Acoustic processing device

Abstract

The present disclosure relates to an acoustic processing device that can suppress the occurrence of excessive atmospheric pressure changes in the eardrums of a user. Provided is an acoustic processing device comprising: a driver unit having a diaphragm; and a housing in which the driver unit is housed. The diaphragm has a vent hole that communicates a first space on a first surface side of the driver unit in the housing and a second space on a second surface side on the reverse side of the first surface. The present disclosure can be applied to, for example, an earphone device.

Description

Acoustic processing device

[0001] The present disclosure relates to an acoustic processing device, and particularly to an acoustic processing device capable of suppressing the occurrence of excessive air pressure changes on the eardrum of a user.

[0002] In an earphone device, a diaphragm provided in a driver unit housed in a housing of a housing portion is vibrated in response to an audio signal from a playback device such as a portable music player, thereby generating a sound corresponding to the audio signal. In this type of earphone device, it is known that excessive air pressure changes may occur on the eardrum of the user when the device is attached and detached, and techniques for suppressing the occurrence of excessive air pressure changes on the eardrum have been proposed.

[0003] For example, Patent Document 1 discloses a technique in which a communication hole is provided in an internal space of a housing that houses a driver unit to communicate a space in front of the driver unit and a space behind the driver unit, and the communication hole is opened and closed by a diaphragm holder.

[0004] Japanese Unexamined Patent Application Publication No. 2017-112531

[0005] In the technique disclosed in Patent Document 1, a communication hole is provided by a plurality of components, but there is a need for a technique that is configured with fewer components and suppresses the occurrence of excessive air pressure changes on the eardrum of the user when the device is attached and detached.

[0006] The present disclosure has been made in view of such a situation, and is intended to suppress the occurrence of excessive air pressure changes on the eardrum of the user when the device is attached and detached.

[0007] An acoustic processing device according to one aspect of the present disclosure includes a driver unit having a diaphragm and a housing that houses the driver unit, and the diaphragm has a ventilation hole that communicates a first space on a first surface side of the driver unit in the housing and a second space on a second surface side opposite to the first surface.

[0008] In one aspect of the present disclosure, an acoustic apparatus is provided, comprising a driver unit having a diaphragm and a housing housing the driver unit, wherein the diaphragm is provided with a ventilation hole that connects a first space on the first side of the driver unit within the housing with a second space on the second side opposite the first side.

[0009] The acoustic processing device described in this disclosure may be an independent device or an internal block constituting a single device.

[0010] This is a cross-sectional view showing an example configuration of one embodiment of an acoustic apparatus to which the present disclosure is applied. This is a cross-sectional view showing a detailed example configuration of the driver unit in Figure 1. This is a diagram illustrating the airflow inside the housing of the earphone device in Figure 1. This is a diagram illustrating the airflow inside the housing of a conventional earphone device. This is a perspective view showing an example of the appearance of a MEMS driver unit. This is a cross-sectional view showing an example configuration of a MEMS driver unit. This is a cross-sectional view showing another example configuration of the driver unit.

[0011] <Device Configuration> Figure 1 is a cross-sectional view showing an example configuration of one embodiment of an acoustic processing device to which the present disclosure is applied. In the embodiments described below, an earphone device that can be worn on the user's ear is described as an example of an acoustic processing device.

[0012] The earphone device 1 in Figure 1 outputs sound (sound waves) corresponding to an audio signal wirelessly transmitted from a playback device such as a portable music player or smartphone. Wireless transmission communication standards include, but are not limited to, Bluetooth® and Wi-Fi (Local Area Network). Alternatively, the earphone device 1 may output sound corresponding to an audio signal transmitted via a wired connection such as a cable.

[0013] The earphone device 1 comprises a housing 11 consisting of a substantially cylindrical housing 11A and a sound conduit 11B protruding from a predetermined location on the housing 11A. The housing 11 is made of a material such as synthetic resin. The housing 11A and the sound conduit 11B are molded integrally, but they may also be made as separate components and joined together. For example, an earpiece is attached to the sound conduit 11B and inserted into the user's ear canal together with the sound conduit 11B. The earpiece has an umbrella shape, for example, made of an elastic material, and when inserted into the user's ear canal, it adheres closely to the inner wall of the ear canal. The housing 11A is provided with a ventilation hole 11C used for ventilation.

[0014] A driver unit 12, which has a circular, disc-shaped form in plan view, is housed inside the housing 11. In the following description, the thickness direction of the driver unit 12 will also be referred to as the vertical direction. Within the housing 11, the space on the upper side of the driver unit 12 (the side facing the eardrum of the user wearing the earphone device 1) will be referred to as space A1, and the space on the lower side of the driver unit 12 (the opposite side of the upper side) will be referred to as space A2. That is, in Figure 1, of space A1 and space A2, space A1 is the space that is worn in the user's ear. Figure 2 shows the detailed configuration of the driver unit 12. The driver unit 12 has a dynamic type structure and generates sound (sound waves) in response to the audio signal from the playback device to which the earphone device 1 is connected. The driver unit 12 has a frame 21, a diaphragm 22, a ring 23, a voice coil 24, a magnet 25, a top plate 26, and a yoke 27. The frame 21 is held by the sides inside the housing 11. The frame 21 may be integrated with the housing 11.

[0015] The frame 21 has a cylindrical shape, and the inner diameter on the upper side of the driver unit 12 is larger than the inner diameter of other parts. In the frame 21, the part with the larger inner diameter holds the ring 23, and the part with the smaller inner diameter holds the magnet 25, top plate 26, and yoke 27. The ring 23 has a ring shape and holds the diaphragm 22 within the frame 21. The frame 21 has an opening on the side of space A2 in order to allow the diaphragm 22 to vibrate smoothly, and the air inside the driver unit 12 can be discharged from the opening to space A2. The magnet 25, top plate 26, and yoke 27 constitute a magnetic circuit. The magnet 25 is a permanent magnet and is formed in a cylindrical shape. The top plate 26 is made of a magnetic material and has a circular shape in plan view. The yoke 27 is made of a magnetic material and has a cylindrical shape with a bottom.

[0016] The yoke 27 has at least a portion of its side fitted with a portion of the frame 21 where the inner diameter is smaller, and a magnet 25 is positioned in the center of the bottom. A top plate 26 is positioned on the upper surface of the magnet 25. The magnet 25 is positioned between the top plate 26 and the yoke 27. The magnetic poles of the magnet 25 are, for example, the north pole on the top plate 26 side and the south pole on the yoke 27 side. The magnetic flux generated by the magnetic circuit is directed across the gap between the top plate 26 and the yoke 27, from the top plate 26 to the yoke 27. In other words, a magnetic gap, which is the gap through which the magnetic flux passes, is formed in the magnetic circuit.

[0017] The diaphragm 22 is made of a synthetic resin such as polyethylene terephthalate (PET) and has a circular shape in plan view. When the diaphragm 22 vibrates in response to an audio signal, sound waves corresponding to the audio signal are generated. The diaphragm 22 has ventilation holes 31. The ventilation holes 31 are holes (micropores) that connect space A1 and space A2 within the housing 11. The ventilation holes 31 are formed in the center of the circular diaphragm 22. The diaphragm 22 and the ventilation holes 31 are concentric circles in plan view. The ventilation holes 31 are provided to send air from space A1 to space A2, and their shape, number, and formation position can be appropriately changed by design, and are not limited to the configuration shown in Figures 1 and 2.

[0018] The voice coil 24 is a coil formed by winding a single wire in a spiral shape, and in plan view it has a ring shape. The voice coil 24 moves vertically in response to the electromagnetic force generated by the current supplied to it and the magnetic flux generated by the magnetic circuit. The voice coil 24 is inserted into the magnetic gap formed by the magnetic circuit, and one end (upper end) is joined to the lower surface of the diaphragm 22. Therefore, the diaphragm 22 vibrates as the voice coil 24 moves vertically. In other words, the diaphragm 22 and the voice coil 24 operate as a single unit.

[0019] In the earphone device 1 configured as described above, by providing a ventilation hole 31 in the diaphragm 22, air from space A1 enters the driver unit 12 housed in the housing 11 through the ventilation hole 31 in the diaphragm 22, passes through the interior, and exits to space A2. In the housing 11, the air that has passed through the interior of the driver unit 12 is discharged from space A2 to the outside of the housing 11 through the ventilation hole 11C. As a result, in the earphone device 1, within the housing 11, air from space A1 passes through the interior of the driver unit 12 and is sent to space A2 and discharged to the outside, thus creating communication between the space inside the user's ear (external auditory canal) and the space outside the housing 11. Therefore, when attaching or detaching the earphone device 1 (when the user attaches or removes the device from their ear), it is possible to suppress excessive pressure changes in the user's eardrum. Furthermore, when wearing the earphone device 1 (while the user is wearing the device in their ear), it is possible to suppress the feeling of blockage caused by wearing the device and improve the user's comfort. Furthermore, even if excessive pressure changes occur in the user's eardrum when wearing the earphone device 1, these can be suppressed.

[0020] Here, the diameter of the ventilation holes 31 formed in the diaphragm 22 can be determined based on the air pressure generated at the eardrum of the user wearing the earphone device 1. For example, if you want to reduce the air pressure generated at the user's eardrum, you can design the diameter of the ventilation holes 31 to be larger to make it easier to expel air to the outside. Conversely, if you want to increase the air pressure generated at the user's eardrum, you can design the diameter of the ventilation holes 31 to be smaller to make it more difficult to expel air to the outside. In other words, the diameter of the ventilation holes 31 can be adjusted according to the amount of air pressure generated at the user's eardrum. In this way, by changing the diameter of the ventilation holes 31, the air pressure generated at the user's eardrum can be easily designed to be the desired size.

[0021] <Airflow path within the housing> Figure 3 is a diagram illustrating the airflow within the housing 11 of the earphone device 1 shown in Figure 1. In Figure 3, the airflow path within the housing 11 is represented by the path R1 indicated by the arrow. As shown in Figure 3, within the housing 11, air from the sound conduit 11B passes through space A1 and enters the driver unit 12 through the ventilation hole 31 of the diaphragm 22. Inside the driver unit 12, the air that enters through the ventilation hole 31 passes through the gap between the lower surface of the diaphragm 22 to which the voice coil 24 is joined and the upper surface of the top plate 26, the magnetic gap formed by the magnetic circuit, and the space within the frame 21, and exits to space A2 through the opening on the space A2 side provided in the frame 21. Then, within the housing 11, the air that has passed through the driver unit 12 is sent to space A2 and discharged to the outside through the ventilation hole 11C.

[0022] For comparison, Figure 4 shows the airflow inside the housing of a conventional earphone device. In Figure 4, the air path inside the housing 111 of the conventional earphone device 101 is represented by the path R2 indicated by the arrow. As shown in Figure 4, in the conventional earphone device 101, a ventilation member 131 is provided on the side of space B1 inside the housing 111, and air from the sound conduit 111B is sent from the space B1 side to the space B2 side through the ventilation holes 132 provided in the member 131. The member 131 is fixed to the inner wall of the housing 111A and has a first surface 131A facing the upper surface of the driver unit 112, with ventilation holes 132 formed on the first surface 131A. The member 131 also has a second surface 131B perpendicular to the first surface 131A, and the second surface 131B holds a part of the frame 121 of the driver unit 112. The driver unit 112 consists of a frame 121, a diaphragm 122, a ring 123, a voice coil 124, a magnet 125, a top plate 126, and a yoke 127, and is held by the side surface inside the housing 111A and the second surface 131B of member 131.

[0023] The ventilation hole 132 is a hole for ventilating space B1 and space B2 within the housing 111. Air entering the ventilation hole 132 on the space B1 side passes through space B3 between the side surface of the housing 111A and the member 131 and is sent to space B2. Then, in the housing 111, the air sent from space B3 to space B2 is discharged to the outside through the ventilation hole 111C. Here, the member 131 is a member fixed to the inner wall of the housing 111A, and the air entering through the ventilation hole 132 passes through space B3 created by the inner wall of the housing 111A and the member 131 (first surface 131A, second surface 131B). Therefore, the housing 111 (housing 111A) requires space to secure space B3, which serves as the air path.

[0024] Compared to the earphone device 1 (Figure 3) of this disclosure, the conventional earphone device 101 (Figure 4) requires a structure to secure a space B3 that serves as an air passage, so the housing 111 (Figure 4) is larger than the housing 11 (Figure 3). In other words, in the conventional earphone device 101, the diaphragm 122 of the driver unit 112 does not have ventilation holes, and ventilation holes 132 that allow air to pass between spaces B1 and B2 inside the housing 111 are provided on the outside of the driver unit 112 to prevent excessive pressure changes in the user's eardrum when attaching or detaching the earphone device 101. However, with this configuration, space is required to arrange the member 131 with the ventilation holes 132 and secure space B3, making it difficult to miniaturize the housing 111.

[0025] On the other hand, the earphone device 1 of this disclosure includes a driver unit 12 having a diaphragm 22 with ventilation holes 31, eliminating the need to provide ventilation members outside the driver unit 12 and thus eliminating the need for space to arrange and secure ventilation members. Therefore, the earphone device 1 of this disclosure can have a smaller housing compared to the conventional earphone device 101. In the earphone device 1 of this disclosure, the housing 11 can be made smaller, which improves the ear comfort, such as preventing the housing 11 from touching the ear when the user puts the earphone device 1 in their ear.

[0026] In conventional earphone devices 101, a separate component (member 131) is provided inside the housing to form a ventilation hole 132, and the ventilation hole 132 is formed by multiple components. In such a configuration, the dimensions of the multiple components and the precision during assembly affect the dimensions of the ventilation hole 132, making dimensional control complicated. Furthermore, the earphone device disclosed in the aforementioned Patent Document 1 has a configuration in which a communication hole is provided that connects the space in front of the driver unit and the space behind the driver unit within the internal space of the housing that houses the driver unit, and this communication hole is opened and closed by a diaphragm holder. However, multiple components are required to provide this communication hole, making the control (adjustment) of the dimensions (diameter size) of the communication hole complicated. For this reason, there has been a need for a configuration that uses fewer components to suppress excessive pressure changes in the user's eardrum when attaching or detaching the device.

[0027] On the other hand, in the earphone device 1 of this disclosure, the ventilation hole 31 is provided on the diaphragm 22 and is formed by a single part (the outer circumference of the ventilation hole 31 is formed by a single part), making it easy to control (adjust) the dimensions (diameter) of the ventilation hole 31. In addition, in the earphone device 1 of this disclosure, by providing the ventilation hole 31 on the diaphragm 22, no specific steps are added during the assembly of the driver unit 12 or the earphone device 1, making assembly easier. In the earphone device disclosed in Patent Document 1, the communication hole connects the space in front of the driver unit and the space behind it, requiring space for this, which increases the size of the housing. However, in the earphone device 1 of this disclosure, by providing a driver unit 12 having a diaphragm 22 with a ventilation hole 31, the housing can be made smaller. In the earphone device 1 of this disclosure, the number of parts (number of components) is reduced compared to the conventional earphone device 101 and the earphone device disclosed in Patent Document 1, making it possible to lower manufacturing costs. In the above explanation, earphone device 1 was described as an earphone device worn on one ear of the user, but an earphone device worn on the other ear is configured similarly.

[0028] <Modification> The above description describes a dynamic driver unit, but this disclosure is also applicable to other types of driver units. For example, this disclosure can be applied to MEMS (Micro Electro Mechanical Systems) type driver units (hereinafter referred to as MEMS driver units) that use MEMS technology, and balanced armature type driver units. MEMS driver units have features such as being small, thin, and providing clear and detailed sound with low sound distortion by using MEMS technology.

[0029] Figure 5 is a perspective view showing an example of the external appearance of the MEMS driver unit 41. Figure 6 is a cross-sectional view showing a cross-section when the MEMS driver unit 41 is cut along the line A-A in Figure 5. As shown in Figure 5, the MEMS driver unit 41 has a rectangular parallelepiped housing 51. On the upper main surface of the housing 51, a hole 52A that functions as a sound hole is formed. Also, a hole 52B that functions as a sound hole is formed on the lower main surface, the bottom surface. The holes 52A and 52B have, for example, a rectangular shape.

[0030] As shown in Figure 6, a diaphragm 61 is provided inside the housing 51. The diaphragm 61 is supported by support parts so as to span across the left and right sides inside the housing 51. Each component of the MEMS driver unit 41 is formed by a MEMS process. The MEMS process includes processes such as thin-film deposition, photolithography, etching, bonding, dicing, and packaging. The diaphragm 61 vibrates in response to the audio signal supplied to the MEMS driver unit 41, generating sound waves corresponding to the audio signal. The sound generated by the diaphragm 61 is emitted from holes 52A and 52B.

[0031] The diaphragm 61 has ventilation holes 71. The MEMS driver unit 41 is housed and fixed in the housing 11 of the earphone device 1 of this disclosure, similar to the driver unit 12 shown in Figure 1, but the ventilation holes 71 provided in the diaphragm 61 allow air to circulate between space A1 and space A2 within the housing 11. As described in Figure 1, space A1 is the space on the upper side of the MEMS driver unit 41 within the housing 11, and space A2 is the space on the lower side of the MEMS driver unit 41. The ventilation holes 71 are formed in the center of the rectangular diaphragm 61. The ventilation holes 71 are circular in shape.

[0032] In the earphone device 1 configured as described above, by providing ventilation holes 71 in the diaphragm 61, air from space A1 enters the MEMS driver unit 41 housed in the housing 11 through the hole 52A, passes through the ventilation holes 71 in the diaphragm 61, and exits to space A2 through the hole 52B. Then, in the housing 11, the air that has passed inside the MEMS driver unit 41 is discharged to the outside through the ventilation holes 11C.

[0033] Thus, in the earphone device 1 of this disclosure, by providing a MEMS driver unit 41 having a diaphragm 61 with ventilation holes 71, there is no need to provide ventilation members outside the MEMS driver unit 41, and the housing 11 can be made smaller. Furthermore, by making the housing 11 smaller, it is possible to improve the fit to the ear. In addition, since the ventilation holes 71 are provided in the diaphragm 61 and formed by a single component, it is possible to construct it with fewer parts, making assembly easier. Moreover, in the earphone device 1 of this disclosure, the number of parts (number of components) is reduced, so it is possible to lower the manufacturing cost.

[0034] Figure 7 is a cross-sectional view showing another configuration example of the driver unit 12. In Figure 7, parts corresponding to those in Figure 2 are given the same reference numerals, and their explanations are omitted. Specifically, the driver unit 12 in Figure 7 has a cylindrical ventilation hole 25A in the center of the magnet 25, compared to the driver unit 12 in Figure 2. In the magnetic circuit, the top plate 26 and yoke 27, which are positioned on the upper and lower surfaces of the magnet 25, have holes at positions corresponding to the ventilation hole 25A, and the space between the lower surface of the diaphragm 22 and the upper surface of the top plate 26 is connected to space A2 through the cylindrical hole formed by the ventilation hole 25A, etc. As a result, inside the driver unit 12, air entering from the ventilation hole 31 passes through the gap between the lower surface of the diaphragm 22 and the upper surface of the top plate 26, and through the cylindrical hole formed by the ventilation hole 25A, etc., and is sent to space A2. Thus, in the earphone device 1, a ventilation hole 31 may be provided in the diaphragm 22 and a ventilation hole 25A in the magnet 25, so that within the housing 11, air from the space A1 side passes through the inside of the driver unit 12 and is sent to the space A2 side and discharged to the outside.

[0035] The acoustic processing device to which this disclosure applies is not limited to earphone devices, but may also be, for example, headphones that can be worn on the ear, hearing aids, or other wearable devices. When the acoustic processing device to which this disclosure applies is an earphone device, it can be configured as a closed-type in-ear headphone, an earplug-type earphone (canal-type earphone), etc. For example, users of closed-type in-ear headphones or canal-type earphones insert the earpiece into the ear canal for use.

[0036] In the above description, a configuration in which the ventilation hole 31 is formed in the center of the diaphragm 22, which has a circular shape, was illustrated as an example in the driver unit 12. However, it is not limited to the center; it may be formed at other locations on the diaphragm 22 as long as it is a position that allows air to pass through the inside of the driver unit 12. In the above description, a configuration in which one ventilation hole 31 is formed in the diaphragm 22 was illustrated as an example, but multiple ventilation holes 31 may be formed. When multiple ventilation holes 31 are formed in the diaphragm 22, the multiple ventilation holes 31 may be arranged randomly or in a specific pattern. However, when multiple ventilation holes 31 are provided, it is necessary to design them taking into consideration factors such as the sound quality provided by the diaphragm 22. In the above description, a configuration in which the ventilation hole 31 formed in the diaphragm 22 has a circular shape was illustrated as an example, but the shape of the ventilation hole 31 is not limited to a circle (or approximately a circle) and may be other shapes. For example, the shape of the ventilation hole 31 may be an ellipse, square, rectangle, polygon, etc.

[0037] The embodiments described herein are not limited to those described above, and various modifications are possible without departing from the spirit of this disclosure. Furthermore, the effects described herein are merely illustrative and not limiting, and other effects may also occur.

[0038] Furthermore, this disclosure can take the following form.

[0039] (1) An acoustic apparatus comprising a driver unit having a diaphragm and a housing housing the driver unit, wherein the diaphragm has a ventilation hole that connects a first space on the first side of the driver unit within the housing with a second space on the second side opposite the first side. (2) The acoustic apparatus according to (1), wherein the diaphragm is made of a circular plate in plan view, and the ventilation hole is formed at the center of the circle on the diaphragm. (3) The acoustic apparatus according to (2), wherein one ventilation hole is formed at the center of the circle. (4) The acoustic apparatus according to any one of (1) to (3), wherein the ventilation hole has a circular shape. (5) The acoustic apparatus according to (4), wherein of the first space and the second space in the housing, the side with the first space is the side that is worn in the user's ear, and the diameter of the ventilation hole is adjusted according to the amount of air pressure generated in the user's eardrum. (6) The sound processing apparatus according to any one of (1) to (5), wherein in the driver unit, air from the first space enters the interior through the ventilation holes of the diaphragm, passes through the interior, and exits into the second space. (7) The sound processing apparatus according to (6), wherein of the first space and the second space in the housing, the side with the first space is the side that is worn in the user's ear, and the housing has a second ventilation hole on the side with the second space for ventilation to the outside. (8) The sound processing apparatus according to any one of (1) to (7), wherein the driver unit is a dynamic type driver unit. (9) The sound processing apparatus according to (8), wherein the driver unit has a magnet for vibrating the diaphragm, and the magnet has a third ventilation hole for sending air that has entered through the ventilation hole to the second space. (10) The sound processing apparatus according to (1), wherein the driver unit is a MEMS driver unit. (11) The sound processing apparatus according to any one of (1) to (10), configured as an earphone device.

[0040] 1 Earphone device, 11 Housing, 11A Housing, 11B Sound conduit, 11C Ventilation hole, 12 Driver unit, 21 Frame, 22 Diaphragm, 23 Ring, 24 Voice coil, 25 Magnet, 25A Ventilation hole, 26 Top plate, 27 Yoke, 31 Ventilation hole, 41 MEMS driver unit, 51 Housing, 52A, 52B Holes, 61 Diaphragm, 71 Ventilation hole

Claims

1. An acoustic apparatus comprising a driver unit having a diaphragm and a housing housing the driver unit, wherein the diaphragm has ventilation holes that connect a first space on the first side of the driver unit within the housing with a second space on the second side opposite the first side.

2. The acoustic apparatus according to claim 1, wherein the diaphragm is made of a circular plate in plan view, and the ventilation hole is formed at the center of the circle on the diaphragm.

3. The acoustic apparatus according to claim 2, wherein one ventilation hole is formed at the center of the circle.

4. The sound processing apparatus according to claim 1, wherein the ventilation hole has a circular shape.

5. The acoustic apparatus according to claim 4, wherein of the first space and the second space in the housing, the side with the first space is the side that is worn in the user's ear, and the diameter of the ventilation hole is adjusted according to the amount of air pressure generated in the user's eardrum.

6. The sound processing apparatus according to claim 1, wherein in the driver unit, air from the first space enters the interior through the ventilation holes of the diaphragm, passes through the interior, and exits into the second space.

7. The acoustic apparatus according to claim 6, wherein, of the first space and the second space in the housing, the side with the first space is the side that is worn on the user's ear, and the housing has a second ventilation hole on the side with the second space for ventilation to the outside.

8. The sound processing apparatus according to claim 1, wherein the driver unit is a dynamic type driver unit.

9. The acoustic apparatus according to claim 8, wherein the driver unit has a magnet for vibrating the diaphragm, and the magnet has a third vent for sending air that has entered through the vent to the second space.

10. The acoustic apparatus according to claim 1, wherein the driver unit is a MEMS driver unit.

11. The sound processing apparatus according to claim 1, configured as an earphone device.

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