A speaker and headphones

Abstract

This invention relates to a loudspeaker and headphones. The loudspeaker includes: a magnetic circuit assembly; a voice coil assembly; a first diaphragm and a second diaphragm spaced apart in the vibration direction; the voice coil assembly includes a first voice coil connected to the first diaphragm and a second voice coil connected to the second diaphragm; the first and second voice coils respectively drive the first and second diaphragms to vibrate synchronously in opposite directions; the magnetic circuit assembly includes a magnetic shield and an inner magnet, the magnetic shield includes a side wall and a bottom wall, the side wall includes a folded structure, the folded structure includes an inner side wall and an outer side wall spaced apart, and an extension connecting the inner and outer side walls, the bottom wall is connected to the inner side wall, a first magnetic gap is formed between the inner side wall and the inner magnet, a second magnetic gap is formed between the inner and outer side walls, the first voice coil is at least partially located within the first magnetic gap, and the second voice coil is at least partially located within the second magnetic gap. The synchronous in opposite-direction vibration of the first and second diaphragms effectively improves the loudspeaker's output capability and meets the usage requirements of specific scenarios.

Description

A loudspeaker and earphone Cross-reference to related applications

[0001] This specification claims priority to Chinese application No. 202410966001.5, filed on July 17, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present specification relates to the field of acoustics, and in particular, to a loudspeaker and earphone. BACKGROUND

[0003] With the continuous improvement of people's living needs, consumers have increasingly high requirements for earphones. In addition to stable output performance, earphones are also required to shield environmental noise and perform normal listening in noisy or even high-noise environments. Therefore, the noise reduction performance of earphones has a great influence on the user's comfort.

[0004] Therefore, it is necessary to provide a loudspeaker and earphone to improve the noise reduction effect of acoustic devices. SUMMARY

[0005] An embodiment of the present specification provides a loudspeaker, comprising: a magnetic circuit assembly; a voice coil assembly, at least part of the voice coil assembly being located in a magnetic gap of the magnetic circuit assembly; a first diaphragm and a second diaphragm, the first diaphragm and the second diaphragm being spaced apart in a vibration direction; wherein the voice coil assembly comprises a first voice coil and a second voice coil arranged along the vibration direction, the first diaphragm is connected with the first voice coil, and the second diaphragm is connected with the second voice coil; the first voice coil and the second voice coil are configured to drive the first diaphragm and the second diaphragm to vibrate synchronously and in opposite directions, respectively; wherein the magnetic circuit assembly comprises a magnetic yoke and an inner magnet, the magnetic yoke comprises a side wall and a bottom wall, the side wall comprises a folded structure, the folded structure comprises an inner side wall and an outer side wall spaced apart in a vertical direction of the vibration direction, and an extension connecting the inner side wall and the outer side wall, the bottom wall is connected with the inner side wall, a first magnetic gap is formed between the inner side wall and the inner magnet, a second magnetic gap is formed between the inner side wall and the outer side wall, the first voice coil is at least partially located in the first magnetic gap, and the second voice coil is at least partially located in the second magnetic gap.

[0006] The embodiments of the present specification also provide an earphone, comprising the loudspeaker as described above, the earphone further comprising: a first shell, the loudspeaker is arranged in the first shell; the first diaphragm of the loudspeaker and an inner wall of the first shell form a first acoustic cavity, the second diaphragm of the loudspeaker and another inner wall of the first shell form a second acoustic cavity, and a third acoustic cavity is formed between the first diaphragm and the second diaphragm; wherein the loudspeaker further comprises a frame, the frame is located between the first diaphragm and the second diaphragm in the vibration direction; and the frame is provided with an opening, the opening is in acoustic communication with the third acoustic cavity. BRIEF DESCRIPTION OF DRAWINGS

[0007] The present specification will be further illustrated in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same numbers represent the same structures, in which:

[0008] FIG. 1 is a schematic diagram of the physiological structure of an exemplary ear according to some embodiments provided by the present application;

[0009] FIG. 2 is a schematic diagram of the wearing state of an earphone when worn on an ear according to some embodiments of the present specification;

[0010] FIG. 3 is a schematic diagram of an exemplary module of a sound generating part according to some embodiments of the present specification;

[0011] FIG. 4 is a schematic diagram of the internal structure of a sound generating part according to some embodiments of the present specification;

[0012] FIG. 5 is a schematic diagram of the frequency response curves of the first sound outlet hole and the second sound outlet hole of the earphone shown in FIG. 4;

[0013] FIG. 6 is a schematic diagram of another exemplary structure of a loudspeaker according to some embodiments of the present specification;

[0014] FIG. 7 is a schematic diagram of the internal structure of the loudspeaker shown in FIG. 6;

[0015] FIG. 8 is a schematic diagram of the frequency response curves of the earphone corresponding to different pressure relief holes according to some embodiments of the present specification;

[0016] FIG. 9 is a schematic diagram of another structure of an earphone according to some embodiments of the present specification;

[0017] FIGS. 10A-10D are schematic diagrams of the distribution of different sizes of first pressure relief holes and second pressure relief holes according to some embodiments of the present specification;

[0018] FIGS. 11A-11D are schematic diagrams of the frequency response curves of the earphone corresponding to FIGS. 10A-10D according to some embodiments of the present specification;

[0019] FIG. 12 is a structural schematic diagram of a first housing according to some embodiments of the present specification;

[0020] FIGS. 13A-13B are schematic diagrams of different relative positions of a first pressure relief hole and a second pressure relief hole according to some embodiments of the present specification;

[0021] FIG. 14 is a schematic diagram of different sizes of a first pressure relief hole and a second pressure relief hole according to some embodiments of the present specification;

[0022] FIGS. 15A-15B are schematic diagrams of different shapes of pressure relief holes according to some embodiments of the present specification;

[0023] FIGS. 16A-16B are schematic diagrams of different numbers of pressure relief holes according to some embodiments of the present specification;

[0024] FIGS. 17A-17F are schematic diagrams of different distributions of non-single concentrated pressure relief holes according to some embodiments of the present specification;

[0025] FIG. 18 is a schematic diagram of relative positions between a first sound outlet hole and a sound adjusting hole according to some embodiments of the present specification;

[0026] FIGS. 19A-19G are schematic diagrams of different exemplary structures of a loudspeaker according to some embodiments of the present specification;

[0027] FIG. 20 is another schematic diagram of a structure of a loudspeaker according to some embodiments of the present specification;

[0028] FIG. 21A is a schematic diagram of a structure of a frame according to some embodiments of the present specification;

[0029] FIG. 21B is a schematic diagram of positions of a frame and an outer magnet according to some embodiments of the present specification;

[0030] FIG. 22 is another schematic diagram of a cross-sectional structure of a sound generating assembly according to some embodiments of the present specification;

[0031] FIG. 23 is a schematic diagram of a structural exploded view of a loudspeaker according to some embodiments of the present specification. DETAILED DESCRIPTION

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present specification, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some examples or embodiments of the present specification, and for those skilled in the art, the present specification can also be applied to other similar scenarios without creative labor. Unless it is obvious from the language environment or otherwise stated, the same reference numbers in the drawings represent the same structure or operation.

[0033] It should be understood that the terms "system," "device," "unit," and / or "module" as used herein are a method of distinguishing different components, elements, parts, sections, or assemblies from one another. However, the terms should not be interpreted as implying that the different components, elements, parts, sections, or assemblies are all disposed in one body or are all located on one joint structure. For example, the terms "system," "device," "unit," and / or "module" can be replaced by the grammatically equivalent terms "mechanism," "element," "part," "section," or "assembly."

[0034] As indicated in the specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "the," and / or "this" are not limited in scope to the singular. Generally, the term "comprises" or "comprising" is used in the sense of "including" or "including but not limited to."

[0035] Flowcharts are used in the specification to illustrate the operations performed by systems in accordance with embodiments of the present specification. It should be understood that the preceding or following operations are not necessarily performed in the order shown. Instead, various steps can be performed in reverse order or simultaneously. Other operations can also be added to or removed from these processes.

[0036] FIG. 1 is a schematic diagram of the physiological structure of an exemplary ear according to some embodiments provided by the present application. Referring to FIG. 1, the exemplary ear can include the external auditory canal 11, the concha cavity 12, the cymba concha 13, the triangular fossa 14, the antihelix 15, the scapha 16, the helix 17, the tragus 18, the crux of the helix 19, and the like. The external auditory canal 11 has a certain depth and extends to the tympanic membrane of the ear, but in the absence of specific description, the external auditory canal 11 can be understood as the entrance thereof away from the tympanic membrane (i.e., the ear hole or ear canal opening). Further, the concha cavity 12, the cymba concha 13, the triangular fossa 14, and the like have a certain volume and depth in three-dimensional space, and the concha cavity 12 is directly connected to the external auditory canal 11, i.e., the aforementioned ear hole can be simply regarded as being located at the bottom of the concha cavity 12.

[0037] Since the external auditory canal 11, the concha cavity 12, the cymba concha 13, the triangular fossa 14, and the like have a certain depth and volume in three-dimensional space, the stable wearing of the earphone can be achieved by means of one or more physiological parts of the ear in terms of the earphone provided by some embodiments of the present specification.

[0038] For example, the earphone can be worn by means of other parts of the ear except the external auditory canal 11 (such as the cymba concha 13, the triangular fossa 14, the antihelix 15, the scapha 16, the helix 17, or a combination thereof); for example, in the wearing state, the whole or part of the structure of the earphone can be in contact with one or more physiological parts of the upper part of the external auditory canal 11 (such as the cymba concha 13, the triangular fossa 14, the antihelix 15, the scapha 16, the helix 17, and the helot 19); for another example, in the wearing state, the whole or part of the structure of the earphone can be located in a first area P1 in FIG. 1 enclosed by the dashed line and containing at least the cymba concha 13 and the triangular fossa 14, or in a second area P2 in FIG. 1 enclosed by the dashed line and containing at least the cymba cavity 12, or in the front side of the helot 19 (i.e., in a third area P3 in FIG. 1 enclosed by the dashed line).

[0039] By means of other parts of the ear except the external auditory canal 11, the earphone can be worn and the sound can be propagated, which not only can "liberate the external auditory canal" and reduce the impact of the earphone on the user's ear health, but also can effectively improve the use experience of the earphone. For example, when the user wears the earphone on the road, the earphone does not block the external auditory canal 11, so that the user can not only receive the sound from the earphone, but also receive the environmental sound (such as the sound of a whistle, a bell, surrounding people, traffic control, etc.), thereby effectively reducing the occurrence of traffic accidents.

[0040] Due to individual differences of different users, the ear parts may have different shapes, sizes, and other size differences. In order to facilitate description and understanding and to reduce or even eliminate individual differences of different users, if not otherwise specified, the earphone structure in different embodiments and the wearing manner thereof on the ear part model with "standard" shape and size are mainly described in the present application. For example, a simulator containing a head and its (left and right) ear parts (such as a GRAS 45BC KEMAR) can be prepared based on ANSI:S3.36, S3.25, and IEC:60318-7 standards as a reference for wearing the earphone, so as to present the scenario of normal wearing of the earphone by most users.

[0041] Therefore, descriptions such as "worn by the user", "in the wearing state", and "under the wearing state" in the present application can refer to the earphone described in the present application worn on the ear part of the aforementioned simulator. Of course, considering the individual differences of different users, the structure, shape, size, thickness, and the like of one or more parts of the ear part can be designed differently according to different shapes and sizes of the ear part, and these different designs can be manifested as different ranges of values of the characteristic parameters of one or more parts of the earphone to adapt to different ear parts.

[0042] It should be noted that in the field of medicine, anatomy, etc., three basic sections of the human body, i.e., a sagittal plane, a coronal plane and a horizontal plane, and three basic axes, i.e., a sagittal axis, a coronal axis and a vertical axis, can be defined. The sagittal plane is a section perpendicular to the ground surface along the front-to-back direction of the body, which divides the human body into two parts; the coronal plane is a section perpendicular to the ground surface along the left-to-right direction of the body, which divides the human body into two parts; and the horizontal plane is a section parallel to the ground surface along the up-to-down direction of the body, which divides the human body into two parts. Correspondingly, the sagittal axis is an axis perpendicular to the coronal plane along the front-to-back direction of the body, the coronal axis is an axis perpendicular to the sagittal plane along the left-to-right direction of the body, and the vertical axis is an axis perpendicular to the horizontal plane along the up-to-down direction of the body.

[0043] Further, the "front side of the ear" described in the present application is a concept relative to the "rear side of the ear", the former refers to the side of the ear away from the head, and the latter refers to the side of the ear towards the head, both of which are for the ear of the user. When the ear of the simulator is observed along the direction of the coronal axis of the human body, the front side profile of the ear shown in FIG. 1 can be obtained.

[0044] It should be noted that the above description of the ear is only for the purpose of illustration and is not intended to limit the scope of the present application. For those skilled in the art, various changes and modifications (for example, part of the structure of the earphone can shield part or all of the external auditory canal 11) can be made according to the description of the present application, and these changes and modifications are still within the protection scope of the present application.

[0045] With the continuous improvement of people's living needs, consumers have increasingly high requirements for earphones. In addition to stable output performance, they also require normal listening in noisy or even high-noise environments. For in-ear earphones, the sound outlet is located in the user's ear canal, and the user's listening is relatively large. At the same time, part of the environmental noise will be blocked outside the ear canal, and at this time, only the noise reduction sound emitted by the earphone is needed to actively reduce the environmental noise entering the ear canal. For open earphones that are not plugged into the ear canal, due to the fact that the sound emitting part of the open earphone is a certain distance away from the ear canal and cannot form a closed sound transmission channel with the ear canal, more environmental noise will enter the ear canal, which will have a more significant impact on the user's listening experience. In addition, due to the open structure and certain distance between the sound outlet of the open earphone and the user's ear canal, the sound output by the earphone may leak to the surrounding environment, causing obvious sound leakage. In order to improve the use experience of open earphones, such as improving the active noise reduction effect, sound output effect, and sound leakage reduction effect of open earphones, it is necessary to provide higher output strength, lower distortion, more stable amplitude frequency response and phase frequency response, and smaller fluctuations of the earphone while considering miniaturization and lightness, so that the earphone has a relatively flat output in a relatively wide frequency range, to provide higher sound output and / or better noise reduction effect.

[0046] The present specification provides an earphone to improve the sound emitting efficiency of the earphone and make the earphone have a relatively flat output in a relatively wide frequency range in the scenario of an open earphone, thereby enhancing the sound output effect and / or the active noise reduction effect.

[0047] FIG. 2 is a schematic diagram of a wearing state of an earphone when worn on an ear according to some embodiments of the present specification, and FIG. 3 is a schematic diagram of an example module of a sound emitting part according to some embodiments of the present specification.

[0048] Referring to FIGS. 2 and 3, some embodiments of the present specification provide an open earphone (hereinafter referred to as an earphone) including a sound emitting part 100 and an ear hook. The ear hook is configured to place the sound emitting part 100 near the ear without blocking the external ear canal 11. It should be noted that due to individual differences of different users, the sound emitting part 100 may partially block the external ear canal 11 when the earphone is worn by different users, but the external ear canal 11 is still not blocked. The following will be described in detail.

[0049] The sound production part 100 includes a first housing 110, a sound production assembly, a microphone assembly 140, and the like. The sound production assembly is arranged inside the first housing 110, and the sound production assembly can include a speaker 120 that can convert electrical signals into corresponding mechanical vibrations to generate sound output (e.g., noise reduction sound, audio played by earphones, and the like). Exemplarily, the sound produced by the speaker 120 can include noise reduction sound, and the noise reduction sound output to the outside of the first housing 110 can be the same in amplitude and opposite in phase to the ambient noise near the external auditory canal 11 to eliminate the ambient noise near the external auditory canal 11, thereby achieving active noise reduction. The sound produced by the speaker 120 can also include other sounds such as conversation sound, played audio, reminder sound, and the like, which, after being output to the outside of the first housing 110, can be directed to the external auditory canal 11 to ensure the user's listening effect.

[0050] In some embodiments, the sound production assembly further includes a limiting assembly 130 for positioning and limiting the speaker 120 inside the first housing 110. On the one hand, by fixing the speaker 120 inside the first housing 110 through the limiting assembly 130, it can be ensured that the sound produced by the speaker 120 is stably output to the outside of the first housing 110 through the acoustic hole arranged in the first housing 110; on the other hand, by limiting the speaker 120 through the limiting assembly 130, it can be avoided that the speaker 120 shakes relative to the first housing 110 when vibrating, thereby ensuring the sound output performance of the sound production part 100.

[0051] The microphone assembly 140 can be used to collect sound signals such as user voice, ambient sound, and the like. Exemplarily, based on the ambient noise collected by the microphone assembly 140, the output of the speaker 120 can be adjusted so that the sound produced by the speaker 120 includes sound signals that cancel out the ambient noise, thereby achieving active noise reduction of the earphone on the ambient noise.

[0052] In some embodiments, the ear hook can include an ear hook housing, a battery assembly, a circuit board assembly, and the like arranged inside the ear hook housing, wherein the battery assembly, the speaker 120, and the microphone assembly are electrically connected to the circuit board assembly. The circuit board assembly can be understood as a collection of the main control board or main board of the earphone and related components, and the circuit board assembly plays a role in regulating and managing all or part of the functional components in the earphone; for example, in the earphone, it is used for converting and processing electrical signals to support the realization of various functions of the earphone (e.g., supporting the earphone to realize switching on and off, switching of played content, increasing and decreasing volume, and the like).

[0053] Referring to FIG. 2, in some embodiments, the ear hook can be divided into a battery portion 200 and an adapter portion 300 along the length direction, and the adapter portion 300 is connected between the battery portion 200 and the sound production portion 100. In the wearing state, part of the battery portion 200 (e.g., the part occupied by the battery assembly and the circuit board assembly) is hung between the auricle and the head, and the other part of the battery portion 200 extends to the side of the auricle away from the head and connects the adapter portion 300, and the sound production portion 100 is worn near the external auditory canal 11 without blocking the external auditory canal 11, so that the earphone is an open earphone. Further, the battery assembly, the circuit board assembly, etc. can be arranged in the battery portion 200, and the adapter portion 300 can be arranged with earphone buttons and adapter boards for electrically connecting the circuit board assembly with the loudspeaker 120, the microphone assembly 140, etc. In some embodiments, the battery assembly, the circuit board assembly, etc. can be arranged at the end of the battery portion 200 away from the adapter portion 300 to balance the center of the earphone and improve the wearing comfort of the earphone.

[0054] In some embodiments, in order to improve the stability of the earphone in the wearing state, the earphone can adopt any one or a combination of the following ways. First, at least part of the ear hook is arranged as a profiled structure (e.g., an arc-shaped hook) that fits at least one of the rear side of the ear and the head, so as to increase the contact area of the ear hook with the ear or the head, thereby increasing the resistance of the earphone to fall off the ear. Second, at least part of the ear hook is arranged as an elastic structure, so that the ear hook has a certain elastic deformation amount in the wearing state, so as to increase the pressure of the ear hook on the ear or the head, thereby increasing the resistance of the earphone to fall off the ear. Third, at least part of the ear hook is arranged to abut against the head in the wearing state, so that the ear hook forms a counterforce to press the ear, so that the sound production portion 100 is pressed on the front side of the ear, thereby increasing the resistance of the earphone to fall off the ear. Fourth, the sound production portion 100 and the ear hook are arranged to respectively clamp the physiological parts such as the area where the helix 17 is located, the area where the concha cavity 12 is located, etc. from the front and rear sides of the ear in the wearing state, thereby increasing the resistance of the earphone to fall off the ear. Fifth, the sound production portion 100 is arranged to at least partially extend into the physiological parts such as the concha cavity 12, the cymba concha 13, the triangular fossa 14, the scaphoid fossa 16, etc. in the wearing state, thereby increasing the resistance of the earphone to fall off the ear.

[0055] In some embodiments, the earphone can be combined with glasses, headphones, head-mounted display devices, AR / VR helmets, etc. For example, the ear hook is omitted or retained, and the sound production portion 100 is worn near the user's ear in a hanging or clamping manner.

[0056] FIG. 4 is a schematic diagram of the internal structure of the sound production portion according to some embodiments of the present specification.

[0057] Please refer to FIG. 2, the sound production portion 100 can have a long axis direction and a short axis direction which are perpendicular to the thickness direction and orthogonal to each other. Among them, the long axis direction can be defined as the direction with the largest extension size in the shape of the two-dimensional projection plane (for example, the projection of the sound production portion 100 on the plane where the outer side surface of the sound production portion 100 is located or the projection on the sagittal plane) of the sound production portion 100 (for example, when the projection shape is a rectangle or an approximate rectangle, the long axis direction is the length direction of the rectangle or the approximate rectangle), and the short axis direction can be defined as the direction perpendicular to the long axis direction in the shape of the sound production portion 100 projected on the sagittal plane (for example, when the projection shape is a rectangle or an approximate rectangle, the short axis direction is the width direction of the rectangle or the approximate rectangle). The thickness direction can be defined as the direction perpendicular to the two-dimensional projection plane, for example, the thickness direction is consistent with the direction of the coronal axis, and both point to the left and right directions of the body. In some embodiments, the thickness direction can also be defined as the direction of the shell close to or away from the ear in the wearing state. In some embodiments, when the sound production portion 100 is in an inclined state in the wearing state, the long axis direction and the short axis direction are still parallel or approximately parallel to the sagittal plane, the long axis direction can have a certain angle with the direction of the sagittal axis, that is, the long axis direction is also correspondingly inclined, and the short axis direction can have a certain angle with the direction of the vertical axis, that is, the short axis direction is also inclined. In some embodiments, the whole or part of the structure of the shell of the sound production portion 100 can extend into the concha cavity 12, that is, the projection of the shell of the sound production portion 100 on the sagittal plane has an overlapping part with the projection of the concha cavity 12 on the sagittal plane. In some embodiments, the long axis direction and the short axis direction of the loudspeaker 120 are consistent with the long axis direction and the short axis direction of the sound production portion 100.

[0058] Please refer to FIG. 2 and FIG. 4, in some embodiments, the first shell 110 of the sound production portion 100 can include multiple different shell walls such as the inner side surface 110a, the outer side surface 110b, the upper side surface 110c, the lower side surface 110d, the front side surface 110e, etc. Among them, the inner side surface 110a is the shell side surface of the first shell 110 in the thickness direction which faces the ear (for example, the external auditory canal 11) in the wearing state; the outer side surface 110b is the shell side surface of the first shell 110 in the thickness direction which is away from the ear (for example, the external auditory canal 11) in the wearing state; the upper side surface 110c is the shell side surface of the first shell 110 in the short axis direction which is close to the top of the head in the wearing state; the lower side surface 110d is the shell side surface of the first shell 110 in the short axis direction which is away from the top of the head in the wearing state; and the front side surface 110e is the shell side surface of the first shell 110 in the long axis direction which faces the back of the ear in the wearing state. It can be understood that these multiple different shell side surfaces can collectively enclose a receiving cavity of the sound production portion 100, and the sound production assembly (such as the loudspeaker 120, etc.) is received and arranged in the receiving cavity.

[0059] To effectively enhance the active noise reduction effect of the earphone in an open application scenario, the earphone can be designed to have a relatively flat output in a wide frequency range. In some embodiments, the frequency response curve of the sound output by the earphone to the outside of the first shell 110 has a first resonance peak and a second resonance peak, and the peak resonance frequency of the first resonance peak is less than the peak resonance frequency of the second resonance peak. In some embodiments, the first resonance peak and the second resonance peak refer to two adjacent continuous resonance peaks on the frequency response curve, and between the two resonance peaks, the frequency response curve has a flat region. The earphone has a higher active noise reduction effect in the frequency range corresponding to the flat region between the first resonance peak and the second resonance peak. Designing the first resonance peak and the second resonance peak can affect the frequency range of the active noise reduction of the earphone; designing the flat region (e.g., flatness, curve height of the flat region, etc.) can affect the effect of the active noise reduction. For example, the flatness of the flat region can reflect the stability of the sound output by the earphone. The more stable the sound output by the earphone, the easier it is to perform active noise reduction, and the better the effect of the active noise reduction. For another example, the curve height of the flat region can reflect the size of the sound that the earphone can output. The larger the sound that the earphone can output, the larger the noise that the earphone can reduce, and the better the effect of the active noise reduction.

[0060] To design the first resonance peak, the second resonance peak, and the flat region therebetween, please refer to FIG. 4. In some embodiments, the loudspeaker 120 can include a magnetic circuit assembly 122 and a voice coil assembly 123, as well as a first diaphragm 121-1 and a second diaphragm 121-2. The voice coil assembly 123 drives the first diaphragm 121-1 and the second diaphragm 121-2 to vibrate in opposite directions synchronously. At least part of the voice coil assembly 123 is located in the magnetic gap of the magnetic circuit assembly 122. The first diaphragm 121-1 and the second diaphragm 121-2 are arranged in a spaced manner in the vibration direction. The voice coil assembly 123 includes a first voice coil 123-1 and a second voice coil 123-2 arranged in the vibration direction, the first diaphragm 121-1 is connected to the first voice coil 123-1, and the second diaphragm 121-2 is connected to the second voice coil 123-2. The first voice coil 123-1 and the second voice coil 123-2 are configured to drive the first diaphragm 121-1 and the second diaphragm 121-2 to vibrate in opposite directions synchronously, respectively. At this time, the first voice coil 123-1 and the second voice coil 123-2 are not directly connected, and can move relative to each other in order to drive the first diaphragm 121-1 and the second diaphragm 121-2 to vibrate in opposite directions synchronously, respectively.

[0061] The first diaphragm 121-1 and an inner wall of the first housing 110 are arranged in a spaced and opposite manner in a vibration direction (i.e., a thickness direction) to form a first acoustic cavity 111-1, the second diaphragm 121-2 and another inner wall of the first housing 110 are arranged in a spaced and opposite manner in the vibration direction to form a second acoustic cavity 111-2, and the first diaphragm 121-1 and the second diaphragm 121-2 form a third acoustic cavity 111-3 therebetween. The third acoustic cavity 111-3 serves as a common cavity between the first diaphragm 121-1 and the second diaphragm 121-2. The first housing 110 is provided with a first acoustic hole that is in acoustic communication with the loudspeaker 120 through the first acoustic cavity 111-1, the first housing 110 is provided with a second acoustic hole that is in acoustic communication with the loudspeaker 120 through the second acoustic cavity 111-2, and the first housing 110 is provided with a third acoustic hole that is in acoustic communication with the loudspeaker 120 through the third acoustic cavity 111-3.

[0062] The connection configuration of the first acoustic cavity 111-1 and the first acoustic hole can be approximately equivalent to a first Helmholtz resonance cavity model, the connection configuration of the second acoustic cavity 111-2 and the second acoustic hole can be approximately equivalent to a second Helmholtz resonance cavity model, and the connection configuration of the third acoustic cavity 111-3 and the third acoustic hole can be approximately equivalent to a third Helmholtz resonance cavity model. The first acoustic hole, the second acoustic hole, and the third acoustic hole serve as neck openings of the respective corresponding Helmholtz resonance cavity models. When the loudspeaker 120 vibrates and outputs sound, the first acoustic hole outputs first sound, the second acoustic hole outputs second sound, and the third acoustic hole outputs third sound. The first sound, the second sound, and the third sound are superimposed to form the sound output by the earphone.

[0063] The flexibility of the first diaphragm 121-1 and the second diaphragm 121-2 in the vibration direction is related to the first resonance peak, the second resonance peak is related to the first acoustic cavity 111-1, the second acoustic cavity 111-2, the third acoustic cavity 111-3, and the flat region is related to the vibration of the first diaphragm 121-1 and the second diaphragm 121-2. Specifically, the flexibility of the first diaphragm 121-1 and the second diaphragm 121-2 in the vibration direction corresponds to the elastic coefficient K of their vibration along the vibration direction. Under the condition that the load is unchanged, the smaller the value of K, the lower the frequency of the first resonance peak. The size of the second resonance peak corresponds to the resonance frequency corresponding to the first Helmholtz resonance cavity model (the second Helmholtz resonance cavity model), which depends on the configuration of the first acoustic cavity 111-1 (the second acoustic cavity 111-2) and the first sound outlet hole (the second sound outlet hole). The flatness of the flat region is related to the vibration consistency of the first diaphragm 121-1 and the second diaphragm 121-2, and the curve height of the flat region is related to the driving force of the first diaphragm 121-1 and the second diaphragm 121-2. In some embodiments, in order to improve the sound output effect and / or active noise reduction effect of the earphone in a wider frequency band, the resonance frequency of the first resonance peak and the resonance frequency of the second resonance peak can be designed to increase the width of the flat region of the frequency response curve of the sound output by the earphone. For example, the first diaphragm 121-1 and the second diaphragm 121-2 can be designed (for example, material, structure) and the like, so as to reduce the resonance frequency of the first resonance peak. For another example, the first acoustic cavity 111-1 and the second acoustic cavity 111-2 can be designed, so as to increase the resonance frequency of the second resonance peak. In some embodiments, the first sound and the second sound have opposite phases to the third sound, so as to collectively cancel out the third sound, thereby improving the sound leakage reduction performance of the earphone. By designing the first acoustic cavity 111-1 and the second acoustic cavity 111-2 to improve the high-frequency resonance frequency of the first sound and the second sound, the earphone has a flat output in a wider frequency range, and the third acoustic cavity 111-3 can also be designed to improve the high-frequency resonance of the third sound. The first sound and the second sound can have opposite phases to the third sound in a wider frequency range, so that the earphone has a better sound leakage reduction effect in a wider frequency range. In some embodiments, by designing the third acoustic cavity 111-3, the vibration capability of the first diaphragm 121-1 and the second diaphragm 121- can also be improved, the output of the earphone is improved, and the listening effect of the user is improved.

[0064] In some embodiments, for the loudspeaker 120 with the first diaphragm 121-1 and the second diaphragm 121-2 synchronously and oppositely vibrating, in order to make the frequency response curve of the sound output by the loudspeaker 120 have a relatively flat region in a relatively large frequency band range, the number, shape, size, position, etc. of one or more acoustic structures (e.g. sound holes, acoustic cavities) of the sound generating part 100 can be designed to increase the resonance frequency of the second resonance peak, optimize the frequency response curve of the sound output by the earphone (specifically the first sound hole 112-1), thereby supporting the earphone to actively reduce noise in a wider frequency band range, and improving the sound output effect of the earphone. At the same time, the design of the acoustic structure corresponding to the third acoustic cavity 111-3 can also improve the vibration capacity of the first diaphragm 121-1 and the second diaphragm 121-2, improve the output performance of the earphone, and improve the listening effect of the user.

[0065] In some embodiments, as shown in FIG. 4, the first acoustic hole in acoustic communication with the first acoustic cavity 111-1 is the first sound hole 112-1, the second acoustic hole in acoustic communication with the second acoustic cavity 111-2 is the second sound hole 112-2, and the third acoustic hole in acoustic communication with the third acoustic cavity 111-3 is the pressure relief hole 113. In some embodiments, the first sound hole 112-1 and the second sound hole 112-2 are both arranged towards the user's ear canal (e.g. the inner side of the first shell 110 shown in FIG. 4), the sound generated by the first diaphragm 121-1 is output through the first sound hole 112-1 and directed to the user's ear canal, and the sound generated by the second diaphragm 121-2 is output through the second sound hole 112-2 and directed to the user's ear canal, thereby increasing the output of the earphone. When applied to an open earphone, since the user's ear canal receives a relatively large amount of environmental noise, improving the output performance of the earphone helps the earphone to actively reduce the relatively large amount of environmental noise. The pressure relief hole 113 is arranged away from the user's ear canal compared to the first sound hole 112-1 and the second sound hole 112-2 (e.g. the outer side of the first shell 110 shown in FIG. 4), and the pressure relief hole 113 can be used to direct the sound generated by the loudspeaker 120 out of the first shell 110 and interfere destructively with the sound leaked through the first sound hole 112-1 and the second sound hole 112-2 in the far field, thereby reducing the sound leakage of the earphone.

[0066] FIG. 5 is a schematic diagram of the frequency response curves of the first sound hole and the second sound hole of the earphone shown in FIG. 4. In FIG. 5, curve L 161 is the frequency response curve of the sound output at the first sound hole 112-1, which can be measured by a test microphone 2 mm away from the first sound hole 112-1 when the first diaphragm 121-1 is driven alone; and curve L 162 is the frequency response curve of the sound output at the second sound hole 112-2, which can be measured by a test microphone 2 mm away from the second sound hole 112-2 when the second diaphragm 121-2 is driven alone. As shown in FIG. 5, curve L161 The output sound pressure levels corresponding to the curves L 162 The difference between the output sound pressure levels corresponding to the curves L

[0067] Figure 6 is another exemplary structural schematic diagram of a loudspeaker according to some embodiments of the present specification, and Figure 7 is an internal structural schematic diagram of the loudspeaker shown in Figure 6. As shown in Figures 6 and 7, in some embodiments, the first acoustic hole in acoustic communication with the first acoustic cavity 111-1 is a first pressure relief hole 113-1, the second acoustic hole in acoustic communication with the second acoustic cavity 111-2 is a second pressure relief hole 113-2, and the third acoustic hole in acoustic communication with the third acoustic cavity 111-3 is a sound outlet hole 112. Among them, the sound outlet hole 112 is arranged towards the user's ear canal, for example, the sound outlet hole 112 can be arranged on the inner side of the first shell 110 shown in Figures 6 and 7; the first pressure relief hole 113-1 and the second pressure relief hole 113-2 are arranged away from the user's ear canal compared with the sound outlet hole 112, for example, the first pressure relief hole 113-1 can be arranged on the upper side of the first shell 110 shown in Figures 6 and 7, and the second pressure relief hole 113-2 can be arranged on the lower side of the first shell 110 shown in Figures 6 and 7. The sound generated by the first diaphragm 121-1 and the second diaphragm 121-2 is output through the sound outlet hole 112 and directed to the user's ear canal, thereby increasing the output of the earphone. When applied to an open earphone, since the user's ear canal receives a large amount of environmental noise, improving the output performance of the earphone helps the earphone to actively reduce the large amount of environmental noise.

[0068] In some embodiments, in order to reduce the difficulty of gas exchange between the third acoustic cavity 111-3 and the outside world, the sound outlet hole 112 can adopt an L-shaped structure, which includes a short edge part located on the front side of the first shell 110 parallel to the short axis direction, and a long edge part located on the inner side of the first shell 110 parallel to the long axis direction, as shown in Figure 6.

[0069] Figure 8 is a schematic diagram of the frequency response curve of an earphone corresponding to different pressure relief holes according to some embodiments of the present specification, and Figure 9 is another structural schematic diagram of an earphone according to some embodiments of the present specification.

[0070] In some embodiments, in the wearing state, the front side of the first housing 110 shown in FIG. 9 can abut the user's pinna, at which time the front side of the first housing 110 can not output sound. In some embodiments, the sound outlet hole 112 is located on the inner side of the first housing 110, and a gap is provided between the front side of the first housing 110 and the loudspeaker 120, which serves as a sound guide channel. The sound guide channel is configured to guide the sound generated by the loudspeaker 120 on the front side to the sound outlet hole 112 for output. That is, compared to FIGS. 6 and 7, in the earphone shown in FIG. 9, the sound generated by the loudspeaker 120 on the short side portion of the sound outlet hole 112 is guided to the long side portion of the sound outlet hole 112 for output through the sound guide channel constituted by the gap between the first housing 110 and the loudspeaker 120. For example, in FIG. 9, the sound outlet hole 112 can only include the long side portion, and the sound output by the loudspeaker 120 on the short side portion of the sound outlet hole 112 can be guided to the long side of the sound outlet hole 112 for output through the sound guide channel constituted by the gap between the first housing 110 and the loudspeaker 120. In some embodiments, the loudspeaker 120 outputs sound through the opening 1251 on the short side portion of the frame 125, which can be in communication with a sound guide channel such as a sound guide tube, thereby guiding the sound to the long side portion of the sound outlet hole 112 for output.

[0071] In FIG. 8, the curve L 191 is the frequency response curve of the earphone shown in FIG. 4, the curve L 192 is the frequency response curve at the first pressure relief hole 113-1 when the earphone shown in FIG. 7 drives the first diaphragm 121-1 alone, the curve L 193 is the frequency response curve at the second pressure relief hole 113-2 when the earphone shown in FIG. 7 drives the second diaphragm 121-2 alone, and the curve L 194 is the frequency response curve of the earphone shown in FIG. 9. As shown in FIG. 8, the curve L 192 is close to and substantially coincides with the curve L 193 , indicating that the vibration consistency of the first diaphragm 121-1 and the second diaphragm 121-2 of the earphone shown in FIG. 7 is relatively high.

[0072] In the flat section (for example, 200Hz-4kHz shown in FIG. 8), at the same frequency, the corresponding output sound pressure level of the curve L 191 is about 4dB higher than that of the curve L 192 , indicating that the output of the earphone shown in FIG. 4 is about 4dB higher than that of the earphone shown in FIG. 7. In some embodiments, this can be due to the fact that the length of the sound outlet hole 112 of the earphone shown in FIG. 7 is relatively long, resulting in non-concentrated sound output.

[0073] In the flat section (for example, 200Hz-4kHz shown in FIG. 8), at the same frequency, the corresponding output sound pressure level of the curve L 194 is about 4dB higher than that of the curve L 192The corresponding output sound pressure level is about 3dB higher, indicating that the sound output from the front side of the first housing 110 is guided to the sound hole 112 on the left side through the sound guide channel (as shown in FIG. 9), which can make the sound output from the sound hole 112 more concentrated, thereby improving the output directivity of the earphone.

[0074] In some embodiments, the width of the sound guide channel can also affect the output of the earphone, and thus affect the active noise reduction effect of the earphone on the larger environmental noise in the open wearing mode. For example, when the sound output by the loudspeaker 120 at the short edge part of the sound hole 112 is guided to the long edge output of the sound hole 112 through the sound guide channel formed by the gap between the first housing 110 and the loudspeaker 120, the gap between the first housing 110 and the loudspeaker 120 serves as the sound guide channel, and the width of the gap between the short edge of the first housing 110 and the short edge of the loudspeaker 120 is the width of the sound guide channel. If the width of the sound guide channel is too small, it will increase the difficulty of sound transmission, reduce the sound transmitted to the long edge part of the sound hole 112, and affect the output sound pressure level of the earphone. If the width of the sound guide channel is too large, it will cause the size of the first housing 110 to be too large or the volume of the third acoustic cavity 111-3 of the loudspeaker 120 to be too small, resulting in a too large resonance frequency of the third acoustic cavity 111-3. In some embodiments, in order to ensure the output sound pressure level of the earphone and at the same time make the resonance frequency of the third acoustic cavity 111-3 appropriate, so that the earphone has a relatively flat and stable output in a wide frequency range, the width of the sound guide channel can be 0.5mm-2mm. In some embodiments, in order to make the earphone have a larger output sound pressure level, the width of the sound guide channel can be 1mm-1.5mm. In some embodiments, the width of the sound guide channel can be 1.3mm, so that the resonance frequency of the third acoustic cavity 111-3 is near 5.5kHz, and the earphone has a relatively flat and stable output in a wide frequency range.

[0075] In some embodiments, the microphone assembly 140 can include a noise cancellation microphone, wherein the noise cancellation microphone can include a first microphone, which can be disposed on the first housing 110 near the user's ear canal to collect ambient noise near the user's ear canal; and the first microphone can be disposed near the acoustic null point of the earphone to reduce the interference of the output of the earphone on the first microphone, and to improve the accuracy of the first microphone in collecting ambient noise near the user's ear canal. In some embodiments, the noise cancellation microphone can further include a second microphone, which can be disposed near the sound outlet hole 112 to collect the sound signal output by the sound outlet hole 112, including the noise cancellation signal, to monitor the effect of active noise cancellation. The first microphone can also be regarded as a feed-forward microphone, which can generate a primary noise signal based on the ambient noise collected by the first microphone to perform active noise cancellation; and the second microphone can also be regarded as a feedback microphone, which can generate a secondary noise signal based on the sound collected by the second microphone, and generate a noise cancellation signal based on the primary noise signal and the secondary noise signal to improve the effect of active noise cancellation.

[0076] In some embodiments, when the first pressure relief hole 113-1 and the second pressure relief hole 113-2 are disposed on the upper side and the lower side of the first housing 110, the acoustic null point region of sound cancellation does not change much when the first pressure relief hole 113-1 and the second pressure relief hole 113-2 are disposed directly opposite or staggered. When the first pressure relief hole 113-1 and the second pressure relief hole 113-2 are disposed at different positions in the length direction gradually away from the front side (i.e., the left-right direction in FIGS. 10A-10D), the acoustic null point region of sound cancellation does not change much. In summary, the first microphone can be disposed near the intersection of the right side and the front side of the first housing 110 to dispose the first microphone near the acoustic null point region of the first housing 110 near the user's ear canal.

[0077] In some embodiments, the microphone assembly 140 can further include a talk microphone, which can be used to collect the user's speech. The talk microphone can include a third microphone and a fourth microphone, wherein the third microphone is disposed on the first housing 110 near the user's mouth (e.g., near the intersection of the front side and the outer side), and the fourth microphone is directed toward the user's mouth along a line connecting the third microphone. In some embodiments, the fourth microphone can be disposed near the acoustic null point of the earphone to reduce the sound collected by the fourth microphone from the sound outlet hole 112 and the pressure relief hole 113, and to avoid echo as much as possible. In some embodiments, the third microphone and the first microphone can be the same microphone. At this time, the first microphone can simultaneously serve as a talk microphone and a noise cancellation microphone, and the first microphone and the fourth microphone can cooperate to perform active noise cancellation when the user is talking, and the second microphone can improve the effect of active noise cancellation.

[0078] In some embodiments, by designing the first pressure relief hole 113-1 and the second pressure relief hole 113-2, the output of the earphone can also be adjusted, thereby adjusting the active noise reduction effect of the earphone on the larger environmental noise in the open wearing mode.

[0079] FIGS. 10A-10D are schematic diagrams of the distribution of different sizes of the first pressure relief hole and the second pressure relief hole, and FIGS. 11A-11D are schematic diagrams of the frequency response curves of the earphone corresponding to FIGS. 10A-10D, according to some embodiments of the present specification. In FIG. 10A, the sizes of the first pressure relief hole 113-1 and the second pressure relief hole 113-2 are both small; in FIG. 10B, the size of the first pressure relief hole 113-1 is small, and the size of the second pressure relief hole 113-2 is large; in FIG. 10C, the size of the first pressure relief hole 113-1 is large, and the size of the second pressure relief hole 113-2 is small; in FIG. 10D, the sizes of the first pressure relief hole 113-1 and the second pressure relief hole 113-2 are both large. In FIGS. 11A-11D, the curve L 231 represents the frequency response curve at the pressure relief hole, and the curve L 232 represents the frequency response curve at the sound hole. The output sound pressure level at the pressure relief hole can be measured by a test microphone arranged at the equivalent pressure relief hole of both the first pressure relief hole 113-1 and the second pressure relief hole 113-2, and the center of the equivalent pressure relief hole can be located at the midpoint of the line connecting the center of the first pressure relief hole 113-1 and the center of the second pressure relief hole 113-2.

[0080] Please refer to FIGS. 10A-11D, as the total opening area of the first pressure relief hole 113-1 and the second pressure relief hole 113-2 increases, the curve L 231 the peak width at high frequencies (e.g., 6 kHz-10 kHz) increases, the curve L 232 peak-to-valley fluctuations occur at high frequencies (e.g., 6 kHz-10 kHz); and when the sizes of the first pressure relief hole 113-1 and the second pressure relief hole 113-2 are different, the curve L 231 multiple peaks occur at high frequencies (e.g., 6 kHz-10 kHz), and the high-frequency vibration characteristics are more abundant.

[0081] In some embodiments, the first pressure relief hole 113-1 and the second pressure relief hole 113-2 can be arranged in a staggered manner in the vibration direction (i.e., the up-down direction in FIGS. 10A-10D) and have different sizes to improve the high-frequency vibration characteristics of the earphone, improve the output performance of the earphone, and thereby improve the active noise reduction effect of the earphone on the larger environmental noise in the open wearing mode.

[0082] In some embodiments, the earphone can further include an EQ (Equalization), which can be used to adjust the proportion of different frequencies in the sound output by the earphone. In order to improve the high frequency output of the earphone, in some embodiments, the proportion of high frequency components in the sound output by the earphone can be increased by adjusting the EQ to compensate for the lack of high frequency output, improve the output performance of the earphone, and thus improve the active noise reduction effect of the earphone on larger environmental noise in an open wearing mode.

[0083] In some embodiments, in order to improve the high frequency output of the earphone and thus improve the active noise reduction effect of the earphone on larger environmental noise in an open wearing mode, the earphone can also be provided with a high frequency unit. The loudspeaker 120 can serve as a low frequency unit, responsible for at least the output of low frequencies (e.g. frequency bands below 6kHz); the high frequency unit can be mainly responsible for the output of high frequency bands (e.g. 6kHz-10kHz). By compensating for the lack of high frequency in the earphone through the high frequency unit, the output performance of the earphone is improved.

[0084] In some embodiments, the working frequency band of the high frequency unit can be greater than 7kHz, i.e. the frequency of the signal input to the high frequency unit can be greater than 7kHz, to reduce the intersection of the working frequencies of the high frequency unit and the loudspeaker 120, so that the earphone can have a relatively flat frequency response curve in a wide frequency range in the low frequency band (e.g. 200Hz-6kHz), improving the output performance of the earphone, and thus improving the active noise reduction effect of the earphone on larger environmental noise in an open wearing mode.

[0085] Please refer to the curves L 231 In some embodiments, at high frequencies, the sound output by the pressure relief hole will resonate, interfere with the signal collection of the second microphone, and affect the active noise reduction effect of the earphone.

[0086] In some embodiments, the acoustic resistance of the pressure relief hole (e.g. first pressure relief hole 113-1, second pressure relief hole 113-2, etc.) can be increased to reduce sound leakage of the pressure relief hole, especially to reduce the influence on the second microphone near the high frequency resonance frequency. In some embodiments, an acoustic resistance net can be provided in the pressure relief hole (e.g. first pressure relief hole 113-1, second pressure relief hole 113-2, etc.) to increase the acoustic resistance of the pressure relief hole.

[0087] FIG. 12 is a structural schematic diagram of a first shell according to some embodiments of the present specification. Referring to FIG. 12, in some embodiments, when the first pressure relief hole 113-1 and the second pressure relief hole 113-2 are respectively arranged on the upper side 110c and the lower side 110d of the first shell 110, by designing the first Helmholtz resonance cavity model and the second Helmholtz resonance cavity model (for example, the number, shape, size, position of sound holes and acoustic cavities, etc.), the resonance frequency of the second resonance peak can be increased, the frequency response curve of the sound output by the speaker 120 has a relatively flat region in a relatively large frequency range, the frequency response curve of the sound output by the earphone (specifically, the sound hole 112) is optimized, and thus the earphone can support active noise reduction in a wider frequency range and improve the sound output effect of the earphone.

[0088] As the size of the pressure relief hole (the first pressure relief hole 113-1, the second pressure relief hole 113-2, etc.) gradually decreases, the resonance peak of the sound generating part 100 at high frequencies (for example, above 4.5 kHz) gradually moves forward. In order to increase the resonance frequency of the second resonance peak of the earphone at high frequencies and make the earphone have a flat output in a wider frequency range, the size of the pressure relief hole should not be too small. Based on this, in some embodiments, the first pressure relief hole 113-1 and the second pressure relief hole 113-2 can adopt a single-hole structure, and the ratio of the size of the first pressure relief hole 113-1 and / or the second pressure relief hole 113-2 to the corresponding size of the first shell 110 is not less than 0.3. For example, in the case where the length of the first shell 110 and the pressure relief hole in the long axis direction is greater than the width in the short axis direction, the ratio of the length of the pressure relief hole to the length of the first shell 110 in the long axis direction can be not less than 0.3; for example, the ratio of the length of the first pressure relief hole 113-1 in the long axis direction to the length of the inner side wall in the long axis direction can be not less than 0.3, and the ratio of the length of the first pressure relief hole 113-1 in the long axis direction to the length of the outer side wall in the long axis direction can be not less than 0.3. In the case where the contour shape of the sound generating part 100 is a central symmetric geometric shape such as a circle, the ratio of the radius of the pressure relief hole to the radius of the corresponding side wall of the first shell 110 can be not less than 0.3. In this way, the resonance frequency of the corresponding acoustic cavity can be relatively large, the second resonance peak of the sound output through the pressure relief hole can be moved to a high frequency range, and finally the earphone can have a relatively flat output in a wider frequency range, thereby improving the active noise reduction effect of the earphone on a larger environmental noise in an open environment.

[0089] FIGS. 13A-13B are schematic diagrams of different relative positions of the first pressure relief hole and the second pressure relief hole according to some embodiments of the present specification. In FIG. 13A, the first pressure relief hole 113-1 and the second pressure relief hole 113-2 are arranged opposite to each other and are located at the center of the corresponding surface; in FIG. 13B, the first pressure relief hole 113-1 and the second pressure relief hole 113-2 are arranged eccentrically in the length direction.

[0090] In some embodiments, the first pressure relief hole 113-1 and the second pressure relief hole 113-2 are arranged in a staggered manner, which can cause the second resonance frequency of the earphone to move forward, resulting in a narrower flat region of the earphone. In order to ensure that the second resonance peak of the sound output through the pressure relief hole moves to the high frequency band, and finally makes the earphone have a relatively flat output in a wider frequency band range, and improves the active noise reduction effect of the earphone on larger environmental noise in an open environment, the first pressure relief hole 113-1 and the second pressure relief hole 113-2 can adopt a single hole structure, and the first pressure relief hole 113-1 and the second pressure relief hole 113-2 are arranged opposite to each other, as shown in FIG. 13A. That is, on a reference plane perpendicular to the vibration direction, the centroid of the projection of the second pressure relief hole 113-2 and the centroid of the projection of the first pressure relief hole 113-1 coincide or approximately coincide.

[0091] Due to the process limitations in actual production process, as well as the design or appearance design requirements of the components of the earphone, the size of the first pressure relief hole 113-1 and the second pressure relief hole 113-2 can be different, which can affect the output of the earphone, and further affect the near-field listening effect of the earphone and the active noise reduction effect of the earphone on larger environmental noise in an open environment.

[0092] FIG. 14 is a schematic diagram of first pressure relief holes and second pressure relief holes with different sizes, according to some embodiments of the present specification.

[0093] In some embodiments, when the size of the first pressure relief hole 113-1 and the second pressure relief hole 113-2 is different, the second resonance frequency of the earphone can move forward, resulting in a narrower flat region of the earphone. In order to ensure that the second resonance peak of the sound output through the pressure relief hole moves to the high frequency band, and finally makes the earphone have a relatively flat output in a wider frequency band range, and improves the active noise reduction effect of the earphone on larger environmental noise in an open environment, in some embodiments, the size of the first pressure relief hole 113-1 and the size of the second pressure relief hole 113-2 can be set to be the same (as shown in FIG. 13A), so as to facilitate ensuring that the sound generating unit 100 has a flat frequency response curve and a small change in phase curve in a wider frequency band range, and enhancing the active noise reduction effect of the earphone in a wider frequency band range.

[0094] FIGS. 15A-15B are schematic diagrams of pressure relief holes with different shapes, according to some embodiments of the present specification. In FIG. 15A, the pressure relief hole is a single concentrated opening, and in FIG. 15B, the pressure relief hole is a single non-concentrated opening (for example, a ring-shaped opening).

[0095] In some embodiments, compared with the single concentrated opening form of the pressure relief hole as shown in FIG. 15A, the single non-concentrated opening form of the pressure relief hole as shown in FIG. 15B can make the position of the peak resonance frequency of the second resonance peak of the sound output by the pressure relief hole be in a higher frequency band, so as to be more conducive to the earphone having a relatively flat acoustic output in a wider frequency band range, and improve the active noise reduction effect of the earphone. In order to ensure that the second resonance peak of the sound output by the pressure relief hole moves to a high frequency band, and finally makes the earphone have a relatively flat output in a wider frequency band range, and improves the active noise reduction effect of the earphone on a larger environmental noise in an open scene, in some embodiments, the first pressure relief hole 113-1 and / or the second pressure relief hole 113-2 can adopt the single non-concentrated opening form as shown in FIG. 15B.

[0096] FIGS. 16A-16B are schematic diagrams of different numbers of pressure relief holes according to some embodiments of the present specification.

[0097] In some embodiments, under the condition that the total opening area of the pressure relief hole is constant, the smaller the size of the single pressure relief hole is, and the more the number of the pressure relief holes is, the more the second resonance peak of the corresponding output sound moves to a high frequency band. In some embodiments, the pressure relief hole (for example, the first pressure relief hole 113-1) can adopt the non-single concentrated opening distribution hole as shown in FIGS. 16A and 16B, that is, the pressure relief hole is a multi-hole structure composed of multiple small holes arranged in an array; in this way, the position of the high frequency peak of the loudspeaker 120 can be made to be relatively high, and the effective area of the sound output can be greatly increased to ensure the active noise reduction effect, while meeting the appearance design requirements of the sound generating part 100 or the earphone.

[0098] When the total area of the pressure relief hole is constant, the size of the single pressure relief hole is too small, although the total number of the pressure relief holes can be increased to increase the resonance peak of the high frequency, but the acoustic resistance of the pressure relief hole will also be increased, which will affect the output sound pressure level. Therefore, in order to ensure the output sound pressure level of the earphone, when the pressure relief hole (for example, the first pressure relief hole 113-1) adopts the multi-hole structure of the non-single concentrated opening form as shown in FIGS. 16A and 16B, that is, the pressure relief hole is a multi-hole structure composed of multiple small holes arranged in an array, the diameter of the single small hole can be not less than 0.2 mm.

[0099] FIGS. 17A-17F are schematic diagrams of different distributions of non-single concentrated vent holes, according to some embodiments of the present application. In FIG. 17A, the non-single concentrated vent holes are distributed on one side of the corresponding side wall of the first housing 110 in the long axis direction, and the corresponding opening rate is 0.15. In FIG. 17B, the non-single concentrated vent holes are distributed in a ring shape on one side of the corresponding side wall of the first housing 110 in the long axis direction, and the corresponding opening rate is 0.15. In FIG. 17C, the non-single concentrated vent holes are distributed in a ring shape on the entire surface of the corresponding side wall of the first housing 110, and the corresponding opening rate is 0.15. In FIG. 17D, the non-single concentrated vent holes are distributed in a ring shape on one side of the corresponding side wall of the first housing 110 in the long axis direction, and the other side of the corresponding side wall in the long axis direction is provided with a sound adjustment hole 113-3, and the corresponding opening rate of the vent holes is 0.15, and the corresponding opening rate of the sound adjustment hole 113-3 is 0.0375. In FIG. 17E, the non-single concentrated vent holes are distributed in the central region of the corresponding side wall of the first housing 110, and the corresponding opening rate is 0.15. In FIG. 17F, the non-single concentrated vent holes are distributed on the entire surface of the corresponding side wall of the first housing 110, and the corresponding opening rate is 0.30. At this time, the first vent hole 113-1 and the second vent hole 113-2 can be designed to face each other or be misaligned. The formula for calculating the opening rate is the ratio of the opening area of the vent hole to the area of the corresponding side wall of the first housing 110, for example, the area ratio of the first vent hole 113-1 to the inner wall surface.

[0100] In some embodiments, the lower the opening rate of the vent hole, the smaller the total area of the vent hole, which leads to a smaller resonance frequency of the second harmonic peak of the sound output by the vent hole, resulting in a narrower flat region of the earphone and affecting the active noise reduction effect of the earphone. When the vent hole is a multi-hole structure composed of an array of multiple small holes (i.e., the vent hole adopts a non-single concentrated vent hole structure), in order to make the earphone have a relatively flat output in a relatively wide frequency range, the opening rate of the vent hole can be not less than 0.1. It can also be understood that, in a reference plane perpendicular to the thickness direction (vibration direction), the area ratio of the projection of the first vent hole 113-1 or the second vent hole 113-2 in the projection of the corresponding side wall (e.g., the upper side wall or the lower side wall) of the first housing 110 is not less than 10%.

[0101] Due to the wearing state, the sound generated by the loudspeaker 120 (specifically the first diaphragm 121-1) in the first acoustic cavity 111-1 will be hindered by the shell side wall (for example, the part of the upper wall of the first shell 110 which is not provided with the first pressure relief hole 113-1) of the first shell 110 and cannot be directly output through the first pressure relief hole 113-1 due to the limitation of the opening size of the first pressure relief hole 113-1, the coverage area relative to the first acoustic cavity 111-1 and other factors, thereby forming a standing wave in the first acoustic cavity 111-1, which will cause the peak resonance frequency of the second resonance peak to move forward (i.e., move to the low frequency band), affecting the active noise reduction effect of the earphone in a wider frequency band range.

[0102] Therefore, in some embodiments, referring to FIG. 17D and FIG. 18, the inner side wall of the first shell 110 can also be provided with a sound adjustment hole 113-3 which communicates with the first acoustic cavity 111-1; based on the communication relationship between the first pressure relief hole 113-1 and the sound adjustment hole 113-3 and the first acoustic cavity 111-1, the peak resonance frequency of the second resonance peak of the sound output through the first pressure relief hole 113-1 to the outside of the first shell 110 can be adjusted by means of the sound adjustment hole 113-3, for example, the peak resonance frequency of the second resonance peak is not less than 1 kHz. At this time, the first pressure relief hole 113-1 can be a single hole structure (for example, a single concentrated hole structure), and the first pressure relief hole 113-1 can also be a multi-hole structure (i.e., a non-single concentrated hole structure).

[0103] Specifically, most of the sound generated by the loudspeaker 120 in the first acoustic cavity 111-1 is output through the first pressure relief hole 113-1, and a small part of the sound is output through the sound adjustment hole 113-3, thereby avoiding the formation of a standing wave in the first acoustic cavity 111-1 as much as possible, so that the peak resonance frequency of the second resonance peak of the frequency response curve of the sound output through the first pressure relief hole 113-1 can be moved to the high frequency band as much as possible, the adjustment of the peak resonance frequency of the resonance peak is realized, and finally the earphone has a relatively flat output in a wider frequency band range, which is beneficial to the active noise reduction of the earphone in a wider frequency band range; at the same time, it is also beneficial to enhance the sound pressure level of the sound output through the first pressure relief hole 113-1, and ensure the listening effect of the user.

[0104] FIG. 18 is a schematic diagram of the relative position between the first sound hole and the sound adjustment hole according to some embodiments of the present specification.

[0105] It is considered that the relative position between the tuning hole 113-3 and the first pressure relief hole 113-1 can affect the output of the loudspeaker 120 or the position of the peak resonance frequency of the resonance peak. Referring to FIG. 18, taking the first pressure relief hole 113-1 and the tuning hole 113-3 as a porous structure for example, L1-X is defined as the minimum distance between any two holes, L2-X is defined as the minimum distance between the boundary of the first acoustic cavity 111-1 and any hole, and LM is defined as the minimum distance between any two holes or the minimum distance between the boundary of the first acoustic cavity 111-1 and any hole. It should be noted that the minimum distance here refers to the distance between the profile edges of any hole or the distance between the profile edges of any hole and the boundary of the acoustic cavity.

[0106] In some embodiments, as LM increases, the corresponding high-frequency peak moves forward accordingly, resulting in a narrower flat region of the earphone and affecting the active noise reduction effect of the earphone. At the same time, the increase of LM means that the opening area of the pressure relief hole is correspondingly reduced, thereby causing the sound pressure level of the output sound to decrease. In order to make the earphone have a relatively flat output in a wider frequency range while ensuring the output sound pressure level of the earphone, in some embodiments, the minimum distance between any two holes or the minimum distance between the boundary of the first acoustic cavity 111-1 and any hole can be set to be not greater than 14 mm; it can also be understood that the minimum distance between the first pressure relief hole 113-1 and the tuning hole 113-3 is not greater than 14 mm, the minimum distance between the boundary of the first acoustic cavity 111-1 and the first pressure relief hole 113-1 is not greater than 14 mm, and the minimum distance between the boundary of the first acoustic cavity 111-1 and the tuning hole 113-3 is not greater than 14 mm. It can also be understood that when the first pressure relief hole 113-1 and / or the tuning hole 113-3 are a porous structure composed of multiple small holes arranged in an array, the minimum distance between any two adjacent small holes is not greater than 14 mm.

[0107] In this way, the sound output by the first pressure relief hole 113-1 can have a relatively flat phase curve in the frequency range before 1 kHz, thereby ensuring that the earphone has a relatively flat output in a wider frequency range, so as to facilitate the active noise reduction of the earphone in a wider frequency range. In addition, as described in the foregoing embodiments, the aperture of each small hole can be set to be not less than 0.2 mm.

[0108] In some embodiments, on a reference plane perpendicular to the thickness direction, the total projection area of the first pressure relief hole 113-1 on the reference plane is defined as S1, the total projection area of the tuning hole 113-3 on the reference plane is defined as S2, and the ratio of the total projection area S1 of the tuning hole 113-3 to the total projection area S1 of the first pressure relief hole 113-1 is defined as SS.

[0109] With the gradual increase of the SS, the corresponding high-frequency peak gradually moves backward, and the sound pressure level of the output sound gradually decreases; the increase of the SS means the increase of the opening area of the sound adjustment hole 113-3, which can effectively realize the pressure relief effect, thereby making the high-frequency peak move backward, but at the same time, due to the increase of the opening area of the sound adjustment hole 113-3, the sound leaked through the sound adjustment hole 113-3 also increases, thereby reducing the sound pressure level of the sound output through the first pressure relief hole 113-1.

[0110] In some embodiments, in order to make the earphone have a relatively flat output in a wider frequency range, while ensuring the output sound pressure level of the earphone, the ratio of the total area of the sound adjustment hole 113-3 to the total area of the first pressure relief hole 113-1 can be set to be less than 23%. By setting the ratio of the total area of the sound adjustment hole 113-3 to the total area of the first pressure relief hole 113-1 to be less than 23%, it can effectively avoid the problem that too much sound leaks from the sound adjustment hole 113-3 due to the too large opening or area ratio of the sound adjustment hole 113-3, thereby reducing the sound pressure level or volume of the first pressure relief hole 113-1.

[0111] In some embodiments, please refer to FIG. 18, in the wearing state, the sound adjustment hole 113-3 is located farther away from the external auditory canal 11 than the first pressure relief hole 113-1. In the open application scenario, since the user's external auditory canal 11 receives a large amount of environmental noise, improving the output performance of the earphone helps the earphone to actively reduce the large environmental noise; therefore, by setting the sound adjustment hole 113-3 to be farther away from the external auditory canal 11 than the first pressure relief hole 113-1, it can avoid the interference and cancellation of the sound output through the sound adjustment hole 113-3 and the sound output through the first pressure relief hole 113-1 in the near field as much as possible, thereby ensuring the user's listening effect.

[0112] For example, on a reference plane perpendicular to the thickness direction, the length of the projection of the first acoustic cavity 111-1 in the long axis direction is not less than the width in the short axis direction, for example, the projection shape of the first acoustic cavity 111-1 can be a rectangle with a length greater than a width, and for another example, the projection shape of the first acoustic cavity 111-1 can be a square or a circle with a length equal to a width. The projection of the first acoustic cavity 111-1 on the reference plane (for example, the area shown by the dashed line frame in FIG. 18) is divided into a first area and a second area along the length direction (for example, the two areas separated by the dashed arrow in FIG. 18), and the ratio of the length of the first area in the long axis direction to the length of the projection of the first acoustic cavity in the long axis direction can be set to be less than 40%, for example, 38.3%. Wherein, the projection of the sound adjustment hole 113-3 on the reference plane is located in the first area, and the projection of the first pressure relief hole 113-1 on the reference plane is located in the second area.

[0113] Therefore, by arranging the sound adjustment hole 113-3 and the first pressure relief hole 113-1 on the corresponding side (for example, the upper side) of the first shell 110 corresponding to different regions of the first acoustic cavity 111-1, the sound adjustment hole 113-3 can be located farther away from the external ear canal than the first pressure relief hole 113-1 in the wearing state, and the sound adjustment hole 113-3 can be distinguished from the first pressure relief hole 113-1 when the sound adjustment hole 113-3 adopts an array of small holes or a large-area centralized hole and is close to the first pressure relief hole 113-1. For example, in the length direction or the diameter direction of the first acoustic cavity 111-1, the holes in the region with a proportion of 38.3% from the boundary of the first acoustic cavity 111-1 can be regarded as sound adjustment holes 113-3.

[0114] It should be noted that the dashed box in FIG. 18 represents the projection boundary of the first acoustic cavity 111-1 on the reference plane; the dashed arrow in FIG. 18 represents the approximate boundary between the first region and the second region in the projected shape of the first acoustic cavity 111-1, wherein the region on the left side of the dashed arrow represents the first region, and the region on the right side of the dashed arrow represents the second region.

[0115] In some embodiments, by designing the magnetic circuit assembly 122 of the loudspeaker 120, the driving force of the voice coil assembly 123 can be improved, so that the output of the earphone can be optimized.

[0116] FIGS. 19A-19G are schematic structural diagrams of different exemplary loudspeakers according to some embodiments of the present specification.

[0117] Referring to FIG. 19A, in some embodiments, the first diaphragm 121-1 is connected with the first voice coil 123-1, and the second diaphragm 121-2 is connected with the second voice coil 123-2. The first voice coil 123-1 and the second voice coil 123-2 drive the first diaphragm 121-1 and the second diaphragm 121-2 to vibrate synchronously and in the same direction, respectively. The first diaphragm 121-1 and the second diaphragm 121-2 are not directly connected, and the first voice coil 123-1 and the second voice coil 123-2 are not directly connected. The first voice coil 123-1 drives the first diaphragm 121-1 to vibrate alone, the second voice coil 123-2 drives the second diaphragm 121-3 to vibrate alone, and the first diaphragm 121-1 and the second diaphragm 121-2 vibrate synchronously and in opposite directions. By the above arrangement, the internal structure of the loudspeaker 120 can be simplified, and the production difficulty can be reduced.

[0118] In some embodiments, in order to improve the output sound of the earphone, improve the listening effect of the earphone, and improve the active noise reduction effect of the earphone on the larger environmental noise, the magnetic circuit assembly 122 can be designed to enhance the magnetic field strength of the magnetic circuit assembly 122 and improve the driving force of the voice coil assembly 123.

[0119] Referring to FIG. 19A, in some embodiments, the magnetic circuit assembly 122 includes a magnetic shield 1221 and an inner magnet 1222, the inner magnet 1222 is arranged in the magnetic shield 1221, and the inner magnet 1222 is provided with a first magnetic conducting plate 1224 on the side facing away from the magnetic shield 1221. The magnetic shield 1221 can include a bottom wall 12211 and a side wall, the side wall can be a folded structure having an opening towards the bottom of the magnetic shield 1221, the folded structure includes an inner side wall 12212 and an outer side wall 12214 arranged in a vertical direction of the vibration direction, and an extension 12213 connecting the inner side wall 12212 and the outer side wall 12214, the bottom wall 12211 is arranged at one end of the inner side wall 12212 close to the opening, and the inner magnet 1222 is arranged on the bottom wall 12211. The end of the inner side wall 12212 away from the opening is connected to the end of the outer side wall 12214 away from the opening through the extension 12213. The inner side wall 12212 of the magnetic shield 1221 and the inner magnet 1222 form a first magnetic gap, and the first voice coil 123-1 is at least partially located in the first magnetic gap; the inner side wall 12212 of the magnetic shield 1221 and the outer side wall 12214 form a second magnetic gap, and at least part of the second voice coil 123-2 is located in the second magnetic gap.

[0120] Since the second voice coil 123-2 is far away from the inner magnet 1222, the magnetic field strength near the second voice coil 123-2 is small, and the second voice coil 123-2 may have a problem of insufficient driving force. In order to improve the driving force of the second voice coil 123-2, thereby improving the driving force of the loudspeaker 120, improving the output of the loudspeaker 120, and improving the effect of active noise reduction of the earphone on larger environmental noise, the magnetic circuit system 122 can be designed.

[0121] Referring to FIG. 19B, in some embodiments, an outer magnet 1223 can be arranged at the outer side wall 12214 of the magnetic shield 1221 (i.e., the outer side wall 12214 can include the outer magnet 1223), so as to increase the magnetic field strength near the second voice coil 123-2, thereby improving the driving force of the second voice coil 123-2, improving the driving force of the loudspeaker 120, improving the output of the loudspeaker 120, and improving the effect of active noise reduction of the earphone on larger environmental noise. At this time, the inner magnet 1222 and the inner side wall 12212 form a first magnetic gap, and the outer magnet 1223 and the inner side wall 12212 form a second magnetic gap. In some embodiments, the magnetization direction of the outer magnet 1223 and the magnetization direction of the inner magnet 1222 can be the same or opposite. For example, the N pole of the inner magnet 1222 can be located at the upper end, and the N pole of the outer magnet 1223 can be located at the upper end (as shown in FIG. 19A). For another example, the N pole of the inner magnet 1222 can be located at the upper end, and the N pole of the outer magnet 1223 can be located at the lower end (as shown in FIG. 19G).

[0122] In some embodiments, when the magnetization directions of the inner magnet 1222 and the outer magnet 1223 are the same (for example, the N poles are both located at the upper end shown in FIG. 19B), the inner side wall 12212 of the magnetic shield 1221 is subjected to the joint action of the inner magnet 1222 and the outer magnet 1223, and the magnetic field saturation phenomenon occurs in the inner side wall 12212, which limits the improvement of the magnetic field strength at the positions of the first voice coil 123-1 and the second voice coil 123-2, affects the driving force of the first voice coil 123-1 and the second voice coil 123-2, and affects the active noise reduction effect of the earphone. In some embodiments, as shown in FIG. 19C, the size of the inner side wall 12212 can be increased to avoid the magnetic field saturation of the inner side wall 12212 as much as possible, so as to improve the magnetic field strength at the positions of the first voice coil 123-1 and the second voice coil 123-2, and further improve the driving force of the loudspeaker 120, the output of the loudspeaker 120, and the active noise reduction effect of the earphone on larger environmental noise. The magnetic circuit system 122 can be designed.

[0123] Referring to Figures 19B and 19C, in some embodiments, to avoid the magnetic circuit assembly 122 becoming too large, the size of the inner magnet 1222 can be reduced while keeping the size of the magnetic circuit assembly 122 unchanged (i.e., the size of the magnetic shield 1221 unchanged), thereby increasing the size of the inner sidewall 12212. In some embodiments, the ratio of the thickness of the inner sidewall 12212 to the size of the magnetic shield 1221 can be 0.05-0.16 in the short-axis or long-axis direction. In some embodiments, to further enhance the driving force of the speaker 120, the ratio of the thickness of the inner sidewall 12212 to the size of the magnetic shield 1221 can be 0.06-0.15 in the short-axis or long-axis direction. In some embodiments, while keeping the size of the magnetic circuit assembly 122 unchanged (i.e., the width of the magnetic shield 1221 unchanged), the thickness of the inner sidewall 12212 is negatively correlated with the size of the inner magnet 1222. For example, in either the minor or major axis direction, when the size of the magnetic shield 1221 is 16mm, the thickness of the inner sidewall 12212 can be 0.8mm-2.5mm; wherein, when the size of the inner magnet 1222 is greater than 4.7mm, the thickness of the inner sidewall 12212 can be 2mm-2.5mm; when the size of the inner magnet 1222 is greater than 5.7mm, the thickness of the inner sidewall 12212 can be 1.5mm-2.5mm; and when the size of the inner magnet 1222 is greater than 6.7mm, the thickness of the inner sidewall 12212 can be 1.2mm. The thickness of the inner wall 12212 can be 1.1mm-2.5mm when the radius of the inner magnet 1222 is greater than 7.7mm; when the radius of the inner magnet 1222 is greater than 8.7mm, the thickness of the inner wall 12212 can be 1mm-2mm; when the radius of the inner magnet 1222 is greater than 9.7mm, the thickness of the inner wall 12212 can be 0.8mm-1.6mm; when the radius of the inner magnet 1222 is greater than 10.7mm, the thickness of the inner wall 12212 can be 0.8mm-1.3mm.

[0124] It should be noted that the ratio of the dimensions of the inner sidewall 12212 to the dimensions of the magnetic shield 1221 refers to the ratio of the thickness of the inner sidewall 12212 along its long axis to the dimensions of the magnetic shield 1221 along its long axis, or the ratio of the thickness of the inner sidewall 12212 along its short axis to the dimensions of the magnetic shield 1221 along its short axis. When the magnetic shield 1221 has a "U"-shaped structure, and only includes sidewalls along its long or short axis, the ratio of the thickness of the inner sidewall 12212 to the dimensions of the magnetic shield 1221 refers to the ratio of the thickness of the inner sidewall 12212 in the corresponding direction to the dimensions of the magnetic shield 1221 in the corresponding direction.

[0125] In some embodiments, as shown in FIG. 19D, the outer magnet 1223 can also be arranged on the inner side wall 12212 (i.e., the inner side wall 12212 can include the outer magnet 1223) to avoid the saturation of the magnetic field of the inner side wall 12212, ensure the magnetic field strength at the positions where the first voice coil 123-1 and the second voice coil 123-2 are located, and thus improve the driving force of the loudspeaker 120, the output of the loudspeaker 120, and the effect of active noise reduction of the earphone on larger environmental noise. At this time, the first magnetic gap is formed between the inner magnet 1222 and the outer magnet 1223, and the second magnetic gap is formed between the outer magnet 1223 and the outer side wall 12214. In some embodiments, the magnetization direction of the outer magnet 1223 can be the same as or opposite to the magnetization direction of the inner magnet 1222.

[0126] In some embodiments, as shown in FIG. 19E, in order to further improve the magnetic field strength at the positions where the first voice coil 123-1 and the second voice coil 123-2 are located, and thus improve the driving force of the loudspeaker 120, the output of the loudspeaker 120, and the effect of active noise reduction of the earphone on larger environmental noise, the inner side wall 12212 of the magnetic conductive cover 1221 can be provided with a first outer magnet 1223-1, and the outer side wall 12214 of the magnetic conductive cover 1221 can be provided with a second outer magnet 1223-2. That is, the inner side wall 12212 can include the first outer magnet 1223-1, and the outer side wall 12214 can include the second outer magnet 1223-2. At this time, the first magnetic gap is formed between the inner magnet 1222 and the first outer magnet 1223-1, and the second magnetic gap is formed between the first outer magnet 1223-1 and the second outer magnet 1223-2. In some embodiments, the magnetization directions of the inner magnet 1222, the first outer magnet 1223-1, and the second outer magnet 1223-2 can be the same or opposite. For example, the magnetization directions of the inner magnet 1222 and the first outer magnet 1223-1 can be the same, and the magnetization directions of the inner magnet 1222 and the second outer magnet 1223-2 can be the same; or the magnetization directions of the inner magnet 1222 and the first outer magnet 1223-1 can be the same, and the magnetization directions of the inner magnet 1222 and the second outer magnet 1223-2 can be opposite; or the magnetization directions of the inner magnet 1222 and the first outer magnet 1223-1 can be opposite, and the magnetization directions of the inner magnet 1222 and the second outer magnet 1223-2 can be the same; or the magnetization directions of the inner magnet 1222 and the first outer magnet 1223-1 can be opposite, and the magnetization directions of the inner magnet 1222 and the second outer magnet 1223-2 can be opposite.

[0127] Please refer to FIG. 19F. When the outer magnet 1223 is arranged on the outer side wall 12214 of the magnetic conductive cover 1221 (i.e., the outer side wall 12214 includes the outer magnet 1223), and the magnetization direction of the inner magnet 1222 is opposite to that of the outer magnet 1223 (for example, the N pole of the inner magnet 1222 can be located at the upper end, and the N pole of the outer magnet 1223 can be located at the lower end), the inner side wall 12212 of the magnetic conductive cover 1221 has a magnetic field zero point, and the inner side wall 12212 is not responsible for magnetic conduction. At this time, the inner side wall 12212 of the magnetic conductive cover 1221 mainly plays a connecting and supporting role. In order to reduce the mass and size of the loudspeaker 120, the thickness of the inner side wall 12212 of the magnetic conductive cover 1221 can be designed to be less than or equal to 0.4 mm. In some embodiments, as shown in FIG. 19G, in order to further reduce the mass and size of the loudspeaker 120, the thickness of the inner side wall 12212 of the magnetic conductive cover 1221 can also be designed to be 0, that is, the structure of the inner side wall 12212 is cancelled.

[0128] In some embodiments, in order to reduce the mass and size of the loudspeaker 120, the inner side wall 12214 can be designed to be perforated and hollow.

[0129] Since the outer magnet 1223 and the inner magnet 1222 need to be installed and connected, the annular side wall of the magnetic conductive cover 1221 needs to reserve at least part of the inner side wall 12212 to connect the outer side wall 12214 with the bottom wall 12211 of the magnetic conductive cover 1221. For example, the outer side wall 12214 of the long side of the magnetic conductive cover 1221 can be connected with the bottom wall 12211 of the magnetic conductive cover 1221 through the inner side wall 12212, and the short side of the magnetic conductive cover 1221 can not be provided with the inner side wall 12212. Wherein, the long side of the magnetic conductive cover 1221 refers to the side parallel to the long axis direction, and the short side of the magnetic conductive cover 1221 refers to the side parallel to the short axis direction.

[0130] In order to improve the vibration consistency of the first diaphragm 121-1 and the second diaphragm 121-2, weaken the distortion of the earphone output, improve the output effect of the loudspeaker 120, and improve the active noise reduction effect of the earphone on the larger environmental noise in the open wearing mode, the driving force of the first voice coil 123-1 and the second voice coil 123-2 can be close or the same. In some embodiments, the size of the inner magnet 1222 and the outer magnet 1223 can be designed to make the magnetic field strength near the first voice coil 123-1 and the second voice coil 123-2 similar, thereby improving the vibration consistency of the first diaphragm 121-1 and the second diaphragm 121-2, weakening the distortion of the earphone output, and improving the active noise reduction effect of the earphone.

[0131] FIG. 20 is another structural schematic diagram of a loudspeaker according to some embodiments of the present specification.

[0132] Referring to FIG. 20, the ratio of the size Wim of the inner magnet 1222 to the size Wom of the outer magnet 1223 is defined as Wim / Wom. The size refers to the size parameter of the relevant component in the direction perpendicular to the vibration direction, for example, the thickness of the outer magnet 1223 refers to the distance between the outer surface and the inner surface of the outer magnet 1223, and the size of the inner magnet 1222 refers to the size of the cross section of the inner magnet 1222. In some embodiments, when the ratio of the size of the inner magnet 1222 to the thickness of the outer magnet 1223 is too small, the size of the inner magnet 1222 is too small, which can result in a small magnetic field strength of the magnetic circuit assembly 122, insufficient driving force of the voice coil assembly 123, and affect the output of the speaker 120; when the ratio of the size of the inner magnet 1222 to the thickness of the outer magnet 1223 is too large, the size of the inner magnet 1222 is too large, which can result in a large size of the speaker 120, affect the wearing of the earphone, and reduce the user experience.

[0133] By designing the size ratio of the outer magnet 1223 and the inner magnet 1222, the electromagnetic conversion efficiency of the speaker 120 can be ensured, the driving force of the voice coil assembly 123 can be improved, the output of the speaker 120 can be improved, the active noise reduction effect of the earphone on the large environmental noise can be improved, and the size of the earphone can be avoided to be too large. For example, the ratio of the size of the inner magnet 1222 in the long axis direction to the thickness of the outer magnet 1223 in the long axis direction can be between 1.7-33; the ratio of the size of the inner magnet 1222 in the short axis direction to the thickness of the outer magnet 1223 in the short axis direction can be between 1.7-33.

[0134] Further, in some embodiments, the ratio of the size of the inner magnet 1222 in the long axis direction to the thickness of the outer magnet 1223 in the long axis direction can be not greater than 6.7 (i.e., the ratio is 1.7-6.7), and the ratio of the size of the inner magnet 1222 in the short axis direction to the thickness of the outer magnet 1223 in the short axis direction can be not greater than 2.7 (i.e., the ratio is 1.7-2.7). By designing the above range, the BL value of the speaker 120 can be significantly improved, and the sound output performance of the speaker 120 can be enhanced, and the active noise reduction effect of the earphone on the large environmental noise can be improved.

[0135] For example, the contour shape of the speaker 120 is circular, and the ratio of the size of the inner magnet 1222 in the radial direction (i.e., equivalent to the long axis direction or the short axis direction) to the thickness of the outer magnet 1223 in the radial direction is between 1.7-33.

[0136] It should be noted that the thickness of the outer magnet 1223 refers to the distance between the outer surface and the inner surface of the outer magnet 1223.

[0137] When the volume of the outer magnet 1223 is too small relative to the volume of the inner magnet 1222, the driving force of the second voice coil 123-2 close to the outer magnet 1223 away from the inner magnet 1222 is small, and the driving force of the first voice coil 123-1 away from the outer magnet 1223 close to the inner magnet 1222 is large, thereby causing a large driving force difference between the first voice coil 123-1 and the second voice coil 123-2; similarly, when the volume of the outer magnet 1223 is too large relative to the volume of the inner magnet 1222, the driving force of the second voice coil 123-2 close to the outer magnet 1223 away from the inner magnet 1222 is large, and the driving force of the first voice coil 123-1 away from the outer magnet 1223 close to the inner magnet 1222 is small, thereby causing a large driving force difference between the first voice coil 123-1 and the second voice coil 123-2. That is, when the volume of the outer magnet 1223 is too different from the volume of the inner magnet 1222, it will cause a large driving force difference between the first voice coil 123-1 and the second voice coil 123-2, affecting the active noise reduction effect of the earphone. In some embodiments, in order to improve the vibration consistency of the first diaphragm 121-1 and the second diaphragm 121-2, weaken the distortion of the earphone output, and improve the active noise reduction effect of the earphone, the ratio of the volume of the outer magnet 1223 to the volume of the inner magnet 1222 can be 0.3-3. In some embodiments, in order to further improve the vibration consistency of the first diaphragm 121-1 and the second diaphragm 121-2, weaken the distortion of the earphone output, and improve the active noise reduction effect of the earphone, the ratio of the volume of the outer magnet 1223 to the volume of the inner magnet 1222 can be 0.5-1.5.

[0138] In some embodiments, as the thickness of the magnetic shield 1221 or the first magnetic guide plate 1224 increases (i.e., the ratio of the size of the magnet to the thickness of the magnetic shield 1221 decreases), the BL value of the loudspeaker 120 gradually increases. However, when the thickness of the magnetic shield 1221 or the first magnetic guide plate 1224 increases to a certain value, excessive increase in the thickness of the magnetic shield 1221 or the first magnetic guide plate 1224 will cause the magnetic induction lines to disperse and not be effectively concentrated near the voice coil assembly 123, resulting in a decrease in the magnetic field near the voice coil assembly 123. When the thickness of the magnetic shield 1221 or the first magnetic guide plate 1224 decreases (i.e., the ratio of the size of the magnet to the thickness of the magnetic shield 1221 increases), the magnetic saturation of the magnetic shield 1221 or the first magnetic guide plate 1224 decreases, reducing the magnetic guiding ability and in turn reducing the magnetic field strength passing through the voice coil assembly 123.

[0139] To improve the electromagnetic conversion efficiency of the loudspeaker 120, improve the output sound pressure level of the loudspeaker 120, and improve the active noise reduction performance of the earphone to the large environmental noise, in some embodiments, the ratio of the size of the inner magnet 1222 to the thickness of the magnetic shield 1221 (for example, the bottom wall 12211) or the first magnetic guide plate 1224 can be between 1-4, and the ratio of the thickness of the outer magnet 1223 to the thickness of the magnetic shield 1221 (for example, the side wall 12212) can be between 1-4.

[0140] In some embodiments, the first voice coil 123-1 and the second voice coil 123-2 can adopt an unequal diameter structure, for example, in a reference plane perpendicular to the vibration direction, there is a gap between the orthographic projection of the first voice coil 123-1 and the orthographic projection of the second voice coil 123-2 in the long axis direction and in the short axis direction, and the orthographic projection of the first voice coil 123-1 is located in the inner circle or the outer circle of the orthographic projection of the second voice coil 123-2. That is, the annular orthographic projection of the first voice coil 123-1 is located in the ring or outside the ring of the annular orthographic projection of the second voice coil 123-2, so that there is a gap between the first voice coil 123-1 and the second voice coil 123-2, and thus an avoidance channel 123-3 allowing the magnetic circuit assembly 122 (for example, the side wall of the magnetic shield 1221) to pass through the voice coil assembly 123 can be formed between the first voice coil 123-1 and the second voice coil 123-2 based on the existence of the gap.

[0141] In some embodiments, the profile shape of the loudspeaker 120 is non-circular, such as rectangular, elliptical, etc.; at this time, the side wall parallel to the long axis direction of the first voice coil 123-1 and the second voice coil 123-2 can be defined as the long side side wall, and the side wall parallel to the short axis direction can be defined as the short side side wall. The size of the short side side wall of the first voice coil 123-1 is smaller than the size of the short side side wall of the second voice coil 123-2, and the size of the long side side wall of the first voice coil 123-1 is smaller than the size of the long side side wall of the second voice coil 123-2. Alternatively, the size of the short side side wall of the first voice coil 123-1 is greater than the size of the short side side wall of the second voice coil 123-2, and the size of the long side side wall of the first voice coil 123-1 is greater than the size of the long side side wall of the second voice coil 123-2.

[0142] In some embodiments, the profile shape of the sound generating unit 100 or the loudspeaker 120 is approximately circular; at this time, the orthographic projection of the first voice coil 123-1 on the reference plane is a first circular ring, the orthographic projection of the second voice coil 123-2 on the reference plane is a second circular ring, and the first circular ring and the second circular ring have different diameters, and the first voice coil 123-1 and the second voice coil 123-2 are all staggered, thereby forming an avoidance channel 123-3.

[0143] By setting the first voice coil 123-1 and the second voice coil 123-2 with the above dimensions, the avoidance channel 123-3 formed between the first voice coil 123-1 and the second voice coil 123-2 can provide avoidance space for the magnetic circuit assembly 122 (e.g., the sidewall of the magnetic shield 1221), which is equivalent to placing the voice coil assembly 123 in the same magnetic gap of the magnetic circuit assembly 123. This not only enhances the stability of the structure of the magnetic circuit assembly 123 itself, providing support for the rapid assembly of the loudspeaker 120, but also facilitates the reduction of assembly difficulty and cost, and avoids the impact of the voice coil assembly 123 touching the magnetic circuit assembly 122 during movement to affect the sound output. At the same time, by setting the above dimensions, the first voice coil 123-1 and the second voice coil 123-2 can avoid reserving a gap in the vibration direction for the magnetic circuit assembly 122 to pass through, thereby reducing the size of the loudspeaker 120 in the vibration direction.

[0144] It should be noted that when the magnetic shield 1221 is a "several" shaped structure and only has a sidewall parallel to the long axis direction (or only has a sidewall parallel to the short axis direction), the first voice coil 123-1 and the second voice coil 123-2 can only have a difference in the size of the short side sidewall (or only have a difference in the size of the long side sidewall) to form the corresponding avoidance channel 123-3.

[0145] FIG. 21A is a structural schematic diagram of a frame according to some embodiments of the present specification, and FIG. 21B is a position schematic diagram of the frame and the outer magnet according to some embodiments of the present specification.

[0146] Please refer to FIG. 4, FIG. 21A and FIG. 21B. In some embodiments, the loudspeaker 120 can further include a frame 125, which is located between the first diaphragm 121-1 and the second diaphragm 121-2 in the vibration direction. The frame 125 can provide a mounting and fixing platform for various components of the loudspeaker 120, and the loudspeaker 120 can be connected to the first housing 110 through the frame 125.

[0147] Since the first diaphragm 121-1 and the second diaphragm 121-2 will simultaneously press the air in the third acoustic cavity 111-3, in order to reduce the vibration resistance of the first diaphragm 121-1 and the second diaphragm 121-2 and enhance the gas exchange efficiency between the third acoustic cavity 111-3 and the outside, an opening 1251 can be provided on the frame 125, which is in communication with the third acoustic cavity 111-3 and the third acoustic hole.

[0148] In some embodiments, the third acoustic cavity 111-3 can be designed to have a larger resonance frequency, so that the second resonance peak has a larger peak resonance frequency, so that the earphone has a smoother sound output in a larger frequency range, providing support for active noise reduction in a wider frequency range, while improving the output effect of the earphone. At the same time, the third acoustic cavity 111-3 can be designed to have a larger high-frequency resonance frequency of the third sound generated by the third acoustic cavity 111-3, so that the third sound can have an opposite phase to the first sound and the second sound in a wider frequency range, so that the third sound and the first sound and the second sound can cancel each other out in a wider frequency range, so that the earphone has a better sound leakage reduction effect in a wider frequency range.

[0149] In some embodiments, the resonance frequency of the third acoustic cavity 111-3 can be greater than 4.5 kHz, so that the second resonance peak has a larger peak resonance frequency, so that the earphone has a smoother sound output in a larger frequency range, providing support for active noise reduction in a wider frequency range, while improving the output effect of the earphone. In some embodiments, in order to further make the earphone have a smoother sound output in a larger frequency range, the resonance frequency of the third acoustic cavity 111-3 can be greater than 5 kHz. In some embodiments, in order to further make the earphone have a smoother sound output in a larger frequency range, the resonance frequency of the third acoustic cavity 111-3 can be greater than 6 kHz.

[0150] Since the third acoustic hole is in communication with the third acoustic cavity 111-3 through the opening 1251, the area of the opening 1251 will also affect the third Helmholtz resonance cavity model. In some embodiments, in order to make the resonance frequency of the third acoustic cavity 111-3 greater than 6 kHz, the number of openings 1251 on the frame 125 can be multiple to increase the total area of the openings 1251.

[0151] In some embodiments, the outer magnet 1223 can include a plurality of sub-magnets arranged in a split manner, as shown in FIG. 21B, and the plurality of sub-magnets are in a separated structure. The plurality of sub-magnets are arranged on the inner wall of the frame 125, and the frame 125 cooperates with the magnetic shield 1221 to fix the outer magnet 1223. The frame 125 can fix the outer magnet 1223 to prevent the outer magnet 1223 from falling off.

[0152] In some embodiments, in order to reduce the difficulty of processing, the position of the opening 1251 on the frame 125 can be staggered with the position of the outer magnet 1223. At the same time, the staggered arrangement of the opening 1251 and the outer magnet 1223 can also avoid the opening 1251 being blocked by the outer magnet 1223, so that the opening 1251 has a larger use area, thereby increasing the resonance frequency of the third acoustic cavity 111-3, improving the second resonance frequency of the sound output by the loudspeaker 120, so that the earphone has a flat output in a wider frequency range, while ensuring the gas exchange between the third acoustic cavity 111-3 and the outside, reducing the difficulty of gas exchange between the third acoustic cavity 111-3 and the outside, reducing the difficulty of volume change of the third acoustic cavity 111-3, reducing the difficulty of synchronous and opposite vibration of the first diaphragm 121-1 and the second diaphragm 121-2, and improving the output of the earphone.

[0153] In some embodiments, the opening 1251 can include a first opening 12511 arranged near the corner of the frame 125, as shown in FIGS. 21A and 21B. In some embodiments, the four corners of the frame 125 can be provided with the first opening 12511, so that the opening 1251 has a larger area, thereby increasing the resonance frequency of the third acoustic cavity 111-3, so that the earphone has a flat output in a wider frequency range, while reducing the difficulty of gas exchange between the third acoustic cavity 111-3 and the outside, reducing the difficulty of synchronous and opposite vibration of the first diaphragm 121-1 and the second diaphragm 121-2, and improving the output of the earphone.

[0154] In some embodiments, the opening 1251 can also include a second opening 12512. In the vibration direction, the size of the outer magnet 1223 is smaller than the size of the frame 125. In the vibration direction, the frame 125 includes a staggered portion (for example, the area near the upper and lower ends of the frame 125) staggered with the outer magnet 1223, and the second opening 12512 is arranged in the staggered portion. The arrangement of the second opening 12512 can further increase the total area of the opening 1251 while ensuring that the opening 1251 is staggered with the outer magnet 1223.

[0155] In some embodiments, on a plane where the port of the third acoustic hole (for example, the pressure relief hole 113 shown in FIG. 4, the sound outlet hole 112 shown in FIGS. 6 and 7) is located, the orthographic projection of the opening 1251 at least partially coincides with the orthographic projection of the third acoustic hole, so that the opening 1251 can be at least partially directly arranged opposite to the third acoustic hole, so that the third acoustic cavity 111-3 can be directly communicated with the outside through the opening 1251 and the third acoustic hole, reducing the barrier between the third acoustic cavity 111-3 and the outside environment, reducing the difficulty of gas exchange between the third acoustic cavity 111-3 and the outside, reducing the difficulty of synchronous and opposite vibration of the first diaphragm 121-1 and the second diaphragm 121-2, and improving the output of the earphone. The plane where the port of the third acoustic hole is located can be the plane where the outer port of the third acoustic hole is located, or the plane where the inner port of the third acoustic hole is located. For example, when the third acoustic hole is the pressure relief hole 113 arranged on the inner side surface of the first shell 110 shown in FIG. 4 or the sound outlet hole 112 shown in FIG. 7, the plane where the end surface of the third acoustic hole is located can be the outer surface or the inner surface of the inner side surface of the first shell 110. For another example, when the third acoustic hole is the L-shaped structure sound outlet hole 112 shown in FIG. 6, on the plane where the port of the long side part of the L-shaped structure is located (the outer surface or the inner surface of the inner side surface), the orthographic projection of the opening 1251 on the long side of the frame 125 parallel to the long axis direction at least partially coincides with the orthographic projection of the long side part of the L-shaped structure; on the plane where the port of the short side part of the L-shaped structure is located (the outer surface or the inner surface of the front side surface), the orthographic projection of the opening 1251 on the short side of the frame 125 parallel to the short axis direction at least partially coincides with the orthographic projection of the short side part of the L-shaped structure.

[0156] In some embodiments, on the plane where the port of the third acoustic hole is located, the orthographic projection of the first opening 12511 at least partially coincides with the orthographic projection of the third acoustic hole. In some embodiments, on the plane where the port of the third acoustic hole is located, the orthographic projection of the second opening 12512 at least partially coincides with the orthographic projection of the third acoustic hole. In some embodiments, on the plane where the port of the third acoustic hole is located, the orthographic projection of the first opening 12511 and the orthographic projection of the second opening 12512 at least partially coincide with the orthographic projection of the third acoustic hole. The third acoustic hole can be a pressure relief hole 113 or a sound outlet hole 112 arranged only on the inner side surface as shown in FIG. 4 or FIG. 7, or an L-shaped structure sound outlet hole 112 as shown in FIG. 6. Through the above arrangement, the total area of the opening 1251 can be further increased while ensuring that the opening 1251 is staggered with the outer magnet 1223. In some embodiments, the projection of the opening 1251 in the long axis direction at least partially coincides with the projection of the third acoustic hole in the long axis direction, so that the opening 1251 can be at least partially directly arranged opposite to the third acoustic hole, to reduce the difficulty of gas exchange between the third acoustic cavity 111-3 and the outside, and improve the output of the earphone.

[0157] FIG. 22 is another cross-sectional structural schematic view of a sound production assembly according to some embodiments of the present specification, and FIG. 23 is a structural exploded schematic view of a loudspeaker according to some embodiments of the present specification.

[0158] In some embodiments, referring to FIGS. 22-23, the outer magnet 1223 can be provided with a second magnetic conducting plate 1225 at the end facing away from the extension 12213. The magnetic circuit assembly 122 further comprises a bracket assembly, which can include a first bracket 122-4 and a second bracket 122-5; wherein the first bracket 122-4 is annularly connected to the outer periphery of the second magnetic conducting plate 1225, and the second bracket 122-5 is annularly connected to the outer periphery of the extension 12213; the first bracket 122-4 and the second bracket 122-5 can be connected to the second magnetic conducting plate 1225 and the extension 12213, respectively, in the form of injection molding, adhesive bonding, bolting, buckling, etc.; the outer periphery of the first diaphragm 121-1 is fixed to the first bracket 122-4 (e.g., adhesive bonding), and the outer periphery of the second diaphragm 121-2 is fixed to the second bracket 122-5 (e.g., adhesive bonding).

[0159] On the one hand, by the cooperation of the first bracket 122-4, the second bracket 122-5, and the second magnetic conducting plate 1225, the former frame 125 or the aforementioned frame 125 in some existing loudspeakers can be replaced, so that the outer magnet 1223 has a larger size, the magnetic flux is enhanced, and thus the driving force of the voice coil assembly 123 is enhanced; at the same time, the structure of the loudspeaker 120 can be more compact, the assembly difficulty can be reduced, and the assembly effect can be improved.

[0160] On the other hand, by the cooperation of the first bracket 122-4 and the second bracket 122-5, and the magnetic conducting cover 1221 and the diaphragm, the internal space of the loudspeaker 120 can be enclosed to form a relatively closed cavity (i.e., the common cavity 111-3), and the first bracket 122-4 and the second bracket 122-5 can be used as a structural connection carrier between the loudspeaker 120 and the first shell 110 or between the loudspeaker 120 and the limiting assembly 130, so as to stably limit the loudspeaker 120 in the interior of the first shell 110, and form the first acoustic cavity 111-1 and the second acoustic cavity 111-2 which are relatively independent of the common cavity 111-3.

[0161] In some embodiments, referring to FIG. 23, the first support 122-4 has a first accommodating groove enclosed by the second magnetic conductive plate 1225, and the second support 122-5 has a second accommodating groove enclosed by the extension 12213; the outer periphery of the second magnetic conductive plate 1225 is inserted into the first accommodating groove, and the outer periphery of the extension 12213 is inserted into the second accommodating groove; for example, the first support 122-4 can be integrally formed on the second magnetic conductive plate 1225 by injection molding, sleeve plating or the like, and the first support 122-4 covers the outer periphery of the second magnetic conductive plate 1225, at this time, the first accommodating groove is equivalent to being naturally formed in the first support 122-4.

[0162] Based on the set accommodating groove, the structural connection area between the support and the corresponding magnetic conductive plate is effectively increased, so that the support and the corresponding magnetic conductive plate can be stably combined as a whole (for example, the support and the corresponding magnetic conductive plate are integrally injection molded), which is beneficial to reduce the number of parts of the loudspeaker 120 and reduce the assembly difficulty of the loudspeaker 120.

[0163] In some embodiments, referring to FIG. 23, the first support 122-4, the second magnetic conductive plate 1225 and the first diaphragm 121-1 collectively form a first chamber 120a in the inside of the loudspeaker 120, and the second support 122-5, the extension 12213 and the second diaphragm 121-2 collectively form a second chamber 120b in the inside of the loudspeaker 120; it can be understood that the first chamber 120a and the second chamber 120b are equivalent to part of the common cavity 111-3, and both are located on the two sides of the magnetic circuit assembly in the vibration direction.

[0164] At this time, referring to FIG. 23, the first support 122-4 and the second support 122-5 are respectively provided with positioning structures 120c and via structures 120d; for the convenience of distinguishing and describing, the positioning structure 120c and the via structure 120d provided on the first support 122-4 are defined as the first positioning structure and the first via structure respectively, and the positioning structure 120c and the via structure 120d provided on the second support 122-5 are defined as the second positioning structure and the second via structure respectively.

[0165] The first positioning structure is located in the first cavity 120a and is mainly used for positioning and limiting the lead wire of the first voice coil 123-1 on the first support 122-4 in the first cavity 120a. The first through-hole structure is arranged through the side wall of the first support 122-4 (for example, the side wall in the short axis direction), so that the lead wire of the first voice coil 123-1 can be led out from the inside of the speaker 120 to be connected to the line board arranged on the periphery of the speaker 120 (the line board can realize the electrical connection between the speaker 120 and the microphone assembly and the circuit board assembly of the earphone). Similarly, the second positioning structure is located in the second cavity 120b and is mainly used for positioning and limiting the lead wire of the second voice coil 123-2 on the second support 122-5 in the second cavity 120b. The second through-hole structure is arranged through the side wall of the second support 122-5, so that the lead wire of the second voice coil 123-2 can be led out from the inside of the speaker 120 to be connected to the line board.

[0166] Therefore, by the cooperation between the corresponding cavities, supports, positioning structures 120c and through-hole structures 120d, the compactness of the overall structure of the speaker 120 can be effectively enhanced, and the lead wire of the voice coil can be limited to avoid interference with the vibration of the diaphragm. In specific implementation, the positioning structure 120c can be a mechanical structure such as a buckle arranged on the corresponding support, or a structure formed by fixing the lead wire of the voice coil by dispensing.

[0167] In some embodiments, referring to FIG. 23, the first support 122-4 and the second support 122-5 are arranged separately in the vibration direction, so that a containing gap surrounding the outer magnet 1223 can be formed therebetween. The line board can be accommodated and fixed in the containing gap, for example, attached and fixed on the outer peripheral surface of the first outer magnet 122-11. Therefore, the overall size of the speaker 120 can be effectively reduced, and the compactness of the structure of the speaker 120 is further enhanced.

[0168] In some embodiments, referring to FIG. 23, one or both of the first support 122-4 and the second support 122-5 is / are provided with an air pressure balance channel 120e, which can be arranged through the corresponding support in a direction perpendicular to the vibration direction (for example, the long axis direction, the short axis direction, etc.). In some embodiments, since the support assembly replaces the frame 125, the air pressure balance channel 120e arranged on the support assembly can be the same as the opening 1251 arranged on the frame 125, and the third acoustic cavity 111-3 communicates with the sound outlet 112 on the first housing 110 through the air pressure balance channel 120e. For example, the air pressure balance channel 120e is also staggered with the outer magnet 1223.

[0169] In some embodiments, the air pressure balance channel 120e can be covered by a gauze, a waterproof and breathable film or the like to improve the waterproof performance of the speaker 120.

[0170] The foregoing has outlined rather generally the features of the present application so that those skilled in the art can appreciate the inventive aspects of the application. The application, both as to organization and content, can be better understood and appreciated, from the following detailed description, taken in conjunction with the drawings of which:

[0171] Also, the use of "one embodiment", "an embodiment", or "some embodiments" throughout this specification is not necessarily a reference to the same embodiment or embodiments. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the application to the exact construction and instrumentalities shown and described above. Accordingly, all suitable modifications and equivalents can be resorted to as falling within the scope of the application.

[0172] Similarly, it is to be noted that the term "comprising" is intended to not exclude other elements or steps. Also, the use of "a" or "an" preceding an element or step does not exclude the presence of a plurality of such elements or steps, that is, "a" or "an" should be interpreted to mean "one or more". It is further noted that the description uses relational terms, such as "top", "bottom", "front", "back", "rear", "one side" and / or the like, which are used for the convenience of the reader and which are intended to be non-limiting.

[0173] Numerical ranges are used as endpoints to provide a range description. Unless otherwise stated, the use of approximation such as "about" or "approximately" or the like in connection with a recited numerical value is meant to encompass minor variations (plus or minus 10%) from the recited value. Accordingly, any numerical value disclosed herein can include any and all reported significant digits and all mathematical equivalents thereof (e.g., "about 10" includes about 9.9, about 10.1, and the like). Ranges disclosed herein are inclusive of the recited endpoints, and independently include the endpoints in any disclosure of separate ranges based on the recited endpoints. In some embodiments, the numerical values are to be considered approximations. Accordingly, unless otherwise indicated, the numerical values are to be understood to be approximations. It is intended that the application be construed as including all such approximations.

[0174] Finally, the language used in the specification should not be construed as limiting the application. In the claims, the use of the terms "including" and "comprising" are not used as meaning that there are no features other than the listed features. In addition, the terms "first", "second", and the like, as used in the claims, are not used to denote any sequence or order, except when explicitly recited based on a preceding use of the terms.

Claims

1. A loudspeaker, comprising: a magnetic circuit assembly; a voice coil assembly, at least a portion of the voice coil assembly being located in a magnetic gap of the magnetic circuit assembly; a first diaphragm and a second diaphragm, the first diaphragm and the second diaphragm being spaced apart in a vibration direction; wherein the voice coil assembly comprises a first voice coil and a second voice coil arranged along the vibration direction, the first diaphragm being connected to the first voice coil, and the second diaphragm being connected to the second voice coil; the first voice coil and the second voice coil being configured to drive the first diaphragm and the second diaphragm to vibrate synchronously and in opposite directions, respectively; wherein the magnetic circuit assembly comprises a magnetic yoke and an inner magnet, the magnetic yoke comprising a side wall and a bottom wall, the side wall comprising a folded structure, the folded structure comprising an inner side wall and an outer side wall spaced apart in a vertical direction along the vibration direction, and an extension connecting the inner side wall and the outer side wall, the bottom wall being connected to the inner side wall, a first magnetic gap being formed between the inner magnet and the inner side wall, and a second magnetic gap being formed between the inner side wall and the outer side wall, at least a portion of the first voice coil being located in the first magnetic gap, and at least a portion of the second voice coil being located in the second magnetic gap.

2. The loudspeaker of claim 1, wherein, the outer side wall comprises an outer magnet, the first magnetic gap being formed between the inner magnet and the inner side wall, and the second magnetic gap being formed between the outer magnet and the inner side wall.

3. The loudspeaker of claim 2, wherein, a polarization direction of the inner magnet is the same as a magnetization direction of the outer magnet, the loudspeaker comprising a long axis direction and a short axis direction, in the short axis direction or the long axis direction, a ratio of a thickness of the inner side wall to a size of the magnetic yoke is 0.05-0.

16.

4. The loudspeaker of claim 2, wherein, the polarization direction of the inner magnet is opposite to the magnetization direction of the outer magnet, and the thickness of the inner side wall is less than or equal to 0.4 mm.

5. The loudspeaker of claim 4, wherein, the inner side wall is hollow.

6. The loudspeaker of claim 1, wherein, the outer side wall comprises an outer magnet, the first magnetic gap being formed between the inner magnet and the outer magnet, and the second magnetic gap being formed between the outer magnet and the outer side wall.

7. The loudspeaker of claim 1, wherein, the inner side wall comprises a first outer magnet, and the outer side wall comprises a second outer magnet, the first magnetic gap being formed between the inner magnet and the first outer magnet, and the second magnetic gap being formed between the first outer magnet and the second outer magnet.

8. The loudspeaker of any one of claims 1-6, wherein, the loudspeaker comprising a long axis direction and a short axis direction, in the short axis direction or the long axis direction, a ratio of a size of the inner magnet to a thickness of the outer magnet is between 1.7 and 33.

9. The loudspeaker of claim 8, wherein, in the long axis direction, the ratio of the size of the inner magnet to the thickness of the outer magnet is between 1.7 and 6.7, and in the short axis direction, the ratio of the size of the inner magnet to the thickness of the outer magnet is between 1.7 and 2.

7. 10.A headphone, comprising the loudspeaker of any one of claims 1-9, the headphone further comprising: a first housing, the loudspeaker being arranged in the first housing; a first acoustic cavity being formed between the first diaphragm of the loudspeaker and an inner wall of the first housing, a second acoustic cavity being formed between the second diaphragm of the loudspeaker and another inner wall of the first housing, and a third acoustic cavity being formed between the first diaphragm and the second diaphragm. The loudspeaker further comprises a frame, which is located between the first diaphragm and the second diaphragm in the vibration direction; the frame is provided with an opening, and the opening is in acoustic communication with the third acoustic cavity.

11. The earphone of claim 10, wherein, The magnetic circuit assembly comprises an outer magnet, and the outer magnet comprises a plurality of sub-magnets arranged in a split manner, and the plurality of sub-magnets of the outer magnet are arranged on the inner wall of the frame.

12. The earphone of claim 10, wherein, In the wearing state, the first shell comprises an inner side surface facing the external auditory canal and an outer side surface opposite to the inner side surface and away from the external auditory canal, the first shell is provided with a first sound outlet hole communicating with the first acoustic cavity, a second sound outlet hole communicating with the second acoustic cavity, and a pressure relief hole communicating with the third acoustic cavity. The first sound outlet hole and the second sound outlet hole are located on the inner side surface of the first shell, and the pressure relief hole is located on the outer side surface of the first shell.

13. The earphone of claim 10, wherein, In the wearing state, the first shell comprises an inner side surface facing the external auditory canal, an outer side surface opposite to the inner side surface and away from the external auditory canal, an upper side surface facing the top of the user's head, and a lower side surface opposite to the upper side surface and facing the bottom of the user's head, the first shell is provided with a first pressure relief hole communicating with the first acoustic cavity, a second pressure relief hole communicating with the second acoustic cavity, and a sound outlet hole communicating with the third acoustic cavity. The sound outlet hole is arranged on the inner side surface of the first shell, and the first pressure relief hole and the second pressure relief hole are arranged on the outer side surface of the first shell.

14. The earphone of claim 10, wherein, In the wearing state, the first shell comprises an inner side surface facing the external auditory canal, an outer side surface opposite to the inner side surface and away from the external auditory canal, an upper side surface facing the top of the user's head, and a lower side surface opposite to the upper side surface and facing the bottom of the user's head, the first shell is provided with a first pressure relief hole communicating with the first acoustic cavity, a second pressure relief hole communicating with the second acoustic cavity, and a sound outlet hole communicating with the third acoustic cavity. The sound outlet hole is arranged on the inner side surface of the first shell, and the first pressure relief hole and the second pressure relief hole are arranged on the upper side surface and the lower side surface of the first shell, respectively.

15. The earphone of claim 14, wherein, In the wearing state, the first shell further comprises a front side surface facing the back of the user, and the sound outlet hole has an L-shaped structure, which comprises a short edge portion on the front side surface of the first shell and a long edge portion on the inner side surface of the first shell.

16. The earphone of any one of claims 13-15, wherein, The opening on the frame is in acoustic communication with the sound outlet hole, and the orthographic projection of the opening and the orthographic projection of the sound outlet hole at least partially overlap on the plane where the port of the sound outlet hole is located.

17. The earphone of claim 15, wherein, The first shell is provided with a gap between the front side surface and the loudspeaker, and the gap serves as a sound guide channel configured to guide the sound generated by the loudspeaker on the front side surface to the sound outlet hole for output; wherein, in the long axis direction, the size of the sound guide channel is 0.5mm-2mm.

18. The earphone of claim 13, wherein, In the vibration direction, the first pressure relief hole and the second pressure relief hole are arranged in a staggered manner.

19. The earphone of claim 13, wherein, The first pressure relief hole has a different size than the second pressure relief hole.

20. The earphone of claim 13 or 14, wherein, The earphone further comprises a microphone assembly, the microphone assembly comprising a third microphone and a fourth microphone, the first microphone being arranged at an intersection of the outer side surface and the front side surface of the first housing, and in a wearing state, a line connecting the fourth microphone and the third microphone is directed towards a mouth of a user.

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