JP2020036207A - Bone conduction head set - Google Patents

Abstract

To provide a bone conduction head set capable of suppressing an input of vibration, outputted from a bone conduction speaker, to a bone conduction microphone via the frame, even in a case where the bone conduction microphone and the bone conduction speaker are integrated by the frame.SOLUTION: A bone conduction head set 5 includes a bone conduction microphone 30 for detecting vibration of the nose hn of a living body, and converting the same into an electric signal, at least two bone conduction speakers 21, 22 for converting an electric signal into mechanical vibration, and a frame 10 to which the bone conduction microphone 30 and the least two bone conduction speakers 21, 22 are attached. The bone conduction microphone 30 has a pair of right and left vibration sensors 31, 32 placed in the central part of the frame 10 via a clip 35. The right side bone conduction speaker 22 and the left side bone conduction speaker 21 are placed symmetrically with respect to the central part of the frame 10. A phase of an electric signal outputted from the right side bone conduction speaker 22 is not inverted, however, a phase of an electric signal outputted from the left side bone conduction speaker 21 is inverted about 180 degrees.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a bone conduction headset.

  Conventionally, a bone conduction microphone that converts the vibration of the throat into sound by closely adhering to the throat and a bone conduction speaker that vibrates near the outer ear of the ear so as to be heard as bone conduction sound are arranged in the same frame. Is known (see Patent Document 1).

International Publication No. WO2018 / 079755

  According to the present disclosure, even in the case of a bone conduction headset in which a bone conduction microphone and a bone conduction speaker are integrated with a frame, the output of vibration from the bone conduction speaker can be suppressed from being input to the bone conduction microphone via the frame. A bone conduction headset is provided.

  One aspect of the present disclosure is a bone conduction microphone that detects mechanical vibration of a nose of a living organism and converts the vibration into an electric signal, at least two bone conduction speakers that convert an electric signal into mechanical vibration, and the bone conduction microphone. A frame on which a microphone and at least two bone conduction speakers are mounted, wherein the bone conduction microphone is disposed at a central portion of the frame and is included in a first bone conduction speaker included in the at least two bone conduction speakers. The speaker and the second bone conduction speaker are symmetrically arranged with respect to the central portion of the frame, and the phase of an electric signal output from the first bone conduction speaker is not inverted, and the second bone conduction speaker is The phase of the electric signal output from the conduction speaker is reversed by approximately 180 degrees, which is a bone conduction headset.

  According to the present invention, even in the case of a bone conduction headset in which a bone conduction microphone and a bone conduction speaker are integrated by a frame, the output of vibration from the bone conduction speaker is input to the bone conduction microphone via the frame. Can be suppressed.

The figure which shows the use condition of the bone conduction headset in 1st Embodiment. Diagram showing the shape of the bone conduction headset The figure which shows the connection of the bone conduction headset of a comparative example The figure which shows the connection of the bone conduction headset of 1st Embodiment. Diagram showing how the vibrations output from the left and right bone conduction speakers propagate to the bone conduction microphone Graph showing frequency characteristics of sound pressure due to vibration detected by bone conduction microphone The figure which shows the external appearance of the glasses type osteoconductive headset in the modification 2 of 1st Embodiment. FIG. 7 is a diagram illustrating a circuit of a bone conduction headset according to the second embodiment. FIG. 10 is a diagram illustrating a circuit of a bone conduction headset according to the third embodiment.

  Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, an unnecessary detailed description may be omitted. For example, a detailed description of a well-known item or a redundant description of substantially the same configuration may be omitted. This is to prevent the following description from being unnecessarily redundant and to facilitate understanding of those skilled in the art. The accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the claimed subject matter.

(History of obtaining one mode of the present disclosure)
In the case of a bone conduction headset in which a bone conduction microphone and a bone conduction speaker are integrated by a frame, vibration output from the bone conduction speaker may be transmitted through the frame and input to the bone conduction microphone. In this case, the bone conduction microphone may input vibration different from the voice uttered by the wearer wearing the bone conduction headset.

  For example, in the case of a call between a plurality of parties, a vibration caused by a signal received from the bone conduction headset on the other side is output from the bone conduction speaker. The vibration output from the bone conduction speaker propagates through the frame and is input to the bone conduction microphone. The signal due to the vibration input to the bone conduction microphone is transmitted to the partner bone conduction headset. In this case, in the bone conduction headset on the other side, a so-called echo phenomenon occurs, in which the sound (word) emitted by oneself (the other side) returns to oneself. For this reason, the other party feels that the call is difficult to hear and is unnatural.

  In the following embodiments, even in the case of a bone conduction headset in which a bone conduction microphone and a bone conduction speaker are integrated by a frame, it is assumed that the output of vibration from the bone conduction speaker is input to the bone conduction microphone via the frame. A bone conduction headset that can be suppressed will be described.

(First embodiment)
FIG. 1 is a diagram illustrating a usage state of the bone conduction headset 5 according to the first embodiment. The bone conduction headset 5 is used while being worn on the face of the person hm. Note that the person hm (human body) is an example of a living body, and may be another living body (for example, an animal).

  FIG. 2 is a diagram showing the shape of the bone conduction headset 5. The bone conduction headset 5 has a frame 10 having a substantially W-shaped curve along the face, bone conduction speakers 21 and 22 attached to both ends of the frame 10, and a central part of the frame 10. And the bone conduction microphone 30 is integrated.

  The frame 10 is formed of, for example, a hard material having a spring property (elasticity). Examples of the hard material include a metal plate having a spring property, such as titanium, stainless steel, and phosphor bronze, which is coated with a resin.

  Bone conduction speakers 21 and 22 are attached to both ends of the frame 10. When the bone conduction headset 5 is worn on the face, the bone conduction speakers 21 and 22 press the face by the spring of the frame 10 to support the bone conduction headset 5. The bone conduction speakers 21 and 22 may be composed of a piezoelectric element and a covering material that covers the piezoelectric element. As the covering material, a resin or a gel material such as silicone hydrogel may be used so as to improve adhesion to the skin surface (for example, tragus) near the outer ear. The gel material is an example of a soft material, and may be another material. The bone conduction speakers 21 and 22 have a substantially spherical shape when the bone conduction headset 5 is not mounted on the face, but are pressed against the frame 10 when the bone conduction headset 5 is mounted on the face. It may be slightly flattened.

  The bone conduction speakers 21 and 22 acquire an electric signal as an audio signal, and output the electric signal as vibration. In other words, the bone conduction speakers 21 and 22 convert the electric signal into vibration (mechanical vibration) and output it. The bone conduction speakers 21 and 22 may output vibration based on a monaural sound signal. In monaural audio, basically, audio signals of the same content may be output in the same phase.

  The bone conduction microphone 30 is disposed so as to sandwich both sides of the nose hn (nose, for example, nose cartilage), and a pair of vibration sensors 31 and 32 for converting vibration of the nasal cavity into voice, and vibrates across the nose hn. And a U-shaped clip 35 connecting the sensors 31 and 32. Note that the vibration sensors 31 and 32 may be provided on only one of the left and right instead of a pair. The clip 35 may be formed of a material having a spring property (for example, a metal coated with a resin, the resin itself) so that the pair of vibration sensors 31 and 32 can press the nose hn from both sides. The vibration sensors 31 and 32 come in contact with any position of the nose hn (nose).

  The vibration sensors 31 and 32 may be composed of a piezoelectric element and a covering material that covers the piezoelectric element. As the covering material, a resin or a gel material such as silicone hydrogel may be used so as to improve adhesion to the skin surface corresponding to the nasal cavity. The gel material is an example of a soft material, and may be another material. The vibration sensors 31 and 32 have a substantially spherical shape when the clip 35 is not fitted on both sides of the nose hn. However, when the clip 35 is fitted on both sides of the nose hn, the vibration sensors 31 and 32 press against the clip 35. It may be slightly flattened.

  The vibration sensors 31 and 32 detect bone conduction sounds. The bone conduction sound is transmitted to the nasal cavity when the person hm moves and speaks the mouth ho, and is detected as the vibration. In other words, the vibration sensors 31 and 32, that is, the bone conduction microphone 30 detects vibration (mechanical vibration) generated around the nose hn and converts the vibration into an electric signal. The vibration sensors 31 and 32 are not limited to those that convert the vibration of the nasal cavity into voice, and may be arranged so as to be in close contact with the throat and convert the vibration of the throat into voice. The bone conduction sound may include, in addition to conversation, an operation sound of a smartphone, an AI (artificial intelligence) speaker, or the like, or may include other sounds.

  The communication module 41 and the battery 45 are housed inside the frame 10. BLE (Bluetooth (registered trademark) Low Energy) communication may be used for communication of the communication module 41. When BLE communication is used, the antenna is formed, for example, in a size of 3 cm to 12 cm, and thus may be formed as a part of the frame or may be housed in the frame. The communication is not limited to the BLE communication, and communication such as a wireless LAN (local area network) may be used.

  The communication module 41 may be housed in one of the left and right of the frame 10. Further, the battery 45 may be housed in the frame 10 on the opposite side of the communication module 41. Note that the communication module 41 and the battery 45 may be accommodated only on one side of the frame 10 so that the transmission characteristics of the vibration of the frame 10 may be uniform.

  In the bone conduction headset 5, a bone conduction microphone 30 is arranged at the center of the frame 10. The vibration sensors 31 and 32 of the bone conduction microphone 30 may be connected to a central portion of the frame 10 via a connection line (a part of the clip 35) of the same length. In this case, it is easy to design so that the vibration transmitted from the left bone conduction speaker 21 and the vibration transmitted from the right bone conduction speaker 22 reach the bone conduction microphone 30 almost simultaneously. In addition, when the bone conduction headset 5 is used, the ear hy is not blocked by the bone conduction speakers 21 and 22, so that the air conduction sound can be heard. Therefore, it is possible to hear the environmental sound coming from the ear. The bone conduction speakers 21 and 22 may cover a part of the ear. Also in this case, the wearer can hear the environmental sound by passing the environmental sound through the other part of the ear.

  FIG. 3 is a diagram showing connection of the bone conduction headset 105 of the comparative example. In the bone conduction headset 105, the positive output line 25p of the left bone conduction speaker 21 and the right bone conduction speaker 25 such that the left bone conduction speaker 21 and the right bone conduction speaker 22 output sound in phase. The plus output line 26p of the conduction speaker 22 is connected, and the minus output line 25m of the left bone conduction speaker 21 and the minus output line 26m of the right bone conduction speaker 22 are connected. The positive output line 25p and the positive output line 26p are connected to the audio positive output terminal (positive electrode) of the communication module 41 connected to the smartphone 80, which is an example of a sound source. The negative output line 25m and the negative output line 26m are connected to the audio negative output terminal (negative electrode) of the communication module 41 connected to the smartphone 80. In addition, the smartphone 80 is provided with a speaker output (+), a speaker output (−), and a ground terminal in addition to a microphone input terminal to which a signal from the bone conduction microphone 30 is input.

  FIG. 4 is a diagram illustrating connection of the bone conduction headset 5 according to the first embodiment. In the bone conduction headset 5, the left bone conduction speaker 21 and the right bone conduction speaker 22 output sound as vibration with a signal having a phase difference of 180 ° (inverted signal). The positive output line 25p of the bone conduction speaker 21 is connected to the minus output line 26m of the right bone conduction speaker 22, and the minus output line 25m of the left bone conduction speaker 21 and the plus output of the right bone conduction speaker 22 are connected. The line 26p is connected. The negative output line 25m and the positive output line 26p are connected to the audio positive output terminal (positive electrode) of the communication module 41 connected to the smartphone 80. The plus output line 25p and the minus output line 26m are connected to the audio minus output terminal (negative electrode) of the communication module 41 connected to the smartphone 80.

  FIG. 5 is a diagram showing how the vibrations output from the left and right bone conduction speakers 21 and 22 propagate to the bone conduction microphone 30. From the bone conduction speaker 21 on the left side, for example, a vibration due to the sound pressure signal S1 is output. The sound pressure signal S1 shows a negative maximum value, a value 0, and a positive maximum value at timings t1, t2, and t3, respectively. On the other hand, vibrations based on the sound pressure signal S2 are output from the right bone conduction speaker 22 as an example. The sound pressure signal S2 shows a positive maximum value, a value 0, and a negative maximum value at timings t1, t2, and t3, respectively.

  Via the left frame portion 10L, the vibration due to the sound pressure signal S1 is transmitted to the bone conduction microphone 30 as shown by the arrow e. Similarly, the vibration due to the sound pressure signal S2 is transmitted to the bone conduction microphone 30 via the right frame portion 10R as indicated by an arrow f. The bone conduction microphone 30 detects these vibrations having phases that cancel each other, converts the detected vibrations into sound, and outputs the sound. In an ideal state where the sound pressure signal S2d due to the vibration transmitted from the right frame portion 10R and the sound pressure signal S1d due to the vibration transmitted from the left frame portion 10L completely cancel each other, the bone conduction microphone 30 is The sound pressure signal Sm having a substantially zero value is output. In this case, the propagation time dt1 for transmitting vibration from the right frame portion 10R to the bone conduction microphone 30 and the propagation time dt2 for transmitting vibration from the left frame portion 10L to the bone conduction microphone 30 are aligned.

  In the present embodiment, the bone conduction microphone 30 detects both the vibrations output from the left and right bone conduction speakers 21 and 22. However, of the vibration sensors 31 and 32, the right vibration sensor 32 The vibration output from the bone conduction speaker 22 may be mainly detected, and the vibration sensor 31 on the left may mainly detect the vibration output from the bone conduction speaker 21 on the left. In this case, the bone conduction microphone 30 can cancel the vibrations output from the left and right bone conduction speakers 21 and 22 by adding the vibrations (sounds) detected by the left and right vibration sensors 31 and 32. .

  In the present embodiment, the shape of the frame 10 is bilaterally symmetric. However, the shape of the frame 10 is bilaterally asymmetric, and by changing the material of the left and right frame portions, the time required for the vibration to propagate to the bone conduction microphone 30 can be reduced. The amplitudes may be uniform. In this case, even if the vibration sensors 31 and 32 are not connected to the center of the frame 10, the sound pressure signals S1 and S2 from the left and right bone conduction speakers 21 and 22 may cancel each other. Thereby, the degree of freedom of the design of the frame 10 is increased.

  When the wavelength of the vibration (sound) output from the bone conduction speakers 21 and 22 is fixed in advance, the bone conduction microphone 30 is disposed at a position where the peak and valley of the vibration (sound) waveform match. In this case, the frame shape can be asymmetrical. Also in this case, even if the vibration sensors 31 and 32 are not connected to the center of the frame 10, the sound pressure signals S1 and S2 from the left and right bone conduction speakers 21 and 22 may cancel each other. Thus, as long as the left and right bone conduction speakers 21 and 22 and the left and right vibration sensors 31 and 32 are integrated into the frame 10, the shape of the frame can be changed.

  FIG. 6 is a graph showing a frequency characteristic of sound pressure due to vibration detected by the bone conduction microphone 30. The vertical axis of the graph represents sound pressure (dB), and the horizontal axis represents frequency (Hz). The solid line signal waveform g1 represents the frequency characteristic of the sound pressure when the vibration output from the bone conduction speakers 21 and 22 of the first embodiment is detected. A dashed signal waveform g2 represents the frequency characteristics of sound pressure when vibrations output from the bone conduction speakers 21 and 22 of the comparative example are detected.

  In the range of 100 Hz to 10000 Hz, the vibration output from the bone conduction speakers 21 and 22 of the first embodiment is generally smaller than the vibration output from the bone conduction speakers 21 and 22 of the comparative example. In particular, in a sound range of 100 Hz to 3000 Hz, for example, in a sound range mainly emitted by a person, compared to the vibration output from the bone conduction speakers 21 and 22 of the comparative example, the sound is output from the bone conduction speakers 21 and 22 of the first embodiment. Vibration is clearly small. One reason for this is considered that the wavelength is longer in the sound range of 100 Hz to 3000 Hz than in the sound range of 3000 Hz or more, and the influence of the U-shaped clip 35 connecting the vibration sensors 31 and 32 is relatively small.

  In general, a telephone call is made without distinction in time between transmission and reception. When a call is made using an integrated bone conduction headset in which a bone conduction speaker and a bone conduction microphone are attached to a frame, when a vibration due to a received signal is output from the bone conduction speaker, the bone conduction microphone generates the vibration. They may be picked up and cause an echo phenomenon. In the case of a transceiver, since the timing of transmission and reception is switched, such a case is unlikely to occur.

  On the other hand, it is assumed that two persons hm and hf talk using the bone conduction headset 5, for example. When the person hm speaks, the bone conduction microphone 30 of the person hm detects the vibration. The bone conduction headset 5 of the person hm transmits a signal based on the detected vibration to the bone conduction headset 5 of the person hf via the communication module 41.

  The bone conduction speakers 21 and 22 of the person hf output vibrations based on the received signals. At this time, the two vibrations, which are output from the left and right bone conduction speakers 21 and 22 and have a phase difference of 180 °, are canceled and suppressed by the bone conduction microphone 30 located at the center of the frame 10.

  The bone conduction microphone 30 of the person hf inputs a signal due to the suppressed vibration, and the bone conduction headset 5 of the person hf transmits a signal due to the suppressed vibration to the bone conduction headset 5 of the person hm. In the bone conduction headset 5 of the person hm, since the sound (word) emitted by the user (the other party) is suppressed, the echo phenomenon is suppressed.

  As described above, the bone conduction headset 5 detects the vibration (mechanical vibration) of the nose (for example, the nose hn) of the human body (an example of a living body) (for example, the person hm) and converts the vibration into an electric signal. 30, two bone conduction speakers 21 and 22 (an example of a first bone conduction speaker and a second bone conduction speaker) for converting an electric signal into a mechanical vibration, a bone conduction microphone 30 and two bone conduction speakers 21 , 22 attached to the frame 10. The bone conduction microphone 30 may include a pair of left and right vibration sensors 31 and 32 disposed at the center of the frame 10 via the clip 35. The right bone conduction speaker 22 (first bone conduction speaker) and the left bone conduction speaker 21 (second bone conduction speaker) included in the two bone conduction speakers are arranged symmetrically with respect to the center of the frame 10. May be. The phase of the electric signal output from the right bone conduction speaker 22 is not inverted, and the phase of the electric signal output from the left bone conduction speaker 22 is inverted by 180 degrees. Alternatively, the phase of the electric signal output from the right bone conduction speaker 22 may be inverted by 180 degrees, and the phase of the electric signal output from the left bone conduction speaker 22 may not be inverted. The number of bone conduction speakers may be three or more. Note that the above-mentioned 180 degrees may allow a slight deviation from the 180 degrees, and may be approximately 180 degrees.

  Thus, in the bone conduction headset 5, the vibration output from the right bone conduction speaker 22 and the vibration output from the left bone conduction speaker 22 cancel each other. The bone conduction microphone 30 hardly detects the vibration output from the bone conduction speakers 21 and 22. Thus, the bone conduction headset 5 can suppress the output from the bone conduction speaker 22 from being input to the bone conduction microphone 30 via the frame 10.

  Also, when using a speaker and a microphone through normal air vibration that does not use bone conduction, sound output from the speaker can be input to the microphone. However, since bone conduction deals with mechanical vibration generated in the human body instead of air vibration, even a small vibration is easily input to the bone conduction microphone. Therefore, it is very useful to be able to suppress the output from the bone conduction speaker 22 from being input to the bone conduction microphone 30 via the frame 10 as compared with the input of the microphone via air vibration.

  Further, the bone conduction headset 5 may further include a communication module 41 that performs BLE communication (an example of communication of an electric signal) with the smartphone 80, for example. The minus output line 25m of the bone conduction speaker 21 on the left side and the plus output line 26p of the bone conduction speaker 22 on the right side are an audio plus output terminal (positive electrode) of the communication module 41 connected to the smartphone 80 (an example of a positive electrode of the audio output terminal). , For example, to the right channel. The plus output line 25p of the left bone conduction speaker 21 and the minus output line 26m of the right bone conduction speaker 22 are a voice negative output terminal (negative pole) of the communication module 41 connected to the smartphone 80 (an example of a negative pole of the voice output terminal). , For example, to the left channel.

  Thus, the bone conduction headset 5 can easily cancel the vibration with a simple configuration in which only the output lines (wirings) are exchanged.

  Further, the frame 10 may be formed of a material including a hard material.

  When the frame 10 is hard, vibration (mechanical vibration) is easily transmitted on the frame 10. Also in this case, the bone conduction headset 5 can reduce the input due to the vibration from the bone conduction speaker 50 to the bone conduction microphone 30 by canceling the left and right sound pressure signals.

  In addition, the bone conduction headset 5 may include a communication module 41 that communicates with the smartphone 80 (an example of another communication module). The communication module 41 may transmit an electric signal input by vibration from the bone conduction microphone 30 and receive an electric signal output by vibration from the bone conduction speakers 21 and 22.

  As a result, the bone conduction headset 5 performs communication between the plurality of communication modules. For example, even when a call is made between the two persons hm and hf, the voice generated by the person hm is transmitted to the bone conduction of the person hf. An echo phenomenon returning to the person hm via the headset can be suppressed.

  In the first embodiment, the communication module 41 and the battery 45 are accommodated in the frame 10, but may be detachably attached to the frame 10. In this case, it is easy to check the operation of the communication module 41 and to exchange and charge the battery 45.

(Modification 1 of the first embodiment)
In the first embodiment, the left bone conduction speaker 21 and the right bone conduction speaker 22 are input to the left and right bone conduction speakers 21 and 22 in order to output inverted signals with inverted signals. The signal lines were swapped. That is, the plus output line 25p of the left bone conduction speaker 21 is connected to the minus output line 26m of the right bone conduction speaker 22, and the minus output line 25m of the left bone conduction speaker 21 and the right bone conduction speaker 22 are connected. Of the positive output line 26p is connected.

  In the first modification, the bone conduction headset 5 changes the phase of the electric signal input to one of the left and right bone conduction speakers 21 and 22 without changing the connection of the signal lines input to the bone conduction speakers 21 and 22. By inverting the signals, the left bone conduction speaker 21 and the right bone conduction speaker 22 can output inverted-phase sounds with inverted signals.

  For example, the bone conduction headset 5 receives an electric signal received from the smartphone 80 via the communication module 41, outputs an electric signal having a phase inverted by 180 °, and inputs the electric signal to one bone conduction speaker. Is provided. The control unit may perform signal processing for inverting the phase of the electric signal output from one of the left and right bone conduction speakers 21. That is, the control unit may invert the phase of the electric signal output from either the left or right bone conduction speaker 21 by the processor executing the program for phase inversion. The control unit may be housed in the frame 10 together with the communication module 41 and the battery 45.

  As described above, the bone conduction headset 5 according to the first modification may further include the control unit that controls the phase of the electric signal. The control unit may send the electric signal to the bone conduction speaker 22 without inverting the phase of the electric signal output from the right bone conduction speaker 22. The control unit may invert the phase of the electric signal output from the left bone conduction speaker 21 by 180 degrees and send the electric signal to the bone conduction speaker 21.

  As a result, the bone conduction headset 5 can electrically connect the left and right bone conduction speakers 21 and 22 with the communication module 41 connected to the smartphone 80 without changing the connection relationship (wiring). , 22 can be canceled. Therefore, the bone conduction headset 5 can reduce the wraparound of the vibration from the bone conduction speakers 21 and 22 to the bone conduction microphone 30 with a simple configuration.

(Modification 2 of the first embodiment)
Modification 2 shows a bone conduction headset having a glasses-type frame. FIG. 7 is a diagram illustrating an appearance of a glasses-type bone conduction headset 5A according to Modification 2 of the first embodiment. Left and right bone conduction speakers 21 and 22 are attached below the left and right temples 111L and 111R of the glasses frame 10A. The bone conduction microphone 30 is attached to the bridge 112 of the glasses frame 10A.

  In this case, the clip 35 of the bone conduction microphone 30 may also serve as the clings of the glasses frame 10A. The vibration sensors 31 and 32 may also serve as pads for supporting the glasses frame so as to sandwich the nose. A prescription lens or a polarized lens may be fitted into the rim of the spectacle frame 10A, a non-prescription lens may be fitted, or an opening may be formed without a lens.

  In the glasses-type bone conduction headset 5A according to the second modification, the bone conduction headset 5A is integrated with the glasses. Therefore, for the person who needs to wear glasses, it is not necessary to separately wear the glasses frame and the frame of the bone conduction headset 5A on the face, and the glasses are not in the way and the usability is improved. In addition, since the eyeglass frame is thicker and longer than the frame 10 of the bone conduction headset 5, the degree of freedom of arrangement of the communication module 41 and the battery 45 housed therein can be improved. In addition, the glasses frame may house a device such as a camera in addition to the communication module 41 and the battery 45.

(Second embodiment)
In the first embodiment, the phases of the electric signals input to the bone conduction speakers 21 and 22 are inverted to cancel the vibration from the bone conduction speakers 21 and 22 detected by the bone conduction microphone 30. In the second embodiment, a case is shown in which the phases of the electric signals input to the bone conduction speakers 21 and 22 are inverted, and the output of the bone conduction microphone 30 is shut off.

  The bone conduction headset according to the second embodiment has substantially the same configuration as that of the first embodiment. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

  FIG. 8 is a diagram illustrating a circuit of the bone conduction headset 5B according to the second embodiment. The bone conduction speakers 21 and 22 are connected so that the phases are inverted, as in the first embodiment. That is, a positive output line 25p of the left bone conduction speaker 21 such that the left bone conduction speaker 21 and the right bone conduction speaker 22 output vibrations (sounds) in opposite phases (inverted signals). The minus output line 26m of the right bone conduction speaker 22 is connected, and the minus output line 25m of the left bone conduction speaker 21 and the plus output line 26p of the right bone conduction speaker 22 are connected.

  Further, the bone conduction headset 5B generates vibration (sound) output from the bone conduction speakers 21 and 22 when the electric signal transmitted from the communication module 41 to the bone conduction speakers 21 and 22 is equal to or larger than the threshold th. If it becomes larger, the electric signal transmitted from the bone conduction microphone 30 to the communication module 41 is cut off. For this reason, the bone conduction headset 5B includes the input cutoff circuit 200. The input cutoff circuit 200 has a diode 201, a capacitor 202, and a transistor 203. The diode 201 is a conversion circuit that converts an AC signal input to the bone conduction speakers 21 and 22 into a DC signal. The transistor 203 and the capacitor 202 form a blocking circuit that blocks an electric signal transmitted from the bone conduction microphone 30 to the communication module 41.

  Further, the bone conduction headset 5B includes an amplification circuit 250 that amplifies the electric signal converted by the bone conduction microphone 30 and transmits the electric signal to the communication module 41. The input cutoff circuit 200 and the amplification circuit 250 are housed inside the frame 10.

  Specifically, the anode of the diode 201 is connected to the voice plus output terminal of the smartphone 80 wirelessly connected via the communication module 41, the minus output line 25m of the left bone conduction speaker 21, and the plus terminal of the right bone conduction speaker 22. Connected to the output line 26p. The cathode of diode 201 is connected to the base of transistor 203 and to one end of capacitor 202, which is an electrolytic capacitor. The other end of the capacitor 202 is grounded. The charge converted into direct current by the diode 201 is stored in the capacitor 202. That is, the voltage of the capacitor 202 is a voltage that is input to the plus output line 26p of the bone conduction speaker 22 and charged by the electric signal rectified by the diode 201. The voltage of the capacitor 202 is a fluctuation value that fluctuates according to an electric signal input to the plus output line 26p of the bone conduction speaker 22.

  The transistor 203 is an NPN transistor, and switches on / off between a collector connected to the input terminal of the bone conduction microphone 30 and a grounded emitter by a base current flowing when the diode 201 is turned on. . Note that the transistor 203 may be another transistor.

  In the input cutoff circuit 200, when an electric signal having a threshold value th or more corresponding to a large vibration (sound) is input to the positive output line 26p of the right bone conduction speaker 22, the diode 201 is turned on (turned on). The threshold value th is a value obtained by adding the forward voltage (about 0.6 V) of the diode 201 to the voltage of the capacitor 202. When no electric charge is stored in the capacitor 202, the threshold value th is the forward voltage of the diode 201 (about 0.6 V).

  When the diode 201 conducts, current flows to the base of the transistor 203, and the transistor 203 is turned on. When the transistor 203 is turned on, the collector-emitter conducts, and the output of the bone conduction microphone 30 is grounded (has a value of 0). That is, vibration (sound) is not detected by the bone conduction microphone 30.

  On the other hand, when an electric signal of less than a predetermined value is input to the plus output line 26p of the bone conduction speaker 22 on the right side, the diode 201 is non-conductive (off). In this case, the transistor 203 is off. Therefore, the output of the bone conduction microphone 30 is input to the amplification circuit 250. The input terminal of the bone conduction microphone 30 receives vibrations canceled from the left bone conduction speaker 21 and the right bone conduction speaker 22.

  The anode of the diode 201 is connected to the negative audio output terminal of the smartphone 80 wirelessly connected via the communication module 41, the positive output line 25p of the left bone conduction speaker 21, and the negative output line of the right bone conduction speaker 22. Even if it is connected to 26 m, the same operation can be performed.

  The amplification circuit 250 includes a transistor 251, resistors R1 and R2, and a capacitor C1, and amplifies and outputs an input signal of vibration (sound) detected by the bone conduction microphone 30.

  This bone conduction headset 5B is output from the left and right bone conduction speakers 21 and 22 when the magnitude of the vibration output from the bone conduction speakers 21 and 22 (that is, the signal level of the electric signal) is less than the threshold th. By inverting the vibration, the vibration transmitted from the bone conduction speaker detected by the bone conduction microphone 30 is suppressed. On the other hand, when the magnitude of the vibration output from the bone conduction speakers 21 and 22 (that is, the signal level of the electric signal) is equal to or greater than the threshold th, the bone conduction headset 5B prevents the bone conduction microphone 30 from detecting the vibration. I do. As a result, even when the vibrations output from the bone conduction speakers 21 and 22 are large and it is difficult to cancel all of the vibrations only by inverting the phase, the bone conduction headset 5B can maintain the bone conduction microphone. 30 output can be cut off. That is, the vibration output from the bone conduction speakers 21 and 22 need not be further detected by the bone conduction microphone 30. Thus, the bone conduction headset 5B can prevent the bone conduction microphone 30 from picking up a large vibration. Further, even when the person hm uses the bone conduction microphone 30 and listens to the sound uttered by the bone conduction speakers 21 and 22, the bone conduction headset 5 </ b> B can suppress howling due to large vibration.

  As described above, the bone conduction headset 5B of the second embodiment includes the diode 201 (an example of a conversion circuit) that converts an AC signal input to the right bone conduction speaker 22 into a DC signal, and the converted DC signal. If the signal level is equal to or greater than the threshold th, the input block circuit 200 that blocks an electric signal transmitted from the bone conduction microphone 30 to the communication module 41 may be provided.

  Thus, for example, when the voice of the other party during a call is loud, the signal level of the electric signal becomes equal to or higher than the threshold th, and the electric signal output from the bone conduction microphone 30 is cut off before reaching the communication module 41. You. Therefore, the bone conduction headset 5B can cut off the output from the bone conduction microphone 30 before being output from the bone conduction speakers 21 and 22 by vibration, and then output the signal output by vibration through the bone conduction microphone 30. Thus, it is possible to avoid reaching the communication module 41 and suppress an echo phenomenon and a howling phenomenon.

  Further, even if the signal level of the electric signal does not exceed the threshold th and the electric signal output from the bone conduction microphone 30 is not cut off, the connection is switched as in the first embodiment. The conduction headset 5B can suppress the electric signals from the bone conduction speakers 21 and 22 from being input to the bone conduction microphone 30 by canceling each other.

(Third embodiment)
In the third embodiment, a case where the output of the bone conduction microphone 30 is simply cut off when the electric signal input to the bone conduction speakers 21 and 22 is larger than the threshold th is shown. That is, the third embodiment shows a case where the phases of the electric signals input to the bone conduction speakers 21 and 22 are not inverted as compared with the second embodiment. In the bone conduction headset according to the third embodiment, the same components as those of the second embodiment are denoted by the same reference numerals, and description thereof will be omitted.

  FIG. 9 is a diagram showing a circuit of a bone conduction headset 5C according to the third embodiment. The same components as those in the second embodiment are denoted by the same reference numerals. In the bone conduction headset 5C, as in the bone conduction speaker of the comparative example, while the phases of the vibrations output from the left and right bone conduction speakers 21 and 22 are aligned, the electric signal input to the bone conduction speakers 21 and 22 is maintained. If the size is equal to or larger than the threshold th, the output of the bone conduction microphone 30 is cut off.

  On the other hand, when the magnitude of the vibration output from the bone conduction speakers 21 and 22 (that is, the signal level of the electric signal) is less than the threshold th, the signals output from the left and right bone conduction speakers 21 and 22 are not inverted. Therefore, the bone conduction microphone 30 detects these vibrations. However, since the level of this vibration is small, the scale of the generation of the echo is small, and it may be a level that does not affect the feeling of use of the person hm (user).

  As described above, the bone conduction headset 5C of the third embodiment includes the diode 201 (an example of a conversion circuit) that converts an AC signal input to the right bone conduction speaker 22 into a DC signal, and the converted DC signal. If the signal level is equal to or greater than the threshold th, the input block circuit 200 that blocks an electric signal transmitted from the bone conduction microphone 30 to the communication module 41 may be provided.

  Thus, for example, when the voice of the other party during a call is loud, the signal level of the electric signal becomes equal to or higher than the threshold th, and the electric signal output from the bone conduction microphone 30 is cut off before reaching the communication module 41. You. Therefore, the bone conduction headset 5B can cut off the output from the bone conduction microphone 30 before being output from the bone conduction speakers 21 and 22 by vibration, and then output the signal output by vibration through the bone conduction microphone 30. Thus, it is possible to avoid reaching the communication module 41 and suppress an echo phenomenon and a howling phenomenon.

  Although various embodiments have been described with reference to the drawings, it is needless to say that the present disclosure is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be made within the scope of the claims, and these naturally belong to the technical scope of the present disclosure. I understand.

  In the above embodiment, the bone conduction microphone 30 is attached so as to sandwich both sides of the nose hn, and detects vibration of the skin of the nose. The bone conduction microphone 30 may be attached to a portion that can be detected as a bone conduction sound, and may be attached to, for example, an external auditory canal or a cheek.

  In the above embodiment, the bone conduction speakers 21 and 22 output the vibration based on the signal received by the communication module 41, but are not limited thereto. For example, the bone conduction speakers 21 and 22 may output a vibration based on the audio signal stored in the memory in a state where the connections are switched as in the first embodiment. Also in this case, the bone conduction headset can suppress the vibrations output from the bone conduction speakers 21 and 22 from canceling each other and inputting to the bone conduction microphone 30.

  In the above embodiment, the processor may be physically configured in any manner. Further, if a programmable processor is used, the processing content can be changed by changing the program, so that the degree of freedom in designing the processor can be increased. The processor may be configured by one semiconductor chip or may be physically configured by a plurality of semiconductor chips. In the case of configuring with a plurality of semiconductor chips, each control of the above-described embodiment may be realized by separate semiconductor chips. In this case, it can be considered that one processor is constituted by the plurality of semiconductor chips. Further, the processor may be configured by a member (such as a capacitor) having a different function from the semiconductor chip. In addition, one semiconductor chip may be configured so as to realize the functions of the processor and other functions. Further, a plurality of processors may be constituted by one processor.

  According to the present disclosure, even in the case of a bone conduction headset in which a bone conduction microphone and a bone conduction speaker are integrated with a frame, the output of vibration from the bone conduction speaker can be suppressed from being input to the bone conduction microphone via the frame. Useful for bone conduction headsets and the like.

5, 5A, 5C, 105 Bone conduction headset 10 Frame 10A Glasses frame 21, 22 Bone conduction speaker 25p, 26p Positive output line 25m, 26m Negative output line 30 Bone conduction microphone 31, 32 Vibration sensor 35 Clip 41 Communication module 45 Battery 80 Smartphone 111L, 111R Temple 200 Input cutoff circuit 201 Diode 202 Capacitor 203, 251 Transistor 250 Amplifier circuit C1 Capacitor hm Person hn Nose ho Mouth Hy Ear R1, R2 Resistance

Claims (6)

A bone conduction microphone that detects mechanical vibration of the nose of a living organism and converts it into an electrical signal;
At least two bone conduction speakers that convert electrical signals into mechanical vibrations;
A frame on which the bone conduction microphone and at least two bone conduction speakers are mounted;
With
The bone conduction microphone is disposed at the center of the frame,
A first bone conduction speaker and a second bone conduction speaker included in at least two of the bone conduction speakers are symmetrically arranged with respect to the central portion of the frame,
The phase of the electric signal output from the first bone conduction speaker is not inverted,
The phase of the electric signal output from the second bone conduction speaker is inverted by about 180 degrees.
Bone conduction headset. A communication module that communicates the electric signal,
A positive electrode of the first bone conduction speaker and a negative electrode of the second bone conduction speaker are connected to a positive electrode of an audio output terminal of the communication module,
A negative electrode of the first bone conduction speaker and a positive electrode of the second bone conduction speaker are connected to a negative electrode of an audio output terminal of the communication module.
The bone conduction headset according to claim 1. A control unit that controls a phase of the electric signal,
The control unit includes:
Sending the electric signal to the bone conduction speaker without inverting the phase of the electric signal output from the first bone conduction speaker,
Inverting the phase of the electrical signal output from the second bone conduction speaker by approximately 180 degrees and sending the electrical signal to the bone conduction speaker;
The bone conduction headset according to claim 1. The frame is formed of a material including a hard material,
The bone conduction headset according to any one of claims 1 to 3. A communication module that communicates with another communication module,
The communication module,
Transmitting an electric signal input by vibration from the bone conduction microphone,
Receiving an electric signal output by vibration from the bone conduction speaker,
The bone conduction headset according to any one of claims 1 to 4. A bone conduction microphone that detects mechanical vibration of the nose of a living organism and converts it into an electrical signal;
At least two bone conduction speakers that convert electrical signals into mechanical vibrations;
A frame on which the bone conduction microphone and at least two bone conduction speakers are mounted;
With
The bone conduction microphone is disposed at the center of the frame,
A first bone conduction speaker and a second bone conduction speaker included in at least two of the bone conduction speakers are symmetrically arranged with respect to the central portion of the frame,
The sound pressure signal output from the first bone conduction speaker and the sound pressure signal output from the second bone conduction speaker are offset near the center.
Bone conduction headset.

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