 1a is disposed. That is, as shown in FIG. 5, when the contact-type microphone 1 a is represented by regions I to IV, respectively, the region III below the user's frontal region among the four regions I to IV. The contact type microphone 1a is disposed on the side. When the user wears the contact microphone 1a on the head in a region (region III in FIG. 4) that abuts on the frontal side divided into four parts, the contact microphone 1a is near the user's cheekbone (see FIG. 3). It is arranged at the position where it makes the best contact (see mark).

  As described above, the contact microphone 1a is disposed at a position where the general user makes the best contact with the vicinity of the user's cheekbone when the neckband type headphone 100B is normally used.

  In addition, although the transmission / reception apparatus demonstrated by the example provided with the contact-type microphone 1a, you may apply the contact-type microphones 1b-1h and 1j-1m so that it may mention later.

  Hereinafter, the contact microphone mounted on the transmission / reception apparatus of the present invention will be described in detail.

  FIG. 6A is a side sectional view of the contact microphone. Here, a contact microphone having a sound collection contact member 12a made of SUS (thickness 200 μm) will be described first with reference to FIG.

  The sound collection contact member 12a is a member that is not included in the conventional contact microphone. In addition, the vibration transmission member 7a and the vibration damping member 8a described later have a slightly different configuration from the vibration transmission member and the vibration damping member of the conventional contact microphone. These are characteristic parts of the contact microphone of the present invention.

[Example 1]
In FIG. 6A, the microphone element 2 of the contact microphone 1a according to the first embodiment (which uses an electret condenser microphone in each embodiment, hereinafter abbreviated as “ECM”) is a sound collection target such as skin. When the body conduction sound 4 such as the voice of the speaker collected from 3 is transmitted to the vibration film 5 via the sound collection contact member 12a and the vibration transmission member 7a, the vibration of the vibration film 5 is converted into an electric signal. Then, it is transmitted to the outside through the lead wire 6.

  The cover member 9 is made of a metal such as aluminum or a plastic such as acrylic or ABS, like the conventional contact microphone, and maintains the mechanical strength of the entire contact microphone 1a, and also serves as a resin injection mold during manufacture. Plays.

  The vibration transmitting member 7a transmits the vibration of the body conduction sound 4 to the microphone element 2 without loss. For the vibration transmitting member 7a, for example, a plastic material such as silicone elastomer or urethane elastomer is used. One of them is in contact with the vibrating membrane 5 of the microphone element 2.

  However, the other side of the vibration transmitting member 7a is not in wide contact with the sound pickup object 3 as in the conventional contact microphone. The vibration transmission member 7a according to the first embodiment is in contact with the vicinity of the substantially central portion of the sound collection contact member 12a, which was not found in the conventional contact microphone. The sound collection contact member 12a is made of, for example, SUS304 having a thickness of 200 μm. In the contact microphone 1a according to the first embodiment, the contact portion between the vibration transmitting member 7a and the sound collection contact member 12a is provided at the approximate center of the sound collection contact member 12a. Of the contact area of the contact portion between the vibration transmitting member 7a and the sound collection contact member 12a, the contact area in the direction parallel to the surface where the sound collection contact member 12a contacts the sound collection object 3 is vibration. It is below the cross-sectional area in the parallel direction in the other part of the transmission member 7a. Furthermore, in the direction parallel to the surface where the sound collection contact member 12a contacts the sound collection object 3, the centers of the microphone element 2, the vibration transmission member 7a, and the sound collection contact member 12a are the sound collection contact. It can also be said that the member 12a is on substantially the same axis in the direction perpendicular to the surface in contact with the sound pickup object 3.

  With the above-described configuration, the contact microphone 1a according to the first embodiment can reflect and suppress the mixing of surrounding background noise due to the noise environment, and can efficiently collect only the vibration of the target sound pickup object. it can. As a result, noise resistance is further improved, and not only normal speech but also non-audible speech and sound such as speaker's murmur can be clearly and easily collected from the sound collection target such as skin. it can. The features and effects will be described in more detail later.

  The vibration damping member 8a prevents the air conduction sound 10 as background noise from entering from the back surface of the contact microphone 1a. For example, the whole of the microphone element 2 except the sound collection opening 11 is made of elastic epoxy resin. It is configured to cover. In addition, unlike the conventional contact microphone, the vibration damping member 8a of the first embodiment is also in contact with the sound collection contact member 12a and is disposed so as to surround the vibration transmission member 7a. The main body of the microphone element 2, the vibration transmitting member 7a, and the damping member 8a are sealed inside by the cover member 9 and the sound collection contact member 12a. The vibration transmitting member 7a is disposed so as to connect a substantially central portion of the sound collecting contact member 12a and a substantially central portion of the sound collecting opening 11 of the microphone element 2. In the case of the first embodiment, the substantially central portion of the sound collection opening 11 of the microphone element 2 is disposed directly below the substantially central portion of the sound collection contact member 12a, and the vibration transmission member 7a is connected so as to connect the shortest distance. Is provided. The vibration film 5 of the microphone element 2 is also basically formed of the same plastic material as that of the vibration transmission member.

  By the way, in order to pick up the body conduction sound 4 such as the skin with high sensitivity using the contact microphone 1a, it is necessary to suppress the reflection of vibration at the interface between the sound pickup object 3 and the vibration transmission member 7a. The reflectance of sound is represented by the Snell rule shown in the following (Formula 1).

r2 = (Z2−Z1) ² / (Z2 + Z1) ² (Formula 1)
Here, r2 is the reflectance at the interface between the two kinds of different substances 1 and 2, Z1: the acoustic impedance of the substance 1 (including the case of air), and Z2: the acoustic impedance of the substance 2.

  As can be seen from the above formula (1), if the acoustic impedances of the two substances in contact with each other are close to each other, the sound reflectance is close to 0 and the degree of attenuation is small. Conversely, if the acoustic impedances of two substances that are in contact with each other are separated, the sound reflectance increases and the degree of attenuation also increases. Therefore, if the acoustic impedance of the vibration transmission member 7a is made as close as that of the sound collection target 3 (skin), the reflection of the in-body conduction sound 4 at the boundary surface between the sound collection target 3 and the vibration transmission member 7a becomes small. The loss of the body conduction sound 4 is suppressed.

(Table 1) is a table showing acoustic impedance values of various materials. As shown in Table 1, it can be seen that the plastic material such as silicone elastomer and urethane elastomer constituting the vibration transmitting member 7 has a value close to the acoustic impedance of the soft tissue (skin). That is, the acoustic impedance of the plastic material is about 248 × 10 ⁴ (kg / m ² · s), and the acoustic impedance of the soft tissue (skin) is close to 135 × 10 ⁴ (kg / m ² · s). doing. Note that the vibrating membrane 5 of the microphone element 2 is also basically a plastic material, and is similar to the vibration transmitting member 7a in that respect.

  As a result, the contact microphone 1a improves the sensitivity of the in-body conduction sound 4 in the microphone element 2 and widens the sound collection band (particularly reduces attenuation in the high frequency range above 2 kHz). It is possible to pick up vibrations of living soft tissue (skin) with high sensitivity when speaking or inaudible muttering.

  The characteristics of the contact microphone 1a of the first embodiment having the above-described configuration will be described below.

As described above, the sound collection contact member 12a included in the contact microphone 1a according to the first embodiment is made of, for example, SUS304 having a thickness of 200 μm, that is, a metal member.
As shown in (Table 1), the acoustic impedance of the metal member is 4160 × 10 ⁴ kg / m ² · s, and the air conduction sound from the outside as well as the soft tissue such as skin assumed as the sound collection target 3 10 and the plastic member constituting the vibration transmitting member 7a.

  That is, in the contact microphone 1a of the first embodiment, such a member with significantly different acoustic impedance is arranged in the transmission path of the in-body conduction sound 4 from the sound collection target 3 to the vibration membrane 5 of the microphone element 2. Will be. In this case, according to the conventional common sense, reflection of the body conduction sound 4 becomes large at the boundary surface between the sound collection contact member 12a and the sound collection object 3 or the vibration transmission member 7a, and the vibration film 5 of the microphone element 2 is not reflected. Should be difficult to communicate.

  However, even if there is such a demerit, the attenuation rate of the external air conduction sound 10 that does not want to be collected as much as possible is greater than the attenuation of the body conduction sound 4 that is desired to be collected. That is, since the contact microphone 1a of the first embodiment has a higher S / N ratio than the conventional contact microphone, the body conduction sound 4 can be collected more efficiently.

  The reason is considered as follows. When the body conduction sound 4 is given to the sound collection contact member 12a of the first embodiment shown in FIG. 6A, the amplitude due to the physical vibration is the largest in the central portion of the sound collection contact member 12a. Become. The path from the central portion of the sound collection contact member 12a where the physical vibration due to the internal conduction sound 4 is the largest to the vibration film 5 of the microphone element 2 is the same as the vibration film 5 of the microphone element 2. A vibration transmission member 7a made of a plastic material is disposed. Thereby, the physical vibration by the body conduction sound 4 can be efficiently transmitted to the vibration film 5 of the microphone element 2.

  In addition, a damping member 8a is disposed around the vibration transmitting member 7a. This means that the air conduction sound 10 coming from outside the central portion of the sound collection contact member 12a is blocked by the vibration damping member 8a and hardly reaches the vibration film 5 of the microphone element 2. means. The main body of the microphone element 2, the vibration transmission member 7a, and the vibration damping member 8a are hermetically sealed by the cover member 9 and the sound collection contact member 12a, so that they are different from conventional contact microphones. There is no room for the air conduction sound 10 from the outside to enter. Therefore, in order for the air conduction sound 10 from the outside to reach the vibration film 5 of the microphone element 2, as a result, the vibration is far away from the periphery of the sound collection contact member 12a and has excellent sound transmission efficiency. The sound collecting contact member 12a with which the transmission member 7a is in contact must be turned to the central portion. During this wraparound, the attenuation of the air conduction sound 10 from the outside becomes larger.

  As described above, the contact-type microphone 1a according to the first embodiment shown in FIG. 6A is more likely to be picked up by the body conduction sound 4 that is originally intended to pick up sound, and external air conduction that does not want to pick up sound as much as possible. The sound 10 has a structure that makes it difficult to collect sound. Therefore, the S / N ratio of the body conduction sound 4 with respect to the external air conduction sound 10 is improved, and the body conduction sound 4 can be collected more efficiently.

  The following shows how much the performance of the contact microphone 1a according to the first embodiment actually improved compared to the conventional contact microphone. In order to judge whether the performance is good or bad, the S / N ratio and the intelligibility of the contact microphone in a noisy environment were evaluated.

  First, a method for evaluating the S / N ratio of the contact microphone according to the present invention including the first embodiment will be described below.

  FIG. 7 is a diagram illustrating a method for evaluating the S / N ratio of a contact microphone. Note that this S / N ratio evaluation method is commonly used for all contact microphones. First, an audio file (distributed by the Acoustical Society of Japan) recording a crowd at the exhibition hall is reproduced as background noise, that is, an external air conduction sound 10 by the reproduction device 13a in a semi-acoustic room, and a speaker is connected via an amplifier 13b. It flows from 13c. In this state, a contact microphone (the contact microphone 1a shown in FIG. 6A in the first embodiment) is worn around the throat at a position measured by the sound level meter as 100 dB. Then, the characters of the syllable 20-word syllables recommended by the Japan Audiological Society are pronounced and recorded every 2 seconds with normal utterances (about 90 dB). Based on the recorded waveform, the sound pressure ratio between the external air conduction sound 10 picked up by the contact microphone 1a and the utterance of the speaker, that is, the body conduction sound 4, is expressed in dB using the following equation (2). Convert to S / N ratio and evaluate.

S / N ratio (dB) = 20 log (S / N) (2)
Further, the recorded voice file of the single syllable 20-word syllable obtained at the time of the previous S / N ratio measurement is listened to by four arbitrary subjects, and the heard characters are recorded. Then, each correct answer rate is calculated to be a single syllable intelligibility, and the single syllable intelligibility is divided by 0.85 and evaluated as a sentence intelligibility. By the way, dividing the syllable intelligibility by 0.85 when calculating the sentence intelligibility is generally said to be "if the correct answer rate of single syllable intelligibility is 85%, the sentence intelligibility will be 100%". This is because.

  Details of such an evaluation method are also described in p117 of “New and Pollution Prevention Technology and Regulation 2009 Noise and Vibration Edition for Qualification Certification Courses such as Pollution Prevention Managers”. As a result of the evaluation by the above method, the S / N ratio of the contact microphone 1a in the first embodiment shown in FIG. 6A is 20 dB, and the sentence intelligibility under 100 dB noise is 75%. all right. On the other hand, the S / N ratio of the conventional contact microphone was 7 dB. From the above, it has been clarified that the S / N ratio of the contact microphone 1a in Example 1 shown in FIG. 6A is considerably improved.

  As described above, the contact microphone 1a of the first embodiment with improved performance can be produced by the following process, for example. First, in FIG. 6A, the damping member 8 a is filled in the cover member 9. At this time, a storage portion (not shown) for storing the microphone element 2 and the vibration transmission member 7a is formed in the vibration damping member 8a by, for example, a casting method of a two-component elastic epoxy resin. Next, a through-hole (not shown) that penetrates the damping member 8a and the cover member 9 is formed, and after the lead wire 6 of the microphone element 2 is passed through the through-hole, the storage portion in the damping member 8a The microphone element 2 is installed on the bottom surface. Thereafter, urethane elastomer is injected and potted into the sound collection opening 11 of the microphone element 2, and the vibration transmitting member 7a is formed by heating at 80 ° C. for 1 hour. At this time, the vibration transmitting member 7a has a hemispherical tip due to its surface tension. Then, the sound collecting contact member 12a, that is, a SUS lid having a thickness of 200 μm, is heat-cured at 80 ° C. for 1 hour by using the two-component elastic epoxy resin used for forming the vibration damping member 8a as an adhesive. When bonded and fixed by the above, the contact microphone 1a shown in FIG. 6A is completed.

In addition, as an elastic epoxy resin used as the damping member 8a in the first embodiment, for example, EP001 (commercial epoxy resin-based elastic adhesive) manufactured by Cemedine Co., Ltd. is mixed in an equal amount with a modified polyamine curing agent and heated to 80 ° C. A cured product is preferably used. Moreover, as a urethane elastomer used as the vibration transmission member 7a in the first embodiment, for example, a gel stock solution of polyurethane human skin manufactured by Exeal Corporation, Inc. (C-15 main ingredient and curing agent are mixed at 3: 1). , Cured at 80 ° C.) is preferably used. Further, the sound collection contact member 12a and the cover member 9 are made of iron, stainless steel, aluminum or the like having a material whose acoustic impedance value is far from the air (415 kg / m ² · s) for transmitting the body air conduction sound 4. In addition to metal (4160 × 10 ⁴ kg / m ² · s), ceramics such as glass (1122 × 10 ⁴ kg / m ² · s) may be used. Furthermore, the exposed surface of the sound collection contact member 12a, that is, the contact surface with the sound collection target such as human skin, the side surface thereof, or the like may be coated with a coating member such as resin. This is particularly effective when the sound collection contact member 12a is made of metal. When metal touches human skin directly, it may feel cold depending on the temperature, or sweat may adhere to the sound collecting contact member, which may cause rust. The coating member is effective in avoiding such problems.

  As described above, when the contact microphone according to the first embodiment is used, the noise resistance is further improved, and normal voices and non-audible muttering voices can be clearly and easily picked up in a noisy environment.

  Hereinafter, the contact-type microphone according to the first embodiment will be described in comparison with the conventional contact-type microphone.

  Conventional contact microphones are assumed to be used in as quiet a noise-free environment as possible. For example, the present invention is applied to a vibration pickup detector that constantly monitors a patient's body conduction sound such as a pulse and a heart sound. The conventional contact microphone attempts to increase S (signal component) in an environment where the S / N ratio N (noise) is as small as possible. Conventional contact microphones are not supposed to be used in a noisy environment. In a noisy environment, for example, a contact microphone close to the speaker unit such as a headphone, or a contact microphone arranged close to the speaker unit in a narrow housing can be used. According to the present inventor, it has been found that the conventional contact type microphone has N (noise) too large under the above-mentioned noise environment, and is not at a practical level.

  On the other hand, the contact microphone 1a according to the first embodiment includes a sound collection contact member 12a disposed so as to cover the sound collection opening 11 of the cover member, and the sound collection contact member 12a includes the sound collection opening. A configuration is adopted in which the sound collection contact member 12a and the diaphragm 5 are opposed to each other via the portion 11. The place where the sound collection contact member 12a faces is the center of the sound collection contact node member 12a. Furthermore, the sound collection contact member 12a uses a material with a far different acoustic impedance Z, thereby improving the S / N ratio, more specifically, reducing N (noise).

  As described above, the contact microphone 1a according to the first embodiment is intended to improve the S / N ratio by reducing N (noise) by the sound collection contact member 12a.

  In the contact microphone 1a according to the first embodiment, the sound collection contact member 12a is disposed so as to cover the sound collection opening 11 of the cover member. For this reason, there was a concern about a decrease in signal components to be detected. However, according to the experiments of the present inventors, it has been found that the sound collection contact member 12a covers the sound collection opening 11, but the signal component reduction is at a level that does not cause a problem in mounting. It is considered that the sound collecting contact member 12a is arranged in the center facing the vibration film 5 and that the material of the sound collecting contact member 12a is greatly different from the acoustic impedance Z. The thickness of the sound collection contact member 12a is also optimized.

  With the above-described configuration, the contact microphone 1a according to the first embodiment can reflect and suppress the mixing of surrounding background noise due to the noise environment, and can efficiently collect only the vibration of the target sound pickup object. it can. As a result, noise resistance is further improved, and not only normal speech but also non-audible speech and sound such as speaker's murmur can be clearly and easily collected from the sound collection target such as skin. it can. It can be mounted on a transmission / reception device in which a microphone can be arranged close to a speaker unit such as a headphone.

[Example 2]
FIG. 6B is a side sectional view of the contact microphone according to the second embodiment of the present invention. Since the configuration of the contact microphone 1b according to the second embodiment has many parts in common with the contact microphone 1a according to the first embodiment described above, description thereof will be omitted. The difference from the first embodiment is a sound collection contact member 12b and a vibration damping member 8b. The contact microphone 1b according to the second embodiment will be described with reference to these points.

  The microphone element 2 of the contact type microphone 1b of the second embodiment shown in FIG. 6B is configured so that the body conduction sound 4 such as the voice of the speaker collected from the sound collection target 3 such as the skin is a sound collection contact member. When transmitted to the diaphragm 5 through the vibration transmission member 12 a and the vibration transmission member 7 a, the vibration of the diaphragm 5 is converted into an electric signal and transmitted to the outside through the conductor 6. Also in the contact microphone 1b according to the second embodiment, the contact portion between the vibration transmitting member 7a and the sound collecting contact member 12b is provided substantially at the center of the sound collecting contact member 12b as in the first embodiment. Yes. Of the contact area of the contact portion between the vibration transmitting member 7a and the sound collection contact member 12b, the contact area in the direction parallel to the surface where the sound collection contact member 12b contacts the sound collection object 3 is vibration. It is below the cross-sectional area in the parallel direction in the other part of the transmission member 7a. Furthermore, in the direction parallel to the surface where the sound collection contact member 12b is in contact with the sound collection object 3, the centers of the microphone element 2, the vibration transmission member 7a, and the sound collection contact member 12b are the sound collection contact. It can also be said that the member 12b is on substantially the same axis in the direction perpendicular to the surface in contact with the sound collection object 3.

  With the above configuration, the contact microphone 1b according to the second embodiment reflects and suppresses the background noise from being mixed due to the noise environment, and can efficiently collect only the vibration of the target sound collecting object. it can. As a result, noise resistance is further improved, and not only normal speech but also non-audible speech and sound such as speaker's murmur can be clearly and easily collected from the sound collection target such as skin. it can.

  The sound collecting contact member 12b of the second embodiment has a cap-shaped contact member made of aluminum metal with a thickness of 1.5 mm, and is fitted and bonded by a nested structure with the cover member 9. The damping member 8b uses an elastic epoxy resin composite material in which silica powder surface-modified with phenylaminosilane (SC6202-SXC manufactured by Admatechs) is dispersed by 50% by weight. Thus, by including an inorganic material filler such as silica, the elastic modulus is increased, and the adhesion with the cover member 9 and the metal part of the microphone element 2 is increased. Further, since the included microphone element 2 is firmly fixed, loss of transmission vibration due to the movement of not only the diaphragm 5 of the microphone element 2 but the entire microphone element 2 is prevented.

  In addition, since the acoustic impedance of the damping member 8b is closer to the acoustic impedance of the metal part of the cover member 9 and the microphone element 2, reflection at the interface between these metal parts and the damping member 8b is suppressed. This is effective in absorption loss of vibration due to the elastic epoxy resin component in the damping member 8b. This will be described in detail in the comparison between Example 4 and Comparative Example 5 described later.

  As the inorganic material filler dispersed in the vibration damping member 8b, those having a particle size of submicron to 100 microns are preferably used. This is because the sub-micron size is generally poorly dispersible and agglomerates and hinders distribution control, and the one below 100 micron is easily dispersed and segregated due to poor dispersibility. This is to lower the target strength.

  In addition to the silica described above, alumina, zirconia, silica, calcium carbonate, kaolin, clay, colloidal silica, titania and the like can be used as the inorganic material filler dispersed in the damping member 8b. These may be used alone or in combination of two or more selected from the above.

  Next, regarding the content of the inorganic material filler dispersed in the vibration damping member 8b, when it is 75% or more, handling by the manufacturing process becomes difficult due to an increase in viscosity, and at the same time, there are frequent problems with the two-component epoxy resin. It has been found that if the content is 5% or less, the vibration control effect is not recognized. Accordingly, the content of the inorganic material filler dispersed in the vibration damping member 8b is preferably in the range of 5 to 75%.

  Further, the metal material employed as the sound collection contact members 12a and 12b in the contact microphones 1a and 1b of the first and second embodiments is SUS or aluminum for the following reason.

  In general, the acoustic impedance Z is determined by the density ρ and the sound speed c in the material as shown in (Expression 3), and the sound speed c in the material is determined by the density ρ and the bulk modulus k as shown in (Expression 4). It is determined.

Z = ρ · c (Formula 3)
c = √ (k / ρ) (Formula 4)
Therefore, from (Equation 3) and (Equation 4), the relationship between the acoustic impedance Z, the density ρ, and the bulk modulus k is derived as follows.

  Z = √ (ρ · k) (Formula 5)

Here, referring to the sound speed c of various metals shown in (Table 2), it can be seen that the sound speed c of iron-based, aluminum-based, and titanium-based metals is relatively larger than other metals. As is clear from (Expression 3), the acoustic impedance Z is proportional to the sound speed c. The acoustic impedance of iron-based, aluminum-based, titanium-based metal, etc. is preferably used because it has a relatively larger value than other metals.

  As described above, when the contact microphone according to the second embodiment is used, noise resistance is further improved, and normal voices and non-audible murmuring voices can be easily picked up clearly in a noisy environment.

[Example 3]
FIG. 8 is a side sectional view of the contact microphone according to the third embodiment of the present invention. FIG. 8A is an overall sectional side view of the contact microphone 1c according to the third embodiment, and FIG. 8B is an enlarged view of the distal end portion of the vibration transmitting member 7a. Since the configuration of the contact microphone 1c of the third embodiment has many parts in common with the above-described first or second embodiment, description thereof will be omitted as much as possible and mainly described above. The difference from the first embodiment will be described below.

  First, also in the contact type microphone 1c of the third embodiment, as in the first and second embodiments, the contact portion between the vibration transmitting member 7a and the sound collection contact member 12b is substantially the center of the sound collection contact member 12b. Is provided. Of the contact area of the contact portion between the vibration transmitting member 7a and the sound collection contact member 12b, the contact area in the direction parallel to the surface where the sound collection contact member 12b contacts the sound collection object 3 is vibration. It is below the cross-sectional area in the parallel direction in the other part of the transmission member 7a. Furthermore, in the direction parallel to the surface where the sound collection contact member 12b is in contact with the sound collection object 3, the centers of the microphone element 2, the vibration transmission member 7a, and the sound collection contact member 12b are the sound collection contact. It can also be said that the member 12b is on substantially the same axis in the direction perpendicular to the surface in contact with the sound collection object 3.

  With the above-described configuration, the contact microphone 1c according to the third embodiment reflects and suppresses background noise from being mixed due to the noise environment, and can efficiently collect only the vibration of the target sound pickup object. it can. As a result, noise resistance is further improved, and not only normal speech but also non-audible speech and sound such as speaker's murmur can be clearly and easily collected from the sound collection target such as skin. it can.

  The damping member 8b is a composite material of an elastic epoxy resin and silica, and the sound collection contact member 12b has a cap shape made of aluminum and having a thickness of 1.5 mm. These points are the same as those of the second embodiment described above. However, the sound collection contact member 12b in the second embodiment is directly fitted and bonded by the nesting structure with the cover member 9, whereas the contact microphone 1c in the third embodiment is the following. It has the following structure.

  That is, first, a metal washer 22 is disposed inside the vibration damping member 8 b so as to surround the microphone element 2. Next, the sound collection contact member 12b and the cover member 9 are fitted and bonded by a nested structure with a plastic or metal upper and lower connection tube 23, respectively. Therefore, the sound collection contact member 12 b and the cover member 9 are indirectly joined via the upper and lower connection tube 23.

  Furthermore, a so-called acoustic fiber 19 is disposed between the microphone element 2 inside the vibration damping member 8b and the sound collection contact member 12b. In the acoustic fiber 19, the vibration transmitting member 7a used also in the first and second embodiments is arranged inside an aluminum cylinder 19a. That is, the acoustic fiber 19 is configured by storing the vibration transmitting member 7a in the cylinder 19a, and the cross section of the cylinder 19a is the back of the contact surface with the sound collection target 3 of the sound collection contact member 12b and the microphone element 2. Opposite to the sound collection opening 11, the side surface of the cylinder 19a is in contact with the damping member 8b. The acoustic fiber 19 prevents the vibration of the body conduction sound 4 transmitted from the sound collection contact member 12b to the vibration transmission member 7a from diffusing to a portion other than the vibration film 5 of the microphone element 2. As a result, the in-body conduction sound 4 from the sound collection contact member 12b is efficiently transmitted to the diaphragm of the microphone element 2 with less loss and efficiency. The acoustic fiber 19 also has a role of preventing the vibration of the air conduction sound 10 transmitted as so-called noise from ambient air from being transmitted to the vibration film 5 of the microphone element 2. .

  Such an indirect joint structure with the washer 22 arranged around the microphone element 2 and the upper and lower connecting tube 23 is provided at the approximate center of the cover member 9 and the sound collection contact member 12b. This is for arranging the microphone element 2 and the acoustic fiber 19. This is particularly effective in the process for producing the contact microphone 1c of the third embodiment described later.

  Next, an enlarged view of a contact portion between the vibration transmission member and the sound collection contact member shown in FIG. The vibration transmitting member 7a generally has a hemispherical shape due to the surface tension of the urethane elastomer precursor before curing, and is in contact with the sound collecting contact member 12b through an arbitrary contact area. In general, the transmitted vibrational energy (sound pressure) is proportional to the contact area. If this contact area is too large, it is transmitted by the excitation force from the air around the contact microphone via the gap 18 slightly present on the contact surface with the sound pickup object 3 (skin) or the surrounding air. A part of the air conduction sound 10 is collected together with the body conduction sound 4 that is originally desired to be collected. As a result, the S / N ratio of the body conduction sound 4 to the air conduction sound 10 becomes a low value. Therefore, the inner diameter of the acoustic fiber 19 is preferably in the range of 0.5 to 5 times the diameter of the sound collection opening 11 of the microphone element 2.

  Such a contact-type microphone 1c according to the third embodiment can be manufactured by the following process, for example.

  In FIG. 8 shown above, first, the main component and the curing agent of urethane elastomer (for example, a gel stock solution of polyurethane human skin (C-15) manufactured by EXCIAL Corporation) are added through the sound collection opening 11 of the microphone element 2. 1), and a part of the vibration transmitting member 7a is formed by heating at 80 ° C. for 1 hour.

  Next, the upper and lower connection tube 23 is arranged inside the cover member 9, the lead wire 6 of the microphone element 2 is passed through the cover member 9, and the microphone element 2 is installed at a substantially central portion of the cover member 9. In that state, a two-component elastic epoxy resin containing, for example, 50 wt% of silica, which is a precursor before the vibration damping member 8 b is cured, is filled up to the height of the microphone element 2. Then, an aluminum (metal) washer 22 having a hole corresponding to the diameter of the microphone element 2 is placed on the epoxy resin that is a precursor before the damping member 8b is cured. At this time, the washer 22 is installed so that the microphone element 2 is disposed substantially at the center inside the through hole of the washer 22. At this time, if the outer diameter of the washer 22 is set slightly smaller than the inner diameter of the upper and lower connecting tube 23, the microphone element 2 can be easily installed at the approximate center of the cover member 9. In this state, the resin is cured by heating at 80 ° C. for 1 hour, and a part of the vibration damping member 8b is formed.

  Further, a cylinder 19 a is disposed on the sound collection opening 11 of the microphone element 2. At this time, the center of the cylinder 19a is set to substantially match the center of the sound collection opening 11. The aforementioned urethane elastomer is injected into the hollow of the cylinder 19a and heated at 80 ° C. for 1 hour. In this manner, the urethane elastomer previously injected from the sound collection opening 11 of the microphone element 2 and the urethane elastomer injected into the cylinder 19a are integrated to form the vibration transmitting member 7a. An acoustic fiber 19 is formed by the vibration transmitting member 7a and the cylinder 19a. Note that the vibration transmitting member 7 a forms a convex hemispherical or semi-elliptical spherical meniscus at the distal end portion of the acoustic fiber 19 by its surface tension.

  Thereafter, the remaining space of the cover member 9 and the upper and lower connecting tube 23 is additionally filled with an appropriate amount of epoxy resin, which is a precursor before the damping member 8b is cured, and is made of aluminum having a thickness of 1.5 mm. When the cup-shaped sound collection contact member 12b is covered and cured at 80 ° C. for 1 hour, the contact microphone 1c of Example 3 is completed.

  Since the sound collection contact member 12b and the cover member 9 of the contact microphone 1c thus completed are substantially concentric cylinders, their centers substantially coincide. The microphone element 2 is disposed substantially at the center of the cover member 9 by the washer 22 described above. Therefore, it can be said that the center of the microphone element 2 and that of the sound collection contact member 12b substantially coincide.

  As described above, the washer 22 helps to arrange the microphone element 2 at substantially the center of the sound collection contact member 12b, and the effect is the same as described in the first embodiment. That is, when the body conduction sound 4 is given to the sound collection contact member 12b, the amplitude due to the physical vibration becomes the largest in the central portion of the sound collection contact member 12b. The path from the central portion of the sound collection contact member 12b where the physical vibration caused by the internal conduction sound 4 is the largest to the vibration film 5 of the microphone element 2 is the same as the vibration film 5 of the microphone element 2. A vibration transmission member 7a made of a plastic material is disposed. Thereby, the physical vibration by the body conduction sound 4 can be efficiently transmitted to the vibration film 5 of the microphone element 2.

  Further, a vibration damping member 8b is disposed around the vibration transmission member 7a. This means that the air conduction sound 10 coming from outside the central portion of the sound collection contact member 12b is blocked by the vibration damping member 8b and hardly reaches the vibration film 5 of the microphone element 2. To do.

  Further, in the case of the third embodiment, the cylinder 19a around the acoustic fiber 19 causes the vibration of the in-body conduction sound 4 transmitted from the sound collection contact member 12b to the vibration transmission member 7a. It is prevented from spreading to other parts. Thereby, the in-body conduction sound 4 from the sound collection contact member 12b is efficiently transmitted to the diaphragm of the microphone element 2 with little loss. The acoustic fiber 19 also has a role of preventing the vibration of the air conduction sound 10 transmitted as so-called noise from ambient air from being transmitted to the vibration film 5 of the microphone element 2. .

  Incidentally, the upper and lower connecting tube 23 helps the acoustic fiber 19 not to fall when the vibration damping member 8b is additionally filled, and prevents the vibration damping member 8b from spilling outside and between the sound collecting contact member 12b. It plays a role of storing an appropriate amount of the damping member 8b so that no space is created in the space.

  The result of evaluating the contact type microphone 1c thus produced by the single syllable 20-word table used in the first embodiment is as follows. That is, the S / N ratio of the contact microphone 1c in the third embodiment is 17 dB, and the S / N ratio in a noise environment is improved as compared with the S / N ratio 7 dB of the conventional contact microphone. It became clear. About the following points, the importance is described in detail by the comparative example shown later. First, the first point is that the contact portion between the vibration transmitting member 7a and the sound collection contact member 12b is substantially at the center of the sound collection contact member 12b. The second point is that the vibration transmitting member 7a inside the acoustic fiber 19, that is, the inner diameter of the acoustic fiber 19, is at least 0.5 to 5 times the diameter of the sound collection opening 11 of the microphone element 2. It is preferable. The third point is that no space is provided between the damping member 8b and the sound collecting contact member 12b, and the damping member 8b is in contact with the sound collecting contact member 12b, the upper and lower connecting tubes 23, and the cover member 9. Is fully filled.

  As described above, when the contact microphone according to the third embodiment is used, noise resistance is further improved, and normal voices and non-audible muttering voices can be clearly and easily picked up in a noisy environment.

[Comparative Example 1]
FIG. 9A is a side cross-sectional view of the contact-type microphone in the comparative example 1 that is in a comparative relationship with the third embodiment of the present invention.

  Although the configuration and the manufacturing method of the contact microphone 1d in the first comparative example are many in common with the contact microphone 1c in the third embodiment described above, they are different in the following points. One is that the vibration transmitting member 7a is also applied and cured on the entire back side of the sound collecting contact member 12b. As a result, the contact area between the vibration transmitting member 7a and the sound collecting contact member 12b is the microphone element 2. It is outside the range of 0.5 to 5 times the diameter of the sound collection opening 11. The other is that a cavity 21 is formed between the sound collection contact member 12b applied and cured on the entire back side of the sound collection contact member 12b and the vibration damping member 8b.

  The S / N ratio of the contact microphone 1d in Comparative Example 1 is 10 dB, and the S / N ratio under a noise environment is not so improved as compared with the S / N ratio of 7 dB of the conventional contact microphone. Became clear. This is because when the vibration transmitting member 7a is applied and cured on the entire back side of the sound collecting contact member 12b, the air conduction sound 10, which is external ambient noise, is transmitted from the periphery of the sound collecting contact member 12b. This is considered to be because the signal is easily transmitted to the microphone element 2 through the member 7a.

  As can be seen from the first comparative example, the vibration transmitting member 7a is accommodated in the inner diameter of the acoustic fiber 19, and is brought into contact with the sound collecting contact member 12b so as not to be excessively large and in contact with the substantially central portion thereof. is necessary. The contact area is preferably at least 0.5 to 5 times the diameter of the sound collection opening 11 of the microphone element 2.

[Comparative Example 2]
FIG. 9B is a side cross-sectional view of the contact-type microphone in Comparative Example 2 that is in contrast with Example 3 of the present invention.

  The configuration and method of making the contact-type microphone 1e in Comparative Example 2 are different in the following points, although there are many parts in common with the contact-type microphone 1c in Example 3 described above. One is that the damping member 8b is applied and cured on the entire back side of the sound collecting contact member 12b, and the vibration transmitting member 7a is not in contact with the sound collecting contact member 12b. The other is that a cavity 21 is formed in the vicinity of the sound collection contact member 12b inside the vibration damping member 8b.

  The S / N ratio of the contact microphone 1e in the comparative example 2 is 5 dB, and the S / N ratio under the noise environment is further deteriorated as compared with the S / N ratio 7 dB of the conventional contact microphone. Became clear. This is because the vibration transmission member 7a is not in contact with the substantially central portion of the sound collection contact member 12b, so that not only the air conduction sound 10 which is noise around the outside, but also the internal conduction sound 4 which is originally desired to be collected. It is thought that absorption loss was caused by the vibration damping member 8b in front.

  As can be seen from Comparative Example 2, the vibration transmitting member 7a needs to be in contact with the sound collecting contact member 12b. The contact is preferably at the approximate center of the sound collection contact member 12b.

[Comparative Example 3]
FIG. 10A is a side cross-sectional view of a contact-type microphone in Comparative Example 3 that is in contrast with Example 3 of the present invention.

  The configuration and method of making the contact microphone 1f in Comparative Example 3 are different in the following points, although there are many parts in common with the contact microphone 1c in Example 3 described above. That is, although the vibration transmitting member 7a is in contact with the sound collecting contact member 12b, a cavity 21 is formed between the vibration damping member 8b and the sound collecting contact member 12b.

  The S / N ratio of the contact microphone 1f in Comparative Example 3 is 12 dB, and the S / N ratio in a noise environment is slightly better than the S / N ratio of 7 dB of the conventional contact microphone. It became clear that it was not as much as Example 3. This is because after the air conduction sound 10 that is noise around the outside has entered the inside of the vibration damping member 8b, reflection is repeated at the interface between the vibration damping member 8b and the air in the cavity 21 generated therein. As a result, it is considered that the signal was transmitted from the acoustic fiber 19 to the microphone element 2. That is, the absorption loss of the air conduction sound 10 by the damping member 8b is inhibited by the cavity 21 generated inside the damping member 8b.

  As can be seen from Comparative Example 3, the cavity 21 is not provided between the vibration damping member 8b and the sound collecting contact member 12b, and the vibration suppressing member 8b has the sound collecting contact member 12b, the upper and lower connecting tubes 23, and the cover. It is necessary to be in full contact with the member 9.

[Comparative Example 4]
FIG. 10B is a side cross-sectional view of the contact-type microphone in Comparative Example 4 that is in contrast with Example 3 of the present invention.

  The configuration and the manufacturing method of the contact microphone 1g in the comparative example 4 are different in the following points, although there are many parts in common with the contact microphone 1c in the third embodiment described above. That is, the contact portion between the vibration transmitting member 7a and the sound collection contact member 12b in the acoustic fiber 19 does not coincide with the approximate center of the cover member 9 and the sound collection contact member 12b. In the comparative example 4, each of the centers of the microphone element 2 and the acoustic fiber 19 is disposed at a substantially intermediate point of a straight line (radius) connecting the center of the sound collection contact member 12b and the circumference.

  The S / N ratio of the contact microphone 1f in Comparative Example 3 is 9 dB, and the S / N ratio in a noise environment is slightly better than the S / N ratio of 7 dB of the conventional contact microphone. It became clear that it was not as much as Example 3. One is that the distance from the contact portion of the vibration transmitting member 7a with the sound collection contact member 12b to one peripheral portion of the sound collection contact member 12b is short, and the air conduction sound 10 which is external ambient noise is generated by the microphone. This is because it is easily transmitted to the element 2. The other is that in the approximate center of the sound collection contact member 12b inside the acoustic fiber 19, the physical vibration of the body conduction sound 4 given to the sound collection contact member 12b is the largest, but this Comparative Example 4 This is because the contact portion between the vibration transmitting member 7a and the sound collecting contact member 12b is not disposed there.

  As can be seen from Comparative Example 4, it is necessary that the microphone element 2 and the acoustic fiber 19 (that is, the center of the vibration transmission member 7a) be arranged at the approximate center of the sound collection contact member 12b.

  As clarified by the above comparative example, the contact portion between the vibration transmitting member 7a and the sound collection contact member 12b needs to be substantially at the center of the sound collection contact member 12b. Moreover, it is preferable that the vibration transmission member 7 a inside the acoustic fiber 19, that is, the inner diameter of the acoustic fiber 19, is at least within a range of 0.5 to 5 times the diameter of the sound collection opening 11 of the microphone element 2. . And, there is no space between the vibration damping member 8b and the sound collection contact member 12b, and the vibration suppression member 8b is in full contact with the sound collection contact member 12b, the upper and lower connecting tubes 23 and the cover member 9. It is necessary to be.

[Modification of Example 3]
As is clear from the previous Example 3 and Comparative Example 4, the contact portion between the vibration transmitting member 7a and the sound collection contact member 12b inside the acoustic fiber 19 is substantially the center of the sound collection contact member 12b. It is necessary to be in However, it is not necessary to arrange the center of the acoustic fiber 19 and the center of the microphone element 2 so as to substantially coincide with the center of the sound collection contact member 12b. An example is described below.

  FIG. 11 is a side sectional view of an application example of a contact microphone using an acoustic fiber according to the third embodiment of the present invention. The acoustic fiber 19b of the contact microphone 1k shown in FIG. 11 confines the vibration transmitted to the sound collection contact member 12c to the microphone element 2 by repeating the reflection by the inner wall of the foldable cylinder 19c. It has a function to communicate. For this reason, as shown in FIG. 11, when a curved free-form cylinder 19c is used, the center of the microphone element 2 can be arranged other than directly below the center of the sound collection contact member 12c. At this time, if the center of the portion where the vibration transmission member 7a disposed inside the acoustic fiber 19b is in contact with the sound collection contact member 12c is substantially coincident with the center of the sound collection contact member 12c. Good. This is because the physical vibration of the body conduction sound 4 applied to the center of the sound collection contact member 12c is the largest. In this way, the degree of freedom in design can be increased with respect to the shape of the contact microphone 1k.

[Example 4]
FIG. 12 is a side sectional view of a contact microphone according to Embodiment 4 of the present invention. FIG. 12A is an overall side sectional view of the contact microphone 1j, and FIG. 12B is an enlarged view of the tip of the vibration transmitting member 7a. Since the configuration of the contact microphone 1j according to the fourth embodiment has many parts in common with the third embodiment described above, description thereof will be omitted as much as possible, and mainly the third embodiment described above. Different parts will be described below. Although the washer 22 arranged in the third embodiment is omitted in the fourth embodiment, the washer 22 may of course be arranged similarly to the third embodiment.

  First, also in the contact microphone 1j of the fourth embodiment, the contact portion between the vibration transmitting member 7a and the sound collecting contact member 12b is substantially the center of the sound collecting contact member 12b as in the first to third embodiments. Is provided. Of the contact area of the contact portion between the vibration transmitting member 7a and the sound collection contact member 12b, the contact area in the direction parallel to the surface where the sound collection contact member 12b contacts the sound collection object 3 is vibration. It is below the cross-sectional area in the parallel direction in the other part of the transmission member 7a. Furthermore, in the direction parallel to the surface where the sound collection contact member 12b is in contact with the sound collection object 3, the centers of the microphone element 2, the vibration transmission member 7a, and the sound collection contact member 12b are the sound collection contact. It can also be said that the member 12b is on substantially the same axis in the direction perpendicular to the surface in contact with the sound collection object 3. In addition, the acoustic fiber 19 is configured by storing the vibration transmitting member 7a in the cylinder 19a. The cross section of the cylinder 19a is the back of the contact surface of the sound collection contact member 12b with the sound collection target 3 and the microphone element. The side surface of the cylinder 19a is in contact with the vibration damping member 8b. With the above configuration, the contact microphone 1j according to the fourth embodiment reflects and suppresses the background noise from being mixed due to the noise environment, and can efficiently collect only the vibration of the target sound collecting object. it can. As a result, noise resistance is further improved, and not only normal speech but also non-audible speech and sound such as speaker's murmur can be clearly and easily collected from the sound collection target such as skin. it can.

  In the contact-type microphone 1j of the fourth embodiment, a characteristic part that does not exist in the third embodiment is that the acoustic fiber 19 is included in the vibration transmitting member 7a at the tip portion where the acoustic fiber 19 contacts the sound collection contact member 12b. This is a bonded plastic ball 20. That is, a member having a hardness higher than that of the vibration transmission member 7a is provided on the contact surface side of the vibration transmission member 7a with the sound collection contact member 12b. As this plastic ball | bowl 20, the thing made from Sato Iron Works, for example is used. In addition, any of urethane rubber, polyacetal, polyamide 66, Teflon (registered trademark), ABS, styrene, acrylic, silicon resin, and the like may be used. In the fourth embodiment, urethane rubber (with a hardness of 80 °) is used from the viewpoint of reliability (lubricity and reliability) that the adhesive force is good with the urethane elastomer employed as the vibration transmitting member 7a and is used by repeatedly vibrating. And a hardness of 95 °) are preferably used as the plastic sphere 20. This urethane rubber has a higher hardness than the vibration transmission member 7a.

  Further, as such a plastic sphere 20, those having a diameter of 2 mmφ, 3/32 inch, 1/8 inch, 5/32 inch or the like corresponding to the diameter of the opening of the vibration film 5 of the microphone element 2 are generally used. It is done.

  Such a plastic ball 20 having a hardness higher than that of the vibration transmission member 7a is encapsulated and bonded to the vibration transmission member 7a at the tip portion where the acoustic fiber 19 contacts the sound collection contact member 12b, thereby collecting the sound. Point contact with the substantially central portion of the contact member 12b is possible. As a result, the vibration transmitted from the sound collection target 3 (skin etc.) to the entire sound collection contact member 12b is concentrated at one point. At the same time, air conduction sound (noise) 10 transmitted from the peripheral portion of the sound collection contact member 12b through the air in the gap 18 with the sound collection target 3 generated when the contact type microphone 1j is attached. However, it becomes easy to be cut. That is, for the air conduction sound 10, the distance to the center of the sound collection contact member 12 b to which it is transmitted as solid vibration (point contact) is farther than the body conduction sound 4 that is originally desired to collect sound. . Then, on the way to the central portion (point contact) of the sound collection contact member 12b, the vibration damping member 8b located in the lower layer of the sound collection contact member 12b absorbs a part of the air conduction sound 10. Therefore, the effect of improving the S / N ratio is increased.

  The results of evaluating the contact microphone 1j thus produced using the single syllable 20-word table as in the first embodiment are as follows. That is, the S / N ratio of the contact microphone in the fourth embodiment is 28 dB, and the S / N ratio under a noise environment is greatly improved as compared with the S / N ratio of 7 dB of the conventional contact microphone. It became clear that Compared with the previous Example 3, the S / N ratio is further improved.

  The sentence intelligibility under 100 dB noise using the contact microphone 1j in Example 4 was 85%.

  As described above, when the contact microphone according to the fourth embodiment is used, noise resistance is further improved, and normal voices and non-audible murmuring voices can be easily picked up clearly in a noisy environment.

[Comparative Example 5]
FIG. 13 is a side cross-sectional view of a contact type microphone in Comparative Example 5 that is in a comparative relationship with Example 4 of the present invention.

  The configuration and the manufacturing method of the contact microphone 1h in the comparative example 5 are different in the following points, although there are many parts in common with the contact microphone 1j in the fourth embodiment described above. That is, in place of the vibration damping member 8b (two-component elastic epoxy resin containing 50 wt% of silica) in the previous Example 4, the vibration damping member constituted by the elastic epoxy resin alone used in the previous Example 1 8a.

  The S / N ratio of the contact microphone 1d in this comparative example 1 is 20 dB, which is comparable to the previous examples 1 and 2, but the performance difference is more than doubled when compared with the example 4. I found out. This is due to the difference in the material of the vibration damping member employed. This difference in material results in a loss coefficient that is reflected in the denominator term indicating noise in the S / N ratio equation shown in Equation 5 above.

  In addition, the elastic epoxy resin is combined with silica to increase the elastic modulus and weight, and the resonance frequency changes in a direction in which the resonance frequency greatly deviates from the vibration film 5 of the microphone element 2. As a result, the vibration of the microphone element 2 itself is reduced by the solid vibration from the sound collection target object 3, and the rate at which the solid vibration from the sound collection target object 3 is converted into the vibration of the vibration film 5 is relatively increased. This plays a role in increasing the numerator term indicating the signal to be collected in the S / N ratio equation shown in (Equation 5).

  From the above, as the vibration damping member to be employed, the vibration damping member 8b made of the composite material of the elastic epoxy resin and silica employed in Example 4 is higher in sound collection than the elastic epoxy resin employed in Comparative Example 5. It turns out that performance can be obtained.

[Example 5]
FIG. 14 is an exploded perspective view of the contact microphone according to the fifth embodiment, and FIG. 15 is a side sectional view of the contact microphone according to the fifth embodiment. FIG. 15A is an overall side sectional view of the contact microphone 1k according to the fifth embodiment, and FIG. 15B is an enlarged view of the distal end portion of the vibration transmitting member 7b. The configuration of the contact microphone 1k according to the fifth embodiment has many parts in common with the above-described second embodiment. Therefore, the description thereof is omitted as much as possible, and mainly the second embodiment described above. Different parts will be described below.

  First, also in the contact type microphone 1k of the fifth embodiment, the contact portion between the vibration transmitting member 7b and the sound collecting contact member 12d is substantially the center of the sound collecting contact member 12d, as in the first to fourth embodiments. Is provided. Of the contact area of the contact portion between the vibration transmitting member 7b and the sound collection contact member 12d, the contact area in the direction parallel to the surface where the sound collection contact member 12d contacts the sound collection object 3 is vibration. It is below the cross-sectional area in the parallel direction in the other part of the transmission member 7b. Furthermore, in the direction parallel to the surface where the sound collection contact member 12d is in contact with the sound collection object 3, the centers of the microphone element 2, the vibration transmission member 7b, and the sound collection contact member 12d are the sound collection contact. It can also be said that the member 12d is on substantially the same axis in the direction perpendicular to the surface in contact with the sound pickup object 3. In addition, the acoustic fiber 19d is configured by storing the vibration transmitting member 7b in the cylinder 19e, and the cross section of the cylinder 19e is the back surface of the contact surface of the sound collection contact member 12d with the sound collection target 3 and the microphone element. 2, the side surface of the cylinder 19e is in contact with the vibration damping member 8b.

  With the configuration described above, the contact microphone 1k according to the fifth embodiment can reflect and suppress the background noise in the surroundings due to the noise environment, and can efficiently collect only the vibration of the target sound collecting object. it can. As a result, noise resistance is further improved, and not only normal speech but also non-audible speech and sound such as speaker's murmur can be clearly and easily collected from the sound collection target such as skin. it can.

  The washer 22 arranged in the fifth embodiment is not arranged in the previous second embodiment. However, as described above, the washer 22 is arranged at substantially the center of the sound collection contact member 12d. This is not a big difference. Of course, the washer 22 may also be arranged in the fifth embodiment.

  Also, the acoustic fiber 19d of the fifth embodiment is not arranged in the previous second embodiment, and is similar to that which appeared in the previous third and fourth embodiments. The acoustic fiber 19d according to the fifth embodiment is one in which a cavity 19e is filled with a vibration transmitting member 7b (described later), and the length and the composition of the inner vibration transmitting member 7b are the same as those of the third embodiment. This is different from that of Example 4. However, it has a function to prevent the vibration of the body conduction sound 4 transmitted from the sound collection contact member 12d to the vibration transmission member 7b from diffusing to parts other than the vibration film 5 of the microphone element 2. The function is the same as in the third and fourth embodiments. Further, the vibration of the air conduction sound 10 transmitted from the surrounding air to the vibration damping member 8 b as so-called noise is also prevented from being transmitted to the vibration film 5 of the microphone element 2. In that respect, the acoustic fiber 19d of the fifth embodiment has the same function as that shown in the third and fourth embodiments.

  The damping member 8b of the fifth embodiment is a composite material of an elastic epoxy resin (not shown) and silica 27, and the sound collection contact member 12d has a cap shape made of aluminum and having a thickness of 1.5 mm. These points are the same as those in the second embodiment. However, the reverse taper-shaped perforation 24 does not penetrate through the sound collection contact member 12d at the approximate center of the back surface of the sound collection contact member 12d of Example 5 that contacts the vibration damping member 8b and the vibration transmission member 7b. (In the case of Example 5, a 6.6 mmφ drill was used to form the perforations 24 so that the hole diameter was 5 mm). That is, among the portions where the sound collection contact member 12d has a contact surface with the sound collection target 3, the thickness at the center is thinner than the periphery. And the vibration transmission member 7b is inject | poured into the reverse taper-shaped perforation 24. FIG.

  The diameter of the perforations 24 controls the distance from the outer periphery of the contact microphone 1k that is considered to transmit the air conduction sound 10 and also controls the area that receives the vertical vibration caused by the body conduction sound 4. The depth of the perforations 24 naturally determines the remaining thickness (for example, 0.5 mm) of the sound collection contact member 12d, and affects the followability of the sound collection target 3 to solid vibration. By adopting such a structure, the solid vibration from the sound collection target 3 (skin etc.) is reduced in the approximate center of the sound collection contact member 12d where the thickness is reduced by an area corresponding to the hole diameter of the perforations 24. Enables highly sensitive sound collection. At the same time, the air conduction sound 10 (noise) is transmitted from the peripheral portion of the sound collection contact member 12d through the ambient air or the air in the gap 18 with the sound collection target 3 generated when the contact type microphone 1k is attached. Even if it is done, since the distance to the substantially central portion of the sound collecting contact member 12d, which is transmitted as solid vibration, is far, it is effective in improving the S / N ratio.

  In addition, as the vibration transmission member 7b employed in the fifth embodiment, an inorganic filler (silica 27 in the fifth embodiment) is combined with the urethane elastomer used in the first to third embodiments to obtain a volume elasticity. What inclined the rate was used. For example, the slope of the volume modulus of elasticity is obtained by using a natural sedimentation method based on the difference in specific gravity of these components before curing, so that a large amount of inorganic filler (silica 27) exists on the sound collection contact member 12d side, and the microphone element 2 This is possible if there is a small amount on the vibrating membrane 5 side. In this way, the volume elastic modulus of the vibration transmitting member 7b is set to the sound collection contact member 12d or the vibration on each of the contact surface with the sound collection contact member 12d and the contact surface with the vibration film 5 of the microphone element 2. It can be close to the membrane 5. In this way, acoustic impedance matching is achieved at each contact surface, and the reflection attenuation of vibration due to the body conduction sound 4 is reduced.

  Such a contact microphone 1k according to the fifth embodiment can be manufactured by the following process, for example. 16-20 is a figure which shows the example of the preparation methods of the contact-type microphone 1k in Example 5 of this invention.

  First, as shown in FIG. 16A, a hole 24 (a hole that does not pass through) is formed in the center of the back side of the sound collection contact member 12d by a lathe drill 26 or the like. Next, as shown in FIG. 16 (b), the metal cylinder 19e is bonded to the central portion on the back side of the sound collecting contact member 12d using the damping member 8b, and cured at 80 ° C. for 1 hour. At this time, the metal cylinder 19e is arranged so that the end cross section of the metal cylinder 19e surrounds the outline of the perforation 24. And as shown in FIG.16 (c), the vibration transmission member 7b which compounded the inorganic filler in the urethane elastomer is inject | poured inside the cavity of the cylinder 19e. This vibration transmission member 7b in which an inorganic filler is combined with a urethane elastomer is preliminarily applied to, for example, a urethane elastomer (for example, a main ingredient and a curing agent of a gel stock solution of polyurethane human skin (C-15) manufactured by Exeal Corporation). A silica filler (particle diameter: several tens to several hundreds μ) surface-treated with γ-aminopropyltrialkoxysilane or glycidoxypropyltrialkoxysilane was dispersed at 20 wt%.

  Further, as shown in FIG. 17 (a), the vibration transmitting member 7b is allowed to stand at room temperature for 5 hours and then cured at 80 ° C. for 1 hour. By such a leaving treatment, as shown in FIG. 17B, the filler (silica 27) contained in the vibration transmitting member 7b naturally settles due to the difference in specific gravity with the urethane elastomer. An acoustic fiber 19d is formed in which a large amount of silica filler is present on the sound collection contact member 12d side and a small amount is present on the vibration film 5 side of the microphone element 2. In other words, the volume elastic modulus of the vibration transmitting member 7b is inclined, and the volume elastic modulus of the vibration transmitting member 7b is set on each of the contact surface with the sound collection contact member 12d and the contact surface with the vibration film 5 of the microphone element 2. The sound collecting contact member 12d or the vibrating membrane 5 can be used. In this way, acoustic impedance matching is achieved at each contact surface, and the reflection attenuation of vibration due to the body conduction sound 4 is reduced. Thereafter, as shown in FIG. 17C, the vibration damping member 8b before curing is filled in the peripheral portion of the acoustic fiber 19d.

  On the other hand, as shown in FIG. 18A, the microphone element 2 connected to the conductive wire 6 is disposed at a substantially central portion of the cover member 9. At this time, the lead wire 6 of the microphone element 2 is passed through a through hole (not shown) provided in the cover member 9 and is taken out of the cover member 9.

  Next, in this state, a two-component elastic epoxy resin containing, for example, 50 wt% of silica, which is a precursor before the vibration damping member 8 b is cured, is filled up to the height of the microphone element 2. Then, as shown in FIG. 18 (b), a washer 22 having a hole corresponding to the diameter of the microphone element 2 is placed on the epoxy resin that is a precursor before the damping member 8 b is cured. At this time, the washer 22 is installed so that the microphone element 2 is disposed substantially at the center inside the through hole of the washer 22. In this state, the resin is cured by heating at 80 ° C. for 1 hour, and a part of the vibration damping member 8b is formed.

  Further, as shown in FIG. 18 (c), the main component and curing agent of urethane elastomer (for example, a gel stock solution of polyurethane human skin (C-15) manufactured by EXCIAL Corporation) from the sound collection opening 11 of the microphone element 2. 7c) is injected and heated and cured at 80 ° C. for 1 hour. This urethane elastomer 7c is equivalent to the one in which the inorganic filler is not combined in the process of producing the vibration transmitting member 7b.

  As shown in FIG. 19, the sound collecting contact member 12d (see FIGS. 16 and 17) and the cover member 9 (see FIG. 18), which have finished the respective operations as described above, are fitted together. At this time, as shown in FIG. 20A, the surplus of the epoxy resin that is the precursor before the vibration damping member 8b is cured is discharged from the discharge hole 25 provided in the sound collecting contact member 12d in advance. . By doing so, a necessary and sufficient damping member 8b is filled without causing a cavity in the damping member 8b or the like. After that, as shown in FIG. 20B, when the weight 31 of about 400 g is placed and heated and cured at 80 ° C. for 1 hour, the contact microphone 1k according to the fifth embodiment is completed.

  At this time, the urethane elastomer 7c filled on the vibrating membrane 5 side inside the microphone element 2 is originally the same as that in which the inorganic filler is not combined in the process of manufacturing the previous vibration transmitting member 7b. Therefore, the urethane elastomer 7c is integrated with the vibration transmission member 7b filled in the cylinder 19e of the acoustic fiber 19d. As a result, the integrated one is also the vibration transmission member 7b. Then, an acoustic fiber 19d is formed in which a large amount of silica filler is present on the sound collection contact member 12d side and hardly exists on the vibration film 5 side of the microphone element 2. In other words, the volume elastic modulus of the vibration transmitting member 7b is inclined, and the volume elastic modulus of the vibration transmitting member 7b is set on each of the contact surface with the sound collection contact member 12d and the contact surface with the vibration film 5 of the microphone element 2. The sound collecting contact member 12d or the vibrating membrane 5 can be used. In this way, acoustic impedance matching is achieved at each contact surface, and the reflection attenuation of vibration due to the body conduction sound 4 is reduced.

  The results of evaluating the contact microphone 1k thus produced using the single syllable 20-word table as in Example 1 are as follows. That is, the S / N ratio of the contact type microphone 1c in the third embodiment is 28.5 dB, and the S / N ratio under the noise environment is significantly larger than the S / N ratio of 7 dB of the conventional contact type microphone. It became clear that it was improving. Further, a part of the vibration transmitting member 7b is structured so as to enter the substantially central portion of the sound collecting contact member 12d, which contributes to a reduction in the height and size of the contact microphone 1k itself.

  As described above, when the contact microphone according to the fifth embodiment is used, the noise resistance is further improved, and normal voices and non-audible muttering voices can be easily picked up clearly in a noisy environment.

[Example 6]
FIG. 21 is a side sectional view of a contact microphone according to Embodiment 6 of the present invention. FIG. 21A is an overall side cross-sectional view of the contact microphone 1m according to the sixth embodiment, and FIG. 21B is a perspective view of the contact microphone 1m according to the sixth embodiment as viewed from above. Since the configuration of the contact microphone 1c of the third embodiment has many parts in common with the above-described first or second embodiment, description thereof will be omitted as much as possible and mainly described above. The difference from the first embodiment will be described below.

  First, also in the contact type microphone 1m of the sixth embodiment, the sound collection contact in the contact area of the contact portion between the vibration transmitting member 7a and the sound collection contact member 12b is the same as in the first to fourth embodiments. The contact area in the direction parallel to the surface where the member 12b contacts the sound collection object 3 is equal to or less than the cross-sectional area in the parallel direction at the other part of the vibration transmitting member 7a. In addition, the acoustic fiber 19 is configured by storing the vibration transmitting member 7a in the cylinder 19a. The cross section of the cylinder 19a is the back of the contact surface of the sound collection contact member 12b with the sound collection target 3 and the microphone element. 2, the side surface of the cylinder 19e is in contact with the vibration damping member 8b. With the above configuration, the contact microphone 1m according to the sixth embodiment reflects and suppresses surrounding background noise due to the noise environment, and can efficiently collect only the vibration of the target sound collecting object. it can. As a result, noise resistance is further improved, and not only normal speech but also non-audible speech and sound such as speaker's murmur can be clearly and easily collected from the sound collection target such as skin. it can.

  The contact microphone 1m shown in the sixth embodiment has a plurality of pairs of the acoustic fiber 19 (may be 19b or 19d) having the vibration transmission member 7a (may be 7b or 7e) and the microphone element 2 described above. doing. By increasing these pairs, the S / N ratio is improved. That is, it leads to enlargement of the molecular term of (Formula 5).

  Note that the central axes of the microphone element 2 and the vibration transmitting member 7a are on substantially the same axis in the direction perpendicular to the surface where the sound collection contact member 12b contacts the sound collection object 3, and are described above. It is desirable that the virtual barycentric point obtained from each center of the plurality of combinations substantially coincides with the center of the sound collection contact member 12b. Incidentally, when the number of the microphone elements 2 increases, the wiring of the conducting wire 6 that they have is hindered. For example, at least two microphone elements 2 may be electrically connected in series.

  The result of evaluation of the contact microphone 1m thus produced using the single syllable 20-word table as in the first embodiment is as follows. The S / N ratio of the contact microphone 1c in Example 3 is 25 dB, and the S / N ratio in a noise environment is also improved as compared with the S / N ratio of 7 dB of the conventional contact microphone. Became clear. That is, increasing the number of microphone elements 2 contributes to improving the S / N ratio of the contact microphone.

  As described above, when the contact microphone according to the sixth embodiment is used, noise resistance is further improved, and normal voices and non-audible murmuring voices can be easily picked up clearly in a noisy environment.

  In addition, the Example of this invention is not restricted to said Example 1- Example 6, What combined these each part can also be considered.

  In this way, the contact microphone with improved noise resistance clearly shows the voice of the speaker and inaudible murmurs in the noise environment such as outdoors or construction sites without mixing background noise. It becomes possible to collect. Also, by applying it to normal voice calls, voice input, voice recognition, and voiceless telephones, voice input without errors to portable information terminals, etc. Realization is possible. Furthermore, the contact microphone according to the present invention can be incorporated into a chin strap of a working or construction helmet, an ear cover for cold protection, or the like. Furthermore, for the purpose of privacy protection, it can also be used as a sensor that detects only the vibration of the vibration detection object without collecting surrounding speech. For example, it is a water flow detection sensor for general household use. In addition, the present invention can be applied to the security field such as detecting a pedestrian's walking pattern by embedding it in the floor and specifying an intruder.

  As described above in detail, according to the present embodiment, the present invention is applied to the headphone 100 (see FIGS. 1 and 2) as a transmission / reception device on which the contact microphones 1a to 1h and 1j to 1m are mounted. The headphone 100 includes contact microphones 1a to 1h and 1j to 1m close to the speaker unit. Specifically, the contact microphones 1a to 1h and 1j to 1m are divided into four parts by a first reference axis in the longitudinal direction of the headband 130 and a second reference axis orthogonal to the first reference axis, and the four parts are divided. Among these, the headband 130 is disposed on the side farther from the headband 130 and in contact with the frontal side of the user than the receiving means. The same applies to the single-ear headphones 100A (see FIG. 4). Further, the neckband type headphone 100B (see FIG. 5) includes contact-type microphones 1a to 1h and 1j to 1m that are orthogonal to the third reference axis and the third reference axis in the longitudinal direction of the neckband 130B. And is arranged in a part of the four parts that are separated from the neckband 130B and in contact with the opposite side of the user's head from the earpiece means.

  As a result, the sound wave from the receiving means is output to the same side as the temporal contact portion in any of the transmission / reception devices of the headphone 100, the one-ear type headphone 100A, and the neckband type headphone 100B. Since the sound waves from the receiving means directly enter the ear, they can be heard as usual, and with the above-mentioned transmitting means, the sound waves picked up from the receiving means are smaller than the user's utterance, so that the other party does not cause howling. A clear and stress-free conversation can be realized.

  As described above, in the present embodiment, the contact microphones 1a to 1h and 1j to 1m having extremely excellent noise resistance are used in the transmission / reception device, thereby realizing a headphone in which the speaker unit and the microphone are arranged close to each other. can do.

(Embodiment 2)
In the first embodiment, the transmission / reception apparatus according to the present invention is applied to headphones, and the contact microphones 1a to 1h and 1j to 1m are mounted on the headphones.

  Embodiment 2 describes an example applied to a mobile terminal device other than headphones.

  FIG. 22 is a perspective view showing a housing of a transmission / reception device on which the contact microphone according to Embodiment 2 of the present invention is mounted.

  As shown in FIG. 22, the mobile terminal device 200 is a bar-type mobile phone. The mobile terminal device 200 may be applied to a high-function communication terminal such as a smart phone, a PDA (Personal Digital Assistants), and a mobile game machine having a transmission / reception function.

  The mobile terminal device 200 includes a housing 201, a battery storage unit 202 formed on the back surface of the housing 201, and a back cover 203 that stores the battery in the battery storage unit 202. The housing 201 and the back cover 203 become an integrated exterior when the back cover 203 is attached.

  The mobile terminal device 200 includes a communication unit 204, a speaker (not shown), a camera 205, and contact microphones 1a to 1h and 1j to 1m in a housing 201.

  The contact-type microphones 1a to 1h and 1j to 1m can be any of the cases 201 as long as the sound collection contact members 12a, 12b, 12c, and 12d (not shown) are in contact with any place of the case 201. May be arranged. That is, it is only necessary to satisfy the condition in which the sound collection contact members 12a, 12b, 12c, and 12d are in contact with the housing 201. For example, in FIG. 22, it is the battery accommodating part side of the housing | casing 201 shown to FIG. 22 (A), or the upper part side of the housing | casing 201 shown to FIG. 22 (B), and all are sound collection contact members 12a, 12b, 12c. , 12d are in contact with the inner surface of the housing 201.

  Note that the contact microphones 1a to 1h and 1j to 1m may be arranged at the position of the mouth when used in the hand. Further, the contact microphones 1a to 1h and 1j to 1m are preferably arranged on the same plane as the speaker so as to correspond to the hands-free call, but are not limited to this arrangement.

  Since the communication means 204 is an example in which the mobile terminal device 200 is applied to a mobile phone, the communication means 204 shows the communication function of the mobile phone body, but the mobile terminal device 200 is a smart phone, PDA, notebook PC, portable game machine. In this case, this part becomes a main body function part of these portable devices.

  The communication means 204 is a wireless communication device that performs carrier communication with a base station via an antenna 204a. The communication means 204 includes a wireless local area network (WLAN), Bluetooth (registered trademark), and UWB (Ultra Wideband) based on the IEEE802.11x standard as wireless communication devices connectable to a network other than the carrier.

  The speaker includes a loudspeaker arrangement for hands-free calling and is not limited to receiver applications used against the ear.

  The camera 205 is an imaging unit made up of, for example, a CCD (Charge Coupled Devices).

  As shown in FIG. 22, the casing 201 of the mobile terminal device 200 is narrow, and the speakers and the contact microphones 1 a to 1 h and 1 j to 1 m have to be arranged close to each other. Moreover, the portable terminal device 200 must be assumed to be used in a noisy environment. For this reason, conventionally, there has been no example of mounting a contact microphone on a mobile terminal device such as a mobile phone.

  According to the present embodiment, the contact type microphones 1a to 1h and 1j to 1m that have noise resistance and can clearly collect only normal voices and non-audible murmuring voices are provided in the mobile terminal device 200. Since it can be mounted, it is possible to realize clear and stress-free conversation with the other party, which has been difficult to realize in the past without causing howling.

  FIG. 23 is a schematic diagram of a transmission / reception apparatus equipped with the contact microphone according to the second embodiment. FIG. 23A is a front view thereof, and FIG. 23B is a cross-sectional view taken along the line AA in FIG. The same components as those in FIG. 22 are denoted by the same reference numerals, and description of overlapping portions is omitted.

  As shown in FIG. 23, in the folding portable terminal device 200A (transmission / reception device), an upper housing 201A and a lower housing 201B are rotatably connected by a hinge 201C.

  The upper housing 201A includes a communication unit 204, a speaker (not shown), a camera 205, and a display 207. The lower housing 201B includes a keyboard 206 and contact microphones 1a to 1h and 1j to 1m.

  The contact microphones 1a to 1h and 1j to 1m are arranged such that sound collecting contact members 12a, 12b, 12c, and 12d (not shown) are in contact with an arbitrary place of the lower housing 201C. The sound collection contact members 12a, 12b, 12c, and 12d may be disposed anywhere as long as they are in contact with the upper casing 201A or the lower casing 201B.

  The keyboard 206 includes numeric keys, cross keys, and various function keys.

  The display 207 is a large display that covers the surface of the housing 201A. The display 207 is configured by an LCD display, an organic EL (Organic Electro-Luminescence) display, or the like, and displays the content of received information, content, and the like.

  FIG. 24 is a perspective view showing an external appearance of a transmission / reception device equipped with the contact microphone according to the second embodiment. FIG. 24A is a view in which the slide is closed, and FIG. 24B is a view in which the slide is opened. The same components as those in FIGS. 22 and 23 are denoted by the same reference numerals, and description of overlapping portions is omitted.

  As shown in FIG. 24, the sliding mobile terminal device 200B (transmission / reception device) includes an upper housing 201D and a lower housing 201E. The upper housing 201D includes a camera 205, a display 207, and a speaker 208. The lower casing 201E includes a communication unit 204, a keyboard 206, and contact microphones 1a to 1h and 1j to 1m.

The contact microphones 1a to 1h and 1j to 1m are arranged such that sound collection contact members 12a, 12b, 12c, and 12d (not shown) are in contact with an arbitrary place of the lower housing 201E (here, the back surface of the keyboard 206). The The sound collection contact members 12a, 12b, 12c, and 12d are arranged on the upper casing 201D.
Alternatively, it may be disposed anywhere as long as it is in contact with the lower housing 201E.

  As shown in FIGS. 23 and 24, the casings of the foldable portable terminal device 200A and the sliding portable terminal device 200B are both narrow, and the speakers and the contact microphones 1a to 1h and 1j to 1m are: Must be placed close together. Further, like the mobile terminal device 200 of FIG. 22, it must be assumed that the mobile terminal device 200 is used in a noisy environment.

  Also in the foldable portable terminal device 200A and the sliding portable terminal device 200B shown in FIGS. 23 and 24, the contact microphones 1a to 1h and 1j to 1m are folded as in the portable terminal device 200 of FIG. It can be mounted on a tatami mat / slide portable terminal device.

  The above description is an illustration of a preferred embodiment of the present invention, and the scope of the present invention is not limited to this.

  In each of the above embodiments, the example in which the transmission / reception device is used for a headphone or a portable terminal device has been described. However, any device may be used as long as the device has a transmission / reception function.

  In the above embodiments, the names of the transmission / reception device and the contact microphone are used. However, this is for convenience of explanation, and the transmission / reception device may be a communication device, and the contact microphone may be a microphone device.

  Furthermore, each part which comprises the said transmission / reception apparatus and a contact-type microphone, for example, the communication means of a transmission / reception apparatus, the kind and shape of a sound collection contact member of a contact-type microphone, an attachment method, etc. are not restricted to embodiment mentioned above.

  The transmission / reception device of the present invention can be applied to a transmission / reception device such as a headphone or a portable wireless device in which a contact microphone is disposed in the vicinity of the speaker unit, and can also be applied to various electronic devices other than portable devices as the transmission / reception device. Is also possible.

1a to 1h, 1j to 1m Contact type microphone 2 Microphone element 3 Sound collecting object (skin, etc.)
4 Body conduction sound 5 Vibration membrane 6 Conductor 7a, 7b Vibration transmitting member 7c Urethane elastomer 8a, 8b Damping member 9 Cover member 10 Air conduction sound 11 Sound collection opening 12a, 12b, 12c, 12d Sound collection contact member 18 Crevice 19, 19b, 19d Acoustic fiber (conduit)
19a, 19c, 19e Cylinder 20 Plastic sphere 21 Cavity 22 Washer 23 Vertical connection tube 24 Perforation (recess)
25 Discharge hole 26 Lathe drill 27 Silica 100 Headphone (Transceiver)
100A single ear headphones (transceiver)
100B Neckband type headphones (transceiver)
110 Left ear covering headphone 120 Right ear covering headphone 130 Headband 130A One ear type headband 130B Neckband 200, 200A, 200B Portable terminal device (transmission / reception device)
204 Communication means

Claims (8)

A case, and a transmission means and a reception means attached to the case,
The housing includes a temporal contact portion that contacts at least the user's temporal region,
The transmission means is
A condenser microphone element having a vibrating membrane;
A vibration transmitting member to the vibrating membrane;
A cover member having an opening and storing the microphone element and the vibration transmitting member;
A sound collection contact member including a metal or ceramics disposed to cover the opening of the cover member,
The vibration transmission member is disposed at a substantially center of the sound collection contact member,
The vibration transmitting member is a transmission / reception device in contact with a vibration film of the microphone element and the sound collection contact member. A vibration control member for storing the vibration transmission member;
The transmission / reception apparatus according to claim 1, wherein the vibration damping member is filled between the cover member and the sound collection contact member or the vibration transmission member.   The transmission / reception apparatus according to claim 1, wherein the transmission means is further arranged at a position where vibration applied to the temporal contact portion of the housing is transmitted directly or indirectly to the sound collection contact member.   The transmission / reception device according to claim 1, wherein the temporal contact portion and the sound collection contact member are the same. A headband that comes into contact with the heads on both sides via the top of the user's head is further attached to the housing,
A first reference axis passing in the longitudinal direction of the headband and passing through the center of the receiving means;
Of the four parts divided by the second reference axis that is orthogonal to the first reference axis and passes through the center of the receiving means,
The transmission / reception apparatus according to claim 1, wherein the transmission / reception apparatus is disposed on a side farther from the headband and in contact with the frontal side of the user than the earpiece. The case is further fitted with neckbands that come into contact with both heads via the user's back head,
A third reference axis in the longitudinal direction of the neckband and passing through the center of the receiving means;
Of the four parts divided by the fourth reference axis orthogonal to the third reference axis and passing through the center of the receiving means,
The transmission / reception apparatus according to claim 1, wherein the transmission / reception apparatus is disposed on a side away from the neckband and in a position in contact with the opposite side of the user's top from the earpiece. A communication means,
The transmission / reception apparatus according to claim 1, wherein the communication unit transmits and receives a sound wave generated by the transmission unit and the reception unit wirelessly or by wire.   The transmission / reception apparatus according to claim 1, wherein the sound collection contact member is in contact with the housing.