Earphone

Abstract

[Problem] To provide an open ear-type earphone that can deliver high-quality sound while suppressing sound leakage.　[Solution] An open ear-type earphone (1A) comprises: a bone conduction vibrator (13) that contacts the back side of the auricle and vibrates in accordance with an audio reproduction signal; and a directional speaker (11) that is provided at a position on the front side of the auricle not to block the earhole and that emits sound toward the ear canal. The open ear-type earphone 1A separates a reproduction signal of audio data into a mid-to-high sound range reproduction signal which is a reproduction signal of a frequency band higher than or equal to a prescribed frequency and a low sound range reproduction signal which is a reproduction signal of a frequency band lower than the prescribed frequency, emits the mid-to-high sound range reproduction signal from the directional speaker 11, and vibrates the bone conduction vibrator 13 in accordance with the low sound range reproduction signal.

Description

Earphone

[0001] The present invention relates to an earphone, and particularly to an open-ear type earphone.

[0002] Non-Patent Document 1 discloses a bone-conduction open-ear type earphone that allows audio data to be heard by bringing a vibrator that vibrates according to a playback signal into contact with the temporal bone near the auricle, such that the vibration (sound wave) of the vibrator is transmitted from the temporal bone to the cochlea. In addition, Non-Patent Document 2 discloses an air-conduction open-ear type earphone that allows audio data to be heard by emitting sound toward the external auditory meatus from a small directional speaker mounted at a position that does not block the ear canal.

[0003] According to these open-ear type earphones, since the vibrator and the directional speaker do not block the ear canal, a user can listen to audio while paying attention to surrounding conditions, for example, during jogging.

[0004] Philips Japan Ltd., "Open-ear Wireless Sports Headphones TAA7607BK / 00", [online], [retrieved on March 18, Reiwa 7], Internet <URL: https: / / www.philips.co.jp / c-p / TAA7607BK_00 / open-ear-wireless-sports-headphones#see-all-benefits> ambie Inc., "ambie", [online], [retrieved on March 18, Reiwa 7], Internet <URL: https: / / ambie.co.jp / pages / about>

[0005] However, since the attenuation rate of sound waves increases with higher frequency, in the bone conduction type open-ear earphones described in Non-Patent Literature 1, sound waves (vibrations of the transducer) in the mid-to-high frequency range (e.g., 800 Hz to 20 kHz) are greatly attenuated before they reach the cochlea from the temporal bone. This results in a problem of degraded audio quality. Furthermore, in the air conduction type open-ear earphones described in Non-Patent Literature 2, sound waves emitted from the directional speaker travel through the air to reach the ear canal, so increasing the volume leads to increased sound leakage in the low frequency range (e.g., 20 Hz to 200 Hz), where the attenuation rate is low.

[0006] This invention has been made in view of the above circumstances, and its purpose is to provide open-ear earphones that allow users to listen to high-quality sound while suppressing sound leakage.

[0007] To solve the above problems, the present invention provides a transducer that vibrates according to the playback signal, which is placed in contact with the back of the auricle, and a directional speaker that emits sound toward the ear canal is provided on the front of the auricle in a position that does not block the ear canal. The playback signal of the audio data is separated into a mid-to-high frequency playback signal, which is a playback signal with a frequency band of a predetermined frequency or higher, and a low-frequency playback signal, which is a playback signal with a frequency band of a predetermined frequency or lower. The mid-to-high frequency playback signal is emitted from the directional speaker, and the transducer is made to vibrate according to the low-frequency playback signal. Here, it is preferable to set the predetermined frequency to a frequency within the range of 200 Hz to 800 Hz.

[0008] For example, the present invention comprises: a receiving means for receiving audio data; a playback means for playing back the audio data received by the receiving means; a separation means for separating the playback signal played back by the playback means into a mid-to-high frequency playback signal which is a playback signal with a frequency band of a predetermined frequency or higher, and a low-frequency playback signal which is a playback signal with a frequency band of a frequency below the predetermined frequency; a directional speaker that emits sound according to the mid-to-high frequency playback signal; and a vibrator that vibrates according to the low-frequency playback signal, wherein the directional speaker is mounted on the front side of the auricle in a position that does not block the ear canal and emits sound toward the external auditory canal, and the vibrator is in contact with the back side of the auricle.

[0009] According to the present invention, low-frequency sound signals, which experience significant sound leakage during air conduction, are transmitted to the cochlea from the back of the auricle via a transducer, while mid-to-high frequency sound signals, which experience significant attenuation during bone conduction, are transmitted through the air via a directional speaker to the ear canal. This allows for the listening of high-quality sound while suppressing sound leakage.

[0010] Figures 1(A) to 1(F) are a front view, top view, bottom view, left side view, rear view, and perspective view of an open-ear earphone 1A according to a first embodiment of the present invention, respectively. Figure 2 is a cross-sectional view of the ear portion showing the open-ear earphone 1A according to a first embodiment of the present invention in a state where it is worn on the ear. Figure 3 is a schematic functional configuration diagram of the circuit board 14. Figures 4(A) to 4(E) are a front view, top view, bottom view, left side view, rear view, and perspective view of a modified example 1A' of the open-ear earphone 1A according to a first embodiment of the present invention, respectively. Figures 5(A) to 5(E) are a front view, top view, bottom view, left side view, rear view, and perspective view of an open-ear earphone 1B according to a second embodiment of the present invention, respectively.

[0011] Embodiments of the present invention will be described below.

[0012] [First Embodiment] First, a first embodiment of the present invention will be described.

[0013] Figures 1(A) to 1(F) are the front view, top view, bottom view, left side view, rear view, and perspective view of the open-ear earphone 1A according to this embodiment, respectively. Note that the left and right external appearances of the open-ear earphone 1A are symmetrical, and the right side view is omitted because it is symmetrical to the left side view except for the internal structure shown by the dashed line. Figure 2 is a cross-sectional view of the ear portion, showing the open-ear earphone 1A according to this embodiment in a state where it is worn in the ear.

[0014] As shown in the figure, the open-ear earphone 1A according to this embodiment is a C-shaped ear cuff type earphone that is worn on the auricle, and comprises a flexible C-shaped arm 10, a directional speaker 11 attached to one end 100 of the arm 10, and an earphone body 12 attached to the other end 101 of the arm 10.

[0015] When the arm 10 is subjected to an external force and bends in a direction that widens the gap between the directional speaker 11 and the earphone body 12, its elasticity biases the directional speaker 11 and the earphone body 12 toward each other. Thus, as shown in Figure 2, when the open-ear earphone 1A is worn on the ear with the directional speaker 11 in contact with the front side of the auricle and the inner surface of the earphone body 12 in contact with the back side of the auricle, the directional speaker 11 and the earphone body 12 are held by the auricle while being held between them. Although not shown, wiring for electrically connecting the directional speaker 11 to the earphone body 12 is provided inside the arm 10. The arm 10 can be made of an elastic material such as rubber or elastomer with a spring or other biasing member inserted into it.

[0016] As shown in Figure 2, the directional speaker 11 is positioned on the outer side of the auricle so as to emit sound towards the ear canal from a position that does not block the ear canal when the open-ear type earphone 1A is worn on the ear.

[0017] The earphone body 12 includes a transducer housing section 120, a circuit board housing section 121, and a connecting section 122 that connects the transducer housing section 120 and the circuit board housing section 121.

[0018] The bone conduction transducer 13 is housed in the transducer housing 120 so as to be in contact with the inner surface of the transducer housing 120 (the surface that contacts the back of the auricle). As a result, as shown in Figure 2, when the open-ear earphone 1A is worn on the ear, the bone conduction transducer 13 is positioned to contact the back of the auricle via the transducer housing 120.

[0019] The circuit board housing section 121 houses a circuit board 14 for driving the directional speaker 11 and the bone conduction transducer 13 according to the audio signal, and a battery (button battery, rechargeable battery, etc.) 15 for supplying power to the circuit board 14.

[0020] The connecting portion 122 is made of a vibration-absorbing material such as rubber, sponge, or elastomer, and prevents vibrations from the bone conduction transducer 13 from being transmitted from the transducer housing portion 120 to the substrate housing portion 121. Although not shown in the figures, wiring for electrically connecting the directional speaker 11 and the bone conduction transducer 13 to the circuit board 14 is provided inside the connecting portion 122.

[0021] Figure 3 is a schematic functional diagram of the circuit board 14.

[0022] As shown in the figure, the circuit board 14 includes a receiving unit 140, a playback unit 141, an audio output unit 142, a drive unit 143, and a power supply unit 144.

[0023] The receiving unit 140 receives audio data wirelessly transmitted from an audio player (not shown), such as a smartphone, using short-range wireless communication such as Bluetooth®.

[0024] The playback unit 141 plays back the audio data received by the receiving unit 140. The playback signal of the audio data is then separated into a mid-to-high frequency playback signal, which is a playback signal in the mid-to-high frequency range above a predetermined frequency (a frequency set within the range of 200 Hz to 800 Hz), and a low-frequency playback signal, which is a playback signal in the low-frequency range below this predetermined frequency. The mid-to-high frequency playback signal is output to the audio output unit 142, and the low-frequency playback signal is output to the drive unit 143.

[0025] The audio output unit 142 outputs the mid-to-high frequency playback signal input from the playback unit 141 to the directional speaker 11.

[0026] The drive unit 143 drives the bone conduction transducer 13 according to the low-frequency reproduction signal input from the playback unit 141.

[0027] The power supply unit 144 then supplies power from the battery 15 to each part 140-144 of the circuit board 14.

[0028] The functional configuration of the circuit board 14 shown in Figure 3 can be realized in hardware, for example, by integrated logic ICs such as ASICs (Application Specific Integrated Circuits) and FPGAs (Field Programmable Gate Arrays), or in software by computers such as DSPs (Digital Signal Processors).

[0029] In the open-ear type earphone 1A with the above configuration, when the receiving unit 140 receives audio data wirelessly transmitted from an audio player (not shown), it outputs this audio data to the playback unit 141. The playback unit 141 plays the audio data input from the receiving unit 140, separates the playback signal into a mid-high frequency playback signal and a low frequency playback signal, and outputs the mid-high frequency playback signal and the low frequency playback signal to the audio output unit 142 and the drive unit 143, respectively. In response, the audio output unit 142 outputs the mid-high frequency playback signal input from the playback unit 141 to the directional speaker 11, and the drive unit 143 drives the bone conduction transducer 13 according to the low frequency playback signal input from the playback unit 141. As a result, the directional speaker 11 emits sound according to the mid-high frequency playback signal, and the bone conduction transducer 13 vibrates according to the low frequency playback signal.

[0030] The audio beam of the mid-to-high frequency reproduction signal emitted from the directional speaker 11, positioned on the outer side of the auricle without blocking the ear canal, enters the ear canal through the ear canal, reaches the eardrum, and is transmitted to the cochlea. In addition, vibrations generated by the bone conduction transducer 13, positioned to contact the back of the auricle via the transducer housing 120 of the earphone body 12, are transmitted from the back of the auricle to the cochlea. As a result, vibrations of audio signals of different frequency bands are transmitted to the cochlea via two different paths (bone conduction and air conduction), allowing the user to hear the sound.

[0031] The first embodiment of the present invention has been described above.

[0032] In this embodiment, low-frequency reproduction signals, which experience significant sound leakage during air conduction, are transmitted to the cochlea from the back of the auricle via the bone conduction transducer 13 (bone conduction). Mid-to-high frequency reproduction signals, which experience significant attenuation during bone conduction, are transmitted through the air via the directional speaker 11 to the external auditory canal and then transmitted to the cochlea via the eardrum (air conduction). Therefore, according to this embodiment, high-quality sound can be heard while suppressing sound leakage.

[0033] Furthermore, in this embodiment, the transducer housing 120, which houses the bone conduction transducer 13, and the circuit board housing 121, which houses the circuit board 14, are connected by a connecting portion 122 formed of a vibration-absorbing member. As a result, the circuit board 14 can reduce the influence of vibrations caused by the bone conduction transducer 13.

[0034] In this embodiment, the earphone body 12 is constructed by connecting the transducer housing 120 and the substrate housing 121 with a connecting portion 122. However, the present invention is not limited to this. If the effects of vibration can be ignored, the connecting portion 122 may be omitted, and the earphone body 12 may be constructed by integrally forming the transducer housing 120 and the substrate housing 121.

[0035] Furthermore, in this embodiment, the earphone body 12 is configured such that both the transducer housing 120 and the substrate housing 121 face the directional speaker 11 (so that when the open-ear earphone 1A is worn on the ear, both the transducer housing 120 and the substrate housing 121 contact the back of the auricle). However, the present invention is not limited to this. For example, as shown in Modification 1A' of the open-ear earphone 1A in Figures 4(A) to (F), the substrate housing 121' may be positioned on the opposite side of the directional speaker 11 from the transducer housing 120', and the two 120' and 121' may be connected by a connecting portion 122' formed of a vibration-absorbing member, thereby configuring the earphone body 12'. In this case, only the transducer housing 120' contacts the back of the auricle. In this Modification 1A' as well, similar to this embodiment, the connecting portion 122' may be omitted, and the earphone body 12' may be configured by integrally forming the transducer housing 120' and the substrate housing 121'.

[0036] [Second Embodiment] Next, a second embodiment of the present invention will be described.

[0037] Figures 5(A) to 5(F) are the front view, top view, bottom view, left side view, rear view, and perspective view, respectively, of the open-ear type earphone 1B according to the second embodiment of the present invention. Note that the left and right external appearances of the open-ear type earphone 1A are symmetrical, and the right side view is symmetrical to the left side view, so it is omitted. Also, the same reference numerals are used for the same components as those used for the open-ear type earphone 1A according to the first embodiment shown in Figure 1.

[0038] As shown in the figure, the open-ear earphone 1B according to this embodiment is a C-shaped ear cuff type earphone that is worn on the auricle, similar to the open-ear earphone 1A according to the first embodiment of the present invention, and comprises a flexible C-shaped arm 10, a directional speaker 11 attached to one end 100 of the arm 10, and an earphone body 16 attached to the other end 101 of the arm 10.

[0039] The earphone body 16 includes a pair of transducer housing sections 160, a circuit board housing section 161, and a pair of connecting sections 162 that connect each of the pair of transducer housing sections 160 to the circuit board housing section 12.

[0040] The bone conduction transducer 13 is housed in the transducer housing 160 so as to be in contact with the inner surface of the transducer housing 160. As a result, when the open-ear earphone 1B is worn on the ear, the bone conduction transducer 13 is positioned to be in contact with the back of the auricle via the transducer housing 160.

[0041] The circuit board housing 161 houses the circuit board 14 and the battery 15. Although not shown in the figure, wiring for electrically connecting the directional speaker 11 to the circuit board 14 is provided inside the circuit board housing 161.

[0042] The connecting portion 162 is formed of a vibration absorbing member having elasticity such as rubber, sponge, or elastomer, and prevents the vibration of the bone conduction vibrator 13 from being transmitted from the vibrator housing portion 160 to the substrate housing portion 161. Although not shown, wiring for electrically connecting the bone conduction vibrator 13 to the circuit board 14 is provided inside the connecting portion 162. Further, the connecting portion 162 connects the vibrator housing portion 160 and the substrate housing portion 161 such that the vibrator housing portion 160 is inclined toward the directional speaker 11 side relative to the substrate housing portion 161 (see FIG. 5(B) and FIG. 5(C)). Thereby, the two vibrator housing portions 160 can be arranged at positions corresponding to the ear shape of each individual user such that the two bone conduction vibrators 13 are in close contact with the back side of the auricle.

[0043] The second embodiment of the present invention has been described above.

[0044] The present embodiment has the following effects in addition to the effects of the first embodiment described above.

[0045] That is, according to the present embodiment, since the low-frequency range reproduction signal is output using the pair of bone conduction vibrators 13, the reproduction volume in the low-frequency range can be further increased, and more powerful audio can be listened to.

[0046] Further, in the present embodiment, when the open-ear type earphone 1B is worn on the ear, the connecting portion 162 deforms according to the shape of the ear. For this reason, the degree of close contact between the two bone conduction vibrators 13 and the back side of the auricle increases, and the transmission efficiency of the vibration of the bone conduction vibrators 13 to the cochlea is improved. Therefore, according to the present embodiment, the quality of the low-frequency range is enhanced, and higher-quality sound can be listened to.

[0047] Note that, in the present embodiment, the earphone main body 16 is configured by connecting each of the pair of vibrator housing portions 160 to the substrate housing portion 161 with the connecting portion 162. However, the present invention is not limited to this. The earphone main body 16 may be configured by omitting the connecting portion 162 and integrally forming the pair of vibrator housing portions 160 and the substrate housing portion 161.

[0048] The respective embodiments of the present invention have been described above.

[0049] It should be noted that the present invention is not limited to the embodiments described above, and numerous modifications are possible within the scope of its essence.

[0050] Furthermore, while the above embodiments described C-shaped ear cuffs that clamp onto the auricle as examples of open-ear earphones, the present invention is not limited to these. The present invention is also applicable to headphones in which an open-ear earphone for the right ear and an open-ear earphone for the left ear are connected by a headband.

[0051] 1A, 1A', 1B: Open-ear earphones 10: Arm 11: Directional speaker 12, 12', 16: Earphone body 13: Bone conduction transducer 14: Circuit board 15: Battery 120, 120', 160: Transducer housing 121, 121', 161: Circuit board housing 122, 122', 162: Connecting section 140: Receiving section 141: Playback section 142: Audio output section 144: Drive section 144: Power supply section

Claims

1. An earphone comprising: a receiving means for receiving audio data; a playback means for playing back the audio data received by the receiving means; a separation means for separating the playback signal played back by the playback means into a mid-to-high frequency playback signal which is a playback signal with a frequency band of a predetermined frequency or higher, and a low-frequency playback signal which is a playback signal with a frequency band below the predetermined frequency; a directional speaker that emits sound according to the mid-to-high frequency playback signal; and a vibrator that vibrates according to the low-frequency playback signal, wherein the directional speaker is mounted on the front side of the auricle in a position that does not block the ear canal and emits sound toward the ear canal, and the vibrator is in contact with the back side of the auricle.

2. An earphone according to claim 1, further comprising a housing that houses the receiving means, the playback means, and the separation means, wherein the vibrator is connected to the housing via a vibration absorbing member.

3. An earphone according to claim 2, comprising a pair of vibrators and a pair of vibration-absorbing members, wherein the pair of vibrators are connected to both sides of the housing via the vibration-absorbing members.

4. An earphone according to claim 3, wherein the vibration absorbing member connects the housing and the vibrator such that the vibrator is inclined with respect to the housing.

5. An earphone according to any one of claims 1 to 4, further comprising an arc-shaped arm to which the directional speaker is connected at one end and the transducer is connected at the other end, wherein the arm biases the transducer relative to the directional speaker such that the anterior auricle is sandwiched between the directional speaker and the transducer.

6. An earphone according to any one of claims 1 to 4, characterized in that the predetermined frequency is set within the range of 200 Hz to 800 Hz.

7. An earphone according to claim 5, characterized in that the predetermined frequency is set within the range of 200 Hz to 800 Hz.

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