JP2002262377A - Bone conduction pickup element and its unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bone conduction pickup element and its unit that can enhance the articulation and the S/N, improve the mount performance and recognize voice excellently. SOLUTION: The bone conduction pickup 10 is inserted to an external auditory meatus of an ear of a user. Then contacts 26, 36 come into contact with an inner wall of the external auditory meatus 40. When the contacts 26, 36 are respectively vibrated on the basis of bone conduction sound, metallic plates 22, 33 are vibrated resulting in causing piezoelectric elements 24, 34 to be bent. An electric signal corresponding to the bent is induced in the piezoelectric elements 24, 34 and outputted externally through lead wires 28, 38. Applying differential calculation to outputs of two pickup elements 20, 30 can reduce the effect of an external noise.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bone conduction (bone conduction) pickup element and a unit thereof.

[0002]

2. Description of the Related Art As a well-known method of recognizing a voice emitted from a human, there are a method of recognizing a voice transmitted in the air and a method of recognizing a voice transmitted in a human body (particularly, a skeleton). is there. Among these, the former recognition method based on air conduction has the advantage of high clarity, but has the disadvantage of being easily affected by ambient noise. On the other hand, the latter bone conduction recognition method has the following disadvantages: (1) low intelligibility due to low high-frequency components important for consonant expression;
(2) The frequency characteristics of the bone-conducted voice are low and high and low in the high frequency range, resulting in poor sound quality. (4) The clarity greatly changes depending on individual differences in the ear canal and the manner of mounting the pickup, (5) It is easy to collect abnormal sounds such as friction of the code (signal line),
(6) There are inconveniences such as easy pick-up of motor noise and (7) poor efficiency and S / N ratio. However, there are advantages such as (1) it can be used even under high noise, and it is suitable for voice communication and voice input under noise, and (2) it is possible to talk hands-free.

[0003] Recently, a speech recognition system has become widespread as a user-friendly interface in the field of computer systems and home electric appliances, and it has been demanded to provide hands-free speech recognition technology. Specifically, there are voice dialing, hands-free voice input, voice input navigation, voice input game, voice input word processor, voice interaction system, voice dictation, voice translation, and the like.

However, in the conventional speech recognition method using air conduction, the recognition rate is extremely reduced when the influence of background noise is large. That is, a relatively high recognition rate can be obtained for a sound emitted at a position close to the microphone. However, as the distance to the microphone increases, the effect of the reflected sound and the effect of the decrease in sound pressure increase, and the recognition rate decreases significantly due to the effects of reverberation and noise. OA equipment and the like will often be used in a noisy environment such as an office, and a navigation device is used in a noise in a car. Further, in the case of a mobile phone or the like, the call environment, that is, the sound transfer characteristic changes as the speaker moves.

[0005] Speech recognition based on bone conduction has attracted attention as a technique capable of satisfactorily recognizing speech even in such various noise environments. Conventional pickups for bone-conducted speech recognition are disclosed in JP-A-58-80997 and JP-A-58-8.
8996; 58-94298;
Various types have been proposed, for example, Nos. 4, 63-45105. Among them, earplug type (ear insertion type) that is inserted into the external auditory canal of a human body has an advantage that it is superior in wearability as compared with a type that is mounted on the surface of a human body.

[0006]

However, the conventional earplug type bone conduction pickup has the following disadvantages. (1) It is easy to fall off. (2) The sensitivity level depends on the size and shape of the external auditory canal and individual differences and the manner of mounting the pickup. (3) The wearing feeling is poor.
Further, since the bone conduction voice vibration of the pickup case itself is picked up, the ambient noise leads to the vibration of the case, and as a result, there is also a disadvantage that it is easily affected by the ambient noise.

On the other hand, for example, bone-conducted speech in the ear canal has a property that the speech spectrum varies depending on the pickup point. In particular, the transmission characteristics from the temporomandibular joint and the head are quite different. From this point of view, there is a possibility that the bone-conducted voice can be satisfactorily recognized by taking into account the detection site of the human body, that is, the pickup point of the bone-conducted voice.

The present invention focuses on these points.
It is an object of the present invention to provide a bone conduction pickup element and a unit thereof capable of improving clarity and S / N ratio, improving wearability, and satisfactorily recognizing voice.

[0009]

In order to achieve the above object, a bone conduction pickup element according to the present invention comprises: a diaphragm having one end fixed; an electroacoustic transducer provided on the diaphragm; A contact that is provided at an end and comes into contact with a detection site of the human body; the contact has an adjustment function of reducing a difference in the gap between the free end of the diaphragm and the detection site of the human body. It is characterized by having.

A bone conduction pickup unit according to the present invention comprises: a diaphragm having one end fixed; an electroacoustic transducer provided on the diaphragm; and a free end provided on the diaphragm and in contact with a detection part of a human body. A plurality of bone-conduction pickup elements, each including a contact that contacts each other, are provided in the case. The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.

[0011]

<Embodiment 1> An embodiment of the present invention will be described in detail below. First, FIGS.
Embodiment 1 will be described with reference to FIG. Figure 1
1 shows a bone conduction pickup according to a first embodiment, in which (A) is a main sectional view and (B) is a side view. FIG. 2 shows a state in which the bone conduction pickup of FIG. 1 is attached to an external auditory canal of a human body. In these drawings, the bone conduction pickup unit 10 includes two pickup elements 20 and 30 in a substantially cylindrical case 12. 1A, the case 12 is closed by a conical base 14, and a hole 16 for a lead wire is provided at the center of the base 14. On the other hand, the right end side of the case 12 in FIG. 1A is open. And
Metal plates 2 are provided above and below the base 14 with the hole 16 interposed therebetween.
2, 32 are attached, each extending along the case 12 to the opening side. The piezoelectric elements 24, 3 are provided on the facing surfaces of the metal plates 22, 32, respectively.
4 are provided. Both surfaces of the piezoelectric element 24 (metal plate 2
Electrodes 25 are provided on the two surfaces (the surface on the opposite side) and electrodes 35 are provided on both surfaces of the piezoelectric element 34 (the surface on the metal plate 32 side and the surface on the opposite side). ing.

At the free ends of the metal plates 22 and 32 on the case opening side, substantially U-shaped contacts 26 and 36 are provided so as to extend around the case ends. These contacts 26,
2, respectively, come into contact with the wall surface of the ear canal 40 of the human body as shown in FIG. On the other hand, a two-core lead 2 is connected to the base 14 side of the metal plate 22 and the electrode 25 of the piezoelectric element 24.
8 are connected to each other. Further, each core wire of a two-core lead wire 38 is connected to the base portion 14 side of the metal plate 32 and the electrode 35 of the piezoelectric element 34, respectively. These lead wires 28 and 38 are respectively led out of the hole 16 of the base 14 to the outside of the case. Bone-conducted voice signals are output from these leads 28 and 38, respectively.

[0013] Of the above parts, the case 12 and the base 1
4 is strong, difficult to transmit vibration,
It is preferable that it is lightweight. For example, the case 12 and the base 1 may be made of a resin material such as ABS, or may be made of metal.
4 may be manufactured and coated with plastic or rubber. The case 12 and the base 14 are
Both may be formed integrally, or may be formed separately and joined.

Next, as the metal plates 22 and 32 of the pickup elements 20 and 30, for example, 42 alloy, phosphor bronze, brass, and stainless steel are preferable. Piezoelectric element 2
Materials having piezoelectric characteristics are used as 4, 34,
For example, PZT is one suitable material. These piezoelectric elements 24 and 34 may have a single-plate structure or a laminated structure.

Since the contacts 26 and 36 are in direct contact with the human body, they are desirably made of a material and a shape which do not harm the human body.
Or rubber. Of course, a configuration in which a metal such as a phosphor bronze or brass plate is covered with a resin such as a vinyl tube may be employed. In the present embodiment, since the contacts 26 and 36 have a substantially U-shape having a spring property, a good wearing feeling can be obtained. Of course, in order to improve the tactile sensation, a known method such as coating the surfaces of the contacts 26 and 36 or pasting a soft foamed rubber material or the like may be applied. As the lead wires 28 and 38, for example, a general insulating-coated conductive wire, a coaxial shielded wire, or the like is used. In this example,
Using a two-core shielded wire, one of the cores
The other cores are connected to the electrodes 25 and 35 provided on the surface of the metal plate 34 and the metal plates 22 and 32, respectively.

Next, the metal plates 22, 32 and the piezoelectric elements 24,
The pickup elements 20 and 30 each constituted by the contact 34 and the contacts 26 and 36 are designed such that the resonance frequency is in a range of, for example, 3.5 to 4 kHz. Further, Q (sharpness) is set so that the critical bandwidth of the auditory characteristics is, for example, about 3 to 6. As is well known, the volume velocity U of the airflow from the mouth of the human body and the vibration velocity V of the laryngeal skin have a relationship of U / V∝F ^{2 with} respect to the frequency F. From this, the bone-conducted sound received by the acceleration-type vibration pickup has an attenuation characteristic of a high-tone range of 6 dB / octave. In order to compensate for this attenuation characteristic, the resonance frequency of the pickup system should be around 3.5 to 4 kHz, and Q should be 3
Set to about 6. By doing so, the frequency characteristics become flat as a whole, and a more natural sound can be obtained.

The contact portions of the contacts 26 and 36 with the inner wall of the ear canal 40 are, for example, 1.5 mm in width and 5.0 in length.
Set to be around mm. If the contact area of the contacts 26 and 36 with the inner wall of the ear canal is too small, good sensitivity to bone conduction sound cannot be obtained. Conversely, if the contact area is too large, the tactile sensation may deteriorate or the inner wall of the ear canal may be damaged. The contact area is set from such a point.

Next, the operation of the present embodiment will be described. Figure 1
The bone conduction pickup unit 10 configured as
As shown in FIG. 2, it is inserted into the ear canal 40 of the user's ear. Then, the contacts 26 and 36 come into contact with the inner wall of the ear canal 40. For example, when inserting as shown in FIG.
The contact 26 contacts the upper inner wall of the ear canal 40 and the contact 3
6 contacts the lower inner wall of the ear canal 40. Therefore, the upper contact 26 mainly picks up, of the voices emitted by the user, those transmitted from the brain side. on the other hand,
The lower contact 36 mainly picks up, of the voices emitted by the user, those transmitted from the chin side.

When the contacts 26 and 36 vibrate based on the bone conduction sound, the contacts 26 and 36 are
2, the metal plates 22 and 33 vibrate, and the piezoelectric elements 24 and 34 bend. The piezoelectric elements 24 and 34 function as a so-called acceleration sensor, and an electric signal corresponding to the bending is induced and output to the outside from the lead wires 28 and 38. In this way, an electric signal corresponding to the bone conduction voice is obtained.

By the way, in the present embodiment, there are two pickup elements 20 and 30, and the bone conduction voice is picked up at different portions. Therefore, sound quality and clarity can be improved as compared with the case where only one pickup element is provided. For example, even if the bone conduction voice picked up by one of the pickup elements has a low treble component,
If the bone-conducted sound picked up by the other pickup element contains a high-frequency component, the high-frequency range is compensated as a whole, and the clarity is improved. Of course, by adjusting the positions of the contacts 26 and 36 with respect to the ear canal 40, a position with a good S / N ratio and clarity may be found.

According to an experiment conducted in connection with the present invention, bone-conducted voice picked up from the upper inner wall of the ear canal 40, that is, from the head side, has a high treble component and tends to have relatively high clarity. It is known. On the other hand, it has also been found that the bone-conducted voice picked up from the lower inner wall of the external auditory meatus 40, that is, the temporomandibular joint side, has a large amount of low-frequency components, and the voice has a low muffled feeling, and the clarity tends to be not necessarily high. This is considered to be due to the fact that the frequency spectrum of the bone-conducted voice in the external auditory canal 40 differs at each pickup point, and in particular, the transmission characteristics from the temporomandibular joint and the transmission characteristics from the head are considerably different. From this point of view, as shown in FIG.
It is considered that if the is mounted so as to be positioned in the up-down direction, voice recognition with high clarity becomes possible.

As described above, according to the present embodiment, the following effects can be obtained. (1) Since the bone-conducted sound is directly picked up by contacting the inner wall of the ear canal, the sensitivity is high. (2) Since bone-conducted vibrations are picked up from places where voice intelligibility is superior, particularly from the head side, the high range characteristics of bone-conducted voices are compensated and excellent in intelligibility. (3) Since the contact has a spring structure, it is possible to correct individual differences in the external auditory canal, and the fit or the wearability is improved.

<Second Embodiment> Next, a second embodiment will be described with reference to FIG. This embodiment has the same basic configuration as that of the first embodiment, except that the case covers almost the entirety. FIG. 3A shows the appearance, and FIG. 3B shows the main cross section. As shown in these figures, the case 50 covers the whole, and the metal plate 22,
The 32 free ends are also covered. Then, the contactors 26 and 36 are inserted through the long holes 52 and 54 provided on the side surface of the head of the case 50.
Are exposed. In this way, by covering the case except for the necessary parts with the case, there are inconveniences such as the user touching the inside of the device to damage the device, or the foreign matter entering the case and hindering the vibration of the pickup elements 20 and 30. Is prevented.

FIG. 3C shows a modification of the case. As shown, the case 51 has a rectangular or elliptical shape in the directions of the contacts 26 and 36. By doing so, the external auditory canal 40 and the side surfaces 51A, 51 of the case 51 are provided.
A gap is formed between B and B, and the inside of the ear and outside air are conducted. For this reason, there are advantages such as simultaneous reception by air conduction and a natural feeling of wearing.

<Embodiment 3> Next, Embodiment 3 will be described with reference to FIGS. In the present embodiment, as shown in FIG.
The charge-up circuit 60,
62 are connected. Of these, the output side of the charge-up circuit 60 is connected to the plus input side (non-inverting input side) of the subtractor 64, and the output side of the charge-up circuit 62 is connected to the minus input side (inverting input side) of the subtractor 64. )It is connected to the. Then, the subtraction output of the subtractor 64 is output as an audio signal.

The charge-up circuits 60 and 62 are provided to amplify the input signals and correct the difference in sensitivity between the two pickup elements 20 and 30, respectively, so that noise canceling is performed most frequently. ing. Also, the pickup elements 20 and 30 are
2, 32 are grounded, and the piezoelectric elements 24, 34
Signals are picked up from the electrodes 25 and 35 side. The polarization directions of the piezoelectric elements 24 and 34 are symmetrical as shown by arrows in FIG. 5A (the same direction as viewed from the electrodes 25 and 35 on the signal extraction side). .

Next, the operation of the present invention will be described. The audio signals output from the pickup elements 20 and 30 are supplied to charge-up circuits 60 and 62, respectively. Outputs of the charge-up circuits 60 and 62 are supplied to a plus input side and a minus input side of the subtractor 64, respectively.
The subtractor 64 subtracts the signal on the minus input side from the signal on the plus input side. Alternatively, it may be considered that the signal on the minus input side is inverted and added to the signal on the plus input side. Therefore, the same phase components included in the audio signals output from the pickup elements 20 and 30 are canceled.

For example, it is assumed that the audio signals output from the pickup elements 20 and 30 have waveforms as shown in FIGS. 4B and 4C, respectively. The signal in FIG.
The signal is inverted as shown in FIG. 4D and added to the signal shown in FIG. Therefore, the signal after the addition is as shown in FIG. For example, if there is ambient noise, the polarization directions of the piezoelectric elements 24 and 34 are symmetrical, so that the piezoelectric elements 24 and 34 are commonly picked up by the pickup elements 20 and 30.
The signals are output as signals having the same phase and the same strength. For this reason, the arithmetic processing by the subtractor 64 is just canceled. The same applies to the fricative noise of the lead wires 28 and 38 and noise due to the movement of the user.

On the other hand, as described above, the phase of the bone conduction sound in the external auditory canal 40 is shifted between the pickup elements 20 and 30. Therefore, all of the bone-conducted voice components are not canceled even if the arithmetic processing is performed by the subtractor 64, and the sound quality is improved by the subtraction of the element output, and the clarity is also improved. Become. Thus, according to the present embodiment, the pickup elements 20, 30
Noise components such as humming noise and noise are well canceled, and it is possible to satisfactorily extract only bone-conducted voice components.

The noise canceling circuit centering on the subtractor 64 may be connected to the ends of the lead wires 28 and 38 or may be provided in the case of the bone conduction pickup unit. In addition, when the polarization directions of the piezoelectric elements 24 and 34 are asymmetric (the opposite directions when viewed from the signal extraction electrodes 25 and 35) as shown in FIG. 5B, the polarities are inverted. Therefore, an adder is used instead of the subtractor 64 (the same applies to the following embodiments).

As described above, according to the present embodiment, the sensitivity and the clarity are improved, and the effects of the surrounding noise, the frictional noise of the cord, the motility noise and the hum noise can be greatly reduced. According to experiments performed on the present invention, 100 d
It has been found that the noise up to B can be canceled well.

<Fourth Embodiment> Next, a fourth embodiment will be described with reference to FIGS. In the present embodiment, as shown in FIG. 6, a radio wave transmitter 66 is connected to the output side of the subtractor 64 of the third embodiment, and a radio wave receiver 68 is provided in the partner device. That is,
In the present embodiment, the signal output of the subtractor 64 is
And wirelessly transmitted by the receiver 68.

FIG. 7 shows a specific application example of the present embodiment. (B) and (C) in the figure are examples of application to a mobile phone. The example of FIG. 7A is an example in which a voice is recorded on the voice recorder 70. The voice recorder 70 is provided with the receiver 68 shown in FIG. on the other hand,
The bone conduction pickup unit 80 has a configuration in which the noise canceling circuits 60 to 64 shown in FIG. 6 and the transmitter 66 are integrated, and this is mounted on the ear of the user 82. For this reason, the voice of the user 82 is picked up by the bone conduction pickup unit 80 and
6 is transmitted to the voice recorder 70. The transmitted voice is received by the receiver 68 of the voice recorder 70, and the voice is recorded. The voice recorder 70
It may be anywhere within the range of the radio wave.

FIG. 7B shows an example in which a portable telephone 72 has a built-in transmitter 74 for receiving and a receiving unit 84 in which a receiver for receiving is integrated is worn by a user 82 on his / her ear. is there. That is, the reception is performed by the transmitter 74 of the mobile phone 72 and the reception unit 84. For the transmission,
This is the same as FIG. For this reason, transmission and reception can be performed even if the mobile phone 72 is far away within a range where radio waves can reach. If both transmission and reception are performed wirelessly by air-conducted voice, a transmission / reception unit 90 including a microphone 86 and an earphone 88 is required as shown in FIG. It is not preferable in terms of aspect. However, according to the present example, it is only necessary to attach the bone conduction pickup unit 80 and the receiving unit 84 to the left and right ears, and the attachment and the appearance are excellent.

FIG. 7D shows an example in which a bone conduction pickup unit 80 is used as a voice input microphone for a PC (personal computer) 100.
According to this, the receiver 68 is provided in the PC 100. On the other hand, the bone conduction pickup unit 80
The noise canceling circuits 60 to 64 shown in FIG. 6 and the transmitter 66 are integrated, and this is mounted on the ear of the user 82. For this reason, the voice of the user 82 is picked up by the bone conduction pickup unit 80 and transmitted from the transmitter 66 to the PC 100. The transmitted voice is received by the receiver 68 of the PC 100, whereby voice input is performed. Since the user 82 and the PC 100 are wireless, the user can move within a range where radio waves can reach.

FIG. 7E shows an example in which the PC 100 can output sound. Transmitter 1 for listening to PC100
This is an example in which a user 82 wears an audio output unit 85 having a built-in receiver 02 and an integrated receiver for reception. That is, the sound output from the PC 100 to the user 82 is performed by the transmitter 102 and the sound output unit 85 of the PC 100. For voice input, see FIG.
Same as (D).

<Fifth Embodiment> Next, a fifth embodiment will be described with reference to FIG. First, in the example of FIG. 8A, the tips of the contacts 26 and 36 are extended to extend the extended portion 11.
0,112 are formed. And the extension 110,
The interval of 112 is different from that of the contacts 26, 3 in the above embodiment.
6 corresponds to the interval. Also, the extension parts 110 and 112
Is bent toward the case 50 side. According to this example, the extensions 110 and 112 contact the inner wall of the ear canal 40. That is, when the bone conduction pickup is worn on the ear, it comes into contact with the inner wall at a position relatively close to the entrance of the ear canal. By devising the shape of the contact as in this example,
The contact area with the ear canal can be adjusted. The transfer function of the bone-conducted voice may change due to the change of the contact area. Further, according to the present embodiment, the contact extension portions 110,
Since the distal end of 112 is bent, there is no danger of the contact getting caught when removing the bone conduction pickup from the ear.

FIG. 8B shows an example in which an earphone 130 is provided on the base 14. A sound signal is supplied to the earphone 130 via a signal line 132, and a sound is output. According to this example, both transmission and reception can be performed only by attaching one pickup to the ear. The transmission is the same as in the above embodiment. In addition, in the case of a reception, a reception voice is output from the earphone 130,
This may be picked up by the bone conduction pickups 20,30. However, since they are picked up as the same signal, they can be canceled by using the noise canceling circuit shown in FIG.
Therefore, there is no possibility of howling.

In the example shown in FIG. 8C, bone conduction pickups 140 and 142 are attached to both the left and right ears, respectively. In the case of this example, the left and right bone conduction pickups 140 and 142 pick up bone conduction sounds from the same portion of the inner wall of the ear canal. Each pickup 140, 142
After amplification by amplifiers 144 and 146,
It is supplied to the phase detecting circuit 148. Phase detection circuit 148
Then, the in-phase component of the input signal is extracted. The external noise is generally considered to be picked up by the left and right bone conduction pickups 140 and 142 at different phases. This is because the noise source and the left and right bone conduction pickups 140, 1
This is because it is considered that the distance from the P.42 is different. However, the bone-conducted voice is generated by the left and right bone-conducted pickups 140 and
The sound source is located between the two. Therefore, it is considered that the bone conduction sounds picked up by the respective pickups 140 and 142 have the same phase. For this reason, the bone conduction voice can be favorably picked up also in the present embodiment.

In particular, when considering an environment such as a factory or an airfield having a high noise level different from that in an automobile or an office, it is necessary to protect both ears with earplugs or earmuffs regardless of the necessity of voice communication. Occurs. Therefore, as in the present embodiment, the pickup elements 140 and 1 are respectively placed on the left and right ears.
It is convenient to attach 42.

<Sixth Embodiment> Next, a sixth embodiment will be described with reference to FIG. This embodiment has the same basic structure as that of the first embodiment, except that a metal plate also serves as a contact, and an earplug for protecting hearing is provided outside the case. is there. FIG. 9A shows an appearance, and FIG. 9B shows a main cross section. As shown in these figures, the case 150 is provided with a spindle-shaped or hemispherical flange-type earplug 152. Earplugs 15
As the second material, for example, a silicone-based resin that is flexible and has a good degree of sealing of the ear canal when worn is suitable. And
The piezoelectric elements 24 and 34 are fixed to the plastic spacer 156 embedded in the base portion 14 and fixed with an adhesive.
Metal plates 160 and 162 are attached respectively.
The plastic spacer 156 is provided for the piezoelectric elements 24 and 3.
This is for fixing the base 4 to the base 14 without making contact with each other, and various known plastics can be used. Electrodes 25 and 35 are provided on the opposing surfaces of the piezoelectric elements 24 and 34, respectively. On the other side, metal plates 160 and 162 also serve as electrodes. Of course, as in the above-described embodiment, electrodes may be provided on the front and back of the piezoelectric elements 24 and 34, respectively.

The metal plates 160 and 162 are
It extends so as to be exposed to the outside from the opening along 0,
The shape is bent near the opening and around the end of the case 150. The exposed portions 160A, 1 of these metal plates
62A is the contact 26, 3 in the first embodiment described above.
6 and respectively contact the wall surfaces of the ear canal 40. However, cushion members 164 and 166 are provided at portions where the exposed portions 160A and 162A are in contact with the ear canal, so as to protect the metal plate from directly contacting the ear canal. As the material of the cushion materials 164, 166,
For example, polyurethane capable of recovering shape is suitable. The length L of the free vibrating portions of the metal plates 160 and 162 shown in the figure is set to about 8 mm so that the resonance frequency is around 3 kHz.

As described above, the earplug 1 is placed outside the case 150.
By providing 52, external noise is cut off when the bone conduction pickup is worn on the ear. For this reason, sensitivity and clarity can be improved. In addition, since the ear plug 152 is made of a highly sealed and soft material, the bone conduction pickup is securely fixed along the shape of the ear canal, thereby reducing noise caused by friction between the bone conduction pickup and the wall of the ear canal. It is also possible to do.

Further, the metal plate 1 exposed from the case 150
The exposed portions 160A, 160B of the
50 is bent so as to go around the end of each, and cushion members 164 and 166 are provided at their ends to serve also as contacts, so that the configuration can be simplified. In addition, since the cushion members 164 and 166 are made of a material whose shape can be recovered, the cushion members 164 and 166 are pressed with a finger and inserted into the ear in a flat shape, so that the bone conduction pickup is attached to the ear. Becomes easier. When the bone conduction pickup is stored in the ear canal, the cushion material 164,
Since the shape of 166 is recovered and comes into contact with the shape of the ear canal wall, the sensitivity and clarity of the pickup are further improved, and the pickup can be worn comfortably.

The present invention has many embodiments, and can be variously modified based on the above disclosure. For example, the following is also included. (1) Various types of piezoelectric elements are known, such as a unimorph type, a bimorph type, and a type using a shim material, and any of them may be used. Also, whether they have a single-layer structure or a laminated structure may be appropriately determined as necessary. The material of each part may be appropriately selected as needed. (2) In the above-described embodiment, two pickup elements are provided in one case. However, of course, only one pickup element may be provided, or more pickup elements may be provided as needed. (3) The above embodiments may be combined.
For example, the earplug 152 and the cushion members 164 and 166 shown in the sixth embodiment are applied to the first to fifth embodiments. (4) In the above embodiment, the bone conduction sound detection site is the ear of the human body.

[0046]

As described above, according to the present invention,
The following effects are obtained. (1) Since the contact element of the pickup element is provided with an adjustment function for reducing the difference in the distance between the human body and the detection site, it is possible to easily correct individual differences in the human body, and to provide a feeling of fit or wearing. The performance is improved. (2) Since the contact is configured to be in contact with the human body, the clarity and S / N ratio of bone-conducted speech recognition are improved, and bone-conducted speech can be well recognized. (3) Since a plurality of the bone conduction pickup elements are provided in the case and noise canceling means is provided, the effect of ambient noise is reduced and bone conduction voice recognition with high clarity becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main cross section and side surfaces of a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a state in which the bone conduction pickup according to the first embodiment is attached to an ear.

FIG. 3 is a diagram illustrating an appearance and a main cross section of a second embodiment of the present invention.

FIG. 4 is a diagram showing a configuration and operation of a third embodiment of the present invention.

FIG. 5 is a diagram showing a relationship between polarization directions of a piezoelectric element.

FIG. 6 is a diagram showing a configuration of a fourth embodiment of the present invention.

FIG. 7 is a diagram showing an application example of the fourth embodiment.

FIG. 8 is a diagram showing a main cross section and a circuit configuration of a fifth embodiment of the present invention.

FIG. 9 is a diagram showing an appearance and a main cross section of a sixth embodiment of the present invention.

[Explanation of symbols]

 10 bone conduction pickup unit 12, 50, 51 ... case 51A, 51B ... side surface 14 ... base 16 ... hole 20, 30 ... pickup element 22, 32 ... metal plate 24, 34 ... piezoelectric element 25, 35 ... electrodes 26, 36 ... contacts 28, 38 ... lead wires 40 ... ear canal 52, 54 ... long holes 60, 62 ... charge-up circuit 64 ... subtractors 66, 74, 102 ... … Transmitter 68… Receiver 70… Voice recorder 72… Mobile phone 80… Bone conduction pickup unit 82… User 84… Reception unit 85… Sound output unit 86… Microphone 88… Earphone 90 ... Transmission / reception unit 100 ... PC 110,112 ... Contact extension part 130 ... Earphone 132 ... Signal line 140,142 ... Bone conduction picker 144, 146, amplifier 148, phase detection circuit 150, case 152, earplugs 154, insertion holes 156, plastic spacers 160, 162, metal plates 160A, 162A, exposed portions 164, 166 … Cushion material

Claims (13)

[Claims] A diaphragm fixed at one end; an electroacoustic transducer provided on the diaphragm; a contact provided at a free end of the diaphragm and in contact with a detection site of a human body; A bone conduction pickup element, characterized in that the contact has an adjustment function for reducing a difference in the distance between the free end of the diaphragm and the detection site of the human body. 2. The bone conduction pickup element according to claim 1, wherein said contact has a spring structure. 3. The bone conduction pickup element according to claim 1, wherein said diaphragm is extended to serve as said contact. 4. A bone comprising: a diaphragm fixed at one end; an electroacoustic transducer provided on the diaphragm; a contact provided at a free end of the diaphragm and in contact with a detection part of a human body. A bone conduction pickup unit, wherein a plurality of conduction conduction elements are provided in a case. 5. The bone conduction pickup element according to claim 1,
The bone conduction pickup unit according to claim 4, wherein the bone conduction pickup unit is one described in any of (3). 6. The bone conduction pickup unit according to claim 4, wherein the plurality of bone conduction pickup elements are arranged in the case with the same dimensions and shape in plane symmetry. 7. The bone conduction pickup unit according to claim 4, wherein only the contact protrudes from the case. 8. The bone conduction pickup unit according to claim 4, further comprising noise canceling means for canceling noise using outputs of a plurality of bone conduction pickup elements. 9. The apparatus according to claim 8, wherein said noise canceling means superposes signals of the same phase detected by said plurality of pickup elements after inverting one of them.
A bone conduction pickup unit as described. 10. The bone conduction pickup unit according to claim 8, wherein said noise canceling means superimposes signals of opposite phases detected by said plurality of pickup elements. 11. The bone conduction pickup unit according to claim 4, further comprising wireless transmission means for transmitting the output of said bone conduction pickup element wirelessly. 12. An apparatus according to claim 4, further comprising audio reproducing means for reproducing externally supplied audio.
2. The bone conduction pickup unit according to any one of 1. 13. The bone conduction pickup unit according to claim 4, further comprising a hearing protection means for protecting a hearing outside the case.