audio equipment

Abstract

To enable a sound image localization by fetching a sound in an external part.SOLUTION: An earphone 10 comprises: a nozzle 11 housing a transducer 20 which becomes a sound source; and a housing 12 that is attached to a base part 11a of the nozzle 11, and houses an electronic circuit and a battery for driving the transducer 20. An inner part of the nozzle 11 is divided into two paths by an interval wall 11c to a direction where the nozzle 11 is extended, the transducer 20 is housed in a first path 11d, and a second path 11e is communicated with a tip end 11b from a base part 11a of the nozzle 11. The earphone is constructed so as to fetch an external sound through the second path 11e opening in the base part 11a of the nozzle 11 when the earphone 10 is worn to each ear.SELECTED DRAWING: Figure 2A

Description

Technical Field

[0001] This embodiment relates to an acoustic device worn on the ear and using a transducer for a sound source.

Background Art

[0002] Conventionally, in the fields of manufacturing, medicine, etc., augmented reality (AR) has been used to provide a human interface to workers. In augmented reality, a worker wears a video device such as a head-mounted display on the head and an acoustic device such as an earphone on the ear, and information is provided by overlapping the surrounding environment. During work, there may be a need to hear external sounds such as an alarm sounding or being spoken to, and as a method for clearly capturing such external sounds, noise cancellation technology and a technology for collecting external sounds with a microphone and reproducing them as used in hearing aids are known (see Patent Document 1).

[0003] On the other hand, a transducer using a piezoelectric element configured by sandwiching a piezoelectric film between a pair of electrodes created by MEMS (micro-electromechanical systems) technology applying semiconductor manufacturing technology is provided. A speaker configured by such a transducer is also provided (see Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In augmented reality settings such as manufacturing and healthcare, when using audio equipment, it is sometimes crucial to know the sound localization of externally acquired sounds, that is, the direction and distance from which the sound originated. This requires capturing sound with high fidelity, including the phase difference of sounds reaching both ears from the outside. Conventional noise-canceling technologies and technologies that reproduce sound collected by microphones sometimes resulted in ambiguous sound localization.

[0006] This embodiment is proposed in view of the above-described circumstances, and aims to provide an audio device that is worn on the ear and can capture external sounds with high sound quality so that it is possible to localize the sound image of the sound taken in from the outside. [Means for solving the problem]

[0007] This embodiment is an acoustic device comprising a nozzle equipped with a transducer that serves as a sound source, and a housing attached to the base of the nozzle that houses an electronic circuit and a battery for driving the transducer, wherein when the acoustic device is worn on the ear, a passage is secured between the tip of the nozzle inserted into the ear canal and the base of the nozzle outside the ear canal, and external sounds are taken in through this passage. [Effects of the Invention]

[0008] According to this embodiment, external sounds can be captured with high sound quality, enabling sound image localization. [Brief explanation of the drawing]

[0009] [Figure 1A] Figure 1A is a left side view of the earphone according to the first embodiment. [Figure 1B] Figure 1B is a front view of the earphone according to the first embodiment. [Figure 1C] Figure 1C is a right side view of the earphone according to the first embodiment. [Figure 2A] Figure 2A is a cross-sectional view of the earphone according to the first embodiment. [Figure 2B] Figure 2B is a longitudinal cross-sectional view of the earphone according to the first embodiment. [Figure 3] Figure 3 is a perspective view showing the support substrate on which the transducer is mounted. [Figure 4A] Figure 4A is a plan view of the earphone transducer according to the first embodiment. [Figure 4B] Figure 4B is a cross-sectional view of the transducer of the earphone according to the first embodiment. [Figure 5A] Figure 5A is a plan view of the transducer of the earphone in the first modified example. [Figure 5B] Figure 5B is a cross-sectional view of the transducer of the earphone of the first modified example. [Figure 6A] Figure 6A is a plan view of the transducer of the earphone in the second modified example. [Figure 6B] Figure 6B is a cross-sectional view of the transducer of the earphone in the second modified example. [Figure 7A] Figure 7A is a left side view of the earphone according to the second embodiment. [Figure 7B] Figure 7B is a front view of the earphone according to the second embodiment. [Figure 7C] Figure 7C is a right side view of the earphone according to the second embodiment. [Figure 8A] Figure 8A is a cross-sectional view of the earphone according to the second embodiment. [Figure 8B] Figure 8B is a longitudinal cross-sectional view of the earphone according to the second embodiment. [Modes for carrying out the invention]

[0010] Next, the present embodiment will be described with reference to the drawings. In the present embodiment, although an earphone is assumed as the acoustic device to be worn on the ear, the acoustic device is not limited to an earphone, and can be applied to other types such as headphones as long as it is an acoustic device worn on the ear. In the description of the drawings described below, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimensions of each component is different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Also, it is a matter of course that there are portions where the dimensional relationships and ratios are different among the drawings.

[0011] In addition, the embodiments shown below are examples for embodying the technical idea, and do not specify the materials, shapes, structures, arrangements, etc. of each component. The embodiments can be variously modified based on the configurations defined in the claims.

[0012] (First Embodiment) The earphone, which is the acoustic device of the first embodiment, includes a nozzle equipped with a transducer serving as a sound source, and a housing attached to the base of the nozzle and storing an electronic circuit and a battery for driving the transducer. When the earphone is worn on the ear, a passage is secured between the tip of the nozzle inserted from the ear canal and the base of the nozzle outside the ear canal, and is configured to allow external sound to be taken in through the passage. External sound can be taken in with high sound quality through the passage that connects the tip of the nozzle and the base of the nozzle outside the ear canal.

[0013] The inside of the nozzle is divided into two passages by a partition wall in the direction in which the nozzle extends. A transducer is installed in one passage, and the other passage communicates from the base to the tip of the nozzle. When the earphone is worn on the ear, external sound may be taken in through the other passage that opens at the base of the nozzle. Together with one passage for transmitting the sound wave generated by the transducer, the other passage for taking in external sound is secured.

[0014] The cross-sectional area of ​​the other passage may be larger than that of the first passage. This ensures that the sound quality of the sound taken in by the other passage is maintained.

[0015] The nozzle may further include a flexible earpiece that surrounds a predetermined area from the tip to the base, and the nozzle may be configured to be wearable via the earpiece that fits into the ear canal. The nozzle can be securely attached to the ear.

[0016] The transducer may include a substrate having a main surface and a back surface; a vibrating membrane formed on the back surface by a recess formed thereon, such that the main surface can vibrate in the direction of separation from the substrate, and the substrate is formed to a predetermined thickness from the main surface; and a driving layer in which a pair of electrode layers are laminated on the vibrating membrane on the main surface such that a piezoelectric layer is sandwiched between them. The driving layer can cause the vibrating membrane to vibrate.

[0017] The vibrating membrane may be connected to the main surface all around its circumference. Because the vibrating membrane is connected to the main surface all around, the structure is robust.

[0018] A slit may be formed on the main surface of the diaphragm in a portion of its circumference, so that the diaphragm forms a cantilever. Due to the cantilever structure, the volume can be increased by increasing the amplitude of the diaphragm.

[0019] Side walls surrounding the vibrating membrane may be formed on the main surface. These walls protect the vibrating membrane and can also serve as supports for the upper part of the surface.

[0020] An inwardly protruding upper hood may be formed at the top of the side wall. This can prevent dust from entering from above.

[0021] A lower circuit board may be attached to the rear, forming a lower hood that protrudes into the recess. This prevents dust from entering from below.

[0022] The transducer may be mounted on the main surface of the support substrate, or it may be mounted inside the nozzle via the support substrate. The support substrate supports the transducer and supplies the drive voltage to the transducer via wires.

[0023] A transducer may be supplied with a voltage from an electronic circuit housed within the transducer, via a support substrate, to drive the drive layer. The voltage that drives the drive layer of the transducer is supplied from the electronic circuit via the support substrate.

[0024] Figures 1A, 1B, and 1C are the left side view, front view, and right side view, respectively, of the earphone 10 according to the first embodiment. Here, for convenience, the direction in Figure 1B is considered the front of the earphone 10. The earphone 10 according to the first embodiment includes a nozzle 11 that is mounted on a transducer which serves as a sound source and extends from a base 11a located outside the ear canal to a tip 11b inserted into the ear canal, a housing 12 attached to the base 11a of the nozzle 11 which houses an electronic circuit and battery for driving the transducer, and a flexible earpiece 13 attached near the tip 11b of the nozzle 11 which surrounds a predetermined range from the tip 11b of the nozzle 11 toward the base 11a.

[0025] Figure 2A is a cross-sectional view taken along the cutting line IIA-IIA in Figure 1A or Figure 1C. Figure 2B is a cross-sectional view taken along the cutting line IIB-IIB in Figure 1B. As shown in Figures 2A and 2B, the nozzle 11 has a cylindrical shape with a predetermined diameter and a predetermined wall thickness, and extends over a predetermined length from the base 11a to the tip 11b. The passage inside the nozzle 11 is divided by a partition wall 11c of a predetermined thickness into a lower first passage 11d and an upper second passage 11e having a larger cross-sectional area than the first passage 11d. A transducer 20 is installed in the first passage 11d. The nozzle 11 may be formed of a suitable resin. Note that the first passage 11d and the second passage 11e are only passages divided by the partition wall 11c inside the nozzle 11, and do not have to be passages divided vertically. Also, the cross-sectional area of ​​the second passage 11e does not have to be larger than the cross-sectional area of ​​the first passage 11d.

[0026] Figure 3 is a perspective view showing the transducer 20 supported on the support substrate 31. In the first passage 11d of the nozzle 11, the transducer 20 is supported and installed on the support substrate 31. As shown in Figures 2A and 2B, the support substrate 31 is supported by the bottom of the first passage 11d, the transducer 20 and the first end of the support substrate 31 are supported by a first support wall 11f formed at the bottom of the first passage 11d and extending radially from the nozzle 11, and the main surface 21a adjacent to the second end of the transducer 20 opposite the first end is supported by a second support wall 11g formed at the top of the first passage 11d and also extending radially from the nozzle 11. In the support substrate 31, air vents 31b are formed directly below the vibrating membrane 21d and recess 21c of the transducer 20 to ensure the entry and exit of air accompanying the vibration of the vibrating membrane 21d (see Figures 4A and 4B).

[0027] Figure 4A is a plan view of the transducer 20. Figure 4B is a cross-sectional view taken along the cutting line IVB-IVB in Figure 4A. The transducer 20 is formed on a plate-shaped silicon substrate 21 that is substantially rectangular in plan view and has a predetermined thickness. On the main surface 21a of the substrate 21, a vibrating membrane 21d is formed by a recess 21c formed on the back surface 21b facing the main surface 21a, so that the main surface 21a can vibrate in the direction of separation from the main surface 21a. Here, vibration in the direction of separation from the main surface 21a means vibration in the direction of moving away from or towards the main surface 21a, that is, vibration along the direction of the normal to the main surface 21a.

[0028] The vibrating membrane 21d is formed as a disc-shaped region having a predetermined diameter at a position slightly off-center from the center of the main surface 21a, which has a substantially rectangular shape, towards one of its shorter sides. A driving layer 22 is laminated on the vibrating membrane 21d, in which a pair of electrode layers, a lower electrode layer 22a and an upper electrode layer 22c, are laminated so as to sandwich a piezoelectric layer 22b, forming a disc-shaped region surrounded by the circumference of the vibrating membrane 21d, with a diameter smaller than that of the vibrating membrane 21d. A pair of electrode pads 23 for supplying a driving voltage to the driving layer 22 are formed along the other shorter side opposite to the aforementioned shorter side.

[0029] The vibrating membrane 21d of the transducer 20 vibrates when driven by the drive layer 22, generating sound waves. The sound waves generated from the transducer 20 within the nozzle 11 travel along the first passage 11d toward the tip 11b of the nozzle 11 and are emitted from the tip 11b of the nozzle 11. In response to the vibration of the vibrating membrane 21d, air enters and exits through the air vent hole 31b located directly below the vibrating membrane 21d and recess 21c of the transducer 20. The transducer 20 can be installed in any desired position within the first passage 11d of the nozzle 11, not limited to near the base 11a of the nozzle 11, but also near the tip 11b of the nozzle 11, in the center of the nozzle 11, etc.

[0030] Referring again to Figures 2A and 2B, the second passage 11e at the top of the nozzle 11 forms a passage that communicates from the opening at the base 11a of the nozzle 11 to the tip 11b of the nozzle 11. When the earphone 10 is worn in the ear, external sounds from the earphone 10 travel from the opening at the base 11a of the nozzle 11 through the second passage 11e to the tip 11b of the nozzle 11 and are emitted from the tip 11b of the nozzle.

[0031] The housing 12 houses an electronic circuit for driving the transducer 20 and a battery for driving the electronic circuit. The electronic circuit may include a wireless amplifier that receives an external wireless signal and converts it into a voltage for driving the transducer 20. The housing 12 blocks the first passage 11d below the partition wall 11c at the base 11a of the nozzle 11, so that a second passage 11e opens at the base 11a of the nozzle 11, and hangs down further, with an air vent 12a formed at the very bottom. The housing 12 may be made of a suitable resin and may be formed integrally with the nozzle 11.

[0032] The earpiece 13 consists of an inner cylinder fixed to the nozzle 11, covering a predetermined range from the tip 11b of the nozzle 11 toward the base 11a, and an outer cylinder that surrounds the nozzle 11 from a predetermined position beyond the tip 11b toward the base 11a, gradually increasing in diameter, and extending beyond the inner cylinder to a predetermined range. The inner cylinder and the outer cylinder are connected at the predetermined position and formed integrally. The earpiece 13 is made of a flexible material with a predetermined thickness so that when the earphone 10 is worn in the ear, it can fit into the ear canal and external auditory canal and support the earphone with appropriate elasticity. The earpiece 13 may be made of an appropriate resin, rubber, or the like.

[0033] In the earphone 10 of the first embodiment, sound waves originating from a transducer 20 mounted in the first passage 11d of the nozzle 11, along with external sound taken in through the second passage 11e of the nozzle 11, are emitted from the tip 11b of the nozzle 11. Since the second passage 11e has a larger cross-sectional area than the first passage 11d, the diffraction of external sound taken in from the opening of the base 11a of the nozzle 11 by the second passage 11e is suppressed, and the degradation of sound quality is reduced. Therefore, with the earphone 10 of this embodiment, external sound can also be taken in with high sound quality, and sound image localization becomes possible.

[0034] Furthermore, in the earphone 10 of the first embodiment, a transducer 20 that drives the diaphragm 21d by a driving layer 22 is used as the sound source. The transducer 20 is small and lightweight because it is manufactured on a silicon substrate using MEMS technology. As a result, the transducer 20 can be installed in the first passage 11d of the nozzle 11, and not only the nozzle 11 but also the entire earphone 10 can be made smaller and lighter. In addition, the transducer 20 is piezoelectric driven and consumes little power. As a result, the earphone 10 can be used for extended periods.

[0035] Furthermore, since the earphones 10 of the first embodiment can take in external sounds with high sound quality, the method of letting people listen to natural sounds, which is known as a method to reduce tinnitus in people with hearing loss, becomes possible while wearing the earphones 10.

[0036] (First variation) Figure 5A is a plan view of the transducer 30 of the first modified example. Figure 5B is a cross-sectional view taken along the cutting line VB-VB in Figure 5A. The transducer 30 of the first modified example differs from the transducer 20 of the first embodiment in that side walls 25 are formed on the main surface 21a of the substrate 21 so as to surround the vibrating membrane 21d. The other configurations are the same as those of the transducer 20 of the first embodiment, so the same reference numerals are used for common components to clarify the correspondence.

[0037] The transducer 30 of the first modified example is formed on a plate-shaped silicon substrate 21 that is substantially rectangular in plan view and has a predetermined thickness. On the main surface 21a of the substrate 21, a vibrating membrane 21d is formed by a recess 21c formed on the back surface 21b facing the main surface 21a, so that the main surface 21a can vibrate in the direction of separation and contact.

[0038] The vibrating membrane 21d is formed as a disc-shaped region having a predetermined diameter at a position slightly off-center from the center of the main surface 21a, which has a substantially rectangular shape, towards one of its shorter sides. A driving layer 22 is laminated on the vibrating membrane 21d, in which a pair of electrode layers, a lower electrode layer 22a and an upper electrode layer 22c, are laminated so as to sandwich a piezoelectric layer 22b, forming a disc-shaped region surrounded by the circumference of the vibrating membrane 21d, with a diameter smaller than that of the vibrating membrane 21d. A pair of electrode pads 23 for supplying a driving voltage to the driving layer 22 are formed along the other shorter side opposite to the aforementioned shorter side.

[0039] On the main surface 21a of the substrate 21, side walls 25 of a predetermined thickness and height are formed so as to surround the vibrating membrane 21d and the drive layer 22 laminated on the vibrating membrane 21d. The side walls 25 are formed along the outer circumference of one short side and within a predetermined range from one short side on a pair of opposing long sides. The remaining portion of the side walls 25 are formed parallel to the other short side between the electrode pad 23 and the vibrating membrane 21d so as to connect to the side walls 25 formed along the outer circumference of the pair of long sides. The side walls 25 may be attached from another silicon substrate or the like, or they may be formed integrally with the substrate 21 by etching.

[0040] In the transducer 30 of the first modified example, the side wall 25 surrounds the vibrating membrane 21d and the drive layer 22 on the main surface 21a and is formed to a predetermined height. Therefore, the vibrating membrane 21d and the drive layer 22 are protected from above. In addition, the side wall 25 maintains a constant height from the main surface 21a to the top at a predetermined height. Therefore, the side wall 25 can serve as a support when the transducer 30 is supported from above.

[0041] (Second variation) Figure 6A is a plan view of the transducer 40 of the second modified example. Figure 6B is a cross-sectional view taken along the cutting line VIB-VIB in Figure 6A. The transducer 40 of the second modified example differs from the transducer 20 of the first embodiment in that the vibrating membrane 21d has a cantilever structure, side walls 26 are formed on the main surface 21a of the substrate 21 so as to surround the vibrating membrane 21d, and a lower substrate 27 is attached to the back surface 21b of the substrate 21. The other configurations are the same as those of the transducer 20 of the first embodiment, so the same reference numerals are used for common components to clarify the correspondence.

[0042] The transducer 40 of the second modified example is formed on a plate-shaped silicon substrate 21 that is substantially rectangular in plan view and has a predetermined thickness. On the main surface 21a of the substrate 21, a vibrating membrane 21d is formed by a recess 21c formed on the back surface 21b facing the main surface 21a, so that the main surface 21a can vibrate in the direction of separation and contact.

[0043] The vibrating membrane 21d is formed as a substantially rectangular region located off-center from the main surface 21a, towards one of its shorter sides, with sides parallel to each side of the rectangle. In the vibrating membrane 21d, slits 21e are formed on three sides: the short side opposite the one short side and the mutually opposing long sides, giving the vibrating membrane 21d a cantilever structure. A drive layer 22 is laminated on the vibrating membrane 21d, in which a pair of electrode layers, a lower electrode layer 22a and an upper electrode layer 22c, are laminated so as to sandwich a piezoelectric layer 22b, forming a substantially rectangular region smaller than the vibrating membrane 21d, surrounded by the periphery of the vibrating membrane 21d. A pair of electrode pads 23 for supplying a drive voltage to the drive layer 22 are formed along the other short side opposite the one short side.

[0044] On the main surface 21a of the substrate 21, side walls 26 of a predetermined thickness and height are formed so as to surround the vibrating membrane 21d and the drive layer 22 laminated on the vibrating membrane 21d. The side walls 26 are formed along the outer circumference of one short side and within a predetermined range from one short side on a pair of opposing long sides. The remaining portion of the side walls 26 are formed parallel to the other short side between the electrode pad 23 and the vibrating membrane 21d so as to connect to the side walls 26 formed along the outer circumference of the pair of long sides. The side walls 26 form a hood that protrudes inward from their tops for a predetermined distance. The side walls 26 may be made from other silicon substrates or the like and attached.

[0045] A lower substrate 27 having a predetermined thickness is attached to the back surface 21b of the substrate 21. Similar to the back surface 21b where the recess 21c is formed, the lower substrate 27 has a roughly rectangular outer circumference with a hole corresponding to the recess 21c, but it forms a hood that extends from around the recess 21c to the recess 21c over a predetermined distance. A silicon substrate, a printed circuit board, or the like may be attached to the lower substrate 27.

[0046] In the second modified transducer 30, the side wall 26 surrounds the vibrating membrane 21d and the drive layer 22 on the main surface 21a and is formed to a predetermined height, protecting the vibrating membrane 21d and the drive layer 22 from above. In the second modified transducer, the vibrating membrane 21d is a cantilever structure with a slit 21e formed in the substrate 21, and the presence of dust is a problem, but the hood of the side wall 26 prevents dust from entering from above. Furthermore, the side wall 26 maintains a constant height from the main surface 21a to a predetermined height at the top. Therefore, the side wall 26 can serve as a support when the transducer 30 is supported from above.

[0047] Furthermore, in the transducer 30 of the second modified example, the lower substrate 27 is attached to the rear surface 21b, and a hood protrudes from the recess 21c. As mentioned above, the diaphragm 21d of the second modified example has a cantilever structure in which a slit 21e is formed in the substrate 21, and the presence of dust is a problem, but the hood of the lower substrate 27 prevents dust from entering from below.

[0048] (Second Embodiment) The earphone, which is an audio device of the second embodiment, comprises a nozzle equipped with a transducer that serves as a sound source, and a housing attached to the base of the nozzle that houses an electronic circuit and a battery for driving the transducer. When the earphone is worn in the ear, a passage is secured between the tip of the nozzle inserted into the ear canal and the base of the nozzle outside the ear canal, allowing external sounds to be taken in through this passage. The other passage allows external sounds to be taken in with high sound quality.

[0049] The nozzle may be configured such that it occupies only a portion of the radial cross-section of the ear canal, with a passage running along the outside of the nozzle from its base to its tip, allowing external sounds to be taken in through the passage opening at the base when the earphone is worn in the ear. The passage on the outside of the nozzle is reserved for taking in external sounds.

[0050] The transducer may include a substrate having a main surface and a back surface; a vibrating membrane formed on the back surface by a recess formed thereon, such that the main surface can vibrate in the direction of separation from the substrate, and the substrate is formed to a predetermined thickness from the main surface; and a driving layer in which a pair of electrode layers are laminated on the vibrating membrane on the main surface such that a piezoelectric layer is sandwiched between them. The driving layer can cause the vibrating membrane to vibrate.

[0051] The vibrating membrane may be connected to the main surface all around its circumference. Because the vibrating membrane is connected to the main surface all around, the structure is robust.

[0052] A slit may be formed on the main surface of the diaphragm in a portion of its circumference, so that the diaphragm forms a cantilever. Due to the cantilever structure, the volume can be increased by increasing the amplitude of the diaphragm.

[0053] Side walls surrounding the vibrating membrane may be formed on the main surface. These walls protect the vibrating membrane and can also serve as supports for the upper part of the surface.

[0054] An inwardly protruding upper hood may be formed at the top of the side wall. This can prevent dust from entering from above.

[0055] A lower circuit board may be attached to the rear, forming a lower hood that protrudes into the recess. This prevents dust from entering from below.

[0056] The transducer may be mounted on the main surface of the support substrate, or it may be mounted inside the nozzle via the support substrate. The support substrate supports the transducer and supplies the drive voltage to the transducer via wires.

[0057] A transducer may be supplied with a voltage from an electronic circuit housed within the transducer, via a support substrate, to drive the drive layer. The voltage that drives the drive layer of the transducer is supplied from the electronic circuit via the support substrate.

[0058] Figures 7A, 7B, and 7C are the left side view, front view, and right side view, respectively, of the earphone 50 of the second embodiment. The earphone 50 of the second embodiment differs from the earphone 10 of the first embodiment in that the structure of the nozzle 51 and housing 52 is different, and the earpiece 13 is absent. Since the other components are the same as those of the earphone 10 of the first embodiment, the same reference numerals will be used for common components to clarify the correspondence.

[0059] The earphone 50 of the second embodiment has a transducer that serves as a sound source, a nozzle 51 that extends from a base 51a to a tip 51b, and a housing 52 attached to the base 51a of the nozzle 51 that houses an electronic circuit for driving the transducer and a battery.

[0060] Figure 8A is a cross-sectional view taken along the cutting line VIIIA-VIIIA in Figure 7A or Figure 7C. Figure 8B is a cross-sectional view taken along the cutting line VIIIB-VIIIB in Figure 7B. Figures 8A and 8B also show a portion of the ear canal and external auditory canal that are in contact with the earphone 50 when the earphone 50 is worn in the ear. As shown in Figures 8A and 8B, the nozzle 51 is an oval-shaped hollow cylinder with a predetermined major and minor axis in its cross-section, for example, with one direction such as the horizontal as the major axis, and extends over a predetermined length from the base 51a to the tip 51b. A transducer 20 is installed in the passage 51c inside the nozzle 51. The nozzle 51 may be formed of a suitable resin.

[0061] The nozzle 51 is configured such that when the earphone 50 is worn in the ear, a passage 103 with a predetermined cross-sectional area is secured between the outer circumference of the nozzle 51 and the ear canal or external auditory canal and its wall. For example, the radial cross-sectional area of ​​the nozzle 51 may be smaller than the cross-sectional area of ​​the passage 103. This passage 103 connects the ear canal 101 to the external auditory canal 102 at the tip 51b of the nozzle 51 along the outer circumference of the nozzle 51. Through this passage 103, the outside of the earphone 50 and the external auditory canal at the tip 51b of the nozzle 51 are connected. The earphone 50 may also be worn in the ear by, for example, attaching a hook (not shown) to the ear.

[0062] Refer again to Figure 3. In the second embodiment, the transducer 20 is also supported by the support substrate 31. The transducer 20 is supported by the support substrate 31 and installed in the passage 51c of the nozzle 51. As shown in Figures 8A and 8B, the support substrate 31 is supported by the bottom of the passage 51c, the transducer 20 and the first end of the support substrate 31 are supported by a first support wall 51f formed at the bottom of the passage 51c and extending radially from the nozzle 51, and the main surface 21a adjacent to the second end of the transducer 20 opposite the first end is supported by a second support wall 51g formed at the top of the passage 51c and also extending radially from the nozzle 51. Air vents 31b are formed in the support substrate 31 directly below the vibrating membrane 21d and recess 21c of the transducer 20, ensuring the entry and exit of air accompanying the vibration of the vibrating membrane 21d.

[0063] Refer again to Figures 4A and 4B. The transducer 20 of the second embodiment has the same configuration as the transducer of the first embodiment. The transducer 20 is formed on a plate-shaped silicon substrate 21 that is substantially rectangular in plan view and has a predetermined thickness. On the main surface 21a of the substrate 21, a vibrating membrane 21d is formed by a recess 21c formed on the back surface 21b facing the main surface 21a, so that the main surface 21a can vibrate in the direction of separation from the substrate 21 which is formed to a predetermined thickness.

[0064] The vibrating membrane 21d is formed as a disc-shaped region having a predetermined diameter at a position slightly off-center from the center of the main surface 21a, which has a roughly rectangular shape, towards one of its shorter sides. A driving layer 22 is laminated on the vibrating membrane 21d, in which a pair of electrode layers, a lower electrode layer 22a and an upper electrode layer 22c, are laminated so as to sandwich a piezoelectric layer 22b, forming a disc-shaped region surrounded by the circumference of the vibrating membrane 21d, with a diameter smaller than that of the vibrating membrane 21d.

[0065] The vibrating membrane 21d of the transducer 20 vibrates when driven by the drive layer 22, generating sound waves. The sound waves generated from the transducer 20 within the nozzle 51 travel along the passage 51c toward the tip 51b of the nozzle 51 and are emitted from the tip 51b of the nozzle 51. In response to the vibration of the vibrating membrane 21d, air enters and exits through the air vent hole 31b located directly below the vibrating membrane 21d and the recess 21c of the transducer 20. The transducer 20 can be installed at any desired position within the passage 51c of the nozzle 51, not limited to the center of the nozzle 51, but also near the tip 51b of the nozzle 51, near the base 51a, etc.

[0066] The housing 52 houses an electronic circuit for driving the transducer 20 and a battery for driving the electronic circuit. The electronic circuit may include a wireless amplifier that receives an external wireless signal and converts it into a voltage for driving the transducer 20. The housing 52 blocks the passage 51c at the base 51a of the nozzle 51 and hangs down further, with an air vent 52a formed at the bottom. The housing 52 may be made of a suitable resin and may be formed integrally with the nozzle 51.

[0067] In addition, in the earphone 50 of the second embodiment, similar to the earphone 10 of the first embodiment, the transducer 30 of the first modified example or the transducer 40 of the second modified example may be used instead of the transducer 20.

[0068] In the earphone 50 of the second embodiment, sound waves originating from a transducer 20 mounted in the passage 51c of the nozzle 51 are emitted from the tip 51b of the nozzle 51, and external sounds are taken in through a passage 103 formed between the outer circumference of the nozzle 51 and the ear canal or ear wall. The passage 103 formed between the outer circumference of the nozzle 51 and the ear canal or ear wall is located outside the nozzle 51 and has a sufficient cross-sectional area, thus reducing the degradation of sound quality. Therefore, with the earphone 50 of the second embodiment, external sounds can be taken in with high sound quality, and sound image localization of external sounds becomes possible.

[0069] Furthermore, in the earphone 50 of the second embodiment, a transducer 20 that drives the diaphragm 21d by a driving layer 22 is used as the sound source. The transducer 20 is small and lightweight and is installed in the passage 51c of the nozzle 51. Therefore, not only the nozzle 51 on which the transducer 20 is mounted, but the entire earphone 50 can be made smaller and lighter. In addition, the transducer 20 is piezoelectric driven and consumes little power. As a result, the earphone 50 can be used for extended periods.

[0070] Furthermore, the earphone 50 of the second embodiment can pick up external sounds with high sound quality. Therefore, even when ambient sounds such as the babbling of a river are constantly played through the earphone 50 as sound therapy to alleviate auditory tension and reduce tinnitus in people with hearing loss, it is possible to hear external sounds. In addition, since the earphone 50 of the second embodiment does not block the ear canal, the burden on the ear when wearing the earphone 50 is reduced.

[0071] As described above, this embodiment has been presented, but the descriptions and drawings that constitute part of the disclosure are illustrative and should not be understood as limiting. Various alternative embodiments, examples, and operational techniques will become apparent to those skilled in the art from this disclosure.

[0072] For example, in this embodiment, earphones are used as an example of an audio device, but the audio device is not limited to this, and may include other types of audio devices such as headphones. Headphones may include closed-type headphones that cover the ears, and planar headphones that are pressed against the ears. In general, an audio device only needs to have a structure in which the tip of a nozzle is inserted into the ear canal and the housing is located around it.

[0073] Furthermore, in this embodiment, a transducer fabricated using MEMS technology was used as an example of a sound source, but the transducer is not limited to this. Other types of transducers, such as voice coil type and balanced armature type, may also be included. [Explanation of symbols]

[0074] 10 earphones 11 nozzles 12 Housing 13 earpieces 20 transducers 21 circuit boards 21a Main surface 21b Back 21c recess 21d vibrating membrane 22 Driving layer

Claims

1. An audio device that is worn on the ear, A nozzle with a transducer, which serves as the sound source, mounted in one of the internal passages, The nozzle is attached to the base of the nozzle and comprises a housing that houses an electronic circuit and a battery for driving the transducer, When the aforementioned acoustic device is worn on the ear, the other passage connecting the tip of the nozzle inserted into the ear canal and the base of the nozzle outside the ear canal is secured by the housing, and the transducer is installed in the one passage so that external sounds can be taken in through the other passage. An acoustic device in which the communication direction of the tip and base of the nozzle in the other passage coincides with the longitudinal direction of the transducer.

2. The acoustic device according to claim 1, wherein the inside of the nozzle is divided into two passages, one passage and the other passage, by a partition wall in the direction in which the nozzle extends, the transducer is installed in the one passage, and the other passage is connected from the base to the tip of the nozzle, so that when the acoustic device is worn on the ear, external sound can be taken in through the other passage which opens at the base of the nozzle.

3. The sound device according to claim 2, wherein the cross-sectional area of ​​the other passage is greater than the cross-sectional area of ​​the first passage.

4. The acoustic device according to claim 2 or 3, further comprising a flexible earpiece that surrounds a predetermined range from the tip to the base of the nozzle, wherein the nozzle is configured to be wearable via the earpiece that is fitted into the ear canal from the ear canal.

5. The sound device according to claim 1, wherein the nozzle has a passage that communicates with the outside of the nozzle from its base to its tip along the external auditory canal, and is configured to occupy only a portion of the cross-section in the radial direction of the external auditory canal so that when the sound device is worn in the ear, external sound can be taken in through the other passage that opens at the base.

6. The sound device according to any one of claims 1 to 5, wherein the transducer comprises a substrate having a main surface and a back surface; a vibrating membrane formed on the back surface by a recess formed thereon so that the main surface can vibrate in a direction away from the surface, the substrate being formed to a predetermined thickness from the main surface; and a driving layer laminated on the vibrating membrane such that a pair of electrode layers sandwich a piezoelectric layer on the main surface.

7. The acoustic device according to claim 6, wherein the vibrating membrane is connected to the main surface around its entire circumference.

8. The acoustic device according to claim 6, wherein a slit is formed on the main surface in a part of the circumference of the vibrating membrane so that the vibrating membrane constitutes a cantilever.

9. The acoustic device according to any one of claims 6 to 8, wherein a side wall surrounding the vibrating membrane is formed on the main surface.

10. The sound device according to claim 9, wherein an upper hood protruding inward is formed at the top of the side wall.

11. The audio device according to any one of claims 6 to 10, wherein a lower substrate is attached to the rear surface to form a lower hood that protrudes into the recess.

12. The acoustic device according to any one of claims 6 to 11, wherein the transducer is mounted on the main surface of a support substrate and is mounted inside the nozzle via the support substrate.

13. The audio device according to claim 12, wherein the transducer is supplied with a voltage from an electronic circuit stored in the transducer via the support substrate to drive the drive layer.

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