Loudspeaker and open-ear headphones

Abstract

A loudspeaker and open-ear headphones. The loudspeaker comprises a first diaphragm, a second diaphragm, a magnetic circuit assembly and a voice coil assembly. Voice coils pass through a magnetic gap of the magnetic circuit assembly. The voice coil assembly comprising a first voice coil and a second voice coil which are arranged and connected in the vibration direction of the first diaphragm and the second diaphragm, the ends of the first voice coil and the second voice coil away from each other being respectively and correspondingly connected to the first diaphragm and the second diaphragm. The magnetic circuit assembly cooperates with the voice coil assembly to drive the first diaphragm and the second diaphragm to vibrate in the same direction. Thus, since the two voice coils share the same magnetic circuit assembly, the two diaphragms can be driven to vibrate synchronously in the same direction under the action of the magnetic field of the magnetic circuit assembly, thereby effectively ensuring consistency in vibration, reducing distortion in sound output, and providing support for improving the active noise-cancelling effect of headphones. Moreover, connecting the two voice coils corresponding to the two diaphragms can enhance the flexibility in configuring the voice coils and the magnetic circuit structure, thereby helping to improve the structural compactness and stability of loudspeakers.

Description

A loudspeaker and an open earphone

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

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

[0003] Open earphones have become an essential tool in people's daily life and work. With the increasing demand of consumers for earphones, open earphones not only need to have stable output performance, but also need to be able to reduce environmental noise in noisy or even high-noise environments to perform normal listening. Therefore, the noise reduction performance has a great influence on the use experience of open earphones, so it is necessary to propose an open earphone to improve the noise reduction effect of the open earphone. SUMMARY

[0004] The technical problem solved by the present application is to provide a loudspeaker and an open earphone applying the loudspeaker.

[0005] According to a first aspect, an embodiment provides a loudspeaker, comprising:

[0006] a first diaphragm and a second diaphragm opposite to each other;

[0007] a magnetic circuit assembly arranged between the first diaphragm and the second diaphragm; and

[0008] a voice coil assembly arranged in a magnetic gap of the magnetic circuit assembly; the voice coil assembly comprises a first voice coil and a second voice coil arranged in a vibration direction of the first diaphragm and the second diaphragm and connected to each other, one end of the first voice coil away from the second voice coil is connected to the first diaphragm, and one end of the second voice coil away from the first voice coil is connected to the second diaphragm; the magnetic circuit assembly cooperates with the voice coil assembly to drive the first diaphragm and the second diaphragm to vibrate in the same direction.

[0009] In one embodiment, the magnetic circuit assembly comprises an inner magnetic circuit member, an outer magnetic circuit member, and a magnetic circuit connecting member; the outer magnetic circuit member surrounds the outer periphery of the inner magnetic circuit member and is connected to the inner magnetic circuit member through the magnetic circuit connecting member to form the magnetic gap between the outer magnetic circuit member and the inner magnetic circuit member; an avoidance passage allowing the magnetic circuit connecting member to pass through the voice coil assembly is formed between the first voice coil and the second voice coil.

[0010] In one embodiment, the inner magnetic circuit member comprises an inner magnet, and the outer magnetic circuit member comprises an outer magnet; the outer magnet surrounds the outer periphery of the inner magnet to form the magnetic gap; the magnetic circuit connecting member passes through the avoiding passage along the vibration direction and is connected between the inner magnet and the outer magnet.

[0011] In one embodiment, the outer magnet is an integral structure surrounding the outer periphery of the inner magnet.

[0012] In one embodiment, the inner magnetic circuit member further comprises a first magnetic conductor, and the outer magnetic circuit member further comprises a second magnetic conductor; wherein:

[0013] The first magnetic conductor is stacked on the inner magnet facing one of the first diaphragm and the second diaphragm, and the second magnetic conductor is stacked on the outer magnet facing the other of the first diaphragm and the second diaphragm; the magnetic circuit connecting member connects the inner magnet through the first magnetic conductor and connects the outer magnet through the second magnetic conductor.

[0014] In one embodiment, at least one of the first magnetic conductor and the second magnetic conductor is an integral structure with the magnetic circuit connecting member.

[0015] In one embodiment, the magnetic circuit connecting member is stacked between the first magnetic conductor and the inner magnet, and the magnetic circuit connecting member at least partially extends from between the first magnetic conductor and the inner magnet and connects the second magnetic conductor.

[0016] In one embodiment, the loudspeaker has a long axis direction and a short axis direction, the long axis direction, the short axis direction and the vibration direction are perpendicular; the length of the loudspeaker in the long axis direction is greater than the width of the loudspeaker in the short axis direction; wherein the ratio of the length of the inner magnet in the long axis direction to the thickness of the side wall of the outer magnet in the long axis direction is between 1.7-33.

[0017] In one embodiment, the ratio of the length of the inner magnetic circuit member in the long axis direction to the thickness of the side wall of the outer magnetic circuit member in the long axis direction is not greater than 6.7.

[0018] In one embodiment, the loudspeaker has a long axis direction and a short axis direction, the long axis direction, the short axis direction and the vibration direction are perpendicular; the length of the loudspeaker in the long axis direction is greater than the width of the loudspeaker in the short axis direction; wherein the ratio of the width of the inner magnet in the short axis direction to the thickness of the side wall of the outer magnet in the short axis direction is between 1.7-33.

[0019] In one embodiment, the ratio of the width of the inner magnetic circuit member in the short axis direction to the thickness of the sidewall of the outer magnetic circuit member in the short axis direction is not greater than 2.7.

[0020] In one embodiment, the inner magnetic circuit member further comprises a third magnetic conductor, and the outer magnetic circuit member further comprises a fourth magnetic conductor, the third magnetic conductor being stacked on the side of the inner magnetic body opposite to the first magnetic conductor in the vibration direction, and the fourth magnetic conductor being stacked on the side of the outer magnetic body opposite to the second magnetic conductor in the vibration direction.

[0021] In one embodiment, the magnetic circuit assembly further comprises a first support and a second support, the first support being connected around the outer periphery of the third magnetic plate, and the outer periphery of the first diaphragm being fixed to the first support, and the second support being connected around the outer periphery of the fourth magnetic plate, and the outer periphery of the second diaphragm being fixed to the second support.

[0022] In one embodiment, the first support has a first accommodating groove enclosing the third magnetic plate, and the outer periphery of the third magnetic plate is inserted into the first accommodating groove and fixed to the first support; and / or the second support has a second accommodating groove enclosing the fourth magnetic plate, and the outer periphery of the fourth magnetic plate is inserted into the second accommodating groove and fixed to the second support.

[0023] In one embodiment, a first cavity is formed between the first support, the third magnetic plate and the first diaphragm, the first support has a first positioning structure and / or a first through-hole structure; wherein the first positioning structure is located in the first cavity and used for positioning the lead wire of the first voice coil; and the first through-hole structure penetrates the sidewall of the first support and communicates with the first cavity, and is used for allowing the lead wire of the first voice coil to pass out of the first cavity.

[0024] and / or a second cavity is formed between the second support, the fourth magnetic plate and the second diaphragm, the second support has a second positioning structure and / or a second through-hole structure; wherein the second positioning structure is located in the second cavity and used for positioning the lead wire of the second voice coil; and the second through-hole structure penetrates the sidewall of the second support and communicates with the second cavity, and is used for allowing the lead wire of the second voice coil to pass out of the second cavity.

[0025] In one embodiment, the magnetic circuit connecting member is made of a weak magnetic conductive material or a non-magnetic conductive material.

[0026] In one embodiment, a gap exists between the orthographic projection of the first voice coil and the orthographic projection of the second voice coil in a reference plane perpendicular to the vibration direction to form the avoidance passage; or a gap exists between the orthographic projection of the first voice coil and the orthographic projection of the second voice coil in a reference plane parallel to the vibration direction to form the avoidance passage.

[0027] In one embodiment, the loudspeaker has a long axis direction and a short axis direction, the long axis direction, the short axis direction and the vibration direction are perpendicular, the side wall of the first voice coil and the second voice coil in the long axis direction is defined as a long side side wall, and the side wall in the short axis direction is defined as a short side side wall.

[0028] In one embodiment, a gap exists between the orthographic projection of the first voice coil and the orthographic projection of the second voice coil in a reference plane perpendicular to the vibration direction to form the avoidance passage; or a gap exists between the orthographic projection of the first voice coil and the orthographic projection of the second voice coil in a reference plane parallel to the vibration direction to form the avoidance passage.

[0029] In one embodiment, the length of the long side side wall of the first voice coil in the long axis direction is greater than the width of the short side side wall of the first voice coil in the short axis direction, and the length of the long side side wall of the second voice coil in the long axis direction is greater than the width of the short side side wall of the second voice coil in the short axis direction.

[0030] In one embodiment, the length of the long side side wall of the first voice coil in the long axis direction is less than the length of the long side side wall of the second voice coil in the long axis direction, and the width of the short side side wall of the first voice coil in the short axis direction is equal to the width of the short side side wall of the second voice coil in the short axis direction.

[0031] In one embodiment, the voice coil assembly further comprises a connecting piece, and the first voice coil is connected to the second voice coil through the connecting piece.

[0032] In one embodiment, the first voice coil comprises a first skeleton surrounding the inner magnetic circuit member and a first coil wound on the outer periphery of the first skeleton, and the second voice coil comprises a second skeleton surrounding the inner magnetic circuit member and a second coil wound on the outer periphery of the second skeleton; wherein the first skeleton and the second skeleton are connected through the connecting piece.

[0033] In one embodiment, at least one of the first skeleton and the second skeleton and the connecting piece are in an integral structure.

[0034] In one embodiment, the first voice coil comprises a first skeleton surrounding the inner magnetic circuit member and a first voice coil wound around the outer periphery of the first skeleton, and the second voice coil comprises a second skeleton surrounding the inner magnetic circuit member and a second voice coil wound around the outer periphery of the second skeleton, and the first skeleton and the second skeleton are connected in the vibration direction.

[0035] According to a second aspect, one embodiment provides an open earphone, comprising a sound generating part and an ear hook, the ear hook is configured to place the sound generating part in a position close to the ear but not blocking the ear canal in the wearing state; wherein the sound generating part comprises a first shell and the loudspeaker of the first aspect, the loudspeaker is arranged in the first shell, the first shell has an inner side wall facing the ear in the wearing state and an outer side wall away from the ear, the inner side wall is spaced apart from the first diaphragm in the vibration direction, and the outer side wall is spaced apart from the second diaphragm in the vibration direction, and the inner side wall and the outer side wall are provided with sound holes.

[0036] According to the loudspeaker of the above-mentioned embodiment, by sharing the same magnetic circuit assembly by the two voice coils, the two diaphragms can be driven to vibrate synchronously and in the same direction under the action of the magnetic field of the magnetic circuit assembly, effectively ensuring the consistency of vibration and reducing the distortion of sound output, thereby supporting the improvement of the active noise reduction effect of the earphone. At the same time, by connecting the two diaphragms corresponding to the two diaphragms, the flexibility of the configuration of the voice coil and the magnetic circuit structure can be enhanced, which is conducive to improving the compactness and stability of the loudspeaker structure and providing support for reducing the assembly difficulty of the loudspeaker. BRIEF DESCRIPTION OF DRAWINGS

[0037] Fig. 1 is a schematic diagram of the profile of the front side of the ear.

[0038] Fig. 2 is a schematic diagram of the wearing state of the earphone when worn on the ear in some embodiments.

[0039] Fig. 3 is a schematic diagram of the outer contour structure of the earphone in some embodiments.

[0040] Fig. 4 is a schematic diagram of the cross-sectional structure of the sound generating part in the long axis direction in some embodiments.

[0041] Fig. 5 is a schematic diagram of the cross-sectional structure of the sound generating part in the short axis direction in some embodiments.

[0042] Fig. 6 is a schematic diagram of the structure of the sound generating part in some embodiments.

[0043] Fig. 7 is a schematic diagram of the cross-sectional structure of the sound generating part in some embodiments (I).

[0044] Fig. 8 is a schematic diagram of the frequency response curve corresponding to different sizes of sound holes in some embodiments.

[0045] FIG. 9 is a diagram of frequency response curves corresponding to sound holes in different positions in some embodiments.

[0046] FIGS. 10A-10C are diagrams of sound holes in different positions in some embodiments.

[0047] FIG. 11 is a diagram of frequency response curves corresponding to first and second sound holes in different relative positions in some embodiments.

[0048] FIGS. 12A and 12B are diagrams of relative positions of first and second sound holes in some embodiments.

[0049] FIG. 13 is a diagram of frequency response curves corresponding to first and second sound holes in different sizes in some embodiments.

[0050] FIG. 14 is a diagram of first and second sound holes in different sizes in some embodiments.

[0051] FIGS. 15A and 15B are diagrams of sound holes in different centers in some embodiments.

[0052] FIG. 16 is a diagram of frequency response curves corresponding to sound holes in different shapes in some embodiments.

[0053] FIGS. 17A and 17B are diagrams of different numbers of sound holes in some embodiments.

[0054] FIG. 18 is a diagram of frequency response curves corresponding to sound holes in different shapes and numbers in some embodiments.

[0055] FIGS. 19A-19F are diagrams of sound holes in different distributions in some embodiments.

[0056] FIG. 20 is a diagram of frequency response curves corresponding to sound holes in FIGS. 19A-19F.

[0057] FIG. 21 is a diagram of relative distances between first sound holes and tuning holes in some embodiments.

[0058] FIG. 22 is a diagram of frequency response curves corresponding to different distances between any two holes or any hole and a boundary of an acoustic cavity in FIG. 21.

[0059] FIG. 23 is a diagram of frequency response curves corresponding to different area ratios of first sound holes and tuning holes in FIG. 21.

[0060] FIG. 24 is a diagram of relative positions between first sound holes and tuning holes in some embodiments.

[0061] FIG. 25 is a diagram of a structure of a sound production assembly in a sound production portion in some embodiments.

[0062] FIG. 26 is a diagram of a structure of a sound production assembly in some embodiments.

[0063] Figure 27 is a cross-sectional structural schematic of a sound emitting assembly in some embodiments.

[0064] Figure 28 is a cross-sectional structural schematic of a loudspeaker in some embodiments (I).

[0065] Figure 29 is an exploded structural schematic of a loudspeaker in some embodiments (I).

[0066] Figure 30 is a structural schematic of a voice coil assembly in some embodiments (I).

[0067] Figure 31 is an exploded structural schematic of the voice coil assembly in Figure 30.

[0068] Figures 32A and 32B are cross-sectional structural schematics of a loudspeaker in some embodiments (II) from different viewing angles.

[0069] Figure 33 is a structural schematic of a voice coil assembly in some embodiments (II).

[0070] Figure 34 is a cross-sectional structural schematic of a loudspeaker in some embodiments (III).

[0071] Figure 35 is a frequency response curve of the loudspeaker in Figure 34.

[0072] Figure 36 is a BL curve of loudspeakers corresponding to different sizes of inner and outer magnets in some embodiments.

[0073] Figure 37 is a cross-sectional structural schematic of a loudspeaker in some embodiments (IV).

[0074] Figures 38A and 38B are BL curves of loudspeakers corresponding to different sizes of magnets and flux guides in Figure 37.

[0075] Figures 39A to 39G are different exemplary structural schematics of a magnetic circuit assembly in some embodiments.

[0076] Figure 40 is a cross-sectional structural schematic of a loudspeaker in some embodiments (V).

[0077] Figure 41 is a cross-sectional structural schematic of the loudspeaker in Figure 40 from another viewing angle.

[0078] Figure 42 is an exploded structural schematic of the loudspeaker in Figure 40.

[0079] Figure 43 is a driving force coefficient of loudspeakers corresponding to different sizes of through holes in some embodiments.

[0080] Figure 44 is a cross-sectional structural schematic of a loudspeaker in some embodiments (V).

[0081] Figure 45A is a structural exploded view of a loudspeaker (II) in some embodiments.

[0082] Figure 45B is a cross-sectional view of the loudspeaker in Figure 45A in the short axis direction.

[0083] Figure 45C is a cross-sectional view of the loudspeaker in Figure 45A in the long axis direction.

[0084] Figure 46A is a structural exploded view of a loudspeaker (III) in some embodiments.

[0085] Figure 46B is a structural exploded view of a loudspeaker (IV) in some embodiments.

[0086] Figure 47A is a structural view of a loudspeaker with a magnetic circuit fixing ring (I) in some embodiments.

[0087] Figure 47B is a structural view of the loudspeaker in Figure 47A from another perspective.

[0088] Figure 48A is a structural view of a loudspeaker with a magnetic circuit fixing ring (II) in some embodiments.

[0089] Figure 48B is a structural view of the loudspeaker in Figure 48A from another perspective.

[0090] Figure 49 is a structural view of a diaphragm assembly in some examples.

[0091] Figure 50 is an enlarged view of a partial structure of the diaphragm assembly in Figure 49.

[0092] Figure 51 is a view of the width of the folded ring and the area of the folded ring where the diaphragm is attached in some embodiments.

[0093] Figure 52 is a BLx curve of a loudspeaker using the diaphragm assembly in Figure 50 in some embodiments.

[0094] Figure 53 is a KMs curve of a loudspeaker in some embodiments where the width of the folded ring and the area of the folded ring where the diaphragm is attached are in different ratios.

[0095] Figure 54 is a view of the width and thickness of the folded ring of a diaphragm assembly in some embodiments.

[0096] Figure 55 is a KMs curve of a loudspeaker in some embodiments where the width and thickness of the folded ring are in different ratios.

[0097] Figure 56 is a view of the height difference between the two ends of the folded ring and the width of the folded ring of a diaphragm in some embodiments.

[0098] Figure 57 is a KMs curve of a loudspeaker in some embodiments where the height difference between the two ends of the folded ring and the width of the folded ring are in different ratios.

[0099] FIG. 58 is a diagram illustrating the height difference between the two ends of the folded ring and the arch height of the folded ring of the diaphragm of the diaphragm assembly in some embodiments.

[0100] FIG. 59 is a diagram illustrating the KMs curve of the loudspeaker in some embodiments at different ratios of the height difference between the two ends of the folded ring and the arch height.

[0101] FIG. 60 is a diagram illustrating the thickness partition of the folded ring of the diaphragm of the diaphragm assembly in some embodiments.

[0102] FIG. 61 is a diagram illustrating the KMs curve of the loudspeaker in some embodiments at different ratios of the thickness of the folded ring.

[0103] FIG. 62 is a diagram illustrating the cross-sectional structure of the middle sticker of the diaphragm assembly in some embodiments.

[0104] FIG. 63 is a diagram illustrating the frequency response curve of the earphone corresponding to different diaphragms in some embodiments. DETAILED DESCRIPTION

[0105] The application will be further described in details by specific embodiments with reference to the drawings. In different embodiments, similar elements are denoted by similar reference numerals. In the following embodiments, many details are described in order to make the application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different cases, or can be replaced by other elements, materials, methods. In some cases, some operations related to the application are not shown or described in the specification in order to avoid the core part of the application being overwhelmed by too much description, and it is not necessary to describe these related operations in detail for those skilled in the art according to the description in the specification and general technical knowledge in the art.

[0106] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various embodiments. At the same time, the steps or actions in the method description can also be sequentially adjusted or adjusted in a manner that is obvious to those skilled in the art. Therefore, the order in the specification and the drawings is only for the purpose of clearly describing a certain embodiment, and does not mean that it is the necessary order, unless otherwise stated that a certain order must be followed.

[0107] The serial numbers of the components in this paper, such as "first", "second", etc., are only used to distinguish the described objects, and do not have any order or technical meaning. Unless otherwise specified, "connection" and "coupling" in this application include direct and indirect connection (coupling).

[0108] Fig. 1 is a physiological structure diagram of an exemplary ear, which can include an external auditory canal 11, a concha cavity 12, a cymba concha 13, a triangular fossa 14, an antihelix 15, a scapha 16, a helix 17, a tragus 18, a crux of the helix 19, and the like, according to some embodiments provided in the present application. As shown in Fig. 1, the external auditory canal 11 has a certain depth and extends to the tympanic membrane of the ear. In the absence of specific description, the external auditory canal 11 can be understood as the entrance thereof (i.e., the ear hole or ear canal opening) away from the tympanic membrane. Further, the concha cavity 12, the cymba concha 13, the triangular fossa 14, and the like have a certain volume and depth in the three-dimensional space. 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.

[0109] 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 the three-dimensional space, the stable wearing of the earphone can be achieved by means of one or more physiological parts of the ear according to some embodiments provided in the present application.

[0110] For example, the wearing of the earphone can be achieved by means of other parts of the ear (such as the cymba concha 13, the triangular fossa 14, the antihelix 15, the scapha 16, the helix 17, and the like, or a combination thereof) other than the external auditory canal 11. For example, in the wearing state, the whole or part of the structure of the earphone can be in contact with the upper part of the external auditory canal 11 (such as one or more physiological parts of the cymba concha 13, the triangular fossa 14, the antihelix 15, the scapha 16, the helix 17, and the crux of the helix 19). For another example, in the wearing state, the whole or part of the structure of the earphone can be located in a first region P1 in Fig. 1 surrounded by the dashed line and containing at least the cymba concha 13 and the triangular fossa 14, or in a second region P2 in Fig. 1 surrounded by the dashed line and containing at least the concha cavity 12, or in the front side of the crux of the helix 19 (i.e., in a third region P3 in Fig. 1 surrounded by the dashed line).

[0111] By means of other parts of the ear (such as the cymba concha 13, the triangular fossa 14, the antihelix 15, the scapha 16, the helix 17, and the like, or a combination thereof) other than the external auditory canal 11, the wearing of the earphone and the propagation of sound can be achieved, 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 user experience of the earphone. For example, when the user wears the earphone on the road, the earphone will 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, and the like), thereby effectively reducing the occurrence of traffic accidents.

[0112] Due to individual differences of different users, there are size differences in the shape and size of the ear. In order to facilitate description and understanding and to reduce or even eliminate individual differences of different users, if not otherwise specified, the ear model with "standard" shape and size is mainly taken as a reference in this application to describe the structure of the earphone in different embodiments and its wearing manner on the ear model. For example, a simulator containing a head and its (left and right) ears (such as GRAS 45BC KEMAR) can be made based on ANSI:S3.36, S3.25 and IEC:60318-7 standards as a reference for wearing earphones to present the scenario of most users normally wearing earphones.

[0113] Therefore, descriptions such as "worn by a user", "in a wearing state" and "in a wearing state" in this application can refer to the earphone described in this application worn on the ear of the aforementioned simulator. Of course, considering the individual differences of different users, the structure, shape, size, thickness, etc. of one or more parts of the ear can be designed differently according to different shapes and sizes of the ear. 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 ears.

[0114] It should be noted that in the fields of medicine, anatomy, etc., the sagittal plane, coronal plane and horizontal plane of the human body can be defined as three basic planes, and the sagittal axis, coronal axis and vertical axis can be defined as three basic axes.

[0115] Among them, the sagittal plane refers to a vertical plane made along the front-back direction of the body, which divides the human body into left and right parts; the coronal plane refers to a vertical plane made along the left-right direction of the body, which divides the human body into front and back parts; the horizontal plane refers to a parallel plane made along the up-down direction of the body, which divides the human body into upper and lower parts. Correspondingly, the sagittal axis refers to an axis perpendicular to the coronal plane along the front-back direction of the body, the coronal axis refers to an axis perpendicular to the sagittal plane along the left-right direction of the body, and the vertical axis refers to an axis perpendicular to the horizontal plane along the up-down direction of the body.

[0116] Further, the "front side of the ear" described in this 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. Among them, observing the ear of the above-mentioned simulator 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.

[0117] 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 of ordinary skill in the art, various changes and modifications can be made to the description of the present application (for example, the partial structure of the earphone can shield part or all of the external auditory canal 11), and these changes and modifications are still within the protection scope of the present application.

[0118] For open earphones, in the wearing state, the sound generating part of the open earphone usually cannot construct a relatively closed sound transmission channel with the external auditory canal 11, which will cause environmental noise to enter the external auditory canal 11 and have a significant impact on the user's hearing.

[0119] In order to be able to weaken or cancel environmental noise in a noisy or even high-noise environment, thereby realizing the active noise reduction function of the earphone and improving the listening effect of the earphone; please refer to FIG. 2 and FIG. 3, some embodiments of the present application provide an open earphone (hereinafter referred to as earphone) including a sound generating part 100 and an ear hook; wherein the ear hook is configured to place the sound generating part 100 in the position near the ear but not to block the external auditory canal 11 in the wearing state, it should be pointed out that due to individual differences of different users, when the earphone is worn by different users, the sound generating part 100 may partially block the external auditory canal 11, but the external auditory canal 11 is still not blocked; the following will be explained in detail.

[0120] In some embodiments, please refer to FIG. 4 to FIG. 6, the sound generating part 100 includes a first housing 110, a sound generating assembly and a microphone assembly, etc., the sound generating assembly is arranged inside the first housing 110, which can include a loudspeaker 120 and a limiting assembly 130; wherein the loudspeaker 120 can convert electrical signals into corresponding mechanical vibrations, thereby generating sound output (such as noise reduction sound, audio played by the earphone, etc.); exemplarily, the sound generated by the loudspeaker 120 can include noise reduction sound, 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 environmental noise near the external auditory canal 11, so as to eliminate the environmental noise near the external auditory canal 11 and realize active noise reduction. The sound generated by the loudspeaker 120 can also include other sounds such as conversation sound, played audio, reminder sound, etc., which can be guided to the external auditory canal 11 after being output to the outside of the first housing 110 to ensure the listening effect of the user.

[0121] The limiting assembly 130 is used to position and limit the loudspeaker 120 inside the first housing 110; on the one hand, by positioning the loudspeaker 120 inside the first housing 110, it can be ensured that the sound generated by the loudspeaker 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 loudspeaker 120, it can avoid the loudspeaker 120 from shaking relative to the first housing 110 when vibrating, thereby ensuring the sound output performance of the sound generating part 100.

[0122] The microphone assembly can collect sound signals, such as user voice, environmental sound, etc. For example, based on the environmental noise collected by the microphone, the output of the speaker 120 can be adjusted so that the sound output by the speaker 120 includes a sound signal that cancels out the environmental noise, thereby achieving active noise reduction of the earphone to the environmental noise.

[0123] In some embodiments, referring to FIGS. 2 and 3, the ear hook can include an ear hook shell and a battery assembly, a circuit board assembly, etc. disposed inside the ear hook shell, 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, the circuit board assembly is used to convert and process electrical signals to support the implementation of various functions of the earphone (such as supporting the earphone to implement power on / off, content playback switching, volume increase / decrease, etc.).

[0124] For example, referring to FIG. 3, the ear hook can be divided into a battery portion 200 and an adapter portion 300 along the length direction of the ear hook, 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 (such as 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 but does not block the external auditory canal 11, so that the earphone functions as an open earphone. Further, the battery assembly and the circuit board assembly, etc. can be disposed in the battery portion 200, and the adapter portion 300 can be provided with earphone buttons and an adapter board for electrically connecting the circuit board assembly with the speaker 120 and the microphone assembly, etc.

[0125] In some embodiments, 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 provided as a profiled structure (such as an arc-shaped hook) that fits at least one of the back of the ear and the head, to increase the contact area of the ear hook with the ear or head, thereby increasing the resistance of the earphone to fall off the ear. Second, at least part of the ear hook is provided as a resilient structure, so that the ear hook has a certain elastic deformation amount in the wearing state, to increase the pressure of the ear hook on the ear or head, thereby increasing the resistance of the earphone to fall off the ear. Third, at least part of the ear hook is provided to abut against the head in the wearing state, so that the ear hook forms a counterforce to hold the ear, so that the sound generating part 100 holds the front side of the ear, thereby increasing the resistance of the earphone to fall off the ear. Fourth, the sound generating part 100 and the ear hook are provided to hold the physiological parts such as the area where the helix 17 is located and the area where the concha cavity 12 is located from both sides of the ear in the wearing state, thereby increasing the resistance of the earphone to fall off the ear. Fifth, the sound generating part 100 is provided to at least partially extend into physiological parts such as the concha cavity 12, the cymba concha 13, the triangular fossa 14, and the scaphoid fossa 16 in the wearing state, thereby increasing the resistance of the earphone to fall off the ear.

[0126] In some embodiments, the earphone can be combined with products such as glasses, headphones, head-mounted display devices, AR / VR helmets, etc.; for example, the ear hook is omitted or retained, and the sound generating part 100 is worn near the user's ear in a hanging, clamping, or other manner.

[0127] In view of the fact that some existing active noise reduction open earphones only support active noise reduction in a relatively narrow frequency band range, to enable the earphone to have a relatively flat output in a wider frequency band range, thereby effectively enhancing the active noise reduction effect of the earphone in an open application scenario, the sound generating part 100 is mainly introduced below.

[0128] Please refer to FIGS. 3-6, 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, both pointing to the left and right 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 102, 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 102 on the sagittal plane.

[0129] Meanwhile, please refer to FIG. 6, the first shell 110 of the sound production portion 100 can include multiple different shell walls such as an inner side wall 110a, an outer side wall 110b, an upper side wall 110c, a lower side wall 110d, etc.; among them, the inner side wall 110a is the shell side wall 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 wall 110b is the shell side wall 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 wall 110c is the shell side wall of the first shell 110 in the short axis direction which is close to the top of the head in the wearing state; and the lower side wall 110d is the shell side wall of the first shell 110 in the short axis direction which is away from the top of the head in the wearing state. It can be understood that these multiple different shell walls can collectively enclose a receiving cavity of the sound production portion 100, and the sound production assembly (for example, the loudspeaker 120, etc.) is accommodated and arranged in the receiving cavity.

[0130] In some embodiments, referring to FIGS. 4-24, inside the first housing 110, a first acoustic cavity 111-1 is formed between the loudspeaker 120 and the inner side wall 110a, and a second acoustic cavity 111-2 is formed between the loudspeaker 120 and the outer side wall 110b; correspondingly, the inner side wall 110a is provided with a first sound outlet hole 112-1 that is in acoustic communication with the loudspeaker 120 through the first acoustic cavity 111-1, and the outer side wall 110b is provided with a second sound outlet hole 112-2 that is in acoustic communication with the loudspeaker 120 through the second acoustic cavity 111-2.

[0131] For example, in some embodiments, the loudspeaker 120 can be a double-diaphragm loudspeaker that includes a first diaphragm 121-1 and a second diaphragm 121-2 arranged opposite to each other in the vibration direction; wherein the first diaphragm 121-1 is arranged opposite to the inner side wall 110a in the vibration direction (i.e., the thickness direction) to form the first acoustic cavity 111-1, and the second diaphragm 121-2 is arranged opposite to the outer side wall 110b in the vibration direction to form the second acoustic cavity 111-2.

[0132] Firstly, the first acoustic cavity 111-1 and the first sound outlet hole 112-1 form a first Helmholtz resonance cavity model, and the second acoustic cavity 111-2 and the second sound outlet hole 112-2 form a second Helmholtz resonance cavity model, and the first sound outlet hole 112-1 and the second sound outlet hole 112-2 serve as the necks of the respective Helmholtz resonance cavity models. When the loudspeaker 120 vibrates and outputs sound, the pressure inside the sound production unit 100 is adjusted based on the second Helmholtz resonance cavity model, which can adjust the frequency response curve of the sound output through the first sound outlet hole 112-1, for example, to make the sound output through the first sound outlet hole 112-1 have a flat frequency response curve and a phase curve with a small change in a wide frequency range, thereby facilitating the active noise reduction of the earphone in a wider frequency range.

[0133] For example, in some embodiments, the frequency response curve of the sound output through the first sound outlet hole 111-1 has a first adjacent resonance peak and a second adjacent resonance peak, and the peak resonance frequency of the first resonance peak is less than the peak resonance frequency of the second resonance peak. With the cooperation of the second Helmholtz resonance cavity, the peak resonance frequency of the second resonance peak and the peak resonance frequency of the first resonance peak can be set to be not less than 3, thereby effectively increasing the width of the flat region of the frequency response curve of the sound output through the first sound outlet hole 112-1, and providing support for the active noise reduction of the earphone in a wider frequency range.

[0134] Secondly, in the case of using a double diaphragm loudspeaker, based on the characteristics that the vibration of the double diaphragm loudspeaker is relatively stable, the vibration consistency of the first diaphragm 121-1 and the second diaphragm 121-2 is good, and the like, under the cooperation of the corresponding sound holes and acoustic cavities, the first resonance peak can be moved to the low frequency band as much as possible, and the second resonance peak can be moved to the high frequency band as much as possible, which helps to increase the width of the flat area of the frequency response curve of the earphone output sound, thereby providing support for the earphone to actively reduce noise in a wider frequency band range. At the same time, when the first diaphragm 121-1 and the second diaphragm 121-2 vibrate in the same direction, under the cooperation of the first sound hole 112-1 and the second sound hole 112-2, the effective area of the sound output can also be greatly increased, and the sound output efficiency can be improved.

[0135] Thirdly, in the wearing state, at least part of the first shell 110 can be located in the concha cavity 12, the inner side wall 110a cooperates with the concha cavity 12 to form an auxiliary cavity in communication with the external auditory canal 11, and the auxiliary cavity is usually in a semi-open state, and the first sound hole 112-1 is located in the auxiliary cavity. In this way, the sound output through the first sound hole 112-1 can be gathered by the auxiliary cavity, and most of the sound will propagate into the external auditory canal 11, and a small part of the sound (such as noise reduction sound) propagating outside the external auditory canal 11 can be counteracted with the ambient noise near the external auditory canal 11, thereby being beneficial to improving the listening effect, enhancing the active noise reduction effect, and also being beneficial to reducing the problem of sound leakage.

[0136] In some embodiments, the ratio of the peak resonance frequency of the second resonance peak to the peak resonance frequency of the first resonance peak can be set to be not less than 13, so as to further increase the width of the flat area of the frequency response curve of the earphone output sound, so that the earphone actively reduces noise in a wider frequency band range. Further, in some embodiments, the ratio of the peak resonance frequency of the second resonance peak to the peak resonance frequency of the first resonance peak can be set to be not less than 20, so that the sound output by the earphone has a more flat frequency response curve and a phase curve with a smaller change amplitude in a wider frequency band range, thereby further enhancing the active noise reduction effect of the earphone.

[0137] In some embodiments, the peak resonance frequency of the first resonance peak of the sound outputted from the first sound outlet hole 112-1 can be set to be no more than 300 Hz; the peak resonance frequency of the second resonance peak can be set to be no less than 1 kHz, for example, no less than 3.65 kHz, no less than 4.5 kHz, no less than 5.8 kHz, no less than 6.7 kHz, no less than 7.5, no less than 7.75, no less than 8.75, no less than 9.25, no less than 9.5, etc.; in this way, the sound outputted from the earphone (specifically, the sound outputted from the first sound outlet hole 112-1) can finally have a flat frequency response curve and a phase curve with a small change in a wide frequency range, thereby facilitating the earphone to achieve an active noise reduction effect in a wider frequency range.

[0138] Since the high-frequency resonance peak of the frequency response curve of the sound outputted from the earphone is mainly affected by the high-frequency peak of the loudspeaker 120 itself and the high-frequency peak formed in the acoustic cavity. Therefore, in some embodiments, by designing the loudspeaker 120 (such as the magnetic circuit, the voice coil, the diaphragm, and the structural relationship therebetween) and the number, shape, size, position, etc. of one or more acoustic structures (such as the sound outlet hole, the acoustic cavity), the frequency response curve of the sound outputted from the earphone (specifically, the first sound outlet hole 112-1) can be optimized to make the flat area of the frequency response curve wider, thereby supporting the earphone to perform active noise reduction in a wider frequency range; which will be described below.

[0139] As described above, the sound generating part 100 provided in some embodiments of the present application will be further introduced below mainly from the size, shape, position, number, etc. of the sound outlet hole (it should be noted that the high-frequency resonance peak, high-frequency peak, etc. described below can be understood as the second resonance peak of the sound outputted from the first sound outlet hole 112-1 in some embodiments).

[0140] Please refer to FIG. 8, which is a frequency response curve diagram of the sound generating part 100 corresponding to the first sound outlet hole 112-1 and the second sound outlet hole 112-2 with different sizes according to some embodiments of the present application. It should be noted that FIG. 8 is the data measured under the condition that the first sound outlet hole 112-1 and the second sound outlet hole 112-2 are single holes with consistent shapes (for example, the short side size is half of the long side size); wherein it can be understood that the area of the shell side wall of the first shell 110 is unchanged, the width size of the sound outlet hole is unchanged, and the ratio of the length size of the sound outlet hole represents the size change of the sound outlet hole.

[0141] In FIG. 8, curve L421 represents the frequency response when the ratio of the long side dimension of the sound hole to the long side dimension of the first shell 110 is 0.1; curve L422 represents the frequency response when the ratio of the long side dimension of the sound hole to the long side dimension of the first shell 110 is 0.3; curve L423 represents the frequency response when the ratio of the long side dimension of the sound hole to the long side dimension of the first shell 110 is 0.5; curve L424 represents the frequency response when the ratio of the long side dimension of the sound hole to the long side dimension of the first shell 110 is 0.7; curve L425 represents the frequency response when the ratio of the long side dimension of the sound hole to the long side dimension of the first shell 110 is 0.9; and curve L426 represents the total sound pressure level of the loudspeaker 120, which can be regarded as the output sound pressure level when the loudspeaker 120 is not wrapped by the first shell 110. In this case, the sound holes with different long side dimensions have the same width dimension, and are arranged at the center positions of the corresponding inner side wall 110a and outer side wall 110b.

[0142] As shown in FIG. 8, as the size of the sound hole gradually decreases, the resonance peak of the sound generating part 100 at high frequencies (e.g., above 4.5 kHz) gradually moves forward, and the peak resonance frequency of the high frequency resonance peak of curve L422 is about 10 kHz.

[0143] Based on this, in some embodiments, please refer to FIGS. 10A to 10C and FIGS. 15A and 15B, the first sound hole 112-1 and the second sound hole 112-2 can adopt a single hole structure; in the case where the length of the first shell 110 and the sound hole in the long axis direction is greater than the width of each in the short axis direction, the ratio of the long side dimension of the sound hole to the long side dimension of the first shell 110 can be not less than 0.3; for example, the ratio of the length of the first sound hole 112-1 in the long axis direction to the length of the inner side wall 110a in the long axis direction can be not less than 0.3, and the ratio of the length of the first sound hole 112-1 in the long axis direction to the length of the outer side wall 110a 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 sound 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 not less than 1 kHz, ensuring that the second resonance peak of the sound output through the sound hole moves to the high frequency band, and finally making the earphone have a relatively flat output in a wider frequency band range, thereby improving the active noise reduction effect of the earphone on the larger environmental noise in the open scene.

[0144] Please refer to FIG. 9, which is a schematic diagram of the frequency response curves of sound holes at different positions according to some embodiments of the present application. It should be noted that FIG. 9 is data measured under the condition that the first sound hole 112-1 and the second sound hole 112-2 are single holes with consistent shapes, and have the same size and arrangement position.

[0145] In FIG. 9, the sound holes corresponding to the curves L441, L442, L443 and L444 are all eccentrically arranged in the length direction of the surface of the first shell 110. The curve L441 represents that the distance between the center of the sound hole and the center of the corresponding side wall in the length direction is 1 mm; the curve L442 represents that the distance between the center of the sound hole and the center of the corresponding side wall in the length direction is 3 mm; the curve L443 represents that the distance between the center of the sound hole and the center of the corresponding side wall in the length direction is 5 mm; and the curve L444 represents that the distance between the center of the sound hole and the center of the corresponding side wall in the length direction is 0 mm, i.e., the sound hole is not eccentrically arranged, but is arranged at the center of the corresponding side wall of the first shell 110.

[0146] As shown in FIG. 9, in the range of 1 kHz-10 kHz, the resonance peak corresponding to the curve L444 has a higher sound pressure level than the other curves, indicating that when the sound hole is located at the center of the corresponding side wall of the first shell 110, the sound pressure level of the sound output by the sound generating unit 100 is slightly higher.

[0147] Based on this, in some embodiments, referring to FIG. 10A, the first sound hole 112-1 and the second sound hole 112-2 can adopt a single-hole structure, and the centroid of the first sound hole 112-1 coincides with the center of the inner side wall 110a, and the centroid of the second sound hole 112-2 coincides with the center of the outer side wall 110b, so that the sound hole is located at the center of the corresponding side wall of the first shell 110. In this way, the sound pressure level of the sound output by the earphone can be increased, the sensitivity of the earphone output can be improved, and the listening effect of the user can be improved.

[0148] As shown in FIG. 9, comparing the curves L441, L442, L443 and L444, the resonance frequencies corresponding to the resonance peaks of the four curves at high frequencies are basically the same, indicating that the different arrangement positions of the sound hole in the form of large-area concentrated holes (i.e., large-area single-hole form) have no effect on the high-frequency peak position of the earphone.

[0149] Based on this, in some embodiments, considering the structure of the earphone and other components, when the sound hole cannot be arranged at the center of the corresponding side wall of the first shell 110, the first sound hole 112-1 or the second sound hole 112-2 can be eccentrically adjusted. Taking the arrangement position of the first sound hole 112-1 as an example; referring to FIG. 10B, the first sound hole 112-1 can be eccentrically arranged in the length direction relative to the center of the inner side wall 110a; referring to FIG. 10C, the first sound hole 112-1 can be eccentrically arranged in the width direction relative to the center of the inner side wall 110a; and the first sound hole 112-1 can also be eccentrically arranged in the length direction and the width direction relative to the center of the inner side wall 110a.

[0150] Please refer to FIG. 11, which is a schematic diagram of the frequency response curves of the sound production unit 100 corresponding to the first sound hole 112-1 and the second sound hole 112-2 arranged in different positions, according to some embodiments of the present application. It should be noted that the data in FIG. 11 is measured under the condition that the first sound hole 112-1 and the second sound hole 112-2 are single holes with the same size and consistent shape (for example, the short side size is half of the long side size).

[0151] In FIG. 11, curve L461 represents the frequency response curve at the first sound hole 112-1 when the first sound hole 112-1 and the second sound hole 112-2 are arranged in alignment; curve L462 represents the frequency response curve at the second sound hole 112-2 when the first sound hole 112-1 and the second sound hole 112-2 are arranged in alignment; curve L463 represents the frequency response curve at the first sound hole 112-1 when the first sound hole 112-1 and the second sound hole 112-2 are arranged in misalignment; and curve L464 represents the frequency response curve at the second sound hole 112-2 when the first sound hole 112-1 and the second sound hole 112-2 are arranged in misalignment. The curves L461, L462, L463 and L464 correspond to the first sound hole 112-1 and the second sound hole 112-2 with the same area. As shown in FIG. 11, compared with the curves L461 and L462, the high-frequency resonance peaks of the curves L463 and L464 obviously move forward from around 10 kHz to around 8 kHz.

[0152] Based on this, in some embodiments, the first sound hole 112-1 and the second sound hole 112-2 can adopt a single-hole structure, and the first sound hole 112-1 and the second sound hole 112-2 are arranged in alignment, as shown in FIG. 12A. In this way, the sound production unit 100 or the earphone can have a relatively flat output in a wider frequency range, thereby improving the active noise reduction effect of the earphone. In other embodiments, the first sound hole 112-1 and the second sound hole 112-2 can also be arranged in misalignment, as shown in FIG. 12B, to meet the appearance requirements of the earphone or the sound production unit 100 or the structural design requirements of various components.

[0153] In the case where the first sound hole 112-1 and the second sound hole 112-2 are arranged in misalignment, the size, shape and acoustic resistance of the first sound hole 112-1 and the second sound hole 112-2 can be designed to ensure that the peak resonance frequency of the second resonance peak of the frequency response curve of the sound output by the first sound hole 112-1 is located in a higher frequency range, and the peak resonance frequency of the resonance peak of the sound output by the second sound hole 112-2 is lower than the peak resonance frequency of the second resonance peak of the sound output by the first sound hole 112-1, so that the earphone has a relatively flat output in a wider frequency range.

[0154] Exemplarily, a sound resistance net is arranged at the second sound outlet hole 112-2, such as a steel net, a gauze, a waterproof and breathable film, or one or more forms of sound resistance nets; the sound resistance net can be arranged in the second acoustic cavity 111-2 and covers the second sound outlet hole 112-2; the sound pressure level of the sound output by the second sound outlet hole 112-2 is reduced through the sound resistance net, and the peak-to-valley suppression of the second resonance peak is formed, which can not only ensure a larger output in a low frequency band, but also avoid the influence of the sound output by the second sound outlet hole 112-2 on the sound output by the first sound outlet hole 112-1, thereby ensuring the active noise reduction effect.

[0155] Due to the process limitations in the actual processing and production process, as well as the design or appearance design requirements of the components of the earphone, the sizes of the first sound outlet hole 112-1 and the second sound outlet hole 112-2 can be different, which can affect the output of the earphone, and further affect the active noise reduction effect of the earphone on the larger environmental noise in an open scene.

[0156] FIG. 13 is a frequency response curve diagram of the sound generating part 100 corresponding to the first sound outlet hole 112-1 and the second sound outlet hole 112-2 with different sizes according to some embodiments of the present application. It should be noted that FIG. 13 is data measured under the condition that the first sound outlet hole 112-1 and the second sound outlet hole 112-2 are single holes with the same shape (for example, the short side size of the sound outlet hole is half of the long side size) and are arranged opposite to each other.

[0157] In FIG. 13, curve L481 represents the frequency response curve at the first sound outlet hole 112-1 when the ratio of the long side size of the first sound outlet hole 112-1 and the second sound outlet hole 112-2 to the long side size of the corresponding surface of the first shell 110 is 0.5; curve L482 represents the frequency response curve at the second sound outlet hole 112-2 when the ratio of the long side size of the first sound outlet hole 112-1 and the second sound outlet hole 112-2 to the long side size of the corresponding surface of the first shell 110 is 0.5; curve L483 represents the frequency response curve at the first sound outlet hole 112-1 when the ratio of the long side size of the first sound outlet hole 112-1 to the long side size of the corresponding surface of the first shell 110 is 0.5 and the ratio of the long side size of the second sound outlet hole 112-2 to the long side size of the corresponding surface of the first shell 110 is 0.2; curve L484 represents the frequency response curve at the second sound outlet hole 112-2 when the ratio of the long side size of the first sound outlet hole 112-1 to the long side size of the corresponding surface of the first shell 110 is 0.5 and the ratio of the long side size of the second sound outlet hole 112-2 to the long side size of the corresponding surface of the first shell 110 is 0.2. The width size of the sound outlet hole with different long side sizes is the same.

[0158] As shown in FIG. 13, compared with the curves L481 and L482, when the size of the first sound hole 112-1 is greater than the size of the second sound hole 112-2, the high-frequency resonance peak of the curve L484 obviously moves forward, the high-frequency resonance peaks of the curves L481, L482 and L483 are located near 10 kHz, and the high-frequency resonance peak of the curve L484 is located near 5 kHz; the curve L483 has a peak valley near 6 kHz, which affects the output of the sound production unit 100; when the size of the first sound hole 112-1 is equal to the size of the second sound hole 112-2, the curves L481 and L482 have approximately the same trend, and the consistency is good, which indicates that the output effect of the sound production unit 100 is improved.

[0159] Based on this, in some embodiments, the size of the first sound hole 112-1 and the size of the second sound hole 112-2 are set to be the same, which is beneficial to ensure that the sound production unit 100 has a flat frequency response curve and a small change in the phase curve in a wider frequency range, and enhances the effect of active noise reduction of the earphone in a wider frequency range.

[0160] In other embodiments, please refer to FIG. 14, in order to meet the design needs, appearance needs and the like of various components of the earphone, the size of the first sound hole 112-1 and the size of the second sound hole 112-2 need to be set to be different, the size of the first sound hole 112-1 can be set to be greater than the size of the second sound hole 112-2, so that the peak value resonance frequency of the resonance peak of the sound output by the first sound hole 112-1 is in a higher frequency band, and at this time, the peak value resonance frequency of the resonance peak of the sound output by the second sound hole 112-2 can be less than the peak value resonance frequency of the resonance peak of the sound output by the first sound hole 112-1.

[0161] When the size of the first sound hole 112-1 and the size of the second sound hole 112-2 are different, a sound resistance net can also be arranged at the second sound hole 112-2, which can be arranged in the second acoustic cavity 111-2 and cover the second sound hole 112-2; the sound resistance net reduces the sound pressure level of the sound output by the second sound hole 112-2, forms a peak valley suppression of the high-frequency resonance peak of the sound, can ensure a larger output in a low frequency band, and can avoid the sound output by the second sound hole 112-2 affecting the sound output by the first sound hole 112-1, thereby ensuring the active noise reduction effect.

[0162] Please refer to FIG. 15A, FIG. 15B and FIG. 16; wherein, FIG. 15A and FIG. 15B are schematic diagrams of sound holes with different shapes of centroids according to some embodiments of the present application, and FIG. 16 is a schematic diagram of frequency response curves of loudspeakers corresponding to sound holes with different shapes according to some embodiments of the present application; in FIG. 16, curve L501 represents the frequency response curve of the sound generating unit 100 corresponding to the sound hole with a single concentrated opening as shown in FIG. 15A, and curve L502 represents the frequency response curve of the sound generating unit 100 corresponding to the sound hole with a single non-concentrated opening (for example, a ring-shaped opening) as shown in FIG. 15B.

[0163] It should be noted that the sound hole represented by curve L501 has the same opening area (i.e., the same opening rate) and the same opening position (i.e., the same position of the center of the corresponding equivalent hole) as the sound hole represented by curve L501; wherein, the opening rate is calculated as the ratio of the opening area of the sound hole to the area of the corresponding shell side wall of the first shell 110, for example, the area ratio of the first sound hole 112-1 to the inner wall surface 110a; both the single concentrated opening and the single non-concentrated opening can be understood as a single-hole structure for the corresponding sound hole.

[0164] As shown in FIG. 16, compared with curve L501, the high-frequency resonance peak of curve L502 is shifted to the right, indicating that the design of the single non-concentrated opening can make the resonance frequency of the corresponding acoustic cavity be at a higher frequency. Therefore, in some embodiments, please refer to FIG. 15B, the first sound hole 112-1 or the second sound hole 112-2 can adopt a single-hole structure in the form of a single non-concentrated opening, which can make the peak value resonance frequency of the resonance peak of the sound output by the sound hole be at a higher frequency band, thereby being more conducive to the earphone having a relatively flat acoustic output in a wider frequency band range, and improving the active noise reduction effect of the earphone.

[0165] Please refer to FIG. 17A, FIG. 17B and FIG. 18; wherein, FIG. 17A and FIG. 17B are schematic diagrams of sound holes with different numbers of sound holes according to some embodiments of the present application; wherein, the total opening areas of the sound holes shown in FIG. 17A and FIG. 17B are the same, i.e., the same opening rate. FIG. 18 is a schematic diagram of frequency response curves of loudspeakers corresponding to sound holes with different opening shapes and different numbers of sound holes according to some embodiments of the present application. In FIG. 18, curve L521 represents the frequency response of the sound generating unit 100 corresponding to the sound hole with a single concentrated opening and an opening rate of 0.25; curve L522 represents the frequency response of the sound generating unit 100 corresponding to the sound hole with a non-single concentrated opening, a large mesh opening, and an opening rate of 0.2178 as shown in FIG. 17A; and curve L523 represents the frequency response of the sound generating unit 100 corresponding to the sound hole with a non-single concentrated opening, a small mesh opening, and an opening rate of 0.1657 as shown in FIG. 17B.

[0166] Referring to FIG. 18, comparing the curves L521, L522, L523, as the size of the single sound hole decreases and the number of sound holes increases, the resonance peak of the corresponding curve at high frequency gradually increases. Therefore, in some embodiments, the sound hole (for example, the first sound hole 112-1) can adopt a non-single concentrated hole distribution hole as shown in FIGS. 17A and 17B, that is, the sound hole is a multi-hole structure composed of multiple small holes arranged in multiple arrays; this can not only make the position of the high-frequency peak of the loudspeaker 120 higher, but also greatly increase the effective area of the sound output, ensure the active noise reduction effect, and at the same time meet the appearance design requirements of the sound generating part 100 or the earphone.

[0167] Referring to FIG. 18, comparing the curves L521, L522, L523, as the size of the single sound hole decreases and the number of sound holes increases, the output sound pressure level of the corresponding curve at high frequency decreases; when the opening rate is constant, if the size of the single sound hole is too small, although the total number of sound holes can be increased to increase the resonance peak at high frequency, the sound resistance of the sound 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 sound hole (for example, the first sound hole 112-1) adopts a multi-hole structure in the form of a non-single concentrated hole, that is, the sound 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.

[0168] Referring to FIGS. 19A to 19F, FIGS. 19A to 19F are schematic diagrams of sound holes with different distributions of non-single concentrated holes according to some embodiments of the present application. Among them, FIG. 19A shows that the non-single concentrated hole sound hole is distributed on one side of the corresponding shell side wall of the first shell 110 in the long axis direction, and the corresponding opening rate is 0.15; FIG. 19B shows that the non-single concentrated hole sound hole is annularly distributed on one side of the corresponding shell side wall of the first shell 110 in the long axis direction, and the corresponding opening rate is 0.15; FIG. 19C shows that the non-single concentrated hole sound hole is annularly distributed on the entire surface of the corresponding shell side wall of the first shell 110, and the corresponding opening rate is 0.15; FIG. 19D shows that the non-single concentrated hole sound hole is annularly distributed on one side of the corresponding shell side wall of the first shell 110 in the long axis direction, and the other side of the corresponding shell side wall in the long axis direction is provided with a pressure relief hole, and the corresponding opening rate of the sound hole is 0.15 and the corresponding opening rate of the pressure relief hole is 0.0375; FIG. 19E shows that the non-single concentrated hole sound hole is distributed in the central region of the corresponding shell side wall of the first shell 110, and the corresponding opening rate is 0.15; FIG. 19F shows that the non-single concentrated hole sound hole is distributed on the entire surface of the corresponding shell side wall of the first shell 110, and the corresponding opening rate is 0.30. At this time, the first sound hole 112-1 and the second sound hole 112-2 can be designed to face each other or can be designed to be staggered.

[0169] Referring to FIG. 20, FIG. 20 is a schematic diagram of frequency response curves of the sound production unit 100 corresponding to different distributions of non-single concentrated sound holes, according to some embodiments of the present disclosure. In FIG. 20, curve L541 corresponds to a ring-shaped distribution of non-single concentrated sound holes on the entire surface of the corresponding side wall of the first shell 110, with a hole opening rate of 0.15; curve L542 corresponds to the sound holes shown in FIG. 19B; curve L543 corresponds to a full opening of the corresponding side wall of the first shell 110, with a hole opening rate of 1; curve L544 corresponds to the sound holes shown in FIG. 19D; curve L545 corresponds to the sound holes shown in FIG. 19E; curve L546 corresponds to the sound holes shown in FIG. 19F; and curve L547 corresponds to the loudspeaker 120 without the first shell 110.

[0170] Referring to FIG. 20, comparing curve L546 and curve L543, the positions of the high-frequency peaks are basically the same, both around 8.3 kHz. Comparing curve L541, curve L542, curve L544, curve L545, and curve L543, the corresponding frequencies of the high-frequency peaks of curve L541, curve L542, curve L544, and curve L545 with a hole opening rate of 0.15 are all lower than the corresponding frequency of the high-frequency peak of curve L513 with a hole opening rate of 0.3. Comparing curve L541, curve L542, curve L544, and curve L545 with a hole opening rate of 0.15, the high-frequency peak of curve L544 is located around 8.3 kHz, and has an additional resonance peak around 6.5 kHz; the high-frequency peak of curve L541 is located around 8.3 kHz, and has an additional resonance peak around 6.1 kHz; the high-frequency peak of curve L545 is located around 7.1 kHz; and the high-frequency peak of curve L542 is located around 6.5 kHz. When the hole opening rate of the sound holes is 0.15, the corresponding high-frequency peaks of curve L541, curve L542, curve L544, and curve L545 are all higher than 6 kHz.

[0171] Based on this, in some embodiments, when the sound holes are a multi-hole structure composed of an array of multiple small holes (i.e., the sound holes adopt a non-single concentrated hole structure), in order to make the earphone have a relatively flat output in a relatively wide frequency range, the hole opening rate of the sound holes can be no less than 0.1; it can also be understood that, on a reference plane perpendicular to the thickness direction, the area ratio of the projection of the first sound hole 112-1 or the second sound hole 112-2 in the projection of the inner side wall 110a is no less than 10%.

[0172] For example, when the opening rate of the sound outlet hole is 0.15, the high-frequency peaks corresponding to the curve L541, the curve L542, the curve L544, and the curve L545 are all higher than 6 kHz, so that the earphone has a relatively flat output in a wider frequency range, and the earphone has a better active noise reduction effect. For another example, the opening rate of the sound outlet hole can be not less than 0.3, so that the earphone has a relatively flat output in a wider frequency range, and the frequency response of the sound outlet hole has a high-frequency peak higher than 8 kHz.

[0173] Due to the wearing state, the first sound outlet hole 112-1 is located close to the outer ear canal 11, and due to the limitation of the opening size of the first sound outlet hole 112-1, the covering area relative to the first acoustic cavity 111-1, and other factors, a part of the sound generated by the loudspeaker 120 (specifically, the first diaphragm 121-1) in the first acoustic cavity 111-1 cannot be directly output through the first sound outlet hole 112-1 due to the obstruction of the shell side wall (for example, the part of the inner side wall 110a where the first sound outlet hole 112-1 is not arranged) of the first shell 110, and thus a standing wave is formed in the first acoustic cavity 111-1, which causes the peak resonance frequency of the second resonance peak to move forward (i.e., to move to a low frequency range), and affects the active noise reduction effect of the earphone in a wider frequency range.

[0174] Therefore, in some embodiments, referring to FIGS. 6, 19D, 21, and 24, the inner side wall 110a is also provided with a sound adjusting hole 113-3 that communicates with the first acoustic cavity 111-1. Based on the communication relationship between the first sound outlet hole 112-1 and the sound adjusting 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 sound outlet hole 112-1 to the outside of the first shell 110 can be adjusted by means of the sound adjusting 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 sound outlet hole 112-1 can be a single-hole structure (for example, a single concentrated opening structure), and the first sound outlet hole 112-1 can also be a multi-hole structure (i.e., a non-single concentrated opening structure).

[0175] Specifically, most of the sound generated by the loudspeaker 120 in the first acoustic cavity 111-1 is output through the first sound outlet hole 112-1, and a small part of the sound is output through the sound adjusting hole 113-3, so as to avoid 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 by the first sound outlet hole 112-1 can be moved to a high frequency range as much as possible, the peak resonance frequency of the resonance peak is adjusted, and finally the earphone has a relatively flat output in a wider frequency range, which is beneficial to the active noise reduction of the earphone in a wider frequency range. At the same time, it is also beneficial to enhance the sound pressure level of the sound output by the first sound outlet hole 112-1, and ensure the listening effect of the user.

[0176] It is considered that the relative position between the sound adjustment hole 113-3 and the first sound outlet hole 112-1 can affect the output of the loudspeaker 120 or the position of the peak resonance frequency of the resonance peak; please refer to FIG. 21, taking the first sound outlet hole 112-1 and the sound adjustment hole 113-3 as a porous structure for example, define L1-X as the minimum distance between any two holes, and define L2-X as 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 from the profile edge of any hole to the boundary of the acoustic cavity.

[0177] Please refer to FIG. 22, which is a schematic diagram of the frequency response curve of the sound generating part 100 corresponding to different L1-X and L2-X according to some embodiments of the present disclosure. In FIG. 6, LM is L1-X or L2-X (i.e. LM is the minimum distance between any two holes or the minimum distance between the boundary of the first acoustic cavity 111-1 and any hole).

[0178] As shown in FIG. 22, when LM = 1.3 mm, the corresponding high-frequency peak is 9.5 kHz, when LM = 2.1 mm, the corresponding high-frequency peak is 9.25 kHz, when LM = 2.7 mm, the corresponding high-frequency peak is 9 kHz, when LM = 3.4 mm, the corresponding high-frequency peak is 8.75 kHz, when LM = 4 mm, the corresponding high-frequency peak is 7.75 kHz, when LM = 6 mm, the corresponding high-frequency peak is 7.5 kHz, when LM = 8 mm, the corresponding high-frequency peak is 6.7 kHz, when LM = 10 mm, the corresponding high-frequency peak is 5.8 kHz, when LM = 12 mm, the corresponding high-frequency peak is 4.5 kHz, and when LM = 14 mm, the corresponding high-frequency peak is 3.65 kHz. As can be seen from FIG. 6, as LM increases, the corresponding high-frequency peak moves forward in turn, which means that the opening area decreases in turn, thereby causing the sound pressure level of the sound output from the inner side wall 110a side to decrease. When LM = 14 mm, the sound pressure level at 1 kHz decreases by 3 dB compared to other smaller LM, which is an acceptable state.

[0179] Therefore, 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 sound outlet hole 112-1 and the sound adjustment 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 sound outlet hole 112-1 is not greater than 14 mm, and the minimum distance between the boundary of the first acoustic cavity 111-1 and the sound adjustment hole 113-3 is not greater than 14 mm. It can also be understood that when the first sound outlet hole 112-1 and / or the sound adjustment 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.

[0180] In this way, the sound output by the first sound outlet hole 112-1 can have a relatively flat phase curve in the frequency range of 1 kHz or less, thereby ensuring that the earphone has a relatively flat output in a wide frequency range, so as to facilitate active noise reduction of the earphone in a wide frequency range. In addition, as described in the foregoing embodiments, the diameter of each small hole can be set to be not less than 0.2 mm.

[0181] Further, in some embodiments, any of the minimum distances described above can be set to be not greater than 10 mm, not greater than 8 mm, or not greater than 6 mm, or not greater than 3.4 mm, etc. For example, when the minimum distance is 10 mm, the peak resonance frequency of the second resonance peak can be adjusted to 5.8 kHz; when the minimum distance is 8 mm, the peak resonance frequency of the second resonance peak can be adjusted to 6.7 kHz; when the minimum distance is 6 mm, the peak resonance frequency of the second resonance peak can be adjusted to 7.5 kHz; and when the minimum distance is 3.4 mm, the peak resonance frequency of the second resonance peak can be adjusted to 8.75 kHz. In this way, by selecting the minimum distance, the peak resonance frequency of the second resonance peak can be moved to a higher frequency band as much as possible, further expanding the width of the flat area of the frequency response curve, so that the earphone can achieve active noise reduction in a wider frequency range.

[0182] In some embodiments, the ratio of the total area of the sound adjustment hole 113-3 to the total area of the first sound outlet hole 112-1 can be set to be less than 23%. Specifically, please refer to FIG. 23, which is a schematic diagram of the frequency response curve of the sound generation part 100 with different area ratios of the sound adjustment hole 113-3 to the first sound outlet hole 112-1 according to some embodiments of the present disclosure. In the reference plane perpendicular to the thickness direction, the total projection area of the first sound outlet hole 112-1 on the reference plane is defined as S1, the total projection area of the sound adjustment hole 113-3 on the reference plane is defined as S2, and the ratio of the total projection area S1 of the sound adjustment hole 113-3 to the total projection area S1 of the first sound outlet hole 112-1 is defined as SS.

[0183] As shown in FIG. 23, as SS gradually increases, the high-frequency peak gradually moves backward, and the sound pressure level of the output sound gradually decreases. The increase of SS means the increase of the opening area of the sound adjustment hole 113-3, which can effectively achieve the pressure relief effect, thereby making the high-frequency peak move backward. However, 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 sound outlet hole 112-1. As can be seen from FIG. 23, when SS is 0% (i.e. no sound adjustment hole 113-3 is set) to 22.7%, the high-frequency peak moves from 8.5 kHz to 9.75 kHz, and the sound pressure level of the output sound decreases by 1 dB, which is within an acceptable range.

[0184] Therefore, the ratio of the total area of the sound adjustment hole 113-3 to the total area of the first sound outlet hole 112-1 is set to be less than 23%, which can effectively avoid the problem that too much sound leaks from the sound adjustment hole 113-3 due to the excessively large opening or area ratio of the sound adjustment hole 113-3, thereby reducing the sound pressure level or volume of the first sound outlet hole 112-1.

[0185] Exemplarily, in some embodiments, the ratio of the total area of the sound adjustment hole 113-3 to the total area of the first sound outlet hole 112-1 is set to be 22.7%, so as to adjust the peak resonance frequency of the second resonance peak to about 9.75 kHz, and further expand the width of the flat region of the frequency response curve of the sound output through the first sound outlet hole 112-1, so that the earphone can actively reduce noise in a wider frequency range.

[0186] In some embodiments, referring to FIG. 24, in the wearing state, the sound adjustment hole 113-3 is located farther away from the external auditory canal 11 than the first sound outlet hole 112-1. In an 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 noise in a larger environment. Therefore, by setting the sound adjustment hole 113-3 to be farther away from the external auditory canal 11 than the first sound outlet hole 112-1, the sound output through the sound adjustment hole 113-3 and the sound output through the first sound outlet hole 112-1 can interfere and cancel each other in the far field, so as to reduce the leakage of the earphone and ensure the listening effect of the user.

[0187] For example, in 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 is divided into a first region and a second region along the length direction, and the ratio of the length of the first region 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%. The projection of the sound adjustment hole 113-3 on the reference plane is located in the first region, and the projection of the first sound outlet hole 112-1 on the reference plane is located in the second region.

[0188] In this way, by setting the tuning hole 113-3 and the first sound outlet hole 112-1 in the inner side wall 110a in different regions corresponding to the first acoustic cavity 111-1, the tuning hole 113-3 can be ensured to be located farther from the external auditory canal than the first sound outlet hole 112-1 in the wearing state, and the tuning hole 113-3 and the first sound outlet hole 112-1 can be distinguished when the tuning hole 113-3 is an array of small holes or a large-area centralized hole and is close to the first sound outlet hole 112-1. For example, in the length direction or the diameter direction of the first acoustic cavity 111-1, the holes in the region from the boundary of the first acoustic cavity 111-1 to 38.3% of the region can be regarded as the tuning hole 113-3.

[0189] It should be noted that the bold dashed line in FIGS. 21 and 24 represents the projection boundary of the first acoustic cavity 111-1 on the reference plane, and the bold solid line with an arrow in FIG. 24 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 bold solid line represents the first region, and the region on the right side of the bold solid line represents the second region.

[0190] In some embodiments, referring to FIGS. 21 and 24, when the first sound outlet hole 112-1 is a multi-hole structure composed of an array of small holes, the aperture of the small hole located in the region of the inner side wall 110a directly opposite the external auditory canal 11 in the wearing state is set to be larger than the aperture of the small hole located in other regions of the inner side wall 110a. For example, among the small holes of the sound outlet hole 112-1, the aperture of the small hole close to the boundary of the first acoustic cavity 111-1 and the tuning hole 113-3 is smaller than the aperture of the small hole at other positions. In this way, by differentiating the apertures of the small holes in the first sound outlet hole 112-1, the sound pressure level of the sound output by the earphone directly opposite the external auditory canal 11 can be improved, thereby ensuring the user's listening effect.

[0191] As provided in some embodiments described above, by setting the acoustic resistance net at the second sound outlet hole 112-2, the sound pressure level of the sound output by the second sound outlet hole 112-2 can be reduced, the peak-to-valley suppression of the high-frequency resonance peak is formed, while ensuring that the earphone has a larger output in the low-frequency band, the output sound of the second sound outlet hole 112-2 can also be avoided to affect the output sound of the first sound outlet hole 112-1, and the active noise reduction effect is improved. In some embodiments, an acoustic resistance net can also be provided at the first sound outlet hole 112-1, for example, the acoustic resistance net can be arranged in the first acoustic cavity 111-2 and covers the first sound outlet hole 112-1 and the sound adjusting hole 113-3. For the sake of distinction and description, the acoustic resistance net at the second sound outlet hole 112-2 is defined as the second acoustic resistance net, and the acoustic resistance net at the first sound outlet hole 112-1 is defined as the first acoustic resistance net; wherein the acoustic impedance ratio of the first acoustic resistance net is set to be smaller than the acoustic impedance ratio of the second acoustic resistance net, for example, the ratio of the acoustic impedance ratio of the second acoustic resistance net to the acoustic impedance ratio of the first acoustic resistance net is not less than 10 (for example, the acoustic impedance ratio of the first acoustic resistance net is less than 10 Rayleigh, and the acoustic impedance ratio of the second acoustic resistance net is greater than 700 Rayleigh).

[0192] Therefore, based on the characteristics of the smaller acoustic impedance ratio of the first acoustic resistance net, the influence on the sound output by the first sound outlet hole 112-1 can be minimized, the sound output effect of the sound generating part 100 close to the external auditory canal 11 side is ensured, and based on the first acoustic resistance net and the second acoustic resistance net, the dustproof, waterproof and other effects in the sound generating part 100 can be achieved.

[0193] As described in some embodiments above, the sound generating assembly can include a loudspeaker 120 and a limiting component 130, which can be used to position and limit the loudspeaker 120 in the first shell 110, in addition, the limiting component 130 can also be used to cooperate with the loudspeaker 120 and the corresponding shell side wall of the first shell 110 to form an acoustic cavity. Specifically, the loudspeaker 120 is arranged in the vibration direction and spaced apart from the inner side wall 110a and the outer side wall 110b, and the limiting component 130 positions and limits the loudspeaker 120 between the inner side wall 110a and the outer side wall 110b, thereby cooperating with the loudspeaker 120 and the inner side wall 110a to form the first acoustic cavity 111-1, and cooperating with the loudspeaker 120 and the outer side wall 110b to form the second acoustic cavity 111-2.

[0194] The limiting component 130 not only affects the structural relationship between the loudspeaker 120 and the first shell 110, but also affects the structure of the acoustic cavity, thereby affecting the active noise reduction of the earphone in a wider frequency range. Therefore, please refer to FIGS. 5-6 and 25-27, the limiting component 130 and its related structures will be mainly described below.

[0195] In some embodiments, referring to FIG. 5, the loudspeaker 120 includes a first diaphragm 121-1 and a second diaphragm 121-2 arranged in an up-down manner along the vibration direction, and the limiting assembly 130 is connected between the loudspeaker 120 and the first shell 110. Exemplarily, one part of the limiting assembly 130 is connected to the inner side wall 110a of the first shell 110 and the other part is connected to the outer side wall 110b of the first shell 110.

[0196] When the loudspeaker 120 is arranged in the first shell 110 together with the limiting assembly 130, the limiting assembly 130 can be connected to the shell side wall of the first shell 110 (it should be noted that the connection can be bonding, clamping, or elastic abutting, etc.), so that the first diaphragm 121-1 is arranged opposite to the inner side wall 110a along the vibration direction, and the loudspeaker 120 and the inner side wall 110a form a first acoustic cavity 111-1 which communicates with the first sound hole 112-1 and the sound adjusting hole 113-3, and the limiting assembly 130 can also make the second diaphragm 121-2 arranged opposite to the outer side wall 110b along the vibration direction, and the loudspeaker 120 and the outer side wall 110b form a second acoustic cavity 111-2 which communicates with the second sound hole 112-2.

[0197] Therefore, the loudspeaker 120 can be stably limited at a predetermined position in the first shell 110 by the limiting assembly 130, so that the loudspeaker 120 and the first shell 110 form corresponding acoustic cavities, thereby creating conditions for improving the output performance of the earphone; at the same time, the limiting assembly 130 can also be combined with the loudspeaker 120 to form a functional monomer (i.e., a sound generating assembly) with a relatively complete structure, which is conducive to the disassembly and maintenance of the sound generating part 100, and also conducive to the design of the related structures (such as the sound hole and the sound adjusting hole 113-3) of the first shell 100 to meet the needs of active noise reduction in a wider frequency band.

[0198] In some embodiments, the limiting assembly 130 can be sealingly connected between the loudspeaker 120 and the first shell 110, specifically, one part of the limiting assembly 130 is sealingly connected to the loudspeaker 120 and the other part is sealingly connected to the first shell 110, and a sealed enclosing structure is formed between the inner side wall 110a and the first diaphragm 121-1 and a sealed enclosing structure is formed between the outer side wall 110b and the second diaphragm 121-2. Exemplarily, the limiting assembly 130 is a ring structure with a sound guide hole in the center; along the vibration direction, the sound guide hole of the limiting assembly 130, the first sound hole 112-1, the second sound hole 112-2, the first diaphragm 121-1 and the second diaphragm 121-2 can at least partially overlap.

[0199] In some embodiments, the limiting component 130 is fixedly connected with the loudspeaker 120 as an integral structure; the limiting component 130 elastically abuts against the inner side wall 110a at one end close to the inner side wall 110a and elastically abuts against the outer side wall 110b at one end close to the outer side wall 110b in the vibration direction. In this way, the limiting component 130 can be combined with the loudspeaker 120 as a functional structure body relatively independent of the first shell 110, which is conducive to reducing the disassembly difficulty of the sound production part 100.

[0200] In some embodiments, referring to FIGS. 25-27, the limiting component 130 includes a second shell, a first sealing ring 131, and a second sealing ring 132; the loudspeaker 120 is arranged in the second shell and sealingly connected with the second shell; for the convenience of distinguishing and describing, the shell wall of the second shell opposite to the inner side wall 110b and spaced from the inner side wall 110b in the vibration direction is defined as a first transverse side wall, the shell wall of the second shell opposite to the outer side wall 110b and spaced from the outer side wall 110b in the vibration direction is defined as a second transverse side wall, and the shell wall of the second shell surrounding the vibration direction is defined as a longitudinal side wall; it can also be understood that the first transverse side wall is arranged in the first acoustic cavity 111-1 facing the inner side wall 110a (or the loudspeaker 120), the second transverse side wall is arranged in the second acoustic cavity 111-2 facing the outer side wall 110b (or the loudspeaker 120), and the loudspeaker 120 is located between the first transverse side wall and the second transverse side wall in the vibration direction. In addition, one end of the first sealing ring 131 in the vibration direction is fixed to the first transverse side wall, and the other end abuts against the inner side wall 110a; one end of the second sealing ring 131 in the vibration direction is fixed to the second transverse side wall, and the other end abuts against the outer side wall 110b.

[0201] Among them, the sound guide hole of the limiting component 130 includes a first sound guide hole 130-1 through the first transverse side wall and the first sealing ring 131, and a second sound guide hole 130-2 through the second transverse side wall and the second sealing ring 132. The first sound guide hole 130-1 guides the first acoustic cavity 111-1, that is, the first acoustic cavity 111-1 includes the cavity space between the first transverse side wall and the inner side wall 110a and the cavity space between the first transverse side wall and the loudspeaker 120 (for example, the second diaphragm 121-1), and the two cavity spaces on both sides of the first transverse side wall are connected through the first sound guide hole 130-1 to form a complete first acoustic cavity 111-1. Similarly, the second sound guide hole 130-2 guides the second acoustic cavity 111-2.

[0202] Therefore, by using the second shell as a peripheral protection structure of the loudspeaker 120, a relatively stable structural assembly space can be provided for the loudspeaker, which not only facilitates the construction of the sound generating assembly into a complete functional monomer, but also facilitates the miniaturization and lightweighting of the sound generating assembly or the sound generating portion 100. For example, the second shell can be made of metal material, so that the shell wall thickness of the second shell is thinner and the mass is lighter while ensuring the mechanical strength of the second shell. At the same time, it is also conducive to the design of the acoustic structure inside the sound generating portion 100, providing support for active noise reduction and the like.

[0203] In some embodiments, the projections of the sound guide hole of the limiting component 130, the first sound outlet hole 112-1, the second sound outlet hole 112-2, the first diaphragm 121-1 and the second diaphragm 121-2 at least partially overlap on a reference plane perpendicular to the vibration direction, so as to ensure that the sound output by the loudspeaker 120 is output to the outside of the first shell 110.

[0204] For example, in some embodiments, the projection of the first sound outlet hole 112-1 falls within the projection of the first sound guide hole 130-1 on a reference plane perpendicular to the vibration direction. Alternatively, in some embodiments, the overlapping area of the projection of the first sound outlet hole 112-1 and the projection of the first sound guide hole 130-1 has a projection area not less than 80% of the projection area of the projection of the first sound guide hole 130-1. In this way, the air in the sound guide hole of the limiting component 130 that is pushed by the diaphragm can be smoothly pushed out of the first sound outlet hole 112-1, ensuring the acoustic output of the loudspeaker 120 and providing support for moving the peak resonance frequency of the first resonance peak of the sound output from the first sound outlet hole 112-1 to a lower frequency band and moving the peak resonance frequency of the second resonance peak to a higher frequency band. Preferably, in some embodiments, the projection of the second sound outlet hole 112-2 falls within the projection of the second sound guide hole 130-2 on a reference plane perpendicular to the vibration direction. Alternatively, in some embodiments, the overlapping area of the projection of the second sound outlet hole 112-2 and the projection of the second sound guide hole 130-2 has a projection area not less than 80% of the projection area of the projection of the second sound guide hole 130-2. In this way, the air in the sound guide hole of the limiting component 130 that is pushed by the diaphragm can be smoothly pushed out of the second sound outlet hole 112-2, ensuring the acoustic output of the loudspeaker 120.

[0205] Similarly, in some embodiments, the projection of the first diaphragm 121-1 falls within the projection of the first sound guide hole 130-1 on a reference plane perpendicular to the vibration direction. Alternatively, in some embodiments, the overlapping area of the projection of the first diaphragm 121-1 and the projection of the first sound guide hole 130-1 on a reference plane perpendicular to the vibration direction has a projection area not less than 80% of the projection area of the projection of the first diaphragm 121-1. In this way, when the first diaphragm 121-1 vibrates, the air pushed by the first diaphragm 121-1 can smoothly enter the sound guide hole of the limiting assembly 130, thereby maximizing the acoustic output of the loudspeaker 120. Preferably, in some embodiments, the projection of the second diaphragm 121-2 falls within the projection of the second sound guide hole 130-2 on a reference plane perpendicular to the vibration direction. Alternatively, in some embodiments, the overlapping area of the projection of the second diaphragm 121-2 and the projection of the second sound guide hole 130-2 on a reference plane perpendicular to the vibration direction has a projection area not less than 80% of the projection area of the projection of the second diaphragm 121-2. In this way, when the second diaphragm 121-2 vibrates, the air pushed by the second diaphragm 121-2 can smoothly enter the sound guide hole of the limiting assembly 130, thereby maximizing the acoustic output of the loudspeaker 120.

[0206] In addition, please refer to FIG. 5. Based on the first sealing ring 131 and the second sealing ring 132, the sound generating assembly can be sealed and fixed in the interior (i.e., the accommodation cavity) of the first shell 110 in a manner such as interference fit, for example, the first sealing ring 131 elastically abuts against the inner side wall 110a, and the second sealing ring 132 elastically abuts against the outer side wall 110b. In this way, the loudspeaker 120 is sealed and fixed in the first shell 110 from both sides in the vibration direction by the first sealing ring 131 and the second sealing ring 132, thereby sealingly forming the first acoustic cavity 111-1 and the second acoustic cavity 111-2.

[0207] It should be noted that the "boundary of the first acoustic cavity 111-1" described in the foregoing embodiments can be defined by the first sealing ring 131, i.e., it can be understood that the projection of the first sealing ring 131 on a reference plane perpendicular to the vibration direction is the boundary of the first acoustic cavity 111-1.

[0208] In some embodiments, the deformation resistance of the first sealing ring 131 and the second sealing ring 132 is less than that of the second shell, for example, the first sealing ring 131 and the second sealing ring 132 can be made of a material such as silicone, and the second shell can be made of a material such as aluminum alloy or other material having a material hardness greater than that of the sealing ring.

[0209] Exemplarily, the first sealing ring 131 and the second sealing ring 132 are made of an elastic material such as silica gel, and the first sealing ring 131 and the second sealing ring 132 can be integrally formed on the second shell by injection molding, sleeve drawing or the like. In this way, the limiting assembly 130 can be constructed as a relatively independent and complete structural member, which is conducive to reducing the disassembly and assembly difficulty of the sound generating assembly and the sound generating portion 100, and enhancing the structural stability of the sound generating assembly and even the sound generating portion 100.

[0210] In some embodiments, a reinforcing structure is arranged at the joint between the second shell and the first sealing ring 131 (and the second sealing ring 132), which can be a sawtooth structure, a hole structure or the like arranged on the first lateral side wall or the second lateral side wall. The reinforcing structure enhances the stability of the connection between the first sealing ring 131 (and the second sealing ring 132) and the second shell structure, so as to avoid the sealing ring from falling off during disassembly of the sound generating portion 100.

[0211] In some embodiments, referring to FIGS. 25-27, the second shell is a split structure including a first cover 133 and a second cover 134. The loudspeaker 120 extends into the first cover 133 at one end in the vibration direction and extends into the second cover 134 at the other end. It can also be understood that the first cover 133 and the second cover 134 cover or cover the opposite ends of the loudspeaker 120 in the vibration direction. The side wall between the loudspeaker 120 and the inner side wall 110a in the first cover 133 is the first lateral side wall, and the side wall between the loudspeaker 120 and the outer side wall 110b in the second cover 134 is the second lateral side wall. The side wall of the first cover 133 and the second cover 134 that surrounds the vibration direction and is fixedly connected with the loudspeaker 120 is the respective longitudinal side wall.

[0212] On the one hand, the relative position relationship between the first cover 133, the second cover 134 and the loudspeaker 120 can form a containing gap 130-4 around the loudspeaker 120 between the first cover 133 and the second cover 134. The containing gap 130-4 provides a structural assembly space for a circuit board 150 electrically connected with the loudspeaker 120 and the microphone assembly, such as a wire, a flat cable, a flexible printed circuit (FPC) and the like. The wire, the flat cable and the flexible printed circuit (FPC) can be accommodated and fixed in the containing gap 130-4, so as to fully utilize the structural space and effectively improve the structural compactness of the sound generating assembly, which is conducive to the miniaturization of the sound generating portion 100 and even the earphone.

[0213] On the other hand, by constructing the first cover 133 and the first sealing ring 131 into independent and complete structural members, and constructing the second cover 134 and the second sealing ring 132 into independent and complete structural members, it is also beneficial to the disassembly and assembly of the loudspeaker 120 and the limiting assembly 130, and reduces the difficulty of disassembly of the sound production assembly.

[0214] In some embodiments, the limiting assembly 130 can also omit the second shell, and directly establish a sealed connection relationship between the loudspeaker 120 and the first shell 110 by using the first sealing ring 131 and the second sealing ring 132; for example, the first sealing ring 131 is clamped and fixed between the loudspeaker 120 and the inner side wall 110a, and cooperates with the loudspeaker 120 and the inner side wall 110a to form the first acoustic cavity 111-1; the second sealing ring 132 is clamped and fixed between the loudspeaker 120 and the outer side wall 110b, and cooperates with the loudspeaker 120 and the outer side wall 110b to form the second acoustic cavity 111-2. At this time, the first sealing ring 131 and the second sealing ring 132 can adopt a ring structure, and can also form corresponding sound guide holes by opening on the first sealing ring 131 and the second sealing ring 132.

[0215] In other embodiments, the limiting assembly 130 can also omit the first sealing ring 131 and the second sealing ring 132, and form the first acoustic cavity 111-1 and the second acoustic cavity 111-2 by using the interference abutting relationship between the second shell (such as the first cover 133 and the second cover 134) and the first shell 110 (such as the inner side wall 110a and the outer side wall 110b).

[0216] In other embodiments, the limiting assembly 130 can also adopt other suitable structures, as long as it can stably fix the loudspeaker 120 in the first shell 110, or can divide the accommodation cavity into the first acoustic cavity 111-1 and the second acoustic cavity 111-2. All of these will not be repeated here.

[0217] In some embodiments, please refer to FIG. 6, the first shell 110 is provided with an opening structure and a positioning structure (for the sake of distinction and description, the positioning structure is defined as a third positioning structure); wherein the opening structure can be formed by the inner side wall 110a, the outer side wall 110b, the upper side wall 110c and the lower side wall 110d, and the opening structure can also be provided through the bottom side wall or the top side wall of the first shell 110 in the short axis direction; that is, the first shell 110 can be formed by a plurality of shell side walls, for example, the inner side wall 110a, the outer side wall 110b, the upper side wall 110c and the lower side wall 110d are integrated structure, and the bottom side wall and the top side wall are provided to cover the opening structure and together with other side walls to form the accommodation cavity of the first shell 110.

[0218] The opening structure is in communication with the accommodating cavity and is mainly used for guiding the sound generating assembly to enter or exit the accommodating cavity to realize the disassembly and assembly of the sound generating assembly and the first shell 110. The third positioning structure can be arranged in the accommodating cavity, for example, the third positioning structure can include a protruding structure, a stepped structure and the like arranged on the inner side wall 110a, the outer side wall 110b, the upper side wall 110c, the lower side wall 110d and the like of the shell side wall, and is mainly used for abutting and limiting the limiting assembly 130 to limit the position of the sound generating assembly in the accommodating cavity, thereby providing support for realizing the precise and rapid assembly of the sound generating assembly.

[0219] In some embodiments, based on the first lateral side wall and the first sound guide hole 130-1, the second lateral side wall and the second sound guide hole 130-2, support can be provided for adjusting the resonance frequency, acoustic impedance ratio and sound pressure level of the sound output by the corresponding sound hole of the corresponding acoustic cavity, so as to enhance the active noise reduction effect.

[0220] Exemplarily, the first sound guide hole 130-1 includes the opening of the first sealing ring 131 and the opening of the first lateral side wall. On a reference plane perpendicular to the vibration direction, the projection of the opening of the first lateral side wall, the projection of the first sound hole 112-1 and the projection of the opening of the first sealing ring 131 exist a first overlapping area; wherein the proportion of the projection of the opening of the first lateral side wall in the first overlapping area is greater than the projection proportion of the first sound hole 112-1; for example, on the reference plane, the projection area proportion of the opening of the first lateral side wall in the first overlapping area can be greater than 30% (for example, greater than 80%), and the projection area proportion of the first sound hole 112-1 can be between 20%-30%. In this way, the opening area of the first sound guide hole 130-1 and the second sound guide hole 130-2 can be reduced as much as possible to affect the sound output.

[0221] Preferably, the second sound guide hole 130-2 includes the opening of the second sealing ring 132 and the opening of the second lateral side wall. On a reference plane perpendicular to the vibration direction, the projection of the opening of the second lateral side wall, the projection of the second sound hole 112-2 and the projection of the opening of the second sealing ring 132 exist a second overlapping area; wherein the proportion of the projection of the opening of the second lateral side wall in the second overlapping area is greater than the projection proportion of the second sound hole 112-2; for example, on the reference plane, the projection area proportion of the opening of the second lateral side wall in the second overlapping area can be greater than 30% (for example, greater than 80%), and the projection area proportion of the second sound hole 112-2 can be between 20%-30%. In this way, the opening area of the first sound guide hole 130-1 and the second sound guide hole 130-2 can be reduced as much as possible to affect the sound output.

[0222] In some embodiments, referring to FIGS. 25 and 26, the second housing has a rib structure 130-3 arranged on the first lateral side wall and the second lateral side wall; for the sake of distinction and description, the rib structure 130-3 of the first lateral side wall is defined as a first rib structure, and the rib structure 130-3 of the second lateral side wall is defined as a second rib structure, the first rib structure is located in the first sound guide hole 130-1, and the second rib structure is located in the second sound guide hole 130-2.

[0223] The first rib structure can be used to support and fix the first sound resistance net in the first acoustic cavity 111-1 in the foregoing embodiments, for example, the first sound resistance net covers the first sound guide hole 130-1 through the first rib structure and is fixed on the side of the first lateral side wall facing the inner side wall 110a; the second rib structure can be used to support and fix the second sound resistance net in the second acoustic cavity 111-1 in the foregoing embodiments, for example, the second sound resistance net covers the second sound guide hole 130-2 through the second rib structure and is fixed on the side of the second lateral side wall facing the outer side wall 110b.

[0224] On the one hand, the rib structure 130-3 can be used to adjust the opening area, shape and distribution of the corresponding sound guide hole, so as to adjust the acoustic characteristics or sound output of the corresponding acoustic cavity, for example, the rib structure 130-3 can be used to form a grid hole structure on the corresponding sound guide hole; on the other hand, the sound resistance net can be fixed on the corresponding side wall of the rib structure 130-3 and the limiting assembly 130 by means of bonding, welding and the like, so as to avoid the sound resistance net from shaking due to air vibration when the loudspeaker 120 is working, thereby avoiding the adverse effects on the sound output (such as frequency response curve, etc.) and ensuring the active noise reduction effect.

[0225] In some embodiments, referring to FIG. 27, in the case that the second housing has a first lateral side wall and a second lateral side wall, the minimum distance between the first lateral side wall and the center of the main body region of the first diaphragm 121-1 is greater than the maximum amplitude of the vibration of the main body region toward the inner side wall 110a, and the minimum distance between the second lateral side wall and the center of the main body region of the second diaphragm 121-2 is greater than the maximum amplitude of the vibration of the main body region toward the outer side wall 110b.

[0226] Therefore, based on the limitation of the distance between the amplitude of the diaphragm and the corresponding side wall, the diaphragm can be prevented from colliding with the limiting assembly 130 during vibration, thereby ensuring the sound output effect.

[0227] It should be noted that the diaphragm generally comprises a main area and a folded ring area surrounding the main area; wherein the main area is capable of moving in the vibration direction under the driving force generated by the cooperation of the magnetic circuit assembly and the voice coil assembly in the loudspeaker 120, so as to generate sound by pushing or extruding the air inside the first shell 110 or inside the loudspeaker 120; and the folded ring area can be elastically deformed with the movement of the main area to provide elastic restoring force for the main area.

[0228] In addition, in some embodiments in which the second shell is omitted or does not have the first lateral side wall or the second lateral side wall, in order to avoid the diaphragm colliding with the corresponding shell side wall in the first shell 110 during vibration, the minimum distance between the center of the main area of the first diaphragm 121-1 and the inner side wall 110a in the vibration direction is set to be greater than the maximum amplitude of vibration of the main area towards the inner side wall 110a, and the minimum distance between the center of the main area of the second diaphragm 121-2 and the outer side wall 110b in the vibration direction is set to be greater than the maximum amplitude of vibration of the main area towards the outer side wall 110b.

[0229] In some embodiments, referring to FIG. 27, the first lateral side wall and the second lateral side wall each have a central portion and an arc-shaped portion surrounding the central portion, and the end of the arc-shaped portion away from the central portion is connected to the longitudinal side wall of the second shell; wherein, in the vibration direction, the central portion of the first lateral side wall faces the main area of the first diaphragm 121-1 (at this time, the first sound guide hole 130-1 can be arranged in the central portion of the first lateral side wall), the arc-shaped portion of the first lateral side wall faces the folded ring area of the first diaphragm 121-1, the central portion of the second lateral side wall faces the main area of the second diaphragm 121-2 (at this time, the second sound guide hole 130-2 can be arranged in the central portion of the second lateral side wall), and the arc-shaped portion of the second lateral side wall faces the folded ring area of the second diaphragm 121-2.

[0230] On the one hand, the second avoiding space 130-5 can be formed between the folded ring area of the first diaphragm 121-1 and the arc-shaped portion of the first lateral side wall, and the second avoiding space 130-6 can be formed between the folded ring area of the second diaphragm 121-2 and the arc-shaped portion of the second lateral side wall, so as to avoid the folded ring area of the diaphragm colliding with the limiting assembly 130 during vibration, thereby ensuring the sound output effect.

[0231] On the other hand, compared with the scheme that the transverse side wall and the longitudinal side wall adopt a right angle mode to transition, based on the arc-shaped part forming an arc-shaped transition structure between the transverse side wall and the longitudinal side wall, the first shell can be configured in a structure form that is adapted to the second shell, so that the corner area between the adjacent side walls of the first shell tends to be curved and smooth, avoiding the presence of a relatively prominent corner; in this way, without affecting the vibration of the diaphragm, the comfort of the sound generating part 100 or the earphone can be improved, and the appearance of the sound generating part 100 can be improved; at the same time, it is also convenient to adapt the design of the outer contour structure of the longitudinal side wall and the loudspeaker 120, for example, by adapting the structure of the longitudinal side wall and the support in the loudspeaker 120 and fixing it, the loudspeaker 120 is stably positioned and fixed inside the second shell.

[0232] As some embodiments described above, the loudspeaker 120 can adopt a double-diaphragm loudspeaker, please refer to FIG. 27, FIG. 29, FIG. 34, FIG. 50 to FIG. 51B, FIG. 40 to FIG. 42, FIG. 45A to FIG. 47B, the loudspeaker 120 includes a first diaphragm 121-1, a second diaphragm 121-2, a magnetic circuit assembly, a voice coil assembly, etc., the first diaphragm 121-1 and the second diaphragm 121-2 are spaced apart and opposite in the vibration direction, the voice coil assembly and the magnetic circuit assembly are arranged between the first diaphragm 121-1 and the second diaphragm 121-2; wherein at least part of the voice coil assembly extends into the magnetic gap of the magnetic circuit assembly, and at least one of the first diaphragm 121-1 and the second diaphragm 121-2 is connected with the voice coil assembly; so as to drive the voice coil assembly to drive the first diaphragm 121-1 and the second diaphragm 121-2 to vibrate synchronously and in the same direction and generate sound through the cooperation of the magnetic circuit assembly and the voice coil assembly.

[0233] Therefore, by the first diaphragm 121-1 and the second diaphragm 121-2 vibrating synchronously and in the same direction, the consistency and stability of the loudspeaker 120 vibration are improved, which helps to move the peak resonance frequency of the low-frequency resonance peak (such as the first resonance peak) of the output sound of the earphone to a lower frequency band, and the peak resonance frequency of the high-frequency resonance peak (such as the second resonance peak) to a higher frequency band, so that the earphone has a relatively flat output in a wider frequency band range, thereby enhancing the active noise reduction effect.

[0234] Based on the consideration that in addition to the structural features such as sound holes, tuning holes, etc., the structure and performance of the loudspeaker 120 itself also have a crucial influence on the active noise reduction of the earphone; for example, the first diaphragm 121-1 and the second diaphragm 121-2 can be indirectly connected through the voice coil assembly, the first diaphragm 121-1 and the second diaphragm 121-2 are directly connected while being connected through the voice coil assembly, which can ensure the consistency of the synchronous and same direction vibration of the two diaphragms, thereby providing support for enhancing the active noise reduction effect.

[0235] The following mainly introduces the related structure of the double-diaphragm loudspeaker 120 in the case that the first diaphragm 121-1 and the second diaphragm 121-2 are indirectly connected through the voice coil assembly.

[0236] In some embodiments, referring to FIGS. 30-38B and 44-46B, the voice coil assembly includes a first voice coil 123-1 and a second voice coil 123-2, the first voice coil 123-1 and the second voice coil 123-2 are arranged in an up-down manner in the vibration direction; wherein one end of the first voice coil 123-1 away from the second voice coil 123-2 is connected to the first diaphragm 121-1, and one end of the second voice coil 123-2 away from the first voice coil 123-1 is connected to the second diaphragm 121-2. The first voice coil 123-1 drives the first diaphragm 121-1 to vibrate, and the second voice coil 123-2 drives the second diaphragm 121-2 to vibrate, so that the first diaphragm 121-1 and the second diaphragm 121-2 vibrate synchronously and in the same direction.

[0237] For example, in some embodiments, the first voice coil 123-1 and the second voice coil 123-2 are connected at the end close to each other in the vibration direction. Wherein the voice coil assembly further includes a connecting piece (for the sake of distinction and description, the connecting piece is defined as a first connecting piece 127), the first connecting piece 127 is connected between the first voice coil 123-1 and the second voice coil 123-2; for another example, the first voice coil 123-1 and the second voice coil 123-2 can be directly bonded by using glue or the like. At this time, the structural connection relationship between the first voice coil 123-1 and the second voice coil 123-2 is equivalent to the formation of an integrated voice coil assembly, thereby realizing the indirect connection between the first diaphragm 121-1 and the second diaphragm 121-2.

[0238] Firstly, the integrated voice coil assembly is used to connect the first diaphragm 121-1 and the second diaphragm 121-2 together, so that the first voice coil 123-1 and the second voice coil 123-2 can share the magnetic circuit assembly. Under the cooperation of the magnetic circuit assembly, not only the consistency of the vibration of the first diaphragm 121-1 and the second diaphragm 121-2 (i.e. synchronous and same direction vibration) can be ensured, but also the driving force of the voice coil assembly can be enhanced, thereby being conducive to the earphone having a relatively flat output in a relatively wide frequency range, and ensuring the active noise reduction effect.

[0239] Secondly, when the first diaphragm 121-1 and the second diaphragm 121-2 vibrate synchronously and in the same direction, the volume of the common cavity 111-3 formed between the two diaphragms will not change with the vibration of the diaphragm, and the gas in the common cavity 111-3 will not hinder the vibration of the first diaphragm 121-1 and the second diaphragm 121-2, but the gas can act as a companion mass and move back and forth with the vibration of the two diaphragms, which is conducive to improving the consistency of the vibration of the first diaphragm 121-1 and the second diaphragm 121-2, thereby improving the output performance of the earphone and ensuring the active noise reduction effect of the earphone.

[0240] Thirdly, the first voice coil 123-1 and the second voice coil 123-2 are connected, which can not only ensure the consistency of the vibration of the first diaphragm 121-1 and the second diaphragm 121-2, but also flexibly adjust the winding direction of the voice coil and the working current direction, so that the voice coil assembly can use the magnetic field distribution of the magnetic circuit assembly.

[0241] Fourthly, in some scenarios where the waterproof requirement of the earphone is relatively high, for example, the earphone is worn when swimming, the first shell 110 often needs to be fully enclosed. At this time, if the vibration directions of the first diaphragm 121-1 and the second diaphragm 121-2 are opposite, the gas in the common cavity 111-3 formed between the first diaphragm 121-1 and the second diaphragm 121-2 is difficult to discharge, which will interfere with the vibration of the first diaphragm 121-1 and the second diaphragm 121-2, thereby affecting the output performance of the earphone; therefore, using the first voice coil 123-1 and the second voice coil 123-2 to drive the first diaphragm 121-1 and the second diaphragm 121-2 to vibrate synchronously and in the same direction can provide support for the full enclosure of the first shell 110 or the loudspeaker itself.

[0242] In some embodiments, referring to FIGS. 27, 29 and 37, the magnetic circuit assembly includes an outer magnetic circuit member 122-1, an inner magnetic circuit member 122-2 and a magnetic circuit connecting member 122-3; wherein the outer magnetic circuit member 122-1 surrounds the outer periphery of the inner magnetic circuit member 122-2, and connects the inner magnetic circuit member 122-2 through the magnetic circuit connecting member 122-3, so as to form a magnetic gap of the magnetic circuit assembly between the outer magnetic circuit member 122-1 and the outer magnetic circuit member 122-1.

[0243] Correspondingly, referring to FIGS. 30 and 31, 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 or in the short axis direction, so that there is a part of the first voice coil 123-1 and the second voice coil 123-2 that are connected to each other and another part that are separated from each other, which can form an avoiding channel 123-3 allowing the magnetic circuit connecting member 122-3 to pass through the voice coil assembly between the first voice coil 123-1 and the second voice coil 123-2 based on the existence of the gap; it can also be understood that, based on a reference plane perpendicular to the vibration direction, the orthographic projection of the first voice coil 123-1 in the reference plane and the orthographic projection of the second voice coil 123-2 in the reference plane can be partially connected or partially overlapped, so as to form the avoiding channel 123-3 at the separated part of the first voice coil 123-1 and the second voice coil 123-2.

[0244] Exemplarily, referring to FIG. 30, the contour shape of the loudspeaker 120 is non-circular, for example, rectangular, elliptical, etc.; at this time, the side wall of the first voice coil 123-1 and the second voice coil 123-2 in the long axis direction can be defined as a long side wall, and the side wall in the short axis direction can be defined as a short side wall; the normal projection of the long side wall of the first voice coil 123-1 on the reference plane is connected or at least partially overlaps with the normal projection of the long side wall of the second voice coil 123-2 on the reference plane, and the normal projection of the short side wall of the first voice coil 123-1 on the reference plane is separated from the normal projection of the short side wall of the second voice coil 123-2 on the reference plane; in this way, the avoidance channel 123-3 can be formed between the short side wall of the first voice coil 123-1 and the short side wall of the second voice coil 123-2.

[0245] Exemplarily, the contour shape of the sound generating unit 100 or the loudspeaker 120 is approximately circular; at this time, the first voice coil 123-1 and the second voice coil 123-2 can be connected through the first connecting piece 127, so as to realize the local connection and local separation between the first voice coil 123-1 and the second voice coil 123-2 by means of the third connecting piece, in the case that the normal projection of the first voice coil 123-1 on the reference plane is a first circular ring, the normal 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, thereby forming the avoidance channel 123-3.

[0246] In this way, by setting the first voice coil 123-1 and the second voice coil 123-2 as an unequal diameter structure with local sizes not equal, 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 connecting piece 122-3, which is equivalent to placing the voice coil assembly in the same magnetic gap of the magnetic circuit assembly, so as to not only enhance the stability of the structure of the magnetic circuit assembly itself, but also provide support for the rapid assembly of the loudspeaker 120, and is conducive to reducing the assembly difficulty and cost, and avoiding the influence of the voice coil assembly on the sound output during the movement process. At the same time, the outer magnetic circuit piece 122-1 adopts a ring structure surrounding the outer periphery of the inner magnetic circuit piece 122-2, which can make the magnetic circuit assembly have a larger design size, so as to increase the driving force of the voice coil assembly by increasing the volume of the magnet, and improve the sound output performance of the loudspeaker 120.

[0247] In some embodiments, referring to FIG. 30, the overall contour shape of the loudspeaker 120 is set to be rectangular, track-shaped, or elliptical, etc. which is adapted to the contour shape of the first shell 110 or the sound production part 100. At this time, the length of the long side wall of the first voice coil 123-1 in the long axis direction is greater than the width of the short side wall of the first voice coil 123-1 in the short axis direction, and the length of the long side wall of the second voice coil 123-2 in the long axis direction is greater than the width of the short side wall of the second voice coil 123-2 in the short axis direction. At the same time, the length of the long side wall of the first voice coil 123-1 in the long axis direction can be set to be less than the length of the long side wall of the second voice coil 123 in the long axis direction. At this time, the long side wall of the first voice coil 123-1 and the short side wall of the second voice coil 123-2 can be connected by the first connecting piece 127. In this way, the avoidance channel 123-2 can be naturally formed between the short side walls of the two voice coils.

[0248] Correspondingly, the length of the magnetic circuit assembly in the long axis direction is greater than the width in the short axis direction, and the short side of the outer magnetic circuit piece 122-1 and the short side of the inner magnetic circuit piece 122-2 are connected by the magnetic circuit connecting piece 122-3 to form a structure in which the long side is not connected and the short side is connected, that is, the magnetic circuit connecting piece 122-3 passes through the magnetic gap between the short side of the inner magnetic circuit piece 122-2 and the short side of the outer magnetic circuit piece 122-1.

[0249] On the one hand, under the premise of ensuring the integrated structure of the voice coil assembly, by connecting the long side walls of the two voice coils, the structural stability of the voice coil assembly itself can be enhanced, and the vibration consistency of the first diaphragm 121-1 and the second diaphragm 121-2 can be improved, which creates conditions for ensuring the active noise reduction effect. On the other hand, the structure of the long side without connection and the short side with connection of the magnetic circuit assembly is conducive to forming a strong and uniform magnetic field between the long side of the inner magnetic circuit piece 122-2 and the long side of the outer magnetic circuit piece 122-1, so that the magnetic field can pass through the magnetic gap as much as possible, realizing the full use of the magnetic field and effectively enhancing the driving force of the voice coil assembly.

[0250] In other embodiments, the first voice coil 123-1 and the second voice coil 123-2 can also have equal diameters, specifically, the orthographic projection of the first voice coil 123-1 and the orthographic projection of the second voice coil 123-2 coincide on the reference plane perpendicular to the vibration direction. At this time, on the reference plane parallel 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 vibration direction, so that the avoidance channel 123-3 can also be formed between them based on the existence of the gap. At this time, after the magnetic circuit connecting piece 122-3 passes through the avoidance channel 123-3 in a direction perpendicular to the vibration direction, the two ends of the magnetic circuit connecting piece 122-3 are connected with the inner magnetic circuit piece 122-2 and the outer magnetic circuit piece 122-1 respectively.

[0251] As described above, the first voice coil 123-1 and the second voice coil 123-2 can be connected by the first connecting member 127. In some embodiments, referring to FIG. 31, the first voice coil 123-1 and the second voice coil 123-2 each include a voice coil skeleton 123a and a coil 123b wound around the outer periphery of the voice coil skeleton; for the sake of distinction and description, the voice coil skeleton 123a and the coil 123b of the first voice coil 123-1 are defined as a first skeleton and a first coil respectively, and the voice coil skeleton and the coil of the second voice coil 123-2 are defined as a second skeleton and a second coil respectively; wherein the first skeleton and the second skeleton are respectively arranged around the inner magnetic circuit member 122-2 between the inner magnetic circuit member 122-2 and the outer magnetic circuit member 122-1, and the first connecting member 127 is connected between the first skeleton and the second skeleton, so as to realize the separation of the coils of the two voice coils and form an avoiding channel 123-3 between the two voice coil skeletons 127-1.

[0252] Based on the connection relationship between the first skeleton, the second skeleton and the first connecting member 127, a skeleton structure of the voice coil is formed. Since the skeleton structure has high structural strength and strong connection stability, the vibration consistency between the first diaphragm 121-1 and the second diaphragm 121-2 can be further ensured, and the voice coil 123-1 and the second voice coil 123-2 of different sizes can be applied.

[0253] In some embodiments, the voice coil assembly can adopt an integrated skeleton structure; specifically, referring to FIG. 31, the first connecting member 127, the first skeleton and the second skeleton are an integrated structure, which can effectively prevent the coil from being separated from the skeleton during the vibration of the voice coil assembly, thereby enhancing the structural stability and integrity of the voice coil assembly itself.

[0254] In some embodiments, the voice coil assembly can adopt a split skeleton structure; specifically, the first skeleton has an extension part extending out of the first coil (for example, the extension part of the first skeleton is located on the long side of the first voice coil 123-1), and the second skeleton has an extension part extending out of the second coil (for example, the extension part of the second skeleton is located on the long side of the second voice coil 123-2), and the extension part of the first skeleton is fixedly connected (for example, bonded) with the extension part of the second skeleton. In this way, the connection of the first voice coil 123-1 and the second voice coil 123-2 and the formation of the skeleton structure can be realized, and the avoiding channel 123-3 can be formed to adapt to the size difference between the first voice coil 123-1 and the second voice coil 123-2. At this time, it can be understood that the first connecting member 127 is omitted to form the skeleton structure of the voice coil assembly, or the extension part of the first voice coil 123-1 and the extension part of the second voice coil 123-2 form the first connecting member 127.

[0255] In some other embodiments, the first skeleton and the second skeleton can also not have the extending portion, in which case the first connecting member 127 can adopt a patch structure, and the first connecting member 127 is attached and fixed on the same side of the first skeleton and the second skeleton, so as to also construct the voice coil assembly of the skeleton structure.

[0256] In some voice coil assemblies adopting the skeleton structure or some voice coil assemblies not adopting the skeleton structure, as for the first connecting member 127 itself, please refer to FIG. 32A, FIG. 32B and FIG. 33, the first connecting member 127 can adopt a bending structure, and the bending structure of the first connecting member 127 can be connected between the first voice coil 123-1 and the second voice coil 123-2 in the long axis direction, or can be connected between the first voice coil 123-1 and the second voice coil 123-2 in the short axis direction; due to the smaller mass of the bending structure, the load of the first voice coil 123-1 and the second voice coil 123-2 can be reduced, the output of the loudspeaker 120 can be improved, and the active noise reduction effect of the earphone on the larger environmental noise in the open wearing mode can be improved; at the same time, it can also be suitable for the first voice coil 123-1 and the second voice coil 123-2 of different sizes.

[0257] Of course, the first connecting member 127 can also adopt other suitable structure forms, for example, the first connecting member 127 can also adopt a gasket structure, in which case the first voice coil 123-1 and the second voice coil 123-2 can adopt a form of clamping the first connecting member 127 and are adhesively fixed with the first connecting member 127; the first connecting member 127 can also adopt a patch structure, and the first connecting member 127 can be attached and fixed on the same side of the first voice coil 123-1 and the second voice coil 123-2. All of the above will not be repeated here.

[0258] In some embodiments, in the case of the voice coil assembly adopting the skeleton structure, the materials of the first skeleton, the second skeleton and the first connecting member 127 can include aluminum alloy, can also include PMI (Polymethacrylimide, polymethacrylimide) material or PC (Polycarbonate, polycarbonate) material, etc., and can also adopt a mixed material (for example, PC material added with glass fiber or carbon fiber, etc.). In this way, the load on the first voice coil 123-1 and the second voice coil 123-3 can be reduced, which is beneficial to improve the driving force coefficient of the loudspeaker 120.

[0259] Fig. 35 is a schematic diagram of the frequency response curve of the loudspeaker shown in Fig. 34; wherein, taking an example that the size of the first voice coil 123-1 is smaller than the size of the second voice coil 123-2, the curve L321 represents the output sound pressure level of the first diaphragm 121-1 corresponding to the small voice coil (the first voice coil 123-1) when the first voice coil 123-1 and the second voice coil 123-2 are simultaneously driven; the curve L322 represents the output sound pressure level of the second diaphragm 121-2 corresponding to the large voice coil (the second voice coil 123-2) when the first voice coil 123-1 and the second voice coil 123-2 are simultaneously driven; the curve L323 represents the output phase of the first diaphragm 121-1 corresponding to the small voice coil (the first voice coil 123-1) when the first voice coil 123-1 and the second voice coil 123-2 are simultaneously driven; and the curve L324 represents the output phase of the second diaphragm 121-2 corresponding to the large voice coil (the second voice coil 123-2) when the first voice coil 123-1 and the second voice coil 123-2 are simultaneously driven.

[0260] It should be noted that the collection environment of the data shown in Fig. 35 can be that the loudspeaker 120 is fixed (for example, handheld, directly fixed by a fixed platform, fixed by a handheld fixing device, etc.), a voltage excitation of 0.5Vrms is used, and the frequency response and phase of the corresponding diaphragm are measured by a test microphone 5mm away from the corresponding diaphragm. When the loudspeaker 120 is fixed, the loudspeaker 120 needs to be avoided from being blocked to avoid affecting the collection effect.

[0261] As shown in Fig. 35, the curve L321 and the curve L322 are relatively flat in the range of 200Hz-10kHz, and no peak and valley appears, which indicates that the vibration consistency of the first diaphragm 121-1 and the second diaphragm 121-2 is good, and the output consistency is good. The phase difference of the curve L323 and the curve L324 in the range of 200-10k is within 180°, which indicates that the vibration phases of the first diaphragm 121-1 and the second diaphragm 121-2 are opposite, and the vibration consistency of the first diaphragm 121-1 and the second diaphragm 121-2 is good. In the frequency range of 200Hz-10kHz, the phase change of the curve L323 or the curve L324 is not greater than 20°, which indicates that the vibration phase consistency of the first diaphragm 121-1 and the second diaphragm 121-2 is good.

[0262] In summary, by connecting the first voice coil 123-1 and the second voice coil 123-2 through the first connecting piece 127, and connecting the first voice coil 123-1 and the first diaphragm 121-1, and connecting the second voice coil 123-2 and the second diaphragm 121-1, the synchronous and same-direction vibration of the first diaphragm 121-1 and the second diaphragm 121-1 can be realized, and the vibration consistency is good.

[0263] It should be noted that, as in some of the foregoing embodiments, the sound pressure level of the sound output by the first sound outlet hole 112-1 is set to be greater than the sound pressure level of the sound output by the second sound outlet hole 112-2; that is, the sound pressure level of the corresponding sound in the frequency range from the peak resonance frequency of the first resonance peak to the peak resonance frequency of the second resonance peak.

[0264] In some embodiments, referring to FIGS. 27 and 37, the inner magnetic circuit member 122-2 includes an inner magnet (defined as a first inner magnet 122-21 for ease of distinction), a first magnetic conducting plate 122-22, and a third magnetic conducting plate 122-23, and the outer magnetic circuit member 122-1 includes an outer magnet (defined as a first outer magnet 122-11 for ease of distinction), a fourth magnetic conducting plate 122-12, and a second magnetic conducting plate 122-13; wherein the first outer magnet 122-11 surrounds the outer periphery of the first inner magnet 122-21 to form a magnetic gap together with the first inner magnet 122-21; for example, the first outer magnet 122-11 can be an integrated annular magnet arranged around the first outer magnet 122-11; the first magnetic conducting plate 122-22 is stacked on the first inner magnet 122-21 facing the first diaphragm 121-1, and the third magnetic conducting plate 122-23 is stacked on the first inner magnet 122-21 facing the second diaphragm 121-2; the fourth magnetic conducting plate 122-12 is stacked on the first outer magnet 122-11 facing the first diaphragm 121-1, and the second magnetic conducting plate 122-13 is stacked on the first outer magnet 122-11 facing the second diaphragm 121-2; for example, the fourth magnetic conducting plate 122-12 and the second magnetic conducting plate 122-13 can each be an integrated annular magnetic conducting plate stacked on both sides of the first outer magnet 122-11; and the magnetic circuit connecting member 122-3 is arranged along the vibration direction through the magnetic gap and the avoiding passage 121-3, and one end of the magnetic circuit connecting member 122-3 is connected to the first magnetic conducting plate 122-22 and the other end is connected to the second magnetic conducting plate 122-13.

[0265] Firstly, through the cooperation of the first inner magnet 122-21 and the first outer magnet 122-11, the magnetic field strength near the voice coil assembly can be effectively increased, the magnetic field distribution is more uniform, the driving force of the voice coil assembly is improved, the vibration consistency of the first diaphragm 121-1 and the second diaphragm 121-2 is ensured, and then the width of the flat area of the frequency response curve of the sound output by the first sound outlet 112-1 is increased, so that the earphone can actively reduce the noise in a wider frequency range. Secondly, based on the stacking arrangement relationship between the first inner magnet 122-21, the first outer magnet 122-11 and the related magnetic conductive body, the structural stability of the magnetic circuit assembly can be further improved, thereby improving the vibration stability of the loudspeaker 120, and facilitating the processing and manufacturing difficulty of the magnetic circuit assembly, so as to facilitate the assembly and formation of the loudspeaker 120. Thirdly, based on the annular structure of the first outer magnet 122-11, the first outer magnet 122-11 can have a larger volume to enhance the magnetic flux and thus the driving force of the loudspeaker 120; and the annular structure of the first outer magnet 122-11 can also reduce the assembly difficulty and improve the assembly efficiency.

[0266] In some embodiments, referring to FIGS. 27 and 37, at least one of the first magnetic conductive plate 122-22 and the second magnetic conductive plate 122-13 is in an integrated structure with the magnetic circuit connector 122-3, which can reduce the number of components of the magnetic circuit assembly, further enhance the structural stability of the magnetic circuit assembly, and reduce the manufacturing difficulty of the magnetic circuit assembly. For example, the first magnetic conductive plate 122-22 is in an integrated structure with the magnetic circuit connector 122-3, and the magnetic circuit connector 122-3 is bent and formed from the outer peripheral edge of the first magnetic conductive plate 122-22 towards the side where the second magnetic conductive plate 122-13 is located along the vibration direction. Correspondingly, the second magnetic conductive plate 122-13 is provided with a fixing structure (such as a groove structure, a notch structure, etc.), which fixes the end of the magnetic circuit connector 122-3 away from the first magnetic conductive plate 122-22 to the second magnetic conductive plate 122-13, thereby facilitating the processing and manufacturing difficulty of the magnetic circuit assembly and even the loudspeaker 120.

[0267] In some embodiments, the magnetic circuit connector 122-3 and the corresponding magnetic conductive plate can also adopt a split combination structure, for example, the surface of the first magnetic conductive plate 122-22 facing the first inner magnet 122-21 is provided with a receiving groove accommodating the magnetic circuit connector 122-3, the magnetic circuit connector 122-3 is inserted into the receiving groove in a stacked form, and the end of the magnetic circuit connector 122-3 extends out of the receiving groove and connects the second magnetic conductive plate 122-13; for another example, the magnetic circuit connector 122-3 is fixed in a stacked manner on the surface of the first magnetic conductive plate 122-22 facing the first inner magnet 122-21, and the two ends of the magnetic circuit connector 122-3 in the long axis direction extend out of the space between the first magnetic conductive plate 122-22 and the first inner magnet 122-21 and connect the second magnetic conductive plate 122-13.

[0268] In this way, the structural connection area between the magnetic circuit connecting piece 122-3 and the corresponding magnetic conducting plate can be effectively increased, and the structural connection strength between the magnetic circuit connecting piece 122-3 and the corresponding magnetic conducting plate can be enhanced, so that the magnetic circuit connecting piece 122-3 can establish a stable structural connection relationship between the outer magnetic circuit piece 122-1 and the inner magnetic circuit piece 122-2.

[0269] In other embodiments, the magnetic circuit connecting piece 122-3 can also adopt an integrated structure or a split combined structure, which is connected between the third magnetic conducting plate 122-23 and the fourth magnetic conducting plate 122-12, and will not be described here.

[0270] In some embodiments, the outer magnetic circuit piece 122-1 can omit the first outer magnetic body 122-11, and the outer magnetic circuit piece 122-1 includes a magnetic conducting ring, which is equivalent to a magnetic conducting ring based on the fourth magnetic conducting plate 122-12 and the second magnetic conducting plate 122-13 being configured as an integrated ring structure. The magnetic conducting ring is wrapped around the outer periphery of the inner magnetic circuit piece 122-2, thereby forming a magnetic gap therebetween; and the magnetic circuit connecting piece 122-3 is connected between the first magnetic conducting plate 122-22 and the magnetic conducting ring along the vibration direction through the avoidance passage 121-3 and the magnetic gap. At least one of the first magnetic conducting plate 122-22 and the magnetic conducting ring can be an integrated structure with the magnetic circuit connecting piece 122-3, or can be a split combined structure. In this way, the number of components of the magnetic circuit assembly can be reduced, and the structural stability of the magnetic circuit assembly can be enhanced.

[0271] In some embodiments, the magnetic circuit connecting piece 122-3 can be made of a weak magnetic conducting material or a non-magnetic conducting material, for example, the magnetic circuit connecting piece 122-3 is made of a spring steel material with high rigidity and weak magnetic conductivity. In this way, the magnetic circuit short circuit between the inner magnetic circuit piece 122-2 and the outer magnetic circuit piece 122-1 can be avoided, or the magnetic circuit connecting piece 122-3 can avoid the magnetic field shunt effect, so as to make the magnetic field pass through the magnetic gap as much as possible, thereby improving the driving force on the voice coil assembly. At the same time, under the premise of ensuring the structural strength of the magnetic circuit assembly, the thickness of the magnetic circuit connecting piece 122-3 can be thinned (for example, perforated or lightened), so that the size of the outer magnetic circuit piece 122-1 (for example, the first outer magnetic body 122-11) can be increased, the electromagnetic conversion efficiency (i.e., the BL value) of the loudspeaker 120 can be improved, and the vibration effect of the vibration can be ensured.

[0272] In some embodiments, all or part of the magnetic conductive plates in the magnetic circuit assembly can also be omitted; for example, when the first magnetic conductive plate 122-22, the third magnetic conductive plate 122-23, the fourth magnetic conductive plate 122-12, and the second magnetic conductive plate 122-13 are omitted, the magnetic circuit connecting piece 122-3 is directly connected between the first outer magnetic body 122-11 and the first inner magnetic body 122-21; specifically, the magnetic circuit connecting piece 122-3 can be made of weakly magnetic or non-magnetic material (such as spring steel material), and the two ends of the magnetic circuit connecting piece 122-3 in the vibration direction are connected with the first outer magnetic body 122-11 and the first inner magnetic body 122-21, respectively. For another example, when the third magnetic conductive plate 122-23 and the fourth magnetic conductive plate 122-12 are omitted, the two ends of the magnetic circuit connecting piece 122-3 in the vibration direction are connected with the first magnetic conductive plate 122-22 and the second magnetic conductive plate 122-13, respectively (for example, the magnetic circuit connecting piece 122-3 can be integrated with at least one of the first magnetic conductive plate 122-22 and the second magnetic conductive plate 122-13); and so on, which will not be repeated here.

[0273] It is considered that the magnetic circuit assembly will affect the electromagnetic conversion efficiency of the loudspeaker 120, thereby affecting the output performance of the loudspeaker 120, and further affecting the active noise reduction effect of the earphone; therefore, by designing the size and relationship of the related components in the magnetic circuit assembly, the performance of the loudspeaker 120 and the active noise reduction effect of the earphone can be improved.

[0274] Please refer to FIG. 36 and FIG. 41, FIG. 36 is a schematic diagram of the electromagnetic conversion efficiency (i.e. BL value) of the loudspeaker with different sizes of the inner magnetic circuit piece 122-2 and the outer magnetic circuit piece 122-1 according to some embodiments of the present application; wherein the data in FIG. 36 is measured under the condition that the width of the magnetic gap is 1.1 mm and the width of the magnetic circuit connecting piece 122-3 is 0.7 mm.

[0275] Referring to FIG. 37, a ratio of the width Wim of the inner magnetic circuit member 122-2 to the width Wom of the outer magnetic circuit member 122-1 is defined as Wim / Wom. In FIG. 36, L701 represents the BL value of the speaker 120 when Wim / Wom is 0.32, L702 represents the BL value of the speaker 120 when Wim / Wom is 0.56, L703 represents the BL value of the speaker 120 when Wim / Wom is 0.85, L704 represents the BL value of the speaker 120 when Wim / Wom is 1.22, L705 represents the BL value of the speaker 120 when Wim / Wom is 1.70, L706 represents the BL value of the speaker 120 when Wim / Wom is 2.35, L707 represents the BL value of the speaker 120 when Wim / Wom is 3.28, L708 represents the BL value of the speaker 120 when Wim / Wom is 4.70, L709 represents the BL value of the speaker 120 when Wim / Wom is 7.19, L710 represents the BL value of the speaker 120 when Wim / Wom is 15.59, and L711 represents the BL value of the speaker 120 when Wim / Wom is 33.43.

[0276] Here, referring to FIG. 37, the width refers to a size parameter of a related component in a direction perpendicular to the vibration direction, for example, the width of the outer magnetic circuit member 122-1 refers to the distance between the outer surface and the inner surface of the outer magnetic circuit member 122-1, and the width of the inner magnetic circuit member 122-2 refers to the width of the cross section of the inner magnetic circuit member 122-2.

[0277] As shown in FIG. 36, the BL value of the speaker 120 is optimal when the ratio of the width of the inner magnetic circuit member 122-2 to the width of the outer magnetic circuit member 122-1 is 7.19, and the BL value of the speaker 120 decreases as the ratio of the width of the inner magnetic circuit member 122-2 to the width of the outer magnetic circuit member 122-1 continues to increase.

[0278] Therefore, by designing the size ratio of the outer magnetic circuit member 122-1 and the inner magnetic circuit member 122-2, the electromagnetic conversion efficiency of the speaker 120 can be ensured, and the driving force of the voice coil assembly can be improved.

[0279] For example, the size of the speaker 120 in the long axis direction is greater than the size in the short axis direction, and in this case, the ratio of the length of the inner magnetic circuit member 122-2 (for example, the first inner magnetic body 122-21) in the long axis direction to the thickness of the side wall of the outer magnetic circuit member 122-1 (for example, the first outer magnetic body 122-11 or the magnetic conductive ring) in the long axis direction is between 1.7 and 33, and the ratio of the width of the inner magnetic circuit member 122-2 in the short axis direction to the thickness of the side wall of the outer magnetic circuit member 122-1 in the short axis direction is between 1.7 and 33.

[0280] Furthermore, in some embodiments, the ratio of the length of the first inner magnet 122-21 in the long axis direction to the thickness of the sidewall of the first outer magnet 122-11 in the long axis direction may not exceed 6.7, and the ratio of the width of the first inner magnet 122-21 in the short axis direction to the thickness of the sidewall of the first outer magnet 122-11 in the short axis direction may not exceed 2.7. This can significantly improve the BL value of the speaker 120, thereby enhancing the sound output performance of the speaker 120.

[0281] For example, the speaker 120 has a circular outline, and the ratio of the thickness of the inner magnetic circuit element 122-2 (e.g., the first inner magnet 122-21) in the radial direction (i.e., the direction corresponding to the major axis or the minor axis) to the thickness of the sidewall of the outer magnetic circuit element 122-1 (e.g., the first outer magnet 122-11 or the magnetic ring) in the radial direction is between 1.7 and 33.

[0282] It should be noted that the sidewall thickness of the external magnetic circuit component 122-1 refers to the distance between the outer peripheral surface and the inner peripheral surface of the external magnetic circuit component 122-1.

[0283] Figures 38A and 38B are schematic diagrams illustrating the electromagnetic conversion efficiency of loudspeakers with magnets and magnetic plates of different sizes according to some embodiments of this application. Figure 38A shows the trend of electromagnetic conversion efficiency of loudspeaker 120 when the thickness of the magnet (e.g., the first inner magnet 122-21) is constant (e.g., 2 mm) and the thickness of the magnetic plate (e.g., the first magnetic plate 122-22) is changed. Figure 38B shows the trend of electromagnetic conversion efficiency of loudspeaker 120 when the thickness of the magnetic plate (e.g., the first magnetic plate 122-22) is constant (e.g., 0.7 mm) and the thickness of the magnet (e.g., the first inner magnet 122-21) is changed.

[0284] As shown in Figure 38A, the BL value of the loudspeaker 120 increases with the increase of the magnetic plate thickness (i.e., the ratio of the magnet thickness to the magnetic guide thickness, h_magnet / h_lead, decreases). However, when the magnetic plate thickness increases to a certain value, the BL value reaches its maximum value. Excessively increasing the magnetic plate thickness will cause the magnetic field lines to disperse and not be effectively concentrated near the voice coil, thus reducing the magnetic field near the voice coil. When the magnetic plate thickness decreases (i.e., the ratio of the magnet thickness to the magnetic guide thickness increases), the magnetic saturation of the magnetic plate will decrease, reducing the magnetic permeability and thus reducing the magnetic field strength passing through the voice coil. The BL value reaches its maximum value when the ratio of the magnet thickness to the magnetic guide thickness is 1.4, but when the ratio of the magnet thickness to the magnetic guide thickness is between 1 and 4, the BL value is relatively large.

[0285] As shown in Figure 38B, the BL value of the loudspeaker 120 increases with the increase of the magnet thickness (i.e., the ratio of the magnet thickness to the magnetic conductor thickness, h_magnet / h_lead, decreases), but the rate of increase of the BL value decreases. This may be because as the magnet thickness increases, the magnetic conductor plate becomes magnetically saturated, and further increasing the magnet thickness does not significantly increase the amount of magnetic field that can be gathered through the magnetic conductor plate and pass through the voice coil. Specifically, when the ratio of the magnet thickness to the magnetic conductor thickness is between 1 and 4, the BL value increases rapidly. When the ratio of the magnet thickness to the magnetic conductor thickness is greater than 4, the rate of increase slows down significantly, the magnetic conductor plate begins to become magnetically saturated, and the overall electromagnetic conversion efficiency of the loudspeaker 120 is reduced.

[0286] Therefore, in order to improve the electromagnetic conversion efficiency of the loudspeaker 120, in some embodiments, the ratio of the thickness of the first inner magnet 122-21 to the thickness of the first magnetic plate 122-22 (and the third magnetic plate 122-23) can be between 1 and 4, and the ratio of the thickness of the first outer magnet 122-11 to the thickness of the fourth magnetic plate 122-12 (and the second magnetic plate 122-13) can be between 1 and 4.

[0287] In some embodiments, referring to Figures 26 to 29, the magnetic circuit assembly further includes a support assembly, which may include a first support 122-4 and a second support 122-5. The first support 122-4 is connected to the outer periphery of the fourth magnetic plate 122-12, and the second support 122-5 is connected to the outer periphery of the second magnetic plate 122-13. The first support 122-4 and the fourth magnetic plate 122-12, as well as the second support 122-5 and the second magnetic plate 122-13, can be connected by injection molding, adhesive, bolts, snaps, or other means. The outer periphery of the first diaphragm 121-1 is fixed to the first support 122-4 (e.g., with adhesive), and the outer periphery of the second diaphragm 121-2 is fixed to the second support 122-5 (e.g., with adhesive).

[0288] On the one hand, by combining the first bracket 122-4, the second bracket 122-5 and the external magnetic circuit component 122-1, the basket in some existing loudspeakers or the frame 125 mentioned in the aforementioned embodiments can be replaced, which can make the first external magnet 122-11 have a larger volume size, enhance the magnetic flux, and thus enhance the driving force of the voice coil assembly; at the same time, it can also make the structure of the loudspeaker 120 more compact, reduce the assembly difficulty and improve the assembly effect.

[0289] On the other hand, by means of the cooperation of the first bracket 122-4 and the second bracket 122-5, as well as the magnetic plate and the diaphragm, the internal space of the speaker 120 can be enclosed to form a relatively closed cavity (i.e., the common cavity 111-3). The first bracket 122-4 and the second bracket 122-5 can serve as structural connection carriers between the speaker 120 and the first housing 110 or between the speaker 120 and the limiting component 130, so as to securely confine the speaker 120 inside the first housing 110 and form a first acoustic cavity 111-1 and a second acoustic cavity 111-2 that are relatively independent of the common cavity 111-3.

[0290] In some embodiments, referring to Figure 29, the first bracket 122-4 has a first receiving groove surrounding the fourth magnetic plate 122-12, and the second bracket 122-5 has a second receiving groove surrounding the second magnetic plate 122-13; wherein, the outer periphery of the fourth magnetic plate 122-12 is inserted into the first receiving groove, and the outer periphery of the second magnetic plate 122-13 is inserted into the second receiving groove; exemplaryly, the first bracket 122-4 can be integrally formed on the fourth magnetic plate 122-12 by injection molding, die-cutting or other methods, and the first bracket 122-4 covers the outer periphery of the fourth magnetic plate 122-12, in which case the first receiving groove is equivalent to being naturally formed in the first bracket 122-4.

[0291] Based on the set receiving groove, the structural connection area between the bracket and the corresponding magnetic plate is effectively increased, so that the bracket and the corresponding magnetic plate can be stably combined into one piece (for example, the bracket and the corresponding magnetic plate are integrally injection molded), which helps to reduce the number of parts of the speaker 120 and reduce the assembly difficulty of the speaker 120.

[0292] In some embodiments, referring to Figures 27 and 29, the first support 122-4, the fourth magnetic plate 122-12, and the first diaphragm 121-1 together form a first chamber 120a inside the speaker 120, and the second support 122-5, the second magnetic plate 122-13, and the second diaphragm 121-2 together form a second chamber 120b inside the speaker 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 the two are located on both sides of the magnetic circuit assembly in the vibration direction.

[0293] At this point, please refer to Figure 29. The first bracket 122-4 and the second bracket 122-5 are each provided with a positioning structure 120c and a through-hole structure 120d. For ease of distinction and description, the positioning structure 120c and the through-hole structure 120d provided on the first bracket 122-4 are respectively defined as the first positioning structure and the first through-hole structure, and the positioning structure 120c and the through-hole structure 120d provided on the second bracket 122-5 are respectively defined as the second positioning structure and the second through-hole structure.

[0294] The first positioning structure is located within the first chamber 120a and is primarily used to position and restrict the wire of the first voice coil 123-1 onto the first bracket 122-4 within the first chamber 120a. The first through-hole structure penetrates the side wall of the first bracket 122-4 (e.g., the side wall in the short axis direction) so that the wire of the first voice coil 123-1 can be led out from the inside of the speaker 120 and connected to the circuit board 150 located around the speaker 120 (this circuit board 150 enables electrical connection between the speaker 120 and the microphone assembly and the headphone circuit board assembly). Similarly, the second positioning structure is located within the second chamber 120b and is primarily used to position and restrict the wire of the second voice coil 123-2 onto the second bracket 122-5 within the second chamber 120b. The second through-hole structure penetrates the side wall of the second bracket 122-5 so that the wire of the second voice coil 123-2 can be led out from the inside of the speaker 120 and connected to the circuit board 150.

[0295] Therefore, through the cooperation between the corresponding chamber, support, positioning structure 120c, and through-hole structure 120d, the overall compactness of the loudspeaker 120 can be effectively enhanced, and the voice coil wire can be restricted to avoid interference with the diaphragm vibration. In specific implementation, the positioning structure 120c can be a mechanical structure such as a clip set on the corresponding support, or it can be a structure formed by fixing the voice coil wire with adhesive.

[0296] In some embodiments, referring to Figure 37, the first support 122-4 and the second support 122-5 are separately arranged in the vibration direction, thus forming an accommodating gap between them that surrounds the outer magnetic circuit component 122-1 (specifically, the first outer magnet 122-11). The circuit board 150 can be housed and fixed within this accommodating gap, for example, by attaching it to the outer peripheral surface of the first outer magnet 122-11. This effectively reduces the overall size of the speaker 120, further enhancing its structural compactness.

[0297] As described in some of the embodiments above, a limiting component 130 is provided between the first housing 110 and the speaker 120; in this case, referring to FIG29, a space for accommodating sealant can be formed at the junction of the limiting component 130 and the speaker 120. For example, the peripheral sidewall of the first cover 133 surrounds the outer periphery of the first bracket 122-4 to form a space for accommodating sealant between the two, and the peripheral sidewall of the second cover 134 surrounds the outer periphery of the second bracket 122-5 to form a space for accommodating sealant between the two. By filling the space for accommodating sealant, a sealed and fixed connection between the limiting component 130 and the speaker 120 is achieved.

[0298] In this way, the sealant in the space can be used to enhance the stability and sealing of the connection between the limiting component 130 and the speaker 120, and the structural gap between the limiting component 130 and the speaker 120 can be eliminated, thereby enhancing the sealing of the first acoustic cavity 111-1 and the second acoustic cavity 111-2, and preventing sound leakage from the joint between the limiting component 130 and the speaker 120 from affecting the sound output of the headphones.

[0299] In some embodiments, referring to FIG29, one or both of the first bracket 122-4 and the second bracket 122-5 are provided with an air pressure balancing channel 120e. The air pressure balancing channel 120e can be arranged to pass through the corresponding bracket in a direction perpendicular to the vibration direction (e.g., the major axis direction, the minor axis direction, etc.), so that the air pressure balancing channel 120e connects the external space of the loudspeaker 120 with the common cavity 111-3 formed between the first bracket 122-4, the second bracket 122-5, the first diaphragm 121-1, the second diaphragm 121-2 and the external magnetic circuit member 122-1.

[0300] When the first diaphragm 121-1 and the second diaphragm 121-2 vibrate synchronously in the same direction, the air pressure balance channel 120e can ensure that the gas in the common cavity 111-3 moves back and forth with the vibration of the two diaphragms. This avoids the first diaphragm 121-1 and the second diaphragm 121-2 from affecting the peaks and valleys of the frequency response curve due to the compression of the gas in the common cavity 111-3, thereby improving the sound output quality of the headphones and thus improving the active noise cancellation effect of the headphones.

[0301] Meanwhile, when the first diaphragm 121-1 and the second diaphragm 121-2 vibrate inconsistently (e.g., vibrating in opposite directions, or vibrating with different amplitudes), the air pressure balance channel 120e can be used to balance the internal and external air pressure of the common cavity 111-3, thereby preventing the gas in the common cavity 111-3 from interfering with the vibration of the first diaphragm 121-1 and the second diaphragm 121-2, and ensuring sound output.

[0302] In some embodiments, the air pressure balance channel 120e can be sealed with a mesh, a waterproof and breathable membrane, etc., to improve the waterproof performance of the speaker 120.

[0303] In some embodiments where the first diaphragm 121-1 and the second diaphragm 121-2 are connected by a voice coil assembly, the magnetic circuit assembly and the voice coil assembly may also adopt other structural combinations to ensure the consistency of synchronous and unidirectional vibration of the two diaphragms, thereby providing support for the shift of the peak resonant frequency of the first resonant peak to the lower frequency range and the shift of the peak resonant frequency of the second resonant peak to the higher frequency range.

[0304] Referring to Figure 39A, the magnetic circuit assembly may include a magnetic shield 1221 and a second inner magnet 1222. The second inner magnet 1222 may be disposed within the voice coil 123. The magnetic shield 1221 and the second inner magnet 1222 are spaced apart in a direction perpendicular to the vibration direction. The sidewall of the magnetic shield 1221 may be a folded structure with an opening facing the bottom of the magnetic shield 1221. The folded structure includes an inner sidewall 12211 and an outer sidewall 12212 of the magnetic shield 1221. A first magnetic gap is formed between the inner sidewall 12211 and the second inner magnet 1222, and at least a portion of the first voice coil 123-1 is located within the first magnetic gap. A second magnetic gap is formed between the inner sidewall 12211 and the outer sidewall 12212 of the magnetic shield 1221, and at least a portion of the second voice coil 123-2 is located within the second magnetic gap. Meanwhile, the first voice coil 123-1 is connected to the first diaphragm 121-1 to drive the first diaphragm 121-1 to vibrate and produce sound; the second voice coil 123-2 is connected to the second diaphragm 121-2 to drive the second diaphragm 121-2 to vibrate and produce sound.

[0305] In this way, by using different voice coils to drive the first diaphragm 121-1 and the second diaphragm 121-2 to vibrate respectively, the first diaphragm 121-1 and the second diaphragm 121-2 can vibrate synchronously and generate sound. For example, the sounds generated and output by the two diaphragms can be superimposed to enhance the output performance of the headphones and improve the effect of active noise cancellation for larger ambient noises. Furthermore, by adjusting the resonant frequency of the headphones, the distortion of the headphone output can be reduced, so that the headphones have a flatter output over a wider frequency range, thereby enhancing the active noise cancellation effect.

[0306] In some embodiments, referring to Figure 39B, a second outer magnet 1223 is disposed on the outer wall 12212 of the magnetic shield 1221. The magnetization direction of the second outer magnet 1223 may be the same as or opposite to the magnetization direction of the second inner magnet 1222. For example, the N pole of the second inner magnet 1222 may be located at the upper end, and the N pole of the second outer magnet 1223 may be located at the upper end (as shown in Figure 39B). Alternatively, the N pole of the second inner magnet 1222 may be located at the upper end, and the N pole of the second outer magnet 1223 may be located at the lower end (as shown in Figure 39G).

[0307] Because the second voice coil 123-2 is relatively far from the second inner magnet 1222, the magnetic field strength near the second voice coil 123-2 is relatively weak, which may result in insufficient driving force for the second voice coil 123-2. Therefore, by setting the second outer magnet 1223, the magnetic field strength near the second voice coil 123-2 can be increased, thereby improving the driving force of the second voice coil 123-2. This helps to improve the output of the speaker 120 and the active noise cancellation effect of the headphones against larger ambient noise.

[0308] In some embodiments, when the magnetization directions of the second inner magnet 1222 and the second outer magnet 1223 are the same (e.g., the N poles are both located at the upper end as shown in Figure 39B), the inner sidewall 12211 of the magnetic shield 1221 is subjected to the combined action of the second inner magnet 1222 and the second outer magnet 1223, and the inner sidewall 12211 exhibits magnetic field saturation, which limits the increase in magnetic field strength at the locations of the first voice coil 123-1 and the second voice coil 123-2, thus affecting the driving force of the first voice coil 123-1 and the second voice coil 123-2.

[0309] Therefore, to avoid the magnetic circuit assembly becoming too large, the size of the second inner magnet 1222 can be reduced while keeping the size of the magnetic circuit assembly unchanged (i.e., the width of the magnetic shield 1222 unchanged), thereby increasing the size of the inner wall 12211. This helps to minimize magnetic field saturation in the inner wall 12211, thereby increasing the magnetic field strength at the locations of the first voice coil 123-1 and the second voice coil 123-2, and ultimately increasing the driving force of the speaker 120. For example, referring to Figures 39B and 39C, the ratio of the thickness of the inner wall 12211 to the width of the magnetic shield 1222 can be 0.05-0.16. Furthermore, to further increase the driving force of the speaker 120, the ratio of the thickness of the inner wall 12211 to the width of the magnetic shield 1222 can be 0.06-0.15.

[0310] Furthermore, while keeping the dimensions of the magnetic circuit assembly constant (i.e., the width of the magnetic shield 1222 constant), the thickness of the inner wall 12211 can be negatively correlated with the radius of the second inner magnet 1222. For example, when the width of the magnetic shield 1222 is 16mm (at which point the radius of the magnetic shield 1222 is 8mm), the thickness of the inner wall 12211 can be 0.8mm-2.5mm; specifically, when the radius of the second inner magnet 1222 is greater than 2.35mm, the thickness of the inner wall 12211 can be 2mm-2.5mm; when the radius of the second inner magnet 1222 is greater than 2.85mm, the thickness of the inner wall 12211 can be 1.5mm-2.5mm; and when the radius of the second inner magnet 1222 is greater than 3.35mm, the thickness of the inner wall 12211 can be 1. The thickness of the inner wall 12211 can be 1.1mm-2.5mm when the radius of the second inner magnet 1222 is greater than 3.85mm; when the radius of the second inner magnet 1222 is greater than 4.35mm, the thickness of the inner wall 12211 can be 1mm-2mm; when the radius of the second inner magnet 1222 is greater than 4.85mm, the thickness of the inner wall 12211 can be 0.8mm-1.6mm; when the radius of the second inner magnet 1222 is greater than 5.35mm, the thickness of the inner wall 12211 can be 0.8mm-1.3mm.

[0311] In some embodiments, as shown in Figure 39D, the second outer magnet 1223 is disposed on the inner sidewall 12211 to prevent magnetic field saturation on the inner sidewall 12211, ensuring the magnetic field strength at the locations of the first voice coil 123-1 and the second voice coil 123-2, thereby increasing the driving force of the speaker 120. In this case, the magnetization direction of the second outer magnet 1223 can be the same as or opposite to the magnetization direction of the second inner magnet 1222.

[0312] In some embodiments, referring to Figure 39E, to further enhance the magnetic field strength at the locations of the first voice coil 123-1 and the second voice coil 123-2, thereby increasing the driving force of the speaker 120, a second external magnet 1223 is provided on both the inner wall 12211 and the outer wall 12212 of the magnetic shield 1221. For ease of distinction and description, the second external magnet 1223 provided on the inner wall 12211 is defined as the third external magnet 1223-1, and the second external magnet 1223 provided on the outer wall 12212 is defined as the fourth external magnet 1223-2. In this case, the magnetization directions of the second inner magnet 1222, the third external magnet 1223-1, and the fourth external magnet 1223-2 can be the same or opposite.

[0313] For example, the magnetization directions of the second inner magnet 1222 and the third outer magnet 1223-1 can be the same, and the magnetization directions of the second inner magnet 1222 and the fourth outer magnet 1223-2 can be the same; or, the magnetization directions of the second inner magnet 1222 and the third outer magnet 1223-1 can be the same, and the magnetization directions of the second inner magnet 1222 and the fourth outer magnet 1223-2 can be opposite; or, the magnetization directions of the second inner magnet 1222 and the third outer magnet 1223-1 can be opposite, and the magnetization directions of the second inner magnet 1222 and the fourth outer magnet 1223-2 can be the same; or, the magnetization directions of the second inner magnet 1222 and the third outer magnet 1223-1 can be opposite, and the magnetization directions of the second inner magnet 1222 and the fourth outer magnet 1223-2 can be opposite.

[0314] In some embodiments, referring to Figure 39F, when a second outer magnet 1223 is disposed on the outer wall 12212 of the magnetic shield 1221, and the magnetization directions of the second inner magnet 1222 and the second outer magnet 1223 are opposite (for example, the N pole of the second inner magnet 1222 can be located at the upper end, and the N pole of the second outer magnet 1223 can be located at the lower end), the inner wall 12211 of the magnetic shield 1221 exhibits a magnetic field zero pole, and the inner wall 12211 is not responsible for magnetic conduction. In this case, the inner wall 12211 of the magnetic shield 1221 mainly serves a connecting and supporting function.

[0315] In some embodiments, as shown in FIG39G, the thickness of the inner sidewall 12211 of the magnetic shield 1221 can be designed to be smaller, or the inner sidewall 12211 can be perforated or hollowed out; for example, the size of the inner sidewall 12211 of the magnetic shield 1221 can be designed to be 0, that is, the inner sidewall 12211 structure is eliminated. This can reduce the mass and size of the speaker 120.

[0316] In some embodiments, since the second outer magnet 1223 and the second inner magnet 1222 need to be connected, the annular sidewall of the magnetic shield 1221 needs to retain at least a portion of the inner sidewall 12211 to connect the outer sidewall 12212 to the bottom of the magnetic shield 1221. Therefore, the outer sidewall 12212 of the long side of the magnetic shield 1221 can be connected to the bottom of the magnetic shield 1221 through the inner sidewall 12211, and the short side of the magnetic shield 1221 may not have an inner sidewall 12211.

[0317] In some embodiments, by designing the dimensions of the second inner magnet 1222 and the second outer magnet 1223, the magnetic field strength near the first voice coil 123-1 and the second voice coil 123-2 is made similar, ensuring that the driving forces of the first voice coil 123-1 and the second voice coil 123-2 are close or the same. This improves the vibration consistency between the first diaphragm 121-1 and the second diaphragm 121-2, thereby supporting the improvement of the output effect of the speaker 120 and the active noise cancellation effect of the headphones in the case of large ambient noise in the open-back wearing mode. For example, the volume ratio of the second outer magnet 1223 to the volume of the second inner magnet 1222 can be 0.3-3.

[0318] When the volume of the second outer magnet 1223 is too small relative to the volume of the second inner magnet 1222, the driving force of the second voice coil 123-2, which is closer to the second outer magnet 1223 and farther from the second inner magnet 1222, is smaller, while the driving force of the first voice coil 123-1, which is farther from the second outer magnet 1223 and closer to the second inner magnet 1222, is larger. This results in a large difference in driving force between the first voice coil 123-1 and the second voice coil 123-2. Similarly, when the volume of the second outer magnet 1223 is too large relative to the volume of the second inner magnet 1222, the driving force of the second voice coil 123-2, which is closer to the second outer magnet 1223 and farther from the second inner magnet 1222, is larger, while the driving force of the first voice coil 123-1, which is farther from the second outer magnet 1223 and closer to the second inner magnet 1222, is smaller. This also results in a large difference in driving force between the first voice coil 123-1 and the second voice coil 123-2.

[0319] In other words, when the volume difference between the second outer magnet 1223 and the second inner magnet 1222 is too large, it will result in a significant difference in driving force between the first voice coil 123-1 and the second voice coil 123-2, affecting the active noise cancellation effect of the headphones. Therefore, in order to further improve the vibration consistency between the first diaphragm 121-1 and the second diaphragm 121-2 and improve the active noise cancellation effect of the headphones, the ratio of the volume of the second outer magnet 1223 to the volume of the second inner magnet 1222 can be 0.5-1.5.

[0320] The following mainly describes the structure of the speaker 120 when the first diaphragm 121-1 and the second diaphragm 121-2 are directly fixedly connected to achieve synchronous and co-directional vibration of the two diaphragms. It can be understood that the direct connection between the first diaphragm 121-1 and the second diaphragm 121-2 can ensure the consistency of the vibration of the two diaphragms, thereby providing support for the shift of the peak resonant frequency of the first resonant peak to the lower frequency range and the shift of the peak resonant frequency of the second resonant peak to the higher frequency range, thus ensuring that the headphones can achieve active noise cancellation in a wider frequency range.

[0321] Please refer to Figures 40 to 42. The first diaphragm 121-1 and the second diaphragm 121-2 are directly connected by the second connector 126 so that the first diaphragm 121-1 and the second diaphragm 121-2 vibrate synchronously and in the same direction. For example, the magnetic circuit assembly may be provided with a through hole that passes through the second inner magnet 1222, the magnetic guide plate at the upper end of the second inner magnet 1222, and the bottom of the magnetic guide cover 1221 at the lower end of the second inner magnet 1222. The second connector 126 is disposed in the through hole, thereby connecting the first diaphragm 121-1 and the second diaphragm 121-2. The through-hole design allows the gas in the common cavity 111-3 between the first diaphragm 121-1 and the second diaphragm 121-2 to move back and forth as an accompanying mass with the vibration of the two diaphragms when the first diaphragm 121-1 and the second diaphragm 121-2 vibrate. This minimizes the compression of the common cavity 111-3 by the two diaphragms and avoids affecting the peaks and valleys of the resonance peaks of the frequency response curve, thereby improving the output quality of the headphones and thus enhancing the active noise cancellation effect of the headphones.

[0322] In some embodiments where the magnetic circuit assembly is formed by combining an outer magnetic circuit component and an inner magnetic circuit component, the through hole can pass through the first magnetic guide plate, the inner magnet, and the second magnetic guide plate, so that the second connector 126 can pass through the inner magnetic circuit component and connect between the first diaphragm 121-1 and the second diaphragm 121-2; this will not be elaborated here.

[0323] In some embodiments, the second connector 126 needs to have high deformation resistance to minimize its own deformation while ensuring the connection between the first diaphragm 121-1 and the second diaphragm 121-2, thereby improving the vibration consistency between the first diaphragm 121-1 and the second diaphragm 121-2. For example, the Young's modulus of the material of the second connector 126 can be 100MPa-150MPa. To further improve the vibration consistency between the first diaphragm 121-1 and the second diaphragm 121-2, the Young's modulus of the material of the second connector 126 can be 110MPa-140MPa, for example, 120MPa.

[0324] In some embodiments, considering the need to improve the vibration consistency between the first diaphragm 121-1 and the second diaphragm 121-2, the contact areas between the two ends of the second connector 126 and the first diaphragm 121-1 and the second diaphragm 121-2 should not be too small, so as to better transmit deformation and power between the first diaphragm 121-1 and the second diaphragm 121-2. However, if the size of the second connector 126 is too large, it will result in an excessively large through-hole size in the magnetic circuit assembly, affecting the driving force coefficient of the speaker 120 and thus affecting the output of the speaker 120.

[0325] Therefore, in order to ensure that the speaker 120 has a large driving force coefficient while improving the vibration consistency between the first diaphragm 121-1 and the second diaphragm 121-2, the dimensions of the second connector 126 can be 3.4mm*1.4mm*4.7mm.

[0326] In some embodiments, to avoid the second connector 126 placing excessive load on the first diaphragm 121-1 and the second diaphragm 121-2, and to ensure the driving force coefficient of the speaker 120, the mass of the second connector 126 should be relatively small. That is, given a fixed size, the density of the second connector 126 should not be too high. Therefore, to reduce the load on the first diaphragm 121-1 and the second diaphragm 121-2, the density of the second connector 126 can be between 100 kg / m³ and 140 kg / m³. Furthermore, to further reduce the load on the first diaphragm 121-1 and the second diaphragm 121-2, the density of the second connector 126 can be between 105 kg / m³ and 120 kg / m³, for example, 110 kg / m³.

[0327] Figure 43 is a schematic diagram of the driving force coefficient of the loudspeaker 120 corresponding to different sizes of through holes according to some embodiments of this application; wherein, taking the second connector 126 as a prism of 3.4mm*1.4mm*4.7mm as an example, the driving force coefficient of the loudspeaker 120 shown in Figure 43 is measured when the through hole size is 0mm*0mm, 2mm*1mm, 4mm*2mm, 5mm*2.5mm, 6mm*3mm, and 10mm*5mm respectively.

[0328] Where the through hole size is 0mm*0mm, it means that no through hole is made. In this case, it can be regarded that the first diaphragm 121-1 and the second diaphragm 121-2 are not directly connected through the second connector 126, but the first voice coil 123-1 and the second voice coil 123-2 are connected, thereby indirectly connecting the first diaphragm 121-1 and the second diaphragm 121-2 (as shown in Figure 44).

[0329] As shown in Figure 43, the larger the size of the through hole, the smaller the driving force coefficient of the speaker 120. Taking the driving force coefficient of the speaker 120 when the through hole size is 0mm*0mm as the benchmark; when the through hole size is 2mm*1mm, the effect on the driving force coefficient of the speaker 120 is negligible; when the through hole size is 4mm*2mm, the driving force coefficient of the speaker 120 decreases by 0.1, which is a small decrease; when the through hole size is 6mm*3mm, the driving force coefficient of the speaker 120 decreases by 0.15.

[0330] Since the second connector 126 is provided through a through hole, the size of the through hole will also affect the size of the second connector 126. If the size of the through hole 126 is too small, the size of the second connector 126 may be too small, the connection strength of the second connector 126 may be insufficient, and the second connector 126 may be prone to breakage and damage.

[0331] Taking all factors into consideration, in some embodiments, in order to enable the speaker 120 to have a large driving force coefficient, the second connector 126 has a suitable size, the length of the through hole can be 2mm-10mm, and the width can be 1mm-5mm.

[0332] In some embodiments, while the first diaphragm 121-1 and the second diaphragm 121-2 are directly connected via the second connector 126, the first voice coil 123-1 and the second voice coil 123-2 can also be connected via the first connector 127. The first connector 127 can prevent relative displacement between the first voice coil 123-1 and the second voice coil 123-2, thereby further improving the vibration consistency between the first diaphragm 121-1 and the second diaphragm 121-2.

[0333] Thus, by directly connecting the first diaphragm 121-1 to the second diaphragm 121-2 and directly connecting the first voice coil 123-1 to the second voice coil 123-2, the probability of separation between the first diaphragm 121-1 and the second diaphragm 121-2 can be further reduced, improving the vibration consistency between the first diaphragm 121-1 and the second diaphragm 121-2. Simultaneously, the direct connection between the first diaphragm 121-1 and the second diaphragm 121-2 via the second connector 126 also reduces the difficulty of achieving precise alignment when connecting the first voice coil 123-1 and the second voice coil 123-2, thereby reducing operational complexity.

[0334] In other embodiments, referring to Figure 44, when the magnetic circuit assembly has a through hole, the first diaphragm 121-1 and the second diaphragm 121-2 may not be directly connected through the second connector 126. Instead, the first voice coil 123-1 and the second voice coil 123-2 are connected through the first connector 127, so that the first diaphragm 121-1 and the second diaphragm 121-2 are indirectly connected. In this case, the through hole can further ensure that the gas in the common cavity 111-3 between the first diaphragm 121-1 and the second diaphragm 121-2 can move back and forth as an accompanying mass with the vibration of the two diaphragms, thereby minimizing the compression of the common cavity 111-3 by the two diaphragms, resulting in frequency response peaks and valleys, improving the output quality of the headphones, and enhancing the active noise cancellation effect of the headphones.

[0335] As in some of the aforementioned embodiments, the second outer magnet 1223 is disposed on the magnetic shield 1221. In this case, when the long side portion and the short side portion of the second outer magnet 1223 are separate structures, in order to fix the second outer magnet 1223 and prevent it from falling off, the magnetic circuit assembly may include a frame 125. The frame 125 is disposed around the second outer magnet 1223, and the frame 125 cooperates with the magnetic shield 1221 to fix the second outer magnet 1223.

[0336] As in some of the aforementioned embodiments, the magnetic circuit assembly may include a magnetic shield 1221, a second inner magnet 1222, a second outer magnet 1223, etc. By improving the design of the magnetic circuit structure, it is helpful to further enhance the driving force of the speaker 120.

[0337] For example, referring to Figures 45A to 45C, the second outer magnet 1223 can be a ring structure, surrounding the magnetic shield 1221. The ring structure of the second outer magnet 1223 allows it to have a larger volume, thereby increasing the magnetic flux and thus enhancing the driving force of the speaker 120. Furthermore, the ring structure of the second outer magnet 1223 also reduces assembly difficulty and improves assembly efficiency.

[0338] In some embodiments where the second outer magnet 1223 has a ring structure and is disposed on the magnetic shield 1221, the magnetic circuit assembly may not have a frame 125, but the second outer magnet 1223 may be installed and fixed by the upper fixing frame 128-1 and the lower fixing frame 128-2.

[0339] Specifically, referring to Figures 45A to 45C, the first diaphragm 121-1 can be fixed to the upper fixing frame 128-1, and the upper side of the second outer magnet 1223 is connected to the upper fixing frame 128-1 through the upper outer magnetic guide plate 128-3; the second diaphragm 121-2 can be fixed to the lower fixing frame 128-2, and the lower side of the second outer magnet 1223 is connected to the lower fixing frame 128-2 through the lower outer magnetic guide plate 128-4. At this time, the lower side of the second inner magnet 1222 is connected to the bottom of the magnetic guide cover 1221, and the upper side of the second inner magnet 1222 is connected to the inner magnetic guide plate 128-5. By designing the upper fixing bracket 128-1 and the lower fixing bracket 128-2, the frame 125 can be eliminated, thereby allowing the magnetic circuit assembly to have a larger design size, which will further increase the volume of the magnets (such as the second inner magnet 1222, the second outer magnet 1223, etc.) to further increase the driving force of the speaker 120.

[0340] In some embodiments, the upper fixing frame 128-1 and the lower fixing frame 128-2 can be made of plastic; and the upper fixing frame 128-1 and the lower fixing frame 128-2 can be connected to the corresponding magnetic plate by injection molding, adhesive, bolts, clips, etc. Of course, the upper fixing frame 128-1 and the lower fixing frame 128-2 can also be made of metal, and the upper fixing frame 128-1 and the lower fixing frame 128-2 can be connected to the corresponding magnetic plate by adhesive, welding, bolts, clips, etc.

[0341] In some embodiments, the outer magnetic plate corresponding to the second outer magnet 1223 (e.g., upper outer magnetic plate 128-3, lower outer magnetic plate 128-4, etc.) may include two interconnected components, one of which is used to connect with the corresponding fixing frame, and the other is used to connect with the second outer magnet 1223. The two components may be separately connected or integrally formed.

[0342] In some embodiments, referring to Figure 46A, the magnetic circuit assembly may further include a magnetic circuit fixing ring 129, which is sleeved on the outside of the upper fixing frame 128-1 and the lower fixing frame 128-2. The magnetic circuit fixing ring 129 connects the fixing frame, the corresponding outer magnetic plate, and the second outer magnet 1223 into a whole, further improving the installation stability of the magnetic circuit assembly, thereby enhancing the vibration stability of the speaker 120. The magnetic circuit fixing ring 129 and the corresponding fixing frame can be separately connected or integrally formed.

[0343] In some embodiments, please refer to Figure 46B, the magnetic circuit assembly may not have an upper fixing frame 128-1 and a lower fixing frame 128-2. Instead, a magnetic circuit fixing ring 129 can be used to replace the upper fixing frame 128-1 and the lower fixing frame 128-2, and the magnetic circuit assembly can be directly assembled and fixed by the magnetic circuit fixing ring 129, thereby reducing the assembly difficulty.

[0344] In some embodiments, the material of the magnetic circuit fixing ring 129 can be the same as that of the upper fixing frame 128-1 and the lower fixing frame 128-2, and the connection method between the magnetic circuit fixing ring 129 and the corresponding fixing frame or the corresponding outer magnetic plate can be the same as the connection method between the corresponding fixing frame and the corresponding outer magnetic plate.

[0345] In some embodiments, please refer to Figures 47A and 47B. The magnetic circuit fixing ring 129 may include two annular sub-rings. The two sub-rings are respectively disposed on the upper and lower sides of the second outer magnet 1223 to install and fix the upper and lower sides of the second outer magnet 1223 and the corresponding outer magnetic plate, fixing frame, etc.

[0346] In some embodiments, please refer to Figures 48A and 48B. The magnetic circuit fixing ring 129 may include two semi-circular sub-rings. The interval between the two sub-rings may be set in the direction of the short side of the speaker 120. In this case, the sub-rings may be installed and fixed on the long side of the outer magnetic plate, the corresponding long side of the second outer magnet 1223, and the corresponding long side of the fixing frame.

[0347] In other embodiments, the spacing between the two sub-rings can also be set in the direction of the long side of the speaker 120; in this case, the sub-rings can be installed and fixed on the short side and part of the long side of the outer magnetic plate, the corresponding short side and part of the corresponding long side of the second outer magnet 1223, and the corresponding short side and part of the corresponding long side of the mounting bracket.

[0348] As mentioned earlier, diaphragm design can also support active noise cancellation for headphones over a wide frequency range. For dual-diaphragm speakers, the structures of the two diaphragms need to be designed in a coordinated manner to ensure that the peak resonant frequency of the first resonant peak of the speaker 120 is low, while avoiding unnecessary distortion during resonance, thereby avoiding affecting the active noise cancellation effect of the headphones and achieving active noise cancellation support over a wide frequency range. Therefore, the following mainly introduces the diaphragm and its related structures.

[0349] In some embodiments, referring to FIG28, the loudspeaker 120 includes a first diaphragm 121-1, a second diaphragm 121-2, a support assembly, a voice coil assembly, and a magnetic circuit assembly, etc.; the first diaphragm 121-1 and the second diaphragm 121-2 are spaced apart and opposite each other in the vibration direction; the support assembly, the voice coil assembly, and the magnetic circuit assembly are disposed between the first diaphragm 121-1 and the second diaphragm 121-2, the support assembly surrounds the periphery of the voice coil assembly, and the support assembly and the voice coil assembly are spaced apart in a radial direction perpendicular to the vibration direction (for the sound-emitting part 100, this radial direction may include the major axis direction and the minor axis direction). The first diaphragm 121-1 and the second diaphragm 121-2 have the same structure and are symmetrically arranged along a reference plane perpendicular to the vibration direction. This arrangement ensures the consistency of the co-directional vibration of the first diaphragm 121-1 and the second diaphragm 121-2, thereby improving the stability of the loudspeaker 120 output.

[0350] In some embodiments, by designing the diaphragm (e.g., the first diaphragm 121-1, the second diaphragm 121-2) to adjust the first resonant peak of the speaker 120 at low frequencies (e.g., below 200Hz), the low-frequency output of the speaker 120 is improved, thereby enhancing the active noise cancellation effect of the headphones on low-frequency environmental noise.

[0351] Figure 63 shows the frequency response curves of headphones with different diaphragms according to some embodiments of this specification. Curve L401 represents the frequency response of the headphones with a PU (polyurethane) diaphragm of 0.35 mm thickness; curve L402 represents the frequency response of the headphones with a PU diaphragm of 0.45 mm thickness; and curve L403 represents the frequency response of the headphones with a PU diaphragm of 0.55 mm thickness. As shown in Figure 63, the low-frequency resonant peak of curve L401 is around 145 Hz, that of curve L402 is around 185 Hz, and that of curve L403 is around 230 Hz. Comparing curves L401, L402, and L403, the resonant frequencies corresponding to the low-frequency resonant peaks gradually decrease as the diaphragm thickness decreases. Therefore, in some embodiments, to enable the speaker 120 to have a flatter output over a wider frequency range and to improve the low-frequency output of the speaker 120, thereby enhancing the active noise cancellation effect of the headphones on low-frequency ambient noise, the low-frequency resonant frequency of the speaker 120 can be between 100Hz and 300Hz, and the diaphragm material can include PU material, with a diaphragm thickness of 0.2mm-0.07mm. In some embodiments, to further reduce the low-frequency resonant frequency of the speaker 120, when the diaphragm material is PU, the diaphragm thickness can be 0.35mm-0.55mm.

[0352] Furthermore, in some embodiments, in order to reduce the resonant frequency of the speaker 120 at low frequencies (e.g., below 300Hz), so that the speaker 120 has a flatter output over a wider frequency range, improve the low-frequency output of the speaker 120, and thereby improve the active noise cancellation effect of the headphones on low-frequency environmental noise, the diaphragm material may include liquid silicone, and the diaphragm thickness may be 0.055mm-0.1mm.

[0353] In some embodiments, for a dual-diaphragm loudspeaker, in order to reduce distortion caused by the unstable vibration of the first diaphragm 121-1 or the second diaphragm 121-2, the stability of the structural connection between the first diaphragm 121-1 or the second diaphragm 121-2 and related components can be optimized using component structure optimization. Referring to Figure 49, taking the first diaphragm 121-1 as an example, the first diaphragm 121-1 includes a diaphragm 1211, a center mount 1212, and a fixing ring 1213. The diaphragm 1211 is connected around the outer periphery of the center mount 1212, and the center mount 1212 is connected to the voice coil assembly (for example, the center mount 1212 of the first diaphragm 121-1 is bonded or welded to the first voice coil 123-1); the portion of the diaphragm 1211 radially away from the center mount 1212 is connected to the fixing ring 1213, and the support assembly is fixedly connected to the fixing ring 1213 (for example, the fixing ring 1213 of the first diaphragm 121-1 is bonded or welded to the first support 122-4).

[0354] It should be noted that the first diaphragm 121-1 and the second diaphragm 121-2, which are assembled from the diaphragm 1211, the center patch 1212, and the fixing ring 1213, can be understood as component structures. That is, the first diaphragm 121-1 can be called the first diaphragm assembly, and the second diaphragm 121-2 can be called the second diaphragm assembly. Taking the first diaphragm assembly as an example, the area occupied by the center patch 1212 on the first diaphragm 121-1 or the center patch 1212 itself can be regarded as the main area of ​​the first diaphragm 121-1, and the area occupied by the diaphragm 1211 on the first diaphragm 121-1 or the diaphragm 1211 itself can be regarded as the folded ring area of ​​the first diaphragm 121-1.

[0355] In some embodiments, the diaphragm 1211 may be made of silicone material. In some embodiments, the inlay 1212 may be made of one or more of magnesium-aluminum alloy, carbon fiber, aluminum-coated polymethacrylimide (PMI, also known as rigid foam) or polyethylene naphthalate (PEN).

[0356] This design, using silicone material with high temperature stability as the surround area of ​​the diaphragm 1211 or diaphragm assembly, effectively improves the temperature stability of the diaphragm assembly, ensuring the sound output and active noise cancellation effects of the speaker 120. Simultaneously, the use of the strong adhesive and high mechanical strength center patch 1212 to establish a structural connection between the voice coil assembly and the diaphragm 1211, and the use of the fixing ring 1213 to establish a structural connection between the support assembly and the diaphragm 1211, effectively enhances the structural stability between the diaphragm assembly and the voice coil assembly, overcoming the poor adhesive performance of silicone material. This ensures smooth vibration of the diaphragm assembly and voice coil assembly to produce sound while preventing the voice coil assembly and diaphragm assembly from detaching during vibration.

[0357] Due to the poor adhesive properties of silicone material, it is difficult to use glue to bond and fix the diaphragm 1211 to the center patch 1212 and the fixing ring 1213. In some embodiments, the diaphragm assembly (i.e., the first diaphragm 121-1 and the second diaphragm 121-2) can be a one-piece structure. For example, the diaphragm 1211, the center patch 1212, and the fixing ring 1213 can be integrally injection molded, which can effectively enhance the stability of the structural connection between the components of the diaphragm assembly.

[0358] Referring to Figures 50 and 51, in some embodiments, the diaphragm 1211 may include a first connecting portion 1211-1, a folded ring portion 1211-2, and a second connecting portion 1211-3; wherein, the first connecting portion 1211-1, the folded ring portion 1211-2, and the second connecting portion 1211-3 are connected sequentially from the inside to the outside in the radial direction, that is: the folded ring portion 1211-2 is connected around the outer periphery of the first connecting portion 1211-1, and the second connecting portion 1211-3 is connected around the outer periphery of the folded ring portion 1211-2.

[0359] Furthermore, in some embodiments, the diaphragm 1211 further includes a third connecting portion 1211-4 and a fourth connecting portion 1211-5; wherein, one end of the third connecting portion 1211-4 in the vibration direction is connected to the connection between the folded ring portion 1211-2 and the first connecting portion 1211-1, which can also be understood as the folded ring portion 1211-2 extending a certain length along the vibration direction toward one side of the magnetic circuit assembly to form the third connecting portion 1211-4; one end of the fourth connecting portion 1211-5 in the vibration direction is connected to the connection between the folded ring portion 1211-2 and the second connecting portion 1211-3, which can also be understood as the folded ring portion 1211-2 extending a certain length along the vibration direction toward one side of the magnetic circuit assembly to form the fourth connecting portion 1211-5.

[0360] In the vibration direction, the inner surface of the first connecting part 1211-1 is attached to the outer surface of the middle patch 1212, and the inner surface of the second connecting part 1211-1 is attached to the outer surface of the fixing ring 1213; in the radial direction, the inner circumferential surface of the third connecting part 1211-4 near the voice coil assembly is attached to the circumferential side of the middle patch 1212, and the outer circumferential surface of the fourth connecting part 1211-5 away from the voice coil assembly is attached to the inner circumferential surface of the fixing ring 1213.

[0361] For ease of distinction and description, in this document, the inner surface refers to the surface closer to the magnetic circuit assembly in the vibration direction, the outer surface refers to the surface farther from the magnetic circuit assembly in the vibration direction, the inner peripheral surface refers to the surface closer to the center point of the diaphragm 1211 in the radial direction, and the outer peripheral surface refers to the surface farther from the center point of the diaphragm 1211 in the radial direction. For example, the inner surface of the first connecting portion 1211-1 is defined as the first surface P1, the inner surface of the second connecting portion 1211-3 is defined as the second surface P2, the inner peripheral surface of the third connecting portion 1211-4 is defined as the third surface P3, the outer peripheral surface of the fourth connecting portion 1211-5 is defined as the fourth surface P4, and the outer peripheral surface of the third connecting portion 1211-4 is defined as the fifth surface P5.

[0362] With this configuration, based on the first surface P1 and the third surface P3, the diaphragm 1211 covers the outer surface and outer peripheral side of the mating center 1212. This can effectively increase the connection area between the diaphragm 1211 and the mating center 1212, enhance the connection strength between the diaphragm 1211 and the mating center 1212, and provide support for the structural connection between the inner surface of the mating center 1212 and the voice coil assembly.

[0363] In some embodiments, when the first surface P1 is bonded to the outer surface of the middle adhesive 1212, the outer surface of the middle adhesive 1212 can be completely covered and bonded by the first connecting portion 1211-1 or the first surface P1. Alternatively, the first connecting portion 1211-1 or the first surface P1 can also circumferentially cover and bond a portion of the outer surface of the middle adhesive 1212. In other embodiments, one or both of the third connecting portion 1211-4 and the fourth connecting portion 1211-5 may be omitted.

[0364] In some embodiments, when the outer surface and outer peripheral side of the middle patch 1212 are covered and bonded by the diaphragm 1211, the lower surface of the middle patch 1212 can also be covered and bonded by the diaphragm 1211 to further enhance the stability of the connection between the diaphragm 1211 and the middle patch 1212.

[0365] Specifically, the diaphragm 1211 also has a fifth connecting portion, which is spaced apart from the first connecting portion 1211-1 in the vibration direction, while the third connecting portion 1211-4 is connected between the fifth connecting portion and the surround portion 1211-2 in the vibration direction. In the vibration direction, the outer surface of the fifth connecting portion is bonded to the edge region of the inner surface of the center mount 1212, while the voice coil assembly is connected to the area of ​​the inner surface of the center mount 1212 not covered by the fifth connecting portion. Thus, the fifth connecting portion further enhances the stability of the structural connection between the diaphragm 1211 and the center mount 1212. To avoid the diaphragm 121b negatively affecting the connection between the voice coil assembly and the center mount 1212, the minimum radial distance between the fifth connecting portion and the voice coil assembly can be set to not less than 0.5 mm.

[0366] In some embodiments, referring to FIG50, the surround portion 1211-2 adopts an arched structure that protrudes from the outer surface of the center patch 1212 or the outer surface of the fixing ring 1213. For example, the surround portion 1211-2 is bent and arched relative to the first connecting portion 1211-1 in the vibration direction, away from the voice coil assembly. In this way, for the loudspeaker 120 as a whole, it is equivalent to the surround portion 1211-2 arching towards the outside of the loudspeaker 120. This not only provides ample space for the magnetic circuit assembly and the like inside the loudspeaker 120, allowing the magnetic circuit assembly to have a larger design size, which is beneficial to enhance the driving force of the magnetic circuit assembly and the voice coil assembly on the diaphragm assembly, but also avoids interference between the diaphragm 1211 and the sound-generating structure such as the magnetic circuit assembly due to deformation during vibration, thus ensuring the quality of sound output.

[0367] Figure 52 shows the BLx curve of the product of magnetic flux density (B) and voice coil length (L) of loudspeaker 120 as a function of the voice coil assembly movement distance (x). Referring to Figure 52, when the voice coil assembly moves to ±0.6 mm, the BLx curve changes by approximately 17%, and when the voice coil assembly moves to ±0.8 mm, the BLx curve changes by approximately 25%. Considering that the KMs curve of the diaphragm assembly is one of the key parameters affecting the distortion of loudspeaker 120, if the proportion of change in the corresponding KMs curve is within a similar range within the range of voice coil assembly movement distance, the BLx curve of loudspeaker 120 will have a better match with the KMs curve of the diaphragm assembly, which is beneficial to giving loudspeaker 120 a lower distortion. For example, when the shape of the KMs curve of the diaphragm assembly and the shape of the BLx curve are a matching "n" shape, the distortion of loudspeaker 120 is lower. Therefore, by designing the structure and dimensional relationships of the diaphragm assembly, the KMs curve of the diaphragm assembly can be adjusted to match the BLx curve of the speaker 120, thereby obtaining a speaker 120 with lower distortion, thus providing support for enhancing the active noise cancellation of the headphones; this will be explained in detail below.

[0368] In some embodiments, referring to FIG51, the minimum radial distance between the fifth surface P5 and the third surface P3 is defined as the first width Ldc, the minimum radial distance between the fifth surface P5 and the fourth surface P4 is defined as the second width Lm, and the ratio of the first width Ldc to the second width Lm is defined as the first ratio LL; the first ratio LL can be between 0.04 and 0.32, which enables the KMs curve of the diaphragm assembly to match the BLx curve of the speaker 120, thereby giving the speaker 120 a lower distortion.

[0369] Specifically, as the second width Lm changes, different first widths Lac will cause significant changes in the shape of the KMs curve of the diaphragm assembly, thereby affecting the distortion of the final speaker 120. Figure 53 shows the KMs curves for different first ratios LL. Referring to Figure 53, when the first ratio LL is small (i.e., when the connection area between the surround portion 1211-2 and the center patch 1212 is closer to the arc-shaped endpoint of the inner side of the surround portion 1211-2), the KMs curve of the diaphragm assembly is "U"-shaped. As the first ratio LL increases, the KMs curve of the diaphragm assembly gradually transitions from "U"-shaped to "n"-shaped, making the KMs curve match the BLx curve. When the first ratio LL is 0.04, although the KMs curve is "U"-shaped, the curve is relatively flat, indicating that the distortion of the speaker 120 is still relatively small. When the first ratio LL is 0.32, the "n"-shaped shape of the KMs curve matches the BLx curve of the speaker 120 better, indicating that the distortion of the speaker 120 is relatively small.

[0370] Therefore, setting the first ratio LL of the diaphragm 1211 to between 0.04 and 0.32 can effectively reduce the distortion of the speaker 120 and ensure that the speaker 120 can provide support for active noise cancellation of the headphones when in use.

[0371] Furthermore, in some embodiments, the first ratio LL can be set to 0.16 to enhance the matching between the KMs curve of the first diaphragm 121-1 and the KMs curve of the second diaphragm 121-2 and the BLx curve of the speaker 120, thereby obtaining a dual-diaphragm speaker with less distortion, thus providing support for improving the active noise cancellation effect of the headphones.

[0372] In some embodiments, referring to Figure 54, the minimum radial distance between the third surface P3 and the fourth surface P4 (i.e., the radial width or span of the folded ring portion 1211-2) is defined as the third width Lmar, and the ratio of the average wall thickness Tmar of the folded ring portion 1211-2 to the third width Lmar is defined as the second ratio TL. Considering the relationship between the width and wall thickness of the folded ring portion 1211-2, it not only affects the compliance (S) of the diaphragm assembly, and thus the f0 (i.e., the resonant frequency) of the loudspeaker 120, but also the KMs curve; therefore, the second ratio TL can be no greater than 0.12.

[0373] Specifically, Figure 55 shows the KMs curves for different second ratios TL. Referring to Figure 55, the smaller the second ratio TL (i.e., the thinner the average wall thickness of the surround portion 1211-2), the flatter the corresponding KMs curve. When the second ratio TL changes from 0.12 to 0.06, the shape of the corresponding KMs curve also changes from a "U" shape to an "n" shape. For example, when the voice coil assembly moves to ±0.6 mm and the second ratio TL is 0.12, the KMs curve changes by about 12%, which is acceptable. Therefore, keeping the second ratio TL of the diaphragm 1211 no higher than 0.12 allows the KMs curve to match the BLx curve, which is beneficial for giving the loudspeaker 120 lower distortion. For example, the second ratio TL can be set to 0.1, 0.06, or other values ​​less than 0.12.

[0374] In some embodiments, referring to Figure 56, the distance between the plane containing the first surface P1 and the second surface P2 (or the height difference between the first surface P1 and the second surface P2 in the vibration direction) is defined as the first height H0, and the ratio of the first height H0 to the third width Lmar is defined as the third ratio HLO. Considering that the width of the folded ring 1211-2 and the height difference between the inner and outer ends of the folded ring 1211-2 in the radial direction will affect the KMs curve, and thus affect the distortion of the loudspeaker 120, the third ratio HLO can be no greater than 0.232.

[0375] Specifically, Figure 57 shows the KMs curves for different third ratios HLO. Referring to Figure 39C, the smaller the third ratio HLO, the flatter the corresponding KMs curve. When the third ratio HLO changes from 0.232 to 0.072, the corresponding KMs curve gradually flattens. For example, when the voice coil assembly moves to ±0.6 mm and the third ratio HLO is 0.232, the KMs curve changes by about 15%, which is acceptable. Therefore, setting the third ratio HLO of the diaphragm 1211 to no greater than 0.232 allows the KMs curve to match the BLx curve, thereby obtaining a loudspeaker 120 with lower distortion.

[0376] In some embodiments, referring to Figure 58, the distance from the vertex of the folded ring portion 1211-2 to the plane containing the second surface P2 (which can also be understood as the arch height of the folded ring portion 1211-2) is defined as the second height Hm, and the ratio of the first height H0 to the second height Hm is defined as the fourth ratio HTO. Considering that the arch height of the folded ring portion 1211-2 and the height difference between the inner and outer ends of the folded ring portion 1211-2 will also affect the KMs curve, and thus affect the distortion of the speaker 120, the fourth ratio HTO can be no greater than 0.36.

[0377] Specifically, Figure 59 shows the KMs curves for different fourth ratios HTO. Referring to Figure 59, the smaller the fourth ratio HTO, the flatter the corresponding KMs curve. When the fourth ratio HTO changes from 0.36 to 0.11, the corresponding KMs curve gradually flattens. For example, when the voice coil assembly moves to ±0.6mm and the fourth ratio HTO is 0.36, the corresponding KMs curve changes by about 17%, which is acceptable. Therefore, by setting the fourth ratio HTO of the diaphragm 1211 to no greater than 0.36, the KMs curve can be matched with the BLx curve, thereby obtaining a loudspeaker 120 with lower distortion.

[0378] Furthermore, in some embodiments, the fourth ratio HTO can be set in the range of 0.36 to 0.11, for example, the fourth ratio HTO is 0.18, 0.24, 0.3, etc. In this case, the KMs curve is flatter, the distortion of the speaker 120 is lower, and it provides support for active noise cancellation of the headphones in a wider frequency range.

[0379] In some embodiments, referring to Figure 60, the folded ring portion 1211-2 is radially divided into a first arc-shaped region A1, a second arc-shaped region A2, and a third arc-shaped region A3, with the arc length of each arc-shaped region being one-third of the arc length of the folded ring portion 1211-2. The first arc-shaped region A1 is the area of ​​the folded ring portion 1211-2 near the fixing ring 1213 or adjacent to the second connecting portion 1211-3, and the third arc-shaped region A3 is the area of ​​the folded ring portion 1211-2 near the center patch 1212 or adjacent to the second connecting portion 1211-3. The ratio of the average wall thickness of the first arc-shaped region A1 to the average wall thickness of the second arc-shaped region A2, and the ratio of the average wall thickness of the third arc-shaped region A3 to the average wall thickness of the second arc-shaped region A2, are both defined as a fifth ratio TT. Considering the wall thickness relationship between different regions of the folded ring portion 1211-2, which has a significant impact on the shape of the KMs curve, the fifth ratio TT can be no greater than 1.2.

[0380] Specifically, Figure 61 shows the KMs curves for different fifth ratios TT. Referring to Figure 61, as the fifth ratio TT changes from 1.2 to 0.8, the corresponding KMs curve gradually flattens. For example, when the voice coil assembly moves to ±0.6mm and the fifth ratio TT is 1.2, the KMs curve changes by about 18%, which is acceptable. Therefore, by setting the fifth ratio TT of the diaphragm 1211 to no greater than 1.2 (e.g., 1.1, 1.0, 0.9, 0.8, etc.), the KMs curve can be matched with the BLx curve, thereby obtaining a speaker 120 with lower distortion. When the speaker 120 is applied to open-back headphones, it can provide support for active noise cancellation over a wider frequency range.

[0381] In some embodiments, the fifth ratio TT can be set to no more than 1.0, that is, the wall thickness of the first arc region A1 and the third arc region A3 is less than the wall thickness of the second arc region A2; thus, the corresponding KMs curve is flatter and the KMs curve is more in line with the BLx curve.

[0382] In some embodiments, referring to Figure 49, the center patch 1212 can adopt an arched structure protruding away from the voice coil assembly along the vibration direction. Specifically, the center patch 1212 has a central region 1212-1, a connecting region 1212-2, and an edge region 1212-3 that are sequentially connected from the inside to the outside in the radial direction. It can also be understood that the connecting region 1212-2 surrounds and connects to the outer periphery of the central region 1212-1, and the edge region 1212-3 surrounds and connects to the outer periphery of the connecting region 1212-2; wherein, the connecting region 1212-2 is in the vibration direction The center patch 1212 is inclined relative to the edge region 1212-3 and the center region 1212-1, so that there is a height difference in the vibration direction between the geometric center of the center region 1212-1 and the plane containing the edge region 1212-3, thereby constructing a dome-shaped structure. The edge region 1212-3 is connected to the diaphragm 1211 and the voice coil assembly. For example, the first connecting part 1211-1 is attached to the outer surface of the edge region 1212-3 in the vibration direction, and the voice coil assembly is connected to the inner surface of the edge region 1212-3 in the vibration direction. For example, the center patch 1212 can be made of carbon fiber material.

[0383] Furthermore, in some embodiments, the edge region 1212-3 may be a planar structure perpendicular to the vibration direction, the center region 1212-1 may be an arc-shaped structure protruding away from the voice coil assembly in the vibration direction, and the connecting region 1212-2 is adaptively connected between the edge region 1212-3 and the center region 1212-1.

[0384] Because the arched center mount 1212 has high strength and height, it is beneficial to improve the high-frequency vibration characteristics of the speaker 120, thereby helping the headphones to perform active noise cancellation over a wider frequency range. At the same time, the arched center mount 1212 can also prevent the diaphragm 1211 from shaking during large-amplitude vibrations, thus ensuring that the voice coil assembly and the magnetic circuit assembly will not collide. In addition, the edge area 1212-3 can provide ample connection area for the voice coil assembly and the diaphragm 1211, ensuring that the voice coil assembly and the diaphragm 1211 can be stably connected to the center mount 1212.

[0385] In other embodiments, the center patch 1212 may also adopt other suitable arched structures, such as omitting the connecting area 1212-2, adopting an arc-shaped structure that protrudes away from the voice coil assembly in the vibration direction, and the edge area 1212-3 surrounding the center area 1212-1 and connecting to the edge of the center area 1212-1; all such details are omitted here. However, it should be noted that the diaphragm of the component structure in the above embodiments can be applied to the loudspeaker 120 of any embodiment provided in this application as needed.

[0386] The above examples illustrate this application only to aid understanding and are not intended to limit its scope. Those skilled in the art to which this application pertains can make various simple deductions, modifications, or substitutions based on the ideas presented.

Claims

1. A loudspeaker, characterized by The loudspeaker comprises: first and second diaphragms opposite to each other; a magnetic circuit assembly arranged between the first and second diaphragms; and a voice coil assembly arranged in a magnetic gap of the magnetic circuit assembly, the voice coil assembly comprising first and second voice coils arranged in a vibration direction of the first and second diaphragms and connected to each other, one end of the first voice coil away from the second voice coil being connected to the first diaphragm, and one end of the second voice coil away from the first voice coil being connected to the second diaphragm, the magnetic circuit assembly and the voice coil assembly cooperating to drive the first and second diaphragms to vibrate in the same direction. The magnetic circuit assembly comprises an inner magnetic circuit member, an outer magnetic circuit member, and a magnetic circuit connecting member, the outer magnetic circuit member surrounding an outer periphery of the inner magnetic circuit member and connected to the inner magnetic circuit member through the magnetic circuit connecting member to form the magnetic gap between the outer magnetic circuit member and the inner magnetic circuit member, and an avoiding passage formed between the first and second voice coils to allow the magnetic circuit connecting member to pass through the voice coil assembly.

2. The loudspeaker of claim 1, wherein The inner magnetic circuit member comprises an inner magnet, and the outer magnetic circuit member comprises an outer magnet, the outer magnet surrounding an outer periphery of the inner magnet to form the magnetic gap, and the magnetic circuit connecting member passing through the avoiding passage in the vibration direction and being connected between the inner and outer magnets.

3. The loudspeaker of claim 2, wherein, The outer magnet is an integral structure surrounding the outer periphery of the inner magnet.

4. The loudspeaker of claim 3, wherein The inner magnetic circuit member further comprises a first magnetic conductor, and the outer magnetic circuit member further comprises a second magnetic conductor, wherein:

5. The loudspeaker of claim 3, wherein, The first magnetic conductor is stacked on the inner magnet facing one of the first and second diaphragms, the second magnetic conductor is stacked on the outer magnet facing the other of the first and second diaphragms, and the magnetic circuit connecting member is connected to the inner magnet through the first magnetic conductor and connected to the outer magnet through the second magnetic conductor. At least one of the first and second magnetic conductors is an integral structure with the magnetic circuit connecting member.

6. The loudspeaker of claim 5, wherein The magnetic circuit connecting member is stacked between the first magnetic conductor and the inner magnet, and at least partially extends from between the first magnetic conductor and the inner magnet to connect the second magnetic conductor.

7. The loudspeaker of claim 5, wherein The loudspeaker has a long axis direction and a short axis direction, the long axis direction, the short axis direction, and the vibration direction being perpendicular to each other, the length of the loudspeaker in the long axis direction being greater than the width of the loudspeaker in the short axis direction, wherein the ratio of the length of the inner magnet in the long axis direction to the thickness of the side wall of the outer magnet in the long axis direction is between 1.7 and 33.

8. The loudspeaker of claim 3, wherein The ratio of the length of the inner magnetic circuit member in the long axis direction to the thickness of the side wall of the outer magnetic circuit member in the long axis direction is not greater than 6.

7.

9. The loudspeaker of claim 8, wherein, The loudspeaker has a long axis direction and a short axis direction, the long axis direction, the short axis direction, and the vibration direction being perpendicular to each other, the length of the loudspeaker in the long axis direction being greater than the width of the loudspeaker in the short axis direction, wherein the ratio of the width of the inner magnet in the short axis direction to the thickness of the side wall of the outer magnet in the short axis direction is between 1.7 and 33.

10. The loudspeaker of claim 3, wherein, ​ 11. The loudspeaker of claim 10, wherein A ratio of a width of the inner magnetic circuit member in the short axis direction to a thickness of the side wall of the outer magnetic circuit member in the short axis direction is not greater than 2.

7.

12. The loudspeaker of claim 5, wherein, The inner magnetic circuit member further comprises a third magnetic conductor, and the outer magnetic circuit member further comprises a fourth magnetic conductor, the third magnetic conductor is stacked on a side of the inner magnet opposite to the first magnetic conductor in the vibration direction, and the fourth magnetic conductor is stacked on a side of the outer magnet opposite to the second magnetic conductor in the vibration direction.

13. The loudspeaker of claim 12, wherein, The magnetic circuit assembly further comprises a first support and a second support, the first support is connected around an outer periphery of the third magnetic plate, and an outer periphery of the first diaphragm is fixed to the first support; the second support is connected around an outer periphery of the fourth magnetic plate, and an outer periphery of the second diaphragm is fixed to the second support.

14. The loudspeaker of claim 13, wherein, The first support has a first accommodating groove surrounding the third magnetic plate, and an outer periphery of the third magnetic plate is inserted into the first accommodating groove and fixed to the first support; and / or the second support has a second accommodating groove surrounding the fourth magnetic plate, and an outer periphery of the fourth magnetic plate is inserted into the second accommodating groove and fixed to the second support.

15. The loudspeaker of claim 13, wherein, A first chamber is formed between the first support, the third magnetic plate and the first diaphragm, the first support has a first positioning structure and / or a first through-hole structure; the first positioning structure is located in the first chamber and used for positioning wires of the first voice coil; and the first through-hole structure penetrates a side wall of the first support and communicates with the first chamber, and is used for allowing the wires of the first voice coil to pass out of the first chamber. A second chamber is formed between the second support, the fourth magnetic plate and the second diaphragm, the second support has a second positioning structure and / or a second through-hole structure; the second positioning structure is located in the second chamber and used for positioning wires of the second voice coil; and the second through-hole structure penetrates a side wall of the second support and communicates with the second chamber, and is used for allowing the wires of the second voice coil to pass out of the second chamber.

16. The loudspeaker of claim 2, wherein The magnetic circuit connecting member is made of a weak magnetic conductive material or a non-magnetic conductive material.

17. The loudspeaker of any one of claims 2-16, wherein, In a reference plane perpendicular to the vibration direction, there is a gap between a projection of the first voice coil and a projection of the second voice coil to form the avoiding channel; or in a reference plane parallel to the vibration direction, there is a gap between a projection of the first voice coil and a projection of the second voice coil to form the avoiding channel.

18. The loudspeaker of claim 17, wherein, The loudspeaker has a long axis direction and a short axis direction, the long axis direction, the short axis direction and the vibration direction are perpendicular, side walls of the first voice coil and the second voice coil in the long axis direction are defined as long side walls, and side walls of the first voice coil and the second voice coil in the short axis direction are defined as short side walls. In a reference plane perpendicular to the vibration direction, there is a gap between a projection of the short side wall of the first voice coil and a projection of the short side wall of the second voice coil to form the avoiding channel between the short side wall of the first voice coil and the short side wall of the second voice coil.

19. The loudspeaker of claim 18, wherein, The length of the long side wall of the first voice coil in the long axis direction is greater than the width of the short side wall of the first voice coil in the short axis direction, and the length of the long side wall of the second voice coil in the long axis direction is greater than the width of the short side wall of the second voice coil in the short axis direction. The length of the long side wall of the first voice coil in the long axis direction is less than the length of the long side wall of the second voice coil in the long axis direction, and the width of the short side wall of the first voice coil in the short axis direction is equal to the width of the short side wall of the second voice coil in the short axis direction.

20. The loudspeaker of claim 17, wherein, The voice coil assembly further comprises a connecting piece, and the first voice coil is connected to the second voice coil through the connecting piece.

21. The loudspeaker of claim 20, wherein, The first voice coil comprises a first skeleton surrounding the inner magnetic circuit member and a first coil wound on the outer periphery of the first skeleton, and the second voice coil comprises a second skeleton surrounding the inner magnetic circuit member and a second coil wound on the outer periphery of the second skeleton; wherein the first skeleton and the second skeleton are connected through the connecting piece.

22. The loudspeaker of claim 21, wherein, At least one of the first skeleton and the second skeleton is in an integral structure with the connecting piece.

23. The loudspeaker of claim 17, wherein, The first voice coil comprises a first skeleton surrounding the inner magnetic circuit member and a first coil wound on the outer periphery of the first skeleton, and the second voice coil comprises a second skeleton surrounding the inner magnetic circuit member and a second coil wound on the outer periphery of the second skeleton, and the first skeleton and the second skeleton are connected in the vibration direction.

24. An open earphone, characterized by The earphone comprises a sound generating part and an ear hook, the ear hook is configured to place the sound generating part in a position close to the ear but not blocking the ear canal in a wearing state; wherein the sound generating part comprises a first shell and a loudspeaker as claimed in any one of claims 1-23, the loudspeaker is arranged in the first shell, the first shell has an inner side wall facing the ear in a wearing state and an outer side wall away from the ear, the inner side wall is spaced opposite to the first diaphragm in the vibration direction, the outer side wall is spaced opposite to the second diaphragm in the vibration direction, and the inner side wall and the outer side wall are provided with sound holes.

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