Earphone port

Abstract

A port tube for an earphone, the port tube configured to acoustically couple a rear acoustic cavity of the earphone to an external environment, the port tube including a first section proximate the rear cavity and defining a first cross-sectional area, a second transition section coupled to the first section and defining a gradually increasing cross-sectional area, a third curved bank-like section coupled to the second section and defining a second cross-sectional area larger than the first cross-sectional area, a fourth transition section coupled to the third section and defining a gradually decreasing cross-sectional area, and a fifth section coupled to the fourth section and defining a third cross-sectional area smaller than the second cross-sectional area.

Description

Technical Field

[0001] This disclosure relates to a port for an earphone and claims the priority of U.S. Patent Application No. 17 / 467,187, filed on September 4, 2021.

Background Art

[0002] An earphone mass port should maintain an air flow even at low frequencies.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Aspects and examples are directed to a mass port for an earphone having an increased diameter and length that is effective in supporting an air flow even at low frequencies of about 2 - 6 Hz.

Means for Solving the Problems

[0004] All examples and features mentioned below can be combined in any technically possible way.

[0005] In one aspect, a port tube for an earphone configured to acoustically couple a rear acoustic cavity of the earphone to an external environment includes a first section proximate to the rear acoustic cavity and defining a first cross-sectional area, a second transition section coupled to the first section and defining a gradually increasing cross-sectional area, a third curved bank-shaped section coupled to the second section and defining a second cross-sectional area larger than the first cross-sectional area, a fourth transition section coupled to the third section and defining a gradually decreasing cross-sectional area, and a fifth section coupled to the fourth section and defining a third cross-sectional area smaller than the second cross-sectional area.

[0006] Some embodiments include one or any combination of the above and / or the following features. In some examples, the first section is curved. In one example, the radius of curvature of the central longitudinal axis of the first section is approximately the same as the radius of curvature of the central longitudinal axis of the third section. In one example, the second and fourth sections each transition by approximately the same amount in cross-sectional area.

[0007] Some embodiments include one or any combination of the above and / or the following features. In one example, the third section includes an inner wall and an outer wall, and the bank is between the inner wall and the outer wall. In one example, the third section further includes a lower wall that intersects the inner wall and the outer wall. In one example, the bank includes an inner wall that is longer than the outer wall. In one example, the bank includes an inner wall having a length that is approximately 20 percent greater than the length of the outer wall.

[0008] Some embodiments include one or any combination of the above and / or the following features. In one example, the fifth section is curved. In one example, the radius of curvature of the central longitudinal axis of the fifth section is smaller than the radius of curvature of the central longitudinal axis of the third section. In one example, the port tube is substantially "S"-shaped along its length between a first end where the port tube is fluidly coupled to the rear acoustic cavity of the earphone and a second end where the port tube is fluidly coupled to the external environment. In one example, the "S"-shape defines a first curvature closest to the first end and a second curvature closest to the second end. In one example, the first curvature has a radius of curvature of the central longitudinal axis of the port tube that is greater than the radius of curvature of the central longitudinal axis of the second curvature of the port tube.

[0009] Some embodiments include one or any combination of the above and / or the following features. In one example, the second cross-sectional area is approximately 12 percent larger than the first cross-sectional area. In one example, the port tube has a length dimension along the longitudinal direction of the port tube and a width dimension across the width of the port tube orthogonal to the longitudinal direction of the port tube, and the width dimension is substantially the same along the entire length dimension. In one example, the first, third, and fifth sections each have a constant cross-sectional area along the longitudinal direction of the first, third, and fifth sections. In one example, the cross-sectional areas of the first and fifth sections are the same, and the cross-sectional area of the third section is larger than the cross-sectional areas of the first and fifth sections.

[0010] In another aspect, a port tube for an earphone configured to acoustically couple a rear acoustic cavity of the earphone to an external environment includes a first curved section proximate to the rear cavity and defining a first cross-sectional area, a second transition section coupled to the first section and defining a gradually increasing cross-sectional area, a third curved bank-shaped section coupled to the second section and defining a second cross-sectional area larger than the first cross-sectional area and including an inner wall, an outer wall, and a bottom wall intersecting the inner and outer walls, the bank including an inner wall having a length greater than the length of the outer wall, a fourth transition section coupled to the third section and defining a gradually decreasing cross-sectional area, and a fifth section coupled to the fourth section and defining a third cross-sectional area smaller than the second cross-sectional area. The second and fourth sections each transition by approximately the same amount in cross-sectional area. The port tube has a length dimension along its length and a width dimension across its width orthogonal to its length, and the width dimension is substantially the same along the entire length dimension. The first, third, and fifth sections each have a constant cross-sectional area along their lengths, the cross-sectional areas of the first and fifth sections are the same, and the cross-sectional area of the third section is larger than the cross-sectional areas of the first and fifth sections.

[0011] Some embodiments include one of the above and / or below features, or any combination thereof. In one example, the radius of curvature of the central longitudinal axis of the fifth section is smaller than the radius of curvature of the central longitudinal axis of the third section. In one example, the second cross-sectional area is approximately 12 percent larger than the first cross-sectional area.

Brief Description of the Drawings

[0012] Various aspects of at least one example will be described below with reference to the accompanying drawings, which are not intended to be drawn to scale. These drawings are included to provide illustration of various aspects and examples and further understanding, and are incorporated herein and constitute a part of this specification, but are not intended as a definition of the limitations of the invention. In the drawings, the same or almost the same components illustrated in the various figures may be denoted by like letters or numbers. For clarity, in all the figures, not all components may necessarily be labeled.

[0013]

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DETAILED DESCRIPTION OF THE INVENTION

[0014] In an example of the present disclosure, the port tube for the earphone is configured to provide an effective air flow even at very low frequencies. This is achieved at least in part by a tube that is proximate to the rear cavity of the earphone and includes a first section having a first cross-sectional area, a second transition section coupled to the first section and defining a gradually increasing cross-sectional area, a third curved bank-shaped section coupled to the second section and defining a second cross-sectional area larger than the first cross-sectional area, a fourth transition section coupled to the third section and defining a gradually decreasing cross-sectional area, and a fifth section coupled to the fourth section and defining a third cross-sectional area smaller than the second cross-sectional area.

[0015] Examples of the systems, methods, and devices described herein are not limited to the details of the components' configurations and arrangements described in the following description or illustrated in the accompanying drawings. The systems, methods, and devices are implementable in other examples and can be implemented or executed in various ways. Specific examples are provided herein for illustrative purposes only and are not intended to be limiting. Specifically, the functions, components, elements, and features discussed in connection with any one or more examples are not intended to be excluded from serving similar roles in any other example.

[0016] The examples disclosed in this specification can be combined with other examples in any manner that is consistent with at least one of the principles disclosed herein. Further, references to "an example", "some examples", "an alternate example", "various examples", "one example", etc. are not necessarily mutually exclusive, and are intended to indicate that the particular features, structures, or characteristics described may be included in at least one example. The appearance of such terms in this specification does not necessarily refer to the same example in all cases.

[0017] Also, the expressions and terms used in this specification are for illustrative purposes only and should not be regarded as limiting. Any reference in this specification to an example, component, element, act, or function of a computer program product, system, and method in the singular may also include embodiments that include a plurality, and any reference in the plural to any example, component, element, act, or function in this specification may also include embodiments that include only the singular. Accordingly, references to the singular or plural are not intended to limit the systems or methods of the present disclosure, their components, acts, or elements. The use of "including", "comprising", "having", "containing", "involving", and variations thereof in this specification means including the items listed below and their equivalents, as well as other items. References to "or" can be interpreted as inclusive such that all terms described with "or" can indicate any of the single, plural, and all of the terms described.

[0018] Some embodiments of the present disclosure describe wearable audio devices of the type known as earphones, headphones, headsets, or earbuds. These devices generally deliver sound into a closed or partially closed volume in the outer ear. Earphones generally deliver sound directly into the user's ear canal.

[0019] The term "headphones" is typically used to refer to a device that fits around, over, or in the ear and radiates acoustic energy directly or indirectly into the ear canal. Headphones are sometimes referred to as earphones, earpieces, headsets, earbuds, or sport headphones and can be wired or wireless. Headphones include an electroacoustic transducer (driver) that converts an audio signal into acoustic energy. This acoustic driver may or may not be housed within an earcup. Headphones may be one for each ear, a single stand-alone unit, or one of a pair of headphones (each including at least one acoustic driver). One headphone can be mechanically connected to the other headphone, for example, by a headband and / or by a lead wire that conveys the audio signal to the acoustic driver within the headphone. Headphones may include components for receiving an audio signal wirelessly. Headphones may include components of an active noise reduction (ANR) system. Headphones may also include other functionality such as a microphone.

[0020] Specific implementations of wearable audio devices that primarily serve the purpose of acoustically outputting audio are presented in some detail, but it should be noted that such presentation of specific implementations is intended to facilitate understanding through examples and should not be construed as limiting either the scope of the disclosure or what is covered by the claims.

[0021] FIG. 1 is a perspective view of a wireless in-ear headphone or earphone 10. The earphone is merely one non-limiting example of an audio device having a target port. Earphone 10 includes a body or housing 12 that houses the active components of the earphone. Portion 14 is coupled to the exit nozzle 20 of body 12 and is flexible so that it can be inserted into the entrance of the ear canal. Sound is delivered through exit opening 15. Battery charging contacts 16, resistance port opening 17, microphone opening 18, and mass port opening 19 are visible. Earphones are known in the art (e.g., disclosed in U.S. Patent No. 9,854,345, the disclosure of which is incorporated herein by reference), and thus the specific details of the earphones are not further described herein. Earphone 10 is an example of a wearable audio device according to the present disclosure, but other types of earphones can use the target port and thus do not limit the scope of the present disclosure.

[0022] FIG. 2A is a partial cross-sectional view of only certain elements of an earphone or earbud 10 useful for a better understanding of the present disclosure. The earphone 10 includes a housing 12 that surrounds an electroacoustic transducer 21. The transducer 21 generates sound pressure within a front acoustic cavity 22 and a rear acoustic cavity 23. The sound within cavities 22 and 23 is out of phase. The sound from cavity 22 is delivered to a nozzle 20 coupled to a user's ear canal (not shown) in a manner known in the art. In some examples, cavity 22 includes a second outlet 17 (FIG. 1), and the second outlet 17 may be a resistive port of a type known in the art. A mass port, partially defined by a channel 51 within an inner dividing plate 52, together with a channel cover 69 that closes the upper portion of the channel 51, has one end open to the rear cavity 23 and the other end open to an external environment 37 outside the housing 12. The plate 52 is configured to divide the acoustics of the earphone from an upper earphone cavity 24, which can accommodate electronics, a battery, and other earphone components (not shown) of a type known in the art. The mass port is a reactive port. In some examples, a second rear resistive port (not shown) is also included. The resistive port can operate in parallel with the reactive port. Reactive and resistive ports within earphones are well known in the art and are thus not further described herein. A microphone opening 18 is configured to conduct external sound to a microphone (not shown).

[0023] Figures 2B and 2C show additional aspects of the earphone 10, including a mass port opening 53 that is open (i.e., fluidly coupled) to the rear cavity 23 and a mass port opening 64 that is fluidly coupled to the external environment 37 via the housing opening 19. The microphone 26 is disposed within the nozzle 20 and is used in an acoustic noise cancellation system as is known in the art. The microphone 29 is disposed within the front cavity 22 and is used in an acoustic noise cancellation system as is known in the art. The internal equalization port 27 fluidly connects the front cavity 22 and the rear cavity 23, thereby creating an acoustic path from the external environment 37, through the mass port, through the rear cavity, through the front cavity, and thereby into the nozzle and the ear canal. Equalization ports within earphones are known in the art and are therefore not further described herein.

[0024] The mass port within the earphone may be configured as a relatively long and thin tube. In one example, the mass port tube within an existing earphone has a length of about 12 mm and a diameter of about 0.5 mm. Due to the boundary layer effect, at very low frequencies, the air within the tube may not be able to move in and out of the tube. If the air does not move in and out of the mass port, the port may be considered to be attenuated or damped, which can lead to the user feeling a blockage effect. Such unrelieved pressure within the ear canal can be bothersome or even uncomfortable for the user. For example, very low frequency vibration sounds caused by the user's footsteps can be transmitted to the earphone at frequencies of about 2 - 6 Hz. If the mass port is blocked at these frequencies, the user will feel / hear pressure in the ear at these 2 - 6 Hz frequencies.

[0025] In the present disclosure, the diameter of the mass port for the earphone is increased so that air can move along the port and in and out of the port even at frequencies of 2 - 6 Hz. In one example, the diameter is increased to about 1 mm, thereby enabling an air flow in and out of the port even at frequencies of 2 - 6 Hz. The acoustic mass of the mass port substantially affects its reactance, and its reactance affects the tuning of the rear acoustic cavity to which the mass port is acoustically coupled. Therefore, in order to keep the tuning the same, it is necessary to at least approximately maintain the acoustic mass of the port. When the length increases from about 12 mm to about 18 - 19 mm and the diameter increases from 0.5 mm to 1 mm, the acoustic mass of the port remains approximately the same. However, earphones are necessarily small. For example, the earphone may have a maximum width of about 16 mm. Therefore, a straight port tube of 18 - 19 mm cannot fit such an earphone. In the present disclosure, the port tube is curved along its length so that its length can be greater than the width of the earphone. In an example of the earphone 10, as will be further described below, the mass port has a substantially "S" shape with two curved portions along the length between its open ends 53 and 64. In other examples, the mass port tube is curved along its length in different ways. For example, the mass port can have a substantially "C" shape, "L" shape, or "G" shape.

[0026] Also, it is useful for the mass port tube to be designed to eliminate the boundary layer effect so that there is a relatively constant air velocity across the diameter of the tube. A constant velocity helps to achieve the desired air flow even at low frequencies. It has been found that such a constant air velocity can be achieved by either or both of varying the cross-sectional area of the port tube along its length and forming a bank in at least one of the curved portions of the tube.

[0027] In the example shown in FIGS. 3A (top view) and 3B (bottom view), the mass port 50 includes a channel 51 formed within the plate 52. The opening 53 is configured to be fluidly coupled to the rear acoustic cavity, and the opening 64 is configured to be fluidly coupled to the external environment (e.g., by connecting to an opening within the earphone housing). A recess 68 adjacent to the channel 51 and extending along the entire length of the channel 51 receives a flat plate 69 (FIGS. 2A - 2C) that covers the channel 51 and thus closes the port 50 except for the openings 53 and 64.

[0028] The channel 51 (and thus the mass port) is positioned along a central longitudinal axis 63. The channel 51 is proximate to the rear acoustic cavity 23 of the earphone and in some examples is about 1 mm 2 and includes a first curved section 54 that defines a first cross - sectional area that is, in some examples, about 1 mm 2 to about 1.12 mm 2 The gradual increase in cross - sectional area achieved by the transition section 56 avoids a sudden increase in cross - sectional area and thus results in a smoother and more laminar air flow.

[0029] In some examples, the increase in the cross - sectional area of the port is achieved by increasing the depth of the port as measured from the surface of the recess 68. In some examples, the increase in depth is within the inner radius of the curve of the port, e.g., within the inner wall 59 (opposite the outer wall 61), creating a bank feature. The location where the depth increases may be other locations along the length of the port, and the goal is to obtain a smooth air flow that is constant across the width of the port and along its length.

[0030] A third curved bank - like section 58 is coupled to the second portion and defines a second cross - sectional area that is larger than the first cross - sectional area. In some examples, this second cross - sectional area is about 1.12 mm 2It is so. The fourth transition section 60 is coupled to the third section 58 and defines a gradually decreasing cross-sectional area, which, in one example, is essentially the opposite of the gradually increasing area of the transition section 56. The fifth curved section 62 is coupled to the fourth section 60 and defines a cross-sectional area smaller than that of the section 58.

[0031] In some examples, the transition sections 56 and 60 each transition by approximately the same amount in terms of cross-sectional area. In some examples, each transition section has a desired change in port cross-sectional area along its length, such as a linear or constant change per unit length. The change in cross-section in some examples depends in part on the curvature and gradient of the ports before and after the transition section. The desired result is to achieve a smooth transition of the port cross-sectional area and to provide a smooth air flow through the transition section.

[0032] In some examples, the tube has a substantially constant width along its length, which, in one example, is about 1.22 mm. In some examples, the cross-sectional areas of the sections 54 and 62 are the same. The cross-sectional area of the section 58 is the largest among all the sections. In some examples, as shown in FIG. 3A, the radius of curvature of the longitudinal port axis along the section 62 is smaller than the radii of curvature of the sections 58 and 54. In some examples, the radii of curvature of the longitudinal port axes along the sections 54 and 58 are approximately the same.

[0033] Figure 4A is a cross-sectional view through channel 51 in the unbanked portion of the mass port, where the inner sidewall 74a and the outer sidewall 76 have the same length as measured from the lower surface of the recess 68. Thereby, the bottom wall 72 is parallel to the lower surface of the recess 68. Figure 4B is a cross-sectional view through channel 51 in the banked portion of the mass port, where the inner sidewall 74b is longer than the outer sidewall 76. Thereby, a bottom wall 72 inclined with respect to the lower surface of the recess 68 is formed. In one example, in the banked section, the length of the inner channel wall increases by about 0.2 mm (for example, its length can increase from about 0.91 mm to about 1.11 mm, which is just over a 20 percent increase). In some examples, the width of the channel is constant along its entire length. In some examples, this width is about 1.22 mm.

[0034] In some examples, as shown in FIG. 5, other sharp corners between the sidewalls and the bottom wall are blended. For example, channel 80 includes a curved inner wall 84 and a curved outer wall 82 that smoothly blend into the bottom wall 86. Such blending can help achieve a more laminar and smooth airflow profile in both the banked and unbanked sections.

[0035] FIG. 6 is a plot of flow resistance (in acoustic ohms) versus pressure (in Pa) for a conventional mass port (plot line 110) and the mass port of the present disclosure of plot line 112 as shown in FIG. 3A. As can be observed, the increased cross-sectional area of the present mass port, achieved with maintenance of the acoustic mass of the port, exhibits a substantially lower flow resistance, which leads to better flow at low frequencies and a significant reduction in the user's perception of the earphone being blocked.

[0036] Although some aspects related to at least one embodiment have been described, it will be understood by those skilled in the art that various changes, modifications, and improvements can be readily conceived. Such changes, modifications, and improvements are part of this disclosure and are intended to be within the scope of the present invention. Therefore, the foregoing description and drawings are merely examples, and the scope of the present invention should be determined from the proper construction of the appended claims and their equivalents.

Description of Reference Numerals

[0037] 10 Earphone 12 Body, Housing 14 Portion 15 Outlet Opening 16 Battery Charging Contact 17 Second Outlet, Resistance Port Opening 18 Microphone Opening 19 Mass Port Opening 20 Nozzle 21 Electroacoustic Transducer 22 Front Acoustic Cavity 23 Rear Acoustic Cavity 24 Upper Earphone Cavity 26 Microphone 27 Internal Equalizing Port 29 Microphone 37 External Environment 50 Mass Port 51 Channel 52 Inner Partition Plate 53 Mass Port Opening, Open End 54 First Curved Section 56 Second Transition Section 58 Third Section 60 Fourth Transition Section 61 Outer Wall 62 Fifth Curved Section 63 Central Longitudinal Axis 64 Mass Port Opening 68 Recess 69 Channel Cover, Plate 72 Bottom Wall 74a inner side wall 74b inner side wall 76 outer side wall 80 channel 82 outer wall 84 inner wall 86 lower wall 110 plot line (conventional mass port) 112 plot line (mass port of the present disclosure)

Claims

1. A port tube for an earphone, wherein the port tube is configured to acoustically couple a rear acoustic cavity of the earphone to an external environment, and the port tube is a first section proximate to the rear acoustic cavity and defining a first cross-sectional area; a second transition section coupled to the first section and defining a cross-sectional area that gradually increases; a third curved bank-shaped section coupled to the second section and defining a second cross-sectional area larger than the first cross-sectional area; a fourth transition section coupled to the third section and defining a cross-sectional area that gradually decreases; a fifth section coupled to the fourth section and defining a third cross-sectional area smaller than the second cross-sectional area, the port tube comprising.

2. The port tube according to claim 1, wherein the first section is curved.

3. The port tube according to claim 2, wherein a radius of curvature of a central longitudinal axis of the first section is substantially the same as a radius of curvature of a central longitudinal axis of the third section.

4. The port tube according to claim 1, wherein each of the second and fourth sections transitions by substantially the same amount in terms of cross-sectional area.

5. The port tube according to claim 1, wherein the third section comprises an inner wall and an outer wall, and the bank is between the inner wall and the outer wall.

6. The port tube according to claim 5, wherein the third section further comprises a lower wall intersecting the inner wall and the outer wall.

7. The port tube according to claim 6, wherein the bank includes the inner wall that is longer than the outer wall.

8. The port tube according to claim 7, wherein the bank includes the inner wall having a length that is approximately 20 percent greater than the length of the outer wall.

9. The port tube according to claim 1, wherein the fifth section is curved.

10. The port tube according to claim 9, wherein a radius of curvature of a central longitudinal axis of the fifth section is smaller than a radius of curvature of a central longitudinal axis of the third section.

11. The port tube according to claim 1, wherein the port tube is substantially in an "S" shape along a length between a first end where the port tube is fluidly coupled to the rear acoustic cavity of the earphone and a second end where the port tube is fluidly coupled to the external environment.

12. The port tube according to claim 11, wherein the "S" shape defines a first curved portion closest to the first end and a second curved portion closest to the second end.

13. The port tube according to claim 12, wherein the first curved portion has a radius of curvature of a central longitudinal axis of the port tube that is larger than a radius of curvature of a central longitudinal axis of the second curved portion of the port tube.

14. The port tube according to claim 1, wherein the second cross-sectional area is approximately 12 percent larger than the first cross-sectional area.

15. The port tube according to claim 1, having a length dimension along the length direction of the port tube and a width dimension across the width of the port tube orthogonal to the length direction of the port tube, wherein the width dimension is substantially the same along the entire length dimension.

16. The port tube according to claim 1, wherein the first, third, and fifth sections each have a constant cross-sectional area along the length direction of the first, third, and fifth sections.

17. The port tube according to claim 16, wherein the cross-sectional areas of the first and fifth sections are the same, and the cross-sectional area of the third section is larger than the cross-sectional areas of the first and fifth sections.

18. A port tube for an earphone, the port tube being configured to acoustically couple a rear acoustic cavity of the earphone to an external environment, the port tube comprising: a first curved section proximate to the rear cavity and defining a first cross-sectional area; a second transition section coupled to the first section and defining a gradually increasing cross-sectional area; a third curved bank-shaped section coupled to the second section and defining a second cross-sectional area larger than the first cross-sectional area, the bank comprising an inner wall, an outer wall, and a lower wall intersecting the inner wall and the outer wall, the bank comprising the inner wall having a length larger than a length of the outer wall; a fourth transition section coupled to the third section and defining a gradually decreasing cross-sectional area; and a fifth curved section coupled to the fourth section and defining a third cross-sectional area smaller than the second cross-sectional area, wherein the second and fourth sections each transition by approximately the same amount in cross-sectional area. The port tube has a length dimension along the length direction of the port tube and a width dimension across the width of the port tube orthogonal to the length direction of the port tube, and the width dimension is substantially the same along the entire length dimension. The first, third, and fifth sections each have a constant cross-sectional area along the length direction of the port tube, the cross-sectional areas of the first and fifth sections are the same, and the cross-sectional area of the third section is larger than the cross-sectional areas of the first and fifth sections, the port tube.

19. The port tube according to claim 18, wherein a radius of curvature of a central longitudinal axis of the fifth section is smaller than a radius of curvature of a central longitudinal axis of the third section.

20. The port tube according to claim 19, wherein the second cross-sectional area is approximately 12 percent larger than the first cross-sectional area.

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