earphones

Abstract

To provide an earphone capable of adjusting internal pressure with a simple housing configuration.SOLUTION: An earphone includes: a housing 11 to which a conduit part 15 for emitting sound to the outside is connected; a fixed pole 17 fixed inside the housing 11; a diaphragm 21 that is arranged to divide a space inside the housing 11 into two and vibrates in accordance with a potential difference generated between the diaphragm and the opposed fixed pole 17 facing each other; a support member 27 for supporting the diaphragm 21 such that a portion of the diaphragm 21 is in contact with the fixed pole 17; and an adjustment hole part 14 that is formed to penetrate a wall on a side opposite to the conduit part 15 in the housing 11 when viewed from the diaphragm 21, and adjusts pressure in the housing 11. A through-membrane hole 22 penetrating the diaphragm 21 is formed in the portion of the diaphragm 21. The support member 27 covers a side opposite to a side in contact with the fixed pole 17 in the portion of the diaphragm 21.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an earphone that converts an electrical signal into sound.

Background Art

[0002] An earphone has a flat fixed electrode (hereinafter also referred to as a fixed pole) and a diaphragm provided opposite to the fixed electrode. Patent Document 1 below discloses a capacitor-type earphone in which a thin-film diaphragm is provided so as to divide the space inside the housing vertically.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an earphone where it is desirable that the pressure on both sides of the diaphragm be equalized inside the housing, for example, when the earphone is attached to or removed from the user's ear, the pressure inside the housing changes. In order to adjust such a pressure change, it has been proposed to provide pressure adjustment holes on both sides of the housing. However, when pressure adjustment holes are provided on both sides of the housing, the structure of the housing becomes complicated and the manufacturing cost of the housing increases.

[0005] Therefore, the present invention has been made in view of these points, and an object thereof is to provide an earphone capable of adjusting the internal pressure with a simple housing configuration.

Means for Solving the Problems

[0006] In one embodiment of the present invention, an earphone is provided comprising: a housing connected to a conduit portion for emitting sound to the outside; a fixed electrode fixed within the housing; a vibrating membrane provided to divide the space within the housing into two halves and vibrating in accordance with the potential difference generated between it and the opposing fixed electrode; a support portion supporting the vibrating membrane such that a part of the vibrating membrane contacts the fixed electrode; and an adjustment hole portion formed in the housing so as to penetrate the wall opposite to the conduit portion as seen from the vibrating membrane, for adjusting the pressure inside the housing, wherein a membrane through-hole is formed in a part of the vibrating membrane that penetrates the vibrating membrane, and the support portion covers the part of the vibrating membrane opposite to the side that contacts the fixed electrode.

[0007] Furthermore, the support portion may be made of an elastic material that has breathability, allowing air to pass through its interior. Furthermore, the elastic material may be a sponge.

[0008] Furthermore, the membrane through-hole may be formed in the central part of the vibrating membrane. Furthermore, a notch may be formed in the support portion in the part facing the membrane penetration hole. [Effects of the Invention]

[0009] According to the present invention, it is possible to realize earphones with a simple housing configuration that allow for adjustment of the internal pressure. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram illustrating the external configuration of earphone 1 according to one embodiment. [Figure 2] This is a schematic diagram illustrating the configuration of the electroacoustic conversion unit 10. [Figure 3] This is a schematic diagram of the view from direction AA in Figure 2. [Figure 4] This is a schematic diagram illustrating the configuration of the vibrating membrane 21 and the support member 27. [Figure 5]This is a schematic diagram illustrating the airflow through the membrane penetration holes 22 of the vibrating membrane 21. [Figure 6] This is a schematic diagram to explain the comparative example. [Figure 7] This is a schematic diagram illustrating the configuration of the support member 37 in a modified example. [Figure 8] This is a schematic diagram illustrating the configuration of the support member 47 in a modified example. [Modes for carrying out the invention]

[0011] <Overview of earphones> An overview of the earphones according to one embodiment will be described with reference to Figure 1.

[0012] Figure 1 is a schematic diagram illustrating the external configuration of an earphone 1 according to one embodiment. In this example, the earphone 1 is a canal-type earphone, but is not limited to this, and may be, for example, an inner-ear type earphone. As shown in Figure 1, the earphone 1 has a cable 4, a connecting part 5, a housing 6, and an earpiece 7.

[0013] Cable 4 is a cable for transmitting electrical signals supplied from the sound source. The connecting portion 5 is a component that connects the cable 4 and the housing 6. The connecting portion 5 is formed of resin or the like so as to cover the cable 4.

[0014] The housing 6 is located between the connecting portion 5 and the earpiece 7. The housing 6 is equipped with an electroacoustic converter that converts electrical signals transmitted via the cable 4 into sound. The detailed configuration of the electroacoustic converter will be described later.

[0015] The earpiece 7 is the part of the earphone 1 that is inserted into the user's ear. The earpiece 7 is attached to the conduit portion (specifically, the conduit portion 15 in Figure 2) that protrudes from the housing 6. The earpiece 7 has an opening 7a for emitting sound generated by the electroacoustic converter.

[0016] In the above earphone 1, when the earphone 1 is worn on or removed from the user's ear, the pressure inside the housing 6 changes. In order to adjust such a pressure change, it is necessary to provide a pressure adjustment hole in the housing 6. In the earphone 1 of the present embodiment, although details will be described later, by providing a film through hole in the diaphragm inside the housing 6, the internal pressure can be appropriately adjusted with a simple configuration of the housing 6.

[0017] <Detailed configuration of the electroacoustic conversion unit> The detailed configuration of the electroacoustic conversion unit will be described while referring to FIGS. 2 to 4.

[0018] FIG. 2 is a schematic diagram for explaining the configuration of the electroacoustic conversion unit 10. FIG. 3 is a schematic diagram when viewed from the A-A direction of FIG. 2. As shown in FIG. 2, the electroacoustic conversion unit 10 includes a housing 11, a conduit portion 15, a fixed electrode 17, a terminal 19, a diaphragm 21, an insulating member 23, a first conductive member 25, a support member 27, and a second conductive member 29.

[0019] The housing 11 forms the housing of the electroacoustic conversion unit 10 and has an internal space in which the fixed electrode 17, the diaphragm 21, etc. are arranged. The housing 11 corresponds to the housing 6 shown in FIG. 1. Here, the housing 11 is made of resin. As shown in FIG. 2, the housing 11 is composed of an ear-side housing 12 and an outer housing 13. The outer housing 13 surrounds the internal space together with the ear-side housing 12.

[0020] The ear-side housing 12 is a part located on the ear side when the earphone 1 is worn on the user's ear. The outer housing 13 is a part located on the side away from the ear when the earphone 1 is worn on the user's ear. In the present embodiment, the ear-side housing 12 corresponds to the first housing, and the outer housing 13 corresponds to the second housing.

[0021] The outer housing 13 has an adjustment hole 14 for adjusting the pressure inside the housing 11. As shown in Figure 2, the adjustment hole 14 is formed to penetrate the outer housing 13, which is the wall of the housing 11 opposite to the conduit 15 when viewed from the vibrating membrane 21. The adjustment hole 14 is formed to protrude from the outer housing 13 toward the internal space, and no protrusions or the like are formed on the outer circumferential surface of the outer housing 13. In this embodiment, the adjustment hole 14 is provided only in the outer housing 13 of the ear-side housing 12 and the outer housing 13. This simplifies the structure of the ear-side housing 12.

[0022] The conduit section 15 functions as a pipe for emitting sound to the outside. As shown in Figure 2, the conduit section 15 is connected to the ear-side housing 12 of the housing 11. Specifically, the conduit section 15 is formed to protrude from the ear-side housing 12. The tip of the conduit section 15 is detachably attached to the earpiece 7 (Figure 1).

[0023] The fixed pole 17 is formed from a flat conductive material (e.g., aluminum). The fixed pole 17 is fixed inside the housing 11. The fixed pole 17 generates an electric field between itself and the diaphragm 21 when a bias voltage is applied, for example, via the terminal 19. Electrical signals input from a sound source are also input to the fixed pole 17 and the diaphragm 21 via the terminal 19 and the first conductive material 25, respectively.

[0024] The fixed electrode 17 has multiple through holes 17a. These multiple through holes 17a are formed at predetermined intervals, as shown in Figure 3. In the portion of the fixed electrode 17 that contacts the central part of the vibrating membrane 21 (specifically, the portion sandwiched between the central part of the vibrating membrane 21 and the second conductive member 29), a through hole 18 is formed, as shown in Figure 2. The diameter of the through hole 18 is larger than the diameter of the through holes 17a.

[0025] Terminal 19 is a conductive terminal for supplying an electrical signal to the fixed pole 17. Terminal 19 is electrically coupled to the fixed pole 17 and receives an electrical signal supplied from the sound source, for example, superimposed on a bias voltage. Terminal 19 is located on the side opposite to the diaphragm 21 when viewed from the fixed pole 17.

[0026] The vibrating membrane 21 is positioned opposite the fixed pole 17 and is a diaphragm that vibrates based on an electrical signal supplied from the sound source. The vibrating membrane 21 is made of a conductive thin film. For example, the vibrating membrane 21 is made of a metal foil or a polymer film with gold vapor deposition. The vibrating membrane 21 is positioned to divide the space inside the housing 11 into two parts. Specifically, as shown in Figure 2, the space inside the housing 11 is divided into a lower region R1 below the vibrating membrane 21 and an upper region R2 above the vibrating membrane 21.

[0027] The vibrating membrane 21 vibrates in response to the potential difference between the terminal 19 and the first conductive member 25, which is generated by an electrical signal. Specifically, the vibrating membrane 21 vibrates in response to the potential difference between it and the fixed pole 17 based on the electrical signals applied to the terminal 19 and the first conductive member 25. More specifically, the vibrating membrane 21 vibrates in response to the change in the magnitude of the AC component of the potential difference between the terminal 19 and the first conductive member 25.

[0028] Figure 4 is a schematic diagram illustrating the configuration of the vibrating membrane 21 and the support member 27. Figure 4 shows the vibrating membrane 21 as viewed from the lower surface 21b. The vibrating membrane 21 has a membrane through-hole 22 that penetrates the membrane. In this case, one membrane through-hole 22 is formed in the center of the vibrating membrane 21. The diameter of the membrane through-hole 22 is 0.1 mm or less in this case for a vibrating membrane 21 with a thickness of 2 μm. The amount of air passing through the membrane through-hole 22 is adjusted by the size of the diameter of the membrane through-hole 22.

[0029] The membrane through-hole 22 is formed here by instantaneously melting the vibrating membrane 21 with heat from a laser to create a hole. In this case, the area around the hole is melted and reinforced by the heat, making it easier to adjust the size of the membrane through-hole 22 and preventing the vibrating membrane 21 from tearing or being damaged due to stress from pressure changes when inserting or removing the earphone 1 from the ear.

[0030] In the above description, one through-hole 22 is formed in the center of the vibrating membrane 21, but this is not limited to this, and for example, multiple through-holes 22 may be formed. The number and diameter of the through-holes 22 can be appropriately selected considering the amount of air permeability, acoustic design, and manufacturing method. Also, in the above description, a gas laser is used to form a circular through-hole 22, but this is not limited to this, and for example, a semiconductor laser may be used to form an elliptical through-hole 22. Thus, the through-hole 22 can take on various shapes.

[0031] The insulating member 23 is provided to secure space for the vibrating membrane 21 to vibrate, and is made of, for example, resin. The insulating member 23 has, for example, an annular shape and is sandwiched between the peripheral edge of the vibrating membrane 21 and the fixed pole 17, as shown in Figure 2. As a result, the peripheral edge of the vibrating membrane 21 is fixed without contacting the fixed pole 17, and the area of ​​the vibrating membrane 21 that is not in contact with the insulating member 23 (the area excluding the central part of the vibrating membrane 21) vibrates in response to electrical signals.

[0032] The first conductive member 25 is a member for applying an electrical signal to the vibrating membrane 21. The first conductive member 25 is formed, for example, from a conductive sheet. As shown in Figure 2, the first conductive member 25 has an annular portion 25a that contacts the peripheral edge of the vibrating membrane 21 and an extended portion 25b that extends upward from at least a part of the annular portion 25a. In practice, the extended portion 25b extends to the connecting portion 5.

[0033] The support member 27 is a support portion that supports the vibrating membrane 21 such that a portion of the vibrating membrane 21 contacts the fixed pole 17. As shown in Figure 2, the support member 27 is located on the lower surface 21b side of the vibrating membrane 21 and supports the vibrating membrane 21 by contacting the lower surface 21b of the vibrating membrane 21. The support member 27 covers the side of the central portion of the vibrating membrane 21 that is opposite to the side that contacts the fixed pole 17. By supporting the lower surface 21b of the vibrating membrane 21 with the support member 27, the central portion of the upper surface 21a of the vibrating membrane 21 is pressed against the fixed pole 17.

[0034] The support member 27 is positioned between the diaphragm 21 and the ear-side housing 12 of the housing 11, so as to be in contact with the lower surface 21b of the diaphragm 21 and the ear-side housing 12. The support member 27 is made of an elastic material and is provided so as to be deformable in accordance with the displacement of the diaphragm 21. For example, when a user removes the earphone 1 from their ear, the inside of the housing 11 is depressurized and the diaphragm 21 is displaced, and the support member 27 deforms in accordance with the displacement of the diaphragm 21.

[0035] As shown in Figure 4, the support member 27 covers the membrane through-hole 22. The support member 27 is made of an elastic material that is permeable and allows air to pass through its interior. Here, the elastic material is, for example, a sponge. Because the support member 27 is permeable in this way, for example, air that has passed through the membrane through-hole 22 of the vibrating membrane 21 can pass through the support member 27 that is in contact with the membrane through-hole 22.

[0036] As shown in Figure 2, the second conductive member 29 is positioned between the fixed electrode 17 and the terminal 19. The second conductive member 29 is positioned to cover the through hole 18 of the fixed electrode 17. The second conductive member 29 has the function of acting as an acoustic resistor between the fixed electrode 17 and the terminal 19, thereby enabling adjustment of the acoustic characteristics. In particular, by using both the first conductive member 25 and the second conductive member 29 described above, a wide range of acoustic characteristics can be adjusted.

[0037] The second conductive member 29 has permeability, allowing air to pass through its interior. For example, the second conductive member 29 is made of conductive fabric. Because the second conductive member 29 has permeability, air in the lower region R1 can easily flow to the upper region R2 by passing through the membrane through-holes 22 of the vibrating membrane 21 and then the second conductive member 29. Similarly, air in the upper region R2 can easily flow to the lower region R1 by passing through the second conductive member 29 and then the membrane through-holes 22.

[0038] <Airflow through membrane penetration holes 22> In this embodiment, by providing membrane through-holes 22 in the vibrating membrane 21, air inside the housing 11 flows through the membrane through-holes 22, thereby regulating the pressure inside the housing 11.

[0039] For example, when the earphone 1 is worn in the user's ear, the pressure in the lower region R1 increases. As a result, the air in the lower region R1 flows out of the housing 11 through the membrane penetration hole 22 and the adjustment hole 14, causing the pressure in the lower region R1 to decrease and the pressures in the lower region R1 and upper region R2 to balance. The above-mentioned airflow will be explained with reference to Figure 5.

[0040] Figure 5 is a schematic diagram illustrating the airflow through the membrane through-holes 22 of the vibrating membrane 21. In Figure 5, the airflow is indicated by dashed arrows. The air in the lower region R1 first heads towards the support member 27. Because the support member 27 is permeable, the air that reaches the support member 27 passes through it. After that, the air passes through the membrane through-holes 22 of the vibrating membrane 21, which are in contact with the support member 27. The air that has passed through the membrane through-holes 22 heads towards the second conductive member 29 via the through-holes 18 of the fixed electrode 17. Because the second conductive member 29 is permeable, the air that reaches the second conductive member 29 passes through it. After that, the air flows through the upper region R2 towards the adjustment hole portion 14 of the outer housing 13. The air then passes through the adjustment hole portion 14 and is discharged outside the housing 11 (see Figure 2).

[0041] Furthermore, if the pressure in the upper region R2 is high, a flow opposite to the flow described above occurs (i.e., air in the upper region R2 flows out of the housing 11 via the membrane penetration hole 22 and the conduit section 15), and air is discharged out of the housing 11 from the adjustment hole section 14, thereby balancing the pressures in the lower region R1 and the upper region R2.

[0042] If a membrane through-hole 22 is provided in the central part of the vibrating membrane 21 (the part supported by the support member 27), the non-vibrating central part of the vibrating membrane 21 can be utilized to form an airflow path. Furthermore, by providing a membrane through-hole 22 in the vibrating membrane 21 that divides the inside of the housing 11 into two regions, a lower region R1 and an upper region R2, the structure of the housing 11 becomes simpler compared to the comparative example shown in Figure 6. The effectiveness of this embodiment will be further explained below in comparison with the comparative example.

[0043] Figure 6 is a schematic diagram illustrating the comparative example. Unlike the vibrating membrane 21 described above, the vibrating membrane 121 of the electroacoustic conversion unit 110 in the comparative example does not have membrane through-holes. Therefore, in the comparative example, in addition to providing an adjustment hole 14 in the outer housing 13 for allowing air from the upper region R2 to flow out of the housing, an adjustment channel 130 is provided in the ear-side housing 112 for allowing air from the lower region R1 to flow out of the housing. Furthermore, the support member 127 and the second conductive member 129 differ from the support member 27 and the second conductive member 29 in that they do not have air permeability.

[0044] The adjustment channel section 130 is a channel through which air flows. For example, when adjusting the pressure in the lower region R1, the air in the lower region R1 flows out of the housing 11 through the adjustment channel section 130. To avoid the air flowing through the adjustment channel section 130 being directed towards the user's ear, the adjustment channel section 130 is formed to be elongated along the outer surface of the ear-side housing 112, as shown in Figure 6. In particular, to reduce the impact on acoustic characteristics, the diameter of the adjustment channel section 130 is made small and the length of the adjustment channel section 130 is made long. Forming such an adjustment channel section 130 would make the structure of the ear-side housing 112 complex, increasing the manufacturing cost of the ear-side housing 112. For example, a diameter of about 0.1 mm is desirable for the adjustment channel section 130, but in this case, a precise mold is required, and utmost care is needed when assembling the mold. In contrast, in this embodiment, the air in the lower region R1 flows out of the housing 11 through the membrane penetration hole 22 without providing an adjustment channel section 130 in the ear-side housing 12. This simplifies the structure of the ear-side housing 12.

[0045] <Variation> Figure 7 is a schematic diagram illustrating the configuration of the support member 37 in a modified example. Figure 7 shows the relationship between the membrane through-hole 22 of the vibrating membrane 21 and the support member 37.

[0046] In the above-described embodiment, the support member 27 is positioned to cover the entire membrane through-hole 22 of the vibrating membrane 21 (see Figure 4). In contrast, in the modified example, as shown in Figure 7, a notch 38 is formed in the cylindrical support member 37 in the portion facing the membrane through-hole 22, exposing the membrane through-hole 22. That is, the notch 38 is cut along the axial direction so that it forms a U-shape when the support member 37 is viewed from above. With such a support member 37, the airflow to the membrane through-hole 22 is good, and the choice of material for the support member 37 is broadened. For example, even if the support member 37 is changed to a different material, the effect on airflow is minimal.

[0047] By providing a notch 38 in the support member 37, for example, air in the lower region R1 can more easily reach the membrane through-hole 22 through the notch 38. In other words, in this modified example, air can more easily reach the membrane through-hole 22 without passing through the support member 37. Therefore, the support member 37 does not need to be made of a breathable material. However, the support member 37 is not limited to this, and may be made of a breathable material.

[0048] The shape of the support member 37 is not limited to the shape shown in Figure 7. For example, a cylindrical support member 37 may have a hole (the diameter of which is larger than the diameter of the membrane through-hole 22) that penetrates the center of the support member 37 along the axial direction. In the case of a support member 37 of this shape, the membrane through-hole 22 does not come into contact with the support member 37. Therefore, variations in air permeability caused by small membrane through-holes 22 being blocked more than expected due to individual differences in the support member 37 or differences in the pressure applied to the vibrating membrane 21 can be suppressed.

[0049] Although only one membrane through-hole 22 is shown in Figure 7, there may be multiple membrane through-holes 22. In this case, the notch 38 of the support member 37 is formed to face at least one of the multiple membrane through-holes 22 (for example, two of the five membrane through-holes 22).

[0050] Figure 8 is a schematic diagram illustrating the configuration of a modified support member 47. Figure 8(a) shows a plan view of the support member 47, and Figure 8(b) shows a cross-sectional view of BB of Figure 8(a). In the support member 47, a groove 48 is formed as a notch on the upper surface 47a that is in contact with the lower surface 21b of the vibrating membrane 21 (see Figure 2). The groove 48 is formed linearly along the radial direction passing through the center of the support member 47 on the upper surface 47a of the cylindrical support member 47. The groove 48 is also formed at a position opposite the membrane through-hole 22. Therefore, air in the lower region R1 can easily reach the membrane through-hole 22 via the groove 48 (see Figure 5). By providing the groove 48 in the support member 47, the airflow to the membrane through-hole 22 is improved, similar to the support member 37 shown in Figure 7, and the choice of material for the support member 47 is broadened.

[0051] In the modified configuration, air flow will occur within the housing 11 via the membrane through-holes 22. For example, air in the lower region R1 will flow out of the housing 11 via the membrane through-holes 22.

[0052] <Effects of this embodiment> The earphone 1 of the above-described embodiment includes a diaphragm 21 provided to divide the space inside the housing 11 into two parts, a support member 27 that supports the diaphragm 21 so that the central part of the diaphragm 21 is in contact with a fixed pole 17, and an adjustment hole 14 formed in the outer housing 13 for adjusting the pressure inside the housing 11. Furthermore, a membrane through-hole 22 is formed in the central part of the diaphragm 21, penetrating the diaphragm 21. As a result, a membrane through-hole 22 is provided in the central part of the diaphragm 21 (the part supported by the support member 27), and an airflow path can be formed by utilizing the non-vibrating central part of the diaphragm 21. Furthermore, by providing a membrane through-hole 22 in the diaphragm 21 which divides the inside of the housing 11 into two parts, a lower region R1 and an upper region R2, for example, air from the lower region R1 can flow out of the housing 11 through the adjustment hole 14 of the outer housing 13, thereby adjusting the pressure inside the housing 11, and thus simplifying the structure of the ear-side housing 12.

[0053] Furthermore, by providing the membrane penetration hole 22, it becomes unnecessary to provide an adjustment channel section (for example, the adjustment channel section 130 shown in Figure 6) in the ear-side housing 12. This eliminates the need to adjust the diameter and length of the adjustment channel section in the housing 11, making it easier to design the air inflow and outflow within the housing 11. In addition, since there is no need to provide an adjustment channel section, the earphone 1 can be made even smaller without compromising sound quality. Moreover, by eliminating the need to adjust the diameter and length of the adjustment channel section, the number of parameters that affect acoustic characteristics (making it difficult to output low-frequency ranges) is reduced, improving the ease of acoustic design.

[0054] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of its gist. For example, all or part of the apparatus can be configured by functionally or physically distributing and integrating in any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of the new embodiments resulting from the combinations are combined with the effects of the original embodiments. [Explanation of symbols]

[0055] 1 earphones 11 Housing 12 Ear-side housing 13 Outer housing 14 Adjustment hole 17 fixed pole 19 terminals 21. Vibrating membrane 22 Membrane through hole 27 Support Member 29 Second conductive member 37 Support member 47 Support members

Claims

1. A housing connected to a conduit that emits sound to the outside, A fixed electrode fixed inside the housing, A vibrating membrane is provided to divide the space within the housing into two sections, and vibrates in accordance with the potential difference generated between it and the opposing fixed pole, A support portion supports the vibrating membrane such that a part of the vibrating membrane contacts the fixed electrode, The housing has an adjustment hole formed so as to penetrate the wall opposite to the conduit portion when viewed from the vibrating membrane, for adjusting the pressure inside the housing, Equipped with, A portion of the vibrating membrane has a membrane through-hole that penetrates the vibrating membrane, The support portion covers the part of the diaphragm opposite to the side that contacts the fixed electrode, in the earphone.

2. The membrane penetration hole is formed in the central part of the vibrating membrane. The earphone according to claim 1.

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